| 1. |
- Eklund, Lena K., et al.
(författare)
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Mutation analysis of the human homologue of drosophila patched and the xeroderma pigmentosum complementation group A genes in squamous cell carcinomas of the skin
- 1998
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Ingår i: Molecular Carcinogenesis. - 0899-1987 .- 1098-2744. ; 21:2, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- The human homologue of Drosophila patched (PTCH), located at chromosome 9q22.3, was recently identified as a candidate tumor suppressor gene for familial and sporadic basal cell carcinomas. Squamous cell carcinomas (SCCs) of the skin display allelic loss in this chromosomal region, which, in addition to the PTCH gene, contains the DNA repair gene xeroderma pigmentosum complementation group A (XPA). Patients with xeroderma pigmentosum are predisposed to non-melanoma skin tumors because of deficient excision repair of ultraviolet-induced DNA damage. Mutation analysis by single-strand conformation analysis and direct DNA sequencing of all 23 exons of the PTCH gene and all six exons of the XPA gene in 14 SCCs did not reveal structural alterations in any of these genes. Additionally, analysis of PTCH expression by in situ hybridization in SCCs revealed no evidence of upregulation of PTCH mRNA, confirming the lack of mutations in this gene. These findings suggest that another, yet to be identified gene or genes on chromosome 9q are involved in SCC tumorigenesis.
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| 2. |
- Gentile, Massimiliano, et al.
(författare)
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p53 and survival in early onset breast cancer : analysis of gene mutations, loss of heterozygosity and protein accumulation
- 1999
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Ingår i: European Journal of Cancer. - 0959-8049 .- 1879-0852. ; 35:8, s. 1202-1207
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Tidskriftsartikel (refereegranskat)abstract
- The p53 protein has proven to be central in tumorigenesis by its cell cycle regulatory properties and both gene mutations and protein accumulation have been associated with poor prognosis in breast cancer. The present study was undertaken to investigate the prognostic significance of gene mutations, p53 protein accumulation and of loss of heterozygosity (LOH) at the TP53 locus in young (age <37 years) breast cancer patients. In total, gene mutations were found in 21 of the 123 patients (17%), LOH in 20 of the 47 informative cases (43%) and protein accumulation in 47 of the 102 available cases (46%). Log rank analysis revealed no significant association between survival and TP53 mutations (in general), p53 protein accumulation or LOH. However, missense mutations localised to the zinc binding domain were significantly (P=0.0007) associated with poorer prognosis. As indicated in this as well as other studies, p53 protein accumulation is frequently found in young breast cancer patients, but this protein overexpression appears to be of minor significance for survival. Nevertheless, the present report also suggests that specific mutations contribute substantially to tumour aggressiveness.
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