Infrequent somatic deletion of the 5' region of the COL1A2 gene in oesophageal squamous cell cancer patients.
Oesophageal squamous cell cancer is the leading cause of cancer death amongst African males in South Africa. DNA was isolated from normal and tumour biopsies of the oesophagi of 33 African patients with squamous cell carcinoma of the oesophagus and was analysed with two dinucleotide repeat polymorphisms, a GT repeat sequence in the first intron, and a CA repeat in the promoter of the human alpha2(I) procollagen gene (COL1A2), using the polymerase chain reaction (PCR). Normal and tumour DNAs from each individual were compared to identify changes present in the tumour DNA, but absent in normal DNA. Twenty two cases were informative (heterozygous) for the promoter polymorphism and 24 cases were informative for the intronic polymorphism. Loss of heterozygosity (LOH) was seen in 2/22 (9.1%) for the promoter and 3/24 (12.5%) for the intronic polymorphism. These changes involved a total of three patients: two patients displayed the lost allele incorporating both the CA repeat and GT repeat loci; the third patient revealed LOH at the intronic polymorphism, but was non-informative (homozygous) for the promoter polymorphism. Deletions within the procollagen genes may represent an as yet unrecognised but rare event in the multistep process of carcinogenesis.
Dietzsch
Erin
E
Division of Medical Biochemistry, Faculty of Health Sciences, University of Cape Town, South Africa.
Parker
M Iqbal
MI
D020121:5' Untranslated Regions / Q000235:genetics*; D000328:Adult; D000368:Aged; D001345:Autoradiography; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D003094:Collagen / Q000235:genetics*; D024042:Collagen Type I; D018900:Dinucleotide Repeats / Q000235:genetics; D004938:Esophageal Neoplasms / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D006801:Humans; D007438:Introns; D019656:Loss of Heterozygosity / Q000235:genetics; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics
D020121:5' Untranslated Regions; D024042:Collagen Type I; D003094:Collagen