| 1. |
- Ali, Mohamad Moustafa, et al.
(author)
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LY6K-AS lncRNA is a lung adenocarcinoma prognostic biomarker and regulator of mitotic progression.
- 2021
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In: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 40:13, s. 2463-2478
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Journal article (peer-reviewed)abstract
- Recent advances in genomics unraveled several actionable mutational drivers in lung cancer, leading to promising therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitors. However, the tumors' acquired resistance to the newly-developed as well as existing therapies restricts life quality improvements. Therefore, we investigated the noncoding portion of the human transcriptome in search of alternative actionable targets. We identified an antisense transcript, LY6K-AS, with elevated expression in lung adenocarcinoma (LUAD) patients, and its higher expression in LUAD patients predicts poor survival outcomes. LY6K-AS abrogation interfered with the mitotic progression of lung cancer cells resulting in unfaithful chromosomal segregation. LY6K-AS interacts with and stabilizes 14-3-3 proteins to regulate the transcription of kinetochore and mitotic checkpoint proteins. We also show that LY6K-AS regulates the levels of histone H3 lysine 4 trimethylation (H3K4me3) at the promoters of kinetochore members. Cisplatin treatment and LY6K-AS silencing affect many common pathways enriched in cell cycle-related functions. LY6K-AS silencing affects the growth of xenografts derived from wildtype and cisplatin-resistant lung cancer cells. Collectively, these data indicate that LY6K-AS silencing is a promising therapeutic option for LUAD that inhibits oncogenic mitotic progression.
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| 2. |
- Mitra, Sanhita, et al.
(author)
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Subcellular distribution of p53 by the p53-responsive lncRNA NBAT1 determines chemotherapeutic response in neuroblastoma.
- 2021
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In: Cancer research. - 1538-7445. ; 81:6, s. 1457-1471
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Journal article (peer-reviewed)abstract
- Neuroblastoma has a low mutation rate for the p53 gene. Alternative ways of p53 inactivation have been proposed in neuroblastoma, such as abnormal cytoplasmic accumulation of wild-type p53. However, mechanisms leading to p53 inactivation via cytoplasmic accumulation are not well investigated. Here we show that the neuroblastoma risk-associated locus 6p22.3-derived tumor suppressor NBAT1 is a p53-responsive lncRNA that regulates p53 subcellular levels. Low expression of NBAT1 provided resistance to genotoxic drugs by promoting p53 accumulation in cytoplasm and loss from mitochondrial and nuclear compartments. Depletion of NBAT1 altered CRM1 function and contributed to the loss of p53-dependent nuclear gene expression during genotoxic drug treatment. CRM1 inhibition rescued p53-dependent nuclear functions and sensitized NBAT1-depleted cells to genotoxic drugs. Combined inhibition of CRM1 and MDM2 was even more effective in sensitizing aggressive neuroblastoma cells with p53 cytoplasmic accumulation. Thus, our mechanistic studies uncover an NBAT1-dependent CRM1/MDM2-based potential combination therapy for high-risk neuroblastoma patients.
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| 3. |
- Vaid, Roshan, et al.
(author)
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METTL3 drives telomere targeting of TERRA lncRNA through m6A-dependent R-loop formation: a therapeutic target for ALT-positive neuroblastoma
- 2024
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In: NUCLEIC ACIDS RESEARCH. - 0305-1048 .- 1362-4962.
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Journal article (peer-reviewed)abstract
- Telomerase-negative tumors maintain telomere length by alternative lengthening of telomeres (ALT), but the underlying mechanism behind ALT remains poorly understood. A proportion of aggressive neuroblastoma (NB), particularly relapsed tumors, are positive for ALT (ALT+), suggesting that a better dissection of the ALT mechanism could lead to novel therapeutic opportunities. TERRA, a long non-coding RNA (lncRNA) derived from telomere ends, localizes to telomeres in a R-loop-dependent manner and plays a crucial role in telomere maintenance. Here we present evidence that RNA modification at the N-6 position of internal adenosine (m(6)A) in TERRA by the methyltransferase METTL3 is essential for telomere maintenance in ALT+ cells, and the loss of TERRA m(6)A/METTL3 results in telomere damage. We observed that m(6)A modification is abundant in R-loop enriched TERRA, and the m(6)A-mediated recruitment of hnRNPA2B1 to TERRA is critical for R-loop formation. Our findings suggest that m(6)A drives telomere targeting of TERRA via R-loops, and this m(6)A-mediated R-loop formation could be a widespread mechanism employed by other chromatin-interacting lncRNAs. Furthermore, treatment of ALT+ NB cells with a METTL3 inhibitor resulted in compromised telomere targeting of TERRA and accumulation of DNA damage at telomeres, indicating that METTL3 inhibition may represent a therapeutic approach for ALT+ NB. [Graphical Abstract]
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