scholarly journals Adipocytes promote ovarian cancer chemoresistance

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiang Yang ◽  
Munir M. Zaman ◽  
Iliyan Vlasakov ◽  
Roopali Roy ◽  
Lan Huang ◽  
...  

Abstract Ovarian cancer (OvCa), while accounting for only 3% of all women’s cancer, is the fifth leading cause of cancer death among women. One of the most significant obstacles to successful OvCa treatment is chemoresistance. The current lack of understanding of the driving mechanisms underlying chemoresistance hinders the development of effective therapeutics against this obstacle. Adipocytes are key components of the OvCa microenvironment and have been shown to be involved in OvCa cell proliferation, however, little is known about their impact on OvCa chemoresistance. In the current study, we found that adipocytes, of both subcutaneous and visceral origin, secrete factors that enhance the resistance of OvCa cells against chemotherapeutic drugs by activating the Akt pathway. Importantly, we have demonstrated that secreted lipids mediate adipocyte-induced chemoresistance. Through a comprehensive lipidomic analysis, we have identified this chemo-protective lipid mediator as arachidonic acid (AA). AA acts on OvCa cells directly, not through its downstream derivatives such as prostaglandins, to activate Akt and inhibit cisplatin-induced apoptosis. Taken together, our study has identified adipocytes and their secreted AA as important mediators of OvCa chemoresistance. Strategies that block the production of AA from adipocytes or block its anti-apoptotic function may potentially inhibit chemoresistance in OvCa patients.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 11101-11101
Author(s):  
Erica Michelle Stringer ◽  
Maxwell N. Skor ◽  
Gini F. Fleming ◽  
Suzanne D. Conzen

11101 Background: Ovarian cancer is the leading cause of death from gynecologic malignancies. High-grade serous ovarian cancer (HGS-OvCa) is often initially sensitive to platinum-based therapy, but relapse rates remain high. The TCGA recently found that HGS-OvCas have a gene expression and mutational profile similar to that of triple negative breast cancer (TNBC). Previously, our group demonstrated that dexamethasone treatment decreased chemotherapy-induced tumor cell apoptosis in TNBC and HGS-OvCa cell lines. We have also shown that glucocorticoid receptor (GR) activation induces expression of anti-apoptotic genes SGK1 and MKP1/DUSP1 in both HGS-OvCa and TNBC cell lines and in primary human ovarian and TNBC tumors. Methods: We examined glucocorticoid receptor (GR), estrogen receptor (ER), and progesterone receptor (PR) expression in a panel of HGS-OvCa cell lines by Western analysis and qRT-PCR. We also performed apoptosis assays with and without mifepristone, glucocorticoid and/or chemotherapy treatment using IncuCyte live-cell imaging technology in order to measure the effect of GR modulation of chemotherapy sensitivity. Results: HGS-OvCa cell lines (including CAOV3, HeyA8, SKOV3, Monty-1) all had detectable GR expression; HeyA8, SKOV3, and Monty-1 cell lines expressed very low levels of ER-alpha while all other HGS-OvCa cell lines did not express any detectable ER-alpha. Furthermore, none of the HGS-OvCa cell lines tested expressed PR.Apoptosis assays revealed that GR activation significantly inhibited gemcitabine/carboplatin-induced apoptosis in HGS-OvCa cell lines and that mifepristone could reverse this cell survival effect, presumably through GR antagonism. Conclusions: These results suggest that treatment with mifepristone, a GR antagonist, reverses GR-mediated cell survival signaling in HGS-OvCa and increases chemotherapy-induced tumor cell death. To further investigate the role of GR activity in HGS-OvCa, we are currently performing xenograft experiments with chemotherapy +/- mifepristone treatment.


2020 ◽  
Vol 16 ◽  
Author(s):  
Zhixiong Xie ◽  
Tianyu Zhang ◽  
Cheng Zhong

Background: During chemotherapy, drugs can damage cancer cells’ DNA and cytomembrane structure, and then induce cell death. However, autophagy can increase the chemotherapy resistance of cancer cells, reducing the effect of chemotherapy. Objective: To block the autophagic flux in cancer cells, it is vital to enhance the anti-cancer efficacy of chemotherapy drugs; for this purpose, we test the gadolinium oxide nanoparticles (Gd2O3 NPs)’ effect on autophagy. Methods: The cytotoxicity of Gd2O3 NPs on HeLa cells was evaluated by a (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Then, monodasylcadaverine staining, immunofluorescence, immunoblot and apoptosis assay were conducted to evaluate the effect of Gd2O3 NPs on autophagy and efficacy of chemotherapy drugs in human ovarian cancer cells. Results: We found that Gd2O3 NPs, which have great potential for use as a contrast agent in magnetic resonance imaging, could block the late stage of autophagic flux in a dose-dependent manner and then cause autophagosome accumulation in HeLa cells. When co-treated with 8 μg/mL Gd2O3 NPs and 5 μg/mL cisplatin, the number of dead HeLa cells increased by about 20% compared with cisplatin alone. We observed the same phenomenon in cisplatin-resistant COC1/DDP cells. Conclusion: We conclude that Gd2O3 NPs can block the late stage of autophagic flux and enhance the cytotoxicity of chemotherapeutic drugs in human ovarian cancer cells. Thus, the nanoparticles have significant potential for use in both diagnosis and therapy of solid tumor.


2020 ◽  
Vol 15 (1) ◽  
pp. 274-283
Author(s):  
Bo Zheng ◽  
Tao Chen

AbstractAmong astrocyte tumors, glioblastoma (GBM) is the most malignant glioma, highly aggressive and invasive, with extremely poor prognosis. Previous research has reported that microRNAs (miRNAs) participate in the progression of many cancers. Thus, this study aimed to explore the role and the underlying mechanisms of microRNA (miR)-489-3p in GBM progression. The expression of miR-489-3p and brain-derived neurotrophic factor (BDNF) mRNA was measured by quantitative real-time polymerase chain reaction. Western blot analysis was used to detect BDNF protein and the PI3K/AKT pathway-related protein. Cell proliferation, apoptosis, migration, and invasion were analyzed using CKK-8 assay, flow cytometry, and transwell assay, respectively. The interaction between BDNF and miR-489-3p was explored by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. MiR-489-3p was down-regulated and BDNF was up-regulated in GBM tissues and cells. MiR-489-3p re-expression or BDNF knockdown inhibited GBM cell proliferation, migration, and invasion, and promoted apoptosis. BDNF was a target of miR-489-3p, and BDNF up-regulation reversed the effects of miR-489-3p on GBM cells. The protein levels of p-AKT and p-PI3K were notably reduced in GBM cells by overexpression of miR-489-3p, but were rescued following BDNF up-regulation. Therefore, miR-489-3p inhibited proliferation, migration, and invasion, and induced apoptosis, by targeting the BDNF-mediated PI3K/AKT pathway in GBM, providing new strategies for clinical treatment of GBM.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sung Min Ju ◽  
Jun Gue Kang ◽  
Jun Sang Bae ◽  
Hyun Ock Pae ◽  
Yeoung Su Lyu ◽  
...  

Apigenin is a member of the flavone subclass of flavonoids present in fruits and vegetables. Apigenin has long been considered to have various biological activities, such as antioxidant, anti-inflammatory, and antitumorigenic properties, in various cell types. Cisplatin was known to exhibit cytotoxic effect to renal cells by inducing apoptosis through activation of p53. The present study investigated the antiapoptotic effects of apigenin on the cisplatin-treated human renal proximal tubular epithelial (HK-2) cells. HK-2 cells were pretreated with apigenin (5, 10, 20 μM) for 1 h and then treated with 40 μM cisplatin for various times. Apigenin inhibited the cisplatin-induced apoptosis of HK-2 cells. Interestingly, apigenin itself exerted cytostatic activity because of its ability to induce cell cycle arrest. Apigenin inhibited caspase-3 activity and PARP cleavage in cisplatin-treated cells. Apigenin reduced cisplatin-induced phosphorylation and expression of p53, with no significant influence on production of ROS that is known to induce p53 activation. Furthermore, apigenin promoted cisplatin-induced Akt phosphorylation, suggesting that enhanced Akt activation may be involved in cytoprotection. Taken together, these results suggest that apigenin ameliorates cisplatin-induced apoptosis through reduction of p53 activation and promotion of PI3K/Akt pathway in HK-2 cells.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 969
Author(s):  
John S. Lazo ◽  
Elizabeth R. Sharlow ◽  
Robert Cornelison ◽  
Duncan J. Hart ◽  
Danielle C. Llaneza ◽  
...  

High grade serous ovarian cancer (OvCa) frequently becomes drug resistant and often recurs. Consequently, new drug targets and therapies are needed. Bioinformatics-based studies uncovered a relationship between high Protein Tyrosine Phosphatase of Regenerating Liver-3 (PRL3 also known as PTP4A3) expression and poor patient survival in both early and late stage OvCa. PTP4A3 mRNA levels were 5–20 fold higher in drug resistant or high grade serous OvCa cell lines compared to nonmalignant cells. JMS-053 is a potent allosteric small molecule PTP4A3 inhibitor and to explore further the role of PTP4A3 in OvCa, we synthesized and interrogated a series of JMS-053-based analogs in OvCa cell line-based phenotypic assays. While the JMS-053 analogs inhibit in vitro PTP4A3 enzyme activity, none were superior to JMS-053 in reducing high grade serous OvCa cell survival. Because PTP4A3 controls cell migration, we interrogated the effect of JMS-053 on this cancer-relevant process. Both JMS-053 and CRISPR/Cas9 PTP4A3 depletion blocked cell migration. The inhibition caused by JMS-053 required the presence of PTP4A3. JMS-053 caused additive or synergistic in vitro cytotoxicity when combined with paclitaxel and reduced in vivo OvCa dissemination. These results indicate the importance of PTP4A3 in OvCa and support further investigations of the lead inhibitor, JMS-053.


Author(s):  
Li-ying Zhang ◽  
Jia-ying Yu ◽  
Yan-long Leng ◽  
Ran-ran Zhu ◽  
Hong-xian Liu ◽  
...  

2022 ◽  
Vol 12 (5) ◽  
pp. 947-952
Author(s):  
Jun Zhang ◽  
Yuying Gao ◽  
Peng Chen ◽  
Yu Zhou ◽  
Sheng Guo ◽  
...  

This study was to explore the mechanism by how exosomes (exo) derived from BMSCs affects cardiomyocyte apoptosis. BMSCs were isolated and incubated with cardiomyocytes while the cardiomyocytes were exposed to sevoflurane or DMSO treatment. Apoptotic cells were calculated and level of apoptosis related proteins was detected by Western blot. Through transfection with microRNA-(miRNA)-312 inhibitor, we evaluated the effect of BMSC-exo on the sevoflurane-induced apoptosis. Sevoflurane significantly inhibited the viability of cardiomyocytes and induced cardiomyocyte apoptosis. Besides, sevoflurane decreased the expression of miR-312 and enhanced Bax expression in cardiomyocytes through restraining the phosphorylation of MAPK/ERK. Treatment with BMSC-exo, however, activated MAPK/ERK signaling by up-regulating miR-312, thereby inhibiting cardiomyocyte apoptosis, promoting cardiomyocyte proliferation, and elevating the level of Bcl-2. In conclusion, BMSC-exo-derived miR-312 inhibits sevoflurane-induced cardiomyocyte apoptosis by activating PI3K/AKT signaling pathway.


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