Early suppressive effects of chemotherapy and cytokine treatment on committed versus primitive haemopoietic progenitors in patient bone marrow

Abstract

These studies investigated the effectiveness of in vivo administration of cytokines in ameliorating potential marrow damage induced by chemotherapy. Breast cancer patients received 5-fluorouracil, leucovorin, doxorubicin and cyclophosphamide (FLAC) followed by either GM-CSF, PIXY321, or no cytokine. Marrow was obtained before and after one or two cycles of FLAC once blood cell counts had recovered. Colony-forming units for granulocytes and macrophages (CFU-GM) were used to indicate the effect of therapy on recovery of committed progenitor cells responsible for early blood cell recovery. The frequency and number of CFU-GM in marrow obtained after FLAC + PIXY321 were significantly lower than in marrow obtained after FLAC+GM-CSF or FLAC without cytokine. CD34+ cell numbers were also reduced after FLAC + PIXY321. CFU-GM production in marrow long-term cultures (LTC) was used to assess the effect of therapy on primitive progenitors. After 5 weeks the number of CFU-GM in LTC of post-therapy marrow from all three treatment arms was < 15% of the number in pre-therapy LTC. Suppressive effects of FLAC on primitive progenitors were observed even when committed progenitors and CD34+ cells had recovered to pre-therapy levels. These results demonstrate that cytokine treatment did not ameliorate suppressive or toxic effects of FLAC on the functional integrity of the marrow.

Post-chemotherapy and cytokine pretreated marrow stromal cell layers suppress hematopoiesis from normal donor CD34+ cells

“…Results in a previous report, 22 demonstrated that postchemotherapy LTC had a reduced capacity for production of committed progenitors. Results in the present report further demonstrate a similar reduced capacity for production of committed progenitors even when the number of CFU-GM and BFU-E in marrow used to initiate LTC was similar in pre-and post-chemotherapy marrows.…”

“…From 1 to 4 weeks later, nonadherent and adherent cells were harvested from two LTC as previously described. 22,34,37 Briefly, the adherent cells were detached from the culture wells by incubating the cell layers at 37°C with 0.25% trypsin and 1 mm EDTA (GIBCO) or a 0.1% solution of type I collagenase (Sigma) prepared in DPBS without Ca +2 and Mg +2 or serum. Effect of post-chemotherapy stromal layers on production of committed progenitors from normal donor CD34 + cells.…”

“…22 Hematopoietic stimulatory cytokines have not been shown to ameliorate suppressive or toxic effects of chemotherapy or radiation on the number of either committed or primitive hematopoietic progenitors in the marrow 22,25,26 and in some cases may have additional suppressive effects on marrow recovery. 22,26 Damage to either the hematopoietic progenitor/stem cell compartment or the marrow microenvironment or both has been implicated as a potential cause for suppressive effects of bone marrow function observed after chemotherapy. 7,19,21,23,24,26,27 A variety of stimulatory and negative factors that regulate the proliferation and differentiation of hematopoietic progenitors are expressed in the marrow microenvironment.…”

“…7,[18][19][20][21][22]24 Bone marrow injury was evident after recovery from the first cycle of chemotherapy and even when peripheral blood counts and the number of committed progenitors and CD34 + cells in the marrow were within the normal range. 22 Hematopoietic stimulatory cytokines have not been shown to ameliorate suppressive or toxic effects of chemotherapy or radiation on the number of either committed or primitive hematopoietic progenitors in the marrow 22,25,26 and in some cases may have additional suppressive effects on marrow recovery. 22,26 Damage to either the hematopoietic progenitor/stem cell compartment or the marrow microenvironment or both has been implicated as a potential cause for suppressive effects of bone marrow function observed after chemotherapy.…”

“…15,16 Previous results demonstrated that marrow from some groups of patients who recovered from high-dose chemotherapy or chemotherapy followed by autologous transplantation had decreased numbers of hematopoietic progenitors such as colony-forming units for granulocytes and macrophages (CFU-GM). [18][19][20][21][22][23] . LTC were also shown to have a reduced capacity to maintain the production of CFU-GM and burst-forming units for erythroid cells (BFU-E).…”