RNA interference-mediated knockdown of insulinoid growth factor receptor-I inhibits cell invasion and metastasis in gastric cancer cells

Objective To study effects of insulinoid growth factor receptor- Ⅰ (IGF- Ⅰ R) inter ference on invasion and metastasis of gastric cancer cells.Methods Small interfering RNA (siRNA) targeting IGF- Ⅰ R mRNA was obtained by in vitro transcription and transfected into MKN28 cells with lipofectin; the IGF- Ⅰ R,matrix metalloproteinase-2 (MMP-2),vascular endothelial growth factor (VEGF),tissue inhibitorof metalloproteinase-1 (TIMP-1) and integrase Interactor 1 ( INI1 ) mRNA levels were analyzed by using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.The abilities of cell invasion and metastasis were evaluated using Boyden' s chamber.Results Overexpression of IGF- Ⅰ R was detected in 3 gastric gancer cell lines.The expression of IGF- Ⅰ R mRNA and protein was significantly inhibited by IGF- Ⅰ R siRNA.The MMP-2 and VEGF expression was decreased,but TIMP-1 and INI1 expression increased (all P ＜ 0.05).Result of Boyden' s chamber showed that inhibition of IGF- Ⅰ R effectively suppressed cell invasion and metastasis of MKN28 cells (P ＜ 0.05 ).Conclusion siRNA against IGF- Ⅰ R could effectively down-regulate the expression of IGF- Ⅰ R in MKN28 cells and suppress cell invasion and metastasis. Key words: Gastric cancer; Insulinoid growth factor receptor- Ⅰ; Small interfering RNA; Metastasis