Project/Area Number |
23510081
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Risk sciences of radiation/Chemicals
|
Research Institution | Nara Medical University |
Principal Investigator |
MORI Toshio 奈良県立医科大学, 医学部, 研究教授 (10115280)
|
Co-Investigator(Kenkyū-buntansha) |
IWAMOTO Takaaki 奈良県立医科大学, 医学部, 博士研究員 (20448773)
|
Project Period (FY) |
2011 – 2013
|
Project Status |
Completed (Fiscal Year 2013)
|
Budget Amount *help |
¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2012: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2011: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
|
Keywords | 人体有害物質 / エストロゲン補充療法 / 乳がん / 4-OHEN-DNA付加体 / 有害化学物質 / ヌクレオチド除去修復 / DNA付加体 |
Research Abstract |
Hormone replacement therapy (HRT) is widely used to decrease menopausal symptoms in post-menopausal women. However, long-term HRT increases the incidence of breast, ovarian and endometrial cancers. 4-Hydroxyequilenin (4-OHEN), a metabolite of equine estrogens present in common HRT formulations (Premarin), is capable of producing bulky 4-OHEN-DNA adducts. An immunological assay using our adduct-specific antibodies revealed that 4-OHEN-DNA adducts are repaired inefficiently in human breast cancer cells. MTS assay revealed that similar 4-OHEN sensitivities are observed between human normal and repair-deficient cells. Moreover, histones including human H1 competitively inhibited the binding of the antibodies to 4-OHEN-DNA adducts in a concentration-dependent manner, which are considered as a model of damage-recognising repair protein. Thus, the formation of DNA adducts with inefficient repair character might be involved in carcinogenesis process of Premarin-induced cancers.
|