Effect of γ-irradiation on cyclin B1 accumulation in hematopoietic cell lines.

(A) Protein lysates (10 μg/lane) of DP16, HL60, and primary mouse thymocytes were prepared at various time points following γ-irradiation, and the levels of cyclin B1 protein measured by Western blot. Cells were treated with 200 cGy of radiation. (B) DNA fragmentation 24 hours following treatment with γ-radiation (+ lanes). Control cells (- lanes) were mock irradiated and maintained under identical conditions. (C) Annexin staining of DP16 and HL60 24 hours following γ-irradiation (white profiles) relative to mock irradiated cells (black profiles). (D) Stimulation of cyclin B1 protein accumulation in primary thymocytes by both 200 rad of γ-radiation and 1 μg of dexamethasone. (E) Thymocyte DNA fragmentation stimulated by radiation and dexamethasone.