[Biological behaviors and chemosensitivity of NSCLC A549 cells after IGF-IR gene silencing by targeting RNAi in vitro].
To investigate the biological behaviors and chemosensitivity of non-small cell lung cancer (NSCLC) cell line A549 after IGF-IR gene silencing by RNA interference (RNAi) in vitro.



Two plasmids siRNA 1 and 2 expressing IGF-IR siRNA with human U6 promoter were constructed,and an unrelated siRNA was used as negative control. NSCLC A549 cells were transfected with sequence-specific siRNA or unrelated siRNA as control. Quantitative RT-PCR and Western blot were used to detect the expression of IGF-IR. NSCLC A549 cells were transfected with siRNA and treated with DDP. MTT assay and flow cytometry were used to assess the effects of IGF-IR silencing on tumor cell proliferation and chemosensitivity.



Transfection of NSCLC cells with siRNA resulted in reduction of IGF-IR mRNA expression by 78.9 % and protein production by 89.8%. The decrease in IGF-IR levels caused significant growth inhibition of A549 cells both at 48 h and at 72 h, and decrease of the IC50 of DDP at 24 h, 48 h and at 72 h. Flow cytometry showed that 77.5% of A549 cells retained in G0/G1 phase.



The sequence specific suppression of IGF-IR gene expression by RNAi enhances sensitivity to DDP in NSCLC cell.
Kong
Min-jian
MJ
Department of Cardiothoracic Surgery, The Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China.
Dong
Ai-qiang
AQ
Wu
Wei
W
Ma
Zhi-yuan
ZY
Cheng
Hai-feng
HF
Qian
Jian-fang
JF
Fan
Jun-qiang
JQ
D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D020868:Gene Silencing; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D010957:Plasmids / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D014162:Transfection
D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017526:Receptor, IGF Type 1