To detect full-length transcript of ts-ARFGEF1 in MCF-7 cell [captureRNA]

Analysis of high-throughput transcriptome sequencing (RNA-seq) data often observed numerous 'non-co-linear' (NCL) transcripts, which may originate from genetic rearrangements (gene fusion) indicated the importance of fusion events and circRNAs in carcinogenesis; however, the role of ts-RNAs remains largely uninvestigated. Here we developed a hybrid sequencing pipeline ("NCLscan-hybrid"), which integrated different types of short (Illumina-based) and extra-long (PacBio-based) RNA-seq data to eliminate potential false positives from experimental artifacts, fusion events, and circRNAs. We applied NCLscan-hybrid to investigate of ts-RNAs in human breast cancer, the most malignant tumors diagnosed in women worldwide. Through multiple experimental validation steps, we confirmed that the intragenic ts-RNA, ts-ARFGEF1, was highly expressed in breast cancer cells but absent in normal breast cells. Furthermore, we experimentally validated that ts-ARGEF1 can contribute to cell proliferation and apoptosis. Analysis of xenograft in nude mice showed that disruption of ts-ARFGEF1 expression can significantly attenuate tumor growth. Microarray analysis revealed that ts-ARFGEF1 knockdown could trigger PERK/ATF4/CHOP signaling pathway, implying the function of ts-ARFGEF1 in ER homeostasis. Taken together, our findings provide an in-depth view of the true complexity of intragenic NCL events and, for the first time, show further insight into the potential roles of intragenic ts-RNAs in tumor cell development. Overall design: We designed oligo probes against NCL junction region of ts-ARFGEF1 and then use it to pull down ts-ARFGEF1. The pull-down products are subjected to nanopore sequencing.