Differentially Expressed Long Noncoding RNAs And Regulatory Mechanism Of LINC02407 In Human Gastric Adenocarcinoma

Research background:Gastric cancer is one of the most common malignant tumors in China and worldwide.It has been accompanied by high morbidity and mortality.The main reason for high mortality is that early gastric cancer is difficult to detect in time,and advanced gastric cancer is prone to metastasis.Drug treatment The effect is also not satisfactory.Although researchers have found some new promising diagnostic and therapeutic targets in gastric cancer in recent years,more new targets still need to be explored.Long non-coding RNA(lnc RNA)refers to non-coding RNA longer than 200 nt.In recent years,a large number of research results have found that lnc RNA has very important regulatory functions in cells and is involved in various biological regulation and pathways.The interaction between lnc RNA and tumors is the focus of current research at home and abroad.Abnormally expressed lnc RNA is often considered as a potential diagnostic biomarker and therapeutic target.At present,studies have found that lnc RNA has important biological functions in gastric cancer,but there are still huge unknowns about its more functional mechanisms,and we urgently need to explore further.Research objectives:Obtain differentially expressed lnc RNAs in gastric cancer and adjacent cancers,analyze their impact on patient prognosis and possible related mechanism pathways,and further select one of the lnc RNA-LINC02407,which is highly expressed in gastric cancer and has a negative effect on the patient's prognosis,and further study the LINC02407 pair The role and mechanism of gastric cancer.Research methods:1.The data of 343 gastric adenocarcinoma samples and 30 adjacent control tissue samples from the TCGA(The Cancer Genome Atlas)public database were extracted and analyzed by R language package.2.The survival time of the samples was extracted,and single-factor survival analysis and COX regression analysis were performed on the differentially expressed lnc RNA.Differentially expressed m RNA was analyzed by GO and KEGG functional enrichment.3.Lnc RNA database,UCSC Genome Brower and RNAfold online tools were used to analyze the basic characteristics of LINC02407.ORFfinder and UCSC Genome Brower were used to analyze the open reading frame and codon mutation rate of LINC02407 to study its coding ability.4.The relative content of LINC02407 in gastric cancer tissues and cells was detected by total RNA extraction,reverse transcription and real-time quantitative PCR.5.Lentivirus and small interfering RNA technology were used to construct an experimental grouping model of LINC02407 overexpression,knockdown and control cells.6.RNA fluorescence in situ hybridization was used to detect the subcellular localization of LINC02407.7.The cell growth,apoptosis and migration ability of each experimental grouping model were examined by CCK8 cell proliferation experiment,apoptosis experiment and cell scratch test.8.A nude mouse model was constructed to study the effect of LINC02407 on gastric cancer tumors.9.Bioinformatics methods predict mi RNAs that may bind to LINC02407,and detect them by double luciferase activity experiments.10.The mi RNA mimics were used to reconstruct experimental groups to study the effects of related mi RNAs on cell proliferation,apoptosis and invasion.11.The bioinformatics method was used to predict the target protein of related mi RNA again,and it was detected and determined by western blot.Research results:1.The lnc RNA with differential expression in gastric cancer and its visualization results were obtained from the TCGA database.Differentially expressed lnc RNAs in gastric cancer were analyzed by single factor Kaplan-Meier analysis and multifactor COX analysis.It was found that in the COX regression model,LINC01210 was protective lnc RNA,LINC01614,LINC01537,LINC02407,C15orf54,and CYMP-AS1 were risk lnc RNA.2.GO function annotation and KEGG pathway enrichment analysis of m RNAs with differential expression in gastric cancer,and found that their functions and mechanisms may be related to signal pathways such as PI3K-Akt and MAPK.3.It was found that the differential expression and survival analysis of LINC02407 in gastric cancer were significantly different,and there were few related studies.Therefore,LINC02407 was selected for experimental research on functional mechanism.4.Characteristic analysis found that LINC02407 was located at chr12: 76252275-76297735 and was 966 nt in length.It was a positive-strand lnc RNA.5.LINC02407 is highly expressed in human gastric cancer tissues and gastric cancer cells.LINC02407 can promote the proliferation and increase the invasiveness of gastric cancer cells,inhibit the apoptosis of gastric cancer cells,and also promote the growth of gastric cancer tumors in nude mice.6.Bioinformatics and double luciferase activity test experiments found that hsa-mi R-6845-5p and hsa-mi R-4455 can be combined with LINC02407.7.Functional experiments suggest that hsa-mi R-6845-5p and hsa-mi R-4455 can inhibit the growth and invasion of gastric cancer cells,and promote apoptosis.8.Bioinformatics methods predicted the target proteins of hsa-mi R-6845-5p and hsa-mi R-4455 and ranked them.Western blot results suggested that the expression of ADGRD1 protein and hsa-mi R-6845-5p and hsa-mi R-4455 were all negatively correlated,that is,the LINC02407-mi R-6845-5p/mi R-4455-ADGRD1 ce RNA mechanism network was finally formed.Research conclusion:1.This study first used the TCGA database for data mining and analysis,and obtained lnc RNA differential expression profiles in gastric cancer.At the same time,the COX regression model learned that LINC01210,LINC01614,LINC01537,LINC02407,C15orf54,and CYMP-AS1 had 6 higher lnc RNAs.Sensitivity and specificity,of which LINC01210 is a protective lnc RNA and the rest are dangerous lnc RNAs.2.LINC02407 is a positive-strand lnc RNA,highly expressed in human gastric cancer tissues and cells.3.LINC02407 can promote the growth and increase the invasiveness of gastric cancer cells,inhibit the apoptosis of gastric cancer cells,and at the same time promote the growth of gastric cancer tumors in nude mice.4.LINC02407 can exert its cancer-promoting effect through the LINC02407-mi R-6845-5p/mi R-4455-ADGRD1 ce RNA mechanism network.Its further mechanism may be related to the expression of ADGRD1 protein,which activates c AMP-PKA and c AMP-AKT/PI3 K signaling pathway related.5.LINC02407 is expected to become a new diagnostic and therapeutic target for gastric cancer.