[Low-dose recombinant human tumor necrosis-alpha in HL-60 leukemic cell line: effect on induced differentiation and regulating expression of c-myc, c-fos proto-oncogenes].

The promyelocytic leukemic cell line HL-60 with 20-200U/ml of low-dose rhTNF-a cultured in liquid culture system in vitro was used to observe the effect on HL-60 by TNF. TNF within dose of 50-200 U/ml can induce HL-60 cell differentiation along the monocytic-macrophage pathway, and inhibit HL-60 cell proliferation. The total RNA of HL-60 cell was used to hybrize to v-myc or v-fos probe by dot blot. We detected the expression changes of c-myc or c-fos proto-oncogene by 1-100U/ml of TNF inducing HL-60 cell for 1-12 hours. TNF could regulate the level of c-myc or c-fos mRNA, the transcription of c-myc was inhibited remarkdly, and the expression of c-fos was increased early. The results indicated that TNF in low-dose have effect on inducing HL-60 cell differentiation and regulating expression of multioncogene.