Pou2F3 (POU class 2 homeobox 3) is found to be ubiquitously expressed in multiple epidermal layer cells to mediating proliferation. Although some POU factors exert a crucial regulation in mammary epithelial cells (MECs), the biological function of Pou2F3 is unclear. In this study, we aimed to investigate the endogenous potential effects of Pou2F3 on the proliferation and the roles of PI3K/AKT/mTOR signaling pathway in MECs. We used small interfering RNA to silence Pou2F3 expression. The interfering efficiency of Pou2F3 was confirmed by using RT-qPCR and Western blot. The cell viability and proliferation were indicated by Cell Counting Kit-8 and EdU assays. Flow cytometry was performed to evaluate the cell apoptosis in MECs. These results demonstrated that Pou2F3 potently suppressed the proliferation and induced the apoptosis of MECs. Consistently, the primary protein expressions of PI3K/AKT/mTOR signaling pathway were examined by Western blot. Pou2F3 silencing significantly increased the phosphorylation of PI3K, AKT and mTOR expressions. Moreover, Pou2F3 silencing reduced the ratio of BCL-2/BAX protein expression. Our findings show that Pou2F3 silencing can induce the proliferation of MECs and decrease the cell apoptosis, which suggest that Pou2F3 may serve as a potential upstream regulator of PI3K/AKT/mTOR signaling pathway in MECs.

Pou2F3（POU 2 类同源框 3）被发现在多个表皮层细胞中普遍表达以介导增殖。尽管一些 POU 因子在乳腺上皮细胞 (MEC) 中发挥着重要的调节作用，但 Pou2F3 的生物学功能尚不清楚。在本研究中，我们旨在研究 Pou2F3 对 MECs 增殖的内源性潜在影响以及 PI3K/AKT/mTOR 信号通路在 MECs 中的作用。我们使用小干扰 RNA 来沉默 Pou2F3 的表达。通过使用 RT-qPCR 和蛋白质印迹证实了 Pou2F3 的干扰效率。通过 Cell Counting Kit-8 和 EdU 测定显示细胞活力和增殖。进行流式细胞术以评估MEC中的细胞凋亡。这些结果表明，Pou2F3 有效地抑制了 MEC 的增殖并诱导了细胞凋亡。始终如一，Western blot检测PI3K/AKT/mTOR信号通路的主要蛋白表达。Pou2F3 沉默显着增加了 PI3K、AKT 和 mTOR 表达的磷酸化。此外，Pou2F3 沉默降低了 BCL-2/BAX 蛋白表达的比率。我们的研究结果表明，Pou2F3 沉默可以诱导 MECs 的增殖并减少细胞凋亡，这表明 Pou2F3 可能作为 MECs 中 PI3K/AKT/mTOR 信号通路的潜在上游调节因子。