pyrimidinones and Colorectal-Neoplasms

Colorectal cancer (CRC) is one of the most common malignancies in the world. Despite intensive advances in diagnosis and treatment of CRC, it is yet one of the leading cause of cancer related morbidity and mortality. Therefore, there is an urgent medical need for alternative therapeutic approaches to treat CRC. The 70 kDa heat shock proteins (Hsp70s) are a family of evolutionary conserved heat shock proteins, which play an important role in cell homeostasis and survival. They overexpress in various types of malignancy including CRC and are typically accompanied with poor prognosis. Hence, inhibition of Hsp70 may be considered as a striking chemotherapeutic avenue. This review summarizes the current knowledge on the progress made so far to discover compounds, which target the Hsp70 family, with particular emphasis on their efficacy in treatment of CRC. We also briefly explain the induction of Hsp70 as a strategy to prevent CRC.

Topics: Antineoplastic Agents; Biological Products; Carbamates; Colorectal Neoplasms; Endoplasmic Reticulum Chaperone BiP; Heat-Shock Proteins; HSP70 Heat-Shock Proteins; Humans; Molecular Targeted Therapy; Purine Nucleosides; Pyrimidinones

Wnt/β-catenin pathway is one of the main/frequent dysregulated pathways in several tumor types, including colon cancer. Aberrant activation of this pathway is associated with cell proliferation, invasive behaviors, and cell resistance, suggesting its potential value as a therapeutic target in treatment of CRC. Several agents have been developed for targeting of this pathway (e.g, natural agents: curcumin, 3,3-diindolylmethane, phytoestrogen; Synthetic/small Wnt inhibitors: Rofecoxib; PRI-724, CWP232291; and monoclonal antibody against frizzled receptors, Vanituctumab). This review summarizes the current knowledge about the therapeutic potential of targeting Wnt pathway with particular emphasis on preclinical/clinical studies in treatment of colorectal cancer. J. Cell. Biochem. 118: 1979-1983, 2017. © 2017 Wiley Periodicals, Inc.

Topics: Animals; Antineoplastic Agents; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Colorectal Neoplasms; Curcumin; Gene Expression Regulation, Neoplastic; Humans; Indoles; Lactones; Molecular Targeted Therapy; Pyrimidinones; Signal Transduction; Sulfones; Wnt Proteins

We conducted a phase I study to evaluate the maximum tolerated dose (MTD), safety, and efficacy of trametinib in combination with TAS-102 in patients with chemotherapy-refractory KRAS-mutant, wild-type PIK3CA/PTEN metastatic colorectal cancer (mCRC).. A 3+3 dose de-escalation single arm phase I clinical trial was performed in patients with chemorefractory mCRC without priorTAS-102 exposure. Patients received fixed dosing of trametinib 2mg oral daily along with de-escalating doses of TAS-102 beginning at 35 mg/m. 25 eligible patients were enrolled in this study. During the dose de-escalation phase, no dose-limiting toxicities (DLT) were observed at the full doses of trametinib/TAS-102 and the MTD was determined to be TAS-102 35 mg/m. Trametinib in combination with TAS-102 demonstrated a manageable safety profile. However, this combination did not achieve meaningful clinical benefit in patients with RAS-mutated PIK3CA and PTEN wild-type refractory mCRC.. NCT03317119.

Topics: Antineoplastic Combined Chemotherapy Protocols; Class I Phosphatidylinositol 3-Kinases; Colorectal Neoplasms; Drug Combinations; Humans; PTEN Phosphohydrolase; Pyridones; Pyrimidinones; Pyrrolidines; Thymine; Trifluridine

Monotherapy with immune checkpoint blockade is ineffective for patients (pts) with microsatellite stable (MSS) metastatic colorectal cancer (mCRC). This study investigates whether the combination of trametinib (T) with durvalumab (D) can alter the immune tumor microenvironment (TME) by successfully priming and activating T-cells.. Open-label, single-center, phase II trial with primary endpoint of immune-related response rate for combination of T+D in refractory MSS mCRC pts (NCT03428126). T is 2 mg/day orally starting 1 week prior to D, which is given 1500 mg intravenously every 4 weeks. Simon 2-stage design used to enroll 29 pts into first stage, requiring a response in two or more pts to proceed to stage 2. Tumor biopsies were collected at baseline (BL) and early on-treatment (OT) at week 4.. Twenty nine treated pts include 48% females, median age 48 years (range 28-75), and median prior therapies 2 (range 1-5). No grade (G) 4 or 5 treatment-related adverse events (TRAE). The most common TRAE of any grade was acneiform rash, 17% being G3. One of 29 pts had confirmed partial response (PR) lasting 9.3 months (mo) for an overall response rate of 3.4%. Seven pts had stable disease (SD) and five pts (1 PR, 4 SD) demonstrated decrease in total carcinoembryonic antigen ng/mL (best percentage reduction: 94%, 95%, 42%, 34%, and 22%, respectively). Median progression-free survival was 3.2 mo (range 1.1-9.3 months). Three pts with both liver and lung metastases demonstrated discrepant responses in which clinical benefit was present in the lung metastases but not liver metastases. Comparison of BL and 4-week OT tumor tissue flow cytometry demonstrated no changes in T-cell infiltration but upregulation expression of PD-1 and Tim3 on CD8 T cells. However, expression of PD-1 and Tim3 as single markers and as coexpressed markers was observed to increase OT relative to BL (p=0.03, p=0.06 and p=0.06, respectively).. T+D demonstrated acceptable tolerability in pts with refractory MSS mCRC. The response rate in the first stage of the study did not meet efficacy criteria to proceed to the second stage. Specific site of metastatic disease may impact outcomes in novel immunotherapy combination trials.. NCT03428126.

Topics: Adult; Aged; Antibodies, Monoclonal; Colorectal Neoplasms; Female; Hepatitis A Virus Cellular Receptor 2; Humans; Lung Neoplasms; Male; Microsatellite Repeats; Middle Aged; Programmed Cell Death 1 Receptor; Pyridones; Pyrimidinones; Tumor Microenvironment

Outcomes in. Patients with newly diagnosed mCRC were registered into FOCUS4 and tested for. FOCUS4-C was conducted between April 2017 and Mar 2020 during which time 718 patients were registered; 247 (34%) were. In this phase II randomized trial, adavosertib improved PFS compared with AM and demonstrates potential as a well-tolerated therapy for

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Cycle Proteins; Colorectal Neoplasms; Enzyme Inhibitors; Female; Follow-Up Studies; Humans; Male; Middle Aged; Mutation; Neoplasm Metastasis; Prognosis; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Quality of Life; ras Proteins; Survival Rate; Tumor Suppressor Protein p53; Watchful Waiting

MEK inhibition may overcome resistance to EGFR inhibition in patients with RAS wildtype (wt) metastatic colorectal cancer (mCRC). We evaluated antitumor activity of trametinib (MEK1/2 inhibitor) with panitumumab (EGFR monoclonal antibody) in a phase II trial.. Patients with KRAS, NRAS, and BRAF wt mCRC with prior 5-FU, irinotecan, oxaliplatin, +/- bevacizumab and no prior anti-EGFR therapy were treated with trametinib 1.5 mg oral daily and panitumumab 4.8 mg/kg IV every 2 weeks. Primary endpoint was clinical benefit rate (CB; CR, PR, or SD ≥24 weeks) by RECIST v1.1. A 2-stage minimax design was used. Serial plasma circulating free DNA (cfDNA) was collected and profiled using Oncomine Lung cfDNA assay.. Fourteen patients were enrolled from November 2015 to April 2019. CB rate was 38% (5/13) and median progression free survival (PFS) was 4.4 months (95% CI, 2.9-7.1). Confirmed overall response rate was 38% (5/13). Treatment-related AE (trAE) included acneiform rash (85%), diarrhea (62%), maculopapular rash (54%), mucositis (46%), and others. Dose modifications and interruptions of trametinib occurred in 69% and panitumumab in 54% of patients. The trial did not progress to stage II accrual due to tolerability and short duration of response. RAS or BRAF mutations cfDNA were detected in 3/13 patients (23%) before radiographic disease progression.. The addition of trametinib to panitumumab led to a high rate of tumor shrinkage in RAS/RAF wt metastatic colorectal cancer, with poor tolerability due to a high incidence of skin toxicity. Median PFS was similar to panitumumab alone in historical control data.

Topics: Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Humans; Panitumumab; Pyridones; Pyrimidinones

KRAS oncogene mutations cause sustained signaling through the MAPK pathway. Concurrent inhibition of MEK, EGFR, and HER2 resulted in complete inhibition of tumor growth in KRAS-mutant (KRASm) and PIK3CA wild-type tumors, in vitro and in vivo. In this phase I study, patients with advanced KRASm and PIK3CA wild-type colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and pancreatic cancer, were treated with combined lapatinib and trametinib to assess the recommended phase 2 regimen (RP2R).. Patients received escalating doses of continuous or intermittent once daily (QD) orally administered lapatinib and trametinib, starting at 750 mg and 1 mg continuously, respectively.. Thirty-four patients (16 CRC, 15 NSCLC, three pancreatic cancers) were enrolled across six dose levels and eight patients experienced dose-limiting toxicities, including grade 3 diarrhea (n = 2), rash (n = 2), nausea (n = 1), multiple grade 2 toxicities (n = 1), and aspartate aminotransferase elevation (n = 1), resulting in the inability to receive 75% of planned doses (n = 2) or treatment delay (n = 2). The RP2R with continuous dosing was 750 mg lapatinib QD plus 1 mg trametinib QD and with intermittent dosing 750 mg lapatinib QD and trametinib 1.5 mg QD 5 days on/2 days off. Regression of target lesions was seen in 6 of the 24 patients evaluable for response, with one confirmed partial response in NSCLC. Pharmacokinetic results were as expected.. Lapatinib and trametinib could be combined in an intermittent dosing schedule in patients with manageable toxicity. Preliminary signs of anti-tumor activity in NSCLC have been observed and pharmacodynamic target engagement was demonstrated.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Non-Small-Cell Lung; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Monitoring; Female; Humans; Lapatinib; Male; Middle Aged; Mutation; Pancreatic Neoplasms; Pharmacogenetics; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Treatment Outcome

Although BRAF inhibitor monotherapy yields response rates >50% in

Topics: Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Drug Resistance, Neoplasm; ErbB Receptors; Female; Humans; Imidazoles; Male; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Oximes; Panitumumab; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones

To evaluate dabrafenib, a selective BRAF inhibitor, combined with trametinib, a selective MEK inhibitor, in patients with BRAF V600-mutant metastatic colorectal cancer (mCRC).. A total of 43 patients with BRAF V600-mutant mCRC were treated with dabrafenib (150 mg twice daily) plus trametinib (2 mg daily), 17 of whom were enrolled onto a pharmacodynamic cohort undergoing mandatory biopsies before and during treatment. Archival tissues were analyzed for microsatellite instability, PTEN status, and 487-gene sequencing. Patient-derived xenografts were established from core biopsy samples.. Of 43 patients, five (12%) achieved a partial response or better, including one (2%) complete response, with duration of response > 36 months; 24 patients (56%) achieved stable disease as best confirmed response. Ten patients (23%) remained in the study > 6 months. All nine evaluable during-treatment biopsies had reduced levels of phosphorylated ERK relative to pretreatment biopsies (average decrease ± standard deviation, 47% ± 24%). Mutational analysis revealed that the patient achieving a complete response and two of three evaluable patients achieving a partial response had PIK3CA mutations. Neither PTEN loss nor microsatellite instability correlated with efficacy. Responses to dabrafenib plus trametinib were comparable in patient-derived xenograft-bearing mice and the biopsied lesions from each corresponding patient.. The combination of dabrafenib plus trametinib has activity in a subset of patients with BRAF V600-mutant mCRC. Mitogen-activated protein kinase signaling was inhibited in all patients evaluated, but to a lesser degree than observed in BRAF-mutant melanoma with dabrafenib alone. PIK3CA mutations were identified in responding patients and thus do not preclude response to this regimen. Additional studies targeting the mitogen-activated protein kinase pathway in this disease are warranted.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Cohort Studies; Colorectal Neoplasms; Female; Follow-Up Studies; Humans; Imidazoles; Male; MAP Kinase Kinase 1; Mice; Microsatellite Instability; Middle Aged; Mutation; Neoplasm Staging; Oximes; Prognosis; Proto-Oncogene Proteins B-raf; PTEN Phosphohydrolase; Pyridones; Pyrimidinones; Xenograft Model Antitumor Assays

Combination BRAF and MEK inhibitor therapy is an active regimen in patients who have BRAF V600E-mutated tumors; however, the clinical efficacy of this therapy is limited by resistance. Preclinically, the addition of heat shock protein 90 (HSP90) inhibition improves the efficacy of BRAF inhibitor therapy in both BRAF inhibitor-sensitive and BRAF inhibitor-resistant mutant cell lines.. Cancer Therapy Evaluation Program study 9557 (ClinicalTrials.gov identifier NCT02097225) is a phase 1 study that was designed to assess the safety and efficacy of the small-molecule HSP90 inhibitor, AT13387, in combination with dabrafenib and trametinib in BRAF V600E/K-mutant solid tumors. Correlative analyses evaluated the expression of HSP90 client proteins and chaperones.. Twenty-two patients with metastatic, BRAF V600E-mutant solid tumors were enrolled using a 3 + 3 design at four dose levels, and 21 patients were evaluable for efficacy assessment. The most common tumor type was colorectal cancer (N = 12). Dose-limiting toxicities occurred in one patient at dose level 3 and in one patient at dose level 4; specifically, myelosuppression and fatigue, respectively. The maximum tolerated dose was oral dabafenib 150 mg twice daily, oral trametinib 2 mg once daily, and intravenous AT13387 260 mg/m. HSP90 inhibition combined with BRAF/MEK inhibition was safe and produced evidence of modest disease control in a heavily pretreated population. Additional translational work may identify tumor types and resistance mechanisms that are most sensitive to this approach.

Topics: Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Humans; Melanoma; Mitogen-Activated Protein Kinase Kinases; Mutation; Oximes; Protein Kinase Inhibitors; Proteomics; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones

The inactivation of tumor suppressor DOC-2/DAB2 interactive protein (DAB2IP) by epigenetic and post-transcriptional modification has been reported in multiple human malignancies. DNA methyltransferase 3A (DNMT3A) is involved in de novo establishment of DNA methylation and plays a vital role in tumorigenesis. However, whether DNMT3A can regulate colorectal cancer (CRC) progression via modulation of DAB2IP remains unclear. In this study, we revealed that DNMT3A was significantly increased in CRC, predicting a poor overall survival. Functionally, ectopic expression of DNMT3A in CRC cells enhanced cell proliferation, whereas DNMT3A knockdown had the opposite effect by inducing cell cycle arrest. Mechanistically, methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP) proved that the expression of DAB2IP was epigenetically suppressed by DNMT3A-mediated promoter methylation in CRC cells. Using dual-luciferase reporter assay and ChIP-PCR assay, we further confirmed that DNMT3A restrained the transcriptional activity of DAB2IP promoter through directly binging to it. In addition, DNMT3A could activate the MEK/ERK signaling pathway via efficiently downregulating DAB2IP. Inhibition of the MEK/ERK cascade abrogated the oncogenic effects of DNMT3A on CRC cells. In conclusion, our study demonstrates that DNMT3A facilitates CRC progression by regulating DAB2IP mediated MEK/ERK activation, providing promising targets for CRC treatment.

Topics: Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; DNA Methylation; DNA Methyltransferase 3A; Extracellular Signal-Regulated MAP Kinases; Humans; Mitogen-Activated Protein Kinase Kinases; Prognosis; Pyridones; Pyrimidinones; ras GTPase-Activating Proteins; RNA Interference; RNA, Small Interfering; Signal Transduction; Survival Analysis

Oncolytic virus (OV) as a promising therapeutic agent can selectively infect and kill tumor cells with naturally inherited or engineered properties. Considering the limitations of OVs monotherapy, combination therapy has been widely explored. MEK inhibitor (MEKi) Trametinib is an FDA-approved kinase inhibitor indicated for the treatment of tumors with BRAF V600E or V600K mutations. In this study, the oncolytic activity in vitro and anti-tumor therapeutic efficacy in vivo when combined with oHSV and MEKi Trametinib were investigated. We found: (1) Treatment with MEKi Trametinib augmented oHSV oncolytic activity in BRAF V600E-mutated tumor cells. (2) Combination treatment with oHSV and MEKi Trametinib enhanced virus replication mediated by down-regulation of STAT1 and PKR expression or phosphorylation in BRAF V600E-mutated tumor cells as well as BRAF wt/KRAS-mutated tumor cells. (3) A remarkably synergistic therapeutic efficacy was shown in vivo for BRAF wt/KRAS-mutated tumor models, when a combination of oHSV including PD-1 blockade and MEK inhibition. Collectively, these data provide some new insights for clinical development of combination therapy with oncolytic virus, MEK inhibition, and checkpoint blockade for BRAF or KRAS-mutated tumors.

Topics: Animals; Antineoplastic Agents; Carcinoma; Cell Line, Tumor; Chlorocebus aethiops; Colorectal Neoplasms; Female; Humans; Lung; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase Kinases; Oncolytic Virotherapy; Oncolytic Viruses; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Simplexvirus; STAT1 Transcription Factor; Vero Cells

Recurrence and metastasis remain major obstacles in colorectal cancer (CRC) treatment. Recent studies suggest that a small subpopulation of cells with a self-renewal ability, called cancer stem-like cells (CSCs), promotes recurrence and metastasis in CRC. Unfortunately, no CSC inhibitor has been demonstrated to be more effective than existing chemotherapeutic drugs, resulting in a significant unmet need for effective CRC therapies. In this study, transcriptomic profiling of metastatic tumors from CRC patients revealed significant upregulation in the Wnt pathway and stemness genes. Thus, we examined the therapeutic effect of the small-molecule Wnt inhibitor ICG-001 on cancer stemness and metastasis. The ICG-001 treatment efficiently attenuated self-renewal activity and metastatic potential. Mechanistically, myeloid ecotropic viral insertion site 1 (MEIS1) was identified as a target gene of ICG-001 that is transcriptionally regulated by Wnt signaling. A series of functional analyses revealed that MEIS1 enhanced the CSC behavior and metastatic potential of the CRC cells. Collectively, our findings suggest that ICG-001 efficiently inhibits CRC stemness and metastasis by suppressing MEIS1 expression. These results provide a basis for the further clinical investigation of ICG-001 as a targeted therapy for CSCs, opening a new avenue for the development of novel Wnt inhibitors for the treatment of CRC metastasis.

Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Colorectal Neoplasms; Gene Expression Profiling; HCT116 Cells; HT29 Cells; Humans; Male; Mice; Mice, Inbred NOD; Myeloid Ecotropic Viral Integration Site 1 Protein; Neoplastic Stem Cells; Pyrimidinones; Small Molecule Libraries; Transcription, Genetic; Wnt Signaling Pathway

Mutations in RAS or BRAF are associated with poor prognosis and resistance to epidermal growth factor receptor (EGFR)-targeted therapy in colorectal cancer (CRC). Despite their common ability to activate downstream genes such as MEK and ERK, the therapeutic benefit of MEK inhibitors for patients with RAS/BRAF mutant CRC is limited, highlighting the need for biomarkers to predict the efficacy of MEK inhibition. Previously, we reported that a change in phosphorylation of ribosomal protein S6 (pS6) after MEK inhibition was significantly associated with sensitivity to MEK inhibition in gastric cancer cells. Here, we investigated the value of the response in pS6 for predicting the efficacy of trametinib, a MEK inhibitor, in patients with RAS/BRAF mutant CRC using patient-derived CRC organoids. We found that a subset of CRC cell lines and organoids were sensitive to trametinib. The change in phosphorylated ERK, a downstream molecule of the RAS/RAF/MEK pathway, was not significantly associated with trametinib sensitivity. On the other hand, only those with sensitivity showed a reduction of pS6 levels in response to trametinib. The change in pS6 after trametinib treatment was detectable by Western blotting, immunohistochemistry or immunocytochemistry. We also demonstrated an impact of MEK inhibition on pS6 in vivo using a xenograft model. Our data suggest that, in combination with patient-derived organoids, immunostaining-based detection of pS6 could be useful for prediction of trametinib sensitivity.

Topics: Aged; Aged, 80 and over; Animals; Antineoplastic Agents; Cell Line, Tumor; Colorectal Neoplasms; Drug Resistance, Neoplasm; Female; Humans; Male; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Phosphorylation; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Ribosomal Protein S6

Topics: Amides; Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Drug Synergism; Female; Humans; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Mice; Mice, Inbred BALB C; Nuclear Proteins; Protein Kinase Inhibitors; Pyrazoles; Pyridones; Pyrimidinones; Ribose; Ribosomal Proteins; Survival Rate; Up-Regulation; Xenograft Model Antitumor Assays

Ribonucleotide reductase (RR) is a unique enzyme for the reduction of NDPs to dNDPs, the building blocks for DNA synthesis and thus essential for cell proliferation. Pan-cancer profiling studies showed that RRM2, the small subunit M2 of RR, is abnormally overexpressed in multiple types of cancers; however, the underlying regulatory mechanisms in cancers are still unclear. In this study, through searching in cancer-omics databases and immunohistochemistry validation with clinical samples, we showed that the expression of MYBL2, a key oncogenic transcriptional factor, was significantly upregulated correlatively with RRM2 in colorectal cancer (CRC). Ectopic expression and knockdown experiments indicated that MYBL2 was essential for CRC cell proliferation, DNA synthesis, and cell cycle progression in an RRM2-dependent manner. Mechanistically, MYBL2 directly bound to the promoter of RRM2 gene and promoted its transcription during S-phase together with TAF15 and MuvB components. Notably, knockdown of MYBL2 sensitized CRC cells to treatment with MK-1775, a clinical trial drug for inhibition of WEE1, which is involved in a degradation pathway of RRM2. Finally, mouse xenograft experiments showed that the combined suppression of MYBL2 and WEE1 synergistically inhibited CRC growth with a low systemic toxicity in vivo. Therefore, we propose a new regulatory mechanism for RRM2 transcription for CRC proliferation, in which MYBL2 functions by constituting a dynamic S-phase transcription complex following the G1/early S-phase E2Fs complex. Doubly targeting the transcription and degradation machines of RRM2 could produce a synthetic inhibitory effect on RRM2 level with a novel potential for CRC treatment.

Topics: Animals; Antineoplastic Agents; Cell Cycle Proteins; Cell Proliferation; Colorectal Neoplasms; Databases, Genetic; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; HCT116 Cells; Humans; Male; Mice, Inbred BALB C; Mice, Nude; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Ribonucleoside Diphosphate Reductase; Signal Transduction; Trans-Activators; Tumor Burden; Xenograft Model Antitumor Assays

Patients with BRAF-mutated colorectal cancer (CRC) have a poor prognosis despite recent therapeutic advances such as combination therapy with BRAF, MEK, and epidermal growth factor receptor (EGFR) inhibitors. To identify microRNAs (miRNAs) that can improve the efficacy of BRAF inhibitor dabrafenib (DAB) and MEK inhibitor trametinib (TRA), we screened 240 miRNAs in BRAF-mutated CRC cells and identified five candidate miRNAs. Overexpression of miR-193a-3p, one of the five screened miRNAs, in CRC cells inhibited cell proliferation by inducing apoptosis. Reverse-phase protein array analysis revealed that proteins with altered phosphorylation induced by miR-193a-3p were involved in several oncogenic pathways including MAPK-related pathways. Furthermore, overexpression of miR-193a-3p in BRAF-mutated cells enhanced the efficacy of DAB and TRA through inhibiting reactivation of MAPK signaling and inducing inhibition of Mcl1. Inhibition of Mcl1 by siRNA or by Mcl1 inhibitor increased the antiproliferative effect of combination therapy with DAB, TRA, and anti-EGFR antibody cetuximab. Collectively, our study demonstrated the possibility that miR-193a-3p acts as a tumor suppressor through regulating multiple proteins involved in oncogenesis and affects cellular sensitivity to MAPK-related pathway inhibitors such as BRAF inhibitors, MEK inhibitors, and/or anti-EGFR antibodies. Addition of miR-193a-3p and/or modulation of proteins involved in the miR-193a-3p-mediated pathway, such as Mcl1, to EGFR/BRAF/MEK inhibition may be a potential therapeutic strategy against BRAF-mutated CRC.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cetuximab; Colorectal Neoplasms; Drug Therapy, Combination; ErbB Receptors; Genes, Tumor Suppressor; Humans; Imidazoles; MicroRNAs; Mitogen-Activated Protein Kinase Kinases; Mutation; Oximes; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; RNA, Small Interfering; Signal Transduction; Transfection

WEE1 plays an important role in the regulation of cell cycle G2/M checkpoints and DNA damage response (DDR). Inhibition of WEE1 can increase the instability of the genome and have anti-tumor effects in some solid tumors. However, it has certain limitations for multiple cancer cells from different lineages. Therefore, we consider the use of synthetic lethal interactions to enhance the therapeutic effect. Our experiments proved that WEE1 inhibitor (WEE1i) can activate the ataxia telangiectasia and RAD3-related (ATR) pathway and that blockage of ATR dramatically sensitized the WEE1i-induced cell death. The tumor-selective synthetic lethality between bioavailable WEE1 and ATR inhibitors led to tumor remission in vivo. Mechanistically, the combination promoted the accumulation of cytosolic double-strand DNA, which subsequently activated the stimulator of the interferon gene (STING) pathway and induced the production of type I interferon and CD8+ T cells, thereby inducing anti-tumor immunity. Furthermore, our study found that immune checkpoint programmed death-ligand 1 is upregulated by the combination therapy, and blocking PD-L1 further enhances the effect of the combination therapy. In summary, as an immunomodulator, the combination of WEE1i with ATR inhibitor (ATRi) and immune checkpoint blockers provides a potential new approach for cancer treatment.

Topics: Animals; Ataxia Telangiectasia Mutated Proteins; B7-H1 Antigen; CD8-Positive T-Lymphocytes; Cell Cycle Proteins; Cell Death; Cell Line, Tumor; Colorectal Neoplasms; Disease Models, Animal; DNA; DNA Damage; DNA, Neoplasm; Drug Synergism; Female; G2 Phase Cell Cycle Checkpoints; Genomic Instability; Humans; Immunity; Immunotherapy; Indoles; Interferon Type I; M Phase Cell Cycle Checkpoints; Membrane Proteins; Mice; Mice, Inbred C57BL; Molecular Targeted Therapy; Morpholines; Ovarian Neoplasms; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Sulfonamides; Tumor Microenvironment; Tumor Stem Cell Assay; Up-Regulation

Paired fresh tumor biopsies were acquired at baseline and on day 15 of treatment from all consenting patients with BM colorectal cancer enrolled in a phase II clinical trial of dabrafenib, trametinib, and panitumumab. For each sample, BM subtype, cell cycle, and immune gene signature expression were determined using RNA-sequencing (RNA-seq), and a Cox proportional hazards model was applied to determine association with progression-free survival (PFS).. Confirmed response rates, median PFS, and median overall survival (OS) were higher in BM1 subtype patients compared with BM2 subtype patients. Evaluation of immune contexture identified greater immune reactivity in BM1, whereas cell-cycle signatures were more highly expressed in BM2. A multivariate model of PFS incorporating BM subtype plus immune and cell-cycle signatures revealed that BM subtype encompasses the majority of the effect.. BM subtype is significantly associated with the outcome of combination dabrafenib, trametinib, and panitumumab therapy and may serve as a standalone predictive biomarker beyond mutational status. Our findings support a more nuanced approach to targeted therapeutic decisions that incorporates assessment of transcriptional context.

Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Colorectal Neoplasms; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; MAP Kinase Kinase 1; Mutation; Oximes; Panitumumab; Prognosis; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Survival Rate

Trametinib is a MEK1/2 inhibitor and exerts anticancer activity against a variety of cancers. However, the effect of Trametinib on colorectal cancer (CRC) is not well understood. In the current study, our results demonstrate the ability of sub-toxic doses of Trametinib to enhance TRAIL-mediated apoptosis in CRC cells. Our findings also indicate that Trametinib and TRAIL activate caspase-dependent apoptosis in CRC cells. Moreover, Mcl-1 overexpression can reduce apoptosis in CRC cells treated with Trametinib with or without TRAIL. We further demonstrate that Trametinib degrades Mcl-1 through the proteasome pathway. In addition, GSK-3β phosphorylates Mcl-1 at S159 and promotes Mcl-1 degradation. The E3 ligase FBW7, known to polyubiquitinate Mcl-1, is involved in Trametinib-induced Mcl-1 degradation. Taken together, these results provide the first evidence that Trametinib enhances TRAIL-mediated apoptosis through FBW7-dependent Mcl-1 ubiquitination and degradation.

Topics: Apoptosis; Cell Line, Tumor; Colorectal Neoplasms; Down-Regulation; F-Box-WD Repeat-Containing Protein 7; Glycogen Synthase Kinase 3 beta; Humans; Myeloid Cell Leukemia Sequence 1 Protein; Phosphorylation; Proteasome Endopeptidase Complex; Protein Binding; Proteolysis; Pyridones; Pyrimidinones; TNF-Related Apoptosis-Inducing Ligand; Ubiquitin; Ubiquitination

Compared with traditional chemotherapeutic drugs, targeted therapeutic medicine has the advantages of high efficacy and less toxic side effects. However, in clinical practice for treatment of colorectal cancer, the primary and acquired resistance of these medicines limits their effectiveness in targeted therapy, therefore impedes the development of precision medicine and personalized therapy. Currently, there are limited number of drugs for targeted therapy of colorectal cancer, mainly monoclonal antibodies against EGFR or VEGFR inhibitors. Trametinib, a MEK inhibitor, has been applied in melanoma patient successfully, but not been used in clinical treatment of colorectal cancer because of its drug resistance. To identify the resistance mechanism of colorectal cancer cells to trametinib and find useful chemical combination to overcome the resistance, we screened primary and acquired cell line first and then tested multiple synergistic drug combinations by using the Chou-Talalay method. We obtained the primary resistant cell lines SW480, CW-2 and the acquired drug-resistant cell line RKO-R as well as a synergistic combination of trametinib and GSK2126458. This combination inhibits the colony formation of colorectal cancer cells and the growth of xenograft tumors in nude mice. Mechanistic analysis showed that trametinib can activate the alternative PI3K-AKT signaling pathway while inhibiting the MAPK pathway, which may be one of the molecular mechanisms of primary and acquired trametinib tolerance in colorectal cancer cells. Importantly, this bypass activation can be blocked by GSK2126458. These results suggest that a combination of trametinib and GSK2126458 is an effective approach for treating colorectal cancer resistance to trametinib.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Drug Resistance, Neoplasm; Humans; Melanoma; Mice, Inbred BALB C; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Pyridones; Pyrimidinones

KRAS‑mutant colorectal cancer (CRC) is a highly malignant cancer with a poor prognosis, however specific therapies targeting KRAS mutations do not yet exist. Anti‑epidermal growth factor receptor (EGFR) agents, including cetuximab and panitumumab, are effective for the treatment of certain patients with CRC. However, these anti‑EGFR treatments have no effect on KRAS‑mutant CRC. Therefore, new therapeutic strategies targeting KRAS‑mutant CRC are urgently needed. To clarify the direct effect of KRAS gene mutations, the present study transduced mutant forms of the KRAS gene (G12D, G12V and G13D) into CACO‑2 cells. A drug‑screening system (Mix Culture assay) was then applied, revealing that the cells were most sensitive to the MEK inhibitor trametinib among tested drugs, Cetuximab, Panitumumab, Regorafenib, Vemurafenib, BEZ‑235 and Palbociclib. Trametinib suppressed phosphorylated ERK (p‑ERK) expression and inhibited the proliferation of KRAS‑mutant CACO‑2 cells. However, low‑dose treatment with trametinib also increased the expression of the anti‑apoptotic protein Bcl‑xL in a dose‑dependent manner, leading to drug resistance. To overcome the resistance of KRAS‑mutant CRC to apoptosis, the combination of trametinib and the Bcl‑xL antagonist ABT263 was assessed by in vitro and in vivo experiments. Compared with the effects of low‑dose trametinib monotherapy, combination treatment with ABT263 had a synergistic effect on apoptosis in mutant KRAS transductants in vitro. Furthermore, in vivo combination therapy using low‑dose trametinib and ABT263 against a KRAS‑mutant (G12V) xenograft synergistically suppressed growth, with an increase in apoptosis compared with the effects of trametinib monotherapy. These data suggest that a low dose of trametinib (10 nM), rather than the usual dose of 100 nM, in combination with ABT263 can overcome the resistance to apoptosis induced by Bcl‑xL expression, which occurs concurrently with p‑ERK suppression in KRAS‑mutant cells. This strategy may represent a promising new approach for treating KRAS‑mutant CRC.

Topics: Aniline Compounds; Animals; Apoptosis; bcl-X Protein; Caco-2 Cells; Cell Proliferation; Colorectal Neoplasms; Extracellular Signal-Regulated MAP Kinases; Humans; Male; Mice; Mice, Inbred BALB C; Mutation; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Sulfonamides

Topics: Celiac Disease; Clostridioides difficile; Colorectal Neoplasms; Endoscopy, Digestive System; Enterocolitis, Pseudomembranous; Foodborne Diseases; Gastroesophageal Reflux; Gastrointestinal Diseases; Humans; Pancreatic Intraductal Neoplasms; Pancreatitis; Proton Pump Inhibitors; Pyrimidinones; Pyrroles; Sulfonamides; Tetrahydroisoquinolines

To determine the role of BRAF

Topics: Aged; Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Neuroendocrine; Cell Line, Tumor; Colorectal Neoplasms; Exons; Female; Follow-Up Studies; G1 Phase Cell Cycle Checkpoints; Humans; Imidazoles; Intestinal Neoplasms; Male; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Mutation; Neuroendocrine Tumors; Oximes; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Stomach Neoplasms; Survival Analysis; Tissue Array Analysis; Vemurafenib; Xenograft Model Antitumor Assays

Despite showing clinical activity in BRAF-mutant melanoma, the MEK inhibitor (MEKi) trametinib has failed to show clinical benefit in KRAS-mutant colorectal cancer. To identify mechanisms of resistance to MEKi, we employed a pharmacogenomic analysis of MEKi-sensitive versus MEKi-resistant colorectal cancer cell lines. Strikingly, interferon- and inflammatory-related gene sets were enriched in cell lines exhibiting intrinsic and acquired resistance to MEK inhibition. The bromodomain inhibitor JQ1 suppressed interferon-stimulated gene (ISG) expression and in combination with MEK inhibitors displayed synergistic effects and induced apoptosis in MEKi-resistant colorectal cancer cell lines. ISG expression was confirmed in patient-derived organoid models, which displayed resistance to trametinib and were resensitized by JQ1 co-treatment. In in vivo models of colorectal cancer, combination treatment significantly suppressed tumor growth. Our findings provide a novel explanation for the limited response to MEK inhibitors in KRAS-mutant colorectal cancer, known for its inflammatory nature. Moreover, the high expression of ISGs was associated with significantly reduced survival of colorectal cancer patients. Excitingly, we have identified novel therapeutic opportunities to overcome intrinsic and acquired resistance to MEK inhibition in colorectal cancer.

Topics: Animals; Azepines; Cell Line, Tumor; Colorectal Neoplasms; Drug Resistance, Neoplasm; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Humans; Interferons; Mice; Mutation; Organoids; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Triazoles; Xenograft Model Antitumor Assays

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Proliferation; Colorectal Neoplasms; Drug Therapy, Combination; Female; Humans; Mice; Mice, Nude; Mutation; Pancreatic Neoplasms; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Drug resistance remains a major clinical problem despite advances in targeted therapies. In recent years, methods to culture cancer cells in three-dimensional (3D) environments to better mimic native tumors have gained increasing popularity. Nevertheless, unlike traditional two-dimensional (2D) cell cultures, analysis of 3D cultures is not straightforward. Most biochemical assays developed for 2D cultures have to be optimized for use with 3D cultures. We addressed this important problem by presenting a simple method of quantitative size-based analysis of growth and drug responses of 3D cultures of cancer cells as tumor spheroids. We used an aqueous two-phase system to form consistently sized tumor spheroids of colorectal cancer cells. Using spheroid images, we computed the size of spheroids over time and demonstrated that growth of spheroids from this analysis strongly correlates with that using a PrestoBlue biochemical assay optimized for 3D cultures. Next, we cyclically treated the tumor spheroids with a MEK inhibitor, trametinib, for 6-day periods with a recovery phase in between. This inhibitor was selected because of mutation of colon cancer cells in the MEK/ERK pathway. We used size measurements to evaluate the efficacy of trametinib and predict development of resistance of colon cancer cells during the cyclical treatment and recovery regimen. This size-based analysis closely matched the biochemical analysis of drug responses of spheroids. We performed molecular analysis and showed that resistance to trametinib emerged due to feedback activation of the PI3K/AKT signaling pathway. Therefore, we combined trametinib with a PI3K/AKT inhibitor, dactolisib, and demonstrated that size-based analysis of spheroids reliably allowed quantifying the effect of the combination treatment to prevent drug resistance. This study established that size measurements of spheroids can be used as a straightforward method for quantitative studies of drug responses of tumor spheroids and identifying drug combinations that block resistance.

Topics: Antineoplastic Agents; Colorectal Neoplasms; Drug Combinations; Drug Resistance, Neoplasm; HCT116 Cells; HT29 Cells; Humans; Imidazoles; Particle Size; Pyridones; Pyrimidinones; Quinolines; Spheroids, Cellular; Tumor Cells, Cultured

KRAS (Kirsten rat sarcoma viral oncogene) or BRAF (v-raf murine sarcoma viral oncogene homolog B1) constitutive activation leads to anti-EGFR (epidermal growth factor receptor) therapy resistance of metastatic colorectal cancer patients. In this article we investigate the effects of anti-MEK (mitogen-activated protein kinase) antibody (trametinib) combined with anti-EGFR (cetuximab) on colon cancer cell lines with different RAS statuses. Even though cetuximab has no effect on RAS cell viability and ERK (extracellular-signal-regulated kinase) phosphorylation (one of the last kinases of the EGFR pathway), trametinib can induce cell death and inhibit the activation of ERK alone or in combination with cetuximab. In a more pathologic context, we observed that KRAS colon cancer patient biopsies treated ex vivo with trametinib and cetuximab also present less ERK phosphorylation. Finally, nine ovarian, endometrial and colon cancer patients with different KRAS statuses were treated with anti-EGFR/anti-MEK combination off label after molecular tumor board decision. KRAS exon 2 patients have significantly longer PFS (progression-free survival) than with previous lines of treatments. We believe that such observations provide a rationale for designing a clinical trial to test this association in RAS exon 2 mutated cancers.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Agents; Cetuximab; Colorectal Neoplasms; ErbB Receptors; Female; Humans; Male; Mice; Middle Aged; Mitogen-Activated Protein Kinases; Neoplasm Metastasis; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Rats

Colorectal cancer remains a leading source of cancer mortality worldwide. Initial response is often followed by emergent resistance that is poorly responsive to targeted therapies, reflecting currently undruggable cancer drivers such as

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Disease Progression; Drosophila; Drug Administration Schedule; Drug Screening Assays, Antitumor; Female; Genes, ras; Genomics; Humans; Male; Middle Aged; Mutation; Neoplasm Metastasis; Precision Medicine; Pyridones; Pyrimidinones; Zoledronic Acid

The mitogen-activated protein kinase (MAPK) pathway plays a central role in colorectal cancers (CRC). In particular, BRAF V600E-mutant tumors, which represent around 10% of CRCs, are refractory to current therapies. Overexpression and secretion of serine peptidase inhibitor Kazal type 1 (SPINK1) are observed in around 50% of CRCs, and its serum level can be used as a biomarker for poor prognosis. Utilizing a recently developed extendable blocking probe assay, we analyzed the BRAF mutation status in a CRC patient cohort (N = 571) using tissue-derived RNA as the starting material. From the same RNA samples, we measured the relative SPINK1 expression levels using a quantitative real-time PCR method. Expression of mutant BRAF V600E correlated with poor prognosis, as did low expression of SPINK1 mRNA. Further, BRAF V600E correlated negatively with SPINK1 levels. In order to investigate the effect of MAPK pathway-targeted therapies on SPINK1 secretion, we conducted in vitro studies using both wild-type and V600E CRC cell lines. BRAF inhibitor vemurafenib, and subsequent MAPK pathway inhibitors trametinib and SCH772984, significantly increased SPINK1 secretion in V600E CRC cell lines Colo205 and HT-29 with a concomitant decrease in trypsin-1 and -2 secretion. Notably, no SPINK1 increase or trypsin-1 decrease was observed in BRAF wild-type CRC cell line Caco-2 in response to MAPK pathway inhibitors. In further mechanistic studies, we observed that only trametinib was able to diminish completely both MEK and ERK phosphorylation in the V600E CRC cells. Furthermore, the key regulator of integrated stress response, activating transcription factor 4 (ATF-4), was downregulated both at mRNA and at protein level in response to trametinib treatment. In conclusion, these data suggest that sustained inhibition of not only MAPK pathway activation, but also ATF-4 and trypsin, might be beneficial in the therapy of BRAF V600E-mutant CRC and that SPINK1 levels may serve as an indicator of therapy response.

Topics: Activating Transcription Factor 4; Adenocarcinoma; Aged; Caco-2 Cells; Cell Line, Tumor; Cohort Studies; Colorectal Neoplasms; Female; HT29 Cells; Humans; Indazoles; Male; Middle Aged; Mitogen-Activated Protein Kinases; Piperazines; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Trypsin Inhibitor, Kazal Pancreatic

The mitogen-activated extracellular signal-regulated kinase 1/2 (MEK1/2) inhibitor trametinib has shown promising therapeutic effects on melanoma, but its efficacy on colorectal cancer (CRC) is limited. Synthetic lethality arises with a combination of two or more separate gene mutations that causes cell death, whereas individual mutations keep cells alive. This study aimed to identify the genes responsible for resistance to trametinib in CRC cells, using a synthetic lethal short hairpin RNA (shRNA) screening approach.. We infected HT29 cells with a pooled lentiviral shRNA library and applied next-generation sequencing to identify shRNAs with reduced abundance after 8-day treatment of 20 nmol/L trametinib. HCT116 and HT29 cells were used in validation studies. Stable ring finger protein 183 (RNF183)-overexpressing cell lines were generated by pcDNA4-myc/his-RNF183 transfection. Stable RNF183-knockdown cell lines were generated by infection of lentiviruses that express RNF183 shRNA, and small interference RNA (siRNA) was used to knock down RNF183 transiently. Quantitative real-time PCR was used to determine the mRNA expression. Western blotting, immunohistochemical analysis, and enzyme-linked immunosorbent assay (ELISA) were used to evaluate the protein abundance. MTT assay, colony formation assay, and subcutaneous xenograft tumor growth model were used to evaluate cell proliferation.. In the primary screening, we found that the abundance of RNF183 shRNA was markedly reduced after treatment with trametinib. Trametinib induced the expression of RNF183, which conferred resistance to drug-induced cell growth repression and apoptotic and non-apoptotic cell deaths. Moreover, interleukin-8 (IL-8) was a downstream gene of RNF183 and was required for the function of RNF183 in facilitating cell growth. Additionally, elevated RNF183 expression partly reduced the inhibitory effect of trametinib on IL-8 expression. Finally, xenograft tumor model showed the synergism of RNF183 knockdown and trametinib in repressing the growth of CRC cells in vivo.. The RNF183-IL-8 axis is responsible for the resistance of CRC cells to the MEK1/2 inhibitor trametinib and may serve as a candidate target for combined therapy for CRC.

Topics: Animals; Cell Movement; Cell Proliferation; Colorectal Neoplasms; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; HT29 Cells; Humans; Mice; Pyridones; Pyrimidinones; RNA, Small Interfering; Synthetic Lethal Mutations; Ubiquitin-Protein Ligases; Xenograft Model Antitumor Assays

Epigenetic modifications are functionally involved in gene expression regulation. In particular, histone posttranslational modifications play a crucial role in functional chromatin organization. Several drugs able to inhibit or stimulate some families of proteins involved in epigenetic histone regulation have been found, a number of which are FDA-approved for the treatment of cutaneous T-cell lymphoma or are in phase I/II/III clinical trials for solid tumors. Although some protein families, such as histone deacetylases and their inhibitors, are well characterized, our understanding of histone lysine demethylases is still incomplete. We describe the in silico, in vitro, and cell-based characterization of the compound PKF118-310, an antagonist of transcription factor 4 (TCF4)/β-catenin signaling, as inhibitor of KDM4A. PKF118-310 potential inhibitor activity was discovered via virtual screening on the crystal structure of KDM4A. A peptide-based histone trimethylation assay developed in-house confirmed its potent KDM4A inhibitor activity. Its protein target was identified by cellular thermal shift assay experiments. PKF118-310 anticancer activity was observed in both liquid and solid tumor cells, and shown to have a dose- and time-dependent effect. We demonstrate the previously unreported inhibitory action of PKF118-310 on KDM4A. Our findings open up the possibility of developing the first KDM4A-specific inhibitors and derivatives.

Topics: Apoptosis; beta Catenin; Cell Proliferation; Colorectal Neoplasms; Epigenesis, Genetic; Gene Expression Regulation, Neoplastic; HCT116 Cells; Histones; Humans; Jumonji Domain-Containing Histone Demethylases; Molecular Docking Simulation; Pyrimidinones; Triazines

AZD1775 is a small molecule WEE1 inhibitor used in combination with DNA-damaging agents to cause premature mitosis and cell death in p53-mutated cancer cells. Here we sought to determine the mechanism of action of AZD1775 in combination with chemotherapeutic agents in light of recent findings that AZD1775 can cause double-stranded DNA (DS-DNA) breaks. AZD1775 significantly improved the cytotoxicity of 5-FU in a p53-mutated colorectal cancer cell line (HT29 cells), decreasing the IC

Topics: Antineoplastic Agents; Apoptosis; Caspase 3; Colorectal Neoplasms; DNA Breaks, Double-Stranded; Fluorouracil; HT29 Cells; Humans; Mitosis; Pyrazoles; Pyrimidines; Pyrimidinones; Tumor Suppressor Protein p53

Inhibitors of the bromodomain and extraterminal domain (BET) protein family attenuate the proliferation of several tumor cell lines. These effects are mediated, at least in part, through repression of c-MYC. In colorectal cancer, overexpression of c-MYC due to hyperactive WNT/β-catenin/TCF signaling is a key driver of tumor progression; however, effective strategies to target this oncogene remain elusive. Here, we investigated the effect of BET inhibitors (BETi) on colorectal cancer cell proliferation and c-MYC expression. Treatment of 20 colorectal cancer cell lines with the BETi JQ1 identified a subset of highly sensitive lines. JQ1 sensitivity was higher in cell lines with microsatellite instability but was not associated with the CpG island methylator phenotype, c-MYC expression or amplification status, BET protein expression, or mutation status of TP53, KRAS/BRAF, or PIK3CA/PTEN Conversely, JQ1 sensitivity correlated significantly with the magnitude of c-MYC mRNA and protein repression. JQ1-mediated c-MYC repression was not due to generalized attenuation of β-catenin/TCF-mediated transcription, as JQ1 had minimal effects on other β-catenin/TCF target genes or β-catenin/TCF reporter activity. BETi preferentially target super-enhancer-regulated genes, and a super-enhancer in c-MYC was recently identified in HCT116 cells to which BRD4 and effector transcription factors of the WNT/β-catenin/TCF and MEK/ERK pathways are recruited. Combined targeting of c-MYC with JQ1 and inhibitors of these pathways additively repressed c-MYC and proliferation of HCT116 cells. These findings demonstrate that BETi downregulate c-MYC expression and inhibit colorectal cancer cell proliferation and identify strategies for enhancing the effects of BETi on c-MYC repression by combinatorial targeting the c-MYC super-enhancer. Mol Cancer Ther; 15(6); 1217-26. ©2016 AACR.

Topics: Animals; Azepines; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colorectal Neoplasms; Drug Synergism; Gene Expression Regulation, Neoplastic; HCT116 Cells; Humans; MAP Kinase Signaling System; Mice; Neoplasm Transplantation; Proto-Oncogene Proteins c-myc; Pyridones; Pyrimidinones; Triazoles; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Cetuximab is a monoclonal antibody that is effective in the treatment of metastatic colorectal cancer (mCRC). Cetuximab blocks epidermal growth factor receptor (EGFR)-ligand interaction and inhibits downstream RAS-ERK activation. However, only some activating mutations in RAS affect cetuximab efficacy, and it is not clear what else mediates treatment success. Here we hypothesized that cetuximab induces immunogenic cell death (ICD) that activates a potent antitumor response. We found that cetuximab, in combination with chemotherapy, fostered ICD in CRC cells, which we measured via the endoplasmic reticulum (ER) stress response and an increase in phagocytosis by dendritic cells. ICD induction depended on the mutational status of the EGFR signaling pathway and on the inhibition of the splicing of X-box binding protein 1 (XBP1), an unfolded protein response (UPR) mediator. We confirmed the enhanced immunogenicity elicited by cetuximab in a mouse model of human EGFR-expressing CRC. Overall, we demonstrate a new, immune-related mechanism of action of cetuximab that may help to tailor personalized medicine.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Calreticulin; Camptothecin; Cell Death; Cell Line, Tumor; Cetuximab; Colorectal Neoplasms; Dendritic Cells; Disease Models, Animal; Endoplasmic Reticulum Stress; Fluorouracil; HCT116 Cells; HT29 Cells; Humans; Indoles; Irinotecan; Leucovorin; Mice; Panitumumab; Phagocytosis; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Sulfonamides; Unfolded Protein Response; Vemurafenib; X-Box Binding Protein 1

Wee1 is a nuclear kinase regulating cell cycle progression, and has emerged as a promising therapeutic target in cancer. Expression of Wee1 has been associated with poor outcome in certain tumor types, but the prognostic impact and clinical significance in colorectal cancer is unknown. The expression of Wee1 was examined by immunohistochemistry in primary colorectal carcinomas from a prospectively collected patient cohort, and associations with clinicopathological parameters and outcome were investigated. Cell culture experiments were performed using the cell lines RKO and SW620, and the relationship with the metastasis-promoting protein S100A4 was investigated. Nuclear expression was detected in 229 of the 258 tumors analyzed (89 %). Wee1 staining was associated with low pT stage, but no other significant associations with demographic or histopathological variables were found. Moderate Wee1 staining intensity was a predictor of favorable metastasis-free and overall survival compared to strong intensity and no or weak staining. The fraction of positive cells was not a prognostic factor in the present cohort. Inhibition of Wee1 expression using siRNA or treatment with the Wee1 inhibitor MK-1775 reduced expression of the metastasis-promoting protein S100A4, but no relationship between Wee1 and S100A4 was found in the patient samples. In conclusion, Wee1 is highly expressed in primary colorectal carcinomas, but few relevant associations with clinicopathological parameters or outcome were found. The lack of clinical significance of Wee1 expression could indicate that other tumor types might be better suited for further development of Wee1 inhibitors.

Topics: Cell Cycle Proteins; Cell Line, Tumor; Colorectal Neoplasms; Humans; Immunohistochemistry; Neoplasm Staging; Nuclear Proteins; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; S100 Calcium-Binding Protein A4

KRAS mutations are an established predictor of lack of response to EGFR-targeted therapies in patients with metastatic colorectal cancer (mCRC). However, little is known about the role of the rarer NRAS mutations as a mechanism of primary resistance to the anti-EGFR monoclonal antibody cetuximab in wild-type KRAS mCRC. Using isogenic mCRC cells with a heterozygous knock-in of the NRAS activating mutation Q61K, we aimed to elucidate the mechanism(s) by which mutant NRAS blocks cetuximab from inhibiting mCRC growth. NRASQ61K/+ cells were refractory to cetuximab-induced growth inhibition. Pathway-oriented proteome profiling revealed that cetuximab-unresponsive ERK1/2 phosphorylation was the sole biomarker distinguishing cetuximab-refractory NRASQ61K/+ from cetuximab-sensitive NRAS+/+ cells. We therefore employed four representative MEK1/2 inhibitors (binimetinib, trametinib, selumetinib, and pimasertib) to evaluate the therapeutic value of MEK/ERK signaling in cetuximab-refractory NRAS mutation-induced mCRC. Co-treatment with an ineffective dose of cetuximab augmented, up to more than 1,300-fold, the cytotoxic effects of pimasertib against NRASQ61K/+ cells. Simultaneous combination of MEK1/2 inhibitors with cetuximab resulted in extremely high and dose-dependent synthetic lethal effects, which were executed, at least in part, by exacerbated apoptotic cell death. Dynamic monitoring of real-time cell growth rates confirmed that cetuximab synergistically sensitized NRASQ61K/+ cellsto MEK1/2 inhibition. Our discovery of a synthetic lethal interaction of cetuximab in combination with MEK1/2 inhibition for the NRAS mutant subgroup of mCRC underscores the importance of therapeutic intervention both in the MEK-ERK and EGFR pathways to achieve maximal therapeutic efficacy against NRAS-mutant mCRC tumors.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Cell Line, Tumor; Cell Proliferation; Cetuximab; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Drug Synergism; ErbB Receptors; GTP Phosphohydrolases; Humans; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Membrane Proteins; Mutation; Niacinamide; Phosphorylation; Protein Kinase Inhibitors; Proteomics; Pyridones; Pyrimidinones; Signal Transduction; Transfection

Findings from a phase I/II study indicate a higher response rate among patients with BRAF-mutant metastatic colorectal cancer treated with an EGFR inhibitor alongside dual, as opposed to single-level, MAPK blockade. Panitumumab combined with trametinib and dabrafenib only modestly increased median progression-free survival, however; a short-lived decrease in responders' BRAF V600E mutant allele fraction and the emergence of RAS mutations may have been contributing factors.

Topics: Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Colorectal Neoplasms; Disease-Free Survival; Humans; Imidazoles; MAP Kinase Signaling System; Mutation; Oximes; Panitumumab; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Treatment Outcome

The tumor suppressor p53 plays a key role in regulation of the cell cycle, apoptosis and senescence in response to various stresses. We screened a library of 7920 chemical compounds for the p53 activator and identified N-[2-(dimethylamino)ethyl]-2,3-dimethyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-9-carboxamide (PTP), which significantly increased p53-mediated reporter activity in colorectal cancer cells. PTP was found to induce p53 protein and activated transcription of downstream genes, such as p21 and PUMA, in HCT116 cells, leading to growth delay, G1-phase cell cycle arrest, cell senescence and cell death. Proximity ligation assay revealed that PTP weakened the interaction between p53 and murine double minute 2 (MDM2) in situ, thereby inhibiting MDM2-mediated p53 degradation. Although DNA damage has been known to promote phosphorylation of p53 and MDM2, thereby preventing their interaction and stabilizing p53, PTP did not cause DNA damage or activate any DNA damage response signaling. Instead, phosphorylation of p53 was mediated by Erk1/2 MAP kinase. In addition, PTP induced acetylation of p53 at Lys382 in a p300-dependent manner, but sirtuin (SIRT)1 and histone deacetylase (HDAC)1, a well-known p53-regulating deacetylase, were not involved. In the present study, the novel anticancer agent PTP was shown to cause the accumulation of p53 by inducing multiple post-translational modifications, as well as cell cycle arrest, senescence and cell death.

Topics: Acetylation; Antineoplastic Agents; Colorectal Neoplasms; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; HCT116 Cells; HT29 Cells; Humans; Phosphorylation; Protein Processing, Post-Translational; Pyrimidines; Pyrimidinones; Thiophenes; Tumor Suppressor Protein p53

Most solid tumors contain a subfraction of cells with stem/progenitor cell features. Stem cells are naturally chemoresistant suggesting that chronic chemotherapeutic stress may select for cells with increased "stemness". We carried out a comprehensive molecular and functional analysis of six independently selected colorectal cancer (CRC) cell lines with acquired resistance to three different chemotherapeutic agents derived from two distinct parental cell lines. Chronic drug exposure resulted in complex alterations of stem cell markers that could be classified into three categories: 1) one cell line, HT-29/5-FU, showed increased "stemness" and WNT-signaling, 2) three cell lines showed decreased expression of stem cell markers, decreased aldehyde dehydrogenase activity, attenuated WNT-signaling and lost the capacity to form colonospheres and 3) two cell lines displayed prominent expression of ABC transporters with a heterogeneous response for stem cell markers. While WNT-signaling could be attenuated in the HT-29/5-FU cells by the WNT-signaling inhibitors ICG-001 and PKF-118, this was not accompanied by any selective growth inhibitory effect suggesting that the cytotoxic activity of these compounds is not directly linked to WNT-signaling inhibition. We conclude that classical WNT-signaling inhibitors have toxic off-target activities that need to be addressed for clinical development.

Topics: Antineoplastic Agents; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; Camptothecin; Cell Line, Tumor; Cell Survival; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Fluorouracil; Gene Expression Regulation, Neoplastic; HCT116 Cells; HT29 Cells; Humans; Hyaluronan Receptors; Irinotecan; Neoplastic Stem Cells; Organoplatinum Compounds; Oxaliplatin; Protein Isoforms; Pyrimidinones; Reverse Transcriptase Polymerase Chain Reaction; Triazines; Wnt Signaling Pathway

CRC is a significant cause of cancer mortality, and new therapies are needed for patients with advanced disease. TAK-733 is a highly potent and selective investigational novel MEK allosteric site inhibitor.. In a preclinical study of TAK-733, a panel of CRC cell lines were exposed to varying concentrations of the agent for 72 hours followed by a sulforhodamine B assay. Twenty patient-derived colorectal cancer xenografts were then treated with TAK-733 in vivo. Tumor growth inhibition index (TGII) was assessed to evaluate the sensitivity of the CRC explants to TAK-733 while linear regression was utilized to investigate the predictive effects of genotype on the TGII of explants.. Fifty-four CRC cell lines were exposed to TAK-733, while 42 cell lines were deemed sensitive across a broad range of mutations. Eighty-two percent of the cell lines within the sensitive subset were BRAF or KRAS/NRAS mutant, whereas 80% of the cell lines within the sensitive subset were PIK3CA WT. Twenty patient-derived human tumor CRC explants were then treated with TAK-733. In total, 15 primary human tumor explants were found to be sensitive to TAK-733 (TGII ≤ 20%), including 9 primary human tumor explants that exhibited tumor regression (TGII > 100%). Explants with a BRAF/KRAS/NRAS mutant and PIK3CA wild-type genotype demonstrated increased sensitivity to TAK-733 with a median TGII of -6%. MEK-response gene signatures also correlated with responsiveness to TAK-733 in KRAS-mutant CRC.. The MEK inhibitor TAK-733 demonstrated robust antitumor activity against CRC cell lines and patient-derived tumor explants. While the preclinical activity observed in this study was considerable, single-agent efficacy in the clinic has been limited in CRC, supporting the use of these models in an iterative manner to elucidate resistance mechanisms that can guide rational combination strategies.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Colorectal Neoplasms; Drug Resistance, Neoplasm; Humans; Immunoblotting; MAP Kinase Kinase Kinases; Mice; Oligonucleotide Array Sequence Analysis; Pyridones; Pyrimidinones; Transcriptome; Xenograft Model Antitumor Assays

Chemoprevention presents a major strategy for the medical management of colorectal cancer. Most drugs used for colorectal cancer therapy induce DNA-alkylation damage, which is primarily repaired by the base excision repair (BER) pathway. Thus, blockade of BER pathway is an attractive option to inhibit the spread of colorectal cancer. Using an in silico approach, we performed a structure-based screen by docking small-molecules onto DNA polymerase β (Pol-β) and identified a potent anti-Pol-β compound, NSC-124854. Our goal was to examine whether NSC-124854 could enhance the therapeutic efficacy of DNA-alkylating agent, Temozolomide (TMZ), by blocking BER. First, we determined the specificity of NSC-124854 for Pol-β by examining in vitro activities of APE1, Fen1, DNA ligase I, and Pol-β-directed single nucleotide (SN)- and long-patch (LP)-BER. Second, we investigated the effect of NSC-124854 on the efficacy of TMZ to inhibit the growth of mismatch repair (MMR)-deficient and MMR-proficient colon cancer cell lines using in vitro clonogenic assays. Third, we explored the effect of NSC-124854 on TMZ-induced in vivo tumor growth inhibition of MMR-deficient and MMR-proficient colonic xenografts implanted in female homozygous SCID mice. Our data showed that NSC-124854 has high specificity to Pol-β and blocked Pol-β-directed SN- and LP-BER activities in in vitro reconstituted system. Furthermore, NSC-124854 effectively induced the sensitivity of TMZ to MMR-deficient and MMR-proficient colon cancer cells both in vitro cell culture and in vivo xenograft models. Our findings suggest a potential novel strategy for the development of highly specific structure-based inhibitor for the prevention of colonic tumor progression.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Caco-2 Cells; Carcinoma; Cell Line, Tumor; Colorectal Neoplasms; Dacarbazine; DNA Polymerase beta; Drug Synergism; Female; HCT116 Cells; HT29 Cells; Humans; Mice; Mice, SCID; Molecular Targeted Therapy; Organophosphates; Pyrimidinones; Temozolomide; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The MAPK pathway is one of the most important pathways for novel anticancer drug development. We performed high-throughput screening for compounds that induce expression of p15INK4b, and identified JTP-74057 (GSK1120212), which is being evaluated in ongoing phase I, II and III clinical trials. We characterized its antitumor activities in vitro and in vivo. JTP-74057 strongly inhibited MEK1/2 kinase activities, but did not inhibit another 98 kinase activities. Treatment by JTP-74057 resulted in growth inhibition accompanied with upregulation of p15INK4b and/or p27KIP1 in most of the colorectal cancer cell lines tested. Daily oral administration of JTP-74057 for 14 days suppressed tumor growth of HT-29 and COLO205 xenografts in nude mice. Notably, tumor regression was observed only in COLO205 xenografts, and COLO205 was much more sensitive to JTP-74057-induced apoptosis than HT-29 in vitro. Treatment with an Akt inhibitor enhanced the JTP-74057-induced apoptosis in HT-29 cells. Finally, JTP-74057 exhibited an additive or a synergistic effect in combination with the standard-of-care agents, 5-fluorouracil, oxaliplatin or SN-38. JTP-74057, a highly specific and potent MEK1/2 inhibitor, exerts favorable antitumor activities in vitro and in vivo. Sensitivity to JTP-74057-induced apoptosis may be an important factor for the estimation of in vivo efficacy, and sensitivity was enhanced by an Akt inhibitor. These results suggest the usefulness of JTP-74057 in therapeutic applications for colorectal cancer patients.

Topics: Animals; Antimetabolites, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Drug Synergism; Female; Fluorouracil; HCT116 Cells; HT29 Cells; Humans; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Mice; Mice, Inbred BALB C; Mice, Nude; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Xenograft Model Antitumor Assays

According to "fluid-mosaic model," plasma membrane is a bilayer constituted by phospholipids which regulates the various cellular activities governed by many proteins and enzymes. Any chemical, biochemical, or physical factor has to interact with the bilayer in order to regulate the cellular metabolism where various physicochemical properties of membrane, i.e., polarization, fluidity, electrostatic potential, and phase state may get affected. In this study, we have observed the in vivo effects of a pro-carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) and the two non steroidal anti-inflammatory drugs (NSAIDs); sulindac and celecoxib on various properties of the plasma membrane of colonocytes, i.e., electric potential, fluidity, anisotropy, microviscosity, lateral diffusion, and phase state in the experimentally induced colorectal cancer. A number of fluorescence probes were utilized like membrane fluidity and anisotropy by 1,6-diphenyl-1,3,5-hexatriene, membrane microviscosity by Pyrene, membrane electric potential by merocyanine 540, lateral diffusion by N-NBD-PE, and phase state by Laurdan. It is observed that membrane phospholipids are less densely packed and therefore, the membrane is more fluid in case of carcinogenesis produced by DMH than control. But NSAIDs are effective in reverting back the membrane toward normal state when co-administered with DMH. The membrane becomes less fluid, composed of low electric potential phospholipids whose lateral diffusion is being prohibited and the membrane stays mostly in relative gel phase. It may be stated that sulindac and celecoxib, the two NSAIDs may exert their anti-neoplastic role in colorectal cancer via modifying the physicochemical properties of the membranes.

Topics: 1,2-Dimethylhydrazine; 2-Naphthylamine; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Celecoxib; Cell Membrane; Chemical Phenomena; Colorectal Neoplasms; Cyclooxygenase 2; Laurates; Male; Membrane Fluidity; Microscopy, Fluorescence; Phosphatidylethanolamines; Pyrazoles; Pyrimidinones; Rats; Rats, Sprague-Dawley; Spectrometry, Fluorescence; Sulfonamides; Sulindac; Viscosity

The purine ring system is undoubtedly one of the most ubiquitous heterocyclic ring systems in nature as it has the distinction of being the parent ring in countless derivatives of biological relevance. It is not surprising then that modified purines possess the potential to impact several areas, including a better understanding of the biological effects of DNA damaging agents, enzyme/substrate interactions, and in the development of more potent medicinal agents. One focus for our research at Georgia Tech has centered around the design and synthesis of a series of extended purine analogues containing a heterocyclic spacer ring, with sites set on investigations into their use as (i) potential anticancer and antiviral agents, (ii) dimensional probes for enzyme and coenzyme binding sites, and (iii) structural probes of the minor groove of DNA. The synthesis and preliminary antitumor activity of two thieno-separated purine analogues are described herein. Tricyclic 1 was synthesized in 12 steps from tribromoimidazole and with an overall yield of 7%. Tricyclic 2 was synthesized in 9 steps with an overall yield of 13%. Both 1 and 2 exhibited growth inhibitory effects on HCT116 colorectal cancer cells in vitro.

Topics: Antineoplastic Agents; Cell Division; Colorectal Neoplasms; Drug Screening Assays, Antitumor; Humans; Purines; Pyrimidines; Pyrimidinones; Thiophenes; Tumor Cells, Cultured