Objective To clarify the role of Rho small GTP-binding protein (Rho) in the
progression of testicular germ cell tumour (GCT), by examining the express
ion 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 consec
utive Japanese patients, and in the corresponding unaffected tissue origina
ting from the same patient, using reverse transcription-polymerase chain re
action. 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 unaf
fected tissues of the resected testis (P < 0.01); the mRNAs of RhoB and Rho
C 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 i
n tumours with seminoma only (P < 0.05).
Conclusions These results suggest that RhoA is involved in testicular germi
nal epithelial carcinogenesis and progression in testicular GCT, indicating
that RhoA may be a useful prognostic marker for progression in testicular
GCT.