Monochromosome transfer and microarray analysis identify a critical tumor-suppressive region mapping to chromosome 13q14 and THSD1 in esophageal carcinoma
Related Experiment Video
Updated: Jul 6, 2026
Development of Compendium for Esophageal Squamous Cell Carcinoma
Published on: April 12, 2024
Josephine M Y Ko1, Pui Ling Chan, Wing Lung Yau
1Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China.
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.
Insights
Loss of chromosome 13q regions is common in esophageal squamous cell carcinoma (ESCC). Researchers identified thrombospondin type I domain-containing 1 (THSD1) as a key tumor suppressor gene, not RB1, in ESCC.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- Loss of chromosome 13q regions is frequent in esophageal squamous cell carcinoma (ESCC).
- Previous studies suggested chromosome 13 harbors tumor suppressor genes critical for ESCC.
- Identifying specific tumor suppressor genes (TSGs) on 13q is crucial for understanding ESCC pathogenesis.
Purpose of the Study:
- To identify novel tumor suppressor genes on chromosome 13q involved in esophageal squamous cell carcinoma.
- To investigate the role of thrombospondin type I domain-containing 1 (THSD1) as a potential TSG in ESCC.
- To elucidate the mechanisms of THSD1 silencing in ESCC.
Main Methods:
- Monochromosome transfer into an ESCC cell line (SLMT-1) to identify tumor suppressor regions.
- Differential gene expression profiling using cDNA microarrays.
- Quantitative reverse transcription-PCR (qRT-PCR) to validate gene expression levels.
- Analysis of loss of heterozygosity and promoter hypermethylation.
- Functional assays involving transfection of THSD1 into ESCC cells.
Main Results:
- Critical tumor suppressor regions on 13q were mapped to 13q12.3, 13q14.11, and 13q14.3.
- Down-regulation of nine candidate 13q14 TSGs, including RB1, was observed in SLMT-1 cells.
- Thrombospondin type I domain-containing 1 (THSD1) was identified as a novel candidate TSG, with its expression restored in tumor-suppressing hybrids.
- THSD1 expression was down-regulated in 100% of tested ESCC and other cancer cell lines.
- THSD1 silencing mechanisms included loss of heterozygosity and promoter hypermethylation.
- Overexpression of THSD1 significantly reduced the colony-forming ability of SLMT-1 cells.
Conclusions:
- THSD1, not RB1, is a strong candidate tumor suppressor gene in esophageal squamous cell carcinoma.
- THSD1 plays a significant role in suppressing tumor growth and its silencing contributes to ESCC development.
- THSD1 represents a potential therapeutic target for esophageal squamous cell carcinoma.
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