Human sequences related to the gp52 coding area of the gene env of MMTV, in peripheral blood mononuclear cells as a putative breast cancer marker?

PB Makhov PhD^a, TF Malivanova PhD^a, AL Denisova PhD MD^b, EB Polevaya PhD MD^b, KP Laktionov MD^b, IN Kryukova PhD^a

^aInstitute of Carcinogenesis CRC RAMS, Moscow, Russian Federation, ^bInstitute of Clinical Oncology CRC RAMS, Moscow, Russian Federation

BACKGROUND: Human sequences, closely related to the env MMTV gene, are expressed in human peripheral blood mononuclear cells (PBMC) of the most of breast cancer (BC) patients. The expression of the sequences is correlated with the detection in human PBMC of an antigen immunologically related to gp52 - the product of the env MMTV gene. Such sequences were isolated and sequenced. It was shown that they demonstrated approximately 96-98% homology with gp52-coding area of the env MMTV gene and only about 18% with HERV-K proviruses. METHODS: PCR using a pair of primers corresponding to the fragment of the gp52-coding area of env MMTV gene. Southern-blot hybridization with gp52-coding area of the env MMTV gene as a probe, followed by PCR reaction for the detection of the specific PCR-products. Sequencing of PCR-products. RESULTS: gp-52-specific PCR-products were detected in DNA samples isolated from PBMC of BC patients and from healthy donors. In 35% cases the samples derived from BC patients were positive. DNA samples derived from PBMC of healthy donors were positive in 1% of the cases. Also, we have find out the following law: The tumors of 7 of 9 env MMTV-positive patients were estrogenic receptor (ER) negative, while the tumors of 6 of 8 env MMTV- negative patients had been carried ER. CONCLUSIONS: These data show that the sequences we studied could be considered as a molecular marker of BC. However, it seems that a hypothetical exogenous retroviral agent exists in humans, plays a role in mammary gland carcinogenesis, and involves lymphocytes in its circulation and distribution.

Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Nice, France; February 7 - 10, 2004; in poster session 791 (Viral infections).