5-氟尿嘧啶（5-FU）基治疗仍然用于结直肠癌（CRC）。表观遗传学因其可逆性和已知的调节功能，已成为癌症研究的焦点。在本研究中，我们将监测在5-FU基治疗开始时以及治疗3个月和6个月后的微小RNA（miRNA）水平的变化，并将其与其预测潜力相关联。在77名CRC患者的外周血中测量了5个miRNA（即miRNA223-3p，miRNA20a-5p，miRNA17-5p，miRNA19a-3p和miRNA7-5p）的表达水平，以及3个蛋白质PTEN，ERK和EGFR的表达。基线时，CRC患者的循环miRNA水平明显高于健康对照组。这个水平在接受3个月5-FU基治疗后显著降低，然后在6个月后显著增加，在反应良好的患者中明显高于对照组。miRNA19a-3p显示出在高ERK，EGFR和PTEN蛋白质水平的患者亚组中具有显著改变的模式，并且其在5-FU基治疗后的6个月水平对于疾病复发和进展的危险性显示出显著意义。© 2023. Springer Nature Limited.

Treatment with 5-fluorouracil (5-FU) based therapy is still used for colorectal cancer (CRC). Epigenetics has become a focus of study in cancer because of its reversibility besides its known regulatory functions. In this study, we will monitor the change in microRNAs (miRNAs) levels with 5-FU-based therapy at baseline and after 3 and 6 months of treatment to be correlated with their prognostic potential. The expression levels of 5 miRNAs, namely miRNA223-3p, miRNA20a-5p, miRNA17-5p, miRNA19a-3p, and miRNA7-5p, were measured in the peripheral blood of 77 CRC patients, along with the expression of 3 proteins PTEN, ERK, and EGFR. At baseline, CRC patients had significantly higher levels of circulating miRNAs than healthy controls. This level was reduced after 3 months of 5-FU-based therapy, then increased after 6 months significantly in responder patients compared to non-responders. MiRNA19a-3p showed that significant pattern of change in the subgroups of patients with high ERK, EGFR, and PTEN protein levels, and its 6 months level after 5-FU-based therapy showed significance for the hazard of increased risk of disease recurrence and progression.© 2023. Springer Nature Limited.