mTOR up-regulation of SNRPA1 contributes to hepatocellular carcinoma development
BIOSCIENCE REPORTS
Authors: Feng, Jing; Guo, Jian; Zhao, Pengyu; Shen, Jing; Chai, Baofeng; Wang, Junping
Abstract
Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death world-wide. Recent studies showed that snRNPs were implicated in human cancer development. The role of SNRPA1, which is a member of U2 snRNPs, in HCC, remains undocumented. Here, we found that SNRPA1 was highly expressed in HCC tissue compared with normal adjacent liver tissues. Up-regulation of SNRPA1 was correlated with the clinical stage of HCC and the overall survival of HCC patients. In vitro and in vivo results showed that knockdown of SNPRA1 inhibited the cell proliferation, colony formation and xenografted tumorigenesis of HCC cells. Apoptosis was induced by SNPRA1 down-regulation. Mechanistically, SNPRA1 was stimulated by mTOR activation. In addition, whole-genome microarray analysis identified that 262 genes were up-regulated and 462 genes were down-regulated by SNPRA1 knockdown in HCC cells. qPCR analysis suggested that the fibroblast growth factor-2 (FGF2), Alpha-fetoprotein (AFP), beta-catenin, Ki-67 and cyclin B1 were down-regulated and caspase 3, p53 as well as p21 were up-regulated after SNRPA1 knockdown. Taken together, our findings implicate that SNPRA1 functions as an oncogene in HCC.
Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals
PLOS ONE
Authors: Tabu, Kazuaki; Mawatari, Seiichi; Oda, Kohei; Kumagai, Kotaro; Inada, Yukiko; Uto, Hirofumi; Saisyoji, Akiko; Hiramine, Yasunari; Hashiguchi, Masafumi; Tamai, Tsutomu; Hori, Takeshi; Fujisaki, Kunio; Imanaka, Dai; Kure, Takeshi; Taniyama, Ohki; Toyodome, Ai; Ijuin, Sho; Sakae, Haruka; Sakurai, Kazuhiro; Moriuchi, Akihiro; Kanmura, Shuji; Ido, Akio
Abstract
Background and aims Direct-acting antivirals (DAAs) against hepatitis C virus (HCV) exert high anti-HCV activity and are expected to show anti-inflammatory effects associated with HCV elimination. Furthermore, hepatocellular carcinoma (HCC) is known to dedifferentiate from hypovascular tumors, such as dysplastic nodules or well-differentiated HCC, to hypervascular tumors. We therefore explored whether or not DAAs can suppress the growth and hypervascularization of hypovascular tumors. Methods We enrolled 481 patients with HCV genotype 1 infection who were treated with Daclatasvir and Asunaprevir therapy. Of these, 29 patients had 33 hypovascular tumors, which were confirmed by contrast-enhanced MRI or CT before therapy. We prospectively analyzed the cumulative incidence of HCC, i.e. the growth or hypervascularization of hypovascular tumors, and compared the HCC development rates between patients with hypovascular tumors and those without any tumors. Results The mean size of the hypovascular tumors was 11.3 mm. Twenty seven of 29 patients who achieved an SVR had 31 nodules, 19 of 31 nodules (61.3%) showed tumor growth or hypervascularization, and 12 (38.7%) nodules showed no change or improvement. The cumulative incidence rates of tumor growth or hypervascularization were 19.4% at 1 year, 36.0% at 2 years, 56.6% at 3 years, and 65.3% at 4 years. Among the patients who achieved a sustained virologic response, the cumulative HCC development rates of patients with hypovascular tumors was significantly higher than in those without any tumors. A Cox proportional hazard analysis showed that a history of HCC therapy, the presence of a hypovascular tumor, and AFP >4.6 ng/mL at the end of treatment were independent risk factors for HCC development. Conclusion Hypovascular tumors developed into HCC at a high rate despite the elimination of HCV by DAAs. As patients with hypovascular tumors were shown to have a high risk of HCC development, they should undergo strict HCC surveillance.