Research Paper Volume 13, Issue 21 pp 24171—24191

LncRNA OTUD6B-AS1 promotes paclitaxel resistance in triple negative breast cancer by regulation of miR-26a-5p/MTDH pathway-mediated autophagy and genomic instability

Peng-Ping Li1, , Rong-Guo Li1, , Yu-Qing Huang1, , Jin-Pian Lu2, , Wei-Jun Zhang1, , Zhen-Yu Wang1, ,

  • 1 Department of Breast-thyroid Surgery, Department of General Surgery, The First Hospital of Xiaoshan District, Hangzhou, Zhejiang Province 311000, China
  • 2 The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province 310000, China

Received: September 8, 2021       Accepted: October 28, 2021       Published: November 5, 2021      

https://doi.org/10.18632/aging.203672
How to Cite

Copyright: © 2021 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Genomic instability (GIN) is pivotal in regulating tumor drug resistance, which blocked the treatment of triple negative breast cancer (TNBC). Although recent studies implied that non-coding RNA (ncRNA)-mediated autophagy abolishment promoted tumorigenesis by up-regulation of GIN, autophagy was known as a risk factor in tumor drug resistance. However, previous study also pointed that up-regulation of autophagy promoted GIN. Therefore, the relationship between autophagy and GIN is not clear, and more work is needed. And, if an ncRNA is identified to be a co-regulator of autophagy and GIN, it will be a potential therapy target of chemotherapy resistance in TNBC. In our study, we recognized both autophagy-GIN-associated microRNA (mi-26a-5p) by big data analysis, which was prognosis-correlated in breast cancer. Next, we identified the up-stream regulators (long non-coding RNA, lncRNA) and down-stream targets of miR-26a-5p by bioinformatics analysis (online public databases). Finally, we established lncRNA OTUD6B-AS1/miR-26a-5p/MTDH signaling pathway, and verified their functions by cytological, molecular biological and zoological experiments. In general, our study found (1) miR-26a-5p was a protective factor of breast cancer, while OTUD6B-AS1 and MTDH were risk factors; (2) OTUD6B-AS1 was the up-stream regulator of miR-26a-5p verified by luciferase; (3) up-regulation of miR-26a-5p and down-regulation of MTDH promoted cellular cytotoxicity of paclitaxel (PTX) in vitro and in vivo. (4) down-regulation of miR-26a-5p, overexpression of MTDH and OTUD6B-AS1 promoted autophagy and DNA damage; (5) up-regulation of OTUD6B-AS1 and MTDH inhibited DNA damage response (DDR) by inhibiting the phosphorylated activation of RAD51, ATR and ATM.

Abbreviations

TNBC: Triple Negative Breast Cancer; PTX: Paclitaxel; GIN: Genomic Instability; lncRNA: Long Non-coding RNA; miRNA: MicroRNA; siRNA: Small Interfere RNA; DDR: DNA Damage Response; DSB: Double Strand Breaks; HR: homologous recombination; NHEJ: Non-Homologous End Binding; RP: Recombination Plasmid; TCGA: The Cancer Genome Atlas.