Complete Tolerogenic Adjuvant Stimulates Regulatory T Cell Response to Immunization.

We have determined in mice the minimum composition required for forming a vaccine adjuvant that stimulates a regulatory T (Treg) cell response to immunization, and we named the adjuvant "complete tolerogenic adjuvant." This new kind of adjuvant may let us use the well-proven "Ag with adjuvant" form of immunization for inducing Treg cell-mediated Ag-specific immunosuppression. The minimum composition consists of dexamethasone, rapamycin, and monophosphoryl lipid A at a mass ratio of 8:20:3. By dissecting the respective role of each of these components during immunization, we have further shown why immunosuppressive and immunogenic agents are both needed for forming true adjuvants for Treg cells. This finding may guide the design of additional, and potentially more potent, complete tolerogenic adjuvants with which we may form numerous novel vaccines for treating immune diseases.

Neferine Targets the Oncogenic Characteristics of Androgen-Dependent Prostate Cancer Cells via Inducing Reactive Oxygen Species.

Castration resistance poses a significant challenge in the management of advanced prostate cancer (PCa), with androgen deprivation therapy (ADT) or chemotherapy being the primary treatment options. However, these approaches often lead to significant side effects and the development of therapeutic resistance. Therefore, it is crucial to explore novel treatment options that can efficiently target PCa, improve patient survival, and enhance their quality of life. Neferine (Nef), a bioactive compound derived from plants, has emerged as a promising candidate for cancer treatment due to its ability to induce apoptosis, autophagy, and cell cycle arrest. In this study, we investigated the potential anticancer effects of Nef in androgen receptor (AR)-positive LNCaP and VCaP cells, representative models of androgen-dependent PCa. Our findings demonstrate that Nef effectively inhibits cell growth, proliferation, and the tumorigenic potential of androgen-dependent PCa cells. Furthermore, Nef treatment resulted in the excessive production of reactive oxygen species (ROS), leading to the activation of key markers of autophagy and apoptosis. These results suggest that Nef has the potential to target the oncogenic characteristics of androgen-dependent PCa cells by exploiting the potency of ROS and inducing autophagy and apoptosis in AR-positive PCa cells. These findings shed light on the therapeutic potential of Nef as a novel treatment option with reduced side effects for androgen-dependent prostate cancer. Further investigations are warranted to assess its efficacy and safety in preclinical and clinical settings.

Localization and RNA Interference-Driven Inhibition of a Brugia malayi-Encoded Interleukin-5 Receptor Binding Protein.

A molecule we termed Brugia malayi IL-5 receptor (IL-5R) binding protein (BmIL5Rbp; also known as Bm8757) was identified from B. malayi filarial worms and found to inhibit human interleukin-5 (IL-5) binding to its human receptor competitively. After the expression and purification of a recombinant BmIL5Rbp and generation of BmIL5Rbp-specific rabbit antibody, we localized the molecule on B. malayi worms through immunohistochemistry and immunoelectron microscopy. RNA interference (RNAi) was used to inhibit BmIL5Rbp mRNA and protein production. BmIL5Rbp was shown to localize to the cuticle of Brugia malayi and to be released in its excretory/secretory products. RNAi inhibited BmIL5Rbp mRNA production by 33%, reduced the surface protein expression by ~50%, and suppressed the release of BmIL5Rbp in the excretory/secretory products. RNAi has been used successfully to knock down the mRNA and protein expression of BmIL5Rbp in the early larval stages of B. malayi and provided a proof of principle for the local inhibition of the human IL-5R. These findings provide evidence that a parasite-encoded IL-5R antagonist may locally inhibit a vital host innate immune activation of IL-5 on eosinophils.

Oncopreventive and oncotherapeutic potential of licorice triterpenoid compound glycyrrhizin and its derivatives: Molecular insights.

Licorice (Glycyrrhiza glabra) is a well-known natural herb used to treat different ailments since ancient times. Glycyrrhizin (GL), which is the primary triterpenoid compound of licorice extract, has been known to have broad-spectrum pharmacological effects. GL is cleaved into glucuronide and the aglycone, glycyrrhetinic acid (GA), which exists in two stereoisomeric forms: 18α- and 18ß-GA. It is well documented that GL and GA have great potential as anti-inflammatory, anticancer, antiviral, anti-diabetic, antioxidant, and hepatoprotective agents. Studies undertaken during the coronavirus disease 2019 pandemic suggest that GL is effective at inhibiting the viral replication of severe acute respiratory syndrome coronavirus 2. The anticancer effects of GL and GA involve modulating various signaling pathways, such as the phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B pathway, the mitogen-activated protein kinase, and the mammalian target of rapamycin/signal transducer and activator of transcription 3, which are mainly involved in regulating cancer cell death, oxidative stress, and inflammation. The potential of GL and GA in preventing cancer development and suppressing the growth and invasion of different cancer types has been reviewed in this paper. This review also provides molecular insights on the mechanism of action for the oncopreventive and oncotherapeutic effects of GL and its derivative, GA, which could help develop more specific forms of these agents for clinical use.

HMGB1-Neutralizing IgM Antibody Is a Normal Component of Blood Plasma.

Extracellular high-mobility group box 1 (HMGB1) is a prototypic damage-associated molecular pattern. Although a homeostatic level of extracellular HMGB1 may be beneficial for immune defense, tissue repair, and tissue regeneration, excessive HMGB1 is linked to inflammatory diseases. This prompts an intriguing question: how does a healthy body control the level of extracellular HMGB1? In this study, in the plasma of both healthy humans and healthy mice, we have identified an anti-HMGB1 IgM autoantibody that neutralizes extracellular HMGB1 via binding specifically to a 100% conserved epitope, namely HMW4 (HMGB198-112). In mice, this anti-HMW4 IgM is produced by peritoneal B-1 cells, and concomitant triggering of their BCR and TLR4 by extracellular HMGB1 stimulates the production of anti-HMW4 IgM. The ability of extracellular HMGB1 to induce its own neutralizing Ab suggests a feedback loop limiting the level of this damage-associated molecular pattern in a healthy body.

Can diallyl trisulfide, a dietary garlic-derived compound, activate ferroptosis to overcome therapy resistance in prostate cancer?

BACKGROUND: Therapy resistance is the underlying reason for poor outcome in prostate cancer (PCa) patients. Diallyl trisulfide (DATS) is an organosulfur compound present in garlic. DATS has been shown to target PCa cells by induction of apoptosis, increase in the production of reactive oxygen species, degradation of ferritin protein and increase in the labile iron (Fe) pool. AIM: We hypothesize that DATS could induce ferroptosis, an Fe-dependent, unique non-apoptotic form of regulated cell death to eliminate therapy resistance encountered by PCa patients. METHODS: In vitro and in vivo studies should be performed to test the hypothesis. RESULTS: As per the hypothesis, DATS would eliminate apoptotic resistance via inducing ferroptosis. CONCLUSION: Since apoptosis resistance has been reported to be the underlying mechanism of therapy resistance in PCa, DATS could be used to effectively target PCa cells by overcoming apoptosis resistance and inducing ferroptosis-mediated cell death of PCa cells.

Eprinomectin, a novel semi-synthetic macrocylic lactone is cytotoxic to PC3 metastatic prostate cancer cells via inducing apoptosis.

Prostate Cancer (PCa) is the second most common cancer among men in United States after skin cancer. Conventional chemotherapeutic drugs available for PCa treatment are limited due to toxicity and resistance issues. Therefore, there is an urgent need to develop more effective treatment for advanced PCa. In this current study, we focused on evaluating the anti-cancer efficacy of Eprinomectin (EP), a novel avermectin analog against PC3 metastatic PCa cells. EP displayed robust inhibition of cell viability of PC3 cells in addition to suppressing the colony formation and wound healing capabilities. Our study showed that EP targets PC3 cells via inducing ROS and apoptosis activation. EP treatment enforces cell cycle arrest at G0/G1 phase via targeting cyclin-dependent kinase 4 (CDK4) and subsequent induction of apoptosis in PC3 cells. At the molecular level, EP effectively inhibited the expression of various cancer stem cell markers such as ALDH1, Sox-2, Nanog, Oct3/4 and CD44. Interestingly, EP also inhibited the activity of alkaline phosphatase, a maker of pluripotent stem cells. Of note, EP treatment resulted in the translocation of ß-catenin from the nucleus to the cytoplasm indicating that EP antagonizes Wnt/ß-catenin signaling pathway. Western blotting analysis revealed that EP downregulated the expression of key cell cycle markers such as cyclin D1, cyclin D3, CDK4, and c-Myc. In addition, EP inhibited the anti-apoptotic markers such as Mcl-1, XIAP, c-IAP1 and survivin in PC3 cells. On the other hand, EP treatment resulted in the activation of pH2A.X, Bad, caspase-9, caspase-3 and cleavage of PARP1. Taken together, our data suggests that EP is a potential agent to treat advanced PCa cells via modulating apoptosis signaling.

Quantitative imaging of the receptor for advanced glycation end-products in prostate cancer.

PURPOSE: Current screening and monitoring of prostate cancer (PCa) is insufficient, producing inaccurate diagnoses. Presence of the receptor for advanced glycation end-products (RAGE) is associated with signature characteristics of PCa development such as cell proliferation, anchorage-independent growth, angiogenesis, migration, invasion, and poor patient survival. Therefore, we developed a preclinical multimodal imaging strategy targeted at RAGE to diagnose and monitor PCa. METHODS: In this work, RAGE-targeted multimodal nanoparticles (64Cu-Cy5-G4-CML) were synthesized and rendered functional for nuclear and optical imaging using previously established methods. The probe's binding affinity and targeting specificity was assessed in androgen-dependent (LNCaP) and androgen-independent (DU145) prostate cancer cells using flow cytometry and confocal microscopy. In vivo PET-CT imaging was used to evaluate RAGE levels in DU145 and LNCaP xenograft models in mice. Then, tumors were excised post-imaging for histological staining and autoradiography to further assess RAGE levels and targeting efficiency of the tracer. Finally, RAGE levels from human PCa samples of varying Gleason Scores were evaluated using Western blot and immunohistochemical staining. RESULTS: PCa cell culture studies confirmed adequate RAGE-targeting with 64Cu-Cy5-G4-CML with KD between 360 and 540 nM as measured by flow cytometry. In vivo PET-CT images of PCa xenografts revealed favorable kinetics, rapid blood clearance, and a non-homogenous, enhanced uptake in tumors, which varied based on cell type and tumor size with mean uptake between 0.5 and 1.4%ID/g. RAGE quantification of human samples confirmed increased RAGE uptake corresponding to increased Gleason scoring. CONCLUSIONS: Our study has shown that RAGE-targeted cancer imaging is feasible and could significantly impact PCa management.

Neferine, an alkaloid from lotus seed embryo targets HeLa and SiHa cervical cancer cells via pro-oxidant anticancer mechanism.

Apoptosis and autophagy are important processes that control cellular homeostasis and have been highlighted as promising targets for novel anticancer drugs. This study aims to investigate the inhibitory effects and mechanisms of Neferine (Nef), an alkaloid from the lotus seed embryos of Nelumbo nucifera (N. nucifera), as a dual inducer of apoptosis and autophagy through the reactive oxygen species (ROS) activation in cervical cancer cells. Nef and N. nucifera extract suppressed the cell viability of HeLa and SiHa cells in a dose-dependent manner. Importantly, Nef showed minimal toxicity to normal cells. Furthermore, Nef inhibited anchorage-independent growth, colony formation and migration ability of cervical cancer cells. Nef induces mitochondrial apoptosis by increasing pro-apoptotic protein bax, cytochrome-c, cleaved caspase-3 and caspase-9, poly-ADP ribose polymerase (PARP) cleavage, DNA damage (pH2 AX) while downregulating Bcl-2, procaspase-3 and procaspase-9, and TCTP. Of note, apoptotic effect by Nef was significantly attenuated in the presence of N-acetylcysteine (NAC), suggesting pro-oxidant activity of this compound. Nef also promoted autophagy induction through increasing beclin-1, atg-4, atg-5 and atg-12, LC-3 activation, and P 62/SQSTM1 as determined by western blot analysis. Collectively, these results demonstrate that Nef is a potent anticancer compound against cervical cancer cells through inducing apoptosis and autophagic pathway involving ROS.

Metalloporphyrin Pd(T4) Exhibits Oncolytic Activity and Cumulative Effects with 5-ALA Photodynamic Treatment against C918 Cells.

Photodynamic therapy is a non-invasive method where light activates a photosensitizer bound to cancer cells, generating reactive oxygen species and resulting in cell death. This study assessed the oncolytic potential of photodynamic therapy, comparing European Medicines Agency and United States Food and Drug Administration-approved 5-aminolevulinic acid (5-ALA) to a metalloporphyrin, Pd(T4), against a highly invasive uveal melanoma cell line (C918) in two- and three-dimensional models in vitro. Epithelial monolayer studies displayed strong oncolytic effects (>70%) when utilizing Pd(T4) at a fraction of the concentration, and reduced pre-illumination time compared to 5-ALA post-405 nm irradiance. When analyzed at sub-optimal concentrations, application of Pd(T4) and 5-ALA with 405 nm displayed cumulative effects. Lethality from Pd(T4)-photodynamic therapy was maintained within a three-dimensional model, including the more resilient vasculogenic mimicry-forming cells, though at lower rates. At high concentrations, modality of cell death exhibited necrosis partially dependent on reactive oxygen species. However, sub-optimal concentrations of photosensitizer exhibited an apoptotic protein expression profile characterized by increased Bax/Bcl-2 ratio and endoplasmic stress-related proteins, along with downregulation of apoptotic inhibitors CIAP-1 and -2. Together, our results indicate Pd(T4) as a strong photosensitizer alone and in combination with 5-ALA against C918 cells.

Cutting edge: Dexamethasone potentiates the responses of both regulatory T cells and B-1 cells to antigen immunization in the ApoE(-/-) mouse model of atherosclerosis.

The immunosuppressant dexamethasone was shown to preferentially deplete CD4+ effector T cells while sparing regulatory T cells (Tregs) in vivo. In the current study, we show that it also preferentially depletes B-2 cells while sparing B-1 cells. In the ApoE(-/-) mouse model of atherosclerosis, in which both Tregs and B-1 cells are thought to play an atheroprotective role, we show that HSP60-targeted immunization in the presence of dexamethasone raises Ag-reactive Tregs and B-1 cells concomitantly and reduces the severity of atherosclerosis. These results indicate that dexamethasone is an adjuvant that potentiates both the Treg and B-1 responses to immunogens. This study shows that B-1 cells with a specificity for a disease-relevant Ag can be raised in vivo by immunization.

Star-shaped tetraspermine enhances cellular uptake and cytotoxicity of T-oligo in prostate cancer cells.

PURPOSE: An oligonucleotide termed 'T-oligo' having sequence homology with telomere overhang has shown cytotoxicity in multiple cancers. We have demonstrated that T-oligo can induce apoptosis in androgen independent prostate cancer cell line DU-145. In this report, we evaluate the use of star-shaped tetraspermine (SSTS) for delivery of T-oligo. METHODS: SSTS was synthesized from spermine and its intrinsic cytotoxicity towards DU-145 cells was compared with spermine and branched polyethyleneimine (bPEI). Atomistic molecular dynamic (MD) simulations were conducted to understand binding and complexation of spermine and SSTS with T-oligo. Complexation was also determined using gel electrophoresis and SYBR gold assay. Complexes were characterized for size, cellular uptake and antiproliferative effect. RESULTS: SSTS exhibited significantly lower toxicity than spermine and bPEI. Its affinity towards T-oligo was significantly higher than spermine as determined by experimental studies and confirmed by MD simulations and it formed stable complexes (TONPs) with T-oligo. TONPs facilitated cellular uptake and nuclear accumulation of T-oligo and their cytotoxic potential was observed at concentration several folds lower than that required for T-oligo alone. CONCLUSION: SSTS significantly enhanced therapeutic benefits associated with the use of T-oligo and can be developed as a delivery vehicle for its in-vivo therapeutic applications.

Dexamethasone promotes tolerance in vivo by enriching CD11clo CD40lo tolerogenic macrophages.

We previously showed that antigen immunization in the presence of the immunosuppressant dexamethasone (a strategy we termed "suppressed immunization") could tolerize established recall responses of T cells. However, the mechanism by which dexamethasone acts as a tolerogenic adjuvant has remained unclear. In the present study, we show that dexamethasone enriches CD11c(lo) CD40(lo) macrophages in a dose-dependent manner in the spleen and peripheral lymph nodes of mice by depleting all other CD11c(+) CD40(+) cells including dendritic cells. The enriched macrophages display a distinct MHC class II (MHC II)(lo) CD86(hi) phenotype. Upon activation by antigen in vivo, CD11c(lo) CD40(lo) macrophages upregulate IL-10, a classic marker for tolerogenic antigen-presenting cells, and elicit a serum IL-10 response. When presenting antigen in vivo, these cells do not elicit recall responses from memory T cells, but rather stimulate the expansion of antigen-specific regulatory T cells. Moreover, the depletion of CD11c(lo) CD40(lo) macrophages during suppressed immunization diminishes the tolerogenic efficacy of the treatment. These results indicate that dexamethasone acts as a tolerogenic adjuvant partly by enriching the CD11c(lo) CD40(lo) tolerogenic macrophages.

MALAT-1 Is a Key Regulator of Epithelial-Mesenchymal Transition in Cancer: A Potential Therapeutic Target for Metastasis.

Metastasis-associated lung adenocarcinoma transcript-1 (MALAT-1) is a long intergenic non-coding RNA (lncRNA) located on chr11q13. It is overexpressed in several cancers and controls gene expression through chromatin modification, transcriptional regulation, and post-transcriptional regulation. Importantly, MALAT-1 stimulates cell proliferation, migration, and metastasis and serves a vital role in driving the epithelial-to-mesenchymal transition (EMT), subsequently acquiring cancer stem cell-like properties and developing drug resistance. MALAT-1 modulates EMT by interacting with various intracellular signaling pathways, notably the phosphoinositide 3-kinase (PI3K)/Akt and Wnt/ß-catenin pathways. It also behaves like a sponge for microRNAs, preventing their interaction with target genes and promoting EMT. In addition, we have used bioinformatics online tools to highlight the disparities in the expression of MALAT-1 between normal and cancer samples using data from The Cancer Genome Atlas (TCGA). Furthermore, the intricate interplay of MALAT-1 with several essential targets of cancer progression and metastasis renders it a good candidate for therapeutic interventions. Several innovative approaches have been exploited to target MALAT-1, such as short hairpin RNAs (shRNAs), antisense oligonucleotides (ASOs), and natural products. This review emphasizes the interplay between MALAT-1 and EMT in modulating cancer metastasis, stemness, and chemoresistance in different cancers.

Identification and characterization of a novel nematode pan allergen (NPA) from Wuchereria bancrofti and their potential role in human filarial tropical pulmonary eosinophilia (TPE).

BACKGROUND: Tropical pulmonary eosinophilia (TPE) is a chronic respiratory syndrome associated with Lymphatic Filariasis (LF), a tropical parasitic infection of the human, transmitted by mosquitoes. The larval form of LF (microfilariae) are trapped in the lungs of TPE subjects have a major role in initiating the TPE syndrome. To date, there are no reports on the potential allergen that is responsible for generating parasite-specific IgE in TPE. METHODOLOGY/PRINCIPAL FINDINGS: In this project, we screened a cDNA expression library of the microfilarial stages of Wuchereria bancrofti with monoclonal IgE antibodies prepared from subjects with clinical filarial infections. Our studies identified a novel molecule that showed significant sequence similarity to an allergen. A blast analysis showed the presence of similar proteins in a number of nematodes parasites. Thus, we named this molecule as Nematode Pan Allergen (NPA). Subsequent functional analysis showed that NPA is a potent allergen that can cause release of histamine from mast cells, induce secretion of proinflammatory cytokines from alveolar macrophages and promote accumulation of eosinophils in the tissue, all of which occur in TPE lungs. CONCLUSIONS/SIGNIFICANCE: Based on our results, we conclude that the NPA protein secreted by the microfilariae of W. bancrofti may play a significant role in the pathology of TPE syndrome in LF infected individuals. Further studies on this molecule can help design an approach to neutralize the NPA in an attempt to reduce the pathology associated with TPE in LF infected subjects.

The dynamic face of cadmium-induced Carcinogenesis: Mechanisms, emerging trends, and future directions.

Cadmium (Cd) is a malleable element with odorless, tasteless characteristics that occurs naturally in the earth's crust, underground water, and soil. The most common reasons for the anthropological release of Cd to the environment include industrial metal mining, smelting, battery manufacturing, fertilizer production, and cigarette smoking. Cadmium-containing products may enter the environment as soluble salts, vapor, or particle forms that accumulate in food, soil, water, and air. Several epidemiological studies have highlighted the association between Cd exposure and adverse health outcomes, especially renal toxicity, and the impact of Cd exposure on the development and progression of carcinogenesis. Also highlighted is the evidence for early-life and even maternal exposure to Cd leading to devastating health outcomes, especially the risk of cancer development in adulthood. Several mechanisms have been proposed to explain how Cd mediates carcinogenic transformation, including epigenetic alteration, DNA methylation, histone posttranslational modification, dysregulated non-coding RNA, DNA damage in the form of DNA mutation, strand breaks, and chromosomal abnormalities with double-strand break representing the most common DNA form of damage. Cd induces an indirect genotoxic effect by reducing p53's DNA binding activity, eventually impairing DNA repair, inducing downregulation in the expression of DNA repair genes, which might result in carcinogenic transformation, enhancing lipid peroxidation or evasion of antioxidant interference such as catalase, superoxide dismutase, and glutathione. Moreover, Cd mediates apoptosis evasion, autophagy activation, and survival mechanisms. In this review, we decipher the role of Cd mediating carcinogenic transformation in different models and highlight the interaction between various mechanisms. We also discuss diagnostic markers, therapeutic interventions, and future perspectives.

Palmitate-derivatized human IL-2: a potential anticancer immunotherapeutic of low systemic toxicity.

PURPOSE AND EXPERIMENTAL DESIGN: Recombinant human IL-2 (rhIL-2) is a potent cytokine and FDA-approved anticancer drug. However, its clinical use has been limited by severe toxicity, associated primarily with systemic administration with excess protein distributing freely throughout the body. We hypothesized that rhIL-2 in alternate forms permitting more restricted localization may exert stronger antitumor efficacy and less toxicity. Here, we have tested the utility of palmitate-derivatized rhIL-2. rhIL-2 was reacted with N-hydroxysuccinimide palmitate ester. The resultant lipidated rhIL-2 (pIL-2), when mixed with cells, could spontaneously transfer from solution to cell surfaces. Next, anticancer efficacy of pIL-2 was assessed in two modalities. For adoptive T cell therapy, antitumor cytotoxic T cells (CTLs) were protein transferred ("painted") with pIL-2 and injected into mice bearing lymphoma. For in situ therapy, pIL-2 was injected intratumorally into mice bearing melanoma. Tumor growth and IL-2-associated toxicity were determined. RESULTS: In the lymphoma model, painting of the antitumor CTLs with pIL-2 markedly increased their viability and titer. In the melanoma model, intratumoral injection of pIL-2, but not rhIL-2, increased the number of activated CD8(+) T cells (IFN-γ(+)) in the spleen, reduced lung metastasis and prolonged the survival of treated mice. Moreover, while repeated intratumoral injection of rhIL-2 at an excessively high dose (10 injections of 10,000 IU/mouse) caused marked vascular leakage syndrome, the same regimen using pIL-2 caused no detectable toxicity. CONCLUSIONS: Transferring spontaneously from solution to cell surfaces, pIL-2 may bypass the current limitations of rhIL-2 and, thus, serve as a more effective and tolerable anticancer drug.

Role of Chromatin and Epigenetic Dysregulation in Prostate Cancer: From Development to Progression and Therapeutic Response.

A multitude of epigenetic modifications and genetic mutations have been found to play pivotal roles in the development and progression of prostate cancer (PCa) [...].

Gene Expression and DNA Methylation as Prognostic Markers in Metastatic Castration-Resistant Prostate Cancer: Analysis of Circulating Tumor Cells and Paired Plasma-Derived Exosomes.

Prostate cancer (PCa) is the most prevalent cancer among men and is the second leading cause of cancer-related death in the United States [...].

Androgen Receptor Signaling in Prostate Cancer Genomic Subtypes.

Prostate cancer (PCa) constitutes a significant cause of mortality, with over 37,000 new deaths each year [...].