Expression of Melanoma Antigen-A in Canine Normal and Mesenchymal Neoplastic Tissues

• Main Authors: Yin-Chu Chen, 陳音竹
• Other Authors: Shih-Chieh Chang
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/23933974640093120159

碩士 === 國立中興大學 === 獸醫學系暨研究所 === 98 === Melanoma antigen-A, MAGE-A, which contained 12 members from A1 to A12 was discovered since 1991. These antigens expressed in various types of tumors but limited expressed in normal human placentas and testicles. However, researches about MAGE-A in dogs were rare. The aims of this study were: first, to establish an immunohistochemistry protocol with MAGE-A antibody 6C1 for canine tissues. Second, to investigate the expression of MAGE-A in canine normal and neoplastic tissues. Third, concerning about canine melanoma, to investigate the expression of MAGE-A subtypes and the correlation between MAGE-A expression rate, clinical characteristics and surviving. Immunohistochemical staining with an antibody 6C1 against MAGE-A1, -A2, -A3, -A6, -A10, -A11, and -A12 was used to detect the expression of MAGE-A in 18 normal tissues, 26 melanomas, 5 nasal malignant tumors, 6 oral malignant tumors, 40 round cell tumors, and 37 soft tissue sarcomas. Besides, according to the highly conserved MAGE-A genes, a pair of primers were used to amplify the specific sequences of each subtype by PCR. The expression of each subtype was affirmed by DNA sequencing. According to our results, normal tissues including skin, skin adnexa, gingiva, muscle, adipose tissue, connective tissue, salivary gland, lymph node, intestine mucosa, mammary gland, liver, cartilage, oviduct, endometrium, cerebellum, and cerebrum showed the negative immunoreaction except for testicular germ cells and ovarian oocytes. The expression rate varied with the tumor type, 75.00% (21/28) of melanomas, 52.50％ (21/40) of round cell tumors, and 40.50％ (15/37) of soft tissue sarcomas showed the positive immunoreaction. Additionally, MAGE-A sequences from one normal testis and nine melanomas were analyzed. MAGE-A sequence from normal canine testis showed 68.6% identity with human MAGE-A2 (NM_005361) and 91.4% identity with canine MAGE-A10 (XM_549339). MAGE-A in canine testicle shared 71.7-95.3% of identities with canine melanoma sequences generated in this study. Based on its limited expression in canine normal tissues and widely expression in various types of canine mesenchymal tumors, MAGE-A might be used for antigen-specific cancer immunotherapy which was regarded as a promising treatment for metastasis cancer, or tumors which were difficult to be excised completely.