c-Met Overexpression Research Articles

Clinical relevance of c-MET overexpression in patients with residual rectal cancer after preoperative chemoradiotherapy.

e15106Background: This study was designed to explore the clinical and prognostic impact of c-MET expression in residual disease after preoperative chemoradiotherapy (CRT) in patients with rectal ca...

Dual-receptor (EGFR and c-MET) inhibition by tumor-suppressive miR-1 and miR-206 in head and neck squamous cell carcinoma.

Our studies of microRNA (miRNA) expression signatures have shown that microRNA-1 (miR-1) and microRNA-206 (miR-206) were downregulated in head and neck squamous cell carcinoma (HNSCC) clinical specimens. The seed sequences of these miRNAs are identical, suggesting that the identification of the molecular targets regulated by miR-1 and miR-206 will provide new insights into novel mechanisms of HNSCC pathogenesis. Our present data showed that restoration of miR-1 and miR-206 significantly inhibited HNSCC cells' aggressiveness. A combination of gene expression data and in silico analysis revealed that several pathways ('pathway in cancer', 'focal adhesion pathway', 'MAPK signaling pathway', 'regulation of actin cytoskeleton pathway' and 'ECM-receptor interaction pathway') were regulated by miR-1 and miR-206. Among them, we found that two growth factor receptors, epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-MET), were directly regulated by both miR-1 and miR-206 in HNSCC cells. Also, downstream oncogenic signaling of these receptors was reduced by restoration of miR-1 or miR-206 expression. Moreover, overexpression of EGFR and c-MET was observed in HNSCC clinical specimens. The identification of targets modulated by tumor-suppressive miR-1 and miR-206 may lead to a better understanding of molecular pathogenesis of HNSCC.

C-Met and ERβ expression differences in basal-like and non-basal-like triple-negative breast cancer.

Basal-like breast cancer (BLBC) and triple-negative breast cancer (TNBC) are two entities of breast cancer that share similar poor prognosis. Even though both cancers have overlaps, there are still some differences between those two types. It has been reported that the c-Met high expression was associated with poor prognosis not only in breast cancer but also in many other cancers. The role of ERβ in pathogenesis and treatment of breast cancer has remained controversial. In this study, we firstly distinguished basal-like from nonbasal-like cancer patients in TNBC patients using CK5/6 and EGFR as markers and next determined the relationship of basal-like breast cancer with c-Met or ERβ expression levels and prognosis in TNBC patients. One hundred twenty-seven patients who had been diagnosed with TNBC were enrolled. The clinical and pathological characteristics of the patients were recorded. The expression of EGFR, CK5/6, ERβ, and c-Met were evaluated with immunohistochemical methods using paraffin blocks. The median age of patients was 50.7years. CK5/6 immunopositivity was 31.5% (40/127), and EGFR was 40.2% (51/127). Of the TNBC cases, 55.1% (71/127) were positive for either CK5/6 or EGFR and were thus classified as basal-like breast cancer. C-Met (P < 0.001) and ERβ (P = 0.002) overexpression, small tumor sizes, a ductal subtype, and high-grade tumor were significantly correlated with BLBC. High c-Met expression was detected in 43.3% patients. Metastatic lymph nodes and tumor size (>5cm), which were both important prognostic predictors, were significantly associated with recurrence and mortality. BLBC typically demonstrates a unique profile. CK5/6 and EGFR expression combination indicates a higher basal-like phenotype possibility. The expression of c-Met and ERβ were significantly related to the basal-like phenotype. The classical markers, lymph node metastasis, and tumor size were found to have important prognostic value. However, high c-Met expression and basal-like phenotypes did not show a direct correlation with poor prognosis.

MiR-206 inhibits HGF-induced epithelial-mesenchymal transition and angiogenesis in non-small cell lung cancer via c-Met /PI3k/Akt/mTOR pathway.

MiR-206 is low expression in lung cancers and associated with cancer metastasis. However, the roles of miR-206 in epithelial-mesenchymal transition (EMT) and angiogenesis in lung cancer remain unknown. In this study, we find that hepatocyte growth factor (HGF) induces EMT, invasion and migration in A549 and 95D lung cancer cells, and these processes could be markedly inhibited by miR-206 overexpression. Moreover, we demonstrate that miR-206 directly targets c-Met and inhibits its downstream PI3k/Akt/mTOR signaling pathway. In contrast, miR-206 inhibitors promote the expression of c-Met and activate the PI3k/Akt/mTOR signaling, and this effect could be attenuated by the PI3K inhibitor. Moreover, c-Met overexpression assay further confirms the significant inhibitory effect of miR-206 on HGF-induced EMT, cell migration and invasion. Notably, we also find that miR-206 effectively inhibits HGF-induced tube formation and migration of human umbilical vein endothelial cells (HUVECs), and the mechanism is also related to inhibition of PI3k/Akt/mTOR signaling. Finally, we reveal the inhibitory effect of miR-206 on EMT and angiogenesis in xenograft tumor mice model. Taken together, miR-206 inhibits HGF-induced EMT and angiogenesis in lung cancer by suppressing c-Met/PI3k/Akt/mTOR signaling. Therefore, miR-206 might be a potential target for the therapeutic strategy against EMT and angiogenesis of lung cancer.

Anti-c-Met monoclonal antibody ABT-700 breaks oncogene addiction in tumors with MET amplification

Backgroundc-Met is the receptor tyrosine kinase for hepatocyte growth factor (HGF) encoded by the MET proto-oncogene. Aberrant activation of c-Met resulting from MET amplification and c-Met overexpression is associated with poor clinical outcome in multiple malignancies underscoring the importance of c-Met signaling in cancer progression. Several c-Met inhibitors have advanced to the clinic; however, the development of inhibitory c-Met-directed therapeutic antibodies has been hampered by inherent agonistic activity.MethodWe generated and tested a bivalent anti-c-Met monoclonal antibody ABT-700 in vitro for binding potency and antagonistic activity and in vivo for antitumor efficacy in human tumor xenografts. Human cancer cell lines and gastric cancer tissue microarrays were examined for MET amplification by fluorescence in situ hybridization (FISH).ResultsABT-700 exhibits a distinctive ability to block both HGF-independent constitutive c-Met signaling and HGF-dependent activation of c-Met. Cancer cells addicted to the constitutively activated c-Met signaling driven by MET amplification undergo apoptosis upon exposure to ABT-700. ABT-700 induces tumor regression and tumor growth delay in preclinical tumor models of gastric and lung cancers harboring amplified MET. ABT-700 in combination with chemotherapeutics also shows additive antitumor effect. Amplification of MET in human cancer tissues can be identified by FISH.ConclusionsThe preclinical attributes of ABT-700 in blocking c-Met signaling, inducing apoptosis and suppressing tumor growth in cancers with amplified MET provide rationale for examining its potential clinical utility for the treatment of cancers harboring MET amplification.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2138-z) contains supplementary material, which is available to authorized users.

Abstract P3-14-08: Preclinical efficacy of targeting c-MET by ARQ197 in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer cell lines

Abstract Background: Triple-negative breast cancer (TNBC), accounts for 15% of all invasive breast cancers (BCs) and has the poorest survival outcome of all BC subtypes. Due to its heterogeneity, TNBC lacks validated therapeutic targets compared with other BC subtypes (Sohn et al., 2014; Foulkes et al., 2010). Therefore, improved approaches to treatment of these cancers are unmet needed. Several molecular targets including: epidermal growth factor receptor (EGFR), poly ADP ribose polymerase (PARP), and hepatocyte growth factor receptor (c-MET) are under clinical investigation for the treatment of this disease (De et al., 2014; Cleator et al., 2007). The MET oncogene encodes a membrane-bound tyrosine kinase implicated in the formation and/or progression of several cancer types including TNBC, and several studies have shown c-Met overexpression to be an independent predictor of poor outcome in BC (Ho-Yen et al., 2014), c-MET may play a critical role in the development of the most aggressive BCs and may be a rational therapeutic target (Graveel et al., 2009). Currently inhibitors targeting c-MET (including ARQ197) are undergoing clinical trials in a variety of cancers including TNBC (Gaule et al., 2014; ClinicalTrials.gov). Recently, PARP inhibitors in combination with chemotherapy, has shown promising results in TNBC in clinical and preclinical studies (Tutt et al., 2010; De et al., 2014). We argue that, blocking the PARP-mediated nuclear machinery for repairing DNA-damage in presence of cytotoxic DNA damaging agents in conjunction with co-targeting c-Met pathway dependent downstream effectors may have a robust anti-tumor activity in TNBC cell lines. Methodology: BT-20 (PIK3CA mutated, H1047R), HCC70 (PTEN null), HCC1937 (PTEN null), MDA-MB-231 (KRAS/BRAF mutated), MDA-MB-468 (PTEN null) and SUM149PT (BRCA1 mutated) cells were used for this study. Growth inhibition, survival/proliferation, colony formation and apoptosis were examined using MTT assay, 2D proliferative /growth assay, 3D-ON-TOP assays, and annexinV staining respectively. Results: 1) For all TNBC cell lines, the IC50 of single agent ARQ197 was from 0.5 µM to 1.5 µM (following 96 hours treatment) 2) ARQ197 as a single agent or in combination with ABT888 or in triple combination dose dependently decreased cell growth/proliferation 3) annexin V positive cells were increased following treatment with single agent ARQ197 or in combination with ABT888 or in triple combination 4) 70-99% anti-proliferative activities were observed on 3D-ON TOP colony formation assay with ARQ197 alone or in combination in all tested cell lines. Conclusion: Our preclinical in vitro drug sensitivity data suggest that administration of c-MET inhibitor may enhance the antitumor activity of PARP inhibitor plus standard cytotoxic agent in TNBC models. Mechanism studies are ongoing, the results of which will be presented in the meeting. Citation Format: Sun Y, Carlson JH, Lin X, De PK, Williams C, Hausman S, Dey N, Leyland-Jones BR. Preclinical efficacy of targeting c-MET by ARQ197 in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer cell lines. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-14-08.

Co-activation of AKT and c-Met triggers rapid hepatocellular carcinoma development via the mTORC1/FASN pathway in mice.

Activation of the AKT/mTOR cascade and overexpression of c-Met have been implicated in the development of human hepatocellular carcinoma (HCC). To elucidate the functional crosstalk between the two pathways, we generated a model characterized by the combined expression of activated AKT and c-Met in the mouse liver. Co-expression of AKT and c-Met triggered rapid liver tumor development and mice required to be euthanized within 8 weeks after hydrodynamic injection. At the molecular level, liver tumors induced by AKT/c-Met display activation of AKT/mTOR and Ras/MAPK cascades as well as increased lipogenesis and glycolysis. Since a remarkable lipogenic phenotype characterizes liver lesions from AKT/c-Met mice, we determined the requirement of lipogenesis in AKT/c-Met driven hepatocarcinogenesis using conditional Fatty Acid Synthase (FASN) knockout mice. Of note, hepatocarcinogenesis induced by AKT/c-Met was fully inhibited by FASN ablation. In human HCC samples, coordinated expression of FASN, activated AKT, and c-Met proteins was detected in a subgroup of biologically aggressive tumors. Altogether, our study demonstrates that co-activation of AKT and c-Met induces HCC development that depends on the mTORC1/FASN pathway. Suppression of mTORC1 and/or FASN might be highly detrimental for the growth of human HCC subsets characterized by concomitant induction of the AKT and c-Met cascades.

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

BackgroundSeveral 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 MethodsThis 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. ResultsLymphovascular 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. ConclusionLVI 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.

Abstract B27: Involvement of c-MET signaling in BCRP/ABCG2 activation and resistance to doxorubicin and photodynamic therapy

Abstract Overexpression of BCRP/ABCG2, a xenobiotic efflux transporter, is related to anticancer drug resistance in tumors. Proto-oncogene c-MET induces cancer cell proliferation, motility, and survival, and its aberrant activation was found to be a prognostic factor in advanced ovarian cancers. In this study, we demonstrate the potential cross-resistance of doxorubicin-resistant ovarian cancer cells to the pheophorbide a (Pba)-based photodynamic therapy (PDT) and suggest c-MET and BCRP/ABCG2 overexpression as an underlying molecular mechanism. The doxorubicin resistant A2780 cell line (A2780DR) showed enhanced resistance to PDT cytotoxicity with decreased level of reactive oxygen species generation and Pba accumulation than A2780. In microarray analysis, BCRP/ABCG2 is the sole drug transporter which was upregulated in A2780DR. The incubation with the BCRP/ABCG2 specific inhibitor reversed the both Pba-PDT and doxorubicin resistance in A2780DR. Importantly, we identified that the expression of c-Met, which is an oncogene activating PI3K signaling, was increased in A2780DR and the inhibition of PI3K/AKT or c-MET repressed resistance to doxorubicin and PDT. Finally, we showed that the pharmacological and genetic inhibition of c-MET diminished levels of BCRP/ABCG2 in A2780DR. Collectively, our results provide evidence that c-MET overexpression is linked to BCRP/ABCG2 activation and this mechanism leads to crossresistance to both chemotherapy and PDT. Citation Format: Bo-hyun Choi, Kyeong-Ah Jung, Mi-Kyoung Kwak. Involvement of c-MET signaling in BCRP/ABCG2 activation and resistance to doxorubicin and photodynamic therapy. [abstract]. In: Proceedings of the Fourth AACR International Conference on Frontiers in Basic Cancer Research; 2015 Oct 23-26; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2016;76(3 Suppl):Abstract nr B27.

Tumor profiling of 431 pancreatic tumors from elderly patients.

257 Background: Pancreatic cancer (PC) is frequently a disease of the elderly and controversy exists as to whether these patients benefit from aggressive treatments. We aimed to investigate biomarker features from tumors taken from elderly PC patients to identify therapeutic implications. We also compared the results to those from younger patients to assess differences. Methods: PC tumors were tested at Caris Life Sciences between 2009 and 2015 by immunohistochemistry, fluorescent/chromogenic in-situ hybridization and sequencing. De-identified biomarker data were analyzed. Results: A total of 431 tumors from PC patients aged &gt; = 75 were analyzed: 50% were samples from pancreas, 50% were from metastatic sites. 26 of 47 genes sequenced carried mutations with frequencies ranging from 0.6% to 84%. The highest mutation rates were seen in KRAS (84%), TP53 (55%), BRCA2 (21%), SMAD4 (12%), ATM (4.4%), BRCA1 (4.2%) and PIK3CA (3.8%). Overexpression of TOPO1 and low expression of ERCC1, RRM1 and TS were seen in 45%, 73%, 86% and 79%, respectively, indicating potential benefit from irinotecan, platinums, gemcitabine and fluoropyrimidine, respectively. Tumor expression of PD-L1 was seen in 14% and tumor-infiltrating lymphocyte expression of PD-1 was seen in 45%. Overexpression of EGFR and cMET were seen in 91% and in 62%, respectively. When compared to 470 tumors from PC patients aged &lt; = 50, KRAS mutations were significantly more common in the elderly than in younger patients (84% vs. 74%, p = 0.0018), while MLH1 mutations were seen exclusively in younger patients (0% vs. 4%, p = 0.0241). Moreover, expression of TOP2A (53%vs. 45%), ERCC1 (36% vs. 27%), RRM1 (20% vs. 14%), SPARC (20% vs. 14%) and PR (5% vs. 1%) were significantly more prevalent in the younger group (all p &lt; 0.05). Conclusions: Tumor profiling of 431 tumors from elderly PC patients suggests therapeutic opportunities including cytotoxic, biological as well as targeted agents for this patient group. A comparison with younger patients indicated that irinotecan, fluoropyrimidine and taxanes may provide equal benefit to elderly and younger patients, while platinums and gemcitabine may be more likely to benefit elderly patients.

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

Backgroundc-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.MethodsCompounds 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.ResultsKRC-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.ConclusionsOur 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2058-y) contains supplementary material, which is available to authorized users.

C-Met as a Molecular Marker for Esophageal Squamous Cell Carcinoma and Its Association with Clinical Outcome.

Background: Epidermal growth factor receptor (EGFR), c-Met, and human epidermal growth factor receptor 2 (HER2) are overexpressed in a variety of human cancers, and may serve as biomarkers for disease prognosis. We examined whether high expression of these molecular markers correlates with poor disease prognosis in esophageal squamous cell cancer (ESCC). Materials and Methods: Expression of EGFR, c-Met, and HER2 protein was detected by immunohistochemistry (IHC) in 180 paraffin-embedded tissue samples from stage IIB-IIIC ESCC patients. The overall survival (OS) rates were calculated according to the Kaplan-Meier method, and the log-rank test was used to evaluate differences between survival curves. The Cox proportional hazards model was used for univariate and multivariate analyses. Results: The median survival of all patients was 46 months. There was no significant difference in OS in terms of HER2 and EGFR status (P = 0.177 and P=0.061, respectively). However, there was a significant difference in OS between c-Met high expression patients and c-Met low expression or negative patients (median: 41.9 months vs. 56.7 months; P = 0.001). Multivariate analysis also showed that, of the covariates analyzed, c-Met high expression was the only prognostic factor for OS (HR: 0.459 [95 % confidence interval: 0.287-0.733]; P = 0.001). Patients with ESCC that had concurrent overexpression of EGFR and c-Met had significantly worse survival than ESCC that displayed overexpression of either EGFR or c-Met individually or that did not have overexpression of either protein (P=0.000). Conclusions: Overexpression of HER2 and EGFR individually is not significantly associated with poor prognosis in ESCC. High expression of c-Met may be indicative of a poorer prognosis in ESCC. In order to promote efficient and rapid development of therapeutic methods in ESCC, further studies are necessary to explore the role of c-Met.

Clinicopathological Significance and Diagnostic Accuracy of c-MET Expression by Immunohistochemistry in Gastric Cancer: A Meta-Analysis

PurposeThe aim of the present study was to elucidate the clinicopathological significance and diagnostic accuracy of immunohistochemistry (IHC) for determining the mesenchymal epidermal transition (c-MET) expression in patients with gastric cancer (GC).Materials and MethodsThe present meta-analysis investigated the correlation between c-MET expression as determined by IHC and the clinicopathological parameters in 8,395 GC patients from 37 studies that satisfied the eligibility criteria. In addition, a concordance analysis was performed between c-MET expression as determined by IHC and c-MET amplification, and the diagnostic test accuracy was reviewed.ResultsThe estimated rate of c-MET overexpression was 0.403 (95% confidence interval [CI], 0.327~0.484) and it was significantly correlated with male patients, poor differentiation, lymph node metastasis, higher TNM stage, and human epidermal growth factor receptor 2 (HER2) positivity in IHC analysis. There was a significant correlation between c-MET expression and worse overall survival rate (hazard ratio, 1.588; 95% CI, 1.266~1.992). The concordance rates between c-MET expression and c-MET amplification were 0.967 (95% CI, 0.916~0.987) and 0.270 (95% CI, 0.173~0.395) for cases with non-overexpressed and overexpressed c-MET, respectively. In the diagnostic test accuracy review, the pooled sensitivity and specificity were 0.56 (95% CI, 0.50~0.63) and 0.79 (95% CI, 0.77~0.81), respectively.ConclusionsThe c-MET overexpression as determined by IHC was significantly correlated with aggressive tumor behavior and positive IHC status for HER2 in patients with GC. In addition, the c-MET expression status could be useful in the screening of c-MET amplification in patients with GC.

471P Prognostic impact of lymphovascular invasion and C-MET overexpression in resected stage IB NSCLC

471P Prognostic impact of lymphovascular invasion and C-MET overexpression in resected stage IB NSCLC

Histomolecular profiling of pleomorphic, spindle cell, and giant cell carcinoma of the lung for targeted therapies

In pleomorphic, spindle cell, and giant cell carcinoma (PSCGC) of the lung, we wondered if an integrated diagnosis including morphological and immunohistochemical features could be related to molecular status. We performed immunohistochemistry on 35 PSCGCs against TTF1, napsin A, p40, ALK, ROS1, and c-MET. Mutational status regarding EGFR, KRAS, BRAF, HER2, and PIK3CA genes was established. Of 18 PSCGCs with adenocarcinomatous or "undifferentiated" carcinoma differentiation, 8 were mutated for EGFR (n = 1), KRAS (n = 2), BRAF (n = 1), HER2 (n = 3), and PIK3CA (n = 1). No PSCGC (0/4) with only squamous cell or adenosquamous (0/2) differentiation was mutated. c-MET overexpression was only seen in PSCGC with adenocarcinomatous or undifferentiated component (n = 5) without squamous cell component. ROS1 and ALK were negative. The presence of a "targetable mutation" was correlated to the presence of morphological or immunohistochemical adenocarcinomatous differentiation (P = .0137). Integrated diagnosis of an adenocarcinomatous component in PSCGC could be associated with the presence of targetable gene mutation. Because only PSCGC with adenocarcinomatous or undifferentiated carcinoma harbors mutations, whereas PSCGC with only squamous or adenosquamous differentiation does not in our study, this might represent a prescreening for patients with PSCGC to be tested for molecular targets. Our results emphasize that careful morphological examination and the use of immunohistochemistry might be useful for the selection of PSCGC tested for a mutational target.

Clinical impact of c-MET expression and mutational status in patients with colorectal cancer lung metastases.

The c-MET tyrosine kinase is known to play a key role in tumour promotion in a variety of cancers. The prognostic significance of c-MET pathway alterations has previously been described in primary colorectal cancer (CRC). However, data on the expression and genetic mutational status of c-MET in CRC pulmonary metastases (PM) are lacking. We aimed to assess the clinical implications of alterations in the c-MET pathway in patients undergoing pulmonary metastasectomy. From April 2009 to November 2013, all patients with complete CRC lung metastasectomy were included in this study and prospectively followed up. Tissue samples of 51 PM and 33 paired primary CRCs were stained immunohistochemically for c-MET and phosphorylated signal transducer and activator of transcription 3 (pSTAT3). Genetic alterations of MET were detected using an exome panel on a next generation sequencing (NGS) platform. Serum hepatocyte growth factor (HGF) levels were measured in a patient subset (n = 10) before and after metastasectomy. c-MET expression was significantly higher at the invasive front of metastases compared with central tumour areas (P = 0.020) and was associated with nuclear pSTAT3 expression (P = 0.042). pSTAT3 but not c-MET overexpression in PM was associated with time to tumour recurrence after metastasectomy (P = 0.036). Expression levels of neither c-MET nor pSTAT3 had an impact on time to lung-specific recurrence. However, patients with c-MET or pSTAT3 overexpression in PM had a significantly worse overall survival after metastasectomy (P = 0.023 and 0.008, respectively). Mutations in the MET gene were identified in 20 patients of our cohort by NGS, which failed to be of prognostic relevance. Serum HGF did not significantly differ between patients with PM and healthy controls. To the best of our knowledge, this is the first structured evaluation of the c-MET axis in the context of pulmonary metastasectomy for CRC. Our results suggest that overexpression of c-MET/pSTAT3 is associated with an impaired prognosis following complete resection. Moreover, this work suggests that the value of c-MET tyrosine kinase inhibitors in the treatment of patients with CRC lung metastases should be assessed in clinical trials.

Abstract 3309: Co-inhibition of ALK and EGFR and/or c-MET on cell growth and response to radiation in ALK-positive NSCLC cells

Abstract ALK (anaplastic lymphoma kinase), EGFR (epidermal growth factor receptor) and c-MET are molecular drivers for a subset of non-small cell lung cancers (NSCLC). Approximately 4-7% of NSCLCs carry the EML4-ALK chromosomal rearrangement. We identified overexpression of EGFR and c-MET in EML4-ALK-positive NSCLC cell lines H3122 and H2228. ALK, EGFR, and c-MET may function cooperatively to modulate tumor growth, stress response, and survival in EML4-ALK-positive cells and co-inhibition may favorably impact tumor control. We therefore investigated the effects of co-inhibition of ALK and EGFR or c-MET on cell survival and response to radiation in EML4-ALK-positive NSCLC cells. Compared with ALK-negative cell lines (H226, A549 and H520), the ALK-positive cell lines (H3122, H2228) were highly sensitive to the ALK inhibitors crizotinb, ceritinib and alectinib, although with differing sensitivity to radiation. Crizotinib, ceritinib and alectinib sensitized H3122 and H2228 to radiation, as evaluated by clonogenic assay. However, knockdown of ALK by siRNA in H3122 and H2228, or overexpression of EML4-ALK in NIH-3T3 cells, had only moderate effects on radiosensitivity. Simultaneous knockdown of ALK and MET, or ALK and EGFR, increased radiosensitivity as assessed by clonogenic survival in H3122 and H2228 cells, while also increasing inhibitory effects on cell growth and proliferation. These results were confirmed in cells treated with the combination of ceritinib and su11274 (c-MET inhibitor) or with ceritinib and erlotinib (EGFR inhibitor). We further assessed the impact of drug alone or in combination with radiation on cell cycle, cell survival and DNA damage repair pathways. To further evaluate ALK function in the cellular response to radiation in NSCLC, we are developing EML4-ALK stable expression cell lines. Evaluation of drug-radiation interactions in xenograft model systems are also under consideration. These data indicate that co-inhibition of ALK and EGFR or c-MET can enhance growth inhibitory effects in ALK-positive cells and augment radiosensitivity in-vitro, suggesting the potential value for ALK inhibitors combined with EGFR/c-MET-targeting for therapeutic benefit in ALK-positive NSCLC patients with or without radiation. Citation Format: Chunrong Li, Shyhmin Huang, Fang Ma, Eric A. Armstrong, David Francis, Lauryn Werner, Paul M. Harari. Co-inhibition of ALK and EGFR and/or c-MET on cell growth and response to radiation in ALK-positive NSCLC cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3309. doi:10.1158/1538-7445.AM2015-3309

Abstract 794: Prognostic value of high c-Met expression in patients with poor prognosis pancreatic adenocarcinoma following surgical resection: comparison of three c-Met scoring methods and exploration of underlying mechanisms of c-Met overexpression

Abstract Context: The HGF/c-Met pathway is an hypoxia-inducible pathway involved in tumor-stroma interactions and invasion in pancreatic ductal adenocarcinoma (PDAC). Assessment of c-Met expression is a critical issue as c-Met inhibitors are under clinical development and are suggested to display antitumor activity only in high c-Met tumors. We aimed to assess the prognostic value of c-Met overexpression in PDAC and explore underlying mechanisms (hypoxia, gene amplification, post transcriptional deregulation). Patients and methods: Patients (Pts) with resected PDAC who had received no perioperative chemo/radiotherapy were retrospectively selected. c-Met immunostaining was graded using a simplified score (high c-Met: ≥20% of cancer cells with 3+ staining) and compared to a standard scale combining staining surface and intensity (SI score) and to the MetMab score. Concordance between entire section and tissue microarray (TMA) was assessed and a computer-assisted quantification algorithm was developed (Aperio® software). Hypoxia was assessed by visual grading of HIF-1α/CA9 immunostaining, necrosis, and automated microvascular density (Aperio®). c-Met gene copy number was assessed by fluorescent in situ hybridization (FISH) and Taqman® based copy number variation (CNV) assay. c-Met mRNA levels were quantified using reverse transcription PCR (RT-PCR). c-Met pathway activation was assessed by immunostaining of phospho-c-Met, phospho-GAB1 and downstream signaling (pAKT, pERK, and pSTAT3) and graded visually. Clinical, pathological, and molecular biomarkers were correlated with disease-free (DFS) and overall (OS) survivals. Results: Thirty-seven Pts were analyzed. The simplified c-Met score displayed the best prognostic value and reproducibility vs both the SI score and the MetMab score; using this score: (a) high c-Met (7/37) was associated with shorter DFS (6.3 vs 33.0 months, HR: 3.456, p = 0.0035) and OS (10.8 vs 39.0 months, HR: 4.257, p = 0.0006); and (b) the kappa index was 0.773±0.122. In multivariate analysis, high c-Met was independently associated with both DFS and OS. c-Met expression was concordant on entire section and TMA in 87.9% of cases, and quantifiable using a specific computer-assisted algorithm. There was no correlation between hypoxia-related markers and c-Met expression. FISH and CNV analysis did not show c-Met gene amplification. mRNA quantification and downstream pathway activation data will be presented. Conclusion: c-Met is an independent prognostic marker in resected PDAC that may help identifying Pts at high risk of recurrence and poor survival. High c-Met expression was not associated with hypoxia or gene amplification in this study. The simplified c-Met scale is a robust and reproducible scoring method that could be used for ongoing larger studies on TMA. Citation Format: Cindy Neuzillet, Annemilaï Tijeras-Raballand, Jérôme Raffenne, Armand de Gramont, Pierre Bedossa, Valérie Paradis, Alain Sauvanet, Jean-Baptiste Bachet, Eric Raymond, Pascal Hammel, Anne Couvelard, Jérôme Cros. Prognostic value of high c-Met expression in patients with poor prognosis pancreatic adenocarcinoma following surgical resection: comparison of three c-Met scoring methods and exploration of underlying mechanisms of c-Met overexpression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 794. doi:10.1158/1538-7445.AM2015-794

WITHDRAWN: Clinicopathological impacts of c-Met overexpression in epithelial ovarian cancer: a meta-analysis and systemic review

// Jung Han Kim 1 , Hyun Joo Jang 2 , Bum Jun Kim 1,3 and Sung Ho Park 4 1 Division of Hemato-Oncology, Department of Internal Medicine, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul, Republic of Korea 2 Department of Internal Medicine, Dongtan Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Gyeonggi-Do, Republic of Korea 3 Department of Internal Medicine, National Army Capital Hospital, The Armed Forces Medical Command, Gyeonggi-Do, Republic of Korea 4 Department of Obstetrics and Gynecology, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul, Korea Correspondence to: Jung Han Kim, email: harricil@hotmail.com Sung Ho Park, email: vth2000@hallym.or.kr Keywords : c-Met; ovarian cancer; prognosis; meta-analysis; review Received: September 30, 2017&nbsp;&nbsp;&nbsp;&nbsp; Accepted: November 13, 2017&nbsp;&nbsp;&nbsp;&nbsp; Epub: January 03, 2018 Abstract c-Met overexpression has been observed in epithelial ovarian cancer (EOC). However, its clinicopathological impacts remain controversial. We conducted this meta-analysis to evaluate the pathologic and prognostic roles of c-Met overexpression in patients with EOC. A systematic computerized search of the electronic databases PubMed, Embase, and Google scholar (August, 2017) was carried out. From six studies, 508 patients with EOC were included in the meta-analysis. Although there was no statistical significance, EOCs with c- Met overexpression tended to show higher FIGO stage (III-IV) (odds ratio = 2.18, 95% confidence interval: 0.86-5.53, P = 0.10) and higher rate of lymph node metastasis (odds ratio = 3.05, 95% confidence interval: 0.85-10.98, P = 0.09), compared with tumors with low c- Met expression. In terms of prognosis, patients with c-Met-high EOC showed significantly worse overall survival than those with c-Met-low tumor (hazard ratio = 2.23, 95% confidence interval: 1.56-3.19, P &lt; 0.0001). In conclusion, this meta-analysis indicates that c-Met ocerexpression represents a potential adverse prognostic marker for patients with EOC.

MicroRNA-206: Effective Inhibition of Gastric Cancer Progression through the c-Met Pathway.

MicroRNAs are endogenous short chain nucleotide RNAs that regulate gene function by direct binding of target mRNAs. In this study, we investigated the effects of microRNA-206 (miR-206) on the development of gastric cancer. miR-206 was first confirmed to be downregulated in gastric cancer specimens. Conversely, upregulation of c-Met was confirmed in tissue samples of human gastric cancer, with its level inversely correlated with miR-206 expression. Introduction of miR-206 inhibited cellular proliferation by inducing G1 cell cycle arrest, as well as migration and invasion. Moreover, important proliferation and/or migration related molecules such as c-Met, CDK4, p-Rb, p-Akt and p-ERK were confirmed to be downregulated by Western blot analysis. Targeting of c-Met also directly affected AGS cell proliferation, migration and invasion. In vivo, miR-206 expressing tumor cells also displayed growth delay in comparison to unaffected tumor cells. Our results demonstrated that miR-206 suppressed c-Met expression in gastric cancer and could function as a potent tumor suppressor in c-Met overexpressing tumors. Inhibition of miR-206 function could contribute to aberrant cell proliferation and migration, leading to gastric cancer development.