[Expression of microRNA 27a and its correlation with drug resistance in human ovarian cancer A2780/Taxol cells].
OBJECTIVE
To investigate the expression of microRNA 27a (miR-27a) and relationship with drug resistance in human ovarian cancer A2780/Taxol cells.


METHODS
A stem-loop-mediated real-time PCR was used to detect miR-27a expression in A2780 and A2780/Taxol cells. The cells were transfected with the mimics or inhibitors of miR-27a or negative control RNA (NC) by lipofectamine 2000. The expressions of MDR1 gene, P-glycoprotein (P-gp) and homeodomain-interacting protein kinase 2 (HIPK2) protein levels were measured by real-time PCR and western blot respectively. Methyl thiazolyl tetrazolium (MTT) assay was used to analyze drug sensitivity. Apoptosis analysis was measured by fluorescence activated cell sorter (FACS).


RESULTS
(1) miR-27a was an average of 2.2-fold higher expression level in A2780/Taxol cells than that in A2780 cells, with a significant difference between the two groups (P<0.05). (2) A2780/Taxol cells transfection with inhibitors of miR-27a showed that the levels of MDR1 mRNA was decreased by 39%, P-gp protein level [(26+/-5)%] decreased than that in the NC group [(43+/-7)%], HIPK2 protein level [(30+/-6)%] increased than that in the NC group [(19+/-4)%], the 50% inhibition concentration (0.5 micromol/L) was less than that in the NC group (6.8 micromol/L), apoptosis rate [(32.5+/-3.6)%] was higher than that in the NC group [(5.6+/-2.1)%], and there were significant differences between two groups (all P<0.05). (3) Transfection of A2780 cells with mimics of miR-27a led to increase MDR1 mRNA expression by 121% as compared with one transfection with NC (P<0.05).


CONCLUSIONS
The expression of miR-27a is upregulated in A2780/Taxol cells, which may regulate MDR1 and P-gp expression by targeting HIPK2.
Li
Zhi-min
ZM
Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Hu
Sha
S
Xiao
Lan
L
Wang
Jing
J
Cai
Jing
J
Yu
Li-li
LL
Wang
Ze-hua
ZH
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D017239:Paclitaxel / Q000494:pharmacology*; D016133:Polymerase Chain Reaction / Q000379:methods; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D002352:Carrier Proteins; C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; C115114:HIPK2 protein, human; D017346:Protein Serine-Threonine Kinases; D017239:Paclitaxel