MET Expression Research Articles

TYRO3 and EPHA2 Expression Are Dysregulated in Breast Cancer.

Receptor tyrosine kinases (RTKs) are involved in cell growth, motility, and differentiation. Deregulation of RTKs signaling is associated with tumor development and therapy resistance. Potential RTKs like TAM (TYRO3, AXL, MERTK), RON, EPH, and MET have been evaluated in many cancers like lung, prostate, and colorectal, but little is known in breast tumors. In this study, 51 luminal breast cancer tissue and 8 triple negative breast cancer (TNBC) subtypes were evaluated by qPCR for the expression of TAM, RON, EPHA2, and MET genes. Statistical analysis was performed to determine the correlation to clinical data. TYRO3 is related to tumor subtype and stage, patient's age, smoking habits, and obesity. MET expression is correlated to EPHA2 and TAM gene expression. EPHA2 expression is also related to aging and smoking habits. The expression levels of the TAM and EPHA2 genes seem to play an important role in breast cancer, being also influenced by the patient's lifestyle.

Effects of methionine supplementation in a reduced protein diet on growth performance, oxidative status, intestinal health, oocyst shedding, and methionine and folate metabolism in broilers under Eimeria challenge

BackgroundThis study investigated effects of different methionine (Met) supplementation levels in a reduced protein diet on growth performance, intestinal health, and different physiological parameters in broilers under Eimeria challenge. A total of 600 fourteen-day-old Cobb500 male broilers were challenged with E. maxima, E. tenella, and E. acervulina, and randomly allocated in a 2 × 5 factorial arrangement. Birds received normal protein diets (20% crude protein, NCP) or reduced protein diets (17% crude protein, LCP), containing 2.8, 4.4, 6.0, 7.6, and 9.2 g/kg of Met.ResultsOn 6 and 9 days post inoculation (DPI), increasing Met level linearly improved the growth performance (P < 0.05). Total oocyst shedding linearly increased as Met level increased (P < 0.05). Duodenal villus height (VH):crypt depth (CD) in the LCP groups were higher on 6 DPI (P < 0.01) while lower on 9 DPI (P < 0.05) compared to the NCP groups. Jejunal CD and duodenal VH:CD changed quadratically as Met level increased (P < 0.05). On 6 DPI, liver glutathione (GSH) and glutathione disulfide (GSSG) linearly increased as Met level increased (P < 0.05). On 9 DPI, GSSG quadratically increased, whereas GSH:GSSG quadratically decreased as Met levels increased (P < 0.05). The expression of amino acid transporters linearly decreased as Met level increased (P < 0.05). The expression of zonula occludens 2 and claudin-1 linearly increased on 6 DPI whereas decreased on 9 DPI as Met level increased (P < 0.05). The expressions of cytokines were lower in the LCP groups than the NCP groups (P < 0.05). Interaction effects were found for the expression of IL-10 and TNFα on 6 DPI (P < 0.05), where it only changed quadratically in the NCP group as Met level increased. The expression of Met and folate metabolism genes were lower in the LCP groups than the NCP groups on 9 DPI (P < 0.05). The expression of these genes linearly or quadratically decreased as Met level increased (P < 0.05).ConclusionThese results revealed the regulatory roles of Met in different physiological parameters including oxidative status, intestinal health, and nutrient metabolism in birds fed reduced protein diet and challenged with Eimeria.

The clinical utility of a circulating tumor cell based cerebrospinal fluid assay in the diagnosis and molecular analysis of leptomeningeal disease in patients with metastatic non-small cell lung cancer.

8644 Background: Leptomeningeal disease (LMD) is associated with significant morbidity and mortality for metastatic non-small cell lung cancer (mNSCLC). The standard of care for diagnosing LMD remains magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) cytology, but these have limited sensitivity. CSF-based liquid biopsy is an emerging strategy for dynamic assessments of CSF-derived tumor cells to monitor intracranial responses and CNS clonal evolution during treatment and at progression. However, data for the feasibility and utility of this approach is limited. We describe our clinical experience to evaluate the use of molecular analysis on CSF-derived circulating tumor cells (CTCs) for mNSCLC. Methods: Patients with mNSCLC who had a lumbar puncture for CSF collection as part of routine clinical care to rule out LMD were included in the study. CSF was evaluated for CTCs and cell-free DNA (cfDNA) with a commercially available assay (CNSide) and subsequent molecular profiling was performed to detect actionable mutations. Patients were analyzed for LMD with CSF cytology and MRI imaging. Molecular testing results from sequencing of tumor tissue and plasma cell tumor DNA were available for all patients. Other than copy number amplification detection for MET, the CSF assay allowed for analysis of MET and HER2 expression via fluorescent in situ hybridization (FISH). Results: The study included 22 patients with mNSCLC (77% female; median age 60 years; 95% adenocarcinoma). Sensitizing EGFR mutations were found in 78% of patients and 18% had an atypical EGFR mutation at initial diagnosis. LMD was diagnosed using the CSF CTC assay in thirteen of the 22 patients (59%) patients. CSF cytology was negative for LMD in five of 13 cases (38%) and furthermore, 2 of these cases (15%) had normal MRI brain imaging. There were sufficient CTCs to perform molecular profiling on seven of the 13 patients (54%). The concordance with tissue NGS was 100% and the driver mutation was identified in all 7 patients with the CSF CTC assay. MET expression and HER2 expression via FISH were noted in 11 patients (50%) and 4 patients (18%) respectively. Conclusions: In this single institution study, we detected a higher sensitivity to diagnose LMD with CNSide. This CSF assay identified 38% of LMD cases which were missed by standard CSF cytology and of note, 15% of the cases found with LMD were missed by both CSF cytology and MRI. In addition, CSF molecular testing using this assay demonstrated high concordance with tissue-based molecular testing. The study illustrates that multigene molecular analysis of CSF CTCs can be a useful tool for diagnosis, monitoring of response to therapy, as well as for the identification of therapeutic targets specific to the CSF especially for patients with oncogene-driven mNSCLC.

Abstract PO1-25-03: Programmed Death-Ligand 1 and Receptor Tyrosine Kinases in Breast Cancer

Abstract Programmed death-ligand 1 (PD-L1) is an immune checkpoint expressed in a wide range of malignancies leading to immune tolerance and cancer cell immune evasion. Receptor tyrosine kinases (RTKs) are key regulators of cancer cell proliferation, survival, and invasion. The Hepatocyte Growth Factor (HGF) receptor, MET, and the Epidermal Growth Factor Receptor (EGFR) are RTKs known for their tumorigenic potential in a variety of human malignancies. This study aimed to evaluate the effect of the small-molecule tyrosine kinase inhibitors (TKIs) on the expression of PD-L1 in breast cancer cells and the effect of their combination with inflammatory cytokines. The study also assessed the association of the expression of the tumoral PD-L1 mRNA with each of MET and EGFR mRNA expression and the tumor features and treatment outcomes in breast cancer patients using the METABRIC dataset publicly available from cBioPortal for Cancer Genomics. The TKIs crizotinib [a MET inhibitor] and gefitinib [an EGFR inhibitor] were used as a single treatment and in combination with the cytokines; tumor necrosis factor-α (TNF-α) or interferon-γ (INF-γ) in MCF7 and MDA-MB-231 breast cancer cells in vitro. The cells were also treated with the mitogens HGF and EGF. The viability of cells after the different treatments was determined using the MTT viability assay. The effects of the combination treatments were analyzed using combination index (CI) analysis. The expression level of PD-L1 in cancer cells was assessed using Western blotting. The combination treatment of crizotinib with TNF-α and INF-γ produced a synergistic growth inhibition of MCF7 and MDA-MB-231 cells with CI values of 0.31 and 0.55, respectively. Alternatively, combined crizotinib and TNF-α produced an antagonist effect on the viability of MCF7 cells (CI=2.49). The combination of gefitinib with TNF-α produced a synergistic growth inhibition in both MCF7 and MDA-MB-231 cells with CI values of 0.39 and 0.78, respectively. Alternatively, gefitinib resulted in an additive effect when combined with INF-γ (CI=0.99) and an antagonistic effect when combined with TNF-α (CI=2.68) in MCF7 and MDA-MB-231 cells, respectively. Treatment with HGF (50 and 100 ng/ml) increased the protein levels of PD-L1 while EGF (50 and 100 ng/ml) reduced its levels in MDA-MB-231 cells. Treatment with the TKIs crizotinib (0.1-4 µM) and gefitinib (1-40 µM) significantly reduced PD-L1 levels in MDA-MB-231 cells compared to vehicle-treated cells. The analysis of the METABRIC dataset revealed that the mRNA expression of PD-L1 was positively correlated with the mRNA expression of the EGFR gene (r= 0.081, p&amp;lt; 0.001) but not the MET gene. A double-high PD-L1/MET expression was significantly associated with younger age at diagnosis, high-grade carcinoma, greater tumor size, hormone receptor-negative status, HER2-positivity, and non-luminal disease compared to patients with a double-low PD-L1/MET expression. Similar findings were reported for patients with a double-high PD-L1/EGFR expression compared to patients with a double-low PD-L1/EGFR expression. Nevertheless, the mRNA expression of the PD-L1, MET, and EGFR genes as well as the co-expression of PD-L1/MET or PD-L1/EGFR genes did not affect the overall survival of breast cancer patients. Collectively, MET and EGFR TKIs could modulate the effects of inflammatory cytokines differently based on the type of cytokine and the molecular subtype of breast cancer cells. The expression of PD-L1 in breast cancer cells was upregulated by HGF while TKIs reduced its expression. The co-expression of the PD-L1 gene with MET and EGFR genes in breast cancer was associated with advanced disease presentation and worse prognosticators in patients. Together, TKIs that target MET or EGFR could be an appealing therapeutic target in breast cancer, particularly in younger patients with the non-luminal disease. Citation Format: Nehad Ayoub, Muhsen Al-Diabat, Moath Al-Shorman, Laith Al-Eitan. Programmed Death-Ligand 1 and Receptor Tyrosine Kinases in Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-25-03.

Expressions and Clinical Significance of Met and YAP in Gastric Cancer Tissue Microarray.

This study is aimed at investigating the expression of Met and YAP in gastric cancer and their impact on clinical prognosis. Tissue samples and clinical data were collected from 89 patients with gastric cancer. Immunohistochemistry was performed to quantify the expression of Met and YAP using tissue microarray. The correlation between the expressions of Met, YAP, and clinicopathological characteristics of patients was determined using a chi-square test. Survival analysis was conducted using the Kaplan-Meier method, while multivariate survival analysis was performed using the Cox proportional hazard model. Bioinformatics analysis was carried out by downloading chip data from TCGA. The expression levels of both Met and YAP were significantly higher in gastric cancer tissues compared to adjacent tissues (P < 0.001). Met expression showed a positive association with P53 and CD133, whereas YAP expression correlated positively with tumor grade and CD133 (P < 0.05). Pearson's analysis revealed a significant correlation between Met expression and VEGFR as well as CD133, while YAP expression correlated with Ki67 and VEGFR (P < 0.05). Patients with high levels of both Met and YAP exhibited decreased survival time (P < 0.01). Furthermore, Met expression, N stage, and VEGFR were identified as independent risk factors for gastric cancer prognosis (P < 0.05), whereas no such association was observed for YAP expression. Bioinformatics analysis demonstrated a significant correlation between the expressions of Met and YAP; both proteins were highly expressed in gastric cancer patients accompanied by markedly reduced survival time. The expressions of Met and YAP are closely associated with the survival outcomes as well as clinicopathological features in patients with gastric cancer. Moreover, our findings highlight that Met serves as an independent prognostic factor for gastric cancer.

Mesothelin promotes brain metastasis of non-small cell lung cancer by activating MET

BackgroundBrain metastasis (BM) is common among cases of advanced non-small cell lung cancer (NSCLC) and is the leading cause of death for these patients. Mesothelin (MSLN), a tumor-associated antigen expressed in many solid tumors, has been reported to be involved in the progression of multiple tumors. However, its potential involvement in BM of NSCLC and the underlying mechanism remain unknown.MethodsThe expression of MSLN was validated in clinical tissue and serum samples using immunohistochemistry and enzyme-linked immunosorbent assay. The ability of NSCLC cells to penetrate the blood-brain barrier (BBB) was examined using an in vitro Transwell model and an ex vivo multi-organ microfluidic bionic chip. Immunofluorescence staining and western blotting were used to detect the disruption of tight junctions. In vivo BBB leakiness assay was performed to assess the barrier integrity. MET expression and activation was detected by western blotting. The therapeutic efficacy of drugs targeting MSLN (anetumab) and MET (crizotinib/capmatinib) on BM was evaluated in animal studies.ResultsMSLN expression was significantly elevated in both serum and tumor tissue samples from NSCLC patients with BM and correlated with a poor clinical prognosis. MSLN significantly enhanced the brain metastatic abilities of NSCLC cells, especially BBB extravasation. Mechanistically, MSLN facilitated the expression and activation of MET through the c-Jun N-terminal kinase (JNK) signaling pathway, which allowed tumor cells to disrupt tight junctions and the integrity of the BBB and thereby penetrate the barrier. Drugs targeting MSLN (anetumab) and MET (crizotinib/capmatinib) effectively blocked the development of BM and prolonged the survival of mice.ConclusionsOur results demonstrate that MSLN plays a critical role in BM of NSCLC by modulating the JNK/MET signaling network and thus, provides a potential novel therapeutic target for preventing BM in NSCLC patients.

Abstract 1980: Validation of a novel Type II HER2 inhibitor through preclinical studies across various cancer models

Abstract HER2 activation through amplification, overexpression or mutation drives many types of human cancers, and has been the target of several therapeutic approaches. The demonstration of clinical benefit of available pan-ERBB and HER2 inhibitors has been hampered by the dose-limiting side effects from their collateral or residual EGFR inhibition. Here we present IAM1363 (also known as ENT-H1), a highly potent and selective irreversible inhibitor of both HER2 wild-type and HER2 oncogenic mutants. IAM1363 binds to HER2 in a type II DFG-out conformation, the only example reported to date for this target. This binding mechanism underlies its strong interactions with HER2, including N-terminally truncated HER2 (p95HER2) and HER2 kinase domain mutants, with cellular IC50s in the low nanomolar range, while sparing WT EGFR. Oral administration of IAM1363 in mice led to tumor regression (TR) in a diverse set of HER2-driven tumor models at levels well below the maximum tolerated dose (MTD). Importantly, strong in vivo efficacy was observed in tumor models that exhibited resistance to the existing HER2-targeting agents. For example, in a p95HER2 xenograft model, IAM1363 caused significant TR, including complete responses, at 100 mg/kg dose, whereas tucatinib achieved at best tumor stasis at MTD and T-DXd showed marginal effect. Besides HER2 truncation, co-occurring EGFR and other receptor tyrosine kinase (RTK) amplification or overexpression can also lead to resistance to HER2-directed treatments. IAM1363 was tested in xenograft models using HER2-amplified/EGFR-high cell lines HCC1954 and SKOV3, and demonstrated robust TRs. Even more strikingly, IAM1363 led to TR in the HCC827 human lung cancer xenograft model with mid-level HER2, and high levels of EGFR and MET expression. The resistance combatting effect of IAM1363 goes beyond co-occurring RTK-mediated mechanism as IAM1363 also showed dose-dependent TR in KYSE410, a human esophageal squamous cancer xenograft model that harbors the KRAS G12C mutation and HER2 amplification. Taken together, IAM1363 represents a promising clinical candidate for the treatment of HER2-driven tumors. Its unique binding mechanism and potent pan-HER2 activity overcome multiple resistance mechanisms, and its strong EGFR avoidance widens the safety margin. Additionally, IAM1363 was found to be consistently enriched in xenograft tumors that had moderate to high HER2 expression levels, and those with HER2 activating mutations. This distinctive pharmacokinetic property facilitates optimal target engagement in tumors, including those occurring in the brain, while minimizing potential systemic side effects. Citation Format: Lana Kulyk, Kelly Chen, Iriny Botrous, Chunmei Zhao, Chang Zhao, Michael Maestre, Shawn Wright, Joseph Dennis, Jeeyoung Park, Abby Adams, Wallace Derricotte, Shane Yost, Mary L. Anderson, Fred Manby, Tom Miller, Chao Zhang, Laurent Gomez, Zhongdong Huang. Validation of a novel Type II HER2 inhibitor through preclinical studies across various cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1980.

Identify novel inflammation-related prognostic signature in pancreatic cancer patients.

Pancreatic cancer (PC) is a malignant tumor of the digestive system with a poor prognosis. PC patients with pancreatitis have a worse prognosis. But nobody reported the relationship between inflammation and prognosis in PC. Based on this, we are going to explore inflammation-related prognostic signature to predict patients' survival and potential therapeutic target. We screened gene expression profile and corresponding clinical information of patients from The Cancer Genome Atlas (TCGA) database. Gene set enrichment analysis (GSEA) was performed to identify differentially expressed genes (DEGs) between tumor and normal tissues with P value < .05. Univariate and multivariate Cox regression analysis was applied to identify possible prognostic inflammation genes and establish an inflammation-related risk score system, which was validated by Kaplan-Meier and Receiver operating characteristic (ROC) curves. Finally, we used the TISIDB database to predict targeted drugs for up-regulated gene hepatocyte growth factor receptor (MET) and used AUTODOCK software for molecular docking. We built a prognostic model consisted of 3 inflammation-related genes (tumor necrosis factor receptor associated factor 1/TFAR1, tyrosine kinase 2/TYK2, MET). According to the median value of those genes' risk score, PC patients were ranked into high- (88) and low-risk (89) groups. Then, the results of the Kaplan-Meier curves and the area under the curve (AUC) of the ROC curves showed this model had a good predictive power (P < .001, AUC = 0.806). The result of human protein atlas (HPA) database showed the expression of TRAF1 and TYK2 were low in pancreatic cancer, the expression of MET was high. TISIDB database founded brigatinib could target to MET. And AUTODOCK showed brigatinib had a nice docking with MET. Taken together, our study suggested that inflammation-associated prognostic signature might be used as novel biomarkers for predicting prognosis in PC patients and potential therapeutic target of the disease.

KIF20B and MET, hub genes of DIAPHs, predict poor prognosis and promote pancreatic cancer progression

BackgroundThe DIAPHs (DIAPH1, DIAPH2, and DIAPH3) are members of the diaphanous subfamily of the formin family. KIF20B and MET, hub genes of DIAPHs, play crucial roles in cytoskeletal remodeling, cell migration, and adhesion. However, their combined prognostic and treatment value in pancreatic adenocarcinoma (PC) warrants further investigation. MethodsMultiomics analysis tools were used to comprehensively assess the genomic expression and prognostic value of KIF20B and MET in PC. Immune cell infiltration, functional enrichment, single-cell RNA-seq (scRNA) analysis, potential therapeutic drugs, and nomograms were established and analyzed. CCK-8 levels, transwell assay, Co-IP assay, mass spectrometry, and western blotting were performed to assess the role of KIF20B and MET as modulators of β-catenin and Lactate Dehydrogenase A (LDHA) in vitro. Xenograft tumor models were used to evaluate the anti-tumor effects in vivo. ResultsDIAPHs, KIF20B, and MET were overexpressed and functioned as poor prognostic markers of PC. Immunoinfiltration analysis revealed that pDC and NK cells were enriched with low expression levels of KIF20B and MET, whereas Th2 cells were enriched with high expression levels of these two genes. The copy number variations (CNVs) in KIF20B and MET were positively correlated with B cell and CD4 + T cell infiltration. Immunological checkpoints NT5E and CD44 were positively correlated with KIF20B and MET expression. Moreover, the nomogram constructed based on KIF20B and MET demonstrated predictive value for overall survival. scRNA-Seq analysis indicated that KIF20B and MET were enriched in endothelial, malignant, B, T, and CD8 + T cells, which correlated with glycolysis and the epithelial-mesenchymal transition (EMT). The interactions of KIF20B and MET with β-catenin and LDHA were verified by Co-IP assay and mass spectrometry. Knockdown of KIF20B and MET downregulates β-catenin and LDHA in vitro. Furthermore, dual knockdown of KIF20B and MET exhibited a synergistic suppressive effect on PC progression in vitro and in vivo. ConclusionDIAPHs, KIF20B, and MET are promising candidates for the prognosis and treatment of PC. More importantly, downregulation of KIF20B and MET inhibited pancreatic cancer progression by regulating LDHA and EMT.

Abstract 18076: MicroRNA-342-3p Rescues Post-Ischemic Cardiac Function in Diabetic Mice via HGF-MET Pathway Activation

Introduction: - Patients with diabetes have a poorer prognosis following myocardial infarction compared to healthy controls. This is partly due to impaired post-ischemic angiogenesis in the diabetic heart. The role of microRNAs (miRs) in angiogenesis is relatively unexplored. miR expression is responsive to stimuli such as hypoxia, metabolic environment, growth factors, etc. Here, we describe how miR-342-3p, a hypoxia-responsive miR, regulates angiogenesis under physiologic and diabetic conditions. Methods: - miR-342-3p or control mimic was injected into the border zone of hearts post-ischemia/reperfusion in male Ldlr -/- mice on a high fat and high sucrose (HFSC) diet. Echocardiography, histology, immunofluorescence, RNA FISH and in vitro assays were used to elucidate the mechanism of action of this miR. Results: - Ejection fraction (EF) and fractional shortening (FS) of miR-342-3p injected hearts were significantly higher by 145% and 173%, respectively, at day 14 compared to controls (p = 0.0204 and p = 0.0095). Capillary density as well as ki67+ endothelial cells were more abundant by 107% and 154%, respectively (p = 0.0371 and p = 0.0242) vs control. RNA sequencing of miR-342-3p overexpressing endothelial cells implicated HGF-MET signaling as one of the top upregulated pathways. Western blots (WB) revealed an increase in MET expression (p = 0.0255) in miR-342-3p overexpressing cells vs control. Decorin (DCN) was identified as a direct target of miR-342-3p and validated by WB and luciferase reporter assays. Hypoxia (2% O 2 ) induced miR-342-3p expression (p = 0.0023) while suppressing DCN levels. However, both high glucose (25 mM) and palmitate (100 μM) treatments blunted the miR-342-3p induction while increasing Decorin levels. Co-IP and microscopy were used to show Decorin-MET co-localization. Lastly, miR-342-3p and DCN were inversely expressed (p = 0.0188 and p = 0.0015 respectively) in diabetic and healthy ECs obtained from patients. Conclusion: - These findings establish a critical role for miR-342-3p in regulating cardiac angiogenesis post-ischemic injury in diabetic mice. Under diabetic conditions, the hypoxia induced expression of miR-342-3p is blunted, leading to Decorin mediated degradation of MET receptors, which impairs angiogenesis.

408P Increased EGFR and MET expression and corresponding tumor microenvironment (TME) change in hepatocellular carcinoma (HCC) tissues after sorafenib (Sora) treatment

408P Increased EGFR and MET expression and corresponding tumor microenvironment (TME) change in hepatocellular carcinoma (HCC) tissues after sorafenib (Sora) treatment

Clinicopathological and prognostic values of MET expression in pancreatic adenocarcinoma based on bioinformatics analysis.

Pancreatic adenocarcinoma (PAAD) is regarded as one of the most lethiferous cancers worldwide because treatment of pancreatic cancer remains challenging and mostly palliative. Little progress had been made to select certain reliable biomarkers as clinical prognosis. In this context, GSE28735 and GSE16515 were obtained from the Gene Expression Omnibus (GEO). GEO2R tool was used to recognize differentially expressed genes (DEGs). 351 DEGs were screened which included 230 up-regulated genes and 121 down-regulated genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze the DEGs and associated signal pathways in the DAVID database. A protein-protein interaction (PPI) network was then constructed to screen 10 hub genes by STRING database and Cityscape software. Analyses of 10 hub genes were performed on GEPIA database and GSCA database, which revealed that MET was high expressed and significantly associated with survival of PAAD patients. Immunohistochemical staining showed that MET was higher expressed in PAAD tissues than adjacent tissues in 20 samples. The clinicopathological analysis revealed that high expression of MET was associated with the degree of differentiation, lymph node metastasis, vascular cancer thrombus and nerve invasion in PAAD tissues (P < .05). Furthermore, the Tumor Immune Estimation Resource (TIMER) database analyzed the correlation between the MET expression level and immune infiltration levels, which elucidated that MET expression was appreciably positively correlated with the infiltration levels of myeloid-derived suppressor cells (MDSCs). Here, these results strongly indicate MET is an unique prognostic biomarker. Its expression level is correlated with certain clinicopathological features and immune cell infiltration.

Impact of SMAD2 and MET Expression on Lymph Node Metastasis of HER2-positive Gastric Cancer Cells.

Intra-tumoral heterogeneity, which is frequently found in various types of cancers, has been suggested to play an important role in cancer progression and metastasis. The findings of our previous study suggested that p-SMAD2 and c-MET signaling might play important roles in the progression to lymph node metastasis of HER2-positive gastric cancer. In this study, we confirmed the effect of SMAD2/MET signaling in the progression of HER2-positive gastric cancer in an animal model. NCI-N87 cells over-expressing ERBB2, SMAD2, MET were used. To confirm the role of SMAD2 and MET expression on lymph node metastasis of gastric cancer, we orthotopically injected NCI-N87 cells with or without the knockdown of both SMAD2 and MET into the gastric walls of BALBc nude mice. The number of metastatic lymph nodes was significantly smaller in the knockdown group compared to that in the control group. However, there was no significant difference in gastric tumor size between the two groups. SMAD2 and MET signaling might play important roles specifically in the progression to lymph node metastasis of HER2-positive gastric cancer. c-MET and SMAD2 may be useful targets for preventing lymph node metastasis in patients with HER2-positive gastric cancer.

Amivantamab plus lazertinib in osimertinib-relapsed EGFR-mutant advanced non-small cell lung cancer: a phase 1 trial

Patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) often develop resistance to current standard third-generation EGFR tyrosine kinase inhibitors (TKIs); no targeted treatments are approved in the osimertinib-relapsed setting. In this open-label, dose-escalation and dose-expansion phase 1 trial, the potential for improved anti-tumor activity by combining amivantamab, an EGFR-MET bispecific antibody, with lazertinib, a third-generation EGFR TKI, was evaluated in patients with EGFR-mutant NSCLC whose disease progressed on third-generation TKI monotherapy but were chemotherapy naive (CHRYSALIS cohort E). In the dose-escalation phase, the recommended phase 2 combination dose was established; in the dose-expansion phase, the primary endpoints were safety and overall response rate, and key secondary endpoints included progression-free survival and overall survival. The safety profile of amivantamab and lazertinib was generally consistent with previous experience of each agent alone, with 4% experiencing grade ≥3 events; no new safety signals were identified. In an exploratory cohort of 45 patients who were enrolled without biomarker selection, the primary endpoint of investigator-assessed overall response rate was 36% (95% confidence interval, 22–51). The median duration of response was 9.6 months, and the median progression-free survival was 4.9 months. Next-generation sequencing and immunohistochemistry analyses identified high EGFR and/or MET expression as potential predictive biomarkers of response, which will need to be validated with prospective assessment. ClinicalTrials.gov identifier: NCT02609776.

Retrospective immunophenotypical evaluation of MET, PD-1/PD-L1, and mTOR pathways in primary tumors and pulmonary metastases of renal cell carcinoma: the RIVELATOR study addresses the issue of biomarkers heterogeneity.

In renal cell carcinoma (RCC), tumor heterogeneity generated challenges to biomarker development and therapeutic management, often becoming responsible for primary and acquired drug resistance. This study aimed to assess the inter-tumoral, intra-tumoral, and intra-lesional heterogeneity of known druggable targets in metastatic RCC (mRCC). The RIVELATOR study was a monocenter retrospective analysis of biological samples from 25 cases of primary RCC and their paired pulmonary metastases. The biomarkers analyzed included MET, mTOR, PD-1/PD-L1 pathways and the immune context. High multi-level heterogeneity was demonstrated. MET was the most reliable biomarker, with the lowest intratumor heterogeneity: the positive mutual correlation between MET expression in primary tumors and their metastases had a significantly proportional intensity (P = 0.038). The intratumor heterogeneity grade was significantly higher for the mTOR pathway proteins. Combined immunophenotypical expression patterns and their correlations with the immune context were uncovered [i.e., mTOR expression in the metastases positively correlated with PD-L1 expression in tumor-infiltrating lymphocytes (TILs), P = 0.019; MET expression was related to PD-1 expression on TILs (P = 0.041, ρ = 0.41) and peritumoral lymphocytes (RILs; P = 0.013, ρ = 0.49)], suggesting the possibility of predicting drug response or resistance to tyrosine kinase, mTOR, or immune checkpoint inhibitors. In mRCC, multiple and multi-level assays of potentially predictive biomarkers are needed for their reliable translation into clinical practice. The easy-to-use immunohistochemical method of the present study allowed the identification of different combined expression patterns, providing cues for planning the management of systemic treatment combinations and sequences in an mRCC patient population. The quantitative heterogeneity of the investigated biomarkers suggests that multiple intralesional assays are needed to consider the assessment reliable for clinical considerations.

Characteristics of Met gene and its relationship with immune index TMB/MMR genes/DDR genes in Chinese NSCLC population.

147 Background: Patients with driver gene mutations in NSCLC can benefit significantly from corresponding targeted therapy, but respond poorly to immunotherapy (such as EGFR, ALK). As a driver gene of NSCLC, the relationship between the characteristics of Met and many immune indicators in the Chinese population is still unclear. This study aims to elucidate the characteristics of the Met gene and its relationship with immune indicators in the Chinese NSCLC population. Methods: 732 Formalin-Fixed Paraffin-Embedded (FFPE) lung adenocarcinoma samples were collected and detected by Next Generation Sequencing 603-gene panel from July 31, 2021 to March 14, 2023 were selected from the study. The biomarkers of immunotherapy (TMB-High [≥10/Mb], MSI-High, and PD-L1 22C3 [TPS], DDR-related genes (ATM, ATR, BRCA1, BRCA2, BRIP1, CHEK1, CHEK2, FANCA, MRE11, PALB2, RAD50, RAD51C, RAD51D) and MMR-related genes (MLH1, MSH2, MSH6, PMS2) were also calculated. Results: Among the 732 subjects included in the previous detection, a total of 32 cases were detected to carry Met-related gene mutations. The detection rate of Met gene was 4.37%, which was consistent with the mutation probability of Met mutation of 4-6% in previous studies. The median age was 65 (13-97). 81% of patients belonged to mutations of unknown clinical significance (26/32); 15% of patients belonged to exon 14 skipping type (5/32); Met amplification accounted for the least, accounting for only 6% (2/32 ). The top 3 loci of mutation frequency were Met_L221W (4/32), MET_Q1067K (2/32), and MET_F206S (2/32). The gene partners of Met co-mutation were analyzed, and the top five genes were PPP2R1A, HIST1H3G, CDKN1B, SYK, and ERBB4. In the analysis of the immune indicators of the Met mutant population and the Met wild-type population, the Mann-Whitney U test found that among the TMB indicators, the mean value of the Met group was 8.09 with a standard deviation of 7.91, and the mean value of the un-Met group was 5.94 with a standard deviation of 4.98. Met was correlated with TMB with statistical difference (P value 0.02). Among the MSI indicators, the mean value of the Met group was 8.16, and the mean value of the un-Met group was 7.76. The correlation between Met and MSI status was not significant. We also paid attention to Met and DDR-related genes and MMR-related genes. Mann-Whitney U analysis showed that there was no significant correlation between MET group and wild-type MET group and DDR gene (p-value: 1.0), but there was a significant relationship between MET group and wild-type MET group and MMR gene (p-value: 0.026). Conclusions: In the Chinese NSCLC population, there is a correlation between Met expression and TMB, and the Met mutation will increase the TMB value. Met expression was significantly correlated with MMR-related gene mutations.

MACC1 and MET as markers associated with progression and metastasis in cutaneous melanoma.

Cutaneous melanoma is the most common lethal malignancy among skin cancers and has a high propensity for metastasis. Understanding the mechanisms governing tumorigenesis, progression and metastasis as well as identifying biomarkers guiding risk stratification and management of the disease is essential. MACC1 has been found to play key roles in cancer cell migration, invasion, epithelial-to-mesenchymal transition, and metastasis in various types of cancer, through activation of MET signaling. In this study, we examined the extent of MACC1 and MET protein expression by immunohistochemical staining in a tissue microarray constructed from twenty-three melanomas and ten melanocytic nevi. We observed significantly higher levels of MACC1 expression on average in metastatic melanomas, comparing to primary melanomas and nevi. MET expression in metastatic melanomas was also significantly higher than in nevi. MACC1 expression does not appear to correlate with MET expression in nevi and primary melanomas. However, this correlation appears stronger in metastatic melanomas, where seven (78%) of nine cases show intermediate to high expression of both MACC1 and MET. The expressions of MACC1 and MET do not show significant differences based on other clinicopathologic factors including patient age, gender, histologic subtypes, depth of invasion, and staging. Our study suggests that high expression of MACC1 or both MACC1 and MET is associated with metastasis of cutaneous melanoma.

Fibroblast Growth Factor 11 Enables Tumor Cell Immune Escape by Promoting T Cell Exhaustion and Predicts Poor Prognosis in Patients with Lung Adenocarcinoma.

Fibroblast growth factor 11 (FGF11) accelerates tumor proliferation in a variety of cancer types. This study aimed to examine the link between FGF11 and the prognosis of lung adenocarcinoma. FGF11 was searched in the Tumor Cancer Genome Atlas (TCGA) and ImmProt databases. The link between FGF11 and lung cancer clinical data was investigated using TCGA and Kaplan-Meier (KM)-plotter databases, and we developed a prediction model. Putative mechanisms of action were investigated using Gene Ontology (GO) and KEGG enrichment analyses. The GeneMANIA and STRING databases were used to search for genes that interact with FGF11, and the Tumor Immune Estimation Resource (TIMER) database was used to discover connections between FGF11 and immune cells, as well as any correlations with immune-related genes. We found that FGF11 expression was higher in the lung adenocarcinoma tissue than in the paracancerous tissue, and patients with high FGF11 expression had a lower overall survival, progression-free survival, and disease specific survival rate than those with low FGF11 expression. The expression of FGF11 was inversely linked to six types of infiltrating immune cells in the TIMER database and was associated with EGFR, VEGFA, BRAF, and MET expressions. The FGF11 gene is negatively correlated with the expression of most immune cells, mainly with various functional T cells including Th1, Th1-like, Treg, and Resting Treg characterization genes. These results indicate that FGF11 has the potential to be a new lung adenocarcinoma biomarker. It increases tumor cell immune escape by boosting T cell exhaustion in the tumor microenvironment, contributing to the poor prognosis of the patients with lung adenocarcinoma. These results provide incentive to further research FGF11 as a possible biomarker and drug target for patients with lung adenocarcinoma.

Exploring circular MET RNA as a potential biomarker in tumors exhibiting high MET activity

BackgroundMET-driven acquired resistance is emerging with unanticipated frequency in patients relapsing upon molecular therapy treatments. However, the determination of MET amplification remains challenging using both standard and next-generation sequencing-based methodologies. Liquid biopsy is an effective, non-invasive approach to define cancer genomic profiles, track tumor evolution over time, monitor treatment response and detect molecular resistance in advance. Circular RNAs (circRNAs), a family of RNA molecules that originate from a process of back-splicing, are attracting growing interest as potential novel biomarkers for their stability in body fluids.MethodsWe identified a circRNA encoded by the MET gene (circMET) and exploited blood-derived cell-free RNA (cfRNA) and matched tumor tissues to identify, stratify and monitor advanced cancer patients molecularly characterized by high MET activity, generally associated with genomic amplification.ResultsUsing publicly available bioinformatic tools, we discovered that the MET locus transcribes several circRNA molecules, but only one candidate, circMET, was particularly abundant. Deeper molecular analysis revealed that circMET levels positively correlated with MET expression and activity, especially in MET-amplified cells. We developed a circMET-detection strategy and, in parallel, we performed standard FISH and IHC analyses in the same specimens to assess whether circMET quantification could identify patients displaying high MET activity. Longitudinal monitoring of circMET levels in the plasma of selected patients revealed the early emergence of MET amplification as a mechanism of acquired resistance to molecular therapies.ConclusionsWe found that measurement of circMET levels allows identification and tracking of patients characterized by high MET activity. Circulating circMET (ccMET) detection and analysis could be a simple, cost-effective, non-invasive approach to better implement patient stratification based on MET expression, as well as to dynamically monitor over time both therapy response and clonal evolution during treatment.

Lack of correlation between MET and PD-L1 expression in non-small cell lung cancer revealed by comparative study of matched biopsies and surgical resection samples

IntroductionBoth MET expression and the PD-L1 tumor proportion score (TPS) are companion diagnostics for treatment of advanced non-small cell lung carcinoma (aNSCLC) patients. We evaluated the rate of correlation between MET expression and the PD-L1 TPS in matched biopsies and surgically resected specimens from NSCLC patients. Patients and MethodsThis retrospective analysis assessed the prevalence and correlation between MET expression (SP44 clone) and the PD-L1 TPS (22C3 clone) by immunohistochemistry together with molecular alterations determined by targeted next-generation sequencing in matched lung biopsy and surgically lung resected specimens from 70 patients with NSCLC. ResultsThe study found a significant correlation between the MET H-score in surgical samples and matched biopsies (P-value < 0.0001), as well as between the PD-L1 TPS in paired biopsies and surgical samples (P-value < 0.0001). However, there was no significant correlation between the MET H-score or expression subgroups and the PD-L1 TPS in both types of paired samples (P-value = 0.47, and P-value = 0.90). The MET H-score was significantly higher in adenocarcinoma compared to squamous cell carcinoma (P-value < 0.0001). A mutational analysis showed that the MET H-score was significantly higher in NSCLC cases with targetable molecular alterations (P-value = 0.0095), while no significant correlation was found for the PD-L1 TPS. ConclusionsOur study found no significant correlation between PD-L1 and MET expression in samples from NSCLC patients, highlighting the importance of personalized treatment strategies based on individual expression profiles. These findings provide valuable insight into the development of effective immunotherapy and targeted therapy for NSCLC patients.