RhoA is associated with invasion and lymph node metastasis in upper urinary tract cancer

To assess the roles of RhoA small GTPase (RhoA) in upper urinary tract cancer by analysing the mRNA and protein levels of RhoA.

The mRNA and protein levels of RhoA in matched sets of tumour, non-tumour and metastatic lymph node tissues of surgical specimens were analysed in 47 consecutive patients with renal pelvic/ureteric cancer, using the polymerase chain reaction after reverse transcription and Western blotting. The relationship between mRNA and protein levels of RhoA in tumour tissues and the clinicopathological features of the patients was also assessed.

The mRNA levels of RhoA and RhoA protein were greater in tumour and metastatic lymph node tissues than in non-tumour tissues (all P < 0.001). The expression levels of RhoA mRNA and protein levels in primary tumours was related to poorly differentiated grade (both P < 0.05) and muscle invasion (P < 0.01 and < 0.001, respectively). Kaplan-Meier plots of survival in patients with low or high RhoA showed that high mRNA and protein levels were associated with a shorter disease-free (P < 0.01) and overall survival (P < 0.001). Multivariate analysis using the Cox proportional hazards model showed that a high RhoA protein level was an independent prognostic factor, second to stage, in disease-free and overall survival (both P < 0.05).

These findings suggest that RhoA is involved in the invasion and metastasis of upper urinary tract cancer, indicating that RhoA may be a useful prognostic factor in this disease.