| The dualistic model of endometrial carcinoma divided endometrial carcinoma into two subtypes of which one is estrogen-related(typeI),the other estrogen-unrelated (type II) .Type I carcinomas are the most common type of endometrial carcinoma, endometrioid carcinoma, develop from endometrial hyperplasia in setting of excess estrogen exposure, express estrogen(ER) and progester- one receptors(PR),and show microsatellite instability (MIN),PTEN and K-ras mutation and a good prognosis, but not p53 mutation and loss of p16 expression. In contrast,type II carcinomas,a minority of endometrial carcinomas,best represented by serous carcinoma, develop from atrophic endometrium ,are negative for ER and PR,show P53 mutation , often loss of p16 expression and a poor prognosis,but infrequently PTEN mutation. Endometrioid adenocarcinoma accounts for up to 80% of the endometrial carcinoma and is characterized by expression of ER and PR and PTEN mutation. The purpose of my experiments are to study the expression, clinical significance and correclation of ER ,PR and PTEN in endometrioid adenocarcinoma ,to study the PTEN expression in hyperplasia of endometrium, and provide the basic theory for the early diagnoses and genetic and hormonal therapy of endometrial carcinoma. Twenty-nine paraffin-embedded endometrioid adenoc- arcinoma specimens and ten paraffin-embedded normal hyperplasia, ten paraffin-embedded simple hyperplasia , ten paraffin-embedded complex hyperplasia, ten paraffin-embedded atypical hyperplasia specimens were obtained from the Department of Pathology of the First Affiliated Hospital of Jilin University between 2000 and 2002.According to the FIGO surgical-pathologic staging, there are 19 cases in I staging ,3 cases in II staging ,4 cases in III staging ,and 3 cases in IV staging .All cases hadn't chemotherapy and radiotherapy before operation. Dewaxed rehydrated 5um paraffin sections underwent microwave antigen retrieval before adding primary anti-PTEN antibody, anti-ER antibody, and anti-PR antibody. Then, immunohistochemistry methods (S-P) was used to stain. According to the intensity of nuclear or somatic staining and the extent (percentage of positive cells), the positive or negative staining of PTEN, ER, and PR was evaluated. Exact probabilities in 2×2 table was applied in statistical analysis.Results:The negative expression rate of PTEN in atypical hyperplasia and endometrioid adenocarcinoma is highter than simple and complex hyperplasia and significant difference.The negative expression rate of PTEN is 55.2% and is related to histologic grade and myometrial invasion whether or not (P<0.05),but not associated with surgical-pathologic staging and depth of myometrial invasion(P>0.05).The positive expression rate of ER and PR is separately 62.1% and 65.5% and significantly associated with pathological grade(P<0.05),but irrelevant to stage and depth of myometrial invasion (P>0.05).The positive expression of ER accouts for up to 92.3% in the positive expression of PTEN ,but 37.5% in the negative expression of PTEN.The positive expression of PR is 92.3% in the positive expression of PTEN, but 43.8% in the negative expression of PTEN. The tumor suppressor gene PTEN, also know as MMAC1 or TEP1,maps to chromosome 10q23.3 and encodes a dual-specificity protein phosphatase and lipid phosphatase, which is able to induce G1 cell cycle block and/or apoptosis via negative regulation of the phosphoinositide-3ˊ-kinase/AKT signaling pathway. PTEN can inhibit the generation and progress of tumor. PTEN mutations or deletion have been observed in multiple forms of human cancer,however,PTEN mutations are most frequently found in the ednometrial carcinoma(32%-55%) specially endomertrioid adenocarcinoma .The loss of PTEN expression is highter than PTEN mutation because of the other factor. Our study with endometrioid adenocarcinoma confirm the hight loss rate of PTEN expression. There are different opinions to the correlation of PTEN protein expression with... |
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