title: Gene-expression profiling to identify genes related to spontaneous tumor regression in a canine cancer model.
abstract: Microarray transcriptome study in cancer has been commonly used to investigate tumorigenic mechanisms. The unique growth pattern of spontaneous regression (SR) after progressive (P) growth in canine transmissible venereal tumor (CTVT) provides a valuable cancer model to study the genome-wide differences in samples between the two stages of growth. In this study, Affymetrix analysis was performed based on the canine genome to compare the gene expression profiles of CTVT P- and SR-phase tumors. A total of 459 (278 up-regulated and 181 down-regulated) genes were identified as being differentially-expressed during the SR phase by the 2-fold method. Further analysis of these genes revealed that the expression of three genes associated with IL-6 production -TIMD-4, GPNMB and PLTP - was significantly higher in SR-phase tumors than in P-phase tumors; these results were also confirmed by real time RT-PCR in tumor tissues of beagles. In addition, we found that Th17-related genes were over-expressed in the SR phase, suggesting autoimmune responses involvement in tumor regression. Although the interaction between CTVT and host immunity were partially investigated in previous studies, our results enable us to gain new insight into the genes and possible mechanisms involved in tumor regression and reveal potentially useful targets for cancer therapy.
authors.affiliation: Animal Cancer Center, School of Veterinary Medicine, Taipei 106, Taiwan, ROC.
authors.forename: Hsin-Chien
authors.initials: HC
authors.lastname: Chiang
authors.forename: Albert Tai-Ching
authors.initials: AT
authors.lastname: Liao
authors.forename: Tong-Rong
authors.initials: TR
authors.lastname: Jan
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Wang
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Lei
authors.forename: Mong-Hsun
authors.initials: MH
authors.lastname: Tsai
authors.forename: Mo-Fen
authors.initials: MF
authors.lastname: Chen
authors.forename: Chien-Yueh
authors.initials: CY
authors.lastname: Lee
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Lin
authors.forename: Rea-Min
authors.initials: RM
authors.lastname: Chu
authors.forename: Chen-Si
authors.initials: CS
authors.lastname: Lin
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D004283:Dog Diseases / Q000235:genetics* / Q000276:immunology*; D004285:Dogs; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D015850:Interleukin-6 / Q000235:genetics; D009365:Neoplasm Regression, Spontaneous / Q000235:genetics* / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000235:genetics; D014685:Venereal Tumors, Veterinary / Q000235:genetics* / Q000276:immunology*
chemical_list: D015850:Interleukin-6; D016212:Transforming Growth Factor beta