Reversal of Multidrug Resistance of Exogenous TNF-α Gene Combined with Verapamil or Tamoxifen / 复旦学报（医学版）

ABSTRACT

Purpose To study the reversal effect on multidrug resistance (MDR) by TNF-α gene combined with verapamil (VRP) or tamoxifen (TAM). Methods By using recombinant retrovirus vector, TNF-α gene was transfected into multidrug-resistant human breast cancer cell line MCF7/ADR. The TNF-α secreting cell clone MCF7/ADR-TNF was obtained by G418 screening. The integrating and secreting of TNF-α were analyzed by PCR and ELISA. MTT assay and formula"I = d/D1 + d/D2" were used to evaluate the reversal effect of multidmg resistance with TNF-α gene combined with verapamil or tamoxifen. ResultsThe level of TNF-α secreted by MCF7/ADR-TNF was 1 737 pg/ml (106cells/48 h). Compared with control,the resistance to ADR of MCF7/ADR-TNF was reversed by 1.6 times. The reversal effect produced by combination of TNF-α gene and VRP was antagonistic. The combination of TNF-α gene and TAM produced synergic effect (interaction index I = 0.64). ConclusionsTNF-α gene combined with TAM has synergic effect on reversing MDR.