Gene expression of PROSC (proline synthetase co-transcribed) in related to cytosine arabinoside sensitivity in human leukemia

Abstract

We examined the PCR differential display analysis of cDNA clones from human leukemia K562 cell line and those of cytosine arabinoside (ara-C) resistant K562 cells. We compared mRNA samples obtained from the two cell lines by amplified restriction fragment length polymorphism (AFLP)-based mRNA fingerprinting; 40 bands were observed in each lane of a gel, and the screened results were five independent, isolated clones. In this study, we isolated the proline synthetase co-transcribed (PROSC) gene from an ara-C sensitive K562 cell line as one of the clones. RNase protection assay and RT-PCR analysis revealed increased expression of PROSC gene in K562 sensitive cells compared with that of ara-C resistant K562 cells. The PROSC gene product is likely a soluble cytoplasmic protein, but its function remains unclear. Thus, the PROSC gene might be related to the sensitivity to ara-C in human leukemia and downregulated in resistant cells.