The Study Of PTPRM Participating In The Progression Of Epithelial Ovarian Cancer Through Wnt/β-catenin

Objective:Ovarian cancer is the third most common gynecological malignant tumor in the world,and its mortality rate ranks first among gynecological malignant tumors,among which epithelial ovarian cancer(EOC)accounts for the majority,which is diagnosed in the late stage of tumor dissemination and metastasis,and its survival rate is low.Protein tyrosine phosphatase receptor type M(PTPRM)is a receptor tyrosine phosphatase,which is involved in the occurrence and development of many malignant tumors.However,the role and exact mechanism of PTPRM in EOC are still unclear.In this study,the expression of PTPRM in epithelial ovarian tumors was detected to analyze the relationship between PTPRM and clinical pathological features and survival prognosis of EOC,and the effects of PTPRM on proliferation and metastasis of EOC cells were further detected in vitro,so as to explore the role and mechanism of PTPRM on the progression and metastasis of EOC and provide experimental basis for new target of EOC treatment.Method:1.We included 57 cases of epithelial ovarian cancer who were hospitalized and operated in our hospital from January 2012 to January 2014,and 18 cases of borderline ovarian epithelial tumors,30 benign epithelial tumors and 15 normal ovarian oviduct tissues were selected as control group.The expression of PTPRM was detected by immunohistochemistry,and its relationship with clinicopathological features and prognosis was analyzed.GEPIA database and Kaplan-Meier Plotter database were used to analyze the relevance between PTPRM expression and the prognosis of ovarian cancer patients.2.The PTPRM gene in ovarian cancer cells SKOV3 and A2780 was knockdown or overexpressed by si RNA or adenovirus,respectively.The knockdown efficiency was detected by q PCR and Western Blotting.The overexpression of PTPRM gene was confirmed by GFP expression and Western Blotting.Then the cell proliferation,clone formation,scratch healing and migration changes of ovarian cancer cell lines were investigated.3.In ovarian cancer cells SKOV3 and A2780 that knocked down or overexpressed the PTPRM gene,the expression of EMT-related proteins was detected by Western Blotting.The effect of PTPRM on Wnt/β-catenin signaling pathway was detected by cellular immunofluorescence and Western Blotting.In SKOV3 cells PTPRM was knocked down and Wnt/β-catenin signaling pathway specific inhibitor XAV939 was added,then detected the migration of SKOV3 cells by cell migration assay.Result:1.The positive rate of PTPRM expression was the highest in normal ovarian and oviduct tissues,followed by benign ovarian epithelial tumors and borderline ovarian epithelial tumors.And patients with ovarian epithelial carcinoma showed the lowest PTPRM expression.There was significantly difference of PTPRM expression among the four groups(P< 0.05).2.The expression of PTRPM in EOC was significantly different in the group comparison of patients’ age,clinical stage,maximum tumor diameter,and tumor recurrence(P<0.05).The positive rate of PTPRM expression decreases significantly with age,clinical stage,and tumor recurrence.The larger the tumor,the higher the positive expression rate of PTPRM.Compared with patients with negative PTPRM expression,the survival rate of patients with positive PTPRM expression was higher,but without significantly difference(Log-rank = 2.878,P=0.090).Univariate Cox screening showed that the expression of PTPRM had no significant ralation to the prognosis of ovarian cancer patients(P=0.128).3.Based on the data from GEPIA database,the expression of PTPRM in ovarian cancer tissues was significantly lower than normal tissues(P< 0.05).The overall survival(OS)in patients with high PTPRM expression was significantly higher than cases with low PTPRM expression(P<0.05).The disease free survival(DFS)in the high PTPRM expression group was also higher,however the difference was not statistically significant(P>0.05).In Kaplan-Meier Plotter database,compared to patients with low PTPRM expression,the OS in the high PTPRM expression group was higher,but without statistically significant(P>0.05).The progression free survival(PFS)was significantly improved in cases with high PTPRM expression(P < 0.05).4.The proliferation level,clonal unit formation ability and migration ability of human ovarian cancer cells were significantly inhibited by PTPRM overexpression.On the contrary,the proliferation level,clonal unit formation ability and migration ability of human ovarian cancer cells were significantly enhanced after knocking down PTPRM gene(P<0.05).5.Through the overexpression of PTPRM,the expression of E-cadherin was increased while the expression of N-cadherin and Vimentin decreased.On the contrary,the expression of E-cadherin was decreased with increased expression of N-cadherin and Vimentin by knocking down of PTPRM gene.6.Overexpression of PTPRM significantly inhibited the entry of β-catenin protein into the nucleus and significantly inhibited the protein level of β-catenin in the nucleus,while knocking down PTPRM significantly promoted the entry of β-catenin protein into the nucleus and significantly increased the protein ofβ-catenin in the nucleus level.After inhibiting the expression of endogenous PTPRM and inhibiting the activity of the Wnt/β-catenin signaling pathway,excessive cell migration caused by the reduction of PTPRM expression was effectively controlled.Conclusion:1.The expression of PTPRM in EOC is low,and the positive rate of PTPRM expression decreases significantly with the increase of EOC stage and tumor recurrence,suggesting that PTPRM plays a role in the progression of EOC as a tumor suppressor.Negative expression of PTPRM may predict adverse clinical outcomes in EOC patients.2.Overexpression of PTPRM inhibited the proliferation and migration of human ovarian cancer cells.PTPRM may inhibit the proliferation and metastasis of EOC by inactivation of Wnt/β-catenin signaling pathway and inhibiting EMT.