Search Results (248)

Prostate cancer continues to be the most common cause of cancer-related disease and mortality among men worldwide, especially in the advanced stages, notably metastatic castration-resistant prostate cancer (mCRPC), which poses significant treatment challenges. Docetaxel, a widely used chemotherapeutic agent, has long served as the standard treatment, offering survival benefits and mitigation. However, its clinical impact is frequently undermined by the development of chemoresistance, which is a formidable challenge that leads to treatment failure and disease progression. The mechanisms driving docetaxel resistance are diverse and complex, encompassing modifications in androgen receptor signaling, drug efflux transporters, epithelial-mesenchymal transition (EMT), microtubule alterations, apoptotic pathway deregulation, and tumor microenvironmental influences. Recent evidence suggests that extracellular RNAs influence drug responses, further complicating the resistance landscape. This review offers a broad discussion on the mechanisms of resistance and explores novel therapeutic approaches to address them. These include next-generation taxanes, targeted molecular inhibitors, immunotherapies, and combination regimens that can be designed to counteract specific resistance pathways. By broadening our understanding of docetaxel resistance, this review highlights potential strategies to improve therapeutic efficacy and the potential to enhance outcomes in patients with advanced treatment-resistant prostate cancer. Full article

Systemic lupus erythematosus (SLE) is characterized by autoimmune dysregulation, elevated autoantibody production, and persistent inflammation, predisposing patients to atherosclerosis (AS). Atherogenesis is dependent on lipid homeostasis and inflammatory processes, with the formation of lipid-laden, macrophage-derived foam cells (MDFC) essential for atherosclerotic lesion progression. Elevated cholesterol levels within lipid rafts trigger heightened pro-inflammatory responses in macrophages via Toll-like receptor 9 (TLR9). Artesunate (ART), an artemisinin derivative sourced from Artemisia annua, exhibits therapeutic potential in modulating inflammation and autoimmune conditions. Nonetheless, its impact and mechanisms in SLE-associated AS (SLE-AS) remain largely unexplored. Our investigation demonstrated that ART could effectively ameliorate lupus-like symptoms and atherosclerotic plaque development in SLE-AS mice. Moreover, ART enhanced cholesterol efflux from MDFC by upregulating ABCA1, ABCG1, and SR-B1 both in vivo and in vitro. Moreover, ART reduced cholesterol accumulation in bone marrow-derived macrophages (BMDMs), thereby diminishing TLR9 recruitment to lipid rafts. ART also suppressed TLR9 expression and its downstream effectors in the kidney and aorta of SLE-AS mice, attenuating the TLR9-mediated inflammatory cascade in CPG2395 (ODN2395)-stimulated macrophages. Through bioinformatics analysis and experimental validation, PPARγ was identified as a pivotal downstream mediator of ART in macrophages. Depleting PPARγ levels reduced the expression of ABCA1, ABCG1, and SR-B1 in macrophages, consequently impeding cholesterol efflux. In conclusion, these findings suggest that ART ameliorates SLE-AS by restoring cholesterol homeostasis through the PPARγ-ABCA1/ABCG1/SR-B1 pathway and suppressing lipid raft-driven TLR9/MyD88 inflammation. Full article

Drug resistance remains a critical barrier to effective treatment in several cancers, particularly triple-negative breast cancer (TNBC). Estrogen receptor α36 (ERα36), a variant of the estrogen receptor in ER-negative breast cancer cells, plays important roles in cancer cell proliferation. We investigated the role of ERα36 in regulating multidrug resistance protein 1 (MDR1) in MDA-MB-231 human breast cancer cells. The activation of ERα36 by BSA-conjugated estradiol (BSA-E2) increased cell viability under Adriamycin exposure, suggesting its involvement in promoting drug resistance. BSA-E2 treatment significantly reduced the intracellular rhodamine-123 levels by activating the MDR1 efflux function, which was linked to increased MDR1 transcription and protein expression. The mechanical ERα36-mediated BSA-E2-induced activation of EGFR and downstream signaling via c-Src led to an activation of the Akt/ERK pathways and transcription factors, NF-κB and CREB. Additionally, ERα36 is involved in activating Wnt/β-catenin pathways to induce MDR1 expression. The silencing of ERα36 inhibited the BSA-E2-induced phosphorylation of Akt and ERK, thereby reducing MDR1 expression via downregulation of NF-κB and CREB as well as Wnt/β-catenin signaling. These findings demonstrated that ERα36 promotes MDR1 expression through multiple non-genomic signaling cascades, including Akt/ERK-NF-κB/CREB and Wnt/β-catenin pathways, and highlight the role of ERα36 as a promising target to enhance chemotherapeutic efficacy in TNBC. Full article

Growth hormone (GH) signaling has been implicated in tumor progression and therapy resistance across multiple cancer types, yet its role in bladder cancer remains largely unexplored. In this study, we investigated the impact of GH and its receptor (GHR) on therapy resistance and disease progression in urothelial carcinoma (UC) through integrated transcriptomic and in vitro analyses. Transcriptomic profiling of The Cancer Genome Atlas bladder cancer cohort revealed that high tumoral GHR expression was associated with differential upregulation of genes involved in drug efflux, epithelial-to-mesenchymal transition (EMT), and extracellular matrix (ECM) remodeling. Notably, elevated GHR levels correlated with significantly reduced overall survival in patients with UC. In parallel, in vitro experiments demonstrated that GH promotes chemoresistance in UC cell lines via upregulation of ATP-binding cassette-containing (ABC) transporters and activation of EMT. GH also modulated ECM-remodeling-associated genes in a chemotherapy-dependent manner, including matrix metalloproteinases and tissue inhibitors of metalloproteinases. Importantly, these effects were abrogated by Pegvisomant, a GHR antagonist, indicating the functional relevance of GH/GHR signaling in the mediation of these phenotypes. Collectively, our findings support a mechanistic role for GH signaling in driving therapy resistance and tumor aggressiveness in bladder cancer and suggest GHR antagonism as a potential therapeutic strategy to improve treatment outcomes. Full article

Cholesterol stress profoundly modulates cellular processes, but its underlying mechanisms remain incompletely understood. To investigate cholesterol-responsive networks, we performed integrated transcriptome (RNA-seq) and metabolome (LC-MS) analyses on HeLa cells treated with cholesterol for 6 and 24 h. Through transcriptomic analysis of cholesterol-stressed HeLa cells, we identified stage-specific responses characterized by early-phase stress responses and late-phase immune-metabolic coordination. This revealed 1340 upregulated and 976 downregulated genes after a 6 h cholesterol treatment, including induction and suppression of genes involved in cholesterol efflux and sterol biosynthesis, respectively, transitioning to Nuclear Factor kappa-B (NF-κB) activation and Peroxisome Proliferator-Activated Receptor (PPAR) pathway modulation by 24 h. Co-expression network analysis prioritized functional modules intersecting with differentially expressed genes. We also performed untargeted metabolomics using cells treated with cholesterol for 6 h, which demonstrated extensive remodeling of lipid species. Interestingly, integrated transcriptomic and metabolic analysis uncovered GFPT1-driven Uridine Diphosphate-N-Acetylglucosamine (UDP-GlcNAc) accumulation and increased taurine levels. Validation experiments confirmed GFPT1 upregulation and ANGPTL4 downregulation through RT-qPCR and increased O-GlcNAcylation via Western blot. Importantly, clinical datasets further supported the correlations between GFPT1/ANGPTL4 expression and cholesterol levels in Non-Alcoholic Steatohepatitis (NASH) liver cancer patients. This work establishes a chronological paradigm of cholesterol sensing and identifies GFPT1 and ANGPTL4 as key regulators bridging glycosylation and lipid pathways, providing mechanistic insights into cholesterol-associated metabolic disorders. Full article

The blood–brain barrier (BBB) is a highly selective interface between the bloodstream and the brain that prevents systemically administered therapeutics from effectively reaching tumor cells. As tumors progress, this barrier undergoes structural and functional alterations, giving rise to the blood–tumor barrier (BTB)—a pathologically modified structure that, despite increased permeability, often exhibits heterogeneous and clinically insufficient drug transport. Although a new generation of therapies is promising, their therapeutic potential cannot be realized unless the challenges posed by these barriers are effectively addressed. Various pharmacological strategies were explored to enhance brain tumor drug delivery. These include receptor-mediated disruption, inhibition of efflux transporters, and the engineering of delivery platforms that leverage endogenous transport pathways—such as carrier-mediated, adsorptive-mediated, and receptor-mediated mechanisms—as well as cell-mediated drug delivery. This review synthesizes (1) the BBB and BTB’s structural characteristics; (2) the influence of the tumor microenvironment (TME) on drug delivery; (3) pharmacological strategies to enhance drug accumulation within brain tumors; (4) the integration of pharmacological methods with neurosurgical techniques to enhance drug delivery. As efforts to improve drug delivery across the BBB and BTB accelerate, this review aims to map the current landscape of pharmacological approaches for enhancing drug penetration into brain tumors. Full article

Familial hypercholesterolemia (FH) is a genetic disorder marked by significantly elevated levels of low-density lipoprotein cholesterol (LDL-C) since childhood, substantially increasing the risk of premature atherosclerosis and cardiovascular disease. While dysfunction of hepatic LDL-C receptors is the main underlying cause, the gastrointestinal tract plays a key role in cholesterol homeostasis and represents an important therapeutic target. Inhibition of intestinal cholesterol absorption has emerged as an effective strategy in the management of pediatric FH, particularly in patients for whom statins may not be the ideal first-line treatment. Ezetimibe, an inhibitor of the Niemann-Pick C1-like 1 (NPC1L1) protein, has been shown to reduce LDL-C levels in children with FH, with a greater efficacy observed when used in combination with statins. Bile acid sequestrants also enhance cholesterol excretion but are often limited by gastrointestinal side effects, while dietary interventions, such as phytosterol supplementation and fiber-enriched diets, provide additional benefits in lowering LDL-C and are generally well tolerated. Emerging therapies, including microbiota-targeted strategies and novel cholesterol absorption inhibitors, show promise for expanding future treatment options. This review explores the mechanisms of intestinal cholesterol absorption and their relevance to pediatric FH. We examine key pathways, including dietary cholesterol uptake through NPC1L1, bile acid reabsorption, and cholesterol efflux mediated by ATP-binding cassette transporters, while also discussing clinical and experimental evidence on pharmacological and dietary interventions that modulate these pathways. A deeper understanding of cholesterol metabolism, the emerging role of the gut microbiota, and innovative therapeutic agents can support the development of more effective and personalized approaches to the treatment of children with FH. Full article

Background/Objectives: Cefiderocol is a novel siderophore cephalosporin with potent in vitro activity against a broad spectrum of Gram-negative bacteria, including carbapenemase-producing Enterobacterales (CPE). However, the recent emergence of resistance in clinical settings raises important concerns regarding its long-term effectiveness. This study aims to investigate the genomic determinants associated with cefiderocol resistance in CPE isolates of human origin. Methods: Comparative genomic analyses were conducted between cefiderocol-susceptible and -resistant CPE isolates recovered from human clinical and epidemiological samples at a tertiary care hospital. Whole-genome sequencing, variant annotation, structural modelling, and pangenome analysis were performed to characterize resistance mechanisms. Results: A total of 59 isolates (29 resistant and 30 susceptible) were analyzed, predominantly comprising Klebsiella pneumoniae, Escherichia coli, and Enterobacter cloacae. The most frequent carbapenemase gene among the resistant isolates was bla_NDM, which was also present in a subset of susceptible strains. The resistant isolates exhibited a significantly higher burden of non-synonymous mutations in their siderophore receptor genes, notably within fecR, fecA, fiu, and cirA. Structural modelling predicted deleterious effects for mutations such as fecR:G104S and fecA:A190T. Additionally, porin loss and loop 3 insertions (e.g., GD/TD) in OmpK36, as well as OmpK35 truncations, were more frequent in the resistant isolates, particularly in high-risk clones such as ST395 and ST512. Genes associated with toxin–antitoxin systems (chpB2, pemI) and a hypothetical metalloprotease (group_2577) were uniquely found in the resistant group. Conclusions: Cefiderocol resistance in CPE appears to be multifactorial. NDM-type metallo-β-lactamases and missense mutations in siderophore uptake systems—especially in those encoded by fec, fhu, and cir operons—play a central role. These may be further potentiated by alterations in membrane permeability, such as porin disruption and efflux deregulation. The integration of genomic and structural approaches provides valuable insights into emerging resistance mechanisms and may support the development of diagnostic tools and therapeutic strategies. Full article

Syringin is a phenylpropanoid glycoside isolated from the bark of Syringa vulgaris. Phillygenin is a lignan obtained mainly from the fruits and flowers of Forsythia intermedia. Both compounds have shown potent anti-inflammatory and antioxidant properties. We investigated the potential role of syringin and phillygenin in preventing lipid deposition in macrophages. Syringin and phillygenin significantly (p < 0.001) reduced lipid deposition in macrophages in a dose-dependent manner. For syringin, the greatest reduction in CD36 receptor expression was found to be over 80% (50 μg/mL) compared to the cholesterol-stimulated control (p < 0.001). Phillygenin inhibited CD36 receptor expression by approximately 25% (50 μg/mL), compared to the stimulated control (p < 0.05). For syringin, the CD36 receptor regulation pathway was PPAR-γ dependent. Phillygenin showed a statistically significant (p < 0.001) increase in the expression of the ABCA1 transporter: 2.5-fold (10 μg/mL), 3-fold (20 μg/mL) and 4-fold (50 μg/mL) compared to the cholesterol-stimulated control. Syringin did not significantly increase ABCA1 expression. For phillygenin, the activation pathway of the ABCA1 transporter was HO-1dependent. Our study showed that syringin inhibits the cholesterol-induced differentiation of macrophages into foam cells. Moreover, phillygenin increased cholesterol efflux from macrophages. Therefore, syringin and phillygenin may be valuable agents in the prevention of early and late atherosclerosis. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, remains a major global health threat. The virus enters host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. Several small-molecule antiviral drugs, including molnupiravir, favipiravir, remdesivir, and nirmatrelvir have been shown to inhibit SARS-CoV-2 replication and are approved for treating SARS-CoV-2 infections. Nirmatrelvir inhibits the viral main protease (M^pro), a key enzyme for processing polyproteins in viral replication. In contrast, molnupiravir, favipiravir, and remdesivir are prodrugs that target RNA-dependent RNA polymerase (RdRp), which is crucial for genome replication and subgenomic RNA production. However, undergoing extensive metabolism profoundly impacts their therapeutic effects. Carboxylesterases (CES) are a family of enzymes that play an essential role in the metabolism of many drugs, especially prodrugs that require activation through hydrolysis. Molnupiravir is activated by carboxylesterase-2 (CES2), while remdesivir is hydrolytically activated by CES1 but inhibits CES2. Nirmatrelvir and remdesivir are oxidized by the same cytochrome P450 (CYP) enzyme. Additionally, various transporters are involved in the uptake or efflux of these drugs and/or their metabolites. It is well established that drug-metabolizing enzymes and transporters are differentially expressed depending on the cell type, and these genes exhibit significant polymorphisms. In this review, we examine how CES-related cellular and genetic factors influence the therapeutic activities of these widely used COVID-19 medications. This article highlights implications for improving product design, targeted inhibition, and personalized medicine by exploring genetic variations and their impact on drug metabolism and efficacy. Full article

Ruxolitinib, a clinically approved JAK1/2 inhibitor used in the treatment of hematologic malignancies and inflammatory conditions, has been shown to interfere with the function of cytotoxic T lymphocytes (CTLs). Previous studies supported the involvement of the multidrug resistance transporter P-glycoprotein (Pgp/ABCB1) in CTL biology; however, the nature of its regulation remains unclear. To address this, we investigated the impact of ruxolitinib on Pgp expression and function in human CD8⁺ T cells. We demonstrate that CD8⁺ T lymphocytes express Pgp dynamically at both the mRNA and protein levels across naïve, short-term, and long-term activation states. Ruxolitinib increased the calcein accumulation in human Pgp-overexpressing NIH-3T3 cells and in CTLs and directly modulated Pgp function by increasing its basal ATPase activity in a concentration-dependent manner (10–100 μM), similar to the effect of the known Pgp substrate/modulator verapamil. Although measurable ATPase stimulation and transport inhibition were observed at supratherapeutic concentrations of ruxolitinib, its Pgp-mediated efflux may also occur at therapeutically relevant concentrations. In contrast, at therapeutically relevant plasma concentrations (1–3 μM), ruxolitinib significantly stabilized the mRNA expression of Pgp during early T-cell receptor (TCR) activation and inhibited the TCR-induced upregulation of Pgp, CD8, and PD-1 surface markers, suggesting its interference with activation-associated differentiation. At these same concentrations, ruxolitinib also impaired CCL19-directed transmigration of CTLs across human umbilical vein endothelial cell (HUVEC) monolayers, indicating disruption of lymphoid homing cues. Collectively, these findings demonstrate that ruxolitinib modulates Pgp at both the transcriptional and functional levels, with distinct concentration dependence. The ability of ruxolitinib to alter CTL activation and migration at clinically relevant plasma concentrations highlights the need for careful evaluation of JAK inhibitor–mediated immunomodulation and its implications for vaccination, transplantation, and T cell-based immunotherapies. Full article

Atherosclerosis is a chronic condition marked by lipid accumulation, inflammation, and endothelial dysfunction, leading to narrowed arteries and an increased risk of heart attacks and strokes. Key proteins involved in this process include PCSK9, LOX-1, ROS, CD36, and ABCA1. PCSK9 degrades LDL receptors, raising blood LDL levels, while LOX-1 and CD36 promote the uptake of oxidized LDL by macrophages, enhancing foam cell formation. ABCA1, on the other hand, facilitates cholesterol efflux to HDL, reducing atherosclerosis risk. Red watermelon (Citrullus lanatus), rich in lycopene, citrulline, and vitamins A, C, and E, has antioxidant and cardioprotective properties. This study aimed to explore the effects of red watermelon extract on the expression of PCSK9, LOX-1, ROS, TNFα, CD36, and ABCA1 in a Wistar rat model of atherosclerosis. In a randomized control trial, male Wistar rats were induced with a high-fat diet (margarine) and treated with red watermelon extract for four weeks. The findings showed that red watermelon extract reduced the expression of PCSK9, LOX-1, CD36, ROS, and TNFα, leading to lower LDL levels, and inhibited foam cell formation. It also increased ABCA1 expression, thus promoting cholesterol efflux and higher HDL levels. Path analysis confirmed that the anti-atherogenic effect of C. lanatus was primarily mediated through the PCSK9-ABCA1-FC axis. This suggests that red watermelon may serve as a natural agent for atherosclerosis prevention by regulating lipid metabolism pathways. Full article

Despite broad anti-cancer efficacy as Toll-Like Receptor (TLR) 7/8 agonists, imidazoquinolines remain limited in use via systemic administration or in situ vaccination therapies due to inflammatory toxicity. One approach to address this challenge involves better targeting the action of imidazoquinolines by caging them as glycoconjugate prodrugs. Within cancer cells, imidazoquinoline glycoconjugates are activated by hydrolases prior to efflux by ABC transport proteins, where they then elicit tumoricidal effects from the assistance of bystander immune cells, such as tumor-infiltrating lymphocytes and associated macrophages, in local proximity. While this concept of Bystander-Assisted ImmunoTherapy (BAIT) has been established at a molecular level in vitro, tolerability or efficacy of BAIT has not been reported in vivo. Here, we evaluate the MTD and tumor growth delay efficacy of a lead BAIT prodrug (BAIT628) in a male C57BL/6 mouse TRAMP-C2 prostate cancer model to further establish this methodology. Overall, we find that systemic BAIT628 is well tolerated at over 5-fold the dose-limiting inflammatory toxicity of the parent imidazoquinoline (up to 5 mg/mouse/day I.P. for 10 days). Analyzing serum cytokines reveals that IL-10 production, elicited by the mannoside caging group, likely contributes to the enhanced MTD. Using BAIT628 as an in situ vaccination immunotherapy (seven times over 3 weeks) resulted in significant tumor growth delay and increased survival, both alone and in combination with a murinized α-PD-L1 checkpoint blockade. The tumor histology of tumor-infiltrating immune cell subsets (CD4⁺, CD8⁺, CD11c⁺) reveals significant increases in CD11c⁺ populations, consistent with TLR7/8 agonism. Overall, BAIT628 is well tolerated and exhibits significant efficacy in the TRAMP-C2 model. These results demonstrate how the BAIT approach can optimize imidazoquinolines for in vivo tolerability and subsequent efficacy as cancer immunotherapeutics. Full article

Chromobacterium spp. use a density-dependent cell-to-cell communication mechanism (quorum sensing, QS) to control various traits, including the pigment violacein biosynthesis. Recently, one of the type strains of this genus, previously deposited in the American Type Culture Collection under accession number C. violaceum 31532, was reclassified as C. subtsugae, making the QS data obtained for the first species irrelevant to the second. The goal of this study is to conduct transcriptomic and genomic analyses of the C. subtsugae ATCC 31532 (formerly C. violaceum ATCC 31532) strain to identify density-dependent regulated genes and the mechanisms of their QS control. Whole transcriptome dataset analysis comparing QS-negative mid-log phase and QS-positive early stationary phase samples revealed 35 down-regulated and 261 up-regulated genes, including 44 genes that increased transcription activity the most (log2 (fold change) > 4.0). In addition to the violacein biosynthesis, QS-controlled traits in C. subtsugae ATCC 31532 included the following: (i) cdeAB-oprM efflux pump; (ii) RND efflux transporter; (iii) chuPRSTUV iron acquisition system; (iv) polyamine transport system; (v) carbohydrate (semialdehydes) metabolic pathways; (vi) SAM/SPASM maturase system XYE (predicted); (vii) prophage proteins; and (viii) fucose-binding lectin II. Subsequent screening of the promoter regions of the up-regulated genes and operons in most cases showed the presence of CsuR AHL-receptor/transcriptional regulator binding sites with 56.25–68.75% similarity to the ideal 16-base-pair palindrome 5′-CTGTCCGATAGGACAG-3′ sequence, supporting the concept of QS control in C. subtsugae ATCC 31532 by the csuI-csuR gene pair. Notably, several transcriptional regulators (MarR, TetR/AcrR, HU family DNA-binding protein, helix-turn-helix domain-containing protein) were found to be under QS control. Based on these data, a hierarchical QS regulatory network in C. subtsugae ATCC 31532 was hypothesized that provides direct control of the target genes via a canonical autoinduction mechanism and further dissemination of the effect via the activity of QS-controlled transcriptional regulators. Full article

Epstein–Barr virus (EBV) constitutes a very common pathogen and a well-characterized carcinogen. EBV has the ability to establish a chronic latent infection, during which only a subset of the viral genes is expressed. EBV is implicated in multiple malignancies, including Hodgkin’s lymphoma (HL). HL mainly affects adolescents and young adults and has an overall favorable prognosis. However, relapsed or refractory disease still poses a therapeutic challenge. EBV does not only induce malignant transformation but also hinders the detection and clearance of the neoplastic cells by the immune system. The proteins and non-coding RNAs expressed in latency IIa, which is associated with HL, employ a variety of mechanisms to target different steps of innate and adaptive immunity, to take advantage of the immunosuppressant effect of immune checkpoints, and to shape the microenvironment to support the survival and proliferation of malignant cells. They suppress the expression or promote the degradation of pattern-recognition receptors, interfere with type I interferon and proinflammatory cytokine mediated signaling, and hinder the effector function of natural killer cells. The processing and presentation of peptides to CD4 and CD8 T cells are also hampered. EBV induces the expression of immune checkpoints, the secretion of immunosuppressive cytokines, and the efflux of regulatory T cells in the tumor microenvironment. The current review provides a comprehensive overview of the molecular mechanisms underlying this complex interplay between EBV and the immune system in HL with focus on clinical data from the pediatric population, which is the key for developing novel, effective therapeutic interventions. Full article