[Expression of IGF-1R in esophageal squamous cell carcinoma and the effect of its silencing by siRNA on the proliferation of esophageal cancer EC9706 cells in vitro].
OBJECTIVE
To explore the correlation of IGF-1R expression with clinical features of esophageal squamous cell carcinoma (ESCC) and to investigate the effect of silencing IGF-1R by siRNA on the proliferation of esophageal cancer cell line EC9706 cells.


METHODS
Immunohistochemistry was used to detect the expresion of IGF-1R in 80 specimens of ESCC and 18 specimens of normal esophageal mucosa. IGF-1R siRNA was transfected into esophageal squamous cell carcinoma EC9706 cells, and the effect of RNAi was assessed by Western blot. The proliferation of EC9706 cells was determined by drawing growth curve, MTT assay and plate colony-forming assay.


RESULTS
The total and strong positive rates of IGF-1R expression were 86.3% and 51.3% in ESCC, and 61.1% and 11.1% in normal esophageal epithelium, respectively. The total and strong positive rates of IGF-1R expression in patients with lymph node metastasis were 94.4% and 74.1%, significantly higher than 69.2% and 3.9%, respectively, in those without lymph node metastasis (P<0.01). A significantly higher IGF-1R expression was associated with lower histological grade (P<0.05). The total and strong rates of IGF-1R expression in 39 patients of stages III and IV were 97.4% and 71.8% , significantly higher than the 75.6% and 31.7%, respectively, in 41 cases of stages I and II (P<0.01). IGF-1R RNAi significantly inhibited IGF-1R expression and the growth of EC9706 cells. The clone formation rate of RNAi-IGF-1R transfected cells was 19.1%, significantly lower than that of 52.3% in non-transfected cells and 49.0% in empty vector-transfected EC9706 cells (P<0.05).


CONCLUSIONS
The overexpression of IGF-1R is colerated with lymph node metastasis, differentiation and clinical stage. Down-regulation of IGF-1R can inhibit the proliferation of esophageal cancer EC9706 cells in vitro.
Department of Oncology, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China.
Wang
W
Ma
Wen
W
Li
Qing-Xia
QX
Fan
Liu-Xing
LX
Wang
Rui-Lin
RL
Wang
Shi-Xin
SX
Lu
D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D034741:RNA, Small Interfering; D017526:Receptor, IGF Type 1