[Effect of cyclophosphamide on murine bone marrow hematopoietic cells and its possible mechanism].

This study was purposed to investigate the effect of chemotherapeutic drug cyclophosphamide (CTX) on normal murine bone marrow hematopoietic cells, especially on the self-renewal, proliferation and differentiation of bone marrow hematopoietic cells, and possible mechanisms. The CTX-treated mouse model was established by CTX 200 mg/kg, ip. The exact time of complete recovery of hematopoiesis was determined by monitoring the recovery level of differential blood counts and the proportion of LKS(+) cells in bone marrow cells. The function of bone marrow hematopoietic cells such as self-renewal, proliferation and differentiation were assessed by non-competitive and competitive bone marrow transplantation. The potential effect of CTX on senescence of bone marrow hematopoietic cells was analyzed by detecting p16(Ink4a) mRNA relative expression and SA-β-galactosidase (gal) staining. The results showed that the CTX could induce long-term but latent damage to bone marrow hematopoietic cell function and lead to the decrease in competency of bone marrow hematopoietic cells to reconstitute while seemingly permitting a complete recovery. Furthermore, the serial-transplantation model showed that these mice received transplantation of bone marrow hematopoietic cells from CTX-treated mice exhibited a high expression of p16(Ink4a) mRNA and SA-β-gal staining. It is concluded that CTX-induced bone marrow cellular senescence may play an important role in CTX-induced long-term injury to bone marrow hematopoietic cells.