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Xu J, Yang R, Hua X, Huang M, Tian Z, Li J, Lam HY, Jiang G, Cohen M, Huang C. lncRNA SNHG1 Promotes Basal Bladder Cancer Invasion via Interaction with PP2A Catalytic Subunit and Induction of Autophagy. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 21:354-366. [PMID: 32650234 PMCID: PMC7340968 DOI: 10.1016/j.omtn.2020.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/15/2020] [Accepted: 06/12/2020] [Indexed: 02/07/2023]
Abstract
Although basal muscle-invasive bladder cancers (MIBCs) are predominant, are more aggressive, and have bad prognoses, molecular mechanisms underlying how basal MIBC formation/progression have been barely explored. In the present study, SNHG1, a long non-coding RNA, was shown to be expressed at higher levels in basal MIBC cells than in other types of bladder BC cells, and its presence could promote basal MIBC cell invasion. The results revealed that SNHG1 specifically induced MMP2 expression via increasing its transcription and mRNA stability. In one mechanism, SNHG1 directly bound with PP2A catalytic subunit (PP2A-c) to inhibit interactions of PP2A-c with c-Jun and then promoted c-Jun phosphorylation that, in turn, mediated MMP2 transcription. In another mechanism, SNHG1 markedly induced autophagy in the cells via induction of increases in the abundance of autophagy-related proteins. The latter initiated autophagy and further abolished miR-34a stability, which reduced overall miR-34a binding directly to the 3' UTR of MMP2 mRNA, thereby promoting MMP2 mRNA stabilization. These results provided novel insight into understanding the specific functions of SNHG1 in basal MIBC. Such findings may ultimately prove highly significant for the design/synthesis of new SNHG1-based compounds for the treatment of basal MIBC patients.
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Affiliation(s)
- Jiheng Xu
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Rui Yang
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Xiaohui Hua
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Maowen Huang
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Zhongxian Tian
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Jingxia Li
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Hoi Yun Lam
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Guosong Jiang
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Mitchell Cohen
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
| | - Chuanshu Huang
- Department of Environmental Medicine, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA.
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Stivarou T, Stellas D, Vartzi G, Thomaidou D, Patsavoudi E. Targeting highly expressed extracellular HSP90 in breast cancer stem cells inhibits tumor growth in vitro and in vivo. Cancer Biol Ther 2016; 17:799-812. [PMID: 27259689 DOI: 10.1080/15384047.2016.1195041] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Breast cancer stem cells (BCSC) have been identified in breast carcinoma as CD44(+)/CD24(-/low) cells, which display tumorigenic activity and have the ability to self-renew, differentiate and metastasize. Previous studies showed that extracellular HSP90 (eHSP90) participates in the invasion and metastatic processes of various cancers including breast cancer. Here, we show for the first time that eHSP90 is over-expressed in mammosphere cultures that are derived from the MDA-MB-231, MDA-MB-453 and MCF-7 breast cancer cell lines. These mammospheres are highly enriched in cells of the CD44(+)/CD24(-/low) BCSC phenotype and additionally show high expression of the BCSC markers CD49f and Sox2. Thus our results indicate that eHSP90 represents a potential novel BCSC marker. Moreover, we present evidence that eHSP90 is functionally involved in BCSC activity in vitro and in vivo. Selective neutralization of eHSP90, using the monoclonal antibody mAb 4C5, has the capacity to inhibit stem cell activity in vitro because the formation of mammosphere-derived colonies is dramatically reduced in its presence. In vivo, the treatment of mice with mAb4C5 using a prophylactic protocol, significantly inhibited the primary growth of MDA-MB-231 and mammosphere-derived tumors. More importantly, administration of this antibody in a therapeutic protocol caused a statistically significant regression of established tumors derived from MDA-MB-231 originating mammospheres. Tumor regression was even greater when mAb 4C5 was administered in combination with paclitaxel. Overall, our findings implicate eHSP90 as a potential novel BCSC biomarker. Moreover they show that eHSP90 participates in BCSC-derived primary tumor growth. Finally, we provide additional support for the possible therapeutic value of mAb4C5 in the treatment of breast cancer.
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Affiliation(s)
- Theodora Stivarou
- a Department of Biomedical Engineering and Technology , Technological Educational Institute of Athens , Athens Greece.,b Department of Biochemistry , Hellenic Pasteur Institute , Athens , Greece
| | - Dimitris Stellas
- c Department of Cancer Biology of the Biomedical Research Foundation of the Academy of Athens , Athens Greece
| | - Georgia Vartzi
- b Department of Biochemistry , Hellenic Pasteur Institute , Athens , Greece
| | - Dimitra Thomaidou
- b Department of Biochemistry , Hellenic Pasteur Institute , Athens , Greece
| | - Evangelia Patsavoudi
- a Department of Biomedical Engineering and Technology , Technological Educational Institute of Athens , Athens Greece.,b Department of Biochemistry , Hellenic Pasteur Institute , Athens , Greece
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A laminin 511 matrix is regulated by TAZ and functions as the ligand for the α6Bβ1 integrin to sustain breast cancer stem cells. Genes Dev 2015; 29:1-6. [PMID: 25561492 PMCID: PMC4281560 DOI: 10.1101/gad.253682.114] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chang et al. found that breast cancer stem cells (CSCs) produce a laminin (LM) 511 matrix that promotes self-renewal and tumor initiation by engaging the α6Bβ1 integrin and activating the Hippo transducer TAZ. TAZ regulates the transcription of the α5 subunit of LM511 and the formation of a LM511 matrix. Understanding how the extracellular matrix impacts the function of cancer stem cells (CSCs) is a significant but poorly understood problem. We report that breast CSCs produce a laminin (LM) 511 matrix that promotes self-renewal and tumor initiation by engaging the α6Bβ1 integrin and activating the Hippo transducer TAZ. Although TAZ is important for the function of breast CSCs, the mechanism is unknown. We observed that TAZ regulates the transcription of the α5 subunit of LM511 and the formation of a LM511 matrix. These data establish a positive feedback loop involving TAZ and LM511 that contributes to stemness in breast cancer.
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