azd-6244 and Lung-Neoplasms

Cancer incidence is rapidly growing. Solid tumors are responsible for a majority of cancers. Recently, molecular-targeted agents have played a significant role in cancer treatment. Ras-Raf-MEK-ERK signaling pathway, is a substantial element in the survival, propagation, and drug resistance of human cancers. MEK is a specific part of the so-called cascade, and ERK proteins are its sole target. Furthermore, their downstream position in the Ras-ERK cascade, is noteworthy to direct their function in patients with upstream mutated genes. MEK1 mutations are responsible for initiating several solid tumors. Selumetinib (AZD6244) is a second-generation, selective, potent, and non-ATP competitive allosteric MEK1 inhibitor. The efficacy of selumetinib in various solid tumors such as colorectal cancer, lung cancer, neurofibroma, and melanoma is investigated. The present paper provides an overview of the MAPK cascade, the role of selumetinib as a MEK1/2 inhibitor, and the related findings of clinical trials for solid tumor treatment.

Topics: Antineoplastic Agents; Benzimidazoles; Cell Line, Tumor; Humans; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases

Selumetinib, a highly specific mitogen-activated protein kinase 1/2 inhibitor, is approved for children older than 2 years of age with neurofibromatosis 1 who have inoperable plexiform neurofibromas. By selectively binding to mitogen-activated protein kinase 1/2 proteins, selumetinib can arrest the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway that regulates critical cellular responses. Selumetinib has shown promising results as a single agent or in combination with conventional chemotherapy and other targeted therapies both preclinically and clinically, in multiple cancers including pediatric low-grade glioma, non-small cell lung cancer, and melanoma, among others. The pharmacokinetic profiles of selumetinib and its active metabolite N-desmethyl selumetinib have been well characterized in both adults and children. Both compounds exhibited rapid absorption and mean terminal elimination half-lives of about 7.5 h, with minimal accumulation at steady state. Three population pharmacokinetic models have been developed in adults and children, characterizing large inter- and intra-patient variabilities, and identifying significant covariates including food intake on selumetinib absorption, weight metrics, age, co-administration of cytochrome modulators, and Asian ethnicity on selumetinib apparent oral clearance. The most common side effects associated with selumetinib are dermatologic, gastrointestinal toxicities, and fatigue. Most toxicities are mild or moderate, generally tolerated and manageable. Cardiovascular and ocular toxicities remain less frequent but can be potentially more severe and require close monitoring. Overall, selumetinib exhibits a favorable safety profile and pharmacokinetic properties, with promising activity in multiple solid tumors, supporting current and further evaluation in combination with conventional chemotherapy and other targeted agents.

Topics: Adult; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Child; Child, Preschool; Humans; Lung Neoplasms; Neurofibroma, Plexiform; Protein Kinase Inhibitors

RAS-RAF-MEK-ERK signaling is implicated in tumor development by promoting cell proliferation and other cancer hallmarks. MEK1/2 kinases are up-regulated in the majority of human cancers due to activation of tyrosine kinase receptors, RAS proteins, BRAF kinase, or some other members of the MAPK pathway. Targeting of MEK1/2 kinases may counterbalance cancer progression.. The authors analyze the scientific publications relevant to selumetinib (AZD6244, ARRY-142886) systematically and provide their expert opinion.. Selumetinib is an oral selective allosteric inhibitor of MEK1 and MEK2 kinases. Single-agent selumetinib is usually administered in hydrogen sulfate capsules 75 mg twice a day; combination with other therapeutic compounds may or may not require reduced dosing of this drug. The established dose for pediatric patients is 25 mg per square meter twice a day. Selumetinib was extensively evaluated in non-small cell lung cancer (NSCLC) patients. Studies utilizing this drug as a monotherapy did not confirm its efficacy toward NSCLC. A phase II trial showed that the addition of selumetinib to docetaxel improved response rates and progression-free survival (PFS) in chemotherapy-pretreated KRAS-mutated NSCLC patients; however, a subsequent phase III study did not confirm these findings. There are several highly successful non-NSCLC selumetinib trials involving, e.g., patients with neurofibromatosis type 1 related tumors and children with low-grade BRAF-driven gliomas.

Topics: Administration, Oral; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Child; Clinical Trials as Topic; Drug Administration Schedule; Female; Humans; Lung Neoplasms; MAP Kinase Kinase Kinase 1; MAP Kinase Kinase Kinase 2; Progression-Free Survival

KRAS is the most frequently mutated oncogene in NSCLC, occurring in around a third of patients. However, this largest genomically defined subgroup of lung cancer patients seem to remain 'undruggable', with any effective targeted therapy approved at the moment. The prognostic and predictive power and thus the clinical utility of KRAS oncogenic mutations in lung cancer are highly debated issues, not supportive of KRAS testing in clinical practice of NSCLC therapy. Areas covered: A phase II trial in KRAS-mutant NSCLC had shown significant improvements in PFS and ORR in patients treated with selumetinib plus docetaxel compared to docetaxel alone. Disappointing data emerged from the next phase III trial in which the addition of selumetinib to docetaxel in patients with advanced KRAS mutant lung cancer did not improve survival or show clinical benefit. Expert opinion: Promising strategies against this common mutation are under evaluation in clinical trials. Combination therapies represent a potential approach for overcoming this complex pathway and potentiating the activity of other antitumor agents, by simultaneous inhibition of the RAS-RAF-MEK-MAPK pathway. Identifying predictive biomarkers, and delineating de novo and acquired resistance mechanisms are essential for future clinical development of MEK inhibitors.

Topics: Animals; Antineoplastic Agents; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Docetaxel; Humans; Lung Neoplasms; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Taxoids

The MAP-kinase pathway, consisting of the kinases RAS, RAF, MEK, and ERK, is crucial for cell proliferation, inhibition of apoptosis, and migration of cells. Direct inhibition of RAS is not yet possible, whereas inhibition of RAF is already established in malignant melanoma and under investigation in non-small-cell lung cancer (NSCLC). Due to their structure and function, the MEK proteins are attractive targets for cancer therapy and are also under investigation in NSCLC. We discuss strategies of targeting the RAS-RAF-MEK-ERK pathway with emphasis on MEK inhibition, either alone or in combination with other targets or conventional chemotherapy.

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Extracellular Signal-Regulated MAP Kinases; Humans; Lung Neoplasms; Molecular Targeted Therapy; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones

During the past few years, oncologists have witnessed the reclassification of non small cell lung cancer (NSCLC) as not one disease, but several molecularly defined subsets of disease with relevant therapeutic implications in the field of molecularly targeted therapies. Two not very common genetically defined subsets of NSCLC, including those with EGFR or ALK activating mutations, and show high sensitivity to tyrosine-kinase inhibitors such that patients frequently have sustained clinical responses to therapy. However, the largest subset harbours an activating KRAS mutation and up to now, no successful targeted therapy has been developed for RAS-mutant lung cancer, with few compounds being assessed by clinical trials. In fact, KRAS has remained an elusive target for cancer therapy for biologic reasons. The chief value of KRAS lies in providing information about the other biomarkers that are directly druggable, that is, EGFR and ALK. The presence of mutated KRAS rules out ALK and EGFR, and KRAS may therefore form part of an efficient pathway in a testing algorithm. Currently, KRAS itself remains undruggable despite decades of effort, but attention has recently focused on inhibition of the Ras-contingent downstream signalling. Selumetinib (AZD6244; ARRY-142886) is an oral, tight-binding, uncompetitive inhibitor of mitogen-activated protein kinase kinases (MEK) 1 and 2, downstream of KRAS, with preclinical evidence of synergistic activity with docetaxel in KRAS-mutant cancers and currently in clinical development. The Ras/RAF/MEK/ERK pathway is frequently deregulated in cancer and a number of inhibitors that target this pathway are currently in clinical development. Recently, in a randomised, phase II trial selumetinib plus docetaxel has proven to improve progression free survival compared to docetaxel alone in previously treated patients with advanced KRAS-mutant NSCLC.

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; DNA Mutational Analysis; DNA, Neoplasm; Humans; Lung Neoplasms; Mutation; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins

Afatinib and selumetinib can be combined in continuous and intermittent dosing schedules, albeit at lower doses than approved for monotherapy. Maximum tolerated dose for continuous and intermittent schedules is afatinib 20 mg once daily and selumetinib 25 mg b.i.d. Because the anticancer activity was limited, further development of this combination is not recommended until better biomarkers for response and resistance are defined.. Antitumor effects of MEK inhibitors are limited in KRAS-mutated tumors because of feedback activation of upstream epidermal growth factor receptors, which reactivates the MAPK and the phosphoinositide 3-kinase-AKT pathway. Therefore, this phase I trial was initiated with the pan-HER inhibitor afatinib plus the MEK inhibitor selumetinib in patients with KRAS mutant, PIK3CA wild-type tumors.. Afatinib and selumetinib were administered according to a 3+3 design in continuous and intermittent schedules. The primary objective was safety, and the secondary objective was clinical efficacy.. Twenty-six patients were enrolled with colorectal cancer (n = 19), non-small cell lung cancer (NSCLC) (n = 6), and pancreatic cancer (n = 1). Dose-limiting toxicities occurred in six patients, including grade 3 diarrhea, dehydration, decreased appetite, nausea, vomiting, and mucositis. The recommended phase II dose (RP2D) was 20 mg afatinib once daily (QD) and 25 mg selumetinib b.i.d. (21 days on/7 days off) for continuous afatinib dosing and for intermittent dosing with both drugs 5 days on/2 days off. Efficacy was limited with disease stabilization for 221 days in a patient with NSCLC as best response.. Afatinib and selumetinib can be combined in continuous and intermittent schedules in patients with KRAS mutant tumors. Although target engagement was observed, the clinical efficacy was limited.

Topics: Afatinib; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Colorectal Neoplasms; Humans; Lung; Lung Neoplasms; Mutation; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras)

Osimertinib is a potent, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). The multi-arm phase Ib TATTON study (NCT02143466) was designed to assess the safety and tolerability of osimertinib in combination with other targeted therapies: selumetinib (MEK1/2 inhibitor), savolitinib (MET-TKI), or durvalumab [anti-programmed cell death ligand 1 (anti-PD-L1) monoclonal antibody].. Patients with advanced EGFR-mutant non-small-cell lung cancer and disease progression on a prior EGFR-TKI were enrolled and allocated to dose-escalating cohorts combining osimertinib 80 mg orally (p.o.) once a day with selumetinib (25-75 mg p.o. twice a day; continuous or intermittent), savolitinib (600-800 mg p.o. once a day), or durvalumab (3-10 mg/kg intravenous every 2 weeks).. At data cut-off (28 February 2018), 77 patients were enrolled and received osimertinib plus selumetinib (n = 36), savolitinib (n = 18), or durvalumab (n = 23). Most common adverse events (any grade), occurring in ≥20% of patients across dose groups, were: selumetinib arm-diarrhea (75%), rash (58%), nausea (47%); savolitinib arm-nausea (67%), rash (56%), vomiting (50%); durvalumab arm-rash (48%), vomiting (43%), diarrhea (39%). Dose-limiting toxicities were reported in the selumetinib 25 mg (n = 1), 50 mg (n = 1), and 75 mg (n = 4) continuous-dose groups, savolitinib 600 mg (n = 1) and 800 mg dose groups (n = 2), and durvalumab 10 mg/kg (n = 1) dose group. The objective response rate was 42% (95% confidence interval 26% to 59%), 44% (22% to 69%), and 43% (23% to 66%) in the selumetinib, savolitinib, and durvalumab arms, respectively.. Our results demonstrate the feasibility of combining osimertinib 80 mg with selumetinib or savolitinib at identified tolerable, active doses. A combination of osimertinib with durvalumab was not feasible due to increased reporting of interstitial lung disease. Osimertinib-based combination therapies represent a compelling approach now being further investigated.. NCT02143466.

Topics: Acrylamides; Aniline Compounds; Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; ErbB Receptors; Humans; Lung Neoplasms; Mutation; Protein Kinase Inhibitors; Pyrazines; Triazines

Current strategies to improve clinical outcomes in v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog-mutant non-small-cell lung cancer (NSCLC) patients include mitogen-activated protein kinase kinase 1 inhibitor and programmed death (PD) 1 (PD-1)/PD ligand 1 (PD-L1) immune checkpoint blockade combinations. Experience from treatment of melanoma suggests that anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and anti-PD-1/PD-L1 combinations improve outcomes, but similar benefits remain to be seen for treatment of NSCLC. This report describes a single center, investigator-initiated phase I/II clinical trial to compare 2 combination schedules of intermittent or continuous selumetinib (AZD6244, ARRY-142886), tremelimumab (anti-CTLA-4), and durvalumab (anti-PD-L1) treatment with historical controls in patients with previously treated, unresectable NSCLC. Forty patients will be accrued at the University of Texas M.D. Anderson Cancer Center. Primary objectives include maximum tolerated dose (dose escalation phase) and progression-free survival (dose expansion phase). Secondary objectives include response rate according to Response Evaluation Criteria In Solid Tumors version 1.1, disease control rate, overall survival, safety, and duration of response. Exploratory objectives are to assess biomarkers of response and resistance on the basis of biopsies and peripheral blood taken before and after treatment using immune profiling, transcriptome, and protein readouts.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Female; Follow-Up Studies; Humans; Immunotherapy; Lung Neoplasms; Male; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Prognosis; Research Design; Survival Rate; Young Adult

Selumetinib (AZD6244, ARRAY-142886) is a mitogen-activated protein kinase kinase inhibitor that has been tested for treatment of non-small cell lung cancer (NSCLC). Selumetinib (75 mg twice daily) plus docetaxel in patients with advanced NSCLC has been assessed in phase 2 (SELECT-2) and phase 3 (SELECT-1) clinical trials. The objective of the current analysis was to investigate the exposure-response relationship of selumetinib in these 2 clinical trials, based on the development of a population pharmacokinetic (PopPK) model for selumetinib and its active metabolite, N-desmethyl selumetinib, in patients with NSCLC. A PopPK model using data from seven phase 1 studies was first developed and served as prior information for the development of the patient PopPK model. The pharmacokinetics (PK) of selumetinib and N-desmethyl selumetinib were modeled simultaneously. A two-compartment model with zero-first order absorption and first-order elimination reasonably described the selumetinib PK. The N-desmethyl metabolite of selumetinib was described by a one-compartment model with first-order elimination. The final PK parameter estimates were similar between patients with NSCLC and patients in the phase 1 population. Selumetinib apparent clearance and central volume of distribution were 11.9 L/h and 32.1 L, respectively, in patients. Individual selumetinib exposure metrics were estimated to investigate the correlation between exposure and efficacy/safety endpoints observed in NSCLC studies. There was no significant difference in progression-free survival (the primary endpoint) among the different quartiles of exposure. Similarly, no significant correlation was observed between selumetinib exposure and other secondary efficacy or safety endpoints. The conclusions are in accordance with the reported clinical findings.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Lung Neoplasms; Male; Middle Aged; Models, Biological; Protein Kinase Inhibitors; Treatment Outcome; Young Adult

Activation of the RAS/RAF/MEK/ERK pathway may confer resistance to chemotherapy in non-small cell lung cancer (NSCLC). Selumetinib (AZD6244, ARRY142886), a MEK1/2 inhibitor combined with chemotherapy in patients with NSCLC was evaluated in two schedules to evaluate efficacy and toxicity.. IND.219 was a three-arm study of first line pemetrexed/platinum chemotherapy with two schedules of selumetinib (Arm A: intermittent given on days 2-19; Arm B: continuous given on days 1-21) versus chemotherapy alone (Arm C). The primary endpoint was objective response rate (ORR); secondary objectives were tolerability, progression-free survival (PFS), overall survival (OS). The trial was stopped at the planned interim analysis.. Arms A/B/C enrolled 20/21/21 patients, ORR was 35% (95% CI 15-59% median duration 3.8 months), 62% (95% CI 38-82%; median duration 6.3 months), 24% (95% CI 8-47%; median duration 11.6 months) respectively. The PFS (months Arm A, B, C) was 7.5, 6.7, 4.0 respectively (hazard ratio (HR) PFS Arm A over Arm C: 0.76 [95% CI, 0.38-1.51, 2-sided p = 0.42]; Arm B over Arm C 0.75 [95% CI 0.37-1.54, p = 0.43]. Skin and gastrointestinal adverse events were more common with the addition of selumetinib. A high incidence of venous thromboembolism was seen in all arms.. Selumetinib combined with chemotherapy was associated with a higher response rate. Continuous selumetinib appeared to be superior to an intermittent schedule. PFS was prolonged with the addition of selumetinib, however this was not statistically significant.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Canada; Carcinoma, Non-Small-Cell Lung; Female; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Pemetrexed; Platinum Compounds; Proto-Oncogene Proteins p21(ras); Survival Analysis

This Phase I study (NCT01605916) investigated the safety, tolerability and pharmacokinetic profile of selumetinib plus docetaxel as second-line therapy in Japanese patients with locally advanced or metastatic non-small cell lung cancer (NSCLC), or selumetinib monotherapy in Japanese patients with advanced solid malignancies.. All enrolled patients received single-dose selumetinib 25, 50 or 75 mg, followed by a 3-day washout. Combination therapy cohorts then started a 21-day cycle of docetaxel 60 mg/m2 plus selumetinib 25 or 75 mg twice-daily (BID) on Day 1. Thereafter, selumetinib BID continued for 20 days; patients received ≤6 cycles. Following single-dosing, monotherapy cohorts underwent a 21-day cycle of selumetinib 25, 50 or 75 mg BID.. Thirty-three patients were enrolled and 25 assigned to treatment (combination, n = 8; monotherapy, n = 17). Most frequent adverse events (AEs) included: vomiting, decreased appetite, diarrhea, nausea and stomatitis (combination cohorts); gastrointestinal disorders, skin and subcutaneous tissue disorders (monotherapy cohorts). Grade 3 dose-limiting toxicities: febrile neutropenia, causally related to combination therapy (n = 3); pneumonitis, selumetinib 50 mg monotherapy (n = 1). Selumetinib 75 mg monotherapy and selumetinib 25 mg plus docetaxel 60 mg/m2 were tolerated; selumetinib 75 mg plus docetaxel 60 mg/m2 was not tolerated. Selumetinib pharmacokinetic profile was similar when administered as a monotherapy or in combination with docetaxel.. Selumetinib 75 mg monotherapy was tolerated in Japanese patients with NSCLC. Due to the overall selumetinib AE profile, the maximum tolerated dose was not determined for combination therapy or monotherapy. Selumetinib 75 mg BID plus docetaxel 60 mg/m2 was not tolerated in this patient population.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Asian People; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Demography; Docetaxel; Dose-Response Relationship, Drug; Female; Humans; Lung Neoplasms; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Taxoids; Treatment Outcome

We investigated selumetinib (AZD6244, ARRY-142886), an oral, potent, and highly selective, allosteric MEK1/2 inhibitor, plus platinum-doublet chemotherapy for patients with advanced/metastatic non-small cell lung cancer.. In this Phase I, open-label study (NCT01809210), treatment-naïve patients received selumetinib (50, 75, 100 mg BID PO) plus standard doses of gemcitabine or pemetrexed plus cisplatin or carboplatin. Primary objectives were safety, tolerability, and determination of recommended Phase II doses.. Fifty-five patients received treatment: selumetinib 50 or 75 mg plus gemcitabine/cisplatin (n=10); selumetinib 50 mg plus gemcitabine/carboplatin (n=9); selumetinib 50, 75 or 100 mg plus pemetrexed/carboplatin (n=21); selumetinib 75 mg plus pemetrexed/cisplatin (n=15). Most frequent adverse events (AEs) were fatigue, nausea, diarrhoea and vomiting. Grade ⩾3 selumetinib-related AEs were reported in 30 (55%) patients. Dose-limiting toxicities (all n=1) were Grade 4 anaemia (selumetinib 75 mg plus gemcitabine/cisplatin), Grade 4 thrombocytopenia/epistaxis and Grade 4 thrombocytopenia (selumetinib 50 mg plus gemcitabine/carboplatin), Grade 4 febrile neutropenia (selumetinib 100 mg plus pemetrexed/carboplatin), and Grade 3 lethargy (selumetinib 75 mg plus pemetrexed/cisplatin). Partial responses were confirmed in 11 (20%) and unconfirmed in 9 (16%) patients.. Standard doses of pemetrexed/carboplatin or pemetrexed/cisplatin were tolerated with selumetinib 75 mg BID. The selumetinib plus gemcitabine-containing regimens were not tolerated.

Topics: Adult; Aged; Anemia; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carboplatin; Carcinoma, Non-Small-Cell Lung; Chemotherapy-Induced Febrile Neutropenia; Cisplatin; Deoxycytidine; Diarrhea; Epistaxis; Fatigue; Female; Gemcitabine; Humans; Lethargy; Lung Neoplasms; Male; Middle Aged; Nausea; Pemetrexed; Protein Kinase Inhibitors; Thrombocytopenia; Vomiting

Combination of selumetinib plus docetaxel provided clinical benefit in a previous phase II trial for patients with KRAS-mutant advanced non-small-cell lung cancer (NSCLC). The phase II SELECT-2 trial investigated safety and efficacy of selumetinib plus docetaxel for patients with advanced or metastatic NSCLC.. Patients who had disease progression after first-line anti-cancer therapy were randomized (2 : 2 : 1) to selumetinib 75 mg b.i.d. plus docetaxel 60 or 75 mg/m2 (SEL + DOC 60; SEL + DOC 75), or placebo plus docetaxel 75 mg/m2 (PBO + DOC 75). Patients were initially enrolled independently of KRAS mutation status, but the protocol was amended to include only patients with centrally confirmed KRAS wild-type NSCLC. Primary end point was progression-free survival (PFS; RECIST 1.1); statistical analyses compared each selumetinib group with PBO + DOC 75 for KRAS wild-type and overall (KRAS mutant or wild-type) populations.. A total of 212 patients were randomized; 69% were KRAS wild-type. There were no statistically significant improvements in PFS or overall survival for overall or KRAS wild-type populations in either selumetinib group compared with PBO + DOC 75. Overall population median PFS for SEL + DOC 60, SEL + DOC 75 compared with PBO + DOC 75 was 3.0, 4.2, and 4.3 months, HRs: 1.12 (90% CI: 0.8, 1.61) and 0.92 (90% CI: 0.65, 1.31), respectively. In the overall population, a higher objective response rate (ORR; investigator assessed) was observed for SEL + DOC 75 (33%) compared with PBO + DOC 75 (14%); odds ratio: 3.26 (90% CI: 1.47, 7.95). Overall the tolerability profile of SEL + DOC was consistent with historical data, without new or unexpected safety concerns identified.. The primary end point (PFS) was not met. The higher ORR with SEL + DOC 75 did not translate into prolonged PFS for the overall or KRAS wild-type patient populations. No clinical benefit was observed with SEL + DOC in KRAS wild-type patients compared with docetaxel alone. No unexpected safety concerns were reported.. Clinicaltrials.gov NCT01750281.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Disease-Free Survival; Docetaxel; Double-Blind Method; Female; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Proto-Oncogene Proteins p21(ras); Taxoids

We conducted a basket clinical trial to assess the feasibility of such a design strategy and to independently evaluate the effects of multiple targeted agents against specific molecular aberrations in multiple histologic subtypes concurrently.. We enrolled patients with advanced non-small-cell lung cancer (NSCLC), small-cell lung cancer, and thymic malignancies who underwent genomic characterization of oncogenic drivers. Patients were enrolled onto a not-otherwise-specified arm and treated with standard-of-care therapies or one of the following five biomarker-matched treatment groups: erlotinib for EGFR mutations; selumetinib for KRAS, NRAS, HRAS, or BRAF mutations; MK2206 for PIK3CA, AKT, or PTEN mutations; lapatinib for ERBB2 mutations or amplifications; and sunitinib for KIT or PDGFRA mutations or amplification.. Six hundred forty-seven patients were enrolled, and 88% had their tumors tested for at least one gene. EGFR mutation frequency was 22.1% in NSCLC, and erlotinib achieved a response rate of 60% (95% CI, 32.3% to 83.7%). KRAS mutation frequency was 24.9% in NSCLC, and selumetinib failed to achieve its primary end point, with a response rate of 11% (95% CI, 0% to 48%). Completion of accrual to all other arms was not feasible. In NSCLC, patients with EGFR mutations had the longest median survival (3.51 years; 95% CI, 2.89 to 5.5 years), followed by those with ALK rearrangements (2.94 years; 95% CI, 1.66 to 4.61 years), those with KRAS mutations (2.3 years; 95% CI, 2.3 to 2.17 years), those with other genetic abnormalities (2.17 years; 95% CI, 1.3 to 2.74 years), and those without an actionable mutation (1.85 years; 95% CI, 1.61 to 2.13 years).. This basket trial design was not feasible for many of the arms with rare mutations, but it allowed the study of the genetics of less common malignancies.

Topics: Adolescent; Adult; Aged; Benzimidazoles; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Class I Phosphatidylinositol 3-Kinases; ErbB Receptors; Erlotinib Hydrochloride; Female; Genes, ras; Humans; Indoles; Lapatinib; Lung Neoplasms; Male; Middle Aged; Molecular Targeted Therapy; Mutation; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; PTEN Phosphohydrolase; Pyrroles; Quinazolines; ras Proteins; Reproducibility of Results; Small Cell Lung Carcinoma; Sunitinib; Thymus Neoplasms; Treatment Outcome; Young Adult

Selumetinib (AZD6244, ARRY-142886)+docetaxel increases median overall survival (OS) and significantly improves progression-free survival (PFS) and objective response rate (ORR) compared with docetaxel alone in patients with KRAS mutant, stage IIIB/IV non-small-cell lung cancer (NSCLC; NCT00890825).. Retrospective analysis of OS, PFS, ORR and change in tumour size at week 6 for different sub-populations of KRAS codon mutations.. In patients receiving selumetinib+docetaxel and harbouring KRAS G12C or G12V mutations there were trends towards greater improvement in OS, PFS and ORR compared with other KRAS mutations.. Different KRAS mutations in NSCLC may influence selumetinib/docetaxel sensitivity.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Codon; Docetaxel; Female; Humans; Lung Neoplasms; Male; Middle Aged; Mutation; Neoplasm Staging; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Retrospective Studies; Taxoids

No targeted therapies are available for KRAS-mutant non-small-cell lung cancer (NSCLC). Selumetinib is an inhibitor of MEK1/MEK2, downstream of KRAS, with preclinical evidence of synergistic activity with docetaxel in KRAS-mutant cancers. We did a prospective, randomised, phase 2 trial to assess selumetinib plus docetaxel in previously treated patients with advanced KRAS-mutant NSCLC.. Eligible patients were older than 18 years of age; had histologically or cytologically confirmed stage IIIB-IV KRAS-mutant NSCLC; had failed first-line therapy for advanced NSCLC; had WHO performance status of 0-1; had not received previous therapy with either a MEK inhibitor or docetaxel; and had adequate bone marrow, renal, and liver function. Patients were randomly assigned (in a 1:1 ratio) to either oral selumetinib (75 mg twice daily in a 21 day cycle) or placebo; all patients received intravenous docetaxel (75 mg/m(2) on day 1 of a 21 day cycle). Randomisation was done with an interactive voice response system and investigators, patients, data analysts, and the trial sponsor were masked to treatment assignment. The primary endpoint was overall survival, analysed for all patients with confirmed KRAS mutations. This study is registered with ClinicalTrials.gov, number NCT00890825.. Between April 20, 2009, and June 30, 2010, we randomly assigned 44 patients to receive selumetinib and docetaxel (selumetinib group) and 43 to receive placebo and docetaxel (placebo group). Of these, one patient in the selumetinib group and three in the placebo group were excluded from efficacy analyses because their tumours were not confirmed to be KRAS-mutation positive. Median overall survival was 9·4 months (6·8-13·6) in the selumetinib group and 5·2 months (95% CI 3·8-non-calculable) in the placebo group (hazard ratio [HR] for death 0·80, 80% CI 0·56-1·14; one-sided p=0·21). Median progression-free survival was 5·3 months (4·6-6·4) in the selumetinib group and 2·1 months (95% CI 1·4-3·7) in the placebo group (HR for progression 0·58, 80% CI 0·42-0·79; one-sided p=0·014). 16 (37%) patients in the selumetinib group and none in the placebo group had an objective response (p<0·0001). Adverse events of grade 3 or higher occurred in 36 (82%) patients in the selumetinib group and 28 (67%) patients in the placebo group. The most common grade 3-4 adverse events were neutropenia (29 [67%] of 43 patients in the selumetinib group vs 23 [55%] of 42 patients in the placebo group), febrile neutropenia (eight [18%] of 44 patients in the selumetinib group vs none in the placebo group), dyspnoea (one [2%] of 44 patients in the selumetinib group vs five [12%] of 42 in the placebo group), and asthenia (four [9%] of 44 patients in the selumetinib group vs none in the placebo group).. Selumetinib plus docetaxel has promising efficacy, albeit with a higher number of adverse events than with docetaxel alone, in previously treated advanced KRAS-mutant NSCLC. These findings warrant further clinical investigation of selumetinib plus docetaxel in KRAS-mutant NSCLC.. AstraZeneca.

Topics: Adult; Aged; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Disease-Free Survival; Docetaxel; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Prospective Studies; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Taxoids

AZD6244 (ARRY-142886) is a potent, selective MEK inhibitor. This study aimed to evaluate the efficacy and safety of AZD6244 versus pemetrexed as second- or third-line treatment in patients with advanced non-small cell lung cancer (NSCLC).. In this randomized phase II study, patients received either 100 mg oral AZD6244 free-base suspension twice daily or 500 mg/m(2) intravenous pemetrexed once every 3 weeks after pretreatment with a corticosteroid, folic acid, and vitamin B12. The primary end point of the study was the disease progression event count.. Eighty-four patients were randomized. Disease progression events were experienced by 28 (70%) and 26 (59%) patients in the AZD6244 and pemetrexed groups, respectively. Median progression-free survival was not statistically significantly different between the AZD6244 and pemetrexed groups (67 versus 90 days, respectively; hazard ratio 1.08, two-sided 80% confidence interval = 0.75-1.54; p = 0.79). Two patients in the AZD6244 group had a best response to treatment of partial response. In the pemetrexed group, one patient achieved a complete response and one patient a partial response. Dermatitis acneiform, diarrhea, nausea, and vomiting were the most frequently reported adverse events with AZD6244, compared with fatigue, anemia, nausea, anorexia, and dermatitis acneiform with pemetrexed.. Oral AZD6244 showed clinical activity as second- or third-line therapy for patients with advanced NSCLC. In an unselected NSCLC population, there is no suggestion that AZD6244 monotherapy offers any advantage over standard treatment with pemetrexed. Based on preclinical data and recent clinical observations, further development of AZD6244 in NSCLC should focus on BRAF or RAS mutation-positive patients and/or AZD6244-based combination regimens.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antimetabolites, Antineoplastic; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cohort Studies; Female; Glutamates; Guanine; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Pemetrexed; Safety; Salvage Therapy; Survival Rate; Treatment Outcome; Young Adult

Topics: A549 Cells; Animals; Antineoplastic Combined Chemotherapy Protocols; Axl Receptor Tyrosine Kinase; Benzimidazoles; Benzocycloheptenes; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Epithelial-Mesenchymal Transition; Humans; Lung Neoplasms; Mice, Inbred Strains; Mitogen-Activated Protein Kinase Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Triazoles; Xenograft Model Antitumor Assays

Osimertinib (OSI) is the first FDA-approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). It can be used for treating non-small cell lung cancer (NSCLC) patients with activating EGFR mutation and for patients who are resistant to first-generation EGFR TKIs due to T790M resistance mutation. However, patients treated with OSI ultimately develop acquired resistance, which prevents its long-term benefit for patients. Therefore, the development of effective strategies to overcome OSI resistance will address a significant clinical challenge and benefit patients by prolonging their survival time. Our previous studies indicated that combination therapy was a promising strategy for overcoming OSI resistance. In this study, we developed nanoparticle (NP) formulations for co-delivery of osimertinib (OSI) and selumetinib (SEL) to treat OSI-resistant NSCLC effectively. We conjugated SEL with PEG through a reactive oxygen species (ROS)-responsive linker to generate polyethylene glycol (PEG)-SEL conjugate prodrug (PEG-S-SEL). Due to the amphiphilic nature of PEG-S-SEL, it can self-assemble in an aqueous solution to form micelle NP and serve as a delivery carrier for OSI. The ROS-responsive linker can facilitate the release of drugs in the tumor microenvironment with elevated ROS levels. OSI and SEL combination NP can overcome OSI resistance by simultaneously inhibiting both EGFR and mitogen-activated protein kinase (MEK), thus effectively inducing apoptosis in OSI-resistant NSCLC cells and inhibiting OSI-resistant tumors in vivo. In conclusion, the OSI+SEL NP combination therapy showed promising anticancer efficacy and demonstrated potential for treating NSCLC patients with OSI acquired resistance. STATEMENT OF SIGNIFICANCE: Osimertinib (OSI) is the first FDA-approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. It has been successfully used for treating non-small cell lung cancer (NSCLC) patients with activating EGFR mutation. However, patients treated with OSI ultimately develop acquired resistance. This study developed OSI and selumetinib (SEL) co-delivering nanoparticles to overcome OSI-acquired resistance in NSCLC. PEG-SEL conjugate functions as reactive oxygen species (ROS)-responsive prodrug and forms micelle nanoparticles through self-assembly to deliver OSI. The combination NP can simultaneously inhibit EGFR and mitogen-activated protein kinase (MEK), thus effectively inducing ap

Topics: Acrylamides; Aniline Compounds; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Mutation; Nanoparticles; Protein Kinase Inhibitors; Tumor Microenvironment

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer most commonly arises through EML4 (Echinoderm Microtuble Like 4)-ALK chromosomal fusion. We have previously demonstrated that combination of the ALK inhibitor crizotinib with the MEK inhibitor selumetinib was highly effective at reducing cell viability of ALK-positive non-small-cell lung cancer (H3122) cells. In this study, we further investigated the efficacy of crizotinib and selumetinib combination therapy in an in vivo xenograft model of ALK-positive lung cancer. Crizotinib decreased tumor volume by 52% compared with control, and the drug combination reduced tumor growth compared with crizotinib. In addition, MEK inhibition alone reduced tumor growth by 59% compared with control. Crizotinib and selumetinib alone and in combination were nontoxic at the dose of 25 mg/kg, with values for ALT (<80 U/l) and creatinine (<2 mg/dl) within the normal range. Our results support the combined use of crizotinib with selumetinib in ALK-positive lung cancer but raise the possibility that a sufficient dose of an MEK inhibitor alone may be as effective as adding an MEK inhibitor to an ALK inhibitor. SIGNIFICANCE STATEMENT: This study contains in vivo evidence supporting the use of combination MEK inhibitors in ALK+ lung cancer research, both singularly and in combination with ALK inhibitors. Contrary to previously published reports, our results suggest that it is possible to gain much of the benefit from combination treatment with an MEK inhibitor alone, at a tolerable dose.

Topics: Anaplastic Lymphoma Kinase; Animals; Benzimidazoles; Cell Line, Tumor; Cell Proliferation; Crizotinib; Disease Models, Animal; Drug Interactions; Humans; Lung Neoplasms; Mice; Mitogen-Activated Protein Kinase Kinases; Protein Kinase Inhibitors; Xenograft Model Antitumor Assays

Entrectinib is a pan-tyrosine-kinase inhibitor that targets oncogenic rearrangements in NTRK, ROS1 and ALK. The combined results of two clinical trials demonstrated the efficacy of entrectinib in ROS1-rearranged NSCLC. Because the development of drug resistance is inevitable, it would be helpful to determine the mechanisms of entrectinib resistance in a ROS1-rearranged tumor model so that future therapeutic strategies can be developed. Here, we characterized the molecular basis of resistance in entrectinib-resistant ROS1-rearranged HCC78 cells (HCC78ER cells). These cells were analyzed by next-generation sequencing and genetic profiling, which revealed the acquisition of KRAS G12C and the amplification of KRAS and FGF3. However, there were no secondary mutations in the ROS1 kinase domain. We also found that sustained ERK activation was involved in entrectinib resistance, and that combined treatment with selumetinib resensitized HCC78ER cells to entrectinib in cell viability and colony formation assays. Our data suggest that activation of the RAS signaling pathway can cause entrectinib resistance in ROS1-rearranged NSCLC, and is unlikely to be overcome by sequential single agent ROS1-targeting strategies against such tumors. Instead, co-targeting ROS1 and MEK may be an effective strategy for overcoming entrectinib resistance in ROS1-rearranged NSCLC.

Topics: Antineoplastic Agents; Apoptosis; Benzamides; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Resistance, Neoplasm; Gene Rearrangement; Humans; Indazoles; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases; Mutation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras)

The dysfunction and mutual compensatory activation of RAF-MEK-ERK and PI3K-PDK1-AKT pathways have been demonstrated as the hallmarks in several primary and recurrent cancers. The strategy of concurrent blocking of these two pathways shows clinical merits on effective cancer therapy, such as combinatory treatments and dual-pathway inhibitors. Herein, we report a novel prototype of dual-pathway inhibitors by means of merging the core structural scaffolds of a MEK1 inhibitor and a PDK1 inhibitor. A library of 43 compounds that categorized into three series (Series I-III) was synthesized and tested for antitumor activity in lung cancer cells. The results from structure-activity relationship (SAR) analysis showed the following order of antitumor activity that 3-hydroxy-5-(phenylamino) indolone (Series III) > 3-alkenyl-5-(phenylamino) indolone (Series I) > 3-alkyl-5-(phenylamino) indolone (Series II). A lead compound 9za in Series III showed most potent antitumor activity with IC

Topics: A549 Cells; Amination; Aniline Compounds; Antineoplastic Agents; Apoptosis; Benzodioxoles; Cell Line, Tumor; Drug Design; Humans; Indoles; Lung Neoplasms; MAP Kinase Signaling System; Phosphatidylinositol 3-Kinase; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyruvate Dehydrogenase Acetyl-Transferring Kinase; raf Kinases; Signal Transduction

Anaplastic lymphoma kinase (ALK) rearrangement, a key oncogenic driver in a small subset of non-small cell lung cancers, confers sensitivity to ALK tyrosine kinase inhibitors (TKIs). Crizotinib, a first generation ALK-TKI, has superiority to standard chemotherapy with longer progression-free survival and higher objective response rate. However, clinical benefit is limited by development of resistance, typically within a year of therapy. In this study the combined effect of crizotinib and the MEK inhibitor selumetinib was investigated in both crizotinib naïve (H3122) and crizotinib resistant (CR-H3122) ALK-positive lung cancer cells. Results showed that combination treatment potently inhibited the growth of both H3122 and CR-H3122 cells, resulting from increased apoptosis and decreased cell proliferation as a consequence of suppressed downstream RAS/MAPK signalling. The drug combination also elicited a greater than 3-fold increase in Bim, a mediator of apoptosis, and p27, a cyclin dependent kinase inhibitor compared to crizotinib alone. The results support the hypothesis that combining MEK inhibitors with ALK inhibitor can overcome ALK inhibitor resistance, and identifies Bim, PARP and CDK1 as druggable targets for possible triple drug therapy.

Topics: Anaplastic Lymphoma Kinase; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Crizotinib; Drug Resistance, Neoplasm; Humans; Lung Neoplasms; MAP Kinase Kinase Kinases; Protein Kinase Inhibitors; Signal Transduction

KRAS is one of the driver oncogenes in non-small-cell lung cancer (NSCLC) but remains refractory to current modalities of targeted pathway inhibition, which include inhibiting downstream kinase MEK to circumvent KRAS activation. Here, we show that pulsatile, rather than continuous, treatment with MEK inhibitors (MEKis) maintains T cell activation and enables their proliferation. Two MEKis, selumetinib and trametinib, induce T cell activation with increased CTLA-4 expression and, to a lesser extent, PD-1 expression on T cells in vivo after cyclical pulsatile MEKi treatment. In addition, the pulsatile dosing schedule alone shows superior anti-tumor effects and delays the emergence of drug resistance. Furthermore, pulsatile MEKi treatment combined with CTLA-4 blockade prolongs survival in mice bearing tumors with mutant Kras. Our results set the foundation and show the importance of a combinatorial therapeutic strategy using pulsatile targeted therapy together with immunotherapy to optimally enhance tumor delay and promote long-term anti-tumor immunity.

Topics: Animals; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; CTLA-4 Antigen; Disease Models, Animal; Female; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Programmed Cell Death 1 Receptor; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Survival Rate; T-Lymphocytes

Kinase inhibitors are important cancer therapeutics. Polypharmacology is commonly observed, requiring thorough target deconvolution to understand drug mechanism of action. Using chemical proteomics, we analyzed the target spectrum of 243 clinically evaluated kinase drugs. The data revealed previously unknown targets for established drugs, offered a perspective on the "druggable" kinome, highlighted (non)kinase off-targets, and suggested potential therapeutic applications. Integration of phosphoproteomic data refined drug-affected pathways, identified response markers, and strengthened rationale for combination treatments. We exemplify translational value by discovering SIK2 (salt-inducible kinase 2) inhibitors that modulate cytokine production in primary cells, by identifying drugs against the lung cancer survival marker MELK (maternal embryonic leucine zipper kinase), and by repurposing cabozantinib to treat FLT3-ITD-positive acute myeloid leukemia. This resource, available via the ProteomicsDB database, should facilitate basic, clinical, and drug discovery research and aid clinical decision-making.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cytokines; Drug Discovery; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Lung Neoplasms; Mice; Molecular Targeted Therapy; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proteomics; Xenograft Model Antitumor Assays

Topics: Antineoplastic Agents; Benzimidazoles; Clinical Trials, Phase III as Topic; Disease Progression; Disease-Free Survival; Humans; Lung Neoplasms; Multicenter Studies as Topic; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Randomized Controlled Trials as Topic; Time Factors; Treatment Outcome

The identification of optimal drug administration schedules to battle the emergence of resistance is a major challenge in cancer research. The existence of a multitude of resistance mechanisms necessitates administering drugs in combination, significantly complicating the endeavor of predicting the evolutionary dynamics of cancers and optimal intervention strategies. A thorough understanding of the important determinants of cancer evolution under combination therapies is therefore crucial for correctly predicting treatment outcomes. Here we developed the first computational strategy to explore pharmacokinetic and drug interaction effects in evolutionary models of cancer progression, a crucial step towards making clinically relevant predictions. We found that incorporating these phenomena into our multiscale stochastic modeling framework significantly changes the optimum drug administration schedules identified, often predicting nonintuitive strategies for combination therapies. We applied our approach to an ongoing phase Ib clinical trial (TATTON) administering AZD9291 and selumetinib to EGFR-mutant lung cancer patients. Our results suggest that the schedules used in the three trial arms have almost identical efficacies, but slight modifications in the dosing frequencies of the two drugs can significantly increase tumor cell eradication. Interestingly, we also predict that drug concentrations lower than the MTD are as efficacious, suggesting that lowering the total amount of drug administered could lower toxicities while not compromising on the effectiveness of the drugs. Our approach highlights the fact that quantitative knowledge of pharmacokinetic, drug interaction, and evolutionary processes is essential for identifying best intervention strategies. Our method is applicable to diverse cancer and treatment types and allows for a rational design of clinical trials.

Topics: Acrylamides; Aniline Compounds; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Clinical Trials, Phase I as Topic; Computer Simulation; Disease Progression; Drug Administration Schedule; Drug Interactions; Drug Resistance, Neoplasm; Humans; Lung Neoplasms; Models, Biological; Neoplasms

KRAS is one of the most commonly mutated oncogenes in non-small cell lung cancer (NSCLC). Resistance to MEK inhibitor monotherapy develops through a variety of mechanisms. CDK4 was reported to have a synthetic lethal interaction with KRAS. In this study, we demonstrated the combination effects of the MEK inhibitor selumetinib and the CDK4/6 inhibitor palbociclib in RAS-driven NSCLC. In vitro, cell lines with CDKN2A mutations were insensitive to selumetinib. We used siRNA and pharmacologic inhibition of CDK4 and found that the combination of selumetinib and palbociclib synergistically inhibited RAS-driven NSCLC cases with CDKN2A mutations but not those with wild type CDKN2A. The combination treatment potentiated growth inhibition and increased the population of cells in G1 phase. Selumetinib completely inhibited p-ERK but not p-RB. The addition of palbociclib markedly inhibited p-RB and downregulated survivin expression. In vivo, the combination treatment inhibited the growth of NSCLC xenografts, which correlated with decreased levels of p-RB, downregulated survivin and decreased Ki-67 staining. These data suggest that the combination treatment of palbociclib and selumetinib is effective in preclinical models of RAS-driven NSCLC with CDKN2A mutations.

Topics: Animals; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Mutation; Piperazines; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Pyridines; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

LKB1 is a commonly mutated tumor suppressor in non-small cell lung cancer that exerts complex effects on signal transduction and transcriptional regulation. To better understand the downstream impact of loss of functional LKB1, we developed a transcriptional fingerprint assay representing this phenotype. This assay was predictive of LKB1 functional loss in cell lines and clinical specimens, even those without detected sequence alterations in the gene. In silico screening of drug sensitivity data identified putative LKB1-selective drug candidates, revealing novel associations not apparent from analysis of LKB1 mutations alone. Among the candidates, MEK inhibitors showed robust association with signature expression in both training and testing datasets independent of RAS/RAF mutations. This susceptibility phenotype is directly altered by RNA interference-mediated LKB1 knockdown or by LKB1 re-expression into mutant cell lines and is readily observed in vivo using a xenograft model. MEK sensitivity is dependent on LKB1-induced changes in AKT and FOXO3 activation, consistent with genomic and proteomic analyses of LKB1-deficient lung adenocarcinomas. Our findings implicate the MEK pathway as a potential therapeutic target for LKB1-deficient cancers and define a practical NanoString biomarker to identify functional LKB1 loss. Cancer Res; 77(1); 153-63. ©2016 AACR.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; AMP-Activated Protein Kinase Kinases; Animals; Benzimidazoles; Biomarkers, Tumor; Drug Resistance, Neoplasm; Female; Heterografts; Humans; Immunoblotting; Lung Neoplasms; MAP Kinase Kinase Kinases; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Mice, SCID; Oligonucleotide Array Sequence Analysis; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Pyridones; Pyrimidinones; Transcriptome

Metformin, widely used as antidiabetic drug, showed antitumoral effects expecially in combination with chemotherapy. Our group recently has demonstrated that metformin and gefitinib are synergistic in LKB1-wild-type NSCLC cells. In these models, metformin as single agent induced an activation and phosphorylation of mitogen-activated-protein-kinase (MAPK) through an increased C-RAF/B-RAF heterodimerization.. Since single agent metformin enhances proliferating signals through the RAS/RAF/MAPK pathway, and several MEK inhibitors (MEK-I) demonstrated clinical efficacy in combination with other agents in NSCLC, we tested the effects of metformin plus MEK-I (selumetinib or pimasertib) on proliferation, invasiveness, migration abilities in vitro and in vivo in LKB1 positive NSCLC models harboring KRAS wild type and mutated gene.. The combination of metformin with MEK-I showed a strong anti-proliferative and proapoptotic effect in Calu-3, H1299, H358 and H1975 human NSCLC cell lines, independently from the KRAS mutational status. The combination reduced the metastatic behaviour of NSCLC cells, via a downregulation of GLI1 trascritional activity, thus affecting the transition from an epithelial to a mesenchymal phenotype. Metformin and MEK-Is combinations also decreased the production and activity of MMP-2 and MMP-9 by reducing the NF-jB (p65) binding to MMP-2 and MMP-9 promoters.. Metformin potentiates the antitumor activity of MEK-Is in human LKB1-wild-type NSCLC cell lines, independently from the KRAS mutational status, through GLI1 downregulation and by reducing the NF-jB (p65)-mediated transcription of MMP-2 and MMP-9.

Topics: AMP-Activated Protein Kinase Kinases; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Chromatin Immunoprecipitation; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Humans; Hypoglycemic Agents; Immunoenzyme Techniques; Lung Neoplasms; MAP Kinase Kinase 1; Metformin; Mice; Mice, Inbred BALB C; Mice, Nude; Niacinamide; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Transcription Factors; Tumor Cells, Cultured; Xenograft Model Antitumor Assays; Zinc Finger Protein GLI1

New targeted treatments are being used for patients affected by certain types of cancers with specific gene dysregulation. These new treatments transform the prognosis for the patients but the exact way in which they work is often incompletely known. This can prove to be problematic with regard to potential side effects. Ophthalmologic side effects are particularly difficult to detect in animal models. MEK inhibitors are among these new targeted treatments for which the indications are broad. One of the reported side effects of MEK inhibitors is the appearance of atypical multifocal serous chorioretinopathies which, when present, occur rapidly after starting the treatment and disappear soon after stopping it. We report two documented cases of serous chorioretinopathies secondary to the use of selumetinib, an MEK inhibitor. Both patients were followed for several months after initiating the treatment, using angiography, OCT, and filtered photographs. Only a very few cases have been reported, and the detailed description of two clear-cut cases and their management, as well as a review of the current literature, seems a good way to approach the management of this complication.

Topics: Aged; Antineoplastic Agents; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Central Serous Chorioretinopathy; Female; Fluorescein Angiography; Humans; Lung Neoplasms; Male; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Protein Kinase Inhibitors; Tomography, Optical Coherence

Pathway inhibition of the RAS-driven MAPK pathway using small-molecule kinase inhibitors has been a key focus for treating cancers driven by oncogenic RAS, yet significant clinical responses are lacking. Feedback reactivation of ERK driven by drug-induced RAF activity has been suggested as one of the major drug resistance mechanisms, especially in the context of oncogenic RAS. To determine whether additional adaptive resistance mechanisms may coexist, we characterized global phosphoproteomic changes after MEK inhibitor selumetinib (AZD6244) treatment in KRAS-mutant A427 and A549 lung adenocarcinoma cell lines employing mass spectrometry-based phosphoproteomics. We identified 9,075 quantifiable unique phosphosites (corresponding to 3,346 unique phosphoproteins), of which 567 phosphosites were more abundant and 512 phosphosites were less abundant after MEK inhibition. Selumetinib increased phosphorylation of KSR-1, a scaffolding protein required for assembly of MAPK signaling complex, as well as altered phosphorylation of GEF-H1, a novel regulator of KSR-1 and implicated in RAS-driven MAPK activation. Moreover, selumetinib reduced inhibitory serine phosphorylation of MET at Ser985 and potentiated HGF- and EGF-induced AKT phosphorylation. These results were recapitulated by pan-RAF (LY3009120), MEK (GDC0623), and ERK (SCH772984) inhibitors, which are currently under early-phase clinical development against RAS-mutant cancers. Our results highlight the unique adaptive changes in MAPK scaffolding proteins (KSR-1, GEF-H1) and in RTK signaling, leading to enhanced PI3K-AKT signaling when the MAPK pathway is inhibited.. This study highlights the unique adaptive changes in MAPK scaffolding proteins (KSR-1, GEF-H1) and in RTK signaling, leading to enhanced PI3K/AKT signaling when the MAPK pathway is inhibited. Mol Cancer Res; 14(10); 1019-29. ©2016 AACR.

Topics: Benzimidazoles; Cell Line, Tumor; Cell Survival; ErbB Receptors; Humans; Lung Neoplasms; Mutation; Phosphoproteins; Phosphorylation; Protein Interaction Maps; Protein Kinase Inhibitors; Proteomics; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-met; Proto-Oncogene Proteins p21(ras); Signal Transduction

Lung squamous cell carcinoma (SCC) is one of the major subtypes of lung cancer. Our current knowledge of oncogenic drivers in this specific subtype of lung cancer is largely limited compared with lung adenocarcinoma (ADC). Through exon array analyses, molecular analyses and functional studies, we here identify the TRA2B-DNAH5 fusion as a novel oncogenic driver in lung SCC. We found that this gene fusion occurs exclusively in lung SCC (3.1%, 5/163), but not in lung ADC (0/119). Through mechanistic studies, we further revealed that this TRA2B-DNAH5 fusion promotes lung SCC malignant progression through regulating a SIRT6-ERK1/2-MMP1 signaling axis. We show that inhibition of ERK1/2 activation using selumetinib efficiently inhibits the growth of lung SCC with TRA2B-DNAH5 fusion expression. These findings improve our current knowledge of oncogenic drivers in lung SCC and provide a potential therapeutic strategy for lung SCC patients with TRA2B-DNAH5 fusion.

Topics: Animals; Axonemal Dyneins; Benzimidazoles; Carcinoma, Squamous Cell; Cell Line; Cell Proliferation; Gene Fusion; Humans; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Matrix Metalloproteinase 1; Mice; Mice, Nude; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Nerve Tissue Proteins; Oncogene Proteins, Fusion; Serine-Arginine Splicing Factors; Signal Transduction; Sirtuins; T-Lymphoma Invasion and Metastasis-inducing Protein 1; Transplantation, Heterologous

PAK1 confers resistance to the estrogen antagonist tamoxifen in breast cancer. However, a role for PAK1 remains to be elucidated for chemoresistance and prognosis in non-small cell lung cancer (NSCLC). We provide evidence that PAK1 confers cisplatin resistance by increasing β-catenin expression through ERK/GSK3β signaling. The increased β-catenin expression promotes sphere cell formation and expression of stemness markers and this β-catenin-induced stemness is responsible for PAK1-mediated cisplatin resistance. We enrolled 87 NSCLC patients who had received cisplatin-based chemotherapy to confirm the association between PAK1 expression and response to chemotherapy and outcomes. PAK1 expression, evaluated by immunohistochemistry, was positively correlated with pERK and β-catenin expression in lung tumors. Patients with high-PAK1, high-pERK, and high-nuclear β-catenin tumors more frequently showed an unfavorable response to cisplatin-based chemotherapy when compared to their counterparts. Kaplan-Meier and Cox regression analysis also indicated a poorer overall survival (OS) and relapse free survival (RFS) in patients with high-PAK1, high-pERK, and high-nuclear β-catenin tumors. In conclusion, PAK1 confers cisplatin resistance in NSCLC via β-catenin-mediated stemness. Therefore, we suggest that clinical use of a combination of the MEK/ERK inhibitor AZD6244 and cisplatin might improve sensitivity to cisplatin-based chemotherapy and outcomes in NSCLC patients who harbor high-PAK1-expressing tumors.

Topics: A549 Cells; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; beta Catenin; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cisplatin; Drug Resistance, Neoplasm; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lung Neoplasms; MAP Kinase Signaling System; Neoplastic Stem Cells; p21-Activated Kinases; Prognosis

KRAS is frequently mutated in non-small cell lung cancers (NSCLC), resulting in activation of the MEK/ERK pathway. Because there are currently no drugs that target oncogenic KRAS, MEK inhibitors have been tested clinically as a possible treatment option for patients with NSCLC. However, KRAS-mutant cancers exhibit resistance to MEK inhibitors. Therefore, a combinational strategy is necessary for effective therapy. To address this, we investigated the therapeutic effects of combining selumetinib, a MEK1/2 inhibitor, with BYL719, a PI3Kα inhibitor.. We evaluated the effects of selumetinib and BYL719 in vitro and in vivo in NSCLC cell lines.. The combination of BYL719 and selumetinib resulted in synergistic cytotoxic activity compared with the single agents alone in KRAS-mutant NSCLC cells. At the molecular level, we found that AKT activation strongly influenced the sensitivity of KRAS-mutant NSCLC cells to selumetinib. Selumetinib upregulated phospho-AKT and phosphorylated BAD at ser136, which is responsible for intrinsic drug resistance in KRAS-mutant NSCLC cells. In contrast, inhibition of the PI3K/AKT pathway by BYL719 hindered selumetinib-induced BAD phosphorylation and increased the antitumor efficacy of selumetinib. Furthermore, selumetinib and BYL719 combination therapy showed synergy in the suppression of A549 xenograft tumor growth. On analysis of the pharmacodynamics, selumetinib and BYL719 together resulted in effective inhibition of both p-ERK and p-AKT expression in tumor tissue.. Taken together, these data suggest that combination treatment with selumetinib and BYL719 is a promising therapeutic approach to overcoming resistance to MEK inhibitors.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Survival; Class I Phosphatidylinositol 3-Kinases; Drug Synergism; Female; Humans; Lung Neoplasms; MAP Kinase Kinase Kinases; Mice, Inbred BALB C; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Thiazoles; Tumor Burden; Xenograft Model Antitumor Assays

With more than 1 million deaths worldwide every year, lung cancer remains an area of unmet need. Accessible human in vitro 3D tissue models are required to improve preclinical predictivity. OncoCilAir™ is a new in vitro model of Non Small Cell Lung Cancer which combines a reconstituted human airway epithelium, human lung fibroblasts and lung adenocarcinoma cell lines. Remarkably, we found that in this 3D microenvironment tumour cells expand by forming nodules, mimicking a human lung cancer feature. OncoCilAir™ mutated for KRAS and expressing the green fluorescent protein were used to test the antitumour potential of the investigational MEK inhibitors selumetinib and trametinib. As primary endpoint, changes in tumour size were assessed by fluorescence measurements. Tumours showed a reduced growth in response to the MEK inhibitors, but halting the selumetinib dosing resulted in tumour relapse. Importantly, toxicity study on the normal part of the cultures revealed that the airway epithelium integrity was also affected by anticancer drug treatments. These results highlight the possibility to assess simultaneously drug efficacy, drug side-effect and tumour recurrence within a single culture model. OncoCilAir™ heralds a new generation of integrated in vitro tumour models that should be valuable tools for drug development, while reducing animal testing.

Topics: Benzimidazoles; Cell Proliferation; Cells, Cultured; Drug Screening Assays, Antitumor; Epithelial Cells; Fibroblasts; Humans; Lung; Lung Neoplasms; Models, Biological; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Tumor Microenvironment

Stabilization of Bcl-2 protein by paxillin (PXN)-mediated ERK activation was recently reported to cause an unfavorable response to 5-Fluorouracil-based chemotherapy. Here, we present evidence from cell and animal models to demonstrate that stabilization of Bcl-2 protein by phosphorylation at Serine 87 (pBcl-2-S87) via PXN-mediated ERK activation is responsible for cancer cell invasiveness and occurs via upregulation of MMP2 expression. Immunostainings of 190 tumors resected from colorectal cancer patients indicated that PXN expression was positively correlated with Bcl-2, pBcl-2-S87, and MMP2 expression. A positive correlation of pBcl-2-S87 with Bcl-2 and MMP2 was also observed in this study population. Patients with high PXN, Bcl-2, pBcl-2-S87, and MMP2 had poor overall survival (OS) and shorter relapse free survival (RFS). In conclusion, PXN promotes Bcl-2 phosphorylation at Serine 87 via PXN-mediated ERK activation, and its stabilization associated with increased tumor formation efficacy in mice and poor patient outcome in colorectal cancer patients.

Topics: Animals; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Colorectal Neoplasms; Dasatinib; Enzyme Activation; Enzyme Induction; Extracellular Signal-Regulated MAP Kinases; Heterografts; Humans; Kaplan-Meier Estimate; Leupeptins; Lung Neoplasms; Matrix Metalloproteinase 2; Mice; Mice, Nude; Neoplasm Invasiveness; Neoplasm Proteins; Paxillin; Phosphorylation; Proportional Hazards Models; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-bcl-2; Recombinant Fusion Proteins; RNA Interference; RNA, Small Interfering; Sulfonamides

Vascular endothelial growth factor (VEGF) is a key stimulator of physiological and pathological angiogenesis. VEGF signals primarily through VEGF receptor 2 (VEGFR2), a receptor tyrosine kinase whose expression is found predominantly on endothelial cells. The purpose of this study was to determine the role of VEGFR2 expression in NSCLC cells. NSCLC cells and tissue sections were stained for VEGFR2 expression by immunohistochemistry (IHC). Immunoblotting and ELISA were used to determine the activation and inhibition of VEGFR2 and its downstream signalling pathways. Five-day proliferation assays were carried out in the presence or absence of VEGF. IHC analysis of NSCLC demonstrated tumour cell VEGFR2 expression in 20% of samples. Immunoblot analysis showed expression of VEGFR2 protein in 3/8 NSCLC cell lines that correlated with VEGFR2 mRNA expression levels. VEGF-dependent VEGFR2 activation was apparent in NSCLC cells, and was associated with increased tumor cell proliferation. Cediranib treatment or siRNA against VEGFR2 inhibited VEGF-dependent increases in cell proliferation. Inhibition of VEGFR2 tyrosine kinase activity using cediranib was more effective than inhibition of AKT (MK2206) or MEK (AZD6244) for overcoming VEGFR2-driven cell proliferation. VEGF treatment did not affect cell survival following treatment with radiation, cisplatin, docetaxel or gemcitabine. Our data suggest that a subset of NSCLC tumour cells express functional VEGFR2 which can act to promote VEGF-dependent tumour cell growth. In this tumour subset, therapies targeting VEGFR2 signalling, such as cediranib, have the potential to inhibit both tumour cell proliferation and angiogenesis.

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Heterocyclic Compounds, 3-Ring; Humans; Lung Neoplasms; Protein Kinase Inhibitors; Quinazolines; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2

Patients with triple-negative breast cancer (TNBC) have a poor prognosis because TNBC often metastasizes, leading to death. Among patients with TNBC, those with extracellular signal-regulated kinase 2 (ERK2)-overexpressing tumors were at higher risk of death than those with low-ERK2-expressing tumors (hazard ratio, 2.76; 95% confidence interval, 1.19-6.41). The MAPK pathway has been shown to be a marker of breast cancer metastasis, but has not been explored as a potential therapeutic target for preventing TNBC metastasis. Interestingly, when we treated TNBC cells with the allosteric MEK inhibitor selumetinib, cell viability was not reduced in two-dimensional culture. However, in three-dimensional culture, selumetinib changed the mesenchymal phenotype of TNBC cells to an epithelial phenotype. Cells that undergo epithelial-mesenchymal transition (EMT) are thought to contribute to the metastatic process. EMT leads to generation of mesenchymal-like breast cancer cells with stem cell-like characteristics and a CD44(+)CD24(-/low) expression pattern. We tested the hypothesis that targeted inhibition of the MAPK pathway by selumetinib inhibits acquisition of the breast cancer stem cell phenotype and prevents lung metastasis of TNBC. TNBC cells treated with selumetinib showed inhibition of anchorage-independent growth, an indicator of in vivo tumorigenicity (P < 0.005), and decreases in the CD44(+)CD24(-/low) fraction, ALDH1 activity, and mammosphere-forming efficiency. Mice treated with selumetinib formed significantly fewer lung metastases than control mice injected with vehicle (P < 0.05). Our data demonstrate that MEK inhibitors can inhibit breast cancer stem cells and may have clinical potential for the prevention of metastasis in certain cases in which tumors are MAPK dependent.

Topics: Animals; Apoptosis; Benzimidazoles; Cell Line, Tumor; Cell Proliferation; Female; Humans; Lung Neoplasms; MAP Kinase Kinase Kinase 1; Mice; Protein Kinase Inhibitors; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

Paxillin (PXN) is required for receptor tyrosine kinase-mediated ERK activation, and the activation of the Raf/MEK/ERK cascade has been linked with Bcl-2 expression. We hypothesized that phosphorylation of PXN by the EGFR/Src pathway might contribute to cisplatin resistance via increased Bcl-2 expression. We show that cisplatin resistance was dependent on PXN expression, as evidenced by PXN overexpression in TL-13 and TL-10 cells and PXN knockdown in H23 and CL1-5 cells. Specific inhibitors of signaling pathways indicated that the phosphorylation of PXN at Y118 and Y31 via the Src pathway was responsible for cisplatin resistance. We further demonstrated that ERK activation was also dependent on this PXN phosphorylation. Bcl-2 transcription was upregulated by phosphorylated PXN-mediated ERK activation via increased binding of phosphorylated CREB to the Bcl-2 promoter. A subsequent increase in Bcl-2 levels by a PXN/ERK axis was responsible for the resistance to cisplatin. Animal models further confirmed the findings of in vitro cells indicating that xenograft tumors induced by TL-13-overexpressing cells were successfully suppressed by cisplatin combined with Src or ERK inhibitor compared with treatment of cisplatin, Src inhibitor or ERK inhibitor alone. A positive correlation of phosphorylated PXN with phosphorylated ERK and Bcl-2 was observed in lung tumors from NSCLC patients. Patients with tumors positive for PXN, phosphorylated PXN, phosphorylated ERK and Bcl-2 more commonly showed a poorer response to cisplatin-based chemotherapy than did patients with negative tumors. Collectively, PXN phosphorylation might contribute to cisplatin resistance via activating ERK-mediated Bcl-2 transcription. Therefore, we suggest that Src or ERK inhibitor might be helpful to improve the sensitivity for cisplatin-based chemotherapy in NSCLC patients with PXN-positive tumors.

Topics: Animals; Antineoplastic Agents; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cisplatin; Dasatinib; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; MAP Kinase Signaling System; Mice; Mice, Nude; Paxillin; Phosphorylation; Pyrimidines; Thiazoles; Xenograft Model Antitumor Assays

Breast cancer (BC) can recur as metastatic disease many years after primary tumor removal, suggesting that disseminated tumor cells survive for extended periods in a dormant state that is refractory to conventional therapies. We have previously shown that altering the tumor microenvironment through fibrosis with collagen and fibronectin deposition can trigger tumor cells to switch from a dormant to a proliferative state. Here, we used an in vivo preclinical model and a 3D in vitro model of dormancy to evaluate the role of Src family kinase (SFK) in regulating this dormant-to-proliferative switch. We found that pharmacological inhibition of SFK signaling or Src knockdown results in the nuclear localization of cyclin-dependent kinase inhibitor p27 and prevents the proliferative outbreak of dormant BC cells and metastatic lesion formation; however, SFK inhibition did not kill dormant cells. Dormant cell proliferation also required ERK1/2 activation. Combination treatment of cells undergoing the dormant-to-proliferative switch with the Src inhibitor (AZD0530) and MEK1/2 inhibitor (AZD6244) induced apoptosis in a large fraction of the dormant cells and delayed metastatic outgrowth, neither of which was observed with either inhibitor alone. Thus, targeting Src prevents the proliferative response of dormant cells to external stimuli, but requires MEK1/2 inhibition to suppress their survival. These data indicate that treatments targeting Src in combination with MEK1/2 may prevent BC recurrence.

Topics: Animals; Antineoplastic Agents; Apoptosis; Benzimidazoles; Benzodioxoles; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Female; Gene Knockdown Techniques; Humans; Lung Neoplasms; MAP Kinase Kinase Kinases; Mice; Mice, Nude; Neoplasm Recurrence, Local; Quinazolines; RNA, Small Interfering; src-Family Kinases; Xenograft Model Antitumor Assays

Therapeutics that target the epidermal growth factor receptor (EGFR) can enhance the cytotoxic effects of ionizing radiation (IR). However, predictive genomic biomarkers of this radiosensitization have remained elusive. By screening 40 non-small cell lung cancer cell (NSCLC) lines, we established a surprising positive correlation between the presence of a KRAS mutation and radiosensitization by the EGFR inhibitors erlotinib and cetuximab. EGFR signaling in KRAS-mutant NSCLC cells promotes chromatin condensation in vitro and in vivo, thereby restricting the number of DNA double-strand breaks (DSB) produced by a given dose of IR. Chromatin condensation in interphase cells is characterized by an unexpected mitosis-like colocalization of serine 10 phosphorylation and lysine 9 trimethylation on histone H3. Aurora B promotes this process in a manner that is codependent upon EGFR and protein kinase C α (PKCα). PKCα, in addition to MEK/ERK signaling, is required for the suppression of DSB-inducible premature senescence by EGFR. Blockade of autophagy results in a mutant KRAS-dependent senescence-to-apoptosis switch in cancer cells treated with IR and erlotinib. In conclusion, we identify EGFR as a molecular target to overcome a novel mechanism of radioresistance in KRAS-mutant tumor cells, which stands in contrast to the unresponsiveness of KRAS-mutant cancers to EGFR-directed agents in monotherapy. Our findings may reposition EGFR-targeted agents for combination with DSB-inducing therapies in KRAS-mutant NSCLC.

Topics: Animals; Apoptosis; Aurora Kinase B; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cellular Senescence; Chromatin; DNA Breaks, Double-Stranded; ErbB Receptors; Erlotinib Hydrochloride; Humans; Lung Neoplasms; Mice; Mutation; Protein Kinase C-alpha; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Quinazolines; Radiation Tolerance; ras Proteins; Xenograft Model Antitumor Assays

Although the EGF receptor tyrosine kinase inhibitors (EGFR-TKI) gefitinib have shown dramatic effects against EGFR mutant lung cancer, patients become resistant by various mechanisms, including gatekeeper EGFR-T790M mutation, MET amplification, and KRAS mutation, thereafter relapsing. AZD6244 is a potent, selective, and orally available MEK1/2 inhibitor. In this study, we evaluated the therapeutic efficacy of AZD6244 alone or with BEZ235, an orally available potent inhibitor of phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR), in gefitinib-resistant non-small cell lung carcinoma (NSCLC) models.. NCI-H1975 with EGFR-T790M mutation, NCI-H1993 with MET amplification and NCI-H460 with KRAS/PIK3CA mutation human NSCLC cells were subcutaneous injected into the athymic nude mice respectively. Mice were randomly assigned to treatment with AZD6244, BEZ235, AZD6244 plus BEZ235, or control for 3 weeks, then all mice were sacrificed and tumor tissues were subjected to western blot analyses and immunohistochemical staining.. AZD6244 could inhibit the tumor growth of NCI-H1993, but slightly inhibit the tumor growth of NCI-1975 and NCI-H460. Combining AZD6244 with BEZ235 markedly enhanced their antitumor effects and without any marked adverse events. Western blot analysis and immunohistochemical staining revealed that AZD6244 alone reduced ERK1/2 phosphorylation, angiogenesis, and tumor cell proliferation. Moreover, MEK1/2 inhibition resulted in decreased AKT phosphorylation in NCI-H1993 tumor model. BEZ235 also inhibited AKT phosphorylation as well as their downstream molecules in all three tumor models. The antiangiogenic effects were substantially enhanced when the agents were combined, which may due to the reduced expression of matrix metallopeptidase-9 in tumor tissues (MMP-9).. In this study, we evaluated therapy directed against MEK and PI3K/mTOR in distinct gefitinib-resistant NSCLC xenograft models. Combining AZD6244 with BEZ235 enhanced their antitumor and antiangiogenic effects. We concluded that the combination of a selective MEK inhibitor and a PI3K/mTOR inhibitor was effective in suppressing the growth of gefitinib-resistant tumors caused by EGFR T790M mutation, MET amplification, and KRAS/PIK3CA mutation. This new therapeutic strategy may be a practical approach in the treatment of these patients.

Topics: Animals; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Caspases; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Resistance, Neoplasm; Drug Synergism; Female; Gefitinib; Humans; Imidazoles; Ki-67 Antigen; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Platelet Endothelial Cell Adhesion Molecule-1; Protein Kinase Inhibitors; Protein Kinases; Quinazolines; Quinolines; Signal Transduction; Tumor Burden; Xenograft Model Antitumor Assays

Selumetinib is a potent and selective inhibitor of MEK1 and 2 that is currently being clinically developed for the treatment of several human malignancies. Initially administered as free-base suspension, a more convenient Hyd-sulfate capsule formulation has recently been developed. Phase I studies revealed that acneiform dermatitis was the dose-limiting toxicity of both the free-base and capsule formulation given two-times a day at the maximum tolerated doses of 100 and 75 mg, respectively, with the capsule formulation resulting into a significantly higher drug bioavailability. Importantly, as a MEK inhibitor, selumetinib could be particularly effective in tumors with a hyperactivated Ras/Raf/MEK/ERK pathway, which might be the case of KRAS-mutant non-small-cell lung cancers (NSCLCs). Accordingly, a recent randomized Phase II study evaluating docetaxel plus selumetinib or placebo in KRAS-mutant pretreated advanced NSCLC patients has demonstrated a significant improvement in terms of response rate, progression-free survival and patient-reported outcomes in favor of the combination arm. These positive results support further clinical evaluation of selumetinib in NSCLC, and confirmatory ongoing and future trials will assess its role according to KRAS-mutation status and in combination regimens with other targeted agents.

Topics: Animals; Antineoplastic Agents; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Drug Evaluation, Preclinical; Genes, ras; Humans; Lung Neoplasms; Mutation; Protein Kinase Inhibitors; Treatment Outcome

mTOR is a highly conserved serine/threonine protein kinase that serves as a central regulator of cell growth, survival, and autophagy. Deregulation of the PI3K/Akt/mTOR signaling pathway occurs commonly in cancer and numerous inhibitors targeting the ATP-binding site of these kinases are currently undergoing clinical evaluation. Here, we report the characterization of Torin2, a second-generation ATP-competitive inhibitor that is potent and selective for mTOR with a superior pharmacokinetic profile to previous inhibitors. Torin2 inhibited mTORC1-dependent T389 phosphorylation on S6K (RPS6KB1) with an EC(50) of 250 pmol/L with approximately 800-fold selectivity for cellular mTOR versus phosphoinositide 3-kinase (PI3K). Torin2 also exhibited potent biochemical and cellular activity against phosphatidylinositol-3 kinase-like kinase (PIKK) family kinases including ATM (EC(50), 28 nmol/L), ATR (EC(50), 35 nmol/L), and DNA-PK (EC(50), 118 nmol/L; PRKDC), the inhibition of which sensitized cells to Irradiation. Similar to the earlier generation compound Torin1 and in contrast to other reported mTOR inhibitors, Torin2 inhibited mTOR kinase and mTORC1 signaling activities in a sustained manner suggestive of a slow dissociation from the kinase. Cancer cell treatment with Torin2 for 24 hours resulted in a prolonged block in negative feedback and consequent T308 phosphorylation on Akt. These effects were associated with strong growth inhibition in vitro. Single-agent treatment with Torin2 in vivo did not yield significant efficacy against KRAS-driven lung tumors, but the combination of Torin2 with mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitor AZD6244 yielded a significant growth inhibition. Taken together, our findings establish Torin2 as a strong candidate for clinical evaluation in a broad number of oncologic settings where mTOR signaling has a pathogenic role.

Topics: Adenosine Triphosphate; Animals; Antineoplastic Agents; Apoptosis; Ataxia Telangiectasia Mutated Proteins; Autophagy; Benzimidazoles; Binding, Competitive; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; DNA-Binding Proteins; Drug Synergism; Humans; Kinetics; Lung Neoplasms; Mice; Naphthyridines; Protein Binding; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; ras Proteins; TOR Serine-Threonine Kinases; Tumor Burden; Tumor Suppressor Proteins; Xenograft Model Antitumor Assays

We sought to determine the frequency and clinical characteristics of patients with lung cancer harboring NRAS mutations. We used preclinical models to identify targeted therapies likely to be of benefit against NRAS-mutant lung cancer cells.. We reviewed clinical data from patients whose lung cancers were identified at six institutions or reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) to harbor NRAS mutations. Six NRAS-mutant cell lines were screened for sensitivity against inhibitors of multiple kinases (i.e., EGFR, ALK, MET, IGF-1R, BRAF, PI3K, and MEK).. Among 4,562 patients with lung cancers tested, NRAS mutations were present in 30 (0.7%; 95% confidence interval, 0.45%-0.94%); 28 of these had no other driver mutations. 83% had adenocarcinoma histology with no significant differences in gender. While 95% of patients were former or current smokers, smoking-related G:C>T:A transversions were significantly less frequent in NRAS-mutated lung tumors than KRAS-mutant non-small cell lung cancer [NSCLC; NRAS: 13% (4/30), KRAS: 66% (1772/2733), P < 0.00000001]. Five of 6 NRAS-mutant cell lines were sensitive to the MEK inhibitors, selumetinib and trametinib, but not to other inhibitors tested.. NRAS mutations define a distinct subset of lung cancers (∼1%) with potential sensitivity to MEK inhibitors. Although NRAS mutations are more common in current/former smokers, the types of mutations are not those classically associated with smoking.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzimidazoles; Cell Line, Tumor; DNA Mutational Analysis; Female; Gene Frequency; Genetic Association Studies; GTP Phosphohydrolases; Humans; Inhibitory Concentration 50; Lung Neoplasms; Male; Membrane Proteins; Middle Aged; Mutation, Missense; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; ras Proteins

Developing proteomic biomarkers is valuable for evaluating therapeutic effects of drugs and generating better treatment strategies. However, conventional protein analysis is often challenging due to inadequate sample size of clinical specimens, lack of assay reproducibility, accuracy, and sensitivity. A novel capillary isoelectricfocusing (IEF) immunoassay system (NanoPro) was used to study the dynamic phosphorylation status of signaling molecules in non-small cell lung cancer (NSCLC) cells treated with EGFR tyrosine kinase and MEK inhibitors. NanoPro showed the same dynamic ERK phosphorylation as Western blotting with good assay reproducibility using 1,000 times less protein. The IEF separation in NanoPro system enables multiple protein phosphorylation isoforms to be resolved and detected simultaneously. With NanoPro, we identified a specific on-target mitogen-activated protein/extracellular signal-regulated kinase (MEK) response pattern to MEK inhibitor PD325901, which was not detectable by Western blot analysis. We also revealed a MEK2 signal that may be associated with NSCLC cell sensitivity to the EGF receptor inhibitor erlotinib, and distinguished erlotinib-sensitive cells from intrinsic as well as acquired resistant cells to erlotinib. Moreover, NanoPro could differentiate human ERK1 isoforms from the mouse isoforms based on their isoelectric point differences and showed that erlotinib effectively inhibited ERK phosphorylation in targeted human xenograft cancer cells but not in surrounding mouse stromal cells. With 8 μg of tumor aspirates, we precisely quantified the response of 18 signaling molecules to erlotinib and MEK1 inhibitor treatments in an NSCLC patient. NanoPro's higher sensitivity, better resolution of protein phosphorylation status, and reduced tissue requirement warrant NanoPro's investigation for future drug development and evaluation of drug effects of targeted therapies.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; Erlotinib Hydrochloride; Extracellular Signal-Regulated MAP Kinases; Humans; Immunoassay; Lung Neoplasms; Lymphatic Metastasis; MAP Kinase Kinase 2; MAP Kinase Signaling System; Mice; Mice, Nude; Molecular Targeted Therapy; Neoplasms, Experimental; Oncogene Proteins; Phosphorylation; Protein Kinase Inhibitors; Quinazolines

To investigate the effect of the selective PI3K inhibitor and MEK inhibitor on KRAS and PTEN co-mutated non-small cell lung cancer cell line NCI-H157 and the relevant mechanisms.. NCI-H157 was cultured routinely and treated with different concentrations of the two inhibitors. Cell proliferation was detected by MTT cell cycle assay. Based on the MTT results the cells were divided into four groups: the control group, PI3K inhibitor group (GDC-0941, 0.5 and 5.0 µmol/L), combination group I (0.5 µmol/L AZD6244 + 0.5 µmol/L GDC-0941) and combination group II (5.0 µmol/L AZD6244 + 5.0 µmol/L GDC-0941). Colony formation assay was performed to detect colony formation efficiency. The cell cycle and apoptosis were analyzed by flow cytometry. The expression of protein related to apoptosis was tested with Western blot.. Cell growth was inhibited by the two inhibitors. Combination groups led to stronger cell proliferation inhibition: combination group Ishowed synergistic effect of their actions and combination group II showed an additive effect; in both groups, there were decreased colony number [(77.2 ± 1.54)/well vs (61.50 ± 2.12)/well, P < 0.01] and [(51.00 ± 4.00)/ well vs (22.50 ± 3.53)/well, P < 0.01]; and enhanced apoptotic ratios [(18.30 ± 0.82)% vs (21.32 ± 0.56)%, P < 0.01] and [(27.14 ± 1.58)% vs (42.45 ± 4.42)%, P < 0.01]. In addition, compared to the PI3K inhibitor alone group, the NCI-H157 cells in the combination groups showed increased G0/G1 phase and decreased S phase (P < 0.01). Western blotting showed that the combination groups demonstrated significantly decreased expression of cyclin D1 and cyclin B1, increased p21 and cleaved PARP and decreased bcl-2/bax ratio, compared to the PI3K inhibitor only group.. The combined inhibition of PI3K (AZD6244) and MEK (GDC-0941) has synergistic effects on the proliferation of NCI-H157 cells, but such effects appear to be in a dose-dependent manner.

Topics: Apoptosis; bcl-2-Associated X Protein; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin B1; Cyclin D1; Dose-Response Relationship, Drug; Drug Synergism; Humans; Indazoles; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins p21(ras); PTEN Phosphohydrolase; ras Proteins; Signal Transduction; Sulfonamides

Epidermal growth factor receptor (EGFR) gene mutations activate the KRAS-RAF-MEK-ERK pathway in lung cancer cells. EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib induce apoptosis of cancer cells, but prolonged treatment is often associated with acquired resistance. Here, we identified a novel MEK1/2 inhibitor, CZ0775, and compared its cytotoxic effects to those of AZD6244 (selumetinib) in non-small cell lung cancer (NSCLC) cell lines harboring EGFR mutations. The lapatinib-sensitive HCC827 and PC9 and lapatinib-resistant H1650 and H1975 cell lines showed poor responses to CZ0775 and AZD6244 monotherapy with an IC50 > 10 μM. By contrast, combination treatment with lapatinib and CZ0775 inhibited cell proliferation and produced a 2-fold higher number of annexin V-labeled cells than lapatinib alone in H1975 cells. Furthermore, combination treatment decreased phosphorylated extracellular signal related kinase (p-ERK) and survivin levels and upregulated the expression of the pro-apoptotic protein BIM. siRNA-mediated BIM depletion reduced caspase-3 activity (~40%) in lapatinib and CZ0775 treated H1975 cells. An in vitro ERK activity assay showed that p-ERK levels were approximately a 3-fold lower in H1975 cells treated with CZ0775 and lapatinib combination than in cells treated with lapatinib alone. CZ0775 was more cytotoxic than AZD6244 when used in combination with lapatinib. Our results suggest that combination treatment with CZ0774 and EGFR inhibitors is a promising therapeutic approach for the treatment of EGFR-TKI-resistant lung cancers and its effect is mediated by the inhibition of ERK and the induction of BIM.

Topics: Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Caspase 3; Cell Line, Tumor; Drug Synergism; ErbB Receptors; Gefitinib; Humans; Lapatinib; Lung Neoplasms; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Membrane Proteins; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Pyridones; Quinazolines; Sulfonamides

Lung adenocarcinoma cells harboring epidermal growth factor receptor (EGFR) mutations are sensitive to EGFR tyrosine kinase inhibitors (TKIs), including gefitinib. Acquired resistance to EGFR-TKIs develops after prolonged treatments. The study was prompt to explore effective strategies against resistance to EGFR-TKIs. We established gefitinib resistant PC-9 cells which harbor EGFR exon 19 deletion. Known mechanisms for intrinsic or acquired EGFR-TKI resistance, including KRAS mutation, HER2 mutation, EGFR T790M mutation and MET gene amplification, were studied, and we did not observe any known mechanisms for intrinsic or acquired resistance to EGFR-TKIs in the resistant cells. In the parental PC-9 cells, labeled as PC-9/wt, gefitinib completely inhibited EGF-induced phosphorylation of EGFR, AKT and ERK. Gefitinib inhibited EGFR phosphorylation, but was unable to block EGF-induced phosphorylation of ERK in resistant cells, labeled as PC-9/gef cells, including PC-9/gefB4, PC-9/gefE3, and PC-9/gefE7 subclones. We detected NRAS Q61K mutation in the PC-9/gef cells but not the PC-9/wt cells. MEK inhibitors, either AZD6244 or CI1040, inhibited ERK phosphorylation and sensitized gefitinib-induced cytotoxicity in PC-9/gef cells. Whereas MEK inhibitors or gefitinib alone did not activate caspases in PC-9/gef cells, combination of gefitinib and AZD6244 or CI1040 induced apoptosis. Our in vivo studies showed that gefitinib inhibited growth of PC-9/wt xenografts but not PC-9/gef xenografts. Furthermore, combination of a MEK inhibitor and gefitinib inhibited growth of both PC-9/wt xenografts and PC-9/gefB4 xenografts. To conclude, persistent activation of ERK pathway contributes to the acquired gefitinib-resistance. Combined treatment of gefitinib and MEK inhibitors may be therapeutically useful for acquired gefitinib-resistance lung adenocarcinoma cells harboring EGFR mutations.

Topics: Animals; Benzimidazoles; Blotting, Western; Cell Line, Tumor; Enzyme Inhibitors; ErbB Receptors; Gefitinib; GTP Phosphohydrolases; Humans; Lung Neoplasms; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Phosphorylation; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Quinazolines; ras Proteins; Receptor, ErbB-2; Xenograft Model Antitumor Assays

Increasing evidence has suggested that high expression level of cyclooxygenase-2 (Cox-2) is associated with the malignancies of non-small cell lung cancer (NSCLC), leading to a rationale of applying Cox-2 inhibitors as adjuvant therapy in the treatment of NSCLC. However, the addition of celecoxib, a selective Cox-2 inhibitor, to chemotherapy in clinical trials failed to benefit the survival of NSCLC patients, which urges the investigation to re-evaluate this strategy for NSCLC treatment. In this study, we observed that celecoxib treatment at clinically relevant concentrations induced epithelial-mesenchymal transition (EMT) in NSCLC cells regardless of Cox-2 status, which, however, was not recapitulated using another Cox-2 inhibitor, etodolac. Celecoxib-stimulated EMT in turn promoted cell invasion and rendered cells resistant to chemotherapy. Further mechanistic investigation by disrupting the integrity of signaling pathways using specific inhibitors or RNA interference revealed that celecoxib-induced EMT in NSCLC cells is indispensable of transforming growth factor-β1/Smad signaling. Instead, the activated MEK/ERK/SNAIL1 signaling largely accounted for celecoxib-induced EMT. Taken together, our study reveals the diverse impacts of Cox-2 inhibitors on EMT in NSCLC cells independent of Cox-2 inhibition, where celecoxib treatment leads to metastasis and chemoresistance via EMT induction. These findings reveal the increased risks of cancer metastasis and chemoresistance by applying Cox-2 inhibitors, celecoxib in particular, in clinical trials of NSCLC treatment and urge intensive preclinical assessment before proceeding to clinical application.

Topics: Animals; Antineoplastic Agents; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Celecoxib; Cell Line, Tumor; Cell Movement; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dogs; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Gene Knockdown Techniques; Heterocyclic Compounds, 3-Ring; Humans; Lung Neoplasms; MAP Kinase Kinase 1; MAP Kinase Kinase 2; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-akt; Pyrazoles; RNA, Small Interfering; Smad Proteins; Sulfonamides; Transforming Growth Factor beta1

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Docetaxel; Female; Humans; Lung Neoplasms; Male; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Taxoids

The mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/AKT signaling pathways interact at multiple nodes in cancer, including at mTOR complexes, suggesting an increased likelihood of redundancy and innate resistance to any therapeutic effects of single pathway inhibition. In this study, we investigated the therapeutic effects of combining the MAPK extracellular signal-regulated kinase (MEK)1/2 inhibitor selumetinib (AZD6244) with the dual mTORC1 and mTORC2 inhibitor (AZD8055). Concurrent dosing in nude mouse xenograft models of human lung adenocarcinoma (non-small cell lung cancers) and colorectal carcinoma was well tolerated and produced increased antitumor efficacy relative to the respective monotherapies. Pharmacodynamic analysis documented reciprocal pathway inhibition associated with increased apoptosis and Bim expression in tumor tissue from the combination group, where key genes such as DUSP6 that are under MEK functional control were also modulated. Our work offers a strong rationale to combine selumetinib and AZD8055 in clinical trials as an attractive therapeutic strategy.

Topics: Animals; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Colorectal Neoplasms; Female; Gene Expression Profiling; Humans; Lung Neoplasms; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase Kinases; Morpholines; Mutation; Neoplasms, Experimental; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Signal Transduction; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Ras/Raf/mitogen-activated protein-extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signaling is critical for tumor cell proliferation and survival. Selumetinib is a potent, selective, and orally available MEK1/2 inhibitor. In this study, we evaluated the therapeutic efficacy of selumetinib alone or with cediranib, an orally available potent inhibitor of all three VEGF receptor (VEGFR) tyrosine kinases, in murine orthotopic non-small cell lung carcinoma (NSCLC) models.. NCI-H441 or NCI-H460 KRAS-mutant human NSCLC cells were injected into the lungs of mice. Mice were randomly assigned to treatment with selumetinib, cediranib, paclitaxel, selumetinib plus cediranib, or control. When controls became moribund, all animals were sacrificed and assessed for lung tumor burden and locoregional metastasis. Lung tumors and adjacent normal tissues were subjected to immunohistochemical analyses.. Selumetinib inhibited lung tumor growth and, particularly at higher dose, reduced locoregional metastasis, as did cediranib. Combining selumetinib and cediranib markedly enhanced their antitumor effects, with near complete suppression of metastasis. Immunohistochemistry of tumor tissues revealed that selumetinib alone or with cediranib reduced ERK phosphorylation, angiogenesis, and tumor cell proliferation and increased apoptosis. The antiangiogenic and apoptotic effects were substantially enhanced when the agents were combined. Selumetinib also inhibited lung tumor VEGF production and VEGFR signaling.. In this study, we evaluated therapy directed against MEK combined with antiangiogenic therapy in distinct orthotopic NSCLC models. MEK inhibition resulted in potent antiangiogenic effects with decreased VEGF expression and signaling. Combining selumetinib with cediranib enhanced their antitumor and antiangiogenic effects. We conclude that combining selumetinib and cediranib represents a promising strategy for the treatment of NSCLC.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Disease Progression; Humans; Lung Neoplasms; Male; Mice; Mice, Nude; Mitogen-Activated Protein Kinases; Molecular Targeted Therapy; Neovascularization, Pathologic; Paclitaxel; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Quinazolines; ras Proteins; Receptors, Vascular Endothelial Growth Factor; Xenograft Model Antitumor Assays

Targeted therapies have demonstrated efficacy against specific subsets of molecularly defined cancers. Although most patients with lung cancer are stratified according to a single oncogenic driver, cancers harbouring identical activating genetic mutations show large variations in their responses to the same targeted therapy. The biology underlying this heterogeneity is not well understood, and the impact of co-existing genetic mutations, especially the loss of tumour suppressors, has not been fully explored. Here we use genetically engineered mouse models to conduct a 'co-clinical' trial that mirrors an ongoing human clinical trial in patients with KRAS-mutant lung cancers. This trial aims to determine if the MEK inhibitor selumetinib (AZD6244) increases the efficacy of docetaxel, a standard of care chemotherapy. Our studies demonstrate that concomitant loss of either p53 (also known as Tp53) or Lkb1 (also known as Stk11), two clinically relevant tumour suppressors, markedly impaired the response of Kras-mutant cancers to docetaxel monotherapy. We observed that the addition of selumetinib provided substantial benefit for mice with lung cancer caused by Kras and Kras and p53 mutations, but mice with Kras and Lkb1 mutations had primary resistance to this combination therapy. Pharmacodynamic studies, including positron-emission tomography (PET) and computed tomography (CT), identified biological markers in mice and patients that provide a rationale for the differential efficacy of these therapies in the different genotypes. These co-clinical results identify predictive genetic biomarkers that should be validated by interrogating samples from patients enrolled on the concurrent clinical trial. These studies also highlight the rationale for synchronous co-clinical trials, not only to anticipate the results of ongoing human clinical trials, but also to generate clinically relevant hypotheses that can inform the analysis and design of human studies.

Topics: AMP-Activated Protein Kinases; Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Biomarkers, Tumor; Clinical Trials, Phase II as Topic; Disease Models, Animal; Docetaxel; Drug Evaluation, Preclinical; Fluorodeoxyglucose F18; Genes, p53; Humans; Lung Neoplasms; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase Kinases; Mutation; Pharmacogenetics; Positron-Emission Tomography; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Randomized Controlled Trials as Topic; ras Proteins; Reproducibility of Results; Taxoids; Tomography, X-Ray Computed; Treatment Outcome

Topics: Animals; Benzimidazoles; Clinical Trials, Phase II as Topic; Disease Models, Animal; Docetaxel; Humans; Lung Neoplasms; Pharmacogenetics; Taxoids

MEK is activated in ∼40% colorectal cancer (CRC) and 20-30% non-small cell lung cancer (NSCLC). Selumetinib is a selective inhibitor of MEK1/2, which is currently in clinical development.. We evaluated the effects of selumetinib in vitro and in vivo in CRC and NSCLC cell lines to identify cancer cell characteristics correlating with sensitivity to MEK inhibition.. Five NSCLC and six CRC cell lines were treated with selumetinib and classified according to the median inhibitory concentration (IC(50)) values as sensitive (≤1 μM) or resistant (>1 μM). In selumetinib-sensitive cancer cell lines, selumetinib treatment induced G1 cell-cycle arrest and apoptosis and suppression of tumour growth as xenografts in immunodeficient mice. Evaluation of intracellular effector proteins and analysis of gene mutations showed no correlation with selumetinib sensitivity. Microarray gene expression profiles revealed that the activation of cAMP-dependent protein kinase A (PKA) was associated with MEK inhibitor resistance. Combined targeting of both MEK and PKA resulted in cancer cell growth inhibition of MEK inhibitor-resistant cancer cell lines in vitro and in vivo.. This study provides molecular insights to explain resistance to an MEK inhibitor in human cancer cell lines.

Topics: Apoptosis; Benzimidazoles; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Cyclic AMP-Dependent Protein Kinases; Drug Resistance, Neoplasm; Enzyme Activation; Gene Expression Profiling; Humans; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases; Mutation; Xenograft Model Antitumor Assays

Mutant KRAS is a feature of more than 25% of non-small cell lung cancers (NSCLC) and represents one of the most prevalent oncogenic drivers in this disease. NSCLC tumors with oncogenic KRAS respond poorly to current therapies, necessitating the pursuit of new treatment strategies. Targeted inhibition of the molecular chaperone Hsp90 results in the coordinated blockade of multiple oncogenic signaling pathways in tumor cells and has thus emerged as an attractive avenue for therapeutic intervention in human malignancies. Here, we examined the activity of ganetespib, a small-molecule inhibitor of Hsp90 currently in clinical trials for NSCLCs in a panel of lung cancer cell lines harboring a diverse spectrum of KRAS mutations. In vitro, ganetespib was potently cytotoxic in all lines, with concomitant destabilization of KRAS signaling effectors. Combinations of low-dose ganetespib with MEK or PI3K/mTOR inhibitors resulted in superior cytotoxic activity than single agents alone in a subset of mutant KRAS cells, and the antitumor efficacy of ganetespib was potentiated by cotreatment with the PI3K/mTOR inhibitor BEZ235 in A549 xenografts in vivo. At the molecular level, ganetespib suppressed activating feedback signaling loops that occurred in response to MEK and PI3K/mTOR inhibition, although this activity was not the sole determinant of combinatorial benefit. In addition, ganetespib sensitized mutant KRAS NSCLC cells to standard-of-care chemotherapeutics of the antimitotic, topoisomerase inhibitor, and alkylating agent classes. Taken together, these data underscore the promise of ganetespib as a single-agent or combination treatment in KRAS-driven lung tumors.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Female; Genes, ras; Humans; Imidazoles; Lung Neoplasms; Mice; Mice, Nude; Mutation; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases; Triazoles; Xenograft Model Antitumor Assays

Topics: Antineoplastic Agents; Benzenesulfonates; Benzimidazoles; Bexarotene; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Crizotinib; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Humans; Lung Neoplasms; Molecular Targeted Therapy; Mutation; Niacinamide; Oncogene Proteins, Fusion; Phenylurea Compounds; Piperidines; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyridines; Quinazolines; Randomized Controlled Trials as Topic; Sorafenib; Tetrahydronaphthalenes; Treatment Outcome

KRAS is frequently mutated in nonsmall cell lung cancer (NSCLC), resulting in the activation of the MAPK/ERK kinase (MEK)/ERK pathway. High-throughput mutation profile has shown that lung cancer frequently harbors comutation of cancer-related genes. Therefore, given that cancer cells have multiple genetic alterations, combinatorial therapeutic strategy is demanded for effective cancer therapy. To address this, we first characterized MEK dependence in four NSCLC cells. Two cells (H358, A549) carried KRAS mutation only, and the other two (H23, H157) harbored comutation of KRAS/PTEN. H358 cells with KRAS mutation only were sensitive to MEK inhibition. However, the other KRAS mutant A549 cells were resistant to MEK inhibition. Previously, we have shown that dual inhibition of EGFR and MEK signaling shows a synergistic effect on KRAS mutant gastric cancer cells by suppressing compensatory activation of AKT. Here we also observed that this combination was effective in KRAS mutant A549 cells. However, the combination was ineffective in H23 and 157 cells with comutation of KRAS/PTEN. Compared to KRAS mutant/PTEN wild-type cells, signal transducer and activator of transcription 3 (STAT3) was significantly activated following MEK inhibition in KRAS/PTEN comutant cells. Combined STAT3 inhibition by a JAK2 inhibitor or gene knockdown with MEK inhibition blocked STAT3 activation, synergistically suppressed cell growth, and induced apoptosis in comutant cells. Taken together, our study provides molecular insights that help explain the heterogeneous response to MEK inhibition in KRAS mutant lung cancers, and presents a rationale for the clinical investigation of combination of MEK and EGFR inhibitor or MEK and JAK2 inhibitor depending on PTEN status.

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Enzyme Activation; Enzyme Inhibitors; Genes, ras; Humans; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases; Mutation; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; STAT3 Transcription Factor

Selumetinib (AZD6244; ARRY-142886) is a tight-binding, uncompetitive inhibitor of mitogen-activated protein kinase kinases (MEK) 1 and 2 currently in clinical development. We evaluated the effects of selumetinib in 31 human breast cancer cell lines and 43 human non-small cell lung cancer (NSCLC) cell lines to identify characteristics correlating with in vitro sensitivity to MEK inhibition. IC(50) <1 micromol/L (considered sensitive) was seen in 5 of 31 breast cancer cell lines and 15 of 43 NSCLC cell lines, with a correlation between sensitivity and raf mutations in breast cancer cell lines (P = 0.022) and ras mutations in NSCLC cell lines (P = 0.045). Evaluation of 27 of the NSCLC cell lines with Western blots showed no clear association between MEK and phosphoinositide 3-kinase pathway activation and sensitivity to MEK inhibition. Baseline gene expression profiles were generated for each cell line using Agilent gene expression arrays to identify additional predictive markers. Genes associated with differential sensitivity to selumetinib were seen in both histologies, including a small number of genes in which differential expression was common to both histologies. In total, these results suggest that clinical trials of selumetinib in breast cancer and NSCLC might select patients whose tumors harbor raf and ras mutations, respectively.

Topics: Benzimidazoles; Biomarkers, Tumor; Blotting, Western; Breast Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cluster Analysis; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Lung Neoplasms; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mutation; Oligonucleotide Array Sequence Analysis; Predictive Value of Tests; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; raf Kinases; ras Proteins

AZD6244 (ARRY-142886) is an inhibitor of MEK1/2 and can inhibit cell proliferation or induce apoptosis in a cell-type dependent manner. The precise molecular mechanism of AZD6244-induced apoptosis is not clear. To investigate mechanisms of AZD6244 induced apoptosis in human lung cancer, we determined the molecular changes of two subgroups of human lung cancer cell lines that are either sensitive or resistant to AZD6244 treatment. We found that AZD6244 elicited a large increase of Bim proteins and a smaller increase of PUMA and NOXA proteins, and induced cell death in sensitive lung cancer cell lines, but had no effect on other Bcl-2 related proteins in those cell lines. Knockdown of Bim by siRNA greatly increased the IC(50) and reduced apoptosis for AZD6244 treated cells. We also found that levels of endogenous p-Thr32-FOXO3a and p-Ser253-FOXO3a were lower in AZD6244-sensitive cells than in AZD6244-resistant cells. In the sensitive cells, AZD6244 induced FOXO3a nuclear translocation required for Bim activation. Moreover, the silencing of FOXO3a by siRNA abrogated AZD6244-induced cell apoptosis. In addition, we found that transfection of constitutively active AKT up-regulated p-Thr32-FOXO3a and p-Ser253-FOXO3a expression and inhibited AZD6244-induced Bim expression in sensitive cells. These results show that Bim plays an important role in AZD6244-induced apoptosis in lung cancer cells and that the PI3K/AKT/FOXO3a pathway is involved in Bim regulation and susceptibility of lung cancer cells to AZD6244. These results have implications in the development of strategies to overcome resistance to MEK inhibitors.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Benzimidazoles; Cell Line, Tumor; Down-Regulation; Enzyme Inhibitors; Forkhead Box Protein O3; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Membrane Proteins; Proto-Oncogene Proteins

AZD6244 and MK2206 are targeted small-molecule drugs that inhibit MEK and AKT respectively. The efficacy of this combination in lung cancer is unknown. Our previous work showed the importance of activated AKT in mediating resistance of non-small cell lung cancer (NSCLC) to AZD6244. Thus we hypothesized that dual inhibition of both downstream MEK and AKT pathways would induce synergistic antitumor activity. In this study, we evaluated the efficacy of AZD6244 and MK2206 individually on a large panel of lung cancer cell lines. Then, we treated 28 human lung cancer cell lines with a combination of AZD6244 and MK2206 at clinically applicable drug molar ratios. The AZD6244-MK2206 combination therapy resulted in a synergistic effect on inhibition of lung cancer cell growth compared to the results of single drug treatment alone. MK2206 enhanced AZD6244-induced Bim overexpression and apoptosis in A549 and H157 cells. When we tested the combination of AZD6244 and MK2206 at ratios of 8∶1, 4∶1, 2∶1, and 1∶8, we found that the synergistic effect of the combination therapy was ratio-dependent. At ratios of 8∶1, 4∶1, and 2∶1, the drug combination consistently demonstrated synergy, whereas decreasing the ratio to 1∶8 resulted in a loss of synergy and produced an additive or antagonistic effect in most cell lines. Furthermore, the AZD6244-MK2206 combination therapy showed synergy in the suppression of A549 and H157 xenograft tumor growth and increased mean animal survival time. The AZD6244-MK2206 combination therapy resulted in effective inhibition of both p-ERK and p-AKT expression in tumor tissue. In addition, a significant increase of apoptosis was detected in tumor tissue from mice treated with AZD6244-MK2206 compared with that from the single agent treated mice. Our study suggests that the combination of AZD6244 and MK2206 has a significant synergistic effect on tumor growth in vitro and in vivo and leads to increased survival rates in mice bearing highly aggressive human lung tumors.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Synergism; Female; Heterocyclic Compounds, 3-Ring; Humans; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogen-Activated Protein Kinase Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Survival Analysis; Tumor Burden; Xenograft Model Antitumor Assays

The mitogen-activated protein (MAP) kinase pathway is important for cell proliferation, survival, and differentiation, and is frequently up-regulated in cancers. The MAP kinase pathway is also activated after exposure to ionizing radiation. We investigated the effects of AZD6244 (ARRY-142886), an inhibitor of MAP kinase/extracellular signal-regulated kinase 1/2, on radiation response.. The effects of AZD6244 on the in vitro radiosensitivity of human cancer cell lines (A549, MiaPaCa2, and DU145) were evaluated using clonogenic assays. DNA damage repair was evaluated using gammaH2AX, and mitotic catastrophe was measured using nuclear fragmentation. Cell cycle effects were measured with flow cytometry. Growth delay was used to evaluate the effects of AZD6244 on in vivo tumor radiosensitivity.. Exposure of each cell line to AZD6244 before irradiation resulted in an increase in radiosensitivity with dose enhancement factors at a surviving fraction of 0.1, ranging from 1.16 to 2.0. No effects of AZD6244 on radiation-induced apoptosis or persistence of gammaH2AX foci after irradiation were detected. Cells treated with AZD6244 had an increased mitotic index and decreased Chk1 phosphorylation at 1 and 2 hours after irradiation. Mitotic catastrophe was increased in cells receiving AZD6244 and irradiation compared with the single treatments. In vivo studies revealed that AZD6244 administration to mice bearing A549 tumor xenografts resulted in a greater than additive increase in radiation-induced tumor growth delay (dose enhancement factor of 3.38).. These results indicate that AZD6244 can enhance tumor cell radiosensitivity in vitro and in vivo and suggest that this effect involves an increase in mitotic catastrophe.

Topics: Adenocarcinoma; Animals; Apoptosis; Benzimidazoles; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Female; Fluorescent Antibody Technique; Humans; In Vitro Techniques; Lung Neoplasms; Male; Mice; Mice, Nude; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Phosphorylation; Prostatic Neoplasms; Radiation-Sensitizing Agents; Tumor Stem Cell Assay; X-Rays; Xenograft Model Antitumor Assays

MEK/ERK activities are increased in many primary lung cancers, and MEK inhibitors have been tested clinically for treatment of non-small cell lung cancers. The molecular mechanisms of resistance to MEK inhibitors have not been clearly demonstrated, however, and no molecular biomarker that can predict lung cancer response to MEK inhibitors is available. By determining the dose-responses of 35 human lung cancer cell lines to MEK-specific inhibitor AZD6244, we identified subsets of lung cancer cell lines that are either sensitive or resistant to this agent. Subsequent molecular characterization showed that treatment with AZD6244 suppressed ERK phosphorylation in both sensitive and resistant cells, suggesting that resistance is not mediated by the activities of MEK/ERK themselves. Interestingly, we found that levels of phosphorylated AKT were dramatically higher in the resistant cancer cells than in the sensitive cells. Stable transfection of dominant-negative AKT into resistant cells by retroviral infection restored their susceptibility to AZD6244. These results indicate that phosphorylated AKT may be a biomarker of response to AZD6244 and that modulation of AKT activity may be a useful approach to overcome resistance to MEK inhibitors.

Topics: Apoptosis; Benzimidazoles; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Flow Cytometry; Humans; Inhibitory Concentration 50; Lung Neoplasms; Mitogen-Activated Protein Kinase Kinases; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Signal Transduction; Transfection; Tumor Cells, Cultured

Novel molecularly targeted agents, given in combination with radiotherapy, have the potential to increase tumor response rates and the survival of patients with lung cancer. AZD6244 is a potent and selective inhibitor of mitogen-activated protein kinase (MAPK) kinase 1/2 (MEK1/2), a critical enzyme within the MAPK/extracellular signal-regulated kinase (ERK) signaling pathway that regulates the proliferation and survival of tumor cells.. This study examined the potential benefit of combining AZD6244 with fractionated radiotherapy using human lung and colon carcinoma xenograft models.. AZD6244 reduced ERK phosphorylation in Calu-6 lung cancer cells in vitro. Administration of AZD6244 for 10 days (25 mg/kg twice daily p.o.) inhibited the tumor growth of Calu-6 xenografts, with regrowth occurring on cessation of drug treatment. When fractionated tumor-localized radiotherapy (5 x 2 Gy) was combined with AZD6244 treatment, the tumor growth delay was enhanced significantly when compared with either modality alone, and this effect was also seen in a colon tumor model. We examined the effect of inhibiting MEK1/2 on the molecular responses to hypoxia, a potential interaction that could contribute to radioresponsiveness. AZD6244 reduced hypoxia-inducible factor-specific transactivation in vivo, shown using Calu-6 dual clone cells that stably express a Firefly luciferase gene under the control of a hypoxia-driven promoter. Furthermore, hypoxia-inducible factor-1 alpha, GLUT-1, and vascular endothelial growth factor levels were reduced by AZD6244, and there was a significant decrease in vascular perfusion in the tumors given combination treatment when compared with the other treatment groups.. These data provide support for the clinical development of AZD6244 in combination with radiotherapy and indicate a potential role for AZD6244 in inhibiting the tumor hypoxia response.

Topics: Animals; Benzimidazoles; Cell Hypoxia; Cell Line, Tumor; Colorectal Neoplasms; Drug Evaluation; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Lung Neoplasms; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Mice; Mitogen-Activated Protein Kinase 1; Murine pneumonia virus; Protein Kinase Inhibitors; Radiation-Sensitizing Agents; Xenograft Model Antitumor Assays