Guo Honghong, Zhu Ling, Huang Lu, Sun Zhen, Zhang Hui, Nong Baoting, Xiong Yuanyan
Key Laboratory of Gene Engineering, Ministry of Education, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510006, China.
Cancers (Basel). 2022 Jun 8;14(12):2827. doi: 10.3390/cancers14122827.
The accumulating evidence demonstrates that the apolipoprotein B mRNA editing enzyme catalytic polypeptide-like (APOBEC), DNA-editing protein plays an important role in the molecular pathogenesis of cancer. In particular, the APOBEC3 family was shown to induce tumor mutations by an aberrant DNA editing mechanism. However, knowledge regarding the reconstitution of the APOBEC family genes across cancer types is still lacking. Here, we systematically analyzed the molecular alterations, immuno-oncological features, and clinical relevance of the APOBEC family in pan-cancer. We found that APOBEC genes were widely and significantly differentially expressed between normal and cancer samples in 16 cancer types, and that their expression levels are significantly correlated with the prognostic value in 17 cancer types. Moreover, two patterns of APOBEC-mediated stratification with distinct immune characteristics were identified in different cancer types, respectively. In ACC, for example, the first pattern of APOBEC-mediated stratification was closely correlated with the phenotype of immune activation, which was characterized by a high immune score, increased infiltration of CD8 T cells, and higher survival. The other pattern of APOBEC-mediated stratification was closely correlated with the low-infiltration immune phenotype, which was characterized by a low immune score, lack of effective immune infiltration, and poorer survival. Further, we found the APOBEC-mediated pattern with low-infiltration immune was also highly associated with the advanced tumor subtype and the CIMP-high tumor subtype (CpG island hypermethylation). Patients with the APOBEC-mediated pattern with immune activation were more likely to have therapeutic advantages in ICB (immunological checkpoint blockade) treatment. Overall, our results provide a valuable resource that will be useful in guiding oncologic and therapeutic analyses of the role of APOBEC family in cancer.
越来越多的证据表明,载脂蛋白B信使核糖核酸编辑酶催化多肽样(APOBEC)DNA编辑蛋白在癌症的分子发病机制中发挥着重要作用。特别是,APOBEC3家族被证明可通过异常的DNA编辑机制诱导肿瘤突变。然而,关于癌症类型间APOBEC家族基因重构的知识仍然匮乏。在此,我们系统分析了泛癌中APOBEC家族的分子改变、免疫肿瘤学特征及临床相关性。我们发现,在16种癌症类型中,正常样本与癌症样本之间APOBEC基因广泛且显著差异表达,且其表达水平与17种癌症类型的预后价值显著相关。此外,在不同癌症类型中分别鉴定出了具有不同免疫特征的两种APOBEC介导的分层模式。例如,在肾上腺皮质癌(ACC)中,第一种APOBEC介导的分层模式与免疫激活表型密切相关该表型的特征为高免疫评分、CD8 T细胞浸润增加及较高生存率。另一种APOBEC介导的分层模式与低浸润免疫表型密切相关,其特征为低免疫评分、缺乏有效的免疫浸润及较差的生存率。此外,我们发现APOBEC介导的低浸润免疫模式也与晚期肿瘤亚型及CIMP高肿瘤亚型(CpG岛高甲基化)高度相关。具有APOBEC介导的免疫激活模式的患者在免疫检查点阻断(ICB)治疗中更可能具有治疗优势。总体而言,我们的结果提供了宝贵的资源,将有助于指导对APOBEC家族在癌症中作用的肿瘤学及治疗分析。