口腔癌為台灣十大癌症之一。本研究之目的在於了解口腔癌及其前期病變之COX-2活性及表現，並評估蜂膠是否具抑制COX-2表現之能力，進而預防口腔癌之發生。以Western blot 觀察口腔粘膜下纖維化 (OSF)、白斑症 (Leukoplakia)及口腔癌的組織中COX-2的表現，結果發現，口腔癌組織中COX-2表現強度最高，其次為白斑，OSF最低。將各種口腔病變細分成輕、中及重等三種程度，則發現COX-2表現強度與口腔病變之嚴重性成正相關。以免疫組織法觀察組織中COX-2表現之情形，發現口腔癌組顯著地高於白斑組及OSF組，另外，口腔癌病變組織較周圍的發炎組織有較顯著之COX-2蛋白質表現。以50ng/ml TPA (12-o-teradecanoylphorbol-13-acetate) 可誘使口腔鱗狀上皮細胞 (KB cell) COX-2之蛋白質過度表現，而在高劑量的蜂膠萃取物處理下，則能明顯抑制COX-2蛋白質的表現。由本研究之結果可知，口腔癌前病變中，可能以白斑癌化之機會最大，其次為OSF。此外，蜂膠具有抑制COX-2之效果，對於口腔癌之預防可能具有功效，但仍有待進一步探討。
Oral cancer has been one of the ten major cancers in Taiwan. This study was to know the COX-2 expression in precancerous lesions tissue and to evaluated the inhibition of propolis on COX-2 expression. By Western blot assay, the COX-2 expression was great in the oral cancer tissue followed by leukoplakia and OSF. The levels of COX-2 expression also showed positive correlation with the severity of each lesions. Immunohistochemistry analysis showed that COX-2 expression in oral cancer tissue was very strong and much higher than in leukoplakia and OSF tissue. Furthermore, Oral cancer tissue indicated higher COX-2 level when compared to its adjacent inflammatory tissue. In vitro study demonstrated that proplis markedly suppressed COX-2 expression of KB cell which was induced by TPA (50ng/ml). All the results showed that moderate leukoplakia could play an important role in the malignant mutation. Moreover, the COX-2 expression of KB cell was decreased by propolis extract. This also suggested that propolis extract was
probably a chemopreventive material for oral cancer.
