Research progress on the development of hepatocyte growth factor/c-Met signaling pathway in gastric cancer:A review

Hepatocyte growth factor(HGF)and its receptor,c-Met,play important roles in the occurrence,development,and treatment of gastric cancer(GC).This review explored the function of the HGF/c-Met signaling pathway in GC and its potential targeted therapeutic mechanisms.As one of the most common malignant tumors worldwide,GC has a complex pathogenesis and limited therapeutic options.Therefore,a thorough understanding of the molecular mechanism of GC is very important for the development of new therapeutic methods.The HGF/c-Met signaling pathway plays an important role in the proliferation,migration,and invasion of GC cells and has become a new therapeutic target.This review summarizes the current research progress on the role of HGF/c-Met in GC and discusses targeted therapeutic strategies targeting this signaling pathway,providing new ideas and directions for the treatment of GC.

Updates on the hepatocyte growth factor/c-Met axis in hepatocellular carcinoma and its therapeutic implications

Hepatocellular carcinoma(HCC) is the fifth most common cancer and is the second leading cause of cancer death. Since the diagnosis of HCC is difficult, in many cases patients with HCC are diagnosed advanced stage of development. Hepatocyte growth factor(HGF)/c-mesenchymal-epithelial transition receptor(c-Met) axis is a key signaling pathway in HCC, either via canonical or non-canonical pathways. Available treatments against HCC based upon HGF/c-Met inhibition can increase patient lifespan, but do not reach the expected therapeutic benefits. In HCC, c-Met monomers can bind other receptor monomers, activating several noncanonical signaling pathways, leading to increased cell proliferation, invasion, motility, and drug resistance. All of these processes are enhanced by the tumor microenvironment, with stromal cells contributing to boost tumor progression through oxidative stress, angiogenesis, lymphangiogenesis, inflammation, and fibrosis. Novel treatments against HCC are being explored to modulate other targets such as microR NAs, methyltransferases, and acetyltransferases, which are all involved in the regulation of gene expression in cancer. This review compiles basic knowledge regarding signaling pathways in HCC, and compounds already used or showing potential to be used in clinical trials.

Effect of hepatocyte growth factor signaling pathway activation on Plasmodium berghei infection

Objective:To explore the effect of hepatocyte growth factor signaling pathway activation on Plasmodium berghei infection.Methods:In this study,hepatocyte growth factor was detected by ELISA and Western blotting assay.Hepatocyte injury was detected by FITC-dextran absorption assay,and hepatocyte growth factor expression was shown to be expressed in the same injury cells by immunofluorescence against hepatocyte growth factor.In addition,Activation of hepatocyte growth factor and its receptor signaling pathway was detected with immunoprecipitation and detection of phosphorylation status.Results:It was found that injury of hepatocytes by sporozoite migration induced the secretion of hepatocyte growth factor and it was hepatocyte growth factor that rendered hepatocytes susceptible to Plasmodium sporozoite infection.In addition,hepatocyte infections depended on activation of the hepatocyte growth factor and its receptor signaling pathway.Conclusions:Our results indicate that hepatocyte growth factor and its receptor may possibly be potential targets for new approaches to malaria treatment.

IGFBPrP1 induces liver fibrosis by inducing hepatic stellate cell activation and hepatocyte apoptosis via Smad2/3 signaling

AIM: To investigate the role and mechanism of insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) in the development of liver fibrosis.

Inducing effects of hepatocyte growth factor on the expression of vascular endothelial growth factor in human colorectal carcinoma cells through MEK and PI3K signaling pathways

Background Vascular endothelial growth factor plays a key role in human colorectal carcinoma invasion and metastasis. However, the regulation mechanism remains unknown. Recent studies have shown that several cytokines can regulate the expression of vascular endothelial growth factor in tumor cells. In this study, we investigated whether hepatocyte growth factor can regulate the expression of vascular endothelial growth factor in colorectal carcinoma cells. Methods Hepatocyte growth factor and vascular endothelial growth factor in human serum were measured by ELISA. The mRNA level of vascular endothelial growth factor was analyzed by reverse transcription-PCR. Western blot assay was performed to evaluate levels of c-Met and several other proteins involved in the MAPK and PI3K signaling pathways in colorectal carcinoma cells. Results Serum hepatocyte growth factor and vascular endothelial growth factor were significantly increased in colorectal carcinoma subjects. In vitro extraneous hepatocyte growth factor markedly increased protein and mRNA levels of vascular endothelial growth factor in colorectal carcinoma cells. Hepatocyte growth factor induced phosphorylation of c-Met, ERK1/2 and AKT in a dose-dependent manner. Specific inhibitors on MEK and PI3K inhibited the hepatocyte growth factor-induced expression of vascular endothelial growth factor in colorectal carcinoma cells.Conclusion This present study indicates that hepatocyte growth factor upregulates the expression of vascular endothelial arowth factor in colorectal carcinoma cells via the MEK/ERK and PI3K/AKT sianalina Pathways.

SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in metastasis of hepatocellular carcinoma (HCC). METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve. RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P 【 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P 【 0.05). CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

Expression of Ezrin,HGF,C-met in pancreatic cancer and non-cancerous pancreatic tissues of rats

BACKGROUND: Recent studies have confirmed that the expression of Ezrin, hepatocyte growth factor (HGF) and its receptor (C-met) is related to the genesis, progress, invasion and metastasis of some malignant tumors. Researches have also found that the biological function of Ezrin is closely related to HGF/C-met in malignant tumors. However, there is no report on the expression levels of Ezrin, HGF and C-met in rat pancreatic cancer induced by dimethylbenzanthracene (DMBA). This study aimed to detect the expression of Ezrin, HGF and C-met in rat pancreatic cancer and non-cancerous pancreatic tissues, and assess its effect in cancer induction by DMBA. METHODS: Ninety Sprague-Dawley rats were divided into 3 groups randomly: 40 in a pancreatic cancer model group (group A), 40 in a trichostatin A (TSA) intervention group (group B), and 10 in a control group (group C). DMBA was directly implanted into the parenchyma of rat pancreas in group A+group B. The rats of group B were treated with 1 ml of TSA saline solution (1 mu g/ml) via intraperitoneal injection weekly. The carcinogenesis of rats executed within 3-5 months in groups A and B was observed by macrograph and microscopy. Meanwhile, the rats in group C were executed within 5 months. The EnVision (TM) immunohistochemistry for detecting the expression levels of Ezrin, HGF and C-met was used in paraffin-embedded sections of the pancreatic specimens. RESULTS: The incidence of pancreatic cancer in group A was 48.6% and in group B 33.3%. The maximal diameter of tumor mass was significantly larger in group A than that in group B (P<0.05). No pathological changes were observed in the pancreas of group C and other main organs of groups A and B. The positive rates of Ezrin, HGF and C-met were significantly higher in ductal adenocarcinoma than in non-cancerous pancreatic tissues of groups A and B (P<0.01). The positive rates of Ezrin, HGF and C-met were significantly higher in ductal adenocarcinoma of group A than those in non-cancerous pancreatic tissues of group A (P<0.05), but there was no significant difference in group B (P>0.05). The positive rates of Ezrin, HGF and C-met in non-cancerous pancreatic tissues proved mild to severe atypical hyperplasia of the ductal epithelia. The pancreas of group C and 2 cases of fibrosarcoma showed the negative expression of Ezrin, HGF and C-met. There was a trend of consistency in the expression of Ezrin, HGF and C-met in ductal adenocarcinoma (P<0.05 or P<0.01). CONCLUSIONS: DMBA directly implanted into the parenchyma of the pancreas can produce a model of pancreatic cancer with a high incidence in a short time. TSA might inhibit the carcinogenesis and growth of pancreatic cancer, and its effects may be related to the inhibition of the expression of Ezrin, HGF and C-met during the process. Ezrin, HGF and C-met may have positive effects on the carcinogenesis of rat pancreas. (Hepatobiliary Pancreat Dis Int 2010; 9: 639-644)

The significance of proto-oncogene HGF/SF receptor c-Met mRNA expression in nasopharyngeal carcinoma

Objective: To explore the expression of c-Met mRNA in nasopharyngeal carcinomas (NPC) and its relation with clinical biological behavior. Methods: In situ hybridisation was used to detect mRNA expression of c-Met in 15 cases of non-tumor nasopharyngeal (NP), 55 cases of NPC. Results: The positive rates of c-Met mRNA in NP and NPC cells were 13.3% (2/15) and 61.8% (34/55) respectively. The expression of c-Met mRNA was significantly correlated with lymph node metastasis, local invasion (skull base erosion), and clinical stage. In cases with cervical lymph node metastasis, local invasion, and clinical stage III and IV (UICC), the positive rates of expression of c-Met mRNA were significantly higher than that in those without the conditions mentioned above (P < 0.05 or P < 0.01). But it was not significantly correlated with age, gender, histo- logic grade, and cranial nerve palsy (P > 0.05). Conclusion: The abnormal expression of c-Met gene was well correlated with the biological behavior of metastasis and invasion. To detection the expression of c-Met mRNA could serve as an important index to estimate the prognosis of NPC. C-Met may be a new diagnostic/therapeutic target of NPC.

Hepatocyte growth factor protects pulmonary endothelial barrier against oxidative stress and mitochondria-dependent apoptosis

Background:Pulmonary microvascular endothelial cells(PMVECs)were not complex,and the endothelial barrier was destroyed in the pathogenesis progress of acute lung injury(ALI)/acute respiratory distress syndrome(ARDS).Previous studies have demonstrated that hepatocyte growth factor(HGF),which was secreted by bone marrow mesenchymal stem cells,could decrease endothelial apoptosis.We investigated whether mTOR/STAT3 signaling acted in HGF protective effects against oxidative stress and mitochondria-dependent apoptosis in lipopolysaccharide(LPS)-induced endothelial barrier dysfunction and ALI mice.Methods:In our current study,we introduced LPS-induced PMEVCs with HGF treatment.To investigate the effects of mammalian target of rapamycin(mTOR)/signal transducer and activator of transcription 3(STAT3)pathway in endothelial oxidative stress and mitochondria-dependent apoptosis,mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 were,respectively,used to inhibit mTOR/STAT3 signaling.Moreover,lentivirus vector-mediatedmTORC1(Raptor)andmTORC2(Rictor)gene knockdown modifications were introduced to evaluatemTORC1 andmTORC1 pathways.Calcium measurement,reactive oxygen species(ROS)production,mitochondrial membrane potential and protein,cell proliferation,apoptosis,and endothelial junction protein were detected to evaluate HGF effects.Moreover,we used the ALI mouse model to observe the mitochondria pathological changes with an electron microscopein vivo.Results:Our study demonstrated that HGF protected the endothelium via the suppression of ROS production and intracellular calcium uptake,which lead to increased mitochondrial membrane potential(JC-1 and mitochondria tracker green detection)and specific proteins(complex I),raised anti-apoptosis Messenger Ribonucleic Acid level(B-cell lymphoma 2 and Bcl-xL),and increased endothelial junction proteins(VE-cadherin and occludin).Reversely,mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 could raise oxidative stress and mitochondria-dependent apoptosis even with HGF treatment in LPS-induced endothelial cells.Similarly,mTORC1 as well as mTORC2 have the same protective effects in mitochondria damage and apoptosis.Inin vivo experiments of ALI mouse,HGF also increased mitochondria structural integrity via the mTOR/STAT3 pathway.Conclusion:In all,these reveal that mTOR/STAT3 signaling mediates the HGF suppression effects to oxidative level,mitochondria-dependent apoptosis,and endothelial junction protein in ARDS,contributing to the pulmonary endothelial survival and barrier integrity.

Focal adhesion kinase and Src phosphorylations in HGF-induced proliferation and invasion of human cholangiocarcinoma cell line, HuCCA-1

AIM: To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.METHODS: Previously isolated HuCCA-1 cells were re-characterized by immunofluorescent staining and reverse transcriptase-polymerase chain reaction assay for the expression of cytokeratin 19, HGF and c-Met mRNA. Cultured HuCCA-1 cells were treated with HGF and determined for cell proliferation and invasion effects by MTT and invasion assays. Western blotting, immunoprecipitation, and co-immunoprecipitation were also performed to study the phosphorylation and interaction of FAK and Src. A novel Src inhibitor (AZM555130) was applied in cultures to investigate the effects on FAK phosphorylation inhibition and on cell proliferation and invasion.RESULTS: HGF enhanced HuCCA-1 cell proliferation and invasion by mediating FAK and Src phosphorylations.FAK-Src interaction occurred in a time-dependent manner that Src was proved to be an upstream signaling molecule to FAK. The inhibitor to Src decreased FAK phosphorylation level in correlation with the reduction of cell proliferation and invasion.CONCLUSION: FAK plays a significant role in signaling pathway of HGF-responsive cell line derived from cholangiocarcinoma. Autophosphorylated Src, induced by HGF, mediates Src kinase activation, which subsequently phosphorylates its substrate, FAK, and signals to cell proliferation and invasion.