抑癌基因 CDH13 和 SHP1 启动子的甲基化及其在子宫内膜癌中 UHRF1/PRMT5 复合物的表观遗传调控。

Methylation of tumor suppressor gene CDH13 and SHP1 promoters and their epigenetic regulation by the UHRF1/PRMT5 complex in endometrial carcinoma.

机构信息

Institute of Pathology and Pathophysiology, Shandong University School of Medicine, Jinan 250012, China; Department of Gynecology and Obstetrics, Tianjin Medical University General Hospital, Tianjin, China.

Tianjin Medical University Cancer Institute and Hospital, National Clinical Research for Cancer, The Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.

出版信息

Gynecol Oncol. 2016 Jan;140(1):145-51. doi: 10.1016/j.ygyno.2015.11.017. Epub 2015 Nov 18.

DOI:10.1016/j.ygyno.2015.11.017

PMID:26597461

Abstract

OBJECTIVE

Epigenetic changes in cancer and precancerous lesions could be utilized as biomarkers for cancer early detection. This study aims to investigate the novel biomarkers in endometrial carcinoma, and explore their epigenetic regulation.

METHODS

Methylation of six tumor suppressor genes (CDH13, SHP1, HIN1, DKK3, CTNNA1 and PCDH8) was evaluated in 155 endometrium samples. Changes of methylation and mRNA expression after treatment with 5-Aza-2'-deoxycytidine (5-Aza-CdR) or/and trichostatin A (TSA) were investigated by MSP and qRT-PCR respectively. Co-immunoprecipitation was used to detect the interactions between UHRF1 and PRMT5 proteins.

RESULTS

CDH13 and SHP1 promoters were highly methylated (81.36% and 86.44%, respectively) in endometrial carcinoma, while CDH13 promoter methylation was also present in complex hyperplasia and atypical hyperplasia (51.72% and 50.00%, respectively). Methylation of CDH13 and SHP1 promoters was associated with age and tumor differentiation or muscular infiltration depth. CDH13 and SHP1 promoters were completely methylated in endometrial carcinoma cell lines and were partially reversed by 5-Aza-CdR or TSA to induce mRNA levels (P<0.01). After combined treatment with these two agents, methylation of CDH13 and SHP1 promoters was completely reversed and expression of their mRNA was significantly increased (P<0.01). Moreover, PRMT5 could bind to UHRF1 and down-regulated by 5-Aza-CdR and/or TSA treatment (P<0.05).

CONCLUSIONS

Our data demonstrate for the first time that SHP1 methylation has high specificity for diagnosis of endometrial carcinoma, while CDH13 promoter methylation plays a role in the earlier stage. Furthermore, UHRF1 could form a complex with PRMT5 to contribute to the endometrial carcinogenesis.

摘要

目的

癌症和癌前病变中的表观遗传变化可作为癌症早期检测的生物标志物。本研究旨在探讨子宫内膜癌中的新型生物标志物，并探讨其表观遗传调控机制。

方法

评估了 155 例子宫内膜样本中六个肿瘤抑制基因（CDH13、SHP1、HIN1、DKK3、CTNNA1 和 PCDH8）的甲基化情况。通过 MSP 和 qRT-PCR 分别检测 5-Aza-2'-脱氧胞苷（5-Aza-CdR）和/或曲古抑菌素 A（TSA）处理后甲基化和 mRNA 表达的变化。采用共免疫沉淀法检测 UHRF1 和 PRMT5 蛋白之间的相互作用。

结果

CDH13 和 SHP1 启动子在子宫内膜癌中高度甲基化（分别为 81.36%和 86.44%），而 CDH13 启动子甲基化也存在于复杂性增生和非典型增生中（分别为 51.72%和 50.00%）。CDH13 和 SHP1 启动子的甲基化与年龄、肿瘤分化或肌层浸润深度有关。在子宫内膜癌细胞系中，CDH13 和 SHP1 启动子完全甲基化，经 5-Aza-CdR 或 TSA 处理后可部分逆转，诱导 mRNA 水平升高（P<0.01）。两种药物联合治疗后，CDH13 和 SHP1 启动子的甲基化完全逆转，mRNA 的表达显著增加（P<0.01）。此外，PRMT5 可与 UHRF1 结合，并经 5-Aza-CdR 和/或 TSA 处理后下调（P<0.05）。