dactolisib and Lung-Neoplasms

Cisplatin, as a first-line chemotherapy drug for advanced wild-type epidermal growth factor receptor (wtEGFR) non-small cell lung cancer (NSCLC), often loses effectiveness because of acquired drug resistance. We found that ataxia-telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) of DNA repair kinases and signal transduction molecules, protein kinase B (AKT)/target mammalian target of rapamycin (mTOR), were significantly phosphorylated in cisplatin-resistant wtEGFR NSCLC cell lines (H358R and A549R) than in their parental cells. Also, BEZ235 (dual phosphatidylinositol-3-kinase (PI3K)/mTOR inhibitor) significantly decreased the phosphorylation levels of these kinases/proteins, as detected by Western blot analysis. In H358R and A549R cells, the results of indirect immunofluorescence, single-cell gel electrophoresis, flow cytometry, methylthiazolyldiphenyl-tetrazolium bromide, clone formation assay, and scratch healing experiment showed that BEZ235 enhanced cisplatin-induced DNA damage and cell apoptosis, and effectively inhibited cellular proliferation/migration when combined with cisplatin. The data indicated that the abnormal activation of ATM/ATR/DNA-PKcs kinases and AKT/mTOR pathway might induce wtEGFR NSCLC cell resistance to cisplatin. The effects of the combination of BEZ235 and cisplatin suggested that BEZ235 should be considered as a combination therapy for patients with cisplatin-resistant wtEGFR NSCLC.

Topics: Ataxia Telangiectasia; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cisplatin; DNA; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases

Cancer continues to be a growing burden, especially in the resource limited regions of the world, and more effective and affordable therapies are highly desirable. In this study, the effect of X-ray irradiation and four inhibitors, viz. those against epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), mammalian target of rapamycin (mTOR) and B-cell lymphoma 2 (Bcl-2) was evaluated in lung, breast, and cervical cancer cell lines, including normal cell lines to determine and compare the potential therapeutic benefit of these treatment modalities. A clonogenic survival assay was used to determine the radiosensitivity and cytotoxicity of inhibitors of EGFR, PI3K/mTOR, and Bcl-2 in the cell lines. From the data, the equivalent dose at which 50% of the cell populations were killed, for cancer and normal cells, was used to determine the relative cellular sensitivity to X-ray irradiation and inhibitor treatment. It was found that breast cancer cell lines were more sensitive to X-ray irradiation, whilst cervical and lung cancer cell lines were more sensitive to EGFR and PI3K/mTOR inhibitor therapy. These data suggest that patients with breast cancer possessing similar characteristics to MDA-MB-231 and MCF-7 cells may derive therapeutic benefit from X-ray irradiation, whilst EGFR and PI3K/mTOR inhibitor therapy may potentially benefit cancer patients possessing cancers similar to HeLa and A549 cells.

Topics: Aniline Compounds; Breast Neoplasms; Cell Line; Cell Survival; ErbB Receptors; Female; Humans; Imidazoles; Lung Neoplasms; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-bcl-2; Quinazolines; Quinolines; Radiation Tolerance; Sulfonamides; TOR Serine-Threonine Kinases; Tyrphostins; Uterine Cervical Neoplasms; X-Rays

Topics: Adenocarcinoma of Lung; Antineoplastic Agents; Apoptosis; Cell Proliferation; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Imidazoles; Lung Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoproteins; Protein Kinase Inhibitors; Proteome; Quinolines; TOR Serine-Threonine Kinases; Tumor Cells, Cultured

One of the main challenges in clinical translation of polymeric micelles is retention of the drug in the nanocarrier system upon its systemic administration. Core crosslinking and coupling of the drug to the micellar backbone are common strategies to overcome these issues. In the present study, polymeric micelles were prepared for tumor cell targeting of the kinase inhibitor dactolisib which inhibits both the mammalian Target of Rapamycin (mTOR) kinase and phosphatidylinositol-3-kinase (PI3K). We employed platinum(II)-based linker chemistry to couple dactolisib to the core of poly(ethylene glycol)-b-poly(acrylic acid) (PEG-b-PAA) polymeric micelles. The formed dactolisib-PEG-PAA unimers are amphiphilic and self-assemble in an aqueous milieu into core-shell polymeric micelles. Folate was conjugated onto the surface of the micelles to yield folate-decorated polymeric micelles which can target folate receptor over-expressing tumor cells. Fluorescently labeled polymeric micelles were prepared using a lissamine-platinum complex linked in a similar manner as dactolisib. Dactolisib polymeric micelles showed good colloidal stability in water and released the coupled drug in buffers containing chloride or glutathione. Folate decorated micelles were avidly internalized by folate-receptor-positive KB cells and displayed targeted cellular cytotoxicity at 50-75 nM IC

Topics: A549 Cells; Acrylic Resins; Antineoplastic Agents; Cell Survival; Drug Carriers; Drug Compounding; Drug Liberation; Drug Stability; Folic Acid; Folic Acid Transporters; Humans; Imidazoles; Lung Neoplasms; Micelles; Phosphoinositide-3 Kinase Inhibitors; Polyethylene Glycols; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

Lung cancer is the most common cause of cancer-related mortality worldwide despite diagnostic improvements and the development of targeted therapies, notably including epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). The phosphoinositide 3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) signaling has been shown to contribute to tumorigenesis, tumor progression, and resistance to therapy in most human cancer types, including lung cancer. Here, we explored the therapeutic effects of co-inhibition of PI3K and mTOR in non-small-cell lung cancer (NSCLC) cells with different EGFR status.. The antiproliferative activity of a dual PI3K/mTOR inhibitor BEZ235 was examined by the WST-1 assay and the soft agar colony-formation assay in 2 normal cell lines and 12 NSCLC cell lines: 6 expressing wild-type EGFR and 6 expressing EGFR with activating mutations, including exon 19 deletions, and L858R and T790 M point mutations. The combination indexes of BEZ235 with cisplatin or an EGFR-TKI, BIBW2992 (afatinib), were calculated. The mechanisms triggered by BEZ235 were explored by western blotting analysis. The anti-tumor effect of BEZ235 alone or combined with cisplatin or BIBW2992 were also studied in vivo.. BEZ235 suppressed tumor growth in vitro and in vivo by inducing cell-cycle arrest at G1 phase, but without causing cell death. It also reduced the expression of cyclin D1/D3 by regulating both its transcription and protein stability. Moreover, BEZ235 synergistically enhanced cisplatin-induced apoptosis in NSCLC cells by enhancing or prolonging DNA damage and BIBW2992-induced apoptosis in EGFR-TKI-resistant NSCLC cells containing a second TKI-resistant EGFR mutant.. The dual PI3K/mTOR inhibition by BEZ235 is an effective antitumor strategy for enhancing the efficacy of chemotherapy or targeted therapy, even as a monotherapy, to restrict tumor growth in lung cancer treatment.

Topics: A549 Cells; Afatinib; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Cycle Checkpoints; Cisplatin; Cyclin D1; Cyclin D3; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Imidazoles; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

The activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling and upregulation of excision repair cross complementation group 1 (ERCC1) are the two most important factors that confer resistance to cisplatin (DDP) therapy in non-small-cell lung cancer (NSCLC). Therefore, inhibition of the PI3K/Akt/mTOR signaling pathway and ERCC1 expression is a potential approach for the treatment of patients with advanced NSCLC. In the present study, whether combined treatment with DDP and BEZ235, a dual PI3K/mTOR inhibitor, could provide a synergistic antitumor effect in A549/DDP cells was investigated, and the possible mechanisms involved were explored. The half-maximal inhibitory concentration (IC50) values were calculated in A549/DDP cells. Synergistic interaction of BEZ235 and DDP was evaluated by combination index (CI) analysis. The levels of phosphorylated Akt (p-Akt), phosphorylated mTOR (p-mTOR), apoptosis-related proteins and ERCC1 were detected by western blot analysis. Apoptotic cells were quantified by flow cytometry and Hoechst 33342 staining. The migration and invasion abilities of A549/DDP cells were evaluated by wound healing and Transwell assays, respectively. It was observed that the dose reduction index (DRI) of BEZ235 was 13.82 and for DDP it was 13.58, and the CI of combination was <1 over a wide range of doses. In addition, the levels of p-Akt, p-mTOR and ERCC1 were significantly elevated by DDP treatment, and were reduced by co-administration of BEZ235 and DDP. Furthermore, the combination treatment significantly induced apoptotic cell death, decreased migration and invasion abilities compared with those treated with either BEZ235 or DDP alone. In conclusion, the combination of BEZ235 with DDP had synergistic antitumor effects in A549/DDP cells as reflected by reduced proliferation, increased apoptosis, and suppression of the migration and invasion abilities of A549/DDP cells, and the mechanism mediating these effects may be associated with the inhibition of PI3K/Akt/mTOR signaling and down-regulation of ERCC1 expression.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Cisplatin; DNA-Binding Proteins; Drug Resistance, Neoplasm; Endonucleases; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Lung Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Cells, Cultured

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

Tumor vessels are leaky and immature, which causes poor oxygen and nutrient supply to tumor vessels and results in cancer cell metastasis to distant organs. This instability of tumor blood vessels also makes it difficult for anticancer drugs to penetrate and reach tumors. Numerous tumor vessel normalization approaches have been investigated for improving drug delivery into tumors. In this study, we investigated whether phosphoinositide 3-kinase (PI3K) inhibitors are able to improve vascular structure and function over the prolonged period necessary to achieve effective vessel normalization. The PI3K inhibitors, HS-173 and BEZ235 potently suppressed tumor growth and hypoxia, and increased tumor apoptosis in animal models. PI3K inhibitors also induced a regular, flat monolayer of endothelial cells (ECs) in vessels, improving stability of vessel structure, and normalized tumor vessels by increasing vascular maturity, pericyte coverage, basement membrane thickness, and tight-junctions. These effects resulted in a decrease in tumor vessel tortuosity and vessel thinning, and improved vessel function and blood flow. The tumor vessel stabilization effect of the PI3K inhibitor HS-173 also decreased the number of metastatic lung nodules in vivo metastasis model. Furthermore, HS-173 improved the delivery of doxorubicin into the tumor region, enhancing its anticancer effects. Mechanistic studies suggested that PI3K inhibitor HS-173-induced vessel normalization reflected changes in endothelial Notch signaling. Taken together, our findings indicate that vessel normalization by PI3K inhibitors restrained tumor growth and metastasis while improving chemotherapy by enhancing drug delivery into the tumor, suggesting that HS-173 may have a therapeutic value as an enhancer or an anticancer drug.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blood Vessels; Cell Line, Tumor; Cell Proliferation; Doxorubicin; Human Umbilical Vein Endothelial Cells; Humans; Imidazoles; Lung Neoplasms; Male; Melanoma, Experimental; Mice, Inbred BALB C; Mice, Nude; Neovascularization, Pathologic; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Pyridines; Quinolines; Signal Transduction; Sulfonamides; Time Factors; Tumor Burden; Tumor Hypoxia; Tumor Microenvironment; Xenograft Model Antitumor Assays

KRAS mutations in non-small-cell lung cancer (NSCLC) patients are considered a negative predictive factor and indicate poor response to anticancer treatments. KRAS mutations lead to activation of the PI3K/akt/mTOR pathway, whose inhibition remains a challenging clinical target. Since the PI3K/akt/mTOR pathway and KRAS oncogene mutations all have roles in cancer cell metabolism, we investigated whether the activity of PI3K/akt/mTOR inhibitors (BEZ235 and BKM120) in cells harboring different KRAS status is related to their metabolic effect. Isogenic NSCLC cell clones expressing wild-type (WT) and mutated (G12C) KRAS were used to determine the response to BEZ235 and BKM120. Metabolomics analysis indicated the impairment of glutamine in KRAS-G12C and serine metabolism in KRAS-WT, after pharmacological blockade of the PI3K signaling, although the net effect on cell growth, cell cycle distribution and caspase activation was similar. PI3K inhibitors caused autophagy in KRAS-WT, but not in KRAS-G12C, where there was a striking decrease in ammonia production, probably a consequence of glutamine metabolism impairment.These findings lay the grounds for more effective therapeutic combinations possibly distinguishing wild-type and mutated KRAS cancer cells in NSCLC, exploiting their different metabolic responses to PI3K/akt/mTOR inhibitors.

Topics: Amino Acid Substitution; Carcinoma, Non-Small-Cell Lung; Cells, Cultured; Cysteine; Glycine; Humans; Imidazoles; Lung Neoplasms; Mutation, Missense; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Quinolines; Signal Transduction

Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. NSCLC development and progression have recently been correlated with the heightened activation of histone deacetylases (HDACs) and PI3K/Akt signaling pathways. Targeted inhibition of these proteins is promising approach for the development of novel therapeutic strategies to treat patients with advanced NSCLC. For this reason, we combined a dual PI3K and mTOR inhibitor, BEZ235 with the HDAC inhibitor Trichostatin A (TSA), to determine their combined effects on human NSCLC. In this study, we initially discovered that co-treatment with BEZ235 and TSA showed a synergistic effect on inhibition of NSCLC cell proliferation and induction of apoptosis. The combination treatment also synergistically suppressed NSCLC migration, invasion and the NSCLC epithelial-mesenchymal transition (EMT) in vitro. The synergistic effect was also evidenced by declines in xenograft growth and metastasis rates and in ki-67 protein expression in vivo. Together, these results indicated that BEZ235 and TSA combination treatment significantly increased anti-tumor activities compared with BEZ235 and TSA alone, supporting a further evaluation of combination treatment for NSCLC.

Topics: A549 Cells; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Imidazoles; Lung Neoplasms; Mice, Inbred BALB C; Mice, Nude; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; TOR Serine-Threonine Kinases; Treatment Outcome; Xenograft Model Antitumor Assays

This study aims to investigate the effects of endoplasmic reticulum stress (ERS) on autophagy, apoptosis and chemoresistance of human small cell lung cancer (SCLC) cells via the PI3K/AKT/mTOR signaling pathway.. The expressions of ERS-related proteins (PEAK, eIF2α and CHOP) up-regulated, autophagy-related proteins (LC3, LC3-II and Beclin1) and apoptosis-related proteins (Bax and procaspase-3) down-regulated in NCI-H446 and H69 cells after tunicamycin treatment for 24 h. Compared with the blank group, the tunicamycin, BEZ235 and tunicamycin + BEZ235 groups exhibited decreased expressions of p-PI3K, p-AKT and p-mTOR, and increased expressions of autophagy-related proteins (LC3, LC3-II and Beclin1) and apoptosis proteins (Bax and procaspase-3), and the most obvious changes were observed in the tunicamycin + BEZ235 group.. CCK-8 assay was applied to select the best cell line from five SCLC cell lines (NCI-H446, H69, H526, H146 and H209). Finally, NCI-H446 and H69 cells were selected for further experiments. NCI-H446/CDDP and H69/CDDP were selected and divided into the blank group, tunicamycin (an ESR inducer) group, BEZ235 (inhibitors of PI3K/AKT/mTOR pathway) group and tunicamycin + BEZ235 group. Cell apoptosis was detected by flow cytometry. Autophagy was observed by fluorescence microscopy and flow cytometry. Western blotting was used to detect the expressions of ERS-related proteins, autophagy-related proteins, apoptosis-related proteins and PI3K/AKT/mTOR pathway-related proteins.. Our findings provide evidence that the activation of ERS could promote autophagy and apoptosis and reverse chemoresistance of human SCLC cells by inhibiting the PI3K/AKT/mTOR pathway.

Topics: Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Proteins; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Endoplasmic Reticulum Stress; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Lung Neoplasms; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Quinolines; Signal Transduction; Small Cell Lung Carcinoma; TOR Serine-Threonine Kinases; Tunicamycin

Malignant pleural mesothelioma (MPM) originates in most of the cases from chronic inflammation of the mesothelium due to exposure to asbestos fibers. Given the limited effect of chemotherapy, a big effort is being made to find new treatment options. The PI3K/mTOR pathway was reported to be upregulated in MPM. We tested the cell growth inhibition properties of two dual PI3K/mTOR inhibitors NVP-BEZ235 and GDC-0980 on 19 MPM cell lines. We could identify resistant and sensitive lines; however, there was no correlation to the downregulation of PI3K/mTOR activity markers. As a result of mTOR inhibition, both drugs efficiently induced long-term autophagy but not cell death. Autophagy blockade by chloroquine in combination with the dual PI3K/mTOR inhibitors significantly induced caspase-independent cell death involving RIP1 in the sensitive cell line SPC212. Cell death in the resistant cell line Mero-82 was less pronounced, and it was not induced via RIP1-dependent mechanism, suggesting the involvement of RIP1 downstream effectors. Cell death induction was confirmed in 3D systems. Based on these results, we identify autophagy as one of the main mechanisms of cell death resistance against dual PI3K/mTOR inhibitors in MPM. As PI3K/mTOR inhibitors are under investigation in clinical trials, these results may help interpreting their outcome and suggest ways for intervention.

Topics: Autophagy; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Drug Synergism; Humans; Imidazoles; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Pleural Neoplasms; Protein Kinase Inhibitors; Pyrimidines; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

A prominent role in the pathogenesis of squamous cell carcinoma of the lung (SQCLC) has been attributed to the aberrant activation of the PI3K signaling pathway, due to amplification or mutations of the p110α subunit of class I phosphatidylinositol 3-kinase (PIK3CA) gene. The aim of our study was to determine whether different genetic alterations of PIK3CA affect the biologic properties of SQCLC and to evaluate the response to specific targeting agents in vitro and in vivo. The effects of NVP-BEZ235, NVP-BKM120, and NVP-BYL719 on two-dimensional/three-dimensional (2D/3D) cellular growth, epithelial-to-mesenchymal transition, and invasiveness were evaluated in E545K or H1047R PIK3CA-mutated SQCLC cells and in newly generated clones carrying PIK3CA alterations, as well as in a xenograft model. PIK3CA mutated/amplified cells showed increased growth rate and enhanced migration and invasiveness, associated with an increased activity of RhoA family proteins and the acquisition of a mesenchymal phenotype. PI3K inhibitors reverted this aggressive phenotype by reducing metalloproteinase production, RhoA activity, and the expression of mesenchymal markers, with the specific PI3K inhibitors NVP-BKM120 and NVP-BYL719 being more effective than the dual PI3K/mTOR inhibitor NVP-BEZ235. A xenograft model of SQCLC confirmed that PIK3CA mutation promotes the acquisition of a mesenchymal phenotype in vivo and proved the efficacy of its specific targeting drug NVP-BYL719 in reducing the growth and the expression of mesenchymal markers in xenotransplanted tumors. These data indicate that PIK3CA mutation/amplification may represent a good predictive feature for the clinical application of specific PI3K inhibitors in SQCLC patients.

Topics: Aminopyridines; Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Class I Phosphatidylinositol 3-Kinases; Disease Models, Animal; Epithelial-Mesenchymal Transition; Humans; Imidazoles; Lung Neoplasms; Morpholines; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Signal Transduction; Thiazoles; Xenograft Model Antitumor Assays

The PI3K/Akt/mTOR axis in lung cancer is frequently activated and implicated in tumorigenesis. Specific targeting of this pathway is therefore an attractive therapeutic approach for lung cancer. However, non-small cell lung cancer cells are resistant to BEZ235, a dual inhibitor of PI3K and mTOR. Interestingly, blockage of Stat3 with a selective inhibitor, S3I-201, or siRNA dramatically sensitized the BEZ235-induced cell death, as evident from increased PARP cleavage. Furthermore, inhibition of Stat3 led to enhancement of cell death induced by LY294002, a PI3K inhibitor. Treatment of cells with a combination of BEZ235 and S3I-201 significantly induced the proapoptotic transcription factor, CHOP, and its targets, Bim and DR4. Knockdown of CHOP or Bim suppressed cell death stimulated by the combination treatment, implicating the involvement of these BEZ235/S3I-201-induced factors in pronounced cell death. Moreover, the BEZ235/S3I-201 combination enhanced TRAIL-induced cell death. Our results collectively suggest that blockage of Stat3 presents an effective strategy to overcome resistance to PI3K/Akt/mTOR inhibition.

Topics: Aminosalicylic Acids; Antineoplastic Agents; Benzenesulfonates; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Imidazoles; Lung; Lung Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Quinolines; RNA Interference; RNA, Small Interfering; Signal Transduction; STAT3 Transcription Factor; TOR Serine-Threonine Kinases

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

Malignant pleural mesothelioma (MPM) is an aggressive disease with a poor prognosis. Studies have shown that both MET and its key downstream intracellular signaling partners, PI3K and mTOR, are overexpressed in MPM. Here we determined the combinatorial therapeutic efficacy of a new generation small molecule inhibitor of MET, ARQ 197, and dual PI3K/mTOR inhibitors NVP-BEZ235 and GDC-0980 in mesothelioma cell and mouse xenograft models. Cell viability results show that mesothelioma cell lines were sensitive to ARQ 197, NVP-BEZ235 and GDC-0980 inhibitors. The combined use of ARQ 197 with either NVP-BEZ235 or GDC-0980, was synergistic (CI<1). Significant delay in wound healing was observed with ARQ 197 (p<0.001) with no added advantage of combining it with either NVP-BEZ235 or GDC-0980. ARQ 197 alone mainly induced apoptosis (20±2.36%) that was preceded by suppression of MAPK activity, while all the three suppressed cell cycle progression. Both GDC-0980 and NVP-BEZ235 strongly inhibited activities of PI3K and mTOR as evidenced from the phosphorylation status of AKT and S6 kinase. The above observation was further substantiated by the finding that a majority of the MPM archival samples tested revealed highly active AKT. While the single use of ARQ 197 and GDC-0980 inhibited significantly the growth of MPM xenografts (p<0.05, p<0.001 respectively) in mice, the combination of the above two drugs was highly synergistic (p<0.001). Our results suggest that the combined use of ARQ 197/NVP-BEZ235 and ARQ 197/GDC-0980 is far more effective than the use of the drugs singly in suppressing MPM tumor growth and motility and therefore merit further translational studies.

Topics: Animals; Antineoplastic Agents; Apoptosis; Bridged Bicyclo Compounds, Heterocyclic; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Drug Synergism; Female; Humans; Imidazoles; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Mice; Mice, Nude; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-met; PTEN Phosphohydrolase; Pyrimidines; Pyrrolidinones; Quinolines; TOR Serine-Threonine Kinases; Wound Healing; Xenograft Model Antitumor Assays

Bronchial carcinoids (BCs) are rare neuroendocrine tumors that are still orphans of medical treatment. Human BC primary cultures may display resistance to everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), in terms of cell viability reduction. Our aim was to assess whether the novel dual phosphatidylinositol 3-kinase (PI3K)/mTOR inhibitor NVP-BEZ235 is effective in everolimus-resistant human BC tissues and cell lines. In addition, we searched for possible markers of the efficacy of mTOR inhibitors that may help in identifying the patients who may benefit from treatment with mTOR inhibitors, sparing them from ineffective therapy. We found that NVP-BEZ235 is twice as potent as everolimus in reducing cell viability and activating apoptosis in human BC tissues that display sensitivity to mTOR inhibitors, but is not effective in everolimus-resistant BC tissues and cell lines that bypass cyclin D1 downregulation and escape G0/G1 blockade. Rebound AKT activation was not observed in response to treatment with either mTOR inhibitor in the 'resistant' BC cells. In addition to total mTOR levels, putative markers of the sensitivity of BCs to mTOR inhibitors are represented by AKT, p70S6K (RPS6KB2), and ERK1/2 (MAPK3/1) protein levels. Finally, we validated these markers in an independent BC group. These data indicate that the dual PI3K/mTOR inhibitor NVP-BEZ235 is more potent than everolimus in reducing the proliferation of human BC cells. 'Resistant' cells display lower levels of mTOR, p70S6K, AKT, and ERK1/2, indicating that these proteins may be useful as predictive markers of resistance to mTOR and PI3K/mTOR inhibitors in human BCs.

Topics: Adult; Aged; Antineoplastic Agents; Carcinoid Tumor; Cell Line, Tumor; Cell Survival; Drug Resistance, Neoplasm; Everolimus; Female; Humans; Imidazoles; Lung Neoplasms; Male; Middle Aged; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Quinolines; Ribosomal Protein S6 Kinases, 70-kDa; Sirolimus; TOR Serine-Threonine Kinases; Young Adult

Acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, is a critical problem in the management of patients with EGFR mutant lung cancer. Several mechanisms have been reported involved in this acquired resistance, including hepatocyte growth factor (HGF) activation of an alternative pathway. PI3K and mTOR are downstream molecules of receptor tyrosine kinases, such as EGFR and Met, and are thought to be ideal targets for controlling various tumor types. We assessed whether BEZ235, a dual inhibitor of PI3K and mTOR, could overcome the EGFR-TKI resistance induced by HGF in an EGFR mutant lung cancer model. Exogenous and endogenous HGF triggered resistance to erlotinib in the PC-9 and HCC827, EGFR mutant lung cancer cell lines. BEZ235 alone inhibited the viability of PC-9 and HCC827 cells in vitro, irrespective of the presence or the absence of HGF. Using a xenograft model of severe combined immunodeficient mice with HGF-gene-transfected PC-9 cells (PC-9/HGF), we found that BEZ235 inhibited tumor growth, whereas erlotinib did not. BEZ235 monotherapy also inhibited the phosphorylation of Akt and p70S6K/S6RP, downstream molecules of PI3K and mTOR, respectively, as well as suppressing tumor-cell proliferation and angiogenesis of PC-9/HGF tumors. These results suggest that BEZ235, even as monotherapy, may be useful in managing HGF-induced EGFR-TKI resistance in EGFR mutant lung cancer.

Topics: Animals; Antineoplastic Agents; Cell Survival; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Female; Humans; Imidazoles; Lung Neoplasms; Mice; Mice, SCID; Mutation; Neoplasm Transplantation; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Quinazolines; Quinolines; Tetrazolium Salts; Thiazoles; TOR Serine-Threonine Kinases; Treatment Outcome

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

BEZ235 is a dual phosphatidylinositol 3-kinase (PI(3)K)/mammalian target of rapamycin (mTOR) inhibitor that is orally available and that has been shown to be effective in several malignancies in vitro. Recently, BEZ235 entered clinical trials for solid tumors. We aimed at investigating if BEZ235 is effective in lung cancer cell lines.. The human lung cancer cell lines EPLC, HCC and H1339 were analysed by fluorescence in situ hybridization, gene sequencing and Western blot analysis. Cells were exposed to BEZ235 and/or cisplatin and the survival fraction was quantified.. In all cell lines, BEZ235 reduced pAkt and pS6 expression indicating interference with the epidermal growth factor (EGF) pathway. Furthermore, BEZ235 inhibited tumor cell growth and added to the effects of cisplatin. This was independent of EGFR amplification and EGFR, KRAS, PI3K and AKT mutation.. The dual PI3K/mTOR inhibitor BEZ235 is effective in lung cancer cell lines and a promising compound to be tested in clinical phase I studies.

Topics: Blotting, Western; Cell Line, Tumor; Cell Survival; Cisplatin; Drug Screening Assays, Antitumor; Humans; Imidazoles; Lung Neoplasms; Models, Biological; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Kinase Inhibitors; Quinolines; Time Factors; TOR Serine-Threonine Kinases

The phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit PI3K, mTOR or both are currently under development. The mTOR allosteric inhibitor, RAD001, and the PI3K/mTOR dual kinase inhibitor, BEZ235, are examples of these agents. We were interested in developing strategies to enhance mTOR-targeted caner therapy. In this study, we found that BEZ235 alone effectively inhibited the growth of rapamycin-resistant cancer cells. Interestingly, the combination of sub-optimal concentrations of RAD001 and BEZ235 exerted synergistic inhibition of the growth of human lung cancer cells along with induction of apoptosis and G1 arrest. Furthermore, the combination was also more effective than either agent alone in inhibiting the growth of lung cancer xenografts in mice. The combination showed enhanced effects on inhibiting mTOR signaling and reducing the expression of c-Myc and cyclin D1. Taken together, our results suggest that the combination of RAD001 and BEZ235 is a novel strategy for cancer therapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Drug Resistance, Neoplasm; Drug Synergism; Eukaryotic Initiation Factor-4F; Everolimus; Female; G1 Phase; Humans; Imidazoles; Lung Neoplasms; Mice; Proto-Oncogene Proteins c-myc; Quinolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Autophagy is a cellular lysosomal degradation pathway essential for regulation of cell survival and death to maintain homeostasis. This process is negatively regulated by mammalian target of rapamycin (mTOR) signaling and often counteracts efficacy of certain cancer therapeutic agents. NVP-BEZ235 (BEZ235) is a novel, orally bioavailable dual PI3K/mTOR inhibitor that has exhibited promising activity against non-small cell lung cancer (NSCLC) in preclinical models. The current study focuses on evaluating the role of BEZ235 in regulating autophagy. BEZ235 was effective in inhibiting the growth of NSCLC cells including induction of apoptosis. It also potently induced the expression of type-II LC3, indicating induction of autophagy. When BEZ235 was used in combination with the lysosomal or autophagic inhibitor chloroquine (CQ), enhanced inhibitory effects on monolayer growth and colony formation of NSCLC cells was observed. In addition, enhanced induction of apoptosis was also detected in cells exposed to the combination of BEZ235 and CQ. Moreover, the combination of BEZ235 and CQ was more effective than each single agent alone in inhibiting the growth of NSCLC xenografts in nude mice. Thus, induction of autophagy by BEZ235 appears to be a survival mechanism that may counteract its anticancer effects. Based on these, we suggest a strategy to enhance BEZ235's anticancer efficacy by blockade of autophagy.

Topics: Animals; Apoptosis; Autophagy; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Chloroquine; Drug Synergism; Female; Humans; Imidazoles; Lung Neoplasms; Mice; Mice, Nude; Proto-Oncogene Proteins c-akt; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Burden; Xenograft Model Antitumor Assays

Immunodeficient animal models are invaluable tools to investigate the metastatic propensity of human tumours. However residual immune responses, in particular natural killer (NK) cells, severely hamper the traffic and growth of human tumour cells. We studied whether a genetically modified mouse host lacking T, B and NK immunity allowed an improved expression of the metastatic phenotype of malignant human tumours. Metastatic spread of a panel of human sarcoma cell lines was studied in double knockout Rag2(-/-);gammac(-/-) mice in comparison with NK-depleted nude mice. Rag2(-/-);gammac(-/-) mice receiving intravenous (i.v.) or subcutaneous (s.c.) human sarcoma cell lines developed extensive multiorgan metastases. Metastatic efficiency in Rag2(-/-);gammac(-/-) was superior than in nude mice in terms of both metastatic sites and metastasis number. Metastatic growth in Rag2(-/-);gammac(-/-) mice was faster than that in nude mice, thus allowing an earlier metastasis evaluation. Most human sarcomas metastasised in the liver of Rag2(-/-);gammac(-/-) mice, a kind of organ preference undetectable in nude mice and specific of sarcomas, as several carcinoma cell lines failed to colonise the liver of Rag2(-/-);gammac(-/-) mice, independently of their metastatic spread to other sites. In vitro analysis of the molecular mechanisms of liver metastasis of sarcomas implicated liver-produced growth and motility factors, in particular the insulin-like growth factor (IGF) axis. NVP-BEZ235, a specific inhibitor of downstream signal transduction targeting PI3K and mTOR, strongly inhibited liver metastasis of human sarcoma cells. In conclusion, the Rag2(-/-);gammac(-/-) mouse model allowed the expression of human metastatic phenotypes inapparent in conventional immunodeficient mice and the preclinical testing of appropriate targeted therapies.

Topics: Animals; Antineoplastic Agents; Chemotaxis; Culture Media, Conditioned; Disease Models, Animal; DNA-Binding Proteins; Enzyme Inhibitors; Female; Humans; Imidazoles; Immune Tolerance; Liver Neoplasms; Lung Neoplasms; Mice; Mice, Knockout; Neoplasm Transplantation; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Sarcoma; Transplantation, Heterologous; Treatment Outcome; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC often harbors oncogenic K-RAS mutations that lead to the aberrant activation of several intracellular networks including the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Oncogenic K-RAS predicts poor prognosis and resistance to treatment with ionizing radiation (IR). Oncogenic K-Ras expression in the respiratory epithelium is sufficient to initiate NSCLC tumorigenesis, which requires the catalytic subunit of PI3K. Thus, effective inhibition of the PI3K signaling should lead to significant antitumor effects. However, therapy with rapamycin analogues has yielded disappointing results due in part to compensatory up-regulation of AKT. We hypothesized that dual PI3K/mTOR blockade would overcome these limitations. We tested this hypothesis with BEZ235, a novel dual PI3K/mTOR inhibitor that has recently entered clinical development. We found that BEZ235 induces a striking antiproliferative effect both in transgenic mice with oncogenic K-RAS-induced NSCLC and in NSCLC cell lines expressing oncogenic K-RAS. We determined that treatment with BEZ235 was not sufficient to induce apoptosis. However, we found that dual PI3K/mTOR blockade effectively sensitizes NSCLC expressing oncogenic K-RAS to the proapoptotic effects of IR both in vitro and in vivo. We conclude that dual PI3K/mTOR blockade in combination with IR may benefit patients with NSCLC expressing oncogenic K-RAS. These findings may have general applicability in cancer therapy, because aberrant activation of PI3K occurs frequently in human cancer.

Topics: Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Combined Modality Therapy; Female; Genes, ras; Humans; Imidazoles; Lung Neoplasms; Mice; Mice, Nude; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinases; Quinolines; Radiation-Sensitizing Agents; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Non-small cell lung cancers with activating mutations in the epidermal growth factor receptor (EGFR) are highly responsive to EGFR tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib. Such cancers are "addicted" to EGFR, and treatment with a TKI invariably leads to down-regulation of the PI3K-AKT-mTOR and MEK-ERK signaling pathways, resulting in apoptosis. Using a dual PI3K-mTOR inhibitor, NVP-BEZ235, we evaluated whether PI3K-mTOR inhibition alone induced apoptosis in these cancers. In contrast to HER2-amplified breast cancers, we found that PI3K-mTOR inhibition did not promote substantial apoptosis in the EGFR mutant lung cancers. However, blocking both PI3K-mTOR and MEK simultaneously led to apoptosis to similar levels as the EGFR TKIs, suggesting that down-regulation of these pathways may account for much of the apoptosis promoted by EGFR inhibition. In EGFR mutant lung cancers, down-regulation of both intracellular pathways converged on the BH3 family of proteins regulating apoptosis. PI3K inhibition led to down-regulation of Mcl-1, and MEK inhibition led to up-regulation of BIM. In fact, down-regulation of Mcl-1 by siRNA was sufficient to sensitize these cancers to single-agent MEK inhibitors. Surprisingly, an AKT inhibitor did not decrease Mcl-1 levels, and when combined with MEK inhibitors, failed to induce apoptosis. Importantly, we observed that the combination of PI3K-mTOR and MEK inhibitors effectively shrunk tumors in a transgenic and xenograft model of EGFR T790M-L858R cancers. These data indicate simultaneous inhibition of PI3K-mTOR and MEK signaling is an effective strategy for treating EGFR mutant lung cancers, including those with acquired resistance to EGFR TKIs.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Breast Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; ErbB Receptors; Erlotinib Hydrochloride; Female; Gefitinib; Humans; Imidazoles; Lung Neoplasms; MAP Kinase Kinase Kinases; Mice; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Protein Kinases; Quinazolines; Quinolines; Receptor, ErbB-2; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays