Department of Pathology, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China.
Department of Infectious Diseases, The First Affiliated Hospital of Jinan University, Guangdong, Guangzhou 510632, P.R. China.
Mol Med Rep. 2022 Apr;25(4). doi: 10.3892/mmr.2022.12639. Epub 2022 Feb 16.
Drug resistance is a major problem to overcome in the treatment of cancer; therefore, identifying therapeutic targets for drug resistance is a point of focus in the field of cancer research. Long non‑coding RNAs (lncRNAs) and microRNAs (miRs) not only affect gene expression regulation during cell proliferation, but also have several potential roles in the drug resistance of malignant tumors. Reverse transcription‑quantitative PCR was used to detect the expression levels of DDX11 antisense RNA 1 (DDX11‑AS1) and miR‑497 in MCF‑7 and MDA‑MB‑231 cells. Cell transfection techniques were used to interfere with the expression levels of DDX11‑AS1 and miR‑497. Cell Counting Kit‑8 and MTT assays were used to detect cell viability. A colony formation assay was used to detect cell proliferation. Wound‑healing and Transwell assays were performed to measure the levels of cell migration and invasion. Western blotting was used to analyze the expression levels of migration‑associated proteins, and immunofluorescence and western blotting were used to determine the expression levels of the epithelial‑mesenchymal transition‑related proteins E‑cadherin and N‑cadherin, respectively. A luciferase reporter gene assay was used to verify the targeted binding of DDX11‑AS1 and miR‑497. The present study demonstrated that the expression levels of lncRNA DDX11‑AS1 were markedly increased in paclitaxel (PTX)‑resistant breast cancer cell lines. By contrast, knockdown of DDX11‑AS1 expression inhibited PTX resistance of breast cancer cells, and suppressed the proliferation, invasion and migration of breast cancer cells, which was achieved via upregulation of miR‑497 expression. In conclusion, knockdown of lncRNA DDX11‑AS1 could inhibit the proliferation, migration and PTX resistance of breast cancer cells by upregulating miR‑497 expression.
耐药性是癌症治疗中需要克服的主要问题；因此，鉴定耐药性的治疗靶点是癌症研究领域的重点。长链非编码 RNA（lncRNA）和 microRNA（miR）不仅在细胞增殖过程中影响基因表达调控，而且在恶性肿瘤的耐药性中具有多种潜在作用。逆转录定量 PCR 用于检测 MCF-7 和 MDA-MB-231 细胞中 DDX11 反义 RNA 1（DDX11-AS1）和 miR-497 的表达水平。细胞转染技术用于干扰 DDX11-AS1 和 miR-497 的表达水平。细胞计数试剂盒-8 和 MTT 测定法用于检测细胞活力。集落形成测定法用于检测细胞增殖。划痕愈合和 Transwell 测定法用于测量细胞迁移和侵袭水平。Western blot 用于分析迁移相关蛋白的表达水平，免疫荧光和 Western blot 分别用于确定上皮-间充质转化相关蛋白 E-钙粘蛋白和 N-钙粘蛋白的表达水平。荧光素酶报告基因测定法用于验证 DDX11-AS1 和 miR-497 的靶向结合。本研究表明，紫杉醇（PTX）耐药乳腺癌细胞系中 lncRNA DDX11-AS1 的表达水平明显升高。相比之下，敲低 DDX11-AS1 的表达抑制了乳腺癌细胞对 PTX 的耐药性，并抑制了乳腺癌细胞的增殖、侵袭和迁移，这是通过上调 miR-497 的表达来实现的。总之，敲低 lncRNA DDX11-AS1 可通过上调 miR-497 的表达抑制乳腺癌细胞的增殖、迁移和 PTX 耐药性。
