Background:N6-methyladenosine(m6A)RNA modification has been demonstrated to be a significant regulatory process in the progression of various tumors,including breast cancer.Fat mass and obesity-associated(FTO)enzyme,i...Background:N6-methyladenosine(m6A)RNA modification has been demonstrated to be a significant regulatory process in the progression of various tumors,including breast cancer.Fat mass and obesity-associated(FTO)enzyme,initially known as the obesity-related protein,is the first identified m6A demethylase.However,the relationship between FTO and breast cancer remains controversial.In this study,we aimed to elucidate the role and clinical significance of FTO in breast cancer and to explore the underlying mechanism.Methods:We first investigated the expression of FTO in breast cancer cell lines and tissues by quantitative reverse transcription-PCR(qRT-PCR),Western blotting,and immunohistochemistry.Wound healing assay and Transwell assay were performed to determine the migration and invasion abilities of SKBR3 and MDAMB453 cells with either knockdown or overexpression of FTO.RNA sequencing(RNA-seq)was conducted to decipher the downstream targets of FTO.qRT-PCR,luciferase reporter assay,and Western blotting were employed to confirm the existence of the FTO/miR-181b-3p/ARL5B axis.The biological function of ADP ribosylation factor like GTPase 5B(ARL5B)in breast cancer cells was evaluated by wound healing assay and Transwell invasion assay.Results:High FTO expression was observed in human epidermal growth factor receptor 2(HER2)-positive breast cancer,predicting advanced progression(tumor size[P<0.001],nuclear grade[P=0.001],peritumoral lymphovascular invasion[P<0.001),lymph node metastasis[P=0.002],and TNM stage[P=0.001])and poor prognosis.Moreover,FTO promoted cell invasion and migration in vitro.Mechanistically,RNA-seq and further confirmation studies suggested that FTO up-regulated ARL5B by inhibiting miR-181b-3p.We further verified that ARL5B also displayed carcinogenic activity in breast cancer cells.Conclusion:Our work demonstrated the carcinogenic activity of FTO in promoting the invasion and migration of breast cancer cells via the FTO/miR-181b-3p/ARL5B signaling pathway.展开更多
背景与目的近年来,研究已证实在包括乳腺癌在内的多种肿瘤的进展中,RNA的N6-甲基腺苷(N6-methyladenosine,m^(6)A)修饰是一个重要的调节过程。脂肪量与肥胖相关(fat mass and obesityassociated,FTO)酶,最初被称为肥胖相关蛋白,是第一...背景与目的近年来,研究已证实在包括乳腺癌在内的多种肿瘤的进展中,RNA的N6-甲基腺苷(N6-methyladenosine,m^(6)A)修饰是一个重要的调节过程。脂肪量与肥胖相关(fat mass and obesityassociated,FTO)酶,最初被称为肥胖相关蛋白,是第一个被发现的m^(6)A去甲基化酶。然而,FTO与乳腺癌之间的关系目前还存在争议。本研究旨在阐明FTO在乳腺癌中的作用及其临床意义,并探讨其作用机制。方法我们首先用定量逆转录–PCR(quantitative reverse transcription-PCR,qRT-PCR)、Western blotting和免疫组织化学法检测了乳腺癌细胞系和组织中FTO的表达。用划痕实验和Transwell实验检测了FTO过表达或表达敲降的SKBR3和MDA-MB453细胞的迁移和侵袭能力。采用RNA测序(RNA sequencing,RNA-seq)分析FTO的下游靶分子。采用qRT-PCR、荧光素酶报告基因分析和Western blotting证实FTO/miR-181b-p/ARL5B轴。用划痕实验和Transwell侵袭实验检测了ADP核糖基化因子样蛋白GTP酶5B(ADP ribosylation factor like GTPase 5B,ARL5B)在乳腺癌细胞中的生物学功能。结果人表皮生长因子受体2(human epidermal growth factor receptor 2,HER2)表达阳性的乳腺癌中FTO高表达,其高表达与肿瘤进展[肿瘤大小(P<0.001)、核分级(P=0.001)、癌旁淋巴及血管浸润(P<0.001)、淋巴结转移(P=0.002)及TNM分期(P=0.001)]及不良预后相关。另外,体外实验证实FTO可增强乳腺癌细胞的迁移及侵袭。在机制方面,RNA测序和进一步的验证实验均表明,FTO可通过抑制miR-181b-3p上调ARL5B的表达。我们进一步证实了ARL5B在乳腺癌细胞中发挥了致癌活性。结论本研究证实了FTO可通过FTO/miR181b-3p/ARL5B通路促进乳腺癌细胞的迁移及侵袭。展开更多
文摘Background:N6-methyladenosine(m6A)RNA modification has been demonstrated to be a significant regulatory process in the progression of various tumors,including breast cancer.Fat mass and obesity-associated(FTO)enzyme,initially known as the obesity-related protein,is the first identified m6A demethylase.However,the relationship between FTO and breast cancer remains controversial.In this study,we aimed to elucidate the role and clinical significance of FTO in breast cancer and to explore the underlying mechanism.Methods:We first investigated the expression of FTO in breast cancer cell lines and tissues by quantitative reverse transcription-PCR(qRT-PCR),Western blotting,and immunohistochemistry.Wound healing assay and Transwell assay were performed to determine the migration and invasion abilities of SKBR3 and MDAMB453 cells with either knockdown or overexpression of FTO.RNA sequencing(RNA-seq)was conducted to decipher the downstream targets of FTO.qRT-PCR,luciferase reporter assay,and Western blotting were employed to confirm the existence of the FTO/miR-181b-3p/ARL5B axis.The biological function of ADP ribosylation factor like GTPase 5B(ARL5B)in breast cancer cells was evaluated by wound healing assay and Transwell invasion assay.Results:High FTO expression was observed in human epidermal growth factor receptor 2(HER2)-positive breast cancer,predicting advanced progression(tumor size[P<0.001],nuclear grade[P=0.001],peritumoral lymphovascular invasion[P<0.001),lymph node metastasis[P=0.002],and TNM stage[P=0.001])and poor prognosis.Moreover,FTO promoted cell invasion and migration in vitro.Mechanistically,RNA-seq and further confirmation studies suggested that FTO up-regulated ARL5B by inhibiting miR-181b-3p.We further verified that ARL5B also displayed carcinogenic activity in breast cancer cells.Conclusion:Our work demonstrated the carcinogenic activity of FTO in promoting the invasion and migration of breast cancer cells via the FTO/miR-181b-3p/ARL5B signaling pathway.
