HIF-1Α and ybx1 mediated up-regulation of NonO/p54nrb in prostate cancer cells

Abstract

This study examines the effect of hypoxia, a pivotal factor in prostate carcinogen esis, on the cellular roles of NonO/p54nrb and YBX1 proteins. NonO/p54nrb is a part of the paraspeckle protein, a nuclear domain that is encoded by the NONO gene in humans and has been demonstrated to interact with the Androgen receptor, SFPQ, and SPI1. In the nucleus, NonO/p54nrb is involved in a variety of processes, such as transcription initiation, RNA processing, transcription elongation, and ter mination while YBX1, binds to both DNA and RNA. Elevated levels of YBX1 and HIF-1α have been observed in prostate carcinoma. The expression profile of NonO/p54nrb was assessed using sqRT-PCR in HUVEC and a panel of nine di verse cancer cell lines from various tissues (prostate, breast, colon, liver, pancreas, and bone). The PC3 prostate cancer cell line exhibited the highest level of NonO/ p54nrb expression. A hypoxic microenvironment was successfully induced with the mimetic agent CoCl2 , with its confirmation obtained by quantifying HIF-1α mRNA levels via Real-Time PCR. To assess the activity of the NonO/p54nrb promoter, a series of 5’ deletion constructs − 730/+529; -516/+529; -336/+529 and − 159/+529 were cloned into the pMetLuc luciferase vector. The basal transcriptional activity of NonO/p54nrb promoter constructs increased under hypoxic conditions at 48 h. Hypoxic up-regulation was also observed at both mRNA and protein levels. The study also analyzed the effect of exogenously produced YBX1 transcription factor on NonO/p54nrb mRNA and protein levels. An upregulation was also observed in all YBX1-transfected promoter fragments. The findings from our study indicate that NonO/p54nrb is transcriptionally upregulated by HIF-1 in PC-3 cell line. Fur thermore, the YBX1 transcription factor enhances NonO/p54nrb expression under both normoxic and hypoxic conditions, with a more pronounced increase observed specifically during hypoxia