Mitochondrial D-Loop instability in thyroid tumours is not a marker of malignancy

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Maximo, V (Author) Other; Lima, J (Author) Other; Soares, P (Author) FMUP; Botelho, T (Author) Other; Gomes, L (Author) Other; Sobrinho Simoes, M (Author) FMUP

Journal

Title: Mitochondrion

Vol. 5

Pages: 333-340

ISSN: 1567-7249

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 30 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-000-16G

DOI: 10.1016/j.mito.2005.06.003

Abstract (EN): Despite the numerous studies describing a high frequency of mitochondrial DNA (mtDNA) somatic mutations in many types of human primary tumors the mechanisms that generate such mutations and the role of mtDNA mutations in tumor development remain unclear. We present the results obtained in the study of mtDNA displacement-loop (D-Loop) region in a series of 66 thyroid tumors, and respective adjacent parenchyma, including benign (adenomas, n = 30) and malignant tumors (follicular carcinomas, n = 17 and papillary carcinomas, n = 19). Three repetitive regions were analyzed [two mononucleotide repetitive (D310 and D568) and one dinucleotide repetitive (D514)]. Thirty-two (48.5%) of the 66 tumors [15/30 (50.0%) adenomas, 8/17 (47.1%) follicular carcinomas and 9/19 (47.4%) papillary carcinomas] harbored somatic insertions in D-Loop repetitive regions. Twenty (30.3%) of the 66 tumors [12/30 (40%) adenomas, 3/17 (17.6%) follicular carcinomas and 5/19 (26.3%) papillary carcinomas] harbored somatic insertions at the D310 mononucleotide repeat. Three (4.6%) of the 66 tumors [1/30 (3.3%) adenomas and 2/17 (11.8%) follicular carcinomas] harbored somatic insertions at the D568 mononucleotide repeat. Fifteen (22.7%) of the 66 tumors [3/30 (10.0%) adenomas, 5/17 (29.4%) follicular carcinomas and 7/19 (36.8%) papillary carcinomas] harbored somatic insertions at the D514 dinucleotide repeat. Five (7.6%) of the 66 tumors [1/30 (3.3%) adenomas, 1/17 (5.9%) follicular carcinomas and 2/19 (10.5%) papillary carcinomas] harbored somatic insertions in more than one region, and in one of them (a carcinoma) alterations were detected in the three regions. We conclude that mutations in the mtDNA D-Loop region are frequent in benign and malignant thyroid tumors and cannot be considered a marker of malignancy. Our study shows, furthermore, two repetitive regions (D310 and D514) that appear to be susceptible to mutation in thyroid tumors.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8