1. Monochromosome transfer and microarray analysis identify a critical tumor-suppressive region mapping to chromosome 13q14 and THSD1 in esophageal carcinoma
- Author
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Josephine Mun Yee Ko, Maria Li Lung, Johnny Cheuk On Tang, Lance D. Miller, Paulisally Hau Yi Lo, Ho Kin Chan, Edison T. Liu, King Chi Chan, Pui Ling Chan, Eric J. Stanbridge, Sai Wah Tsao, Fung Mei Kwong, Li Chun Yang, Wing Lung Yau, Simon Law, Gopesh Srivastava, and Zhuo You Yu
- Subjects
Cancer Research ,Esophageal Neoplasms ,Bisulfite sequencing ,Biology ,Hydroxamic Acids ,Transfection ,Deoxycytidine ,Loss of heterozygosity ,Cell Line, Tumor ,Chromosome Segregation ,Gene expression ,Gene silencing ,Humans ,Genes, Tumor Suppressor ,Promoter Regions, Genetic ,Molecular Biology ,Gene ,Alleles ,In Situ Hybridization, Fluorescence ,Tumor Stem Cell Assay ,Chromosome 13 ,Cell Line, Transformed ,Chromosomes, Human, Pair 13 ,Microarray analysis techniques ,Genome, Human ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression Profiling ,Chromosome Mapping ,Epithelial Cells ,DNA Methylation ,Microarray Analysis ,Gene Expression Regulation, Neoplastic ,Oncology ,DNA methylation ,Cancer research ,Thrombospondins ,Microsatellite Repeats - Abstract
Loss of chromosome 13q regions in esophageal squamous cell carcinoma (ESCC) is a frequent event. Monochromosome transfer approaches provide direct functional evidence for tumor suppression by chromosome 13 in SLMT-1, an ESCC cell line, and identify critical regions at 13q12.3, 13q14.11, and 13q14.3. Differential gene expression profiles of three tumor-suppressing microcell hybrids (MCH) and their tumorigenic parental SLMT-1 cell line were revealed by competitive hybridization using 19k cDNA oligonucleotide microarrays. Nine candidate 13q14 tumor-suppressor genes (TSG), including RB1, showed down-regulation in SLMT-1, compared with NE1, an immortalized normal esophageal epithelial cell line; their average gene expression was restored in MCHs compared with SLMT-1. Reverse transcription-PCR validated gene expression levels in MCHs and a panel of ESCC cell lines. Results suggest that the tumor-suppressing effect is not attributed to RB1, but instead likely involves thrombospondin type I domain-containing 1 (THSD1), a novel candidate TSG mapping to 13q14. Quantitative reverse transcription-PCR detected down-regulation of THSD1 expression in 100% of ESCC and other cancer cell lines. Mechanisms for THSD1 silencing in ESCC involved loss of heterozygosity and promoter hypermethylation, as analyzed by methylation-specific PCR and clonal bisulfite sequencing. Transfection of wild-type THSD1 into SLMT-1 resulted in significant reduction of colony-forming ability, hence providing functional evidence for its growth-suppressive activity. These findings suggest that THSD1 is a good candidate TSG. (Mol Cancer Res 2008;6(4):592–603)
- Published
- 2008