Gene Expression Profile of Resistant vs Sensitive Breast Cancer Tissues to Taxane Treatment

The present project aims to evaluate the gene expression profile of breast cancer tissue resistant to treatment with taxanes. Biopsies from tumor tissues were obtained from breast cancer patients without prior treatment. Histopathological analysis and ex vivo exposure to antineoplastic chemotherapeutics were carried out. Alamar Blue and lactate dehydrogenase release assays were performed for quantitative analysis of tumor viability after treatment and to asses the sensibility or resistant behaviour. Sensitive and resistant tumor tissues samples without prior exposure to therapeutic drugs were analyzed by gene expression microarrays. Two resistant and two sensitive samples were analyzed by duplicated (for a total of 8 microarrays). Total RNA was isolated using the Rneasy Plus mini kit (Qiagen) and converted to doble stranded cDNA by the cDNA synthesis kit system (Roche). Doble stranded DNAs were label with Cy3 and hybridized to Gene expression arrays 12x35k (Roche) which consist of aproximately 132k probes for 42k genes.