Abstract
Insulin-like growth factor 1 receptor (IGF1R) is a tyrosine kinase receptor implicated in tumourigenesis that may be an attractive target for anti-cancer treatment. In this study, the expression and clinical significance of IGF1R were investigated in serum and lung cancer tissues from small cell lung cancinoma (SCLC). We also compared the effect of IGF1R up-regulation and IGF1R inhibition on viability and apoptosis of NCI-H446 cells. We found the concentration of IGF1R in blood serum was significantly increased and positive IGF1R protein in cancer tissue was more prevalent in SCLC. A statistically significant correlation among IGF1R-positve tumors, lymph node metastasis and local invasion was discussed. Furthermore, IGF1R overexpression lead to an increase of cell survival and suppressed cell apoptosis, IGF1R silencing mediated by RNAi abrogate this response of NCI-H446 cells. Our results further demonstrated that the effects of these treatments may be assigned to the effective inhibition of lung cancer cells from Akt/P27Kip1 pathway in IGF-1R signaling. These features may have important implications for future anti-IGF1R therapeutic approaches.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and written expression of this article. This work was partly supported by grants from the Guangdong Scientific Project of China (2011B080701039) and the Guangdong Medical University Scientific Research Foundation for the Returned Overseas Chinese Scholars (XH-1004).