Multidrug resistance in cancer: role of ATP-dependent transporters

Nanotherapeutic strategies exploiting biological traits of cancer stem cells

Cancer stem cells (CSCs) represent a distinct subpopulation of cancer cells that orchestrate cancer initiation, progression, metastasis, and therapeutic resistance. Despite advances in conventional therapies, the persistence of CSCs remains a major obstacle to achieving cancer eradication. Nanomedicine-based approaches have emerged for precise CSC targeting and elimination, offering unique advantages in overcoming the limitations of traditional treatments. This review systematically analyzes recent developments in nanomedicine for CSC-targeted therapy, emphasizing innovative nanomaterial designs addressing CSC-specific challenges. We first provide a detailed examination of CSC biology, focusing on their surface markers, signaling networks, microenvironmental interactions, and metabolic signatures. On this basis, we critically evaluate cutting-edge nanomaterial engineering designed to exploit these CSC traits, including stimuli-responsive nanodrugs, nanocarriers for drug delivery, and multifunctional nanoplatforms capable of generating localized hyperthermia or reactive oxygen species. These sophisticated nanotherapeutic approaches enhance selectivity and efficacy in CSC elimination, potentially circumventing drug resistance and cancer recurrence. Finally, we present an in-depth analysis of current challenges in translating nanomedicine-based CSC-targeted therapies from bench to bedside, offering critical insights into future research directions and clinical implementation. This review aims to provide a comprehensive framework for understanding the intersection of nanomedicine and CSC biology, contributing to more effective cancer treatment modalities.

Enhanced chemotherapy in thyroid carcinoma: A MnO2-silica nanoreactor activated by H2O2/GSH for hypoxia relief

Thyroid cancer is the most prevalent endocrine cancer that threats to the health of human being seriously, and characterized with resistance to various therapeutic modalities. The therapeutic efficacy of oxygen-dependent chemotherapy is hindered by hypoxia within tumor tissue heavily. Therefore, the supply of oxygen in situ is an effective strategy to improve the chemotherapeutic outcomes. The emergence of nanomedicine open an novel gate for tumor treatment, however, there is still lack of nanoplatforms for sufficient oxygen supply to improve the chemotherapeutic efficiency. In this study, MnO2 nanoenzyme was decorated onto glutathione (GSH)-sensitive mesoporous silica, and an intelligent nanoreactor was subsequently constructed by loading saikosaponin-d (SSD) into the mesopore channels and modified with folic acid. Upon targeted delivery to thyroid tumor cells, the Mn2+ hydrolyzed from nanoreactor facilitated the decomposition of endogenous H2O2 in the tumor, alleviating the hypoxic tumor microenvironment. Simultaneously, the tetrasulfide bonds of silica were cleaved by cytoplasmic L-GSH, releasing the loaded cargoes. Consequently, a remarkably enhanced chemotherapeutic effect of SSD was achieved both in vitro and in vivo. The mechanism underlying the tumor cell-killing effect was attributed to the generation of copious amounts of O2via disrupting the PI3K/Akt signaling pathway via transcriptome sequencing. The outstanding biocompatibility of the H2O2/GSH dual-sensitive Mn-based nanoreactor offered an exceptional chemotherapeutic effect against malignant tumors.

Co-expression of HIF1A with multi-drug transporters (P-GP, MRP1, and BCRP) in chemoresistant breast, colorectal, and ovarian cancer cells

Therapeutic resistance poses a significant challenge in treating most cancers and often leads to poor clinical outcomes and even treatment failure. One of the primary mechanisms that confer multidrug resistance phenotype to cancer cells is the hyperactivity of certain drug efflux transporters. P-GP, MRP1, and BCRP are the key ABC efflux pumps that collectively extrude a broad spectrum of chemotherapeutic drugs. Besides, HIF1A, a master transcription regulatory protein, is also associated with cancer development and therapeutic resistance. Thereby, this study aimed to delve into the mechanisms of drug resistance, specifically focusing on HIF1A-driven overexpression of ABC transporters. A total of 57 chemoresistant and 57 paired control tissue samples (breast, colorectal, and ovarian) from Bangladeshi cancer patients were analyzed to determine the co-expression level of ABC transporters and HIF1A. Molecular docking was also conducted to evaluate the interactions of HIF1A protein and hypoxia response element (HRE) sequences in the promoter regions transporter genes. This study revealed that HIF1A is significantly overexpressed in chemoresistant tissues, suggesting its pivotal role in chemoresistance mechanisms across malignancies and its potential as a target to overcome therapeutic resistance. The findings from this study also suggest a direct upregulation of ABCB1, ABCC1, and ABCG2 transcription by HIF1A in chemoresistant cancer cells by binding to the HRE sequence in the promoter regions. Thus, inhibition of these interactions of HIF1A appears to be a promising approach to reverse chemoresistance. The findings of this study can serve as a foundation for future research, resolving molecular intricacies to improve treatment outcomes in chemoresistant patients.

Pharmacological, computational, and mechanistic insights into triptolide's role in targeting drug-resistant cancers

As a promising candidate for tackling drug-resistant cancers, triptolide, a diterpenoid derived from the Chinese medicinal plant Tripterygium wilfordii, has been developed. This review summarizes potential antitumor activities, including the suppression of RNA polymerase II, the suppression of heat shock proteins (HSP70 and HSP90), and the blockade of NF-kB signalling. Triptolide is the first known compound to target cancer cells specifically but spare normal cells, and it has success in treating cancers that are difficult to treat, including pancreatic, breast, and lung cancers. It acts against the tolerance mechanisms, including efflux pump upregulation, epithelial-mesenchymal transition, and cancer stem cells. Triptolide modulates important cascades, including PI3K/AKT/mTOR, enhancing the efficacy of conventional therapies. Nonetheless, its clinical application is constrained by toxicity and bioavailability challenges. Emerging drug delivery systems, such as nanoparticles and micellar formulations, are being developed to address these limitations. It has strong interactions with key anticancer targets, like PARP, as determined in preclinical and computational studies consistent with its mechanism of action. Early-phase clinical trials of Minnelide, a water-soluble derivative of triptolide, are promising, but additional work is necessary to optimize dosing, delivery, and safety. This comprehensive analysis demonstrates that triptolide may constitute a repurposed precision medicine tool to overcome tolerance in cancer therapy.

OXPHOS inhibition overcomes chemoresistance in triple negative breast cancer

The hypothesis of a significant shift from oxidative phosphorylation (OXPHOS) to glycolysis in a number of solid tumors has been dominant for many years. Recently, however, evidence has begun to accumulate that OXPHOS is the major mode of energy production in many neoplasias, especially those that have undergone chemo- or radiotherapy, and especially in chemoresistant malignancies. In the present work, we demonstrated that chemoresistant triple-negative breast cancer cells prefer to obtain energy via OXPHOS to a greater extent than cells sensitive to chemotherapeutic agents, and therefore the former can be affected by some OXPHOS inhibitors. From a drug library containing several dozen antimicrobials, we selected those that inhibit OXPHOS in resistant TNBC cells and lead to mitochondrial dysfunction. We have also identified several pathways by which inhibition of growth suppression of chemoresistant cells occurs, including increased oxidative stress and mitophagy. Experiments in mice showed that selected OXPHOS inhibitors preferentially suppress tumor growth from chemoresistant but not from chemosensitive cells. The results of the present study suggest combinatorial therapy of such inhibitors and conventional anticancer drugs on resistant forms of tumors, if the latter show enhanced OXPHOS.

SATB2 Expression Affects Chemotherapy Metabolism and Immune Checkpoint Gene Expression in Colorectal Cancer

BACKGROUND

Special AT-rich binding protein-2 (SATB2) is a nuclear matrix associated protein regulating gene expression which is normally expressed in colonic tissue. Loss of SATB2 expression in colorectal cancer (CRC) has negative implications for prognosis and has been associated with chemotherapy resistance. Furthermore, recent evidence suggests SATB2 may influence immune checkpoint (IC) expression. We hypothesized that SATB2 expression may be associated with altered expression of chemotherapy resistance associated and IC genes.

METHODS

Clinicopathologic and gene expression data were extracted from The Cancer Genome Atlas PanCancer Atlas. SATB2 expression was compared by clinicopathologic characteristic and by using multivariate regression analysis to explore associations with chemotherapy and IC gene expression.

RESULTS

About 553 patients were included for analysis. Lower quartile SATB2 expression was associated with worse disease specific survival (P = .04). MSI (P < .001) and mucinous (P < .001) tumors were associated with reduced SATB2 expression independently. SATB2 varied by consensus molecular subtype (P < .001) and was lowest in CMS1. On multivariate analysis, SATB2 was negatively associated with 5-FU related metabolism genes, while more complex but significant relationships were seen with oxaliplatin and irinotecan related genes. Low SATB2 expression was associated with increased expression of PD-1, PD-L1, TIM-3 and CTLA-4 IC genes.

CONCLUSION

The positive prognostic influence of SATB2 expression is reaffirmed in this study. This effect may be explained by the negative association between SATB2 and 5-FU-resistance related gene expression. Enhanced IC gene expression in SATB2 low cases suggests a potential role for IC inhibition in this setting, but further study is required.

Diallyl disulfide in oncotherapy: molecular mechanisms and therapeutic potentials

Garlic possesses a broad spectrum of medicinal properties, such as anti-cancer, antioxidant, anti-diabetic effects, and protective effects on the heart, nervous system, and liver. Diallyl disulfide (DADS), an oil-soluble organic sulfur-containing compound in garlic, has garnered attention in recent years for its demonstrated anti-cancer efficacy in various cancer types such as leukemia, breast cancer, hepatocellular carcinoma, stomach cancer, and prostate cancer. The anticancer properties of DADS are attributed to its ability to suppress cancer cell proliferation, impede invasion and metastasis, as well as induce apoptosis, promote differentiation, and facilitate cell cycle arrest. Although many literatures have reviewed the pharmacokinetics, molecular mechanisms of anti-cancer effects and some clinical trials of DADS, the specific mechanisms and clinical-translational therapeutic potentials have not been elucidated. This comprehensive review focuses on delineating the molecular mechanisms underlying the anticancer effects of DADS, with a particular emphasis on its potential utility as a therapeutic intervention in the clinical management of cancer, and analyzes the challenges and coping strategies faced in the application of DADS as an anti-cancer drug, pointing out the directions for scientific research.

Overcoming P-glycoprotein-mediated multidrug resistance in cancer cells through micelle-forming PHPMA-b-PPO diblock copolymers for doxorubicin delivery

Multidrug resistance (MDR) represents one of the major concerns in cancer therapy as it may cause reduced efficacy of chemotherapeutic drugs due to the overexpression of ABC transporters, particularly P-glycoprotein (P-gp). This study explores the potential of novel amphiphilic diblock (DB) copolymers composed of poly[N-(2-hydroxypropyl)methacrylamide]-based copolymers (PHPMA) and poly(propylene oxide) (PPO) to overcome MDR mechanisms. The DB copolymers and their doxorubicin (Dox) conjugates significantly increased Dox accumulation in P-gp positive cells, markedly sensitizing them to Dox cytotoxic activity. The underlying mechanisms included depletion of intracellular ATP with subsequent inhibition of P-gp mediated drug efflux, an altered mitochondrial membrane potential, and increased ROS production. Moreover, the DB-Dox conjugates inhibited tumor growth in vivo more effectively compared to the corresponding PHPMA-based drug delivery system. Copolymers with additionally loaded PPO in the micelle core demonstrated superior efficacy in terms of P-gp inhibition, ATP depletion, and chemosensitizing effect in vitro, as well as antitumor activity in vivo. DB copolymers effectively depleted ATP levels both in vitro and in vivo using patient-derived xenograft (PDX) models, underscoring their capacity to enhance the effectiveness of standard chemotherapy and translational potential.

Coumarin MAMMEA A/BB cytotoxicity inhibits the chemoresistance and migration of glioblastoma cells in vitro

High-grade gliomas are the most aggressive brain tumors, which have no effective treatment. This work investigated a new anti-glioma strategy using mammea A/BB in vitro, a 4-phenylcoumarin isolated from the roots of Kielmeyera argentea. This work evaluated the cytotoxicity of mammea A/BB to human glioblastoma (U251), rat glioma (C6) cells and rat astrocytes in primary culture, comparing to temozolomide (TMZ) by MTT test. Cell migration assay, morphological analysis of DAPI-labeled nuclei and immunofluorescence for P-glycoprotein (P-gp) were also performed. After 72 h, the mammea A/BB significantly induced cytotoxicity in a concentration-dependent manner in U251 and C6 cells, with the EC50 27 ± 2 μM and 57 ± 14 μM, respectively. The natural compound was not cytotoxic to astrocytes in primary culture up to 200 μM. It was possible to observe a significant inhibition of tumoral cell migration in treatments with 10 mM mammea A/BB. Both cell lines were resistant to TMZ, but significantly sensitive to mammea A/BB. The percentage of picnotic nuclei of cells treated with 30 mM mammea A/BB was higher than the control. Besides, the treatment with mammea A/BB showed no significant difference in P-gp expression, but it was increased in TMZ treatment after 72 h. Even with cell lines presenting different molecular profiles, the results indicate that mammea A/BB is a promising candidate as a new antitumor drug against glioma cells in vitro.

Restoration of A2M reduces drug resistance and malignancy in paclitaxel-resistant lung cancer cells

The development of acquired paclitaxel resistance poses a significant challenge in managing lung cancer clinically. Understanding the mechanism and developing effective strategies to counter paclitaxel resistance are highly desired. To explore the potential mechanisms of acquired paclitaxel resistance, we established a series of lung cancer cell lines exhibiting different levels of resistance to paclitaxel. Transcriptomic RNA-sequencing revealed a progressive decrease in alpha-2-macroglobulin (A2M) levels as paclitaxel resistance advanced in NCI-H446 cells. This was accompanied by the upregulation of known paclitaxel resistance inducers ABCB1, TMEM243, and ID1. A2M loss was further validated in paclitaxel-resistant A549 and HCC827 lung cancer cells. TCGA and CPTAC analyses demonstrated that A2M is downregulated in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), inversely correlating with tumor progression. Restoring A2M expression inhibited proliferation and invasion in paclitaxel-resistant lung cancer cells, suggesting its tumor-suppressing role in lung cancer. Notably, restoring A2M re-suppressed the expression of the paclitaxel resistance mediators (ABCB1, TMEM243 and ID1) in the drug-resistant cells, and re-sensitized them to paclitaxel. In summary, our data indicate that A2M is progressively lost during the development of paclitaxel resistance in lung cancer, and restoring A2M may help overcome this resistance. Thus, A2M deficiency may serve as both a predictor and a therapeutic target for paclitaxel resistance in lung cancer.

Discovery and biological evaluation of hederagenin derivatives as non-substrate inhibitors of P-glycoprotein-mediated multidrug resistance

Multidrug Resistance (MDR) is an essential cause of failure of tumor chemotherapy, and P-glycoprotein (P-gp) overexpression is one of the major causes of MDR in tumor cells. Hederagenin (HRG) derivatives showed significant inhibitory effects in P-gp-mediated tumor MDR. Herein, we designed and synthesized 30 HRG derivatives and evaluated these compounds' tumor MDR reversal ability. For the first time, we identified a potential P-gp non-substrate inhibitor of the HRG derivatives 15, which binds to non-substrate active sites in transmembrane structural domains (TMDs) with high binding affinity. Subsequent assays confirmed that 15 exerted significant tumor MDR reversal activity by binding to P-gp and inhibiting P-gp function rather than affecting its expression. It could not be pumped out of the cell by P-gp. In addition, 15 inhibited Rhodamine123 efflux, rendered the KBV cells sensitive to paclitaxel (Ptx), blocked the cells in the G2/M phase, and induced apoptosis. Notably, 15 increased Ptx sensitivity in vivo, significantly inhibited the growth of KBV cell-derived xenograft tumors in nude mice, with a tumor suppression rate as high as 63.71 %.

Insights into interactions between taxanes and P-glycoprotein using biophysical and in silico methods

Multidrug resistance mediated by P-glycoprotein (Pgp) is a significant obstacle to cancer chemotherapy. Taxane drugs, including paclitaxel, docetaxel, and cabazitaxel, are used to treat multiple types of cancer. All taxane drugs are Pgp substrates, but cabazitaxel is also a Pgp inhibitor, indicating potential differential interactions between Pgp and different taxanes. Here, we showed for the first time that cabazitaxel had a partial inhibitory effect on the ATPase activity at concentrations higher than 10 µM. We found the KD of paclitaxel, docetaxel, and cabazitaxel to Pgp are 0.85 µM, 40.59 µM, and 13.53 µM, respectively. Based on acrylamide quenching, paclitaxel induced Pgp into a wide inward-facing open conformation at a high concentration but a slightly occluded conformation at lower concentrations. Both docetaxel and cabazitaxel shifted Pgp towards occluded states, each drug resulting in a unique degree of occlusion. Furthermore, molecular docking and energy calculations revealed that cabazitaxel binds with the "access tunnel" and blocks the subsequent nucleotide-binding domain dimerization. Our results indicate that the preference of taxanes for different binding sites on Pgp leads to distinct transport mechanisms. These results provide valuable insight into the interaction between taxanes and Pgp, which will enhance future drug development.

A comprehensive review on overcoming the multifaceted challenge of cancer multidrug resistance: The emerging role of mesoporous silica nanoparticles

Multidrug resistance (MDR) is a significant challenge in tumor treatment, severely reducing the effectiveness of anticancer drugs and contributing to high mortality rates. This article overviews the various factors involved in the development of MDR, such as changes in drug targets, increased DNA repair mechanisms, and the impact of the tumor microenvironment. It also emphasizes the potential of mesoporous silica nanoparticles (MSNs) as a drug delivery system to combat MDR. With their unique characteristics-such as a high surface area, adjustable pore sizes, and the ability to be functionalized for targeted delivery-MSNs serve as excellent carriers for the simultaneous delivery of chemotherapeutics and siRNAs aimed at reversing resistance pathways. The paper focuses on innovative methods using MSNs for direct intranuclear delivery of their cargos to overcome efflux barrier and improve the effectiveness of combination therapies. This review highlights a promising approach for enhancing cancer treatment outcomes by integrating advanced nanotechnology with traditional therapies, addressing the ongoing challenge of MDR in oncology.

Reversal of doxorubicin-resistance of MCF-7/Adr cells via multiple regulations by glucose oxidase loaded AuNRs@MnO2@SiO2 nanocarriers

Targeting to multiple MDR mechanisms is a desired strategy for efficient reversal of multidrug resistance (MDR). Herein, a multi-functional and hierarchical-structured AuNRs@MnO2@SiO2 (AMS) nanocarrier is reported for multiple regulations of MDR. The glucose oxidase (GOx) loaded AMS (AMS/G) showed efficient capabilities of hypoxia-relieving, O2-generation enhanced cancer starvation therapy (CST), and near-infrared (NIR) laser photothermal therapy (PTT) to MCF-7/Adr, a doxorubicin (Dox)-resistant breast cancer cell line. It was revealed that hypoxia inducible factor-1α and heat shock protein 90, can be significantly down-regulated by AMS/G. The Dox resistance and the adenosine triphosphate (ATP)-binding cassette (ABC) transporters: P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), and breast cancer resistance protein (BCRP), can be dramatically reversed by the AMS/G+NIR treatment. Specifically, the hypoxia-relieving function can down-regulate all the three ABC transporters. The enhanced CST decreases the expression of MRP1. The PTT diminishes the BCRP and MRP1. Assisted by the multiple and synergistic reversal mechanisms, the Dox co-loaded AMS/G (AMS/D/G) with NIR laser significantly inhibited the cell proliferation, migration, and drug efflux at both normoxia and hypoxia conditions. Cell apoptosis is greatly induced in a caspase-3 dependent manner. Tumor ATP depletion and Dox accumulation were confirmed in vivo. The tumor growth inhibition is greatly and synergistically enhanced, without inducing obvious side effects. Collectively, the nanostructured AMS/D/G can inhibit multiple ABC transporters and provide a promisingly platform for highly efficient reversal of tumor drug resistance.

P-glycoprotein and Alzheimer's Disease: Threats and Opportunities

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects more than 50 million people worldwide. One of the hallmark features of AD is the accumulation of amyloid β-peptide (Aβ) protein in the brain. P-glycoprotein (P-gp) is a membrane-bound protein expressed in various tissues, including the cerebrovascular endothelium. It plays a crucial role in the efflux of toxic substances, including Aβ, from the brain. Aberrations in P-gp levels or activity have been implicated in the pathogenesis of AD by promoting the accumulation of Aβ in the brain. Therefore, modulating the P-gp function represents a promising therapeutic strategy for treating AD. P-gp has multiple substrate binding sites, creating the potential for substrates to fall into complementation groups based on these sites; two substrates in the same complementation group may compete with one other, but two substrates in different groups may exhibit cooperativity. Thus, a given P-gp substrate may interfere with Aβ efflux whereas another may promote clearance. These threats and opportunities, as well as other aspects of P-gp relevance to AD, are discussed here.

Current progress and remaining challenges of peptide-drug conjugates (PDCs): next generation of antibody-drug conjugates (ADCs)?

Drug conjugates have emerged as a promising alternative delivery system designed to deliver an ultra-toxic payload directly to the target cancer cells, maximizing therapeutic efficacy while minimizing toxicity. Among these, antibody-drug conjugates (ADCs) have garnered significant attention from both academia and industry due to their great potential for cancer therapy. However, peptide-drug conjugates (PDCs) offer several advantages over ADCs, including more accessible industrial synthesis, versatile functionalization, high tissue penetration, and rapid clearance with low immunotoxicity. These factors position PDCs as up-and-coming drug candidates for future cancer therapy. Despite their potential, PDCs face challenges such as poor pharmacokinetic properties and low bioactivity, which hinder their clinical development. How to design PDCs to meet clinical needs is a big challenge and urgent to resolve. In this review, we first carefully analyzed the general consideration of successful PDC design learning from ADCs. Then, we summarised the basic functions of each component of a PDC construct, comprising of peptides, linkers and payloads. The peptides in PDCs were categorized into three types: tumor targeting peptides, cell penetrating peptide and self-assembling peptide. We then analyzed the potential of these peptides for drug delivery, such as overcoming drug resistance, controlling drug release and improving therapeutic efficacy with reduced non-specific toxicity. To better understand the potential druggability of PDCs, we discussed the pharmacokinetics of PDCs and also briefly introduced the current PDCs in clinical trials. Lastly, we discussed the future perspectives for the successful development of an oncology PDC. This review aimed to provide useful information for better construction of PDCs in future clinical applications.

Genomic Insights into Oral Cancer Highlight Mutant SIGMAR1 as a Critical Target to Overcome Chemoresistance

Oral cancer (OC) is a highly aggressive malignancy characterized by uncontrolled cell proliferation in the oral cavity. Recent studies have highlighted the role of Sigma-1 receptor (SIGMAR1) mutations in cancer progression, disrupting cellular homeostasis, altering gene and protein expression, and promoting drug resistance. However, its role in OC remains scarce. This study investigated SIGMAR1 mutations, expression profiles, and their potential link to drug resistance in OC. Using 2008 OC samples from the TCGA Pan-Cancer Atlas, we identified SIGMAR1 genetic alterations in 4% of cases, including missense mutations, deletions, and amplifications. In the HN13 OC cell line, Sanger sequencing revealed a novel heterozygous Asp-to-Gly (c.585C > G) missense mutation. Quantitative RT-PCR and Western blot analyses showed SIGMAR1 overexpression in HN13 cells compared to non-tumor oral keratinocytes (NOK-SI). Silencing SIGMAR1 increased HN13 cell sensitivity to cisplatin, indicating its role in drug resistance. This study is the first to report the c.585C > G mutation in SIGMAR1 and demonstrate its contribution to cisplatin resistance, a major chemotherapy challenge to OC treatment. These findings highlight SIGMAR1's critical role in OC pathogenesis and its potential as a therapeutic target to overcome chemoresistance. The results also pave the way for future research into RNA-based therapies and precision oncology interventions.

Inhibition of ABCG2 by SCO-101 Enhances Chemotherapy Efficacy in Cancer

Chemotherapy resistance, particularly multidrug resistance (MDR), remains a significant barrier to effective cancer treatment, leading to high mortality rates. The development of novel therapeutic strategies targeting key molecular mechanisms to counteract drug resistance is thus an urgent clinical need. In this study, we evaluated the potential of the small molecule SCO-101 to restore chemotherapy sensitivity in drug-resistant cancer cells. Using in silico and in vitro models such as molecular docking, cell viability, colony formation, dye efflux, transporter assays and chemotherapy retention, we assessed the impact of SCO-101 on drug retention and response in several drug-resistant cancer cells. SCO-101 was found to inhibit the activity of breast cancer resistance protein (BCRP/ABCG2) and UDP Glucuronosyltransferase Family 1 Member A1 (UGT1A1), two key proteins involved in drug resistance by cellular drug excretion and drug metabolism. Our results demonstrate that inhibition of these proteins by SCO-101 leads to increased intracellular drug accumulation, enhancing the cytotoxic effects of chemotherapy agents. Additionally, we identified a strong correlation between high ABCG2 expression and MDR in non-drug-resistant models, where cells exhibiting elevated ABCG2 levels displayed chemotherapy resistance, which was effectively reversed by SCO-101 co-treatment. These findings highlight the therapeutic potential of SCO-101 in overcoming MDR by inhibiting drug efflux mechanisms and metabolism, thereby enhancing chemotherapy efficacy. SCO-101 is currently undergoing clinical trials as an orally administered drug and is considered a promising strategy for improving cancer treatment outcomes in patients with drug-resistant tumors.

Matrix metalloproteinase-driven epithelial-mesenchymal transition: implications in health and disease

Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells, defined by apical-basal polarity and tight intercellular junctions, acquire migratory and invasive properties characteristic of mesenchymal cells. Under normal conditions, EMT directs essential morphogenetic events in embryogenesis and supports tissue repair. When dysregulated, EMT contributes to pathological processes such as organ fibrosis, chronic inflammation, and cancer progression and metastasis. Matrix metalloproteinases (MMPs)-a family of zinc-dependent proteases that degrade structural components of the extracellular matrix-sit at the nexus of this transition by dismantling basement membranes, activating pro-EMT signaling pathways, and cleaving adhesion molecules. When normally regulated, MMPs promote balanced ECM turnover and support the cyclical remodeling necessary for proper development, wound healing, and tissue homeostasis. When abnormally regulated, MMPs drive excessive ECM turnover, thereby promoting EMT-related pathologies, including tumor progression and fibrotic disease. This review provides an integrated overview of the molecular mechanisms by which MMPs both initiate and sustain EMT under physiological and disease conditions. It discusses how MMPs can potentiate EMT through TGF-β and Wnt/β-catenin signaling, disrupt cell-cell junction proteins, and potentiate the action of hypoxia-inducible factors in the tumor microenvironment. It discusses how these pathologic processes remodel tissues during fibrosis, and fuel cancer cell invasion, metastasis, and resistance to therapy. Finally, the review explores emerging therapeutic strategies that selectively target MMPs and EMT, ranging from CRISPR/Cas-mediated interventions to engineered tissue inhibitors of metalloproteinases (TIMPs), and demonstrates how such approaches may suppress pathological EMT without compromising its indispensable roles in normal biology.

Albumin-based delivery systems: Recent advances, challenges, and opportunities

Albumin and albumin-based biomaterials have been explored for various applications, including therapeutic delivery, as therapeutic agents, as components of tissue adhesives, and in tissue engineering applications. Albumin has been approved as a nanoparticle containing paclitaxel (Abraxane®), as an albumin-binding peptide (Victoza®), and as a glutaraldehyde-crosslinked tissue adhesive (BioGlue®). Albumin is also approved as a supportive therapy for various conditions, including hypoalbuminemia, sepsis, and acute respiratory distress syndrome (ARDS). However, no other new albumin-based systems in a hydrogel format have been used in the clinic. A review of publicly available clinical trials indicates that no new albumin drug delivery formats are currently in the clinical development pipeline. Although albumin has shown promise as a carrier of therapeutics for various diseases, including diabetes, cancers, and infectious diseases, its potential for treating blood-borne diseases such as HIV and leukemia has not been translated. This review offers a perspective on the use of albumin-based drug delivery systems for a broader range of disease applications, considering the protein properties and a review of the currently approved albumin-based technologies. This review supports ongoing efforts to advance biomedical research and clinical interventions through albumin-based delivery systems.

Filtering cells with high mitochondrial content depletes viable metabolically altered malignant cell populations in cancer single-cell studies

BACKGROUND

Single-cell transcriptomics has transformed our understanding of cellular diversity, yet noise from technical artifacts and low-quality cells can obscure key biological signals. A common practice is filtering out cells with a high percentage of mitochondrial RNA counts (pctMT), typically indicative of cell death. However, commonly used filtering thresholds, primarily derived from studies on healthy tissues, may be overly stringent for malignant cells, which often naturally exhibit higher baseline mitochondrial gene expression.

RESULTS

We examine nine public single-cell RNA-seq datasets from various cancers, including 441,445 cells from 134 patients, and public spatial transcriptomics data, assessing the viability of malignant cells with high pctMT. Our analysis reveals that malignant cells exhibit significantly higher pctMT than nonmalignant cells, without a notable increase in dissociation-induced stress scores. Malignant cells with high pctMT show metabolic dysregulation, including increased xenobiotic metabolism, relevant to therapeutic response. Analysis of pctMT in cancer cell lines further reveals links to drug resistance. We also observe associations between pctMT and malignant cell transcriptional heterogeneity, as well as patient clinical features.

CONCLUSIONS

This study provides insights into the functional characteristics of malignant cells with elevated pctMT, challenging current quality control practices in tumor single-cell RNA-seq analyses and offering potential improvements in data interpretation for future cancer studies.

A pH-Responsive Dendritic-DNA-Based Nanohydrogel for Dual Drug Delivery

The rational design of multifunctional drug delivery systems capable of achieving precise drug release remains a huge challenge. Herein, we designed a stimuli-responsive dendritic-DNA-based nanohydrogel as a nanocarrier to achieve the co-delivery of doxorubicin and HMGN5 mRNA-targeting antisense oligonucleotides, thus achieving dual therapeutic effects. The nanocarrier, constructed from dendritic DNA with three crosslinking branches and one loading branch, formed biocompatible and programmable DNA nanohydrogels. The C-rich sequences in the crosslinking branches conferred pH sensitivity, while the loading strand enabled efficient incorporation of a shielding DNA/ASO complex. DOX encapsulation yielded a chemo-gene co-delivery platform. Upon cellular uptake by cancer cells, the nanocarrier disassembled in the acidic tumor microenvironment, releasing DOX for chemotherapy and ASOs via toehold-mediated strand displacement (TMSD) for targeted gene silencing. Cellular studies demonstrated significantly enhanced cancer cell inhibition compared to single-agent treatments, highlighting strong combined effects. This study provides a novel strategy for tumor-microenvironment-responsive co-delivery, enabling precise, on-demand release of therapeutic agents to enhance combined chemo-gene therapy.

Biomimetic Synthesis of Cucurbalsaminone A

Cucurbalsaminones, notable for their unique 5/6/3/6/5-fused pentacyclic triterpenoid structure, are potent inhibitors of P-glycoprotein. In this study, we propose a biosynthetic pathway starting from lanosterol, aiming to elucidate how these types of complex structures are synthesized by nature. Based on this, we present the first synthesis of cucurbalsaminone A in a biomimetic fashion. This synthesis emphasizes key steps including allylic oxidation/olefin isomerization, Lewis acid-mediated sequential migration of Me and H, and the oxa-di-π-methane rearrangement.

Advancements in elucidating the mechanisms of Sorafenib resistance in hepatocellular carcinoma

Primary liver cancer is a major global health challenge, of which hepatocellular carcinoma is the most common. For patients with advanced liver cancer, Sorafenib is a first-line targeted drug that occupies a dominant position in clinical applications. Sorafenib is a multi-kinase inhibitor commonly used in clinical practice, which can effectively inhibit tumor cell proliferation, promote cell apoptosis, and inhibit angiogenesis. However, the emergence of drug resistance has hindered the development of treatment programs, which is an urgent problem to be solved. Recent studies have revealed many mechanisms and influencing factors of Sorafenib resistance (such as epigenetic regulation, programmed cell death, metabolic reprogramming, and tumor microenvironment changes). This review not only summarizes the above mechanisms, but also summarizes the combined application of Sorafenib with other drugs (such as molecular targeted drugs, other anti-angiogenesis drugs, cytotoxic drugs, immunotherapy drugs, etc .). Finally, potential strategies and research directions to overcome drug resistance (such as targeting epigenetic pathways or metabolic reprogramming) are discussed to provide suggestions for future in-depth research and clinical applications.

Novel 1,2,4-triazole-derived Schiff base derivatives: Design, synthesis, and multi-enzyme targeting potential for therapeutic applications

This study synthesized a series of Schiff base derivatives featuring a 1,2,4-triazole framework and characterized through FT-IR, 1H NMR, 13C NMR, 19F NMR, MS, and elemental analysis. Subsequently, the inhibitory activities of these compounds were systematically evaluated in vitro against human carbonic anhydrase (hCA) isozymes I and II, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE). The results revealed that compounds 5a and 5c were particularly effective against cholinesterase enzymes, demonstrating their potential for neuroprotective applications. Meanwhile, compounds 5f and 5g exhibited remarkable inhibition of hCA I and II isozymes, suggesting their promise as selective inhibitors for therapeutic areas. Furthermore, molecular docking analyses revealed strong and specific interactions between the active compounds and enzyme binding sites, further supported by molecular dynamics simulations. Additionally, ADMET profiling of all compounds indicated favourable pharmacokinetic properties. The ADMET results suggest that these compounds hold significant potential for clinical applications in central nervous system and various disorders. These findings strongly suggest that the synthesized compounds are promising candidates for addressing unmet therapeutic needs in neurodegenerative and metabolic disorders, with potential applications in multi-enzyme targeting therapies.

PEGylated Liposomes of Disulfiram and Paclitaxel: A Promising Chemotherapeutic Combination Against Chemoresistant Breast Cancer

Background: Steric stabilization of liposomes using PEGylation has been used widely in pharmaceutical research to overcome the limitations of conventional liposomes and to extend circulation time. PEGylation tended to improve the physicochemical stability and reverse the chemoresistance in multidrug-resistant (MDR) breast cancer cell lines. In this study, PEGylated formulations of disulfiram (DS) and paclitaxel (PAC) were developed using the ethanol-based proliposome technology. Methods: PEGylated liposomal formulations of disulfiram (DS) and paclitaxel (PAC) were developed using the ethanol-based proliposome approach combined with high-pressure homogenization (HPH). The liposomes were characterized for particle size, polydispersity index (PDI), zeta potential, drug loading efficiency (DLE%), and drug entrapment efficiency (DEE%). Cytotoxicity studies were performed on sensitive (MCF7, MDA-MB-231) and chemoresistant (MDA-MB-231PAC10) breast cancer cell lines using the MTT assay to assess the anti-ancer potential of the formulations. Synergistic cytotoxic effects of DS and PAC co-delivery were also evaluated. Results: There was no significant difference in drug loading (DLE%) and drug entrapment efficiency (EE%) between conventional liposomes and the developed PEGylated vesicles. DS demonstrated higher loading in liposomes than PAC, and a greater cytotoxic effect on both sensitive (MCF7 and MDA-MB-231) and chemoresistant (MDA-MB-231PAC10) human breast cancer cell lines. For both DS- and PAC-loaded liposomes, PEGylation did not compromise the cytotoxic effect on both sensitive and chemoresistant cells. Interestingly, the combination of DS- and PAC-loaded PEGylated liposomes had significantly higher cytotoxic effect and lower IC50 than that of each drug alone. Conclusions: Overall, PEGylated liposomal formulation of DS and PAC acted synergistically to reverse the multidrug resistance in breast cancer cells and could serve as a promising system for delivery of PAC and DS simultaneously in one formulation using an alcohol-based proliposome formulation.

Research advances in natural sesquiterpene lactones: overcoming cancer drug resistance through modulation of key signaling pathways

Cancer remains a significant global health challenge, with current chemotherapeutic strategies frequently limited by the emergence of resistance. In this context, natural compounds with the potential to overcome resistance have garnered considerable attention. Among these, sesquiterpene lactones, primarily derived from plants in the Asteraceae family, stand out for their potential anticancer properties. This review specifically focuses on five key signaling pathways: PI3K/Akt/mTOR, NF-κB, Wnt/β-catenin, MAPK/ERK, and STAT3, which play central roles in the mechanisms of cancer resistance. For each of these pathways, we detail their involvement in both cancer development and the emergence of drug resistance. Additionally, we investigate how sesquiterpene lactones modulate these pathways to overcome resistance across diverse cancer types. These insights highlight the potential of sesquiterpene lactones to drive the advancement of novel therapies that can effectively combat both cancer progression and drug resistance.

The human ABCG2 transporter engages three gates to control multidrug extrusion

The human ABCG2 transporter plays roles in physiological detoxification across barriers and in anticancer multidrug resistance. The translocation pathway for drug extrusion and its gating mechanism remains elusive. Here, we demonstrate that the ABCG2 multidrug transporter holds two cavities that are delineated by three regulatory gates, indicating a substrate translocation channel. Drugs are trapped in the central cavity after entering through the pivotal intracellular entry gate. This flexible cavity is surrounded by a cluster of three highly conserved phenylalanines. Their aromatic side chains enact a "clamp-push-seal" motion to ensure unidirectional substrate movement. The unique residues T435 and N436 act as critical selectors for ligands, determining the broad substrate specificity. The upper cavity is covered by the lid architecture, constituting the final gate before multidrug extrusion. This work unravels deep mechanistic details on how the translocation channel utilizes pivotal gating steps, including the sequence of events that drive ABCG2-mediated multidrug efflux.

A Nomogram Based on Tumor Response to Induction Chemotherapy and Plasma Epstein-Barr Virus DNA Level after Induction Chemotherapy to Explore Individualized Treatment of Patients with Locally Advanced Nasopharyngeal Carcinoma

Purpose

To explore the influence of Epstein-Barr virus (EBV) DNA levels before and after induction chemotherapy (IC), tumor response to IC, and baseline factors on overall survival (OS) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC). A nomogram was subsequently constructed to explore the individualized optimal cumulative cisplatin dose (CCD) in concurrent chemoradiotherapy (CCRT).

Methods

A total of 581 LA-NPC patients were included, randomly divided into training and validation cohorts in a 7:3 ratio. In the training cohort, a nomogram was subsequently established based on multivariate Cox regression analysis and then validated. Subsequently, patients were classified into different risk groups based on the nomogram, and the impact of different levels of CCD on survival outcomes was evaluated.

Results

EBV DNA levels after IC, tumor response to IC, age, and LDH were independent prognostic factors of OS. Schoenfeld residual analysis indicated overall satisfaction of the proportional hazards assumption for the Cox regression model. The C-index of the nomogram was 0.758 (95% CI: 0.695-0.821) for the training cohort and 0.701 (95% CI: 0.589-0.813) for the validation cohort. Calibration curves demonstrated good correlation between the nomogram and actual survival outcomes. DCA confirmed the clinical utility enhancement of the nomogram over the TNM staging system. For OS, patients in the medium/high-risk group with a CCD > 200 mg/m² had better outcomes than those with CCD ≤ 200 mg/m², although the difference was not statistically significant (p = 0.097). No significant difference was observed in local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) across various levels of CCD in different risk subgroups (p > 0.05).

Conclusion

The nomogram based on EBV DNA levels after IC, tumor response, LDH, and age effectively predicts OS in LA-NPC patients, aids in risk stratification, and may guide treatment decisions.

Repurposing ProTAME for Bladder Cancer: A Combined Therapeutic Approach Targeting Cell Migration and MMP Regulation

Bladder cancer, the fourth most common cancer type among men, remains a therapeutic challenge due to its heterogeneity and frequent development of chemoresistance. Cisplatin-based chemotherapy, often combined with gemcitabine, is the standard treatment, yet resistance and off-target effects in non-cancerous tissues limit its efficacy. This study evaluated the effects of cisplatin, gemcitabine, and the APC/C inhibitor proTAME, both individually and in combination, on cell migration and MMP2/MMP9 expression in RT4 bladder cancer and ARPE-19 normal epithelial cells. Molecular docking analyses were conducted to investigate the interactions of these compounds with MMP2 and MMP9. IC20 values for gemcitabine, cisplatin, and proTAME were applied in scratch-wound healing and quantitative real-time PCR (qRT-PCR) assays. Docking results predicted that proTAME may interact favorably with MMP2 (-9.2 kcal/mol) and MMP9 (-8.7 kcal/mol), showing high computational binding affinities and potential key hydrogen bonds; however, these interactions require further experimental validation. Scratch-wound healing and qRT-PCR assays demonstrated that proTAME-containing combinations were associated with reduced cell migration and decreased MMP2 and MMP9 expression in RT4 cells. Cisplatin combined with proTAME showed the most pronounced reduction in MMP expression and cell migration, with proTAME alone also exhibiting notable inhibitory effects. In ARPE-19 cells, gemcitabine and cisplatin upregulated MMP2 and MMP9 expression, suggesting a potential stress response, whereas proTAME mitigated this effect. These differential effects show the importance of tumor-specific responses in RT4 cells, where proTAME shows promise in enhancing the efficacy of chemotherapy by modulating MMP-related pathways involved in tumor migration and invasion. In conclusion, this study highlights the potential of proTAME as a repurposed agent in bladder cancer treatment due to its association with reduced cell migration and MMP downregulation. While these in vitro and in silico findings suggest a promising role for proTAME in combination therapies, further validation in advanced preclinical models is necessary to assess its therapeutic applicability and safety.

DOT1L Mediates Stem Cell Maintenance and Represents a Therapeutic Vulnerability in Cancer

Tumor-initiating cancer stem cells (CSC) pose a challenge in human malignancies as they are largely treatment resistant and can seed local recurrence and metastasis. Epigenetic mechanisms governing cell fate decisions in embryonic and adult stem cells are deregulated in CSCs. This review focuses on the methyltransferase disruptor of telomeric silencing protein 1-like (DOT1L), which methylates histone H3 lysine 79 and is a key epigenetic regulator governing embryonic organogenesis and adult tissue stem cell maintenance. DOT1L is overexpressed in many human malignancies, and dysregulated histone H3 lysine 79 methylation is pathogenic in acute myeloid leukemia and several solid tumors. DOT1L regulates core stem cell genes governing CSC self-renewal, tumorigenesis, and multidrug resistance. Recent work has situated DOT1L as an attractive stem cell target in cancer. These reports showed that DOT1L is overexpressed and its protein activated specifically in malignant stem cells compared with bulk tumor cells, making them vulnerable to DOT1L inhibition in vitro and in vivo. Although early DOT1L inhibitor clinical trials were limited by inadequate drug bioavailability, accumulating preclinical data indicate that DOT1L critically regulates CSC self-renewal and might be more effective when given with other anticancer therapies. The appropriate combinations of DOT1L inhibitors with other agents and the sequence and timing of drug delivery for maximum efficacy warrant further investigation.

Epigenetic code underlying EGFR-TKI resistance in non-small cell lung cancer: Elucidation of mechanisms and perspectives on therapeutic strategies

Non-small-cell lung cancer (NSCLC) is the most common lung cancer subtype, and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the core drugs used for its treatment. However, the emergence of drug resistance poses a significant challenge to their clinical efficacy. As a significant role-player in cancer development and maintenance, histone modifications, DNA methylation and noncoding RNA (ncRNA) changes have been proven to play a crucial part in driving EGFR-TKI resistance, which provides promising potential therapeutic targets and biomarkers for overcoming drug resistance. This review delves into the complex epigenetic mechanisms that cause EGFR-TKI resistance and emphasizes the potential of combined epigenetic therapies, aiming to provide better-targeted treatment options for NSCLC patients with NSCLC and drive innovative strategies to overcome the challenges of drug resistance.

Cancer stem-like cells stay in a plastic state ready for tumor evolution

Cell plasticity emerges as a novel cancer hallmark and is pivotal in driving tumor heterogeneity and adaptive resistance to different therapies. Cancer stem-like cells (CSCs) are considered the root of cancer. While first defined as tumor-initiating cells with the potential to develop a heterogeneous tumor, CSCs further demonstrate their roles in cancer metastasis and adaptive therapeutic resistance. Generally, CSCs come from the malignant transformation of somatic stem cells or the de-differentiation of other cancer cells. The resultant cells gain more plasticity and are ready to differentiate into different cell states, enabling them to adapt to therapies and metastatic ecosystems. Therefore, CSCs are likely the nature of tumor cells that gain cell plasticity. However, the phenotypic plasticity of CSCs has never been systematically discussed. Here, we review the distinct intrinsic signaling pathways and unique microenvironmental niches that endow CSC plasticity in solid tumors to adapt to stressful conditions, as well as emerging opportunities for CSC-targeted therapy.

Targeted nanodelivery systems for personalized cancer therapy

Conventional cancer therapies such as chemotherapy face challenges such as poor tumor targeting, systemic toxicity, and drug resistance. Nanotechnology offers solutions through advanced drug delivery systems that preferentially accumulate in tumors while avoiding healthy tissues. Recent innovations have enabled the optimization of engineered nanocarriers for extended circulation and tumor localization via both passive and active targeting mechanisms. Passive accumulation exploits the leaky vasculature of tumors, whereas active strategies use ligands to selectively bind cancer cell receptors. Multifunctional nanoparticles also allow the combination of imaging, multiple therapeutic modalities and on-demand drug release within a single platform. Overall, precisely tailored nanotherapeutics that leverage unique pathophysiological traits of malignancies provide opportunities to overcome the limitations of traditional treatment regimens. This emerging field promises more effective and personalized nanomedicine approaches to detect and treat cancer. The key aspects highlighted in this review include the biological barriers associated with nanoparticles, rational design principles to optimize nanocarrier pharmacokinetics and tumor uptake, passive and active targeting strategies, multifunctionality, and reversal of multidrug resistance.

Targeting epithelial-mesenchymal transition signaling pathways with Dietary Phytocompounds and repurposed drug combinations for overcoming drug resistance in various cancers

The epithelial-to-mesenchymal transition (EMT) is a crucial step in metastasis formation. It enhances the ability of cancer cells' to self-renew and initiate tumors, while also increasing resistance to apoptosis and chemotherapy. Among the signaling pathways a few signaling pathways such as Notch, TGF-beta, and Wnt-beta catenin are critically involved in the epithelial-to-mesenchymal transition (EMT) acquisition. Therefore, regulating EMT is a key strategy for controlling malignant cell behavior. This is done by interconnecting other signaling pathways in many cancer types. Although there is extensive preclinical evidence regarding EMT's function in the development of cancer, there is still a deficiency in clinical translation at the therapeutic level. Thus, there is a need for medications that are both highly effective and with low cytotoxic for modulating EMT transitions at ground level. Thus, this led to the study of the evaluation and efficiency of phytochemicals found in dietary sources of fruits and vegetables and also the combination of small molecular repurposed drugs that can enhance the effectiveness of traditional cancer treatments. This review summarises major EMT-associated pathways and their cross talks with their mechanistic insights and the role of different dietary phytochemicals (curcumin, ginger, fennel, black pepper, and clove) and their natural analogs and also repurposed drugs (metformin, statin, chloroquine, and vitamin D) which are commonly used in regulating EMT in various preclinical studies. This review also investigates the concept of low-toxicity and broad spectrum ("The Halifax Project") approach which can help for site targeting of several key pathways and their mechanism. We also discuss the mechanisms of action, models for our dietary phytochemicals, and repurposed drugs and their combinations used to identify potential anti-EMT activities. Additionally, we also analyzed existing literature and proposed new directions for accelerating the discovery of novel drug candidates that are safe to administer.

Computational development of mushroom-6-glucan/paclitaxel as a synergistic complementary medicine for breast cancer therapy

BACKGROUND

Breast cancer is chemo-resistant and highly metastatic, often resulting in patient mortality. One of the primary factors contributing to the metastasis and chemotherapy resistance is the presence of cancer stem-like cells. We posited that the natural polysaccharide known as 6-glucans, derived from Pleurotus ostreatus, could effectively counteract the chemotherapy resistance associated with cancer stem-like cells in breast cancer.

METHODS

We computationally developed a specific dual combinatorial therapy involving 6-glucans and Paclitaxel (PTX) and tested on preclinical 3D mammosphere human tumor models representing receptor-positive and receptor-negative breast cancer. Using this preclinical 3D spheroid technology, we tested the anti-cancer properties of these predicted treatment combinations on mammospheres containing human breast cancer stem cells.

RESULTS

Among the 40 distinct combinations examined, computational prediction revealed that the addition of 2.0 mg/mL of 6-glucans to a low dose of 3.0 µg/mL PTX was the sole combination demonstrating a synergistic effect. This optimized synergistic combination therapy displayed a significant inhibitory impact on human cancer epithelial and stem cell migration, evasion, and colony formation. The inclusion of 6-glucans also augmented apoptosis in both breast cancer cells and stem cells, leading to a six-fold reduction in BrdU labeled cells and an increased arrest of cells in the sub-G0 phase. These effects were mediated through mitochondrial dysfunction and the downregulation of associated oncogenes.

CONCLUSION

Our study revealed that the computationally predicted 6-glucans-based binary complementary medicine exhibited sequence- and concentration-dependent anticancer synergistic effects.

Cancer stem cells and tumor-associated macrophages as mates in tumor progression: mechanisms of crosstalk and advanced bioinformatic tools to dissect their phenotypes and interaction

Cancer stem cells (CSCs) are a small subset within the tumor mass significantly contributing to cancer progression through dysregulation of various oncogenic pathways, driving tumor growth, chemoresistance and metastasis formation. The aggressive behavior of CSCs is guided by several intracellular signaling pathways such as WNT, NF-kappa-B, NOTCH, Hedgehog, JAK-STAT, PI3K/AKT1/MTOR, TGF/SMAD, PPAR and MAPK kinases, as well as extracellular vesicles such as exosomes, and extracellular signaling molecules such as cytokines, chemokines, pro-angiogenetic and growth factors, which finely regulate CSC phenotype. In this scenario, tumor microenvironment (TME) is a key player in the establishment of a permissive tumor niche, where CSCs engage in intricate communications with diverse immune cells. The "oncogenic" immune cells are mainly represented by B and T lymphocytes, NK cells, and dendritic cells. Among immune cells, macrophages exhibit a more plastic and adaptable phenotype due to their different subpopulations, which are characterized by both immunosuppressive and inflammatory phenotypes. Specifically, tumor-associated macrophages (TAMs) create an immunosuppressive milieu through the production of a plethora of paracrine factors (IL-6, IL-12, TNF-alpha, TGF-beta, CCL1, CCL18) promoting the acquisition by CSCs of a stem-like, invasive and metastatic phenotype. TAMs have demonstrated the ability to communicate with CSCs via direct ligand/receptor (such as CD90/CD11b, LSECtin/BTN3A3, EPHA4/Ephrin) interaction. On the other hand, CSCs exhibited their capacity to influence immune cells, creating a favorable microenvironment for cancer progression. Interestingly, the bidirectional influence of CSCs and TME leads to an epigenetic reprogramming which sustains malignant transformation. Nowadays, the integration of biological and computational data obtained by cutting-edge technologies (single-cell RNA sequencing, spatial transcriptomics, trajectory analysis) has significantly improved the comprehension of the biunivocal multicellular dialogue, providing a comprehensive view of the heterogeneity and dynamics of CSCs, and uncovering alternative mechanisms of immune evasion and therapeutic resistance. Moreover, the combination of biology and computational data will lead to the development of innovative target therapies dampening CSC-TME interaction. Here, we aim to elucidate the most recent insights on CSCs biology and their complex interactions with TME immune cells, specifically TAMs, tracing an exhaustive scenario from the primary tumor to metastasis formation.

Vodobatinib overcomes cancer multidrug resistance by attenuating the drug efflux function of ABCB1 and ABCG2

Multidrug resistance (MDR) remains a significant obstacle in cancer treatment, primarily attributable to the overexpression of ATP-binding cassette (ABC) transporters such as ABCB1 and ABCG2 within cancer cells. These transporters actively diminish the effectiveness of cytotoxic drugs by facilitating ATP hydrolysis-dependent drug efflux, thereby reducing intracellular drug accumulation. Given the absence of approved treatments for multidrug-resistant cancers and the established benefits of combining tyrosine kinase inhibitors (TKIs) with conventional anticancer drugs, we investigate the potential of vodobatinib, a potent c-Abl TKI presently in clinical trials, to restore sensitivity to chemotherapeutic agents in multidrug-resistant cancer cells overexpressing ABCB1 and ABCG2. Results indicate that vodobatinib, administered at sub-toxic concentrations, effectively restores the sensitivity of multidrug-resistant cancer cells to cytotoxic drugs in a concentration-dependent manner. Moreover, vodobatinib enhances drug-induced apoptosis in these cells by inhibiting the drug-efflux function of ABCB1 and ABCG2, while maintaining their expression levels. Moreover, we found that while vodobatinib enhances the ATPase activity of ABCB1 and ABCG2, the overexpression of these transporters does not induce resistance to vodobatinib. These results strongly suggest that increased levels of ABCB1 or ABCG2 are unlikely to play a significant role in the development of resistance to vodobatinib in cancer patients. Overall, our findings unveil an additional pharmacological facet of vodobatinib against ABCB1 and ABCG2 activity, suggesting its potential incorporation into combination therapy for a specific subset of patients with tumors characterized by high ABCB1 or ABCG2 levels. Further investigation is warranted to fully elucidate the clinical implications of this therapeutic approach.

3D Bioprinted Multidrug Resistance (MDR)-Dependent Tumor Spheroids

Multidrug resistance (MDR) refers to the ability of cancer cells to resist various anticancer drugs and release them from the cells. This phenomenon is widely recognized as a significant barrier that must be overcome in chemotherapy. MDR varies depending on the number and expression level of the ATP-binding cassette transporter (ABC transporter), which is expressed differently in various cancer cells. Therefore, the dose of anticancer drugs should be adjusted according to the extent of MDR. The demand for drug screening that considers the differences in MDR is increasing in the process of drug discovery. In this study, three types of tumor spheroids were fabricated from HeLa (MRP1-/BCRP-), HepG2 (MRP1+/BCRP-), and A549 cells (MRP1+/BCRP+) using three-dimensional (3D) bioprinting. The fabricated tumor spheroids maintained their own MDR phenotypes. The EC50 values of doxorubicin (DOX) against the three tumor spheroids were more than 2-fold higher than those against the 2D cells. In addition, the EC50 value of DOX against tumor spheroids was proportional to the number of ABC transporters. The EC50 value of DOX against A549 tumor spheroids had the largest value of 9.5 μM among the three spheroids. In addition, the EC50 values of DOX against HepG2 and A549 tumor spheroids were remarkably reduced when they were treated with ABC transporter inhibitors, such as MK-571 against MRP1 and/or NOV against BCRP. These results demonstrate the successful construction of a 3D bioprinting-based screening platform to quantitatively evaluate the anticancer efficacy of chemodrugs, considering the MDR of cancer cells.

Doxorubicin and topotecan resistance in ovarian cancer: Gene expression and microenvironment analysis in 2D and 3D models

This study explores the mechanisms underlying chemotherapy resistance in ovarian cancer (OC) using doxorubicin (DOX) and topotecan (TOP)-resistant cell lines derived from the drug-sensitive A2780 ovarian cancer cell line. Both two-dimensional (2D) monolayer cell cultures and three-dimensional (3D) spheroid models were employed to examine the differential drug responses in these environments. The results revealed that 3D spheroids demonstrated significantly higher resistance to DOX and TOP than 2D cultures, suggesting a closer mimicry of in vivo tumour conditions. Molecular analyses identified overexpression of essential drug resistance-related genes, including MDR1 and BCRP, and extracellular matrix (ECM) components, such as MYOT and SPP1, which were more pronounced in resistant cell lines. MDR1 and BCRP overexpression contribute to chemotherapy resistance in OC by expelling drugs like DOX and TOP. Targeting these transporters with inhibitors or gene silencing could improve drug efficacy, making them key therapeutic targets to enhance treatment outcomes for drug-resistant OC. The study further showed that EMT-associated markers, including VIM, SNAIL1, and SNAIL2, were upregulated in the 3D spheroids, reflecting a more mesenchymal phenotype. These findings suggest that factors beyond gene expression, such as spheroid architecture, cell-cell interactions, and drug penetration, contribute to the enhanced resistance observed in 3D cultures. These results highlight the importance of 3D cell culture models for a more accurate representation of tumour drug resistance mechanisms in ovarian cancer, providing valuable insights for therapeutic development.

A review on phytochemicals as combating weapon for multidrug resistance in cancer

One can recognize multidrug resistance (MDR) and residue as a biggest difficulty in cancer specialist. Chemotherapy-resistant cancer may be successfully treated by combining MDR-reversing phytochemicals with anticancer drugs. Though, clinical application of phytochemicals either alone or in conjunction with chemotherapy is still in its early stages or requires more research to determine their safety and efficacy. In this review we highlighted topics related to MDR in cancer, including an introduction to subject, mechanism of action of efflux pump, specific proteins involved in drug resistance, altered drug targets, increased drug metabolism, and potential role of phytochemicals in overcoming drug resistance.

The association of ABC proteins with multidrug resistance in cancer

Multidrug resistance (MDR) poses one of the primary challenges for cancer treatment, especially in cases of metastatic disease. Various mechanisms contribute to MDR, including the overexpression of ATP-binding cassette (ABC) proteins. In this context, we reviewed the literature to establish a correlation between the overexpression of ABC proteins and MDR in cancer, considering both in vitro and clinical studies. Initially, we presented an overview of the seven subfamilies of ABC proteins, along with the subcellular localization of each protein. Subsequently, we identified a panel of 20 ABC proteins (ABCA1-3, ABCA7, ABCB1-2, ABCB4-6, ABCC1-5, ABCC10-11, ABCE1, ABCF2, ABCG1, and ABCG2) associated with MDR. We also emphasize the significance of drug sequestration by certain ABC proteins into intracellular compartments. Among the anticancer drugs linked to MDR, 29 were definitively identified as substrates for at least one of the three most crucial ABC transporters: ABCB1, ABCC1, and ABCG2. We further discussed that the most commonly used drugs in standard regimens for mainly breast cancer, lung cancer, and acute lymphoblastic leukemia could be subject to MDR mediated by ABC transporters. Collectively, these insights will aid in conducting new studies aimed at a deeper understanding of the clinical MDR mediated by ABC proteins and in designing more effective pharmacological treatments to enhance the objective response rate in cancer patients.

Boron Clusters Escort Doxorubicin Squashing Into Exosomes and Overcome Drug Resistance

Exosome-based drug delivery holds significant promise for cancer chemotherapy. However, current methods for loading drugs into exosomes are inefficient and cost-prohibitive for practical application. In this study, boron clusters are mixed with doxorubicin (DOX) and exosomes, enabling the efficient encapsulation of DOX into exosomes through a superchaotropic effect. Exosomes loaded with DOX and boron clusters (EDB) exhibit superior permeability and the ability to deliver higher concentrations of DOX into DOX-resistant breast cancer cells. Mechanistic analysis reveals that boron clusters form a supramolecular complex with DOX, which facilitates sustained drug release and effectively inhibits P-glycoprotein-mediated DOX efflux. As a result, EDB significantly enhance apoptosis in DOX-resistant breast cancer cells and suppress tumor growth in cases where DOX alone is ineffective, thereby extending the survival of nude mice. In summary, boron clusters effectively facilitate the incorporation of DOX into exosomes and inhibit DOX efflux, offering a novel strategy to overcome DOX resistance.

Chitosan and hyaluronic acid in colorectal cancer therapy: A review on EMT regulation, metastasis, and overcoming drug resistance

Up to 90% of cancer-related fatalities could be attributed to metastasis. Therefore, understanding the mechanisms that facilitate tumor cell metastasis is beneficial for improving patient survival and results. EMT is considered the main process involved in the invasion and spread of CRC. Essential molecular components like Wnt, TGF-β, and PI3K/Akt play a role in controlling EMT in CRC, frequently triggered by various factors such as Snail, Twist, and ZEB1. These factors affect not only the spread of CRC but also determine the reaction to chemotherapy. The influence of non-coding RNAs, especially miRNAs and lncRNAs, on the regulation of EMT is clear in CRC. Exosomes, involved in cell-to-cell communication, can affect the TME and metastasis of CRC. Pharmacological substances and nanoparticles demonstrate promise as efficient modulators of EMT in CRC. Chitosan and HA are two major carbohydrate polymers with considerable potential in inhibiting CRC. Chitosan and HA can be employed to modify nanoparticles to enhance cargo transport for reducing CRC. Additionally, chitosan and HA-modified nanocarriers, which can be utilized as potential approaches in suppressing EMT and reversing drug resistance in CRC, can inhibit EMT and chemoresistance, crucial components in tumorigenesis.

Technological advances in clinical individualized medication for cancer therapy: from genes to whole organism

Efforts have been made to leverage technology to accurately identify tumor characteristics and predict how each cancer patient may respond to medications. This involves collecting data from various sources such as genomic data, histological information, functional drug profiling, and drug metabolism using techniques like polymerase chain reaction, sanger sequencing, next-generation sequencing, fluorescence in situ hybridization, immunohistochemistry staining, patient-derived tumor xenograft models, patient-derived organoid models, and therapeutic drug monitoring. The utilization of diverse detection technologies in clinical practice has made "individualized treatment" possible, but the desired level of accuracy has not been fully attained yet. Here, we briefly summarize the conventional and state-of-the-art technologies contributing to individualized medication in clinical settings, aiming to explore therapy options enhancing clinical outcomes.

Core-Shell Nanoparticles with Sequential Drug Release Depleting Cholesterol for Reverse Tumor Multidrug Resistance

Multidrug resistance (MDR) facilitates tumor recurrence and metastasis, which has become a main cause of chemotherapy failure in clinical. However, the current therapeutic effects against MDR remain unsatisfactory, mainly hampered by the rigid structure of drug-resistant cell membranes and the uncontrolled drug release. In this study, based on a sequential drug release strategy, we engineered a core-shell nanoparticle (DOX-M@CaP@ATV@HA) depleting cholesterol for reverse tumor MDR. DOX-M@CaP@ATV@HA could accurately target tumor cells due to the active targetability of hyaluronic acid (HA) toward CD44 receptors. The calcium phosphate (CaP) shell was cleaved in the lysosomal acidic environment so that the cholesterol-lowering drug atorvastatin (ATV) was rapidly released to diminish cholesterol and P-glycoprotein (P-gp) level on the membrane, thereby boosting tumor cell drug uptake. Next, doxorubicin (DOX) was gradually released from the hydrophobic core of the mPEG-DSPE micelle, inflicting irreversible DNA damage and triggering apoptosis. The nanosystem was proven both in vitro and in vivo to reverse MDR effectively and exhibited a remarkable therapeutic efficacy on drug-resistant tumors with high biosafety. In conclusion, DOX-M@CaP@ATV@HA effectively reverses MDR via cholesterol depletion, which provides an innovative strategy for tumor MDR treatment.

The Role of Elacridar, a P-gp Inhibitor, in the Re-Sensitization of PAC-Resistant Ovarian Cancer Cell Lines to Cytotoxic Drugs in 2D and 3D Cell Culture Models

Chemotherapy resistance is a significant barrier to effective cancer treatment. A key mechanism of resistance at the single-cell level is the overexpression of drug transporters in the ABC family, particularly P-glycoprotein (P-gp), which leads to multidrug resistance (MDR). Inhibitors of these transporters can help re-sensitize cancer cells to chemotherapeutics. This study evaluated elacridar (GG918 and GF120918), a potent third-generation P-gp inhibitor, for its ability to reverse MDR in paclitaxel (PAC)-resistant ovarian cancer cell lines. Sensitive and PAC-resistant cells were cultured in two-dimensional (2D) and three-dimensional (3D) models. MDR1 gene expression was analyzed using Q-PCR, and P-gp protein expression was examined via Western blot and immunofluorescence. Drug sensitivity was evaluated with MTT assays, and P-gp activity was analyzed by flow cytometry and fluorescence microscopy. Elacridar effectively inhibited P-gp activity and increased sensitivity to PAC and doxorubicin (DOX) in 2D cultures but not cisplatin (CIS). In 3D spheroids, P-gp activity inhibition was observed via Calcein-AM staining. However, no re-sensitization to PAC occurred and limited improvement was observed for DOX. These findings suggest that elacridar effectively inhibits P-gp in both 2D and 3D conditions. However, its ability to overcome drug resistance in 3D models is limited, highlighting the complexity of tissue-specific resistance mechanisms.

Targeting cyclin-dependent kinase 11: a computational approach for natural anti-cancer compound discovery

Cancer, a leading global cause of death, presents considerable treatment challenges due to resistance to conventional therapies like chemotherapy and radiotherapy. Cyclin-dependent kinase 11 (CDK11), which plays a pivotal role in cell cycle regulation and transcription, is overexpressed in various cancers and is linked to poor prognosis. This study focused on identifying potential inhibitors of CDK11 using computational drug discovery methods. Techniques such as pharmacophore modeling, virtual screening, molecular docking, ADMET predictions, molecular dynamics simulations, and binding free energy analysis were applied to screen a large natural product database. Three pharmacophore models were validated, leading to the identification of several promising compounds with stronger binding affinities than the reference inhibitor. ADMET profiling indicated favorable drug-like properties, while molecular dynamics simulations confirmed the stability and favorable interactions of top candidates with CDK11. Binding free energy calculations further revealed that UNPD29888 exhibited the strongest binding affinity. In conclusion, the identified compound shows potential as a CDK11 inhibitor based on computational predictions, suggesting their future application in cancer treatment by targeting CDK11. These computational findings encourage further experimental validation as anti-cancer agents.

Combination effects of Pistachio hull and carfilzomib on NF-κB p65, MDR1, MRP1, and Caspase3 gene expression in breast cancer cell line

OBJECTIVE

This study aimed to investigate the synergistic effects of the chemotherapy drug Carfilzomib (CFZ) and Pistachio hull extract on the SK-BR3 breast cancer cell line.

METHODS

In this experimental study, we evaluated the effect of Pistachio hull extract and CFZ as standalone treatments on cell viability using the MTT assay at 24- and 48-hours post-treatment. Following this, we conducted combination therapy analyses to assess the potential synergistic relationship between Pistachio hull extract and CFZ after 24- and 48-hours of treatment on both the SK-BR3 breast cancer cell line and the MCF10A normal cell line. We utilized real-time PCR to measure the expression levels of MDR1, MRP1, NF-κB p65, and Caspase3 genes. Additionally, the NF-κB p65 transcription factor was evaluated using ELISA after 24- and 48-hours.

RESULTS

The MTT assay revealed IC50 values of 2.014 mg/mL and 1.031 mg/mL in the SK-BR3 cell line, and 3.265 mg/mL and 2.994 mg/mL in the MCF10A cell line at 24- and 48-hours post-treatment with Pistachio hull extract. CFZ concentrations of 0.181 × 10- 3 mg/mL and 0.0057 × 10- 3 mg/mL in the SK-BR3 cell line, as well as 5.54 × 10- 3 mg/mL and 2.51 × 10- 3 mg/mL in the MCF10A cell line, inhibited growth by up to 50%. The analysis of combination therapy indicated a synergistic effect between the two treatments after both 24- and 48-hours of exposure. Real-time PCR results demonstrated significant alterations in the expression of MDR1, MRP1, NF-κB p65, and Caspase3 genes, along with changes in NF-κB p65 protein levels in both cell lines following treatment with Pistachio hull extract, CFZ, or their combination compared to the control group (p < 0.05).

CONCLUSION

The findings highlight the effectiveness of CFZ as a proteasome inhibitor when used in conjunction with Pistachio hull extract in breast cancer cell lines. Therefore, both CFZ and Pistachio hull extract, whether administered alone or in combination, represent promising molecular targets for breast cancer treatment.

Design, synthesis and biological evaluation of biaryl amide derivatives as modulators of multi-drug resistance

The emergence of multi-drug resistance (MDR) presents a significant impediment to the efficacy of cancer treatment. Aberrant expression of ABC (ATP-binding cassette) transporters is acknowledged as one of the underlying factors contributing to MDR. P-glycoprotein (P-gp, MDR1, ABCB1), breast cancer resistance protein (BCRP, ABCG2), and MDR-associated protein 1 (MRP1, ABCC1) are members of the ABC transporter, and their over-expression usually occurs in drug-resistant tumor cells. In this work, the structure-activity relationships of the biaryl amide skeleton were systematically investigated via structural optimization step by step, which led to the identification of an exceptionally potent resistance reversal agent, D2. Compound D2 effectively reversed MDR to paclitaxel and cisplatin in A2780/T, A2780/CDDP and A549/T cell lines. It could directly bind to P-gp and downregulate the expression of both P-gp and MRP1. The treatment with D2 increased the intracellular accumulation of Rh123 and inhibited P-gp-mediated drug efflux of Rh123 in A2780/T cells. Therefore, compound D2 exhibits promising potential in overcoming multidrug resistance (MDR) induced by P-gp in cancer.