Significance Of The Expression Of P16 Protein And Ki-67 Antigen In Gastric MALT Lymphoma

Background and Objective:Gastric lymphoma has high incidence rate in the primary lymphoma in digestive tract. The origin of gastric MALT lymphoma is the extranodal marginal zone B cell in folliculus lymphaticus of gastric mucosa, with the background of inflammation by the persistent infection of Helicobactor Pylori. The primary low potential malignant lymphomas in gastric are almost MALT lymphomas.Our study is to detect the expression of pl6 protein and Ki-67 antigen in gastric MALT lymphoma and normal gastric mucosa, to investigate the clinical significance of the pl6 protein and Ki-67 antigen expression in the occurrence and development of gastric MALT lymphoma.Materials and Methods:To select the 47 samples of gastric MALT lymphoma by pathologic diagnosis in the department of pathology of the PLA general hospital from March, 1993 to June, 2005. The 20 samples of comparison are obtained from the gastric ulcer or duodenal ulcer after surgery. By using immunohistochemial methods, we detected the expression of pl6 protein and Ki-67 antigen in 20 cases of normal gastric tissue and 47 cases of gastric MALT lymphoma.Results:The positive rate of pl6 protein is 21.3% and 90% in gastric MALT lymphoma and normal gastric tissue respectively. The positive rate of pl6 protein in gastric MALT lymphoma was lower than that in normal gastric tissue (p<0.05) . The positive rate of p16 protein in gastric MALT lymphoma with lymph nodemetastasis was lower than that without lymph node metastasis (p<0.05) . The expression of pl6 was related to the degree of lymph node metastasis. The positive rate of Ki-67 LI (labelling index) in gastric MALT lymphoma was higher than that in normal gastric tissue. The expression of Ki-67 hasn't been found to have relation to the degree of lymph node metastasis. A negative correlation was found between the expression of pl6 protein and the Ki-67 LI (p<0.05); the cell proliferative activity in gastric MALT lymphoma with a negative pl6 expression was significantly higher than that in those with a positive pl6 expression.Conclusions:1. The positive rate of pl6 protein in gastric MALT lymphoma was lower than that in normal gastric tissue. The positive rate of pl6 protein in gastric MALT lymphoma with lymph node metastasis was lower than that without lymph node metastasis. The deletion of pl6 was related to the occurrence and development of gastric MALT lymphoma.2. The positive rate of Ki-67 LI (labelling index) in gastric MALT lymphoma was higher than that in normal gastric tissue. The expression of Ki-67 hasn't been found to have relation to the degree of lymph node metastasis.3. A negative correlation was found between the expression of pl6 protein and the Ki-67 L I. Deletion of pl6 gene and subsequent irregulation of cell cycle play an important role in the occurrence and development of gastric MALT lymphoma. Detection of p16 protein will contribute to the prognosis and therapy of gastric MALT lymphoma. Both pl6 and Ki-67 may help to predict the possibility of lymth node metastasis and prognosis in gastric MALT lymphoma.