Yang Zhi-Xue, Zhang Bo, Wei Jinrong, Jiang Guo-Qin, Wu Yan-Lin, Leng Bing-Jing, Xing Chun-Gen
1Department of General Surgery, The Second Affiliated Hospital, Soochow University, Suzhou, 215004 Jiangsu China.
2Department of Radiology, The Second Affiliated Hospital, Soochow University, Suzhou, 215004 Jiangsu China.
Cancer Cell Int. 2018 Jan 30;18:16. doi: 10.1186/s12935-018-0512-4. eCollection 2018.
Recent studies have shown that laminin subunit alpha 4 (LAMA4) plays an important role in carcinogenesis. However, its molecular biological function in triple-negative breast cancer (TNBC) has not been entirely clarified. This study investigated the expression of LAMA4 in TNBC and its effect on cell proliferation, migration and invasion. Furthermore, we also identified the potential miRNA directly targeting LAMA4.
Western blot, Real-time quantitative PCR (qPCR) and immunohistochemical staining (IHC) were used to detect the expression of LAMA4 in TNBC. The effects of LAMA4 on TNBC cell proliferation, migration and invasion were also explored in vitro. The potential miRNA that targets LAMA4 was determined by dual luciferase reporter assay and verified by qPCR and western blot analysis.
Our study showed LAMA4 mRNA (p = 0.001) and protein (p = 0.005) expression in TNBC tissue samples were elevated compared with adjacent normal tissue samples, and LAMA4 was mainly expressed in the cytoplasm of breast carcinoma cells. Knockdown of LAMA4 inhibited TNBC cell proliferation, migration and invasion in vitro. Moreover, further study revealed that LAMA4 was a putative target of miR-539, and miR-539 negatively regulated LAMA4 expression by directly targeting its 3'-UTR.
Our study suggested that miR-539 suppressed the expression of LAMA4. LAMA4 plays an important role in tumor progression and may be an important target in treatment of TNBC.
最近的研究表明，层粘连蛋白α4亚基（LAMA4）在肿瘤发生中起重要作用。然而，其在三阴性乳腺癌（TNBC）中的分子生物学功能尚未完全阐明。本研究调查了LAMA4在TNBC中的表达及其对细胞增殖、迁移和侵袭的影响。此外，我们还鉴定了直接靶向LAMA4的潜在微小RNA（miRNA）。
采用蛋白质免疫印迹法、实时定量聚合酶链反应（qPCR）和免疫组织化学染色（IHC）检测LAMA4在TNBC中的表达。体外探讨LAMA4对TNBC细胞增殖、迁移和侵袭的影响。通过双荧光素酶报告基因检测确定靶向LAMA4的潜在miRNA，并通过qPCR和蛋白质免疫印迹分析进行验证。
我们的研究表明，与相邻正常组织样本相比，TNBC组织样本中LAMA4信使核糖核酸（mRNA）（p = 0.001）和蛋白质（p = 0.005）表达升高，且LAMA4主要表达于乳腺癌细胞的细胞质中。敲低LAMA4可抑制TNBC细胞在体外的增殖、迁移和侵袭。此外，进一步研究表明LAMA4是miR-539的假定靶点，miR-539通过直接靶向其3'-非翻译区（UTR）负向调节LAMA4表达。
我们的研究表明miR-539抑制LAMA4的表达。LAMA4在肿瘤进展中起重要作用，可能是TNBC治疗的重要靶点。
