22P - Study of the role played by natural antisens transcripts (NAT) in breast cancer through the regulation of the expression of their paired protein co...

Date 04 May 2017
Event IMPAKT 2017
Session Welcome reception and Poster Walk
Topics Breast Cancer
Presenter Sonia El Guendi
Authors S. El Guendi1, S. Wenric1, B. Charloteaux2, L. Karim3, B. Hennuy3, W. Bezzaou1, M. Boukerroucha4, G. Jerusalem4, C. Josse1, V. Bours1
  • 1Human Genetics, GIGA Ulg, 4000 - Liège/BE
  • 2Plateform Genomics, GIGA Ulg, 4000 - Liège/BE
  • 3Plateforme Genomics, GIGA Ulg, 4000 - Liège/BE
  • 4Medical Oncology Department, CHU Liège, 4000 - Liège/BE

Abstract

Body

Advances in RNA Sequencing allowed a deeper understanding of the breast cancer. The human genome encodes around 20 000 protein-coding genes, representing only 2% of the total genome sequences. In contrast, whole transcriptome sequencing demonstrated that at least 90% of the human genome is actively transcribed, highlighting the fact that the transcriptome is not limited to coding transcripts but mainly comprises non-coding RNA (ncRNA). Often expressed at low level, these non-coding RNA represent 1/5 of transcripts. Many of them were demonstrated to be implicated in gene expression regulation, which is adding a new level of complexity, and it is likely that they play biological functions that are still widely unknown. The longer of these non-coding transcripts are long non-coding RNA (lncARN) that are more than 200 bases. Among them, Natural Antisens Transcripts (NAT) are sequences that are complementary and overlapping to those of coding gene transcripts. NAT have long been considered as transcriptional background noise, but with the introduction of strand specific technology in RNA sequencing, it became clear that, as lncRNA, they are involved in several eukaryotic cells processes such as alternative splicing, RNA stability, or chromosome X inactivation. In this work, 22 breast cancers positive for estrogen receptor and their corresponding healthy tissues were analyzed by strand-specific paired-end RNA sequencing. RT-qPCR and comparative genomic hybridization (CGH) were also performed to confirm results. Differential expression analysis of NAT between tumorous and healthy tissues was performed, as well as expression correlation analysis with their paired protein coding genes.These analyses on pairs of PC and NAT genes revealed a list of protein coding genes which are enriched in genes linked to overall survival in breast cancer (TCGA cohort) and preferentially correlated with prognostic factors T of TNM's classification in the 22 patient’s cohort. This work allows thus to clarify the role played by NAT to regulate their protein coding gene counterpart on the same locus in the breast cancer pathology

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