抽菸、砷代謝能力、發炎因子之基因多形性與泌尿上皮細胞癌

Cigarette Smoking, Arsenic Methylation Capability, Gene Polymorphisms of Inflammatory Factors and Urothelial Carcinoma

吳佳璋(Chia-Chang Wu)

指導教授 ： 薛玉梅

臺北醫學大學/公共衛生暨營養學院/公共衛生學系暨研究所/博士(2013年)

摘要

抽菸、二手菸及無機砷暴露是泌尿上皮細胞癌的重要危險因子。慢性砷暴露可能產生活性氧化物種，進而誘導ㄧ些發炎細胞激素例如腫瘤壞死因子alpha (Tumor necrosis factor-alpha, TNF-α)、介白素-6 (Interleukin-6, IL-6)及介白素-8(Interleukin-8, IL-8)。過去研究顯示TNF-?恁BIL-6及 IL-8與許多癌症(包括泌尿上皮細胞癌)的發生及惡化有關。因此，本論文主要目的在探討抽菸、二手菸暴露、無機砷甲基化指標及發炎因子基因多行性(TNF-?? -308 G/A, IL-6 -174 G/C及IL-8 -251 T/A)的合併作用對於罹患泌尿上皮細胞癌的影響。

本論文是以醫院為基礎的病例對照研究，從2002年9月至2009年5月總共納入261位泌尿上皮細胞癌個案及672未曾罹患任何惡性腫瘤之對照個案。參與本研究者除了完成問卷訪視外，同時會收集提供8毫升的血液及50毫升的尿液。利用液相色譜法-質譜聯用方法分析尿中香菸代謝產物[free 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)及NNAL-glucuronides, (NNAL-Gluc)]。另外，採用高效能液相層析儀-氫化原子吸收光譜儀測定尿液的砷物種。發炎因子基因多形性(TNF-?? -308 G/A, IL-6 -174 G/C及IL-8 -251 T/A)則是利用聚合酵素鏈鎖反應-限制片段長度多形性來判定。

以不抽菸者與尿液總砷濃度< 15.40 (μg/g creatinine)為參考組時，有抽菸習慣者與尿液總砷濃度?d?n15.40 (μg/g creatinine)者則分別具有3.20 及6.45倍罹患泌尿上皮細胞癌的顯著危險性。
與沒有二手菸暴露同時尿液總砷濃度低的個案比較，具有二手菸暴露同時尿液總砷濃度高的個案具有顯著較高罹患泌尿上皮細胞癌的危險性(OR=2.71)。有抽菸者同時又有二手菸暴露及尿液總砷濃度高者具有最顯著的罹患泌尿上皮細胞癌危險性(OR=10.82)。進一步分析顯示，
如以低尿液總NNAL濃度、低尿液總砷濃度為參考組，則高尿液總NNAL濃度及高尿液總砷濃度的個案有顯著較高罹患泌尿上皮細胞癌的危險性(OR=3.29)。相較於高NNAL-Gluc/free NNAL比值及低尿液總砷濃度者，低NNAL-Gluc/free NNAL比值及高尿液總砷濃度者具有顯著較高罹患泌尿上皮細胞癌危險性(OR=30.33)。此外，相較於具有低尿液總砷濃度、低累積抽菸暴露量與TNF-?? -308 G/G+G/A及IL-8 -251 T/A+ A/A 基因型者為參考組，具有高尿液總砷濃度、高累積抽菸暴露量與TNF-?? -308 A/A 及 IL-8 -251 T/T 基因型的個案有顯著較高罹患泌尿上皮細胞癌危險性(OR=8.45)。

關鍵字

抽菸 ； 二手菸 ； 無機砷 ； 腫瘤壞死因子 ； 介白素 ； 泌尿上皮細胞癌

並列摘要

Cigarette smoking, exposure to secondhand smoke, and arsenic exposure are well known risk factors for developing urothelial carcinoma (UC). Chronic exposure to arsenic can generate reactive oxidative species, which can induce certain proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-??), interleukin-6 (IL-6) and interleukin-8 (IL-8). TNF-??, IL-6 and IL-8 have been shown to be involved in the development and progression of various cancers, including UC. We investigated the combined effects of cigarette smoking, exposure to secondhand smoke, the polymorphism of TNF-?? -308 G/A, IL-6 -174G/C, IL-8 -251 T/A and the arsenic methylation indices on the risk of developing UC.
We conducted a hospital-based, case-control study involving 261 UC patients and 672 cancer-free control subjects between September 2002 and May 2009. Participants completed questionnaires and then provided 8ml blood sample and 50 ml urine samples. Urine samples were analyzed for free 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (free NNAL) and NNAL- glucuronides (NNAL-Gluc) using liquid chromatography-tandem mass spectrometry. Urinary arsenic species were analyzed by using high performance liquid chromatography-hydride generator-atomic absorption spectrometry. The polymorphism of TNF-?? -308 G/A, IL-6 -174G/C and IL-8 -251 T/A were determined using polymerase chain reaction-restriction fragment length polymorphism.
Subjects who had smoked > 100 cigarettes in their life (ever smokers) and had a high urinary total arsenic level (?d15.40 μg/g creatinine), had increased risks of developing UC (3.20 and 6.45-fold), respectively, compared to subjects who were never smokers and had a low urinary total arsenic level. Subjects who had high urinary total arsenic levels and had been exposed to secondhand smoke had increased chances (2.71-fold) for developing UC, compared to subjects who were not exposed to secondhand smoke and had low urinary total arsenic levels. Ever smokers who had been exposed to secondhand smoke and had a high urinary total arsenic level had the greatest increased risk for developing UC (10.82-fold). As to the cigarette metabolites, subjects with high urinary total NNAL and high total arsenic had higher UC risk (OR=3.29) than those with low total NNAL and low total arsenic. Subjects with a lower ratio of NNAL-Gluc/free NNAL and higher total arsenic had a higher UC risk (OR=30.33) than those with a higher NNAL-Gluc/free NNAL ratio and lower total arsenic. Moreover, study subjects who had both high urinary total arsenic and high cumulative cigarette exposure and carried the TNF-?? -308 A/A and IL-8 -251 T/T polymorphisms had a significantly increased UC risk (OR=8.45) comparing to those who had both low urinary total arsenic and low cumulative cigarette exposure and carried the TNF-?? -308 G/G+G/A and IL-8 -251 A/A+A/T polymorphisms.

並列關鍵字

cigarette smoking ； secondhand smoke ； arsenic exposure ； tumor necrosis factor ； interleukin ； urothelial carcinoma

參考文獻

References

1. IARC. Some drinking water disinfectants and contaminats, including arsenic. IARC Monogr

Eval Carcinog Risk Human. 84: 1-477, 2004.

2. Chen, C.J., Chen, C.W., Wu, M.M., and Kuo, T.L. Cancer potential in liver, lung, bladder and

kidney due to ingested inorganic arsenic in drinking water. British Journal of Cancer, 66 (5):