Selective Hypoxia-Sensitive Oxomer Formation by FIH Prevents Binding of the NF-κB Inhibitor IκBß to NF-κB Subunits.

Pharmacologic inhibitors of cellular hydroxylase oxygen sensors are protective in multiple preclinical in vivo models of inflammation. However, the molecular mechanisms underlying this regulation are only partly understood, preventing clinical translation. We previously proposed a new mechanism for cellular oxygen sensing: oxygen-dependent, (likely) covalent protein oligomer (oxomer) formation. Here, we report that the oxygen sensor factor inhibiting HIF (FIH) forms an oxomer with the NF-κB inhibitor ß (IκBß). The formation of this protein complex required FIH enzymatic activity and was prevented by pharmacologic inhibitors. Oxomer formation was highly hypoxia-sensitive and very stable. No other member of the IκB protein family formed an oxomer with FIH, demonstrating that FIH-IκBß oxomer formation was highly selective. In contrast to the known FIH-dependent oxomer formation with the deubiquitinase OTUB1, FIH-IκBß oxomer formation did not occur via an IκBß asparagine residue, but depended on the amino acid sequence VAERR contained within a loop between IκBß ankyrin repeat domains 2 and 3. Oxomer formation prevented IκBß from binding to its primary interaction partners p65 and c-Rel, subunits of NF-κB, the master regulator of the cellular transcriptional response to pro-inflammatory stimuli. We therefore propose that FIH-mediated oxomer formation with IκBß contributes to the hypoxia-dependent regulation of inflammation.

Role of inflammatory signaling pathways involving the CD40-CD40L-TRAF cascade in diabetes and hypertension-insights from animal and human studies.

CD40L-CD40-TRAF signaling plays a role in atherosclerosis progression and affects the pathogenesis of coronary heart disease (CHD). We tested the hypothesis that CD40L-CD40-TRAF signaling is a potential therapeutic target in hyperlipidemia, diabetes, and hypertension. In mouse models of hyperlipidemia plus diabetes (db/db mice) or hypertension (1 mg/kg/d angiotensin-II for 7 days), TRAF6 inhibitor treatment (2.5 mg/kg/d for 7 or 14 days) normalized markers of oxidative stress and inflammation. As diabetes and hypertension are important comorbidities aggravating CHD, we explored whether the CD40L-CD40-TRAF signaling cascade and their associated inflammatory pathways are expressed in CHD patients suffering from comorbidities. Therefore, we analyzed vascular bypass material (aorta or internal mammary artery) and plasma from patients with CHD with diabetes and/or hypertension. Our Olink targeted plasma proteomic analysis using the IMMUNO-ONCOLOGY panel revealed a pattern of step-wise increase for 13/92 markers of low-grade inflammation with significant changes. CD40L or CD40 significantly correlated with 38 or 56 other inflammatory targets. In addition, specific gene clusters that correlate with the comorbidities were identified in isolated aortic mRNA of CHD patients through RNA-sequencing. These signaling clusters comprised CD40L-CD40-TRAF, immune system, hemostasis, muscle contraction, metabolism of lipids, developmental biology, and apoptosis. Finally, immunological analysis revealed key markers correlated with comorbidities in CHD patients, such as CD40L, NOX2, CD68, and 3-nitrotyrosine. These data indicate that comorbidities increase inflammatory pathways in CHD, and targeting these pathways will be beneficial in reducing cardiovascular events in CHD patients with comorbidities.

Van Gogh-like 2 is essential for the architectural patterning of the mammalian biliary tree.

BACKGROUND & AIMS: In the developing liver, bipotent epithelial progenitor cells undergo lineage segregation to form hepatocytes, which constitute the bulk of the liver parenchyma, and biliary epithelial cells (cholangiocytes), which comprise the bile duct (a complex tubular network that is critical for normal liver function). Notch and TGFß signalling promote the formation of a sheet of biliary epithelial cells, the ductal plate, that organises into discontinuous tubular structures. How these structures elongate and connect to form a continuous duct remains undefined. We aimed to define the mechanisms by which the ductal plate transitions from a simple sheet of epithelial cells into a complex and connected bile duct. METHODS: By combining single-cell RNA sequencing of embryonic mouse livers with genetic tools and organoid models we functionally dissected the role of planar cell polarity in duct patterning. RESULTS: We show that the planar cell polarity protein VANGL2 is expressed late in intrahepatic bile duct development and patterns the formation of cell-cell contacts between biliary cells. The patterning of these cell contacts regulates the normal polarisation of the actin cytoskeleton within biliary cells and loss of Vangl2 function results in the abnormal distribution of cortical actin remodelling, leading to the failure of bile duct formation. CONCLUSIONS: Planar cell polarity is a critical step in the post-specification sculpture of the bile duct and is essential for establishing normal tissue architecture. IMPACT AND IMPLICATIONS: Like other branched tissues, such as the lung and kidney, the bile ducts use planar cell polarity signalling to coordinate cell movements; however, how these biochemical signals are linked to ductular patterning remains unclear. Here we show that the core planar cell polarity protein VANGL2 patterns how cell-cell contacts form in the mammalian bile duct and how ductular cells transmit confluent mechanical changes along the length of a duct. This work sheds light on how biological tubes are patterned across mammalian tissues (including within the liver) and will be important in how we promote ductular growth in patients where the duct is mis-patterned or poorly formed.

Elevation of truncated (48 kDa) form of unconventional myosin 1C in blood serum correlates with severe Covid-19.

In Covid-19 and autoimmune patients, there are several similarities revealed in the immune responses (Liu et al., 2021; Woodruff et al., 2020). Earlier, we firstly detected a truncated (48 kDa) form of the unconventional Myosin 1C (48/Myo1C) in a fraction of proteins soluble in 10% 2,2,2-trichloroacetic acid (TCA). These proteins were obtained from blood serum of patients with autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis (Kit et al., 2018). Here, we demonstrated that content of 48/Myo1C was also elevated in blood serum of the severe Covid-19 patients. Whereas in blood of 28 clinically healthy human individuals regularly tested for Covid-19 infection, the amount of this protein was undetectable or very low, in blood of 16 of 28 patients hospitalized with severe course of this disease, its amount was significantly increased. Dexamethasone, steroid hormone which is widely used for treatment of severe Covid-19 patients, induced time-dependent elevation of the 48/Myo1C in blood of such patients. The 48/Myo1C dose-dependently suppressed the viability of anti-CD3-activated lymphocytes of human peripheral blood. Recently, we used affinity chromatography on the magnetic poly(glycidyl-methacrylate) (mag-PGMA-NH2) microparticles functionalized with Myo1C and MALDI-TOF mass spectrometry with molecular modeling in silico in order to identify potential molecular partners of the 48/Myo1C. It was found that 48/Myo1C might bind to component 3 of the complement system and the anti-thrombin-III (Starykovych et al., 2021). Thus, the mechanisms of the pathogenic action of truncated form of Myo1C in severe COVID-19 patients may involve a suppression of the immune cells, as well as modulation of complement and coagulation cascades.

The molecular mechanisms of apoptosis accompanied with the epigenetic regulation of the NY-ESO-1 antigen in non-small lung cancer cells treated with decitabine (5-aza-CdR).

Dysregulated epigenetic modifications are common in lung cancer but have been reversed using demethylating agent like 5-Aza-CdR. 5-Aza-CdR induces/upregulates the NY-ESO-1 antigen in lung cancer. Therefore, we investigated the molecular mechanisms accompanied with the epigenetic regulation of NY-ESO-1 in 5-Aza-CdR-treated NCI-H1975 cell line. We showed significant induction of the NY-ESO-1 protein (**p < 0.0097) using Cellular ELISA. Bisulfite-sequencing demonstrated 45.6% demethylation efficiency at the NY-ESO-1 gene promoter region and RT-qPCR analysis confirmed the significant induction of NY-ESO-1 at mRNA level (128-fold increase, *p < 0.050). We then investigated the mechanism by which 5-Aza-CdR inhibits cell proliferation in the NCI-H1975 cell line. Upregulation of the death receptors TRAIL (2.04-fold *p < 0.011) and FAS (2.1-fold *p < 0.011) indicate activation of the extrinsic apoptotic pathway. The upregulation of Voltage-dependent anion-selective channel protein 1 (1.9-fold), Major vault protein (1.8-fold), Bax (1.16-fold), and Cytochrome C (1.39-fold) indicate the activation of the intrinsic pathway. We also observed the differential expression of protein Complement C3 (3.3-fold), Destrin (-5.1-fold), Vimentin (-1.7-fold), Peroxiredoxin 4 (-1.6-fold), Fascin (-1.8-fold), Heme oxygenase-2 (-0.67-fold**p < 0.0055), Hsp27 (-0.57-fold**p < 0.004), and Hsp70 (-0.39-fold **p < 0.001), indicating reduced cell growth, cell migration, and metastasis. The upregulation of 40S ribosomal protein S9 (3-fold), 40S ribosomal protein S15 (4.2-fold), 40S ribosomal protein S18 (2.5-fold), and 60S ribosomal protein L22 (4.4-fold) implied the induction of translation machinery. These results reiterate the decisive role of 5-Aza-CdR in lung cancer treatment since it induces the epigenetic regulation of NY-ESO-1 antigen, inhibits cell proliferation, increases apoptosis, and decreases invasiveness.

Co-exposure to urban particulate matter and aircraft noise adversely impacts the cerebro-pulmonary-cardiovascular axis in mice.

Worldwide, up to 8.8 million excess deaths/year have been attributed to air pollution, mainly due to the exposure to fine particulate matter (PM). Traffic-related noise is an additional contributor to global mortality and morbidity. Both health risk factors substantially contribute to cardiovascular, metabolic and neuropsychiatric sequelae. Studies on the combined exposure are rare and urgently needed because of frequent co-occurrence of both risk factors in urban and industrial settings. To study the synergistic effects of PM and noise, we used an exposure system equipped with aerosol generator and loud-speakers, where C57BL/6 mice were acutely exposed for 3d to either ambient PM (NIST particles) and/or noise (aircraft landing and take-off events). The combination of both stressors caused endothelial dysfunction, increased blood pressure, oxidative stress and inflammation. An additive impairment of endothelial function was observed in isolated aortic rings and even more pronounced in cerebral and retinal arterioles. The increase in oxidative stress and inflammation markers together with RNA sequencing data indicate that noise particularly affects the brain and PM the lungs. The combination of both stressors has additive adverse effects on the cardiovascular system that are based on PM-induced systemic inflammation and noise-triggered stress hormone signaling. We demonstrate an additive upregulation of ACE-2 in the lung, suggesting that there may be an increased vulnerability to COVID-19 infection. The data warrant further mechanistic studies to characterize the propagation of primary target tissue damage (lung, brain) to remote organs such as aorta and heart by combined noise and PM exposure.

Aryl Hydrocarbon Receptor Promotes Cell Growth, Stemness Like Characteristics, and Metastasis in Human Ovarian Cancer via Activation of PI3K/Akt, ß-Catenin, and Epithelial to Mesenchymal Transition Pathways.

Ovarian cancer (OC) ranks first in cancer-related deaths out of all female reproductive malignancies with high-pitched tumor relapse and chemoresistance. Several reports correlate cancer occurrences with exposure to xenobiotics via induction of a protein receptor named aryl hydrocarbon receptor (AhR). However, the effect of AhR on OC proliferation, expansion, and chemoresistance remains unrevealed. For this purpose, OC cells A2780 and A2780cis cells were treated with AhR activator, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and the effects were determined by Real-Time Cell Analyzer, clonogenic assay, flow cytometry, immunoblotting and wound healing assay. Our results showed that activation of AhR by TCDD in A2780 cells induced the PI3K/AKT pathway followed by induction of anti-apoptotic proteins BCL-2, BCL-xl, and MCL-1. In addition, a significant increase in stemness marker aldehyde dehydrogenase (ALDH1) was observed. This effect was also associated with an accumulation of ß-catenin, a Wnt transcription factor. Moreover, we observed induction of epithelial to mesenchymal transition (EMT) upon AhR activation. In conclusion, the results from the current study confirm that AhR mediates OC progression, stemness characteristics, and metastatic potential via activation of PI3K/Akt, Wnt/ß-catenin, and EMT. This study provides a better insight into the modulatory role of AhR that might help in developing novel therapeutic strategies for OC treatment.

Dynamic liquid biopsy components as predictive and prognostic biomarkers in colorectal cancer.

Colorectal cancer (CRC) is one of the most common cancers worldwide. The diagnosis, prognosis and therapeutic monitoring of CRC depends largely on tissue biopsy. However, due to tumor heterogeneity and limitations such as invasiveness, high cost and limited applicability in longitudinal monitoring, liquid biopsy has gathered immense attention in CRC. Liquid biopsy has several advantages over tissue biopsy including ease of sampling, effective monitoring, and longitudinal assessment of treatment dynamics. Furthermore, the importance of liquid biopsy is signified by approval of several liquid biopsy assays by regulatory bodies indicating the powerful approach of liquid biopsy for comprehensive CRC screening, diagnostic and prognostics. Several liquid biopsy biomarkers such as novel components of the microbiome, non-coding RNAs, extracellular vesicles and circulating tumor DNA are extensively being researched for their role in CRC management. Majority of these components have shown promising results on their clinical application in CRC including early detection, observe tumor heterogeneity for treatment and response, prediction of metastases and relapse and detection of minimal residual disease. Therefore, in this review, we aim to provide updated information on various novel liquid biopsy markers such as a) oral microbiota related bacterial network b) gut microbiome-associated serum metabolites c) PIWI-interacting RNAs (piRNAs), microRNA(miRNAs), Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and d) circulating tumor DNAs (ctDNA) and circulating tumor cells (CTC) for their role in disease diagnosis, prognosis, treatment monitoring and their applicability for personalized management of CRC.

Novel Post-translational Modifications in Human Serum Albumin.

AIM: This study aims to identify novel post-translational modifications in human serum albumin by mass spectrometry. BACKGROUND: Serum albumin is the most abundant protein in plasma, has many physiological functions, and is in contact with most of the cells and tissues of the human body. Post-translational modifications (PTMs) may affect functions, stability, and localization of albumin. METHODS: Human serum albumin (HSA) was used for tryptic digestion in-solution or in-gel. Mass spectrometry was applied to identify PTMs in HSA. 3-dimensional modeling was applied to explore the potential impact of PTMs on known functions of albumin. RESULTS: Here, we report the identification of 61 novel PTMs of human serum albumin. Phosphorylation, glycosylation, nitrosylation, deamidation, methylation, acetylation, palmitoylation, geranylation, and farnesylation are some examples of the identified PTMs. Mass spectrometry was used for the identification of PTMs in a purified HSA and HSA from the human plasma. Threedimensional modeling of albumin with selected PTMs showed the location of these PTMs in the regions involved in albumin interactions with drugs, metals, and fatty acids. The location of PTMs in these regions may modify the binding capacity of albumin. CONCLUSION: This report adds 61 novel PTMs to the catalog of human albumin.

Differences in protein expression, at the basal state and at 2 h of insulin infusion, in muscle biopsies from healthy Arab men with high or low insulin sensitivity measured by hyperinsulinemic euglycemic clamp.

Background: Skeletal muscle is the main site for insulin-dependent glucose disposal. The hyperinsulinemic euglycemic clamp (HIEC) is the gold standard for the assessment of insulin sensitivity (IS). We have previously shown that insulin sensitivity, measured by HIEC, varied widely among a group of 60 young healthy men with normoglycemia. The aim of this study was to correlate the proteomic profile of skeletal muscles to insulin sensitivity. Methods: Muscle biopsies from 16 subjects having the highest (M ≥ 13; n = 8, HIS) and lowest (M ¾ 6, n = 8, LIS) IS were obtained at baseline and during insulin infusion after stabilization of the blood glucose level and glucose infusion rate at the end of the HIEC. The samples were processed using a quantitative proteomic analysis approach. Results: At baseline, 924 proteins were identified in the HIS and LIS groups. Among the 924 proteins detected in both groups, three were suppressed and three were increased significantly in the LIS subjects compared with the HIS subjects. Following insulin infusion, 835 proteins were detected in both groups. Among the 835 proteins, two showed differential responsiveness to insulin; ATP5F1 protein was decreased, and MYLK2 was higher in the LIS group compared with that in the HIS group. Our data suggest that alteration in mitochondrial proteins and an increased number of proteins involved in fast-twitch fiber correlate to insulin sensitivity in healthy young Arab men. Conclusions: These results suggest a change in a small number of differentially expressed proteins. A possible reason for this small change could be our study cohorts representing a homogeneous and healthy population. Additionally, we show differences in protein levels from skeletal muscle in low and high insulin sensitivity groups. Therefore, these differences may represent early events for the development of insulin resistance, pre-diabetes, and type 2 diabetes.

Therapeutic Effects of Curcumol in Several Diseases; An Overview.

Curcumae Rhizoma, also known as Ezhu is a traditional Chinese medicine that has been used for many centuries against several diseases. The rhizome of the plant is composed of curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin), and essential volatile oils including curcumol, curdione, and germacrone. While curcuminoids have been extensively studied for their antimicrobial, antioxidant, anti-inflammatory and anticancer properties, the therapeutic efficacy of curcumol is still emerging. Recent studies have shown anticancer properties of curcumol against multiple solid tumors such as breast, colorectal, head and neck, and lung adenocarcinomas. The underlying anti-tumor mechanisms revealed inhibition of several signaling pathways (NF-κB, MAPK, PI-3K/AKT, and GSK-3ß) associated with cell proliferation, survival, anti-apoptosis, invasion and metastasis. Besides curcumol, extracts from the Curcumae Rhizoma roots possess many other terpenoids such as ß-elemene, δ-elemene, germacrone, furanodiene and furanodienone with known anticancer properties. In this review, we comprehensively focused on the composition of Curcumae Rhizoma essential oils, their structure, isolation and therapeutic uses of curcumol to aid in the improvement and development of novel drugs with minimal cytotoxicity, enhanced efficacy, and less cost.

Dysregulated Phosphorylation of p53, Autophagy and Stemness Attributes the Mutant p53 Harboring Colon Cancer Cells Impaired Sensitivity to Oxaliplatin.

Colorectal cancer (CRC) forms one of the highest ranked cancer types in the world with its increasing incidence and mortality rates despite the advancement in cancer therapeutics. About 50% of human CRCs are reported to have defective p53 expression resultant of TP53 gene mutation often contributing to drug resistance. The current study was aimed to investigate the response of wild-type TP53 harboring HCT 116 and mutant TP53 harboring HT 29 colon cancer cells to chemotherapeutic drug oxaliplatin (OX) and to elucidate the underlying molecular mechanisms of sensitivity/resistance in correlation to their p53 status. OX inhibited growth of wild-type p53-harboring colon cancer cells via p53/p21-Bax mediated apoptosis. Our study revealed that dysregulated phosphorylation of p53, autophagy as well as cancer stemness attributes the mutant p53-harboring colon cancer cells impaired sensitivity to OX.

Unleashing the immune response to NY-ESO-1 cancer testis antigen as a potential target for cancer immunotherapy.

INTRODUCTION: Cancer Immunotherapy has recently emerged as a promising and effective modality to treat different malignancies. Antigenic profiling of cancer tissues and determination of any pre-existing immune responses to cancer antigens may help predict responses to immune intervention in cancer. NY-ESO-1, a cancer testis antigen is the most immunogenic antigen to date. The promise of NY-ESO-1 as a candidate for specific immune recognition of cancer comes from its restricted expression in normal adult tissue but frequent occurrence in multiple tumors including melanoma and carcinomas of lung, esophageal, liver, gastric, prostrate, ovarian, and bladder. MAIN BODY: This review summarizes current knowledge of NY-ESO-1 as efficient biomarker and target of immunotherapy. It also addresses limitations and challenges preventing a robust immune response to NY-ESO-1 expressing cancers, and describes pre-clinical and clinical observations relevant to NY-ESO-1 immunity, holding potential therapeutic relevance for cancer treatment. CONCLUSION: NY-ESO-1 induces strong immune responses in cancer patients but has limited objective clinical responses to NY-ESO-1 expressing tumors due to effect of competitive negative signaling from immune-checkpoints and immune-suppressive tumor microenvironment. We propose that combination therapy to increase the efficacy of NY-ESO-1 specific immunotherapeutic interventions should be explored to unleash the immune response against NY-ESO-1 expressing tumors.

Claudin-1, A Double-Edged Sword in Cancer.

Claudins, a group of membrane proteins involved in the formation of tight junctions, are mainly found in endothelial or epithelial cells. These proteins have attracted much attention in recent years and have been implicated and studied in a multitude of diseases. Claudins not only regulate paracellular transepithelial/transendothelial transport but are also critical for cell growth and differentiation. Not only tissue-specific but the differential expression in malignant tumors is also the focus of claudin-related research. In addition to up- or down-regulation, claudin proteins also undergo delocalization, which plays a vital role in tumor invasion and aggressiveness. Claudin (CLDN)-1 is the most-studied claudin in cancers and to date, its role as either a tumor promoter or suppressor (or both) is not established. In some cancers, lower expression of CLDN-1 is shown to be associated with cancer progression and invasion, while in others, loss of CLDN-1 improves the patient survival. Another topic of discussion regarding the significance of CLDN-1 is its localization (nuclear or cytoplasmic vs perijunctional) in diseased states. This article reviews the evidence regarding CLDN-1 in cancers either as a tumor promoter or suppressor from the literature and we also review the literature regarding the pattern of CLDN-1 distribution in different cancers, focusing on whether this localization is associated with tumor aggressiveness. Furthermore, we utilized expression data from The Cancer Genome Atlas (TCGA) to investigate the association between CLDN-1 expression and overall survival (OS) in different cancer types. We also used TCGA data to compare CLDN-1 expression in normal and tumor tissues. Additionally, a pathway interaction analysis was performed to investigate the interaction of CLDN-1 with other proteins and as a future therapeutic target.

Anticancer Activity of Camel Milk via Induction of Autophagic Death in Human Colorectal and Breast Cancer Cells

Background/ Objective: Camel milk is traditionally known for its human health benefits and believed to be a remedy for various human ailments including cancer. The study was aimed to evaluate the inhibitory effects of commercially available camel milk on cancer cells and its underlying mechanism(s). Materials and Methods: Two cell lines: colorectal cancer HCT 116 and breast cancer MCF-7 were cultured with different doses of camel milk. The effects of camel milk on cell death were determined by MTT assay, viability by trypan blue exclusion assay and migration by in vitro scratch assay. The mechanism was elucidated by western blotting and confocal microscopy was used to confirm autophagy. Results: Camel milk significantly reduced proliferation, viability as well as migration of both the cells. The accumulation of LC3-II protein along with reduction in expression of p62 and Atg 5-12, the autophagy proteins implied induction of autophagy. The (GFP)-LC3 puncta detected by confocal microscopy confirmed the autophagosome formation in response to camel milk treatment. Conclusion: Camel milk exerted antiproliferative effects on human colorectal HCT 116 and breast MCF-7 cancer cells by inducing autophagy.

Squamous Cell Carcinomas of the Head and Neck Cancer Response to Programmed Cell Death Protein-1 Targeting and Differential Expression of Immunological Markers: A Case Report.

Targeting the programmed cell death protein-1 (PD-1)/PD-1 ligand (PD-L1) pathway has been shown to enhance T cell-mediated antitumor immunity. Clinical responses are limited to subgroups of patients. The search for biomarkers of response is a strategy to predict response and outcome of PD-1/PD-L1 checkpoint intervention. The NY-ESO-1 cancer testis antigen has been considered as a biomarker in head and neck squamous cell carcinoma (HNSCC) patients and can induce both specific NY-ESO-1 antibody and T cells responses. Here, we correlated clinical responsiveness to anti-PD-1 (nivolumab) treatment with immunity to NY-ESO-1 in a patient with recurrent HNSCC. The patient was treated with second-line treatment of nivolumab and had a stable disease for over 7 months. His NY-ESO-1 antibody was found to be lower after the third (****p < 0.0001) and the fifth (****p < 0.0001) cycles of treatment compared to base line, and this was in line with the stability of the disease. The NY-ESO-1-specific T cells response of the patient was found to be increased after the third and the fifth (**p = 0.002) cycles of treatment but had a significant decline after progression (**p = 0.0028). The PD-1 expression by the patient's T cells was reduced 15-folds after nivolumab treatment and was uniquely restricted to the CD8+ T cells population. Several cytokines/chemokines involved in immune activation were upregulated after nivolumab treatment; two biomarkers were reduced at progression [interleukin (IL)-10: ****p < 0.0001 and CX3CL1: ****p < 0.0001]. On the other hand, some cytokines/chemokines contributing to immune inhibition were downregulated after nivolumab treatment; two biomarkers were increased at progression (IL-6: ****p < 0.0001 and IL-8: ****p < 0.0001). This data support the notion that the presence of anti-NY-ESO-1 integrated immunity and some cytokines/chemokines profile may potentially identify a response to PD-1 blockade in HNSCC patients.

Targeting of X-linked inhibitor of apoptosis protein and PI3-kinase/AKT signaling by embelin suppresses growth of leukemic cells.

The X-linked inhibitor of apoptosis (XIAP) is a viable molecular target for anticancer drugs that overcome apoptosis-resistance of malignant cells. XIAP is an inhibitor of apoptosis, mediating through its association with BIR3 domain of caspase 9. Embelin, a quinone derivative isolated from the Embelia ribes plant, has been shown to exhibit chemopreventive, anti-inflammatory, and apoptotic activities via inhibiting XIAP activity. In this study, we found that embelin causes a dose-dependent suppression of proliferation in leukemic cell lines K562 and U937. Embelin mediated inhibition of proliferation correlates with induction of apoptosis. Furthermore, embelin treatment causes loss of mitochondrial membrane potential and release of cytochrome c, resulting in subsequent activation of caspase-3 followed by polyadenosin-5'-diphosphate-ribose polymerase (PARP) cleavage. In addition, embelin treatment of leukemic cells results in a decrease of constitutive phosphorylations/activation level of AKT and downregulation of XIAP. Gene silencing of XIAP and AKT expression showed a link between XIAP expression and activated AKT in leukemic cells. Interestingly, targeting of XIAP and PI3-kinase/AKT signaling augmented inhibition of proliferation and induction of apoptosis in leukemic cells. Altogether these findings raise the possibility that embelin alone or in combination with inhibitors of PI3-kinase/AKT pathway may have therapeutic usage in leukemia and possibly other malignancies with up-regulated XIAP pathway.

Multiple DNA Interactions Contribute to the Initiation of Telomerase Elongation.

Telomerase maintains telomere length and chromosome integrity by adding short tandem repeats of single-stranded DNA to the 3' ends, via reverse transcription of a defined template region of its RNA subunit. To further understand the telomerase elongation mechanism, we studied the primer utilization and extension activity of the telomerase from the budding yeast Naumovozyma castellii (Saccharomyces castellii), which displays a processive nucleotide and repeat addition polymerization. For the efficient initiation of canonical elongation, telomerase required 4-nt primer 3' end complementarity to the template RNA. This DNA-RNA hybrid formation was highly important for the stabilization of an initiation-competent telomerase-DNA complex. Anchor site interactions with the DNA provided additional stabilization to the complex. Our studies indicate three additional separate interactions along the length of the DNA primer, each providing different and distinct contributions to the initiation event. A sequence-independent anchor site interaction acts immediately adjacent to the base-pairing 3' end, indicating a protein anchor site positioned very close to the catalytic site. Two additional anchor regions further 5' on the DNA provide sequence-specific contributions to the initiation of elongation. Remarkably, a non-telomeric sequence in the distal 25- to 32-nt region negatively influences the initiation of telomerase elongation, suggesting an anchor site with a regulatory role in the telomerase elongation decision.

Potential therapeutic targets of Guggulsterone in cancer.

Natural compounds capable of inducing apoptosis in cancer cells have always been of considerable interest as potential anti-cancer agents. Many such compounds are under screening and development with their potential evolution as a clinical drug benefiting many of the cancer patients. Guggulsterone (GS), a phytosterol isolated gum resin of the tree Commiphora mukul has been widely used in Indian traditional medicine as a remedy for various diseses. GS has been shown to possess cancer chemopreventive and therapeutic potential as established by in vitro and in vivo studies. GS has been shown to target constitutively activated survival pathways such as PI3-kinase/AKT, JAK/STAT, and NFκB signaling pathways that are involved in the regulation of growth and inflammatory responses via regulation of antiapoptotic and inflammatory genes. The current review focuses on the molecular targets of GS, cellular responses, and the animal model studies in various cancers. The mechanistic action of GS in different types of cancers also forms a part of this review. The perspective of translating this natural compound into a clinically approved drug with its pros and cons is also discussed.