scholarly journals Plexin-A2 Promotes The Proliferation And The Development Of Tumors From Glioblastoma Derived Cells

2021 ◽  
Author(s):  
Gera Neufeld ◽  
Shira Toledano ◽  
Adi D. Sabag ◽  
Tanya Liburkin-Dan ◽  
Ofra Kessler

The semaphorin guidance factors receptor Plexin-A2 transduces sema6A and sema6B signals and when associated with neuropilins can also transduce sema3C signals. Inhibition of plexin-A2 expression in U87MG glioblastoma cells resulted in strong inhibition of cell proliferation and tumor forming ability. Knock-out of the plexin-A2 gene using CRISPR/Cas9 also inhibited cell proliferation which was rescued following re-expression of the plexin-A2 cDNA or expression of a truncated plexin-A2 lacking the extracellular domain. Inhibition of plexin-A2 expression resulted in cell cycle arrest at the G2/M stage, and was accompanied by changes in cytoskeletal organization, cell flattening, and by the expression of senescence associated β-galactosidase. It was also associated with reduced AKT phosphorylation and enhanced phosphorylation of p38MAPK. We find that the pro-proliferative effects of plexin-A2 are mediated by FARP2 and FYN since mutations in the FARP2 binding domain of plexin-A2 or in the FYN phosphorylation sites of plexin-A2 compromised the rescue of the proliferative activity by the plexin-A2 intracellular domain. Our results suggest that plexin-A2 may represent a novel target for the development of anti-tumorigenic therapeutics.

2021 ◽  
Vol 19 (1) ◽  
pp. 119-127
Author(s):  
Ibrahim O. Barnawi ◽  
Fahd A. Nasr ◽  
Omar M. Noman ◽  
Ali S. Alqahtani ◽  
Mohammed Al-zharani ◽  
...  

Abstract Different phytochemicals from various plant species exhibit promising medicinal properties against cancer. Juniperus phoenicea is a plant species that has been found to present medicinal properties. Herein, crude extract and fractions of J. phoenicea were examined to determine its anticancer properties against several cancer cells. The active fraction was chosen to assess its activity on cell cycle progression and apoptosis induction by annexin and propidium iodide (PI) biomarkers. Further, phytochemical screening for possible contents of active fraction using gas chromatography–mass spectrometry (GC-MS) analysis was conducted. It was demonstrated that cell proliferation was suppressed, and the MCF-7 cell line was the most sensitive to J. phoenicea chloroform fraction (JPCF), with the IC50 values of 24.5 μg/mL. The anti-proliferation activity of JPCF in MCF-7 cells was linked to the aggregation of cells in the G1 phase, increases in early and late apoptosis as well as necrotic cell death. Contents analysis of JPCF using GC-MS analysis identified 3-methyl-5-(2′,6′,6′-trimethylcyclohex-1′-enyl)-1-penten-3-ol (16.5%), methyl 8-oxooctanoate (15.61%), cubenol (13.48%), and 7-oxabicyclo [2.2.1] heptane (12.14%) as major constituents. Our present study provides clear evidence that J. phoenicea can inhibit cell proliferation, trigger cell cycle arrest, and induce apoptosis in tested cancer cells.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Pan Wang ◽  
Sheng Gong ◽  
Jinyu Pan ◽  
Junwei Wang ◽  
Dewei Zou ◽  
...  

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.


2015 ◽  
Vol 100 (5) ◽  
pp. 1771-1779 ◽  
Author(s):  
Maomei Ruan ◽  
Min Liu ◽  
Qianggang Dong ◽  
Libo Chen

Abstract Context: The aberrant silencing of iodide-handling genes accompanied by up-regulation of glucose metabolism presents a major challenge for radioiodine treatment of papillary thyroid cancer (PTC). Objective: This study aimed to evaluate the effect of tyrosine kinase inhibitors on iodide-handling and glucose-handling gene expression in BHP 2-7 cells harboring RET/PTC1 rearrangement. Main Outcome Measures: In this in vitro study, the effects of sorafenib or cabozantinib on cell growth, cycles, and apoptosis were investigated by cell proliferation assay, cell cycle analysis, and Annexin V-FITC apoptosis assay, respectively. The effect of both agents on signal transduction pathways was evaluated using the Western blot. Quantitative real-time PCR, Western blot, immunofluorescence, and radioisotope uptake assays were used to assess iodide-handling and glucose-handling gene expression. Results: Both compounds inhibited cell proliferation in a time-dependent and dose-dependent manner and caused cell cycle arrest in the G0/G1 phase. Sorafenib blocked RET, AKT, and ERK1/2 phosphorylation, whereas cabozantinib blocked RET and AKT phosphorylation. The restoration of iodide-handling gene expression and inhibition of glucose transporter 1 and 3 expression could be induced by either drug. The robust expression of sodium/iodide symporter induced by either agent was confirmed, and 125I uptake was correspondingly enhanced. 18F-fluorodeoxyglucose accumulation was significantly decreased after treatment by either sorafenib or cabozantinib. Conclusions: Sorafenib and cabozantinib had marked effects on cell proliferation, cell cycle arrest, and signal transduction pathways in PTC cells harboring RET/PTC1 rearrangement. Both agents could be potentially used to enhance the expression of iodide-handling genes and inhibit the expression of glucose transporter genes.


2014 ◽  
Vol 84 (5) ◽  
pp. 578-584 ◽  
Author(s):  
Hongjian Yang ◽  
Xiangming He ◽  
Yabing Zheng ◽  
Weiliang Feng ◽  
Xianghou Xia ◽  
...  

2020 ◽  
Author(s):  
Wenbao Lu ◽  
Meicen Zhou ◽  
Bing Wang ◽  
Xueting Liu ◽  
Bingwei Li

Abstract Background: Dysregulation of cell cycle progression is one of the common features of human cancer cells, however, its mechanism remains unclear. This study aims to clarify the role and the underlying mechanisms of Roquin1 in cell cycle arrest induction in breast cancer.Methods: Public cancer databases were analyzed to identify the expression pattern of Roquin1 in human breast cancers and the significant association with patient survival. Quantitative real-time PCR and western blots were performed to detect the expression of Roquin1 in breast cancer samples and cell lines. Cell counting, MTT assay, flow cytometry, and in vivo study were conducted to investigate the effects of Roquin1 on cell proliferation, cell cycle progression and tumor progression. RNA-sequencing was applied to identify the differential genes and pathways regulated by Roquin1. RNA immunoprecipitation assay, luciferase reporter assay, mRNA half-life detection, RNA affinity binding assay, and RIP-ChIP were used to explore the molecular mechanisms of Roquin1.Results: We showed that Roquin1 expression in breast cancer tissues and cell lines was inhibited, and the reduction in Roquin1 expression was associated with poor overall survival and relapse free survival of patients with breast cancer. Roquin1 overexpression inhibited breast cancer cell proliferation and induced G1/S cell cycle arrest without causing significant apoptosis. In contrast, knockdown of Roquin1 promoted breast cancer cell growth and cycle progression. Moreover, in vivo induction of Roquin1 by adenovirus significantly suppressed breast tumor growth and metastasis. Mechanistically, Roquin1 selectively destabilizing cell cycle–promoting genes, including Cyclin D1, Cyclin E1, cyclin dependent kinase 6 (CDK6) and minichromosome maintenance 2 (MCM2) through targeting the stem–loop structure in the 3’untranslated region (3’UTR) of mRNAs via its ROQ domain, leading to the downregulation of cell cycle–promoting mRNAs.Conclusions: Our findings demonstrated that Roquin1 was a novel breast tumor suppressor and could induce G1/S cell cycle arrest by selectively downregulating the expression of cell cycle–promoting genes, which might as a potential molecular target for breast cancer treatment.


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