Downregulation of the enhancer of zeste homolog 1 transcriptional factor predicts poor prognosis of triple-negative breast cancer patients

PeerJ

article

Wei Peng¹  Wei Tang²  Jian-Di Li²  Rong-Quan He¹  Jia-Yuan Luo³  Zu-Xuan Chen⁴  Jiang-Hui Zeng⁵  Xiao-Hua Hu¹  Jin-Cai Zhong¹  Yang Li¹  Fu-Chao Ma¹  Tian-Yi Xie⁶  Su-Ning Huang⁷  Lian-Ying Ge⁸ 

[1] Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University;Department of Breast Surgery, Guangxi Medical University Cancer Hospital;Department of Pathology, First Affiliated Hospital of Guangxi Medical University;Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University;Department of Clinical Laboratory, The Third Affiliated Hospital of Guangxi Medical University/Nanning Second People’s Hospital;Department of Traditional Chinese Medicine, The First Affiliated Hospital of Guangxi Medical University;Department of Radiotherapy, Guangxi Medical University Cancer Hospital;Department of Endoscopy, Guangxi Medical University Cancer Hospital

关键词: Triple-negative breast cancer;    EZH1;    Transcriptional regulation;    Molecular approaches;   

DOI  :  10.7717/peerj.13708

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer and lacks effective biomarkers. This study seeks to unravel the expression status and the prospective transcriptional mechanisms of EZH1/EZH2 in TNBC tissue samples. Moreover, another objective of this study is to reveal the prognostic molecular signatures for risk stratification in TNBC patients. Methods To determine the expression status of EZH1/EZH2 in TNBC tissue samples, microarray analysis and immunohistochemistry were performed on in house breast cancer tissue samples. External mRNA expression matrices were used to verify its expression patterns. Furthermore, the prospective transcriptional mechanisms of EZH1/EZH2 in TNBC were explored by performing differential expression analysis, co-expression analysis, and chromatin immunoprecipitation sequencing analysis. Kaplan–Meier survival analysis and univariate Cox regression analysis were utilized to detect the prognostic molecular signatures in TNBC patients. Nomogram and time-dependent receiver operating characteristic curves were plotted to predict the risk stratification ability of the prognostic-signatures-based Cox model. Results In-house TMAs (66 TNBC vs. 106 non-TNBC) and external gene microarrays, as well as RNA-seq datasets (1,135 TNBC vs. 6,198 non-TNBC) results, confirmed the downregulation of EZH1 at both the protein and mRNA levels (SMD = −0.59 [−0.80, −0.37]), as is opposite to that of EZH2 (SMD = 0.74 [0.40, 1.08]). The upregulated transcriptional target genes of EZH1 were significantly aggregated in the cell cycle pathway, where CCNA2, CCNB1, MAD2L1, and PKMYT1 were determined as key transcriptional targets. Additionally, the downregulated transcriptional targets of EZH2 were enriched in response to the hormone, where ESR1 was identified as the hub gene. The six-signature-based prognostic model produced an impressive performance in this study, with a training AUC of 0.753, 0.981, and 0.977 at 3-, 5-, and 10-year survival probability, respectively. Conclusion EZH1 downregulation may be a key modulator in the progression of TNBC through negative transcriptional regulation by targeting CCNA2, CCNB1, MAD2L1, and PKMYT1.

【 授权许可】

CC BY