Objectives: B7-H3 and B7-H4 proteins are expressed in breast cancer tissues, but their relationships with respect to tumor immune surveillance and outcomes in breast cancer are not conclusive. Methods: We first examined B7-H3 and B7-H4 mRNA expression in the Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets. Next, mRNA and protein expression were assessed by RNAscope in situ hybridization (ISH) and immunohistochemistry in 10 pairs of breast cancer and matched normal tissues. Immunohistochemical staining of B7-H3, B7-H4, CD3, and CD8 was performed in tissue microarray slides containing 198 breast cancer samples. Association of B7-H3 and B7-H4 expression with survival was verified using the publicly accessible BreastMark tool. Results: B7-H3 and B7-H4 mRNA expression were significantly higher in breast cancer samples in the TCGA dataset than in normal breast tissues in the GTEx dataset. RNAscope ISH and immunohistochemistry showed that B7-H3 and B7-H4 mRNA and protein appeared to be mainly expressed in cancer cells. Expression of B7-H3 and B7-H4 tended to be associated with low-density scores of stromal tumor-infiltrating lymphocytes (TILs) as well as molecular subtypes. Expressions of B7-H3 and B7-H4 were negatively correlated with stromal CD3+ and CD8+ T cell infiltration density. B7-H3 and B7-H4 expression was not associated with survival, which was verified by BreastMark analysis. Conclusion: Expression levels of B7-H3 and B7-H4 were independent of clinical outcomes of breast cancer. There was an inverse relationship between the expression of B7-H3 and B7-H4 in breast cancer and the density of stromal TILs and CD8+ T lymphocytes. This inverse relationship may represent a promising target in the field of breast cancer immunotherapy.

中文翻译：

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B7-H3 和 B7-H4 在乳腺癌中的表达及其与临床病理变量和 T 细胞浸润的关联

目的：B7-H3 和 B7-H4 蛋白在乳腺癌组织中表达，但它们与肿瘤免疫监视和乳腺癌预后的关系尚无定论。方法：我们首先检查了基因型组织表达 (GTEx) 和癌症基因组图谱 (TCGA) 数据集中的 B7-H3 和 B7-H4 mRNA 表达。接下来，通过 RNAscope 原位杂交 (ISH) 和免疫组织化学在 10 对乳腺癌和匹配的正常组织中评估 mRNA 和蛋白质表达。B7-H3、B7-H4、CD3 和 CD8 的免疫组织化学染色在含有 198 个乳腺癌样本的组织微阵列载玻片中进行。B7-H3 和 B7-H4 表达与存活的关联使用可公开访问的 BreastMark 工具进行验证。结果：B7-H3 和 B7-H4 mRNA 在 TCGA 数据集中的乳腺癌样本中的表达显着高于 GTEx 数据集中的正常乳腺组织。RNAscope ISH和免疫组织化学显示B7-H3和B7-H4 mRNA和蛋白质似乎主要在癌细胞中表达。B7-H3 和 B7-H4 的表达往往与间质肿瘤浸润淋巴细胞 (TIL) 以及分子亚型的低密度评分相关。B7-H3和B7-H4的表达与基质CD3+和CD8+T细胞浸润密度呈负相关。B7-H3 和 B7-H4 的表达与生存无关，这已通过乳房标记分析得到证实。结论：B7-H3 和 B7-H4 的表达水平与乳腺癌的临床结果无关。B7-H3和B7-H4在乳腺癌中的表达与间质TILs和CD8+T淋巴细胞的密度呈负相关。这种反向关系可能代表了乳腺癌免疫治疗领域的一个有希望的靶点。