BET inhibition induces synthetic lethality in PTEN deficient colorectal cancers via dual action on p21CIP1/WAF1.

Loss of PTEN tumor suppressor is an important event during colorectal cancer (CRC) development and is a target for therapeutic exploitation. This study reports that bromodomain and extra-terminal motif (BET) is a synthetic lethal partner of PTEN in CRC. BET inhibition (BETi) selectively induced G1 cell cycle arrest and apoptosis in PTEN-/- CRC. Further, BETi selectively and dose-dependently suppressed the growth of PTEN-/- CRC tumor xenografts in mice and patient-derived organoids. Mechanistically, PTEN-deficient CRC cells elevated the level of cytoplasmic p21CIP1/WAF1 that is hyper-phosphorylated at Thr145 by AKT. BETi suppressed AKT activation in PTEN-deficient CRC cells, followed by the reduction in p21 phosphorylation at Thr145, thereby promoting its nuclear translocation. In addition, BETi suppressed MYC level and this in turn increased the total p21 level in the nuclei. Over-expression of a phospho-mimetic p21 mutant (T145D) significantly rescued the BETi effect on PTEN-deficient CRC. These results suggest that BETi has a dual action on p21: elevating the level of p21 by inhibiting MYC and converting the oncogenic (cytoplasmic) p21 into the tumor-suppressive (nuclear) p21 by inhibiting AKT. Taken together, this study identified the synthetic lethal interaction between PTEN and BET, and provides a potential actionable target for CRC with PTEN loss.

Anti-inflammatory effects of neuregulin-1 in HaCaT keratinocytes and atopic dermatitis-like mice stimulated with Der p 38.

Neuregulin (NRG)-1 plays fundamental roles in several organ systems after binding to its receptors, ErbB2 and ErbB4. This study examines the role of NRG-1 in atopic dermatitis (AD), a chronic skin disease that causes dryness, pruritus, and inflammation. In mice administered Der p 38, the skin presents AD-like symptoms including filaggrin downregulation and infiltration of neutrophils and eosinophils. Noticeably, there is an increased expression of NRG-1, ErbB2, and ErbB4 in the skin. Upregulation of these proteins is significantly correlated to the clinical skin severity score. In human keratinocyte HaCaT cells, exposure to Der p 38 decreased filaggrin expression, and NRG-1 alone had no effect on the expression. However, co-treatment of Der p 38 with NRG-1 enhanced the filaggrin expression decreased by Der p 38. Pre-treatment with AG879 (an ErbB2 inhibitor) or ErbB4 siRNA blocked the recovery of filaggrin expression in the cells after co-treatment with Der p 38 and NRG-1. Der p 38 treatment enhanced the secretion of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein-1 (MCP-1). Co-treatment of Der p 38 with NRG-1 lowered the cytokine secretion increased by Der p 38, although NRG-1 alone was not effective on cytokine alteration. Neutrophil apoptosis was not altered by NRG-1 or supernatants of cells treated with NRG-1, but the cell supernatants co-treated with Der p 38 and NRG-1 blocked the anti-apoptotic effects of Der p 38-treated supernatants on neutrophils, which was involved in the activation of caspase 9 and caspase 3. Taken together, we determined that NRG-1 has anti-inflammatory effects in AD triggered by Der p 38. These results will pave the way to understanding the functions of NRG-1 and in the future development of AD treatment.

ER translocon inhibitor ipomoeassin F inhibits triple-negative breast cancer growth via blocking ER molecular chaperones.

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer where no effective therapy has been developed. Here, we report that the natural product ER translocon inhibitor ipomoeassin F is a selective inhibitor of TNBC cell growth. A proteomic analysis of TNBC cells revealed that ipomoeassin F significantly reduced the levels of ER molecular chaperones, including PDIA6 and PDIA4, and induced ER stress, unfolded protein response (UPR) and autophagy in TNBC cells. Mechanistically, ipomoeassin F, as an inhibitor of Sec61α-containing ER translocon, blocks ER translocation of PDIA6, inducing its proteasomal degradation. Silencing of PDIA6 or PDIA4 by RNA interferences or treatment with a small molecule inhibitor of the protein disulfide isomerases in TNBC cells successfully recapitulated the ipomoeassin F phenotypes, including the induction of ER stress, UPR and autophagy, suggesting that the reduction of PDIAs is the key mediator of the pharmacological effects of ipomoeassin F. Moreover, ipomoeassin F significantly suppressed TNBC growth in a mouse tumor xenograft model, with a marked reduction in PDIA6 and PDIA4 levels in the tumor samples. Our study demonstrates that Sec61α-containing ER translocon and PDIAs are potential drug targets for TNBC and suggests that ipomoeassin F could serve as a lead for developing ER translocon-targeted therapy for TNBC.

MDM2 inhibition is synthetic lethal with PTEN loss in colorectal cancer cells via the p53-dependent mechanism.

Colorectal cancer (CRC) driven by PTEN deficiency exhibits high risk of metastasis, advancement of tumor stages and chemotherapy resistance, where no effective therapy has been developed. In this study, we performed a synthetic lethal drug screening in CRC and found that PTEN-deficient CRC cells are highly vulnerable to MDM2 inhibition. MDM2 inhibitor treatment or its silencing selectively inhibited the growth of PTEN-deficient CRC in vitro and in mice models. Mechanistically, PTEN loss increased the level of active AKT and subsequently increased MDM2 phosphorylation, thereby limiting the p53 functions in PTEN-/- CRC cells. MDM2 inhibition in turn activated p53 in CRC, particularly in PTEN-/- CRC cells. The synthetic lethal effect of MDM2 inhibitor was largely dependent on p53, because p53 silenced cells or cells lacking p53 failed to exhibit synthetic lethality in PTEN-deficient cells. We further showed that MDM2 inhibition led to the p53-dependent reversal of Bcl2-Bax ratio, which contributed to mitochondria-mediated apoptotic cell death in PTEN-deficient CRC. This study suggests that pharmacological targeting of MDM2 could be a potential therapeutic strategy for PTEN-deficient CRC.

Diterpene and biflavone derivatives from Thuja koraiensis and their cytotoxicities against A549 cells.

During the screening of the cytotoxicity of rare Korean endemic plants, the extract of Thuja koraiensis Nakai displayed potent cytotoxicity against the adenocarcinomic human alveolar basal epithelial A549 cell line. Through a series of separations via column chromatography, three undescribed abietanes, an undescribed labdane along with a labdane, and a biflavonoid were purified from methylene chloride (CH2Cl2) fraction possessing a potent cytotoxic effect. Extensive 1D and 2D NMR spectroscopic data analyses, in combination with quantum chemical calculations were conducted to establish the planar and absolute configurations of thujakoraienes A-C. The chemical structure of thujakoraiene D was elucidated by spectroscopic data analysis and competing enantioselective acylation. Thujakoraienes A and C along with 7,7″-di-O-methylamentoflavone, showed cytotoxic effects on A549 cells, with IC50 values of 64.86, 47.97, and 16.14 µM, respectively. Finally, thujakoraiene C and 7,7″-di-O-methylamentoflavone were identified as potent cytotoxic compounds in A549 cells, followed by an additional cytotoxicity test in the normal human lung fibroblast MRC-5 cell line. This is the first study on the non-volatile chemicals in the extract of T. koraiensis and comparison of chemical profiles of T. orientalis and T. koraiensis.

Inhibitory Effect of Biotransformed-Fucoidan on the Differentiation of Osteoclasts Induced by Receptor for Activation of Nuclear Factor-κB Ligand.

Bone homeostasis is regulated by constant remodeling through osteogenesis by osteoblasts and osteolysis by osteoclasts and osteoporosis can be provoked when this balance is broken. Present pharmaceutical treatments for osteoporosis have harmful side effects and thus, our goal was to develop therapeutics from intrisincally safe natural products. Fucoidan is a polysaccharide extracted from many species of brown seaweed, with valuable pharmaceutical activities. To intensify the effect of fucoidan on bone homeostasis, we hydrolyzed fucoidan using AMG, Pectinex and Viscozyme. Of these, fucoidan biotransformed by Pectinex (Fu/Pec) powerfully inhibited the induction of tartrate-resistant acid phosphatase (TRAP) activity in osteoclasts differentiated from bone marrow macrophages (BMMs) by the receptor for activation of nuclear factor-κB ligand (RANKL). To investigate potential of lower molecular weight fucoidan it was separated into >300 kDa, 50-300 kDa, and <50 kDa Fu/Pec fractions by ultrafiltration system. The effects of these fractions on TRAP and alkaline phosphatase (ALP) activities were then examined in differentiated osteoclasts and MC3T3-E1 osteoblasts, respectively. Interestingly, 50-300 kDa Fu/Pec suppressed RANKL-induced osteoclasts differentiation from BMMs but did not synergistically enhance osteoblasts differentiation induced by osteogenic agents. In addition, this fraction inhibited the expressions of NFATc1, TRAP, OSCAR, and RANK, which are all key transcriptional factors involved in osteoclast differentiation, and those of Src, c-Fos and Mitf, as determined by RT-PCR. In conclusion, enzymatically low-molecularized 50-300 kDa Fu/Pec suppressed TRAP by downregulating RANKL-related signaling, contributing to the inhibition of osteoclasts differentiation, and represented a potential means of inducing bone remodeling in the background of osteoporosis.

Aurora kinase A inhibition induces synthetic lethality in SMAD4-deficient colorectal cancer cells via spindle assembly checkpoint activation.

SMAD4 loss-of-function mutations have been frequently observed in colorectal cancer (CRC) and are recognized as a drug target for therapeutic exploitation. In this study, we performed a synthetic lethal drug screening with SMAD4-isogenic CRC cells and found that aurora kinase A (AURKA) inhibition is synthetic lethal with SMAD4 loss. Inhibition of AURKA selectively inhibited the growth of SMAD4-/- CRC in vitro and in vivo. Mechanistically, SMAD4 negatively regulated AURKA level, resulting in the significant elevation of AURKA in SMAD4-/- CRC cells. Inhibition of AURKA induced G2/M cell cycle delay in SMAD4+/+ CRC cells, but induced apoptosis in SMAD4-/- CRC cells. We further observed that a high level of AURKA in SMAD4-/- CRC cells led to abnormal mitotic spindles, leading to cellular aneuploidy. Moreover, SMAD4-/- CRC cells expressed high levels of spindle assembly checkpoint (SAC) proteins, suggesting the hyperactivation of SAC. The silencing of key SAC proteins significantly rescued the AURKA inhibition-induced cell death in SMAD4-/- cells, suggesting that SMAD4-/- CRC cells are hyper-dependent on AURKA activity for mitotic exit and survival during SAC hyperactivation. This study presents a unique synthetic lethal interaction between SMAD4 and AURKA and suggests that AURKA could be a potential drug target in SMAD4-deficient CRC.

Oat Extract Avenanthramide-C Reverses Hippocampal Long-Term Potentiation Decline in Tg2576 Mice.

Memory deterioration in Alzheimer's disease (AD) is thought to be underpinned by aberrant amyloid ß (Aß) accumulation, which contributes to synaptic plasticity impairment. Avenanthramide-C (Avn-C), a polyphenol compound found predominantly in oats, has a range of biological properties. Herein, we performed methanolic extraction of the Avns-rich fraction (Fr. 2) from germinated oats using column chromatography, and examined the effects of Avn-C on synaptic correlates of memory in a mouse model of AD. Avn-C was identified in Fr. 2 based on 1H-NMR analysis. Electrophysiological recordings were performed to examine the effects of Avn-C on the hippocampal long-term potentiation (LTP) in a Tg2576 mouse model of AD. Avn-C from germinated oats restored impaired LTP in Tg2576 mouse hippocampal slices. Furthermore, Avn-C-facilitated LTP was associated with changes in the protein levels of phospho-glycogen synthase kinase-3ß (p-GSK3ß-S9) and cleaved caspase 3, which are involved in Aß-induced synaptic impairment. Our findings suggest that the Avn-C extract from germinated oats may be beneficial for AD-related synaptic plasticity impairment and memory decline.

Pathogenic Mechanism of Der p 38 as a Novel Allergen Homologous to RipA and RipB Proteins in Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic relapsing pruritic disease encompassing skin inflammation and barrier dysfunction. House dust mites are key allergens that augment the development of atopic dermatitis. We aimed to investigate the pathogenic mechanism of AD due to Der p 38, recently identified by us. The frequency of IgE reactivity to Der p 38 in AD subjects was 52.6% (10/19) in the skin prick test and 57.9% (11/19) in the dot blot assay. In human keratinocyte HaCaT cells, Der p 38 triggered the impairment of filaggrin expression and induced pro-inflammatory cytokines such as IL-6, IL-8 and MCP-1 through TLR4, PI3K, AKT, c-Jun N-terminal kinase (JNK) and NF-κB pathway. Supernatants from Der p 38-treated cells blocked filaggrin expression and neutrophil apoptosis. The anti-apoptotic effect of the Der p 38-released molecules on neutrophils was accomplished by inhibition of the caspase 9/3 pathway, and by increased MCL-1 expression and BCL-2/BAX expression ratio. In C57BL/6 wild type (WT) mice, Der p 38 induced a dose-dependent increase of AD-like skin lesions, with enhanced expressions of total and Der p 38-specific IgE. Der p 38 also diminished the expressions of skin barrier proteins and induced JNK activation. However, the AD-like features following cutaneous Der p 38 exposure were observed to be reduced in the TLR4 knockout (KO) group, as compared to the WT group. Skin infiltration of neutrophils, eosinophils and mast cells was increased in the WT mice, but was not portrayed in the TLR4 KO mice. These findings indicate that Der p 38 is a novel mite allergen that triggers AD by lowering skin barrier proteins and increasing inflammatory cells. Results of this study have thereby paved the way to unveil the pathogenic mechanisms of AD.

Der p 38 Is a Bidirectional Regulator of Eosinophils and Neutrophils in Allergy.

The house dust mite is the most common cause of allergic diseases, and TLR4 acts as an overarching receptor for allergic responses. This study aimed to identify novel allergen binding to TLR4 in house dust mites and unveil its unique role in allergic responses. Der p 38 was purified and characterized by liquid chromatography tandem mass spectrometry-based peptide mapping. Biolayer interferometry and structure modeling unveiled TLR4-binding activity and the structure of recombinant Der p 38. The allergenicity of Der p 38 was confirmed by a skin prick test, and basophil activation and dot blot assays. The skin prick test identified 24 out of 45 allergic subjects (53.3%) as Der p 38+ subjects. Der p 38-augmented CD203c expression was noted in the basophils of Der p 38+ allergic subjects. In animal experiments with wild-type and TLR4 knockout BALB/c mice, Der p 38 administration induced the infiltration of neutrophils as well as eosinophils and exhibited clinical features similar to asthma via TLR4 activation. Persistent Der p 38 administration induced severe neutrophil inflammation. Der p 38 directly suppressed the apoptosis of allergic neutrophils and eosinophils, and enhanced cytokine production in human bronchial epithelial cells, inhibiting neutrophil apoptosis. The mechanisms involved TLR4, LYN, PI3K, AKT, ERK, and NF-κB. These findings may contribute to a deep understanding of Der p 38 as a bridge allergen between eosinophilic and neutrophilic inflammation in the pathogenic mechanisms of allergy.

Der f 38 Is a Novel TLR4-Binding Allergen Related to Allergy Pathogenesis from Dermatophagoides farinae.

It is difficult to treat allergic diseases including asthma completely because its pathogenesis remains unclear. House dust mite (HDM) is a critical allergen and Toll-like receptor (TLR) 4 is a member of the toll-like receptor family, which plays an important role in allergic diseases. The purpose of this study was to characterize a novel allergen, Der f 38 binding to TLR4, and unveil its role as an inducer of allergy. Der f 38 expression was detected in the body and feces of Dermatophagoides farinae (DF). Electron microscopy revealed that it was located in the granule layer, the epithelium layer, and microvilli of the posterior midgut. The skin prick test showed that 60% of allergic subjects were Der f 38-positive. Der f 38 enhanced surface 203c expression in basophils of Der f 38-positive allergic subjects. By analysis of the model structure of Der p 38, the expected epitope sites are exposed on the exterior side. In animal experiments, Der f 38 triggered an infiltration of inflammatory cells. Intranasal (IN) administration of Der f 38 increased neutrophils in the lung. Intraperitoneal (IP) and IN injections of Der f 38 induced both eosinophils and neutrophils. Increased total IgE level and histopathological features were found in BALB/c mice treated with Der f 38 by IP and IN injections. TLR4 knockout (KO) BALB/c mice exhibited less inflammation and IgE level in the sera compared to wild type (WT) mice. Der f 38 directly binds to TLR4 using biolayer interferometry. Der f 38 suppressed the apoptosis of neutrophils and eosinophils by downregulating proteins in the proapoptotic pathway including caspase 9, caspase 3, and BAX and upregulating proteins in the anti-apoptotic pathway including BCL-2 and MCL-1. These findings might shed light on the pathogenic mechanisms of allergy to HDM.

Natural products targeting cancer cell dependency.

Precision cancer medicine is a tailored treatment approach for individual cancer patients with different genomic characteristics. Mutated or hyperactive oncogenes have served as main drug targets in current precision cancer medicine, while defective or inactivated tumor suppressors in general have not been considered as druggable targets. Synthetic lethality is one of very few approaches that enable to target defective tumor suppressors with pharmacological agents. Synthetic lethality exploits cancer cell dependency on a protein or pathway, which arises when the function of a tumor suppressor is defective. This approach has been proven to be effective in clinical settings since the successful clinical introduction of BRCA-PARP synthetic lethality for the treatment of breast and ovarian cancer with defective BRCA. Subsequently, large-scale screenings with RNAi, CRISPR/Cas9-sgRNAs, and chemical libraries have been applied to identify synthetic lethal partners of tumor suppressors. Natural products are an important source for the discovery of pharmacologically active small molecules. However, little effort has been made in the discovery of synthetic lethal small molecules from natural products. This review introduces recent advances in the discovery of natural products targeting cancer cell dependency and discusses potentials of natural products in the precision cancer medicine.

Aurora kinase A, a synthetic lethal target for precision cancer medicine.

Recent advances in high-throughput sequencing technologies and data science have facilitated the development of precision medicine to treat cancer patients. Synthetic lethality is one of the core methodologies employed in precision cancer medicine. Synthetic lethality describes the phenomenon of the interplay between two genes in which deficiency of a single gene does not abolish cell viability but combined deficiency of two genes leads to cell death. In cancer treatment, synthetic lethality is leveraged to exploit the dependency of cancer cells on a pathway that is essential for cell survival when a tumor suppressor is mutated. This approach enables pharmacological targeting of mutant tumor suppressors that are theoretically undruggable. Successful clinical introduction of BRCA-PARP synthetic lethality in cancer treatment led to additional discoveries of novel synthetic lethal partners of other tumor suppressors, including p53, PTEN, and RB1, using high-throughput screening. Recent work has highlighted aurora kinase A (AURKA) as a synthetic lethal partner of multiple tumor suppressors. AURKA is a serine/threonine kinase involved in a number of central biological processes, such as the G2/M transition, mitotic spindle assembly, and DNA replication. This review introduces synthetic lethal interactions between AURKA and its tumor suppressor partners and discusses the potential of AURKA inhibitors in precision cancer medicine.

Molecular landscape and subtype-specific therapeutic response of nasopharyngeal carcinoma revealed by integrative pharmacogenomics.

Nasopharyngeal carcinoma (NPC) is a malignant head and neck cancer type with high morbidity in Southeast Asia, however the pathogenic mechanism of this disease is poorly understood. Using integrative pharmacogenomics, we find that NPC subtypes maintain distinct molecular features, drug responsiveness, and graded radiation sensitivity. The epithelial carcinoma (EC) subtype is characterized by activations of microtubule polymerization and defective mitotic spindle checkpoint related genes, whereas sarcomatoid carcinoma (SC) and mixed sarcomatoid-epithelial carcinoma (MSEC) subtypes exhibit enriched epithelial-mesenchymal transition (EMT) and invasion promoting genes, which are well correlated with their morphological features. Furthermore, patient-derived organoid (PDO)-based drug test identifies potential subtype-specific treatment regimens, in that SC and MSEC subtypes are sensitive to microtubule inhibitors, whereas EC subtype is more responsive to EGFR inhibitors, which is synergistically enhanced by combining with radiotherapy. Through combinational chemoradiotherapy (CRT) screening, effective CRT regimens are also suggested for patients showing less sensitivity to radiation. Altogether, our study provides an example of applying integrative pharmacogenomics to establish a personalized precision oncology for NPC subtype-guided therapies.

Egg Quality Parameters, Production Performance and Immunity of Laying Hens Supplemented with Plant Extracts.

This study examined the effects of Mentha arvensis (MA) and Geranium thunbergii (GT) extracts in drinking water on the production performance, egg quality, cholesterol content of egg yolk, proximate composition, and sensory qualities of egg and immunity parameters in laying hens. Ninety-six 28-week-old Hy-Line Brown layers were randomly divided into four dietary treatments for 16 weeks. The dietary treatments were (1) control, (2) T1 (0.01% 1 MA:1 GT), (3) T2 (0.05% 1 MA:1 GT), and (4) T3 (0.1% 1 MA:1 GT). Egg production increased significantly with increasing levels of MA and GT. The egg weight was increased in T2, and the feed intake was highest in T2 and T3 (p < 0.05). The Haugh unit and egg shape index were significantly better in T3 and the control than with other treatments (p < 0.05). The content of yolk cholesterol was significantly lower (p < 0.05) in T2 and T3. On the other hand, there were no significant differences in the egg proximate composition. A significant increase in the serum interleukin 6 (IL-6), tumor necrosis factor (TNFα) and immunoglobulins (IgG and IgA) concentration was observed in the birds fed plant extracts when compared to the control. On average, T2 and T3 showed significantly lower (p < 0.05) concentrations of NH3 gas from the feces as compared to the control. This study suggests that MA and GT supplementation could improve the laying performance, egg quality, and immunity, and decrease the egg yolk cholesterol content in a dose-dependent manner.

CBD Suppression of EAE Is Correlated with Early Inhibition of Splenic IFN-γ + CD8+ T Cells and Modest Inhibition of Neuroinflammation.

In this study cannabidiol (CBD) was administered orally to determine its effects and mechanisms in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). We hypothesized that 75 mg/kg of oral CBD given for 5 days after initiation of disease would reduce EAE severity through suppression of either the early peripheral immune or late neuroimmune response. EAE was induced in C57BL/6 mice at two different magnitudes, and peripheral inflammatory and neuroinflammatory responses were measured at days 3, 10, and 18. Th1, Th17, Tc1, Tc17, Tregs, and myeloid derived suppressor cells (MDSC) were identified from the lymph nodes and spleens of each mouse to determine if CBD altered the suppressor cell or inflammatory cell populations in secondary lymphoid tissues. Additionally, neuroinflammation was identified in brain and spinal cord tissues using various immunohistochemical techniques and flow cytometry. Early treatment of EAE with oral CBD reduced clinical disease at the day 18 timepoint which correlated with a significant decrease in the percentage of MOG35-55 specific IFN-γ producing CD8+ T cells in the spleen at day 10. Analysis of both T cell infiltration and lesion size within the spinal cord also showed a moderate reduction in neuroinflammation within the central nervous system (CNS). These results provide evidence that oral CBD suppressed the peripheral immune response that precedes neuroinflammation; however, analysis of the neuroinflammatory endpoints also suggest that the modest reduction in neuroinflammation was only partially responsible for CBD's neuroprotective capability. Graphical Abstract CBD was administered orally for the first 5 days following initiation of EAE. CBD attenuated clinical disease, and we found that CBD suppressed IFN-γ producing CD8+ T cells in the spleen at day 10. There was also modest suppression of neuroinflammation. Together these data demonstrate that early, oral administration of CBD protected mice from disease, but the modest effects on neuroinflammation suggest other mechanisms participate in CBD's neuroprotective effect in EAE.

The ameliorative effects of capsidiol isolated from elicited Capsicum annuum on mouse splenocyte immune responses and neuroinflammation.

Capsidiol, is an anti-fungal phytoalexin produced by plants of Solanaceae. Capsidiol was examined in cultures of primary splenocytes (SPLCs) isolated from healthy C57BL/6 mice and from those with induced experimental autoimmune encephalomyelitis (EAE) as a mouse model for autoimmune neurodegenerative multiple sclerosis (MS). We also examined the impact of capsidiol in IFN-γ-stimulated mouse BV2 microglial cells. Capsidiol resulted in a significant reduction in the anti-CD3/CD28 (αCD3/CD28)-induced IFN-γ+ CD4+ (Th1) and IFN-γ+ CD8+ (Tc1) populations as well as in the production of cytokines (IFN-γ, IL-17A, IL-6, IL-2, TNF-α, and IP-10). Specifically, the CD4+ and CD8+ populations (T-bet+ IFN-γ- , T-bet+ IFN-γ+ , and T-bet- IFN-γ+ ) and cytokine production mediated by Th1/Tc1 polarization were diminished by 25 µM capsidiol. MOG35-55 restimulation of SPLCs from EAE mice resulted in an increase in antigen-specific T cells, including Th1, IL-17A+ CD4+ (Th17), and IL-17A+ CD8+ (Tc17) populations. By contrast, capsidiol resulted in a decrease in the proportions of Th17 and Tc17 cells; MOG35-55 -specific cytokine production was also diminished by capsidiol. Capsidiol treatment resulted in diminished levels of IFN-γ-induced nitric oxide and IL-6; expression of iNOS and COX-2 were suppressed by 50 µM capsidiol in IFN-γ-stimulated BV2 cells. This is the first report of capsidiol-mediated immunomodulatory and antineuroinflammatory activities that may serve to prevent neurodegeneration.

Bromodomain and extra-terminal motif (BET) inhibition is synthetic lethal with loss of SMAD4 in colorectal cancer cells via restoring the loss of MYC repression.

The tumor suppressor SMAD4 is frequently mutated in colorectal cancer (CRC). However, no effective targeted therapies exist for CRC with SMAD4 loss. Here, we employed a synthetic lethality drug screening in isogenic SMAD4+/+ and SMAD4-/- HCT116 CRC cells and found that bromodomain and extra-terminal motif (BET) inhibitors, as selective drugs for the growth of SMAD4-/- HCT116 cells. BET inhibition selectively induced G1 cell cycle arrest in SMAD4-/- cells and this effect was accompanied by the reprogramming of the MYC-p21 axis. Mechanistically, SMAD4 is a transcription repressor of MYC, and MYC in turn represses p21 transcription. SMAD4-/- cells lost MYC repression ability, thereby causing the cells addicted to the MYC oncogenic signaling. BET inhibition significantly reduced MYC level and restored p21 expression in SMAD4-/- cells, inducing the selective growth arrest. The ectopic overexpression of MYC or the silencing of p21 could rescue the BET inhibitor-induced growth arrest in SMAD4-/- cells, verifying this model. Tumor xenograft mouse experiments further demonstrated the synthetic lethality interaction between BET and SMAD4 in vivo. Taken together, our data suggest that BET could be a potential drug target for the treatment of SMAD4-deficient CRC.

Physico-chemical attributes, sensory evaluation and oxidative stability of leg meat from broilers supplemented with plant extracts.

This feeding trial was conducted to investigate the effects of Mentha arvensis (MA) and Geranium thunbergii (GT) in drinking water on physicochemical attributes, sensory qualities, proximate analysis and oxidative stability of broiler leg meat. One hundred and twenty broiler chicks were assigned to 1 of 4 dietary treatments for 5 weeks. The dietary treatments were 1) control, 2) T1 (0.1% 1 MA:1 GT), 3) T2 (0.1% 1 MA:4 GT), 4) T3 (0.1% 4 MA: 1 GT). The water holding capacity and cooking loss were improved (p < 0.05) in T2 and T3. The flavor, texture and acceptability of leg meat by consumers were significantly increased in T2 relative to the control (p < 0.05). The crude protein content was increased in T3 while the crude fat decreased in T2 (p < 0.05). Moreover, broilers supplemented with plant extracts had the lowest leg meat TBARS (thiobarbituric acid reactive substances) values after 2 weeks of storage as compared with the control. Total phenolic contents and 1-1-diphenyl 2 picrylhydrazyl (DPPH) activity were also better in the T2 group (p < 0.05) compared with the control, whereas 2,2-Azinobis-3 ethytlbenzothiazoline-6-sulfonic acid (ABTS+) remained unaffected. Overall, these results demonstrate that broiler drinking water with the inclusion of plant extract combination can be used to enhance the oxidative stability, shelf life and quality characteristics of broiler leg meat without compromising the growth performance.

Synthetic lethality of RB1 and aurora A is driven by stathmin-mediated disruption of microtubule dynamics.

RB1 mutational inactivation is a cancer driver in various types of cancer including lung cancer, making it an important target for therapeutic exploitation. We performed chemical and genetic vulnerability screens in RB1-isogenic lung cancer pair and herein report that aurora kinase A (AURKA) inhibition is synthetic lethal in RB1-deficient lung cancer. Mechanistically, RB1-/- cells show unbalanced microtubule dynamics through E2F-mediated upregulation of the microtubule destabilizer stathmin and are hypersensitive to agents targeting microtubule stability. Inhibition of AURKA activity activates stathmin function via reduced phosphorylation and facilitates microtubule destabilization in RB1-/- cells, heavily impacting the bipolar spindle formation and inducing mitotic cell death selectively in RB1-/- cells. This study shows that stathmin-mediated disruption of microtubule dynamics is critical to induce synthetic lethality in RB1-deficient cancer and suggests that upstream factors regulating microtubule dynamics, such as AURKA, can be potential therapeutic targets in RB1-deficient cancer.