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Computational prediction of miRNA and miRNA-disease relationship. Quan Zou ( 邹权 ) PH.D.&Professor School of Computer Sci&Tech Tianjin University, China. Contents. background microRNA identification isomiR microRNA and disease outlook. Background- miRNA.
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Computational prediction of miRNA and miRNA-disease relationship Quan Zou (邹权) PH.D.&Professor School of Computer Sci&Tech Tianjin University, China
Contents • background • microRNA identification • isomiR • microRNA and disease • outlook
Background-miRNA Crucial regulatory molecule: 1/3 human genes cell development cell proliferation cell apoptosis tumorigenesis …
Precursor, Pre-miRNA 1. mining the pre-miRNA, miRNA cell nucleus mature miRNA cytoplasm 2. predicting the targets target
Identification of microRNA AUCGUGCAGAGACUAGACUGACAUCGUGCAGAGACUAGACUGACAUCGUGCAGAGACUAGACUGACAUCGUGCAGAGA CUAGACUGACAUCGUGCAGAGACUAG ACUGAC >1 tgcgcgaauucacccauggauccauucaucuuccaagggcaccagc >2 agcgcgaauuccaagucacccauggauccauucaucuggcagcgu >3 agucgcgaauucaucaucuuccaagggcacccauggauccaucca
Ref: Xue C, et al. Classification of real and pseudo microRNA precursors using local structure-sequence features and support vector machine. BMC Bioinformatics, 2005, 6(1): 310.
Ref: Xue C, et al. Classification of real and pseudo microRNA precursors using local structure-sequence features and support vector machine. BMC Bioinformatics, 2005, 6(1): 310.
microRNA prediction based on machine learning obvious differences weak generalization
Importance of negative samples Negative Testing Set Positive Training Set Decision Boundary Negative Training Set
Importance of negative samples Negative Testing Set Positive Training Set New Negative Training Set New Decision Boundary
Flow Human CDs Extend Blast 100nt 100nt Human Mature microRNAs Mature-like Reads Compute Secondary Structures Extract Parameter Filter Prediction Model Rebuilt Original Negative Set Mined Sequences innovation point Replace
Leyi Wei, Minghong Liao, Yue Gao, Rongrong Ji, Zengyou He*, Quan Zou(邹权)*. Improved and Promising Identification of Human MicroRNAs by Incorporating a High-quality Negative Set. IEEE/ACM Transactions on Computational Biology and Bioinformatics. 2014, 11(1):192-201 (SCI, IF2011=1.543)
Dinoflagellates genome (甲藻) Lin, et al. The Symbiodinium kawagutii genome illuminates dinoflagellate gene expression and coral symbiosis. Science. 2015, 350(6261): 691-694.
miRNAfamily classification • PFAM(~2000)VS miRNAfamily(~2000) • Troubles • Multiple classes • Few samples • imbalaned 1
Quan Zou*, Yaozong Mao, Lingling Hu, Yunfeng Wu, Zhiliang Ji*. miRClassify: An advanced web server for miRNA family classification and annotation. Computers in Biology and Medicine. 2014, 45:157-160.(SCI, IF2011=1.089) ESIhigh cited paper 1
Question UGAGGUAGUAGGUUGUAUAGUU UACACUGUGGAUCCGGUGAGGUAGUAGGUUGUAUAGUUUGGAAUAUUACCACCGGUGAACUAUGCAAUUUUCUACCUUACCGGAGACAGAACUCUUCGA ------uaca gga U --- aaua cugu uccggUGAGGUAGAGGUUGUAUAGUUu gg u |||| ||||||||||||| |||||||||||||| || gaca aggccauuccauc uuuaacguaucaag cc u agcuucucaa --g u ugg acca 1
Contents • background • microRNA identification • isomiR • microRNA and disease • outlook
Why called isomiR? • isoform vs isomiR
Background-isomiR • miRNA variants, isomiRs, physiological isoforms • Various length distributions, 5’/3’ ends The annotated miRNA sequence is only one specific isomiR in the miRNA locus • Imprecise and alternative cleavage • Modification/addition events • SNP • RNA editing
Materials and methods Public databases, in-house sequencing datasets, published data Bioinformatics & biostatistics Software/script Molecular biology method Data analysis: Biology/interaction Data analysis: Method/prediction Data analysis: Evolution/miRNA*
Where does isomiR happen? • across different species • normal vs cancer • isomiR data - TCGA
isomiR difference in cancer • 3’ addition: not dominant • IsomiR expression: Stable across different samples • Abnormal isomiR pattern in cancer cells and tissues
Contents • background • microRNA identification • isomiR • microRNA and disease • outlook
Ref:Quan Zou, et al. Prediction of microRNA-disease associations based on social network analysis methods. BioMed Research International. 2015, 2015: 810514
Similarity between two microRNAs (B) (C) (A) targets of miR2 targets of miR1 targets of miR2 targets of miR2 targets of miR1 targets of miR1
miR1 Strength g2 0.7 0.4 0.5 0.8 0 0.8 g1 0.9 g4 0.6 0.7 g3 targets network Strength(wij) miR1 Strength Function similarity of targets 0 0.5 0.8 0.7 g1 g2 g3 g4 FSmiR miR2 miR2 Ref: Yungang Xu, et al. Inferring the Soybean (Glycine max) microRNA functional network based on target gene network . Bioinformatics, 2014, 30 (1):94-103.
Outlook How many novel microRNAs are still left? All the microRNA research methods can be extended to ncRNA and lncRNA isomiR would be the next hot topic in microRNA research Diseases would be the hot spots for ever!
Thanks! Quan Zou, PhD&Professor School of Computer Science and Technology Tianjin University Email: zouquan@nclab.net http://lab.malab.cn/~zq/