Downregulation Of RbAp48 Inhibits Proliferation,Invasion,and Migration Of Endometrial Adenocarcinoma Cells

Background:Endometrial carcinoma is also called uterine cancer,are commonly seen in perimenopausal and postmenopausal elderly women,clinical symptoms are mainly prolonged menstruation,menorrhagia and abnormal vaginal bleeding after menopause,is one of the most common malignant tumor of the female reproductive system,in recent years,the incidence of endometrial carcinoma has kept on rising,it badly threaten the health of female.Endometrial cancer have many subtypes,such as gland carcinoma,serous papillary carcinoma,clear cell carcinoma and undifferentiated carcinoma.Adenocarcinoma is the most common subtype of endometrial cancer in patients,accounting for about 80%-90%.The incidence of endometrial cancer is related to natural environment,family heredity,abdominal obesity,? diabetes,history of ovarian cancer,early menarche,late menopause,inappropriate use female progestogen and infertility,and many other unkown factors.At present,for early patients,the mainly treament is surgery,chemotherapy and radiotherapy,significantly improve patients 5 years survival rate,but for patients with advanced stage,for most,the prognosis is poor.Therefore the early diagnosis of endometrial carcinoma,new treatment approach,therapeutic targets,and targeted therapy drugs is still continuing.PcG protein is an important transcription factor that regulates the growth and development of tumor,first discovered in fruit flies,it is highly conserved among species.PcG protein mainly composed of two protein complexes:PRC1 and PRC2,PRC1 contains at least 10 protein subunits,like RING1A/1B,BMI1;PRC2 was composed of EZH2,RbAp48,SUZ12 and EED.Retinoblastoma associated protein-48(RbAp48),as a subunit of PRC2,is a member of the WD-40 family relatively conservative in plants and animals,consist of CAF-1 complex?E(Z)complex?NURF complex?NuRD complex and SIN3 complex.In recent years,RbAp48 has received extensive attention in many kinds of tumors such as cervical cancer,lung cancer,breast cancer,colorectal cancer,liver cancer,leukemia,AIDS.Studies have shown that the main function of RbAp48 is to promote tumor cell proliferation,invasion and migration;but its inhibition function have also been reported.Until now,there is no report about the study of RbAp48 in endometrial adenocarcinoma.AimsThe purpose of this study is to explore the expression of RbAp48 in normal endometrium specimens(hyperplasia period,secretory period,menopause period),atypical hyperplasia and varying degrees of differentiation of endometrial adenocarcinoma samples and analyze the clinical relevance in adenocarcinoma tissues.To understand the effect of down-regulation RbAp48 expression on proliferation,invasion and migration in endometrial adenocarcinoma KLE,HEC1A cell lines.Searching for potential molecular targets for the treatment of endometrial adenocarcinoma,and to provide theoretical support for the next step of clinical treatment.Methods1)Specimen collection,IHC method was used to detect the expression of 72 cases of normal endometrium specimens(21 cases of hyperplasia period,secretory 27 cases,24 cases of menopause),27 cases of atypical hyperplasia and 52 cases of varying degrees of differentiation of endometrial adenocarcinoma samples RbAp48 protein.2)To analyze the relationship between RbAp48 expression and clinicopathological features in endometrial adenocarcinoma tissues.3)Using lentivirus interference endometrial adenocarcinoma KLE and HEC1A cell lines RbAp48 expression,Western blotting was used to detect the expression of RbAp48,and the interference sequence with high efficiency was selected for the next experiment.4)Plate clone formation,CCK8 and transwell invasion and migration experiments were used to observe the effect of down-regulation of RbAp48 on the function of endometrial adenocarcinoma KLE and HEC1A cell lines.5)SPSS 16.0 software was employed for data statistical analysis.Using Pearson chi-square test or Fisher's exact test to analyze the expression of RbAp48 in normal endometrial tissue,atypical hyperplasia and adenocarcinoma tissues,and RbAp48 expression clinical pathological features in adenocarcinoma tissues;Student's T-test was used to analyze the experiment of cell function.All the results are presented in mean± SD.P<0.05 was considered significance.Results1)The expression of RbAp48 in normal endometrium tissue(proliferative phase,secretory phase,menopausal period)and atypical hyperplasia tissue was lower.Endometrial adenocarcinoma tissues RbAp48 expression was higher than normal endometrium tissues and atypical hyperplasia tissues,and poorly differentiation of RbAp48 expression is higher than highly and moderately degree.2)In endometrial adenocarcinoma tissues,RbAp48 expression related with FIG)staging,distant metastasis,taken progestin,myometrial invasion,obesity and diabetes(P<0.01,P<0.05),but age,menarche age,dysmenorrhea,BMI,metastasis of pelvic lymph node,lymphvascular space involvement(P>0.05).3)In vitro,the proleration,invasion and migration of KLE and HEC1A cell lines decreased significantly after down-regulation of RbAp48(P<0.05).ConclusionsRbAp48 are expressed in normal endometrium tissues,endometrial atypical hyperplasia tissues and endometrial adenocarcinoma tissues.Endometrial adenocarcinoma tissues RbAp48 expression is significantly up-regulated suggesting that it may play an important role in endometrial adenocarcinoma.In vitro,down-regulation of RbAp48 inhibition of KLE and HEC1A cell lines proleration,invasion and migration ability.