Study On The Mechanism Of LINC01220 Promoting The Progression Of Endometrial Carcinoma

Background Endometrial carcinoma((EC))is a malignant tumor that occurs in the endometrium.It is the most common female reproductive tract tumor,accounting for 20-30% of the total.Its etiology and pathogenesis have not been fully elucidated,lack of effective early non-invasive diagnostic methods and indicators to evaluate the efficacy of drugs,especially high-grade,poorly differentiated or special types of EC are difficult to treat,and the prognosis is poor.Early detection and diagnosis of endometrial carcinoma will significantly prolong the survival of patients and improve their prognosis,which has important clinical significance.Long non-coding RNA(lnc RNA)is a kind of RNA molecule in eukaryotes,which can regulate gene expression at epigenetic,transcriptional and post-transcriptional levels,and has been confirmed to play an important role in tumor development.Elucidating the specific mechanism of lnc RNA in the development of endometrial carcinoma is helpful to improve the treatment of EC,which is of great significance to improve the survival rate of patients with EC.LINC01220 is located on the chromosome 14q24.3,the official full name: long inter-gene non-protein coding RNA1220.At present,there is no research report on the relationship between LINC01220 and tumor at home and abroad.Objective We investigate the mechanism of lnc RNA and MAPK signaling pathway in the occurrence and development of EC and the regulatory relationship between them.Methods The whole genome expression profile data of EC and paracancerous tissues in TCGA database were downloaded.LINC01220 expression in EC and paracancerous tissues of patients in our hospital was detected by q RT-PCR.Furthermore,the relationship between LINC01220 expression and clinicopathological features of EC patients was analyzed.After transfected with sh-LINC01220 and pc DNA-MAPK11 in EC cells,proliferative,colony formation abilities and apoptosis were determined by CCK-8,colony formation assay and flow cytometry,respectively.Western blot was conducted to determine the regulatory role of LINC01220 on MAPK11.Results High expression of LINC01220 in EC To explore the role of lnc RNAs in EC,we first downloaded the whole genome expression profile data of EC and paracancerous tissues in TCGA database.Among them,LINC01220 expression was markedly higher in EC tissues than that of paracancerous tissues,and the differential expression ratio was the highest.Next,q RT-PCR was performed to detect the expression of LINC01220 in EC and paracancerous tissues of patients in our hospital.The results also showed the higher expression of LINC01220 in EC tissues than that of paracancerous tissues of 30 EC patients enrolled in our hospital.Furthermore,the relationship between LINC01220 expression and clinicopathological features of EC patients was analyzed.As the data indicated,LINC01220 expression was associated with International Federation of Gynecology and Obstetrics(FIGO)of EC patients.EC patients with Grade III had higher expression of LINC01220 than thsoe with Grade I-II.Besides,EC patients with FIGO III-IV showed higher expression of LINC01220 compared with those with FIGO I-II.These data suggested that LINC01220 may be closely related to the development of EC.Knocking down of LINC01220 inhibited proliferation and induced apoptosis of EC cells To further explore the biological function of LINC01220,GSEA was conducted.The results showed that the main function of LINC01220 is enriched in apoptosis.Subsequently,sh-LINC01220 was constructed and verified for its transfection efficacy in three EC cell lines.Among them,LINC01220 expression markedly decreased in Ishikawa and RL95-2 cells,which were selected for the following experiments.CCK-8 results revealed that OD value of EC cells transfected with sh-LINC01220 gradually decreased after cell culture for 6 h,24 h,48 h,72 h,and 96 h,respectively.Similarly,colony formation abilities of Ishikawa and RL95-2 cells reduced after LINC01220 knockdown.Moreover,apoptotic rate of EC cells remarkably increased after LINC01220 knockdown.These results indicated that knockdown of LINC01220 can inhibit the proliferation and clonality of EC cells and promote apoptosis in vitro.MAPK11 promoted EC development and is regulated by LINC01220 We evaluated the correlation between LINC01220 expression and the genome-wide gene in EC expression profiles by the Cor package.The results showed that LINC01220 expression is positively correlated with MAPK11.A large number of studies have reported that MAPK11 serves as an oncogene in tumors.In this study,LINC01220 knockdown downregulated protein level of MAPK11 in Ishikawa and RL95-2 cells.Then the pc DNA-MAPK11 was transfected to Ishikawa and RL95-2cell lines and the results showed that the m RNA and protein level of MAPK11 were significantly up-regulated.Furthermore,MAPK11 overexpression enhanced proliferative rate of EC cells,as well as their colony formation ability.The above results indicated that MAPK11 promotes the progression of EC and is regulated by LINC01220.MAPK11 overexpression reversed the knockdown effect of LINC01220 on EC cells To further examine the roles of MAPK11 and LINC01220 in EC,we knocked down LINC01220 and overexpressed MAPK11 in EC cells at the same time.LINC01220 knockdown reduced proliferative ability of Ishikawa cells,which was enhanced after MAPK11 overexpression.Similar results were obtained in RL95-2 cells as well.Subsequently,colony formation ability was determined in co-transfected EC cells.LINC01220 knockdown markedly decreased colony formation ability of EC cells,whereas co-transfected cells showed an enhanced ability.Rescue experiments were also conducted to determine cell apoptosis in co-transfected EC cells.Previous experiments have already found the stimulated cell apoptosis after LINC01220 knockdown.However,apoptotic rate of EC cells markedly decreased after co-transfected with sh-LINC01220 and pc DNA-MAPK11.The above results suggested that MAPK11 can reverse the tumor suppressing effect of sh-LINC01220 on EC.Conclusions1.LINC01220 and MAPK11 play a central role of oncogenes in the occurrence and development of endometrial carcinoma and are expected to become potential therapeutic targets for endometrial cancer.2.Gene interference can effectively knock down the expression of LINC01220 in endometrial cancer cell lines Ishikawa and RL95-2,and the knockdown of LINC01220 can significantly affect the malignant biological behavior of endometrial cancer cells.3.LINC01220 may promote the proliferation and inhibit the apoptosis of endometrial cancer cell lines Ishikawa and RL95-2 by up-regulating MAPK11,and finally promote the occurrence and development of endometrial carcinoma.