scholarly journals Circadian Clock Protein PERIOD2 Suppresses the PI3K/Akt Pathway and Promotes Cisplatin Sensitivity in Ovarian Cancer

2020 ◽  
Author(s):  
Zhaoxia Wang ◽  
Fengyan Li ◽  
Meiyan Wei ◽  
Sanyuan Zhang ◽  
Tong Wang

Abstract Background Circadian clock protein PERIOD2 (PER2) acts as a tumor suppressor in cancer; however, little is known about its involvement in chemosensitivity. Methods This study aimed to investigate the role and underlying mechanisms of PER2 in ovarian cancer sensitivity to cisplatin. Overexpression and knockdown of PER2 were performed to explore its role in ovarian cancer cell sensitivity to cisplatin both in vitro and in vivo. The protein levels of PI3K, AKT, caspase 3, E-cadherin, and other drug resistance-related molecules were determined in parental SKOV3 and SKOV3/DDP cells as well as in xenograft tumor tissues. Results Compared with parental cells, SKOV3/DDP cells had dramatically decreased PER2 expression, possibly due to hypermethylation in the PER2 promoter. PER2 overexpression significantly inhibited proliferation while promoting cisplatin-induced apoptosis in SKOV3 and SKOV3/DDP cells. In agreement, PER2-overexpressing SKOV3/DPP cells yielded significantly reduced tumor mass in cisplatin-treated mice compared with control cells. Mechanistically, PER2 overexpression remarkably reduced the protein amounts of PI3K, AKT, and MDR1, while increasing those of caspase 3 and E-cadherin in tumor tissues. Knockdown of PER2 exhibited opposite effects. PER2 overexpression also reduced the serum levels of TNF-α and IL-6 in tumor-bearing mice before the initiation of cisplatin treatment. Conclusion This study suggests that loss of PER2 contributes to cisplatin resistance in SKOV3 cells, possibly by activating the PI3K/AKT pathway and EMT, inhibiting apoptosis, and promoting drug efflux and inflammatory responses. Overexpression of PER2 could reverse these alterations and sensitize both parental SKOV3 and SKOV3/DDP cells to cisplatin.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e16508-e16508
Author(s):  
Ivy Wilkinson-Ryan ◽  
Dirk Spitzer ◽  
Robert Mach ◽  
Suwanna Vangveravong ◽  
Peter S Goedegebuure ◽  
...  

e16508 Background: Platinum resistance continues to be a major barrier to the successful treatment of ovarian cancer. Overexpression of the X-linked inhibitor of apoptosis proteins (XIAP) contribute to platinum resistance in ovarian cancer through inhibition of caspases and up regulation of Akt activity. Second mitochondrial-derived activators of caspases (SMAC) is an endogenous protein that binds to and reverses XIAP-mediated inhibition of caspases. In order to exploit the SMAC-mediated pro-apoptotic pathway pharmacologically, SMAC mimetics have been developed and shown to induce apoptosis in cancer cells in vitro and in vivo. Untargeted cytotoxic cancer drugs bind to both malignant and normal tissue leading to significant toxicity. We have shown previously that solid tumors upregulate the sigma-2 receptor. We have also shown that sigma-2 ligands are internalized into cancer cells and are therefore an appealing vehicle for tumor targeted therapy. The goal of this study is to test if a conjugate drug of sigma-2 ligand and a SMAC mimetic (sigma-2/SMAC) in combination with chemotherapy is capable of overcoming chemoresistance in ovarian cancer. Methods: SKOV3 and OVCAR3 ovarian cancer cell lines were treated with sigma2/SMAC (1-16μM) and/or cisplatin (.5-10μg/mL). Viability assays were used to detect cell death. Luminescence-based caspase assays were used to compare the activity of caspase-3, -7, and -9 between treatment groups to document involvement of the XIAP survival pathway. Results: We found that sigma2-SMAC is synergistic when used in combination with cisplatin. Compared to untreated cells, SKOV3 cells treated with sigma/2SMAC (4uM), cisplatin .5ug/mL, or combination therapy showed 52.6%, 117.7%, and 34.8% viability respectively (p<.05). Cisplatin and sigma2/SMAC remained synergistic at increasing doses. Similar results were observed in OVCAR3 cells. Caspase-3 and -7 increased in combination therapy 1.2-fold over Sigma/2SMAC alone (4uM) and 7-fold over cisplatin alone (.5ug/mL) in SKOV3 cells (p<.05). Conclusions: This study suggests that the sigma2/SMAC conjugate provides a targeted means for overcoming chemoresistance in ovarian cancer through inhibition of XIAP and activation of caspases.


2020 ◽  
Vol Volume 12 ◽  
pp. 11897-11908
Author(s):  
Zhaoxia Wang ◽  
Fengyan Li ◽  
Meiyan Wei ◽  
Sanyuan Zhang ◽  
Tong Wang

2012 ◽  
Vol 33 (6) ◽  
pp. 817-822 ◽  
Author(s):  
Ling-ling Dong ◽  
Lian Liu ◽  
Chun-hong Ma ◽  
Ji-sheng Li ◽  
Chao Du ◽  
...  

2013 ◽  
Vol 647 ◽  
pp. 391-395
Author(s):  
Liu Sen ◽  
Song Liu

Regulation of daily physiological functions with approximate a 24-hour periodicity, or circadian rhythms, is a characteristic of eukaryotes. So far, cyanobacteria are only known prokaryotes reported to possess circadian rhythmicity. The circadian system in cyanobacteria comprises both a post-translational oscillator (PTO) and a transcriptional/translational feedback loop (TTFL). The PTO can be reconstituted in vitro with three purified proteins (KaiA, KaiB, and KaiC) with the existence of ATP. Phase of the nanoclockwork has been associated with the phosphorylation states of KaiC, with KaiA promoting the phosphorylation of KaiC, and KaiB de-phosphorylating KaiC. Here we studied the evolution of the KaiB protein. The result will be helpful in understanding the evolution of the circadian clock system.


2018 ◽  
Vol 104 (5) ◽  
pp. 330-337 ◽  
Author(s):  
Li-qian Zhang ◽  
Su-qing Yang ◽  
Xiang-dong Qu ◽  
Xian-jun Chen ◽  
Hong-sheng Lu ◽  
...  

Purpose: Ovarian cancer is one of the leading causes of death for women worldwide. The present study aims to investigate the role of G protein-coupled receptor 137 (GPR137) in the biological activities of ovarian cancer cells. Methods: (QUERY: Please supply Methods for Abstract) Results: G protein-coupled receptor 137 was highly expressed in clinical ovarian cancer tissues and exhibited the highest protein levels in SKOV3 cells and OVCAR3 cells. Knockdown of GPR137 caused significant decreases in cell proliferative rates and colony formation abilities in SKOV3 cells and OVCAR3 cells and also inhibited the in vivo tumorigenesis in a xenograft model. It was observed that knockdown of GPR137 inhibited cell motility by up to 40% in SKOV3 cells and approximately 65% in OVCAR3 cells in wound-healing assay. Cell migration abilities were consistently inhibited by 68.2% in SKOV3 cells and 59.3% in OVCAR3 cells, whereas cell invasion abilities were inhibited by 64.0% and 74.2% in SKOV3 and OVCAR3 cells, respectively, after knockdown of GPR137. When GPR137 was depleted, epithelial markers were increased, while mesenchymal markers decreased. Conclusions: Our data suggest that GPR137 plays pro-oncogenic roles in ovarian cancer via regulation of the PI3K/AKT pathway. These observations might pave new insights into therapeutic strategies against human ovarian cancer.


2016 ◽  
Vol 36 (2) ◽  
pp. 918-928 ◽  
Author(s):  
Long Li ◽  
Zhaoning Duan ◽  
Jihui Yu ◽  
Hong-Xing Dang

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 192 ◽  
Author(s):  
Yuli Yan ◽  
Xingyu Liu ◽  
Jie Gao ◽  
Yin Wu ◽  
Yuxin Li

Background: Dracocephalum peregrinum L., a traditional Kazakh medicine, has good expectorant, anti-cough, and to some degree, anti-asthmatic effects. Diosmetin (3′,5,7-trihydroxy-4′-methoxyflavone), a natural flavonoid found in traditional Chinese herbs, is the main flavonoid in D. peregrinum L. and has been used in various medicinal products because of its anticancer, antimicrobial, antioxidant, estrogenic, and anti-inflammatory effects. The present study aimed to investigate the effects of diosmetin on the proliferation, invasion, and migration of glioma cells, as well as the possible underlying mechanisms. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), scratch wound, and Transwell assays were used to demonstrate the effects of diosmetin in glioma. Protein levels of Bcl-2, Bax, cleaved caspase-3, transforming growth factor-β (TGF-β), E-cadherin, and phosphorylated and unphosphorylated smad2 and smad3 were determined by Western blots. U251 glioma cell development and progression were measured in vivo in a mouse model. Results: Diosmetin inhibited U251 cell proliferation, migration, and invasion in vitro, the TGF-β signaling pathway, and Bcl-2 expression. In contrast, there was a significant increase in E-cadherin, Bax, and cleaved caspase-3 expression. Furthermore, it effectively reduced the tumorigenicity of glioma cells and promoted apoptosis in vivo. Conclusion: The results of this study suggest that diosmetin suppresses the growth of glioma cells in vitro and in vivo, possibly by activating E-cadherin expression and inhibiting the TGF-β signaling pathway.


Chemotherapy ◽  
2019 ◽  
Vol 64 (3) ◽  
pp. 119-128 ◽  
Author(s):  
Tian-Mei Zhang

Objective: To investigate whether TRIAP1inhibition affects the ovarian cancer cell resistance to cisplatin (DDP) via the Cyt c/Apaf-1/caspase-9 pathway by in vitro and in vivo experiments. Methods: CCK8 assay was performed to find out how treatment with both TRIAP1 siRNA and DDP affects the cell viability of SKOV3 cells and DDP-resistant human ovarian carcinoma cell line SKOV3/DDP. SKOV3/DDP cells were transfected with control siRNA or TRIAP1 siRNA before 24 h of treatment with DDP (5 μg/mL). Flow cytometry was employed to detect cell apoptosis and Western blot to examine the expressions of Cyt c/Apaf-1/caspase-9 pathway-related proteins. SKOV3/DDP cells transfected with control siRNA or TRIAP1 siRNA were subcutaneously injected into BALB/c-nu/nu nude mice followed by the intraperitoneal injection of DDP (4 mg/kg). Cyt c/Apaf-1/caspase-9 pathway in transplanted tumors was detected by immunohistochemistry. Results: TRIAP1 expression declined in SKOV3 cells when compared with SKOV3/DDP cells. The proliferation rate was lower in SKOV3/DDP cells transfected with TRIAP1 siRNA combined with treatment of DDP (1, 2, 4, 6, 8, 16, 32 μg/mL) than in those transfected with control siRNA. Moreover, the TRIAP1 siRNA group had an increased SKOV3/DDP cell apoptosis rate with the activation of the Cyt c/Apaf-1/caspase-9 pathway. During DDP treatment, nude mice in TRIAP1 siRNA group had slower growth and smaller size of transplanted tumor than those in control siRNA group, with increased expression of Cyt c, Apaf-1, and caspase-9. Conclusion: TRIAP1 inhibition may enhance the sensitivity of SKOV3/DDP cells to cisplatin via activation of the Cyt c/Apaf-1/caspase-9 pathway.


2018 ◽  
Vol 25 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Biao Wan ◽  
Leheyi Dai ◽  
Li Wang ◽  
Ying Zhang ◽  
Hong Huang ◽  
...  

Clinical implications of the BRCA2 expression level on treatments of ovarian cancer are controversial. Here, we demonstrated that platinum-resistant cancer had a higher percentage of high BRCA2 level (87.5% vs 43.6%, P = 0.001), and that patients with a low BRCA2 level in cancer tissues had longer progression-free survival (with a median time of 28.0 vs 12.0 months, P < 0.001) and platinum-free duration (with a median time of 19.0 vs 5.0 months, P < 0.001) compared with those with a high BRCA2 level. In human ovarian cancer cell lines CAOV-3 and ES-2, cisplatin induced an upregulation of the RAD51 protein, which was inhibited after silencing BRCA2; silencing BRCA2 enhanced the action of cisplatin in vitro and in vivo. Knockdown of BRCA2 promoted cisplatin-induced autophagy. Interestingly, the autophagy blocker chloroquine enhanced cisplatin in BRCA2-silenced cells accompanied by an increase in apoptotic cells, which did not occur in BRCA2-intact cells; chloroquine enhanced the efficacy of cisplatin against BRCA2-silenced CAOV-3 tumors in vivo, with an increase in LC3-II level in tumor tissues. Sensitization of cisplatin was also observed in BRCA2-silenced CAOV-3 cells after inhibiting ATG7, confirming that chloroquine modulated the sensitivity via the autophagy pathway. These data suggest that a low BRCA2 level can predict better platinum sensitivity and prognosis, and that the modulation of autophagy can be a chemosensitizer for certain cancers.


2021 ◽  
Vol 11 ◽  
Author(s):  
Dan Zou ◽  
Jin Bai ◽  
Enting Lu ◽  
Chunjiao Yang ◽  
Jiaqing Liu ◽  
...  

Epithelial ovarian cancer (EOC) has a poor prognosis and high mortality rate; patients are easy to relapse with standard therapies. So, there is an urgent need to develop novel drugs. In this study, differentially expressed genes (DEGs) of EOC were identified in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Enrichment and protein–protein interaction (PPI) analyses were performed. The drug candidate which has the possibility to treat EOC was predicted by Connectivity Map (CMAP) databases. Moreover, molecular docking was selected to calculate the binding affinity between drug candidate and hub genes. The cytotoxicity of drug candidates was assessed by MTT and colony formation analysis, the proteins coded by hub genes were detected by Western blots, and apoptosis analysis was evaluated by flow cytometry. Finally, 296 overlapping DEGs (|log 2 fold change|&gt;1; q-value &lt;0.05), which were principally involved in the cell cycle (p &lt; 0.05), and cyclin-dependent kinase 1 (CDK1) were screened as the significant hub gene from the PPI network. Furthermore, the 21 drugs were extracted from CMAPs; among them, piperlongumine (PL) showed a lower CMAP score (-0.80, -62.92) and was regarded as the drug candidate. Furthermore, molecular docking results between PL and CDK1 with a docking score of –8.121 kcal/mol were close to the known CDK1 inhibitor (–8.24 kcal/mol). Additionally, in vitro experiments showed that PL inhibited proliferation and induced apoptosis via targeting CDK1 in EOC SKOV3 cells. Our results reveal that PL may be a novel drug candidate for EOC by inhibiting cell cycle.


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