Caspase-8 expression in the IGR-N-91 experimental metastatic model. A) Western Blot analyses of caspases-3, -8, -9, Bcl-2 and Bax expressions in cell lines of the IGR-N-91 experimental model. Semi-quantitative RT-PCR analyses of caspase-8 mRNA expressions and GAPDH as internal control. PTX: Primary Tumor Xenograft, BM: Bone Marrow, Myoc: Myocardium. B) Whole extracts from the IGR-N-91 and SH-EP cell lines, and four IGR-N-91 primary tumor xenografts were analyzed by immunoblotting for caspase-8 expression. β-actin was used as loading control.