ABSTRACT
The type 1 insulin-like growth factor receptor (IGF-1R) and its downstream signaling components have been increasingly recognized to drive the development of malignancies, including non-small cell lung cancer (NSCLC). This study aimed to investigate the effects of IGF-1R and its inhibitor, AG1024, on the progression of lung cancer. Tissue microarray and immunohistochemistry were employed to detect the expressions of IGF-1 and IGF-1R in NSCLC tissues (n=198). Western blotting was used to determine the expressions of IGF-1 and phosphorylated IGF-1R (p-IGF-1R) in A549 human lung carcinoma cells, and MTT assay to measure cell proliferation. Additionally, the expressions of IGF-1, p-IGF-1R and IGF-1R in a mouse model of lung cancer were detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction (FQ-PCR), respectively. The results showed that IGF-1 and IGF-1R were overexpressed in NSCLC tissues. The expression levels of IGF-1 and p-IGF-1R were significantly increased in A549 cells treated with IGF-1 as compared to those treated with IGF-1+AG1024 or untreated cells. In the presence of IGF-1, the proliferation of A549 cells was significantly increased. The progression of lung cancer in mice treated with IGF-1 was significantly increased as compared to the group treated with IGF-1+AG1024 or the control group, with the same trend mirrored in IGF-1/p-IGF-1R/IGF-1R at the protein and/or mRNA levels. It was concluded that IGF-1 and IGF inhibitor AG1024 promotes lung cancer progression.