Analysis of the translatome by ribosome profiling in colorectal cancer Joana Silva1,2, Hugo Santos2,3, Margarida Gama-Carvalho2,3, Luísa Romão1,2 2Biosystems 1Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal; & Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; 3Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal Background Objectives Colorectal cancer (CRC) is the 3rd most common and the 4th deadliest cancer in the world[1]. CRC tumorigenesis is based in a continuous accumulation of genetic alterations leading to changes of the overall gene expression profiles[2]. Genome-wide analyses of the gene expression profiles of CRC are useful to reveal the molecular and cellular pathways and the regulatory mechanisms involved in the carcinogenesis process, and then translate this information to clinical application[2-4]. Main goal: Determine the changes between the translatome of CRC and normal colorectal cells, to understand its role in CRC tumorigenesis process v Green and Hudson (2005)[9] Ribosome profiling is a highly accurate technique to monitor and quantify in vivo translation by deep sequencing of mRNA fragments covered with translating ribosomes in order to map the exact position of ribosomes in the transcripts[5,6]. This technique identifies translation beyond the known annotated genes: other start sites leading to alternative ORFs (AltORFs) overlapping or not the main proteincoding ORF; upstream open reading frames (uORFs) in 5’ untranslated regions (5’UTR), as well as, ORFs in 3’UTR [5,7,8]. Objective 1: Analysis of the translatome of a CRC cell line (HCT116) and other nonneoplasic and cancer cell lines by available ribosome profiling data Objective 2: Bioinformatics and gene ontology analysis of the differentially translated mRNAs Objective 3: Study of the function of short open reading frames (sORFs) and/or the corresponding peptides towards CRC progression Objective 4: Validation of the obtained results in primary cell cultures of CRC and in normal colon mucosa Adapted from Ingolia et al. (2011)[10] Results 1. Ribosome profilling data analysis Gene ID Workflow Datasets available: • CRC cell line (HCT116) • Non-neoplasic Objective 1 mammary gland cell line (MCF-10A) Objective 2 Gene ID Protein ID ABCF1 Q8NE71 ABCF2 Q9UG63 ABCF3 Q9NUQ8 Adapted Crappé et al. (2014)[11] Analysis parameters for 5’UTR: • uniquely mapped reads • reads with 26-34 nts (relevant ribosome-protected fragments, RPFs) ABCE1 P61221 • number of reads per transcript – more than 10 reads 5’UTRs differentially enriched in RPFs (p<0.05) • • • • • • • • • • • • • • • • • ABCF2 Molecular function • Cell adhesion regulation • Angiogenesis • Cell migration Conclusions 1. Our computational analysis of ribosome profiling data from HCT116 vs MCF-10A cell lines was able to identified 1666 5’ untranslated regions (5’UTRs) differentially expressing RPFs: • 5’UTRs with an increased accumulation of RPFs were enriched in cell cycle regulatory genes; • 5’UTR with decreased RPFs accumulation were enriched in genes involved in cell adhesion, migration, and angiogenesis. 2. ABCE1 and ABCF2 5’UTR shows several uORFs, as identified by ribosome profiling analysis. Biological process Q8NE71 Transporter activity Translation elongation factor Translation initiation ATPase activity ATP/protein/RNA and ribosome binding Q9UG63 • • • • Transporter activity Translation elongation factor Biological ATPase activity process ATP binding Transporter activity ABCE1 Translation elongation factor P61221 ATPase activity ATP binding • • Positive regulation Transporter activity of • translation Translation elongation factor • • Transport ATPase activity • • Ribosome biogenesis ATP/protein binding • Inflamatory response • • • • • ATPase activity ATP/protein binding Ribonuclease inhibitor activity (ex. Transport RNaseL) Ribossome recycling • • • • Positive regulation of translation Transport Ribosome biogenesis Inflamatory response • Transport Localization • • • Nucleus • Defense response to virus Cytoplasm Ribosome • • Response to vírus Mitochondrial • RNA turnover envelope • • Negative regulation of catalytic activity Localization • • • Nucleus Cytoplasm Ribosome • Mitochondrial envelope • Membrane • • Cytopalsm Mitochondrial matrix Transport Gene Ontology Consortium: http://pantherdb.org/ (accessed in 18 May 2016); Quick GO, EMBL-EBI: http://www.ebi.ac.uk/QuickGO/ (acessed in 19 May 2016); Young et al., 2015 Transporter activity Translation elongation factor • Defense response to virus • Membrane ATPase activity ATP/protein binding Gene ID sORF ID Annotation Sequence ATPase activity ATP/protein binding Ribonuclease inhibitorABCE1 activity (ex. RNaseL) Ribossome recycling • Negative regulation of catalytic GTGCGGCGGCTGGGCACCGCCATTTTGGCCGGTGGCCGTGAGAACA activity CGCTGTGTGGCTGA • Cytopalsm • Mitochondrial GTGGCCGTGAGAACACGCTGTGTGGCTGAAAAGTGA matrix Transport HCT116:92826 • Response to vírus HCT116:93970 5’UTR • RNA turnover • ABCF2 HCT116:184591 Gene Ontology Consortium: http://pantherdb.org/ (accessed in 18 May 2016); Quick GO, EMBL-EBI: http://www.ebi.ac.uk/QuickGO/ (acessed in 19CTGTTGCGACATAGGCCGAGCAGCGAGGCCCAGTGA May 2016); Young et al., 2015 Gene enrichement analysis (goseq): • Cell cycle regulation • RNA metabolism Molecular function • • • • • Transporter activity Translation elongation factor Translation initiation ABCF3 Q9NUQ8 ATPase activity ATP/protein/RNA and ribosome binding SORFs.ORG: http://www.sorfs.org/ (accessed in 18 May 2016)) ABCF1, ABCF2, ABCF3 and ABCE1 have differential transcription levels between the different colorectal cell lines Poorly enriched RPFs Gene enrichement analysis (goseq): ABCF1 Protein ID 3. ABCF1, ABCF2, ABCF3 and ABCE1 transcripts were down-regulated in HCT116 cells in comparison to the non-neoplasic colorectal cell line (NCM460) and two CRC cell lines (CaCo-2 and SW480). Semi-quatitative RT-PCR Enriched in RPFs 2. Bioinformatics and gene ontology analysis References [1] Ferlay J, Soerjomataram I, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray F (2015). Int J Cancer 136: E359-386.; [2] Kheirelseid EAH, Miller N, Chang KH, Nugent M, Kerin MJ (2013). J Gastrointest Oncol 4: 144-157.; [3] Kitahara O, Furukawa Y, Tanaka T, Kihara C, Ono K, Yanagawa R, Nita ME, Takagi T, Nakamura Y, Tsunoda T (2001). Cancer Res 61: 3544-3549.; [4] Garnis C, Buys TPH, Lam WL (2004). Mol Cancer 3: 1-23.; [5] Ingolia NT, Brar GA, Stern-Ginossar N, Harris MS, Talhouarne GJS, Jackson SE, Wills MR, Weissman JS (2014). Cell Rep 8: 1365-1379.; [6] Ingolia NT, Ghaemmaghami S, Newman JRS, Weissman JS (2009). Science 324: 218-223.; [7] Jackson R, Standart N (2015). RNA 21: 652-654.; [8] Young DJ, Guydosh NR, Zhang F, Hinnebusch AG, Green R (2015). Cell 162: 872-884.; [9] Green JE, Hudson T (2005). Nat Rev Cancer 5: 184-198.; [10] Ingolia NT, Lareau LF, Weissman JS (2011). Cell 147: 789-802.; [11] Crappé J, Ndah E, Koch A, Steyaert S, Gawron D, De Keulenaer S, De Meester E, De Meyer T, Van Criekinge W, Van Damme P, Menschaert G (2013). Nucleic Acids Res 43: e29. ACKNOWLEDGEMENTS: This work was partially supported by Fundação para a Ciência e a Tecnologia (UID/MULTI/04046/2013 to BioISI from FCT/MCTES/PIDDAC). Joana Silva is supported by a fellowship from Fundação para a Ciência e a Tecnologia (SFRH/BD/106081/2015)