Biomarker analysis by tissue microarray technology of Bik, Bcl-2, Bax, ER-α, ER-β, Her2/neu, PCNA, P53, pRB proteins and apoptotic index (by TUNEL) in breast cancer Mexican biopsies.

CTRC-AACR San Antonio Breast Cancer Symposium: 2008 Abstracts Abstract #4043 Background: The development and progression of epithelial cancers are the results of changes in many genetic networks. Through massive analysis techniques various prognostic factors have been studied to determine proteins implicated in cancer. A new technology used is tissue microarray (TMAs), which allows the assessment of several patients at different stages in a single slide. Methods: TMA blocks with up to 128 cylinders were made by using 1.5-mm diameter tissue cores from each paraffin block. In a series of 70 formalin-fixed carcinomas, we analyzed the immuno-expression of Bik, Bcl-2, Bax, ER-α, ER-β, Her2, PCNA, P53 and RB proteins. For apoptosis detection the TUNEL technique was used. Expression profiles for these tumors were generated with an unsupervised clustering and a T Test analysis. Results: We developed TMAs with samples from Mexican women with breast cancer at different stages (type I, II and III) and compared these with those of non affected breast tissue of the same women's samples. Through a hierarchical cluster we found three subgroups of tumors according to protein expression behavior. The apoptotic process was found in low grade 4.28%; moderate grade 90% and high grade 5.71% of samples. Statistical analysis revealed that Bax gene ( p=0.000 ) expression was significantly increased in samples stage I and underexpressed in samples stage IIIA. The Bcl-2 gene was under-expressed in the majority of samples of the stage II. Even when the Bik gene was detected the protein level was over-expressed in 44.29% of the cases with noa significant correlation with apoptosis (TUNEL) ( p=0.006) . The samples where there were more alterations of the studied proteins were understood in the stages IIA (T2N0M0) and IIB (T2N1M0). ![][1] Conclusions: The analysis of specimens of several patients in different stages of the disease turns out to be useful to establish a better diagnosis and prognosis. Differential regulation of these genes, especially Bik and Bax, may contribute to the biological nature of a clinically more aggressive and highly proliferative breast cancers. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4043. [1]: /embed/graphic-1.gif