[Small interfering RNA-mediated COX-2 gene silencing enhances chemosensitivity of KB/VCR cells by suppressing MDR-1 gene expression and P-glycoprotein activity].
OBJECTIVE
To investigate the effect of small interfering RNA (siRNA)-mediated COX-2 gene silencing in enhancing the chemosensitivity of KB/VCR cell lines.


METHODS
KB/VCR cells were trasnfected with COX-2 siRNA were examined for expressions of COX-2 and MDR-1 mRNAs with RT-PCR and for Rho-123 accumulation using flow cytometry. MTT assay was used to analyze the proliferation of the transfected KB/VCR cells.


RESULTS
Compared with the negative and blank control groups, COX-2 siRNA transfection resulted in significant growth inhibition of KB/VCR cells exposed to vincristine (P<0.01), down-regulated the expressions of COX-2 and MDR-1 mRNAs, and obviously increased Rho-123 accumulation in KB/VCR cells.


CONCLUSIONS
COX-2 gene silencing can enhance the chemosensitivity of KB/VCR cells to vincristine, the mechanism of which may involve down-regulated MDR-1 gene expression and inhibition of P-glycoprotein activity.
Department of Oral and Maxillofacial Surgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. E-mail: moxianchao1988@163.com.
Xianchao
X
Mo
Weizhong
W
Li
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D007624:KB Cells; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014162:Transfection; D014750:Vincristine
C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014750:Vincristine; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human