C-MET inhibitors in the treatment of lung cancer

Advancing Lung Cancer Treatment with Combined c-Met Promoter-Driven Oncolytic Adenovirus and Rapamycin

Lung cancer remains a formidable health challenge due to its high mortality and morbidity rates. Non-small cell lung cancer (NSCLC) constitutes approximately 85% of all lung cancer cases, with small cell lung cancer (SCLC) accounting for the remainder. Both NSCLC and SCLC cells express receptor tyrosine kinases, which may be overexpressed or mutated in lung cancer, leading to increased activation. The c-Met receptor tyrosine kinase, crucial for cell transformation and tumor growth, invasion, and metastasis, became the focus of our study. We used an E1B55KD-deleted, replication-selective oncolytic adenovirus (Ad.What), driven by the c-Met promoter, targeting lung cancer cells with c-Met overexpression, thus sparing normal cells. Previous studies have shown the enhanced antitumor efficacy of oncolytic adenoviruses when combined with chemotherapeutic agents. We explored combining rapamycin, a selective mTOR inhibitor with promising clinical trial outcomes for various cancers, with Ad.What. This combination increased infectivity by augmenting the expression of coxsackievirus and adenovirus receptors and αV integrin on cancer cells and induced autophagy. Our findings suggest that combining a c-Met promoter-driven oncolytic adenovirus with rapamycin could be an effective lung cancer treatment strategy, offering a targeted approach to exploit lung cancer cells' vulnerabilities, potentially marking a significant advancement in managing this deadly disease.

Pyrazolopyridine-based kinase inhibitors for anti-cancer targeted therapy

The need for effective cancer treatments continues to be a challenge for the biomedical research community. In this case, the advent of targeted therapy has significantly improved therapeutic outcomes. Drug discovery and development efforts targeting kinases have resulted in the approval of several small-molecule anti-cancer drugs based on ATP-mimicking heterocyclic cores. Pyrazolopyridines are a group of privileged heterocyclic cores in kinase drug discovery, which are present in several inhibitors that have been developed against various cancers. Notably, selpercatinib, glumetinib, camonsertib and olverembatinib have either received approval or are in late-phase clinical studies. This review presents the success stories employing pyrazolopyridine scaffolds as hinge-binding cores to address various challenges in kinase-targeted drug discovery research.

Mesenchymal-Epithelial Transition Kinase Inhibitor Therapy in Patients with Advanced Papillary Renal-Cell Carcinoma: A Systematic Review and Meta-Analysis

Papillary subtypes of renal-cell carcinoma (pRCC) represent 10-15% of the cases and commonly have MET alterations. This systematic review and single-arm meta-analysis evaluated MET inhibitor therapy (METi) efficacy and safety in adults with confirmed advanced pRCC. The search strategy included PubMed, Web-of-science, Cochrane, and Scopus. We used the DerSimonian/Laird random effect model for all analyses; p-value < 5% was considered significant, and heterogeneity was assessed with I2. Three clinical trials and six cohort studies were included with 504 patients; 31% were MET-driven. Our pooled analysis demonstrated an objective response rate (ORR) in MET-driven, MET-independent, and overall patients of: 36% (95%CI: 10-62), 0% (95%CI: 0-3), and 21% (95%CI: 1-41), respectively. One-year disease control and progression-free survival rates were, respectively, 70% (95%CI: 52-88) and 15% (95%CI: 10-20). Twelve- and twenty-four-month survival rates were, respectively, 43% (95%CI: 23-64) and 10% (95%CI: 0-30). The prevalence of adverse events of any grade and grades 3-5 were 96% (95%CI: 91-100) and 44% (95%CI: 37-50), respectively. We suggest METi has anti-tumor activity and is tolerable in patients with advanced pRCC.

Transcriptional responses of liver and spleen in Lota lota to polyriboinosinic polyribocytidylic acid

Introduction

The cultured Lota lota can meet the market demand in the context of the decline of wild resources, but the disease in the high-density culture process also deserves attention. Therefore, understanding the immune regulation mechanisms of L. lota will be the basis for obtaining high benefits in artificial culture.

Methods

To explore the viral response mechanism of L. lota, RNA-seq was applied to identify the transcriptomic changes of the liver and spleen in L. lota by poly (I:C) stress.

Results

The DEGs (liver: 2186 to 3123; spleen 1542 to 2622) and up-regulated genes (liver: 1231 to 1776; spleen 769 to 1502) in the liver and spleen increased with the prolongation (12h to 48h) of poly (I:C)-stimulation time. This means L. lota needs to mobilize more functional genes in response to longer periods of poly (I:C)-stimulation. Despite the responses of L. lota to poly (I:C) showed tissue-specificity, we hypothesized that both liver and spleen of L. lota can respond to poly (I:C) challenge may be through promoting apoptosis of DNA-damaged cells, increasing the activity of immune-enhancing enzymes, and increasing energy supply based on DEGs annotation information.

Conclusions

Our results demonstrate the transcriptional responses of L. lota to poly (I:C)-stimulation, and these data provide the first resource on the genetic regulation mechanisms of L. lota against viruses. Furthermore, the present study can provide basic information for the prevention of viral diseases in L. lota artificial culture process.

Analysis of genomic alterations in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare and special type of non-Hodgkin lymphoma with a significantly worse median overall prognosis than that of non-Hodgkin lymphoma outside the brain. Clarifying the genomic characteristics and alterations in PCNSL could provide clues regarding its distinctive pathophysiology and new treatment options. However, current knowledge about the genomics of PCNSL is limited. In this study, next-generation sequencing (NGS) was performed to investigate the genomic profile of PCNSL. Samples from 12 patients diagnosed with PCNSL at our institution were analyzed for gene mutations using NGS. This study showed that missense mutations were the most common mutation type. C > A/G > T accounted for most of the single-base mutations, which reflected the preference of the tumor sample mutation type and may serve as an important prognostic factor. The most significantly mutated gene was myeloid differentiation factor 88 (MYD88) (0.55), followed by CD79B, LRP1B, and PRDM1 (0.36). None of the cases showed a high tumor mutational burden. In addition to the traditional driver genes, we also identified some new possible ones such as MET, PIM1, and RSBN1L. Enrichment analysis revealed that genes mutated in PCNSL were involved in many pathways and functional protein activities, such as the extracellular matrix and adhesion molecules. The most common genetic alterations in PCNSL were identified using NGS. Mutations in multiple genes highlights the complex molecular heterogeneity of PCNSL. Enrichment analysis revealed possible pathogenesis. Further exploration of new driver genes could provide novel insights into diagnosis and precision medicine for PCNSL.

Adaptive c-Met-PLXDC2 Signaling Axis Mediates Cancer Stem Cell Plasticity to Confer Radioresistance-associated Aggressiveness in Head and Neck Cancer

Radiotherapy plays an essential role in the treatment of head and neck squamous cell carcinoma (HNSCC), yet radioresistance remains a major barrier to therapeutic efficacy. A better understanding of the predominant pathways determining radiotherapy response could help develop mechanism-informed therapies to improve cancer management. Here we report that radioresistant HNSCC cells exhibit increased tumor aggressiveness. Using unbiased proteome profiler antibody arrays, we identify that upregulation of c-Met phosphorylation is one of the critical mechanisms for radioresistance in HNSCC cells. We further uncover that radioresistance-associated HNSCC aggressiveness is effectively exacerbated by c-Met but is suppressed by its genetic knockdown and pharmacologic inactivation. Mechanistically, the resulting upregulation of c-Met promotes elevated expression of plexin domain containing 2 (PLXDC2) through activating ERK1/2-ELK1 signaling, which in turn modulates cancer cell plasticity by epithelial-mesenchymal transition (EMT) induction and enrichment of the cancer stem cell (CSC) subpopulation, leading to resistance of HNSCC cells to radiotherapy. Depletion of PLXDC2 overcomes c-Met-mediated radioresistance through reversing the EMT progress and blunting the self-renewal capacity of CSCs. Therapeutically, the addition of SU11274, a selective and potent c-Met inhibitor, to radiation induces tumor shrinkage and limits tumor metastasis to lymph nodes in an orthotopic mouse model. Collectively, these significant findings not only demonstrate a novel mechanism underpinning radioresistance-associated aggressiveness but also provide a possible therapeutic strategy to target radioresistance in patients with HNSCC.

Significance

This work provides novel insights into c-Met-PLXDC2 signaling in radioresistance-associated aggressiveness and suggests a new mechanism-informed therapeutic strategy to overcome failure of radiotherapy in patients with HNSCC.

Therapeutic strategies for non-small cell lung cancer: Experimental models and emerging biomarkers to monitor drug efficacies

While new targeted therapies have considerably changed the treatment and prognosis of non-small cell lung cancer (NSCLC), they are frequently unsuccessful due to primary or acquired resistances. Chemoresistance is a complex process that combines cancer cell intrinsic mechanisms including molecular and genetic abnormalities, aberrant interactions within the tumor microenvironment, and the pharmacokinetic characteristics of each molecule. From a pharmacological point of view, two levers could improve the response to treatment: (i) developing tools to predict the response to chemo- and targeted therapies and (ii) gaining a better understanding of the influence of the tumor microenvironment. Both personalized medicine approaches require the identification of relevant experimental models and biomarkers to understand and fight against chemoresistance mechanisms. After describing the main therapies in NSCLC, the scope of this review will be to identify and to discuss relevant in vitro and ex vivo experimental models that are able to mimic tumors. In addition, the interests of these models in the predictive responses to proposed therapies will be discussed. Finally, this review will evaluate the involvement of novel secreted biomarkers such as tumor DNA or micro RNA in predicting responses to anti-tumor therapies.

EZH2/hSULF1 axis mediates receptor tyrosine kinase signaling to shape cartilage tumor progression

Chondrosarcomas are primary cancers of cartilaginous tissue and capable of alteration to highly aggressive, metastatic, and treatment-refractory states, leading to a poor prognosis with a five-year survival rate at 11 months for dedifferentiated subtype. At present, the surgical resection of chondrosarcoma is the only effective treatment, and no other treatment options including targeted therapies, conventional chemotherapies, or immunotherapies are available for these patients. Here, we identify a signal pathway way involving EZH2/SULF1/cMET axis that contributes to malignancy of chondrosarcoma and provides a potential therapeutic option for the disease. A non-biased chromatin immunoprecipitation sequence, cDNA microarray analysis, and validation of chondrosarcoma cell lines identified sulfatase 1 (SULF1) as the top EZH2-targeted gene to regulate chondrosarcoma progression. Overexpressed EZH2 resulted in downregulation of SULF1 in chondrosarcoma cell lines, which in turn activated cMET pathway. Pharmaceutical inhibition of cMET or genetically silenced cMET pathway significantly retards the chondrosarcoma growth and extends mice survival. The regulation of EZH2/SULF1/cMET axis were further validated in patient samples with chondrosarcoma. The results not only established a signal pathway promoting malignancy of chondrosarcoma but also provided a therapeutic potential for further development of effective target therapy to treat chondrosarcoma.

The hepatocyte growth factor/mesenchymal epithelial transition factor axis in high-risk pediatric solid tumors and the anti-tumor activity of targeted therapeutic agents

Clinical trials completed in the last two decades have contributed significantly to the improved overall survival of children with cancer. In spite of these advancements, disease relapse still remains a significant cause of death in this patient population. Often, increasing the intensity of current protocols is not feasible because of cumulative toxicity and development of drug resistance. Therefore, the identification and clinical validation of novel targets in high-risk and refractory childhood malignancies are essential to develop effective new generation treatment protocols. A number of recent studies have shown that the hepatocyte growth factor (HGF) and its receptor Mesenchymal epithelial transition factor (c-MET) influence the growth, survival, angiogenesis, and metastasis of cancer cells. Therefore, the c-MET receptor tyrosine kinase and HGF have been identified as potential targets for cancer therapeutics and recent years have seen a race to synthesize molecules to block their expression and function. In this review we aim to summarize the literature that explores the potential and biological rationale for targeting the HGF/c-MET pathway in common and high-risk pediatric solid tumors. We also discuss selected recent and ongoing clinical trials with these agents in relapsed pediatric tumors that may provide applicable future treatments for these patients.

MET Mutation Is a Potential Therapeutic Target for Advanced Endometrial Cancer

Simple Summary

Endometrial cancer is the most common gynecological cancer in developed countries. At initial diagnosis, extra-uterine spread is observed in about 25% of patients. Chemotherapy is the suggested mode of treatment for patients with extra-uterine metastasis; however, the 5-year overall survival rate of these patients remains poor. The development of new therapeutic strategies to improve the poor clinical outcome of patients with advanced endometrial cancer is still in great demand. In this study, we aim to understand the genomic landscape of advanced endometrial cancer and identify new therapeutic targets. Integrated genomic, pathological, and clinical data are analyzed to identify the survival-associated genomic alterations. In addition, the impacts of the genomic alterations are examined in silico, in vitro, and in vivo. The results of this study may aid in developing biomarker-guided treatments for patients with advanced endometrial cancer.

Abstract

An optimal therapeutic regimen for endometrial cancer with extra-uterine metastasis is unavailable. This study aims to improve our understanding of the genomic landscape of advanced endometrial cancer and identify potential therapeutic targets. The clinical and genomic profiles of 81 patients with stage III or IV endometrial cancer were integrated. To identify genomic aberrations associated with clinical outcomes, Cox proportional hazard regression was used. The impacts of the genomic aberrations were validated in vitro and in vivo. The mutation status of MET, U2AF1, BCL9, PPP2R1A, IDH2, CBL, BTK, and CHEK2 were positively correlated with poor clinical outcomes. MET mutations occurred in 30% of the patients who presented with poor overall survival (hazard ratio, 2.606; 95% confidence interval, 1.167~5.819; adjusted p-value, 0.067). Concurrent MET and KRAS mutations presented with the worst outcomes. MET mutations in hepatocyte growth factor (HGF)-binding (58.1%) or kinase (16.2%) domains resulted in differential HGF-induced c-MET phosphorylation. Different types of MET mutations differentially affected tumor growth and displayed different sensitivities to cisplatin and tyrosine kinase inhibitors. MET N375S mutation is a germline variant that causes chemoresistance to cisplatin, with a high incidence in Eastern Asia. This study highlights the ethnic differences in the biology of the disease, which can influence treatment recommendations and the genome-guided clinical trials of advanced endometrial cancer.

Analysis of the Protein-Protein Interaction Network Identifying c-Met as a Target of Gigantol in the Suppression of Lung Cancer Metastasis

BACKGROUND/AIM

c-Met (mesenchymal-epithelial transition factor) facilitates cancer progression and is recognized as a promising drug target. The molecular target of gigantol from Dendrobium draconis in suppressing cancer metastasis is largely unknown.

MATERIALS AND METHODS

Proteins affected by gigantol treatment were subjected to proteomic and bioinformatic analysis. Protein-Protein interaction (PPI) networks were constructed by the Search Tool for the Retrieval of Interacting Genes (STRING). The Kyoto Encyclopedia of Genes and Genomes (KEGG) database and hub gene were used to enrich the dominant pathways. Western blot analysis and immunofluorescence were used to validate the effect of gigantol on the target protein and signaling.

RESULTS

Gigantol down-regulates 41 adhesion proteins and 39-migratory proteins, while it up-regulates 30 adhesion-related proteins and 22 proteins controlling cell migration. The key components of our constructed PPI network comprised 41 proteins of cell adhesion enriched in 40 nodes with 25 edges, 39 proteins of cell migration enriched in 39 nodes with 76 edges in down-regulated proteins, 30 proteins of cell adhesion enriched in 30 nodes with 21 edges, and 22 proteins of cell migration enriched in 22 nodes with 22 edges in up-regulated protein. c-Met was identified as a central protein of the PPI network in the largest degree. KEGG mapper further suggested that c-Met, PI3K, and AKT were the regulatory proteins affected by gigantol. To confirm, the effects of gigantol on c-Met, the p-PI3K, PI3K, p-AKT, and AKT proteins were investigated by western blotting and the results showed a consistent effect of gigantol in the suppression of the c-Met/PI3K/AKT signal. Next, immunofluorescence showed a dramatic decrease in c-Met, PI3K and AKT activation in response to gigantol.

CONCLUSION

c-Met is an important target of gigantol treatment in lung cancer cells. Gigantol suppresses metastasis-related cell motility through decreasing c-Met resulting in PI3K/AKT signaling disruption.

Low-Dose Crizotinib, a Tyrosine Kinase Inhibitor, Highly and Specifically Sensitizes P-Glycoprotein-Overexpressing Chemoresistant Cancer Cells Through Induction of Late Apoptosis in vivo and in vitro

We investigated possible conditions or drugs that could target P-glycoprotein (P-gp)-overexpressing drug-resistant KBV20C cancer cells. Specifically, we focused on identifying a single treatment with a relatively low half maximal inhibitory concentration (IC₅₀). Our approach utilized repurposing drugs, which are already used in clinical practice. We evaluated 13 TKIs (gefitinib, imatinib, erlotinib, nilotinib, pazopanib, masatinib, sunitinib, sorafenib, regorafenib, lapatinib, vandetanib, cediranib, and crizotinib) for their sensitizing effects on P-gp-overexpressing drug-resistant KBV20C cells. We found that crizotinib had a much greater sensitization effect than the other tested drugs at relatively low doses. In a detailed quantitative analysis using both lower doses and time-duration treatments, we demonstrated that crizotinib, which increased the levels of apoptosis and G2 arrest, was the best TKI to induce sensitization in P-gp-overexpressing KBV20C cells. Upon comparing resistant KBV20C cells and sensitive KB parent cells, crizotinib was found to markedly sensitize drug-resistant KBV20C cancer cells compared with other TKIs. This suggests that crizotinib is a resistant cancer cell-sensitizing drug that induces apoptosis. In mice bearing xenografted P-gp-overexpressing KBV20C cells, we confirmed that crizotinib significantly reduced tumor growth and weight, without apparent side effects. In addition, although lapatinib and crizotinib have a high P-gp inhibitory activity, we found that co-treatment with crizotinib and vincristine (VIC) did not have much of a sensitization effect on KBV20C cells, whereas lapatinib had a high sensitization effect on VIC-treated KBV20C cells. This suggests that crizotinib is a single-treatment specific drug for resistant cancer cells. These findings provide valuable information regarding the sensitization of drug-resistant cells and indicate that low-dose crizotinib monotherapy may be used in patients with specific P-gp-overexpressing chemoresistant cancer.

Secondary Resistant Mutations to Small Molecule Inhibitors in Cancer Cells

Secondary resistant mutations in cancer cells arise in response to certain small molecule inhibitors. These mutations inevitably cause recurrence and often progression to a more aggressive form. Resistant mutations may manifest in various forms. For example, some mutations decrease or abrogate the affinity of the drug for the protein. Others restore the function of the enzyme even in the presence of the inhibitor. In some cases, resistance is acquired through activation of a parallel pathway which bypasses the function of the drug targeted pathway. The Catalogue of Somatic Mutations in Cancer (COSMIC) produced a compendium of resistant mutations to small molecule inhibitors reported in the literature. Here, we build on these data and provide a comprehensive review of resistant mutations in cancers. We also discuss mechanistic parallels of resistance.

C-MET-dependent signal transduction mediates retinoblastoma growth by regulating PKM2 nuclear translocation

Mesenchymal epithelial transition (C-MET) factor overexpression has been found in many types of cancer and has served as an important molecular target for therapeutic intervention. However, the role of C-MET in retinoblastoma remains largely unclear. The present study aimed to investigate the potential role and mechanism of C-MET in Y79 retinoblastoma cells. We found that C-MET was highly expressed in Y79 retinoblastoma cells, and, in addition, the levels of C-MET were positively correlated with cell proliferation and retinoblastoma growth. Inhibition of C-MET suppressed Y79 retinoblastoma cell proliferation and tumour growth. Mechanistically, we showed that HGF-induced C-MET-dependent signal transduction resulted in ERK 1/2 phosphorylation, which subsequently promoted the nuclear translocation of PKM2. Nuclear PKM2 further interacted with histone H3 and contributed to C-MET-dependent cyclin D1 and c-Myc expression and cell proliferation. These findings highlight the role of C-MET in Y79 retinoblastoma cells and reveal a C-MET-dependent signal transduction mechanism. C-MET may be a potential therapeutic target for retinoblastoma. SIGNIFICANCE OF THE STUDY: We demonstrated a new target of retinoblastoma, C-MET. C-MET-dependent signal transduction promotes Y79 retinoblastoma cell proliferation and tumour growth through ERK 1/2/PKM2/histone H3 signalling pathway. C-MET may be a potential target for retinoblastoma therapy.

A drug discovery platform to identify compounds that inhibit EGFR triple mutants

Receptor tyrosine kinases (RTKs) are transmembrane receptors of great clinical interest due to their role in disease. Historically, therapeutics targeting RTKs have been identified using in vitro kinase assays. Due to frequent development of drug resistance, however, there is a need to identify more diverse compounds that inhibit mutated but not wild-type RTKs. Here, we describe MaMTH-DS (mammalian membrane two-hybrid drug screening), a live-cell platform for high-throughput identification of small molecules targeting functional protein-protein interactions of RTKs. We applied MaMTH-DS to an oncogenic epidermal growth factor receptor (EGFR) mutant resistant to the latest generation of clinically approved tyrosine kinase inhibitors (TKIs). We identified four mutant-specific compounds, including two that would not have been detected by conventional in vitro kinase assays. One of these targets mutant EGFR via a new mechanism of action, distinct from classical TKI inhibition. Our results demonstrate how MaMTH-DS is a powerful complement to traditional drug screening approaches.

cGAMP inhibits tumor growth in colorectal cancer metastasis through the STING/STAT3 axis in a zebrafish xenograft model

The leading cause of mortality due to colorectal cancer (CRC) is highly associated with the development of liver metastases. Recently, we described cGAMP that is closely related to the metastatic state wherein the progress of metastatic tumors is associated with favorable outcomes in a zebrafish xenograft model. cGAMP was administered and the expression levels of type-I interferons were induced amongst tumor tissues to illuminate the overall measure of the induced STING/STAT3 axis in colorectal liver metastases. Furthermore, cGAMP-STING dependent STAT3 activation resulted in the inhibition of tumor cell proliferation, viability, and invasion in vitro. The subtotal reduction in tumor growth attributed to a large number of infiltrating inflammatory cells in vivo. We showed that cGAMP inhibited migration through angiogenesis by up-regulating IL-2, TNF-α, and IFN-γ, whereas STAT3 down-regulation inhibited CXCL8, BCL-2, and VEGFA expression. The importance of cGAMP in inhibiting the invasion front of CRC confirmed that the cGAMP dependent activation of STING/STAT3 axis played a key role in the inhibition of tumor progression.

Antitumor Activity of DFX117 by Dual Inhibition of c-Met and PI3Kα in Non-Small Cell Lung Cancer

Aberrant activation of hepatocyte growth factor (HGF)/c-Met signaling pathway caused by gene amplification or mutation plays an important role in tumorigenesis. Therefore, c-Met is considered as an attractive target for cancer therapy and c-Met inhibitors have been developed with great interests. However, cancers treated with c-Met inhibitors inevitably develop resistance commonly caused by the activation of PI3K/Akt signal transduction pathway. Therefore, the combination of c-Met and PI3Kα inhibitors showed synergistic activities, especially, in c-Met hyperactivated and PIK3CA-mutated cells. In our previous study, we rationally designed and synthesized DFX117(6-(5-(2,4-difluorophenylsulfonamido)-6-methoxypyridin-3-yl)-N-(2-morpholinoethyl) imidazo[1,2-a]pyridine-3-carboxamide) as a novel PI3Kα selective inhibitor. Herein, the antitumor activity and underlying mechanisms of DFX117 against non-small cell lung cancer (NSCLC) cells were evaluated in both in vitro and in vivo animal models. Concurrent targeted c-Met and PI3Kα by DFX117 dose-dependent inhibited the cell growth of H1975 cells (PIK3CA mutation and c-Met amplification) and A549 cells (KRAS mutation). DFX117 subsequently induced G0/G1 cell cycle arrest and apoptosis. These data highlight the significant potential of DFX117 as a feasible and efficacious agent for the treatment of NSCLC patients.

Safety and Tolerability of c-MET Inhibitors in Cancer

The role of aberrant hepatocyte growth factor receptor (c-MET, also known as tyrosine-protein kinase MET)/hepatocyte growth factor (HGF) signaling in cancer progression and invasion has been extensively studied. c-MET inhibitors have shown promising pre-clinical and early phase clinical trial anti-tumor activity in several tumor types, although results of most phase III trials with these agents have been negative. To date, two small molecule c-MET inhibitors, cabozantinib and crizotinib, have been approved by regulatory authorities for the treatment of selected cancer types, but several novel c-MET inhibitors (either monoclonal antibodies or small molecule c-MET tyrosine kinase inhibitors) and treatment combinations are currently under study in different settings. Here we provide an overview of the mechanism of action and rationale of c-MET inhibition in cancer, the efficacy of approved agents, and novel promising c-MET-inhibitors and novel targeted combination strategies under development in different cancer types, with a focus on the safety profile and tolerability of these compounds.

BPI-9016M, a c-Met inhibitor, suppresses tumor cell growth, migration and invasion of lung adenocarcinoma via miR203-DKK1

Activation of c-Met plays a critical role in tumorigenesis, migration and invasion in lung cancer. Here, we explored the therapeutic efficacy of a novel small-molecule c-Met inhibitor (BPI-9016M) in lung adenocarcinoma and investigated the underlying molecular mechanisms. Method: BPI-9016M, a c-Met tyrosine kinase receptor inhibitor, was used to treat patient-derived xenografts (PDX) from lung adenocarcinoma in NOD/SCID mice. Immunohistochemistry and Western blot analysis were used to determine the expression of c-Met and its downstream signaling molecules. CCK8, wound healing, and trans-well assays were used to analyze cell proliferation, spreading, migration and invasion. RNA sequencing and quantitative real-time PCR (qPCR) was used to screen and validate the expression of downstream genes in lung adenocarcinoma cells treated with BPI-9016M. Luciferase reporter assay was used to detect the interaction between miRNA and the targeted gene. Results: BPI-9016M significantly suppressed growth in three out of four lung adenocarcinoma PDX models, particularly in the tumors with high expression of c-Met. In lung adenocarcinoma cell lines, BPI-9016M treatment resulted in increased miR203, which reduced migration and invasion and also repressed Dickkopf-related protein 1 (DKK1) expression. Forced overexpression of DKK1 or down-regulation of miR203 reversed the inhibitory effect of BPI-9016M on migration and invasion. C-Met was verified to positively and negatively associate with DKK1 and miR203, respectively. High expression of c-Met/DKK1 or low expression of miR203 related to poor outcome of lung adenocarcinoma patients. Furthermore, we observed significantly enhanced tumor cell growth inhibition upon combining BPI-9016M treatment with miR203 mimics or DKK1 siRNA. Conclusion: Our data indicated that BPI-9016M is an effective agent against lung adenocarcinoma, particularly in tumors with c-Met activation, and likely functions through upregulation of miR203 leading to reduced DKK1 expression.

Prolonged co-treatment with HGF sustains epithelial integrity and improves pharmacological rescue of Phe508del-CFTR

Cystic fibrosis (CF), the most common inherited disease in Caucasians, is caused by mutations in the CFTR chloride channel, the most frequent of which is Phe508del. Phe508del causes not only intracellular retention and premature degradation of the mutant CFTR protein, but also defective channel gating and decreased half-life when experimentally rescued to the plasma membrane (PM). Despite recent successes in the functional rescue of several CFTR mutations with small-molecule drugs, the folding-corrector/gating-potentiator drug combinations approved for Phe508del-CFTR homozygous patients have shown only modest benefit. Several factors have been shown to contribute to this outcome, including an unexpected intensification of corrector-rescued Phe508del-CFTR PM instability after persistent co-treatment with potentiator drugs. We have previously shown that acute co-treatment with hepatocyte growth factor (HGF) can significantly enhance the chemical correction of Phe508del-CFTR. HGF coaxes the anchoring of rescued channels to the actin cytoskeleton via induction of RAC1 GTPase signalling. Here, we demonstrate that a prolonged, 15-day HGF treatment also significantly improves the functional rescue of Phe508del-CFTR by the VX-809 corrector/VX-770 potentiator combination, in polarized bronchial epithelial monolayers. Importantly, we found that HGF treatment also prevented VX-770-mediated destabilization of rescued Phe508del-CFTR and enabled further potentiation of the rescued channels. Most strikingly, prolonged HGF treatment prevented previously unrecognized epithelial dedifferentiation effects of sustained exposure to VX-809. This was observed in epithelium-like monolayers from both lung and intestinal origin, representing the two systems most affected by adverse symptoms in patients treated with VX-809 or the VX-809/VX-770 combination. Taken together, our findings strongly suggest that co-administration of HGF with corrector/potentiator drugs could be beneficial for CF patients.

Scutellarin Increases Cisplatin-Induced Apoptosis and Autophagy to Overcome Cisplatin Resistance in Non-small Cell Lung Cancer via ERK/p53 and c-met/AKT Signaling Pathways

Cisplatin, as the first-line anti-tumor agent, is widely used for treatment of a variety of malignancies including non-small cell lung cancer (NSCLC). However, the acquired resistance has been a major obstacle for the clinical application. Scutellarin is a active flavone extracted from Erigeron breviscapus Hand-Mazz that has been shown to exhibit anticancer activities on various types of tumors. Here, we reported that scutellarin was capable of sensitizing A549/DDP cells to cisplatin by enhancing apoptosis and autophagy. Mechanistic analyses indicated that cisplatin-induced caspase-3-dependent apoptosis was elevated in the presence of scutellarin through activating extracellular signal-regulated kinases (ERK)-mediated p53 pathway. Furthermore, scutellarin also promoted cisplatin-induced cytotoxic autophagy, downregulated expression of p-AKT and c-met. Deficiency of c-met reduced p-AKT level, and inhibition of p-AKT or c-met improved autophagy in A549/DDP cells. Interestingly, loss of autophagy attenuated the synergism of this combination. In vivo, the co-treatment of cisplatin and scutellarin notably reduced the tumor size when compared with cisplatin treatment alone. Notably, scutellarin significantly reduced the toxicity generated by cisplatin in tumor-bearing mice. This study identifies the unique role of scutellarin in reversing cisplatin resistance through apoptosis and autophagy, and suggests that combined cisplatin and scutellarin might be a novel therapeutic strategy for patients with NSCLC.

Cabozantinib: A Multitargeted Oral Tyrosine Kinase Inhibitor

Cabozantinib is an oral small-molecule multitargeted tyrosine kinase inhibitor (TKI) that may confer an advantage over other TKIs that target a single receptor. It was approved by the U.S. Food and Drug Administration for the treatment of both advanced renal cell carcinoma and progressive metastatic medullary thyroid cancer, and it is being investigated for a wide array of other malignancies. Rationale for use, clinical trial data, and current recommendations for cabozantinib in renal cell cancer, thyroid cancer, prostate cancer, hepatocellular cancer, and lung cancer are detailed in this article. Common adverse events are reviewed, and management strategies for select adverse events are discussed. Implications for contemporary practitioners are also provided because use of this novel agent is likely to increase as more studies are completed.

Phase 1b Trial of Ficlatuzumab, a Humanized Hepatocyte Growth Factor Inhibitory Monoclonal Antibody, in Combination With Gefitinib in Asian Patients With NSCLC

Hepatocyte growth factor (HGF)/c-Met pathway dysregulation is a mechanism for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Ficlatuzumab (AV-299; SCH 900105), a humanized IgG₁ κ HGF inhibitory monoclonal antibody, prevents HGF/c-Met pathway ligand-mediated activation. This phase 1b study assessed the safety/tolerability, pharmacokinetics/pharmacodynamics, and antitumor activity of ficlatuzumab plus gefitinib in Asian patients with previously treated advanced non-small cell lung cancer (NSCLC). Patients received intravenous ficlatuzumab either 10 mg/kg (cohort 1; n = 3) or 20 mg/kg (cohort 2; n = 12) every 2 weeks plus oral gefitinib 250 mg daily. Patients tolerated the drug combination well. Four treatment-related grade 3/4 adverse events were reported in 3 patients (cohort 2). Pharmacokinetic profiles for ficlatuzumab and gefitinib were consistent with prior single-agent trials. Partial responses were achieved in 5 patients (4 confirmed), all in cohort 2; objective response rate (ORR) was 33% (duration, 1.9-6.4 months). Responding patients had no prior EGFR TKI treatment, 2 without an EGFR mutation. Four additional patients had disease stabilization (cohort 2; duration, 2.7-9.1 months; 42% ORR). The recommended phase 2 dose for ficlatuzumab plus gefitinib 250 mg/day was 20 mg/kg every 2 weeks. This drug combination has shown preliminary dose-related antitumor activity in advanced NSCLC.

The efficacy and safety of tivantinib in the treatment of solid tumors: a systematic review and meta-analysis

BACKGROUND

Tivantinib was designed to kill cancers by targeting the mesenchymal-epithelial transition (MET) protein. Although numerous tivantinib clinical trials are ongoing, tivantinib's efficacy and safety are still not clear. This meta-analysis was done to evaluate tivantinib's efficacy and safety in solid tumor treatment.

MATERIALS AND METHODS

PUBMED, EMBASE, and other databases were searched for eligible tivantinib clinical trials. The hazard ratio (HR) and 95% confidence interval (CI) of progression-free and overall survival (PFS and OS, respectively) were pooled and analyzed to evaluate tivantinib's efficacy. Data concerning adverse events (Grade ≥ 3) were pooled to calculate relative risks (RRs) with 95% CI for tivantinib-treated compared with control arms.

FINDINGS

Patients (1824) from six randomized control trials (RCTs) were enrolled. Compared with controls, tivantinib produced a significant improvement in PFS (HR, 0.73; 95% CI 0.65-0.83) but not in OS. In the non-small-cell lung cancer (NSCLC) subgroup, tivantinib combined with erlotinib prolonged patients' PFS when compared with controls (HR, 0.75; 95% CI, 0.65-0.86). In the white population, tivantinib also significantly improve PFS between treatment and control arms (HR, 0.75; 95% CI, 0.65-0.87). Tivantinib significantly improved OS in patients with high levels of MET expression. Tivantinib was shown to increase the risk of anemia and neutropenia.

INTERPRETATION

Tivantinib was better in prolonging PFS (not OS) in patients with solid tumors. High MET expression cancers may benefit from tivantinib. Tivantinib appeared to be well-tolerated by patients.

New Strategies Using Antibody Combinations to Increase Cancer Treatment Effectiveness

Antibodies have proven their high value in antitumor therapy over the last two decades. They are currently being used as the first-choice to treat some of the most frequent metastatic cancers, like HER2⁺ breast cancers or colorectal cancers, currently treated with trastuzumab (Herceptin) and bevacizumab (Avastin), respectively. The impressive therapeutic success of antibodies inhibiting immune checkpoints has extended the use of therapeutic antibodies to previously unanticipated tumor types. These anti-immune checkpoint antibodies allowed the cure of patients devoid of other therapeutic options, through the recovery of the patient’s own immune response against the tumor. In this review, we describe how the antibody-based therapies will evolve, including the use of antibodies in combinations, their main characteristics, advantages, and how they could contribute to significantly increase the chances of success in cancer therapy. Indeed, novel combinations will consist of mixtures of antibodies against either different epitopes of the same molecule or different targets on the same tumor cell; bispecific or multispecific antibodies able of simultaneously binding tumor cells, immune cells or extracellular molecules; immunomodulatory antibodies; antibody-based molecules, including fusion proteins between a ligand or a receptor domain and the IgG Fab or Fc fragments; autologous or heterologous cells; and different formats of vaccines. Through complementary mechanisms of action, these combinations could contribute to elude the current limitations of a single antibody which recognizes only one particular epitope. These combinations may allow the simultaneous attack of the cancer cells by using the help of the own immune cells and exerting wider therapeutic effects, based on a more specific, fast, and robust response, trying to mimic the action of the immune system.

Hepatocyte growth factor reduces sensitivity to the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib, in lung adenocarcinoma cells harboring wild-type EGFR

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy is an option for lung cancers harboring wild-type EGFR when chemotherapeutic reagents have failed. In this study, we found that the EGFR-TKI, gefitinib, modestly suppressed proliferation of the lung cancer cell lines, A549 and H358, which both harbor wild-type EGFR. Treatment with hepatocyte growth factor (HGF) reduced the sensitivity to gefitinib, whereas sensitivity was restored by treatment with an HGF antibody, a MET inhibitor, or depletion of MET but not ErbB3 gene. Moreover, both PI3K/mTOR inhibitors and MEK inhibitors suppressed proliferation of A549 cells, whereas only PI3K/mTOR inhibitors effectively suppressed cell viability of EGFR mutant PC-9 cells. Our findings suggest that HGF reduced the gefitinib sensitivity through MET and downstream PI3K and MAPK pathways. Combined use of EGFR-TKI and MET inhibitors or inhibition of downstream signaling molecules might be a better second or third line choice for a group of patients with advanced lung cancer harboring wild-type EGFR.

Occurrence and significance of morphologic changes in patients with metastatic triple negative breast cancer treated with Cabozantinib

OBJECTIVE

To compare performance of RECIST1.1 and Choi criteria in assessment of patients with metastatic triple-negative breast cancer treated with cabozantinib.

METHODS

Thirty patients with metastatic triple-negative breast cancer enrolled in phase 2 clinical trial received cabozantinib. Clinical benefit rates assessed by prospectively determined RECIST1.1 and retrospectively assessed Choi criteria were compared.

RESULTS

Decreased tumor density (≥15%) at first follow-up was seen in 22/30(73%) patients. CBR was 40% (95%CI:23-59%) by RECIST1.1, and 73% (95%CI:54-88%) by Choi (NPV=100%, 95%CI:63-100%; PPV=55%, 95%CI:32-76%).

CONCLUSIONS

Morphologic changes are seen in the majority of patients treated with cabozantinib, making Choi criteria valuable in response assessment.

Crizotinib, a MET inhibitor, inhibits growth, migration, and invasion of breast cancer cells in vitro and synergizes with chemotherapeutic agents

MET is a receptor tyrosine kinase known for its pleiotropic effects in tumorigenesis. Dysregulations of MET expression and/or signaling have been reported and determined to be associated with inferior outcomes in breast cancer patients rendering MET a versatile candidate for targeted therapeutic intervention. Crizotinib is a multi-targeted small-molecule kinase inhibitor for MET, ALK, and ROS1 kinases. This study evaluated the anti-proliferative, cytotoxic, anti-migratory, and anti-invasive effects of crizotinib in breast cancer cells in vitro. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) colorimetric assay. In vitro wound-healing assay was used to examine the effect of crizotinib on breast cancer cell migration. The expressions of Ki-67, MET, and phospho-MET receptors were characterized using immunofluorescence staining. Results showed that crizotinib has significant anti-proliferative activity on all mammary tumor cells with IC₅₀ values of 5.16, 1.5, and 3.85 µM in MDA-MB-231, MCF-7, and SK-BR-3 cells, respectively. Crizotinib induced cytotoxic effects in all breast cancer cells examined. Combined treatment of small dose of crizotinib with paclitaxel or doxorubicin exhibited a highly synergistic inhibition of growth of MDA-MB-231 and MCF-7 cells with combination index values <1 while no significant effect was observed in SK-BR-3 cells compared with individual compounds. Treatment with crizotinib demonstrated a remarkable reduction in the expression of Ki-67 protein in all 3 tested cell lines. Crizotinib inhibited migration and invasion of MDA-MB-231 cells in a dose-dependent fashion. Crizotinib reduced MET receptor activation in MDA-MB-231 cells when treated at effective concentrations. In conclusion, crizotinib suppressed proliferation, migration, and invasion of breast cancer cells in vitro. The results of this study demonstrated that combined treatment of crizotinib with chemotherapeutic agents resulted in a synergistic growth inhibition of specific breast cancer cell lines.

Role and Therapeutic Targeting of the HGF/MET Pathway in Glioblastoma

Glioblastoma (GBM) is a lethal brain tumor with dismal prognosis. Current therapeutic options, consisting of surgery, chemotherapy and radiation, have only served to marginally increase patient survival. Receptor tyrosine kinases (RTKs) are dysregulated in approximately 90% of GBM; attributed to this, research has focused on inhibiting RTKs as a novel and effective therapy for GBM. Overexpression of RTK mesenchymal epithelial transition (MET), and its ligand, hepatocyte growth factor (HGF), in GBM highlights a promising new therapeutic target. This review will discuss the role of MET in cell cycle regulation, cell proliferation, evasion of apoptosis, cell migration and invasion, angiogenesis and therapeutic resistance in GBM. It will also discuss the modes of deregulation of HGF/MET and their regulation by microRNAs. As the HGF/MET pathway is a vital regulator of multiple pro-survival pathways, efforts and strategies for its exploitation for GBM therapy are also described.

Targeted therapies for the treatment of non-small-cell lung cancer: Monoclonal antibodies and biological inhibitors

The usual treatments for patients with non-small-cell lung cancer (NSCLC), such as advanced lung adenocarcinoma, are unspecific and aggressive, and include lung resection, radiotherapy and chemotherapy. Recently, treatment with monoclonal antibodies and biological inhibitors has emerged as an effective alternative, generating effective results with few side effects. In recent years, several clinical trials using monoclonal antibodies presented potential benefits to NSCLC, and 4 of them are already approved for the treatment of NSCLC, such as cetuximab, bevacizumab, nivolumab and pembrolizumab. Also, biological inhibitors are attractive tolls for biological applications. Among the approved inhibitors are crizotinib, erlotinib, afatinib and gefitinib, and side effects are usually mild to intense. Nevertheless, biological molecule treatments are under development, and several new monoclonal antibodies and biological inhibitors are in trial to treat NSCLC. Also under trial study are as follows: anti-epidermal growth factor receptor (EGFR) antibodies (nimotuzumab and ficlatuzumab), anti-IGF 1 receptor (IGF-1R) monoclonal antibody (figitumumab), anti-NR-LU-10 monoclonal antibody (nofetumomab) as well as antibodies directly affecting the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) molecule (ipilimumab and tremelimumab), to receptor activator of nuclear factor-kappa B ligand (RANKL) (denosumab) or to polymerase enzyme (veliparib and olaparib). Among new inhibitors under investigation are poly-ADP ribose polymerase (PARP) inhibitors (veliparib and olaparib) and phosphatidylinositol 3-kinase (PI3K) inhibitor (buparlisib). However, the success of immunotherapies still requires extensive research and additional controlled trials to evaluate the long-term benefits and side effects.

The Efficacy and Risk Profile of c-Met inhibitors in Non-small Cell Lung Cancer: a Meta-analysis

c-MET inhibitors are considered as a kind of novel drugs in non-small cell lung cancer (NSCLC) treatment. However, the results of different clinical studies involving c-MET inhibitors were not consistent. In this report, we performed Meta-analysis to investigate the beneficial and harmful effects of these drugs from 9 studies including 1611 patients in target drug groups and 1605 patients in control groups. As a result, patients in target drugs group had longer progression free survival (PFS) (HR 0.80, 95% CI 0.66-0.99, p = 0.04) but not overall survival (OS) than those in control group, especially in Asian (HR 0.57, 95% CI 0.42-0.76, p < 0.001), Non-squamous (HR 0.79, 95% CI 0.64-0.97, p = 0.03), Phase III (HR 0.66, 95% CI 0.50-0.86, p = 0.002), previous treated (HR 0.77, 95% CI 0.63-0.95, p = 0.01) and small molecular compounds subgroups (HR 0.62, 95% CI 0.50-0.78, p < 0.001). In addition, target drugs did not affect the objective response rate (ORR) but improved disease control rate (DCR) (RR 1.22, 95% CI 1.02-1.46, p = 0.03) of NSCLC patients. Our study first indicated that targeting c-MET therapies improved PFS and DCR in advanced or metastatic NSCLC patients, especially in previous treated Asian patients with adenocarcinoma.

miR-129 predicts prognosis and inhibits cell growth in human prostate carcinoma

MicroRNAs (miRNAs) are a class of small, well-conserved, non-coding RNAs that are increasingly identified as diagnostic and prognostic biomarkers in a number of cancers. Deregulated miR-129 is closely associated with tumorigenesis and cancer progression. However, the potential role of miR-129 in prostate cancer remains largely elusive. The present study investigated the role of miR-129 as a prognostic biomarker for tumor progression and clinical prognosis in prostate cancer patients. The examined prostate cancer tissues exhibited a significant reduction in miR-129 expression compared with the normal tissues (P=0.013). The expression levels of miR-129 were negatively correlated with histological grade (P<0.001), high preoperative prostate-specific antigen serum levels (P<0.001), pathological stage (P<0.001), high Gleason score (P<0.001), lymph node metastasis (P=0.002), angiolymphatic invasion (P=0.018), and biochemical recurrence (BCR; P=0.001). Use of the Kaplan-Meier analysis demonstrated that low miR-129 expression was closely associated with poorer BCR-free survival. Multivariate survival analysis indicated that miR-129 expression may be an independent prognostic marker for BCR-free survival in prostate cancer patients (P<0.001). Overexpression of miR-129 markedly attenuated prostate cancer cell growth by rescuing cell cycle-regulated protein expression. The present study suggests that miR-129 is downregulated in the cancerous tissues of prostate cancer patients, which was associated with poor BCR-free survival. Thus, it may be considered as a novel independent prognostic biomarker for prostate cancer. In addition, downregulation of miR-129 may serve a critical role in the proliferation of prostate cancer cells.

Clinical Significance of C-MET Overexpression and Epidermal Growth Factor Receptor Mutation in Platinum-Based Adjuvant Chemotherapy Outcome in Surgically Resected Lung Adenocarcinoma

PURPOSE

We retrospectively assessed the role of C-MET expression and epidermal growth factor receptor (EGFR) mutation on survival following platinum-based adjuvant chemotherapy. The impact of C-MET on survival was also investigated in relation to EGFR mutation status.

METHODS

We enrolled 311 patients with resected lung adenocarcinoma (high-risk stage 1B-3A), and performed immunohistochemistry (IHC) using C-MET- and mutant EGFR (EGFRmut)-specific antibodies in tissue microarrays.

RESULTS

Adjuvant chemotherapy was administered to 151 patients, 96 of whom relapsed and 85 died by the end of the study. On IHC, C-MET and EGFRmut were positive in 141 (45.3 %) and 88 (28.3 %) cases, respectively. On univariate analysis, adjuvant chemotherapy prolonged relapse-free survival (RFS) and overall survival (OS) in C-MET(+) patients (RFS p = 0.035; OS p = 0.013) but not in C-MET(-) patients. On multivariate analysis, adjuvant chemotherapy was a positive independent prognostic factor in C-MET(+) (RFS p = 0.013; OS p = 0.006) but not in C-MET(-) patients. In addition, univariate analysis showed no effect of EGFRmut status on RFS and OS after chemotherapy, whereas multivariate analysis revealed that adjuvant chemotherapy increased RFS in both EGFRmut(+) and EGFRmut(-) patients [EGFRmut(+) p = 0.033; EGFRmut(-) p = 0.030]. C-MET was a negative prognostic factor for RFS (p = 0.045) and OS (p = 0.007) in the EGFRmut(-) group but not in the EGFRmut(+) group, on multivariate analysis.

CONCLUSIONS

Our data indicate that patients with C-MET overexpression should be considered for adjuvant chemotherapy, and that C-MET negatively correlates with survival in patients with wild-type, but not mutant, EGFR.

Immunotherapy for non-small cell lung cancer: current concepts and clinical trials

Recent successes in immunotherapeutic strategies are being investigated to combat cancers that have less than ideal responses to standard of care treatment, such as non-small-cell lung cancer. In this paper, we summarize concepts and the current status of immunotherapy for non-small cell lung cancer, including salient features of the major categories of immunotherapy-monoclonal antibody therapy, immune checkpoint blockade, immunotoxins, anticancer vaccines, and adoptive cell therapy.

Prognostic Impact of Multiple Clinicopathologic Risk Factors and c-MET Overexpression in Patients Who Have Undergone Resection of Stage IB Non-Small-Cell Lung Cancer

BACKGROUND

Several studies have suggested risk factors for poor survival in stage IB non-small-cell lung cancer (NSCLC) patients. However, these factors are not definite indicators of adjuvant chemotherapy for stage IB cancer, and most of them can be used to consider adjuvant chemotherapy. We aimed to determine the clinicopathologic factors and assess whether c-MET is a prognostic factor in stage IB NSCLC patients who have undergone surgery. Additionally, we determined the relevance of the factors and the recurrence pattern in these patients.

PATIENTS AND METHODS

This study included 115 patients who underwent resection of pathologic stage IB NSCLC between January 2005 and December 2013. We retrospectively reviewed the clinicopathologic data and performed immunohistochemical analysis for c-MET. Recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were evaluated according to clinicopathologic factors and c-MET expression.

RESULTS

Lymphovascular invasion (LVI) and c-MET overexpression were significantly associated with poor RFS. A large tumor with visceral pleural invasion (VPI) or LVI, moderate/poor differentiation with LVI, and VPI with LVI were negative prognostic factors for RFS and CSS. c-MET overexpression with a large tumor, VPI, or LVI was an independent prognostic factor for poor RFS and CSS, and LVI was a significant factor for distant recurrence.

CONCLUSION

LVI and c-MET overexpression might be associated with poor prognosis in stage IB NSCLC patients. Additionally, survival might be poor in stage IB patients with multiple pathologic risk factors. Moreover, there is a high possibility of distant recurrence in patients with LVI.

Novel c-Met inhibitor suppresses the growth of c-Met-addicted gastric cancer cells

BACKGROUND

c-Met signaling has been implicated in oncogenesis especially in cells with c-met gene amplification. Since 20 % of gastric cancer patients show high level of c-Met expression, c-Met has been identified as a good candidate for targeted therapy in gastric cancer. Herein, we report our newly synthesized c-Met inhibitor by showing its efficacy both in vitro and in vivo.

METHODS

Compounds with both triazolopyrazine and pyridoxazine scaffolds were synthesized and tested using HTRF c-Met kinase assay. We performed cytotoxic assay, cellular phosphorylation assay, and cell cycle assay to investigate the cellular inhibitory mechanism of our compounds. We also conducted mouse xenograft assay to see efficacy in vivo.

RESULTS

KRC-00509 and KRC-00715 were selected as excellent c-Met inhibitors through biochemical assay, and exhibited to be exclusively selective to c-Met by kinase panel assay. Cytotoxic assays using 18 gastric cancer cell lines showed our c-Met inhibitors suppressed specifically the growth of c-Met overexpressed cell lines, not that of c-Met low expressed cell lines, by inducing G1/S arrest. In c-met amplified cell lines, c-Met inhibitors reduced the downstream signals including Akt and Erk as well as c-Met activity. In vivo Hs746T xenograft assay showed KRC-00715 reduced the tumor size significantly.

CONCLUSIONS

Our in vitro and in vivo data suggest KRC-00715 is a potent and highly selective c-Met inhibitor which may have therapeutic potential in gastric tumor with c-Met overexpression.

MET Gene Amplification and MET Receptor Activation Are Not Sufficient to Predict Efficacy of Combined MET and EGFR Inhibitors in EGFR TKI-Resistant NSCLC Cells

Epidermal growth factor receptor (EGFR), member of the human epidermal growth factor receptor (HER) family, plays a critical role in regulating multiple cellular processes including proliferation, differentiation, cell migration and cell survival. Deregulation of the EGFR signaling has been found to be associated with the development of a variety of human malignancies including lung, breast, and ovarian cancers, making inhibition of EGFR the most promising molecular targeted therapy developed in the past decade against cancer. Human non small cell lung cancers (NSCLC) with activating mutations in the EGFR gene frequently experience significant tumor regression when treated with EGFR tyrosine kinase inhibitors (TKIs), although acquired resistance invariably develops. Resistance to TKI treatments has been associated to secondary mutations in the EGFR gene or to activation of additional bypass signaling pathways including the ones mediated by receptor tyrosine kinases, Fas receptor and NF-kB. In more than 30–40% of cases, however, the mechanisms underpinning drug-resistance are still unknown. The establishment of cellular and mouse models can facilitate the unveiling of mechanisms leading to drug-resistance and the development or validation of novel therapeutic strategies aimed at overcoming resistance and enhancing outcomes in NSCLC patients. Here we describe the establishment and characterization of EGFR TKI-resistant NSCLC cell lines and a pilot study on the effects of a combined MET and EGFR inhibitors treatment. The characterization of the erlotinib-resistant cell lines confirmed the association of EGFR TKI resistance with loss of EGFR gene amplification and/or AXL overexpression and/or MET gene amplification and MET receptor activation. These cellular models can be instrumental to further investigate the signaling pathways associated to EGFR TKI-resistance. Finally the drugs combination pilot study shows that MET gene amplification and MET receptor activation are not sufficient to predict a positive response of NSCLC cells to a cocktail of MET and EGFR inhibitors and highlights the importance of identifying more reliable biomarkers to predict the efficacy of treatments in NSCLC patients resistant to EGFR TKI.

Profile of ceritinib in the treatment of ALK+ metastatic non-small-cell lung cancer

Lung cancer has become one of the leading causes of death in both men and women in the United States, with approximately 230,000 new cases and 160,000 deaths each year. Approximately 80% of lung cancer patients are diagnosed with non-small-cell lung cancer (NSCLC), a subset of epithelial lung cancers that are generally insensitive to chemotherapy. An estimated 3%–7% of NSCLC patients harbor tumors containing anaplastic lymphoma kinase (ALK) gene rearrangement as an oncogenic driver. Subsequent development of the first-generation tyrosine kinase inhibitor crizotinib demonstrated substantial initial ALK+-tumor regression, yet ultimately displayed resistance in treated patients. The recently approved tyrosine kinase inhibitor ceritinib has been shown to be an effective antitumor agent against crizotinib-naïve and -resistant ALK+-NSCLC patients. In this review, we will provide an overview of biology and management of ALK+-NSCLC with a special focus on clinical development of ceritinib.