Role and prognostic value of matrix metalloproteinase-7 in the migration and immune cell infiltration of hepatocellular carcinoma / 临床肝胆病杂志

ABSTRACT

ObjectiveTo investigate the role and prognostic value of matrix metalloproteinase-7 （MMP7） in the migration and immune cell infiltration of hepatocellular carcinoma. MethodsMMP7_siRNA for downregulating the target gene MMP7 and pMMP7 for upregulating MMP7 were constructed and were used to transfect hepatocellular carcinoma cell line （MHCC97H）. RT-qPCR and Western Blot were used to measure the mRNA and protein expression levels of the target gene in cells. Scanning electron microscopy and Transwell assay were used to observe the changes in cell pseudopodia and migration ability， and bioinformatics methods were used to investigate the correlation of MMP7 with immune cells and immune infiltration score in TCGA and TIMER databases in patients with hepatocellular carcinoma， as well as the association between MMP7 and the prognosis of patients with hepatocellular carcinoma. The Spearman method was used for correlation analysis. Sanger Box online tool was used to assess the value of MMP7 in the overall survival curve and disease-specific survival of hepatocellular carcinoma. The Kaplan-Meier method was used to plot survival curves， and the Log-rank test was used for comparison of prognosis between different samples. ResultsAfter MHCC97H cells were transfected with MMP7_siRNA or pMMP7， there was a significant reduction or increase in the expression of the target gene MMP7； after downregulation of MMP7， there were significant reductions in the number and length of the pseudopodia， while after MMP7 overexpression， there were significant increases in the number and length of filopodia with radial arrangement. The Transwell chamber assay showed that MMP7_siRNA2 significantly reduced the migration ability of cells （P<0.05）， and there was a significant increase in migration ability after pMMP7 transfection. The expression of MMP7 was significantly correlated with B lymphocytes （r=0.37， P<0.05）， CD4+ T lymphocytes （r=0.40， P<0.05）， neutrophils （r=0.49， P<0.05）， macrophages （r=0.49， P<0.05）， and dendritic cells （r=0.47， P<0.05）. In the TCGA database， the patients with hepatocellular carcinoma were divided into MMP7 high expression group with 267 patients and MMP7 low expression group with 146 patients based on overall survival， and the results showed that the MMP7 high expression group had a significantly shorter overall survival time than the MMP7 low expression group （P<0.05）； based on the disease-specific survival time， the patients were divided into MMP7 high expression group with 257 patients and MMP7 low expression group with 145 patients， and the analysis showed that the MMP7 high expression group also had a significantly shorter disease-specific survival time than the MMP7 low expression group （P<0.05）. ConclusionMMP7 promotes the migration of hepatocellular carcinoma cells and plays a major role in immune cell infiltration， and the expression of MMP7 is also significantly associated with the prognosis of hepatocellular carcinoma.