Breast cancer (BC) is one of the most common malignancies globally in women, with high mortality rate as a result of tumour metastasis. MicroRNAs play vital roles in the occurrence and development of human cancer. This study aimed to investigate the biological roles of miR-1323 in BC. The expression levels of miR-1323 were detected by quantitative real-time PCR assay. The effect of miR-1323 on BC cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assay. Wound healing analysis and Matrigel Transwell assay were conducted to evaluate miR-1323-mediated BC cell migration and invasion. A luciferase reporter assay was used to test the target of miR-1323. We found that miR-1323 levels were downregulated in BC tissues and serums. Low-miR-1323 levels were associated with lymph node metastasis and advanced clinical stage. Tumour protein D52 (TPD52) was identified as a direct target of miR-1323. Low expression of miR-1323 contributed to the overexpression of TPD52 leading to enhanced BC progression. Our findings suggest that silencing of miR-1323 enhances BC development by regulating TPD52 expression, suggesting that miR-1323 and TPD52 may serve as potential therapeutic targets for BC treatment.

中文翻译：

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MicroRNA-1323下调通过靶向肿瘤蛋白D52促进乳腺癌细胞的迁移和侵袭。

乳腺癌（BC）是全球女性中最常见的恶性肿瘤之一，由于肿瘤转移而导致较高的死亡率。MicroRNA在人类癌症的发生和发展中起着至关重要的作用。这项研究旨在调查miR-1323在卑诗省的生物学作用。通过实时定量PCR检测miR-1323的表达水平。通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴化物和集落形成测定法确定miR-1323对BC细胞增殖的影响。进行伤口愈合分析和Matrigel Transwell分析以评估miR-1323介导的BC细胞迁移和侵袭。萤光素酶报告基因测定用于测试miR-1323的靶标。我们发现在BC组织和血清中miR-1323的水平下调。低miR-1323水平与淋巴结转移和晚期临床阶段有关。肿瘤蛋白D52（TPD52）被确定为miR-1323的直接靶标。miR-1323的低表达导致TPD52的过表达，导致BC进程增强。我们的发现表明，miR-1323的沉默通过调节TPD52的表达来增强BC的发展，这表明miR-1323和TPD52可以作为BC治疗的潜在治疗靶点。