Somatostatin receptor expression profile as a potential criterion for discrimination between seminoma and non-seminoma testicular tumors.

The expression of five (sstl-sst5) somatostatin (SRIF) receptor mRNAs was compared between normal and tumoral testicular samples diagnosed as either seminoma or non-seminoma. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that all testicular tissues studied (total of 24) contained sst5 receptor transcripts, whereas the sst2 was absent in all of them. In contrast to the normal tissue samples, both types of tumors (total of 12) did not contain sst4 transcripts, sst3 mRNA was expressed in normal and non-seminoma samples, but not in seminomas. sstl transcripts were not found in normal and seminoma tissues. However, all studied non-seminomas contained this mRNA. Our data thus points to a specific pattern of SRIF receptor mRNA expression in each type of the samples analyzed. Moreover, they further indicate that the presence of sstl and sst3 transcripts might be used as an additional criterion to distinguish between seminoma and non-seminoma tumors.