AIM: To assess the expression of cyclooxygenase-2 (COX-2),nitric oxide synthase (iNOS), p53 and Ki-67 in gastric mucosaassociated lymphoid tissue (MALT) lymphoma and clarify the relationship between COX-2 expression a...AIM: To assess the expression of cyclooxygenase-2 (COX-2),nitric oxide synthase (iNOS), p53 and Ki-67 in gastric mucosaassociated lymphoid tissue (MALT) lymphoma and clarify the relationship between COX-2 expression and iNOS or p53 expression in these patients.METHODS: The expressions of COX-2, iNOS, p53 and Ki-67 were detected in 32 gastric MALT lymphoma specimens and 10 adjacent mucosal specimens by immunohistochemical Envision method.RESULTS: COX-2 and iNOS expressions were significantly higher in gastric MALT lymphoma tissues than those in adjacent normal tissues. The expression of COX-2 was observed in 22 of 32 cases of MALT lymphoma tissues (68.8%). A positive cytoplasmic immunoreactivity for iNOS was detected in 17 of 31 cases (53.1%). COX-2 expression in gastric MALT lymphoma tissues was positively correlated with iNOS expression (r=-0.448, P=0.010) and cell proliferative activity analyzed by Ki-67 labeling index (r=0.410, P=0.020).The expression of COX-2 protein did not correlate with age,sex, stage of disease, lymph node metastasis or differentiation.The accumulation of p53 nuclear phosphoprotein was detected in 19(59.4%) of tumors, p53 protein was expressed in 11 of 23 assessed LG tumors and in 8 of 9 assessed HG tumors.The difference of p53 positivity was found statistically significant between LG and HG cases (P=0.0302). The p53 accumulation correlated with advanced clinical stage (stage Ⅲ+Ⅳ vs stage Ⅰ+Ⅱ, P=0.017). There was a significant positive correlation between COX-2 expression and p53 accumulation status (r=0.403,/=0.022). The mean PI of Ki-67 in each grade group were 36.0±7.73% in HG and 27.4±9.21% in LG. High-proliferation rate correlated with HG tumors (r=0.419, P=0.017). The correlation coefficient showed a significant positive correlation between PI and COX-2 expression in MALT lymphoma patients (r=-0.410,P=0.020).CONCLUSION: COX-2 expresses in the majority of gastric MALT lymphoma tissues and correlates with cellular proliferation and iNOS expression. COX-2 overexpression is closely associated with p53 accumulation status, iNOS and COX-2 may play a synergistic role in the pathogenesis of gastric MALT lymphoma.展开更多
文摘AIM: To assess the expression of cyclooxygenase-2 (COX-2),nitric oxide synthase (iNOS), p53 and Ki-67 in gastric mucosaassociated lymphoid tissue (MALT) lymphoma and clarify the relationship between COX-2 expression and iNOS or p53 expression in these patients.METHODS: The expressions of COX-2, iNOS, p53 and Ki-67 were detected in 32 gastric MALT lymphoma specimens and 10 adjacent mucosal specimens by immunohistochemical Envision method.RESULTS: COX-2 and iNOS expressions were significantly higher in gastric MALT lymphoma tissues than those in adjacent normal tissues. The expression of COX-2 was observed in 22 of 32 cases of MALT lymphoma tissues (68.8%). A positive cytoplasmic immunoreactivity for iNOS was detected in 17 of 31 cases (53.1%). COX-2 expression in gastric MALT lymphoma tissues was positively correlated with iNOS expression (r=-0.448, P=0.010) and cell proliferative activity analyzed by Ki-67 labeling index (r=0.410, P=0.020).The expression of COX-2 protein did not correlate with age,sex, stage of disease, lymph node metastasis or differentiation.The accumulation of p53 nuclear phosphoprotein was detected in 19(59.4%) of tumors, p53 protein was expressed in 11 of 23 assessed LG tumors and in 8 of 9 assessed HG tumors.The difference of p53 positivity was found statistically significant between LG and HG cases (P=0.0302). The p53 accumulation correlated with advanced clinical stage (stage Ⅲ+Ⅳ vs stage Ⅰ+Ⅱ, P=0.017). There was a significant positive correlation between COX-2 expression and p53 accumulation status (r=0.403,/=0.022). The mean PI of Ki-67 in each grade group were 36.0±7.73% in HG and 27.4±9.21% in LG. High-proliferation rate correlated with HG tumors (r=0.419, P=0.017). The correlation coefficient showed a significant positive correlation between PI and COX-2 expression in MALT lymphoma patients (r=-0.410,P=0.020).CONCLUSION: COX-2 expresses in the majority of gastric MALT lymphoma tissues and correlates with cellular proliferation and iNOS expression. COX-2 overexpression is closely associated with p53 accumulation status, iNOS and COX-2 may play a synergistic role in the pathogenesis of gastric MALT lymphoma.
