Elevated expression of Gsα in intrahepatic cholangiocarcinoma associates with poor prognosis

Background The stimulatory G protein a subunit (G s α) plays important roles in diverse cell processes including tumorigenesis. Activating mutations in G s α gene (GNAS) have been reported to be associated with poor prognosis in various human carcinomas. Furthermore, G s α signaling is crucial in promoting liver regeneration by interacting with growth factor signaling, indicating that G s α might play a promoting role in cancer development. However, little is known about the correlation between G s α levels and clinicopathological parameters in intrahepatic cholangiocarcinoma (ICC). Methods We performed immunoblotting to examine the expression levels of G s α and Ki67 proteins in tumor tissues and the corresponding adjacent tissues. A total of 74 pair of specimens resected from 74 ICC patients were examined. The association between G s α levels and clinicopathological findings and prognosis of the patients was evaluated. Results Western blotting demonstrated that the expression of G s α was significantly higher in ICC tissues compared with that in their corresponding adjacent tissues. G s α protein was highly expressed in about half of ICC tissues (48.6%, 36/74) while only 28.4% (21/74) of tumor adjacent tissues showed G s α high expression ( P =0.011). High G s α expression in ICC was significantly associated with the numbers of tumor nodules ( P =0.037) and lymph node metastases ( P =0.010). Moreover, the level of G s α was significantly and positively correlated with Ki67 expression ( P s α high group were significantly lower than those in the G s α low group ( P =0.004 and P =0.005, respectively). Conclusions High G s α expression is correlated with poor prognosis in ICC patients. G s α might serve as a potential prognostic indicator of ICC.