(A) Expression of apoptosis-related genes during culture with IL-6. 1A9-M cells were cultured with 20 ng/mL of IL-6 for the indicated time periods. Total RNAs were isolated and subjected to Northern blot analysis using the cDNAs of BCL2, BCL-XL, Bax, Bak, p53, and β-actin as probes. (B) Expression of BCL2 protein during culture with IL-6. 1A9-M cells were cultured with 20 ng/mL of IL-6 for the indicated periods. Whole cellular lysates were obtained and subjected to Western blot analysis using an antimouse BCL2 antibody.