Abstract 4083: Long stress-responsive non-coding transcripts identified in a whole genome screen have altered expression in cancer

Abstract

The number of non-coding transcripts (NCTs) exceeds the number of transcripts that code for protein. Their diverse and important functions are now being identified and utilized in the lab as well as in the clinic. Utilizing the Affymetrix Gene Chip Human Tiling 1.0R Array Set, we analyzed the transcription across the entire genome in both normal human bronchial epithelial cells (NHBE) alone and cells exposed to the tobacco carcinogen (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone), NNK. We focused our efforts on the identification and function of novel long non-coding transcripts that had increased expression after exposure to NNK. We report on the identification of 12 long NNK-induced non-coding transcripts (NiTs) that are 300 nucleotides and larger in length. We first validated that these transcripts were indeed stress responsive using quantitative real-time RT-PCR (qPCR) and by Northern blot analysis revealed that these transcripts were between two and four kilobases in length. We also show using qPCR that these transcripts are more abundantly expressed in normal rapidly growing tissues or tissues that are under cellular stress. We show that there is altered expression of NiTs in a panel of lung cancer cell lines and many of these transcripts had increased expression in many breast cancer cell lines. We further analyzed one of these transcripts, NiT5 and identified it to be a 2.5 kb antisense, polyadenylated transcript by RLM-RACE and by Northern Blot analysis. Isolating nuclear and cytoplasmic fractions in BT474 cells, we identified Nit5 to be localized in the nucleus and found it to be transcribed by RNA polymerase III. NiT5 also has increased expression in breast, ovarian and cervical cancer-derived cell lines relative to normals from these three sites, but not increased expression in lung cancer cell lines. In summary, our results suggest that these novel long non-coding transcripts play an important role in stress also may play a role in cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4083.