[Development of drug resistance and alteration of cell cycle in lung cancer: a flow cytometric study].
OBJECTIVE
To study the relationship between the expression of multidrug resistance-associated protein (MRP) and P-glycoprotein (P-gp) and alteration of cell cycle during the process of drug resistance in lung cancer.


METHODS
Lung adenocarcinoma cell line GLC-82 was treated with low concentration of adriamycin. At 0, 24, 48, 72 and 96 hr following adriamycin treatment, the expression of MRP and P-gp, and cell cycle were examined by bi-parameter flow cytometry.


RESULTS
Treatment of GLC-82 cells with adriamycin at a final concentration of 0.05 microgram/ml resulted in progressive decrease in cells in G1 phase and increase in cells in S phase of the cell cycle. The expression level of P-gp was very low and showed little change with time. In contrast, MRP expression was significantly increased in a time-dependent manner, and was positively correlated with changes in S phase of the cell cycle.


CONCLUSIONS
MRP expression may play a major role in the development of resistance to adriamycin.
Xu
M
M
Department of Oncology, Nan Fan Hospital, First Military University, Guangzhou 510515, China.
Li
J
J
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D004273:DNA, Neoplasm / Q000032:analysis; D004317:Doxorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D004273:DNA, Neoplasm; D004317:Doxorubicin; D027425:ATP-Binding Cassette, Sub-Family C Proteins