Medroxyprogesterone acetate does not protect human bone marrow progenitor cells exposed to adriamycin in vitro

Evaluation of the Effect of Medroxyprogesterone Acetate on Bone Marrow Progenitor Cells

Various clinical studies have demonstrated that high-dose medroxyprogesterone acetate (HD-MPA) can reduce hematologic toxicity in patients receiving chemotherapy for advanced solid tumors. The underlying mechanism(s) of this action is still unknown. A direct effect of MPA on hemopoietic cells has been postulated, but in vitro studies have given contradictory results. To clarify the biologic activity of MPA on hemopoiesis we have evaluated in vitro growth of pluripotent and committed progenitor cells from bone marrow cells which were preincubated in vitro with various doses of MPA and subsequently treated with or without the S-phase-specific drug arabinoside-cytosine (Ara-C). Four healthy subjects and 8 patients with advanced stage solid tumors with no bone marrow involvement were studied. In our experimental model we did not observe any effect of MPA on Ara-C killing of progenitor cells from either bone marrow mononuclear cells or bone marrow mononuclear cells depleted of T-lymphocytes and adherent cells. These results suggest that MPA does not act directly (or indirectly through the production of cytokines by T-lymphocytes and/or monocytes and macrophages) on bone marrow progenitors. In addition, the supposed mechanism of rendering stem cells less susceptible to the insult of cytotoxic drugs by lowering the number of progenitors in the S-phase has been ruled out by cell kinetic studies.

Effects of high dose medroxyprogesterone acetate on endogenous granulocyte macrophage-colony stimulating factor secretion and bone marrow cellularity in patients under cytotoxic chemotherapy

Endogenous cytokine release and bone marrow cellularity of cancer patients receiving chemotherapy were investigated to elucidate the effect of high dose medroxyprogesterone acetate (MPA). MPA (1000 mg/day p.o.) was started after the first cycle of chemotherapy in patients with neutropenia. Administration of MPA was stopped a week after the second cycle of chemotherapy. Blood samples and bone marrow aspirations were obtained for granulocyte macrophage-colony stimulating factor (GM-CSF) assay one week after the first and second cycles of chemotherapy. GM-CSF levels and bone marrow cellularities were compared before and after MPA treatment. Twelve of fifteen patients included in the study had a significant decrease in endogenous cytokine (GM-CSF) secretion after high dose MPA treatment. This result supports the hypothesis that decreased cytokine release leads to a decrease in myeloid progenitor cell proliferation and protects cells from the cytotoxic effects of chemotherapy. As a result of this protection, the myeloid cell population increases in bone marrow. No changes in erythrocytes and platelet counts were obtained.

Effect of high-dose medroxyprogesterone acetate on tumor necrosis factor-alpha release in patients with chemotherapy-induced neutropenia

The aim of the study was to investigate the effects of high-dose medroxyprogesterone acetate (MPA) on the tumor necrosis factor-alpha (TNF-alpha) release in patients with chemotherapy-induced neutropenia. We also evaluated the effects of high-dose MPA on hematological parameters (leukocyte, neutrophil, platelet, hemoglobin, hematocrit) and side effects of MPA. One week following the first cycle chemotherapy, 20 patients who developed neutropenia were enrolled in the study. One gram/day MPA was administered orally to the patients and was continued from one week following the first chemotherapy cycle to one week after the second chemotherapy cycle. The patients received the second chemotherapy cycle at the same dosages as the first cycle. Before MPA treatment TNF-alpha levels were lower than post-treatment levels, but the difference was not statistically significant (P > 0.05). The differences in the mean leukocyte and neutrophil counts before and after the high-dose MPA treatment were statistically significant (p < 0.05).

Clinical and laboratory evaluation of the myeloprotective effect of medroxyprogesterone acetate in head and neck cancer

The action of high-dose medroxyprogesterone acetate (MPA) was studied by analysing the behaviour of colony-forming-unit granulocyte-macrophage (CFU-GM) during chemotherapy. 21 non-pretreated men with locally advanced carcinoma of the head and neck were randomised into two arms: A (11 patients) received three alternating cycles of cisplatin, 5-fluorouracil (CF)/cisplatin, methotrexate, bleomycin, vincristine and then CF every 4 weeks and B (10 patients) were treated with the same schedule plus 1000 mg per day of MPA. MPA was administered 14 days before the start of chemotherapy (day 0) and continued daily up to the 90th day. Bone marrow was harvested in arm A on days 0, +14 and +90, and in B, also on day -14. There was diverse CFU-GM behaviour in the two arms on the 14th day. These data support the hypothesis that the myeloprotective effect of MPA is due to induction of a mitotic rest in the stem cells, which protects them from drug action.