Effects of Induced Differentiation on Sensitivity to Cyclophosphamide in Murine Erythroleukemia Cells
MetadataShow full item record
Friend erythroleukemia cells induced to differentiate show increased resistance to 4-hydroperoxycyclophosphamide as determined by alkaline elution. DNA-crosslinking studies using phosphoramide mustard, a bifunctional alkylating agent and product of 4-hydroperoxycyclophosphamide metabolism, also show increased resistance in cells induced with hexamethylene bisacetamide (HMBA). Aldehyde dehydrogenase, an enzyme believed to cause resistance to cyclophosphamide in Ll2l0 cells, is very abundant in cyclophosphamide resistant primitive HEL and K562 cell lines, but almost negligible in Cyclophosphamide sensitive differentiated HL-60 and ML-1 cell lines. However no increase in aldehyde dehydrogenase levels were found in HMBA induced Friend erythroleukemia cells, as determined by spectrofluorimetry and fluorescence activated cell sorting, suggesting that increased levels of aldehyde dehydrogenase are not responsible for the increased resistance in differentiated Friend cells.