Knockdown of BAG3 synergizes with olaparib to kill ovarian cancer cells via repressing autophagy

2020 ◽  
pp. jim-2020-001602
Author(s):  
Kexin Wang ◽  
Jianhua Zheng

This study aimed at expounding the synergistic effect of Bcl-2-associated athanogene 3 (BAG3) knockdown and poly ADP-ribose polymerase (PARP) inhibitor on ovarian cancer (OC) cells and the potential mechanism. Short hairpin RNA (shRNA) targeting BAG3 (sh-BAG3) was transfected into SK-OV-3 (SKOV-3 ;SKOV3) and A2780 cells, and western blot assay was used to detect transfection efficiency. Cell proliferation and apoptosis were detected by the cell counting kit-8 method, 5-Bromodeoxyuridine (BrdU) experiment and flow cytometry analysis, respectively. The expressions of apoptosis-related proteins Bax and Bcl-2, as well as the expressions of autophagy-related proteins LC3-I, LC3-II and Beclin-1, were examined by western blot assay. Additionally, the cells were treated with autophagy activator rapamycin to investigate whether the tumor-suppressive function of BAG3 knockdown+PARP inhibitor was dependent on autophagy. In this work, we demonstrated that BAG3 knockdown further sensitized OC cells to olaparib treatment, reducing cellular viability and promoting apoptosis. Both sh-BAG3 and olaparib decreased the expression of Beclin-1 and the LC3-Ⅱ:LC3-I ratio, and their synergism further inhibited the process of autophagy. However, the aforementionede effects were reversed after the cells were treated with rapamycin. Based on these results, we concluded that BAG3 knockdown synergizes with olaparib to kill OC cells in vitro by repressing autophagy.

2014 ◽  
Vol 24 (8) ◽  
pp. 1373-1380 ◽  
Author(s):  
Yu Qin ◽  
Xuejiao Zhao ◽  
Yong Fang

ObjectivesOverexpression of histone deacetylases and activation of the phosphatidylinositol 3-kinase/mammalian target of rapamycin pathway are common aberrations in ovarian cancer. For this reason, simultaneous inhibition of such targets is a rational therapeutic strategy to treat patients with ovarian cancer. This study aimed to investigate the biological effect of the histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), in combination with the dual mTOR complex 1 and mTOR complex 2 inhibitor, PP242, against ovarian cancer cells.Materials and MethodsThe effects of SAHA and PP242 on the growth of SKOV3 and A2780 cells were examined using Cell Counting Kit-8. The apoptosis was analyzed through flow cytometry, and the expression of apoptosis-related proteins was investigated through Western blotting. Induction of autophagy was determined through fluorescence microscopy using a stably transfected green fluorescent protein/microtubule-associated protein light chain 3 construct to visualize autophagosome formation. The expression of autophagy-related proteins was determined through Western blot analysis. The effect of SAHA and PP242 on the growth of ovarian cancer was also examined in an orthotopic ovarian cancer model.ResultsThe combination of SAHA and PP242 significantly inhibited cell proliferation and synergistically increased apoptosis and autophagy compared with each agent alone in vitro. In vivo, this combination exhibited greater inhibition on tumor growth than monotreatments did and it significantly prolonged the survival time of the mice.ConclusionsThese results suggest that the combination of SAHA and PP242 may lead to a novel strategy in treating patients with ovarian cancer.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1028
Author(s):  
Nikolaos Nikoleousakos ◽  
Panagiotis Dalezis ◽  
Aikaterini Polonifi ◽  
Elena G. Geromichalou ◽  
Sofia Sagredou ◽  
...  

We evaluated three newly synthesized B-lactam hybrid homo-aza-steroidal alkylators (ASA-A, ASA-B and ASA-C) for their PARP1/2 inhibition activity and their DNA damaging effect against human ovarian carcinoma cells. These agents are conjugated with an alkylating component (POPA), which also served as a reference molecule (positive control), and were tested against four human ovarian cell lines in vitro (UWB1.289 + BRCA1, UWB1.289, SKOV-3 and OVCAR-3). The studied compounds were thereafter compared to 3-AB, a known PARP inhibitor, as well as to Olaparib, a standard third-generation PARP inhibitor, on a PARP assay investigating their inhibitory potential. Finally, a PARP1 and PARP2 mRNA expression analysis by qRT-PCR was produced in order to measure the absolute and the relative gene expression (in mRNA transcripts) between treated and untreated cells. All the investigated hybrid steroid alkylators and POPA decreased in vitro cell growth differentially, according to the sensitivity and different gene characteristics of each cell line, while ASA-A and ASA-B presented the most significant anticancer activity. Both these compounds induced PARP1/2 enzyme inhibition, DNA damage (alkylation) and upregulation of PARP mRNA expression, for all tested cell lines. However, ASA-C underperformed on average in the above tasks, while the compound ASA-B induced synthetic lethality effects on the ovarian cancer cells. Nevertheless, the overall outcome, leading to a drug-like potential, provides strong evidence toward further evaluation.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhenhua Du ◽  
Lei Wang ◽  
Yu Xia

Abstract Background Ovarian cancer (OC) is the gynecologic cancer with the highest mortality. Circular RNAs (circRNAs) play a vital role in the development and progression of cancer. This study aimed to explore the potential role of circ_0015756 in OC and its molecular mechanism. Methods The levels of circ_0015756, microRNA-942-5p (miR-942-5p) and Cullin 4B (CUL4B) were determined by quantitative real-time PCR (qRT-PCR) or Western blot assay. Cell proliferation, apoptosis, migration and invasion were assessed by Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry and transwell assay. The levels of proliferation-related and metastasis-related proteins were measured by Western blot assay. The relationship between miR-942-5p and circ_0015756 or CUL4B was verified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Xenograft assay was used to analyze tumor growth in vivo. Results Circ_0015756 and CUL4B levels were increased, while miR-942-5p level was decreased in OC tissues and cells. Depletion of circ_0015756 suppressed proliferation, migration and invasion and promoted apoptosis in OC cells. Down-regulation of circ_0015756 hindered OC cell progression via modulating miR-942-5p. Also, up-regulation of miR-942-5p impeded OC cell development by targeting CUL4B. Mechanistically, circ_0015756 up-regulated CUL4B via sponging miR-942-5p. Moreover, circ_0015756 silencing inhibited tumor growth in vivo. Conclusion Knockdown of circ_0015756 suppressed OC progression via regulating miR-942-5p/CUL4B axis, suggesting that circ_0015756 might be a potential therapeutic target for ovarian cancer.


Author(s):  
Hairong Yao ◽  
Dantong Liu ◽  
Fangyuan Gao ◽  
Qian Li ◽  
Shikai Liu

IntroductionOvarian cancer (OC) is the malignant tumor with the highest mortality among gynecological cancers. Chemotherapy resistance is a major obstacle to OC therapy. Circular RNAs (circRNAs) play crucial roles in cancer development and chemoresistance. However, the role and potential mechanism of has-circ-001567 (circ-VPS13C) in chemoresistance of OC remain unknown.Material and methodsThe levels of circ-VPS13C, miR-106b-5p and 14-3-3 zeta (YWHAZ) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Cell Counting Kit-8 (CCK-8) assay was used to assess cell viability and calculate the half inhibition concentration (IC50) of cisplatin (DDP). The levels of autophagy-related markers were measured by western blot assay. Cell apoptosis and migration were evaluated by flow cytometry and transwell assay, respectively. The binding relationship between miR-106b-5p and circ-VPS13C or YWHAZ was confirmed by dual-luciferase reporter assay. Xenograft assay was performed to explore the role of circ-VPS13C in vivo.ResultsCirc-VPS13C and YWHAZ were up-regulated, while miR-106b-5p was down-regulated in DDP-resistant OC tissues and cells. Knockdown of circ-VPS13C enhanced DDP sensitivity by repressing autophagy in DDP-resistant cells. Circ-VPS13C increased DDP resistance via sponging miR-106b-5p. Moreover, miR-106b-5p directly targeted YWHAZ. Up-regulation of YWHAZ alleviated the decrease in DDP resistance caused by circ-VPS13C depletion. In addition, circ-VPS13C silencing decreased DDP resistance in vivo.ConclusionsCirc-VPS13C knockdown enhanced DDP sensitivity of OC through modulation of autophagy via the miR-106b-5p/YWHAZ axis, providing a new biomarker for improving the efficacy of OC chemotherapy.


2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Fang Li ◽  
Sumei Niu ◽  
Jing Sun ◽  
Huaishi Zhu ◽  
Qiujie Ba ◽  
...  

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) presents great promise as an anticancer agent for human cancer therapy. In this study, a magnetofection agent (polyMAG-l000) was evaluated forin vitrodelivery of TRAIL gene towards drug-resistant A2780/DDP ovarian cancer cells. Transfection experiments showed that polyMAG-l000 was able to transfect A2780/DDP cellsin vitro, leading to a higher level of TRAIL gene expression in the presence of a static magnetic field as compared to other transfection agent, such as Lipofectamine 2000. TRAIL gene expression in the A2780/DDP cells was also confirmed by Western blot analysis. Moreover, the TRAIL gene expression exhibited remarkable decrease in the cell viability, as determined by MTT assay. Importantly, PolyMAG-l000-mediated TRAIL gene transfection in the presence of anticancer drug cisplatin (CDDP) induced much higher percentages of apoptotic A2780/DDP cells, compared to TRAIL gene transfection or CDDP treatment alone. A further study by Western blot analysis indicated that cytochromecrelease and caspase-9 cleavage pathway were associated with the initiation of the apoptosis in A2780/DDP cells. The results of this study indicate that polyMAG-l000 can be used as an efficient agent for TRAIL gene transfection in ovarian cancer cells.


2021 ◽  
Author(s):  
Yue Li ◽  
Mingxu Fu ◽  
Ling Guo ◽  
Xiaoxiao Sun ◽  
Yuhang Chen ◽  
...  

Abstract Background: Metastases and recurrence of ovarian cancer after surgery and chemotherapy account for most cancer-related deaths, yet the mechanism underlying metastases and recurrence remains poorly understood. Recent evidence demonstrates that although long-lasting cells were considered tumor suppressors, senescent cancer cells, can induce the metastases and recurrence. In this study, we focused on the fate of ovarian cancer cells treated with carboplatin and explored the mechanism underlying ovarian cancer cell recovery from chemotherapy-induced senescence. Methods: SÁ-β-galactosidase staining was used to detect the impact of carboplatin on senescence of ovarian cancer cells. Cell proliferation was determined using direct cell counting, clone formation assay and 3D tumor spheroid formation assay. Lentivirus-mediated transduction was used to silence or upregulate EGFR expression. Quantitative real-time PCR and western blot analysis validated the efficacy of the knockdown or overexpression effect. Immunofluorescence staining and western blot analysis were used to examined the expression of EGFR and NF-KB. Cell death was determined using trypan blue staining assay. Results: Ovarian cancer cells treated by carboplatin exhibit a senescence-like phenotype indicated by SA-β-galactosidase positive staining. Importantly, carboplatin-induced senescence-like phenotype is reversible. In ovarian cancer cells, EGFR positively regulated cells proliferation, decreased carboplatin-induced senescence and upregulated the NF-κB1 protein level. EGFR/NF-κB1 upregulation promoted the recovery of ovarian cancer cells from senescence and chemoresistance to carboplatin. Conclusions: Ovarian cancer cells treated with carboplatin displayed a reversible senescence-like phenotype that could be combined with EGFR or NF-κB1 inhibitors to improve treatment effects.


2020 ◽  
Vol 159 (3) ◽  
pp. 850-859
Author(s):  
Catharina Wichmann ◽  
Daniel Martin Klotz ◽  
Hans-Joachim Zeiler ◽  
Ralf Axel Hilger ◽  
Konrad Grützmann ◽  
...  

Tumor Biology ◽  
2018 ◽  
Vol 40 (5) ◽  
pp. 101042831877365 ◽  
Author(s):  
Nirmala Jagadish ◽  
Rukhsar Fatima ◽  
Aditi Sharma ◽  
Sonika Devi ◽  
Vitusha Suri ◽  
...  

SPAG9 is a novel tumor associated antigen, expressed in variety of malignancies. However, its role in ovarian cancer remains unexplored. SPAG9 expression was validated in ovarian cancer cells by real time PCR and Western blot. SPAG9 involvement in cell cycle, DNA damage, apoptosis, paclitaxel sensitivity and epithelial- mesenchymal transition (EMT) was investigated employing RNA interference approach. Combinatorial effect of SPAG9 ablation and paclitaxel treatment was evaluated in in vitro. Quantitative PCR and Western blot analysis revealed SPAG9 expression in A10, SKOV-3 and Caov3 compared to normal ovarian epithelial cells. SPAG9 ablation resulted in reduced cellular proliferation, colony forming ability and enhanced cytotoxicity of chemotherapeutic agent paclitaxel. Effect of ablation of SPAG9 on cell cycle revealed S phase arrest and showed decreased expression of CDK1, CDK2, CDK4, CDK6, cyclin B1, cyclin D1, cyclin E and increased expression of tumor suppressor p21. Ablation of SPAG9 also resulted in increased apoptosis with increased expression of various pro- apoptotic molecules including BAD, BID, PUMA, caspase 3, caspase 7, caspase 8 and cytochrome C. Decreased expression of mesenchymal markers and increased expression of epithelial markers was found in SPAG9 ablated cells. Combinatorial effect of SPAG9 ablation and paclitaxel treatment was evaluated in in vitro assays which showed that ablation of SPAG9 resulted in increased paclitaxel sensitivity and caused enhanced cell death. In vivo ovarian cancer xenograft studies showed that ablation of SPAG9 resulted in significant reduction in tumor growth. Present study revealed therapeutic potential of SPAG9 in ovarian cancer.


2021 ◽  
Author(s):  
Xiangrong Cui ◽  
Huancheng Su ◽  
Jiaolin Yang ◽  
Xueqing Wu ◽  
Kai Huo ◽  
...  

Abstract Background: MTHFD2 is a folate-coupled metabolic enzyme, which has been proved to participant in the metabolic reprogramming and tumor cell-sustaining proliferative capacity. However, the function of MTHFD2 in the development of ovarian cancer and its potential molecular mechanisms is still unclear. Materials and methods: The expression, various mutations, prognosis, and related network signaling pathways of MTHFD2 were analyzed using bioinformatics-related websites, including Oncomine, GEPIA, UCSC, cBioPortal, KM Plotter, TISIDB and TIMER. The prognostic value of MTHFD2 expression was validated by our own ovarian cancer samples using RT-qPCR. The migration ad invasion of ovarian cancer cells were further analyzed by CCK-8 and transwell assay. The Western-blot assay was performed to explore the protein levels of MTHFD2 and MOB1A. Results: We obtained the following important results. (1) MTHFD2 expression was markedly up-regulated in ovarian cancer than normal samples. (2) Among patients with ovarian cancer, those with higher MTHFD2 expression was associated with lower survival rate. (3) The major mutation type of MTHFD2 in ovarian cancer samples was missense mutation. (4) MTHFD2 knockdown inhibited proliferation, migration, invasion, as well as the expression of MOB1A in vitro. Conclusion: MTHFD2, as a NAD+-dependent enzyme, accelerated tumor progression by up-regulating MBO1A, suggesting that this protein may be an independent prognostic factor and a potential therapeutic target for future ovarian cancer treatments.


2020 ◽  
Author(s):  
Jun Liu ◽  
Wenshuai Zhu ◽  
Jianqin Ji

Abstract Background Osteosarcoma (OS) is a common aggressive primary sarcoma of bone. Drug resistance is a huge obstacle to chemotherapy for cancer. This study aimed to investigate the role and mechanism of circ_0002060 in OS resistance to doxorubicin (DOX). Methods The levels of circ_0002060, miR-198 and ATP binding cassette subfamily B member 1 (ABCB1) were measured by quantitative real-time polymerase chain reaction or western blot assay. Kaplan-Meier analysis was performed to determine the relationship between circ_0002060 expression and overall survival. The half inhibition concentration (IC50) of doxorubicin was calculated by Cell Counting Kit-8 (CCK-8) assay. Cell proliferation was assessed by colony formation assay. Cell apoptosis was monitored by flow cytometry. The levels of apoptosis-related proteins were measured by western blot assay. Xenograft assay was utilized to analyze the effect of circ_0002060 on DOX resistance in vivo . The interaction among circ_0002060, miR-198 and ABCB1 were confirmed by dual-luciferase reporter assay, RNA immunoprecipitation assay or RNA pull-down assay. Results Circ_0002060 and ABCB1 were up-regulated, while miR-198 was down-regulated in OS tissues and DOX-resistant OS cells. Circ_0002060 silence reduced DOX resistance in vitro and in vivo . Moreover, circ_0002060 enhanced DOX resistance via sponging miR-198. Besides, miR-198 decreased DOX resistance by binding to ABCB1. In addition, circ_0002060 sponged miR-198 to up-regulate ABCB1 expression. Conclusion Circ_0002060 enhanced doxorubicin resistance of OS by regulating miR-198/ABCB1 axis, which provides potential therapeutic targets for OS therapy.


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