Molecular Neuro-Oncology Unit, IRCCS Foundation "C,Besta" Neurological Institute, via Celoria 11, 20133 Milan, Italy.
Mol Cancer. 2013 Dec 11;12:160. doi: 10.1186/1476-4598-12-160.
The NF-kB family of transcription factors is up-regulated in inflammation and different cancers. Recent data described heterozygous deletions of the NF-kB Inhibitor alpha gene (NFKBIA) in about 20% of glioblastomas (GBM): deletions were mutually exclusive with epidermal growth factor receptor (EGFR) amplification, a frequent event in GBM. We assessed the status of NFKBIA and EGFR in 69 primary GBMs and in corresponding neurospheres (NS). NFKBIA deletion was investigated by the copy number variation assay (CNV); EGFR amplification by CNV ratio with HGF; expression of EGFR and EGFRvIII by quantitative PCR or ReverseTranscriptase PCR. Heterozygous deletions of NFKBIA were present in 3 of 69 primary GBMs and, surprisingly, in 30 of 69 NS. EGFR amplification was detected in 36 GBMs: in corresponding NS, amplification was lost in 13 cases and reduced in 23 (10 vs 47 folds in NS vs primary tumors; p < 0.001). The CNV assay was validated investigating HPRT1 on chromosome X in females and males. Results of array-CGH performed on 3 primary GBMs and 1 NS line were compatible with the CNV assay. NS cells with NFKBIA deletion had increased nuclear activity of p65 (RelA) and increased expression of the NF-kB target IL-6. In absence of EGF in the medium, EGFR amplification was more conserved and NFKBIA deletion less frequent point to a low frequency of NFKBIA deletions in GBM and suggest that EGF in the culture medium of NS may affect frequency not only of EGFR amplifications but also of NFKBIA deletions.
NF-kB 转录因子家族在炎症和不同癌症中上调。最近的数据描述了 NF-kB 抑制剂 alpha 基因 (NFKBIA) 的杂合性缺失约占胶质母细胞瘤 (GBM) 的 20%：缺失与表皮生长因子受体 (EGFR) 扩增相互排斥，这是 GBM 中的一个常见事件。我们评估了 69 例原发性 GBM 及其相应神经球 (NS) 中 NFKBIA 和 EGFR 的状态。NFKBIA 缺失通过拷贝数变异分析 (CNV) 进行检测；EGFR 扩增通过与 HGF 的 CNV 比值进行检测；通过定量 PCR 或逆转录 PCR 检测 EGFR 和 EGFRvIII 的表达。在 69 例原发性 GBM 中有 3 例存在 NFKBIA 杂合性缺失，令人惊讶的是，在 69 例 NS 中有 30 例存在 NFKBIA 缺失。在 36 例 GBM 中检测到 EGFR 扩增：在相应的 NS 中，扩增在 13 例中丢失，在 23 例中减少（NS 与原发性肿瘤相比，扩增减少 10 倍至 47 倍；p<0.001）。在女性和男性的染色体 X 上的 HPRT1 上验证了 CNV 检测。对 3 例原发性 GBM 和 1 例 NS 系进行的 array-CGH 分析结果与 CNV 检测结果一致。具有 NFKBIA 缺失的 NS 细胞具有更高的 p65（RelA）核活性和 NF-kB 靶标 IL-6 的表达。在培养基中没有 EGF 的情况下，EGFR 扩增更为保守，NFKBIA 缺失频率较低，这表明在 NS 的培养基中 EGF 不仅可能影响 EGFR 扩增的频率，还可能影响 NFKBIA 缺失的频率。
