Effect of cisplatin administration on the proliferation and differentiation of bone marrow cells of tumour-bearing mice.

In the present study the effect of tumour growth with respect to two tumour systems (Dalton's lymphoma [DL] and P815) on the in vitro, colony-forming ability (CFA) and proliferation of the bone marrow cells (BMC) of C3H/He mice was investigated. The P815-bearing mice showed an enhanced bone marrow colony forming ability in vitro, in response to L929 conditioned medium (L929 CM) used as a source of CSF. On the other hand, DL-bearing mice did not have any significant alteration in this process compared to normal mice. In vivo, administration of cisplatin resulted in a significant rise in the CFA of normal as well as DL- or P815-bearing mice. The tumour-conditioned medium (TCM) and ascitic fluid (AF) of P815 but not of DL, was found to support the in vitro colony formation of BMC obtained from cisplatin-treated or untreated mice. The number of CFU-granulocyte-macrophage was predominantly high in the cultures of BMC incubated with TCM or AF of P815. The TCM and AF of P815 also enhanced the in vitro proliferation of BMC obtained from cisplatin-treated or untreated mice. In vivo, administration of cisplatin in normal mice resulted in enhanced numbers of peritoneal exudate macrophages (PEM) and PBL. Similarly, the number of PEM and PBL was augmented in both the P815- and DL-bearing mice. However, cisplatin administration in the tumour-bearing mice decreased the count of PEM, while the number of leucocytes remain unaffected. This study indicates that the cancer chemotherapeutic drug cisplatin can influence the differentiation of the bone marrow progenitor cells in response to tumour growth in situ.