LncRNA Transcriptomics Analysis And Functional Study In Cml Multidrug-resistant Cells

Background: The problem currently difficult for chronic myeloid leukemia(CML)to overcome is resistance.Although the use of tyrosine kinase inhibitors(TKIs)has achieved significant clinical effects,many patients have unexplained resistance.MDR remains a daunting challenge in the use of chemotherapy drugs and is a barrier to treating leukemia.ABCB1 is a well-known factor that causes MDR and is closely related to adverse tumor prognosis and recurrence.We performed lncRNA and mRNA sequencing on adriamycin-resistant CML cells and their matched sensitive cells to investigate the expression of lncRNAs and mRNAs in K562/ADR cells.Our research shows that inhibition of LINC02432 can increase the sensitivity of K562/ADR cells to doxorubicin.The mechanism indicates that inhibition of LINC02432 can reduce the expression of ABCB1.This study is to reveal the molecular mechanism of abnormal expression of ABCB1 mediated by lncRNA in leukemia cells and provide valuable experimental data for reversing the multidrug resistance of leukemia cells and improving the prognosis of patients.Objectives: The differentially expressed lncRNAs and mRNAs in K562/ADR cells were screened and identified,and the mechanism of lncRNA-mediated K562/ADR resistance was analyzed by bioinformatics.The mechanism of LINC02432 mediating ABCB1 overexpression in K562/ADR cells leading to multidrug resistance has been explored to provide an experimental basis for reversing the multidrug resistance of CML cells and enhancing their sensitivity to drugs.Methods: The differentially expressed lncRNAs were screened by analyzing the lncRNA sequencing of K562/ADR and K562 in CML.The function of the encoded transcripts was predicted by analyzing the GO and KEGG pathway enrichment.The target genes of lncRNA were predicted through the correlation analysis of the expression levels of lncRNAs and mRNAs.Cytoscape.exe was used to construct a co-expression network of differentially expressed lncRNAs and mRNAs.The gene expression levels of candidate differentially expressed lncRNAs in K562 and K562/ADR cells were detected by qRT-PCR.LINC02432 was inhibited by using siRNA and lncRNA smart silencer technology.CCK-8 was used to detect the cell growth and proliferation ability.The molecular mechanism that LINC02432 enhances the sensitivity of K562/ADR cells to doxorubicin was explored.Results: A total of 176 differentially expressed lncRNAs and 1801 mRNAs were detected.There were 91 up-regulated lncRNAs and 85down-regulated lncRNAs and 751 up-regulated mRNAs and 1050down-regulated mRNAs;GO analysis showed that the differentially expressed mRNAs were enriched in BP(biological process),CC(cell component),and MF(molecular function).The top three rankings of BP are "cellular metabolic process","metabolic process" and "organic substance metabolic process".The top three CC rankings are "intracellular part","intracellular" and "intracellular organelle".The top three MF rankings are "binding","protein binding",and "molecular function".KEGG pathway analysis shows that differentially expressed mRNAs are mainly enriched in cancer-related pathways and signaling pathways.For example "VEGF signaling pathway"(enriched 13 differential genes),"Chronic myeloid leukemia"(enriched 15 differential genes),"Renal cell carcinoma"(enriched 14 differential genes),"Melanoma"(enriched 15(Different genes),"Acute myeloid leukemia"(enriched 13 differential genes),"Bladder cancer"(enriched 10 differential genes),"Non-small cell lung cancer"(enriched 13 differential genes),"Viral carcinogenesis"(enriched 37 differential genes),and "Glioma"(enriched 16 differential genes).By constructing a network diagram of lncRNA and mRNA co-expression,LINC01419,CCDC26,LINC02432,and LINC01515 and ABCB1 may have an interaction relationship.LINC01515,CCDC26,LINC01419,LINC02432,DUXAP8,LINC00857,and ZEB1-AS1 are highly expressed in K562 / ADR.Using siRNA to knock down LINC01419,CCDC26,LINC02432,and LINC01515.Inhibiting the expression of LINC02432 can increase the sensitivity of K562/ADR to doxorubicin and decreace the gene expression of multidrug resistance gene ABCB1.Conclusion: The lncRNA expression profiles of doxorubicin-resistant cells K562/ADR and sensitive cells K562 were established.The expressions of LINC01515,CCDC26,LINC01419,LINC02432,DUXAP8,LINC00857 and ZEB1-AS1 were up-regulated in K562 / ADR,which may be related to the mechanism of K562 / ADR resistance.Inhibiting the expression of LINC02432 can increase the sensitivity of K562 / ADR to doxorubicin.The mechanism of enhancing drug sensitivity may be related to reducing the expression of ABCB1 and regulating the VEGF signaling pathway.