E.A. Kudinova, O.V. Burmenskaya, V.K. Bozhenko, E.F. Vaskevich, O.S. Nepsha, N.V. Melnikova, I.D. Trocenko, D.Yu. Trofimov, G.T. Sukhih

We have studied modalities of apoptosis gene complex expression rate in normal breast, fibroadenoma and breast cancer. Quantitative assessment of mRNA expression rates was performed for four genes with pro- and antiapoptotic activities: BCL-2 and BAG1 possess antiapoptotic features, BAX and NDRG1, on the contrary, have proapoptotic functions. 134 tissue samples have been studied: 57 cases of breast cancer (I-IV stages), 16 fibroadenomas and 66 conditionally normal tissue samples that were resected from unchanged breast mass during the operations for fibroadenoma. RNA extraction, reverse transcription and RT-PCR have been performed according to standard protocols. Expression of BCL-2 and NDRG1 decreased from normal samples to fibroadenoma and breast cancer, achieving lowest rates in a case of cancer. Tumor size positively correlated with NDRG1 expression, and negatively with BAG rate, but there was no correlation with BCL2 and BAX. Increased BAX expression has been detected in a case of metastatic breast samples. Also BCL2 and BAG expression rates were negatively correlated with malignancy degree (G) that positively correlated with BAX. These data show progradiate decrease of pro- and antyapoptotic genes expression during malignization process. It is interesting that the rate of antyapoptotic genes (BAG, BCL2) expression is decreasing along with G and tumor metastatic potential. There is discordance between our finding and the results of some other investigators. Further investigations are needed to determine new features of apoptosis genes expression on the mRNA and protein level