大肠癌（CRC）是世界范围内第三高发的恶性肿瘤，也是癌症相关死亡的最关键原因。尽管分子和手术靶向药物的最新进展已经提高了CRC患者的治疗效果，但CRC患者的5年死亡率仍然非常低。证据表明，微小RNA（miRNA）在CRC的发展和扩散中起着重要作用。miRNA是一种短非编码RNA，据显示能够调控肿瘤抑制基因和癌基因的表达。miRNA表达谱已经被用于临床实践中，作为评估癌症患者肿瘤发生、进展和对药物反应的诊断和预测生物标志物。通过调控其靶基因，失调的miRNA与恶性特征相关（如增强的增殖和侵袭能力，细胞周期异常，逃避凋亡和促进血管生成）。本综述提供了循环miRNA、肿瘤抑制性和致癌性miRNA以及CRC失调miRNA的潜在原因的最新总结。此外，我们将探讨miRNA在CRC耐药中的关键作用。© 2023. 作者，独家授权给Springer Science+Business Media, LLC，Springer Nature的一部分。

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.