c-Met Expression Research Articles

Cancer-Associated Fibroblasts Promote Radioresistance of Breast Cancer Cells via the HGF/c-Met Signaling Pathway

Cancer-associated fibroblasts (CAFs) are an integral part of the tumor microenvironment (TME), which is involved in therapy resistance. This study aimed to investigate the role of CAFs in radiosensitivity of breast cancer cells. The CAFs were isolated from the breast cancer tissues, and the conditioned medium was collected to culture breast cancer cells. Radiation-induced DNA damage was evaluated by immunofluorescence and western blotting. Cytokine array and enzyme-linked immunosorbent assay were performed to analyze the secretion of cytokines and growth factors. An in vitro clonogenic survival assay and in vivo xenograft mouse model were performed to determine the radiosensitivity of breast cancer cells. Finally, the expression of hepatocyte growth factor (HGF) and c-Met in the breast cancer tissues were detected by immunohistochemistry. The CAFs were found to secrete HGF to activate the c-Met signaling pathway, which induced epithelial-to-mesenchymal transition, growth, and radioresistance of breast cancer cells. Furthermore, radiation was observed to enhance HGF secretion by CAFs and increase c-Met expression in breast cancer cells, which led to HGF/c-Met signaling pathway activation. Moreover, radiation-induced tumor necrosis factor α (TNFα) secretion by breast cancer cells promoted CAF proliferation and HGF secretion. Additionally, HGF and c-Met high expression were associated with worse recurrence-free survival in patients with breast cancer who had received radiation therapy. The findings revealed that HGF and TNFα are critical for the crosstalk between breast cancer cells and CAFs in the TME and that the HGF/c-Met signaling pathway is a promising therapeutic target for radiosensitizing breast cancer.

Vascular Niche Facilitates Acquired Drug Resistance to c-Met Inhibitor in Originally Sensitive Osteosarcoma Cells.

Osteosarcoma (OS) is the most common primary bone tumor in children and adolescents characterized by drug resistance and poor prognosis. As one of the key oncogenes, c-Met is recognized as a promising therapeutic target for OS. In this report, we show that c-Met inhibitor PF02341066 specifically killed OS cells with highly phosphorylated c-Met in vitro. However, the inhibitory effect of PF02341066 was abrogated in vivo due to interference from the vascular niche. OS cells adjacent to microvessels or forming vascular mimicry suppressed c-Met expression and phosphorylation. Moreover, VEGFR2 was activated in OS cells and associated with acquired drug resistance. Dual targeting of c-Met and VEGFR2 could effectively shrink the tumor size in a xenograft model. c-Met-targeted therapy combined with VEGFR2 inhibition might be beneficial to achieve an ideal therapeutic effect in OS patients. Together, our results confirm the pivotal role of tumor heterogeneity and the microenvironment in drug response and reveal the molecular mechanism underlying acquired drug resistance to c-Met-targeted therapy.

Thymoquinone-treated mouse mesenchymal stem cells-derived conditioned medium inhibits human breast cancer cells in vitro

Breast cancer is now the most prevalent cancer in females, therefore, it is essential to identify factors affecting its initiation and progression. Mesenchymal stem cells (MSCs) have received considerable attention in stem cell-based therapies and drug delivery applications. Because the therapeutic potential of MSCs is primarily achieved by their paracrine effects, thus identifying and employing bioactive molecules that promote the paracrine activity of MSCs is crucial for their efficient use in cancer treatment. Thymoquinone (TQ) has many biomedical properties, including anti-inflammatory, anti-diabetic, anti-aging, anti-cancer, etc. In addition, it has been found that TQ affects the self-renewal and immunomodulatory properties of MSCs. The present study aimed to investigate the effect of TQ-treated mouse bone marrow-derived MSCs conditioned medium (TQ-MSC-CM) on the biological characteristics of breast cancer cell line MCF7. MSCs were cultured and treated with TQ for 24 h. The TQ-MSC-CM and MSC-CM were collected, and their effects were investigated on ROS production, mitochondrial membrane potential (MMP), cell death, cell cycle, and migration of MCF7 cells by DCFDA-cellular ROS assay, Rhodamine-123 MMP assay, Annexin-PI staining and Caspase-3/7 activity assays, PI-staining and flow-cytometry, and in vitro wound healing assay, respectively. Moreover, the effects of TQ-MSC-CM and MSC-CM were studied on Cdk4, Sox2, c-Met, and Bcl2 gene expression by real-time PCR. Results demonstrated that MSC-CM and TQ-MSC-CM did not have a significant effect on the apoptosis induction in MCF7 cells; however, they significantly stimulated necrosis in the cells. Although TQ-MSC-CM promoted ROS production in MCF7 cells, it decreased the MMP of the cells. TQ-MSC-CM also induced Bcl2 anti-apoptosis gene expression and Casp-3/7 activity in cells. In addition, although MSC-CM induced MCF7 cells to enter the cell cycle, TQ-MSC-CM inhibited its progression. TQ-MSC-CM also downregulated the Cdk4 and Sox2 gene expression. Furthermore, TQ-MSC-CM induced the migration potential of MCF7 in a c-Met-independent manner. Altogether, we conclude that TQ may induce programmed necrosis and inhibits the proliferation and migration of the breast cancer cells by affecting the paracrine activity of MSCs.

Expression of c-MET in Estrogen Receptor Positive and HER2 Negative Resected Breast Cancer Correlated with a Poor Prognosis.

Introduction: The mesenchymal-epithelial transition factor (c-MET) receptor is overexpressed in about 14−54% of invasive breast cancers, but its prognostic value in clinical practice is still unclear. Methods: In order to investigate the relationship between c-MET expression levels and prognosis, we retrospectively reviewed the clinical features and outcomes of 105 women with estrogen receptor positive HER2 negative (ER+/HER2-) resected breast cancer. We used the Kaplan Meier method to estimate Disease Free Survival (DFS) and Breast Cancer Specific Survival (BCSS) in the subgroups of patients with high (≥50%) and low (<50%) c-MET expression. Univariate and multivariate Cox proportional regression models were performed to assess the prognostic impact of clinicopathological parameters for DFS an BCSS. Results: High c-MET values significantly correlated with tumor size, high Ki67 and low (<20%) progesterone receptor expression. At a median follow up of 60 months, patients with high c-MET tumor had significantly worse (p = 0.00026) and BCSS (p = 0.0013). Univariate analysis showed a significant association between large tumor size, elevated Ki67, c-MET values and increased risk of recurrence or death. The multivariate COX regression model showed that tumor size and high c-MET expression were independent predictors of DFS (p = 0.019 and p = 0.022). Moreover, large tumor size was associated with significantly higher risk of cancer related death at multivariate analysis (p = 0.017), while a trend towards a poorer survival was registered in the high c-MET levels cohort (p = 0.084). Conclusions: In our series, high c-MET expression correlated with poor survival outcomes. Further studies are warranted to validate the clinical relevance and applicability of c-MET as a prognostic factor in ER+/HER2- early BC.

ODP300 c-MET expression in MEN1-associated neuroendocrine tumors

Abstract Multiple studies have shown that approximately 50-70% of patients with MEN1 die of causes directly related to MEN1 particularly gastroenteropancreatic (GEP) neuroendocrine tumors (NETs). While non-functional GEP-NETs are the most common in the general population, gastrinomas (40%) are the most common functional GEP-NETs in patients with MEN1. c-MET is a proto-oncogene that encodes for c-MET, a tyrosine kinase receptor which promotes tumor cell motility, proliferation, survival, invasion, and metastasis. Studies in patients with sporadic gastrinomas and pancreatic NETs (PNETs) have shown that c-MET expression correlates with decreased survival. While c-MET inhibitors are currently in various stages of investigation for treatment of carcinoids and sporadic PNETs, data regarding their efficacy in patients with MEN1-related GEP NETs is lacking. The majority of trials in patients with GEP-NETs exclude or do not report the number of patients with MEN1. Importantly, somatic MEN1 mutations are observed in 20-40% of sporadic NETs (gastrinomas, PNETs, lung NETs, etc.) but correlation of cMET expression with the presence of somatic or germline MEN1 mutations has not been reported. We sought to investigate the expression of c-MET in tumor tissue from germline MEN1 patients with metastatic GEP-NETs. Methods We identified subjects with a germline positive MEN1 mutation and pathologically confirmed distant metastasis who had a follow-up visit between 2018-2020. Of these, we selected subjects with available tissue specimens (including either multiple organ sources or different tumor types). Where available, we identified specimens from multiple source or tumor types. Immunohistochemistry (IHC) to detect c-MET was performed with anti-MET (Cell Signaling) using the DAKO IHC kit (Agilent). IHC slides were imaged and observed to score the level of c-MET staining (-, 1+ to 5+). A score of 3+ or higher was considered consistent with overexpression. We investigated if age at initial GEP-NET presentation, tumor type, tissue source, tumor grade, total number of surgeries for GEP-NET, number of sites of distant metastasis and disease status from overall GEP-NET burden over the preceding 12 months (stable/progressive) predicted c-MET expression. Results Eight subjects with available tissue specimens were identified, of which six had tissue from multiple organs while five had tissue from multiple tumor types. Six subjects (75%) showed increased expression of c-MET in one or more tumor specimen(s). The frequency of c-MET overexpression varied with tumor types – carcinoids (n=2/2; 100%), gastrinomas (n=3/5; 60%) and non-functional tumors (n=3/6; 50%). c-MET expression also varied among different tumors in the same patient. Tumor tissue from liver (n=2/2), duodenum (n=3/4), stomach (n=1/1), ovary (n=1/1), pancreas (n= 1/5), and lymph nodes (n=1/3), all showed over-expression of c-MET. No clear predictors of c-MET overexpression emerged. Conclusion Our finding suggests a role for c-MET expression in personalizing therapy for patients with MEN1-related NETs with distant metastases. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 12:48 p.m. - 12:53 p.m.

Role of hypoxia on microRNA-dependant regulation of HGFA - HGF - c-Met signalling pathway in human progenitor and mature endothelial cells.

Hepatocyte growth factor (HGF) is considered to be one of the key pro-angiogenic cytokines that stimulates endothelial cells to proliferate and migrate. The activation of the precursor form of HGF is primarily undertaken by the serine protease HGFA. Research indicates that HIF-1α hypoxia stimulates the expression of HGFA, which is synthesized by a range of cells including fibroblasts, endothelium, and macrophages. To date, little is known about the potential role of epigenetic factors in the regulation of the HGFA - HGF - c-Met signalling pathway. The literature suggests that there are several microRNAs (miRNAs, miRs) directly affecting the expression of c-Met under normoxic conditions. The main objective of the research described was to explore the effect of chemically-induced hypoxia on the expression of miRNA molecules in human progenitor and mature endothelial cells, with particulate attention paid to those miRNAs that may specifically affect the HGFA - HGF - c-Met signalling pathway. This publication sheds new light on the role of miRNAs in hypoxia, as well as identifying several miRNAs directly involved in the regulation of HGFA, HGF and c-Met expression in hypoxic conditions. The results indicate that hsa-miR-335-5p, hsa-miR-425-5p and hsa-miR-101-3p are the major miRNAs that appear to play an important role in the regulation of the HGFA - HGF - c-Met signalling pathway.

Relationship between 18F-fluorodeoxyglucose PET/computed tomography metabolic parameters and clinicopathology in endometrial cancer.

Endometrial cancer (EC) is the most common invasive gynecological malignancy. This study aimed to retrospectively analyze the relationship between 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) parameters and clinicopathological factors in EC patients, and assess whether 18F-FDG PET/CT can be applied for predicting the expressed status of histologic molecular markers. Pretreatment clinicopathological characteristics and 18F-FDG PET/CT parameters of maximum standard uptake value (SUVmax), metabolic tumor volume and total lesion glycolysis of primary lesion (MTV-P and TLG-P), and combination of primary lesion and metastases (MTV-C and TLG-C) were retrospectively reviewed in 101 patients with EC. The median age of these 101 patients was 55 years (range, 35-85 years), and 95 patients (94.1%) presented with abnormal vaginal bleeding, 26 patients (25.7%) with elevated serum cancer antigen 125 (CA-125) and 46 patients (45.5%) with increased human epididymis protein 4 (HE4). Sixty-nine cases were at International Federation of Gynecology and Obstetrics (FIGO) stage I, eight at stage II, 20 at stage III, and four at stage IV. FDG uptake was avid in all cases, and the median SUVmax, MTV-P, TLG-P, MTV-C, and TLG-C were 12.9 (range, 2.8-34.2), 8.1 (range, 0.9-547.8), 52.2 (range, 2.5-4420.6), 8.2 (range, 0.9-790.3), and 58.4 (range, 2.5-6972.2), respectively. Estrogen receptor (ER) and progesterone receptor (PR) positive expressions were in 93.1% (94/101) and 90.1% (91/101) patients, respectively. The median Ki-67 index of 101 cases was 40% (range, 0-95%). P53 pattern was tested in 89 patients and 24 cases were mutant type (27.0%). Mesenchymal-epithelial transition factor (c-Met) expression was investigated in 86 patients, and the positivity was in 36 patients (41.9%). Higher PET/CT metabolic parameters were observed in patients with elevated CA-125 and HE4, advanced FIGO stage and higher Ki-67 index (P < 0.05), but had no association with ER/PR expression, P53 pattern, and c-Met expression (P > 0.05). FDG uptake in EC was associated with serum CA-125 and HE4, FIGO stage, and Ki-67 index, but no correlations were found between glucose metabolism and ER/PR, P53, and c-Met.

HSF4 promotes tumor progression of colorectal cancer by transactivating c-MET.

Heat shock factors (HSFs) are a family of transcription factors, composed of HSF1, HSF2, and HSF4, to regulate cell stress reaction for maintaining cellular homeostasis in response to adverse stimuli. Recent studies have disclosed the roles of HSF1 and HSF2 in modulating tumor development, including colorectal cancer (CRC). However, HSF4, which is closely associated with pathology of congenital cataracts, remains less studied in tumors. In this study, we aimed to describe the regulatory effects of HSF4 and underlying molecular mechanism in CRC progression. By bioinformatic analysis of TCGA database and TMA-IHC assay, we identified that the expression of HSF4 was significantly upregulated in CRCs compared with normal colonic tissues and was a prognostic factor of poor outcomes of CRC patients. Function assays, including CCK-8, colony formation, transwell assays, and xenografted mouse model, were employed to verify that HSF4 promoted cell growth, colony formation, invasion of CRC cells in vitro, and tumor growth in vivo as a potential oncogenic factor. Mechanistically, results of Chromatin immunoprecipitation (ChIP) and immunoblotting assays revealed that HSF4 associated directly to MET promoter to enhance expression of c-MET, a well-known oncogene in multiple cancers, thus fueling the activity of downstream ERK1/2 and AKT signaling pathways. In further rescue experiments, restoration of c-MET expression abolished inhibitory cell growth and invasion induced by downregulated HSF4 expression. To sum up, our findings describe a crucial role of HSF4 in CRC progression by enhancing activity of c-MET and downstream ERK1/2 and AKT signaling pathways, and highlight HSF4 as a potential therapeutic target for anti-CRC treatment.

Glioma cancer stem cells modulating the local tumor immune environment.

Glioma stem cells (GSCs) drive the resistance mechanism in glioma tumors and mediate the suppression of innate and adaptive immune responses. Here we investigate the expression of mesenchymal-epithelial transition factor (c-Met) and Fas receptor in GSCs and their role in potentiating the tumor-mediated immune suppression through modulation of tumor infiltrating lymphocyte (TIL) population. Tumor tissues were collected from 4 patients who underwent surgery for glioblastoma. GSCs were cultured as neurospheres and evaluated for the co-expression of CD133, c-Met and FasL through flow cytometry. TILs were isolated and evaluated for the lymphocyte subset frequencies including CD3 +, CD4 +, CD8 +, regulatory T cells (FOXP3 + CD25) and microglia (CD11b + CD45) using flow cytometry. Our findings revealed that a significant population of GSCs in all four samples expressed c-Met (89–99%) and FasL (73–97%). A significantly low microglia population was found in local immune cells ranging from 3 to 5%. We did not find a statistically significant correlation between expressions of c-Met + GSC and FasL + GSC with local and systemic immune cells. This may be regarded to the small sample size. The percent c-Met + and FasL + GSC population appeared to be related to percent cytotoxic T cells, regulatory T cells and microglia populations in glioblastoma patients. Further investigation is warranted in a larger sample size.

A c-MET-Targeted Topical Fluorescent Probe cMBP-ICG Improves Oral Squamous Cell Carcinoma Detection in Humans

IntroductionThe postoperative survival of oral squamous cell carcinoma (SCC) relies on precise detection and complete resection of original tumors. The mucosal extension of the tumor is evaluated visually during surgery, but small and flat foci are difficult to detect. Real-time fluorescence imaging may improve detection of tumor margins.Materials and MethodsIn the current study, a peptide-based near-infrared (NIR) fluorescence dye, c-MET-binding peptide-indocyanine green (cMBP-ICG), which specifically targets tumor via c-MET binding, was synthetized. A prospective pilot clinical trial then was conducted with oral SCC patients and intraoperatively to assess the feasibility of cMBP-ICG used to detect tumors margins. Fluorescence was histologically correlated to determine sensitivity and specificity.ResultsThe immunohistochemistry (IHC) results demonstrated increased c-Met expression in oral SCC compared with normal mucosa. Tumor-to-background ratios ranged from 2.71 ± 0.7 to 3.11 ± 1.2 in different concentration groups. From 10 patients with oral SCC, 60 specimens were collected from tumor margins. The sensitivity and specificity of discriminative value derived from cMBP-ICG application in humans were respectively 100% and 75%.ConclusionsTopical application of cMBP-ICG is feasible and safe for optimizing intraoperative visualization and tumor margin detection in oral SCC patients, which could clinically increase the probability of complete resections and improve oncologic outcomes.

MiR-23b-3p suppresses epithelial-mesenchymal transition, migration, and invasion of hepatocellular carcinoma cells by targeting c-MET

BackgroundAberrant expression of c-MET is known to be associated with tumor recurrence and metastasis by promoting cell proliferation, epithelial-mesenchymal transition (EMT), and migration in hepatocellular carcinoma (HCC). Recently, miR-23b-3p has been identified as a tumor suppressor, but detailed role of miR-23b-3p in HCC is still unclear. Our study aimed to investigate how miR-23b-3p is associated with the malignant potential of HCC cells. MethodsHCC tissues and their adjacent non-tumor tissues were acquired from 30 patients with HCC. Expression of EMT- or stemness-related genes were examined in the two HCC cell lines. Migration of HCC cells was analyzed using transwell and wound healing assays. Resultsc-MET was overexpressed in HCC tissues compared to the adjacent non-tumor tissues. c-MET knockdown inhibited EMT and reduced migration and invasion of HCC cells. Furthermore, c-MET was a target of miR-23b-3p, and miR-23b-3p expression was decreased in HCC tissues compared to non-tumor tissues. Treatment of miR-23b-3p inhibitor in HCC cells promoted EMT, cell migration, and invasion. In contrast, miR-23b-3p overexpression suppressed EMT, cell migration, and invasion, concomitantly reducing c-MET expression. Transfection of miR-23b-3p inhibitor with concomitant c-MET knockdown mitigated the effects of miR-23b-3p inhibitor on EMT in HCC cells. In addition, transforming growth factor beta1 (TGF-β1) stimulation after miR-23b-3p overexpression induced neither the mesenchymal phenotype nor migratory property of HCC cells. ConclusionIn this study, we confirmed that miR-23b-3p downregulation significantly increased EMT, migration, and invasion of HCC cells. In addition, c-MET was confirmed to be a target of miR-23b-3p in HCC cells and regulated the functional effects of miR-23b-3p. These results suggest that miR-23b-3p can be used as a prognostic biomarker and candidate target for HCC treatment.

Radiation modulates expression and related activities of c-Met protein in oral tongue squamous cell carcinoma cell lines

Objectivesc-Met, a receptor tyrosine kinase, is involved in the growth, invasion and metastasis of a variety of cancers. In a set of cell lines from several solid tumors, a five-fold increase in c-Met expression after irradiation has been reported. This study aimed to assess if c-Met is likewise abundantly expressed in oral tongue squamous cell carcinoma (OTSCC) upon exposure to irradiation, followed by a Met-induced biological response.Materials and methodsSix OTSCC cell lines were exposed to gamma radiation doses of 2, 4, and 6 Gray. The changes in c-Met protein levels were assessed by western blot and flow cytometry. c-Met gene expression, cell migration, proliferation and cell cycle assays were performed as phenotypic readouts.ResultsIrradiation resulted in upregulation of c.Met in all cell lines with different time kinetics. On average the cells displayed minimal c-Met expression on their surface ranging from 5 to 30% of total protein. Abrupt downregulation of c-Met surface expression occurred one hour after radiation but recovered 48 h post-radiation. Intracellularly, the highest level of expression was found on day 5 after radiation exposure. Irradiation induced aggressive invasive potential of the cells as determined in cell migration assays, particularly in cell lines with the highest c-Met expression.ConclusionsThese results provide novel insights into both intracellular and extracellular dynamics of c-Met expression profiles upon irradiation of OTSCC cells in vitro. It might also suggest that radiation enhances cell migration, indicative of invasiveness, through c-Met up-regulation, at least for certain types of OTSCC cells.

Retraction: MiR-144 Inhibits Uveal Melanoma Cell Proliferation and Invasion by Regulating c-Met Expression.

Retraction: MiR-144 Inhibits Uveal Melanoma Cell Proliferation and Invasion by Regulating c-Met Expression.

Mutant KRAS modulates colorectal cancer cells invasive response to fibroblast-secreted factors through the HGF/C-MET axis.

Genetic alterations influencethe malignant potential of cancer cells, and so does the tumor microenvironment. Herein, we combined the study of KRAS oncogenic effects in colorectal cancer cells with the influence of fibroblast-derived factors. Results revealed that mutant KRAS regulates cell fate through both autonomous and nonautonomous signaling mechanisms. Specifically, processes such as proliferation and cell-cell aggregation were autonomously controlled by mutant KRAS independently of the stimulation with fibroblasts conditioned media. However, cancer cell invasion revealed to be a KRAS-dependent nonautonomous effect, resulting from the cooperation between fibroblast-derived HGF and mutant KRAS regulation of C-MET expression. C-MET downregulation upon KRAS silencing rendered cells less responsive to HGF and thus less invasive. Yet, in one cell line, KRAS inhibition triggered invasion upon stimulation with fibroblasts conditioned media. Inhibition of PIK3CA oncogene did not promote invasion, thus showing a KRAS-specific effect. Moreover, the invasive capacity also depended on the HGF-C-MET axis. Overall, our study awards oncogenic KRAS an important role in modulating the response to fibroblast-secreted factors either by promoting or impairing invasion, and depicts the HGF-C-MET axis as a putative therapeutic target to impair the invasive properties of mutant KRAS cancer cells.

Overexpression of Metastasis-Associated in Colon Cancer 1-Antisense RNA 1 (MACC1-AS1) in Bone Marrow Mesenchymal Stem Cells (BMSCs) Inhibits miR-145-5P and Promotes Chemotherapy Resistance of Colorectal Cancer

BMSCs have the potential of multipotent differentiation. This study aimed to investigate the interaction between MACC1-AS1 and miR-145-5P in BMSCs and their effect on chemotherapy resistance in colorectal cancer (CRC). BMSCs extracted from mouse marrow were transfected with MACC1-AS1 mimic, or MACC1-AS1 NC (control group). CRC cells were treated wtih gemcitabine and then co-cultured with BMSCs to measure cell viability and invasiveness by MTT and Transwell assay, along with analysis of the expression of MACC1, miR-145-5P, HGF, C-met, P-gp, and MRP. Successful isolation of BMSCs was confirmed by flow cytometry with positive expression of CD44, CD105, and CD90 (purity &gt; 95%). Functionally, overexpression of MACC1-AS1 in BMSCs increased CRC cell viability and invasion, attenuated the inhibitory effect of gemcitabine (p &lt; 0.05). Up-regulation of MACC1-AS1 (9.23±1.21) as demonstrated by RT-qPCR, resulted in a decline of miR-145-5P expression (4.23±1.22) in CRC cells (p &lt; 0.05). In addition, overexpression of MACC1-AS1 increased the expression of HGF, C-met, and multidrug resistance-associated proteins (P-gp, and MRP). In conclusion, overexpression of MACC1-AS1 in BMSCs inhibits miR-145-5P expression to promote colorectal cancer cell progression possibly via activating HGF/C-met pathway and inducing resistance to chemotherapy.

C-Met: A Promising Therapeutic Target in Bladder Cancer.

Mesenchymal-epithelial transition factor (c-Met) belongs to the tyrosine kinase receptor family and is overexpressed in various human cancers. Its ligand is hepatocyte growth factor (HGF), and the HGF/c-Met signaling pathway is involved in a wide range of cellular processes, including cell proliferation, migration, and metastasis. Emerging studies have indicated that c-Met expression is strongly associated with bladder cancer (BCa) development and prognosis. Therefore, c-Met is a potential therapeutic target for BCa treatment. Recently, the aberrant expression of noncoding RNAs was found to play a significant role in tumour progression. There is a close connection between c-Met and noncoding RNA. Herein, we summarized the biological function and prognostic value of c-Met in BCa, as well as its potential role as a drug target. The relation of c-Met and ncRNA was also described in the paper.

The HDAC inhibitor GCJ-490A suppresses c-Met expression through IKKα and overcomes gefitinib resistance in non-small cell lung cancer.

Objective:The novel compound GCJ-490A has been discovered as a pan-histone deacetylase (HDAC) inhibitor that exerts potent inhibitory activity against HDAC1, HDAC3, and HDAC6. Because of the important roles of HDACs in lung cancer development and the high distribution of GCJ-490A in lung tissue, we explored the anti-tumor potency of GCJ-490A against non-small cell lung cancer (NSCLC) in vitro and in vivo in this study.Methods:The in vitro effects of GCJ-490A alone or combined with the EGFR inhibitor gefitinib against NSCLC were measured with proliferation, apoptosis, and colony formation assays. NSCLC xenograft models were used to investigate the efficacy of GCJ-490A combined with gefitinib for the treatment of NSCLC in vivo. Western blot assays, luciferase reporter assays, chromatin immunoprecipitation assays, quantitative real time-PCR, immunohistochemistry, and transcription factor activity assays were used to elucidate possible mechanisms.Results:GCJ-490A effectively inhibited NSCLC cell proliferation and induced apoptosis in vitro and in vivo. Interestingly, inhibition of HDAC1 and HDAC6 by GCJ-490A increased histone acetylation at the IKKα promoter and enhanced IKKα transcription, thus decreasing c-Met. Moreover, this c-Met downregulation was found to be essential for the synergistic anti-tumor activity of GCJ-490A and gefitinib.Conclusions:These findings highlight the promising potential of HDAC inhibitors in NSCLC treatment and provide a rational basis for the application of HDAC inhibitors in combination with EGFR inhibitors in clinical trials.

MACC1 Promotes the Progression and Is a Novel Biomarker for Predicting Immunotherapy Response in Colorectal Cancer.

Aims As one of the most prevalent malignant diseases in the world, the mechanisms of metastasis in colon cancer are poorly understood. The aim of this study was to investigate the role of the HGF/c-MET axis in the proliferation and metastasis in colon cancer. Methods The effect of MACC1 on cell proliferation and metastasis was analyzed through a series of in vitro experiments. The role of MACC1 in cancer cells was demonstrated by overexpression and silencing of MACC1 in gain or loss function experiments. To investigate the relationship between MACC1 and c-MET/HGF, we detected c-MET protein expression by disrupting with or overexpressing MACC1. The bioinformatics analysis was used to investigate the correlation between MACC1 and c-MET, and the c-MET expression after the interference of HGF with MACC1 was determined. Subsequently, the function of c-MET was verified in colon cancer cells by a series of experiments. The mouse tumor transplantation model experiment is most suitable in vivo. Results The results indicated that the overexpression of MACC1 could accelerate proliferation and facilitate metastasis in colon cancer cell lines. Furthermore, c-MET was determined to be the downstream regulator of MACC1. The addition of HGF could stimulate the expression of MACC1. With further exploration, we proved that c-MET is downstream of MACC1 in colon cancer and that overexpression of c-MET in colon cancer enhances cell proliferation and migration capability. At last, MACC1 expression level negatively correlates with the infiltration levels and several immune checkpoint biomarkers. High MACC1 expression has a lower response rate with ICIs in COAD. Conclusions We found that, under the regulation of the MACC1/HGF/c-MET axis, the proliferation and metastasis of colorectal cancer are increased by MACC1, which can be a novel biomarker for predicting ICIs response in colorectal cancer. Our findings provide a new idea for the targeted treatment of colorectal cancer.

P-023 Exogenous glial cell-derived neurotrophic factor contributes hepatocyte growth factor-induced in vitro organization of Sertoli cells on matrigel-based three-dimensional culture

Abstract Study question Does glial cell-derived neurotrophic factor (GDNF), a crucial factor for spermatogonial stem cell (SSC) self-renewal, have a role in in vitro tubule-formation capacity of Sertoli cells? Summary answer Exogenous GDNF treatment together with hepatocyte growth factor (HGF) significantly increased the in vitro tubule-forming capacity of Sertoli cells on matrigel-based three-dimensional (3D) culture system. What is known already GDNF increases the tubule-forming capacity of HGF in vitro by regulating c-Met expression during renal tubulogenesis. In vitro testicular organization of Sertoli cells consists of two stages: testicular cord-like structures and tubule-like structures. HGF secreted from Sertoli cells plays a direct role in forming seminiferous tubules in vivo and in vitro by activating c-Met. GDNF maintains SSC numbers by activating GFRα1 and Ret receptors in SSCs and can also directly phosphorylate c-Met in GFRα1-positive cells. Study design, size, duration Four groups were established using the 15P-1 Sertoli cell line: Control, HGF-administrated, GDNF-administrated and, HGF and GDNF-administrated. All groups were pursued on a matrigel-based 3D culture system for seven days. Experiments were repeated three times in all groups. Kit ligand (KitL, Sertoli cell marker; positive control) and c-kit (germ cell marker; negative control) were used as the control for Sertoli cell characterization. This work was supported by TUBITAK (SBAG-120S554) and Akdeniz University Research Foundation (TYL-2020-5481). Participants/materials, setting, methods The cord-forming and tubule-forming capacity of Sertoli cells on matrigel-based 3D culture was evaluated under an inverted microscope, and c-Met and p-c-Met expression levels were analyzed using western blot. In addition to KitL and c-kit protein expression, zonula occludens-1 (ZO-1) protein expression for polarization of Sertoli cells was evaluated by immunofluorescence staining. Data were analyzed using one-way ANOVA and Tukey post hoc test for multiple comparisons. p &amp;lt; 0.05 was considered statistically significant. Main results and the role of chance In the first 24 hours, interaction and aggregation between Sertoli cells began. The highest cellular interaction was found in the group treated with HGF and GDNF compared to the other groups (p &amp;lt; 0.05). At 48 and 72 hours, the formation of cord-like structures was observed by forming connections between the clusters formed in all groups in the first 24 hours. The number of cord-like structures was higher in the groups treated with only HGF and HGF and GDNF at 48th and 72nd hours (p &amp;lt; 0.05). At 96th and 120th hours, structures forming spaces were observed, and these structures were determined to be lumen-like structures. The capacity of 15P-1 Sertoli cells to form tubule-like structures was higher in the HGF and GDNF treated groups than in the other groups (p &amp;lt; 0.05). c-Met and p-c-Met protein expression levels were high in HGF, GDNF, HGF, and GDNF groups compared to control (P &amp;lt; 0.05). Sertoli cells retained their identity until the end of the culture and formed tight junctions in the HGF and GDNF-administrated group as evaluated by ZO-1 expression. Limitations, reasons for caution The cord- and tubule-forming capacity of Sertoli cells was evaluated in vitro utilizing exogenous GDNF treatment but the effect of testicular endothelial cell-derived GDNF should be also evaluated. Wider implications of the findings Exogenous GDNF treatment enhances HGF-induced in vitro tubule-formation capacity of Sertoli cells by directly phosphorylating c-Met in Sertoli cells. Our findings highlight the importance of designing studies related to GDNF-induced cell signaling pathway for in vitro tubulogenesis of Sertoli cells to support ex vivo spermatogenesis. Trial registration number None

The study of direct and indirect effects of radiofrequency ablation on tumor microenvironment in liver tumor animal model

BackgroundDirect and indirect effects of radiofrequency ablation (RFA) on tumor microenvironment of the liver tumor have been noted, which was reported to be related to a variety of tyrosine protein kinase or cytokinetic pathway, but have not been thoroughly investigated and conclusive.PurposeTo elucidate direct and indirect effects of RFA on tumor microenvironment in the liver tumor model, and to explore the role of the specific inhibitor in tumor growth by targeting the key pathway of RFA.Materials and methodsOne hundred and ten mice with H22 liver tumor were used in animal experiments. Eighty-four mice were randomized into three groups: control, direct RFA and indirect RFA (a block slide was inside the middle of the tumor). The growth rate of the residual tumor after RFA was calculated (n = 8 each group) and the pathologic changes at different time points (6 h, 24 h, 72 h and 7d after RFA) were evaluated (n = 5 in each subgroup). After semi-quantitative analysis of the pathological staining, the most significant marker after RFA was selected. Then, the specific inhibitor (PHA) was applied with RFA and the tumor growth and pathological changes were evaluated and compared with RFA alone. The Kruskal-Wallis test was used for evaluating the significance of different treatments in the pathological positive rate of specific markers in tumor. The two-way analysis of variance was used to determine the significance of treatment in tumor growth or body weight.ResultsThe growth rate of the residual tumor in the direct RFA group was faster than the indirect RFA group (P = 0.026). The pathological analysis showed the expression of HSP70 (73 ± 13% vs 27 ± 9% at 24 h, P < 0.001), SMA (70 ± 18% vs 18 ± 7% at 6 h, P < 0.001) and Ki-67 (51 ± 11% vs 33 ± 14% at 7d, P < 0.001) in the direct RFA group was higher than those in the indirect RFA group after RFA. On the other hand, the expression of c-Met (38 ± 11% vs 28 ± 9% at 24 h, P = 0.01), IL-6 (41 ± 10% vs 25 ± 9% at 24 h, P < 0.001) and HIF-α (48 ± 10% vs 28 ± 8% at 24 h, P < 0.001) in the indirect RFA group was higher than those in the direct RFA group. And the expression of c-Met increased mostly in both direct and indirect RFA group compared to the baseline (53 and 65% at 72 h). Then the specific inhibitor of c-Met-PHA was applied with RFA. The growth rate of the tumor was significantly slower in the RFA + PHA group than the RFA alone group (1112.9 ± 465.6 mm3 vs 2162.7 ± 911.1 mm3 at day 16, P = 0.02).ConclusionDirect and indirect effects of RFA on tumor microenvironment changed at different time points and resulted in increased residual tumor growth in the animal model. It can be potentially neutralized with specific inhibitor of related pathways, such as tyrosine-protein kinase c-Met.