Detection of somatic mutations in breast cancer and non-cancerous chromosomal disorders by the application of comparative genomic hybridization

• Main Author: Alwohhaib, M.
• Published: Swansea University 2000
• Subjects: 616.994
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635770

The aim of this study was to detect chromosomal imbalances in breast cancer and non-cancerous chromosomal disorders by comparative genomic hybridization (CGH). Initially, the technique was developed to be used on different types of samples. The samples used include DNA of patients suffering from different syndromes, frozen breast tumours tissue samples, and archival paraffin - embedded breast-tumour tissue sections. CGH application on the different syndromes have shown copy number changes in chromosome Y in two kabuki syndrome patients, imbalances at the X and Y chromosomes of the fragile X patients, a deletion at 15q11-q13 of a Prader-Willi syndrome patient, and gain in 7q21 qter of a cystic fibrosis patient. Furthermore, the CGH technique was able to detect an accumulation of genetic changes in the paraffin embedded archival samples for women who are under 40 years of age suffering from breast cancer. CGH was also applied to look for the copy number changes in the genome of 21 Kuwaiti women who have been diagnosed with primary breast cancer at Kuwait cancer control centre. Chromosomal regions 1q, 8p, 8q and 6q are detected to be abnormal in these patients which need further investigation. Finally, PCR-SSCP was used to detect the mutations in exons 5, 6, 7 and 8 of the P53 gene in 21 breast cancer patients. SSCP detected 3/21 mutations. They were then characterised by direct sequencing. These mutations were a transition of G → A at codon 77 of exon 5, insertion of fair nucleotides between codons 163 and 164 of exon 5, and insertion of two nucleotides into codons 241 of exon 7.