Duan, Y;Yue, K;Ye, B;Chen, P;Zhang, J;He, Q;Wu, Y;Lai, Q;Li, H;Wu, Y;Jing, C;Wang, X;
PMID: 36813772 | DOI: 10.1038/s41419-023-05667-6
Long non-coding RNAs (LncRNAs) are implicated in malignant progression of human cancers. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-known lncRNA, has been reported to play crucial roles in multiple malignancies including head and neck squamous cell carcinoma (HNSCC). However, the underlying mechanisms of MALAT1 in HNSCC progression remain to be further investigated. Here, we elucidated that compared with normal squamous epithelium, MALAT1 was notably upregulated in HNSCC tissues, especially in which was poorly differentiated or with lymph nodes metastasis. Moreover, elevated MALAT1 predicted unfavorable prognosis of HNSCC patients. The results of in vitro and in vivo assays showed that targeting MALAT1 could significantly weaken the capacities of proliferation and metastasis in HNSCC. Mechanistically, MALAT1 inhibited von Hippel-Lindau tumor suppressor (VHL) by activating EZH2/STAT3/Akt axis, then promoted the stabilization and activation of β-catenin and NF-κB which could play crucial roles in HNSCC growth and metastasis. In conclusion, our findings reveal a novel mechanism for malignant progression of HNSCC and suggest that MALAT1 might be a promising therapeutic target for HNSCC treatment.
Miao, H;Wu, F;Li, Y;Qin, C;Zhao, Y;Xie, M;Dai, H;Yao, H;Cai, H;Wang, Q;Song, X;Li, L;
PMID: 36563164 | DOI: 10.1126/sciadv.abq7289
Understanding how long noncoding RNAs (lncRNAs) cooperate with splicing factors (SFs) in alternative splicing (AS) control is fundamental to human biology and disease. We show that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-documented AS-implicated lncRNA, regulates AS via two SFs, polypyrimidine tract-binding protein 1 (PTBP1) and PTB-associated SF (PSF). MALAT1 stabilizes the interaction between PTBP1 and PSF, thereby forming a functional module that affects a network of AS events. The MALAT1-stabilized PTBP1/PSF interaction occurs in multiple cellular contexts; however, the functional module, relative to MALAT1 only, has more dominant pathological significance in hepatocellular carcinoma. MALAT1 also stabilizes the PSF interaction with several heterogeneous nuclear ribonucleoparticle proteins other than PTBP1, hinting a broad role in AS control. We present a model in which MALAT1 cooperates with distinct SFs for AS regulation and pose that, relative to analyses exclusively performed for lncRNAs, a comprehensive consideration of lncRNAs and their binding partners may provide more information about their biological functions.
bioRxiv : the preprint server for biology
Hazra, R;Utama, R;Naik, P;Dobin, A;Spector, DL;
PMID: 36711961 | DOI: 10.1101/2023.01.20.524887
Glioblastoma multiforme (GBM) is an aggressive, heterogeneous grade IV brain tumor. Glioblastoma stem cells (GSCs) initiate the tumor and are known culprits of therapy resistance. Mounting evidence has demonstrated a regulatory role of long non-coding RNAs (lncRNAs) in various biological processes, including pluripotency, differentiation, and tumorigenesis. A few studies have suggested that aberrant expression of lncRNAs is associated with GSCs. However, a comprehensive single-cell analysis of the GSC-associated lncRNA transcriptome has not been carried out. Here, we analyzed recently published single-cell RNA-sequencing datasets of adult human GBM tumors, GBM organoids, GSC-enriched GBM tumors, and developing human brains to identify lncRNAs highly expressed in GBM. To categorize GSC populations in the GBM tumors, we used the GSC marker genes SOX2, PROM1, FUT4, and L1CAM. We found three major GSC population clusters: radial glia, oligodendrocyte progenitor cells, and neurons. We found 10â€"100 lncRNAs significantly enriched in different GSC populations. We also validated the level of expression and localization of several GSC-enriched lncRNAs using qRT-PCR, single-molecule RNA FISH, and sub-cellular fractionation. We found that the radial glia GSC-enriched lncRNA PANTR1 is highly expressed in GSC lines and is localized to both the cytoplasmic and nuclear fractions. In contrast, the neuronal GSC-enriched lncRNAs LINC01563 and MALAT1 are highly enriched in the nuclear fraction of GSCs. Together, this study identified a panel of uncharacterized GSC-specific lncRNAs. These findings set the stage for future in-depth studies to examine their role in GBM pathology and their potential as biomarkers and/or therapeutic targets in GBM.
Clinical and translational medicine
Liu, L;Hu, L;Long, H;Zheng, M;Hu, Z;He, Y;Gao, X;Du, P;Zhao, H;Yu, D;Lu, Q;Zhao, M;
PMID: 36447054 | DOI: 10.1002/ctm2.1117
The aberrant differentiation of T follicular helper (Tfh) cells plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanism of regulating Tfh cells differentiation remains unclear. Long noncoding RNAs (lncRNAs) act as important regulators in the processes of innate and adaptive immune response. Whether lncRNAs are involved in regulating Tfh cell differentiation and autoimmune responses need to be further identified.The characters and functions of human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were investigated by a series of biochemical assays and cell transfection assay. mIl21-AS1 regulating humoral immune response in vivo was explored by keyhole limpet haemocyanin (KLH) and chronic graft versus host disease (cGVHD) model.Human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were identified and cloned. We uncovered that IL21-AS1 was highly expressed in CD4+ T cells of SLE patients and Tfh cells, which promoted differentiation of Tfh cells. Mechanistically, IL21-AS1 bound heterogeneous nuclear ribonucleoprotein U and recruited acetyltransferases CREB-binding protein to the promoter of IL21, leading to the transcriptional activation of IL21 and Tfh cells differentiation through increasing Histone H3 acetylation level on IL21 promoter. Moreover, Tfh proportion and antibodies production were significantly increased in mIl21-AS knock-in mice immunized with KLH. mIl21-AS1 overexpression also exacerbated the lupus-like phenotype in cGVHD mice model.Our results demonstrate that IL21-AS1 activates IL21 transcription via epigenetic mechanism to promote germinal centre response, adding insight into the molecular regulation of autoimmune pathogenesis and providing a novel target for SLE treatment.