Aim: Cisplatin resistance remains a major obstacle to the effective treatment of tongue squamous cell carcinoma (TSCC). This study is dedicated to elucidating the role and mechanism of circular RNA (circRNA) hsa-circ-0001030 in modulating cisplatin sensitivity and metabolic reprogramming in TSCC.
Methods: CircRNA sequencing, quantitative polymerase chain reaction, and RNA fluorescence in situ hybridization were used to test hsa-circ-0001030 expression in TSCC tissues and cell lines. Gain-of-function assays (colony formation, cell counting kit-8, Transwell assay, and xenograft models) were conducted to evaluate proliferation, invasion, and cisplatin response. Mechanistic studies, including RNA pull-down, RNA-binding protein immunoprecipitation, and western blotting, were performed to identify pyruvate kinase M2 (PKM2) as a binding partner of hsa-circ-0001030 and to assess glycolytic activity, glucose uptake, and lactate production.
Results: Hsa-circ-0001030 was markedly downregulated in TSCC and cisplatin-resistant cells. Overexpression of hsa-circ-0001030 suppressed tumor growth, migration, and glycolytic flux, while enhancing cisplatin sensitivity both in vitro and in vivo. Mechanistically, hsa-circ-0001030 directly bound to PKM2 at nucleotides 138-169, inhibited PKM2 enzymatic activity, restraining tetramer formation and increased tyrosine 105 (Tyr105) phosphorylation and thereby blocking PKM2-driven glycolysis. Clinically, low hsa-circ-0001030 expression correlated with advanced tumor-node-metastasis stage, poor differentiation, and unsatisfying prognosis in TSCC patients.
Conclusion: Hsa-circ-0001030 acted as a tumor-suppressive circRNA that might depress PKM2-dependent metabolic reprogramming and cisplatin resistance in TSCC, highlighting its potential as a prognostic biomarker and therapeutic target for overcoming chemoresistance.
Aim: Antibody-drug conjugates (ADCs) feature an antibody recognizing a specific protein joined to a potent toxic payload. Numerous ADCs have received U.S. Food and Drug Administration (FDA) approval; however, clinical resistance arises. Resistance mechanisms include decreased expression or mutation of the antibody target, impaired payload release, or increased expression of adenosine triphosphate (ATP)-binding cassette (ABC) efflux transporters associated with multidrug resistance. We therefore sought to characterize the interactions of ABC multidrug transporters with ADC payloads.
Methods: We performed a high-throughput screen with 27 common ADC payloads using cell lines expressing ABC transporters P-glycoprotein [P-gp, encoded by ABC subfamily B member 1 (ABCB1)] or ABC subfamily B member G2 (ABCG2, encoded by ABCG2). Confirmatory assays were also performed using cells transfected to express P-gp, ABCG2, or multidrug resistance-associated protein 1 (MRP1, encoded by ABCC1).
Results: Several commonly used ADC payloads were substrates of P-gp, including calicheamicin γ1, monomethyl auristatin E, mertansine (DM1), and ravtansine (DM4). All the pyrrolobenzodiazepines tested - SJG136, SGD-1882, SG2057, and SG3199 - were substrates of P-gp, ABCG2, and MRP1. The modified anthracyclines nemorubicin and its metabolite PNU-159682 were poorly transported by both ABCB1 and ABCG2 and displayed nanomolar to picomolar toxicity. Further, we found that the efficacy of the FDA-approved ADC mirvetuximab soravtansine, with DM4 as the toxic payload, was decreased in cell lines expressing P-gp. In contrast, Duocarmycin DM and PNU-159682 were exquisitely toxic to a panel of 99 cancer cell lines of varying origins.
Conclusion: Several commonly used ADC payloads can be transported by ABC transporters, potentially leading to transporter-mediated drug resistance in patients. Future ADCs should be developed using payloads that are not ABC transporter substrates.
The reciprocal feedback between cancer stem cells (CSCs) and cancer-associated fibroblasts (CAFs) is increasingly recognized as a driver of therapeutic resistance and tumor evolution. According to the “soil and seed” hypothesis, CAFs create a biochemical and biomechanical “soil” for CSCs to seed, grow, and thrive. In turn, CSCs manipulate and transform fibroblasts to promote CSC traits, thus completing the loop of CAF-CSC crosstalk through bidirectional molecular communication within the tumor microenvironment. This review encompasses recent advances in CAF heterogeneity, including conserved and malignancy-specific subtypes, as well as the molecular dialogue driving resistance. We also briefly discuss emerging therapeutic approaches, particularly the potential of natural compounds to target both CSCs and CAFs. By bridging mechanistic insights with translational innovations, this review provides a roadmap for breaking the CSC-CAF alliance, offering hope for overcoming therapeutic resistance and improving cancer outcomes.
Aim: Non-small cell lung cancer (NSCLC) represents most lung cancer cases and remains associated with poor outcomes, mainly due to multidrug resistance (MDR). Extracellular vesicles (EVs) are crucial for intercellular communication and significantly influence chemotherapy resistance. This study aimed to characterize the EVs proteome of drug-sensitive and MDR NSCLC cell lines to identify therapeutic targets to counteract MDR.
Methods: EVs derived from NSCLC cells were isolated by ultracentrifugation and analyzed for size by nanoparticle tracking analysis, for morphology by transmission electron microscopy, and for EVs markers by Western blotting (WB). Proteomic profiling was performed using liquid chromatography-mass spectrometry (LC-MS), followed by WB validation of relevant proteins. Cell growth and viability were assessed using sulforhodamine B or CellTiter-Glo assays. P-glycoprotein [P-gp, also known as ABCB1: adenosine triphosphate (ATP)-binding cassette subfamily B member 1] activity was determined by rhodamine-123 accumulation assay. SRC-related signaling was investigated by WB.
Results: EVs from the multidrug resistant (MDR) derivative of NCI-H460, a human NSCLC cell line, displayed nine up- and eight down-regulated proteins compared with the drug-sensitive parental cells, including reduced SRC. WB results showed higher phosphorylated form of SRC (p-SRC) expression in MDR cells than in sensitive cells. In contrast, EVs from both cell lines had similar expression levels, suggesting selective intracellular retention in MDR cells. The SRC inhibitor bosutinib potentiated the activity of chemotherapeutics that are P-gp substrates in 2D and in 3D spheroids, without affecting the viability of the human lung fibroblast cell line MRC-5. Moreover, bosutinib reduced P-gp activity, likely by downregulating of phosphorylated caveolin-1.
Conclusion: These findings show reduced selective packaging of p-SRC into EVs shed by MDR cells (MDR-EVs), suggesting an important role for this protein in the MDR phenotype and its potential as a molecular target. Bosutinib, an SRC inhibitor, might be useful as a chemosensitizer of MDR cells.
Aim: Resistance to frontline intensive chemotherapy remains a major clinical challenge in acute myeloid leukemia (AML). Currently, refractory AML is mostly observed in certain genotypes. In in vitro experiments, primary resistance in AML has been associated with nucleotide metabolism. However, the relationship between in vivo nucleotide metabolism, genotype, and the occurrence of complete remission (CR) remains largely unexplored. We aimed to investigate the potential association between in vivo nucleotide pools at AML diagnosis, genotype, and the efficacy of frontline intensive chemotherapy.
Methods: In this prospective pilot study, we quantified the intracellular nucleotide pools in peripheral blood (PBMC) and bone marrow mononuclear cells (BMMC) from 70 AML patients at diagnosis. Nucleotide levels were compared depending on genotype data and the occurrence of CR after the frontline intensive chemotherapy.
Results: No relationship was observed between nucleotide levels and genotype. Specific alterations of certain nucleotide levels in cells from patients who did not achieve CR were identified: elevated guanosine triphosphate (GTP) levels in BMMC and uridine monophosphate (UMP) levels in PBMC, as well as reduced adenosine monophosphate (AMP) levels and energy ratios [AMP/adenosine triphosphate (ATP), AMP + adenosine diphosphate (ADP)/ATP] in PBMC. These results may suggest impaired activity of enzymes such as UMP/cytidine monophosphate (CMP) kinase and reduced AMP-activated protein kinase (AMPK) activation in patients who did not achieve CR.
Conclusion: Our study provides the first in vivo data linking specific alterations in intracellular nucleotide levels to the efficacy of the frontline intensive chemotherapy in AML. These findings offer a novel perspective on the role of nucleotide metabolism in the primary resistance in frontline intensive chemotherapy.
Antibody-drug conjugates (ADCs) targeting trophoblast cell-surface antigen 2 (TROP2) have emerged as a promising therapeutic strategy for the treatment of triple-negative breast cancer (TNBC) and ovarian carcinoma, two malignancies characterized by poor prognosis and limited therapeutic options. ADCs are complex molecules that combine the specificity of monoclonal antibodies with the cytotoxic potency of chemotherapeutic agents, enabling selective delivery of drugs to tumor cells while minimizing systemic toxicity. Recent advances in ADC technology have led to the development of several TROP2-targeting agents, including sacituzumab govitecan and datopotamab deruxtecan, which have demonstrated significant efficacy and acceptable safety in patients with advanced or treatment-resistant TNBC and ovarian carcinoma. Clinical trials have reported improvements in progression-free and overall survival, as well as objective response rates, compared to standard therapies. However, emerging evidence indicates that both primary and acquired resistance mechanisms may limit the long-term efficacy of these agents. Current research efforts are focused on elucidating these resistance pathways, optimizing combination strategies with immunotherapy and targeted agents, and expanding the application of TROP2-targeting ADCs to other tumor types. The integration of biomarker-driven patient selection and next-generation ADC technologies offers new opportunities to overcome resistance and enhance clinical benefit. This review provides a comprehensive overview of the development, clinical implementation, and resistance mechanisms of TROP2-targeting ADCs in TNBC and ovarian carcinoma, underscoring their potential to reshape the therapeutic landscape of these challenging cancers.
Aim: Acute myeloid leukemia (AML) is an aggressive hematological malignancy. Conventional risk stratification in AML fails to predict patient responses to targeted therapies such as Venetoclax, hindering precision medicine and the development of strategies to overcome drug resistance.
Methods: We established an integrated multi-omics framework incorporating messenger RNA (mRNA)/long non-coding RNA (lncRNA) expression, DNA methylation, copy number alterations, and somatic mutation data. Using nine complementary clustering algorithms, we identified molecular subtypes in a discovery cohort and validated them in independent external cohorts. The multi-omics classification subsequently guided the screening of high-risk subtypes specific sensitizers to Venetoclax, with candidate efficacy validated through in vitro and in vivo experiments.
Results: We identified three molecularly distinct AML subtypes with unique clinical features, a classification that was subsequently validated in independent external cohorts. Cluster 2 demonstrated the most favorable prognosis, while Cluster 3, characterized by high tumor protein 53 (TP53) mutation frequency and significant immune infiltration, exhibited the poorest outcomes and pronounced resistance to Venetoclax. Multi-omics-guided drug screening revealed that Cluster 3 displays particular sensitivity to both Elesclomol and the clinically available proteasome inhibitor Bortezomib. Through comprehensive in vitro and in vivo validation, we demonstrated that both agents significantly enhance the therapeutic efficacy of Venetoclax. Of particular translational relevance, the Venetoclax-Bortezomib combination leverages an agent with an established safety profile, offering a readily implementable strategy for near-future clinical translation.
Conclusion: Our study establishes a novel multi-omics classification system that provides a robust foundation for investigating biological heterogeneity, elucidating resistance mechanisms, and developing effective combination strategies to achieve personalized therapy in AML.
Malignant pleural mesothelioma (MPM) remains one of the most aggressive thoracic malignancies, characterized by profound resistance to conventional modalities such as surgery, chemotherapy, and radiotherapy, resulting in persistently poor survival outcomes. The advent of immune checkpoint inhibitors (ICIs) has fundamentally reshaped the therapeutic landscape of MPM. Notably, dual programmed cell death protein 1 (PD-1)/cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade has demonstrated superior efficacy over monotherapy in multiple phase I/II trials and has been established as a novel first-line standard of care. Nevertheless, the high incidence of resistance continues to pose a major clinical challenge. This therapeutic bottleneck is largely attributed to the unique biology of MPM, including a profoundly immunosuppressive tumor microenvironment, aberrantly activated signaling pathways, and complex metabolic reprogramming, which together form a multilayered defense network against immune attack. In response to this intricate resistance architecture, recent research efforts have increasingly focused on the development of precision combination strategies. By rationally integrating ICIs with anti-angiogenic agents, chemotherapy, metabolic modulators, and next-generation cellular immunotherapies [e.g., chimeric antigen receptor T cells (CAR-T), chimeric antigen receptor-natural killer (CAR-NK)], these approaches aim to dismantle immune evasion barriers and reinvigorate antitumor immunity. Concurrently, the discovery of novel biomarkers and their integration with multi-omics data are enabling more precise patient stratification, signaling the advent of an era of personalized immunotherapy for MPM. This review provides a systematic synthesis of the latest clinical advances and fundamental breakthroughs in MPM immunotherapy, with a particular focus on dissecting the multifactorial mechanisms underlying therapeutic resistance. Its core contribution lies in constructing a forward-looking framework for next-generation treatment strategies. It critically evaluates the translational potential of emerging approaches, including arginine deprivation therapy for argininosuccinate synthase 1 (ASS1)-deficient tumors, CAR-T cells, T-cell receptor fusion constructs, and oncolytic virotherapy. By integrating these innovative modalities with biomarker-guided patient selection, this review delineates a roadmap for transitioning MPM management from empirical therapy toward precision immuno-oncology, with the ultimate goal of achieving durable disease control in this challenging malignancy.
Lung cancer represents the most prevalent and lethal malignancy worldwide. Although tyrosine kinase inhibitors targeting the epidermal growth factor receptor (EGFR) demonstrate clinical efficacy, the emergence of resistance remains a major therapeutic obstacle. This review comprehensively examines how six key post-translational modifications (PTMs) of EGFR - phosphorylation, palmitoylation, ubiquitination, glycosylation, acetylation, and S-nitrosylation - collectively govern its signaling dynamics, protein turnover, and subcellular trafficking. Based on this mechanistic framework, we propose a novel classification of resistance subtypes: membrane-retained, degradation-evading, nuclear-localized, and mitochondrial-localized EGFR, each defined by distinct PTM signatures and spatial localization. Furthermore, we analyze the intricate crosstalk among these PTMs, revealing hierarchical and often cooperative relationships that ultimately determine the fate and function of EGFR. Our analysis suggests that targeting specific spatial PTM hubs or their interactive networks, rather than EGFR alone, offers a promising strategy to overcome resistance. We also emphasize the need to integrate multi-PTM profiling with spatial proteomics to inform precision combination therapies. This work proposes a shift in the therapeutic paradigm from mere kinase inhibition toward reprogramming the pathological PTM network underlying resistant lung cancer.
Aim: Multidrug resistance (MDR) often arises from lysosomal sequestration of chemotherapeutics. This study aims to design and evaluate lysosome-targeting membrane-intercalating conjugated oligoelectrolytes (MICOEs) for their potential to reverse MDR via dual-mode lysosomal membrane disruption, and to identify the most effective candidate.
Methods: Three MICOEs featuring a pyridothiadiazole-thienothiophene-pyridothiadiazole (PTTP) conjugated backbone with quaternary ammonium-terminated 4-, 6-, and 8-carbon alkyl chains at both ends (PTTP-DC4, PTTP-DC6, PTTP-DC8) were synthesized and characterized. Their photophysical properties, cellular uptake, and sublocalization were assessed in doxorubicin (DOX)-resistant Michigan Cancer Foundation-7/adriamycin-resistant (MCF-7/ADR) cells. Lysosomal integrity and contents release were evaluated via acridine orange and cathepsin B assays. Proteomic analysis was performed to uncover mechanisms. The combinational effect of PTTP-DC6 and DOX was tested in drug-resistant two-dimensional (2D) and three-dimensional (3D) cell models.
Results: Among PTTP-DCns (where n = 4, 6, and 8, corresponding to PTTP-DC4, PTTP-DC6, and PTTP-DC8), PTTP-DC6 showed optimal lysosomal accumulation and induced lysosomal membrane permeabilization (LMP) through both physical membrane interaction and light-triggered reactive oxygen species generation. Proteomic analysis revealed significant enrichment of pathways associated with oxidative stress and lysosomal dysfunction. Pretreatment with PTTP-DC6 at low doses, particularly under mild light irradiation, significantly enhanced DOX sensitivity in resistant 2D monolayers and 3D spheroid models.
Conclusion: PTTP-DC6 overcomes MDR by dual-mode LMP induction, providing a simple strategy to resensitize resistant cancers to conventional chemotherapy.
Aim: Osteosarcoma remains aggressive with poor prognosis, particularly in chemotherapy-resistant cases. This study aimed to characterize transcriptional features of chemoresistant osteosarcoma cells, establish a prognostic resistance signature, and identify therapeutic vulnerabilities.
Methods: Single-cell RNA sequencing (scRNA-seq) was performed on paired pre- and post-neoadjuvant chemotherapy (NAC) specimens from three patients (6 samples; 16,272 cells). Resistance trajectories were reconstructed using Monocle 3 pseudotime analysis. A nine-gene resistance score was validated in the Peking University People’s Hospital (PKPH) bulk RNA-seq cohort (n = 70) and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database (n = 87), with drug sensitivities predicted via oncoPredict.
Results: Chemotherapy reduced the malignant cell fraction but triggered expansion of cancer-associated fibroblasts and endothelial cells, creating a stromal-dominant, immune-sparse residual niche. Surviving tumor cells upregulated a nine-gene module along the resistance trajectory: KCNMA1, KIF21A, MIR181A1HG, RPS27, PDPN, ADIRF, PRELP, PHEX, and COL9A2. In an independent unpaired scRNA-seq cohort (two pre- and three post-chemotherapy samples), this signature remained associated with features of chemotherapy resistance. Higher scores correlated with poorer histopathologic response (r = -0.35, P = 0.006) and shorter progression-free survival [PKPH: hazard ratio (HR) = 2.4, 95% confidence interval (CI) 1.2-4.8, P = 0.01; TARGET: HR = 2.1, 95%CI 1.1-4.0, P = 0.02]. Of 198 compounds screened, only Pictilisib, a phosphoinositide 3-kinase (PI3K) inhibitor, showed lower predicted IC50 in the high-score subset across both datasets. However, the paired discovery cohort warrant further validation.
Conclusion: Our paired scRNA-seq approach identifies a nine-gene signature linking pre-treatment tumor biology to NAC response and outcome. The enhanced Pictilisib sensitivity in chemoresistant tumors positions PI3K blockade as a strategy meriting prospective testing in refractory osteosarcoma.
Immune-checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1) have substantially improved outcomes for patients with multiple cancer types; however, primary (intrinsic) resistance remains common and limits durable responses. Mechanistically, such resistance can arise from impaired interferon-γ signaling (including Janus kinases-signal transducer and activator of transcription dysfunction), tumor-intrinsic oncogenic pathway alterations [e.g., phosphatase and tensin homolog (PTEN) loss with downstream phosphoinositide 3-kinase/protein kinase B hyperactivation and Wnt/β-catenin-associated immune escape], and tumor-extrinsic immunosuppression mediated by PD-L1-upregulated suppressive myeloid populations such as myeloid-derived suppressor cells. These pathways converge on reduced T-cell effector function, compromised immune recognition, and reinforcement of an immunosuppressive tumor microenvironment (TME), collectively diminishing the clinical benefit of PD-1/PD-L1 blockade. In this review, we synthesize current evidence on primary (intrinsic) resistance to PD-1/PD-L1 blockade and discuss how nanomaterial-enabled interventions can be mechanistically matched to these resistance determinants. The nanotechnology-based therapeutic strategies were classified as four categories: (i) modulation of resistance-associated signaling pathways; (ii) direct blockade/interception of the PD-1/PD-L1 axis; (iii) immune-checkpoint gene silencing; and (iv) TME reprogramming.
The glymphatic system in the brain controls the cerebrospinal fluid (CSF) circulation and metabolic waste clearance, which is crucial for understanding the mechanisms and therapeutic opportunities of various brain pathologies. With the rapidly growing interest in its relationship with neurodegenerative conditions, including Alzheimer’s disease, its underlying processes are still not fully understood and remain under active investigation. A representative finding is that the glymphatic flow is passively driven by factors such as vascular pulsation, and studies have been conducted to modulate the glymphatic system using external stimuli to enhance waste clearance or to leverage CSF pathways for delivering chemotherapeutic agents. Particularly, glymphatic flow modulation holds great potential for improving drug delivery to the brain via intrathecal administration as an alternative to conventional systemic delivery, which is restricted by the blood-brain barrier (BBB). This review focuses on ultrasound (US) techniques for glymphatic system modulation, with the aim of augmenting glymphatic flow and ultimately improving drug delivery for brain cancer therapy. Given the limited number of cancer-related studies in the field, we comprehensively review US-based glymphatic modulation research to date and identify their implications and future opportunities for brain cancer applications.
Aim: This study investigates the anticancer activity of naphthalene- and ferrocene-based 2-pyrazolines against colorectal cancer (CRC) cell lines and assesses their potential to overcome chemotherapy resistance.
Methods: Several 2-pyrazoline derivatives were synthesized and tested for anticancer activity across various cell lines, including p53 wild-type (WT) and knockout (KO) colon cancer cells and vinblastine-resistant KB-V1 cervix carcinoma cells. Compounds Clac10 (5c) and Clac12 (5e) were studied for their effects on colony and spheroid formation, cell cycle, and apoptosis. Molecular docking and cellular thermal shift assays explored their binding to histamine receptor H1 (HRH1). In vivo antitumor efficacy was tested on HCT116 xenografts in NSG mice.
Results: Compounds Clac10 and Clac12 significantly inhibited the proliferation of both p53 WT and KO colon cancer cells, as well as drug-resistant KB-V1 cells. When combined with 5-fluorouracil (5-FU), they showed synergistic antiproliferative effects in HCT and DLD1 cells. These compounds reduced colony and spheroid formation, induced cell cycle arrest, and promoted apoptosis by downregulating cyclin D1 and antiapoptotic proteins [B-cell lymphoma-extra large (Bcl-XL), B-cell lymphoma 2 (Bcl-2), myeloid cell leukemia 1 (Mcl-1)]. Molecular docking and thermal shift assays confirmed binding to HRH1, affecting histamine-induced extracellular signal-regulated kinase (ERK) and glycogen synthase kinase 3 beta (GSK3B) signaling. In vivo, Clac10 significantly reduced HCT116 xenograft growth, decreased Ki-67 and phosphorylated-glycogen synthase kinase 3 beta (p-GSK3B) levels, and increased cleaved caspase-3.
Conclusion: Naphthalene-based 2-pyrazoline compounds Clac10 and Clac12 showed a potent anticancer activity against colon cancer lines. They inhibit tumor growth by targeting HRH1 signaling, indicating potential as CRC therapies and resistance-overcoming agents. Further studies are needed to explore their clinical potential.
Non-coding RNAs (ncRNAs) have emerged as key regulators of cancer–immune crosstalk, especially in an era when immune checkpoint inhibitors and other immunomodulatory therapies are reshaping the cancer treatment landscape. Accumulating evidence continues to indicate that ncRNAs, including microRNAs, long non-coding RNAs and circular RNAs, critically connect oncological signaling with immune interactions, thereby influencing clinical outcomes. In this review, we summarize how ncRNAs modulate key immune checkpoint axes, particularly programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4). We also discuss ncRNA networks that are actively involved in modern cancer immunotherapies, such as T cell–based therapies, macrophage and dendritic cell engineering, cytokine therapies, cancer vaccines and oncolytic viruses. Building on these mechanistic insights, we outline the potential of ncRNAs as biomarkers for predicting response and prognosis, as future therapeutic targets to improve and enhance immunotherapy combinations, along with key barriers in the field and emerging solutions. Altogether, the evidence not only highlights ncRNAs as rising stars in precision immuno-oncology, but also motivates future opportunities to incorporate ncRNAs into clinical consideration.