Study of IL-18 genetic polymorphism in oral cancer

• Main Authors: Ying-Tsai Wang, 王盈彩
• Other Authors: 楊順發
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/24524401916006972284

碩士 === 中山醫學大學 === 生化暨生物科技研究所 === 101 === All malignant tumors occurred in the oral cavity are generally called as oral cancers which can be found in any parts of oral cavity, and most of them are developed from the squamous cells of mucous membrane. A great majority of oral cancers in Taiwan are tongue cancers and buccal mucosa cancer. The squamous cell carcinoma in the oral cavity is highly invasive and easily metastatic to lymph nodes, and patients usually have poor prognosis and lower survival rates. Therefore, we need to understand more about the mechanism of how oral cancers become highly invasive in order to prevent and cure them more effectively. Interleukin-18 (IL-18), also known as interferon-gamma inducing factor, is a multi-functional inflammatory cytokine which can be secreted by various cells, and among them mainly are macrophages. Besides regulating both congenital and acquired immunity, IL-18 also play an important role in controlling inflammatory reactions while it has been proved that it has effects of promoting and inhibiting tumor growth. Other studies also found that IL-18 was highly expressed in the serum of patients suffering from various kinds of cancers and was recognized as an important index of tumor growth. Therefore, the purpose of this study was to access the correlations between IL-18 polymorphism and the susceptibility and the severity of oral cancers. We collected 559 healthy adults as control group and 567 patients with oral cancers using Real-Time PCR to analyze the single nucleotide polymorphisms of IL-18 -137 G/C (rs187238) and -607 A/C (rs1946518) and to access the correlations between IL-18 SNP and clinical parameters including tumor stage, tumor size, lymphatic metastasis, distant metastasis and cell differentiation. Our statistical results showed that there was a significant difference between the frequency distribution of genetic variants in loci -137 of IL-18 in oral cancers and control groups. That is, there was a significant difference of susceptibility between patients with a GC genotype and a GG genotype (OR= 1.704, p=0.001) and between patients with GC+CC geneotype (OR= 1.706, p=0.001), We also found that the tumor staging was most likely in I/II, the tumor sizing was most likely less than T2, and the lymph node was most likely not to metastasis while IL-18 -607 SNP showed less correction with oral cancer. In sum, we believed that IL-18 -137 SNP is related to the susceptibility of patients with oral cancers in the central Taiwan and it could be considered as a correlation factor of the development of oral cancers.