Expression of Hrk in human cell lines and CD34⁺ progenitor cells.

Two megakaryoblastic cell lines were cultured in the absence of IL-3 (Mo7e) or GM-CSF (UT7). Bone marrow-derived CD34⁺ cells were cultured with (+GFs) and without (−GFs) growth factors (IL-3, IL-6, and stem cell factor) for 36 hours. At the indicated time intervals, cells were analyzed for the expression of Hrk and Bax by Western blot.