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The acquired resistance to various drugs in cancer is mediated by P-glycoprotein (P-gp) which is encoded by the mdr-1 gene. An increased level of mdr-1/P-gp was demonstrated after chemotherapy administered to treat cancer in humans. To clarify the direct effect of anticancer drugs on mdr-1/P-gp expression, we investigated the change in transport of adriamycin (ADR), and the expression of the mdr-1 gene and P-gp in an ADR-treated, multidrug-resistant leukemic cell line (K562/ADR500). The addition of ADR induced the over-expression of mdr-1/P-gp, which led to a transient decrease in the intracellular accumulation of ADR although the difference was not statistically significant. A maximal effect was observed after 4 h incubation, returning to the baseline level after further incubation for 12-24 h. The phosphorylation of P-gp was inversely correlated with the levels of P-gp. These observations suggest that ADR itself modulates both the expression and function of P-gp. Determination of the optimal schedule for administering adriamycin is essential to achieving the optimal effect in treating cancer.
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
April 2004,
BMC cancer,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
July 1996,
Clinical science (London, England : 1979),
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
October 1989,
The Journal of biological chemistry,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
October 1990,
Gan to kagaku ryoho. Cancer & chemotherapy,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
January 1993,
Haematologica,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
January 1998,
Anticancer research,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
September 1991,
British journal of haematology,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
February 2002,
Leukemia research,
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
October 1995,
Journal of chemotherapy (Florence, Italy),
S Kato, and
J Nishimura, and
Y Yufu, and
H Ideguchi, and
T Umemura, and
H Nawata
January 1999,
Annals of oncology : official journal of the European Society for Medical Oncology,
