The effect of Curcumin on multi-level immune checkpoint blockade and T cell dysfunction in head and neck cancer.

BACKGROUND: Despite recent advances in understanding the complex immunologic dysfunction in the tumor microenvironment (TME), fewer than 20% of patients with head and neck squamous cell carcinoma (HNSCC) respond to immune checkpoint blockade (ICB). Thus, it is important to understand how inhibitory IC receptors maintain the suppressed dysfunctional TME, and to develop more effective combination immunotherapy. This study evaluated the immune-modulating effects of Curcumin, which has well-established anti-cancer and chemopreventive properties, and its long-term safety as a phytochemical drug. METHODS: We carried out the western blot and small interfering RNA (siRNA) transfection assay to evaluate the effects of Curcumin on IC ligands and IC ligands function in HNSCC. Through T-cell cytotoxicity assay and measurements of cytokine secretion, we assessed the effects of combination of Curcumin with programmed death-ligand 1 (PD-L1) Ab on cancer cell killing. Flow cytometry were used to analyze the effects of Curcumin on the expression of programmed cell death protein 1 (PD-1) and T-cell immunoglobulin and mucin-domain3 (TIM-3) on CD4, CD8 and Treg. Immunofluorescence, immunohistochemistry and western blot were used to detecte the cytokine (IFN-γ, Granzyme B), IC receptors (PD-1 and TIM-3) and its ligands (PD-L1, PD-L2, Galectin-9) in xenograft mouse model and 4-nitroquinoline-1-oxide (4-NQO) oral cancer model. RESULTS: We found that Curcumin decreased the expression of IC ligands such as PD-L1, PD-L2, and Galectin-9 in HNSCC, leading to regulation of epithelial-to-mesenchymal transition-associated tumor invasion. Curcumin also effectively restored the ability of CD8+ cytotoxic T cells to lyse cancer cells. To evaluate the effect of Curcumin on the TME further, the 4-NQO oral cancer model was used. Curcumin increased T-cell proliferation, tumor-infiltrating lymphocytes (TILs), and effector cytokines, and decreased the expression of PD-1, TIM-3, suppressive IC receptors and their ligands (PD-L1, PD-L2, and Galectin-9) in the TME, implying reinvigoration of the exhausted CD8+ T cells. In addition, Curcumin inhibited expression of CD4+CD25+FoxP3+ Treg cells as well as PD-1 and TIM-3. CONCLUSIONS: These results show that Curcumin reinvigorates defective T cells via multiple (PD-1 and TIM-3) and multi-level (IC receptors and its ligands) IC axis suppression, thus providing a rationale to combine Curcumin with conventional targeted therapy or ICB as a multi-faceted approach for treating patients with HNSCC.

The most reliable time point for intact parathyroid hormone measurement to predict hypoparathyroidism after total thyroidectomy with central neck dissection to treat papillary thyroid carcinoma: a prospective cohort study.

PURPOSE: We assessed the optimal time for intact parathyroid hormone (iPTH) measurement for early detection of post-total thyroidectomy (TT) hypocalcemia in patients with papillary thyroid carcinoma (PTC). METHODS: In this single-center prospective cohort study, 143 patients who underwent TT with central neck dissection with or without lateral neck dissection for PTC were included. Biochemical profiles including iPTH, corrected total calcium, and ionized calcium within 24 h after surgery were analyzed. RESULTS: The 4-h postoperative iPTH was the most reliable predictor of post-TT transient or permanent hypoparathyroidism (cutoff for hypocalcemia was 3.75 pg/mL, AUC = 0.885, P < 0.001, sensitivity 81.6%, specificity 86.0%; cutoff for permanent hypocalcemia was 2.48 pg/mL, AUC = 0.819, P < 0.001, sensitivity 100%, specificity 57.8% calculated using ROC curves). CONCLUSIONS: The 4-h postoperative iPTH can most accurately predict hypoparathyroidism after TT with central neck dissection to treat PTC and facilitate the early discharge of low-risk postoperative hypoparathyroidism patients and decrease unnecessary overnight observation and calcium supplementation.

Novel Scaffolds for Dual Specificity Tyrosine-Phosphorylation-Regulated Kinase (DYRK1A) Inhibitors.

DYRK1A is one of five members of the dual-specificity tyrosine (Y) phosphorylation-regulated kinase (DYRK) family. The DYRK1A gene is located in the Down syndrome critical region and regulates cellular processes related to proliferation and differentiation of neuronal progenitor cells during early development. This has focused research on its role in neuronal degenerative diseases, including Alzheimer's and Down syndrome. Recent studies have also shown a possible role of DYRK1A in diabetes. Here we report a variety of scaffolds not generally known for DYRK1A inhibition, demonstrating their effects in in vitro assays and also in cell cultures. These inhibitors effectively block the tau phosphorylation that is a hallmark of Alzheimer's disease. The crystal structures of these inhibitors support the design of optimized and novel therapeutics.

Protective effect of Artemisia asiatica (Pamp.) Nakai ex Kitam ethanol extract against cisplatin-induced apoptosis of human HaCaT keratinocytes: Involvement of NF-kappa B- and Bcl-2-controlled mitochondrial signaling.

BACKGROUND: Oral mucositis is a common adverse effect of antineoplastic chemotherapy limiting sufficient dose of chemoregimen. Numerous attempts to mitigate chemotherapy-induced oral mucositis have failed to identify an appropriate treatment. HYPOTHESIS: We hypothesize that Artemisia asiatica (Pamp.) Nakai ex Kitam ethanol extract (Aa-EE) would mitigate cisplatin-induced cytotoxicity to oral mucosal epithelial cells. STUDY DESIGN: In vitro experimental study. METHODS: Cell viability and wound healing assay were performed. Apoptosis, mitochondrial membrane potential (MMP) change, and changes in apoptosis-related signaling were demonstrated in human primary keratinocyte (HaCaT). RESULTS: Cisplatin inhibited HaCaT cell proliferation and migration. Aa-EE protected against these effects. Cisplatin treatment of HaCaT cells caused apoptosis and changes in MMP. Aa-EE inhibited cisplatin-induced apoptosis, and stabilized the cisplatin-induced loss of MMP. Western blots revealed that Aa-EE reduced the expression of cytochrome c and cleaved caspase-3 and inhibited nuclear translocation of nuclear factor-kappa B (NF-κB), compared with the levels observed after cisplatin treatment, whereas Bcl-2 expression was increased by Aa-EE. CONCLUSION: Collectively, our results suggest that Aa-EE protects HaCaT cells by inhibiting cisplatin-induced mitochondrial damage associated with Bcl-2 activity and by inhibiting nuclear translocation of NF-κB.

Selective inhibitor of platelet-activating factor acetylhydrolases 1b2 and 1b3 that impairs cancer cell survival.

Platelet-activating factor acetylhydrolases (PAFAHs) 1b2 and 1b3 are poorly characterized serine hydrolases that form a complex with a noncatalytic protein (1b1) to regulate brain development, spermatogenesis, and cancer pathogenesis. Determining physiological substrates and biochemical functions for the PAFAH1b complex would benefit from selective chemical probes that can perturb its activity in living systems. Here, we report a class of tetrahydropyridine reversible inhibitors of PAFAH1b2/3 discovered using a fluorescence polarization-activity-based protein profiling (fluopol-ABPP) screen of the NIH 300,000+ compound library. The most potent of these agents, P11, exhibited IC50 values of ∼40 and 900 nM for PAFAH1b2 and 1b3, respectively. We confirm selective inhibition of PAFAH1b2/3 in cancer cells by P11 using an ABPP protocol adapted for in situ analysis of reversible inhibitors and show that this compound impairs tumor cell survival, supporting a role for PAFAH1b2/3 in cancer.

ThermoMouse: an in vivo model to identify modulators of UCP1 expression in brown adipose tissue.

Obesity develops when energy intake chronically exceeds energy expenditure. Because brown adipose tissue (BAT) dissipates energy in the form of heat, increasing energy expenditure by augmenting BAT-mediated thermogenesis may represent an approach to counter obesity and its complications. The ability of BAT to dissipate energy is dependent on expression of mitochondrial uncoupling protein 1 (UCP1). To facilitate the identification of pharmacological modulators of BAT UCP1 levels, which may have potential as antiobesity medications, we developed a transgenic model in which luciferase activity faithfully mimics endogenous UCP1 expression and its response to physiologic stimuli. Phenotypic screening of a library using cells derived from this model yielded a small molecule that increases UCP1 expression in brown fat cells and mice. Upon adrenergic stimulation, compound-treated mice showed increased energy expenditure. These tools offer an opportunity to identify pharmacologic modulators of UCP1 expression and uncover regulatory pathways that impact BAT-mediated thermogenesis.

Protective effects of Korean red ginseng on radiation-induced oral mucositis in a preclinical rat model.

Numerous studies' attempts to improve radiation-induced oral mucositis have not produced a qualified treatment yet. Our aim was to investigate the effectiveness of Korean red ginseng (KRG) on radiation-induced damage in an in vivo rat model. After 20 Gy of irradiation, rats were divided randomly into the following 4 groups: control, KRG only, radiotherapy (RT) only, and RT + KRG group. The rats were monitored in terms of survival rate, activity, mucositis grade, oral intake, and body weight. The tongue, buccal mucosa, and submandibular gland (SMG) were harvested, and the weight of the SMG was analyzed. The samples then underwent hematoxylin and eosin, TUNEL, and immunohistochemical staining. Radiation-induced severe oral mucositis and SMG injury led to poor oral intake and delayed healing, resulting in the death of some rats. We found that survival rate, oral intake, and body weight increased. Moreover, rats treated with KRG showed less severe mucositis and decreased histologic changes of the oral mucosa and SMG. Furthermore, we showed that the protective effects of KRG were caused by inhibition of the apoptotic signal transduction pathway linked to caspase-3. In conclusion, KRG protects the oral mucosa and SMG from radiation-induced damage by inhibiting caspase-mediated apoptosis in rats.

Protective effects of Korean red ginseng against radiation-induced apoptosis in human HaCaT keratinocytes.

Radiation-induced oral mucositis is a dose-limiting toxic side effect for patients with head and neck cancer. Numerous attempts at improving radiation-induced oral mucositis have not produced a qualified treatment. Ginseng polysaccharide has multiple immunoprotective effects. Our aim was to investigate the effectiveness of Korean red ginseng (KRG) on radiation-induced damage in the human keratinocyte cell line HaCaT and in an in vivo zebrafish model. Radiation inhibited HaCaT cell proliferation and migration in a cell viability assay and wound healing assay, respectively. KRG protected against these effects. KRG attenuated the radiation-induced embryotoxicity in the zebrafish model. Irradiation of HaCaT cells caused apoptosis and changes in mitochondrial membrane potential (MMP). KRG inhibited the radiation-induced apoptosis and intracellular generation of reactive oxygen species (ROS), and stabilized the radiation-induced loss of MMP. Western blots revealed KRG-mediated reduced expression of ataxia telangiectasia mutated protein (ATM), p53, c-Jun N-terminal kinase (JNK), p38 and cleaved caspase-3, compared with their significant increase after radiation treatment. The collective results suggest that KRG protects HaCaT cells by blocking ROS generation, inhibiting changes in MMP, and inhibiting the caspase, ATM, p38 and JNK pathways.

Evaluation of NHS carbamates as a potent and selective class of endocannabinoid hydrolase inhibitors.

Monoacylglycerol lipase (MAGL) is a principal metabolic enzyme responsible for hydrolyzing the endogenous cannabinoid (endocannabinoid) 2-arachidonoylglycerol (2-AG). Selective inhibitors of MAGL offer valuable probes to further understand the enzyme's function in biological systems and may lead to drugs for treating a variety of diseases, including psychiatric disorders, neuroinflammation, and pain. N-Hydroxysuccinimidyl (NHS) carbamates have recently been identified as a promising class of serine hydrolase inhibitors that shows minimal cross-reactivity with other proteins in the proteome. Here, we explore NHS carbamates more broadly and demonstrate their potential as inhibitors of endocannabinoid hydrolases and additional enzymes from the serine hydrolase class. We extensively characterize an NHS carbamate 1a (MJN110) as a potent, selective, and in-vivo-active MAGL inhibitor. Finally, we demonstrate that MJN110 alleviates mechanical allodynia in a rat model of diabetic neuropathy, marking NHS carbamates as a promising class of MAGL inhibitors.

A novel fluorophosphonate inhibitor of the biosynthesis of the endocannabinoid 2-arachidonoylglycerol with potential anti-obesity effects.

BACKGROUND AND PURPOSE: The development of potent and selective inhibitors of the biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG) via DAG lipases (DAGL) α and ß is just starting to be considered as a novel and promising source of pharmaceuticals for the treatment of disorders that might benefit from a reduction in endocannabinoid tone, such as hyperphagia in obese subjects. EXPERIMENTAL APPROACH: Three new fluorophosphonate compounds O-7458, O-7459 and O-7460 were synthesized and characterized in various enzymatic assays. The effects of O-7460 on high-fat diet intake were tested in mice. KEY RESULTS: Of the new compounds, O-7460 exhibited the highest potency (IC50 = 690 nM) against the human recombinant DAGLα, and selectivity (IC50 > 10 µM) towards COS-7 cell and human monoacylglycerol lipase (MAGL), and rat brain fatty acid amide hydrolase. Competitive activity-based protein profiling confirmed that O-7460 inhibits mouse brain MAGL only at concentrations ≥ 10 µM, and showed that this compound has only one major 'off-target', that is, the serine hydrolase KIAA1363. O-7460 did not exhibit measurable affinity for human recombinant CB1 or CB2 cannabinoid receptors (Ki > 10 µM). In mouse neuroblastoma N18TG2 cells stimulated with ionomycin, O-7460 (10 µM) reduced 2-AG levels. When administered to mice, O-7460 dose-dependently (0-12 mg·kg⁻¹, i.p.) inhibited the intake of a high-fat diet over a 14 h observation period, and, subsequently, slightly but significantly reduced body weight. CONCLUSIONS AND IMPLICATIONS: O-7460 might be considered a useful pharmacological tool to investigate further the role played by 2-AG both in vitro and in vivo under physiological as well as pathological conditions.