Determination of mechanisms of multiple drug resistance in MCF-7 cell line developed against paclitaxel and vincristine by microarray analysis

METHODS

Paclitaxel and vincristine were applied to MCF-7 cell line in
stepwise manner. The resistance levels of the cells were determined
by XTT test. The levels of all of the genes in resistant
and sensitive cells were determined by microarray assay.

RESULTS

MCF-7/400nMPac and MCF-7/120nMVinc cells are 150- and
30-fold resistant compared to sensitive MCF-7. Upregulation
of MDR1 gene is found to be important in resistance. The
expression levels of the genes encoding detoxifying enzymes
were upregulated and some apoptotic gene levels were downregulated.
Changes in expression levels of metastatic genes,
some oncogenes, cell cycle, and tubulin-related genes were
found.

CONCLUSION

According to these results, change in expression level of
MDR1 gene seems to be important in resistance in MCF-7
cells.

Keywords: Apoptotic pathway; beta tubulin; multiple drug resistance; MCF-7; microarray analysis