■由于缺乏有效的治疗靶点,三阴性乳腺癌(TNBC)患者的治疗选择仍然限于主要疗法。因此,迫切需要发现和鉴定用于治疗和诊断该疾病的新分子靶标。在这项研究中,我们分析了端粒酶逆转录酶(TERT)甲基化状态与TERT表达的相关性,预后,和免疫浸润在TNBC中,并确定了TERT甲基化在调节TNBC预后和免疫治疗中的作用。
■与转录组相关的数据,从癌症基因组图谱(TCGA)数据库获得TNBC患者的临床病理特征和甲基化。检测TERT表达水平和差异甲基化位点(DMS)。计算TERT表达与DMS之间的相关性。绘制Kaplan-Meier曲线以分析TNBC患者的生存与DMS之间的关系。DMSs和TERT的表达与免疫微环境的几种免疫学特征(免疫细胞浸润,免疫调节剂,免疫相关的生物学途径,和免疫检查点)进行评估。使用中山大学肿瘤防治中心(SYSUCC)的40例TNBC患者对结果进行了验证。
■确定了六个DMS。其中,4个位点(cg11625005、cg07380026、cg17166338和cg26006951)位于TERT启动子内,其中两个位点(cg07380026和cg26006951)与TNBC患者的预后显著相关。使用来自SYSUCC的40个TNBC样品的进一步验证显示cg26006951CpG位点的高甲基化与不良生存预后相关(P=0.0022)。TERT表达与病理N分期和临床分期显著相关,和cg07380026在TCGA队列中与病理T和N分期显著相关。此外,甲基化位点cg26006951、cg07380026和TERT表达与免疫细胞浸润显著相关,常见的免疫调节剂,和TNBC患者免疫检查点受体淋巴细胞活化基因3(LAG-3)的水平。
■TERT启动子甲基化在TNBC中TERT表达调控和肿瘤微环境中起重要作用。它与总生存率和LAG-3表达有关。TERT启动子超甲基化可能是预测TNBC中对TERT抑制剂和免疫检查点抑制剂的反应的潜在分子生物标记。
Treatment options for patients with triple-negative breast cancer (TNBC) remain limited to mainstay therapies owing to a lack of efficacious therapeutic targets. Accordingly, there is an urgent need to discover and identify novel molecular targets for the treatment and diagnosis of this disease. In this study, we analyzed the correlation of telomerase reverse transcriptase (TERT) methylation status with TERT expression, prognosis, and immune infiltration in TNBC and identified the role of TERT methylation in the regulation TNBC prognosis and immunotherapy.
Data relating to the transcriptome, clinicopathological characteristics and methylation of TNBC patients were obtained from The Cancer Genome Atlas (TCGA) database. TERT expression levels and differential methylation sites (DMSs) were detected. The correlations between TERT expression and DMSs were calculated. Kaplan-Meier curves was plotted to analyze the relationship between the survival of TNBC patients and the DMSs. The correlations of DMSs and TERT expression with several immunological characteristics of immune microenvironment (immune cell infiltration, immunomodulators, immune-related biological pathways, and immune checkpoints) were assessed. The results were validated using 40 TNBC patients from Sun Yat-sen University Cancer Center (SYSUCC).
Six DMSs were identified. Among them, four sites (cg11625005, cg07380026, cg17166338, and cg26006951) were within the TERT promoter, in which two sites (cg07380026 and cg26006951) were significantly related to the prognosis of patients with TNBC. Further validation using 40 TNBC samples from SYSUCC showed that the high methylation of the cg26006951 CpG site was associated with poor survival prognosis (P=0.0022). TERT expression was significantly correlated with pathological N stage and clinical stage, and cg07380026 were significantly associated with pathological T and N stages in the TCGA cohort. Moreover, the methylation site cg26006951, cg07380026 and TERT expression were significantly correlated with immune cell infiltration, common immunomodulators, and the level of the immune checkpoint receptor lymphocyte activation gene 3 (LAG-3) in TNBC patients.
TERT promotertypermethylation plays an important role in TERT expression regulation and tumor microenvironment in TNBC. It is associated with overall survival and LAG-3 expression. TERT promoter hypermethylation may be a potential molecular biomarker for predicting response to the TERT inhibitors and immune checkpoint inhibitors in TNBC.