Knockdown of the M2 Isoform of Pyruvate Kinase (PKM2) with shRNA Enhances the Effect of Docetaxel in Human NSCLC Cell Lines In Vitro.
OBJECTIVE
The aim of our study was to explore the relationships between the M2 isoform of pyruvate kinase (PKM2) and the sensitivity of human non-small cell lung cancer (NSCLC) cells to docetaxel in vitro.


METHODS
With the method of plasmid transfection, we silenced the expression of PKM2 successfully in A549 and H460 cells. Western blotting and real-time PCR were applied to detect PKM2 expression at protein and gene levels. Cell viability was examined by CCK8 assay. Cell cycle distribution and apoptosis were examined by flow cytometry. P21 and Bax were detected.


RESULTS
Expression of PKM2 mRNA and protein were significantly decreased by shRNA targeting PKM2. Silencing of PKM2 increased docetaxel sensitivity of human NSCLC A549 and H460 cells in a collaborative manner, resulting in strong suppression of cell viability. The results of flow cytometric assays suggested that knockdown of PKM2 or docetaxel treatment, whether used singly or in combination, blocked the cells in the G2/M phase, which is in consistent with the effect of the two on the expression of p21. Cells with PKM2 silencing were more likely to be induced into apoptosis by docetaxel although knockdown of PKM2 alone can't induce apoptosis significantly, which is in consistent with the effect of the two on Bax expression.


CONCLUSIONS
The results suggest that PKM2 knockdown could serve as a chemosensitizer to docetaxel in non-small lung cancer cells through targeting PKM2, leading to inhibition of cell viability, increase of cell arrest of G2/M phase and apoptosis.
Department of Oncology, Jinshan Hospital, Medical Center of Fudan University, Shanghai, China.
Sujuan
S
Yuan
Department of Oncology, Jinshan Hospital, Medical Center of Fudan University, Shanghai, China. qiaotk@163.com.
Tiankui
T
Qiao
Department of Oncology, Jinshan Hospital, Medical Center of Fudan University, Shanghai, China.
Xibing
X
Zhuang
Department of Oncology, Jinshan Hospital, Medical Center of Fudan University, Shanghai, China.
Wei
W
Chen
Department of Radiotherapy, Donghua Hospital of Sun Yat-sen University, Dongguan, China.
Na
N
Xing
Department of Oncology, Jinshan Hospital, Medical Center of Fudan University, Shanghai, China.
Qi
Q
Zhang
D017209:Apoptosis / Q000187:drug effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D000077143:Docetaxel; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D035683:MicroRNAs; D020033:Protein Isoforms; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D043823:Taxoids / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000187:drug effects*
D000077143:Docetaxel; D035683:MicroRNAs; D020033:Protein Isoforms; D011770:Pyruvate Kinase; D034741:RNA, Small Interfering; D043823:Taxoids; C549242:MIRN7-1 microRNA, human
The M2 isoform of pyruvate kinase; apoptosis; cell cycle; chemotherapy; docetaxel; non-small cell lung cancer; shRNA