Hepatocyte Growth Factor Affects The Invasion And Metastasis Of Head And Neck Squamous Cell Carcinoma Through PI3K/Akt And JNK Signaling Pathways

Objective: Squamous cell carcinoma of the head and neck(SCCHN)is the sixth common cancer in the world.More than half of patients diagnosed with SCCHN will have local recurrence or distant metastasis,and 10% of patients will have metastasis at first.For patients with recurrent and metastatic head and neck squamous cell carcinoma,controlling symptoms and prolonging survival are the goals of treatment.Because of the severity of its malignancy and the large proportion,it has always been the focus of many medical researchers.Due to our limited understanding of the overall mechanism,various current treatment measures are limited.Hepatocyte growth factor(HGF)and Hepatocyte growth factor receptor(Met)are the most widely bioactive cytokines,which are overexpressed in a variety of tumor cells.It has a biological effect of promoting proliferation,invasion and metastasis in the occurrence and development of tumors,which has become a new hotspot in basic and clinical research.HGF and its receptor can stimulate the differentiation,proliferation,regeneration,movement,migration and morphogenesis of various types of cells.The growth,invasion and metastasis of many malignant tumors are related to the HGF/Met system.However,its role in head and neck squamous cell carcinoma(SCCHN)remains unclear.In this study,the role and molecular mechanism of HGF in the malignant progression of SCCHN were investigated,in order to provide valuable experimental basis for the treatment of SCCHN.Methods: This experiment is to take highly invasive SCCHN cell line as the object,and conduct the following studies by RT-PCR,Western blot,gelatin zymography,chemotactic invasion assay,immunofluorescence assay,statistical analysis of correlation between clinical features,luciferase reporter assay.1.Real-time PCR and Western blot were used to detect the expression of RNA and protein in tissues and cells.2.Immunohistochemistry was used to detect the expression of HGF in tissue samples and Ki-67 in mice with subcutaneous tumorigenesis.3.Lentivirus-mediated RNAi knockdown method was used to regulate the expression of different molecules in cells.4.Chemotaxis and invasion assays were used to detect the metastatic ability of the cells.5.Chi-square test,Spearman analysis and Cox regression analysis was conducted on the relationship between HGF expression and clinicopathological features of SCCHN.6.The role of HGF in tumor growth in vivo was studied by subcutaneous tumor transplantation in mice.7.Double luciferase gene reporter assay was used to detect FOXOs activity.8.The changes of cytoskeleton were detected by immunofluorescence.9.The activity of MMP-9 was detected by gelatin zymography.Results: Part 1: 1.HGF is highly expressed in SCCHN cells and tissues.HGF induces chemotaxis and invasion of SCCHN cells.2.There is a statistical correlation between HGF and clinical characteristics of poor prognosis of SCCHN,which can be used as a tumor marker to predict poor clinical outcome of patients.3.HGF promotes SCCHN cells to form xenograft tumor faster,with larger volume and mass in mice.Part 2: 1.HGF regulates the invasion and metastasis of SCCHN cells through PI3K/Akt pathway.2.HGF regulates SCCHN cell invasion and metastasis through JNK pathway.3.In the occurrence and development of SCCHN induced by HGF,PI3K/Akt is the upstream molecule of JNK,and HGF regulates the metastasis of SCCHN cells through the PI3K/Akt/JNK pathway.4.HGF regulates FOXO transcription by activating Akt pathway.Part 3: 1.HGF enhances the protein activity and expression of MMP-9.2.HGF enhances the chemotaxis and invasion ability of SCCHN cells through MMP-9.3.HGF upregulates MMP-9 by activating PI3K/Akt and JNK signaling pathways,thereby increasing the metastatic properties of SCCHN cells.Conclusion: 1.HGF is highly expressed in SCCHN cells and tissues,and suggests a poor prognosis,which can be used as a tumor marker to predict adverse clinical outcomes.2.HGF promotes the invasion and metastasis of SCCHN cells and promote tumor growth in vivo.3.In SCCHN,HGF regulates cell invasion and metastasis through PI3K/Akt and JNK signaling pathways,and Akt,as an upstream target,induces JNK activation in PI3K/Akt and JNK signaling pathways.4.HGF negatively regulates PI3K/Akt pathway through FOXOs transcription factor in SCCHN cells.5.HGF enhances the chemotaxis and invasion ability of SCCHN cells through MMP-9.6.MMP-9 mediates HGF to affect cell chemotactic and migration through PI3K/Akt/JNK pathway,and HGF upregulates the expression of MMP-9 by activating PI3K/Akt/JNK signaling pathway,thus increasing the metastasis characteristics of SCCHN cells.