- Title
- The N-Myc-responsive lncRNA MILIP promotes DNA double-strand break repair through non-homologous end joining
- Creator
- Wang, Pei Lin; Teng, Liu; Zhao, Xiao Hong; La, Ting; Zhang, Yuan Yuan; Li, Jin Ming; Hu, Bin; Xu, Dengfei; Cang, Shundong; Wang, Li; Jin, Lei; Thorne, Rick F.; Feng, Yu Chen; Zhang, Xu Dong; Liu, T; Zhang, XD; Yue, Yi Meng; Han, Man Man; Yan, Qianqian; Ye, Kaihong; Tang, Cai Xia; Zhang, Sheng Nan; Qi, Teng Fei
- Relation
- NHMRC.1177087
- Relation
- Proceedings of the National Academy of Sciences Vol. 119, Issue 49, no. e2208904119
- Publisher Link
- http://dx.doi.org/10.1073/pnas.2208904119
- Publisher
- National Academy of Sciences
- Resource Type
- journal article
- Date
- 2022
- Description
- Significance: Here, we report that the lncRNA MILIP is transcriptionally regulated by N-Myc and functions to promote DNA double-strand break repair in neuroblastoma cells. MILIP is distinguished from other lncRNAs implicated in DNA repair through its scaffolding role in Ku complex formation, a requisite step to initiate the nonhomologous end-joining pathway. Our findings substantiate the long-postulated role of N-Myc in regulating DNA repair in neuroblastoma cells and reveal the functional importance of MILIP in cell survival, proliferation, and resistance to genotoxic stress, with practical implications of MILIP targeting, alone and in combination with DNA-damaging therapeutics, for neuroblastoma treatment. Abstract: The protooncoprotein N-Myc, which is overexpressed in approximately 25% of neuroblastomas as the consequence of MYCN gene amplification, has long been postulated to regulate DNA double-strand break (DSB) repair in neuroblastoma cells, but experimental evidence of this function is presently scant. Here, we show that N-Myc transcriptionally activates the long noncoding RNA MILIP to promote nonhomologous end-joining (NHEJ) DNA repair through facilitating Ku70–Ku80 heterodimerization in neuroblastoma cells. High MILIP expression was associated with poor outcome and appeared as an independent prognostic factor in neuroblastoma patients. Knockdown of MILIP reduced neuroblastoma cell viability through the induction of apoptosis and inhibition of proliferation, retarded neuroblastoma xenograft growth, and sensitized neuroblastoma cells to DNA-damaging therapeutics. The effect of MILIP knockdown was associated with the accumulation of DNA DSBs in neuroblastoma cells largely due to decreased activity of the NHEJ DNA repair pathway. Mechanistical investigations revealed that binding of MILIP to Ku70 and Ku80 increased their heterodimerization, and this was required for MILIP-mediated promotion of NHEJ DNA repair. Disrupting the interaction between MILIP and Ku70 or Ku80 increased DNA DSBs and reduced cell viability with therapeutic potential revealed where targeting MILIP using Gapmers cooperated with the DNA-damaging drug cisplatin to inhibit neuroblastoma growth in vivo. Collectively, our findings identify MILIP as an N-Myc downstream effector critical for activation of the NHEJ DNA repair pathway in neuroblastoma cells, with practical implications of MILIP targeting, alone and in combination with DNA-damaging therapeutics, for neuroblastoma treatment.
- Subject
- lncRNA; N-Myc; MYCN; DNA repair; neuroblastoma; SDG 3; Sustainable Development Goals
- Identifier
- http://hdl.handle.net/1959.13/1483574
- Identifier
- uon:51136
- Identifier
- ISSN:0027-8424
- Language
- eng
- Reviewed
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