Mitochondrial DNA alterations in thyroid cancer.
BACKGROUND
Alterations in mitochondrial DNA have been identified in a number of solid tumor types, including gastric, head and neck, breast, colorectal, lung, and bladder carcinomas. Recently, a homopolymeric C stretch (D310) located within the noncoding D-loop of the mitochondrial genome was identified and described as a mutational hotspot. The objective of the present study was to examine a series of thyroid cancers for genetic alterations in this region.


METHODS
Seventy-two (72) thyroid cancers were examined for alterations in D310 using PCR-based methods. The primary tumors tested included 35 papillary carcinomas, 18 medullary carcinomas, 9 anaplastic carcinomas, 9 follicular carcinomas, and 1 insular carcinoma.


RESULTS
Alterations in D310 were observed in 2/35 papillary carcinomas (5.7%), 1/18 medullary carcinomas (5.6%), 1/9 anaplastic carcinomas (11.1%), and 1/9 follicular carcinomas (11.1%). Overall, the rate of alterations was 5/72 (6.9%).


CONCLUSIONS
Mutations in the D310 region of the D-loop of mitochondrial DNA are found in thyroid tumors of varying histologic types and grades. This mutation rate is lower than the reported rate of alteration in tumors of epithelial origin, and shows no relationship to histologic grade.
Tong
Betty C
BC
Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Ha
Patrick K
PK
Dhir
Karan
K
Xing
Mingzhao
M
Westra
William H
WH
Sidransky
David
D
Califano
Joseph A
JA
D000230:Adenocarcinoma / Q000235:genetics*; D018263:Adenocarcinoma, Follicular / Q000235:genetics*; D002277:Carcinoma / Q000235:genetics*; D002291:Carcinoma, Papillary / Q000235:genetics*; D004252:DNA Mutational Analysis; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000235:genetics*
D017931:DNA Primers; D004272:DNA, Mitochondrial; D004273:DNA, Neoplasm