Breast cancer is the most common malignant tumor among women worldwide. Although increasing evidence indicates that long noncoding RNAs (lncRNAs) play critical roles during breast tumorigenesis and progression, the involvement of most lncRNAs in breast cancer remains largely unknown. In the current study, we demonstrated that LINC00665 promotes breast cancer cell proliferation, migration, and invasion. Accumulating evidence indicates that many lncRNAs can function as endogenous miRNA sponges by competitively binding common miRNAs. In this study, we demonstrated that LINC00665 functions as a sponge for miR-379-5p, reducing the ability of miR-379-5p to repress LIN28B. LINC00665 promoted breast cancer progression and induced an epithelial-mesenchymal transition-like phenotype via the upregulation of LIN28B expression. Clinically, LINC00665 expression was increased but miR-379-5p expression was decreased in breast cancer tissues compared with that in normal breast tissues in the TCGA database. Furthermore, the expression of LINC00665 was negatively related with miR-379-5p expression. Collectively, our results reveal the LINC00665-miR-379-5p-LIN28B axis and shed light on breast cancer therapy.

中文翻译：

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LINC00665通过调节miR-379-5p / LIN28B轴促进乳腺癌的进展。

乳腺癌是全世界女性中最常见的恶性肿瘤。尽管越来越多的证据表明，长的非编码RNA（lncRNA）在乳腺癌的发生和发展过程中起着至关重要的作用，但大多数lncRNA参与乳腺癌的情况仍是未知之数。在当前的研究中，我们证明了LINC00665可以促进乳腺癌细胞的增殖，迁移和侵袭。越来越多的证据表明，许多lncRNA可以通过竞争性结合常见的miRNA充当内源性miRNA海绵。在这项研究中，我们证明LINC00665充当miR-379-5p的海绵，降低了miR-379-5p抑制LIN28B的能力。LINC00665通过LIN28B表达的上调促进乳腺癌的进展并诱导上皮-间质转化样表型。临床上 与TCGA数据库中正常乳腺组织相比，乳腺癌组织中LINC00665表达增加，但miR-379-5p表达减少。此外，LINC00665的表达与miR-379-5p表达负相关。总的来说，我们的研究结果揭示了LINC00665-miR-379-5p-LIN28B轴，为乳腺癌治疗提供了启示。