Previous studies had shown that microRNA-638 (miR-638) exhibited different effects in malignant tumors. Moreover, the function of miR-638 has not been reported in breast cancer. Hence, we designed this research to explore the function of miR-638 in breast cancer. Firstly, miR-638 expressions were measured in breast cancer tissues via RT-qPCR. Protein expressions were detected through immunocytochemical (IHC) assay and western blot analysis. Then, Cell Counting Kit-8 (CCK-8) assay and Transwell assay were conducted to observe proliferation and motility of the cells. Dual luciferase assay was performed to confirm the binding site between miR-638 and Homeobox protein Hox-A9 (HOXA9). Reduced expression of miR-638 was detected in breast cancer. And low miR-638 expression was related to poor prognosis in patients with breast cancer. Functionally, the viability, migration, and invasion of the breast cancer cells were suppressed by miR-638 overexpression. Furthermore, miR-638 can directly bind to HOXA9, and increased expression of HOXA9 was also detected in breast cancer. In particular, HOXA9 upregulation can impair anti-tumor effect of miR-638 in breast cancer, and miR-638 can hinder the Wnt/β-cadherin pathway and epithelial-mesenchymal transition (EMT) in breast cancer. miR-638 inhibits breast cancer progression through binding to HOXA9.

中文翻译：

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MicroRNA-638通过靶向HOXA9和抑制Wnt/β-cadherin通路抑制乳腺癌的进展

先前的研究表明，microRNA-638（miR-638）在恶性肿瘤中表现出不同的作用。此外，尚未报道 miR-638 在乳腺癌中的功能。因此，我们设计了这项研究来探索 miR-638 在乳腺癌中的功能。首先，通过 RT-qPCR 在乳腺癌组织中测量 miR-638 的表达。通过免疫细胞化学 (IHC) 测定和蛋白质印迹分析检测蛋白质表达。然后，进行细胞计数试剂盒8（CCK-8）测定和Transwell测定，观察​​细胞的增殖和运动。进行双荧光素酶测定以确认 miR-638 和同源盒蛋白 Hox-A9 (HOXA9) 之间的结合位点。在乳腺癌中检测到 miR-638 的表达降低。miR-638低表达与乳腺癌患者预后不良有关。在功能上，miR-638过表达抑制了乳腺癌细胞的活力、迁移和侵袭。此外，miR-638 可以直接与 HOXA9 结合，并且在乳腺癌中也检测到 HOXA9 的表达增加。特别是，HOXA9 上调可削弱 miR-638 在乳腺癌中的抗肿瘤作用，而 miR-638 可阻碍乳腺癌中的 Wnt/β-钙粘蛋白通路和上皮间质转化（EMT）。miR-638 通过与 HOXA9 结合抑制乳腺癌进展。和 miR-638 可以阻碍乳腺癌中的 Wnt/β-钙粘蛋白通路和上皮间质转化 (EMT)。miR-638 通过与 HOXA9 结合抑制乳腺癌进展。和 miR-638 可以阻碍乳腺癌中的 Wnt/β-钙粘蛋白通路和上皮间质转化 (EMT)。miR-638 通过与 HOXA9 结合抑制乳腺癌进展。