1.The Functions And Molecular Mechanism Of Long Noncoding RNA LINC01089 Inhibits Breast Cancer Through Wnt/B-catenin Signaling 2.The Expression And Functions Of Zinc Finger Protein ZNF582 In Breast Cancer

PART 1 THE FUNCTIONS AND MOLECULAR MECHANISM OF LONG NONCODING RNA LINC01089 INHIBITS BREAST CANCER THROUGH WNT/B-CATENIN SIGNALINGPurposes: With the ongoing advance of genome analysis platforms,it has been showed that about 80-90% of the human genome is transcribed into RNA,while less than 2% of the whole genome sequences have the capacity to encode for proteins.Emerging evidence has indicated crucial roles for long noncoding RNAs in breast cancer development and progression.Our study aims to investigate the biological functions and underlying mechanisms of LINC01089 in breast cancer(BC).Methods: 1.The expression and clinical data from the online databaseThe Cancer Genome Atlas(TCGA)were downloaded from the c Bio Portal for Cancer Genomics.Then we analyzed the correlations between LINC01089 expression and the clinical factors of breast cancer patients.2.RT-q PCR assay was performed to verify the expression of LINC01089 in breast cancer tissues and cell lines.3.The biological functions of LINC01089 in breast cancer were determined in vitro.4.Western blot and RT-q PCR assay were used to explore the underlying mechanism between LINC01089 and Wnt/β-catenin signaling pathway in breast cancer.Results: 1.Low LINC01089 expression was significantly correlated with the age,lymph node metastasis,and poor prognosis of patients with BC.According to the results of the multivariate Cox regression analysis,LINC01089 was an independent prognostic indicator of overall survival and recurrence-free survival.2.LINC01089 was downregulated in BC tissues and cell lines.3.Functional studies revealed a significant suppression of proliferation,migration,and invasion of LINC01089-overexpressing cells.Additionally,increased LINC01089 expression induced cell apoptosis and cell cycle arrest in G0/G1 phase.Loss-of-function assays partially confirmed these results.4.Mechanistically,LINC01089 blocked the Wnt/β-catenin pathway and the expression of downstream target genes by inhibiting β-catenin expression at the transcriptional level.Conclusion: Based on our results,LINC01089 potentially represents anovel prognostic indicator in BC patients,and functions as a tumor suppressor through blocking the Wnt/β-catenin pathway.PART 2 THE EXPRESSION AND FUNCTIONS OF ZINC FINGER PROTEIN ZNF582 IN BREAST CANCERPurposes: Zinc finger protein family is one of the most common transcription factors in mammals.It can regulate gene expression at the level of transcription and translation by specifically binding to DNA or RNA sequences.ZNF582,a member of zinc finger protein family,is a newly discovered tumor suppressor gene.This part aims to explore the inhibitory effect of ZNF582 on breast cancer.Methods: 1.The association between ZNF582 expression and methylation levels of its DNA promoter region was measured by online database Meth HC and Disease Meth.2.RT-q PCR assay was carried out to identify the expression level of ZNF582 in breast cancer tissues and cell lines.3.The correlation between ZNF582 expression and survival of breast cancer patients was predicted by online database Kaplan-Meier Plotter.4.In vitro studies were performed to investigate the roles of ZNF582 in breast cancer.Results: 1.The methylation level of ZNF582 was negatively correlated with ZNF582 expression in DNA promoter region.2.The expression profiles of ZNF582 were significantly downregulated in breast cancer tissues and several cell lines.3.The low expression level of ZNF582 was negatively correlated with the recurrence-free survival and distantdisease free survival of breast cancer patients.4.Function studies were showed that the abilities of cell proliferation,migration and invasion were notably suppressed in ZNF582-overexpressing cells.In addition,increased ZNF582 expression induced cell apoptosis and cell cycle arrest in G2/M phase.Conclusion: Zinc finger protein ZNF582 is downregulated in BC,and acts as a tumor suppressor to inhibit tumor cell proliferation and invasion.