Department of Gastroenterology, The Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, PR China; Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha 410013, Hunan Province, PR China.
Department of Gastroenterology, The Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, PR China; Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha 410013, Hunan Province, PR China.
Life Sci. 2021 Jul 15;277:119569. doi: 10.1016/j.lfs.2021.119569. Epub 2021 May 4.
Long noncoding RNA (LncRNA) urothelial cancer associated 1 (UCA1) was dysregulated in colorectal cancers (CRC) and promoted tumor progression of CRC. The aims of this study are to further investigate the underlying mechanism.
Short hairpin RNAs (shRNAs) were applied for gene knockdown. microRNA mimic and pcDNA-UCA1 plasmids were transfected for miR-495 and UCA1 overexpression, respectively. MTT was applied to determine cell viability and sensitivity of 5-fluorouracil (FU). Transwell assays were performed to evaluate cell migration/invasion. Angiogenesis was evaluated by tube formation. Western blotting and quantitative PCR were utilized for protein and mRNA detection, respectively. The interaction of UCA1, miR-495 and SP1/SP3 were explored by dual-luciferase assay. RNA pulldown was adopted to determine the UCA1/miR-495 interaction.
UCA1 was significantly upregulated in CRC tissues. UCA1 enhanced cell proliferation, migration/invasion, angiogenesis, epithelial-mesenchymal transition, and resistance to 5-FU in CRC cell lines. MiR-495 was inversely correlated to the expression of UCA1. The results indicated that UCA1 sponged miR-495, leading to the disinhibition of SP1/SP3 expression. SP1/SP3 induced the expression of DNA methyltransferases and, in turn, contributed to UCA1 mediated tumor-promoting actions. Reduction of SP1/SP3 exerted anti-cancer effects, which can be reversed by forced expression of UCA1.
UCA1-miR-495-SP1/SP3 axis is dysregulated in CRC and contributed to malignant phenotypes of CRC. UCA1-SP1/SP3 may form a positive feedback loop in CRC.
长链非编码 RNA（LncRNA）尿路上皮癌相关 1（UCA1）在结直肠癌（CRC）中失调，并促进 CRC 的肿瘤进展。本研究旨在进一步探讨其潜在机制。
应用短发夹 RNA（shRNA）进行基因敲低。转染 microRNA 模拟物和 pcDNA-UCA1 质粒分别用于 miR-495 和 UCA1 的过表达。MTT 用于测定细胞活力和 5-氟尿嘧啶（FU）的敏感性。Transwell 测定用于评估细胞迁移/侵袭。血管生成通过管形成评估。Western blot 和定量 PCR 分别用于蛋白和 mRNA 的检测。双荧光素酶测定用于探索 UCA1、miR-495 和 SP1/SP3 的相互作用。RNA 下拉法用于确定 UCA1/miR-495 相互作用。
UCA1 在 CRC 组织中显著上调。UCA1 增强 CRC 细胞系中的细胞增殖、迁移/侵袭、血管生成、上皮-间充质转化和对 5-FU 的耐药性。miR-495 与 UCA1 的表达呈负相关。结果表明，UCA1 海绵吸附 miR-495，导致 SP1/SP3 表达的去抑制。SP1/SP3 诱导 DNA 甲基转移酶的表达，进而有助于 UCA1 介导的肿瘤促进作用。减少 SP1/SP3 发挥抗癌作用，而强制表达 UCA1 可逆转这种作用。
UCA1-miR-495-SP1/SP3 轴在 CRC 中失调，导致 CRC 的恶性表型。UCA1-SP1/SP3 可能在 CRC 中形成正反馈环。
