Preparation of M1 cells overexpressing cyclin D1 and/or bcl-2.
(A) Northern blot analysis on expression of cyclin D1, bcl-2, or both in each transfectant. Total cellular RNA was extracted from each clone, and Northern blot analysis was performed with 32P-labeled probe for cyclin D1 or bcl-2. (B) Changes in total viable cell number during the culture with (lower panel) or without (upper panel) recombinant human (rh) interleukin 6 (IL-6). M1-V1, M1-D1, M1-bcl-2, and M1-W cells were seeded at a cell density 100/μL and subjected to the culture in the absence or presence of rhIL-6 (20 ng/mL). Total viable cell number was counted by trypan blue dye exclusion method: M1-V1, open circle; M1-D1, closed circle; M1-bcl-2, open square; M1-W, closed square. The results are shown as the mean ± SD of triplicate cultures.
