title: Monochromosome transfer and microarray analysis identify a critical tumor-suppressive region mapping to chromosome 13q14 and THSD1 in esophageal carcinoma.
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.
authors.affiliation: Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China.
authors.forename: Josephine M Y
authors.initials: JM
authors.lastname: Ko
authors.forename: Pui Ling
authors.initials: PL
authors.lastname: Chan
authors.forename: Wing Lung
authors.initials: WL
authors.lastname: Yau
authors.forename: Ho Kin
authors.initials: HK
authors.lastname: Chan
authors.forename: King Chi
authors.initials: KC
authors.lastname: Chan
authors.forename: Zhuo You
authors.initials: ZY
authors.lastname: Yu
authors.forename: Fung Mei
authors.initials: FM
authors.lastname: Kwong
authors.forename: Lance D
authors.initials: LD
authors.lastname: Miller
authors.forename: Edison T
authors.initials: ET
authors.lastname: Liu
authors.forename: Li Chun
authors.initials: LC
authors.lastname: Yang
authors.forename: Paulisally H Y
authors.initials: PH
authors.lastname: Lo
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Stanbridge
authors.forename: Johnny C O
authors.initials: JC
authors.lastname: Tang
authors.forename: Gopesh
authors.initials: G
authors.lastname: Srivastava
authors.forename: Sai Wah
authors.initials: SW
authors.lastname: Tsao
authors.forename: Simon
authors.initials: S
authors.lastname: Law
authors.forename: Maria L
authors.initials: ML
authors.lastname: Lung
mesh_terms: D000483:Alleles; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002874:Chromosome Mapping; D020090:Chromosome Segregation; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D019175:DNA Methylation / Q000187:drug effects; D003841:Deoxycytidine / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D004938:Esophageal Neoplasms / Q000235:genetics*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016147:Genes, Tumor Suppressor; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D017404:In Situ Hybridization, Fluorescence; D046228:Microarray Analysis; D018895:Microsatellite Repeats / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019699:Thrombospondins / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D014410:Tumor Stem Cell Assay
chemical_list: D006877:Hydroxamic Acids; C511241:THSD1 protein, human; D019699:Thrombospondins; D003841:Deoxycytidine; C012589:trichostatin A