Generating IGF1 signatures in human melanoma cell lines by activation of IGF1 or ihibition of IGF1R

To generate IGF1 signatures in human melanoma cell lines. Recombinant human IGF1 (rhIGF1) was added to WM35, known to be responsive to rhIGF1, whereas constitutive IGF1 signaling in Mel-624 was abrogated by siRNA directed against the IGF1 receptor (siIGF1R). Experiments were performed in triplicate in normoxia (O2 concentration, 21%) and hypoxia (1% O2), because hypoxia has been suspected to play an adverse role in melanoma. After generating GEP data, we created signatures of genes significantly (p ≤0.0001, q ≤0.05) and consistently upregulated in rhIGF1-treated WM35 cells, or similarly downregulated in siIGF1R-treated Mel-624 cells, as compared to control cells at the same O2 concentration. To find out whether IGF1 signatures generated in human melanoma cell lines are predictive of outcome in melanoma patients, we generated IGF1 signatures in two cell lines WM35 and Mel-624. The expression of IGF1 signatures were then tested by using GSSA (Gene Signature Survival Analysis) method to find out correlation with clinical outcome of melanoma patients.