An LOH and mutational investigation of the ST7 gene locus in human esophageal carcinoma.
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.
Wang
Suna
S
Department of Medicine, Division of Gastroenterology and Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore 21201, USA.
Mori
Yuriko
Y
Sato
Fumiaki
F
Yin
Jing
J
Xu
Yan
Y
Zou
Tong-Tong
TT
Olaru
Andreea
A
Kimos
Martha C
MC
Perry
Kellie
K
Selaru
Florin M
FM
Deacu
Elena
E
Sun
Menghong
M
Shi
Ying-Chang
YC
Shibata
David
D
Abraham
John M
JM
Greenwald
Bruce D
BD
Meltzer
Stephen J
SJ
D000230:Adenocarcinoma / Q000235:genetics; D002277:Carcinoma / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7; D021901:DNA, Intergenic; D004938:Esophageal Neoplasms / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007438:Introns; D019656:Loss of Heterozygosity; D009154:Mutation; D018307:Neoplasms, Squamous Cell / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D040641:Quantitative Trait Loci; D012016:Reference Values; D017422:Sequence Analysis, DNA; D025521:Tumor Suppressor Proteins
D021901:DNA, Intergenic; D011506:Proteins; C412123:ST7 protein, human; D025521:Tumor Suppressor Proteins