c-Met Expression Research Articles

Chidamide increases the sensitivity of Non-small Cell Lung Cancer to Crizotinib by decreasing c-MET mRNA methylation.

Introduction: Crizotinib is a kinase inhibitor targeting c-MET/ALK/ROS1 used as the first-line chemical for the treatment of non-small cell lung cancer (NSCLC) with ALK mutations. Although c-MET is frequently overexpressed in 35-72% of NSCLC, most NSCLCs are primarily resistant to crizotinib treatment.Method: A set of NSCLC cell lines were used to test the effect of chidamide on the primary crizotinib resistance in vitro and in vivo. Relationships between the synergistic effect of chidamide and c-MET expression and RNA methylation were systemically studied with a battery of molecular biological assays.Results: We found for the first time that chidamide could sensitize the effect of crizotinib in a set of ALK mutation-free NSCLC cell lines, especially those with high levels of c-MET expression. Notably, chidamide could not increase the sensitivity of NSCLC cells to crizotinib cultured in serum-free medium without hepatocyte growth factor (HGF; a c-MET ligand). In contrast, the addition of HGF into the serum-/HGF-free medium could restore the synergistic effect of chidamide. Moreover, the synergistic effect of chidamide could also be abolished either by treatment with c-MET antibody or siRNA-knockdown of c-MET expression. While cells with low or no c-MET expression were primarily resistant to chidamide-crizotinib cotreatment, enforced c-MET overexpression could increase the sensitivity of these cells to chidamide-crizotinib cotreatment. Furthermore, chidamide could decrease c-MET expression by inhibiting mRNA N6-methyladenosine (m6A) modification through the downregulation of METTL3 and WTAP expression. Chidamide-crizotinib cotreatment significantly suppressed the activity of c-MET downstream molecules.Conclusion: Chidamide downregulated c-MET expression by decreasing its mRNA m6A methylation, subsequently increasing the crizotinib sensitivity of NSCLC cells in a c-MET-/HGF-dependent manner.

Curcumol inhibits the proliferation and metastasis of melanoma via the miR-152-3p/PI3K/AKT and ERK/NF-κB signaling pathways.

Melanoma is the most aggressive and treatment-resistant form of skin cancer. Curcumol is a Chinese medicinal herb traditionally used as a cancer remedy. However, the molecular mechanisms underlying the anticancer activity of curcumol in melanoma remains largely unknown. In the present study, we observed that Curcumol decreased mouse melanoma B16 cell proliferation and migration. The xenograft tumor assay showed that curcumol reduced melanoma volume and lung metastasis. Curcumol upregulated the expression of E-cadherin and downregulated the expression of N-cadherin, MMP2 and MMP9 in mouse melanoma B16 cell. Western blot analysis revealed that curcumol reduced the translocation of p65 to the nucleus and decreased p-ERK. Furthermore, curcumol attenuated c-MET, P13K and p-AKT protein expression and upregulated miR-152-3p gene expression. The dual-luciferase reporter assay indicated that c-MET was a target gene of miR-152-3p. Reduced expression of miR-152-3p partially attenuated the effect of curcumol on mouse melanoma B16 cell proliferation and migration. The decrease in c-MET, P13K and p-AKT protein expression following curcumol treatment in mouse melanoma B16 cells was notably attenuated by the miR-152-3p inhibitor. Taken together, our findings suggested that curcumol attenuated melanoma progression and concomitantly suppressed ERK/NF-κB signaling and promoted miR-152-3p expression to inactivate the c-MET/PI3K/AKT signaling pathway.

The prognostic value of HGF-c-MET signaling pathway in Gastric Cancer: a study based on TCGA and GEO databases

Gastric cancer is a heterogeneous tumor that underlying molecular mechanisms are largely unclear. This study aimed to elucidate the expression level of HGF-c-MET in gastric cancer patients and to investigate the prognostic and diagnostic value of HGF-c-MET. In silico analysis of the TCGA and GEO database found that HGF and c-MET mRNA expression are significantly higher in gastric cancer tissues than those in peritumor tissues. Both higher mRNA expression of HGF and c-MET were associated with a poorer prognosis. c-MET expression was modulated by methylation in the promoter regions. HGF was positively correlated with CD8+ T cell, CD4+ T cell, macrophage, neutrophil and dendritic cell. Furthermore, functional enrichment analysis and protein-protein interaction networks further shown that HGF-c-MET and related proteins mainly participated in growth factor receptor binding, protein tyrosine kinase activity and signaling receptor binding. Finally, outcome of GSEA analysis showed 13 shared KEGG pathways enriched in high expressed group of HGF and c-MET.

Thiosemicarbazones suppress expression of the c-Met oncogene by mechanisms involving lysosomal degradation and intracellular shedding

Considering the role of proto-oncogene c-Met (c-Met) in oncogenesis, we examined the effects of the metastasis suppressor, N-myc downstream-regulated gene-1 (NDRG1), and two NDRG1-inducing thiosemicarbazone-based agents, Dp44mT and DpC, on c-Met expression in DU145 and Huh7 cells. NDRG1 silencing without Dp44mT and DpC up-regulated c-Met expression, demonstrating that NDRG1 modulates c-Met levels. Dp44mT and DpC up-regulated NDRG1 by an iron-dependent mechanism and decreased c-Met levels, c-Met phosphorylation, and phosphorylation of its downstream effector, GRB2-associated binding protein 1 (GAB1). However, incubation with Dp44mT and DpC after NDRG1 silencing or silencing of the receptor tyrosine kinase inhibitor, mitogen-inducible gene 6 (MIG6), decreased c-Met and its phosphorylation, suggesting NDRG1- and MIG6-independent mechanism(s). Lysosomal inhibitors rescued the Dp44mT- and DpC-mediated c-Met down-regulation in DU145 cells. Confocal microscopy revealed that lysosomotropic agents and the thiosemicarbazones significantly increased co-localization between c-Met and lysosomal-associated membrane protein 2 (LAMP2). Moreover, generation of c-Met C-terminal fragment (CTF) and its intracellular domain (ICD) suggested metalloprotease-mediated cleavage. In fact, Dp44mT increased c-Met CTF while decreasing the ICD. Dp44mT and a γ-secretase inhibitor increased cellular c-Met CTF levels, suggesting that Dp44mT induces c-Met CTF levels by increasing metalloprotease activity. The broad metalloprotease inhibitors, EDTA and batimastat, partially prevented Dp44mT-mediated down-regulation of c-Met. In contrast, the ADAM inhibitor, TIMP metallopeptidase inhibitor 3 (TIMP-3), had no such effect, suggesting c-Met cleavage by another metalloprotease. Notably, Dp44mT did not induce extracellular c-Met shedding that could decrease c-Met levels. In summary, the thiosemicarbazones Dp44mT and DpC effectively inhibit oncogenic c-Met through lysosomal degradation and metalloprotease-mediated cleavage.

High Expression of c-Met, PKCλ and ALDH1A3 Predicts a Poor Prognosis in Late-stage Breast Cancer.

Co-expression of c-Met and ALDH1A3 indicates a poor prognosis in stage III-IV breast cancers and contributes to cell proliferation and tumor formation by ALDH1-positive breast CSCs. PKCλ is overexpressed and contributes to a poor prognosis in several cancers. A breast cancer genomics data set (METABRIC, n=2509) was downloaded and analyzed, as was the effect c-Met and PKCλ inhibitors on ALDH1high cell viability and tumor-sphere formation. c-Met expression correlates with expression of PKCλ in breast cancer. Stage III-IV breast cancer patients with c-Methigh PKCλhigh ALDH1A3high have a poorer prognosis than patients with c-Metlow PKCλlow ALDH1A3low Foretinib and auranofin suppressed cell viability and tumor-sphere formation by ALDH1high cells. These results suggest that c-Met and PKCλ are cooperatively involved in cancer progression and contribute to poor prognoses in breast cancer. c-Met and PKCλ are potentially useful prognostic markers and therapeutic targets in late-stage breast cancer.

Role of Metastasis-Related Genes in Cisplatin Chemoresistance in Gastric Cancer.

The role of metastasis-related genes in cisplatin (CDDP) chemoresistance in gastric cancer is poorly understood. Here, we examined the expression of four metastasis-related genes (namely, c-met, HMGB1, RegIV, PCDHB9) in 39 cases of gastric cancer treated with neoadjuvant therapy with CDDP or CDDP+5-fluorouracil and evaluated its association with CDDP responsiveness. Comparison of CDDP-sensitive cases with CDDP-resistant cases, the expression of c-met, HMGB1, and PCDHB9 was correlated with CDDP resistance. Among them, the expression of HMGB1 showed the most significant correlation with CDDP resistance in multivariate analysis. Treatment of TMK-1 and MKN74 human gastric cancer cell lines with ethyl pyruvate (EP) or tanshinone IIA (TAN), which are reported to inhibit HMGB1 signaling, showed a 4–5-fold increase in inhibition by CDDP. Treatment with EP or TAN also suppressed the expression of TLR4 and MyD88 in the HMGB1 signal transduction pathway and suppressed the activity of NFκB in both cell lines. These results suggest that the expression of these cancer metastasis-related genes is also related to anticancer drug resistance and that suppression of HMGB1 may be particularly useful for CDDP sensitization.

Activation of extracellular signal-regulated kinase is associated with hepatocellular carcinoma with aggressive phenotypes.

Sorafenib inhibits multiple kinase signaling pathways, including the rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, and is a promising therapy for hepatocellular carcinoma (HCC). However, the role of ERK activation in HCC remains unclear. This study was designed to investigate the potential link between ERK activation and aggressive HCC phenotypes. We evaluated nuclear ERK expression by immunohistochemistry in 154 resected HCC nodules from 136 patients. We then investigated the associations of ERK expression with the clinicopathological characteristics of HCC, c-MET expression, and the molecular subclass biomarkers Ki-67, keratin19 (KRT19, CK19, or K19), and sal-like protein4. Multivariate Cox regression analysis was carried out to determine independent prognostic factors for overall survival and recurrence-free survival. The effects of ERK activation by hepatocyte growth factor (HGF) on eight HCC cell lines were further examined. High-level nuclear expression of ERK was observed in 20 (13%) of 154 nodules and was significantly associated with higher serum alpha-fetoprotein levels (P = 0.034), poorer differentiation (P = 0.003), a higher Ki-67 index (P < 0.001), high-level expression of c-MET (P = 0.008), KRT19 (P = 0.002), or sal-like protein4 (P < 0.001), and shorter overall survival (multivariate hazard ratio 3.448; P = 0.028) and recurrence-free survival (multivariate hazard ratio 2.755; P = 0.004). HCC cells treated with hepatocyte growth factor showed enhanced cell proliferation together with ERK activation and upregulated KRT19 expression, both of which were inhibited by sorafenib. High-level ERK activation is associated with a KRT19-positive highly proliferative subtype of HCC with a dismal prognosis. These findings support the key role of the hepatocyte growth factor/c-MET/ERK axis in HCC progression.

Expression of c-Met in Primary and Recurrent Hepatocellular Carcinoma

Background:The clinical course of hepatocellular carcinoma (HCC) is complicated, because it often recurs and shows multiple lesions, some of which progress to a more malignant form, shortening the life of the patient. The hepatocyte growth factor receptor c-Met has been shown to play an important role in the pathogenesis of HCC, but the influence of c-Met expression on the clinical course of HCC remains to be fully elucidated. Methods:We randomly selected and included 600 tumor specimens obtained from the primary and recurrent lesions of 319 HCC cases between 1995 and 2007. The expression of c-Met was determined by immunohistochemistry using archived formalin-fixed paraffin-embedded samples. We analyzed the correlation between c-Met expression and clinical parameters, including survival. In addition, we examined c-Met expression in the malignant transition of HCC in all cases including recurrent lesions. Results:Survival analysis using the multivariate Cox proportional-regression model revealed that the prognosis was significantly better in the primary cases with high c-Met expression than in those with low c-Met expression (hazard ratio 0.159, 95% confidence interval 0.065–0.391; p < 0.001). During the course of recurrence, some cases with high c-Met expression returned to low c-Met expression. Among 40 cases with high c-Met expression, 29 survived more than 2 years after detecting the high c-Met expression. Conclusion:High expression of c-Met may be a prognostic factor for a good, rather than a poor, HCC prognosis. The involvement of c-Met expression in the malignant transition of recurrent HCC is obscure.

Thymoquinone promotes mouse mesenchymal stem cells migration in vitro and induces their immunogenicity in vivo

Mesenchymal stem cells (MSCs) have unique potentials, including migration and immunomodulation. Identification of the factors that enhance these activities can improve clinical applications of MSCs. This study aimed to investigate total antioxidant capacity (TAC) and migration potential of mouse MSCs exposed to thymoquinone (TQ) in vitro, and to examine the effect of TQ-treated MSCs on the expression of mouse immune cell markers. The results of total antioxidant capacity and wound healing assays showed that TQ increased the rate of MSCs TAC and migration in a dose- and time-dependent manner. The maximum TAC and migration were detected at 600 and 250 ng/ml of TQ, respectively. Functionally, the real-time PCR data analysis indicated that TQ induced c-Met and Cxcr4 expression and therefore, there may be a correlation between upregulation of these genes and increased MSCs migration. TQ also enhanced the up and down regulating impact of MSCs on Rorγt and Plzf expression and the expression of Tcf4 in mouse immune cells, respectively. Overall, this study declares that TQ increases the TAC of MSCs. It also proposes that TQ may, through activation of c-MET and CXCR4 signalling pathways, promote MSCs migration. TQ may also augment MSCs immunogenicity through its influence on the expression of genes involved in commitment of mouse immune system cells in vivo.

The Role of c-Met as a Biomarker and Player in Innate and Acquired Resistance in Non-Small-Cell Lung Cancer: Two New Mutations Warrant Further Studies

The c-Met receptor is a therapeutically actionable target in non-small-cell lung cancer (NSCLC), with one approved drug and several agents in development. Most suitable biomarkers for patient selection include c-Met amplification and exon-14 skipping. Our retrospective study focused on the frequency of different c-Met aberrations (overexpression, amplification and mutations) in 153 primary, therapy-naïve resection samples and their paired metastases, from Biobank@UZA. Furthermore, we determined the correlation of c-Met expression with clinicopathological factors, Epidermal Growth Factor Receptor (EGFR)-status and TP53 mutations. Our results showed that c-Met expression levels in primary tumors were comparable to their respective metastases. Five different mutations were detected by deep sequencing: three (E168D, S203T, N375S) previously described and two never reported (I333T, G783E). I333T, a new mutation in the Sema(phorin) domain of c-Met, might influence the binding of antibodies targeting the HGF-binding domain, potentially causing innate resistance. E168D and S203T mutations showed a trend towards a correlation with high c-Met expression (p = 0.058). We found a significant correlation between c-MET expression, EGFR expression (p = 0.010) and EGFR mutations (p = 0.013), as well as a trend (p = 0.057) with regards to TP53 mutant activity. In conclusion this study demonstrated a strong correlation between EGFR mutations, TP53 and c-Met expression in therapy-naïve primary resection samples. Moreover, we found two new c-Met mutations that warrant further studies.

TR1801-ADC: a highly potent cMet antibody-drug conjugate with high activity in patient-derived xenograft models of solid tumors.

cMet is a well‐characterized oncogene that is the target of many drugs including small molecule and biologic pathway inhibitors, and, more recently, antibody–drug conjugates (ADCs). However, the clinical benefit from cMet‐targeted therapy has been limited. We developed a novel cMet‐targeted ‘third‐generation’ ADC, TR1801‐ADC, that was optimized at different levels including specificity, stability, toxin–linker, conjugation site, and in vivo efficacy. Our nonagonistic cMet antibody was site‐specifically conjugated to the pyrrolobenzodiazepine (PBD) toxin–linker tesirine and has picomolar activity in cancer cell lines derived from different solid tumors including lung, colorectal, and gastric cancers. The potency of our cMet ADC is independent of MET gene copy number, and its antitumor activity was high not only in high cMet‐expressing cell lines but also in medium‐to‐low cMet cell lines (40 000–90 000 cMet/cell) in which a cMet ADC with tubulin inhibitor payload was considerably less potent. In vivo xenografts with low–medium cMet expression were also very responsive to TR1801‐ADC at a single dose, while a cMet ADC using a tubulin inhibitor showed a substantially reduced efficacy. Furthermore, TR1801‐ADC had excellent efficacy with significant antitumor activity in 90% of tested patient‐derived xenograft models of gastric, colorectal, and head and neck cancers: 7 of 10 gastric models, 4 of 10 colorectal cancer models, and 3 of 10 head and neck cancer models showed complete tumor regression after a single‐dose administration. Altogether, TR1801‐ADC is a new generation cMet ADC with best‐in‐class preclinical efficacy and good tolerability in rats.

Abstract B034: IFIT1 and IFIT3 function as Hsp90 co-chaperones to modulate the drug response in human oral squamous cell carcinoma

Abstract Oral squamous cell carcinoma (OSCC) is one of the most common malignant cancers with poor clinical outcome in the patients treated with chemotherapeutics. To improve the potential treatment approaches for OSCC patients, it is an urgent need to understand the molecular signaling mechanism involved in OSCC drug resistance. The failure of chemotherapy or targeted therapy is due to the development of drug resistance to anti-cancer drugs by various intrinsic cellular mechanisms. In the tumor microenvironment, cancer cells are exposed to many cellular components such as growth factors, extracellular matrix, and cytokines, etc. Interferons are pleiotropic cytokines promote cancer cells to acquire malignant phenotype and drug resistance through transcriptional induction of interferon-stimulated genes (ISGs). The human interferon-induced protein with tetratricopeptide repeats (IFIT) genes: IFIT1, IFIT2, IFIT3, and IFIT5 are well-known ISGs with multiple tetratricopeptide motifs that mediate protein-protein interactions. We have previously shown that high IFIT1 or IFIT3 expression promoted OSCC invasion and metastasis by EGFR signaling via enhancing EGFR endocytic recycling. However, the clinical significance of IFIT1 and IFIT3 in OSCC drug resistance remains unexplored. In the present study, we found that overexpression of IFIT1 or IFIT3 proteins in OSCC cells notably increased the resistance to DNA damaging agents including cisplatin, carboplatin, and oxaliplatin. In addition, xenograft tumors derived from IFIT1 or IFIT3-overexpressed cells showed resistance to cisplatin compared to controls. Intriguingly, our protein-protein interaction studies have revealed that IFIT1 and IFIT3 interacted with molecular chaperone Hsp90. Furthermore, ectopic expression of IFIT1 or IFIT3 induced C-terminal phosphorylation of Hsp90-α and subsequently activated of its client proteins, such as EGFR, AKT, p38, and SAPK/JNK in OSCC cells. Also, IFIT1 or IFIT3-overexpressed cells showed resistance to Hsp90 inhibitors such as geldanamycin and ganetespib. Suppression of Hsp90 activation by ganetespib resulted in decreased activation of downstream client proteins in IFIT1- or IFIT3-overexpressing cells. Moreover, IFIT1- or IFIT3-overexpressing cells showed enhanced expression of cancer stem cell marker c-Met compared to vector control cells. These results suggested a novel role of IFIT1 and IFIT3 in activating Hsp90 and several downstream signaling regulators which are critical for drug resistance in OSCC cells. Collectively, our results indicate that IFIT1 and IFIT3 possibly act as co-chaperones and serve as potentially important therapeutic targets for OSCC treatment in the future. Citation Format: Vijaya Pidugu, Hima Pidugu, Yu-Hsiang Teng, Te-Chang Lee. IFIT1 and IFIT3 function as Hsp90 co-chaperones to modulate the drug response in human oral squamous cell carcinoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B034. doi:10.1158/1535-7163.TARG-19-B034

Abstract A039: Lower cellular activation of cMET signaling network is associated with reduced recurrence risk in stage II colorectal cancer

Abstract Colorectal cancer (CRC) has one of the highest worldwide incidences and mortality rates. About 25% of stage II patients develop recurrence within 5 years. However, use of adjuvant chemotherapy yields minimal therapeutic benefit. Clinical decision-making in this population would be informed by prognostic and predictive biomarkers that help indicate more targeted interventions and/or intensified disease monitoring. Higher cMET expression has been shown to be a prognostic marker in CRC and has been evaluated as a drug target in several cancers, including CRC. cMET acts as the receptor for hepatocyte growth factor (HGF), and is associated with increased proliferation, migration and morphogenesis of epithelial cells via activation of multiple downstream pathways including PI3K/AKT, MAPK and the NF-kB pathways. Here, we investigated whether increased cellular expression of multiple markers in the cMET/adjacent pathways was correlated with clinical outcome. The study population consisted of 283 patients with stage II CRC, without neoadjuvant treatment. Using a multiplexed immunofluorescence method (MxIF) with cell-level quantification (Cell DIVETM, GE Healthcare), 41 biomarkers in the cMET, mTOR, MAPK and associated pathways, and lymphocyte markers were analyzed in an iterative sequence of staining, imaging and dye inactivation, followed by image registration, cell segmentation and biomarker intensity-quantitation. Poor quality images and cells were filtered based on poor segmentation and tissue quality following manual review. Images that did not perfectly register were also excluded. For epithelial cell analysis, all stromal cells were filtered, resulting in a total of 559,952 epithelial cells. K-means clustering was conducted on cMET and related pathways (cMET, pGSK3β, 4EBP1, p4EBP1, S6, pS6, pStat3, pp38MAPK, pNFkBp65, pNFkBp105, EGFR, pERK1/2, HER2, IGF1R, CA-IX, Glut1, SLC7A5 and Ki67). Cluster analysis identified 6 cell clusters with varying expression levels of cMET and other pathway markers. A cluster corresponding to low cMET network activation (cMETLow) was correlated with reduced risk of recurrence (cox pH model Likelihood ratio test p-value = 0.056). Furthermore, MMR proficient patients (who had a higher recurrence rate) had a significantly greater proportion of cells with elevated cMET and related pathway marker (cMETHigh) s(p= 0.007). They also had a significantly lower fraction of infiltrating helper T cells (CD3+CD4+, pvalue 0.076) and CD68+ cells in the epithelial region, compared to MMR deficient patients (p=0.005). Further research will include continuing in-depth analysis of MMR status, cMET pathway and lymphocyte response as well as the role of cellular heterogeneity. In summary, comprehensive cMET pathway analysis using a multiplexed single cell approach indicates for the first time an association between low cMET network activation and superior clinical outcomes. Citation Format: Elizabeth McDonough, Anup Sood, Fiona Ginty, Sanghee Cho, John Graf, Jochen Prehn, Philip Dunne, Andreas Lindner, Manuela Salvucci, Daniel Longley, Mark Lawler, Travis Hollmann, Jinru Shia. Lower cellular activation of cMET signaling network is associated with reduced recurrence risk in stage II colorectal cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A039. doi:10.1158/1535-7163.TARG-19-A039

Increased expression of hematological and neurological expressed 1 (HN1) is associated with a poor prognosis of hepatocellular carcinoma and its knockdown inhibits cell growth and migration partly by down-regulation of c-Met.

Hematologic and neurological expression 1 (HN1) has been reported to involved in certain cancers, but its role in hepatocellular carcinoma (HCC) is largely unknown. The contribution of HN1 to HCC progression was investigated in the present study. We found that HN1 was significantly up-regulated in HCC tissues, compared with normal tissues, by analyzing the Oncomine and Human Protein Atlas database; and found that high expression of HN1 was markedly associated with worse overall survival, relapse-free survival, progression- free survival and disease-specific survival in HCC patients via exploring the Kaplan-Meier plotter database. Functional assays revealed that HN1 knockdown by siRNA induced G1 cell cycle arrest, and inhibited the growth and migration of HCC cells; accordingly, HN1 over-expression promoted HCC cells proliferation and migration. Further studies indicated that HN1 knockdown reduced the expression of cyclin D1 and CDK4, while upregulated the cell cycle inhibitor p21WAF1/Cip1. Moreover, HN1 knockdown decreased c-Met (receptor tyrosine kinase of hepatocyte growth factor) expression, and suppressed ERK activation, which is a common downstream signaling pathway triggered by c-Met; consistently, HN1 over-expression reversed these effects. Meanwhile, down-regulation of c-Met partly eliminated the effect of HN1 over-expression in HCC cells. Thus, the present findings suggested that HN1 promotes the progression of HCC to some extent by up-regulating the expression of c-Met, and may act as a potential biomarker and therapeutic target for the treatment of HCC.

C-met mediates invasion and chemotherapy resistance in high grade serous ovarian cancer

Abstract Background High grade serous ovarian cancer (HGSOC) is characterised by progressive chemo-resistance. Survival in advanced HGSOC is poor and new therapies are urgently required. The receptor tyrosine kinase c-Met, through gene amplification or protein over-expression, has emerged as a major target and mediator of chemo-resistance in HGSOC. Methods Novel chemo-resistant HGSOC cell lines were investigated for c-Met expression, activation with exogenous HGF and downstream signalling via western blot analysis. c-Met internalisation was assessed with fluorescent confocal microscopy, following staining with c-Met and the endosomal marker EEA-1. Human samples from HGSOC patients were obtained via Barts/UCLH Gynae Tissue Bank. Tissue sections underwent immunohistochemical staining for c-Met. Cancer associated fibroblasts (CAFs) isolated from HGSOC patients’ omentum were assessed by ELISA to detect HGF secretion. The effect of c-Met inhibitors on HGSOC cell line c-Met activation, migration, survival and invasion was investigated via western blot, transwell migration assay, cell viability in anoikis (CellTiter-Glo) and organotypic cultures. Results Immunostaining detected c-Met in HGSOC patient samples, with strong intensity in the malignant epithelial cells, at the plasma membrane but also in the cytoplasm. c-Met expression is significantly increased in novel cisplatin and carboplatin resistant HGSOC cells, versus isogenic parental cells. c-Met activation in HGSOC cells leads to its rapid endocytosis. Impairing endocytosis pharmacologically reduces c-Met signalling. Chemo-resistant HGSOC cells are more migratory and invasive than parental cells. Primary CAFs secrete various levels of HGF as determined by ELISA. CAFs also increase HGSOC cells’ invasion in organotypic cultures. Targeting c-Met pharmacologically reduces migration, invasion and survival of chemo-resistant HGSOC cells. Conclusions This study confirms c-Met as a therapeutic target using in vitro models and human HGSOC tissues. c-Met endocytosis in HGSOC has been illustrated here, for the first time. Further work is ongoing to develop novel biomarkers for accurate patient selection, exploiting c-Met intracellular localisation. Legal entity responsible for the study The authors. Funding Barts Charity. Disclosure All authors have declared no conflicts of interest.

Long non-coding RNA SNHG4 promotes cervical cancer progression through regulating c-Met via targeting miR-148a-3p

ABSTRACT Long non-coding RNA (lncRNA) SNHG4 has been shown to be associated with the development of a variety of cancers. The purpose of this study was to investigate the effect of SNHG4 on cervical cancer (CC) and the corresponding mechanism. The qRT-PCR was used to determine the expressions of SNHG4 and miR-148a-3p in CC cell lines and tissues. Cell apoptosis and proliferation were measured by flow cytometry and MTT assay, respectively. The interaction between SNHG4, miR-148a-3p and c-Met was verified by bioinformatics, dual-luciferase reporter gene and RNA immunoprecipitation (RIP), and the effect of SNHG4 on the growth of CC tumor in vivo was explored. The expression of SNHG4 was increased in both CC cell lines and tissues, while the expression of miR-148a-3p was down-regulated. Meanwhile, silencing SNHG4 remarkably inhibited CC cell proliferation and promoted apoptosis. In addition, miR-148a-3p was a direct target gene of SNHG4, and down-regulation of miR-148a-3p could observably reverse the effect of silencing SNHG4 on the proliferation and apoptosis of CC cells. More importantly, SNHG4 could up-regulate the expression of c-Met by targeting and interacting with miR-148a-3p. Finally, in vivo experiments confirmed that silence SNHG4 down-regulated the expression of c-Met by promoting miR-148a-3p, and ultimately suppressed the growth of CC tumor in vivo. In conclusion, SNHG4 could be used as a competitive endogenous RNA to bind to miR-148a-3p, thereby up-regulating the expression of c-Met and ultimately promoting the progression of CC, which provided a potential therapeutic target for the targeted treatment of CC.

Tivantinib Hampers the Proliferation of Glioblastoma Cells via PI3K/Akt/Mammalian Target of Rapamycin (mTOR) Signaling.

BackgroundGlioblastoma, the most common and malignant glial tumor, often has poor prognosis. Tivantinib has shown its potential in treating c-Met-high carcinoma. No studies have explored whether tivantinib inhibits the development of glioblastoma.Material/MethodsThe correlation between c-Met expression and clinicopathological characteristics of glioblastoma was investigated. U251 and T98MG glioblastoma cells treated with tivantinib, PI3K inhibitor (LY294002), PI3K activator (740 Y-P), and/or mammalian target of rapamycin (mTOR) inhibitor were subjected to MTT assay or colony formation assay to evaluate cell proliferation. The expression of mTOR signaling and caspase-3 in tivantinib-treated glioblastoma cells was differentially measured by western blotting.ResultsIn a group of Chinese patients, expression of c-Met was elevated with the size of glioblastoma, but not with the other clinicopathological characteristics, including gender, age, grade, IDH status, 1p/19q status, and Ki67 status. High dose of tivantinib (1 μmol/L) obviously repressed the proliferation and colony formation of U251 and T98MG glioblastoma cells, but low dose (0.1 μmol/L) of tivantinib failed to retard cell proliferation. Tivantinib blocked PI3K/Akt/mTOR signaling but did not change the expression of cleaved caspase-3. PI3K activator 740 Y-P (20 μmol/L) significantly rescued tivantinib-induced decrease of cell proliferation. Tivantinib (1 μmol/L) in combination with PI3K inhibitor LY294002 (0.5 μmol/L) and mTOR inhibitor rapamycin (0.1 nmol/L) largely inhibited the proliferation of glioblastoma cells.Conclusionsc-MET inhibitor tivantinib blocks PIKE/Akt/mTOR signaling and hampers the proliferation of glioblastoma cells, which endows the drug a therapeutic effect.

EP1.01-95 Up-Regulation of c-Met by Cox-2 Promotes Resistance of Gefitinib in NSCLC Patients

c-Met amplification is one of the reasons for Gefitinib resistance in NSCLC patients. 1.Explore the mechanism of the up-regulation of c-Met by Cox-2; 2.Combination of Cox-2 inhibitor and Gefitinib can overcome Gefitinib resistance in cells or animal study; 3.Test the expression pattern or activity of Cox-2 in NSCLC patients, and evaluate the possibility of Cox-2 serving as biomarker for Gefitinib resistance and prognosis for NSCLC patients. 1.Both c-met and Cox-2 are highly expressed in Gefitinib resistant lung cancer cell lines; 2.Cox-2 is highly expressed in malignant lung adenocarcinoma than in matched normal tissues; 3.Inhibition of Cox-2 can decrease c-Met expression， and promote apoptosis induced by Gefitinib in Gefitinib resistant cells. Up-regulation of c-Met by Cox-2 promotes resistance of Gefitinib in NSCLC patients

Preliminary Results of Safety and PK of Telisotuzumab Vedotin (T) in Japanese Patients with Advanced Solid Tumors

Abstract Background c-Met is a receptor tyrosine kinase overexpressed in 30-50% of solid tumors. c-Met protein overexpression have been associated with poor clinical outcomes in many cancers. T (teliso-v, ABBV-399) is a first-in-class c-Met specific antibody drug conjugate that is cytotoxic to cancer cells with overexpressed c Met and demonstrates antitumor activity in human tumor xenografts. This Ph 1 study evaluates safety, PK and preliminary efficacy of T in Japanese patients (pts) with advanced solid tumors. Methods In this non-randomized, dose-escalation Ph 1 study (NCT03311477) in Japanese pts, 3 pts were treated with 2.4 mg/kg every 3 weeks (Q3W) and 6 pts with 2.7 mg/kg Q3W. Serial blood samples were collected in Cycle 1 and 3 for PK assessments. IHC of c-Met status was retrospectively evaluated. Results As of Nov 2018, 9 pts were enrolled. 8 pts experienced adverse events (AEs). The most frequent treatment-emergent AEs (any grade) were neuropathy (44%), decreased appetite (33%) and nausea (33%). 5 pts (56%) had dose interruption due to an AE. Grade 3/4 AEs including decreased neutrophil count in 2 pts (22%). There were no dose limiting toxicities and 2.7 mg/kg Q3W was tolerable. 2 pts (ovarian and urothelial carcinoma) had confirmed partial responses, both of which are ongoing. c-Met expression levels from archived specimens from these 2 pts were not high (H-Score:35 and 10, respectively). Median progression free survival was 7 (95% CI; 1, not calculated) months. The maximum observed serum concentration (Cmax) of T was 55.5-63.0 µg/mL (%CV: 22-26%) and the area under the serum concentration-time curve (AUCinf) of T was 4400-5200 µg*h/mL (%CV: 19-23%) across the 2 doses in Japanese pts. The half-life for T and the free MMAE payload was determined to be 3-4 days and 4-6 days respectively. Conclusions Preliminary safety, PK and efficacy in Japanese pts with solid tumors suggest T was tolerated and showed encouraging anti-cancer effects, warranting continued study.

The prognostic analysis of the some clinicopathological parameters and gene protein expressions in malignant mesothelioma.

Mesothelioma is an aggressive tumour that originates in serous surfaces. The primary end point of this study was to invastigate the relationship of progression free survival (PFS) and overall survival (OS) with the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels in the tumour tissue of pleural and peritoneal mesothelioma cases. The study included 53 patients diagnosed with mesothelioma between 2005 and 2016. The cases were separated into 2 groups as pleural and peritoneal. The effects on OS and PFS were examined of the c-Met, EGFR, PTEN, PDGFR-alpha, PI3K/AKT and mTOR expression levels and also clinicopathological parameters and the treatments given. In the statistical analysis of the data obtained, IBM SPSS vn 20.0 software was used. Of the 53 patients included in the study, 39 (73.6%) were diagnosed with pleural mesothelioma and 14 (26.4%) with peritoneal mesothelioma. According to the c-Met and mTOR expression, OS and PFS of the peritoneal cases with high expression (2+, 3+) was seen to be significantly better than that of the peritoneal cases with low expression (0, 1+) (p<0.05). According to the PDGFR expression, OS and PFS of the pleural cases with low expression (0, 1+) was seen to be significantly better than that of the pleural cases with high expression (2+, 3+) (p<0.05). The examination of c-MET, PDGFR-alpha and m-TOR expression in the in the tumor tissue of mesothelioma cases may be important in determining prognosis.