Objective: To investigate the expression of splicing factor proline- and glutamine-rich (SFPQ) in hepatocellular carcinoma (HCC) and its actions.
Methods: The expression levels of SFPQ mRNA and protein in tumor tissues and their adjacent tissues were determined by real-time quantitative PCR and Western blot. The difference in SFPQ mRNA abundance between normal liver tissue and HCC tissue were analyzed by using TCGA and GEO database. The relations of SFPQ mRNA level with the clinical stage, histopathological grade and survival time of HCC patients as well as the correlation of the SFPQ mRNA with the proliferation gene PCNA and Ki-67, and cell cycle protein CCNE1 and CDK2 were analyzed by using TCGA database. The changes in proliferation and cell cycle in HCC HepG2 and Hep3B cells after SFPQ knock down were observed.
Results: The results of tissue sample analysis showed that the expression levels of both SFPQ mRNA and protein were significantly higher in HCC tissue than those in the adjacent tissue (both P<0.05). The results of database analysis showed that the SFPQ mRNA abundance in HCC tissue was significantly higher than that in normal liver tissue, SFPQ mRNA level was increased with the increase of histopathological grade and the progression of clinical stage, the survival rate was significantly reduced in patients with high SFPQ mRNA expression, and SFPQ mRNA expression was positively correlated with the expressions of PCNA, Ki-67, CCNE1 and CDK2 (P<0.05). In both HepG2 and Hep3B cells after SFPQ knockdown, the proliferative abilities were significantly decreased with significant G1 phase arrest (all P<0.05).
Conclusion: SFPQ expression is increased in HCC, and the increased SFPQ may accelerate HCC progression via regulating cell cycle and promoting proliferation of the HCC cells.