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. |
- Juvvuna, Prasanna Kumar, et al.
(author)
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NBAT1/CASC15-003/USP36 control MYCN expression and its downstream pathway genes in neuroblastoma.
- 2021
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In: Neuro-oncology advances. - : Oxford University Press (OUP). - 2632-2498. ; 3:1
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Journal article (peer-reviewed)abstract
- MYCN has been an attractive therapeutic target in neuroblastoma considering the widespread amplification of the MYCN locus in neuroblastoma, and its established role in neuroblastoma development and progression. Thus, understanding neuroblastoma-specific control of MYCN expression at the transcriptional and post-transcriptional level would lead to identification of novel MYCN-dependent oncogenic pathways and potential therapeutic strategies.By performing loss- and gain-of-function experiments of the neuroblastoma hotspot locus 6p22.3 derived lncRNAs CASC15-003 and NBAT1, together with coimmunoprecipitation and immunoblotting of MYCN, we have shown that both lncRNAs post-translationally control the expression of MYCN through regulating a deubiquitinase enzyme USP36. USP36 oncogenic properties were investigated using cancer cell lines and in vivo models. RNA-seq analysis of loss-of-function experiments of CASC15-003/NBAT1/MYCN/USP36 and JQ1-treated neuroblastoma cells uncovered MYCN-dependent oncogenic pathways.We show that NBAT1/CASC15-003 control the stability of MYCN protein through their common interacting protein partner USP36. USP36 harbors oncogenic properties and its higher expression in neuroblastoma patients correlates with poor prognosis, and its downregulation significantly reduces tumor growth in neuroblastoma cell lines and xenograft models. Unbiased integration of RNA-seq data from CASC15-003, NBAT1, USP36, and MYCN knockdowns and neuroblastoma cells treated with MYCN inhibitor JQ1, identified genes that are jointly regulated by the NBAT1/CASC15-003/USP36/MYCN pathway. Functional experiments on one of the target genes, COL18A1, revealed its role in the NBAT1/CASC15-003-dependent cell adhesion feature in neuroblastoma cells.Our data show post-translational regulation of MYCN by NBAT1/CASC15-003/USP36, which represents a new regulatory layer in the complex multilayered gene regulatory network that controls MYCN expression.
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3. |
- Mahale, Sagar, et al.
(author)
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HnRNPK maintains single strand RNA through controlling double-strand RNA in mammalian cells.
- 2022
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In: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Journal article (peer-reviewed)abstract
- Although antisense transcription is a widespread event in the mammalian genome, double-stranded RNA (dsRNA) formation between sense and antisense transcripts is very rare and mechanisms that control dsRNA remain unknown. By characterizing the FGF-2 regulated transcriptome in normal and cancer cells, we identified sense and antisense transcripts IER3 and IER3-AS1 that play a critical role in FGF-2 controlled oncogenic pathways. We show that IER3 and IER3-AS1 regulate each other's transcription through HnRNPK-mediated post-transcriptional regulation. HnRNPK controls the mRNA stability and colocalization of IER3 and IER3-AS1. HnRNPK interaction with IER3 and IER3-AS1 determines their oncogenic functions by maintaining them in a single-stranded form. hnRNPK depletion neutralizes their oncogenic functions through promoting dsRNA formation and cytoplasmic accumulation. Intriguingly, hnRNPK loss-of-function and gain-of-function experiments reveal its role in maintaining global single- and double-stranded RNA. Thus, our data unveil the critical role of HnRNPK in maintaining single-stranded RNAs and their physiological functions by blocking RNA-RNA interactions.
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4. |
- Subhash, Santhilal, 1987, et al.
(author)
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Sperm Originated Chromatin Imprints and LincRNAs in Organismal Development and Cancer
- 2020
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In: iScience. - : Elsevier BV. - 2589-0042. ; 23:6
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Journal article (peer-reviewed)abstract
- Importance of sperm-derived transcripts and chromatin imprints in organismal development is poorly investigated. Here using an integrative approach, we show that human sperm transcripts are equally important as oocyte. Sperm-specific and sperm-oocyte common transcripts carry distinct chromatin structures at their promoters correlating with corresponding transcript levels in sperm. Interestingly, sperm-specific H3K4me3 patterns at the lincRNA promoters are not maintained in the germ layers and somatic tissues. However, bivalent chromatin at the sperm-specific protein-coding gene promoters is maintained throughout the development. Sperm-specific transcripts reach their peak expression during zygotic genome activation, whereas sperm-oocyte common transcripts are present during early preimplantation development but decline at the onset of zygotic genome activation. Additionally, there is an inverse correlation between sperm-specific and sperm-oocyte lincRNAs throughout the development. Sperm-lincRNAs also show aberrant activation in tumors. Overall, our observations indicate that sperm transcripts carrying chromatin imprints may play an important role in human development and cancer.
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5. |
- Schneider, Edith, et al.
(author)
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MicroRNA-708 is a novel regulator of the Hoxa9 program in myeloid cells.
- 2020
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In: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 34, s. 1253-1265
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Journal article (peer-reviewed)abstract
- MicroRNAs (miRNAs) are commonly deregulated in acute myeloid leukemia (AML), affecting critical genes not only through direct targeting, but also through modulation of downstream effectors. Homeobox (Hox) genes balance self-renewal, proliferation, cell death, and differentiation in many tissues and aberrant Hox gene expression can create a predisposition to leukemogenesis in hematopoietic cells. However, possible linkages between the regulatory pathways of Hox genes and miRNAs are not yet fully resolved. We identified miR-708 to be upregulated in Hoxa9/Meis1 AML inducing cell lines as well as in AML patients. We further showed Meis1 directly targeting miR-708 and modulating its expression through epigenetic transcriptional regulation. CRISPR/Cas9 mediated knockout of miR-708 in Hoxa9/Meis1 cells delayed disease onset in vivo, demonstrating for the first time a pro-leukemic contribution of miR-708 in this context. Overexpression of miR-708 however strongly impeded Hoxa9 mediated transformation and homing capacity in vivo through modulation of adhesion factors and induction of myeloid differentiation. Taken together, we reveal miR-708, a putative tumor suppressor miRNA and direct target of Meis1, as a potent antagonist of the Hoxa9 phenotype but an effector of transformation in Hoxa9/Meis1. This unexpected finding highlights the yet unexplored role of miRNAs as indirect regulators of the Hox program during normal and aberrant hematopoiesis.
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