人PSF蛋白结合长非编码RNA的筛选及鉴定

Binding of mouse VL30-1 long non-coding RNA(lncRNA) to polypyrimidine tract-binding protein-associated splicing factor (PSF) protein releases PSF from proto-oncogene promoter and reverses the expressional repression. This reversible mechanism that regulates gene transcription plays a key role in tumorigenesis in mice. The PSF gene is highly conserved in mice and humans, while the VL30-1 gene is absent from the human genome. Using RNA affinity chromatograph (RNA-SELEX), we identify four human PSF (hPSF)-binding lncRNA fragments encoded by retrotransposon L1PA16 and MER11C, non-coding gene MALAT-1 and a unknown gene, respectively, from a nuclear RNA library constructed from human melanoma cell line yusac. We confirm their hPSF-binding capacity by UV cross-linking assay in vitro and RNA immunoprecipitation (RNA-IP) in vivo. Remarkably, the unidentified lncRNA is only expressed in human melanoma lines but not in human normal lines or other types of human tumor lines. Our results suggest that human genome substantially encodes PSF-binding lncRNAs, which could be involved in human tumorgenesis , similar to VL30-1 lncRNA involved in mice tumorgenesis.