尿液筛查鉴定 PLA2G16 为前列腺癌检测的场缺陷甲基化生物标志物。

Screening of urine identifies PLA2G16 as a field defect methylation biomarker for prostate cancer detection.

机构信息

Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, WI, United States of America.

Department of Urology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States of America.

出版信息

PLoS One. 2019 Jun 24;14(6):e0218950. doi: 10.1371/journal.pone.0218950. eCollection 2019.

DOI:10.1371/journal.pone.0218950

PMID:31233548

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6590820/

Abstract

BACKGROUND

Prostate cancer (PC) is a multifocal disease. DNA methylation alterations are not restricted to the immediate peritumor environment, but spatially widespread in the adjacent and distant histologically normal prostate tissues. In the current study, we utilized high-throughput methylation arrays to identify epigenetic changes in the urine from men with and without cancer.

DESIGN, SETTING, AND PARTICIPANTS: DNA urine samples were enriched for methylated fragments using MBD methyl-binding antibodies and applied to high density CytoScanHD arrays. Significant loci were validated using quantitative pyrosequencing and binary logistic regression modeling applied to urine sample analyses in a training (n = 83) and validation approach (n = 84). Methylation alterations in prostate tissues using pyrosequencing at the PLA2G16 locus were examined in 38 histologically normal specimens from men with (TA, n = 26) and without (NTA, n = 12) cancer and correlated to gene expression.

RESULTS

Methylation microarrays identified 3,986 loci showing significantly altered methylation in the urine samples from patients with PC compared to those without (TA vs NTA; p<0.01). These loci were then compared against subjects with their prostates removed to exclude non-prostate cell markers yielding 196 significant regions. Multiple CpGs adjacent to PLA2G16 CpG island showed increased methylation in TA compared to NTA (p<0.01) in a large validation study of urine samples. The predictive accuracy of PLA2G16 methylation at CG2 showed the highest predictive value at 0.8 (odds ratio, 1.37; 95% confidence interval, 1.16-1.62; p<0.001). Using a probability cutoff of 0.065, the sensitivity and specificity of the multivariate model was 92% and 35%. When histologically normal prostate tissues/biopsies from patients with PC (TA) were compared to subjects without cancer, significant hypermethylation of PLA2G16 was noted (odds ratio, 1.35; 95% confidence interval, 1.07-1.71; p = 0.01).

CONCLUSION

PLA2G16 methylation defines an extensive field defect in histologically normal prostate tissue associated with PC. PLA2G16 methylation in urine and prostate tissues can detect the presence of PC.

摘要

背景

前列腺癌（PC）是一种多灶性疾病。DNA 甲基化改变不仅局限于肿瘤周围环境，而且在相邻和远处组织学正常的前列腺组织中广泛存在。在本研究中，我们利用高通量甲基化芯片来鉴定有和无癌症男性尿液中的表观遗传变化。

设计、环境和参与者：使用 MBD 甲基结合抗体富集尿液中的 DNA 甲基化片段，并将其应用于高密度 CytoScanHD 芯片。在训练组（n=83）和验证组（n=84）中，通过定量焦磷酸测序和二元逻辑回归模型对显著位点进行验证，对尿液样本进行分析。使用焦磷酸测序在 PLA2G16 基因座检测组织中 PLA2G16 基因的甲基化改变，该基因座在 38 个有（TA，n=26）和无（NTA，n=12）癌症的男性的组织学正常标本中进行研究，并与基因表达相关。

结果

甲基化微阵列鉴定出 3986 个在 PC 患者尿液样本中与无癌症患者（TA 与 NTA；p<0.01）相比表现出显著甲基化改变的基因座。然后，这些基因座与前列腺切除的受试者进行比较，以排除非前列腺细胞标记物，得到 196 个显著区域。与 NTA 相比，TA 中 PLA2G16 CpG 岛附近的多个 CpG 显示出更高的甲基化（p<0.01），这在对尿液样本的大型验证研究中得到了证实。CG2 处 PLA2G16 甲基化的预测准确性最高，预测值为 0.8（优势比，1.37；95%置信区间，1.16-1.62；p<0.001）。使用概率截断值 0.065，多元模型的灵敏度和特异性分别为 92%和 35%。当将 PC 患者（TA）的组织学正常前列腺组织/活检与无癌症患者进行比较时，发现 PLA2G16 显著高甲基化（优势比，1.35；95%置信区间，1.07-1.71；p=0.01）。