Effect of dimethylsulfoxide and hexamethylene bisacetamide on the JOK-1 hairy cell leukemia derived cell line propagated in the nude mouse

The JOK-1 hairy cell leukemia derived cell line has been propagated as a subcutaneous tumor in nude mice. After the tumor had been serially transplanted for at least two successive generations, mice were treated with either dimethylsulfoxide or hexamethylene bisacetamide (HMBA). These agents have been shown to induce terminal leukemic cell differentiation in vitro. Our results indicated that these agents had an in vivo growth inhibitory effect, with HMBA exerting a dose-dependent response. Histopathological examination revealed massive areas of necrosis with no overt signs of cellular differentiation. These data suggest that in vitro inducers of differentiation may act via another mechanism in vivo.