Expression of carboxypeptidase X M14 family member 2 accelerates the progression of hepatocellular carcinoma via regulation of the gp130/JAK2/Stat1 pathway

Abstract

Background: Carboxypeptidase X, M14 family member 2 (CPXM2) has been reported to be involved with several human malignancies. However, the impact of CPXM2 on human hepatocellular carcinoma (HCC) tumorigenesis has not been studied. Materials and Methods: Using immunohistochemistry, the detailed CPXM2 expression patterns were examined in HCC cell lines and tissues. Additionally, a hepatic stellate cell line overexpressing CPXM2 and an HCC CPXM2-knockdown cell line were established by lipofection of an expression plasmid or short hairpin RNA, respectively. The transfection efficiencies were confirmed by reverse transcription-quantitative PCR, Western blotting and immunofluorescence. Moreover, Western blotting was conducted to determine the phosphor-ylation levels of the tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription 3 (Stat1) pathway. Furthermore, gp130-specific hairpin RNA was used to knockdown gp130 expression in hepatic stellate cells overexpressing CPXM2. The malignant phenotype of cultured HCC cells was assessed by a Cell Counting Kit-8 (CCK8) assay, plate cloning assay, Matrigel invasion assay and wound-healing assay in vitro. Results: It was demonstrated that CPXM2 was upregulated in HCC, and its upregulation predicted a poor prognosis. Besides, the upregulation of CPXM2 markedly enhanced the metastatic potential of HCC via the gp130/JAK2/Stat1 signaling pathway in vitro. Conclusion: In summary, this evidence suggests a positive role for CPXM2 in HCC progression via modulation of the gp130/JAK2/Stat1 signaling pathway in HCC.