嚼食檳榔與血管加壓素轉化酶插入/刪除基因多型性在引發口腔與口腔外疾病之相關性研究

檳榔是目前在全世界佔第四位具有產生心理及生理性成癮作用的物質。很多人有嚼食檳榔的習慣是因生理上的反應，包括嚼食後有提神以及全身覺得舒暢的感覺，然而雖僅是一種輕微的心理與精神上的反應，但長期使用對口腔將可造成口腔癌前病變或者口腔癌之危險，在對口腔外身體之影響則與糖尿病、高血壓與中心性肥胖等有關。回顧文獻發現，基因與環境因子之交互作用將使個體對於疾病有不同的感受性。研究也指出血管加壓素轉化酶與人類細胞色素氧化酶P450基因多型性與罹患癌症之易感性有相關。血管加壓素轉化酶將影響腫瘤細胞的增生、遷移、血管新生以及轉移之情形。而人類細胞色素氧化酶P450為一種第一期酵素，其參與對有害物質之代謝與活化。因此為探討血管加壓素轉化酶與人類細胞色素氧化酶P450基因多型性，在嚼食檳榔引發口腔癌前病變與口腔癌以及對口腔外疾病之影響，本論文藉由高檳榔嚼食率之南台灣原住民與平地漢族來探討兩個主題: (A)血管加壓素轉化酶與人類細胞色素氧化酶P450基因多型性對嚼食檳榔者引發口腔癌前病變與口腔癌之研究; (B)發炎細胞激素與血管加壓素轉化酶基因在嚼食檳榔引發口腔外疾病之相關性。研究首先在南台灣原住民以檳榔嚼食累積時間配對，61位嚼食檳榔罹患口腔癌前病變之疾病組與61位嚼食檳榔之健康對照組，研究血管加壓素轉化酶基因多型性與口腔癌前病變之相關性，經研究發現血管加壓素轉化酶DD 基因型與D allele之比率在疾病組顯著高於對照組，並且進一步經由條件羅吉斯迴歸分析，發現DD基因型(adjusted OR = 8.10, 95% CI = 2.04-32.19, P = 0.003)與D allele (adjusted OR = 5.26, 95% CI = 2.13-13.00, P = 0.0003)為嚼食檳榔者罹患口腔癌前病變的高危險因子。更進一步研究血管加壓素轉化酶對口腔癌之影響，在此研究我們收集88位口腔癌前病變之患者與186位口腔癌之病人以及120位無口腔疾病之對照組，所有參與研究之個案都為平地漢族，且為檳榔嚼食者以及都為男性，研究結果與在原住民族群的研究發現一致，血管加壓素轉化酶DD 基因型，不但與嚼食嚼食引發口腔癌前病變及口腔癌有相關性外，且與淋巴轉移有相關性。經由免疫組織化學染色方法發現血管加壓素轉化酶在上皮變異(dysplasia)之口腔黏膜組織與鱗狀上皮細胞癌組織有很強的蛋白質表現。另外在本研究對CYP1A1基因多型性與檳榔嚼食者罹患口腔癌前病變之相關性研究，則發現CYP1A1基因多型性在南台灣原住民嚼食檳榔引發口腔癌前病變無顯著之相關性，可能因種族差異所致。在第二研究主題嚼食檳榔與口腔外疾病之研究，以1,258位南台灣原住民為研究對象，發現檳榔嚼食與中心性肥胖、高三酸甘油脂、高血糖以及代謝症候群有關聯性。另外研究繼續以189位嚼食檳榔無飲酒與吸菸的實驗組與256位無嚼食檳榔、飲酒與吸菸的對照組，經分析發現DD基因型的檳榔嚼食者與ID及II基因型檳榔嚼食者相比較有顯著較低的高血壓比率與較低之收縮壓及脈搏壓。進ㄧ步以複迴歸模式分析且經調整相關干擾因子後，發現帶有DD基因型之檳榔嚼食者與降低收縮壓有相關性，由此研究結果證實我們的研究假設，嚼食檳榔與血管加壓素轉化酶基因多型性具有調控身體代謝之作用。總結研究結果，血管加壓素轉化酶基因多型性在南台灣嚼食檳榔者引發口腔癌前病變與口腔癌具有相關性且與淋巴轉移有關聯性。此外嚼食檳榔與代謝症候群具有相關性，而發炎細胞激素在此作用中扮演重要角色。另外，伴隨基因的易感性與環境因子的交互作用對血壓之調控具有關聯性。上述研究發現不但顯示檳榔對身體之作用是不容忽視，並且證實基因的多型性與發炎細胞激素在嚼食檳榔引發口腔與口腔外疾病的病理機轉中皆扮演著重要之角色。

關鍵字

嚼食檳榔；血管加壓素轉化酶基因；人類細胞色素氧化酶P450基因；發炎細胞激素；口腔癌前病變；口腔癌；淋巴轉移；口腔外疾病

並列摘要

Areca nut/betel quid (BQ, Areca catechu) is said to be the fourth most commonly used psychoactive substance in the world. Many people acquire the habit of chewing BQ due to its physiological effects, including increased stamina and a general feeling of well being. It shows mild psycho-stimulatory effects but with prolonged use, there is an increased risk of oral precancerous lesion (OPL) and oral cancer, and is an increased risk of extra-oral diseases such as diabetes, hypertension, central obesity, and so on. In addition, previous studies suggested that genetic factor is involved in susceptibility to the development of the diseases. It has been showed that angiotensin- converting enzyme (ACE) and cytochrome P450s (CYPs) polymorphhisms are associated with cancer susceptibility. ACE is differentially expressed in several malignancies and influences tumor cell proliferation, tumor cell migration, angiogenesis, and metastatic behavior. In addition, CYPs are the phase I enzymes in the activation pathway. To further clarify the role of ACE and CYP1A1 polymorphisms in association with risk of OPL and oral cancer and extra-oral diseases in betel quid chewers. The present study enrolled aboriginal and Hen subjects of Southern Taiwan with a high prevalence of BQ chewing to investigate: (A) ACE and CYP1A1 polymorphisms in association with risk of OPL and oral cancer in BQ chewers; (B) inflammatory cytokines and ACE polymorphisms and BQ chewing in association with extra-oral diseases. A total of 61 BQ chewers having OPL were studied to compare with 61 asymptomatic BQ chewers matched for BQ chewing duration and dosage. The frequency of homozygote for ACE DD genotype and D variant is significantly higher in the case subjects than those of the controls. Further, the DD genotype (AOR = 8.10, 95% CI = 2.04-32.19, P = 0.003) and D allele (AOR = 5.26, 95% CI = 2.13-13.00, P = 0.0003) are significantly associated with higher risk of OPL by conditional logistic regression analysis. Further, ACE I/D polymorphisms were studied in 88 OPL patients, 186 oral cancer patients, and 120 without any oral lesions control subjects, all study subjects were male gender and BQ chewers. The results found that ACE DD genotype is associated not only with higher risk of OPL and oral cancer but also is associated with lymph node metastasis in Hen population of BQ chewers. Using immunohistochemical method, we showed up-regulation of ACE in basal keratinocytes in dysplasias as well as in the central cells of squamous cell carcinomas. However, in the present another study, the association of cytochrome P4501A1 (A2455G) polymorphism with risk of OPL in BQ chewers, CYP 1A1 ploymorphism was not found in association with OPL in Taiwan Southern aboriginal population with BQ chewing. The results may be dut to racial differences. To study the extra-oral effects of BQ chewing a total of 1,258 aboriginal subjects of Southern Taiwan were enrolled. BQ chewing subjects had significantly higher prevalence of dysglycemia, central obesity, hyper-triglyceridemia, and metabolic syndrome (MetS) than those of non-chewers, and was independently associated with MetS. A total of 189 BQ chewing subjects and 256 non-chewing controls were studied. BQ chewers with the DD genotype had significantly lower blood pressure, pulse pressure and prevalence of hypertension compared to those of chewers with II or ID genotypes. Multiple regression analysis confirmed that BQ chewers with the DD genotype accounted for a significant age, sex, and waist to hip ratio adjusted decrease in systolic blood pressure. This finding supports the hypothesis that BQ chewing and ACE I/D polymorphism may regulate the human metabolic effect. In conclusion, the ACE gene polymorphism may be considered as a factor of increased susceptibility to OPL and oral cancer and associated with the induction of lymph node metastasis of oral cancer disease in Taiwanese. In addition, chronic BQ chewing is an independent contributor of MetS. Inflammatory cytokines are involved in BQ chewing related metabolic derangements. Further, concomitant genetic susceptibility and environmental factors determine the level of blood pressure. This study suggested that BQ chewing related systemic effects are not to be ignored and evidenced that genetic polymorphism and inflammatory cytokines play an important role in the BQ induced oral and extra-oral disease pathophylogy.

並列關鍵字

betel quid chewing ； angiotensin-converting enzyme polymorphism ； cytochrome P450 1A1 polymorphism ； inflammatory cytokines ； oral precancerous lesion ； oral cancer ； lymph node metastasis ； extra-oral diseases