Targeting the HGF/MET pathway in gastric cancer

Metabolism-associated genes in occurrence and development of gastrointestinal cancer: Latest progress and future prospect

Gastrointestinal (GI) cancer remains one of the most prevalent cancers in the world. The occurrence and progression of GI cancer involve multiple events. Metabolic reprogramming is one of the hallmarks of cancer and is intricately related to tumorigenesis. Many metabolic genes are involved in the occurrence and development of GI cancer. Research approaches combining tumor genomics and metabolomics are more likely to provide deeper insights into this field. In this paper, we review the roles of metabolism-associated genes, especially those involved in the regulation pathways, in the occurrence and progression of GI cancer. We provide the latest progress and future prospect into the different molecular mechanisms of metabolism-associated genes involved in the occurrence and development of GI cancer.

MET transcriptional regulator/serine peptidase inhibitor kunitz type 1 panel operating through HGF/c-MET axis as a prognostic signature in pan-cancer

Dysregulations in transcription factors (TFs) and their genetic products play important roles in tumorigenesis, tumor progression and metastasis. However, prognostic value of the transcriptional regulatory networks in different cancers has not been investigated in depth. The purpose of our study was to identify and validate a potential predictive signature that combines TFs and their regulatory products in eight solid tumors. We used bioinformatics analysis to identify MET Transcriptional Regulator (MACC1) and Serine Peptidase Inhibitor Kunitz Type 1 (SPINT1) as candidate TFs with the respective downstream regulatory proteins for patient prognosis in pan‐cancer. Subsequent molecular analysis of clinical gastric cancer tissue samples further verified the negative correlation between MACC1 and SPINT1. Further, we showed that mechanistically, MACC1/SPINT1 mediated the pro‐HGF proteolysis and c‐Met phosphorylation in HGF/c‐MET signaling pathway. Kaplan‐Meier plots and receiver operating characteristics analysis revealed that the two‐gene signature combining MACC1 with SPINT1 was effective in predicting survival in all eight cancer cohorts tested. In conclusion, our study clarified the regulatory relationship between MACC1 and SPINT1 in the context of the HGF/c‐MET signaling pathway and determined MACC1/SPINT1 panel as a valuable signature for the prediction of prognosis in patients for multiple solid cancer types.

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

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

Analysis of the Effect of Increased α2,3-Sialylation on RTK Activation in MKN45 Gastric Cancer Spheroids Treated with Crizotinib

In the scenario of personalized medicine, targeted therapies are currently the focus of cancer drug development. These drugs can block the growth and spread of tumor cells by interfering with key molecules involved in malignancy, such as receptor tyrosine kinases (RTKs). MET and Recepteur d'Origine Nantais (RON), which are RTKs frequently overactivated in gastric cancer, are glycoprotein receptors whose activation have been shown to be modulated by the cellular glycosylation. In this work, we address the role of sialylation in gastric cancer therapy using an innovative 3D high-throughput cell culture methodology that mimics better the in vivo tumor features. We evaluate the response to targeted treatment of glycoengineered gastric cancer cell models overexpressing the sialyltransferases ST3GAL4 or ST3GAL6 by subjecting 3D spheroids to the tyrosine kinase inhibitor crizotinib. We show here that 3D spheroids of ST3GAL4 or ST3GAL6 overexpressing MKN45 gastric cancer cells are less affected by the inhibitor. In addition, we disclose a potential compensatory pathway via activation of the Insulin Receptor upon crizotinib treatment. Our results suggest that cell sialylation, in addition of being involved in tumor progression, could play a critical role in the response to tyrosine kinase inhibitors in gastric cancer.

A 18FDG PET/CT-based volume parameter is a predictor of overall survival in patients with local advanced gastric cancer

Objective

The present study investigated the prognosis value of preoperative fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with local advanced gastric cancer (LAGC).

Methods

In total, 144 patients [median age 63 (range: 48−80) years old] with LAGC underwent¹⁸F-FDG PET/CT prior to any treatment. The maximum standardized uptake values (SUV_max), mean standardized uptake values (SUV_mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were measured on PET/CT and correlated with clinicopathological features and survival.

Results

Significant differences in SUV_mean, SUV_max, MTV and TLG were found according to Lauren’s classification, histologic grade and T category (P<0.05). During the 26.5-month follow-up, 51 (35.4%) patients died and 70 (48.6%) exhibited disease progression. The optimal thresholds of MTV and TLG were 15.1 cm³ and 47.3 cm³, respectively. The 3-year progression-free survival (PFS) and overall survival (OS) for patients with high TLG values were 30% and 38% compared to 38% and 47% for low TLG values, respectively (P<0.05). Univariate and multifactor analyses demonstrated that lymph node metastasis and T stage were independent prognostic factors for PFS; T stage, histologic grade and TLG were independent prognostic factors for OS (P<0.05). Molecular markers had no relationship with patient’s outcomes.

Conclusions

Metabolic activity of primary gastric tumors from ¹⁸F-FDG PET/CT is a prognostic factor in patients with LAGC.

Long-lasting discussion: Adverse effects of intraoperative blood loss and allogeneic transfusion on prognosis of patients with gastric cancer

Gastrectomy with radical lymph node dissection is the most promising treatment avenue for patients with gastric cancer. However, this procedure sometimes induces excessive intraoperative blood loss and requires perioperative allogeneic blood transfusion. There are lasting discussions and controversies about whether intraoperative blood loss or perioperative blood transfusion has adverse effects on the prognosis in patients with gastric cancer. We reviewed laboratory and clinical evidence of these associations in patients with gastric cancer. A large amount of clinical evidence supports the correlation between excessive intraoperative blood loss and adverse effects on the prognosis. The laboratory evidence revealed three possible causes of such adverse effects: anti-tumor immunosuppression, unfavorable postoperative conditions, and peritoneal recurrence by spillage of cancer cells into the pelvis. Several systematic reviews and meta-analyses have suggested the adverse effects of perioperative blood transfusions on prognostic parameters such as all-cause mortality, recurrence, and postoperative complications. There are two possible causes of adverse effects of blood transfusions on the prognosis: Anti-tumor immunosuppression and patient-related confounding factors (e.g., preoperative anemia). These factors are associated with a worse prognosis and higher requirement for perioperative blood transfusions. Surgeons should make efforts to minimize intraoperative blood loss and transfusions during gastric cancer surgery to improve patients’ prognosis.

Hepatic blood flow by perfusion computed tomography as an imaging biomarker for patients with gastric cancer

Perfusion computed tomography (PCT) is a less invasive imaging modality that provides information about tissue hemodynamics at the capillary level. The present study aimed to investigate the correlation between hepatic perfusion and gastric cancer progression. A total of 136 patients with gastric adenocarcinoma were evaluated in the present study. Prior to initial treatment, liver PCT was performed across the hepatic hilar plane and the hepatic blood flow (HBF) was measured using the dual-input deconvolution method. HBF was compared with clinicopathological factors, patient prognosis and circulating serum proangiogenic cytokines. The median HBF was 217 ml/min/100 g tissue. Patients with high HBF had larger tumors (43 mm vs. 71, P<0.001) and more advanced tumor-node stages (P<0.001 for both). When both patient groups of operable and inoperable were compared by their respective median HBF values, each high-HBF group had a significantly worse prognosis (P=0.002 and P=0.024), notably in the inoperable group, with <1-year survival. In 17 postoperative recurrent patients, the high-HBF at recurrence group also had a significantly worse postrecurrent prognosis (P=0.019). HBF was an independent prognostic factor (hazard ratio, 2.019; P=0.048) and was strongly associated with serum vascular endothelial growth factor level (R=0.607, P<0.001). HBF was significantly correlated with gastric cancer progression, and is an easily measured imaging biomarker reflecting patient survival.

Roles of Fibroblast Activation Protein and Hepatocyte Growth Factor Expressions in Angiogenesis and Metastasis of Gastric Cancer

This study aims to explore the roles of fibroblast activation protein (FAP) and hepatocyte growth factor (HGF) expressions in the angiogenesis and metastasis of gastric cancer (GC). From May 2012 to December 2015, 110 GC patients who received surgical treatment in the First Hospital of Qinhuangdao were selected. The HGF and FAP expressions in 110 cases of GC, 130 cases of normal gastric mucosa and 115 cases of gastric ulcer were detected by streptavidin-perosidase (SP) method. Venous blood HGF level of GC patients was tested by enzyme-linked immunosorbent assay (ELISA). The micro-vessel number of the patients in the three groups were calculated and analyzed. In GC group, positive expression rates of FAP and HGF protein were 61.8% and 67.3% respectively, which were both higher than those in normal gastric mucosa and gastric ulcer groups. The micro-vessel numbers in patients of the normal gastric mucosa and gastric ulcer groups are far less than that in GC group. FAP, HGF and micro-vessel density (MVD) were significantly correlated with infiltration depth, tumor-node-metastasis (TNM) staging, lymph node metastasis (LNM) and distant metastasis. The results of ELISA showed that serum HGF level was related to tumor size, infiltration degree, TNM staging, LNM and distant metastasis. FAP and HGF expressions in GC were positively correlated with MVD, and the expressions of FAP and HGF in GC were in positive correlation. Our study provided evidence that high FAP and HGF expressions may be positively correlated with the angiogenesis and metastasis of GC.

Peritumoral stromal neutrophils are essential for c-Met-elicited metastasis in human hepatocellular carcinoma

Inflammation is a component of tumor progression mechanisms. Neutrophils are a common inflammatory infiltrate in many tumors, but their regulation and functions in neoplasia are not understood. Here, we showed, in detailed studies of c-Met molecule in 225 untreated patients with hepatocellular carcinoma (HCC), that high infiltration of neutrophils in HCC tissues determined malignant cell c-Met-associated clinical outcome of patients. High infiltration of neutrophils in HCCs determined malignant cell c-Met-associated clinical outcome of patients. Neutrophils were enriched predominantly in invading tumor edge of HCCs; the accumulated neutrophils were the major source of c-Met ligand HGF in HCCs. Exposure to HCC environments resulted in neutrophil activation and the following HGF production. Inhibiting the activities of Erk1/2, p38, and NF-κB, but not the phosphorylation of AKT or JNK, successfully attenuated the neutrophil HGF production induced by HCC environments. Further investigation revealed that GM-CSF was an important determinant in malignant cell-elicited neutrophil HGF production in vitro and in vivo. Moreover, we demonstrated that tumor neutrophils, via HGF/c-Met interaction, actively enhanced the metastasis of malignant cells in vitro and in vivo. These data provide direct evidence supporting the critical role of neutrophils in human tumor progression and reveal a fine-tuned collaborative action between cancer cells and immune cells in tumor milieu, which reroutes the immune activation into a tumor-promoting direction.

Gastric cancer: somatic genetics as a guide to therapy

Gastric cancer is the leading cause of cancer-related mortality across the world, with poor prognosis and a median overall survival of ≤12 months for advanced stage gastric cancer. Environmental, genetic and other predisposing factors contribute to the development of gastric cancer and a predominant factor was found to be infection of Helicobacter pylori Advances in understanding the deranged signalling pathways that are critical for normal cellular homeostasis helped in the development of novel drugs that target specific proteins and pathways to curtail the growth of gastric cancer. Genetic studies revealed several single nucleotide polymorphisms, chromosomal aberrations and epigenetic alterations that likely play a major role in elevating the susceptibility to develop gastric cancer. Methylation pattern of specific genes may likely prove to be a valid biomarker for early detection of gastric cancer, but much progress is needed to establish specific markers. Important developments have been made in targeting human epidermal growth factor receptor-2 and vascular endothelial growth factor receptor 2 for treating advanced gastro-oesophageal junction cancer, using specific monoclonal antibodies. Lack of efficacy with regard to targeting other signalling pathways including mesenchymal-epithelial transition/hepatocyte growth factor and mammalian target of rapamycin is probably due to suboptimal patient selection for these clinical trials, which is probably due to the lack of appropriate biomarkers, to decide on responsive patient population. Besides the development of antagonists for the cell growth-related signalling pathways, advances are also being made to tackle gastric cancer by immunotherapies, targeting immune check-points, which may hold promise for better treatment options in future.

Metastasis-associated in colon cancer-1 in gastric cancer: Beyond metastasis

Metastasis-associated in colon cancer-1 (MACC1) is an oncogene that was first identified in colon cancer. The upstream and downstream of MACC1 form a delicate regulatory network that supports its tumorigenic role in cancers. Multiple functions of MACC1 have been discovered in many cancers. In gastric cancer (GC), MACC1 has been shown to be involved in oncogenesis and tumor progression. MACC1 overexpression adversely affects the clinical outcomes of GC patients. Regarding the mechanism of action of MACC1 in GC, studies have shown that it promotes the epithelial-to-mesenchymal transition and accelerates cancer metastasis. MACC1 is involved in many hallmarks of GC in addition to metastasis. MACC1 promotes vasculogenic mimicry (VM) via TWIST1/2, and VM increases the tumor blood supply, which is necessary for tumor progression. MACC1 also facilitates GC lymphangiogenesis by upregulating extracellular secretion of VEGF-C/D, indicating that MACC1 may be an important player in GC lymphatic dissemination. Additionally, MACC1 supports GC growth under metabolic stress by enhancing the Warburg effect. In conclusion, MACC1 participates in multiple biological processes inside and outside of GC cells, making it an important mediator of the tumor microenvironment.

Clinical impact of tumour biology in the management of gastroesophageal cancer

The characterization of oesophageal and gastric cancer into subtypes based on genotype has evolved in the past decade. Insights into the molecular landscapes of gastroesophageal cancer provide a roadmap to assist the development of new drugs and their use in combinations, for patient stratification, and for trials of targeted therapies. Trastuzumab is the only approved treatment for gastroesophageal cancers that overexpress HER2. Acquired resistance usually limits the duration of response to this treatment, although a number of new agents directed against HER2 have the potential to overcome or prolong the time until resistance occurs. Beyond that, anti-VEGFR2 therapy with ramucirumab was the first biological treatment strategy to produce a survival benefit in an unselected population of patients with chemotherapy-refractory gastroesophageal cancer. Large initiatives are starting to address the role of biomarker-driven targeted therapy in the metastatic and in the perioperative setting for patients with this disease. Immunotherapy also holds promise, and our understanding of subsets of gastroesophageal cancer based on patterns of immune response continues to evolve. Efforts are underway to identify more relevant genomic subsets through genomic screening, functional studies, and molecular characterization. Herein, we provide an overview of the key developments in the treatment of gastroesophageal cancer, and discuss potential strategies to further optimize therapy by targeting disease subtypes.

Current Molecular Targeted Therapy in Advanced Gastric Cancer: A Comprehensive Review of Therapeutic Mechanism, Clinical Trials, and Practical Application

Despite the great progress in the treatment of gastric cancer, it is still the third leading cause of cancer death worldwide. Patients often miss the opportunity for a surgical cure, because the cancer has already developed into advanced cancer when identified. Compared to best supportive care, chemotherapy can improve quality of life and prolong survival time, but the overall survival is often short. Due to the molecular study of gastric cancer, new molecular targeted drugs have entered the clinical use. Trastuzumab, an antibody targeting human epidermal growth factor receptor 2 (HER2), can significantly improve survival in advanced gastric cancer patients with HER2 overexpression. Second-line treatment of advanced gastric cancer with ramucirumab, an antibody targeting VEGFR-2, alone or in combination with paclitaxel, has been proved to provide a beneficial effect. The VEGFR-2 tyrosine kinase inhibitor, apatinib, can improve the survival of advanced gastric cancer patients after second-line chemotherapy failure. Unfortunately, none of the EGFR targeting antibodies (cetuximab or panitumumab), VEGF targeting monoclonal antibodies (bevacizumab), mTOR inhibitor (everolimus), or HGF/MET pathway targeting drugs has a significant survival benefit. Many other clinical trials based on molecular markers are underway. This review will summarize targeted therapies for advanced gastric cancer.

MiR-449c inhibits gastric carcinoma growth

AIMS

Gastric carcinoma (GC) is among the leading causes of cancer-related deaths in China. Growing evidence indicates that dysregulation of miRNAs contributes to GC development. Although it has been shown that miR-449c acts as a tumor suppressor in lung cancer, the role of miR-449c in GC remains unclear.

MAIN METHODS

Here, we analyzed miR-449c levels in GC tissues and cell lines by RT-qPCR. We also overexpressed and inhibited miR-449c by transfecting miRNA mimics and antisense oligonucleotides (ASO), respectively. Cell growth was analyzed by MTT assay, and cell apoptosis was evaluated by FACS analysis. MiR-449c target genes were predicted using bioinformatics algorithms and confirmed by a dual luciferase reporter assay.

KEY FINDINGS

We detected lower miR-449c levels in GC tissues; the low miR-449c levels correlated with low survival rate. Overexpression of miR-449c inhibited cell growth and promoted apoptosis, while depletion of miR-449c increased cell growth and suppressed apoptosis. Moreover, the 3' UTR of MET, an oncogene that activates tumor cell growth, appeared to be targeted by miR-449c.

SIGNIFICANCE

Together, we showed that the reduced miR-449c levels in GC tissues promote GC growth, which possibly contributes to the low survival rate of GC patients. Mechanistically, miR-449c may target MET to suppress GC cell growth.

Integrated analysis of gene expression and DNA methylation changes induced by hepatocyte growth factor in human hepatocytes

Hepatocellular carcinoma (HCC) is the one of most common malignant tumors. The tumor microenvironment has a role in not only supporting growth and survival of tumor cells, but also triggering tumor recurrence and metastasis. Hepatocyte growth factor (HGF), one of the important growth factors in the tumor microenvironment, has an important role in angiogenesis, tumorigenesis and regeneration. However, the exact mechanism by which HGF regulates HCC initiation and development via epigenetic reprogramming has remained elusive. The present study focused on the epigenetic modification and target tumor-suppressive genes of HGF treatment in HCC. Expression profiling and DNA methylation array were performed to investigate the function of HGF and examine global genomic DNA methylation changes, respectively. Integrated analysis of gene expression and DNA methylation revealed potential tumor suppressor genes (TSGs) in HCC. The present study showed the multiple functions of HGF in tumorous and nontumorous pathways and global genomic DNA methylation changes. HGF treatment upregulated the expression of DNA methyltransferase 1 (DNMT1). Overexpression of DNMT1 in HCC patients correlated with the malignant potential and poor prognosis of HCC. Furthermore, integration analysis of gene expression and DNA methylation changes revealed novel potential tumor suppressor genes TSGs including MYOCD, PANX2 and LHX9. The present study has provided mechanistic insight into epigenetic repression of TSGs through HGF-induced DNA hypermethylation.

Mesenchymal stem cell-based NK4 gene therapy in nude mice bearing gastric cancer xenografts

Mesenchymal stem cells (MSCs) have been recognized as promising delivery vehicles for gene therapy of tumors. Gastric cancer is the third leading cause of worldwide cancer mortality, and novel treatment modalities are urgently needed. NK4 is an antagonist of hepatocyte growth factor receptors (Met) which are often aberrantly activated in gastric cancer and thus represent a useful candidate for targeted therapies. This study investigated MSC-delivered NK4 gene therapy in nude mice bearing gastric cancer xenografts. MSCs were transduced with lentiviral vectors carrying NK4 complementary DNA or enhanced green fluorescent protein (GFP). Such transduction did not change the phenotype of MSCs. Gastric cancer xenografts were established in BALB/C nude mice, and the mice were treated with phosphate-buffered saline (PBS), MSCs-GFP, Lenti-NK4, or MSCs-NK4. The tropism of MSCs toward gastric cancer cells was determined by an in vitro migration assay using MKN45 cells, GES-1 cells and human fibroblasts and their presence in tumor xenografts. Tumor growth, tumor cell apoptosis and intratumoral microvessel density of tumor tissue were measured in nude mice bearing gastric cancer xenografts treated with PBS, MSCs-GFP, Lenti-NK4, or MSCs-NK4 via tail vein injection. The results showed that MSCs migrated preferably to gastric cancer cells in vitro. Systemic MSCs-NK4 injection significantly suppressed the growth of gastric cancer xenografts. MSCs-NK4 migrated and accumulated in tumor tissues after systemic injection. The microvessel density of tumor xenografts was decreased, and tumor cellular apoptosis was significantly induced in the mice treated with MSCs-NK4 compared to control mice. These findings demonstrate that MSC-based NK4 gene therapy can obviously inhibit the growth of gastric cancer xenografts, and MSCs are a better vehicle for NK4 gene therapy than lentiviral vectors. Further studies are warranted to explore the efficacy and safety of the MSC-based NK4 gene therapy in animals and cancer patients.