RESUMEN
<p><b>OBJECTIVE</b>To explore the expressions of P33ING1, P53 and their relationships with apoptosis in anal canal carcinoma (ACC).</p><p><b>METHODS</b>The expressions of P33ING1, P53 proteins were measured by immunohistochemistry method (SP method), and apoptosis was detected in 42 cases with ACC, 36 cases with anal canal adenoma (ACA) or anal canal papilloma (ACP), and 40 cases with paraanal inflammatory mass(PAIM).</p><p><b>RESULTS</b>The positive expression rates of P33ING1 and P53 proteins were 40.5% (17/42), 97.2% (35/36) and 97.5% (39/40), 50.0% (21/42), 22.2% (8/36) and 27.5% (11/40) respectively, and the average apoptosis indexes(AI) were (10.27+/- 1.23) per thousand, (42.75+/- 0.98) per thousand and (42.67+/- 1.04) per thousand respectively in ACC, ACA or ACP and PAIM. There were significant differences in the positive expression rates of P33ING1, P53 and apoptosis index between ACC and the other two groups respectively (P< 0.05). Among 21 cases of ACC with positive expression of P53 protein,there were 18 cases with P33ING1 negative expression.</p><p><b>CONCLUSIONS</b>P33ING1 expression decrease in ACC, which may play an important role in the carcinogenesis and progression of ACC. P33ING1 and P53 may have an synergistic effect of suppressing cell growth and accelerating cell apoptosis.</p>