[Absence of herpesvirus saimiri STPC oncogene in salivary gland tumors and epithelial thymus tumors].

AIM AND METHODS

The oncoprotein STP-C-488 induces salivary gland and thymic epithelial tumours when expressed as a transgene in mice (MURPHY et al. 1994). Given the enigmatic tumorigenesis of corresponding tumours in humans, we now investigated genomic DNA and RNA from 11 thymomas, 5 pleomorphic adenomas and control autopsy material (n = 8) for the occurrence of the STP-C-488 sequences by Southern-blotting, Northern-blotting and PCR.

RESULTS

All tumor samples and control tissues were negative for the STP-C-488 in Southern-blot and Northern-blot-hybridization. PCR analyses did not reveal amplification products of the length expected for STP-C-488. However, a PCR fragment of a different size was found in 50% of the thymomas and pleomorphic adenomas, but in only one of 8 controls. The sequence of this PCR product revealed local homologies with various herpesviruses.

CONCLUSION

The oncoprotein STP-C-488 is not involved in the tumorigenesis of human thymomas and salivary gland tumours. Whether the novel sequences amplified preferentially from these tumours play a role in pathogenesis needs further investigation.