Therapeutic Strategies for Ovarian Cancer in Point of HGF/c-MET Targeting

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway

AIM

To explore the effects of hepatocyte growth factor (HGF) on retinal pigment epithelium (RPE) cell behaviors.

METHODS

The human adult retinal pigment epithelial cell line-19 (ARPE-19) were treated by HGF or mesenchymal-epithelial transition factor (MET) inhibitor SU11274 in vitro. Cell viability was detected by a Cell Counting Kit-8 assay. Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay, respectively. The expression levels of MET, phosphorylated MET, protein kinase B (AKT), and phosphorylated AKT proteins were determined by Western blot assay. The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.

RESULTS

HGF increased ARPE-19 cells' viability, proliferation and migration, and induced an increase of phosphorylated MET and phosphorylated AKT proteins. SU11274 significantly reduced cell viability, proliferation, and migration and decreased the expression of MET and AKT proteins. SU11274 suppressed HGF-induced increase of viability, proliferation, and migration in ARPE-19 cells. Additionally, SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.

CONCLUSION

HGF enhances cellular viability, proliferation, and migration in RPE cells through the MET/AKT signaling pathway, whereas this enhancement is suppressed by the MET inhibitor SU11274. HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

Deubiquitinase BRCC3 promotes the migration, invasion and EMT progression of colon adenocarcinoma by stabilizing MET expression

BACKGROUND

Breast cancer type 1 susceptibility protein/breast cancer type 2 susceptibility protein-containing complex subunit 3 (BRCC3), a deubiquitinase (DUBs), is overexpressed in various cancers. However, the underlying biological roles of BRCC3 in adenocarcinoma colon (COAD) have yet to be decrypted.

OBJECTIVE

In this work, we explored the potential biological function of BRCC3 in the natural process of COAD cells.

METHODS

The expression levels of BRCC3 in COAD tissues and cell lines were investigated via quantitative real time polymerase chain reaction and western blotting analyses. Meanwhile, short hairpin RNAs targeting BRCC3 (sh-BRCC3) or mesenchymal-epithelial transition factor (MET) (sh-MET) were used to investigate the biological function, including proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) progression in COAD cells. Furthermore, the expression levels of EMT-related biomarkers were detected with western blotting analysis. Furthermore, we also performed Co-IP assay to identify the correlation between BRCC3 and MET.

RESULTS

BRCC3 expression was increased in COAD tissues and cell lines. ShRNA-mediated downmodulation of BRCC3 in COAD cell lines induced EMT progression. BRCC3 knockdown resulted in decreased migration as well as invasion and increased apoptosis of SW480 and Lovo cells. Besides, MET was regulated by BRCC3 and involved in the migration, invasion, and EMT in SW480 and Lovo cells. Finally, we uncovered that the overexpressed MET reversed the effects of BRCC3 knockdown in COAD cell development.

CONCLUSIONS

BRCC3 acted as a critical factor in the development of COAD by deubiquitinating and stabilizing MET, which might provide an emerging biomarker for the therapeutic and diagnosis strategy of COAD.

The anti-tumor effects of AZD4547 on ovarian cancer cells: differential responses based on c-Met and FGF19/FGFR4 expression

BACKGROUND

The FGF/FGFR signaling pathway plays a critical role in human cancers. We analyzed the anti-tumor effect of AZD4547, an inhibitor targeting the FGF/FGFR pathway, in epithelial ovarian cancer (EOC) and strategies on overcoming AZD4547 resistance.

METHODS

The effect of AZD4547 on cell viability/migration was evaluated and in vivo experiments in intraperitoneal xenografts using EOC cells and a patient-derived xenograft (PDX) model were performed. The effect of the combination of AZD4547 with SU11274, a c-Met-specific inhibitor, FGF19-specific siRNA, or an FGFR4 inhibitor was evaluated by MTT assay.

RESULTS

AZD4547 significantly decreased cell survival and migration in drug-sensitive EOC cells but not drug-resistant cells. AZD4547 significantly decreased tumor weight in xenograft models of drug-sensitive A2780 and SKOV3ip1 cells and in a PDX with drug sensitivity but not in models with drug-resistant A2780-CP20 and SKOV3-TR cells. Furthermore, c-Met expression was high in SKOV3-TR and HeyA8-MDR cells, and co-administration of SU11274 and AZD4547 synergistically induced cell death. In addition, expressions of FGF19 and FGFR4 were high in A2780-CP20 cells. Combining AZD4547 with FGF19 siRNA or with a selective FGFR4 inhibitor led to significantly reduced cell proliferation in A2780-CP20 cells.

CONCLUSIONS

This study showed that AZD4547 has significant anti-cancer effects in drug-sensitive cells and PDX models but not in drug-resistant EOC cells. In drug-resistant cells, the expression level of c-Met or FGF19/FGFR4 may be a predictive biomarker for AZD4547 treatment response, and a combination strategy of drugs targeting c-Met or FGF19/FGFR4 together with AZD4547 may be an effective therapeutic strategy for EOC.

SMYD3 Modulates the HGF/MET Signaling Pathway in Gastric Cancer

Gastric cancer (GC) is the third most deadly cancer worldwide. Considerable efforts have been made to find targetable drivers in order to improve patient outcomes. MET is one of the most important factors involved in GC initiation and progression as it plays a major role in GC invasiveness and is related to cancer stemness. Unfortunately, treatment strategies targeting MET are still limited, with a proportion of patients responding to therapy but later developing resistance. Here, we showed that MET is a molecular partner of the SMYD3 methyltransferase in GC cells. Moreover, we found that SMYD3 pharmacological inhibition affects the HGF/MET downstream signaling pathway. Extensive cellular analyses in GC models indicated that EM127, a novel active site-selective covalent SMYD3 inhibitor, can be used as part of a synergistic approach with MET inhibitors in order to enhance the targeting of the HGF/MET pathway. Importantly, our data were confirmed in a 3D GC cell culture system, which was used as a surrogate to evaluate stemness characteristics. Our findings identify SMYD3 as a promising therapeutic target to impair the HGF/MET pathway for the treatment of GC.