Search Results (619)

Chemotherapy remains a cornerstone in the treatment of esophageal cancer (EC), yet chemoresistance remains a critical challenge, leading to poor outcomes and limited therapeutic success. Mitochondrial DNA (mtDNA) has emerged as a pivotal player in mediating these responses, influencing cellular metabolism, oxidative stress regulation, and apoptotic pathways. This review provides a comprehensive overview of the mechanisms by which mtDNA alterations, including mutations and copy number variations, drive chemoresistance in EC. Specific focus is given to the role of mtDNA in metabolic reprogramming, including its contribution to the Warburg effect and lipid metabolism, as well as its impact on epithelial–mesenchymal transition (EMT) and mitochondrial bioenergetics. Recent advances in targeting mitochondrial pathways through novel therapeutic agents, such as metformin and mitoquinone, and innovative approaches like CRISPR/Cas9 gene editing, are also discussed. These interventions highlight the potential for overcoming chemoresistance and improving patient outcomes. By integrating mitochondrial diagnostics with personalized treatment strategies, we propose a roadmap for future research that bridges basic mitochondrial biology with translational applications in oncology. The insights offered in this review emphasize the critical need for continued exploration of mtDNA-targeted therapies to address the unmet needs in EC management and other diseases associated with mitochondria. Full article

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

Oral squamous cell carcinoma (OSCC) is a prevalent and aggressive malignancy with poor prognosis, largely due to its high metastatic potential and resistance to conventional therapies. Recent advances in cancer biology have underscored the significance of regulated cell death pathways, including apoptosis, autophagic cell death (ACD), necroptosis, pyroptosis, and ferroptosis, in modulating tumor progression and therapeutic responses. This review provides the current insights into the molecular mechanisms underlying these cell death pathways and explores their therapeutic relevance in OSCC. Restoration of apoptosis using BH3 mimetics, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptor agonists, and p53 reactivators shows promise for sensitizing OSCC cells to treatment. Autophagy plays context-dependent roles in cancer, acting as a tumor suppressor during early carcinogenesis by maintaining cellular homeostasis, and as a tumor promoter in established tumors by supporting cancer cell survival under stress. Targeting necroptosis and pyroptosis has emerged as a novel strategy for inducing cancer cell death, with compounds such as acetylshikonin and okanin demonstrating antitumor effects. Additionally, the induction of ferroptosis via lipid peroxidation and glutathione peroxidase 4 (GPX4) inhibition offers a promising avenue for overcoming drug resistance, with agents such as quercetin and trifluoperazine exhibiting preclinical success. Integration of these therapeutic approaches may enhance the OSCC treatment efficacy, reduce chemoresistance, and provide novel prognostic biomarkers for clinical management. Future studies should focus on optimizing combinatorial strategies that effectively leverage these pathways to improve OSCC patient outcomes. Full article

Nucleobase and nucleoside analogs are critical components of antimetabolite chemotherapy treatments used to disrupt DNA replication and induce apoptosis in rapidly proliferating cancer cells. However, the development of resistance to these agents remains a major clinical challenge. This review explores the epigenetic mechanisms that contribute to acquired chemoresistance, focusing on DNA methylation, histone modifications, and non-coding RNAs (ncRNAs). These epigenetic alterations regulate key processes such as DNA repair, drug metabolism, cell transport, and autophagy, enabling cancer cells to survive and resist therapeutic pressure. We highlight how dysregulation of DNA methyltransferases (DNMTs) and histone acetyltransferases (HATs) modulates expression of transporters (e.g., hENT1, ABCB1), DNA repair enzymes (e.g., Polβ, BRCA1/2), and autophagy-related genes (e.g., CSNK2A1, BNIP3). Furthermore, emerging roles for long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in regulating nucleoside export and DNA damage response pathways underscore their relevance as therapeutic targets. The interplay of these epigenetic modifications drives resistance to agents such as gemcitabine and 5-fluorouracil across multiple tumor types. We also discuss recent progress in therapeutic interventions, including DNMT and HDAC inhibitors, RNA-based therapeutics, and CRISPR-based epigenome editing. Full article

Transcription factors (TFs) are proteins that control gene expression by binding to specific DNA sequences and are essential for cell development, differentiation, and homeostasis. Dysregulation of TFs is implicated in numerous diseases, including cancer, autoimmune disorders, and neurodegeneration. While TFs were traditionally considered “undruggable” due to their lack of well-defined binding pockets, recent advances have made it possible to modulate their activity using diverse pharmacological strategies. Major TF families include NF-κB, p53, STATs, HIF-1α, AP-1, Nrf2, and nuclear hormone receptors, which take part in the regulation of inflammation, tumor suppression, cytokine signaling, hypoxia and stress response, oxidative stress, and hormonal response, respectively. TFs can perform multiple functions, participating in the regulation of opposing processes depending on the context. NF-κB, for instance, plays dual roles in immunity and cancer, and is targeted by proteasome and IKKβ inhibitors. p53, often mutated in cancer, is reactivated using MDM2 antagonist Nutlin-3, refunctionalizing compound APR-246, or stapled peptides. HIF-1α, which regulates hypoxic responses and angiogenesis, is inhibited by agents like acriflavine or stabilized in anemia therapies by HIF-PHD inhibitor roxadustat. STATs, especially STAT3 and STAT5, are oncogenic and targeted via JAK inhibitors or novel PROTAC degraders, for instance SD-36. AP-1, implicated in cancer and arthritis, can be inhibited by T-5224 or kinase inhibitors JNK and p38 MAPK. Nrf2, a key antioxidant regulator, can be activated by agents like DMF or inhibited in chemoresistant tumors. Pharmacological strategies include direct inhibitors, activators, PROTACs, molecular glues, and epigenetic modulators. Challenges remain, including the structural inaccessibility of TFs, functional redundancy, off-target effects, and delivery barriers. Despite these challenges, transcription factor modulation is emerging as a viable and promising therapeutic approach, with ongoing research focusing on specificity, safety, and efficient delivery methods to realize its full clinical potential. Full article

Introduction: An inverse association between high mammographic breast density (MBD) and pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC) for early breast cancer (EBC) has been reported. However, the relationship of MBD to relapse-free (RFS) and breast cancer-specific survival (BCSS) is unexplored. This study aims to validate the relationship between MBD and NAC pCR in EBC and to assess correlations with RFS and BCSS. Materials & Methods: MBD was measured on contralateral mammograms in 127 women before NAC using Cumulus software. The percent dense area was correlated with patient and tumour characteristics, pCR, RFS and BCSS. Results: Mean MBD was higher in relapsing patients (p = 0.041) but did not vary by pCR or BC-deaths. As a dichotomous variable, no difference was seen between high and low MBD cohorts for pCR (17.5 vs. 25.0%, p = 0.15), BC relapse (38 vs. 30%, p = 0.15) or BC death (32 vs. 25%, p = 0.20). A planned analysis by body mass index (BMI) demonstrated high MBD associated with lower pCR (0% vs. 28.1%, p = 0.036) and trends for higher relapse (56% vs. 28%, p = 0.063) and BC deaths (56 vs. 28%, (p = 0.071)) in obese patients. No relationship was observed in non-obese patients. Conclusions: Obesity and high MBD may interact to cause chemoresistance. Further research in these patients is warranted. Full article

High-grade osteosarcoma (HGOS) is the most common primary malignant bone tumor in children and adolescents. Poor response to chemotherapy is linked to worse prognosis and increased risk of recurrence and metastasis. However, current assessment methods, such as tumor necrosis evaluation, are time-consuming and delay treatment decisions. Thus, identifying molecular pathways and predictive biomarkers is essential for guiding early therapeutic strategies. In this study, RNA-seq analysis of HGOS tissues revealed enrichment of cholesterol biosynthesis and mitotic pathways in poor responders. Additionally, high HMGCR expression, as analyzed from TCGA data, was associated with poor prognosis in sarcoma. Functional validation using SaOS-2 cells, which exhibited poor drug sensitivity and elevated HMGCR levels, demonstrated that simvastatin enhanced the efficacy of cisplatin and doxorubicin by inducing mitochondrial-mediated apoptosis and downregulating anti-apoptotic proteins. Simvastatin also reduced cell migration and invasion by suppressing epithelial–mesenchymal transition and extracellular matrix degradation. Mechanistically, simvastatin disrupted Ras prenylation and inhibited downstream oncogenic signaling pathways, including Akt/mTOR and Akt/GSK3, which regulate survival and metastasis-associated gene expression. These findings suggest that the cholesterol biosynthesis pathway particularly plays a critical role in chemoresistance and metastasis in HGOS and may serve as a promising predictive molecular target for guiding early therapeutic strategies. Full article

Head and neck squamous cell carcinoma (HNSCC) remains challenging to treat despite multimodal therapeutic approaches. Cisplatin treatment is effective and cost-efficient, although chemoresistance and disease recurrence limit its efficacy. Understanding the mechanisms of cisplatin resistance and the identification of compounds to target resistant tumor cells are critical for improving patient outcomes. We have demonstrated that cisplatin-induced senescent HN30 HNSCC cells can be eliminated by ABT-263 (navitoclax), a BCL-2/BCL-X_L inhibitor that has senolytic properties. Here, we report the development of a cisplatin-resistant cell line (HN30R) for the testing of ABT-263 and the PROTAC BET degraders ARV-825 and ARV-771. ABT-263 was ineffective in sensitizing HN30R cells to cisplatin, largely due to a lack of senescence induction. However, the BET degraders in combination with cisplatin promoted apoptotic cell death in both HN30 and HN30R cells. The effectiveness of ARV-825 did not appear to depend on the cells entering into senescence, indicating that it was not acting as a conventional senolytic. ARV-825 treatment downregulated BRD4 and its downstream targets, c-Myc and Survivin, as well as decreased the expression of RAD51, a DNA repair marker. These results suggest that the BET degraders ARV-825 and ARV-771 may be effective in improving the response of chemoresistant head and neck cancer to cisplatin treatment. Full article

Background: MYB is a key transcription factor that plays an essential role in regulating hematopoiesis, particularly influencing cell proliferation, differentiation, and apoptosis. It has been extensively implicated in the pathogenesis and progression of leukemia, as well as in determining patient prognosis and responsiveness to chemotherapy. Despite these well-documented roles, the precise molecular mechanisms by which MYB contributes to chemotherapy resistance in leukemia remain largely undefined. Methods: In this study, we investigated the potential role of MYB in regulating ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, which has recently emerged as a novel therapeutic target in cancer. We overexpressed and knockdown MYB in human leukemia K562 cells and evaluated changes in ferroptosis-related markers, as well as cell proliferation and migration capacities, in the context of treatment with the chemotherapeutic agent sorafenib. Results: Our findings demonstrated that MYB overexpression significantly enhanced the resistance of human leukemia cells to sorafenib, while MYB knockdown increased their drug sensitivity. Mechanistically, MYB was found to upregulate ferritin heavy chain 1 (FTH1), thereby suppressing sorafenib-induced ferroptosis and cell death. Further, FTH1 knockdown significantly reduced the proliferation and migration ability of K562 cells and enhanced sorafenib-induced ferroptosis. Rescue experiments confirmed that FTH1 is required for MYB induced sorafenib resistance and ferroptosis inhibition in human leukemia cells. Conclusions: Collectively, this study identifies the MYB-FTH1 axis as a novel regulatory pathway modulating ferroptosis and chemoresistance in leukemia cells, providing potential therapeutic targets for improving treatment precision and preventing disease relapse. Full article

Background: Targeted therapies, such as endocrine agents, have significantly improved outcomes for patients with estrogen receptor alpha-positive (ERα+) breast cancer. Unfortunately, for patients with triple-negative breast cancer (TNBC), which lack expression of ERα and HER2, there remains a dearth of targeted adjuvant agents. We discovered that estrogen receptor beta (ERβ) is expressed in approximately 20% of TNBC cases, and its activation has been shown to inhibit proliferation, invasion, and migration in preclinical models. However, it remains unclear whether ERβ-targeted therapies maintain efficacy following the development of chemoresistance. Methods: To address this question, we generated ERβ+ TNBC cell line models with acquired resistance to paclitaxel or doxorubicin. We then assessed their response to ERβ-targeted therapies and analyzed transcriptomic changes associated with chemoresistance and ERβ ligand treatment. Results: Chemotherapy-resistant ERβ+ TNBC cells retained sensitivity to ERβ-targeted therapies and, in some cases, exhibited enhanced responsiveness. ERβ expression did not compromise chemotherapy efficacy in treatment-naïve cells. Chemotherapy-resistant cells had a vastly altered transcriptome and surprisingly, a heavily reduced ERβ transcriptome, compared to sensitive cells despite the maintenance of ERβ-driven anti-neoplastic activity. Conclusions: These findings suggest that ERβ remains a relevant drug target in chemotherapy-refractory disease and has aided in the refinement of a minimal ERβ transcriptomic signature associated with response to ERβ-targeting agents, further informing the primary mechanisms through which ERβ elicits its tumor suppressive effects. Full article

Background: Chemotherapy has a broad-spectrum anti-tumor effect and is still the core strategy for cancer treatment. However, the side effects caused by its cytotoxicity, the chemoresistance caused by tumor heterogeneity and abnormal microenvironment seriously restrict the efficacy of chemotherapy. Metformin presents the ability to sensitize chemotherapy by interfering with metabolic processes of tumor cells. However, as a dynamic process, metabolic intervention requires a specific time sequence law to optimize its role. Methods: Different administration sequences were screened by in vitro experiments to determine the optimal sequence of metformin and docetaxel. The anti-tumor effect of administration sequence in vivo was investigated in mouse models. The therapeutic advantages were comprehensively evaluated by tumor size, weight change, and survival rate. The immunofluorescent staining and transcriptome analysis were performed to study the mechanisms of the sequential administration strategy. Results: Compared with the subsequent administration and concurrent administration, pretreatment with metformin exhibited a stronger ability toward cell cycle arrest and tumor inhibition with low-dose docetaxel. Moreover, this pre-administration sequence could enhance the anti-tumor immune responses and prevent postoperative recurrence. Conclusions: The optimized chemotherapy sensitization mediated by metabolic intervention required an appropriate administration sequence, which also strengthened the anti-tumor immune responses. Full article

The detection of volatile organic compound (VOC) biomarkers from the volatolome for the anticipated diagnosis of severe diseases such as cancers is made difficult due to the presence of high quantities of H₂O in the collected samples. It has been shown that water molecules tend to compete or combine themselves with analytes, which requires either their removal or the development of more sensitive and discriminant sensors. In this later prospect, a positive effect of poly(hedral oligomeric silsesquioxanes) (POSS) is sought out to enhance the sensitivity of carbon nanotube-based quantum resistive vapour sensors (vQRS). POSS, once copolymerized with methyl methacrylate or styrene, can be used as nano-spacers amplifying the disconnection of the nano-junctions due to swelling of the polymer upon the diffusion of VOC. The amplitude of this phenomenon, which is at the origin of the chemo-resistive behaviour of vQRS, was compared with that of homologue transducers made of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA)-coated carbon nanotube (CNT) random networks. The presence of POSS in PS-based sensors has enhanced their sensitivity by 213 times for toluene, by 268 times for acetone, by 4 times for ethanol, and by 187 times for cyclohexane. Similarly, the presence of POSS in PMMA chains increases the sensitivity of sensors to cyclohexane by 10 times, to ethanol by 45 times, to toluene by 244 times, and to acetone and butanone by 4 times. All transducers were made by spray layer by layer (sLbL) to obtain a hierarchically structured conducting architecture. The transducers’ surface was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) to observe the CNT coating and dispersion level in the matrix. All sensors were tested with twenty-one VOC part of lung and skin cancer biomarkers by using a dynamic vapour analysis (DVA). The vQRS based on POSS copolymers demonstrated much larger chemo-resistive responses (A_R) than the sensors based only on pure polymers and were found to be very selective towards cyclohexane and hexene-1. The PMMA-co-POSS/CNT sensor was able to detect down to 12 ppm of VOC with a very high signal-to-noise ratio (SNR) and to discriminate six VOC among them all with a PCA (principal component analysis) projection. Full article

Lifestyle, diet, and genetics are established risk factors for developing colorectal cancer (CRC). In recent years, the role of the gut microbiota (GM) has been increasingly highlighted in several studies, suggesting an effect on both the disease’s pathogenesis and the efficacy and tolerability of treatments. We conducted a search on Medline, aiming to identify published studies exploring the role of the GM in the development and treatment of CRC. Dysbiosis, an imbalance in GM, is common in CRC patients and is associated with precancerous lesions, aggressive tumors, and varied therapy outcomes. Restoring GM balance can reduce treatment complications and may improve prognosis. The review details how GM influences CRC through metabolite production, inflammation modulation, and immune response alteration. Diet significantly impacts GM composition, with processed meats and high-fat diets increasing CRC risk, while fiber-rich diets are protective. The role of the GM in CRC treatments like surgery, chemotherapy, radiotherapy, and immunotherapy is also explored, noting its influence on complications, chemoresistance, and treatment efficacy. Future strategies involving GM modulation through diet, probiotics, and fecal microbiota transplantation (FMT) show promise for CRC prevention and treatment, warranting further research. Full article

The bone marrow microenvironment is a dynamic and complex niche that plays a central role in the development, progression, and therapeutic resistance of leukemia. Among the various stromal and immune cells that compose this microenvironment, adipocytes are increasingly recognized as active participants rather than passive bystanders. These cells contribute to leukemia pathophysiology by supplying leukemic cells with vital metabolic fuels such as free fatty acids and glutamine, which support cellular bioenergetics and biosynthesis. Furthermore, adipocytes secrete adipokines—including leptin, adiponectin, and others—that influence leukemic cell proliferation, apoptosis, and chemoresistance. Leukemic cells, in turn, are not merely recipients of these signals, but actively remodel the marrow niche to their advantage. They can suppress adipogenesis, inhibit the differentiation of mesenchymal stem cells into adipocytes, or reprogram existing adipocytes to adopt a tumor-supportive phenotype. These transformed adipocytes may enhance leukemic cell survival, dampen immune responses, and create a metabolic sanctuary that enables resistance to standard chemotherapies. This reciprocal and dynamic interaction between leukemic cells and adipocytes contributes significantly to minimal residual disease and relapse, posing a major challenge for durable remission. Recent advances in tissue engineering—such as organ-on-chip and 3D co-culture systems—offer promising platforms to recapitulate and study these leukemia–adipocyte interactions with high fidelity. These models facilitate mechanistic insights and provide a foundation for developing novel therapeutic strategies aimed at disrupting the metabolic and paracrine crosstalk within the leukemic niche. Targeting the adipocyte–leukemia axis represents a compelling and underexplored avenue for improving leukemia treatment by sensitizing malignant cells to existing therapies and overcoming the protective influence of the bone marrow microenvironment. Full article

Although 60% of AML patients respond well to standard chemotherapy, most patients eventually relapse, develop chemoresistance, and do not survive more than five years. Targeted therapies, including analogs of imiquimod belonging to the family of imiqualines, emerged as promising agents against AML. Notably, the first-generation imiqualine EAPB0503 proved selective potency against nucleophosmin-1-mutant (NPM1c) AML. Recently, chemical modifications of EAPB0503 led to the development of the lead compound from the second generation, EAPB02303. Here, we demonstrate that EAPB02303 displays 200-fold greater potency, broader activity across AML subtypes, and, importantly, a distinct mechanistic profile when compared to EAPB0503. Unlike EAPB0503, which primarily targeted NPM1c AML cells, EAPB02303 exhibits broad-spectrum activity across various AML subtypes. Remarkably, EAPB02303 anti-leukemic activity was attributed to the inhibition of PI3K/AKT/mTOR signaling activity. Nevertheless, NPM1c AML cells were more sensitive to EAPB02303, likely due to its ability to promote NPM1c protein degradation. In vivo, EAPB02303 potently reduced the leukemic burden and improved organ tumor infiltration in both wt-NPM1 and NPM1c AML xenograft mice. Yet, the significant prolonged survival was exclusive to NPM1c AML xenografts, likely due to superior response conferred by NPM1c degradation. Overall, these findings highlight the potential of EAPB02303 as a powerful therapeutic agent for a range of AML subtypes, supporting its further development for broader clinical use. Full article