CAMSAP3-mediated regulation of HMGB1 acetylation and subcellular localization in lung cancer cells: Implications for cell death modulation

BACKGROUND

Deregulation of cell death is a common characteristic of cancer, and resistance to this process often occurs in lung cancer. Understanding the molecular mechanisms underlying an aberrant cell death is important. Recent studies have emphasized the involvement of calmodulin-regulated spectrin-associated protein 3 (CAMSAP3) in lung cancer aggressiveness, its influence on cell death regulation remains largely unexplored.

METHODS

CAMSAP3 was knockout in lung cancer cells using CRISPR-Cas9 system. Cell death and autophagy were evaluated using MTT and autophagic detection assays. Protein interactions were performed by proteomic analysis and immunoprecipitation. Protein expressions and their cytoplasmic localization were analyzed through immunoblotting and immunofluorescence techniques.

RESULTS

This study reveals a significant correlation between low CAMSAP3 expression and poor overall survival rates in lung cancer patients. Proteomic analysis identified high mobility group box 1 (HMGB1) as a candidate interacting protein involved in the regulation of cell death. Treatment with trichostatin A (TSA), an inhibitor of histone deacetylases (HDACs) resulted in increased HMGB1 acetylation and its translocation to the cytoplasm and secretion, thereby inducing autophagic cell death. However, this process was diminished in CAMSAP3 knockout lung cancer cells. Mechanistically, immunoprecipitation indicated an interaction between CAMSAP3 and HMGB1, particularly with its acetylated form, in which this complex was elevated in the presence of TSA.

CONCLUSIONS

CAMSAP3 is prerequisite for TSA-mediated autophagic cell death by interacting with cytoplasmic acetylated HMGB1 and enhancing its release.

SIGNIFICANT

This finding provides molecular insights into the role of CAMSAP3 in regulating cell death, highlighting its potential as a therapeutic target for lung cancer treatment.

CAMSAP2 enhances lung cancer cell metastasis by mediating RASAL2 degradation

AIMS

Cancer metastasis significantly contributes to mortality in lung cancer patients. Calmodulin-regulated spectrin-associated protein family member 2 (CAMSAP2) plays a significant role in cancer cell migration; however, its role in lung cancer metastasis and the underlying mechanism remain largely unknown. The present study aimed to investigate the impact of CAMSAP2 on lung cancer.

MAIN METHODS

The clinical relevance of CAMSAP2 in lung cancer patients was assessed using public database. RNA interference experiments were conducted to investigate role of CAMSAP2 in cell migration through transwell and wound healing assays. Molecular mechanisms were explored by identifying the possible interacting partners and pathways using the BioGRID and KEGG pathway analyses. The impact of CAMSAP2 on Ras protein activator-like 2 (RASAL2)-mediated lung cancer metastasis was investigated through biochemical assays. Additionally, in vivo experimentation using a murine tail vein metastasis model was performed to comprehend CAMSAP2's influence on metastasis.

KEY FINDINGS

A high expression level of CAMSAP2 was associated with poor overall survival in lung cancer patients and it positively correlated with cell migration in non-small cell lung cancer (NSCLC) cell lines. Knockdown of CAMSAP2 inhibited lung cancer cell motility in vitro and metastasis in vivo. Proteomic and biochemical analyses revealed the interaction between CAMSAP2 and RASAL2, which facilitates the degradation of RASAL2 through the ubiquitin-proteasome system. These degradation processes resulted in the activation of the extracellular signal-regulated kinase (ERK) signaling pathway, thereby promoting lung cancer metastasis. Collectively, the results of this study suggest that CAMSAP2 is a crucial regulator of cancer cell migration and metastasis and a promising therapeutic target for lung cancer.

Targeting Alpha7 Nicotinic Acetylcholine Receptors in Lung Cancer: Insights, Challenges, and Therapeutic Strategies

Alpha7 nicotinic acetylcholine receptor (α7 nAChR) is an ion-gated calcium channel that plays a significant role in various aspects of cancer pathogenesis, particularly in lung cancer. Preclinical studies have elucidated the molecular mechanism underlying α7 nAChR-associated lung cancer proliferation, chemotherapy resistance, and metastasis. Understanding and targeting this mechanism are crucial for developing therapeutic interventions aimed at disrupting α7 nAChR-mediated cancer progression and improving treatment outcomes. Drug research and discovery have determined natural compounds and synthesized chemical antagonists that specifically target α7 nAChR. However, approved α7 nAChR antagonists for clinical use are lacking, primarily due to challenges related to achieving the desired selectivity, efficacy, and safety profiles required for effective therapeutic intervention. This comprehensive review provided insights into the molecular mechanisms associated with α7 nAChR and its role in cancer progression, particularly in lung cancer. Furthermore, it presents an update on recent evidence about α7 nAChR antagonists and addresses the challenges encountered in drug research and discovery in this field.

Piper retrofractum ameliorates imiquimod-induced skin inflammation via modulation of TLR4 axis and suppression of NF-κB activity

Chronic inflammation is a significant concern due to its association with various pathological conditions. As a result, extensive research has been conducted to identify new natural products that can effectively treat acute inflammation, which has the potential to inhibit the chronic inflammation. In our study, we aimed to identify Indonesian medicinal plants with the ability to inhibit proinflammatory agents, specifically targeting NF-κB, a crucial regulator of gene transcription involved in the production of proinflammatory proteins/cytokines. Through a series of identification processes, we found that Piper retrofractum (Javanese chili) extract demonstrated promising inhibitory effects on NF-κB and proinflammatory molecules. Further investigation was conducted using a variety of assays, including reporter assay, viability test, ELISA, and Western blotting. The results revealed that the extract significantly reduced LPS, NO, COX-2, IL-6, IL-1, and NF-κB through the TLR4 axis. Notably, Piper retrofractum extract was found to enhance the survival of human keratinocytes by protecting them from cell death induced by TRAIL, a member of the TNF superfamily. Moreover, immunohistochemistry analysis in an Imiquimod-induced skin inflammation mice model showed downregulation of COX-2 and IL-1β expression upon treatment with the extract. In conclusion, our findings suggest that Piper retrofractum extract possesses anti-inflammatory properties by reducing proinflammatory cytokine production through inhibition of NF-κB signaling pathway. These promising results highlight the potential of Piper retrofractum extract as a candidate for future drug development in the clinical treatment of inflammation-related conditions, offering hope for the advancement of therapeutic interventions.

Drug-induced altered self-presentation increases tumor immunogenicity

Anti-human immunodeficiency virus (HIV) drug abacavir (ABC) binds to the specific allele of human leukocyte antigen (HLA-B*57:01) and activates CD8+ T cells by presenting altered abnormal peptides. Here, we examined the effect of ABC-induced altered self-presentation by HLA-B*57:01 on immunogenicity of cancer cells and CD8+ T-cell-dependent anti-tumor immunity. We established human-mouse chimeric HLA-B*57:01-expressing tumor cell lines (B16F10 and 3LL) and tested the anti-tumor effect of ABC in vivo. ABC treatment inhibited the growth of HLA-B*57:01-expressing tumors by a CD8+ T-cell-dependent mechanism. ABC treatment induced CXCR3-dependent infiltration of CD8+ T cells into HLA-B*57:01-expressing tumors, and activated those tumor-infiltrating CD8+ T cells to proliferate and secrete IFN-γ. The activation of CD8+ T cells using drug-induced altered self-presentation may be a new strategy to increase tumor immunogenicity and improve the efficacy of immunotherapy.

Facilitated on-line supercritical fluid extraction - supercritical fluid chromatography for nonpolar and polar compounds from milk thistle seeds

Plant seeds, as those from milk thistle (Silybum marianum), are a valuable source of nonpolar and polar compounds with potentially interesting biological activity. The main nonpolar compounds are triglycerides, which are also the main components of all vegetable oils. In addition, specific polar compounds - flavonolignans, called silymarin, have been found in large amounts in milk thistle seeds extract. These flavonoids derivatives have different biological activity, for instance hepatoprotective effects. In order to extract and analyze both nonpolar (triglycerides) and polar compounds (flavonolignans) from milk thistle seeds through a sequential methodology, an on-line supercritical fluid extraction - supercritical fluid chromatography (SFE-SFC) method was developed. Different ways of transferring the extracts from SFE to SFC (i.e. direct on-column transfer and loop transfer) were compared, and particularly for their effect on chromatographic quality. In this respect, nonpolar and polar compounds caused different issues, especially as polar compounds required a significant portion of co-solvent in the extraction step, favoring early elution in the chromatographic column. First, on-line SFE-SFC was used for triglycerides analysis and allowed the comparison of transfer modes. Then, on-line kinetics were performed to measure defatting time before polar molecules extraction. Finally, the eventual benefit of loop transfer was also investigated for the analysis of flavonolignans, polar molecules whose analysis can be difficult by on-line SFE-SFC. The aim of this paper is to discuss the versatility of on-line SFE-SFC and how challenging the coupling can be, especially when both non-polar and polar molecules must be analyzed independently in a single sample.

Calorie Restriction Impairs Anti-Tumor Immune Responses in an Immunogenic Preclinical Cancer Model

(1) Background: Although the important role of dietary energy intake in regulating both cancer progression and host immunity has been widely recognized, it remains unclear whether dietary calorie restriction (CR) has any impact on anti-tumor immune responses. (2) Methods: Using an immunogenic B16 melanoma cell expressing ovalbumin (B16-OVA), we examined the effect of the CR diet on B16-OVA tumor growth and host immune responses. To further test whether the CR diet affects the efficacy of cancer immunotherapy, we examined the effect of CR against anti-PD-1 monoclonal antibody (anti-PD-1 Ab) treatment. (3) Results: The CR diet significantly slowed down the tumor growth of B16-OVA without affecting both CD4+ and CD8+ T cell infiltration into the tumor. Although in vivo depletion of CD8+ T cells facilitated B16-OVA tumor growth in the control diet group, there was no significant change in the tumor growth in the CR diet group with or without CD8+ T cell-depletion. Anti-PD-1 Ab treatment lost its efficacy to suppress tumor growth along with the activation and metabolic shift of CD8+ T cells under CR condition. (4) Conclusions: Our present results suggest that a physical condition restricted in energy intake in cancer patients may impair CD8+ T cell immune surveillance and the efficacy of immunotherapy.

Development of a Novel CD26-Targeted Chimeric Antigen Receptor T-Cell Therapy for CD26-Expressing T-Cell Malignancies

Chimeric-antigen-receptor (CAR) T-cell therapy for CD19-expressing B-cell malignancies is already widely adopted in clinical practice. On the other hand, the development of CAR-T-cell therapy for T-cell malignancies is in its nascent stage. One of the potential targets is CD26, to which we have developed and evaluated the efficacy and safety of the humanized monoclonal antibody YS110. We generated second (CD28) and third (CD28/4-1BB) generation CD26-targeted CAR-T-cells (CD26-2G/3G) using YS110 as the single-chain variable fragment. When co-cultured with CD26-overexpressing target cells, CD26-2G/3G strongly expressed the activation marker CD69 and secreted IFNgamma. In vitro studies targeting the T-cell leukemia cell line HSB2 showed that CD26-2G/3G exhibited significant anti-leukemia effects with the secretion of granzymeB, TNFα, and IL-8, with 3G being superior to 2G. CD26-2G/3G was also highly effective against T-cell lymphoma cells derived from patients. In an in vivo mouse model in which a T-cell lymphoma cell line, KARPAS299, was transplanted subcutaneously, CD26-3G inhibited tumor growth, whereas 2G had no effect. Furthermore, in a systemic dissemination model in which HSB2 was administered intravenously, CD26-3G inhibited tumor growth more potently than 2G, resulting in greater survival benefit. The third-generation CD26-targeted CAR-T-cell therapy may be a promising treatment modality for T-cell malignancies.

High throughput LC/ESI-MS/MS method for simultaneous analysis of 20 oral molecular-targeted anticancer drugs and the active metabolite of sunitinib in human plasma

Many types of oral molecular-targeted anticancer drugs are clinically used in cancer genomic medicine. Combinations of multiple molecular-targeted anticancer drugs are also being investigated, expecting to prolong the survival of patients with cancer. Therapeutic drug monitoring of oral molecular-targeted drugs is important to ensure efficacy and safety. A liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) has been used for simultaneous determination of these drugs in human plasma. However, the sensitivity of mass spectrometers and differences in the therapeutic range of drugs have rendered the development of simultaneous LC/ESI-MS/MS methods difficult. In this study, a simultaneous quantitative method for 20 oral molecular-targeted anticancer drugs and the active metabolite of sunitinib was developed based on the results of linear range shifts of the calibration curves using four ion abundance adjustment techniques (collision energy defects, in-source collision-induced dissociation, secondary product ion selected reaction monitoring, and isotopologue selected reaction monitoring). The saturation of the detector for the seven analytes was resolved by incorporating optimal ion abundance adjustment techniques. Furthermore, the reproducibility of this method was confirmed in validation tests, and plasma from patients was measured by this method to demonstrate its usefulness in actual clinical practice. This analytical method is expected to make a substantial contribution to the promotion of personalized medicine in the future.

DPP8 Selective Inhibitor Tominostat as a Novel and Broad-Spectrum Anticancer Agent against Hematological Malignancies

DPP8/9 inhibition induces either pyroptotic or apoptotic cell death in hematological malignancies. We previously reported that treatment with the DPP8/9 inhibitor 1G244 resulted in apoptotic cell death in myeloma, and our current study further evaluates the mechanism of action of 1G244 in different blood cancer cell lines. Specifically, 1G244 inhibited DPP9 to induce GSDMD-mediated-pyroptosis at low concentrations and inhibited DPP8 to cause caspase-3-mediated-apoptosis at high concentrations. HCK expression is necessary to induce susceptibility to pyroptosis but does not participate in the induction of apoptosis. To further characterize this DPP8-dependent broad-spectrum apoptosis induction effect, we evaluated the potential antineoplastic role for an analog of 1G244 with higher DPP8 selectivity, tominostat (also known as 12 m). In vitro studies demonstrated that the cytotoxic effect of 1G244 at high concentrations was enhanced in tominostat. Meanwhile, in vivo work showed tominostat exhibited antitumor activity that was more effective on a cell line sensitive to 1G244, and at higher doses, it was also effective on a cell line resistant to 1G244. Importantly, the weight loss morbidity associated with increasing doses of 1G244 was not observed with tominostat. These results suggest the possible development of novel drugs with antineoplastic activity against selected hematological malignancies by refining and increasing the DPP8 selectivity of tominostat.

Simultaneous and sialic acid linkage-specific N- and O-linked glycan analysis by ester-to-amide derivatization

Characterization of O-glycans linked to serine or threonine residues in glycoproteins has mostly been achieved using chemical reaction approaches because there are no known O-glycan-specific endoglycosidases. Most O-glycans are modified with sialic acid residues at the non-reducing termini through various linkages. In this study, we developed a novel approach for sialic acid linkage-specific O-linked glycan analysis through lactone-driven ester-to-amide derivatization combined with non-reductive β-elimination in the presence of hydroxylamine. O-glycans released by non-reductive β-elimination were efficiently purified using glycoblotting via chemoselective ligation between carbohydrates and a hydrazide-functionalized polymer, followed by modification of methyl or ethyl ester groups of sialic acid residues on solid-phase. In-solution lactone-driven ester-to-amide derivatization of ethyl-esterified O-glycans was performed, and the resulting sialylated glycan isomers were discriminated by mass spectrometry. In combination with PNGase F digestion, we carried out simultaneous, quantitative, and sialic acid linkage-specific N- and O-linked glycan analyses of a model glycoprotein and human cartilage tissue. This novel glycomic approach will facilitate detailed characterization of biologically relevant sialylated N- and O-glycans on glycoproteins.

CAMSAP3 negatively regulates lung cancer cell invasion and angiogenesis through nucleolin/HIF-1α mRNA complex stabilization

AIMS

Cancer metastasis is a major cause of lung cancer-related mortality, so identification of related molecular mechanisms is of interest. Calmodulin-regulated spectrin-associated protein 3 (CAMSAP3) has been implicated in lung cancer malignancies; however, its role in metastatic processes, including invasion and angiogenesis, is largely unknown.

MAIN METHOD

The clinical relevance of CAMSAP3 expression in lung cancer was evaluated. The relevance of CAMSAP3 expression to in vitro cell invasion and angiogenesis was assessed in human lung cancer cells and endothelial cells, respectively. The molecular mechanism was identified by qRT-PCR, immunoprecipitation, mass spectrometry, and RNA immunoprecipitation. The in vivo metastatic and angiogenic activities of lung cancer cells were assessed.

KEY FINDINGS

Low CAMSAP3 expression was found in malignant lung tissues and strongly correlated with a poor prognosis in lung adenocarcinoma (LUAD). CAMSAP3-knockout NSCLC exhibited high invasive ability, and CAMSAP3 knockout induced HUVEC proliferation and tube formation; these effects were significantly attenuated by reintroduction of exogenous wild-type CAMSAP3. Mechanistically, in the absence of CAMSAP3, the expression of hypoxia-inducible factor-1α (HIF-1α) was upregulated, which increased the levels of downstream HIF-1α targets such as vascular endothelial growth factor A (VEGFA) and matrix metalloproteinases (MMPs) 2 and 9. Proteomic analysis revealed that nucleolin (NCL) bound to CAMSAP3 to regulate HIF-1α mRNA stabilization. In addition, CAMSAP3-knockout lung cancer cells displayed highly aggressive behavior in metastasis and angiogenesis in vivo.

SIGNIFICANCE

This study reveals that CAMSAP3 plays a negative regulatory role in lung cancer cell metastatic behavior both in vitro and in vivo through NCL/HIF-1α mRNA complex stabilization.

Two cyanobacterial response regulators with diguanylate cyclase activity, Rre2 and Rre8, participate in biofilm formation

Phototrophic bacteria face diurnal variations of environmental conditions such as light and osmolarity, that affect their carbon metabolism and ability to generate organic compounds. The model cyanobacterium, Synechocystis sp. PCC 6803 forms a biofilm when it encounters extreme conditions like high salt stress, but the molecular mechanisms involved in perception of environmental changes that lead to biofilm formation are unknown. Here, we studied two two-component regulatory systems (TCSs) that contain diguanylate cyclases (DGCs), which produce the second messenger c-di-GMP, as potential components of the biofilm-inducing signaling pathway in Synechocystis. Analysis of single mutants provided evidence for involvement of Rre2 and Rre8 in biofilm formation. A bacterial two-hybrid assay showed that the response regulators, Rre2 and Rre8 each formed a TCS with a specific histidine kinase, Hik12 and Hik14, respectively. The in vitro assay showed that Rre2 had DGC activity regardless of its de/phosphorylation status, whereas Rre8 required phosphorylation for DGC activity. Hik14-Rre8 likely functioned as an inducible sensing system in response to environmental change. Biofilm assays with Synechocystis mutants suggested that pairs of hik12-rre2 and hik14-rre8 responded to high salinity-induced biofilm formation. Inactivation of hik12-rre2 and hik14-rre8 did not affect the performance of the light reactions of photosynthesis. These data suggest that Hik12-Rre2 and Hik14-Rre8 participate in biofilm formation in Synechocystis by regulating c-di-GMP production via the DGC activity of Rre2 and Rre8.

Understanding the mechanism of CO2-Assisted electrospray ionization for parameter optimization in supercritical fluid chromatography mass spectrometry

Supercritical fluid chromatography (SFC) is often coupled with electrospray ionization mass spectrometry (ESI-MS) for analyte detection because of its detection capability to a wide range of chemical properties. However, MS sensitivity is highly dependent on the chromatographic conditions, so that it is important to understand the ionization mechanism to determine the optimal chromatographic conditions. The ionization mechanism in SFC/ESI-MS is different to that of liquid chromatography because of the use of CO₂ as a mobile phase. Some studies have suggested that alkoxycarbonic acids are formed in the mixture of CO₂ and the alcohol modifier, and these species contribute to ionization in CO₂-assisted SFC/ESI-MS. Therefore, in this study, we investigated CO₂-assisted ESI to test this hypothesis, and we confirmed that methoxylcarbonic acid is generated in CO₂/methanol mixtures and contributed to ion generation and detection because it acts as a proton donor in positive-ion mode. However, methoxylcarbonic acid interfered with ionization in negative-ion mode. Addition of ammonium acetate, which is often added to the modifier for negative ion detection in SFC/MS analysis, did not contribute to the recovery of MS sensitivity, although it tended to suppress the formation of metoxylcarbonic acid. This is likely due to ion suppression and neutralization of the negative sites of the analytes by anions or cations derived from ammonium acetate in the negative ion mode. Thus, additive-free methanol/CO₂ was the most suitable mobile phase for obtaining high sensitivity in SFC/MS. To demonstrate the practicality of these findings, we tested our optimal mobile phase selection for pesticide analysis. In addition, we tested the addition of 0, 1, and 5 mM ammonium formate to the modifier and make-up solvent, and found that the addition of 1 mM ammonium formate gave the best results in pesticides analysis. In SFC/MS, salt is often added to improve separation or prevent desorption, but our findings suggest that the concentration of salt must be kept as low as possible to achieve highly sensitive MS detection. The results of this study reveal the best selection of the optimal conditions for the modifier and make-up solvent for CO₂-assisted SFC/MS analysis and will be useful for the method development in SFC/MS.

Enhancement of thermoelectric power factor via electron energy filtering in Cu doped MoS2 on carbon fabric for wearable thermoelectric generator applications

The design and construction of state-of-the-art wearable thermoelectric materials are important for the development of self-powered wearable thermoelectric generators (WTEGs). Molybdenum disulfide (MoS₂) has been reported as a noteworthy thermoelectric (TE) material because of its large intrinsic bandgap and high carrier mobility. In this work, Cu-doped two-dimensional layered MoS₂ nanosheets were grown on carbon fabric (CF) via a hydrothermal method. The electrical conductivity, Seebeck coefficient, and power factor for the Cu-doped MoS₂ were found to increase with increasing temperature. The maximum Seebeck coefficient was obtained for a MoS₂ sample doped with 4 at% of Cu (CM4) was ∼10 μV/K at 303 K and ∼13 μV/K at 373 K. The enhancement in the Seebeck coefficient was attributed to an energy-filtering effect caused by the interfacial barrier between MoS₂ and Cu. In addition, a thermoelectric device was designed with four pairs of TE materials, where CM4 (4 at%) was used as a p-type material and Cu wire was used as an n-type material. These p- and n-type materials were connected electrically in series and thermally in parallel to generate a voltage of 190.7 μV at a temperature gradient of 8 K.

Combining Molecular Dynamics and Machine Learning to Analyze Shear Thinning for Alkane and Globular Lubricants in the Low Shear Regime

Lubricants with desirable frictional properties are important in achieving an energy-saving society. Lubricants at the interfaces of mechanical components are confined under high shear rates and pressures and behave quite differently from the bulk material. Computational approaches such as nonequilibrium molecular dynamics (NEMD) simulations have been performed to probe the molecular behavior of lubricants. However, the low-shear-velocity regions of the materials have rarely been simulated owing to the expensive calculations necessary to do so, and the molecular dynamics under shear velocities comparable with that in the experiments are not clearly understood. In this study, we performed NEMD simulations of extremely confined lubricants, i.e., two molecular layers for four types of lubricants confined in mica walls, under shear velocities from 0.001 to 1 m/s. While we confirmed shear thinning, the velocity profiles could not show the flow behavior when the shear velocity was much slower than thermal fluctuations. Therefore, we used an unsupervised machine learning approach to detect molecular movements that contribute to shear thinning. First, we extracted the simple features of molecular movements from large amounts of MD data, which were found to correlate with the effective viscosity. Subsequently, the extracted features were interpreted by examining the trajectories contributing to these features. The magnitude of diffusion corresponded to the viscosity, and the location of slips that varied depending on the spherical and chain lubricants was irrelevant. Finally, we attempted to apply a modified Stokes-Einstein relation at equilibrium to the nonequilibrium and confined systems. While systems with low shear rates obeyed the relation sufficiently, large deviations were observed under large shear rates.

Online SFE-SFC-MS/MS colony screening: A high-throughput approach for optimizing (-)-limonene production

Conventional analysis of microbial bioproducers requires the extraction of metabolites from liquid cultures, where the culturing steps are time consuming and greatly limit throughput. To break through this barrier, the current study aims to directly evaluate microbial bioproduction colonies by way of supercritical fluid extraction-supercritical fluid chromatography-triple quadrupole mass spectrometry (SFE-SFC-MS/MS). The online SFE-SFC-MS/MS system offers great potential for high-throughput analysis due to automated metabolite extraction without any need for pretreatment. This is the first report of SFE-SFC-MS/MS as a method for direct colony screening, as demonstrated in the high-throughput screening of (-)-limonene bioproducers. Compared with conventional analysis, the SFE-SFC-MS/MS system enables faster and more convenient screening of highly productive strains.

GSTA4 Governs Melanoma Immune Resistance and Metastasis

IMPLICATIONS

Considering the importance of GSTA4 in controlling IFNγ responsiveness and the metastatic potential of other melanoma cells, our results highlight a novel mechanism whereby cancer cells escape from host immunity and gain metastatic ability by acquiring resistance to oxidative stress responses through the upregulation of GSTA4.

Russelioside A, a Pregnane Glycoside from Caralluma tuberculate, Inhibits Cell-Intrinsic NF-κB Activity and Metastatic Ability of Breast Cancer Cells

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a potential target for inflammatory-breast cancer treatment as it participates in its pathogenesis, such as tumor initiation, progression, survival, metastasis, and recurrence. In this study, we aimed to discover a novel anti-cancer treatment from natural products by targeting NF-κB activity. Using the 4T1-NFκB-luciferase reporter cell line, we tested three pregnane glycosides extracted from the herb Caralluma tuberculata and discovered that Russelioside A markedly suppressed NF-κB activity in breast cancer. Russelioside A inhibited NF-κB (p65) transcriptional activity and its phosphorylation. Following NF-κB inhibition, Russelioside A exerted anti-proliferative and anti-metastatic effects in breast cancer cells in vitro. Moreover, it inhibited the NF-κB constitutive expression of downstream pathways, such as VEGF-b, MMP-9, and IL-6 in 4T1 cells. In addition, it reduced the metastatic capacity in a 4T1 breast cancer model in vivo. Collectively, our conclusions reveal that Russelioside A is an attractive natural compound for treating triple-negative breast cancer growth and metastasis through regulating NF-κB activation.

Flavanols and Flavanes from Crinum asiaticum and Their Effects on LPS Signaling Pathway Through the Inhibition of NF-κB Activation

Three new flavanols, (2R,3S)-7-methoxy-flavan-3-ol (1: ), (2R,3S)-7-hydroxy-flavan-3-ol (2: ), and (2R,3S)-2'-hydroxy-7-methoxy-flavan-3-ol (3: ), together with two known flavans (4: and 5: ), were isolated from the chloroform extract of Crinum asiaticum. Their structures were elucidated by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS, and CD data. The isolated compounds 1: and 3: -5: showed inhibitory activity toward LPS-induced nitric oxide (NO) production. Further investigation of the NF-κB pathway mechanisms indicated that 1: and 3: -5: inhibited the LPS-induced IL-6 production and p65 subunit phosphorylation of NF-κB in RAW264.7 cells, with an effective dose of 10 µM.

Interval- and cycle-dependent combined effect of STING agonist loaded lipid nanoparticles and a PD-1 antibody

Programmed cell death 1 (PD-1) blockade combination to other drugs have attracted the interest of scientists for treating tumors resistant to PD-1 blockade. In this study, the impact of the interval, order of administration, and number of cycles of immunotherapeutic combination of stimulator of interferon genes (STING) pathway agonist loaded lipid nanoparticle (STING-LNP) and PD-1 antibody for inducing the optimal combined antitumor activity against a melanoma lung metastasis is reported. One cycle had no effect, but two and three cycles resulted in a combinedantitumor effect. The interval between the administration was found to influence the induction of the combined effect. The second and third doses increased the gene expression of the NK cell activation marker, interferon γ (IFN-γ), PD-1 and a ligand of PD-1 (PD-L1), whereas the first dose failed. NK cells in the lung showed an increase in the expression of the activation markers and PD-1 after the second dose. The combined antitumor effect of this combination therapy against melanoma lung metastasis model could be dependent on the interval as well as the number of doses of STING-LNP.These findings suggest the importance of the protocol setting when combining a nano system loaded with an immune adjuvant and PD-1 antibody.

Evaluation of chimeric antigen receptor of humanized rabbit-derived T cell receptor-like antibody

T-cell receptor (TCR)-like antibodies that specifically recognize antigenic peptides presented on major histocompatibility complex (MHC) molecules have been developed for next-generation cancer immunotherapy. Recently, we reported a rapid and efficient method to generate TCR-like antibodies using a rabbit system. We humanized previously generated rabbit-derived TCR-like antibodies reacting Epstein-Barr virus peptide (BRLF1p, TYPVLEEMF) in the context of HLA-A24 molecules, produced CAR-T cells, and evaluated their anti-tumor effects using in vitro and in vivo tumor models. Humanization of the rabbit-derived TCR-like antibodies using the complementarity-determining region grafting technology maintained their specificity and affinity. We prepared a second-generation chimeric antigen receptor (CAR) using scFv of the humanized TCR-like antibodies and then transduced them into human T-cells. The CAR-T cells specifically recognized BRLF1p/MHC molecules and lysed the target cells in an antigen-specific manner in vitro. They also demonstrated anti-tumor activity in a mouse xenograft model. We report the generation of CAR-T cells using humanized rabbit-derived TCR-like antibodies. Together with our established and efficient generation procedure for TCR-like antibodies using rabbits, our platform for the clinical application of humanized rabbit-derived TCR-like antibodies to CAR-T cells will help improve next-generation cancer immunotherapy.

Acridone Derivatives from Atalantia monophyla Inhibited Cancer Cell Proliferation through ERK Pathway

The present study aimed to investigate the effect of acridone alkaloids on cancer cell lines and elucidate the underlying molecular mechanisms. The ten acridone alkaloids from Atalantia monophyla were screened for cytotoxicity against LNCaP cell lines by a WST-8 assay. Then, the most potential acridone, buxifoliadine E, was evaluated on four types of cancer cells, namely prostate cancer (LNCaP), neuroblastoma (SH SY5Y), hepatoblastoma (HepG2), and colorectal cancer (HT29). The results showed that buxifoliadine E was able to significantly inhibit the proliferation of all four types of cancer cells, having the most potent cytotoxicity against the HepG2 cell line. Western blotting analysis was performed to assess the expression of signaling proteins in the cancer cells. In HepG2 cells, buxifoliadine E induced changes in the levels of Bid as well as cleaved caspase-3 and Bax through MAPKs, including Erk and p38. Moreover, the binding interaction between buxifoliadine E and Erk was investigated by using the Autodock 4.2.6 and Discovery Studio programs. The result showed that buxifoliadine E bound at the ATP-binding site, located at the interface between the N- and C-terminal lobes of Erk2. The results of this study indicate that buxifoliadine E suppressed cancer cell proliferation by inhibiting the Erk pathway.

Marginols A‒H, unprecedented pimarane diterpenoids from Kaempferia marginata and their NO inhibitory activities

Kaempferia marginata rhizomes are used as an herb in food and as traditional medicine for the treatment of inflammatory-related diseases in Asian countries. In contrast to the previously reported phytochemical investigation of Thai and Chinese K. marginata rhizomes, which demonstrated the presence of sandaracopimaradiene and ent-sandaracopimaradiene, our first investigation of Vietnamese K. marginata rhizomes led to the isolation of eight undescribed pimarane diterpenoids, marginols A‒H, along with 18 known pimarane diterpenoids. The structures of these compounds were elucidated by spectroscopic techniques, including 1D and 2D NMR, HRESIMS, and CD spectroscopy and/or by comparisons of their NMR data with previously reported data. Furthermore, evaluations of the NO production inhibitory activity against LPS-stimulated RAW264.7 cells revealed that the undescribed compounds, marginols B and D‒G, and the known compounds, sandaracopimaradien-6β,9α-diol-1-one and 6-acetoxysandaracopimardien-9-ol-1-one, showed potent activities. These results provide insights into the chemodiversity of Vietnamese K. marginata rhizomes as well as their traditional usage from the viewpoint of their chemical constituents.

Ethyl P-Methoxycinnamate: An Active Anti-Metastasis Agent and Chemosensitizer Targeting NFκB from Kaempferia galanga for Melanoma Cells

The most common type of skin cancer is melanoma. While significant advances in chemotherapy have occurred in a few instances, only marginal progress has been made in treating metastatic melanoma. Natural medicine has traditionally been used to treat various illnesses, including cancer. The purpose of this study was to identify the active compound in Kaempferia galanga, which could be used to treat melanoma as an anti-metastasis and chemosensitizer agent. The active compound in K. galanga was isolated and identified using chromatography and spectroscopy techniques, and given six compounds. Inhibitory activity on NFκB activation and cell viability was determined using reporter assay methods. Among the isolated compounds, ethyl p-methoxycinnamate (EPMC) demonstrated potent NFκB inhibitory activity against melanoma cell B16F10- NFκB Luc2 with an IC50 of 88.7 μM. Further investigation was conducted by evaluating the anti-metastasis effect of EPMC in vitro by using wound-healing assays, invasion tests, and molecular mechanism assays using Western blotting. NFκB has been implicated in tumorigenesis through the PI3K/Akt/NFκB pathway. The results of this study indicated that EPMCs act as inhibitors of p38 and thereby Akt phosphorylation inhibitors at serine 473, inhibiting NFκB-dependent transcription. Further analysis with paclitaxel demonstrated that the combinations could sensitize to apoptosis in response to well-known chemotherapy agents. Additional studies were conducted using the human melanoma cancer cell line SK-Mel 28. Along with the induction of apoptosis, we observed an increase in p-γH2AX expression (a molecular marker for double strand breaks in DNA damage) in response to treatment with paclitaxel and EPMC. The result showed EPMC to be a potential, viable adjuvant for improving the clinical efficacy of anti-metastatic and cancer chemotherapy.

Hierarchically ordered macroporous TiO2 architecture via self-assembled strategy for environmental remediation

Hierarchical orderd macroporous TiO₂ architecture (HOMTA) was prepared with aid of ethylenediamine (EDA) and investigated the impact of amine molecules on the properties of TiO₂ architecture. The different variation of amine molecules (EDA) leads to tunning the morphology under hydrothermal approach which is confirmed by FESEM and TEM analysis. The XRD and Raman studies confirms the crystal structure of anatase and brookite phase of TiO₂. The surface of the architecture strongly depended on the concentration of EDA which plays a vital role in surface area which is revealed by Brunauer Emmett-Teller (BET) analysis. The obtained HOMTA was employed as photocatalyst and active photoanode in the dye sensitized solar cells (DSSC). The DSSC device exhibits excellent efficiency (η) of 5.27% for the EDA capped TiO₂ (S5) which had high surface area (167.11 m²/g) for better dye loading, whereas the lower concentration of EDA capped TiO₂ (S1, S2, S3 and S4) resulted the efficiency of 2.14, 3.90, 3.25 and 4.37%, respectively. The efficiency of photocatlysis degradation of the prepared samples (S1, S2, S3, S4 and S5) was 94.8, 90.47, 91.41, 91.32 and 93.75% under light source. The excellent photocatalysis property was achieved by S5 within 6 min due to high surface area which inducing more active site.

Novel super-neutralizing antibody UT28K is capable of protecting against infection from a wide variety of SARS-CoV-2 variants

Many potent neutralizing SARS-CoV-2 antibodies have been developed and used for therapies. However, the effectiveness of many antibodies has been reduced against recently emerging SARS-CoV-2 variants, especially the Omicron variant. We identified a highly potent SARS-CoV-2 neutralizing antibody, UT28K, in COVID-19 convalescent individuals who recovered from a severe condition. UT28K showed efficacy in neutralizing SARS-CoV-2 in an in vitro assay and in vivo prophylactic treatment, and the reactivity to the Omicron strain was reduced. The structural analyses revealed that antibody UT28K Fab and SARS-CoV-2 RBD protein interactions were mainly chain-dominated antigen-antibody interactions. In addition, a mutation analysis suggested that the emergence of a UT28K neutralization-resistant SARS-CoV-2 variant was unlikely, as this variant would likely lose its competitive advantage over circulating SARS-CoV-2. Our data suggest that UT28K offers potent protection against SARS-CoV-2, including newly emerging variants.

Crucial contribution of GPR56/ADGRG1, expressed by breast cancer cells, to bone metastasis formation

From a mouse triple-negative breast cancer cell line, 4T1, we previously established 4T1.3 clone with a high capacity to metastasize to bone after its orthotopic injection into mammary fat pad of immunocompetent mice. Subsequent analysis demonstrated that the interaction between cancer cells and fibroblasts in a bone cavity was crucial for bone metastasis focus formation arising from orthotopic injection of 4T1.3 cells. Here, we demonstrated that a member of the adhesion G-protein-coupled receptor (ADGR) family, G-protein-coupled receptor 56 (GPR56)/adhesion G-protein-coupled receptor G1 (ADGRG1), was expressed selectively in 4T1.3 grown in a bone cavity but not under in vitro conditions. Moreover, fibroblasts present in bone metastasis sites expressed type III collagen, a ligand for GPR56/ADGRG1. Consistently, GPR56/ADGRG1 proteins were detected in tumor cells in bone metastasis foci of human breast cancer patients. Deletion of GPR56/ADGRG1 from 4T1.3 cells reduced markedly intraosseous tumor formation upon their intraosseous injection. Conversely, intraosseous injection of GPR56/ADGRG1-transduced 4T1, TS/A (mouse breast cancer cell line), or MDA-MB-231 (human breast cancer cell line) exhibited enhanced intraosseous tumor formation. Furthermore, we proved that the cleavage at the extracellular region was indispensable for GPR56/ADGRG1-induced increase in breast cancer cell growth upon its intraosseous injection. Finally, inducible suppression of Gpr56/Adgrg1 gene expression in 4T1.3 cells attenuated bone metastasis formation with few effects on primary tumor formation in the spontaneous breast cancer bone metastasis model. Altogether, GPR56/ADGRG1 can be a novel target molecule to develop a strategy to prevent and/or treat breast cancer metastasis to bone.

SOX10 regulates melanoma immunogenicity through an IRF4-IRF1 axis

Loss-of-function mutations of JAK1/2 impair cancer cell responsiveness to IFN-γ and immunogenicity. Therefore, an understanding of compensatory pathways to activate IFN-γ signaling in cancer cells is clinically important for the success of immunotherapy. Here we demonstrate that the transcription factor SOX10 hinders immunogenicity of melanoma cells through the IRF4-IRF1 axis. Genetic and pharmacological approaches revealed that SOX10 repressed IRF1 transcription via direct induction of a negative regulator, IRF4. The SOX10-IRF4-IRF1 axis regulated PD-L1 expression independently of JAK-STAT pathway activity, and suppression of SOX10 increased the efficacy of combination therapy with an anti-PD-1 antibody and HDAC inhibitor against a clinically relevant melanoma model. Thus, the SOX10-IRF4-IRF1 axis serves as a potential target that can bypass JAK-STAT signaling to immunologically warm up melanoma with a "cold" tumor immune microenvironment.

Anti-metastatic Effects of Baicalein by Targeting STAT3 Activity in Breast Cancer Cells

Signal transducer and activator of transcription 3 (STAT3) is considered a potential target for cancer treatment because of its relationship with cellular transformation and tumor initiation and progression. In this study, we aimed to identify a new anti-cancer drug candidate from natural products by targeting STAT3 activity. Using STAT3-luciferase reporter cell line, we screened the chemical library of natural products and found that baicalein, a flavone isolated from the roots of Scutelleria baicalensis, strongly suppressed STAT3 activity in breast cancer cells. Baicalein inhibited STAT3 transcriptional activity and its phosphorylation, and further exhibited anti-proliferative effects in breast cancer cells. Moreover, baicalein suppressed the production of interleukin (IL)-6 and the metastatic potential of breast cancer cells both in vitro and in vivo. Collectively, our study suggests baicalein as an attractive phytochemical compound for reducing metastatic potential of breast cancer cells by regulating STAT3 activity.

NKG2D defines tumor-reacting effector CD8+ T cells within tumor microenvironment

For successful immunotherapy for cancer, it is important to understand the immunological status of tumor antigen-specific CD8⁺ T cells in the tumor microenvironment during tumor progression. In this study, we monitored the behavior of B16OVA-Luc cells in mice immunized with a model tumor antigen ovalbumin (OVA). Using bioluminescence imaging, we identified the time series of OVA-specific CD8⁺ T-cell responses during tumor progression: initial progression, immune control, and the escape phase. As a result of analyzing the status of tumor antigen-specific CD8⁺ cells in those 3 different phases, we found that the expression of NKG2D defines tumor-reacting effector CD8⁺ T cells. NKG2D may control the fate and TOX expression of tumor-reacting CD8⁺ T cells, considering that NKG2D blockade in OVA-vaccinated mice delayed the growth of the B16OVA-Luc2 tumor and increased the presence of tumor-infiltrating OVA-specific CD8⁺ T cells.

STING agonist loaded lipid nanoparticles overcome anti-PD-1 resistance in melanoma lung metastasis via NK cell activation

Background

Resistance to an immune checkpoint inhibitor (ICI) is a major obstacle in cancer immunotherapy. The causes of ICI resistance include major histocompatibility complex (MHC)/histocompatibility locus antigen (HLA) class I loss, neoantigen loss, and incomplete antigen presentation. Elimination by natural killer (NK) cells would be expected to be an effective strategy for the treatment of these ICI-resistant tumors. We previously demonstrated that a lipid nanoparticle containing a stimulator of an interferon gene (STING) agonist (STING-LNP) efficiently induced antitumor activity via the activation of NK cells. Thus, we evaluated the potential of reducing ICI resistance by STING-LNPs.

Methods

Lung metastasis of a B16-F10 mouse melanoma was used as an anti-programmed cell death 1 (anti-PD-1)-resistant mouse model. The mice were intravenously injected with the STING-LNP and the mechanism responsible for the improvement of anti-PD-1 resistance by the STING-LNPs was analyzed by RT-qPCR and flow cytometry. The dynamics of STING-LNP were also investigated.

Results

Although anti-PD-1 monotherapy failed to induce an antitumor effect, the combination of the STING-LNP and anti-PD-1 exerted a synergistic antitumor effect. Our results indicate that the STING-LNP treatment significantly increased the expression of CD3, CD4, NK1.1, PD-1 and interferon (IFN)-γ in lung metastases. This change appears to be initiated by the type I IFN produced by liver macrophages that contain the internalized STING-LNPs, leading to the systemic activation of NK cells that express PD-1. The activated NK cells appeared to produce IFN-γ, resulting in an increase in the expression of the PD ligand 1 (PD-L1) in cancer cells, thus leading to a synergistic antitumor effect when anti-PD-1 is administered.

Conclusions

We provide a demonstration to show that a STING-LNP treatment can overcome PD-1 resistance in a B16-F10 lung metastasis model. The mechanism responsible for this indicates that NK cells are activated by stimulating the STING pathway which, in turn, induced the expression of PD-L1 on cancer cells. Based on the findings reported herein, the STING-LNP represents a promising candidate for use in combination therapy with anti-PD-1-resistant tumors.

Functional characterization of multiple PAS domain-containing diguanylate cyclases in Synechocystis sp. PCC 6803

Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a second messenger known to control a variety of bacterial processes. The model cyanobacterium, Synechocystis sp. PCC 6803, has a score of genes encoding putative enzymes for c-di-GMP synthesis and degradation. However, most of them have not been functionally characterized. Here, we chose four genes in Synechocystis (dgcA-dgcD), which encode proteins with a GGDEF, diguanylate cyclase (DGC) catalytic domain and multiple Per-ARNT-Sim (PAS) conserved regulatory motifs, for detailed analysis. Purified DgcA, DgcB and DgcC were able to catalyze synthesis of c-di-GMP from two GTPs in vitro. DgcA had the highest activity, compared with DgcB and DgcC. DgcD did not show detectable activity. DgcA activity was specific for GTP and stimulated by the divalent cations, magnesium or manganese. Full activity of DgcA required the presence of the multiple PAS domains, probably because of their role in protein dimerization or stability. Synechocystis mutants carrying single deletions of dgcA-dgcD were not affected in their growth rate or biofilm production during salt stress, suggesting that there was functional redundancy in vivo. In contrast, overexpression of dgcA resulted in increased biofilm formation in the absence of salt stress. In this study, we characterize the enzymatic and physiological function of DgcA-DgcD, and propose that the PAS domains in DgcA function in maintaining the enzyme in its active form.

Design and synthesis of 2-Substituted-4-benzyl-5-methylimidazoles as new potential Anti-breast cancer agents to inhibit oncogenic STAT3 functions

STAT3 signaling is known to be associated with tumorigenesis and further cancer cell-intrinsic activation of STAT3 leads to altered regulation of several oncogenic processes. Given the importance of STAT3 in cancer development and progression particularly breast cancer, it is crucial to discover new chemical entities of STAT3 inhibitor to develop anti-breast cancer drug candidates. Herein, 4-benzyl-2-benzylthio-5-methyl-1H-imidazole (2a) and 4-benzyl-5-methyl-2-[(2,6-difluorobenzyl)thio]-1H-imidazole (2d) from a group of thirty imidazole-bearing compounds showed greater STAT3 inhibition than their lead compounds VS1 and the oxadiazole derivative MD77. Within all tested compounds, ten derivatives effectively inhibited the growth of the two tested breast cancer cells with IC₅₀ values ranging from 6.66 to 26.02 µM. In addition, the most potent derivatives 2a and 2d inhibited the oncogenic function of STAT3 as seen in the inhibition of colony formation and IL-6 production of breast cancer cell lines. Modeling studies provided evidence for the possible interactions of the synthesized compounds with the key residues of the STAT3-SH2 domain. Collectively, our present study suggests 2-substituted-4-benzyl-5-methylimidazoles are a new class of anti-cancer drug candidates to inhibit oncogenic STAT3 function.

Synthetic E-guggulsterone derivative GSD-1 inhibits NF-κB signaling and suppresses the metastatic potential of breast cancer cells

Guggulsterone (GS) [4,17(20)-pregnadiene-3,16-dione], is the main active phytosterol constituent in guggul, the gum resin of Commiphora wightii (Arnott.) Bhand./Commiphora mukul Engl. tree, and is known for its medicinal effects. In this study, we report that GSD-1, a structurally-related synthetic GS derivative, strongly inhibits NF-κB activation induced by TNF-α. GSD-1 prevented the nuclear translocation of p65 through the blockade of IκBα degradation and p65 phosphorylation, and further inhibited the activation of upstream kinases, including transforming growth factor-β activated kinase 1 (TAK1), IκB kinase (IKK) α, and IKKβ. Furthermore, GSD-1 inhibited the cell-intrinsic activation of NF-κB, and exerted its direct anti-cancer and anti-metastatic effects in both murine and human breast cancer cell lines. This study demonstrated GSD-1 to be an attractive compound to target NF-κB activation that has potential for treating breast cancer growth and metastasis.

Identification of Ophiocordyceps gracilioides by Its Anti-tumor Effects through Targeting the NFκB-STAT3-IL-6 Inflammatory Pathway

Although more than 400 species of Cordyceps s.l. have been identified, most have not been well explored regarding their potential for medicinal use. In this study, the profiles of constituents of ten different species of Ophiocordyceps, which is an unexplored species of Cordyceps, were analyzed and their anti-tumor effects were further examined. Although all Ophiocordyceps samples exhibited similar peak patterns, Ophiocordyceps gracilioides (O. grac) had a distinct constituent profile from the other samples. Furthermore, O. grac was the most active in suppressing the transcriptional activities of both nuclear factor-kappa B (NF-κB) and signal transducer and activator of transcription (STAT)3, and the production of interleukin (IL)-6 from breast cancer cells. This study demonstrated that O. grac is a relatively unexplored Cordyceps s.l. that may have medicinal potential to inhibit the NFκB-STAT3-IL-6 inflammatory pathway in cancer.

Anti-metastatic effects of ergosterol peroxide from the entomopathogenic fungus Ophiocordyceps gracilioides on 4T1 breast cancer cells

Ophiocordyceps gracilioides is an entomoparasitic ascomycetes whose bioactivity has not been examined in detail. In this study, we identified the bioactive compounds ergosterol peroxide (EPO) and ergosterol (ERG) from the MeOH extract of O. gracilioides mycelia related to its anti-cancer effects by targeting the Nuclear Factor kappa B (NF-ĸB)/Signal Transducer and Activator of Transcription 3 (STAT3) inflammatory pathways. Using gene-reporter assays, we demonstrated that EPO markedly inhibits both NF-ĸB and STAT3 activity in 4T1 cells, whereas ERG had limited effect. Consistent with their effects on NF-ĸB and STAT3 activity, EPO, but not ERG, exerted anti-proliferative effects on 4T1 cells. Furthermore, EPO significant inhibited both the migration and invasion of 4T1 cells in vitro, and pre-treatment of 4T1 cells with EPO significantly inhibited the formation of experimental lung metastases in vivo. Collectively, we demonstrated that ERG and EPO can be isolated from O. gracilioides mycelia, and further identified EPO as an active constituent of its anti-metastatic effects through the inhibition of NF-ĸB and STAT3 inflammatory pathways in 4T1 breast cancer cells.

Anti-inflammatory effects of Morus alba Linne bark on the activation of toll-like receptors and imiquimod-induced ear edema in mice

Background

Morus alba L. bark has been widely used in traditional medicine for treating several inflammatory diseases, such as hypertension, diabetes mellitus and coughing; however, the molecular mechanisms underlying its anti-inflammatory effects are not well understood.

Methods

We examined the effects of an extract of Morus alba L. bark (MabE) on Toll-like receptor (TLR) ligand-induced activation of RAW264.7 macrophages using a luciferase reporter assay and immunoassays. For the in vivo experiment, we used an imiquimod-induced ear edema model to examine the anti-inflammatory effects of MabE.

Results

MabE inhibited the TLR ligand-induced activation of NF-κB in RAW264.7 cells without affecting their viability. Consistent with the inhibition of NF-κB activation, MabE also inhibited the production of IL-6 and IL-1β from TLR ligand-treated RAW264.7 cells. In vivo MabE treatment inhibited the ear swelling of IMQ-treated mice, in addition to the mRNA expression of IL-17A, IL-1β and COX-2. The increases in splenic γδT cells in IMQ-treated mice and the production of IL-17A from splenocytes were significantly inhibited by MabE treatment.

Conclusion

Our study suggests that the anti-inflammatory effects of MabE on the activation of the macrophage cell line RAW246.7 by TLRs and IMQ-induced ear edema are through the inhibition of NF-κB activation and IL-17A-producing γδT cells, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03291-5.

ASK1 suppresses NK cell-mediated intravascular tumor cell clearance in lung metastasis

Tumor metastasis is the leading cause of death worldwide and involves an extremely complex process composed of multiple steps. Our previous study demonstrated that apoptosis signal‐regulating kinase 1 (ASK1) deficiency in mice attenuates tumor metastasis in an experimental lung metastasis model. However, the steps of tumor metastasis regulated by ASK1 remain unclear. Here, we showed that ASK1 deficiency in mice promotes natural killer (NK) cell‐mediated intravascular tumor cell clearance in the initial hours of metastasis. In response to tumor inoculation, ASK1 deficiency upregulated immune response‐related genes, including interferon‐gamma (IFNγ). We also revealed that NK cells are required for these anti‐metastatic phenotypes. ASK1 deficiency augmented cytokine production chemoattractive to NK cells possibly through induction of the ligand for NKG2D, a key activating receptor of NK cells, leading to further recruitment of NK cells into the lung. These results indicate that ASK1 negatively regulates NK cell‐dependent anti‐tumor immunity and that ASK1‐targeted therapy can provide a new tool for cancer immunotherapy to overcome tumor metastasis.

Development of a simultaneous analytical method for clozapine and its metabolites in human plasma using liquid chromatography/electrospray ionization tandem mass spectrometry with linear range adjusted by in-source collision-induced dissociation

Clozapine (CLZ) is a key drug in treatment-resistant schizophrenia. Therapeutic drug monitoring (TDM) of CLZ and its metabolites, N-desmethylclozapine and clozapine N-oxide, is required to monitor and manage the risks of side effects. Although quantification methods for TDM have been developed for CLZ and its metabolites, they were not sufficiently accurate for the quantification of CLZ owing to the upper limits of the calibration curves. An analytical method using high-performance liquid chromatography/electrospray ionization tandem mass spectrometry was developed and validated for the simultaneous measurement of CLZ and its metabolites in human plasma. To expand the concentration range of the calibration curves, we used a linear range shift technique using in-source collision-induced dissociation (CID). Using our approach, the linearity and quantitative range were improved compared to those reported by previous studies, and were sufficient for TDM in clinical practice. The intra- and inter-assay accuracy was 84.6%-114.8%, and the intra- and inter-assay precisions were ≤9.1% and ≤9.9%, respectively. Moreover, all samples from patients with treatment-resistant schizophrenia were successfully quantified. Therefore, our novel analytical method using in-source CID had the appropriate performance to measure the plasma concentrations of CLZ and its metabolites for TDM in clinical practice.

Simultaneous analysis of drugs administered to lung-transplanted patients using liquid chromatography-tandem mass spectrometry for therapeutic drug monitoring

Several drugs are administered to lung-transplanted patients, which are monitored using therapeutic drug monitoring (TDM). Therefore, we developed and validated a liquid chromatography-tandem mass spectrometry method to simultaneously analyze immunosuppressive drugs such as mycophenolic acid, antifungal drugs such as voriconazole and itraconazole, and its metabolite hydroxyitraconazole. Chromatographic separation was achieved using a C18 column and gradient flow of mobile phase comprising 20 mM aqueous ammonium formate and 20 mM ammonium formate-methanol solution. A simple protein precipitation treatment was performed using acetonitrile/methanol and mycophenolic acid-² H₃ , voriconazole-² H₃ , itraconazole-² H₄ , and hydroxyitraconazole-² H₄ as internal standards. The linearity ranges of mycophenolic acid, voriconazole, itraconazole, and hydroxyitraconazole were 100-20,000, 50-10,000, 5-1000, and 5-1000 ng/mL, respectively. The retention time of each target was less than 2 min. The relative errors in intra- and inter-day were within ±7.6%, the coefficient of variation was 8.9% or less for quality control low, medium, and high, and it was 15.8% or less for lower limit of quantitation. Moreover, the patient samples were successfully quantified, and they were within the linear range of measurements. Therefore, our new method may be useful for TDM in lung-transplanted patients.

Targeting PSMD14 inhibits melanoma growth through SMAD3 stabilization

Although melanoma therapy is improved by novel molecular targeted reagents, including vemurafenib, aberrant proliferation and early metastasis remain obstacles for melanoma; therefore, novel target molecules for melanoma need to be identified. In this study, we focused on deubiquitinating enzymes, which regulate protein stability through ubiquitin–proteasome systems, and identified 26S proteasome non-ATPase regulatory subunit 14 (PSMD14) as a molecule related to melanoma growth using siRNA library screening. Similar to a previous report, PSMD14 knockdown strongly induced p21 expression and inhibited RB phosphorylation in melanoma. After in silico analysis, TGF-β signaling was identified as a negatively correlated gene set with PSMD14 expression. Although TGF-β signaling is also related to the invasive phenotype of melanoma, PSMD14 knockdown suppressed melanoma migration and reduced SLUG expression, suggesting that targeting PSMD14 suppresses both growth and migration. Furthermore, SMAD3 expression increased in nucleus and SMAD3 degradation was delayed after PSMD14 knockdown. Thus, our present study suggests that targeting PSMD14 can inhibit melanoma growth and migration through either SMAD3 accumulation or SLUG reduction, respectively.

Anti‑inflammatory compounds moracin O and P from Morus alba Linn. (Sohakuhi) target the NF‑κB pathway

Accumulating evidence suggests that inflammation is linked to multiple pathological processes and induces cellular and molecular damage through the activation of inflammatory signaling pathways, including the NF-κB pathway. The aim of the present study was to identify natural anti-inflammatory products that can target NF-κB activity, in order to establish a novel therapeutic approach for inflammatory diseases. Using a 4T1 breast cancer cell line that expresses the firefly luciferase gene under the control of an NF-κB response element, 112 natural products were tested for their anti-inflammatory properties. Sohakuhi (Morus alba Linn. bark) extract was observed to strongly suppress NF-κB activity without affecting cell viability. To further examine the anti-inflammatory effect of Sohakuhi, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cellular damage of human HaCaT keratinocytes was evaluated. While TRAIL triggered the phosphorylation of the p65 subunit of NF-κB, leading to cellular damage in HaCaT cells, treatment with Sohakuhi extract protected HaCaT cells against TRAIL-induced cellular damage. Moreover, Sohakuhi treatment also upregulated the anti-apoptotic proteins Bcl-xL and Bcl-2. Importantly, through chemical fractionation of Sohakuhi extract, moracin O and P were confirmed to mediate its anti-inflammatory effects. Collectively, the present results indicated that Sohakuhi and moracin may represent potential candidates for the development of novel anti-inflammatory drugs.

Antimetastatic effects of thalidomide by inducing the functional maturation of peripheral natural killer cells

Thalidomide and its analogues are known as immunomodulatory drugs (IMiDs) that possess direct antimyeloma effects, in addition to other secondary effects, including antiangiogenic, antiinflammatory, and immunomodulatory effects. Although the involvement of natural killer (NK) cells in the antitumor effects of IMiDs has been reported, it is unclear whether IMiDs inhibit cancer cell metastasis by regulating the antitumor function of NK cells. In this study, we examined the protective effects of thalidomide against cancer metastasis by focusing on its immunomodulatory effects through NK cells. Using experimental lung metastasis models, we found that pharmacological effects of thalidomide on host cells, but not its direct anticancer tumor effects, are responsible for the inhibition of lung metastases. To exert the antimetastatic effects of thalidomide, both γ‐interferon (IFN‐γ) production and direct cytotoxicity of NK cells were essential, without notable contribution from T cells. In thalidomide‐treated mice, there was a significant increase in the terminally differentiated mature CD27^lo NK cells in the peripheral tissues and NK cells in thalidomide‐treated mice showed significantly higher cytotoxicity and IFN‐γ production. The NK cell expression of T‐bet was upregulated by thalidomide treatment and the downregulation of glycogen synthase kinase‐3β expression was observed in thalidomide‐treated NK cells. Collectively, our study suggests that thalidomide induces the functional maturation of peripheral NK cells through alteration of T‐bet expression to inhibit lung metastasis of cancer cells.

Pharmacological targeting of natural killer cells for cancer immunotherapy

Natural killer (NK) cells are innate lymphocytes that rapidly respond to cancer cells without prior sensitization or restriction to the cognate antigen in comparison with tumor antigen-specific T cells. Recent advances in understanding NK-cell biology have elucidated the molecular mechanisms underlying the differentiation and maturation of NK cells, in addition to the control of their effector functions by investigating the receptors and ligands involved in the recognition of cancer cells by NK cells. Such clarification of NK-cell recognition of cancer cells also revealed the mechanism by which cancer cells potentially evade NK-cell-dependent immune surveillance. Furthermore, the recent clinical results of T-cell-targeted cancer immunotherapy have increased the expectations for new immunotherapies by targeting NK cells. However, the potential use of NK cells in cancer immunotherapy is not fully understood. In this review, we discuss the current evidence and future potential of pharmacological targeting of NK cells in cancer immunotherapy.