c-Met Expression Research Articles

P1.22-19 Determination of the Membranous Expression of cMET in Patients with Advanced NSCLC and RET Fusions

P1.22-19 Determination of the Membranous Expression of cMET in Patients with Advanced NSCLC and RET Fusions

CircNOLC1 Promotes Colorectal Cancer Liver Metastasis by Interacting with AZGP1 and Sponging miR-212-5p to Regulate Reprogramming of the Oxidative Pentose Phosphate Pathway.

Liver metastasis is a common cause of death in progressive colorectal cancer patients, but the molecular mechanisms remain unclear. Here, it is reported that a conserved and oxidative pentose phosphate pathway-associated circular RNA, circNOLC1, plays a crucial role in colorectal cancer liver metastasis. It is found that circNOLC1 silencing reduces the oxidative pentose phosphate pathway-related intermediate metabolites and elevates NADP+ /NADPH ratio and intracellular ROS levels, thereby attenuating colorectal cancer cell proliferation, migration, and liver metastasis. circNOLC1 interacting with AZGP1 to activate mTOR/SREBP1 signaling, or sponging miR-212-5p to upregulate c-Met expression, both of which can further induce G6PD to activate oxidative pentose phosphate pathway in colorectal cancer liver metastasis. Moreover, circNOLC1 is regulated by the transcription factor YY1 and specifically stabilized HuR induces its parental gene mRNA expression. The associations between circNOLC1 and these signaling molecules are validated in primary CRC and corresponding liver metastasis tissues. These findings reveal that circNOLC1 interacting with AZGP1 and circNOLC1/miR-212-5p/c-Met axis plays a key role in oxidative pentose phosphate pathway-mediated colorectal cancer liver metastasis, which may provide a novel target for precision medicine of colorectal cancer.

HGF/C-Met Expression in Epithelial Ovarian Carcinogenesis and Its Potential as Molecular Targeted Therapy

Background: The Mesenchymal-Epithelial Transition factor (C-Met) is a tyrosine kinase receptor (TKR) that binds to a ligand called Hepatocyte Growth Factor (HGF). Recent studies conducted on patients with epithelial ovarian cancer (EOC) reported that high expression of C-Met was associated with poorer clinicopathological grading and outcomes. Therefore, this study aimed to further explore the downstream pathway specifically activated when the HGF/C-Met complex was formed, the interplay between C-Met and other molecules, as well as the impact on EOC when these interactions were inhibited through designated molecular targeted therapy.Methods: The search strategy using the PubMed search engine (https://pubmed.ncbi.nlm.nih.gov/) was conducted on September 21, 2022, with the keywords: “HGF/C-Met and ovarian cancer”. The search resulted in 261 articles, and they were filtered by “published in the last five years,” which yielded 67 articles. These articles then underwent further screening, resulting in 40 articles for analysis. A systematic literature review was conducted to improve the quality of this study. Approximately 150 articles were thoroughly examined and organized using a reference manager, then 15 with the greatest impact and clinical relevance to this study were selected. Results: The HGF/C-Met complex was found to stimulate signaling pathways linked to the growth of epithelial cells and also caused the phosphorylation of tyrosine residues on other tyrosine receptors. The activation of C-Met affected the downstream pathways involving molecules associated with cell proliferation and survival, such as epidermal growth factor receptor (EGFR), p53, and KRAS. C-Met can be combined with other tyrosine kinase inhibitors in chemotherapy to enhance the initiation of cell death (apoptosis) in cancer cells.Conclusions: The HGF/C-Met mediated a signaling cascade that played an essential role in the tumorigenesis of ovarian carcinoma and had the potential to be a targeted molecular therapy in EOC

Near-Infrared Imaging of Colonic Adenomas In Vivo Using Orthotopic Human Organoids for Early Cancer Detection.

Colorectal cancer is a leading cause of cancer-related morbidity and mortality worldwide. Premalignant lesions that are flat and subtle in morphology are often missed in conventional colonoscopies. Patient-derived adenoma colonoids with high and low cMet expression and normal colonoids were implanted orthotopically in the colon of immunocompromised mice to serve as a preclinical model system. A peptide specific for cMet was labeled with IRDye800, a near-infrared (NIR) fluorophore. This peptide was administered intravenously, and in vivo imaging was performed using a small animal fluorescence endoscope. Quantified intensities showed a peak target-to-background ratio at ~1 h after intravenous peptide injection, and the signal cleared by ~24 h. The peptide was stable in serum with a half-life of 3.6 h. Co-staining of adenoma and normal colonoids showed a high correlation between peptide and anti-cMet antibody. A human-specific cytokeratin stain verified the presence of human tissues implanted among surrounding normal mouse colonic mucosa. Peptide biodistribution was consistent with rapid renal clearance. No signs of acute toxicity were found on either animal necropsy or serum hematology and chemistries. Human colonoids provide a clinically relevant preclinical model to evaluate the specific uptake of a NIR peptide to detect premalignant colonic lesions in vivo.

Assessing the safety and activity of cabozantinib combined with lanreotide in gastroenteropancreatic and thoracic neuroendocrine tumors: rationale and protocol of the phase II LOLA trial

BackgroundWell-differentiated (WD) neuroendocrine tumors (NETs) are a group of rare neoplasms with limited therapeutic options. Cabozantinib is an inhibitor of multiple tyrosine kinases with a pivotal role in NET pathogenesis, including c-MET and Vascular Endothelial Growth Factor Receptor 2 (VEGFR2). LOLA is the first prospective phase II trial aiming to assess the safety and activity of cabozantinib combined with lanreotide in WD NETs of gastroenteropancreatic (GEP), thoracic and of unknown origin.MethodsThis is a multicenter, open-label, double-cohort, non comparative, non-randomized, three-stage phase II trial. Eligible patients have to meet the following inclusion criteria: diagnosis of advanced or metastatic, progressive, non-functioning WD thoracic NETs, GEP-NETs or NETs of unknown origin with Ki67 ≥ 10%; positive 68 Ga-PET uptake or somatostatin receptor 2 immunohistochemical (IHC) stain; maximum 1 prior systemic regimen for metastatic disease. Two cohorts will be considered: pNETs and carcinoids (typical or atypical lung and thymus NETs, gastro-intestinal NETs or NETs of unknown origin). In stage I, the primary objective is to find the optimal dose of cabozantinib in combination with lanreotide and to evaluate the safety of the combination (percentage of patients experiencing grade 3–5 toxicities according to NCI-CTCAE version 5.0). Starting dose of cabozantinib is 60 mg/day continuously, plus lanreotide 120 mg every 28 days. In stage II and III, co-primary endpoints are safety and overall response rate (ORR) according to RECIST version 1.1. The uninteresting antitumor activity is fixed in ORR ≤ 5%. Secondary endpoints are progression-free survival and overall survival. Exploratory objectives include the assessment of c-MET, AXL and VEGFR2 IHC expression, to identify predictive or prognostic tissue biomarkers. Enrolment started in July 2020, with an expected trial duration of 42 months comprehensive of accrual, treatment and follow-up. Considering a drop-out rate of 5%, the maximum number of enrolled patients will be 69.DiscussionSupported by a solid rationale, the trial has the potential to generate milestone data about the synergistic effects of cabozantinib plus lanreotide in a group of NET patients with relatively aggressive disease and limited therapeutic options.Trial registrationLOLA is registered at ClinicalTrials.gov (NCT04427787) and EudraCT (2019–004506-10).

Decanoic Acid Exerts Its Anti-Tumor Effects via Targeting c-Met Signaling Cascades in Hepatocellular Carcinoma Model.

DA, one of the medium-chain fatty acids found in coconut oil, is suggested to have diverse biochemical functions. However, its possible role as a chemoprevention agent in HCC has not been deciphered. Aberrant activation of c-Met can modulate tumor growth and progression in HCC. Here, we report that DA exhibited pro-found anti-tumor effects on human HCC through the suppression of HGF/c-Met signaling cascades in vitro and in vivo. It was noted that DA inhibited HGF-induced activation of c-Met and its downstream signals. DA induced apoptotic cell death and inhibited the expression of diverse tumorigenic proteins. In addition, DA attenuated tumor growth and lung metastasis in the HCC mouse model. Similar to in vitro studies, DA also suppressed the expression of c-Met and its downstream signals in mice tissues. These results highlight the substantial potential of DA in the prevention and treatment of HCC.

Efficacy and safety of immunotherapy combined with single-agent chemotherapy as second- or later-line therapy for metastatic non-small cell lung cancer.

This study sought to assess the efficacy and safety of immunotherapy combined with single-agent chemotherapy as a second- or later-line setting for metastatic non-small cell lung cancer (NSCLC) and to provide clinical evidence for this treatment regimen. The predictive value of extracellular vesicle (EV) membrane proteins was explored in patients who underwent this treatment. Clinical data from patients diagnosed with metastatic NSCLC who received immunotherapy plus single-agent chemotherapy as a second- or later-line setting were retrospectively collected between March 2019 and January 2022. A total of 30 patients met the inclusion criteria, and all were pathologically confirmed to have NSCLC. Short-term efficacy, progression-free survival (PFS), EV markers for response prediction, and adverse events were assessed. Efficacy data were available for all 30 patients and included a partial response in 5 patients, stable disease in 18 patients, and disease progression in 7 patients. The objective response rate was 16.7%, the disease control rate was 76.7%, and the median PFS was 3.2 months. Univariate analysis showed that PFS was not associated with sex, age, smoking status, treatment lines, prior use of immunotherapy, or prior use of antiangiogenic drugs. The EV membrane proteins MET proto-oncogene, receptor tyrosine kinase (c-MET), epidermal growth factor receptor (EGFR), and vascular endothelial growth factor receptor 2 (VEGFR2) at baseline were associated with poor prognosis and correlated with the efficacy of immunotherapy plus chemotherapy. According to the receiver operating characteristics and Kaplan-Meier curve analyses, patients with high c-MET, EGFR, and VEGFR2 expression at baseline had significantly shorter PFS than those with low expression. In addition, VEGFR2 expression was increased after combined immunotherapy in responders, which was decreased in non-responders. The most common grade 2 or higher adverse events were neutropenia, gastrointestinal reactions, and thyroid dysfunction, all of which were tolerated. Immunotherapy plus single-agent chemotherapy as a second- or later-line treatment is safe, effective, and tolerable for metastatic NSCLC. EV markers can be used as predictive markers of efficacy in patients with metastatic NSCLC treated with immunotherapy plus chemotherapy to help monitor treatment efficacy and guide treatment decisions.

Hypoxia-induced HIF-1α promotes Listeria monocytogenes invasion into tilapia.

HIF-1α is a nuclear transcription factor, and its activity is tightly regulated by the level of available oxygen in cells. Here, we investigated the roles of HIF-1α in the invasion of Listeria monocytogenes into tilapia under hypoxic environments. We found that the expression levels of HIF-1α in examined tissues of hypoxic tilapia were significantly upregulated, indicating that the tissue cells have been in hypoxic conditions. After 24-h infection with L. monocytogenes, we found that bacterial burden counts increased significantly in all examined tissues of hypoxic fish. To explore why the bacterial count increased significantly in the tissues of hypoxic fish, we modulated HIF-1α expression through RNAi technology. The results indicated that c-Met expression levels were positively related to HIF-1α expression. Since c-Met is the receptor of InlB that plays critical roles in the adhesion and invasion of L. monocytogenes, the ∆InlB strain was used to further explore the reason for the significant increase in bacterial counts in hypoxic fish. As expected, the decrease in the adhesion ability of ∆InlB suggested that InlB mediates L. monocytogenes infection in tilapia. After being infected with ∆InlB strain, we found that the bacterial counts in hypoxic fish were not affected by hypoxic conditions or HIF-1α expression levels. These findings indicate that HIF-1α may promote the internalization of InlB by upregulating c-Met expression and therefore contributes to the invasion of L. monocytogenes into hypoxic tilapia. IMPORTANCE Listeria monocytogenes is a zoonotic food-borne bacterial pathogen with a solid pathogenicity for humans. After ingestion of highly contaminated food, L. monocytogenes is able to cross the intestine invading phagocytic and nonphagocytic cells and causes listeriosis. China is the world's largest supplier of tilapia. The contamination rate of L. monocytogenes to tilapia products was as high as 2.81%, causing a severe threat to public health. This study revealed the underlying regulatory mechanisms of HIF-1α in the invasion of L. monocytogenes into tilapia under hypoxic environments. This study will be helpful for better understanding the molecular mechanisms of hypoxic environments in L. monocytogenes infection to tilapia. More importantly, our data will provide novel insights into the prevention and control of this pathogen in aquaculture.

α-Fetoprotein contributes to the malignant biological properties of AFP-producing gastric cancer.

This study aimed to investigate whether α-fetoprotein (AFP) could affect the malignant behavior of AFP-producing gastric cancer (AFP-GC) and to explore the relationship between AFP and mesenchymal-epithelial transition factor (c-Met) in AFP-GC. In this study, 23 patients with AFP-GC (AFP[+]) and 18 patients with common gastric cancer (AFP[-]) were evaluated for the c-Met expression using immunohistochemical analysis. The AFP-GC cell line, GCIY, was used. The AFP endoribonuclease-prepared small interfering RNA (siRNA) and eukaryotic AFP overexpression vector were used to increase/knockdown the expression of AFP. Afterward, the c-Met expression was evaluated by polymerase chain reaction and western blot. The proliferation, migration, and invasion of GCIY cells were estimated before and after the AFP overexpression/knockdown. The c-Met expression in both groups was the same (p > 0.05), and AFP[+] group had a higher positive incidence of the c-Met expression than the AFP[-] group (p < 0.01). Furthermore, the c-Met expression frequency was decreased by AFP knockdown and increased by AFP overexpression (p < 0.01). The cell counting kit-8 cell proliferation assay, cell invasion, and migration assays confirmed that the AFP could affect the malignant biological behavior of AFP-GC. These findings suggest that AFP contributes to the malignant biological properties of AFP-GC and the high expression of c-Met in AFP-GC.

Plasma microRNA-195, −34c, and − 1246 as novel biomarkers for the diagnosis of trastuzumab-resistant HER2-positive breast cancer patients

Recently, miRNAs have been regarded as potential candidates for mediating therapeutic functions by targeting genes related to drug response. In this study, we suggested that plasma miRNAs may be correlated with response to trastuzumab in HER2-positive breast cancer patients. To determine whether miR-195, miR-23b-3p, miR-1246, and miR-34c-3p are involved in trastuzumab resistance, we screened their expressions in the BT-474 cell line, which was followed by plasma analysis from 20 trastuzumab-resistant HER2-positive breast cancer patients and 20 nonresistance subjects. Then, TargetScan, Pictar, and miRDB were applied to find the possible targets of the selected miRNAs. In addition, the expression status of admitted targets was evaluated. Our results showed that in resistant BT-474 cells, miR-1246, and miR-23b-3p were significantly upregulated, and miR-195-5p and miR-34c-3p were downregulated. In plasma analysis, we found miR-195-5p, miR-34c-3p, and miR-1246 meaningfully diminished in the resistant group, while the expression of miR-23b-3p was not statistically different. The expression levels of confirmed targets by qRT-PCR showed that the expression of RAF1, AKT3, c-MET, CCND1, PHLPP2, MYB, MAP2K1, and PTEN was significantly upregulated, while the expression of CCNG2 was significantly downregulated. The networks of miRNAs with their confirmed targets improved comprehension of miRNA-mediated therapeutic responses to trastuzumab and might be proposed for more characterization of miRNA functions. Moreover, these data indicated that miR-195-5p, miR-34c-3p, and miR-1246 could be possible biomarkers for prognosis and early detection of the trastuzumab-resistant group from the sensitive group of HER2-positive breast cancer patients.

Low co-expression of PD-L1 and oncogenic receptor tyrosine kinases HER2 and cMET in urothelial carcinoma is associated with discordant expression between primary and metastatic sites

Novel regimens targeting immune checkpoints and the cMET or HER2 pathways are under investigation in metastatic urothelial carcinoma (mUC) though co-expression of these molecular targets has not been defined. We sought to characterize the protein co-expression rates of PD-L1, cMET and HER2 in primary and metastatic mUC lesions and agreement rates in paired biopsies.We assessed PD-L1, cMET and HER2 protein expression by immunohistochemistry (IHC) in archival mUC samples identified from an institutional database (n = 143). Correlation of expression between primary and metastatic biopsies was performed in patients with available paired biopsies (n = 79). Protein expression levels by predefined thresholds were measured, and Cohen's kappa statistics (κ) were utilized to assess the agreement in expression between paired primary and metastatic samples.In primary tumors (n = 85), high expression of PD-L1, cMET, and HER2 was observed in 14.1%, 34.1%, and 12.9%, respectively. In metastatic samples (n = 143), high expression of PD-L1, cMET and HER2 was detected in 9.8%, 41.3%, and 9.8%, respectively. Expression agreement rates between paired specimens (n = 79) were PD-L1: 79.7% (κ = 0.09), cMET: 69.6% (κ = 0.35), HER2: 84.8% (κ = 0.17). High PD-L1/cMET co-expression was observed in only 5.1% (n = 4) of primary and 4.9% (n = 7) of metastatic specimens. High co-expression of PD-L1/HER2 occurred in 3.8% (n = 3) of primary samples and no metastatic samples. The overall co-expression agreement between paired samples was 55.7% (κ = 0.22) for PD-L1/cMET and 67.1% (κ = 0.06) for PD-L1/HER2, but agreement for high co-expression between paired samples was very low (2.5% for PD-L1/cMET and 0% for PD-L1/HER2).Tumor co-expression of high cMET or HER2 and PD-L1 is low in this cohort. Agreement of high co-expression between primary and metastatic sites is rare. Biomarker-based strategies used in selection of patients for contemporary trials testing combinations of immune checkpoint inhibitors with either cMET or HER2-targeted agents should account for discordant biomarker expression between primary and metastatic sites.

Identification of c-Met as a novel target of γ-glutamylcyclotransferase.

γ-Glutamylcyclotransferase (GGCT) is highly expressed in multiple types of cancer tissues and its knockdown suppresses the growth of cancer cells in vitro and in vivo. Although GGCT is a promising target for cancer therapy, the mechanisms underlying the antitumor effects remain unclear. The knockdown of GGCT inhibited the MEK-ERK pathway, and activated the tumor suppressor retinoblastoma gene (RB) at the protein level in cancer cell lines. c-Met was down-regulated by the knockdown of GGCT in cancer cells and its overexpression attenuated the dephosphorylation of RB and cell cycle arrest induced by the knockdown of GGCT in lung cancer A549 cells. STAT3 is a transcription factor that induces c-Met expression. STAT3 phosphorylation and its nuclear expression level were decreased in GGCT-depleted A549 and prostate cancer PC3 cells. The simultaneous knockdown of AMPK and GGCT restored the down-regulated expression of c-Met, and attenuated the dephosphorylation of STAT3 and MEK-ERK-RB induced by the knockdown of GGCT in PC3 cells. An intraperitoneal injection of a GGCT inhibitor decreased c-Met protein expression in a mouse xenograft model of PC3 cells. These results suggest that the knockdown of GGCT activates the RB protein by inhibiting the STAT3-c-Met-MEK-ERK pathway via AMPK activation.

Two Enhances the Cisplatin Sensitivity of Cervical Cancer Cells via Suppression of c-MET Expression.

The drug resistance of chemotherapeutic agents leads to unsatisfactory survival rates for cervical cancer (CC) patients. We aimed to explore the effect of FOXP2 on the sensitivity of CC cells to cisplatin (DDP) and its mechanism in Changde, China in 2018. A Total of 6 cervical cancer tissue samples including 3 patients with cisplatin sensitivity and 3 patients with cisplatin resistance, who received DDP-based treatment, were obtained from Changde First People's Hospital, Changde City during 2021, and FOXP2 level was detected by Western blot. The expression levels of FOXP2 and c-MET (hepatocyte growth factor receptor, c-MET) in cells were determined by q-PCR and Western blot analysis. The cell survival, apoptosis, and clone formation were analyzed by flow cytometry, MTT assay, or clone formation assay. Dual-luciferase reporter assays and Chromatin immunoprecipitation were applied to verify the regulation between FOXP2 and c-MET. FOXP2 was downregulated in cisplatin-resistant cervical cancer tissues and cells compared with control. FOXP2 overexpression in SiHa/DDP cells inhibited cell proliferation and promoted cell apoptosis, whereas down-regulation of FOXP2 in SiHa cells had the opposite result. FOXP2 enhanced chemosensitive to DDP in CC cells. FOXP2 is negatively correlated with c-MET expression level in SiHa and SiHa/DDP cells. Mechanistically, FOXP2 binds to the promoter region of c-MET to regulate its expression in CC cells negatively. Overexpression of c-MET can attenuate the enhancement of DDP-induced apoptosis caused by FOXP2 overexpression. This is a novel study on the role of FOXP2 in promoting the DDP sensitivity of CC cells by inhibiting c-MET. The FOXP2/c-MET signaling axis uncovered in the present study may be a novel therapeutic target for the DDP therapy resistance of CC.

C-Met is a chimeric antigen receptor T-cell target for treating recurrent nasopharyngeal carcinoma

Background aimsRadiation therapy is the standard treatment for patients with nasopharyngeal carcinoma (NPC), but relapse occurs in 10% to 20% of patients. The treatment of recurrent nasopharyngeal carcinoma (rNPC) remains challenging. Chimeric antigen receptors (CAR)-T-cell therapy has achieved good outcomes in the treatment of leukemia and seems to be a promising therapeutic strategy for solid tumors. c-Met has been found to be highly expressed in multiple cancer types, and the activation of c-Met leads to the proliferation and metastasis of cancer cells. However, the expression of c-Met in rNPC tissues and whether it can be used as a target for CAR-T therapy in rNPC remain to be investigated. MethodsWe detected the expression of c-Met in 24 primary human rNPC tissues and three NPC cell lines and constructed two different antibody-derived anti-c-Met CARs, namely, Ab928z and Ab1028z. To estimate the function of these two different c-Met-targeted CAR-T cells, CD69 expression, cytotoxicity and cytokine secretion of CAR-T cells were assessed after coculture with target cells. A cell line-derived xenograft mouse model also was used to evaluate these two anti-c-Met CAR-T cells. Furthermore, we determined whether combination with an anti-EGFR antibody could promote the antitumor effect of CAR-T cells in a patient-derived xenograft mouse model. ResultsHigh c-Met expression was detected in 23 of 24 primary human rNPC tissues by immunohistochemistry staining and in three NPC cell lines by flow cytometry. Ab928z-T cells and Ab1028z-T cells showed significantly upregulated expression of CD69 after coculture with targeted cells. However, Ab1028z-T cells showed superior cytokine secretion and antitumor activity. Furthermore, Ab1028z-T cells effectively suppressed tumor growth compared with control CAR-T cells, and the combination with nimotuzumab further enhanced the tumor-clearing ability of Ab1028z-T cells. ConclusionsWe found that c-Met is highly expressed in rNPC tissues and confirmed its potential as a CAR-T target for rNPC. Our study provides a new idea for the clinical treatment of rNPC.

HGF-Based CAR-T Cells Target Hepatocellular Carcinoma Cells That Express High Levels of c-Met

ABSTRACT Background CAR-T is emerging as an effective treatment strategy for hematologic malignancies, however its effectiveness for treating solid tumors, such as Hepatocellular Carcinoma (HCC) is limited. Here, we screened a variety of CAR-T cells that target c-Met to investigate their potential to induce HCC cell death in vitro. Methods Human T cells were transduced to express CARs by lentiviral vector transfection. c-Met expression in human HCC cell lines and CARs expression were monitored by flow cytometry. Tumor cell killing was evaluated by Luciferase Assay System Kit. The concentrations of cytokine were tested by Enzyme-linked immunosorbent assays. Knock down and overexpression studies targeting c-Met were conducted to assess the targeting specificity of CARs. Results We found that CAR T cells expressing a minimal amino-terminal polypeptide sequence comprising the first kringle (kringle 1) domain (denoted as NK1 CAR-T cells), efficiently killed HCC cell lines that expressed high levels of the HGF receptor c-Met. Furthermore, we report that while NK1 CAR-T cells were efficient at targeting SMMC7221 cells for destruction, and its potency was significantly attenuated in parallel experiments with cells stably expressing short hairpin RNAs (shRNAs) that suppressed c-Met expression. Correspondingly, overexpression of c-Met in the embryonic kidney cell line HEK293T led to their enhanced killing by NK1 CAR-T cells. Conclusion Our studies demonstrate that a minimal amino-terminal polypeptide sequence comprising the kirngle1 domain of HGF is highly relevant to the design of effective CAR-T cell therapies that kill HCC cells expressing high levels of c-Met.

1175-P: The Alteration of Serum Level and Expression of c-MET in Gestational Diabetes Mellitus (GDM)

Objective: The aim of this study was to explore changes in serum levels and tissue expression of HGF and c-MET, and to determine how HGF/c-MET signaling contributes to the pathophysiology of GDM. Methods: A total of 44 pregnant women with normal glucose tolerance (NGT) and 32 pregnant women with GDM were studied. Blood samples were taken just before delivery, and placenta and visceral adipose tissue were taken immediately after cesarean delivery. Serum levels of HGF, soluble c-MET and insulin were measured by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of HGF and c-MET was measured in the placenta and visceral adipose tissue. In addition, we investigated pregnancy of high fat diet (HFD) mice as an animal model of GDM. The glucose tolerance test (GTT) was performed at GD 10, and measured the serum levels of Hgf and soluble c-Met at GD 16. After scarifying mice, we measured the weight and expression of mRNA of Hgf and c-Met in WAT, placenta, liver and muscle. Results: Serum soluble c-MET levels were significantly higher in the GDM group (p &amp;lt;0.001). In multiple logistic regression analysis, soluble serum c-MET level was strongly associated with GDM (OR 9.063, p=0.027). There were more patients with increased mRNA expression of HGF and c-MET in placenta. Interestingly, the protein expression of HGF and c-MET in maternal visceral fat tissue was significantly higher in the GDM group. In mouse study, maternal serum levels of soluble c-Met in pregnant HFD (PH) mice were higher than in non-pregnant HFD (NPH) mice and pregnant chow diet (PC) mice. Relative mRNA expression of Hgf was significantly increased in eWAT of PH than PC mice. Relative c-Met mRNA expression was significantly increased in sWAT of PH than PC mice. Conclusion: We observed the differences in serum levels and expression of HGF and c-MET between GDM and control pregnant women in human and mice model. Our results suggest that HGF/c-MET signaling may be altered in GDM, which associated with insulin resistance and pathophysiology in GDM. Disclosure H.Kim: None. J.Lee: None. Y.Jung: None. M.Lee: None. J.Kim: None. K.Joung: None. B.Ku: Speaker's Bureau; AstraZeneca, Boehringer-Ingelheim, Eli Lilly and Company, Sanofi, Novo Nordisk, LG Chem. Funding National Research Foundation of Korea (2022R1F1A1074608)

Phase 1 multicenter dose escalation and dose expansion study of antibody-drug conjugate (ADC) MYTX-011 in subjects with non-small cell lung cancer.

TPS9147 Background: cMET is a receptor tyrosine kinase and proto-oncogene whose activity is upregulated across a wide range of cancers. In NSCLC, expression of cMET is upregulated by DNA amplification (2% to 5%), exon 14 skipping mutations (2% to 4%), and overexpression (30% to 60%). In NSCLC, cMET upregulation has also been demonstrated to be a resistance mechanism for several approved EGFR-targeted kinase inhibitors, and this may limit their effectiveness. Despite the approval of MET tyrosine kinase inhibitors, almost half of patients do not respond to these inhibitors and resistance is inevitable. MYTX-011 is an ADC incorporating the clinically validated vcMMAE linker-payload conjugated to a novel, pH-dependent anti-cMET antibody. In preclinical studies, MYTX-011, compared to a surrogate of an advanced clinical stage cMET ADC, showed markedly higher ( &gt; 3 fold) internalization and increased cytotoxicity in cMET+ tumor cells in vitro, which translates to greater (≥3 fold) efficacy in high or moderate c-Met+ xenograft models in vivo. PK and toxicity studies revealed that MYTX-011 exhibited favorable PK characteristics, and a toxicity profile similar to previously described MMAE-based ADCs. Methods: MYTX-011-01 (ClinicalTrials.gov Identifier: NCT05652868) is a first-in-human Phase 1 dose escalation and dose expansion study. MYTX-011 will be administered intravenously every 21 days for a maximum of 2 years. Part 1 (dose escalation) will assess the safety and tolerability of MYTX-011 in patients with advanced NSCLC and identify the recommended Phase 2 dose (RP2D). Part 2 (dose expansion) will include subjects with NSCLC with cMET overexpression or MET amplification/exon 14 skipping mutations. In Part 1, subjects will be enrolled to evaluate the safety of escalating doses of MYTX-011 as a single-agent and to establish the RP2D and/or MTD. The dose escalation scheme is based on a 3-subject cohort minimum Bayesian Optimal Interval (BOIN) design. The RP2D will be selected as a biologically active dose at or below the MTD (or the highest dose tested if an MTD is not identified during the study) and will be informed by safety, tolerability, pharmacokinetic data, and preliminary anti-tumor activity of MYTX-011 based on RECIST 1.1. Part 2 of the study will be initiated once the RP2D has been determined and will enroll subjects into different cohorts based on cMET IHC positivity cutoff and/or presence of MET genetic alterations ( MET amplification or exon 14 skipping). All cohorts are defined to explore preliminary antitumor activity in populations with different thresholds of cMET positivity that were selected based on data for cMET expression and efficacy observed with MYTX-011 in preclinical models, published data for responses to cMET targeting agents, and on the prevalence of subject tumors with different expression levels. Enrollment in the MYTX-011-01 study is ongoing. Clinical trial information: NCT05652868 .

Tissue-Engineered Hepatocyte Sheets Supplemental with Adipose-derived Stem Cells.

The ability to engineer biologically viable hepatocytes and tissue matrices with long-term functional maintenance has attracted considerable interest in the fields of hepatocyte transplantation and liver tissue engineering. Here, newly developed hepatocyte sheets supplemented with adipose-derived stem cells (ADSCs) were evaluated to assess the effects of ADSCs on hepatocyte function and engraftment into the subcutaneous space. Eight-week-old male C57BL/6J mice were used as donors and 6-week-old male C.B-17/Icr-scid/scid mice were used as recipients. Hepatocyte-ADSC composite sheets were developed using temperature-responsive culture dishes. Hepatocyte viability in the hepatocyte-ADSC composite sheets was evaluated in an in vitro assay, and the outcome of subcutaneous transplantation of the sheet was evaluated. Hepatocyte viability was sustained in the hepatocyte-ADSC composite sheets in vitro. Albumin secretion was significantly higher (p = 0.015) in the hepatocytes of the hepatocyte-ADSC composite sheets (70.5 μg/mL) than in hepatocyte-only sheets (24.0 μg/mL). Cytokine assays showed that hepatocyte growth factor and interleukin-6 were contributed by ADSCs and not hepatocytes, which were not capable of constitutively secreting them. Immunohistochemically, phosphorylated STAT3 and c-MET expression in hepatocytes in the hepatocyte-ADSC composite sheets was significantly higher than that in the hepatocyte-only sheets. Engraftment of the transplanted hepatocyte-ADSC composite sheets was significantly enhanced without pretreatment of the subcutaneous tissue to induce a vascular network. In the hepatocyte-ADSC composite sheets, the viability of the hepatocytes was significantly maintained as the co-cultured ADSCs provided cytokines, enhancing pivotal cell signaling necessary for hepatocyte activity.

Preclinical evaluation of a novel EGFR&c-Met bispecific near infrared probe for visualization of esophageal cancer and metastatic lymph nodes.

This study aimed to establish a near infrared fluorescent (NIRF) probe based on an EGFR&c-Met bispecific antibody for visualization of esophageal cancer (EC) and metastatic lymph nodes (mLNs). EGFR and c-Met expression were assessed by immunohistochemistry. EGFR&c-Met bispecific antibody EMB01 was labeled with IRDye800cw. The binding of EMB01-IR800 was assessed by enzyme linked immunosorbent assay, flow cytometry, and immunofluorescence. Subcutaneous tumors, orthotopic tumors, and patient-derived xenograft (PDX) were established for in vivo fluorescent imaging. PDX models using lymph nodes with or without metastasis were constructed to assess the performance of EMB01-IR800 in differential diagnosis of lymph nodes. The prevalence of overexpressing EGFR or c-Met was significantly higher than single marker either in EC or corresponding mLNs. The bispecific probe EMB01-IR800 was successfully synthesized, with strong binding affinity. EMB01-IR800 showed strong cellular binding to both Kyse30 (EGFR overexpressing) and OE33 (c-Met overexpressing) cells. In vivo fluorescent imaging showed prominent EMB01-IR800 uptake in either Kyse30 or OE33 subcutaneous tumors. Likewise, EMB01-IR800 exhibited superior tumor enrichment in both thoracic orthotopic esophageal squamous cell carcinoma and abdominal orthotopic esophageal adenocarcinoma models. Moreover, EMB01-IR800 produced significantly higher fluorescence in patient-derived mLNs than in benign lymph nodes. This study demonstrated the complementary overexpression of EGFR and c-Met in EC. Compared to single-target probes, the EGFR&c-Met bispecific NIRF probe can efficiently depict heterogeneous esophageal tumors and mLNs, which greatly increased the sensitivity of tumor and mLN identification.

The Receptor Tyrosine Kinase c-Met Promotes Lipid Accumulation in 3T3-L1 Adipocytes.

The receptor tyrosine kinase c-Met is elaborated in embryogenesis, morphogenesis, metabolism, cell growth, and differentiation. JNJ38877605 (JNJ) is an inhibitor of c-Met with anti-tumor activity. The c-Met expression and its role in adipocyte differentiation are unknown. Here, we investigated the c-Met expression and phosphorylation, knockdown (KD) effects, and pharmacological inhibition of c-Met by JNJ on fat accumulation in murine preadipocyte 3T3-L1 cells. During 3T3-L1 preadipocyte differentiation, strikingly, c-Met expression at the protein and mRNA levels and the protein phosphorylation on Y1234/1235 and Y1349 is crucial for inducing its kinase catalytic activity and activating a docking site for signal transducers were increased in a time-dependent manner. Of note, JNJ treatment at 20 μM that strongly inhibits c-Met phosphorylation without altering its total expression resulted in less lipid accumulation and triglyceride (TG) content with no cytotoxicity. JNJ further reduced the expression of adipogenic regulators, including CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), and perilipin A. Moreover, JNJ treatment increased cAMP-activated protein kinase (AMPK) and liver kinase B-1 (LKB-1) phosphorylation but decreased ATP levels. Significantly, KD of c-Met suppressed fat accumulation and triglyceride (TG) quantity and reduced the expression of C/EBP-α, PPAR-γ, FAS, ACC, and perilipin A. Collectively, the present results demonstrate that c-Met is a novel, highly conserved mediator of adipogenesis regulating lipid accumulation in murine adipocytes.