Abstract
The purpose of the present study is to explore the correlation between regulatory associated protein of mTOR (Raptor) and clinicopathologic features in hepatocellular carcinoma (HCC), including patient survival. Immunohistochemistry was used to examine the expression of Raptor in 90 HCC tissues and peritumoral liver tissues. The relationship between tumor Raptor expression and clinicopathologic characteristics was analyzed. Survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. The significance of various survival variables was analyzed using multivariate Cox proportional hazards model. We found that Raptor protein was detected in cytoplasmic compartment. Significantly lower Raptor expression was observed in HCC compared to peritumoral liver cells (P=0.048). The tumor expression levels of Raptor significantly inversely correlated with clinical stage (P=0.026). Patients with high Raptor expression had better recurrence-free survival (P=0.010). Further, we observed that Raptor expression was positively associated with recurrence-free survival of HCC patients with tumor capsule (P=0.043) and without portal vein tumor thrombus (P=0.033) classifications. Finally, we found that Raptor was an independent prognostic factor of recurrence-free survival for patients with HCC (P=0.042). To conclude, our results support that decreased cytoplasmic expression of Raptor is a potentially unfavorable factor in the progression and prognosis of HCC.