Construction and analysis of tree models for chromosomal classification of diffuse large B-cell lymphomas

• Published in: World journal of gastroenterology : WJG Vol. 13; no. 11; pp. 1737 - 1742
• Main Authors: Jiang, Hui-Yong, Huang, Zhong-Xi, Zhang, Xue-Feng, Desper, Richard, Zhao, Tong
• Format: Journal Article
• Language: English
• Published: United States Department of General Surgery, General Hospital of Shenyang Military Region, Shenyang 110016, Liaoning Province, China%Department of Pathology,Nanfang Hospital, Southern Medical University, Guangzhou 510515, Guangdong Province, China%Department of Biology, University College London, Darwin Building, Gower Street, London, WC1E 6BT,United Kingdom 21.03.2007; Baishideng Publishing Group Co., Limited
• Subjects: Chromosome Aberrations - classification; Decision Trees; DNA, Neoplasm - genetics; Gene Dosage - genetics; Gene Expression Profiling - classification; Humans; Lymphoma, Large B-Cell, Diffuse - classification; Lymphoma, Large B-Cell, Diffuse - genetics; Models, Biological; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Rapid Communication; 弥漫性B细胞淋巴瘤; 染色体; 树型模型; 比较基因杂交; 肿瘤发生; Subclassification; Comparative gene hybridization; Tree model; Tumorigenesis; Lymphoma
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v13.i11.1737

AIM： To construct tree models for classification of diffuse large B-cell lymphomas （DLBCL） by chromosome copy numbers, to compare them with cDNA microarray classification, and to explore models of multi-gene, multi-step and multi-pathway processes of DLBCL tumorigenesis. METHODS： Maximum-weight branching and distance- based models were constructed based on the comparative genomic hybridization （CGH） data of 123 DLBCL samples using the established methods and software of Desper et al. A maximum likelihood tree model was also used to analyze the data. By comparing with the results reported in literature, values of tree models in the classification of DLBCL were elucidated. RESULTS： Both the branching and the distance-based trees classified DLBCL into three groups. We combined the classification methods of the two models and classified DLBCL into three categories according to their characteristics. The first group was marked by ＋Xq, ＋Xp, -17p and ＋13q; the second group by ＋3q, ＋18q and ＋18p; and the third group was marked by -6q and ＋6p. This chromosomal classification was consistent with cDNA classification. It indicated that -6q and ＋3q were two main events in the tumorigenesis of lymphoma. CONCLUSION： Tree models of lymphoma established from CGH data can be used in the classification of DLBCL. These models can suggest multi-gene, multistep and multi-pathway processes of tumorigenesis.Two pathways, -6q preceding ＋6q and ＋3q preceding ＋18q, may be important in understanding tumorigenesis of DLBCL. The pathway, -6q preceding ＋6q, may have a close relationship with the tumorigenesis of non-GCB DLBCL.