Search Results (2,635)

Background/Objectives: DNA-damaging agents can contribute to genetic instability, and such agents are often used in cancer chemotherapeutic regimens due to their cytotoxicity. Thus, understanding the mechanisms involved in DNA damage processing can not only enhance our knowledge of basic DNA repair mechanisms but may also be used to develop improved chemotherapeutic strategies to treat cancer. The high-mobility group box protein 1 (HMGB1) is a known nucleotide excision repair (NER) cofactor, and its family member HMGB3 has been implicated in chemoresistance in ovarian cancer. Here, we aim to understand the potential role(s) of HMGB3 in processing DNA damage. Methods: A potential role in NER was investigated using HMGB3 knockout human cell lines in response to UV damage. Subsequently, potential roles in DNA interstrand crosslink (ICL) and DNA double-strand break (DSB) repair were investigated using mutagenesis assays, metaphase spreads, foci formation, a variety of DNA repair assays, and TagSeq analyses in human cells. Results: Interestingly, unlike HMGB1, HMGB3 does not appear to play a role in NER. We found evidence to suggest that HMGB3 is involved in the processing of both DSBs and ICLs in human cells. Conclusions: These novel results elucidate a role for HMGB3 in DNA damage repair and, surprisingly, also indicate a distinct role of HMGB3 in DNA damage repair from that of HMGB1. These findings advance our understanding of the role of HMGB3 in chemotherapeutic drug resistance and as a target for new chemotherapeutic strategies in the treatment of cancer. Full article

Heparanase is the only human enzyme responsible for heparan sulfate (HS) breakdown, an activity that remodels the extracellular matrix (ECM) and strongly drives cancer metastasis and angiogenesis. Compelling evidence implies that heparanase promotes essentially all aspects of the tumorigenic process, namely, tumor initiation, vascularization, growth, metastasis, and chemoresistance. A key mechanism by which heparanase accelerates cancer progression is by enabling the release and bioavailability of HS-bound growth factors, chemokines, and cytokines, residing in the tumor microenvironment and supporting tumor growth and metastasis. The currently available heparanase inhibitors are mostly HS/heparin-like compounds that lack specificity and exert multiple off-target side effects. To date, only four such compounds have progressed to clinical trials, and none have been approved for clinical use. We have generated and characterized an anti-heparanase monoclonal antibody (A54 mAb) that specifically inhibits heparanase enzymatic activity (ECM degradation assay) and cellular uptake. Importantly, A54 mAb attenuates xenograft tumor growth and metastasis (myeloma, glioma, pancreatic, and breast carcinomas) primarily when administered (syngeneic or immunocompromised mice) in combination with conventional anti-cancer drugs. Co-crystallization of the A54 Fab fragment and the heparanase enzyme revealed that the interaction between the two proteins takes place adjacent to the enzyme HS/heparin binding domain II (HBDII; Pro271-Ala276), likely hindering heparanase from interacting with HS substrates via steric occlusion of the active site cleft. Collectively, we have generated and characterized a novel mAb that specifically neutralizes heparanase enzymatic activity and attenuates its pro-tumorigenic effects in preclinical models, paving the way for its clinical examination against cancer, inflammation, and other diseases. Full article

Multiple myeloma (MM) is a neoplasm of plasma cells. Despite the development of increasingly advanced treatments, multiple myeloma remains challenging to cure completely. Consequently, the underlying mechanisms of this neoplasm are being investigated to identify new therapeutic targets and understand chemoresistance. A particular focus has been placed on the MM bone marrow microenvironment, with chemokines being one of its key components. This review examines the role of chemokines that activate the CXCR2 and CXCR3 receptors in both monoclonal gammopathy of undetermined significance (MGUS) and MM, highlighting all CXC chemokines and their receptors, including CXCL1, CXCL8/IL-8, CXCL9, CXCL10, and platelet factor 4. We focus on the direct effects of selected CXC chemokines on MM cells, specifically their roles in proliferation, migration, interaction with bone marrow cells, the formation of extramedullary disease, and chemoresistance. Additionally, we explore the impact of these chemokines on the MM bone marrow microenvironment, particularly in relation to mesenchymal stromal cells, myeloid-derived suppressor cells, osteoclasts, M2 macrophages, and natural killer cells, as well as processes such as bone destruction and angiogenesis. Finally, we discuss the potential use of drugs targeting the two chemokine axes described, with a focus on inhibitors and adoptive cell therapy. Full article

Oral tongue squamous cell carcinoma (OTSCC) is a common type of oral cancer influenced by genetic, epigenetic, and environmental factors like exposure to environmental toxins. These environmental toxins can decrease the effectiveness of established chemotherapy drugs, such as Irinotecan, used in OTSCC treatment. Bioinformatics, drug discovery, and machine learning techniques were employed to investigate the impact of Irinotecan on OTSCC patients by identifying targets and signaling pathways, including those that positively influence protein phosphorylation, protein tyrosine kinase activity, the PI3K-Akt (Phosphatidylinositol 3-kinase- Protein Kinase B) signaling system, cancer pathways, focal adhesion, and the HIF-1 (Hypoxia-Inducible Factor 1) signaling pathway. Later, the protein–protein interactions (PPIs) network, along with twelve cytoHubba approaches to finding the most interacting molecule, was employed to find the important proteins BCL2 and EGFR. Drugs related to BCL2 and EGFR were extracted from the DGIdb database for further molecular docking. Molecular docking revealed that Docetaxel, Paclitaxel, Imatinib, Ponatinib, Ibrutinib, Sorafenib, and Etoposide showed more binding affinity than Irinotecan (i.e., −9.8, −9.6). Of these, Paclitaxel (−10.3, −11.4) and Imatinib (−9.9, −10.4) are common in targeting BCL2 and EGFR. Using these identified candidate genes and pathways, we may be able to uncover new therapeutic targets for the treatment of OTSCC. Furthermore, molecular dynamics (MD) simulations were performed for selected ligand–receptor complexes, revealing stable binding interactions and favorable energetic profiles that supported the docking results and strengthened the reliability of the proposed drug repurposing strategy. Full article

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies due to late diagnosis, poor drug penetration, and intrinsic chemoresistance. Targeted delivery strategies are urgently needed to enhance therapeutic precision while minimizing systemic toxicity. Here, we developed an AS1411 aptamer-functionalized liposomal platform encapsulating siRNA against metastasis-associated protein 2 (MTA2), a chromatin remodeling factor that suppresses the tumor suppressor PTEN and activates PI3K/AKT signaling. The AS1411 aptamer, which binds nucleolin overexpressed on PDAC cells, was conjugated to cationic liposomes via copper-free click chemistry. The resulting AS1411-Lipm[siRNA] exhibited high siRNA encapsulation efficiency, selective uptake by nucleolin-positive PDAC cells, and enhanced endosomal escape. Treatment of MIA PaCa-2 cells with AS1411-Lipm[siRNA] significantly reduced MTA2 expression by ~60%, substantially restored PTEN, and inhibited AKT phosphorylation by ~50%, leading to decreased cell viability, impaired migration by ~75%, and increased apoptosis by ~35%, while sparing nucleolin-negative cells. These findings highlight AS1411-Lipm[siRNA] as a promising platform for selective siRNA delivery and potent molecular inhibition in PDAC therapy. Full article

BQ323636.1 (BQ) is a splice variant of NCOR2. Its overexpression is associated with endocrine therapy and chemoresistance in estrogen receptor-positive (ER+ve) breast cancer. This study investigates how BQ overexpression drives doxorubicin (DOX) resistance by enhancing androgen receptor (AR) signaling and non-homologous end joining (NHEJ). BQ overexpressed breast cancer cell lines (MCF-7, T-47D, BT-549, MDA-MB-453), showed increased AR activity (ARE-luciferase assay) and demonstrated DOX resistance (EC50 > 10-fold with DHT, p < 0.05), as assessed via cell viability, TUNEL, and comet assays. RNA-sequencing (GSE295979, GSE2048) revealed the involvement of AR signaling. BQ upregulated cell cycle-related kinase (CCRK), stabilizing KU70, a key NHEJ protein, resulting in enhanced NHEJ activity (EJ5-GFP assay, p < 0.01). Co-immunoprecipitation confirmed the interaction between CCRK and KU70, and CCRK was found to modulate the protein stability of KU70. AR inhibition with bicalutamide in BQ overexpressing cells reversed DOX resistance. Xenograft models validated AR-dependent DOX resistance. In ER+ve breast cancer patient samples, high CCRK expression correlated with DOX resistance (p = 0.002) and metastasis (p = 0.001). Kaplan–Meier analysis showed poorer overall survival (p < 0.001) and disease-specific survival (p < 0.001) in cancers with high CCRK. Cox-regression analysis showed that high CCRK was a poorer prognostic factor of overall survival (p < 0.001; RR 3.056, 95% CI 1.661, 5.621, AR (p < 0.001; RR 3.420, 95% CI 1.783, 6.562), and disease-specific survival (p < 0.001; RR 2.731, 95% CI 1.472, 5.067). The BQ-AR-CCRK-KU70 axis represents a novel mechanism of DOX resistance in ER+ve breast cancer, suggesting AR or CCRK inhibition as a potential therapeutic strategy. Full article

Acute myeloid leukemia (AML) proliferation is significantly influenced by the interactions between leukemia blasts and the bone marrow (BM) microenvironment. Specifically, bone marrow mesenchymal stem cells (BMSCs) derived from AML patients (AML-MSCs) are known to support leukemia growth and facilitate disease progression. Studies have demonstrated that the transfer of mitochondria from MSCs to AML blasts not only aids in disease progression but also contributes to chemotherapy resistance. Furthermore, BM stromal cells can trigger a metabolic shift in malignant cells from mitochondrial respiration to glycolysis, which enhances both growth and chemo-resistance. This study focuses on identifying transcriptional and metabolic alterations in AML-MSCs to uncover potential targeted therapies for AML. We employed RNA sequencing and microarray analysis on MSCs cocultured with leukemic cells (MLL-AF9) and on MSCs isolated from both non-leukemic and MLL-AF9 leukemic mice. The Gene Set Enrichment Analysis (GSEA) indicated a significant downregulation of gene sets associated with oxidative phosphorylation and glycolysis in AML-MSCs. Furthermore, coculture of MSCs from wild-type mice (WT-MSCs) and a healthy donor individual (HD-MSCs) with AML cells demonstrated reduced oxidative phosphorylation and glycolysis. These metabolic changes were consistent in AML-MSCs derived from both leukemic mice and patients. Our results indicate that AML cells diminish the metabolic capacity of MSCs, specifically targeting oxidative phosphorylation and glycolysis. These findings suggest potential metabolic vulnerabilities that could be exploited to develop more effective therapeutic strategies for AML. Full article

The ribosome in eukaryotic cells is a macromolecular complex composed of four ribonucleic acids and over 80 proteins. This organelle facilitates protein synthesis in cells, and its activity is strongly upregulated in human cancers. Immune cells, a variety of cellular stressors and numerous structurally and mechanistically distinct anti-cancer agents have been shown to induce ribosomal RNA degradation in tumour cells in vitro and in vivo—a phenomenon we termed “RNA disruption”. RNA disruption can be quantified in cultured cell lines and patient samples using the RNA disruption assay (RDA). Unlike well-known high-throughput anti-cancer drug sensitivity assays, RDA can distinguish between dying and arrested tumour cells, making it an attractive assay for anti-cancer drug discovery and development. Low tumour RNA disruption during neoadjuvant chemotherapy (as measured using RDA) is strongly associated with residual disease and reduced disease-free survival, making it a potentially valuable chemo-resistance assessment tool. High RNA disruption may also indicate chemo-responsiveness. RDA holds the prospect of being a useful tool to escalate or de-escalate neoadjuvant chemotherapy in cancer patients. Moreover, the assay’s ability to predict treatment outcomes during neoadjuvant chemotherapy may permit its use in adaptive clinical trials and in drug approval by regulatory agencies. This review provides insight into the cellular processes involved in chemotherapy-induced RNA disruption. It also describes the results of clinical studies on tumour RNA disruption in cancer patients and suggests possible approaches that could be considered for the utilization of RDAs in the clinical management of breast cancer patients undergoing current neoadjuvant chemotherapy regimens. Full article

Recent years have provided numerous reports on the mechanisms of action of psychiatric medications (antidepressants, antipsychotics, mood stabilizers, and antidementia drugs) that directly inhibit the growth of cancer cells, as well as on their indirect effects on the psyche and immune system, and their supportive effects on chemotherapeutic agents. The mechanisms of the anticancer activity of psychiatric drugs include inhibition of dopamine and N-methyl-D-aspartate receptors that work via signaling pathways (PI3K/AKT/mTOR/NF-κB, ERK, Wnt/ß-catenin, and bcl2), metabolic pathways (ornithine decarboxylase, intracellular cholesterol transport, lysosomal enzymes, and glycolysis), autophagy, Ca²⁺-dependent signaling cascades, and various other proteins (actin-related protein complex, sirtuin 1, p21, p53, etc.). The anticancer potential of psychiatric drugs seems to be extremely broad, and the most extensive anticancer literature has been reported on antidepressants (fluoxetine, amitriptyline, imipramine, mirtazapine, and St John’s Wort) and antipsychotics (chlorpromazine, pimozide, thioridazine, and trifluoperazine). Among mood stabilizers, lithium and valproates have the largest body of literature. Among antidementia drugs, memantine has documented anticancer effects, while there is limited evidence for galantamine. Of the new psychiatric substances, the antipsychotic drug brexpiprazole and the antidepressant vortioxetine have a very interesting body of literature regarding glioblastoma, based on in vitro and in vivo animal survival studies. Their use in brain tumors and metastases is particularly compelling, as these substances readily cross the blood–brain barrier (BBB). Moreover, the synergistic effect of psychiatric drugs with traditional cancer treatment seems to be extremely important in the fight against chemo- and radio-resistance of tumors. Although there are some studies describing the possible carcinogenic effects of psychiatric drugs in animals, the anticancer effect seems to be extremely significant, especially in combination treatment with radio/chemotherapy. The emerging evidence supporting the anticancer properties of psychiatric drugs presents an exciting frontier in oncology. The anticancer properties of psychiatric drugs may prove particularly useful in the period between chemotherapy and radiotherapy sessions to maintain the tumor-inhibitory effect. While further research is necessary to elucidate the mechanisms, clinical implications, dose-dependence of the effect, and clear guidelines for the use of psychiatric medications in cancer therapy, the potential for these commonly prescribed medications to contribute to cancer treatment enhances their value in the management of patients facing the dual challenges of mental health and cancer. Full article

Next-generation sequencing has overturned the dogma of biliary sterility, revealing low-biomass microbiota along the gut–biliary axis with metabolic and immunologic effects. This review synthesizes evidence on composition, function, and routes of colonization across benign and malignant disease. In cholelithiasis, Proteobacteria- and Firmicutes-rich consortia provide β-glucuronidase, phospholipase A₂, and bile salt hydrolase, driving bile supersaturation, nucleation, and recurrence. In primary sclerosing cholangitis, primary biliary cholangitis, and autoimmune hepatitis, intestinal dysbiosis and disturbed bile acid pools modulate pattern recognition receptors and bile acid signaling (FXR, TGR5), promote Th17 skewing, and injure cholangiocytes; bile frequently shows Enterococcus expansion linked to taurolithocholic acid. Distinct oncobiomes characterize cholangiocarcinoma subtypes; colibactin-positive Escherichia coli and intratumoral Gammaproteobacteria contribute to DNA damage and chemoresistance. In hepatocellular carcinoma, intratumoral microbial signatures correlate with tumor biology and prognosis. We critically appraise key methodological constraints—sampling route and post-sphincterotomy contamination, antibiotic prophylaxis, low biomass, and heterogeneous analytical pipelines—and outline a translational agenda: validated microbial/metabolomic biomarkers from bile, tissue, and stent biofilms; targeted modulation with selective antibiotics, engineered probiotics, fecal microbiota transplantation, and bile acid receptor modulators. Standardized protocols and spatial, multi-omic prospective studies are required to enable risk stratification and microbiota-informed therapeutics. Full article

Epigenetic regulation is critical to B cell development, guiding gene expression via DNA methylation, histone modifications, chromatin remodeling, and noncoding RNAs. In mature B cell neoplasms, particularly diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and chronic lymphocytic leukemia (CLL), these mechanisms are frequently disrupted. Recurrent mutations in key epigenetic regulators such as EZH2, KMT2D, CREBBP, and TET2 lead to altered chromatin states, repression of tumor suppressor genes, and enhanced oncogenic signaling. Dysregulation of specific microRNAs (e.g., miR-155, miR-21) further contributes to pathogenesis and therapeutic resistance. In DLBCL, hypermethylation of SMAD1 and CREBBP mutations are associated with immune evasion and chemoresistance. In FL, EZH2 gain-of-function and KMT2D loss-of-function mutations alter germinal center B cell programming, while in CLL, DNA hypomethylation patterns reflect the cell of origin and correlate with clinical outcome. Targeted therapies such as the EZH2 inhibitor tazemetostat have demonstrated efficacy in EZH2-mutant FL, while HDAC and BET inhibitors show variable responses across B cell malignancies. The limitations of current epigenetic therapies reflect the complexity of targeting epigenetic dysregulation rather than therapeutic futility. These challenges nonetheless highlight the relevance of epigenetic alterations as biomarkers and therapeutic targets, with potential to improve the management of mature B cell neoplasms. Full article

Background/Objectives: Despite advances in diagnosis and treatment, colorectal cancer (CRC) remains one of the most prevalent and challenging malignancies worldwide. The dysregulation of microRNAs (miRNAs) has emerged as a critical factor in CRC onset, progression, and therapeutic resistance. This study aims to provide an overview of global research trends on miRNAs in CRC, (i) identifying the most studied miRNAs, (ii) exploring under-investigated areas, and (iii) highlighting emerging themes and potential future directions. Methods: To assess the evolution of the global miRNA–CRC research trends, we conducted a bibliometric analysis of 828 CRC–miRNA-focused articles published between 2008 and 2024, sourced from the Scopus database. Bibliometric mapping was performed using the R/Bibliometrix package and by leveraging a customized Python-based pipeline, which is useful for extracting and validating miRNA identifiers (miRNA IDs) based on the miRBase database. This miRNA ID-related approach enabled us to systematically identify the most frequently studied miRNAs over time while highlighting underexplored miRNA. Results: The analysis revealed a substantial and accelerating publication growth rate, delineating three major phases in CRC–miRNA research. China emerged as the leading contributor in terms of the publication volume. miR-21, miR-34a, and miR-195-5p were among the most frequently studied miRNAs, underscoring their relevance to CRC biology and therapy. Keyword and citation analyses identified key thematic areas, such as cell proliferation, epithelial–mesenchymal transition, and chemoresistance, especially to oxaliplatin and 5-fluorouracil. Emerging research frontiers included ferroptosis, ceRNA networks, and exosome-mediated miRNA transport. An analysis of the collaborations indicated strong intra-national collaborations, with room for expanding international research networks. Conclusions: This study provides an in-depth bibliometric landscape of the CRC-related miRNA research by highlighting influential studies and journals while identifying gaps and underexplored topics. These insights offer valuable guidance for future translational and clinical research on this topic. Full article

Cisplatin is an effective chemotherapeutic drug, but is limited both by its toxicity and its tendency to induce drug resistance rapidly in some patients. Tissue transglutaminase 2 (TG2), which is overexpressed in various cancers, has two main isoforms: a long (TG2-L) and a short form (TG2-S). While TG2-L supports cell survival, conversely, TG2-S promotes cell death. Evidence increasingly suggests that TG2 may be a suitable target for combating chemoresistance in a variety of human cancers. Here, we show that cisplatin toxicity towards wild-type MCF-7 breast cancer cells is associated with reduced TG2-L and TG2-S expression, whereas approximately doubling the TG2-L expression through the retinoic acid pre-treatment of these cells induces survival in the presence of cisplatin at levels similar to those seen in long-term cisplatin-co-cultured cells, which have reduced sensitivity. The treatment of cisplatin-surviving cells with cisplatin alone did not significantly alter the levels of either TG2 isoform, whereas the cisplatin challenge of cisplatin-surviving MCF-7 cells following 20 µM retinoic acid pre-treatment resulted in increased levels of TG2-L, increased TG2 enzyme activity, and no significant change in TG2-S levels, with increased cell survival. These findings suggest a subtype-specific regulatory effect of RA in cisplatin-surviving MCF-7 cells, with TG2-L upregulated at higher RA concentrations, potentially contributing to altered cisplatin sensitivity. Anti-TG2 siRNA silencing reduced cisplatin IC50 to base levels in both wild-type and cisplatin-surviving MCF-7 cells, supporting the notion that the modulation of TG2 expression could offer a significant benefit to cisplatin efficacy. Preventing excessive retinoic acid exposure may also be a mechanism for maximising cisplatin efficacy, considering TG2 modulation. Full article

Background and Clinical Significance: Acute megakaryoblastic leukemia (AMKL) is a rare and aggressive hematologic malignancy. The presence of genetic abnormalities often increases the complexity of AMKL. Among these, patients with monosomy 7 constitute a high-risk group associated with a poorer prognosis and greater chemoresistance. We report the case of a 10-year-old boy who had AMKL along with monosomy 7 and familial GATA2 deficiency. The case highlights the diagnostic and therapeutic challenges faced, as well as the critical importance of early genetic screening and timely hematopoietic stem cell transplantation (HSCT). Case Presentation: A 10-year-old boy presented with easy bruising and pancytopenia. AMKL was diagnosed with the help of a bone marrow biopsy and immunophenotyping. Genetic testing showed a GATA2 mutation and monosomy 7. Two induction cycles with daunorubicin and cytarabine were administered but failed to eliminate residual disease. The patient also developed pneumonia of a fungal origin. HSCT was delayed due to liver toxicity and elevated minimal residual disease (MRD). Azacitidine and venetoclax stabilized the disease, thereby allowing for successful haploidentical HSCT. The patient achieved complete remission with full donor chimerism. Conclusions: This case emphasizes the importance of early molecular diagnostics in pediatric AMKL. Identifying GATA2 mutations and monosomy 7 early can help guide risk stratification and the timing of HSCT. Multimodal therapy, which includes the use of infection control and targeted agents, is important for improving the outcomes in high-risk patients. Full article

Therapeutic resistance remains a critical barrier in effective cancer treatment, contributing to disease recurrence, progression, and reduced patient survival. In recent years, natural bioactive compounds have emerged as promising adjuncts in oncology due to their ability to modulate multiple biological processes involved in resistance. This review explores current evidence on the role of natural compounds in influencing cancer cell behavior and their interactions with the tumor microenvironment. By organizing these compounds into chemical families, we provide a structured overview of their potential to enhance the efficacy of standard chemotherapy and reduce resistance-related mechanisms. We also highlight innovative strategies, including combination therapies and advanced drug delivery systems, that aim to improve their clinical applicability. Overall, this work underscores the relevance of integrating natural bioactives into modern cancer therapy and calls for further translational research to bridge preclinical findings with clinical implementation. Full article