ABSTRACT
The development of resistance to current standard-of-care treatments, such as androgen receptor (AR) targeting therapies, remains a major challenge in the management of advanced prostate cancer. There is an urgent need for therapeutic strategies targeting key resistance drivers, such as AR variants like AR-V7 and steroidogenic enzymes like AKR1C3, to improve outcomes for patients with advanced prostate cancer. Here, we designed, synthesized, and characterized a class of LX compounds targeting both AR/AR variants and AKR1C3. Molecular docking indicated that LX compounds bound to the AKR1C3 active sites. LX1 blocked AKR1C3 enzymatic activity, suppressing the conversion of androstenedione into testosterone. LX compounds also reduced AR/AR-V7 expression and downregulated their target genes. In vitro, LX1 inhibited the growth of prostate cancer cells resistant to antiandrogens, including enzalutamide, abiraterone, apalutamide, and darolutamide. Treatment with LX1 in vivo significantly decreased tumor growth, lowered serum PSA levels, and reduced intratumoral testosterone levels, without affecting mouse body weight. Furthermore, LX1 overcame resistance to enzalutamide treatment, and the combination of LX1 with enzalutamide further suppressed tumor growth. Collectively, the dual effect of LX1 in reducing intratumoral testosterone and AR signaling, along with its synergy with standard therapies in resistant models, underscores its potential as a valuable treatment option for advanced prostate cancer.
ABSTRACT
The mammalian bromodomain and extra-terminal domain (BET) family of proteins consists of four conserved members (Brd2, Brd3, Brd4, and Brdt) that regulate numerous cancer-related and immunity-associated genes. They are epigenetic readers of histone acetylation with broad specificity. BET proteins are linked to cancer progression due to their interaction with numerous cellular proteins including chromatin-modifying factors, transcription factors, and histone modification enzymes. The spectacular growth in the clinical development of small-molecule BET inhibitors underscores the interest and importance of this protein family as an anticancer target. Current approaches targeting BET proteins for cancer therapy rely on acetylation mimics to block the bromodomains from binding chromatin. However, bromodomain-targeted agents are suffering from dose-limiting toxicities because of their effects on other bromodomain-containing proteins. In this review, we provided an updated summary about the evolution of small-molecule BET inhibitors. The design of bivalent BET inhibitors, kinase and BET dual inhibitors, BET protein proteolysis-targeting chimeras (PROTACs), and Brd4-selective inhibitors are discussed. The novel strategy of targeting the unique C-terminal extra-terminal (ET) domain of BET proteins and its therapeutic significance will also be highlighted. Apart from single agent treatment alone, BET inhibitors have also been combined with other chemotherapeutic modalities for cancer treatment demonstrating favorable clinical outcomes. The investigation of specific biomarkers for predicting the efficacy and resistance of BET inhibitors is needed to fully realize their therapeutic potential in the clinical setting.
Subject(s)
Antineoplastic Agents , Neoplasms , Animals , Humans , Nuclear Proteins/genetics , Transcription Factors/metabolism , Cell Cycle Proteins/genetics , Neoplasms/metabolism , Antineoplastic Agents/pharmacology , Chromatin , Mammals/metabolismABSTRACT
Hepatocellular carcinoma (HCC) is the predominant type of liver cancer and a leading cause of cancer-related death globally. It is also a sexually dimorphic disease with a male predominance both in HCC and in its precursors, non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH). The role of the androgen receptor (AR) in HCC has been well documented; however, AR-targeted therapies have failed to demonstrate efficacy in HCC. Building upon understandings of AR in prostate cancer (PCa), this review examines the role of AR in HCC, non-androgen-mediated mechanisms of induced AR expression, the existence of AR splice variants (AR-SV) in HCC and concludes by surveying current AR-targeted therapeutic approaches in PCa that show potential for efficacy in HCC in light of AR-SV expression.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Non-alcoholic Fatty Liver Disease , Male , Humans , Female , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Non-alcoholic Fatty Liver Disease/pathologyABSTRACT
As a key regulator for hormone activity, human aldo-keto reductase family 1 member C3 (AKR1C3) plays crucial roles in the occurrence of various hormone-dependent or independent malignancies. It is a promising target for treating castration-resistant prostate cancer (CRPC). However, the development of AKR1C3 specific inhibitors remains challenging due to the high sequence similarity to its isoform AKR1C2. Here, we performed a combined in silico study to illuminate the inhibitory preference of 3-(3,4-dihydroisoquinolin-2(1H)-ylsulfonyl)benzoic acids for AKR1C3 over AKR1C2, of which compound 38 can achieve up to 5000-fold anti-AKR1C3 selectivity. Our umbrella sampling (US) simulations together with end-point binding free energy calculation MM/GBSA uncover that the high inhibition selectivity originates from the different binding modes, namely "Inward" and "Outward," of this compound series in AKR1C3 and AKR1C2, respectively. In AKR1C3/38, the tetrahydroquinoline moiety of 38 is accommodated inside the SP1 pocket and interacts favorably with surrounding residues, while, in AKR1C2/38, the SP1 pocket is too small to hold the bulky tetrahydroquinoline group that instead moves out of the pocket with 38 transitioning from an "Inward" to an "Outward" state. Further 3D-QSAR and energy decomposition analyses suggest that SP1 in AKR1C3 prefers to bind with a rigid bicyclic moiety and the modification of the R3 group has important implication for the compound's activity. This work is the first attempt to elucidate the selectivity mechanism of inhibitors toward AKR1C3 at the atomic level, which is anticipated to propel the development of next-generation AKR1C3 inhibitors with enhanced efficacy and reduced "off-target" effect for CRPC therapy.
Subject(s)
Hydroxyprostaglandin Dehydrogenases , Prostatic Neoplasms, Castration-Resistant , Male , Humans , Aldo-Keto Reductase Family 1 Member C3/metabolism , Hydroxyprostaglandin Dehydrogenases/metabolism , 3-Hydroxysteroid Dehydrogenases/metabolism , Benzoates/chemistry , Computer Simulation , Protein Isoforms , HormonesABSTRACT
The bromodomain and extra-terminal (BET) domain family of proteins, which include its prototypical member Brd4, is implicated in a variety of cancers and viral infections due to their interaction with cellular and viral proteins. BET proteins contain two bromodomains, a common protein motif that selectively binds acetylated lysine on histones. However, they are structurally distinct from other bromodomain-containing proteins because they encode a unique C-terminal extra-terminal (ET) domain that is important for the protein-protein interactions including jumonji C-domain-containing protein 6 (JMJD6) and histone-lysine N-methyltransferase NSD3 (NSD3). Brd4 functions primarily during transcription as a passive scaffold linking cellular and viral proteins to chromatin. The rapid development of clinical inhibitors targeting Brd4 highlights the importance of this protein as an anticancer target. Current therapeutic approaches focus on the development of small molecule acetylated lysine mimics of histone marks that block the ability of the bromodomains to bind their chromatin marks. Thus far, bromodomain-targeted agents have shown dose-limiting toxicities due to off-target effects on other bromodomain-containing proteins. Here, we exploited a viral-host protein interaction interface to design peptides for the disruption of BET protein function. A murine leukemia virus (MLV) integrase-derived peptide (ET binding motif, EBM) and its shorter minimal binding motif (pentapeptide LKIRL) were sufficient to directly bind the Brd4 ET domain and reduce cellular proliferation of an acute myeloid leukemia cell line. Using computational and biochemical approaches, we identified the minimal essential contacts between EBM and LKIRL peptides and the Brd4 ET domain. Our findings provide a structural foundation for inhibiting BET/Brd4-mediated cancers by targeting the ET domain with small peptide-based inhibitors.
ABSTRACT
Targeting androgen signaling with the second-generation anti-androgen drugs, such as enzalutamide (Enza), abiraterone (Abi), apalutamide (Apal), and darolutamide (Daro), is the mainstay for the treatment of castration-resistant prostate cancer (CRPC). While these treatments are effective initially, resistance occurs frequently. Continued expression of androgen receptor (AR) and its variants such as AR-V7 despite AR-targeted therapy contributes to treatment resistance and cancer progression in advanced CRPC patients. This highlights the need for new strategies blocking continued AR signaling. Here, we identify a novel AR/AR-V7 degrader (ARVib) and found that ARVib effectively degrades AR/AR-V7 protein and attenuates AR/AR-V7 downstream target gene expression in prostate cancer cells. Mechanistically, ARVib degrades AR/AR-V7 protein through the ubiquitin-proteasome pathway mediated by HSP70/STUB1 machinery modulation. ARVib suppresses HSP70 expression and promotes STUB1 nuclear translocation, where STUB1 binds to AR/AR-V7 and promotes its ubiquitination and degradation. ARVib significantly inhibits resistant prostate tumor growth and improves enzalutamide treatment in vitro and in vivo. These data suggest that ARVib has potential for development as an AR/AR-V7 degrader to treat resistant CRPC.
Subject(s)
Prostatic Neoplasms , Receptors, Androgen , Humans , Male , Signal TransductionABSTRACT
An androgen receptor (AR) is an intensively studied treatment target for castration-resistant prostate cancer that is irresponsive to conventional antiandrogen therapeutics. Binding function 3 (BF3) inhibitors with alternative modes of action have emerged as a promising approach to overcoming antiandrogen resistance. However, how these BF3 inhibitors modulate AR function remains elusive, hindering the development of BF3-targeting agents. Here, we performed an integrated computational study to interrogate the binding mechanism of several known BF3 inhibitors with ARs. Our results show that the inhibitory effect of the BF3 antagonists arises from their allosteric modulation of the activation function (AF2) site, which alters the dynamic coupling between the BF3 and AF2 sites as well as the AF2-coactivator (SRC2-3) interaction. Moreover, the per-residue binding energy analyses reveal the "anchor" role of the linker connecting the phenyl ring and benzimidazole/indole in these BF3 inhibitors. Furthermore, the allosteric driver-interacting residues are found to include both "positive", e.g., Phe673 and Asn833, and "negative" ones, e.g., Phe826, and the differential interactions with these residues provide an explanation why stronger binding does not necessarily result in higher inhibitory activities. Finally, our allosteric communication pathway analyses delineate how the allosteric signals triggered by BF3 binding are propagated to the AF2 pocket through multiple short- and/or long-ranged transmission pathways. Collectively, our combined computational study provides a comprehensive structural mechanism underlying how the selected set of BF3 inhibitors modulate AR function, which will help guide future development of BF3 antagonists.
Subject(s)
Prostatic Neoplasms , Receptors, Androgen , Androgen Antagonists , Androgen Receptor Antagonists/pharmacology , Binding Sites , Humans , Male , Models, MolecularABSTRACT
Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 is a novel and highly pathogenic coronavirus and is the causative agent of the coronavirus disease 2019 (COVID-19). The high morbidity and mortality associated with COVID-19 and the lack of an approved drug or vaccine for SARS-CoV-2 underscores the urgent need for developing effective antiviral therapies. Therapeutics that target essential viral proteins are effective at controlling virus replication and spread. Coronavirus Spike glycoproteins mediate viral entry and fusion with the host cell, and thus are essential for viral replication. To enter host cells, the Spike proteins of SARS-CoV-2 and related coronavirus, SARS-CoV, bind the host angiotensin-converting enzyme 2 (ACE2) receptor through their receptor binding domains (RBDs). Here, we rationally designed a panel of ACE2-derived peptides based on the RBD-ACE2 binding interfaces of SARS-CoV-2 and SARS-CoV. Using SARS-CoV-2 and SARS-CoV Spike-pseudotyped viruses, we found that a subset of peptides inhibits Spike-mediated infection with IC50 values in the low millimolar range. We identified two peptides that bound Spike RBD in affinity precipitation assays and inhibited infection with genuine SARS-CoV-2. Moreover, these peptides inhibited the replication of a common cold causing coronavirus, which also uses ACE2 as its entry receptor. Results from the infection experiments and modeling of the peptides with Spike RBD identified a 6-amino-acid (Glu37-Gln42) ACE2 motif that is important for SARS-CoV-2 inhibition. Our work demonstrates the feasibility of inhibiting SARS-CoV-2 with peptide-based inhibitors. These findings will allow for the successful development of engineered peptides and peptidomimetic-based compounds for the treatment of COVID-19.
Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Antiviral Agents/pharmacology , Drug Design , Peptide Fragments/pharmacology , SARS-CoV-2/drug effects , Antiviral Agents/metabolism , HEK293 Cells , Humans , Molecular Docking Simulation , Peptide Fragments/metabolism , Protein Conformation , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolismABSTRACT
PURPOSE: Most patients with prostate cancer receiving enzalutamide or abiraterone develop resistance. Clinical evidence indicates that serum levels of dehydroepiandrosterone sulfate (DHEAS) and biologically active DHEA remain in the high range despite antiandrogen treatment. The conversion of DHEAS into DHEA by steroid sulfatase (STS) may contribute to sustained intracrine androgen synthesis. Here, we determine the contribution of STS to treatment resistance and explore the potential of targeting STS to overcome resistance in prostate cancer. EXPERIMENTAL DESIGN: STS expression was examined in patients and cell lines. In vitro, STS activity and expression were modulated using STS-specific siRNA or novel STS inhibitors (STSi). Cell growth, colony formation, androgen production, and gene expression were examined. RNA-sequencing analysis was conducted on VCaP cells treated with STSi. Mice were treated with STSis with or without enzalutamide to determine their effects in vivo. RESULTS: STS is overexpressed in patients with castration-resistant prostate cancer (CRPC) and resistant cells. STS overexpression increases intracrine androgen synthesis, cell proliferation, and confers resistance to enzalutamide and abiraterone. Inhibition of STS using siRNA suppresses prostate cancer cell growth. Targeting STS activity using STSi inhibits STS activity, suppresses androgen receptor transcriptional activity, and reduces the growth of resistant C4-2B and VCaP prostate cancer cells. STSis significantly suppress resistant VCaP tumor growth, decrease serum PSA levels, and enhance enzalutamide treatment in vitro and in vivo. CONCLUSIONS: These studies suggest that STS drives intracrine androgen synthesis and prostate cancer proliferation. Targeting STS represents a therapeutic strategy to treat CRPC and improve second-generation antiandrogen therapy.
Subject(s)
Androgens/biosynthesis , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms/drug therapy , Steryl-Sulfatase/genetics , Androgen Antagonists/pharmacology , Androgens/genetics , Androstenes/adverse effects , Androstenes/pharmacology , Benzamides/adverse effects , Benzamides/pharmacology , Carcinogenesis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dehydroepiandrosterone/metabolism , Dehydroepiandrosterone Sulfate/metabolism , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation, Neoplastic/drug effects , Humans , Male , Neoplasm Staging , Nitriles/adverse effects , Nitriles/pharmacology , Phenylthiohydantoin/adverse effects , Phenylthiohydantoin/pharmacology , Prostatic Neoplasms, Castration-Resistant/blood , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology , RNA-SeqABSTRACT
BACKGROUND: Previous studies found that Vitamin E (VE) could recruit protein kinase B (Akt1) to the membrane by targeting its unconventional lipid-binding site, which led to the dephosphorylation of Akt1 at Ser473, eventually deactivating the enzyme. METHODS: A series of VE-like compounds with varying types and lengths of the linker groups are designed to study the VE-driven membrane recruitment of Akt1 using a combined molecular docking and molecular dynamics (MD) simulation approach. RESULTS: We find that the linker groups with only one methylene linker and multiple hydrogen bond donors are optimal for achieving a balance between binding to the protein and partitioning into the membrane to form a stable protein-ligand-membrane ternary complex. These polar linkers are found to form stable hydrogen bonds with the lipid head groups during the MD simulations, which turns out critical for ensuring that the chromanol ring of the VE-like compounds resides above the membrane surface to fully engage in the protein. CONCLUSIONS: Our results reveal the molecular determinants of the linker groups for VE derivatives' ability to anchor Akt1 to the membrane. GENERAL SIGNIFICANCE: These findings will facilitate the design of membrane interfacial compounds to recruit specific proteins to the membrane to modulate the protein function.
Subject(s)
Cell Membrane/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Vitamin E/metabolism , Binding Sites , Humans , Hydrogen Bonding , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Domains , Proto-Oncogene Proteins c-akt/chemistry , Vitamin E/analogs & derivativesABSTRACT
Purpose: Neovascularization (NV) and retinal vascular leakage are major causes of impaired vision in ocular diseases. The purpose of this study was to identify novel phenylphthalimide analogs with therapeutic effects on NV and vascular leakage and to explore the mechanism of action. Methods: Antiangiogenic activities of novel phenylphthalimide analogs were assessed in vitro by using VEGF ELISA and endothelial cell proliferation assay. Their efficacies on retinal vascular leakage were evaluated using rat models of oxygen-induced retinopathy (OIR) and streptozotocin (STZ)-induced diabetes. The in vivo antiangiogenic activity was evaluated using topical administration in the alkali burn-induced corneal NV model. The expression of VEGF and intercellular adhesion molecule-1 (ICAM-1) were measured using ELISA. Results: Thalidomide and three novel analogs all showed inhibitory effects on endothelial cell proliferation and VEGF expression in vitro. Through intravitreal injection, all of the compounds reduced retinal vascular leakage in the OIR and STZ-induced diabetic models. Among these compounds, (2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3-dione (DAID) displayed the most potent efficacy and reduced retinal vascular leakage in a dose-dependent manner in both the OIR and STZ-diabetes models. Topical administration of DAID also inhibited alkali burn-induced corneal NV. Furthermore, DAID attenuated the overexpression of VEGF and ICAM-1 in the retina of the OIR model. Intravitreal injection of DAID did not result in any detectable side effects, as shown by electroretinogram and retinal histological analysis. Conclusions: DAID is a novel phenylphthalimide analog with potent effects on NV and retinal vascular leakage through downregulation of VEGF and inflammatory factors and has therapeutic potential.
Subject(s)
Corneal Neovascularization/drug therapy , Retinal Diseases/drug therapy , Retinal Vessels/pathology , Thalidomide/administration & dosage , Angiogenesis Inhibitors/administration & dosage , Animals , Cell Proliferation , Cells, Cultured , Corneal Neovascularization/metabolism , Corneal Neovascularization/pathology , Disease Models, Animal , Electroretinography , Enzyme-Linked Immunosorbent Assay , Intravitreal Injections , Male , Rats , Rats, Sprague-Dawley , Retinal Diseases/pathology , Retinal Diseases/physiopathology , Retinal Vessels/drug effects , Vascular Endothelial Growth Factor A/biosynthesisABSTRACT
[This corrects the article DOI: 10.18632/oncotarget.13466.].
ABSTRACT
BACKGROUND/AIM: Cancer is a leading cause of death. Hence, this study aimed at the optimization of niclosamide derivatives for the development of new potential anticancer agents. MATERIALS AND METHODS: Niclosamide derivatives were synthesized and tested against a panel of human cancer cells: MDA and MCF7 breast cancer cells, PC3 and DU-145 prostate cancer cells, Hela cervical cancer cells, and HL-60 acute promyelocytic leukemia cells. They were also tested in nuclear factor-ĸappa B (NFĸB), V-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS), and mitochondria transmembrane potential (MTP) assays. RESULTS: N-(3,5-Bis(trifluoromethyl)phenyl)-5-chloro-2-hydroxybenzamide exhibited the most significant cytotoxicity against HL-60 cells, while 5-chloro-N-(2-chlorophenyl)-2-hydroxybenzamide was the most active in the NFĸB assay and 5-chloro-N-(3,5-difluorophenyl)-2-hydroxybenzamide in the MTP assay. 5-chloro-N-(2-chloro-4-(trifluoromethyl) phenyl)-2-hydroxybenzamide and 5-chloro-2-hydroxy-N-(4-hydroxyphenyl)benzamide inhibited both HL-60 cell proliferation and NFĸB. CONCLUSION: In-depth study of the most promising compounds is highly encouraged to further develop into potential anticancer agents those derivatives found to be significantly active.
Subject(s)
Antineoplastic Agents/pharmacology , Niclosamide/analogs & derivatives , Niclosamide/pharmacology , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Membrane Potential, Mitochondrial/drug effects , NF-kappa B/antagonists & inhibitors , NF-kappa B/metabolism , Niclosamide/chemistry , Proto-Oncogene Proteins p21(ras)/antagonists & inhibitors , Proto-Oncogene Proteins p21(ras)/metabolism , Structure-Activity RelationshipABSTRACT
New targeted therapy approaches for certain subtypes of breast cancer, such as triple-negative breast cancers and other aggressive phenotypes, are desired. High levels of the mitotic checkpoint kinase Mps1/TTK have correlated with high histologic grade in breast cancer, suggesting a potential new therapeutic target for aggressive breast cancers (BC). Novel small molecules targeting Mps1 were designed by computer assisted docking analyses, and several candidate compounds were synthesized. These compounds were evaluated in anti-proliferative assays of a panel of 15 breast cancer cell lines and further examined for their ability to inhibit a variety of Mps1-dependent biological functions. The results indicate that the lead compounds have strong anti-proliferative potential through Mps1/TTK inhibition in both basal and luminal BC cell lines, exhibiting IC50 values ranging from 0.05 to 1.0µM. In addition, the lead compounds 1 and 13 inhibit Mps1 kinase enzymatic activity with IC50 values from 0.356µM to 0.809µM, and inhibited Mps1-associated cellular functions such as centrosome duplication and the spindle checkpoint in triple negative breast cancer cells. The most promising analog, compound 13, significantly decreased tumor growth in nude mice containing Cal-51 triple negative breast cancer cell xenografts. Using drug discovery technologies, computational modeling, medicinal chemistry, cell culture and in vivo assays, novel small molecule Mps1/TTK inhibitors have been identified as potential targeted therapies for breast cancers.
Subject(s)
Breast Neoplasms/drug therapy , Cell Cycle Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/therapeutic use , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/therapeutic use , Animals , Female , Humans , Mice , Mice, Nude , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacologyABSTRACT
Epithelial ovarian cancer (EOC) is the leading cause of gynecologic cancer mortality worldwide. Platinum-based therapy is the standard first line treatment and while most patients initially respond, resistance to chemotherapy usually arises. Major signaling pathways frequently upregulated in chemoresistant cells and important in the maintenance of cancer stem cells (CSCs) include Wnt/ß-catenin, mTOR, and STAT3. The major objective of our study was to investigate the treatment of ovarian cancer with targeted agents that inhibit these three pathways. Here we demonstrate that niclosamide, a salicylamide derivative, and two synthetically manufactured niclosamide analogs (analog 11 and 32) caused significant inhibition of proliferation of two chemoresistant ovarian cancer cell lines (A2780cp20 and SKOV3Trip2), tumorspheres isolated from the ascites of EOC patients, and cells from a chemoresistant patient-derived xenograft (PDX). This work shows that all three agents significantly decreased the expression of proteins in the Wnt/ß-catenin, mTOR and STAT3 pathways and preferentially targeted cells that expressed the ovarian CSC surface protein CD133. It also illustrates the potential of drug repurposing for chemoresistant EOC and can serve as a basis for pathway-oriented in vivo studies.
Subject(s)
Niclosamide/pharmacology , Ovarian Neoplasms/metabolism , Proteins/metabolism , Signal Transduction/drug effects , Animals , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Humans , Mice , Niclosamide/analogs & derivatives , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/pathology , STAT3 Transcription Factor/metabolism , TOR Serine-Threonine Kinases/metabolism , Wnt Proteins/metabolism , Xenograft Model Antitumor Assays , beta Catenin/metabolismABSTRACT
Persistent activation of signal transducers and activators of transcription 3 (STAT3) is commonly detected in many types of cancer including pancreatic cancer. Whether STAT3 is activated in stem cell-like pancreatic cancer cells and the effect of STAT3 inhibition, is still unknown. Flow cytometry was used to isolate pancreatic cancer stem-like cells which are identified by both aldehyde dehydrogenase (ALDH)-positive (ALDH+) as well as cluster of differentiation (CD) 44-positive/CD24-positive subpopulations (CD44+/CD24+). STAT3 activation and the effects of STAT3 inhibition by STAT3 inhibitors, LLL12, FLLL32, and Stattic in ALDH+ and CD44+/CD24+ cells were examined. Our results showed that ALDH+ and CD44+/CD24+ pancreatic cancer stem-like cells expressed higher levels of phosphorylated STAT3, an active form of STAT3, compared to ALDH-negative (ALDH-) and CD44-negative/CD24-negative (CD44-/CD24-) pancreatic cancer cells, suggesting that STAT3 is activated in pancreatic cancer stem-like cells. Small molecular STAT3 inhibitors inhibited STAT3 phosphorylation, STAT3 downstream target gene expression, cell viability, and tumorsphere formation in ALDH+ and CD44+/CD24+ cells. Our results indicate that STAT3 is a novel therapeutic target in pancreatic cancer stem-like cells and inhibition of activated STAT3 in these cells by STAT3 inhibitors may offer an effective treatment for pancreatic cancer.
Subject(s)
Anthraquinones/pharmacology , Curcumin/analogs & derivatives , Neoplastic Stem Cells/metabolism , Pancreatic Neoplasms/pathology , STAT3 Transcription Factor/antagonists & inhibitors , STAT3 Transcription Factor/metabolism , Sulfonamides/pharmacology , Aldehyde Dehydrogenase/metabolism , CD24 Antigen/metabolism , Cell Survival/drug effects , Curcumin/pharmacology , Enzyme Activation , Humans , Hyaluronan Receptors/metabolism , Spheroids, Cellular/drug effects , Tumor Cells, CulturedABSTRACT
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are diseases with high mortality. Macrophages and neutrophils are responsible for inflammatory responses in ALI and ARDS, which are characterized by excessive production of proinflammatory mediators in bronchoalveolar lavage fluid (BALF) and plasma. Aberrant activation of the JAK/STAT pathway is critical for persistent inflammation in many conditions such as infection and autoimmunity. Given the importance of the STAT3 transcription factor in activating macrophages and neutrophils and augmenting inflammation, we investigated the therapeutic potential of inhibiting STAT3 activity using the small-molecule STAT3 inhibitor, LLL12. Our results demonstrate that LPS induces STAT3 activation in macrophages in vitro and in CD45+CD11b+ cells from BALF in the LPS-induced ALI model in vivo. LLL12 treatment inhibits LPS-induced lung inflammation in the ALI model, which is accompanied by suppression of LPS-induced STAT3 activation and an inhibition of macrophage and inflammatory cell infiltration in lung and BALF. LLL12 treatment also suppresses expression of proinflammatory genes including IL-1ß, IL-6, TNF-α, iNOS, CCL2, and MHC class II in macrophages and inflammatory cells from BALF and serum as determined by ELISA. Furthermore, hyperactivation of STAT3 in LysMCre-SOCS3fl/fl mice accelerates the severity of inflammation in the ALI model. Both pre- and post-LPS treatment with LLL12 decrease LPS-induced inflammatory responses in mice with ALI. Importantly, LLL12 treatment attenuates STAT3 phosphorylation in human peripheral blood mononuclear cells induced by plasma from patients with ARDS, which suggests the feasibility of targeting the STAT3 pathway therapeutically for patients with ALI and ARDS.
Subject(s)
Acute Lung Injury/metabolism , Acute Lung Injury/prevention & control , STAT3 Transcription Factor/metabolism , Acute Lung Injury/chemically induced , Acute Lung Injury/pathology , Animals , Anthraquinones/pharmacology , Bronchoalveolar Lavage Fluid/cytology , Cell Separation , Chemokines/metabolism , Disease Models, Animal , Gene Deletion , Gene Expression Regulation/drug effects , Humans , Inflammation/genetics , Inflammation/pathology , Inflammation Mediators/metabolism , Integrases/metabolism , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides , Macrophages/drug effects , Macrophages/metabolism , Mice, Inbred C57BL , Myeloid Cells/drug effects , Myeloid Cells/metabolism , Pneumonia/genetics , Pneumonia/pathology , Respiratory Distress Syndrome/blood , Sulfonamides/pharmacology , Suppressor of Cytokine Signaling 3 Protein/metabolismABSTRACT
OBJECTIVE: Niclosamide has shown activity against ovarian cancer in vitro; however, it has low bioavailability in vivo. Therefore, we investigated the cytotoxicity of niclosamide analogs in combination with carboplatin against ovarian cancer patient ascites cells and tissue slices. MATERIALS/METHODS: Tumorspheres were isolated from ascites collected from patients undergoing ovarian cancer surgery and plated at 10,000 cells per 50 µL into low attachment plates. Tumor slices were also processed at the time of surgery. These were treated concurrently with niclosamide or analogs (0.1-5 µM) and carboplatin (5-150 µM). At 48 hours, cell viability was assessed with ATPlite assay. Western blotting was used to determine expression of Wnt/ß-catenin proteins in ascites cells. RESULTS: Cytotoxicity of niclosamide and its analogs in combination with carboplatin was demonstrated in 24 patient ascites samples. Increased cytotoxicity was seen with 2 analogs in 23 patient ascites samples when compared with niclosamide. Similar cytotoxicity was produced in an ex vivo tumor slice model. Western blot analysis showed decreased expression of Wnt/ß-catenin proteins with niclosamide and analog treatment in a dose-dependent fashion. CONCLUSIONS: The niclosamide-like analogs produced cytotoxicity both alone and in combination with carboplatin against tumorspheres from patient ascites and slices from solid tumor samples. Tumor slices showed similar cytotoxicity to matched ascites samples. Western blots showed down-regulation of Wnt pathway-associated proteins in patient samples treated with niclosamide analogs. These results suggest that more soluble niclosamide analogs may be useful for the treatment of ovarian cancer in combination with chemotherapy.
Subject(s)
Adenocarcinoma, Clear Cell/drug therapy , Ascites/drug therapy , Carboplatin/therapeutic use , Cystadenocarcinoma, Serous/drug therapy , Endometrial Neoplasms/drug therapy , Niclosamide/therapeutic use , Ovarian Neoplasms/drug therapy , Adenocarcinoma, Clear Cell/metabolism , Adenocarcinoma, Clear Cell/pathology , Aged , Antinematodal Agents/therapeutic use , Antineoplastic Agents/therapeutic use , Ascites/metabolism , Ascites/pathology , Blotting, Western , Cell Survival/drug effects , Cystadenocarcinoma, Serous/metabolism , Cystadenocarcinoma, Serous/pathology , Drug Therapy, Combination , Endometrial Neoplasms/metabolism , Endometrial Neoplasms/pathology , Female , Humans , Neoplasm Grading , Neoplasm Staging , Niclosamide/analogs & derivatives , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Prognosis , Wnt Proteins/metabolism , beta Catenin/metabolismABSTRACT
Colon tumors are a major cause of cancer death, yet their molecular intricacies are not fully understood. We demonstrate that the histone demethylases JMJD2A, JMJD2B and JMJD2C are overexpressed in colon cancer cell lines, whereas another related protein, JMJD2D, is not. Interestingly, despite their high homology, the intracellular localization of JMJD2A-C is different in colon and other cancer cells, with JMJD2A being present comparably in the cytoplasm and nucleus, JMJD2B more prevalent in the nucleus and JMJD2C strongly associated with chromatin. This suggests that each of these three proteins performs different, non-redundant functions. Moreover, we show that JMJD2C (also called KDM4C) forms complexes with ß-catenin, an oncoprotein whose overexpression is crucial for the development of most colonic tumors. In addition, JMJD2C downregulation reduced both growth and clonogenic capacity of HCT-116 colon cancer cells. Further, JMJD2C was required for efficient expression of the growth stimulatory proteins FRA1 and cyclin D1 as well as the survival factor BCL2. Lastly, we identified derivatives of curcumin as in vitro inhibitors of JMJD2 enzymes, suggesting that these curcuminoids could be useful for decreasing JMJD2 activity in vivo. In conclusion, our data highlight that overexpression of JMJD2C confers a pro-growth effect on colon cancer cells and, therefore, its inhibition by curcuminoids or other small molecules could be beneficial as an adjuvant therapy for colon cancer patients.
ABSTRACT
The rapid development of new anticancer drugs that are safe and effective is a common goal shared by basic scientists, clinicians and patients. The current review discusses one such agent, namely niclosamide, which has been used in the clinic for the treatment of intestinal parasite infections. Recent studies repeatedly identified niclosamide as a potential anticancer agent by various high-throughput screening campaigns. Niclosamide not only inhibits the Wnt/ß-catenin, mTORC1, STAT3, NF-κB and Notch signaling pathways, but also targets mitochondria in cancer cells to induce cell cycle arrest, growth inhibition and apoptosis. A number of studies have established the anticancer activities of niclosamide in both in vitro and in vivo models. Moreover, the inhibitory effects of niclosamide on cancer stem cells provide further evidence for its consideration as a promising drug for cancer therapy. This article reviews various aspects of niclosamide as they relate to its efficacy against cancer and associated molecular mechanisms.