Paclitaxel resistance in triple negative breast cancer involves novel functional genomic aberrations in the ABCB1 gene.. Homo sapiens

Five Triple Negative Breast Cancer cell lines were exposed to increasing concentration of Paclitaxel untill they acquired resistance. In order to identify changes in gene expression associated with resistance to PTX, we performed gene expression profiling on parental and resistant cell lines. Of ~22000 genes surveyed by microarray analysis, 5.0%, 3.7%, 9.0%, 7.3%, and 5.4% of the genes showed changes in expression of 2-fold or greater (p value < 0.05) in BT20, SUM149, MDA-MB-231, MDA-MB-436 and MDA-MB-468 cell lines, respectively. Overall design: Parental and resistant cells growing were seeded at a density of 0.8x106 per well in 6 well-plates and incubated without drug for 24 hours. Cells were harvested and total RNA from parental and resistant cell lines were extracted using the AllPrep DNA/RNA Mini kit. Four independent RNA extraction from different cell passage was performed for all cell lines except for MDA-MB-468. Three independent replicate is presented for MDA-MB-468 P and MDA-MB-468 R. .