Sorafenib triggers ferroptosis via inhibition of HBXIP/SCD axis in hepatocellular carcinoma.

Sorafenib, which inhibits multiple kinases, is an effective frontline therapy for hepatocellular carcinoma (HCC). Ferroptosis is a form of iron-dependent programmed cell death regulated by lipid peroxidation, which can be induced by sorafenib treatment. Oncoprotein hepatitis B X-interacting protein (HBXIP) participates in multiple biological pro-tumor processes, including growth, metastasis, drug resistance, and metabolic reprogramming. However, the role of HBXIP in sorafenib-induced ferroptotic cell death remains unclear. In this study, we demonstrated that HBXIP prevents sorafenib-induced ferroptosis in HCC cells. Sorafenib decreased HBXIP expression, and overexpression of HBXIP blocked sorafenib-induced HCC cell death. Interestingly, suppression of HBXIP increased malondialdehyde (MDA) production and glutathione (GSH) depletion to promote sorafenib-mediated ferroptosis and cell death. Ferrostatin-1, a ferroptosis inhibitor, reversed the enhanced anticancer effect of sorafenib caused by HBXIP silencing in HCC cells. Regarding the molecular mechanism, HBXIP transcriptionally induced the expression of stearoyl-CoA desaturase (SCD) via coactivating the transcriptional factor ZNF263, resulting in the accumulation of free fatty acids and suppression of ferroptosis. Functionally, activation of the HBXIP/SCD axis reduced the anticancer activity of sorafenib and suppressed ferroptotic cell death in vivo and in vitro. HBXIP/SCD axis-mediated ferroptosis can serve as a novel downstream effector of sorafenib. Our results provide new evidence for clinical decisions in HCC therapy.

Protective effect of rosuvastatin pretreatment against acute myocardial injury by regulating Nrf2, Bcl-2/Bax, iNOS, and TNF-α expressions affecting oxidative/nitrosative stress and inflammation.

Cardiovascular disorders are the leading cause of death globally. Rosuvastatin is a member of statins (inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase) with many pleiotropic properties. This study investigated cardioprotective effects of rosuvastatin in isoprenaline-induced myocardial injury. Male rats were given rosuvastatin (1, 5, or 10 mg/kg, oral) daily for 1 week and on seventh and eighth day isoprenaline (150 mg/kg, subcutaneous) was given to induce cardiac injury. On ninth day, rats were euthanized and different samples were harvested for analysis. Isoprenaline administration resulted in increased cardiac mass, increased cardiac injury marker levels (cTnI, CK-MB, ALT, and AST), increased lipid/protein oxidation, and increased cardiac nitrite levels. It also decreased superoxide dismutase, CAT, GST, and glutathione reductase activities, and total antioxidant activity. Isoprenaline also increased TNF-α and IL-6 levels. Decreased mRNA expression of Nrf2 and Bcl-2 along with increased mRNA expression of Bax, eNOS and iNOS genes was observed in isoprenaline treated animals. Histopathological evaluations of rosuvastatin pre-treated groups showed reduction of myocardial necrosis. Pretreatment with rosuvastatin (5 and 10 mg/kg) reduced many of these pathological changes. The current study showed that rosuvastatin significantly reduces myocardial injury induced by isoprenaline.

Oncolytic adenovirus carrying SPAG9-shRNA enhanced the efficacy of docetaxel for advanced prostate cancer.

Sperm-associated antigen 9 (SPAG9) is closely related to the growth and metastasis of advanced prostate cancer. Docetaxel (DTX) is the gold standard for chemotherapy of prostate cancer, but its side effects decrease the life quality of patients. Therefore, it is urgent to develop combination therapy to increase chemotherapy efficacy for advanced prostate cancer. Oncolytic adenovirus carrying a short hairpin RNA (shRNA) targeting SPAG9 (ZD55-shSPAG9) was applied alone or in combination with docetaxel in prostate cancer cells. Cells were analyzed by cell counting kit-8, Hocehst-33258, transwell and western blot analysis. For in vivo experiments, nude mice were loaded with prostate cancer cells. ZD55-shSPAG9 effectively silenced the expression of SPAG9 in prostate cancer cells in vitro and in vivo. The replication of ZD55-shSPAG9 in prostate cancer cells was not affected by docetaxel, but the combined use of ZD55-shSAPAG9 and docetaxel has a better inhibitory effect on tumor growth and invasion in vitro and in vivo. Our study showed that the combined use of ZD55-shSPAG9 and docetaxel may be a new approach to the treatment of advanced prostate cancer.

SMYD2-mediated TRAF2 methylation promotes the NF-κB signaling pathways in inflammatory diseases.

BACKGROUND: The methylation of lysine residues has been involved in the multiple biological and diseases processes. Recently, some particular non-histone proteins have been elucidated to be methylated by SMYD2, a SET and MYND domain protein with lysine methyltransferase activity. METHODS: SMYD2 was evaluated in synovial tissue and cells derived from rheumatoid arthritis patients. We confirmed TRAF2 could be methylated by SMYD2 using Mass spectrometry, pull-down, immunoprecipitation, methyltransferase assay, ubiquitination assay, luciferase reporter assays, and western blot analyses. Using loss- and gain-of function studies, we explored the biological functions of SMYD2 in vitro and in vivo. Using acute and chronic inflammation with different mice models to determine the impact of SMYD2. RESULTS: Here, we first time confirmed that the cytoplasmic protein TRAF2 as the kernel node for NF-κB signaling pathway could be methylated by SMYD2. SMYD2-mediated TRAF2 methylation contributed to the durative sensitization of NF-κB signaling transduction through restraining its own proteolysis and enhancing the activity. In addition, we found knocking down of SMYD2 has different degrees of mitigation in acute and chronic inflammation mice models. Furthermore, as the lysine-specific demethylase, LSD1 could resist methylation on TRAF2 induced by SMYD2. CONCLUSIONS: Our data uncovered an unprecedented cytoplasmic protein network that employed methylation of TRAF2 for the maintenance of NF-κB activation during inflammatory diseases.

Everolimus and plicamycin specifically target chemoresistant colorectal cancer cells of the CMS4 subtype.

Colorectal cancers (CRC) can be classified into four consensus molecular subtypes (CMS), among which CMS1 has the best prognosis, contrasting with CMS4 that has the worst outcome. CMS4 CRC is notoriously resistant against therapeutic interventions, as demonstrated by preclinical studies and retrospective clinical observations. Here, we report the finding that two clinically employed agents, everolimus (EVE) and plicamycin (PLI), efficiently target the prototypic CMS4 cell line MDST8. As compared to the prototypic CMS1 cell line LoVo, MDST8 cells treated with EVE or PLI demonstrated stronger cytostatic and cytotoxic effects, increased signs of apoptosis and autophagy, as well as a more pronounced inhibition of DNA-to-RNA transcription and RNA-to-protein translation. Moreover, nontoxic doses of EVE and PLI induced the shrinkage of MDST8 tumors in mice, yet had only minor tumor growth-reducing effects on LoVo tumors. Altogether, these results suggest that EVE and PLI should be evaluated for their clinical activity against CMS4 CRC.

Synergistic efficacy of inhibiting MYCN and mTOR signaling against neuroblastoma.

BACKGROUND: Neuroblastoma (NB) patients with MYCN amplification or overexpression respond poorly to current therapies and exhibit extremely poor clinical outcomes. PI3K-mTOR signaling-driven deregulation of protein synthesis is very common in NB and various other cancers that promote MYCN stabilization. In addition, both the MYCN and mTOR signaling axes can directly regulate a common translation pathway that leads to increased protein synthesis and cell proliferation. However, a strategy of concurrently targeting MYCN and mTOR signaling in NB remains unexplored. This study aimed to investigate the therapeutic potential of targeting dysregulated protein synthesis pathways by inhibiting the MYCN and mTOR pathways together in NB. METHODS: Using small molecule/pharmacologic approaches, we evaluated the effects of combined inhibition of MYCN transcription and mTOR signaling on NB cell growth/survival and associated molecular mechanism(s) in NB cell lines. We used two well-established BET (bromodomain extra-terminal) protein inhibitors (JQ1, OTX-015), and a clinically relevant mTOR inhibitor, temsirolimus, to target MYCN transcription and mTOR signaling, respectively. The single agent and combined efficacies of these inhibitors on NB cell growth, apoptosis, cell cycle and neurospheres were assessed using MTT, Annexin-V, propidium-iodide staining and sphere assays, respectively. Effects of inhibitors on global protein synthesis were quantified using a fluorescence-based (FamAzide)-based protein synthesis assay. Further, we investigated the specificities of these inhibitors in targeting the associated pathways/molecules using western blot analyses. RESULTS: Co-treatment of JQ1 or OTX-015 with temsirolimus synergistically suppressed NB cell growth/survival by inducing G1 cell cycle arrest and apoptosis with greatest efficacy in MYCN-amplified NB cells. Mechanistically, the co-treatment of JQ1 or OTX-015 with temsirolimus significantly downregulated the expression levels of phosphorylated 4EBP1/p70-S6K/eIF4E (mTOR components) and BRD4 (BET protein)/MYCN proteins. Further, this combination significantly inhibited global protein synthesis, compared to single agents. Our findings also demonstrated that both JQ1 and temsirolimus chemosensitized NB cells when tested in combination with cisplatin chemotherapy. CONCLUSIONS: Together, our findings demonstrate synergistic efficacy of JQ1 or OTX-015 and temsirolimus against MYCN-driven NB, by dual-inhibition of MYCN (targeting transcription) and mTOR (targeting translation). Additional preclinical evaluation is warranted to determine the clinical utility of targeted therapy for high-risk NB patients.

miR-424-5p shuttled by bone marrow stem cells-derived exosomes attenuates osteogenesis via regulating WIF1-mediated Wnt/ß-catenin axis.

Emerging evidence proves that exosomes contain specific microRNAs(miRNAs) contribute to osteogenic differentiation of bone marrow stem cells (BMSCs). However, the role and mechanism of bone marrow stem cells (BMSCs)-derived exosomes overexpressing miR-424-5p in osteoblasts remains unclear. Firstly, the BMSCs-derived exosomes were isolated, and identified by Western blot with the exosome surface markers CD9, CD81 and CD63. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the level of miR-424-5p in exosomes, and western blot was implemented to verify the WIF1/Wnt/ß-catenin expression. The binding association between miR-424-5p and WIF1 was determined by the dual-luciferase reporter gene assay. Functional enhancement experiments were adopted to determine the role of exosome-carried miR-424-5p and WIF1/Wnt/ß-catenin in osteogenic differentiation. ALP staining was adopted, and levels of RUNX2, OCN, and OPN were monitored using qRT-PCR to determine osteogenic differentiation. As a result, In vivo experiments showed that RUNX2, OCN and OPN levels decreased and the ALP activity was dampened after miR-424-5p overexpression in exosomes. Besides, exosomes overexpressing miR-424-5p attenuated osteogenic development via WIF1/Wnt/ß-catenin. Our findings may bring evidence for miR-424-5p as a new biomarker for the treatment of osteoporosis.

Soluble epoxide hydrolase deletion attenuated nicotine-induced arterial stiffness via limiting the loss of SIRT1.

Arterial stiffness, a consequence of smoking, is an underlying risk factor of cardiovascular diseases. Epoxyeicosatrienoic acids (EETs), hydrolyzed by soluble epoxide hydrolase (sEH), have beneficial effects against vascular dysfunction. However, the role of sEH knockout in nicotine-induced arterial stiffness was not characterized. We hypothesized that sEH knockout could prevent nicotine-induced arterial stiffness. In the present study, Ephx2 (the gene encodes sEH enzyme) null (Ephx2-/-) mice and wild-type (WT) littermate mice were infused with or without nicotine and administered with or without nicotinamide [NAM, sirtuin-1 (SIRT1) inhibitor] simultaneously for 4 wk. Nicotine treatment increased sEH expression and activity in the aortas of WT mice. Nicotine infusion significantly induced vascular remodeling, arterial stiffness, and SIRT1 deactivation in WT mice, which was attenuated in Ephx2 knockout mice (Ephx2-/- mice) without NAM treatment. However, the arterial protective effects were gone in Ephx2-/- mice with NAM treatment. In vitro, 11,12-EET treatment attenuated nicotine-induced matrix metalloproteinase 2 (MMP2) upregulation via SIRT1-mediated yes-associated protein (YAP) deacetylation. In conclusion, sEH knockout attenuated nicotine-induced arterial stiffness and vascular remodeling via SIRT1-induced YAP deacetylation.NEW & NOTEWORTHY We presently show that sEH knockout repressed nicotine-induced arterial stiffness and extracellular matrix remodeling via SIRT1-induced YAP deacetylation, which highlights that sEH is a potential therapeutic target in smoking-induced arterial stiffness and vascular remodeling.

Kaempferol alleviates human endothelial cell injury through circNOL12/miR-6873-3p/FRS2 axis.

BACKGROUND: Atherosclerosis, inflammatory disease, is a major reason for cardiovascular diseases and stroke. Kaempferol (Kae) has been well-documented to have pharmacological activities in the previous studies. However, the detailed mechanisms by which Kae regulates inflammation, oxidative stress, and apoptosis in Human Umbilical Vein Endothelial Cells (HUVECs) remain unknown. METHODS AND RESULTS: The real-time quantitative polymerase chain reaction (RT-qPCR) was used to measure expression levels of circNOL12, nucleolar protein 12 (NOL12), miR-6873-3p, and Fibroblast growth factor receptor substrate 2 (FRS2) in HUVECs treated with either oxidized low-density lipoprotein (ox-LDL) alone or in combination with Kae. The cells viability was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assay. The inflammation and oxidative stress were assessed by checking inflammatory factors, Reactive Oxygen Species (ROS), Superoxide Dismutase (SOD), and Malondialdehyde (MDA) levels in ox-LDL-induced HUVECs. The apoptotic cells were quantified by flow cytometry assay. The western blot assay was used for measuring protein expression. The interaction relationship between miR-6873-3p and circNOL12 or FRS2 was analyzed by dual-luciferase reporter and RNA pull-down assays. Treatment with Kae could inhibit ox-LDL-induced the upregulation of circNOL12 in HUVECs. Importantly, Kae weakened ox-LDL-induced inflammation, oxidative stress, and apoptosis in HUVECs, which was abolished by overexpression of circNOL12. What's more, miR-6873-3p was a target of circNOL12 in HUVECs, and the upregulation of miR-6873-3p overturned circNOL12 overexpression-induced effects on HUVECs treated with ox-LDL and Kae. FRS2 was negatively regulated by miR-6873-3p in HUVECs. CONCLUSION: Kae alleviated ox-LDL-induced inflammation, oxidative stress, and apoptosis in HUVECs by regulating circNOL12/miR-6873-3p/FRS2 axis.

Antagonizing the spindle assembly checkpoint silencing enhances paclitaxel and Navitoclax-mediated apoptosis with distinct mechanistic.

Antimitotic drugs arrest cells in mitosis through chronic activation of the spindle assembly checkpoint (SAC), leading to cell death. However, drug-treated cancer cells can escape death by undergoing mitotic slippage, due to premature mitotic exit. Therefore, overcoming slippage issue is a promising chemotherapeutic strategy to improve the effectiveness of antimitotics. Here, we antagonized SAC silencing by knocking down the MAD2-binding protein p31comet, to delay mitotic slippage, and tracked cancer cells treated with the antimitotic drug paclitaxel, over 3 days live-cell time-lapse analysis. We found that in the absence of p31comet, the duration of mitotic block was increased in cells challenged with nanomolar concentrations of paclitaxel, leading to an additive effects in terms of cell death which was predominantly anticipated during the first mitosis. As accumulation of an apoptotic signal was suggested to prevent mitotic slippage, when we challenged p31comet-depleted mitotic-arrested cells with the apoptosis potentiator Navitoclax (previously called ABT-263), cell fate was shifted to accelerated post-mitotic death. We conclude that inhibition of SAC silencing is critical for enhancing the lethality of antimitotic drugs as well as that of therapeutic apoptosis-inducing small molecules, with distinct mechanisms. The study highlights the potential of p31comet as a target for antimitotic therapies.

The paradoxical pharmacological mechanisms of lenalidomide and bortezomib in the treatment of multiple myeloma.

The combination of bortezomib (Velcade, PS-341) and lenalidomide (Revlimid) for the treatment of multiple myeloma was proved by USA Food and Drug Administration in 2006. Lenalidomide prevents the proliferation of multiple myeloma cells through binding to cereblon and promoting the ubiquitinational degradation of IKZF1 (Ikaros)/IKZF3 (Aiolos). However, the proteasome inhibitor bortezomib would inhibit the ubiquitinational degradation of IKZF1/IKZF3. How bortezomib could not block the antiproliferative effect of lenalidomide on multiple myeloma cells, which is the paradoxical pharmacological mechanisms in multiple myeloma. In this review, we summarized recent advances in molecular mechanisms underlying the combination of bortezomib and lenalidomide for the treatment multiple myeloma, discussed the paradoxical pharmacological mechanisms of lenalidomide and bortezomib in the treatment of multiple myeloma.

First-in-Human, Single- and Multiple-Ascending-Dose Studies in Healthy Subjects to Assess Pharmacokinetics, Pharmacodynamics, and Safety/Tolerability of Iberdomide, a Novel Cereblon E3 Ligase Modulator.

Pharmacokinetics, pharmacodynamics, and safety/tolerability of iberdomide (CC-220), a highly potent oral cereblon E3 ligase modulator (CELMoD), were evaluated in escalating single-dose (0.03, 0.1, 0.3, 1, 2, 4, 6 mg) and multiple-dose (0.3 mg once daily for 14 days, 1 mg once daily for 28 days, 0.3 mg once daily for 28 days, or 1 mg once daily for 7 days with a 7-day washout, then once daily for 7 more days) studies in healthy subjects (n = 99). Iberdomide exposure increased in a dose-proportional manner. Terminal half-life was 9-13 hours after a single dose. Iberdomide decreased peripheral CD19+ B lymphocytes (Emax , 92.4%; EC50 , 0.718 ng/mL), with modest reductions in CD3+ T lymphocytes (Emax , 34.8%; EC50 , 0.932 ng/mL). Lipopolysaccharide-stimulated proinflammatory cytokines (IL-1α, IL-1ß) were reduced, but anti-CD3-stimulated IL-2 and interferon-γ were increased. Iberdomide 1 mg once daily partially decreased T-cell-independent antibody responses to PPV23 but did not change tetanus toxoid recall response. Pharmacodynamic data suggest dose-dependent, differential immunomodulatory effects on B and T lymphocytes. Iberdomide was tolerated up to 6 mg as a single dose and at 0.3 mg once daily for 4 weeks. Grade 3 asymptomatic neutropenia was observed following 1 mg once daily for 21 days; a 7-day drug holiday alleviated neutropenia. Further investigation of iberdomide in autoimmune and hematological diseases is warranted.

Long non-coding RNA H19 promotes the proliferation, migration and invasion while inhibits apoptosis of hypertrophic scarring fibroblasts by targeting miR-3187-3p/GAB1 axis.

BACKGROUND: It had been reported that long non-coding RNA (lncRNA) H19 was associated with the proliferation of fibroblasts. However, the regulatory mechanism of H19 remains unclear. Thus, the study was designed to explore the underlying mechanism of H19 in the process of Hypertrophic scarring (HS). METHODS: The expression levels of H19, miR-3187-3p, and growth factor receptor binding 2-associated binding protein 1 (GAB1) in HS tissues and HS fibroblasts were measured by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The biological behaviors of HS fibroblasts, such as cell proliferation, apoptosis, migration, and invasion were assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT), colony formation, flow cytometry, and transwell assays, respectively. The protein expression level was quantified by western blot assay. The interaction association between miR-3187-3p and H19 or GAB1 was predicted by Starbase database analysis and confirmed by dual-luciferase reporter assay, respectively. RESULTS: H19 was significantly increased in HS tissues and HS fibroblasts. Loss-of-functional experiments revealed that knockdown of H19 inhibited the development of HS. Moreover, silencing of H19 impeded the proliferation, migration, and invasion, while enhanced apoptosis of HS fibroblasts by increasing miR-3187-3p expression. In addition, overexpression of GAB1 could abolish miR-3187-3p overexpression-induced effects on cell proliferation, apoptosis, migration, and invasion of HS fibroblasts. Mechanistically, H19 could act as a sponge of miR-3187-3p to upregulate the expression of GAB1 in HS fibroblasts. CONCLUSION: Collectively, our results revealed that H19 promoted the proliferation, migration, and invasion, while impeded apoptosis of HS fibroblasts by targeting miR-3187-3p/GAB1 axis.

DOK3 is involved in microglial cell activation in neuropathic pain by interacting with GPR84.

Adaptor molecule downstream of kinase-3 (DOK3) is a vital regulator of innate immune responses in macrophages and B cells, and G-protein-coupled receptor 84 (GPR84) is significant in mediating the biosynthesis and maintenance of inflammatory mediators that are induced by neuropathic pain in microglia. In the present study, we determined the role of DOK3 in activating microglia-induced neuropathic pain and investigated the underlying mechanisms associated with GPR84. We found that knockdown of DOK3 in microglial cells dramatically reduced the levels of inflammatory factors, and we uncovered a physical association between DOK3 and GPR84 in the induction of inflammatory responses. We also observed that neuropathic pain and inflammatory responses induced by chronic constriction injury (CCI) of the sciatic nerve or intrathecal injection of a GPR84 agonist were compromised in DOK3-/- mice in vivo. Finally, enforced expression of DOK3 provoked inflammatory responses, and administration of pregabalin relieved neuropathic pain via inhibition of DOK3 expression. In conclusion, DOK3 induced neuropathic pain in mice by interacting with GPR84 in microglia. We hypothesize that targeting the adaptor protein DOK3 may open new avenues for pharmaceutical approaches to the alleviation of neuropathic pain in the spinal cord.

KLHL22 maintains PD-1 homeostasis and prevents excessive T cell suppression.

Aberrant programmed cell death protein 1 (PD-1) expression on the surface of T cells is known to inhibit T cell effector activity and to play a pivotal role in tumor immune escape; thus, maintaining an appropriate level of PD-1 expression is of great significance. We identified KLHL22, an adaptor of the Cul3-based E3 ligase, as a major PD-1-associated protein that mediates the degradation of PD-1 before its transport to the cell surface. KLHL22 deficiency leads to overaccumulation of PD-1, which represses the antitumor response of T cells and promotes tumor progression. Importantly, KLHL22 was markedly decreased in tumor-infiltrating T cells from colorectal cancer patients. Meanwhile, treatment with 5-fluorouracil (5-FU) could increase PD-1 expression by inhibiting the transcription of KLHL22. These findings reveal that KLHL22 plays a crucial role in preventing excessive T cell suppression by maintaining PD-1 expression homeostasis and suggest the therapeutic potential of 5-FU in combination with anti-PD-1 in colorectal cancer patients.

Mechanism of miRNA-based Aconitum leucostomum Worosch. Monomer inhibition of bone marrow-derived dendritic cell maturation.

Delvestidine (DLTD) is a monomeric compound isolated from Aconitum leucostomum Worosch, a widely used medicine for local treatment of rheumatoid arthritis (RA). Studies have shown that Aconitum leucostomum Worosch. can inhibit maturation of bone marrow-derived dendritic cells (BMDCs). Further, microRNAs (miRNAs) have regulatory effects on DC maturity and function. However, the mechanism underlying DLTD effects on DC maturity and RA remains to be elucidated. This study investigated whether DLTD-mediated inhibition of DC maturation is regulated by miRNAs. LPS-induced mature BMDCs were treated with DLTD for 48 h. CD80 and CD86 expression on BMDCs was detected by flow cytometry, and levels of inflammatory factors IL-6, IL-23, IL-1ß, and TNF-α were detected by ELISA and PCR. Further, gene expression and miRNA expression profiles were investigated by bioinformatics analysis and verified by PCR. DLTD was found to inhibit CD80 and CD86 expression on the surface of BMDCs and secretion of inflammatory factors IL-6, IL-23, IL-1ß, and TNF-α. In total, 54 differentially expressed miRNAs were detected, including 29 up-regulated and 25 down-regulated miRNAs after DLTD treatment. Analysis of biological information revealed that the differentially expressed target genes mainly regulated biological processes, including cell differentiation, cell cycle, and protein kinase complexes. Additionally, miR-511-3p downstream targets Calcr, Fzd10, and Eps8, were closely related to BMDCs maturation. DLTD may induce BMDCs maturity through regulation of miRNAs that affect Calcr, Fzd10, and Eps8 gene signals.

Interdiction of Protein Folding for Therapeutic Drug Development in SARS CoV-2.

In this article, we predict the folding initiation events of the ribose phosphatase domain of protein Nsp3 and the receptor binding domain of the spike protein from the severe acute respiratory syndrome (SARS) coronavirus-2. The calculations employ the sequential collapse model and the crystal structures to identify the segments involved in the initial contact formation events of both viral proteins. The initial contact locations may provide good targets for therapeutic drug development. The proposed strategy is based on a drug binding to the contact location, thereby aiming to prevent protein folding. Peptides are suggested as a natural choice for such protein folding interdiction drugs.

NADPH oxidase subunit NOXO1 is a target for emphysema treatment in COPD.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and death worldwide. Peroxynitrite, formed from nitric oxide, which is derived from inducible nitric oxide synthase, and superoxide, has been implicated in the development of emphysema, but the source of the superoxide was hitherto not characterized. Here, we identify the non-phagocytic NADPH oxidase organizer 1 (NOXO1) as the superoxide source and an essential driver of smoke-induced emphysema and pulmonary hypertension development in mice. NOXO1 is consistently upregulated in two models of lung emphysema, Cybb (also known as NADPH oxidase 2, Nox2)-knockout mice and wild-type mice with tobacco-smoke-induced emphysema, and in human COPD. Noxo1-knockout mice are protected against tobacco-smoke-induced pulmonary hypertension and emphysema. Quantification of superoxide, nitrotyrosine and multiple NOXO1-dependent signalling pathways confirm that peroxynitrite formation from nitric oxide and superoxide is a driver of lung emphysema. Our results suggest that NOXO1 may have potential as a therapeutic target in emphysema.

Down-Regulation of the Mammalian Target of Rapamycin (mTOR) Pathway Mediates the Effects of the Paeonol-Platinum(II) Complex in Human Thyroid Carcinoma Cells and Mouse SW1736 Tumor Xenografts.

BACKGROUND This study aimed to investigate the effects of the paeonol-platinum(II) (PL-Pt[II]) complex on SW1736 human anaplastic thyroid carcinoma cell line and the BHP7-13 human thyroid papillary carcinoma cell line in vitro and on mouse SW1736 tumor xenografts in vivo. MATERIAL AND METHODS The cytotoxic effects of the PL-Pt(II) complex on SW1736 cells and BHP7-13 cells was measured using the MTT assay. Western blot measured the expression levels of cyclins, cell apoptotic proteins, and signaling proteins. DNA content and apoptosis were detected by flow cytometry. SW1736 cell thyroid tumor xenografts were established in mice followed by treatment with the PL-Pt(II) complex. RESULTS Treatment of the SW1736 and BHP7-13 cells with the PL-Pt(II) complex reduced cell proliferation in a dose-dependent manner, with an IC50 of 1.25 µM and 1.0 µM, respectively, and increased the cell fraction in G0/G1phase, inhibited p53, cyclin D1, promoted p27 and p21 expression, and significantly increased the sub-G1 fraction. Treatment with the PL-Pt(II) complex increased caspase-3 degradation, reduced the expression of p-4EBP1, p-4E-BP1 and p-S6, and reduced the expression of p-ERK1/2 and p-AKT. Treatment with the PL-Pt(II) complex reduced the volume of the SW1736 mouse tumor xenografts on day 14 and day 21, and reduced AKT phosphorylation and S6 protein expression and increased degradation of caspase-3. CONCLUSIONS The cytotoxic effects of the PL-Pt(II) complex in human thyroid carcinoma cells, including activation of apoptosis and an increased sub-G1 cell fraction of the cell cycle, were mediated by down-regulation of the mTOR pathway.

Tubulin Resists Degradation by Cereblon-Recruiting PROTACs.

Dysregulation of microtubules and tubulin homeostasis has been linked to developmental disorders, neurodegenerative diseases, and cancer. In general, both microtubule-stabilizing and destabilizing agents have been powerful tools for studies of microtubule cytoskeleton and as clinical agents in oncology. However, many cancers develop resistance to these agents, limiting their utility. We sought to address this by developing a different kind of agent: tubulin-targeted small molecule degraders. Degraders (also known as proteolysis-targeting chimeras (PROTACs)) are compounds that recruit endogenous E3 ligases to a target of interest, resulting in the target's degradation. We developed and examined several series of α- and ß-tubulin degraders, based on microtubule-destabilizing agents. Our results indicate, that although previously reported covalent tubulin binders led to tubulin degradation, in our hands, cereblon-recruiting PROTACs were not efficient. In summary, while we consider tubulin degraders to be valuable tools for studying the biology of tubulin homeostasis, it remains to be seen whether the PROTAC strategy can be applied to this target of high clinical relevance.