[Screening for drug resistance related microRNAs in K562 and K562/A02 cell lines].
OBJECTIVE
To explore the relationship between microRNA and drug resistance in leukemia treatment by screening and identifying the microRNAs which differentially express in K562 cell line and its adriamycin resistant cells-K562/A02 cell line.


METHODS
The drug resistance potency of K562/A02 cells was evaluated by MTT assay. P-gp expression of K562 and K562/A02 cells were detected by flow cytometry (FCM). The differentially expressed microRNAs in K562 and K562/A02 cells were analyzed by microarray technique and Real Time RT-PCR.


RESULTS
The resistance to adriamycin (ADM) of K562/A02 cells was 180 fold greater than that of K562 cells. P-gp expression rate of K562 and K562/A02 cells was 0.2% and 86%, respectively. Twenty-two microRNAs expressed differentially in K562 and K562/A02 cells (P < 0.01). As compared to K562 cells, expressions of miR-221, miR-155 and miR-451 were up-regulated by more than two fold, while expression of miR-98, miR-181a, let-7f, let-7g, miR-424 and miR-563 down-regulated by more than two fold in K562/A02 cells. The results of real time RT-PCR were consistent with that of microarray. Of note, differential expressions of miR-451, miR-155, miR-221, let-7f and miR-424 were remarkable.


CONCLUSIONS
K562/A02 cells show a different microRNA expression profile as compared to its parental K562 cells, suggesting microRNAs including miR-221, miR-155, miR-451, let-7f and miR-424 may be involved in the mechanism of drug resistance in leukemia. These differentially expressed microRNAs provide potential novel targets for overcoming drug-resistance.
Department of Hematology, the Second Xiangya Hospital, Central South University, Changsha 410011, China.
Yi-Xiong
YX
Cao
Chong-Wen
CW
Dai
Guang-Sen
GS
Zhang
D004317:Doxorubicin; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D006801:Humans; D020014:K562 Cells; D035683:MicroRNAs / Q000235:genetics
D035683:MicroRNAs; D004317:Doxorubicin