Expression of Tiam1 and Rac1 proteins in renal cell carcinoma and its clinical-pathological features.

PURPOSE

To explore the connections between Tiam1 and Rac1 expression in renal cell carcinoma (RCC), and its pathological type, grading, invasion and metastasis.

METHODS

Tiam1 and Rac1 expression was measured in 60 specimens of RCC (including 42 clear cell cases, 12 papillary cases, and 6 chromophobe cases) and a 10-specimen control group using quantum dots IHC labeling, complete with clinical and pathological records, dated 2008 to 2014, were taken from the archives of the Department of Pathology, People's Hospital of Wuhan University. The expressions of Tiam1 and Rac1 proteins in specimens were measured using immunohistochemical (IHC) and quantum dots-labeling methods to examine their relationships to the clinical and pathological characteristics of RCC. The HIPAS-1000 software was used to quantitatively analyze on the results to obtain absorbance and positive area ratio (PAR) values, and SPSS 15.0 was used to perform single-factor analysis of variance and q verification. Spearman's rank correlation test is used to verify the correlation between absorbance and PAR of the two proteins.

RESULTS

1. QDs IHC staining. Tiam1 and Rac1 expression is high in RCC, and low in surrounding tissues (P<0.05). 2. Expression levels of both proteins show no correlation with patient sex, age, or tumor size (P>0.05), yet correlate with the differentiation, stage, and lymphatic metastasis of tumors (P<0.05). Spearman's test shows a positive correlation between the expression levels of Tiam1 and Rac1 in RCC tissues (r=0.425, P<0.05).

CONCLUSION

1. Abnormal Tiam1 and Rac1 expression may be an early molecular event in RCC, suggesting they are carcinogens related to proto-oncogenes. 2. Tiam1 and Rac1 expression levels correlate with the differentiation, stage, and lymphatic metastasis of RCC, suggesting they play important roles in its invasion and metastasis. 3. The expression levels of Tiam1 and Rac1 are positively correlated within RCC, suggesting a synergy between the two in controlling its pathogenesis and development.