scholarly journals Inhibition of Prostate Cancer DU-145 Cells Proliferation by Anthopleura anjunae Oligopeptide (YVPGP) via PI3K/AKT/mTOR Signaling Pathway

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 325 ◽  
Author(s):  
Xiaojuan Li ◽  
Yunping Tang ◽  
Fangmiao Yu ◽  
Yu Sun ◽  
Fangfang Huang ◽  
...  

We investigated the antitumor mechanism of Anthopleura anjunae oligopeptide (AAP-H, YVPGP) in prostate cancer DU-145 cells in vitro and in vivo. Results indicated that AAP-H was nontoxic and exhibited antitumor activities. Cell cycle analysis indicated that AAP-H may arrest DU-145 cells in the S phase. The role of the phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein (PI3K/AKT/mTOR) signaling pathway in the antitumor mechanism of APP-H was investigated. Results showed that AAP-H treatment led to dose-dependent reduction in the levels of p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448), whereas t-AKT and t-PI3K levels remained unaltered compared to the untreated DU-145 cells. Inhibition of PI3K/AKT/mTOR signaling pathway in the DU-145 cells by employing inhibitor LY294002 (10 μM) or rapamycin (20 nM) effectively attenuated AAP-H-induced phosphorylation of AKT and mTOR. At the same time, inhibitor addition further elevated AAP-H-induced cleaved-caspase-3 levels. Furthermore, the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mouse model were also investigated. Immunohistochemical analysis showed that activated AKT, PI3K, and mTOR levels were reduced in DU-145 xenografts. Western blotting showed that AAP-H treatment resulted in dose-dependent reduction in p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448) levels, whereas t-AKT and t-PI3K levels remained unaltered. Similarly, Bcl-xL levels decreased, whereas that of Bax increased after AAP-H treatment. AAP-H also increased initiator (caspase 8 and 9) and executor caspase (caspase 3 and 7) levels. Therefore, the antitumor mechanism of APP-H on DU-145 cells may involve regulation of the PI3K/AKT/mTOR signaling pathway, which eventually promotes apoptosis via mitochondrial and death receptor pathways. Thus, the hydrophobic oligopeptide (YVPGP) can be developed as an adjuvant for the prevention or treatment of prostate cancer in the future.

Author(s):  
Jian Li ◽  
Danli Ye ◽  
Peng Shen ◽  
Xiaorong Liu ◽  
Peirong Zhou ◽  
...  

Abstract Background: The X-linked gene WTX (also called AMER1), has been reported to act as a tumor suppress gene in Wilms tumor. Our previous study reported that WTX expression was significantly reduced in gastric cancer (GC), but the function and mechanism of WTX loss had not been fully elucidated yet. Methods: WTX/miR-20a-5p expression was analyzed in paraffin-embedded archived GC tissues and validated in public databases. KEGG pathway analyses were performed to explore the mechanism of WTX in GC progression. The role of WTX/miR-20a-5p in cell growth, migration, invasion and angiogenesis was investigated in vitro and in vivo. Western blot, immunohistochemistry, RT-PCR, luciferase assay, and Co-immunoprecipitation (Co-IP) were used to detect the regulation of WTX and PI3K/AKT/mTOR signaling by miR-20a-5p.Results: We revealed that WTX served as a tumor suppressor whose loss associated with the aggressive feature of GC by showing hyperproliferation in vitro and high metastasis phenotype in vivo. And WTX expression level was positively correlated with the overall survival of GC patients. Microarray, bioinformatics analysis, and verification experiments showed that WTX loss activated PI3K/AKT/mTOR pathway, and promoted the proliferation and invasion of GC cells. We also discovered that the miR-20a-5P aberrant upregulation was one of the reasons inducing WTX loss in GC which stimulated PI3K phosphorylation to activate PI3K/AKT/mTOR signaling pathway, thus promoted GC progression.Conclusions: This study unveiled the mechanism of GC progression which was, at least partially, caused by miR-20a-5p aberrant upregulation which inhibited WTX expression and thus activate PI3K/AKT/mTOR signaling pathway. It provided a comprehensive understanding of the action of miR-20a-5p/WTX/PI3K/AKT/mTOR signaling pathway in the progression and metastasis of GC.


2021 ◽  
Author(s):  
Tao Hou ◽  
Weichao Dan ◽  
Tianjie Liu ◽  
Bo Liu ◽  
Yi Wei ◽  
...  

Abstract BackgroundThe mammalian target of Rapamycin (mTOR) pathway serves as a crucial regulator of various biological processes such as cell growth and cancer progression. In bladder cancer, recent discoveries showing the cancer-promoting role of mTOR complex 1 have attracted wide attention. However, the regulation of mTOR signaling in bladder cancer is complicated and the underlying mechanism remains elusive. Here, we report that the deubiquitinating enzyme, ovarian tumor domain-containing protein 5 (OTUD5), can activate the mTOR signaling pathway, promote cancer progression, and show its oncogenic potential in bladder cancer.MethodsThe expression of OTUD5 in bladder cancer was analyzed using bladder cancer tissue microarrays and Western blotting analysis. Meanwhile, to demonstrate the role of OTUD5-RNF186-Sestrin2-mTOR axis in bladder cancer, we have adopted a series of biochemical and molecular biological methods to verify in vivo and in vitro. The methods used included quantitative real time PCR assay; western blot assay; Immunofluorescence staining assay; MTT assay; colony formation assay; Co-immunoprecipitation assay; In vivo ubiquitination assay; Immunohistochemical assay and Bladder Cancer xenograft animal model.ResultsIn our study, we found that OTUD5 deubiquitinated a RING-type E3 ligase, RNF186, and stabilized its function. In addition, the stabilization of RNF186 further led to the degradation of Sestrin2, which is an inhibitor of mTOR signaling pathway. ConclusionTogether, we first proved that OTUD5 can promote bladder cancer progression through the OTUD5-RNF186-Sestrin2-mTOR axis and provided novel insights into the diagnosis and treatment of bladder cancer.


2021 ◽  
Vol 20 ◽  
pp. 153303382199007
Author(s):  
Wenlin Liu ◽  
Jiandong Zhan ◽  
Rong Zhong ◽  
Rui Li ◽  
Xiaoli Sheng ◽  
...  

Background: Laryngeal cancer is one of the most common malignant tumors among head and neck cancers. Accumulating studies have indicated that long noncoding RNAs (lncRNAs) play an important role in laryngeal cancer occurrence and progression, however, the functional roles and relative regulatory mechanisms of lncRNA growth arrest-specific transcript 5 (GAS5) in laryngeal cancer progression remain unclear. Methods: The expression of lncRNA GAS5 in both laryngeal cancer tissues and cell lines was evaluated using quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay. The relationships between lncRNA GAS5 expression and clinical parameters were also analyzed. To determine the biological function of lncRNA GAS5, a lncRNA GAS5-specific plasmid was first transfected into laryngeal cancer cells using lentiviral technology. Cell counting kit-8 assay, flow cytometry, and Transwell assays were used to detect in vitro cell proliferation, apoptosis, cycle distribution, and metastasis abilities, respectively. Furthermore, in vivo cell growth experiments were also performed using nude mice. Additionally, western blotting was performed to identify the underlying regulatory mechanism. Results: In the current study, lncRNA GAS5 was downregulated in laryngeal cancer tissues and its low expression was closely associated with poor tumor differentiation, advanced TNM stage, lymph node metastasis, and shorter overall survival time. In addition, lncRNA GAS5 upregulation significantly inhibited laryngeal cancer cell proliferation both in vitro and in vivo. Moreover, in response to lncRNA GAS5 overexpression, more laryngeal cancer cells were arrested at the G2/M stage, accompanied by increased cell apoptosis rates and suppressed migration and invasion capacities. Mechanistically, our data showed that the overexpression of lncRNA GAS5 significantly regulated the PI3K/AKT/mTOR signaling pathway. Conclusion: LncRNA GAS5 might act as a suppressor gene during laryngeal cancer development, as it suppressed cell proliferation and metastasis by regulating the PI3K/AKT/mTOR signaling pathway; thus, lncRNA GAS5 is a promising therapeutic biomarker for the treatment of laryngeal cancer.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Zhenjian Xu ◽  
Junzhe Chen ◽  
Anping Xu

Abstract Background and Aims Our previous study found a new regulatory T cell subpopulation, CD4+CD126lowFoxp3+ regulatory T cells (CD4+CD126lowFoxp3+ Treg). This cell can maintain a stable immune regulatory function in the inflammatory state. Through in vivo and in vitro experiments, we have confirmed that CD4+CD126lowFoxp3+ Treg has an immunotherapeutic effect on T cell-mediated mouse models of autoimmune diseases such as colitis and collagen-induced arthritis (CIA). Further experimental studies showed that CD4+CD126lowFoxp3+ Treg could reduce the kidney injury caused by autoantibodies and prolong the survival time of lupus mice. However, the mechanism of CD4+CD126lowFoxp3+ Treg immunotherapy in lupus nephritis is not clear. The purpose of this study was to explore the mechanism of CD4+CD126lowFoxp3+ Treg immunotherapy in mice with lupus nephritis. Method In vitro experiments CD4+CD126lowFoxp3+ Treg or CD4+CD126lowFoxp3+ Treg pretreated with PD-1 inhibitor were co-cultured with T or B lymphocytes of lupus mice under different in vitro culture condition. The expression levels of Akt and mTOR of Treg in each group were measured under immunoinflammatory conditions. To observe the effects and differences of Treg groups on the activation, proliferation and differentiation of T or B cells and other immunomodulatory effects. In vivo experiments CD4+CD126lowFoxp3+ Treg (2 × 106/mouse) and CD4+CD126lowFoxp3+ Treg (2 × 106/mouse) pretreated with PD-1 inhibitor and PBS were injected into NZM2328 lupus mice, respectively. After cell injection, urine protein was measured weekly. Autoantibody expression in lupus mice was measured every two weeks. The effects of Treg on the proliferation and differentiation of T/B cells in lupus mice were observed. The therapeutic effects of Treg on lupus mice were observed. Results Compared with CD4+CD126lowFoxp3+ Treg, the expression of Akt and mTOR increases in PD-1 inhibitors pretreatment cells. The activation, proliferation and differentiation functions of T or B lymphocytes of lupus mice were significantly weakened by immunosuppression of PD-1 inhibitors pretreated Treg in vitro, indicating that CD4+CD126lowFoxp3+ Treg may inhibit Akt-mTOR signaling pathway through PD-1 in in vitro. Compared with CD4+CD126lowFoxp3+ Treg, the activation, proliferation and differentiation functions of T or B lymphocytes of lupus mice were significantly weakened by immunosuppression of PD-1 inhibitors pretreated Treg in vivo. And its therapeutic effect on lupus mice was ineffective, indicating that CD4+CD126lowFoxp3+ Treg may inhibit Akt-MTOR signaling pathway through PD-1 in vivo. Conclusion CD4+CD126lowFoxp3+ Treg may inhibit the Akt-mTOR signaling pathway by expressing PD-1, and maintain stable immunomodulatory function in the inflammatory state, thus producing immunotherapeutic effect on lupus nephritis mice.


2020 ◽  
Author(s):  
Wen-Hao Zhou ◽  
Yi-Ming Su ◽  
Yu Zhang ◽  
Bang-Min Han ◽  
Hai-Tao Liu ◽  
...  

Abstract Background Docetaxel is a first-line chemotherapy for the treatment of patients with castration-resistant prostate cancer (CRPC). Despite the good initial response of docetaxel, drug resistance will inevitably occur. Mechanisms underlying docetaxel resistance are not well elaborated. Endothelial cells (ECs) have been implicated in the progression and metastasis of prostate cancer (PCa). However, little attention has been paid to the role of ECs in the development of docetaxel resistance in PCa. Methods Here, we sought to investigate the function and mechanism of ECs involving in the docetaxel resistance of PCa. The 22Rv1 and C4-2B PCa cell lines were cultured with or without human umbilical vein endothelial cells (HUVEC). The proliferation of each PCa cell line was assessed by CCK8 and EdU assays. Cell viability of each PCa cell line treated with docetaxel was evaluated by CCK8. Apoptosis was measured by flow cytometry. Quantitative reverse transcription (RT)-PCR assay was used to determine the expression of ETS related gene (ERG) in each PCa cell line and FGF2 in HUVEC. The proteins including ERG, Caspase3, PARP, Akt, p-Akt, mTOR and p-mTOR were quantified by western blotting. ERG overexpressing C4-2B cells(C4-2B-ERG) were constructed by transfection with pLenti6.3-ERG lentivirus. C4-2B-ERG cells were knocked down by transfecting with ERG siRNAs. Differentially expressed cytokines between the serum-free media from 22Rv1 and 22Rv1/HUVEC co-culture system were detected by human cytokine array and determined by ELISA assay. Tumors were induced in mice by injecting 22Rv1 cells with or without HUVEC and treated with docetaxel. Tumor growth and apoptosis were examined by immunohistochemistry and TUNEL respectively. Results ECs promoted proliferation and inhibited apoptosis in PCa cells (in vitro) and mouse xenograft tumors induced by these cells (in vivo) under docetaxel treatment. ECs secreted FGF2 to induce ERG expression and activate the Akt/mTOR signaling pathway in PCa cells contributing to docetaxel resistance. Blocking FGF2 could reverse the enhancing effects of HUVEC on docetaxel resistance in PCa cells. Inhibition of the Akt/mTOR signaling pathway could alleviate chemoresistance mediated by ERG. Conclusion ECs promote docetaxel resistance via FGF2/ERG/Akt/mTOR signaling pathway in PCa cells. Targeting FGF/ FGFR signaling may represent a promising therapeutic strategy to overcome docetaxel resistance.


2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Guangtao Han ◽  
Yubiao Zhang ◽  
Haohuan Li

Osteoarthritis (OA) is a chronic joint disease characterized by cholesterol accumulation in chondrocytes, cartilage degeneration, as well as extracellular matrix (ECM) destruction, and joint dysfunction. Curcumin, a chemical that can reduce cholesterol levels in OA patients, also can inhibit the progression of OA. However, a high concentration of curcumin may also trigger apoptosis in normal chondrocytes. Besides curcumin, probucol that is found can also effectively decrease the cholesterol level in OA patients. Considering that high cholesterol is a risk factor of OA, it is speculated that the combination treatment of curcumin and probucol may be effective in the prevention of OA. To investigate the possible effects of such two chemicals on OA pathophysiology, chondrocyte apoptosis and autophagy behavior under inflammatory cytokine stress were studied, and specifically, the PI3K-Akt-mTOR signaling pathway was studied. Methods. Cell proliferation, colony formation, and EdU assay were performed to identify the cytotoxicity of curcumin and probucol on chondrocytes. Transwell assay was conducted to evaluate chondrocyte migration under TNF-α inflammation stress. Immunofluorescence, JC-1, flow cytometry, RT-PCR, and western blot were used to investigate the signal variations related to autophagy and apoptosis in chondrocytes and cartilage. A histological study was carried out on OA cartilage. Glycosaminoglycan (GAG) release was determined to evaluate the ECM degradation under stress. Results. Compared with a single intervention with curcumin or probucol, a combined treatment of these two chemicals is more effective in terms of protecting chondrocytes from stress injury induced by inflammatory cytokines. The promoted protection may be attributed to the inhibition of apoptosis and the blockage of the autophagy-related PI3K/Akt/mTOR pathway. Such results were also verified in vitro by immunofluorescence staining of OA chondrocytes and in vivo by immunohistochemistry staining of cartilage. Besides, in vivo studies also showed that when applied in combination, curcumin and probucol could block the PI3K-AKT-mTOR signaling pathway; promote COL-II expression; suppress P62, MMP-3, and MMP-13 expression; and inhibit TNF-α-stimulated cartilage degradation. Moreover, the combined medication could help reduce the release of ECM GAGs in OA cartilage and alleviate the severity of OA. Conclusion. A combined treatment of curcumin and probucol could be used to protect chondrocytes from inflammatory cytokine stress via inhibition of the autophagy-related PI3K/Akt/mTOR pathway both in vitro and in vivo, which might be of potential pharmaceutical value for OA prevention and therapy.


Author(s):  
Dan Wei ◽  
Shaofei Wu ◽  
Jie Liu ◽  
Xiaoqian Zhang ◽  
Xiaoling Guan ◽  
...  

Theobromine, a methylxanthine present in cocoa, has been shown to possess many beneficial pharmacological properties such as anti-oxidative stress, anti-inflammatory property, and anti-microbial activity. In this study, we investigated the effects of theobromine on NAFLD and the possible underlying mechanisms in vivo and in vitro. The results showed that theobromine reduced body weight, fat mass and improved dyslipidemia. Theobromine decreased liver weight, mitigated liver injury, and significantly reduced hepatic TG level in mice with obesity. Histological examinations also showed hepatic steatosis was alleviated after theobromine treatment. Furthermore, theobromine reversed the elevated mRNA and protein expression of SREBP-1c, FASN, CD36, FABP4 and the suppressed expression of PPARα, CPT1a in the liver of mice with obesity, which were responsible for lipogenesis, fatty acid uptake and fatty acid oxidation respectively. In vitro, theobromine also downregulated SREBP-1c, FASN, CD36, FABP4 and upregulated PPARα, CPT1a mRNA and protein levels in hepatocytes in a dose-dependent manner, while these changes were reversed by L-Leucine, an mTOR agonist. The present study demonstrated that theobromine improved NAFLD by inhibiting lipogenesis, fatty acid uptake and promoting fatty acid oxidation in the liver and hepatocytes, which might be associated with its suppression of mTOR signaling pathway.


2020 ◽  
Author(s):  
Xinyu Wang ◽  
Bowen Shi ◽  
Yue Zhao ◽  
Qijue Lu ◽  
Xiang Fei ◽  
...  

Abstract Background: Hexokinase domain component 1 (HKDC1) plays an oncogenic role in certain types of cancer, such as lymphoma, liver cancer, and breast cancer. Previous bioinformatics study revealed that HKDC1 was significantly upregulated in lung adenocarcinoma (LUAD). However, its biological functions and potential mechanism in LUAD have not been studied. Methods: We performed bioinformatics analysis, quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, immunohistochemistry, and a series of functional assays in vitro and in vivo to investigate the roles of HKDC1 in LUAD. Results: We discovered that HKDC1 was highly expressed in LUAD tissues and cell lines, and the positive expression of HKDC1 was correlated with aberrant clinicopathological characteristics in LUAD patients. Furthermore, HKDC1 could serve as a prognostic predictor for LUAD patients. Overexpression of HKDC1 promoted proliferation, migration, invasion, glycolysis, EMT and tumorigenicity, whereas knockdown of HKDC1 produced the opposite functional effects. Mechanistically, HKDC1 could regulate the AMPK/mTOR signaling pathway to perform its biological function. Conclusions: Our findings suggest that HKDC1 plays an oncogenic role in LUAD. Targeting this gene may provide a promising therapeutic target to delay LUAD progression.


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