Elevated expression of Gsα in intrahepatic cholangiocarcinoma associates with poor prognosis

BACKGROUND:The stimulatory G protein α subunit(Gsα)plays important roles in diverse cell processes including tu morigenesis. Activating mutations in Gsα gene(GNAS) have been reported to be associated with poor prognosis in various human carcinomas. Furthermore, Gsα signaling is crucial in promoting liver regeneration by interacting with growth factor signaling, indicating that Gsα might play a promoting role in cancer development. However, little is known about the correlation between Gsα levels and clinicopathological pa rameters in intrahepatic cholangiocarcinoma(ICC). METHODS:We performed immunoblotting to examine the expression levels of Gsα 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 Gsα levels and clinicopathological find ings and prognosis of the patients was evaluated.RESULTS:Western blotting demonstrated that the expression of Gsα was significantly higher in ICC tissues compared with that in their corresponding adjacent tissues. Gsα 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 Gsα high expression(P=0.011). High Gsα 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 Gsα was significantly and positivelycorrelated with Ki67 expression(P<0.001). In addition, the recurrence-free survival rate and overall survival rate in the Gsα high group were significantly lower than those in the Gsα low group(P=0.004 and P=0.005, respectively).CONCLUSIONS:High Gsα expression is correlated with poor prognosis in ICC patients. Gsα might serve as a potential prognostic indicator of ICC.

Loss of Dicer1 impairs hepatocyte survival and leads to chronic inflammation and progenitor cell activation

AIM:To investigate the continuous hepatic histopathological processes which occur in response to the loss of Dicer1.METHODS:We generated a hepatocyte-selective Dicer1 knockout mouse and observed the gradual hepatic histopathological changes in the mutant liver.Immunohistochemistry and Western blotting were performed to detect Dicer1 expression.We performed hematoxylin and eosin staining,Periodic acid-Schiff staining,Oil Red O staining,and Masson's trichrome staining to detect histological changes in Dicer1-deficient livers.Ki67 immunohistochemistry,terminal deoxynucleotidyl transferase-mediated d UTP nickend labeling assay,and Western blotting were used to determine hepatocyte proliferation and apoptosis.Serum biochemistry,cytokine assays,and flow cytometric analysis were performed to quantity liver necrosis and inflammation.Fibrogenic markers were determined by Western blotting and q PCR.CK19,CD133,and OV6 immunofluorescence were used to observe liver progenitor cells.Immunofluorescence and q PCR were performed to reveal embryonic gene expression.We also performed histological staining and Western blotting to analyze hepatocellular carcinoma(HCC) development.RESULTS:Dicer1 inactivation resulted in significant architecture disorganization and metabolism disruptionin the liver.Dicer1 disruption impaired hepatocyte survival and resulted in profound cell apoptosis and continuous necrosis.In contrast to previous reports,the mutant liver exhibited chronic inflammation and progressive fibrosis,and could not be repopulated by Dicer1-positive cells.In addition,extensive activation of hepatic progenitor cells was observed.Primary HCC was observed as early as 4 mo after birth.CONCLUSION:Hepatic loss of Dicer1 results in complex chronic pathological processes,including hepatocyte death,inflammatory infiltration,chronic fibrosis,compensatory proliferation,progenitor activation,and spontaneous hepatocarcinogenesis.