吡脱匹林（THP）是临床实践中广泛使用的抗肿瘤药物，但其在治疗过程中的敏感性降低限制了其应用。本研究旨在调查LncRNA Miat敲除在改善THP敏感性中的作用和机制。我们通过CCK8、TUNEL、流式细胞术、伤口愈合实验、Transwell、Ca2+、实时定量PCR（RT-qPCR）和Western blot评估了Miat过表达/敲除对THP介导的4T1抗癌活性的作用。结果显示，与HC11小鼠乳腺上皮细胞相比，4T1小鼠乳腺癌细胞中Miat表达较高，而THP降低了4T1中的Miat表达。与单独应用THP相比，Miat敲除进一步降低了细胞存活率，促进了凋亡并抑制了迁移。这可能与4T1中钙离子的减少有关。总之，Miat敲除通过抑制钙通道增强了THP对4T1的敏感性。© 2023 Wiley Periodicals LLC.

Pirarubicin (THP) is a widely used antitumor agent in clinical practice, but its reduced sensitivity during treatment has limited its use. The aim of this study was to investigate the role and mechanism of LncRNA Miat knockdown in improving THP sensitivity. We assessed the role of Miat overexpression/knockdown on THP-mediated 4T1 anticancer activity by CCK8, TUNEL, flow cytometry, wound healing assay, Transwell, Ca2+ , real time quantitative PCR (RT-qPCR) and Western blot. The results showed that Miat expression was higher in 4T1 mouse breast cancer cells than in HC11 mouse mammary epithelial cells, while THP decreased Miat expression in 4T1. Miat knockdown in combination with further reduced cell viability, promoted apoptosis and inhibited migration compared to THP alone. This may be related to the reduction of calcium ions in 4T1. In conclusion, Miat knockdown enhanced the sensitivity of THP to 4T1 by inhibiting calcium channels.© 2023 Wiley Periodicals LLC.