Expression Of Tumor Suppreor Gene PTEN And Cell Cycle Regulator P27 In Endometrial Adnocarcinoma

PrefaceThe inactivation of anti - oncogene and the activation of oncogene have a close relationship with the pathogenesis of tumor. And, The inactivation of anti - oncogene plays a more important role in this procession than the activation inactivation. Anti - oncogene PTEN ( phosphatase and tension homologue deleted on chromosome 10) has been focused on ever since it was found in 1997,tuta-tion or deletion on this gene or its abnormal protein expression can be relative to the pathogenesis of many tumors. Recent studies indicate that PTEN has a high mutation rate in the tissues of endometrial adenocarcinoma, and the mutation of PTEN can be reflected by deletion of protein expression. PTEN gets PIP₃ de-phosphorylated and lowers the level of intracell PIP₃, blocks Akt protein kinase (PKB ) , by its activity of fatty phosphatase ( PTEN has twice phosphatase activities, the other is protein tyrosine phosphatase) . And so,blocks cell cycle at Gl phase , or activates cell apoptosis, that is a negative regulation. P27 is a new cyclin dependent kinase inhibitor reported in 1994,which has a close relationship with the regulation of cell cycle. It participates the regulation of cell cycle, controls the development and differentiation of cells, blocks entry to S phase from Gl phase, and inhibits cell cleavage and cell generation. In studies of colon carcinoma, breast carcinoma, pulmonary carcinoma and endocrine secretion carcinoma, people that P27kipl protein expression is relevant to the development, differentiation, metastasis and progonosis. There have been reports about the effects of P27kip1 to endometrial adenocarcinoma abroad, but few are seen in our country. The over expression of PTEN can mediate development inhabitation of glioblast at G₀/G₁ phase, which blocks entry to S phase from G₁ phase. PTEN can also activate P27kipl combind with cyclin E/cyclin dependent enzyme 2conjugate, so depress the activity of cyclin dependent enzyme 2. It blocks entry to S phase from G₁phase, stagnating the cell cycle at G₁ phase. We examined the non - expression of PTEN and P27 in tissues of endometrial adenocarcinoma , at different patho - classification levels, different muscular layer infiltration levels and different FIGO stages, and compared it with that of endometrium a-typical hyperplasia and that of normal endometrium tissues, to find the relationship between expression deletion of PTEN/P27 and endometrial adenocarcinoma , the relationship between expression deletion of PTEN/P27 in endometrial adenocarcinoma and the pathological features mo( endometrial adenocarcinoma.MethodsExpression of PTEN and P27 in 42 cases of endometrial adenocarcinoma , 8 atypical hyperplasia and 12 proliferative phase of endometrium, diagnosed by first affiliated hospital of china medical university during dec,2002 and apr, 2004 , were detected immunohistochemically. in these cases . 42 cases of endometrial adenocarcinoma includes 19 G{ ,12 G2 and 11 G3 by differentiation ,or 8 non -obvious infiltration, 22 shallow infiltration and 12 deep infiltration by infiltration, or 26 stage I ,8 stage Hand 8 stage HI by FIGO staging.ResultsPTEN was mainly in cytoplasm ,and P27 mainly in nucleus, the positive rate of PTEN in proliferative phase of endometrium, atypical hyperplasia and endometrial adenocarcinoma were 100% , 50% and 38.19% respectively. Correspondingly, P27 were 100% ,40% and 40.47%. PTEN and P27 both expressed in proliferative phase of endometrium. The expression of PTEN in endometrial adenocarcinoma was the lowest. The difference in positive rate of PTEN or P27 between endometrial adenocarcinoma and normal endometrium was significant (p < 0.05) , and the difference in non - expression of them beween atypical hyperplasia and endometrial adenocarcinoma was not significant(p > 0.05). No obvious relationship between the expression of PTEN in endometrial adenocarcinomaand FIGO staging , Pathematology classing or muscular layer infiltration was found. As the maligant extent of endometrial adenocarcinoma augmenting, the expression of PTEN showed a decreased trend. Following the increasement of FIGO staging, the decreasement of Pathematology classing and the deepening of muscular layer infiltration , the expression of P27 showed a decreased trend (p < 0.01). The expression of PTEN was positively correlated to P27 in endometrial adenocarcinoma.ConclusionsPTEN and P27 are related to endometrial adenocarcinoma. But no obvious relationship between the expression of PTEN in endometrial adenocarcinoma and FIGO staging , Pathematology classing or muscular layer infiltration was found. As the maligant extent of endometrial adenocarcinoma augmenting, the expression of PTEN shows a decreased trend. Following the increasement of FIGO staging, the decreasement of Pathematology classing and the deepening of muscular layer infiltration , the expression of P27 shows a decreased trend(p <0. 01). P27 is closely related to the prognosis of endometrial adenocarcinoma. these imply that PTEN and P27 play an important role in endometrial adenocarcinoma , and detecting the expression of PTEN and P27 conduces to the diagnosis and prognosis of endometrial adenocarcinoma.