The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Canada.
Clin Cancer Res. 2012 Aug 15;18(16):4334-44. doi: 10.1158/1078-0432.CCR-12-0199. Epub 2012 Jul 2.
To assess inflammation-related gene expression in nonmalignant fallopian tube epithelium (FTE) from BRCA1/2 mutation carriers and control patients obtained during the luteal and follicular phase, and to determine the impact of BRCA1 and disabled homolog 2 (DAB2) on NF-κB-mediated proinflammatory signaling.
A list of inflammation-related and NF-κB-responsive genes was compiled through gene set enrichment and PubMed database search, corresponding probes identified, and unpaired t tests conducted to identify differentially expressed genes in previously profiled FTE samples. ES2 and A549 cells were cotransfected with DAB2- or BRCA1-targeting siRNA and an NF-κB-responsive luciferase reporter, treated with TNF-α and luciferase activity determined. To determine whether DAB2 or BRCA1 alters mRNA expression of NF-κB target genes, cells were transfected with siRNA, treated with TNF-α, and harvested for total RNA extraction and quantitative real-time PCR.
A subset of BRCA1-mutated luteal phase samples previously found to group with adnexal high-grade serous carcinomas (HGSCs) differentially expressed 124 inflammation-associated probesets relative to remaining FTE samples. These samples also differentially expressed 264 probes relative to other luteal phase samples exposed to the same postovulatory environment. Both BRCA1- and DAB2-targeting siRNA increased TNF-α-induced NF-κB activity and mRNA expression of NF-κB-dependent target gene SOD2 relative to nontargeting siRNA, suggesting that both proteins repress proinflammatory signaling.
These data provide evidence of elevated proinflammatory signaling in a subset of BRCA1-mutated luteal phase FTE, consistent with an altered response to ovulation-associated cytokines. Furthermore, both BRCA1 and DAB2 affect NF-κB activity, indicating a novel link between BRCA mutation status, ovulation, and predisposition to HGSC.
评估 BRCA1/2 突变携带者和对照患者非恶性输卵管上皮（FTE）中的炎症相关基因表达，并确定 BRCA1 和Disabled homolog 2（DAB2）对 NF-κB 介导的促炎信号的影响。
通过基因集富集和 PubMed 数据库搜索编制了一份炎症相关和 NF-κB 反应基因列表，确定了相应的探针，并进行了未配对 t 检验，以鉴定以前分析的 FTE 样本中的差异表达基因。将 ES2 和 A549 细胞与 DAB2 或 BRCA1 靶向 siRNA 共转染，并与 NF-κB 反应性荧光素酶报告基因一起处理，测定荧光素酶活性。为了确定 DAB2 或 BRCA1 是否改变 NF-κB 靶基因的 mRNA 表达，将细胞转染 siRNA，用 TNF-α处理，并提取总 RNA 进行定量实时 PCR。
先前发现与附件高级别浆液性癌（HGSCs）聚集的一组 BRCA1 突变黄体期样本与其余 FTE 样本相比，有 124 个炎症相关探针集差异表达。与暴露于相同排卵后环境的其他黄体期样本相比，这些样本也有 264 个探针差异表达。与非靶向 siRNA 相比，BRCA1 和 DAB2 靶向 siRNA 均增加了 TNF-α诱导的 NF-κB 活性和 NF-κB 依赖性靶基因 SOD2 的 mRNA 表达，表明这两种蛋白均抑制促炎信号。
这些数据提供了证据表明 BRCA1 突变黄体期 FTE 中存在升高的促炎信号，与排卵相关细胞因子的改变反应一致。此外，BRCA1 和 DAB2 均影响 NF-κB 活性，表明 BRCA 突变状态、排卵和 HGSC 易感性之间存在新的联系。
