Expression of RhoA Protein in the OSCC

Objectives: Rho (Ras homologue) family paly an important role in intracellular signal-transduction pathway. Not until recently have they been found to overexpress in many kinds of tumors. So the members of the Rho family of small guanosine triphosphatases would be new markers for tumor diagnosis, new markers for the prediction of melastatic potential and new important prognostic factors. Moreover, they have the potential as therapeutic targets for the prevention of cancer invasion and metastasis. So we choice RhoA protein to evaluate the expression of RhoA protein in squamous cell carcinoma of oral (OSCC) and its clinical significance. Methods: The expression of RhoA was detected with SABC immunohistochemical staining in 40 surgically resected tumor and 30 norma1 oral mucosae. Results: In normal oral mucosae, there were no expression of RhoA. The incidence of RhoA protein positivty in OSCC was 62.5%, significantly higher than normal oral mucosae (P=0.001).There were no significant correlation between RhoA expression and tumor differentiation and invasion(P=0.962,P=0.133), but significant correlation between RhoA expression and lymph metastasis and PTNM stage (P=0.023, P=0.046). Conclusions: Rho GTPases were previously shown to have an important role in cancer development and progression, including cell transformation, proliferation, invasion, metastasis, and angiogenesis. However, there is still little information available on the clinical significance of Rho GTPases expression in human cancer specimens. In our study, RhoA is highly expressed in OSCC. Our results demonstrated immunohistochemically that the expression of RhoA protein appeared to be correlated with tumour progression of OSCC. RhoA is a useful marker of predicting the metastatic potential of OSCC, and detectation of the expression of RhoA may be useful for evaluating prognosis and guiding treatment.