Bladder cancer (BCa) ranks among the predominant malignancies affecting the urinary system. Cisplatin (CDDP) remains a cornerstone therapeutic agent for BCa management. Recent insights suggest pivotal roles of circular RNA (circRNA) and N6-methyladenosine (m6A) in modulating CDDP resistance in BCa, emphasizing the importance of elucidating these pathways to optimize cisplatin-based treatments. Comprehensive bioinformatics assessments were undertaken to discern circ_104797 expression patterns, its specific interaction domains, and m6A motifs. These findings were subsequently corroborated through experimental validations. To ascertain the functional implications of circ_104797 in BCa metastasis, in vivo assays employing CRISPR/dCas13b-ALKBH5 were conducted. Techniques, such as RNA immunoprecipitation, biotin pull-down, RNA pull-down, luciferase reporter assays, and western blotting, were employed to delineate the underlying molecular intricacies. Our investigations revealed an elevated expression of circ_104797 in CDDP-resistant BCa cells, underscoring its pivotal role in sustaining cisplatin resistance. Remarkably, demethylation of circ_104797 markedly augmented the potency of cisplatin-mediated apoptosis. The amplification of circ_104797 in CDDP-resistant cells was attributed to enhanced RNA stability, stemming from an augmented m6A level at a distinct adenosine within circ_104797. Delving deeper, we discerned that circ_104797 functioned as a microRNA reservoir, specifically sequestering miR-103a and miR-660-3p, thereby potentiating cisplatin resistance. Our findings unveil a previously uncharted mechanism underpinning cisplatin resistance and advocate the potential therapeutic targeting of circ_104797 in cisplatin-administered patients with BCa, offering a promising avenue for advanced BCa management.

中文翻译：

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N6-甲基腺苷修饰的 circ_104797 通过充当 RNA 海绵维持膀胱癌的顺铂耐药性

膀胱癌（BCa）是影响泌尿系统的主要恶性肿瘤之一。顺铂 (CDDP) 仍然是 BCa 治疗的基石治疗药物。最近的研究表明，环状 RNA (circRNA) 和 N6-甲基腺苷 (m6A) 在调节 BCa 中的 CDDP 耐药性中发挥着关键作用，强调了阐明这些途径以优化基于顺铂的治疗的重要性。我们进行了全面的生物信息学评估，以辨别 circ_104797 表达模式、其特定相互作用域和 m6A 基序。这些发现随后通过实验验证得到证实。为了确定 circ_104797 在 BCa 转移中的功能意义，采用 CRISPR/dCas13b-ALKBH5 进行了体内测定。RNA 免疫沉淀、生物素 Pull-down、RNA Pull-down、荧光素酶报告基因测定和蛋白质印迹等技术被用来描述潜在的分子复杂性。我们的研究揭示了 circ_104797 在 CDDP 耐药性 BCa 细胞中表达升高，强调了其在维持顺铂耐药性中的关键作用。值得注意的是，circ_104797 的去甲基化显着增强了顺铂介导的细胞凋亡的效力。CDDP 抗性细胞中 circ_104797 的扩增归因于 RNA 稳定性的增强，这是由于 circ_104797 内不同腺苷的 m6A 水平增加所致。通过更深入的研究，我们发现 circ_104797 作为 microRNA 库发挥作用，特异性地隔离 miR-103a 和 miR-660-3p，从而增强顺铂耐药性。我们的研究结果揭示了一种以前未知的顺铂耐药机制，并提倡在接受顺铂治疗的 BCa 患者中使用 circ_104797 进行潜在的治疗靶点，为先进的 BCa 管理提供了一条有希望的途径。