Down-regulated CMTM7 promotes metastasis of hepatocellular carcinoma via its family member CMTM3

Abstract Background Human chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTM) members are found deregulated in various cancers and play a role in cancer development. Recent studies showed that CMTM7 was down-regulated in liver cancer and functioned as a tumor suppressor. Methods The expression of CMTM7 in hepatocellular carcinoma (HCC) tissues was measured by bioinformatics analysis, Western blot, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). CCK8 and cell colony formation assays were conducted to detect the cell proliferation. Cell invasion and migration ability was assessed by wound healing and Transwell assays. Results We identified a decreased expression of CMTM7 in HCC tissues was closely related to the metastasis and prognosis of HCC patients. To explore the effect of CMTM7 on the biological function of HCC cells, we over-expressed CMTM7 in two HCC cell lines, SK-Hep-1 and Bel-7402 cells. Cell proliferation was reduced significantly after exogenous expression of CMTM7, detected by both CCK8 and colony formation assay. Moreover, the invasion and migration ability of HCC cells were also inhibited by exogenous expression of CMTM7 in wound healing and Transwell assay. Furthermore, there was a significantly positive correlation between CMTM7 and CMTM3 both in HCC cells and tumor tissues. Conclusions Our results suggest that down-regulated CMTM7 promotes metastasis of HCC through inducing the expression of its family member CMTM3.