Breast cancer is a common malignant tumor suffered predominantly by women worldwide, which results in serious levels of morbidity and mortality. To control the effects of the cancer, it is critically important to elucidate the pathophysiological processes by which it occurs and develops. Reports have demonstrated that long noncoding RNAs perform a critical role in the development and metastasis of cancers. The lncRNA TTN‐AS1 is considered carcinogenic. Nevertheless, the importance and biological functions of TTN‐AS1 in breast cancer require greater exploration. In the current paper, we observed that TTN‐AS1 expression was significantly upregulated in breast cancer tissues/cells compared with those that are healthy. TTN‐AS1 enhanced the proliferation, migration, invasion, and epithelial‐mesenchymal transformation of breast cancer cells. Furthermore, a direct target of TTN‐AS1, miR‐139‐5p was negatively regulated. In addition, zinc finger E‐box binding homeobox 1 (ZEB1) is an important nuclear transcription factor, the expression of which is increased in multiple tumors. Here, we also found that ZEB1 is a target of miR‐139‐5p, of which TTN‐AS1 could regulate the expression through competition with miR‐139‐5p. That is, TTN‐AS1 promoted proliferation and invasion of breast cancer cells by interaction with the miR‐139‐5p/ZEB1 axis. In conclusion, the present study aimed to illustrate the significance of TTN‐AS1 in breast cancer metastasis and contribute to potentially innovative strategies for its treatment.

中文翻译：

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lncRNA TTN-AS1通过调节miR-139-5p/ZEB1轴促进乳腺癌细胞的增殖、侵袭和上皮间质转化。

乳腺癌是一种常见的恶性肿瘤，在全世界范围内主要由女性罹患，其发病率和死亡率非常高。为了控制癌症的影响，阐明癌症发生和发展的病理生理过程至关重要。报告表明，长非编码RNA在癌症的发生和转移中发挥着关键作用。lncRNA TTN-AS1 被认为具有致癌性。然而，TTN-AS1 在乳腺癌中的重要性和生物学功能需要更多的探索。在本文中，我们观察到与健康组织/细胞相比，乳腺癌组织/细胞中 TTN-AS1 的表达显着上调。TTN-AS1增强乳腺癌细胞的增殖、迁移、侵袭和上皮间质转化。此外，TTN-AS1 的直接靶标 miR-139-5p 受到负调控。此外，锌指E盒结合同源盒1（ZEB1）是一种重要的核转录因子，其表达在多种肿瘤中增加。在这里，我们还发现ZEB1是miR-139-5p的靶标，TTN-AS1可以通过与miR-139-5p竞争来调节其表达。也就是说，TTN-AS1通过与miR-139-5p/ZEB1轴相互作用促进乳腺癌细胞的增殖和侵袭。总之，本研究旨在阐明 TTN-AS1 在乳腺癌转移中的重要性，并为其治疗的潜在创新策略做出贡献。