scholarly journals PAF promotes stemness and radioresistance of glioma stem cells

2017 ◽  
Vol 114 (43) ◽  
pp. E9086-E9095 ◽  
Author(s):  
Derrick Sek Tong Ong ◽  
Baoli Hu ◽  
Yan Wing Ho ◽  
Charles-Etienne Gabriel Sauvé ◽  
Christopher A. Bristow ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dna Replication ◽  
Therapeutic Option ◽  
Nuclear Antigen ◽  
Glioma Stem Cells ◽  
Cell Frequency ◽  
Self Renewal ◽  
Dna Damage Signaling ◽  
Proliferating Cell ◽  
Tumor Initiating Cell

An integrated genomic and functional analysis to elucidate DNA damage signaling factors promoting self-renewal of glioma stem cells (GSCs) identified proliferating cell nuclear antigen (PCNA)-associated factor (PAF) up-regulation in glioblastoma. PAF is preferentially overexpressed in GSCs. Its depletion impairs maintenance of self-renewal without promoting differentiation and reduces tumor-initiating cell frequency. Combined transcriptomic and metabolomic analyses revealed that PAF supports GSC maintenance, in part, by influencing DNA replication and pyrimidine metabolism pathways. PAF interacts with PCNA and regulates PCNA-associated DNA translesion synthesis (TLS); consequently, PAF depletion in combination with radiation generated fewer tumorspheres compared with radiation alone. Correspondingly, pharmacological impairment of DNA replication and TLS phenocopied the effect of PAF depletion in compromising GSC self-renewal and radioresistance, providing preclinical proof of principle that combined TLS inhibition and radiation therapy may be a viable therapeutic option in the treatment of glioblastoma multiforme (GBM).

scholarly journals Expression of Piwi Genes during the Regeneration of Lineus sanguineus (Nemertea, Pilidiophora, Heteronemertea)

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1484
Author(s):  
Cong-Mei Xu ◽  
Shi-Chun Sun
Keyword(s):  
Stem Cells ◽  
Proliferating Cell Nuclear Antigen ◽  
Direct Evidence ◽  
Nuclear Antigen ◽  
Regeneration Capacity ◽  
Pluripotent Cells ◽  
Self Renewal ◽  
Proliferating Cell ◽  
Anterior Regeneration

The transposon silencer piwi genes play important roles in germline determination and maintenance, gametogenesis, and stem-cell self-renewal, and the expression of certain piwi genes is indispensable for regeneration. Knowledge about piwi genes is needed for phylum Nemertea, which contains members (e.g., Lineus sanguineus) with formidable regeneration capacity. By searching the L. sanguineus genome, we identified six Argonaute genes including three ago (Ls-Ago2, Ls-Ago2a, and Ls-Ago2b) and three piwi (Ls-piwi1, Ls-piwi2, and Ls-piwi3) genes. In situ hybridization revealed that, in intact females, Ls-piwi2 and Ls-piwi3 were not expressed, while Ls-piwi1 was expressed in ovaries. During regeneration, Ls-piwi1 and Ls-pcna (proliferating cell nuclear antigen) had strong and similar expressions. The expression of Ls-piwi1 became indetectable while Ls-pcna continued to be expressed when the differentiation of new organs was finished. During anterior regeneration, expression signals of Ls-piwi2 and Ls-piwi3 were weak and only detected in the blastema stage. During posterior regeneration, no expression was observed for Ls-piwi2. To date, no direct evidence has been found for the existence of congenital stem cells in adult L. sanguineus. The “pluripotent cells” in regenerating tissues are likely to be dedifferentiated from other type(s) of cells.

scholarly journals Maneuvers on PCNA Rings during DNA Replication and Repair

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 416 ◽  
Author(s):  
Dea Slade
Keyword(s):  
Dna Replication ◽  
Protein Interactions ◽  
Proliferating Cell Nuclear Antigen ◽  
Binding Proteins ◽  
Nuclear Antigen ◽  
Vast Number ◽  
Post Translational Modifications ◽  
Dna Replication And Repair ◽  
Replicative Polymerases ◽  
Proliferating Cell

DNA replication and repair are essential cellular processes that ensure genome duplication and safeguard the genome from deleterious mutations. Both processes utilize an abundance of enzymatic functions that need to be tightly regulated to ensure dynamic exchange of DNA replication and repair factors. Proliferating cell nuclear antigen (PCNA) is the major coordinator of faithful and processive replication and DNA repair at replication forks. Post-translational modifications of PCNA, ubiquitination and acetylation in particular, regulate the dynamics of PCNA-protein interactions. Proliferating cell nuclear antigen (PCNA) monoubiquitination elicits ‘polymerase switching’, whereby stalled replicative polymerase is replaced with a specialized polymerase, while PCNA acetylation may reduce the processivity of replicative polymerases to promote homologous recombination-dependent repair. While regulatory functions of PCNA ubiquitination and acetylation have been well established, the regulation of PCNA-binding proteins remains underexplored. Considering the vast number of PCNA-binding proteins, many of which have similar PCNA binding affinities, the question arises as to the regulation of the strength and sequence of their binding to PCNA. Here I provide an overview of post-translational modifications on both PCNA and PCNA-interacting proteins and discuss their relevance for the regulation of the dynamic processes of DNA replication and repair.

MicroRNA‐30a suppresses self‐renewal and tumorigenicity of glioma stem cells by blocking the NT5E‐dependent Akt signaling pathway

2020 ◽  
Vol 34 (4) ◽  
pp. 5128-5143
Author(s):  
Lilei Peng ◽  
Yang Ming ◽  
Ling Zhang ◽  
Jie Zhou ◽  
Wei Xiang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Akt Signaling ◽  
Glioma Stem Cells ◽  
Akt Signaling Pathway ◽  
Self Renewal

scholarly journals HAUSP Stabilizes SOX2 through Deubiquitination to Maintain Self-renewal and Tumorigenic Potential of Glioma Stem Cells

2021 ◽  
Author(s):  
Zhi Huang ◽  
Kui Zhai ◽  
Qiulian Wu ◽  
Xiaoguang Fang ◽  
Qian Huang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Glioma Stem Cells ◽  
Posttranslational Regulation ◽  
Malignant Growth ◽  
Self Renewal ◽  
Animal Survival ◽  
Promising Target ◽  
Tumorigenic Potential ◽  
Therapeutic Opportunity

Glioblastoma (GBM) is the most lethal brain tumor containing glioma stem cells (GSCs) that promote malignant growth and therapeutic resistance. The self-renewal and tumorigenic potential of GSCs are maintained by core stem cell transcription factors including SOX2. Defining the posttranslational regulation of SOX2 may offer new insights into GSC biology and potential therapeutic opportunity. Here, we discover that HAUSP stabilizes SOX2 through deubiquitination to maintain GSC self-renewal and tumorigenic potential. HAUSP is preferentially expressed in GSCs in perivascular niches in GBMs. Disrupting HAUSP by shRNA or its inhibitor P22077 promoted SOX2 degradation, induced GSC differentiation, impaired GSC tumorigenic potential, and suppressed GBM tumor growth. Importantly, pharmacological inhibition of HAUSP synergized with radiation to inhibit GBM growth and extended animal survival, indicating that targeting HAUSP may overcome GSC-mediated radioresistance. Our findings reveal an unappreciated crucial role of HAUSP in the GSC maintenance and provide a promising target for developing effective anti-GSC therapeutics to improve GBM treatment.

scholarly journals Nrf2 is required to maintain the self-renewal of glioma stem cells

BMC Cancer ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Jianhong Zhu ◽  
Handong Wang ◽  
Qing Sun ◽  
Xiangjun Ji ◽  
Lin Zhu ◽  
...  
Keyword(s):  
Stem Cells ◽  
The Self ◽  
Glioma Stem Cells ◽  
Self Renewal

scholarly journals Phosphorylation of PCNA by EGFR inhibits mismatch repair and promotes misincorporation during DNA synthesis

2015 ◽  
Vol 112 (18) ◽  
pp. 5667-5672 ◽  
Author(s):  
Janice Ortega ◽  
Jessie Y. Li ◽  
Sanghee Lee ◽  
Dan Tong ◽  
Liya Gu ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Mismatch Repair ◽  
Posttranslational Modifications ◽  
Growth Factor Receptor ◽  
Nuclear Antigen ◽  
Dna Mismatch ◽  
Epidermal Growth ◽  
Mismatch Recognition ◽  
Proliferating Cell

Proliferating cell nuclear antigen (PCNA) plays essential roles in eukaryotic cells during DNA replication, DNA mismatch repair (MMR), and other events at the replication fork. Earlier studies show that PCNA is regulated by posttranslational modifications, including phosphorylation of tyrosine 211 (Y211) by the epidermal growth factor receptor (EGFR). However, the functional significance of Y211-phosphorylated PCNA remains unknown. Here, we show that PCNA phosphorylation by EGFR alters its interaction with mismatch-recognition proteins MutSα and MutSβ and interferes with PCNA-dependent activation of MutLα endonuclease, thereby inhibiting MMR at the initiation step. Evidence is also provided that Y211-phosphorylated PCNA induces nucleotide misincorporation during DNA synthesis. These findings reveal a novel mechanism by which Y211-phosphorylated PCNA promotes cancer development and progression via facilitating error-prone DNA replication and suppressing the MMR function.

Sign in / Sign up

Export Citation Format

Share Document