Objectives  To determine the relationship between hOGG1 loss of heterozygosity (LOH), Hashimoto thyroiditis (HT), and papillary thyroid cancer (PTC). Hashimoto thyroiditis is an autoimmune mediated chronic inflammatory disease previously shown to coexist with papillary PTC. To further define the relationship between HT and PTC, we report an analysis of hOGG1, a major repair gene for free radical–induced oxidative DNA damages, in thyroidectomy specimens.

Design  Tissue samples from 20 cases of PTC, 20 cases of HT, and 15 cases of benign goiter were included in this study. Samples of DNA collected from laser-capture microdissection of thyroidectomy specimens were analyzed for hOGG1 LOH by polymerase chain reaction (PCR) amplification using 5 fluorescent-labeled microsatellite markers followed by fragment analysis.

Setting  A university tertiary care center and regional veterans' hospital.

Patients  Fifty-five patients undergoing partial or total thyroidectomies for various indications (PTC, HT, or goiter).

Interventions  Pathology specimens were analyzed by laser capture microdissection and PCR for hOGG1.

Main Outcome Measure  The presence of hOGG1 in all thyroid specimens.

Results  Amplification by PCR was successful for all 5 markers in 18 cases of PTC, 15 cases of HT, and 12 cases of benign thyroid. Among these samples, hOGG1 LOH was found in 17 of 18 PTC specimens (94%), 11 of 15 HT specimens (73%), and 1 of 12 benign goiter specimens (8%).

Conclusions  hOGG1 LOH is strongly associated with PTC and HT but not with benign thyroid. We hypothesize that thyroid follicular epithelia accumulate aberrant genetic changes in long-standing HT, which may represent a precursor lesion of PTC.

Cholesterol oxides, in particular 7-ketocholesterol, are proatherogenic compounds that induce cell death in the vascular wall when localized in lipid raft domains of the cell membrane. Deleterious effects of 7-ketocholesterol can be prevented by vitamin E, but the molecular mechanism involved is unclear. In this study, unlike -tocopherol, the -tocopherol vitamin E form was found to prevent 7-ketocholesterol-mediated apoptosis of A7R5 smooth muscle cells. To be operative, -tocopherol needed to be added to the cells before 7-ketocholesterol, and its anti-apoptotic effect was reduced and even suppressed when added together or after 7-ketocholesterol, respectively. Both pre- and co-treatment of the cells with -tocopherol resulted in the redistribution of 7-ketocholesterol out of the sphingolipid/cholesterol-enriched (lipid raft) domains. In turn, fewer amounts of -tocopherol associated with lipid rafts on 7-ketocholesterol-pretreated cells compared with untreated cells, with no prevention of cell death in this case. In further support of the implication of lipid raft domains, the dephosphorylation/inactivation of Akt-PKB was involved in the 7-ketocholesterol-induced apoptosis. Akt-PKB dephosphorylation was prevented by -tocopherol, but not -tocopherol pretreatment.