table_1.xlsx

BackgroundRecently, immune-checkpoint blockade has shown striking clinical results in different cancer patients. However, a significant inter-individual and inter-tumor variability exists among different cancers. The expression of the toxins granzyme A (GZMA) and perforin 1 (PRF1), secreted by effector cytotoxic T cells and natural killer (NK) cells, were recently used as a denominator of the intratumoral immune cytolytic activity (CYT). These levels are significantly elevated upon CD8+ T-cell activation as well as during a productive clinical response against immune-checkpoint blockade therapies. Still, it is not completely understood how different tumors induce and adapt to immune responses.MethodsHere, we calculated the CYT across different cancer types and focused on differences between primary and metastatic tumors. Using data from 10,355, primary tumor resection samples and 2,787 normal samples that we extracted from The Cancer Genome Atlas and Genotype-Tissue Expression project databases, we screened the variation of CYT across 32 different cancer types and 28 different normal tissue types. We correlated the cytolytic levels in each cancer type with the corresponding patient group’s overall survival, the expression of several immune-checkpoint molecules, as well as with the load of tumor-infiltrating lymphocytes (TILs), and tumor-associated neutrophils (TANs) in these tumors.ResultsWe found diverse levels of CYT across different cancer types, with highest levels in kidney, lung, and cervical cancers, and lowest levels in glioma, adrenocortical carcinoma (ACC), and uveal melanoma. GZMA protein was either lowly expressed or absent in at least half of these tumors; whereas PRF1 protein was not detected in almost any of the different tumor types, analyzing tissue microarrays from 20 different tumor types. CYT was significantly higher in metastatic skin melanoma and correlated significantly to the TIL load. In TCGA-ACC, skin melanoma, and bladder cancer, CYT was associated with an improved patient outcome and high levels of both GZMA and PRF1 synergistically affected patient survival in these cancers. In bladder, breast, colon, esophageal, kidney, ovarian, pancreatic, testicular, and thyroid cancers, high CYT was accompanied by upregulation of at least one immune-checkpoint molecule, indicating that similar to melanoma and prostate cancer, immune responses in cytolytic-high tumors elicit immune suppression in the tumor microenvironment.ConclusionOverall, our data highlight the existence of diverse levels of CYT across different cancer types and suggest that along with the existence of complicated associations among various tumor-infiltrated immune cells, it is capable to promote or inhibit the establishment of a permissive tumor microenvironment, depending on the cancer type. High levels of immunosuppression seem to exist in several tumor types.

近期，免疫检查点阻断疗法在多种癌症患者中展现出显著的临床疗效。然而，不同癌症之间存在着显著的个体差异和肿瘤差异。效应毒性T细胞和自然杀伤细胞分泌的毒素颗粒酶A（GZMA）和穿孔素1（PRF1）的表达，被最近用作评估肿瘤内免疫溶解活性（CYT）的指标。这些水平在CD8+ T细胞激活以及针对免疫检查点阻断疗法的有效临床反应期间显著升高。尽管如此，不同肿瘤如何诱导和适应免疫反应尚不完全明了。本研究通过计算不同癌症类型的CYT，重点关注原发性肿瘤和转移性肿瘤之间的差异。利用我们从癌症基因组图谱和基因型-组织表达项目数据库中提取的10,355个原发性肿瘤切除样本和2,787个正常样本数据，我们对32种不同癌症类型和28种不同正常组织类型的CYT变化进行了筛选。我们将每种癌症类型的溶解水平与相应患者群体的总生存期、多种免疫检查点分子的表达、肿瘤浸润淋巴细胞（TILs）和肿瘤相关中性粒细胞（TANs）的负荷进行了相关性分析。结果表明，不同癌症类型中存在不同的CYT水平，其中肾脏、肺和宫颈癌的CYT水平最高，而胶质瘤、肾上腺皮质癌（ACC）和葡萄膜黑色素瘤的CYT水平最低。在这些肿瘤中，GZMA蛋白在至少一半的肿瘤中表达低或不存在；而PRF1蛋白在几乎所有不同肿瘤类型中均未检测到，这是通过对20种不同肿瘤类型的组织微阵列进行分析得出的。在转移性皮肤黑色素瘤中，CYT显著升高，且与TIL负荷显著相关。在TCGA-ACC、皮肤黑色素瘤和膀胱癌中，CYT与患者预后改善相关，并且GZMA和PRF1的高水平协同作用对这些癌症患者的生存率产生了积极影响。在膀胱、乳腺、结肠、食管、肾脏、卵巢、胰腺、睾丸和甲状腺癌中，高CYT伴随至少一种免疫检查点分子的上调，表明与黑色素瘤和前列腺癌类似，溶解活性高的肿瘤中的免疫反应在肿瘤微环境中引发免疫抑制。结论总体而言，我们的数据突出了不同癌症类型中CYT水平的多样性，并表明，伴随着各种肿瘤浸润免疫细胞之间复杂的相互关系，CYT的存在能够根据癌症类型促进或抑制容许性肿瘤微环境的建立。在多种肿瘤类型中似乎存在高水平的免疫抑制。