Human G-protein gamma 7 in extrahepatic cholangiocarcinoma and its clinicopathological significance.

BACKGROUND AND OBJECTIVES

Several studies have found a down-regulated G-gamma 7 gene in gastrointestinal tract cancers. We evaluated the expression and clinicopathological significance of the human G protein gamma 7 (G-gamma 7) in human extra-hepatic cholangiocarcinoma (EHCC).

METHODS

The expression of G-gamma 7 expression was studied in 21 patients with EHCC. G-gamma 7 mRNA expression was tested by using RealTime reverse transcription polymerase chain reaction (RT-PCR).To visualize the localization of G-gamma 7, an immunohistochemistry study was also performed. The G-gamma 7 expression was compared among cancer tissues, peri-cancerous bile duct tissues and normal bile duct tissues. The clinicopathological significance of G-gamma 7 expression was also studied.

RESULTS

Expression of G-gamma 7 mRNA and protein were significantly lower in EHCC tissue than in pericancerous bile duct tissue and normal bile duct tissues. G-gamma 7 mRNA and protein expression were significantly lower in poorly differentiated EHCC tissues than in moderate differentiated and well differentiated EHCC tissues (P<.01). There was no significant correlation between G-gamma 7 expression and host factors such as age, gender, clinical staging or the status of preoperative hepatic function

CONCLUSIONS

EHCC has a down-regulated expression of G-gamma 7. Reduced expression of G-gamma 7 is associated with the histological grade of EHCC and may prove to be a useful marker for predicting the prognosis of human EHCC.