Background: SIRT7 is one of the histone deacetylases and is NAD-dependent. It forms a complex with ETS-like transcription factor 4 (ELK4), which deacetylates H3K18ac and works as a transcriptional suppressor. Overexpression of SIRT7 and deacetylation of H3K18ac have been shown to be associated with aggressive clinical behavior in some cancers, including hepatocellular carcinoma (HCC). The present study investigated the immunohistochemical expression of SIRT7, H3K18ac, and ELK4 in hepatocellular carcinoma.
Methods: A total of 278 HCC patients were enrolled in this study. Tissue microarray blocks were made from existing paraffin-embedded blocks. Immunohistochemical expressions of SIRT7, H3K18ac and ELK4 were scored and analyzed.
Results: High SIRT7 (p = .034), high H3K18ac (p = .001), and low ELK4 (p = .021) groups were associated with poor outcomes. Age < 65 years (p = .028), tumor size ≥ 5 cm (p = .001), presence of vascular emboli (p = .003), involvement of surgical margin (p = .001), and high American Joint Committee on Cancer stage (III&V) (p < .001) were correlated with worse prognoses. In multivariate analysis, H3K18ac (p = .001) and ELK4 (p = .015) were the significant independent prognostic factors.
Conclusions: High SIRT7 expression with poor overall survival implies that deacetylation of H3K18ac contributes to progression of HCC. High H3K18ac expression with poor prognosis is predicted due to a compensation mechanism. In addition, high ELK4 expression with good prognosis suggests another role of ELK4 as a tumor suppressor beyond SIRT7's helper. In conclusion, we could assume that the H3K18ac deacetylation pathway is influenced by many other factors.
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http://dx.doi.org/10.4132/jptm.2016.05.20 | DOI Listing |
Cell Death Dis
December 2024
Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Urology, Peking University Cancer Hospital & Institute, Beijing, 100142, China.
Cisplatin (CDDP) resistance has been established to significantly impact Bladder Cancer (BCa) therapy. On the other hand, the crucial regulatory involvement of SIRT7 and EZH2 in bladder cancer development is well known. Herein, the collaborative regulatory roles and underlying mechanisms of SIRT7 and EZH2 in CDDP resistance in bladder cancer were explored.
View Article and Find Full Text PDFJ Cell Mol Med
May 2024
Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China.
Diabetic kidney disease (DKD), a primary microvascular complication arising from diabetes, may result in end-stage renal disease. Epigenetic regulation of endothelial mesenchymal transition (EndMT) has been recently reported to exert function in metabolic memory and DKD. Here, we investigated the mechanism which Sirt7 modulated EndMT in human glomerular endothelial cells (HGECs) in the occurrence of metabolic memory in DKD.
View Article and Find Full Text PDFAntioxid Redox Signal
July 2024
Department of Histology and Embryology, College of Basic Medicine, Chongqing Medical University, Chongqing, P.R. China.
Nat Commun
September 2023
Endoscopy Center, Department of Gastroenterology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
The proline synthesis is importantly involved in tumor growth under hypoxia, while the underlying mechanism remains to be further investigated. Here we show that pyrroline-5-carpoxylate reductase-1 (PYCR1), displaying a constant nuclear localization, is phosphorylated by nuclear IGF1R at Tyrosine 135 under hypoxia; this phosphorylation promotes the binding of PYCR1 to ELK4 and thus PYCR1 recruitment to ELK4-targeted genes promoter. Under hypoxia, ELK4-binding ability and enzymatic activity of PYCR1 are both required for ELK4-Sirt7-mediated transcriptional repression and cell growth maintenance, in which PYCR1-catalyzed NAD production stimulates the deacetylation activity of Sirt7 on H3K18ac that restrains genes transcription.
View Article and Find Full Text PDFJ Biol Chem
August 2023
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China; The Innovation of Seed Design, Chinese Academy of Sciences, Wuhan, China. Electronic address:
SIRT7 is a member of the sirtuin family proteins with nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase activity, which can inhibit the activity of hypoxia-inducible factors independently of its enzymatic activity. However, the role of SIRT7 in affecting hypoxia signaling in vivo is still elusive. Here, we find that sirt7-null zebrafish are more resistant to hypoxic conditions, along with an increase of hypoxia-responsive gene expression and erythrocyte numbers, compared with their wildtype siblings.
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