Sun Ming, Liu Xiang-Hua, Wang Ke-Ming, Nie Feng-qi, Kong Rong, Yang Jin-song, Xia Rui, Xu Tong-Peng, Jin Fei-Yan, Liu Zhi-Jun, Chen Jin-fei, Zhang Er-Bao, De Wei, Wang Zhao-Xia
Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
Mol Cancer. 2014 Mar 21;13:68. doi: 10.1186/1476-4598-13-68.
Recent evidence indicates that long noncoding RNAs (lncRNAs) play a critical role in the regulation of cellular processes, such as differentiation, proliferation and metastasis. These lncRNAs are found to be dysregulated in a variety of cancers. BRAF activated non-coding RNA (BANCR) is a 693-bp transcript on chromosome 9 with a potential functional role in melanoma cell migration. The clinical significance of BANCR, and its' molecular mechanisms controlling cancer cell migration and metastasis are unclear.
Expression of BANCR was analyzed in 113 non-small cell lung cancer (NSCLC) tissues and seven NSCLC cell lines using quantitative polymerase chain reaction (qPCR) assays. Gain and loss of function approaches were used to investigate the biological role of BANCR in NSCLC cells. The effects of BANCR on cell viability were evaluated by MTT and colony formation assays. Apoptosis was evaluated by Hoechst staining and flow cytometry. Nude mice were used to examine the effects of BANCR on tumor cell metastasis in vivo. Protein levels of BANCR targets were determined by western blotting and fluorescent immunohistochemistry.
BANCR expression was significantly decreased in 113 NSCLC tumor tissues compared with normal tissues. Additionally, reduced BANCR expression was associated with larger tumor size, advanced pathological stage, metastasis distance, and shorter overall survival of NSCLC patients. Reduced BANCR expression was found to be an independent prognostic factor for NSCLC. Histone deacetylation was involved in the downregulation of BANCR in NSCLC cells. Ectopic expression of BANCR impaired cell viability and invasion, leading to the inhibition of metastasis in vitro and in vivo. However, knockdown of BANCR expression promoted cell migration and invasion in vitro. Overexpression of BANCR was found to play a key role in epithelial-mesenchymal transition (EMT) through the regulation of E-cadherin, N-cadherin and Vimentin expression.
We determined that BANCR actively functions as a regulator of EMT during NSCLC metastasis, suggesting that BANCR could be a biomarker for poor prognosis of NSCLC.
近期证据表明，长链非编码RNA（lncRNA）在细胞分化、增殖和转移等细胞过程的调控中发挥关键作用。这些lncRNA在多种癌症中表达失调。BRAF激活非编码RNA（BANCR）是位于9号染色体上的一个693碱基对的转录本，在黑色素瘤细胞迁移中具有潜在功能作用。BANCR的临床意义及其控制癌细胞迁移和转移的分子机制尚不清楚。
采用定量聚合酶链反应（qPCR）分析113例非小细胞肺癌（NSCLC）组织和7种NSCLC细胞系中BANCR的表达。运用功能获得和功能缺失方法研究BANCR在NSCLC细胞中的生物学作用。通过MTT和集落形成试验评估BANCR对细胞活力的影响。通过Hoechst染色和流式细胞术评估细胞凋亡。使用裸鼠在体内检测BANCR对肿瘤细胞转移的影响。通过蛋白质印迹法和荧光免疫组织化学法测定BANCR靶点蛋白质水平。
与正常组织相比，113例NSCLC肿瘤组织中BANCR表达显著降低。此外，BANCR表达降低与NSCLC患者肿瘤体积较大、病理分期较晚、转移距离较远及总生存期较短相关。发现BANCR表达降低是NSCLC的独立预后因素。组蛋白去乙酰化参与NSCLC细胞中BANCR的下调。BANCR的异位表达损害细胞活力和侵袭能力，导致体外和体内转移受到抑制。然而，敲低BANCR表达可促进体外细胞迁移和侵袭。发现BANCR的过表达通过调节E-钙黏蛋白、N-钙黏蛋白和波形蛋白的表达在上皮-间质转化（EMT）中起关键作用。
我们确定BANCR在NSCLC转移过程中作为EMT的调节因子发挥积极作用，提示BANCR可能是NSCLC预后不良的生物标志物。
