Frequent loss of heterozygosity (LOH) on human chromosome 7q31 has been reported in numerous malignancies. Suppressor of tumorigenicity 7 (ST7) has been identified as a candidate tumor suppressor gene in this region. To identify whether 7q31 and genetic alterations of ST7 were involved in human esophageal carcinogenesis, we performed LOH mapping of a 5.4 cM region at 7q31-q35 in 43 primary esophageal carcinomas, as well as mutational analyses of the ST7 gene in tumors with LOH in this region. Of 43 tumors, 12 (28%) showed LOH at 7q31-q35. These included four (22%) of 18 squamous cell carcinomas and eight (32%) of 25 adenocarcinomas. The peak LOH locus was D7S480, lying 4.2 Mb telomeric to ST7 and showing LOH in eight of 37 informative tumors, or 22%. No mutations were found in the entire coding or flanking intronic regions of the ST7 gene among 12 tumors with 7q-LOH. In addition, quantitative RT-PCR analyses of ST7 mRNA expression levels in 11/13 normal-tumor pairs failed to show more than a 50% decrease in tumor ST7 mRNA relative to matched normal tissues. These data suggest that LOH at 7q31-q35 is involved in the origin or progression of at least a subset of esophageal carcinomas, but that ST7 is not the target gene of this somatic event.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Jan 23 2003|
- Esophageal cancer
ASJC Scopus subject areas
- Molecular Biology
- Cancer Research