Down-regulation of RASA1 Is Associated with Poor Prognosis in Human Hepatocellular Carcinoma

Background/Aim: RASA1 (p120RasGAP), encodes Ras GTPase-activating protein 1 and, is a potent tumor suppressor gene that is frequently inactivated in several human cancer types. However, its precise role in hepatocellular carcinoma (HCC) has been blurred. Materials and Methods: We hypothesized that RASA1 plays a crucial role in tumor pathogenesis and progression of HCC. RASA1 expression levels were analyzed in 226 cases of HCC by immunohistochemistry. Results: It was found that 38.68% (41/106) of the high-grade HCC samples and 54.17% (65/120) of the low-grade HCC samples expressed RASA1 protein. The difference between RASA1 expression in high-grade and low-grade HCC was statistically significant (p=0.02). Additionally, RASA1 high expression was inversely associated with larger tumor size (p < 0.001). Although RASA1 is known as a tumor suppressor, its role in overall survival (OS) in HCC is unclear. Kaplan-Meier survival analysis showed that patients with low level of RASA1 expression correlated with a significantly poorer survival compared to those with high level of RASA1 expression. Conclusion: These data support that RASA1 could serve as an independent prognostic marker for HCC patients.