Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota 55905, USA.
Otol Neurotol. 2010 Aug;31(6):991-7. doi: 10.1097/MAO.0b013e3181e40e4f.
B7-H1 is expressed in vestibular schwannomas.
Little is known about how benign human vestibular schwannomas interact with antibody-mediated or cell-mediated immunity. We report on the aberrant expression of a novel T-cell coregulatory molecule, B7 homolog 1 (B7-H1), in vestibular schwannomas and discuss the implications of B7-H1 expression and tumor aggressiveness and a potential regulator of B7-H1 expression.
Immunohistochemical staining for B7-H1, CD8+, CD3+, and CD4+ lymphocytes were performed on 48 fresh-frozen vestibular schwannoma tissue specimens. A clinical review of patient presenting symptoms and tumor characteristics was performed. Real-time polymerase chain reaction was used to determine if there was differential expression of B7-H1 messenger RNA and microRNA-513, a known regulator of B7-H1, in several strongly positive and negative B7-H1 vestibular schwannomas.
Nine (19%) of 48 tumors were negative, 23 (48%) tumors were 1+ mildly positive (<20% section area), and 16 (33%) stained 2+ strongly positive (>or=20% section area) for B7-H1. The average number of CD8 cells per high-power field was 2.1 for positive-staining tumors and 1.0 for negative tumors (p = 0.16). Failure of tumor control with stereotactic radiation (p = 0.029) was significantly greater in the strongly positive B7-H1 tumors. Real-time polymerase chain reaction did not show significant differential expression of microRNA-513 (p = 0.62) or B7-H1 messenger RNA (p = 0.35) between the tumors showing strong and negative immunohistochemical staining for B7-H1 protein.
Vestibular schwannoma tumors express B7-H1, which has been associated with immune tolerance and adverse disease characteristics in several malignancies. Growing tumors that were surgically removed after failed stereotactic radiation therapy were significantly more likely to strongly express B7-H1 protein, which lends some credibility to the hypothesis that immuno-evasion may play some role in their continued growth. Although clinical trends were seen, greater statistical power is required to evaluate whether B7-H1 expression correlates with more aggressive tumor growth or poorer hearing class. B7-H1 seems to be expressed in equal amounts at the RNA level in all vestibular schwannoma tumors that suggests that differential protein expression is occurring at the posttranscriptional level. However, microRNA-513 does not regulate B7-H1 protein expression in these tumors.
B7-H1 在前庭神经鞘瘤中表达。
关于良性人类前庭神经鞘瘤如何与抗体介导或细胞介导的免疫相互作用，我们知之甚少。我们报告了一种新型 T 细胞共调节分子 B7 同源物 1（B7-H1）在前庭神经鞘瘤中的异常表达，并讨论了 B7-H1 表达与肿瘤侵袭性和潜在的 B7-H1 表达调节剂的相关性。
对 48 例新鲜冷冻的前庭神经鞘瘤组织标本进行 B7-H1、CD8+、CD3+和 CD4+淋巴细胞的免疫组织化学染色。对患者的临床表现和肿瘤特征进行临床回顾。使用实时聚合酶链反应确定在几个强阳性和阴性 B7-H1 前庭神经鞘瘤中 B7-H1 信使 RNA 和 microRNA-513（已知的 B7-H1 调节剂）是否存在差异表达。
9 例（19%）肿瘤为阴性，23 例（48%）肿瘤为 1+轻度阳性（<20%切片面积），16 例（33%）肿瘤为 2+强阳性（>或=20%切片面积）。阳性染色肿瘤的高倍视野中 CD8 细胞的平均数量为 2.1，而阴性肿瘤为 1.0（p=0.16）。立体定向放疗失败后肿瘤控制不良（p=0.029）在 B7-H1 强阳性肿瘤中更为显著。实时聚合酶链反应未显示 B7-H1 蛋白免疫组织化学染色强阳性和阴性肿瘤之间 microRNA-513（p=0.62）或 B7-H1 信使 RNA（p=0.35）的显著差异表达。
前庭神经鞘瘤肿瘤表达 B7-H1，这与几种恶性肿瘤中的免疫耐受和不良疾病特征有关。在立体定向放射治疗失败后被手术切除的生长中的肿瘤强烈表达 B7-H1 蛋白的可能性显著增加，这使得免疫逃避可能在其持续生长中发挥一定作用的假设具有一定可信度。尽管观察到了临床趋势，但需要更大的统计效力来评估 B7-H1 表达是否与更具侵袭性的肿瘤生长或更差的听力分级相关。B7-H1 似乎在所有前庭神经鞘瘤肿瘤中的 RNA 水平上以相等的量表达，这表明差异的蛋白质表达发生在转录后水平。然而，microRNA-513 并未调节这些肿瘤中的 B7-H1 蛋白表达。
