The endogenous retrovirus-derived long noncoding RNA TROJAN promotes triple-negative breast cancer progression via ZMYND8 degradation
SCIENCE ADVANCES
Authors: Jin, Xi; Xu, Xiao-En; Jiang, Yi-Zhou; Liu, Yi-Rong; Sun, Wei; Guo, Ya-Jie; Ren, Yi-Xing; Zuo, Wen-Jia; Hu, Xin; Huang, Sheng-Lin; Shen, Hong-Jie; Lan, Fei; He, Yun-Fei; Hu, Guo-Hong; Di, Gen-Hong; He, Xiang-Huo; Li, Da-Qiang; Liu, Suling; Yu, Ke-Da; Shao, Zhi-Ming
Abstract
Human endogenous retroviruses (HERVs) play pivotal roles in the development of breast cancer. However, the detailed mechanisms of noncoding HERVs remain elusive. Here, our genome-wide transcriptome analysis of HERVs revealed that a primate long noncoding RNA, which we dubbed TROJAN, was highly expressed in human triple-negative breast cancer (TNBC). TROJAN promoted TNBC proliferation and invasion and indicated poor patient outcomes. We further confirmed that TROJAN could bind to ZMYND8, a metastasis-repressing factor, and increase its degradation through the ubiquitin-proteasome pathway by repelling ZNF592. TROJAN also epigenetically up-regulated metastasis-related genes in multiple cell lines. Correlations between TROJAN and ZMYND8 were subsequently confirmed in clinical samples. Furthermore, our study verified that antisense oligonucleotide therapy targeting TROJAN substantially suppressed TNBC progression in vivo. In conclusion, the long noncoding RNA TROJAN promotes TNBC progression and serves as a potential therapeutic target.
Mapping Bromodomains in breast cancer and association with clinical outcome
SCIENTIFIC REPORTS
Authors: Perez-Pena, Javier; Paez, Raquel; Nieto-Jimenez, Cristina; Corrales Sanchez, Veronica; Galan-Moya, Eva M.; Pandiella, Atanasio; Gyorffy, Balazs; Ocana, Alberto
Abstract
A specific family of proteins that participate in epigenetic regulation is the bromodomain (BRD) family of proteins. In this work, we aimed to explore the expression of the BRD family at a transcriptomic level in breast cancer, and its association with patient survival. mRNA level data from normal breast and tumor tissues were extracted from public datasets. Gene set enrichment analysis (GSEA) was performed to identify relevant biological functions. The KM Plotter Online tool was used to evaluate the relationship between the presence of different genes and patient clinical outcome. mRNA level data from HER2+ breast cancer patients sensible and resistant to trastuzumab were also evaluated. The BRD family was an enriched function. In HER2 positive tumors the combined analyses of BRD2, BAZ1A, TRIM33 and ZMYND8 showed a detrimental relapse free survival (RFS). Similarly, the combined analysis of BRD2, BAZ1A, PHIP, TRIM33, KMT2A, ASH1L, PBRM1, correlated with an extremely poor overall survival (OS). The prognosis was confirmed using an independent dataset from TCGA. Finally, no relation between expression of BRD genes and response to trastuzumab was observed in the HER2 population. Upregulation of some BRD genes is associated with detrimental outcome in HER2 positive tumors, regardless trastuzumab treatment.