Castration-resistant prostate cancer (CRPC) is characterized by reactivation of androgen receptor (AR) signaling, in part by elevated expression of AR splice variants (ARv) including ARv7, a ...constitutively active, ligand binding domain (LBD)-deficient variant whose expression has been correlated with therapeutic resistance and poor prognosis. In a screen to identify small-molecule dual inhibitors of both androgen-dependent and androgen-independent AR gene signatures, we identified the chalcone C86. Binding studies using purified proteins and CRPC cell lysates revealed C86 to interact with Hsp40. Pull-down studies using biotinylated-C86 found Hsp40 present in a multiprotein complex with full-length (FL-) AR, ARv7, and Hsp70 in CRPC cells. Treatment of CRPC cells with C86 or the allosteric Hsp70 inhibitor JG98 resulted in rapid protein destabilization of both FL-AR and ARv, including ARv7, concomitant with reduced FL-AR- and ARv7-mediated transcriptional activity. The glucocorticoid receptor, whose elevated expression in a subset of CRPC also leads to androgen-independent AR target gene transcription, was also destabilized by inhibition of Hsp40 or Hsp70.
, Hsp40 or Hsp70 inhibition demonstrated single-agent and combinatorial activity in a 22Rv1 CRPC xenograft model. These data reveal that, in addition to recognized roles of Hsp40 and Hsp70 in FL-AR LBD remodeling, ARv lacking the LBD remain dependent on molecular chaperones for stability and function. Our findings highlight the feasibility and potential benefit of targeting the Hsp40/Hsp70 chaperone axis to treat prostate cancer that has become resistant to standard antiandrogen therapy.
These findings highlight the feasibility of targeting the Hsp40/Hsp70 chaperone axis to treat CRPC that has become resistant to standard antiandrogen therapy.
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The anti-cancer activity and cytotoxicity of phosphonium and ammonium-based ionic liquids (ILs) have been determined for the first time via NCI’s in vitro 60 human tumor cell lines. Cell line data ...and hollow fiber study has demonstrated the potential of ILs to be developed as therapeutic agent.
The anti-cancer activity and cytotoxicity of phosphonium and ammonium-based ionic liquids (ILs) have been determined for the first time via NCI’s in vitro 60 human tumor cell lines. The preliminary SAR showed that the chain length of alkyl substitution on the cations plays crucial role towards anti-tumor activity and cytotoxicity of these ionic liquids. In general, phosphonium-based ILs were found to be more active and less cytotoxic as compared to ammonium ILs. Cell line data and hollow fiber study has demonstrated the potential of ILs to be developed as therapeutic agent.
A nuclear disaster may result in exposure to potentially lethal doses of ionizing radiation (IR). Hematopoietic acute radiation syndrome (H-ARS) is characterized by severe myelosuppression, which ...increases the risk of infection, bleeding, and mortality. Here, we determined that activation of nuclear factor erythroid-2-related factor 2 (NRF2) signaling enhances hematopoietic stem progenitor cell (HSPC) function and mitigates IR-induced myelosuppression and mortality. Augmenting NRF2 signaling in mice, either by genetic deletion of the NRF2 inhibitor Keap1 or by pharmacological NRF2 activation with 2-trifluoromethyl-2'-methoxychalone (TMC), enhanced hematopoietic reconstitution following bone marrow transplantation (BMT). Strikingly, even 24 hours after lethal IR exposure, oral administration of TMC mitigated myelosuppression and mortality in mice. Furthermore, TMC administration to irradiated transgenic Notch reporter mice revealed activation of Notch signaling in HSPCs and enhanced HSPC expansion by increasing Jagged1 expression in BM stromal cells. Administration of a Notch inhibitor ablated the effects of TMC on hematopoietic reconstitution. Taken together, we identified a mechanism by which NRF2-mediated Notch signaling improves HSPC function and myelosuppression following IR exposure. Our data indicate that targeting this pathway may provide a countermeasure against the damaging effects of IR exposure.
The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) cause life‐threatening diseases in millions of people worldwide, in particular, in patients with cancer, and there is an ...urgent need for antiviral agents against this infection. While in vitro activities of artemisinins against SARS‐CoV‐2 and cancer have recently been demonstrated, no study of artemisinin and/or synthetic peroxide‐based hybrid compounds active against both cancer and SARS‐CoV‐2 has been reported yet. However, the hybrid drug's properties (e. g., activity and/or selectivity) can be improved compared to its parent compounds and effective new agents can be obtained by modification/hybridization of existing drugs or bioactive natural products. In this study, a series of new artesunic acid and synthetic peroxide based new hybrids were synthesized and analyzed in vitro for the first time for their inhibitory activity against SARS‐CoV‐2 and leukemia cell lines. Several artesunic acid‐derived hybrids exerted a similar or stronger potency against K562 leukemia cells (81–83 % inhibition values) than the reference drug doxorubicin (78 % inhibition value) and they were also more efficient than their parent compounds artesunic acid (49.2 % inhibition value) and quinoline derivative (5.5 % inhibition value). Interestingly, the same artesunic acid‐quinoline hybrids also show inhibitory activity against SARS‐CoV‐2 in vitro (EC50 13–19 μm) and no cytotoxic effects on Vero E6 cells (CC50 up to 110 μM). These results provide a valuable basis for design of further artemisinin‐derived hybrids to treat both cancer and SARS‐CoV‐2 infections.
Hybrid power: New artemisinin‐ and synthetic peroxide‐based hybrids, highly active in vitro against leukemia cell lines and SARS‐CoV‐2, were synthesized. Remarkably, the most active anti‐cancer hybrid compounds are also the most potent and selective against SARS‐CoV‐2.
In squamous cell carcinoma (SCC), macrophages responding to interleukin (IL)-33 create a TGF-β-rich stromal niche that maintains cancer stem cells (CSCs), which evade chemotherapy-induced apoptosis ...in part via activation of the NRF2 antioxidant program. Here, we examined how IL-33 derived from CSCs facilitates the development of an immunosuppressive microenvironment. CSCs with high NRF2 activity redistributed nuclear IL-33 to the cytoplasm and released IL-33 as cargo of large oncosomes (LOs). Mechanistically, NRF2 increased the expression of the lipid scramblase ATG9B, which exposed an “eat me” signal on the LO surface, leading to annexin A1 (ANXA1) loading. These LOs promoted the differentiation of AXNA1 receptor+ myeloid precursors into immunosuppressive macrophages. Blocking ATG9B’s scramblase activity or depleting ANXA1 decreased niche macrophages and hindered tumor progression. Thus, IL-33 is released from live CSCs via LOs to promote the differentiation of alternatively activated macrophage, with potential relevance to other settings of inflammation and tissue repair.
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•CSCs export IL-33 from the nucleus by activating NRF2•CSCs generate IL-33-containing LOs via ATG9B•ANXA1 on the LO surface facilitates IL-33 delivery to niche precursor cells•LOs induce CSC niche macrophages, thus promoting invasive tumor progression
Interleukin (IL)-33 release is associated with cell death in the tumor microenvironment, and it has varied effects on tumor development and progression. In a model of squamous cell carcinoma, Erickson et al. show that cancer stem cells produce large oncosomes that deliver IL-33 specifically to niche macrophage precursors, promoting the differentiation of these cells into an immune-suppressive phenotype.
Y box binding protein 1 (YB-1) is a multifunctional protein associated with tumor progression and the emergence of treatment resistance (TR). Here, we report an azopodophyllotoxin small molecule, ...SU056, that potently inhibits tumor growth and progression via YB-1 inhibition. This YB-1 inhibitor inhibits cell proliferation, resistance to apoptosis in ovarian cancer (OC) cells, and arrests in the G1 phase. Inhibitor treatment leads to enrichment of proteins associated with apoptosis and RNA degradation pathways while downregulating spliceosome pathway. In vivo, SU056 independently restrains OC progression and exerts a synergistic effect with paclitaxel to further reduce disease progression with no observable liver toxicity. Moreover, in vitro mechanistic studies showed delayed disease progression via inhibition of drug efflux and multidrug resistance 1, and significantly lower neurotoxicity as compared with etoposide. These data suggest that YB-1 inhibition may be an effective strategy to reduce OC progression, antagonize TR, and decrease patient mortality.
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•Azopodophyllotoxin small molecule, SU056, inhibits YB-1•YB-1 inhibition decreases OC cell proliferation and resistance to apoptosis•YB-1 inhibition sensitizes OC cells for paclitaxel treatment
Tailor et al. reported azopodophyllotoxin derivative SU056 as a Y box binding protein 1 (YB-1) inhibitor. YB-1 inhibitor co-treatment sensitizes ovarian cancer cells for paclitaxel treatment.
Development of tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL oncogene constitutes an effective approach for the treatment of chronic myeloid leukemia (CML) and/or acute lymphoblastic ...leukemia. However, currently available inhibitors are limited by drug resistance and toxicity. Ponatinib, a third-generation inhibitor, has demonstrated excellent efficacy against both wild type and mutant BCR-ABL kinase, including the “gatekeeper” T315I mutation that is resistant to all other currently available TKIs. However, it is one of the most cardiotoxic of the FDA-approved TKIs. Herein, we report the structure-guided design of a novel series of potent BCR-ABL inhibitors, particularly for the T315I mutation. Our drug design paradigm was coupled to iPSC–cardiomyocyte models. Systematic structure–activity relationship studies identified two compounds, 33a and 36a, that significantly inhibit the kinase activity of both native BCR-ABL and the T315I mutant. We have identified the most cardiac-safe TKIs reported to date, and they may be used to effectively treat CML patients with the T315I mutation.
The sulfamide functional group has been extensively employed in organic synthesis to discover probes and drugs in various applications such as cancer, human immunodeficiency virus (HIV), virus, and ...diabetes. Herein, we describe the synthesis of 7-membered symmetric and unsymmetric sulfamide compounds and their biological evaluation through the National Cancer Institute (NCI) panel of 60 human tumor cell lines (NCI-60) and the mechanism of action study. The results of a study from the NCI-60 cell line exhibited that many synthesized cyclic sulfamide compounds inhibited breast cancer (MDA-MB-468). The mechanism of action study of a representative compound 18 showed the inhibition of proliferation and apoptosis in A549 lung cancer cells.
Small molecules that disrupt leukocyte trafficking have proven effective in treating patients with multiple sclerosis (MS). We previously reported that chemerin receptor chemokine-like receptor 1 ...(CMKLR1) is required for maximal clinical and histological experimental autoimmune encephalomyelitis (EAE); and identified CMKLR1 small molecule antagonist 2-(α-naphthoyl) ethyltrimethylammonium iodide (α-NETA) that significantly suppressed disease onset in vivo. Here we directly compared α-NETA versus FDA-approved MS drug Tecfidera for clinical efficacy in EAE; characterized key safety/toxicity parameters for α-NETA; identified structure-activity relationships among α-NETA domains and CMKLR1 inhibition; and evaluated improved α-NETA analogs for in vivo efficacy. α-NETA proved safe and superior to Tecfidera in suppressing clinical EAE. In addition, we discovered structurally differentiated α-NETA analogs (primarily ortho- or para-methoxy substitutions) with significantly improved target potency in vitro and improved efficacy in vivo. These findings suggest that α-NETA-based CMKLR1 inhibitors may prove safe and effective in treating demyelinating diseases and potentially other autoimmune disorders.
Cancer remains a leading cause of death worldwide, resulting in continuous efforts to discover and develop highly efficacious anticancer drugs. High‐throughput screening of heterocyclic compound ...libraries is one of the promising approaches that provided several new lead molecules with a novel mechanism of action. On the basis of the promising anticancer potential of imidazoquinoxaline as well as the structurally similar imidazoquinoline‐derived scaffold, we prepared a set of C6‐substituted benzimidazo1,2‐aquinoxaline derivatives via two novel synthetic routes using commercially available starting materials, with good to excellent yields and evaluated their anticancer activity against the NCI‐60 cancer cell lines. The one‐dose (10 µM) anticancer screening of the synthesized compounds in the NCI‐60 cell line panel revealed that the substituents have a significant role in the activity. In particular, the indole (7f), imidazole (7g), and benzimidazole (7h) derivatives showed significant activity against the triple‐negative breast cancer cell line, MDA‐MB‐468. The lead compounds also exhibited notable IC50 values against another breast cancer cell line, MCF‐7. Furthermore, it was observed that these compounds were relatively nontoxic to normal cell lines: HEK293 (human embryonic kidney cell line) and MCF12A (nontumorigenic human breast epithelial cell line). The IC50 values against healthy cells were at least 5‐ to 11‐fold higher, offering a new class of heterocycles that can be further developed as promising therapeutics for cancer treatment.
A series of C6‐substituted benzimidazo1,2‐aquinoxaline derivatives was prepared via two novel synthetic routes using commercially available starting materials and their anticancer activities were evaluated against the NCI‐60 cancer cell panel. The indole (7f), imidazole (7g), and benzimidazole (7h) derivatives showed significant activity against the triple‐negative breast cancer cell line, MDA‐MB‐468.
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