Expression data from HeLa cells overexpressing AK125393

Expression of RAD51, a crucial player in homologous recombination (HR) and DNA double-strand break (DSB) repair, is dysregulated in human tumors, and can contribute to genomic instability and tumor progression. To further understand RAD51 regulation we functionally characterized a long non-coding (lnc) RNA, AK125393, dubbed TODRA (Transcribed in the Opposite Direction of RAD51), transcribed 69bp upstream to RAD51, in the opposite direction. TODRA overexpression in HeLa cells induced expression of TPIP, a member of the TPTE family which includes PTEN. Similar to PTEN, we found that TPIP co-activates E2F1 induction of RAD51. HeLa cells were transfected with either an empty vector or an AK1253893 minigene. RNA was extracted from duplicates of each experiment and hybridized to affymetrix microarray.

RAD51作为同源重组（homologous recombination, HR）与DNA双链断裂（DNA double-strand break, DSB）修复的核心因子，其表达失调在人类肿瘤中广泛存在，并可促进基因组不稳定与肿瘤进展。为进一步阐明RAD51的调控机制，研究人员对长链非编码RNA（long non-coding RNA, lncRNA）AK125393开展了功能表征，该RNA被命名为TODRA（即RAD51反义转录本，Transcribed in the Opposite Direction of RAD51），其转录起始位点位于RAD51上游69bp处，转录方向与RAD51完全相反。在HeLa细胞中过表达TODRA可诱导TPIP的表达，TPIP属于包含PTEN的TPTE家族成员。与PTEN功能相似，研究发现TPIP可协同激活E2F1介导的RAD51转录。随后研究人员将HeLa细胞分别转染空载体或AK1253893小基因（minigene），提取各实验组重复样本的总RNA，并与Affymetrix微阵列进行杂交实验。