RESUMO
BACKGROUND: The heterogeneity of breast tumors presents a challenge in disease management, necessitating an understanding of the molecular mechanisms driving breast tumorigenesis. Aberrant expression of microRNAs is known to promote tumor growth and progression. Our previous RNA-sequencing dataset revealed the upregulation of miR-362-5p and miR-454-3p in breast tumors. We investigated potential role of miR-362-5p and miR-454-3p in breast cancer using MDAMB231 and MCF7 cell lines. METHODS AND RESULTS: The expression of miR-362-5p and miR-454-3p were altered in MCF7 and MDAMB231 using mimics and inhibitors. The effect on cell viability, cell cycle progression and migration was assessed using Alamar blue assay, flow cytometry and wound healing assay. Further, the expression of potential target genes were measured using real-time PCR. Our results indicated that an increased expression of miR-362-5p promoted cell growth and survival in MCF7, but decreased cell migration. In contrast, miR-362-5p overexpression reduced cancer cell growth, survival and migration in MDAMB231. Overexpression of miR-454-3p was oncogenic in both cell lines but suppressed migration in the aggressive cell line MDAMB231. CONCLUSION: Two microRNAs, miR-362-5p and miR-454-3p, were evaluated for functional activity in breast cancer cell lines and they showed increased proliferative signals and tumorigenic properties.
Assuntos
Neoplasias da Mama/metabolismo , Proliferação de Células/genética , MicroRNAs/metabolismo , Transdução de Sinais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ciclo Celular/genética , Movimento Celular/genética , Sobrevivência Celular/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , MicroRNAs/genética , Oncogenes , Interferência de RNA , Transfecção , Regulação para Cima/genéticaRESUMO
Breast cancer is a major cause of cancer-related death in women worldwide. Non-coding RNAs are a potential resource to be used as an early diagnostic biomarker for breast cancer. Circular RNAs are a recently identified group of non-coding RNA with a significant role in disease development with potential utility in diagnosis/prognosis in cancer. In this study, we identified 26 differentially expressed circular RNAs associated with early-stage breast cancer. RNA sequencing and two circRNA detection tools (find_circ and DCC) were used to understand the circRNA expression signature in breast cancer. We identified hsa_circ_0006743 (circJMJD1C) and hsa_circ_0002496 (circAPPBP1) to be significantly up-regulated in early-stage breast cancer tissues. Co-expression analysis identified four pairs of circRNA-miRNA (hsa_circ_0023990 : hsa-miR-548b-3p, hsa_circ_0016601 : hsa_miR-1246, hsa_circ_0001946 : hsa-miR-1299 and hsa_circ_0000117:hsa-miR-502-5p) having potential interaction. The miRNA target prediction and network analysis revealed mRNA possibly regulated by circRNAs. We have thus identified circRNAs of diagnostic implications in breast cancer and also observed circRNA-miRNA interaction which could be involved in breast cancer development.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , RNA Circular/genética , RNA Mensageiro/genética , Neoplasias da Mama/genética , Feminino , Humanos , Prognóstico , Análise de Sequência de RNA , Taxa de SobrevidaRESUMO
Breast cancer is the most common malignancy among women, with the highest incidence rate worldwide. Dysregulation of long noncoding RNAs during the preliminary stages of breast carcinogenesis is poorly understood. In this study, we performed RNA sequencing to identify long noncoding RNA expression profiles associated with early-stage breast cancer. RNA sequencing was performed on six invasive ductal carcinoma (IDC) tissues along with paired normal tissue samples, seven ductal carcinoma in situ tissues, and five apparently normal breast tissues. We identified 375 differentially expressed lncRNAs (DElncRNAs) in IDC tissues compared to paired normal tissues. Antisense transcripts (~ 58%) were the largest subtype among DElncRNAs. About 20% of the 375 DElncRNAs were supported by typical split readings leveraging their detection confidence. Validation was performed in n = 52 IDC and paired normal tissue by qRT-PCR for the identified targets (ADAMTS9-AS2, EPB41L4A-AS1, WDFY3-AS2, RP11-295M3.4, RP11-161M6.2, RP11-490M8.1, CTB-92J24.3, and FAM83H-AS1). We evaluated the prognostic significance of DElncRNAs based on TCGA datasets and report that overexpression of FAM83H-AS1 was associated with patient poor survival. We confirmed that the downregulation of ADAMTS9-AS2 in breast cancer was due to promoter hypermethylation through in vitro silencing experiments and pyrosequencing.