Cell Signaling Technology Inc., Danvers, MA, USA.
Am J Surg Pathol. 2009 Jul;33(7):984-91. doi: 10.1097/PAS.0b013e318198d666.
NUT midline carcinoma (NMC) is a uniformly lethal malignancy that is defined by rearrangement of the nuclear protein in testis (NUT) gene on chromosome 15q14. NMCs are morphologically indistinguishable from other poorly differentiated carcinomas, and the diagnosis is usually made currently by fluorescence in situ hybridization (FISH). As normal NUT expression is confined to testis and ovary, we reasoned that an immunohistochemical (IHC) stain for NUT would be useful in diagnosing NMC. To this end, we raised a highly specific rabbit monoclonal antibody, C52, against a recombinant NUT polypeptide, and developed an IHC staining protocol. The sensitivity and specificity of C52 staining was evaluated in a panel of 1068 tissues, predominantly diverse types of carcinomas (n=906), including 30 NMCs. Split-apart FISH for NUT rearrangement was used as a "gold standard" diagnostic test for NMC. C52 immunoreactivity among carcinomas was confined to NMCs. IHC staining had a sensitivity of 87%, a specificity of 100%, a negative predictive value of 99%, and a positive predictive value of 100%. Two new cases of NMC containing BRD4-NUT fusions were detected by C52 IHC, but missed by conventional FISH. In both instances, these tumors contained cryptic BRD4-NUT rearrangements, as confirmed by FISH using a refined set of probes. Some germ cell tumors, including 64% of dysgerminomas, showed weak NUT immunoreactivity, consistent with the expression of NUT in normal germ cells. We conclude that IHC staining with the C52 monoclonal antibody is a highly sensitive and specific test that reliably distinguishes NMC from other forms of carcinoma. The NUT antibody is being prepared for commercial release and will be available in the near future.
NUT 中线癌（NMC）是一种均匀致命的恶性肿瘤，其特征是 15q14 染色体上的核蛋白 in testis（NUT）基因重排。NMC 在形态上与其他低分化癌无法区分，目前通常通过荧光原位杂交（FISH）进行诊断。由于正常 NUT 表达局限于睾丸和卵巢，我们推测 NUT 的免疫组织化学（IHC）染色将有助于诊断 NMC。为此，我们针对重组 NUT 多肽产生了一种高度特异性的兔单克隆抗体 C52，并开发了 IHC 染色方案。我们在一个包含 1068 种组织的面板中评估了 C52 染色的敏感性和特异性，主要是各种类型的癌（n=906），包括 30 种 NMC。用于 NMC 诊断的“金标准”检测方法是 NUT 重排的分裂 FISH。IHC 染色在 NMC 中仅限于癌。IHC 染色的敏感性为 87%，特异性为 100%，阴性预测值为 99%，阳性预测值为 100%。C52 IHC 检测到 2 例含有 BRD4-NUT 融合的新的 NMC 病例，但常规 FISH 漏诊。在这两种情况下，这些肿瘤均包含隐匿性 BRD4-NUT 重排，通过使用一组改良探针进行 FISH 得到证实。一些生殖细胞瘤，包括 64%的卵黄囊瘤，显示出微弱的 NUT 免疫反应性，与正常生殖细胞中的 NUT 表达一致。我们得出结论，C52 单克隆抗体的 IHC 染色是一种高度敏感和特异的检测方法，可可靠地区分 NMC 与其他类型的癌。NUT 抗体即将商业化并将很快上市。
