The Effects And Mechanism Of CD105 In Drug-resistant Choriocarcinoma Cells

Chriocarcinoma is a highly aggressive tumor which usually occurs in women of child-bearing age.Due to the application of useful chemotherapeutic drugs,the overall curing rate of choriocarcinoma is higher than 90%and the majority of patients could achieve complete remission only rely on chemotherapy.With the 20%recurrent patients died of lacking effective therapy,however,drug-resistance is the main conditional factor of treatment.That emphasizes the necessity to find a new approach for the treatment of these patients with drug-resistance.But the mechanism response to chemoresistance in choriocarcinoma cells is not clearly defined.CD105(Endoglin)is a member of transforming growth factor-?(TGF-?)superfamily receptors.As a new mareker of tumor vesell endothelial cells,CD 105 has well specificity in the assessment of tumor angiogenesis.Recently,anti-angiogenic agents have received extensive attention as new therapeutic modalities,and CD 105 has become an additional target by which intratumoral angiogenesis may be targeted.However,endoglin may serve in a capacity beyond angiogenesis alone.Studies in the breast cancer and ovarian cancer suggest that endoglin is upregulated not only in tumor endothelial cells,but also in actual tumor cells,and is associated with poor prognosis.Additionally,we have found CD 105 is overexpressed in the drug-resistant choriocarcinoma cells than parental cells.Based on these results,we hypothesize that CD 105 is involved in the process of choriocarcinoma chemoresistance.This study may provide insight for the molecular mechanisim of drug-resistant choriocarcinoma and be a reference for future targetd treatment of chemoresistant choriocarcinoma patients.The main results of this study are as follows:1.CD105 is involved in the drug-resistance of choriocarcinoma cells,andinfluences the biological behaviors of choriocarcinoma cells.The drug-resistant choriocarcinoma cells,JEG-3/FR to FUDR and JEG-3/MR to MTX,were established by intermittent drug-induction.Western blot and real-time PCR showed that the protein and mRNA of CD 105 in JEG-3/FR and JEG-3/MR cells were upregulated than JEG-3 cells.Soluble CD 105 in the supernants of JEG-3/FR and JEG-3/MR were increased than that of JEG-3.Lentiviral vectors were used to establish the CD 105 overexpression cells,as well as CD 105 konckdown cells and their vector cells of JEG-3.RNA interference technology was performed to establish CD 105 konckdown cells of JEG-3/FR and JEG-3/MR.CCK-8 assay,transwell experiment and flow cytometry were applied to assess the drug-sensitivity,invasion and migration,and apopotosis of above cells respectivity.Results showed that overexpression of CD105 could decrease the drug-sensitivity,promote the invasion and migration,and inhibit the apoptosis of choriocarcinoma cells.Knockdown of CD 105 could reverse the chemoresistance of drug-resistant chriocarcinoma cells.2.CD105 mediates drug-resistance in choriocarcinoma cells throughBMP9/Smads pathway.Cell viability and drug-sensitivity were assessed after BMP9 added to CD 105 overexpression and knockdown cells.Results showed BMP9 treatment could promote cell proliferation and decrease drug-sensitivity.However,these functions couldn't be activated without CD 105 expression.Western blot,real-time PCR and immunofluorescence demonstrated the consistency of expressions between CD 105 and BMP9 in choriocarcinoma cells.Western blot experiments also indicated that BMP9 could induce Smad1/5/8 and Smad3 phosphorylation in dose-dependent and time-dependent manners,which proved that CD 105 mediated drug-resistance in choriocarcinoma cells through BMP9/Smads pathway.3.CD105 and BMP9 are associated with prognosis of choriocarcinoma patients.High expressions indicate high recurrent risk after chemotherapy.Immunohistochemical stainings of CD 105 and BMP9 in choriocarcinoma cells were performed on patients who received hysterectomy during chemotherapy.The relationships between clinical and pathological characteristics were analyzed.Results showed the expressions of CD 105 and BMP9 were consistent in choriocarcinoma and significantly associated with disease recurrence,but unrelated with patients age and serum p-hCG.In summary,this study explored the role of CD 105 in the drug-resistance of choriocarcinoma cells,its possible mechanism and clinical significance.These findings provided a reference for study of the mechanism in drug-resistant choriocarcinoma and confirmed a possible new approach for reversing the chemoresistance in chriocarcinoma patients.