Analysis of gene expression in HIMeg cells before and after induced differentiation:Application of mRNA differential display

Objective: In human megakaryocytic leukemia HIMeg cells, differentially expressed genes regulated byinduced differentiation will be cloned, and from which the key genes in the process of induced differentiation will beidentified. Metbods: The human megakaryocytic leukemia cell line HIMeg was treated with 13-cis retinoic acid for4 d, then total cellular RNA was extracted and reversely transcribed to first strand cDNA. The first strand cDNAwas subjected to PCR based mRNA differential display (mRNA DD), cDNA cloning and sequence analysis- Results: From 5 cDNA fragment candidates obtained, RNA dot blot analysis demonstrated non-regulation in 3, undetectable signals in 1, and altered gene expression in one cDNA fragment which is designated MDI-1 (mRNAdownregulated after induced differentiation ). The nucleotide sequence data reported here will appear in the GenBank under the accession number AF026526. Conclusion: A cDNA fragment was cloned, whose gene expressionwas inhibited after 13-cis retinoic acid-induced differentiation. Further studies are required to determine its fulllength sequence, gene structure and biological function(s).