Molecular genetic analysis of the BRCA2 tumor suppressor gene region in cutaneous squamous cell carcinomas.
BACKGROUND
Germ line mutations of the BRCA2 tumor suppressor gene with subsequent loss of the remaining wild-type BRCA2 allele have been identified in up to 35% of familial breast cancer cases. A high frequency of allelic loss at the BRCA2 gene locus has also been reported in a variety of sporadic epithelial tumors including oesophageal squamous cell carcinomas (SCC), and sporadic head and neck SCC.


OBJECTIVE
The present study aimed to examine the integrity of the BRCA2 gene in cutaneous SCC.


METHODS
Allelic imbalance/loss of heterozygosity (AI/LOH) was examined in 22 histologically confirmed cutaneous SCC at two microsatellite markers, D13S260 (centromeric to the BRCA2 gene) and D13S267 (telomeric to the BRCA2 gene). Immunohistochemical analysis of BRCA2 protein expression was also examined in the cutaneous SCC.


RESULTS
AI/LOH at the D13S260 locus was found in eight of the 19 informative SCC, and AI/LOH at the D13S267 locus was found in 12 of the 18 informative SCC. Seven SCC showed allelic loss at both markers, and six SCC showed retention of heterozygosity at both markers. Expression of BRCA2 protein was only detected in six of the normal epidermises and three of the 21 SCC examined.


CONCLUSIONS
AI/LOH of the BRCA2 gene region was found to be common in the cutaneous SCC.
Gray
Sarah E
SE
Molecular Oncology Laboratory, Pathology Department, Royal College of Surgeons in Ireland and Beaumont Hospital, Dublin, Ireland.
Kay
Elaine
E
Leader
Mary
M
Mabruk
Mohamed
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051017:Apoptosis Regulatory Proteins; D024682:BRCA2 Protein / Q000235:genetics* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D005260:Female; D024522:Genes, BRCA2; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D008967:Molecular Biology; D009367:Neoplasm Staging; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D051017:Apoptosis Regulatory Proteins; C118024:BLID protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm