PMID- 21486456 OWN - NLM STAT- MEDLINE DCOM- 20110922 LR - 20211020 IS - 1755-8794 (Electronic) IS - 1755-8794 (Linking) VI - 4 DP - 2011 Apr 12 TI - Virtual CGH: an integrative approach to predict genetic abnormalities from gene expression microarray data applied in lymphoma. PG - 32 LID - 10.1186/1755-8794-4-32 [doi] AB - BACKGROUND: Comparative Genomic Hybridization (CGH) is a molecular approach for detecting DNA Copy Number Alterations (CNAs) in tumor, which are among the key causes of tumorigenesis. However in the post-genomic era, most studies in cancer biology have been focusing on Gene Expression Profiling (GEP) but not CGH, and as a result, an enormous amount of GEP data had been accumulated in public databases for a wide variety of tumor types. We exploited this resource of GEP data to define possible recurrent CNAs in tumor. In addition, the CNAs identified by GEP would be more functionally relevant CNAs in the disease pathogenesis since the functional effects of CNAs can be reflected by altered gene expression. METHODS: We proposed a novel computational approach, coined virtual CGH (vCGH), which employs hidden Markov models (HMMs) to predict DNA CNAs from their corresponding GEP data. vCGH was first trained on the paired GEP and CGH data generated from a sufficient number of tumor samples, and then applied to the GEP data of a new tumor sample to predict its CNAs. RESULTS: Using cross-validation on 190 Diffuse Large B-Cell Lymphomas (DLBCL), vCGH achieved 80% sensitivity, 90% specificity and 90% accuracy for CNA prediction. The majority of the recurrent regions defined by vCGH are concordant with the experimental CGH, including gains of 1q, 2p16-p14, 3q27-q29, 6p25-p21, 7, 11q, 12 and 18q21, and losses of 6q, 8p23-p21, 9p24-p21 and 17p13 in DLBCL. In addition, vCGH predicted some recurrent functional abnormalities which were not observed in CGH, including gains of 1p, 2q and 6q and losses of 1q, 6p and 8q. Among those novel loci, 1q, 6q and 8q were significantly associated with the clinical outcomes in the DLBCL patients (p < 0.05). CONCLUSIONS: We developed a novel computational approach, vCGH, to predict genome-wide genetic abnormalities from GEP data in lymphomas. vCGH can be generally applied to other types of tumors and may significantly enhance the detection of functionally important genetic abnormalities in cancer research. FAU - Geng, Huimin AU - Geng H AD - Department of Computer Science, University of Nebraska at Omaha, Omaha, NE 68182, USA. FAU - Iqbal, Javeed AU - Iqbal J FAU - Chan, Wing C AU - Chan WC FAU - Ali, Hesham H AU - Ali HH LA - eng GR - CA36727/CA/NCI NIH HHS/United States GR - CA84967/CA/NCI NIH HHS/United States GR - P20 RR16469/RR/NCRR NIH HHS/United States GR - U10 CA114778/CA/NCI NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20110412 PL - England TA - BMC Med Genomics JT - BMC medical genomics JID - 101319628 SB - IM MH - Chromosomes, Human/genetics MH - Comparative Genomic Hybridization/*methods MH - *Gene Expression Profiling MH - Genes, Neoplasm/genetics MH - Humans MH - Lymphoma, Large B-Cell, Diffuse/*genetics MH - *Oligonucleotide Array Sequence Analysis MH - Reproducibility of Results MH - *Systems Integration MH - *User-Computer Interface PMC - PMC3086850 EDAT- 2011/04/14 06:00 MHDA- 2011/09/23 06:00 PMCR- 2011/04/12 CRDT- 2011/04/14 06:00 PHST- 2010/06/23 00:00 [received] PHST- 2011/04/12 00:00 [accepted] PHST- 2011/04/14 06:00 [entrez] PHST- 2011/04/14 06:00 [pubmed] PHST- 2011/09/23 06:00 [medline] PHST- 2011/04/12 00:00 [pmc-release] AID - 1755-8794-4-32 [pii] AID - 10.1186/1755-8794-4-32 [doi] PST - epublish SO - BMC Med Genomics. 2011 Apr 12;4:32. doi: 10.1186/1755-8794-4-32.