Expression and significance of IGF1,IGF1R and AKT,the components of IGF signaling pathway,in primary adenocarcinoma of the lung

Objective To investigate the expression of IGF1,IGF1R and AKT,the componets of IGF signaling pathway,in primary adenocarcinoma of the lung as well as the correlation between expression and clinicopathological characteristics and clinical follow-up.Methods The expression of IGF1,IGF1R and AKT was investigated in 31 specimens from patients with primary adenocarcinoma of the lung and in 12 specimens from patients with benign lung diseases by immunohistochemistry and Western blotting.Results IGF1,IGF1R and AKT were overexpressed in cancer compared with benign lung tissues(P=0.0252,0.0016 and 0.0071,respectively).IGF1 and IGF1R as well as IGF1 and AKT expressions were strongly associated with each other in adenocarcinoma(P=0.0344 and 0.0179,respectively).The expression of IGF1 and IGF1R was significantly higher in lung cancers with higher stages(Ⅲ+Ⅳ) than in those with lower stages(Ⅰ+Ⅱ)(P=0.0109 and 0.0303,respectively).IGF1,IGF1R and AKT were statistically higher in lung cancers with metastasis in local lymph node than in those without metastasis in local lymph node(P=0.0468,0.0490 and 0.0443,respectively).IGF1 and IGF1R were significantly higher in tumors with poor differentiation than in those with moderate or well differentiation(P=0.0484 and 0.0291,respectively).IGF1 or IGF1R positive cases were correlated with significantly shorter patient survival(median,10 months for IGF1 positive cases versus 14 months for negative cases,P=0.0103;13 months for IGF1R positive cases versus 26 months for negative cases,P=0.0056).Univariate but not multivariate analysis revealed that IGF1 and IGF1R expressions were the prognostic factors of adenocarcinoma of lung.However,AKT was of no significance.Conclusions The expression of IGF1,IGF1R and AKT,the components of IGF signaling pathway,may play an important role in the initiation and progression of human adenocarcinoma of the lung.Further investigation in this pathway may reveal its implication in prognosis and therapy of lung cancer.