Construction of siRNA expression vector targeting IGF-1R and its ability to induce cell apoptosls in hmnan lung cancer cells / 中华胸心血管外科杂志

ABSTRACT

Objective Insulin-like growth factor-1 receptor (IGF-1R),similar to insulin receptor,is one of the families of re- ceptor tyrosine kinases.,which has been found to be overexpressed in a variety of cancer.It is the main proliferation and survival sig- nal molecule in cancer cell and plays an important role in cancer growth and progress.Blocking signal transduction of IGF-1R by vari- ous strategies can suppress tumor growth and induce regression of established tumor.This study is to construct the siRNA expression vector targeting IGF-1R and to evaluate its ability to induce cell apoptosis in human lung cancer cells.Methods Two siRNA expres- sion vector,pENTR/U6-shRNA-1 and pENTR/U6-shRNA-2 targeting IGF-1R,were constructed using pENTR/U6 vector,and a vector targeting hieiferase gene,pENTR/U6-shRNA-Iuc,was constructed as control.After vectors were transfected into A549 for 48h, knockdown of IGF-1R mRNA and protein and Akt phosphorylation were accessed,and DNA ladder and flow cytometry were used for cell apoptosis.Results siRNA expression vectors targeting IGF-1R were successfully constructed,which was confirmed by PCR and DNA sequencing,pENTR/U6-shRNA-1 and pENTR/U6-shRNA-2 demonstrated the expression were (22.1?2.5) % and (80.1? 3.9) % in IGF-1R mRNA level,(15.2?3.1)% and (47.1?4.1)% in protein level,respectively,compared with pENTR/U6- shRNA-luc.Suppression of IGF-1R by pENTR/U6-shRNA-1 blunted Akt phosphorylation,increased cell apoptosis induced by 3% ethanol,and retained 77.5 % A549 cells in the G0/G1 phase.Conclusion siRNA expression vector targeting IGF-1R can effectively suppress the expression of IGF-1R expression in A549.This study suggests that DNA vector-based RNAi has the potential to be effec- tive and practical cancer gene therapy strategy.