Janice E. Chin

TL;DR: Results are consistent with a function for P-glycoprotein as an energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells.

TL;DR: A highly sensitive, specific, and quantitative protocol for measuring the levels of MDR1 mRNA in clinical samples, based on the polymerase chain reaction is devised, which was found to be effective in most solid tumors and leukemias tested.

TL;DR: Evidence is presented that multidrug-resistant sublines of human KB carcinoma cells, selected for resistance to either colchicine, vinblastine, or Adriamycin (doxorubicin), display amplification of two different DNA sequences homologous to the hamster mdr gene, suggesting that the mdr1 gene is involved inMultidrug resistance in human cells.

TL;DR: Results suggest that increased expression of mdr1 mRNA is a common mechanism for multidrug resistance in human cells and that Activation of the m dr1 gene by mutations or epigenetic changes may precede its amplification during the development of resistance.

TL;DR: The structure of the human MDR gene family is examined by Southern hybridization of DNA from different multidrug-resistant cell lines with subfragments of MDR1 cDNA and by cloning and sequencing of genomic fragments and no evidence for any other cross-hybridizing MDR genes is found.