scholarly journals Topical MTII Therapy Suppresses Melanoma Through PTEN Upregulation and Cyclooxygenase II Inhibition

2020 ◽  
Vol 21 (2) ◽  
pp. 681
Author(s):  
Jian-Ching Wu ◽  
Han-En Tsai ◽  
Yi-Hsiang Hsiao ◽  
Ji-Syuan Wu ◽  
Chieh-Shan Wu ◽  
...  
Keyword(s):  
Critical Role ◽  
Immunohistochemical Analysis ◽  
Melanoma Cells ◽  
Synthetic Analogue ◽  
Tensin Homolog ◽  
Melanoma Model ◽  
Cox 2 ◽  
Induced Apoptosis

Melanotan II (MTII), a synthetic analogue of the alpha-melanocyte stimulating hormone (α-MSH), has been applied for skin tanning in humans. However, the carcinogenic consequence of topical MTII has been equivocal. This study aims to delineate the anti-neoplastic efficacy and mechanism of MTII using the B16-F10 melanoma model in vitro and in vivo. It was found that, despite a lack of influence on proliferation, MTII potently inhibited the migration, invasion, and colony-forming capability of melanoma cells. Moreover, topical MTII application significantly attenuated the tumor progression in mice bearing established melanoma. Histological analysis revealed that MTII therapy induced apoptosis while inhibiting the proliferation and neovaluarization in melanoma tissues. By immunoblot and immunohistochemical analysis, it was found that MTII dose-dependently increased the phosphatase and tensin homolog (PTEN) protein level while reducing PTEN phosphorylation, which resulted in the inhibition of AKT/nuclear factor kappa B (NFκB) signaling. Consistently, MTII treatment inhibited cyclooxygenase II (COX-2) expression and prostaglandin E2 (PGE2) production in melanoma cells. Finally, studies of antibody neutralization suggest that the melanocortin 1 receptor (MC1R) plays a critical role in MTII-induced PTEN upregulation and melanoma suppression. Together, these results indicate that MTII elicits PTEN upregulation via MC1R, thereby suppressing melanoma progression through downregulating COX-2/PGE2 signaling. Hence, topical MTII therapy may facilitate a novel therapeutic strategy against melanoma.

scholarly journals RNF141 interacts with KRAS to promote colorectal cancer progression

Oncogene ◽  
2021 ◽  
Author(s):  
Jiuna Zhang ◽  
Xiaoyu Jiang ◽  
Jie Yin ◽  
Shiying Dou ◽  
Xiaoli Xie ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Plasma Membrane ◽  
Tumor Growth ◽  
Cancer Progression ◽  
Critical Role ◽  
Ring Finger ◽  
Immunohistochemical Analysis ◽  
Bimolecular Fluorescence Complementation

AbstractRING finger proteins (RNFs) play a critical role in cancer initiation and progression. RNF141 is a member of RNFs family; however, its clinical significance, roles, and mechanism in colorectal cancer (CRC) remain poorly understood. Here, we examined the expression of RNF141 in 64 pairs of CRC and adjacent normal tissues by real-time PCR, Western blot, and immunohistochemical analysis. We found that there was more expression of RNF141 in CRC tissue compared with its adjacent normal tissue and high RNF141 expression associated with T stage. In vivo and in vitro functional experiments were conducted and revealed the oncogenic role of RNF141 in CRC. RNF141 knockdown suppressed proliferation, arrested the cell cycle in the G1 phase, inhibited migration, invasion and HUVEC tube formation but promoted apoptosis, whereas RNF141 overexpression exerted the opposite effects in CRC cells. The subcutaneous xenograft models showed that RNF141 knockdown reduced tumor growth, but its overexpression promoted tumor growth. Mechanistically, liquid chromatography-tandem mass spectrometry indicated RNF141 interacted with KRAS, which was confirmed by Co-immunoprecipitation, Immunofluorescence assay. Further analysis with bimolecular fluorescence complementation (BiFC) and Glutathione-S-transferase (GST) pull-down assays showed that RNF141 could directly bind to KRAS. Importantly, the upregulation of RNF141 increased GTP-bound KRAS, but its knockdown resulted in a reduction accordingly. Next, we demonstrated that RNF141 induced KRAS activation via increasing its enrichment on the plasma membrane not altering total KRAS expression, which was facilitated by the interaction with LYPLA1. Moreover, KRAS silencing partially abolished the effect of RNF141 on cell proliferation and apoptosis. In addition, our findings presented that RNF141 functioned as an oncogene by upregulating KRAS activity in a manner of promoting KRAS enrichment on the plasma membrane in CRC.

scholarly journals Function of Native OmtA In Vivo and Expression and Distribution of This Protein in Colonies of Aspergillus parasiticus

2002 ◽  
Vol 68 (11) ◽  
pp. 5718-5727 ◽  
Author(s):  
Li-Wei Lee ◽  
Ching-Hsun Chiou ◽  
John E. Linz
Keyword(s):  
Fusion Protein ◽  
Aspergillus Parasiticus ◽  
Polyclonal Antibodies ◽  
Critical Role ◽  
Immunohistochemical Analysis ◽  
Cell Types ◽  
Temporal Association ◽  
Thin Sections

ABSTRACT The activities of two enzymes, a 168-kDa protein and a 40-kDa protein, OmtA, purified from the filamentous fungus Aspergillus parasiticus were reported to convert the aflatoxin pathway intermediate sterigmatocystin to O-methylsterigmatocystin in vitro. Our initial goal was to determine if OmtA is necessary and sufficient to catalyze this reaction in vivo and if this reaction is necessary for aflatoxin synthesis. We generated A. parasiticus omtA-null mutant LW1432 and a maltose binding protein-OmtA fusion protein expressed in Escherichia coli. Enzyme activity analysis of OmtA fusion protein in vitro confirmed the reported catalytic function of OmtA. Feeding studies conducted with LW1432 demonstrated a critical role for OmtA, and the reaction catalyzed by this enzyme in aflatoxin synthesis in vivo. Because of a close regulatory link between aflatoxin synthesis and asexual sporulation (conidiation), we hypothesized a spatial and temporal association between OmtA expression and conidiospore development. We developed a novel time-dependent colony fractionation protocol to analyze the accumulation and distribution of OmtA in fungal colonies grown on a solid medium that supports both toxin synthesis and conidiation. OmtA-specific polyclonal antibodies were purified by affinity chromatography using an LW1432 protein extract. OmtA was not detected in 24-h-old colonies but was detected in 48-h-old colonies using Western blot analysis; the protein accumulated in all fractions of a 72-h-old colony, including cells (0 to 24 h) in which little conidiophore development was observed. OmtA in older fractions of the colony (24 to 72 h) was partly degraded. Fluorescence-based immunohistochemical analysis conducted on thin sections of paraffin-embedded fungal cells from time-fractionated fungal colonies demonstrated that OmtA is evenly distributed among different cell types and is not concentrated in conidiophores. These data suggest that OmtA is present in newly formed fungal tissue and then is proteolytically cleaved as cells in that section of the colony age.

scholarly journals AIMP2-DX2 Promotes the Proliferation, Migration, and Invasion of Nasopharyngeal Carcinoma Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qingsong Cao ◽  
Jie Zhang ◽  
Tao Zhang
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Protein Expression ◽  
Southern China ◽  
Immunohistochemical Analysis ◽  
Prognostic Indicator ◽  
Trna Synthetase ◽  
Migration And Invasion ◽  
Induced Apoptosis

Nasopharyngeal carcinoma (NPC) is a head and neck tumor with high degree of malignancy and with high incidence especially in southern China. AIMP2-DX2, one isoform of the aminoacyl-tRNA synthetase interacting multifunctional proteins (AIMPs), is shown to be a potential target in many cancers. However, the detailed mechanisms of AIMP2-DX2 in NPC development remain to be elucidated. Here, we found that the mRNA expression level of AIMP2-DX2 was significantly increased in NPC specimens, compared with normal nasopharyngeal tissues. Microarray immunohistochemical analysis of NPC specimens and Kaplan–Meier analysis showed that patients with high AIMP2-DX2 protein expression had shorter overall survival than those with low AIMP2-DX2 level. Furthermore, mRNA and protein expression levels of AIMP2-DX2 were both increased in cultured NPC cell lines (5-8F, CNE-2Z, and CNE-1), by being compared with normal nasopharyngeal cell line NP69. Overexpression of AIMP2-DX2 remarkably promoted the cell viability, cell migration, and invasion of cultured NPC cells. Genetic knockdown of AIMP2-DX2 by shRNA lentiviruses significantly suppressed the proliferation, migration, and invasion and induced apoptosis of NPC cells. Inhibition of AIMP2-DX2 decreased the highly expressed level of matrix metalloproteinase- (MMP-) 2 and MMP-9, further suppressed proliferation, migration, and invasion in cultured NPC cells in vitro, and inhibited tumor growth in a xenograft mouse model in vivo. Taken together, these results suggest that AIMP2-DX2 plays an important role in the regulation of NPC and could be a potential therapeutic target and prognostic indicator for the treatment of NPC.

scholarly journals ROS-mediated inactivation of the PI3K/AKT pathway is involved in the antigastric cancer effects of thioredoxin reductase-1 inhibitor chaetocin

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Chuangyu Wen ◽  
Huihui Wang ◽  
Xiaobin Wu ◽  
Lu He ◽  
Qian Zhou ◽  
...  
Keyword(s):  
Critical Role ◽  
Thioredoxin Reductase ◽  
Akt Pathway ◽  
Ros Generation ◽  
In Vivo Models ◽  
M Phase ◽  
Tumorigenesis And Progression ◽  
Induced Apoptosis

Abstract Novel drugs are urgently needed for gastric cancer (GC) treatment. The thioredoxin-thioredoxin reductase (TRX-TRXR) system has been found to play a critical role in GC tumorigenesis and progression. Thus, agents that target the TRX-TRXR system may be highly efficacious as GC treatments. In this study, we showed that chaetocin, a natural product isolated from the Chaetomium species of fungi, inhibited proliferation, induced G2/M phase arrest and caspase-dependent apoptosis in both in vitro and in vivo models (cell xenografts and patient-derived xenografts) of GC. Chaetocin inactivated TRXR-1, resulting in the accumulation of reactive oxygen species (ROS) in GC cells; overexpression of TRX-1 as well as cotreatment of GC cells with the ROS scavenger N-acetyl-L-cysteine attenuated chaetocin-induced apoptosis; chaetocin-induced apoptosis was significantly increased when GC cells were cotreated with auranofin. Moreover, chaetocin was shown to inactivate the PI3K/AKT pathway by inducing ROS generation; AKT-1 overexpression also attenuated chaetocin-induced apoptosis. Taken together, these results reveal that chaetocin induces the excessive accumulation of ROS via inhibition of TRXR-1. This is followed by PI3K/AKT pathway inactivation, which ultimately inhibits proliferation and induces caspase-dependent apoptosis in GC cells. Chaetocin therefore may be a potential agent for GC treatment.

scholarly journals Targeting Rad51 as a strategy for the treatment of melanoma cells resistant to MAPK pathway inhibition

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Elena Makino ◽  
Lisa Marie Fröhlich ◽  
Tobias Sinnberg ◽  
Corinna Kosnopfel ◽  
Birgit Sauer ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Metastatic Melanoma ◽  
Mapk Pathway ◽  
Critical Role ◽  
Melanoma Cells ◽  
Mapk Signaling ◽  
Transcriptional Level ◽  
Mapk Inhibitor

Abstract Rad51 is an essential factor of the homologous recombination DNA repair pathway and therefore plays an important role in maintaining genomic stability. We show that RAD51 and other homologous recombination repair genes are overexpressed in metastatic melanoma cell lines and in melanoma patient samples, which correlates with reduced survival of melanoma patients. In addition, Rad51 expression in melanoma cells was regulated on a transcriptional level by the MAPK signaling pathway with Elk1 as the main downstream transcriptional effector. Most strikingly, melanoma cells which developed resistance towards MAPK inhibitors could be efficiently targeted by Rad51 inhibitors similar to their sensitive counterparts, leading to DNA damage, G2/M arrest and apoptosis. Furthermore, the treatment of MAPK inhibitor resistant cells with Rad51 inhibitors enhances the susceptibility of these cells for MAPK inhibitor treatment in vitro and in vivo. These data indicate that Rad51 plays a critical role in the survival of metastatic melanoma cells and is a promising target for the therapy of melanoma irrespective of its MAPK inhibitor resistance status.

scholarly journals Expression Pattern and Regulatory Role of microRNA-23a in Conjugated Linoleic Acids-Induced Apoptosis of Adipocytes

2016 ◽  
Vol 40 (3-4) ◽  
pp. 668-680 ◽  
Author(s):  
Renli Qi ◽  
Qi Wang ◽  
Jing Wang ◽  
Jinxiu Huang ◽  
Shan Jiang ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Critical Role ◽  
Fat Cells ◽  
Conjugated Linoleic Acids ◽  
Cellular Mechanisms ◽  
Over Expression ◽  
Functional Studies ◽  
Induced Apoptosis

Background/Aims: Conjugated linoleic acids (CLAs) are known to induce apoptosis in adipocytes; however, the cellular mechanisms involved remained illdefined. We explored the different apoptotic induction effects of two CLA isomers on adipocytes and then investigated the expression and function of microRNAs (miRNAs) related to the apoptosis. Methods: TUNEL and FCM assays were used to detect CLAs-induced adipocyte apoptosis. Microarrays were used to compare the differential expression of miRNAs. MiR-23a, a miRNA that showed significant changes in expression in the CLA-treated cells, was selected for the subsequent functional studies via over-expression and knock down in in vivo and in vitro experiments. Results: C9, t11-CLA exhibited a stronger induction of apoptosis in the differentiated 3T3-L1 adipocytes than t10, c12-CLA. However, t10, c12-CLA could rapidly activate NF-κB, which may have caused their different apoptotic effects. MiR-23a was markedly down-regulated by the CLAs treatment and miR-23a over-expression attenuated CLA-induced apoptosis. Apoptosis protease-activating factor 1 (APAF1) was identified as a target gene of miR-23a. In an in vivo experiment endogenous miR-23a was down-regulated in mice fed with a mixture of both CLAs. The mice also exhibited less fat deposition and more apoptotic fat cells in adipose tissue. Moreover, endogenous miR-23a was suppressed in mice via intravenous injection with an antagomir which resulted in decreased body weight, increased number of apoptotic fat cells and increased APAF1 expression in adipose tissue. Conclusion: Taken together, our results suggest that miR-23a plays a critical role in CLA-induced apoptosis in adipocytes via controlling APAF1 expression.

scholarly journals Chitosan-Based Nanoparticles for Intracellular Delivery of ISAV Fusion Protein cDNA into Melanoma Cells: A Path to Develop Oncolytic Anticancer Therapies

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Claudia Robles-Planells ◽  
Giselle Sánchez-Guerrero ◽  
Carlos Barrera-Avalos ◽  
Silvia Matiacevich ◽  
Leonel E. Rojo ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Chitosan Nanoparticles ◽  
Syncytium Formation ◽  
Melanoma Cells ◽  
Current Evidence ◽  
Infectious Salmon Anemia ◽  
Melanoma Model ◽  
Anemia Virus

Oncolytic virus therapy has been tested against cancer in preclinical models and clinical assays. Current evidence shows that viruses induce cytopathic effects associated with fusogenic protein-mediated syncytium formation and immunogenic cell death of eukaryotic cells. We have previously demonstrated that tumor cell bodies generated from cells expressing the fusogenic protein of the infectious salmon anemia virus (ISAV-F) enhance crosspriming and display prophylactic antitumor activity against melanoma tumors. In this work, we evaluated the effects of the expression of ISAV-F on the B16 melanoma model, both in vitro and in vivo, using chitosan nanoparticles as transfection vehicle. We confirmed that the transfection of B16 tumor cells with chitosan nanoparticles (NP-ISAV) allows the expression of a fusogenically active ISAV-F protein and decreases cell viability because of syncytium formation in vitro. However, the in vivo transfection induces a delay in tumor growth, without inducing changes on the lymphoid populations in the tumor and the spleen. Altogether, our observations show that expression of ISAV fusion protein using chitosan nanoparticles induces cell fusion in melanoma cells and slight antitumor response.

Angiotensin II increases the expression of the transcription factor ETS-1 in mesangial cells

2008 ◽  
Vol 294 (5) ◽  
pp. F1094-F1100 ◽  
Author(s):  
Damien D. Pearse ◽  
Run-Xia Tian ◽  
Jessica Nigro ◽  
Julian B. Iorgulescu ◽  
Leopold Puzis ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Angiotensin Ii ◽  
Nadph Oxidase ◽  
Mesangial Cells ◽  
Critical Role ◽  
Ang Ii ◽  
Specific Sequence ◽  
Cox 2

Maladaptive activation of the renin-angiotensin system (RAS) has been shown to play a critical role in the pathogenesis of chronic kidney disease. Reactive oxygen species (ROS) are critical signals for many of the nonhemodynamic effects of angiotensin II (ANG II). We have demonstrated that ANG II increases mesangial and cortical cyclooxygenase-2 (COX-2) expression and activity via NADPH oxidase-derived ROS. The transcription factor ETS-1 (E26 transformation-specific sequence) has been identified as a critical regulator of growth-related responses and inflammation. The present studies were designed to determine: 1) whether ANG II induces ETS-1 expression in vitro in cultured rat mesangial cells and in vivo in rats infused with ANG II; and 2) whether ROS and COX-2 are mediators of ETS-1 induction in response to ANG II. Mesangial cells stimulated with ANG II (10−7 M) exhibited a significant increase in ETS-1 expression that was prevented by the angiotensin type 1 receptor blocker candesartan. NADPH oxidase inhibition with dyphenilene iodinium or apocynin also prevented ETS-1 induction, establishing the role of ROS as mediators of ETS-1 expression in response to ANG II. COX-2 inhibition prevented ETS-1 expression in response to ANG II, suggesting that COX-2 is required for ETS-1 induction. By utilizing short interfering RNAs against ETS-1, we have also determined that ETS-1 is required to induce the production of fibronectin in response to ANG II. Furthermore, rats infused with ANG II manifested increased glomerular expression of ETS-1. These studies unveil novel pathways that may play an important role in the pathogenesis of renal injury when RAS is activated.

The dietary flavonoid isoliquiritigenin induced apoptosis and suppressed metastasis in melanoma cells: An in vitro and in vivo study

Life Sciences ◽  
2021 ◽  
Vol 264 ◽  
pp. 118598
Author(s):  
Shijian Xiang ◽  
Haiyan Zeng ◽  
Fan Xia ◽  
Qiufeng Ji ◽  
Jianwen Xue ◽  
...  
Keyword(s):  
Melanoma Cells ◽  
In Vivo Study ◽  
Dietary Flavonoid ◽  
Induced Apoptosis

scholarly journals Levosimendan Protects against Doxorubicin-Induced Cardiotoxicity by Regulating the PTEN/Akt Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ling-Li Li ◽  
Li Wei ◽  
Ning Zhang ◽  
Wen-Ying Wei ◽  
Can Hu ◽  
...  
Keyword(s):  
Critical Role ◽  
Cardiac Injury ◽  
Protective Role ◽  
Akt Inhibitor ◽  
Morphological Examination ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Myocardial Apoptosis

Background and Aims. Myocyte apoptosis plays a critical role in the development of doxorubicin- (DOX-) induced cardiotoxicity. In addition to its cardiotonic effect, laboratory evidence indicates that levosimendan can inhibit apoptosis, but its role in DOX-induced cardiac injury remains unclear. Therefore, the present study is aimed at exploring whether levosimendan could attenuate DOX-induced cardiotoxicity. Methods. Levosimendan (1 mg/kg) was administered to mice through oral gavage once daily for 4 weeks, and the mice were also subjected to an intraperitoneal injection of DOX (5 mg/kg) or saline, once a week for 4 weeks, to create a chronic model of DOX-induced cardiotoxicity. A morphological examination and biochemical analysis were used to evaluate the effects of levosimendan. H9C2 cells were used to verify the protective role of levosimendan in vitro. And an Akt inhibitor was utilized to verify the cardioprotection of levosimendan. Results. Levosimendan reduced the cardiac dysfunction and attenuated the myocardial apoptosis induced by DOX in vivo and in vitro. Levosimendan also inhibited the activation of phosphatase and tensin homolog (PTEN) and upregulated P-Akt expression both in vivo and in vitro. And inhibition of Akt abolished the cardioprotection of levosimendan in vitro. Conclusion. Levosimendan may protect against DOX-induced cardiotoxicity via modulation of the PTEN/Akt signaling pathway.

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