Overexpression of RhoA mRNA is associated with advanced stage in testicular germ cell tumour

OBJECTIVE: To clarify the role of Rho small GTP-binding protein (Rho) in the progression of testicular germ cell tumour (GCT), by examining the expression levels of mRNAs of Rho genes in testicular GCT. PATIENTS AND METHODS: The mRNA levels of the RhoA, RhoB and RhoC genes were analysed in the surgical specimens of testicular GCT tissues from 45 consecutive Japanese patients, and in the corresponding unaffected tissue originating from the same patient, using reverse transcription-polymerase chain reaction. The expression levels in tumour tissues were compared with those in unaffected tissues and the relationship between their expression levels in tumours and tumour stage evaluated. The expression levels of mRNAs of the Rho genes were also evaluated between tumours with seminoma only, and mixed tumours with seminoma and nonseminoma. RESULTS: The mRNA levels of RhoA were greater in tumour tissues than in unaffected tissues of the resected testis (P < 0.01); the mRNAs of RhoB and RhoC were not detected in either tissue. The increase in RhoA mRNA levels was related to tumour stage (P < 0.05). The mRNA levels of RhoA in seminomatous and nonseminomatous areas where both were present were higher than those in tumours with seminoma only (P < 0.05). CONCLUSIONS: These results suggest that RhoA is involved in testicular germinal epithelial carcinogenesis and progression in testicular GCT, indicating that RhoA may be a useful prognostic marker for progression in testicular GCT.