Faculty Opinions recommendation of K48-linked KLF4 ubiquitination by E3 ligase Mule controls T-cell proliferation and cell cycle progression.

Multiple Sclerosis (MS) is a debilitating central nervous system disorder associated with inflammatory T cells. Activation and expansion of inflammatory T cells is thought to be behind MS relapses and influence disease severity. Protein arginine N-methyltransferase 5 (PRMT5) is a T cell activation-induced enzyme that symmetrically dimethylates proteins and promotes T cell proliferation. However, the mechanism behind PRMT5-mediated control of T cell proliferation and whether PRMT5 contributes to diseases severity is unclear. Here, we evaluated the role of PRMT5 on cyclin/cdk pairs and cell cycle progression, as well as PRMT5’s link to disease severity in an animal model of relapsing-remitting MS. Treatment of T helper 1 (mTh1) cells with the selective PRMT5 inhibitor, HLCL65, arrested activation-induced T cell proliferation at the G1 stage of the cell cycle, suggesting PRMT5 promotes cell cycle progression in CD4+ T cells. The Cyclin E1/Cdk2 pair promoting G1/S progression was also decreased after PRMT5 inhibition, as was the phosphorylation of retinoblastoma. In the SJL mouse relapsing-remitting model of MS, the highest PRMT5 expression in central nervous system-infiltrating cells corresponded to peak and relapse timepoints. PRMT5 expression also positively correlated with increasing CD4 Th cell composition, disease severity and Cyclin E1 expression. These data indicate that PRMT5 promotes G1/S cell cycle progression and suggest that this effect influences disease severity and/or progression in the animal model of MS. Modulating PRMT5 levels may be useful for controlling T cell expansion in T cell-mediated diseases including MS.

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Epigallocatechin-3-Gallate Directly Suppresses T Cell Proliferation through Impaired IL-2 Utilization and Cell Cycle Progression

Journal of Nutrition ◽

10.3945/jn.110.124743 ◽

2010 ◽

Vol 140 (8) ◽

pp. 1509-1515 ◽

Cited By ~ 26

Author(s):

Munkyong Pae ◽

Zhihong Ren ◽

Mohsen Meydani ◽

Fu Shang ◽

Simin Nikbin Meydani ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

T Cell ◽

Cell Cycle Progression ◽

T Cell Proliferation ◽

Cycle Progression

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Inhibition of T Cell Proliferation by Macrophage Tryptophan Catabolism

Journal of Experimental Medicine ◽

10.1084/jem.189.9.1363 ◽

1999 ◽

Vol 189 (9) ◽

pp. 1363-1372 ◽

Cited By ~ 1012

Author(s):

David H. Munn ◽

Ebrahim Shafizadeh ◽

John T. Attwood ◽

Igor Bondarev ◽

Achal Pashine ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

T Cells ◽

T Cell ◽

Cell Cycle Progression ◽

Antigen Presenting Cells ◽

T Cell Proliferation ◽

Cycle Progression ◽

Tryptophan Catabolism ◽

Antigen Presenting

We have recently shown that expression of the enzyme indoleamine 2,3-dioxygenase (IDO) during murine pregnancy is required to prevent rejection of the allogeneic fetus by maternal T cells. In addition to their role in pregnancy, IDO-expressing cells are widely distributed in primary and secondary lymphoid organs. Here we show that monocytes that have differentiated under the influence of macrophage colony-stimulating factor acquire the ability to suppress T cell proliferation in vitro via rapid and selective degradation of tryptophan by IDO. IDO was induced in macrophages by a synergistic combination of the T cell–derived signals IFN-γ and CD40-ligand. Inhibition of IDO with the 1-methyl analogue of tryptophan prevented macrophage-mediated suppression. Purified T cells activated under tryptophan-deficient conditions were able to synthesize protein, enter the cell cycle, and progress normally through the initial stages of G1, including upregulation of IL-2 receptor and synthesis of IL-2. However, in the absence of tryptophan, cell cycle progression halted at a mid-G1 arrest point. Restoration of tryptophan to arrested cells was not sufficient to allow further cell cycle progression nor was costimulation via CD28. T cells could exit the arrested state only if a second round of T cell receptor signaling was provided in the presence of tryptophan. These data reveal a novel mechanism by which antigen-presenting cells can regulate T cell activation via tryptophan catabolism. We speculate that expression of IDO by certain antigen presenting cells in vivo allows them to suppress unwanted T cell responses.

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Fbxl8 suppresses lymphoma growth and hematopoietic transformation through degradation of cyclin D3

Oncogene ◽

10.1038/s41388-020-01532-4 ◽

2020 ◽

Author(s):

Akihiro Yoshida ◽

Jaewoo Choi ◽

Hong Ri Jin ◽

Yan Li ◽

Sagar Bajpai ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Cell Cycle Progression ◽

Human Cancer ◽

E3 Ligase ◽

Protein Stabilization ◽

Cyclin D3 ◽

Deficient Mutant ◽

Cycle Progression ◽

Functional Investigation

Abstract Overexpression of D-type cyclins in human cancer frequently occurs as a result of protein stabilization, emphasizing the importance of identification of the machinery that regulates their ubiqutin-dependent degradation. Cyclin D3 is overexpressed in ~50% of Burkitt’s lymphoma correlating with a mutation of Thr-283. However, the E3 ligase that regulates phosphorylated cyclin D3 and whether a stabilized, phosphorylation deficient mutant of cyclin D3, has oncogenic activity are undefined. We describe the identification of SCF-Fbxl8 as the E3 ligase for Thr-283 phosphorylated cyclin D3. SCF-Fbxl8 poly-ubiquitylates p-Thr-283 cyclin D3 targeting it to the proteasome. Functional investigation demonstrates that Fbxl8 antagonizes cell cycle progression, hematopoietic cell proliferation, and oncogene-induced transformation through degradation of cyclin D3, which is abolished by expression of cyclin D3T283A, a non-phosphorylatable mutant. Clinically, the expression of cyclin D3 is inversely correlated with the expression of Fbxl8 in lymphomas from human patients implicating Fbxl8 functions as a tumor suppressor.

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Restoration of microRNA-212 causes a G0/G1 cell cycle arrest and apoptosis in adult T-cell leukemia/lymphoma cells by repressing CCND3 expression

Journal of Investigative Medicine ◽

10.1136/jim-2016-000233 ◽

2016 ◽

Vol 65 (1) ◽

pp. 82-87 ◽

Cited By ~ 3

Author(s):

Haihao Wang ◽

Qiannan Guo ◽

Peiwen Yang ◽

Guoxian Long

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

T Cell ◽

Cell Lines ◽

Cell Cycle Progression ◽

Cyclin D3 ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Cycle Progression ◽

Adult T Cell Leukemia

Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive T-cell malignancy. This study was designed to explore the expression and functional significance of microRNA (miR)-212 in ATL. The expression of miR-212 in human ATL tissues and cell lines were investigated. Gain-of-function experiments were carried out to determine the roles of miR-212 in cell proliferation, tumorigenesis, cell cycle progression, and apoptosis. We also identified and functionally characterized the target genes of miR-212 in ATL cells. Compared with normal lymph node biopsies, lymphoma samples from ATL patients displayed underexpression of miR-212 (p=0.0032). Consistently, miR-212 was downregulated in human ATL cell lines, compared with normal T lymphocytes. Restoration of miR-212 significantly (p<0.05) inhibited ATL cell proliferation and tumorigenesis in mice. Overexpression of miR-212 led to an accumulation of G0/G1-phase cells and a concomitant reduction of S-phase cells. Moreover, enforced expression of miR-212-induced significant apoptosis in ATL cells. CCND3, which encodes a cell cycle regulator cyclin D3, was identified as a direct target of miR-212 in ATL cells. Rescue experiments with a miR-212-resistant variant of CCND3 demonstrated that overexpression of CCND3 restored cell-cycle progression and attenuated apoptotic response in miR-212-overexpressing ATL cells. Taken together, miR-212 exerts growth-suppressive effects in ATL cells largely by targeting CCND3 and may have therapeutic potential in ATL.

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STAU2 protein level is controlled by caspases and the CHK1 pathway and regulates cell cycle progression in the non-transformed hTERT-RPE1 cells

BMC Molecular and Cell Biology ◽

10.1186/s12860-021-00352-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Lionel Condé ◽

Yulemi Gonzalez Quesada ◽

Florence Bonnet-Magnaval ◽

Rémy Beaujois ◽

Luc DesGroseillers

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Proliferation ◽

Dna Damage ◽

Steady State ◽

Posttranscriptional Regulation ◽

Cell Cycle Progression ◽

Rna Binding ◽

Regulation Of Gene Expression ◽

Cycle Progression

AbstractBackgroundStaufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from theSTAU2gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation.ResultsCRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism.ConclusionsThese results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway.

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LMNB2 promotes the progression of colorectal cancer by silencing p21 expression

Cell Death and Disease ◽

10.1038/s41419-021-03602-1 ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Chen-Hua Dong ◽

Tao Jiang ◽

Hang Yin ◽

Hu Song ◽

Yi Zhang ◽

...

Keyword(s):

Colorectal Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Gene Set Enrichment Analysis ◽

Molecular Therapy ◽

Cycle Progression ◽

Cancer Tissues

AbstractColorectal cancer is the second common cause of death worldwide. Lamin B2 (LMNB2) is involved in chromatin remodeling and the rupture and reorganization of nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, the role of LMNB2 in colorectal cancer (CRC) is poorly understood. This study explored the biological functions of LMNB2 in the progression of colorectal cancer and explored the possible molecular mechanisms. We found that LMNB2 was significantly upregulated in primary colorectal cancer tissues and cell lines, compared with paired non-cancerous tissues and normal colorectal epithelium. The high expression of LMNB2 in colorectal cancer tissues is significantly related to the clinicopathological characteristics of the patients and the shorter overall and disease-free cumulative survival. Functional analysis, including CCK8 cell proliferation test, EdU proliferation test, colony formation analysis, nude mouse xenograft, cell cycle, and apoptosis analysis showed that LMNB2 significantly promotes cell proliferation by promoting cell cycle progression in vivo and in vitro. In addition, gene set enrichment analysis, luciferase report analysis, and CHIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter, whereas LMNB2 has no effect on cell apoptosis. In summary, these findings not only indicate that LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, but also suggest the potential value of LMNB2 as a clinical prognostic marker and molecular therapy target.

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Hyperbaric oxygen promotes not only glioblastoma proliferation but also chemosensitization by inhibiting HIF1α/HIF2α-Sox2

Cell Death Discovery ◽

10.1038/s41420-021-00486-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Pan Wang ◽

Sheng Gong ◽

Jinyu Pan ◽

Junwei Wang ◽

Dewei Zou ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Cell Cycle Arrest ◽

Hyperbaric Oxygen ◽

Cell Cycle Progression ◽

Malignant Progression ◽

Cycle Progression ◽

Chemotherapy Sensitivity ◽

Hypoxic Conditions ◽

Cycle Arrest

AbstractThere exists a consensus that combining hyperbaric oxygen (HBO) and chemotherapy promotes chemotherapy sensitivity in GBM cells. However, few studies have explored the mechanism involved. HIF1α and HIF2α are the two main molecules that contribute to GBM malignant progression by inhibiting apoptosis or maintaining stemness under hypoxic conditions. Moreover, Sox2, a marker of stemness, also contributes to GBM malignant progression through stemness maintenance or cell cycle arrest. Briefly, HIF1α, HIF2α and Sox2 are highly expressed under hypoxia and contribute to GBM growth and chemoresistance. However, after exposure to HBO for GBM, whether the expression of the above factors is decreased, resulting in chemosensitization, remains unknown. Therefore, we performed a series of studies and determined that the expression of HIF1α, HIF2α and Sox2 was decreased after HBO and that HBO promoted GBM cell proliferation through cell cycle progression, albeit with a decrease in stemness, thus contributing to chemosensitization via the inhibition of HIF1α/HIF2α-Sox2.

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The Role of EGFR/PI3K/Akt/cyclinD1 Signaling Pathway in Acquired Middle Ear Cholesteatoma

Mediators of Inflammation ◽

10.1155/2013/651207 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 16

Author(s):

Wei Liu ◽

Hongmiao Ren ◽

Jihao Ren ◽

Tuanfang Yin ◽

Bing Hu ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Signaling Pathways ◽

Signaling Pathway ◽

External Auditory Canal ◽

Cell Cycle Progression ◽

Critical Role ◽

Immunohistochemical Method ◽

Cycle Progression ◽

Middle Ear Cholesteatoma

Cholesteatoma is a benign keratinizing and hyper proliferative squamous epithelial lesion of the temporal bone. Epidermal growth factor (EGF) is one of the most important cytokines which has been shown to play a critical role in cholesteatoma. In this investigation, we studied the effects of EGF on the proliferation of keratinocytes and EGF-mediated signaling pathways underlying the pathogenesis of cholesteatoma. We examined the expressions of phosphorylated EGF receptor (p-EGFR), phosphorylated Akt (p-Akt), cyclinD1, and proliferating cell nuclear antigen (PCNA) in 40 cholesteatoma samples and 20 samples of normal external auditory canal (EAC) epithelium by immunohistochemical method. Furthermore,in vitrostudies were performed to investigate EGF-induced downstream signaling pathways in primary external auditory canal keratinocytes (EACKs). The expressions of p-EGFR, p-Akt, cyclinD1, and PCNA in cholesteatoma epithelium were significantly increased when compared with those of control subjects. We also demonstrated that EGF led to the activation of the EGFR/PI3K/Akt/cyclinD1 signaling pathway, which played a critical role in EGF-induced cell proliferation and cell cycle progression of EACKs. Both EGFR inhibitor AG1478 and PI3K inhibitor wortmannin inhibited the EGF-induced EGFR/PI3K/Akt/cyclinD1 signaling pathway concomitantly with inhibition of cell proliferation and cell cycle progression of EACKs. Taken together, our data suggest that the EGFR/PI3K/Akt/cyclinD1 signaling pathway is active in cholesteatoma and may play a crucial role in cholesteatoma epithelial hyper-proliferation. This study will facilitate the development of potential therapeutic targets for intratympanic drug therapy for cholesteatoma.

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