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Updated: Aug 14, 2026
FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Localization of a putative tumor suppressor gene in the sub-telomeric region of chromosome 8p
J B Sunwoo1, P C Sun, V K Gupta
1Department of Otolaryngology - Head and Neck Surgery, Washington University School of Medicine, St Louis, Missouri, USA.
Abstract:
Several regions of chromosome arm 8p are frequently deleted in a variety of human malignancies including those of the prostate, head and neck, lung, and colon, suggesting that there is more than one tumor suppressor gene on this chromosome arm. Both laryngeal and oral squamous cell carcinomas exhibit three distinct and nonoverlapping regions of deletion on 8p. We have further refined the localization of the putative suppressor in 8p23 by using eight microsatellite loci to create a high resolution deletion map of 150 squamous cell carcinomas of the larynx and oral cavity. These new data demonstrate that there are two distinct classes of deletion within this relatively small region of the chromosome and suggest two possible locations for the gene within the D8S264 to D8S1788 interval. We also determined that there is little difference between the allelic loss frequencies of microsatellites mapping near the telomeric ends of other chromosome arms and loci mapping to more centromere proximal regions of the same arm. These data suggest that the high allelic loss frequencies seen at 8p23 loci are not the result of a generalized instability of chromosome ends and are instead consistent with the activation of a specific suppressor gene.
Insights
Tumor suppressor genes on chromosome 8p are frequently deleted in cancers. This study refines the location of a specific suppressor gene in the 8p23 region, identifying two distinct deletion classes in squamous cell carcinomas.
Area of Science:
- Genetics
- Oncology
- Molecular Biology
Background:
- Multiple tumor suppressor genes are suspected on chromosome arm 8p due to frequent deletions in various human cancers.
- Laryngeal and oral squamous cell carcinomas specifically show three distinct deletion regions on 8p.
Purpose of the Study:
- To refine the localization of a putative tumor suppressor gene within the 8p23 region.
- To investigate the nature of deletions in this specific chromosomal area.
Main Methods:
- Utilized eight microsatellite loci to construct a high-resolution deletion map.
- Analyzed 150 cases of squamous cell carcinoma of the larynx and oral cavity.
- Compared allelic loss frequencies between telomeric and centromeric regions.
Main Results:
- Identified two distinct classes of deletions within the 8p23 region, specifically between D8S264 and D8S1788.
- Found no significant difference in allelic loss frequencies between telomeric and centromeric microsatellite loci.
- Observed high allelic loss frequencies at 8p23 loci, not attributable to general chromosome end instability.
Conclusions:
- The data suggest the presence of at least one specific tumor suppressor gene in the 8p23 region.
- The observed deletion patterns are consistent with the activation of a specific suppressor gene, rather than generalized chromosomal instability.
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