XPD Regulates MIAT/miR-29a-3p/COL4A1 Axis to Impede Hepatocellular Carcinoma Development.

Xeroderma pigmentosum group D (XPD) has been reported to inhibit cell growth of hepatocellular carcinoma (HCC). This work attempted to reveal the underlying mechanism of XPD in HCC. In this study, XPD and miR-29a-3p were down-regulated, and MIAT and COL4A1 were up-regulated in tumor tissues of HCC patients. The same phenomena were also observed in HCC cell lines. XPD overexpression enhanced E-cadherin expression, reduced N-cadherin and Vimentin expression, and repressed the migration and invasion of HepG2 and Hep3B cells. MIAT or COL4A1 overexpression reversed the effect of XPD on the invasion, migration, and epithelial-mesenchymal transition (EMT) of HCC cells. MIAT overexpression-mediated promotion of malignant phenotypes of HCC cells was reversed by COL4A1 deficiency. In terms of mechanics, MIAT enhanced COL4A1 expression by sponging miR-29a-3p. XPD interacted with P53. XPD overexpression repressed MIAT expression, which was abrogated by P53 silencing. Thus, XPD recruited P53 to repress MIAT expression. In vivo, XPD up-regulation inhibited tumor growth and reduced the metastatic lesions in intrahepatic, lung, and kidney tissues of mice. In conclusion, this study demonstrated that XPD recruited P53 to regulate the MIAT/miR-29a-3p/COL4A1 axis, which contributed to inhibiting migration, invasion, EMT, and metastasis of HCC. Thus, XPD may be a valuable target for HCC treatment.