| 篇名 |
Smoking-induced Human Breast Cancer Formation through Induction of α9-nicotinic Acetylcholine Receptor |
| 作者 |
Yuan-Soon Ho, Chia-Hwa Lee, Chih-Hsiung Wu |
| 卷期/出版年月 |
44卷2期 (2011/4) |
| 頁次 |
47-52 |
| 摘要 |
Tobacco is a substance that contains human carcinogens and may contribute to the
risk for tumor formation in the lung and colon via nicotinic acetylcholine receptors
(nAChRs). Nicotine receptors are a family of ligand-gated ion channels that mediate
the effects of the neurotransmitter acetylcholine and are among the most wellunderstood
receptors. The α4ß2 nAChR is known to exist in the central nervous
system (CNS) and functions as a transmitter, whereas the α7-nAChR is a wellestablished
molecule that is involved in lung cancer tumorigenesis. Previously,
however, there was no direct evidence to provide a link between tobacco carcinogens
and cellular molecules involved in breast tumorigenesis. Recently, two large cohort
epidemiological studies undertaken in the USA and Japan have indicated that breast
cancer risk is associated with both active and passive smoking. Analysis of α9-
nAChR expression in clinical tumor tissues indicated that the α9-nAChR is
important for tumor carcinogenesis in vivo and nicotine-induced transformation of
normal human breast epithelial cells in vitro. Long-term exposure to estrogen and
nicotine significantly increases α9-nAChR expression and forms a positively
regulated loop and that can be blocked by several chemicals and natural
compounds. In this paper, the structure and functional relationship of the nAChR
will be discussed. The role of nAChR in breast cancer formation and its implication
for prevention of cancer formation will also be discussed. |
| 關鍵詞 |
smoking, nicotine, α9-nicotinic acetylcholine receptor, breast cancer,tumor marker |
| 分類 |
Mini Review |
