PDF(Pubmed)
Abstract：
Current investigations have illuminated the essential roles played by circular RNAs (circRNAs) in driving breast cancer (BC) tumorigenesis. However, the functional implications and molecular underpinnings of most circRNAs in BC are not well characterized. Here, Circular RNA (circRNA) expression profiles were analyzed in four surgically resected BC cases along with adjacent non-cancerous tissues applying RNA microarray analysis. The levels and prognostic implications of circRREB1 in BC were subjected to quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). Experimental manipulation of circRREB1 levels in both in vivo and in vitro settings further delineated its role in BC cell growth, invasion, and metastasis. The mechanical verification of circRREB1\'s interaction with GNB4 was established through RNA pull-down, mass spectrometry, Western blot analysis, RNA immunoprecipitation assays (RIP), fluorescence ISH (FISH), and rescue experiments. We found that circRREB1 exhibited significant upregulation in BC tissues and cells, implicating its association with an unfavorable prognosis in BC patients. CircRREB1 knockdown elicited anti-proliferative, anti-migratory, anti-invasive, and pro-apoptotic effects in BC cells, whereas its upregulation exerted opposing influences. Follow-up mechanistic examinations suggested that circRREB1 might interact with GNB4 directly, inducing the activation of Erk1/2 signaling and driving BC progression. Our findings collectively indicate that the interplay of circRREB1 with GNB4 promotes Erk1/2 signaling, thereby fostering BC progression, and positioning circRREB1 as a candidate therapeutic target for intervention in BC.
摘要：
目前的研究已经阐明了环状RNA（circularRNAs，circRNAs）在驱动乳腺癌（BC）肿瘤发生中所起的重要作用。然而,BC中大多数circRNAs的功能含义和分子基础没有得到很好的表征。这里,应用RNA微阵列分析,在四个手术切除的BC病例以及邻近的非癌组织中分析环状RNA(circularRNA)表达谱。对BC中circRREB1的水平和预后意义进行定量实时PCR（qRT-PCR）和原位杂交（ISH）。体内和体外环境中circRREB1水平的实验操作进一步描绘了其在BC细胞生长中的作用，入侵,和转移。通过RNA下拉建立了circRREB1与GNB4相互作用的机械验证，质谱,蛋白质印迹分析,RNA免疫沉淀测定（RIP），荧光ISH(FISH)，和救援实验。我们发现circRREB1在BC组织和细胞中表现出显著的上调,提示其与BC患者预后不良有关。CircRREB1敲低引起抗增殖，反迁徙,防侵入性,和对BC细胞的促凋亡作用，而它的上调施加了相反的影响。后续机制检查表明，circRREB1可能直接与GNB4相互作用，诱导Erk1/2信号的激活和驱动BC进展。我们的发现共同表明，circRREB1与GNB4的相互作用促进了Erk1/2信号传导，从而促进BC进展，并将circRREB1定位为BC干预的候选治疗靶点。
