In vitro restoration of polyclonal hematopoiesis in a chronic myelogenous leukemia after in vitro treatment with 4- hydroperoxycyclophosphamide

Abstract

Bone marrow cells of a 45-year-old female with Philadelphia chromosome (Ph1)-positive, early-phase chronic myelogenous leukemia (CML), who was heterozygous for the glucose-6-phosphate dehydrogenase (G6PD) locus, were pretreated in vitro with 4-hydroperoxycyclophosphamide (4-HC) and tested for G6PD activity in several colony formation assays and for karyotypic abnormalities. All cells within the mixed (CFU-GEMM), the erythroid burst (BFU-E), and the granulocyte-macrophage (CFU-GM) colonies expressed type A and type B G6PD activity and a normal karyotype, whereas untreated cells expressed type A G6PD and the Ph1 chromosome. This reversal of G6PD activity type and the disappearance of the Ph1 chromosome in colonies grown from 4-HC-treated cells indicate that this cytotoxic agent spares a residual normal stem cell population in bone marrow cells of early-phase CML patients. This finding, in turn, suggests a therapeutic approach in CML based on in vitro chemotherapy of autologous bone marrow grafts.

Bone Marrow Transplantation

“…Chronic myelogenous leukaemia (CML) has become the major indication for AlloBMT [13,14,33,108,114,262] for 3 main reasons: 1) despite recent, exciting advances in the knowledge on the molecular biology of the disease [263][264][265][266][267] and the provocative perspectives of treatment with alpha-IFN [269], there is not (yet?) any evidence of a medical cure of CML; 2) there is, instead, hard evidence that AlloBMT is capable of curing the disease [262,263,[269][270][271][272]; 3) there is no real competition (yet?) between Allo-and AutoBMT, despite new, highly sophisticated techniques [136,272].…”

“…any evidence of a medical cure of CML; 2) there is, instead, hard evidence that AlloBMT is capable of curing the disease [262,263,[269][270][271][272]; 3) there is no real competition (yet?) between Allo-and AutoBMT, despite new, highly sophisticated techniques [136,272]. An estimated collection of 1500 patients with CML have been treated with AlloBMT; 1202 are registered at the IBMTR and over 200 in Seattle [271].…”

“…There are, however, some new and interesting developments, which have been reviewed recently [509]. Many approaches have been devised for eliminating the Ph-positive stem cells in the autograft, including long-term marrow cultures [136,510,511), ex-vivo exposure of the marrow to cyclophosphamide derivatives [272], long-term treatment of patients with IFN-alpha and still other methods, but none of them has produced consistently reproducible results [509]. Also ex vivo marrow incubated with IFN-gamma has been utilised [512].…”

Biological and chemical selection of ph‐negative clones

“…Experimental as well as clinical findings indicating some retention of functionally competent Ph-negative hematopoietic stem cells [9, 101 support a role for autologous bone marrow transplantation (ABMT) in CML [ 11-141. Recently, a selective antileukemic effect of the cyclophosphamide derivative mafosfamide on Ph-positive CML cells has been demonstrated in vitro [15]. Such an effect is also supported by a transient phase of Ph-negative hematopoiesis following ABMT with mafosfamide purged marrow [16].…”

Mafosfamide (ASTA‐Z‐7654) in vitro treatment of bone marrow does not eradicate Philadelphia‐positive cells in chronic myeloid leukaemia

“…If this residual normal stem cell population could be procured, one could hope for acureof CML by ABMT. Recently, Degliantoni et a1 ( 5 ) reported restoration of apparently normal haemopoiesis in vitro in a case of CML following treatment of bone marrow with 4-hydroxyperoxycyclophosphamide (4-HC). We have examined the in vitro cleansing effect of another cyclophosphamide analogue, Mafosfamide (ASTA-2-7654 = 4-Sulphoethylthiocyclophosphamide) (ASTA-Werke, Bielefeld, FRG), in9cases of Philadelphia chromosome-positive CML.…”