scholarly journals ATM Regulated PTEN Degradation Is XIAP E3 Ubiquitin Ligase Mediated in p85α Deficient Cancer Cells and Influence Platinum Sensitivity

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1271 ◽  
Author(s):  
Reem Ali ◽  
Muslim Alabdullah ◽  
Islam Miligy ◽  
Makhliyo Normatova ◽  
Roya Babaei-Jadidi ◽  
...  

Ataxia-telegiectasia mutated (ATM), phosphatase and tensin homolog (PTEN), and p85α are key tumour suppressors. Whether ATM regulates PTEN expression and influence platinum sensitivity is unknown. We generated ATM knockdowns (KD) and CRISPR knock outs (KO) in glioblastoma (LN18, LN229) and ovarian cancer cells (OVCAR3, OVCAR4). Doxycycline inducible PTEN expression was generated in LN18 and LN229 cells. Transient KD of p85α, CK2, and XIAP was accomplished using siRNAs. Stable p85α knock-in was isolated in LN18 cells. Molecular biology assays included proteasome activity assays, PCR, flow cytometry analysis (cell cycle, double strand break accumulation, apoptosis), immunofluorescence, co-immunoprecipitation, clonogenic, invasion, migration, and 3D neurosphere assays. The clinicopathological significance of ATM, PTEN, p85α, and XIAP (X-linked inhibitor of apoptosis protein) was evaluated in 525 human ovarian cancers using immunohistochemistry. ATM regulated PTEN is p85α dependant. ATM also controls CK2α level which in turn phosphorylates and stabilizes PTEN. In addition, p85α physically interacts with CK2α and protects CK2α from ATM regulated degradation. ATM deficiency resulted in accumulation of XIAP/p-XIAP levels which ubiquitinated PTEN and CK2α thereby directing them to degradation. ATM depletion in the context of p85α deficiency impaired cancer cell migration and invasion reduced 3D-neurosphere formation and increased toxicity to cisplatin chemotherapy. Increased sensitivity to platinum was associated with DNA double strand breaks accumulation, cell cycle arrest, and induction of autophagy. In ovarian cancer patients, ATM, PTEN, p85α, and XIAP protein levels predicted better progression free survival after platinum therapy. We unravel a previously unknown function of ATM in the regulation of PTEN throμgh XIAP mediated proteasome degradation.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Huan Lu ◽  
Guanlin Zheng ◽  
Xiang Gao ◽  
Chanjuan Chen ◽  
Min Zhou ◽  
...  

Abstract Background Propofol is a kind of common intravenous anaesthetic agent that plays an anti-tumor role in a variety of cancers, including ovarian cancer. However, the working mechanism of Propofol in ovarian cancer needs further exploration. Methods The viability and metastasis of ovarian cancer cells were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assays. Flow cytometry was used to evaluate the cell cycle and apoptosis. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the abundance of circular RNA vacuolar protein sorting 13 homolog C (circVPS13C) and microRNA-145 (miR-145). The target relationship between miR-145 and circVPS13C was predicted by circinteractome database and verified by dual-luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) assay and RNA-pull down assay. Western blot assay was used to detect the levels of phosphorylated extracellular regulated MAP kinase (p-ERK), ERK, p-MAP kinse-ERK kinase (p-MEK) and MEK, in ovarian cancer cells. Results Propofol treatment suppressed the viability, cell cycle and motility and elevated the apoptosis rate of ovarian cancer cells. Propofol up-regulated miR-145 in a dose-dependent manner. Propofol exerted an anti-tumor role partly through up-regulating miR-145. MiR-145 was a direct target of circVPS13C. Propofol suppressed the progression of ovarian cancer through up-regulating miR-145 via suppressing circVPS13C. Propofol functioned through circVPS13C/miR-145/MEK/ERK signaling in ovarian cancer cells. Conclusion Propofol suppressed the proliferation, cell cycle, migration and invasion and induced the apoptosis of ovarian cancer cells through circVPS13C/miR-145/MEK/ERK signaling in vitro.


2021 ◽  
Vol 17 (1) ◽  
pp. 127-134
Author(s):  
Min Wei ◽  
Hongjuan Jin ◽  
ShuLi Yang ◽  
Zhuo Li ◽  
Xinlei Wang ◽  
...  

IntroductionOvarian cancer is the most frequent cause of gynecological cancer related mortality in woman. This study was designed to investigate the role and therapeutic potential of miRNA-101 in ovarian cancer.Material and methodsExpression analysis was carried out by real-time quantitative polymerase chain reaction. Transfections were performed with the help of Lipofectamine 2000 reagent. AO/EB and annexin V/PI staining was used to detect apoptosis and flow cytometry was used for cell cycle analysis. Western blotting was employed for cell cycle analysis.ResultsIt was found that miRNA-101 was significantly down-regulated in ovarian cancer cells. The over-expression of miRNA-101 causes a significant decrease in the viability of ovarian cancer cells via the initiation of apoptosis and sub-G1 arrest of OVACAR-3 cells. It was indicated that PTEN was the potential target of miRNA-101 in OVACAR-3 cells. There was 4.5-fold up-regulation of PTEN expression in ovarian cancer cell lines and the over-expression of miRNA-101 in OVACAR-3 cells resulted in the down-regulation of PTEN expression. The inhibition of PTEN in the OVACAR-3 cells arrested the proliferation of these cells. The over-expression of miRNA-101 causes significant down-regulation in PI3K and AKT expression of OVACAR-3 cells.ConclusionsIt can be concluded that miRNA-101 acts as a tumor suppressor which may be beneficial in the treatment of ovarian cancer.


Phytomedicine ◽  
2016 ◽  
Vol 23 (8) ◽  
pp. 800-809 ◽  
Author(s):  
Le-Le Zhang ◽  
Yu-Lian Xu ◽  
Zheng-Hai Tang ◽  
Xiao-Huang Xu ◽  
Xin Chen ◽  
...  

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 379
Author(s):  
Hyocheol Bae ◽  
Sunwoo Park ◽  
Changwon Yang ◽  
Gwonhwa Song ◽  
Whasun Lim

Phytosterols, which are present in a variety of foods, exhibit various physiological functions and do not have any side effects. Here, we attempted to identify functional role of campesterol in regulation of oxidative stress by leading to cell death of ovarian cancer. We investigated the effects of campesterol on cancer cell aggregation using a three-dimensional (3D) culture of human ovarian cancer cells. The effects of campesterol on apoptosis, protein expression, proliferation, the cell cycle, and the migration of these cells were determined to unravel the underlying mechanism. We also investigated whether campesterol regulates mitochondrial function, the generation of reactive oxygen species (ROS), and calcium concentrations. Our results show that campesterol activates cell death signals and cell death in human ovarian cancer cells. Excessive calcium levels and ROS production were induced by campesterol in the two selected ovarian cancer cell lines. Moreover, campesterol suppressed cell proliferation, cell cycle progression, and cell aggregation in ovarian cancer cells. Campesterol also enhanced the anticancer effects of conventional anticancer agents. The present study shows that campesterol can be used as a novel anticancer drug for human ovarian cancer.


2021 ◽  
Vol 246 (11) ◽  
pp. 1297-1306
Author(s):  
Qian Zhong ◽  
Ying Xiong ◽  
Chen Ling ◽  
Yanping Qian ◽  
Xia Zhao ◽  
...  

We previously reported that cyclin D1 silencing interferes with RAD51 accumulation and increases the sensitivity of BRCA1 wild-type ovarian cancer cells to olaparib. However, the mechanisms associated with cyclin D1 overexpression in ovarian cancer are not fully understood. TargetScan predicted the potential binding sites for microRNA-20b (miR-20b) and the 3′-untranslated region of cyclin D1 mRNA; thus, we used luciferase reporter assay to verify those binding sites. The Kaplan-Meier method and log-rank test were used to examine the relationship between miR-20b and progression-free survival of ovarian cancer patients in The Cancer Genome Atlas ( n = 367) dataset. In vitro experiments were performed to evaluate the effects of miR-20b on cyclin D1 expression, cell cycle and response to olaparib. A peritoneal cavity metastasis model of ovarian cancer was established to determine the effect of miR-20b on the sensitivity of olaparib. Immunohistochemistry was performed to evaluate molecular mechanisms. In this work, we demonstrated that miR-20b down-regulates cyclin D1, increases the sensitivity of ovarian cancer cells to olaparib, reduces the expression of RAD51, and induces cell cycle arrest in G0/G1 phase. Ovarian cancer patients with higher expression of miR-20b had significantly longer progression-free survival. These results indicate that miR-20b may be a potential clinical indicator for the sensitivity of ovarian cancer to olaparib and the survival of ovarian cancer patients. Our findings suggest that miR-20b may have therapeutic value in combination with olaparib treatment for ovarian cancer.


2020 ◽  
Vol 19 (2) ◽  
pp. 206-210
Author(s):  
Feng Chen ◽  
Bei Zhang

Lupeol exhibits multiple pharmacological activities including, anticancerous, anti-inflammatory, and antioxidant. The aim of this study was to explore the anticancerous activity of lupeol on ovarian cancer cells and examine its mechanism of action. To this end, increasing concentrations of lupeol on cell viability, cell cycle, and apoptosis in Caov-3 cells were evaluated. Lupeol inhibited cell viability, induced G1 phase arrest in cell cycle, increased cell apoptosis, and inhibited the ratio of phospho-Akt/protein kinase B and phospho-mammalian target of rapamycin/mammalian target of rapamycin. In conclusion, these data suggest that lupeol may play a therapeutic role in ovarian cancer.


2019 ◽  
Vol 19 (4) ◽  
pp. 473-486 ◽  
Author(s):  
Katarzyna Bednarska-Szczepaniak ◽  
Damian Krzyżanowski ◽  
Magdalena Klink ◽  
Marek Nowak

Background: Adenosine released by cancer cells in high amounts in the tumour microenvironment is one of the main immunosuppressive agents responsible for the escape of cancer cells from immunological control. Blocking adenosine receptors with adenosine analogues and restoring immune cell activity is one of the methods considered to increase the effectiveness of anticancer therapy. However, their direct effects on cancer cell biology remain unclear. Here, we determined the effect of adenosine analogues on the response of cisplatinsensitive and cisplatin-resistant ovarian cancer cells to cisplatin treatment. Methods: The effects of PSB 36, DPCPX, SCH58261, ZM 241385, PSB603 and PSB 36 on cisplatin cytotoxicity were determined against A2780 and A2780cis cell lines. Quantification of the synergism/ antagonism of the compounds cytotoxicity was performed and their effects on the cell cycle, apoptosis/necrosis events and cisplatin incorporation in cancer cells were determined. Results: PSB 36, an A1 receptor antagonist, sensitized cisplatin-resistant ovarian cancer cells to cisplatin from low to high micromolar concentrations. In contrast to PSB 36, the A2AR antagonist ZM 241385 had the opposite effect and reduced the influence of cisplatin on cancer cells, increasing their resistance to cisplatin cytotoxicity, decreasing cisplatin uptake, inhibiting cisplatin-induced cell cycle arrest, and partly restoring mitochondrial and plasma membrane potentials that were disturbed by cisplatin. Conclusion: Adenosine analogues can modulate considerable sensitivity to cisplatin of ovarian cancer cells resistant to cisplatin. The possible direct beneficial or adverse effects of adenosine analogues on cancer cell biology should be considered in the context of supportive chemotherapy for ovarian cancer.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1866
Author(s):  
Katia A. Mesquita ◽  
Reem Ali ◽  
Rachel Doherty ◽  
Michael S. Toss ◽  
Islam Miligy ◽  
...  

FEN1 plays critical roles in long patch base excision repair (LP-BER), Okazaki fragment maturation, and rescue of stalled replication forks. In a clinical cohort, FEN1 overexpression is associated with aggressive phenotype and poor progression-free survival after platinum chemotherapy. Pre-clinically, FEN1 is induced upon cisplatin treatment, and nuclear translocation of FEN1 is dependent on physical interaction with importin β. FEN1 depletion, gene inactivation, or inhibition re-sensitizes platinum-resistant ovarian cancer cells to cisplatin. BRCA2 deficient cells exhibited synthetic lethality upon treatment with a FEN1 inhibitor. FEN1 inhibitor-resistant PEO1R cells were generated, and these reactivated BRCA2 and overexpressed the key repair proteins, POLβ and XRCC1. FEN1i treatment was selectively toxic to POLβ deficient but not XRCC1 deficient ovarian cancer cells. High throughput screening of 391,275 compounds identified several FEN1 inhibitor hits that are suitable for further drug development. We conclude that FEN1 is a valid target for ovarian cancer therapy.


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