Clinicopathological Significance Of Major Histocompatibility Complex Class Ⅰ-related Chain A Expression In Tongue Squamous Cell Carcinoma

OBJECTIVE: To investigate the clinicopathological significance of MICA expression in tongue squamous cell carcinoma.METHODS: MICA expression in 43 patients of squamous cell carcinoma of tongue and 10 cases of normal tongue mucous were analyzed by immunohistochemical SP menthod. Statistical analysis was carried out using SPSS11.5 package among patients categorized according to most disease parameters tested(age, gender, tumor size, grade of differentiation, regional lymph node status and disease stage).RESULTS: MICA was expressed at spinous cells, vascular epithelial cells , lymphocytes and plasmocyte, but not at stratum corneum, basement membrane and muscle cells in normal oral mucosa and paratumor tissue. In tongue cancer tissue, more than 80% tumor cells stained positive for MICA. MICA was positively expressed at infiltrated tissue. The positive granules as superficial yellow, buffy or brown were positioned at cytoplasm and membrane. The extent of MICA expression was significantly different between normal mucosa, tumor-adjacent tissue and tumor tissue(P<0.05), with normal mucosa lower than tumor-adjacent tissue (P < 0.05). MICA expression in tumor-adjacent tissue was higher than tumor tissue, and the difference between well-differentiated tumor and low-differentiated tumor was statistically significant (P < 0.05). The extent of MICA expression was not significantly different between normal mucosa and well-differentiated tumor(P > 0.05),also between normal mucosa and low-differentiated normal(P>0.05). The extent of MICA expression was not significantly different in age, gender, tumor size, regional lymph node status and disease stage (P>0.05). CONCLUSION: The results suggest that the expression of MICA may be an important feature of tongue squamous cell carcinoma. MICA may be considered a promising immunotherapy target of tongue cancer.