CpG 甲基化能否作为癌症中免疫浸润的替代标志物?
Can CpG methylation serve as surrogate markers for immune infiltration in cancer?
机构信息
Department of Microbiology and Immunology, Weill Cornell Medicine, New York City, NY, United States.
Department of Microbiology and Immunology, Weill Cornell Medicine, New York City, NY, United States.
出版信息
Adv Cancer Res. 2019;143:351-384. doi: 10.1016/bs.acr.2019.03.007. Epub 2019 Apr 17.
Recent reports describe how genome-wide transcriptional analysis of cancer tissues can be exploited to identify molecular signatures of immune infiltration in cancer. We hypothesize that immune infiltration in cancer may also be defined by changes in certain epigenetic signatures. In this context, a primary objective is to identify site-specific CpG markers whose levels of methylation may be highly indicative of known transcriptional markers of immune infiltration such as GZMA, PRF1, T cell receptor genes, PDCD1, and CTLA4. This has been accomplished by integrating genome-wide transcriptional expression and methylation data for different types of cancer (melanoma, kidney cancers, lung cancers, gliomas, head and neck cancer). Our findings establish that cancers of related histology also have a high degree of similarity in immune-infiltration CpG markers. For example, the epigenetic immune infiltration signatures in lung adenocarcinoma (LUAD), mesothelioma (MESO), lung squamous cell carcinoma (LUSC), and head and neck squamous cell carcinoma (HNSC) are distinctly similar. So are glioblastoma multiforme (GBM) and brain lower grade glioma (LGG); and kidney renal papillary cell carcinoma (KIRP) and kidney renal clear cell carcinoma (KIRC). Kidney chromophobe (KICH), on the other hand has markers that are unique to this cohort. The strong relationships between immune infiltration and CpG methylation (for certain sites) in cancer tissues were not observed upon integrated analysis of publicly available cancer cell line datasets. Results from comparative pathways analyses offer further justification to methylation at certain CpG sites as being indicators of cancer immune infiltration, and possibly of predicting patient response to immunotherapeutic drugs. Achieving this target objective would significantly enhance therapeutic outcomes employing immunotherapy through focused patient-centric personalized medicine.
最近的报告描述了如何利用癌症组织的全基因组转录分析来鉴定癌症中免疫浸润的分子特征。我们假设癌症中的免疫浸润也可以通过某些表观遗传特征的变化来定义。在这种情况下,一个主要目标是确定特定的 CpG 标记物,其甲基化水平可能高度指示已知的免疫浸润转录标记物,如 GZMA、PRF1、T 细胞受体基因、PDCD1 和 CTLA4。这是通过整合不同类型癌症(黑色素瘤、肾癌、肺癌、神经胶质瘤、头颈部癌)的全基因组转录表达和甲基化数据来实现的。我们的发现表明,具有相关组织学的癌症在免疫浸润 CpG 标记物方面也具有高度相似性。例如,肺腺癌 (LUAD)、间皮瘤 (MESO)、肺鳞状细胞癌 (LUSC) 和头颈部鳞状细胞癌 (HNSC) 的表观遗传免疫浸润特征明显相似。多形性胶质母细胞瘤 (GBM) 和低级别胶质瘤 (LGG) 也是如此;肾透明细胞癌 (KIRC) 和肾乳头状细胞癌 (KIRP) 也是如此。另一方面,肾嫌色细胞癌 (KICH) 具有该队列特有的标记物。在对公开可用的癌细胞系数据集进行综合分析时,并未观察到癌症组织中免疫浸润和 CpG 甲基化(对于某些位点)之间的强关系。比较途径分析的结果进一步证明,某些 CpG 位点的甲基化可以作为癌症免疫浸润的指标,并可能预测患者对免疫治疗药物的反应。实现这一目标将通过以患者为中心的个性化医学显著增强免疫疗法的治疗效果。