scholarly journals Clonal chondroprogenitors maintain telomerase activity and Sox9 expression during extended monolayer culture and retain chondrogenic potential

2009 ◽  
Vol 17 (4) ◽  
pp. 518-528 ◽  
Author(s):  
I.M. Khan ◽  
J.C. Bishop ◽  
S. Gilbert ◽  
C.W. Archer
Keyword(s):  
Monolayer Culture ◽  
Telomerase Activity ◽  
Sox9 Expression ◽  
Chondrogenic Potential

scholarly journals In vitro expansion impaired the stemness of early passage mesenchymal stem cells for treatment of cartilage defects

2017 ◽  
Vol 8 (6) ◽  
pp. e2851-e2851 ◽  
Author(s):  
Tongmeng Jiang ◽  
Guojie Xu ◽  
Qiuyan Wang ◽  
Lihui Yang ◽  
Li Zheng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Mononuclear Cells ◽  
Telomerase Activity ◽  
Cartilage Defects ◽  
Cell Based Therapy ◽  
Chondrogenic Potential ◽  
First Choice

Abstract In vitro cultured autologous mesenchymal stem cells (MSCs) within passage 5 have been approved for clinical application in stem cell-based treatment of cartilage defects. However, their chondrogenic potential has not yet been questioned or verified. In this study, the chondrogenic potential of bone marrow MSCs at passage 3 (P3 BMSCs) was investigated both in cartilage repair and in vitro, with freshly isolated bone marrow mononuclear cells (BMMNCs) as controls. The results showed that P3 BMSCs were inferior to BMMNCs not only in their chondrogenic differentiation ability but also as candidates for long-term repair of cartilage defects. Compared with BMMNCs, P3 BMSCs presented a decay in telomerase activity and a change in chromosomal morphology with potential anomalous karyotypes, indicating senescence. In addition, interindividual variability in P3 BMSCs is much higher than in BMMNCs, demonstrating genomic instability. Interestingly, remarkable downregulation in cell cycle, DNA replication and mismatch repair (MMR) pathways as well as in multiple genes associated with telomerase activity and chromosomal stability were found in P3 BMSCs. This result indicates that telomerase and chromosome anomalies might originate from expansion, leading to impaired stemness and pluripotency of stem cells. In vitro culture and expansion are not recommended for cell-based therapy, and fresh BMMNCs are the first choice.

Efficacy of decitabine in malignant meningioma cells: relation to promoter demethylation of distinct tumor suppressor and oncogenes and independence from TERT

2020 ◽  
pp. 1-10
Author(s):  
Louise Stögbauer ◽  
Christian Thomas ◽  
Andrea Wagner ◽  
Nils Warneke ◽  
Eva Christine Bunk ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Tumor Suppressor ◽  
Promoter Methylation ◽  
Tumor Suppressor Genes ◽  
Telomerase Activity ◽  
High Grade ◽  
Htert Promoter ◽  
Men 1 ◽  
Meningioma Cell ◽  
Tert Expression

OBJECTIVEChemotherapeutic options for meningiomas refractory to surgery or irradiation are largely unknown. Human telomerase reverse transcriptase (hTERT) promoter methylation with subsequent TERT expression and telomerase activity, key features in oncogenesis, are found in most high-grade meningiomas. Therefore, the authors investigated the impact of the demethylating agent decitabine (5-aza-2ʹ-deoxycytidine) on survival and DNA methylation in meningioma cells.METHODShTERT promoter methylation, telomerase activity, TERT expression, and cell viability and proliferation were investigated prior to and after incubation with decitabine in two benign (HBL-52 and Ben-Men 1) and one malignant (IOMM-Lee) meningioma cell line. The global effects of decitabine on DNA methylation were additionally explored with DNA methylation profiling.RESULTSHigh levels of TERT expression, telomerase activity, and hTERT promoter methylation were found in IOMM-Lee and Ben-Men 1 but not in HBL-52 cells. Decitabine induced a dose-dependent significant decrease of proliferation and viability after incubation with doses from 1 to 10 μM in IOMM-Lee but not in HBL-52 or Ben-Men 1 cells. However, effects in IOMM-Lee cells were not related to TERT expression, telomerase activity, or hTERT promoter methylation. Genome-wide methylation analyses revealed distinct demethylation of 14 DNA regions after drug administration in the decitabine-sensitive IOMM-Lee but not in the decitabine-resistant HBL-52 cells. Differentially methylated regions covered promoter regions of 11 genes, including several oncogenes and tumor suppressor genes that to the authors’ knowledge have not yet been described in meningiomas.CONCLUSIONSDecitabine decreases proliferation and viability in high-grade but not in benign meningioma cell lines. The effects of decitabine are TERT independent but related to DNA methylation changes of promoters of distinct tumor suppressor genes and oncogenes.

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