Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 64108, USA.
Breast Cancer Res. 2010;12(5):R74. doi: 10.1186/bcr2644. Epub 2010 Sep 23.
IκB Kinase ε (IKKε) is a member of the IKK family which plays an important role in the activation of nuclear factor-κB (NF-κB). Overexpressed in over 30% of breast cancers, IKKε has been recently identified as a potential breast cancer oncogene. The purpose of this study is to examine the therapeutic potential of IKKε siRNA on human breast cancer cells.
Eight siRNAs targeting different regions of the IKKε mRNA were designed, and the silencing effect was screened by quantitative real time RT-PCR. The biological effects of synthetic siRNAs on human breast cancer cells were investigated by examining the cell proliferation, migration, invasion, focus formation, anchorage-independent growth(via soft agar assay), cell cycle arrest, apoptosis (via annexing binding), NF-κB basal level, and NF-κB related gene expressions upon the IKKε silencing.
Silencing of IKKε in human breast cancer cells resulted in decrease of focus formation potential and clonogenicity as well as in vitro cell migration/invasion capabilities. Moreover, knockdown of IKKε suppressed cell proliferation. Cell cycle assay showed that the anti-proliferation effect of IKKε siRNA was mediated by arresting cells in G(0)/G(1) phase, which was caused by down-regulation of cyclin D(1). Furthermore, we demonstrated that silencing of IKKε inhibited the NF-κB basal activity as well as the Bcl-2 expression. Significant apoptosis was not observed in breast cancer cells upon the silencing of IKKε. The present study provided the first evidence that silencing IKKε using synthetic siRNA could inhibit the invasiveness properties and proliferation of breast cancer cells.
Our results suggested that silencing IKKε using synthetic siRNA may offer a novel therapeutic strategy for breast cancer.
IκB 激酶 ε（IKKε）是 IKK 家族的一员，在核因子-κB（NF-κB）的激活中发挥重要作用。IKKε在超过 30%的乳腺癌中过表达，最近被鉴定为潜在的乳腺癌癌基因。本研究旨在研究 IKKεsiRNA 对人乳腺癌细胞的治疗潜力。
设计了针对 IKKεmRNA 不同区域的 8 条 siRNA，并通过定量实时 RT-PCR 筛选出沉默效果。通过检测细胞增殖、迁移、侵袭、焦点形成、锚定独立生长（通过软琼脂测定）、细胞周期停滞、凋亡（通过 Annexin 结合）、NF-κB 基础水平以及 IKKε 沉默后 NF-κB 相关基因表达，研究了合成 siRNA 对人乳腺癌细胞的生物学影响。
人乳腺癌细胞中 IKKε 的沉默导致焦点形成潜能和克隆形成能力以及体外细胞迁移/侵袭能力下降。此外，IKKε 的敲低抑制了细胞增殖。细胞周期测定表明，IKKεsiRNA 的抗增殖作用是通过将细胞阻滞在 G0/G1 期来介导的，这是由细胞周期蛋白 D1 的下调引起的。此外，我们证明了 IKKε 的沉默抑制了 NF-κB 的基础活性和 Bcl-2 的表达。在乳腺癌细胞中，IKKε 的沉默并没有观察到明显的凋亡。本研究首次证明，使用合成 siRNA 沉默 IKKε 可以抑制乳腺癌细胞的侵袭性和增殖。
我们的研究结果表明，使用合成 siRNA 沉默 IKKε 可能为乳腺癌提供一种新的治疗策略。
