The great escape: tumour cell plasticity in resistance to targeted therapy

Hyperdifferentiated murine melanoma cells promote adaptive anti-tumor immunity but activate the immune checkpoint system

Accumulating evidence suggests that phenotype switching of cancer cells is essential for therapeutic resistance. However, the immunological characteristics of drug-induced phenotype-switching melanoma cells (PSMCs) are unknown. We investigated PSMC elimination by host immunity using hyperdifferentiated melanoma model cells derived from murine B16F10 melanoma cells. Exposure of B16F10 cells to staurosporine induced a hyperdifferentiated phenotype associated with transient drug tolerance. Staurosporine-induced hyperdifferentiated B16F10 (sB16F10) cells expressed calreticulin on their surface and were phagocytosed efficiently. Furthermore, the inoculation of mice with sB16F10 cells induced immune responses against tumor-derived antigens. Despite the immunogenicity of sB16F10 cells, they activated the PD-1/PD-L1 immune checkpoint system and strongly resisted T cell-mediated tumor destruction. However, in vivo treatment with immune checkpoint inhibitors successfully eliminated the tumor. Thus, hyperdifferentiated melanoma cells have conflicting immunological properties - enhanced immunogenicity and immune evasion. Inhibiting the ability of PSMCs to evade T cell-mediated elimination might lead to complete melanoma eradication.

Alternative Approach to Avoid Drug Resistance: Polyhedral Inorganic and Metallomacrobicyclic 3D-Shaped Guests Strongly Binding to Allosteric Sites and/or Macromolecular Interfaces

The emergence of drug resistance is one of the global problems. Prospective approach for its solution is based on the development of new and improved pharmacological principles, including the use of allosteric inhibitors of biomacromolecules and the generation of those unfolded or misfolded. Allosteric sites as hosts can be sterically blocked by rigid 3D-shaped effectors as guests. Because host bioreceptors recognize only their external surface, the nature of abiotic and artificial 3D-molecular platforms plays no important role in the supramolecular host-guest binding. Another of their modus operandi is based on blocking a surface of supramolecular interactions between biomacromolecules to cause the appearance of misfolded macromolecular assemblies or their disaggregation. 3D-shaped polyhedral inorganic and metallocomplex molecules, the periphery of which is decorated with terminal biorelevant or vector group(s), seem to be promising antitumor and antiviral drug candidates, in the case of which the emergence of drug resistance is not observed.

Drug-induced tolerant persisters in tumor: mechanism, vulnerability and perspective implication for clinical treatment

Cancer remains a significant global health burden due to its high morbidity and mortality. Oncogene-targeted therapy and immunotherapy have markedly improved the 5-year survival rate in the patients with advanced or metastatic tumors compared to outcomes in the era of chemotherapy/radiation. Nevertheless, the majority of patients remain incurable. Initial therapies eliminate the bulk of tumor cells, yet residual populations termed drug-tolerant persister cells (DTPs) survive, regenerate tumor and even drive distant metastases. Notably, DTPs frequently render tumor cross-resistance, a detrimental phenomenon observed in the patients with suboptimal responses to subsequent therapies. Analogous to species evolution, DTPs emerge as adaptative products at the cellular level, instigated by integrated intracellular stress responses to therapeutic pressures. These cells exhibit profound heterogeneity and adaptability shaped by the intricate feedforward loops among tumor cells, surrounding microenvironments and host ecology, which vary across tumor types and therapeutic regimens. In this review, we revisit the concept of DTPs, with a focus on their generation process upon targeted therapy or immunotherapy. We dissect the critical phenotypes and molecule mechanisms underlying DTPs to therapy from multiple aspects, including intracellular events, intercellular crosstalk and the distant ecologic pre-metastatic niches. We further spotlight therapeutic strategies to target DTP vulnerabilities, including synthetic lethality approaches, adaptive dosing regimens informed by mathematical modeling, and immune-mediated eradication. Additionally, we highlight synergistic interventions such as lifestyle modifications (e.g., exercise, stress reduction) to suppress pro-tumorigenic inflammation. By integrating mechanistic insights with translational perspectives, this work bridges the gap between DTP biology and clinical strategies, aiming for optimal efficacy and preventing relapse.

Optimal adaptive therapeutic schedules for metastatic castrate-resistant prostate cancer based on bilevel optimization problem

Abiraterone acetate has established itself as an effective treatment for metastatic castrate-resistant prostate cancer (mCRPC). However, disease progression remains inevitable with conventional long-term maximum tolerated dose (MTD) therapy due to the development of drug resistance. Adaptive therapy (AT), rooted in Darwinian evolutionary dynamics, offers a novel approach to combat drug resistance. By dynamically adjusting drug doses, AT aims to enhance treatment outcomes. Despite successful clinical trials and extensive theoretical studies on AT, significant challenges persist in determining optimal adaptive therapeutic schedules tailored to individual patients. This study presents a biochemically motivated mathematical model incorporating competition between drug-sensitive and drug-resistant cancer cells, incorporating mutated migration factors identified through prostate-specific antigen (PSA) data. Theoretical analyses, including the stability of equilibrium states and the existence of periodic solutions, validate the model's interpretability and support the feasibility of adapted periodic therapy. We propose an optimal adaptive periodic therapy framework, formulating a bilevel dynamic optimization problem with constraints to establish personalized adaptive therapeutic schedules for prostate cancer. Optimal solutions identify therapeutic switches and doses under adaptive therapy. We compare our proposed framework with other adaptive strategies regarding overall survival and total drug doses through numerical simulations and quantitative analysis, demonstrating superior performance. Our model presents a promising tool for integration into clinical research trials, offering individualized adaptive therapeutic schedules to enhance precision management of mCRPC.

Epigenomic analysis identifies DTP subpopulation using HOPX to develop targeted therapy resistance in lung adenocarcinoma

Genomic studies have identified oncogenic drivers in lung cancer, enabling effective targeted therapies. However, patients who initially respond inevitably experience regrowth. The drug-tolerant persister (DTP) stage is a key source of non-genetic resistance, yet its epigenetic regulation remains unclear. Using single-cell chromatin accessibility profiling (scATAC-seq), we identified two distinct DTP subpopulations in EGFR- and KRAS-inhibited models. The integrative network and pathway analysis revealed that one subpopulation is associated with cell cycle, while the other is enriched in developmental pathways. HOPX was the most enriched alveolar signature gene in the latter. It was transiently upregulated with cytoplasmic-to-nuclear translocation, and its deletion significantly delayed DTP regrowth. Mechanistically, HOPX regulates NF-κB activation and repressive histone modifications. Combining targeted therapy with NF-κB or histone-methyltransferase inhibitors nearly abolished DTP regrowth. These findings highlight a potential anti-relapse strategy by targeting developmental pathways to modulate key lineage factors during lung regeneration in patients relapsing on targeted therapy.

Pharmacological inhibition of PLK1/PRC1 triggers mitotic catastrophe and sensitizes lung cancers to chemotherapy

Polo-like kinase 1 (PLK1) signaling drives tumor malignancy and chemotherapy resistance, which is an unmet clinical need. Recruiting PLK1 to the central spindle during anaphase is necessary for its function in promoting cancer cell proliferation, which is achieved by binding to microtubule-associated protein regulating of cytokinesis (PRC1) located in the spindle. However, the role of PLK1/PRC1 signaling in chemotherapy resistance is unknown. In this study, we identified a small molecule B4 which inhibited PLK1/PRC1 signaling through disrupting the formation of PLK1/PRC1 protein complexes. In the presence of blocking PLK1/PRC1 signaling, enhanced sensitivity of drug-resistant tumors to traditional chemotherapy was found. Suppression of PLK1 activity by B4 inhibited disease progression in allograft models, and combination with cisplatin elicited dramatic regression of drug-resistant tumors. Our findings provide a promising strategy to target the PLK1 signaling cascade and demonstrate a potential modality to enhance sensitivity to chemotherapy in non-small cell lung cancer (NSCLC).

Evolutionary and immune microenvironment dynamics during neoadjuvant treatment of esophageal adenocarcinoma

Locally advanced esophageal adenocarcinoma remains difficult to treat and the ecological and evolutionary dynamics responsible for resistance and recurrence are incompletely understood. Here, we performed longitudinal multiomic analysis of patients with esophageal adenocarcinoma in the MEMORI trial. Multi-region multi-timepoint whole-exome and paired transcriptome sequencing was performed on 27 patients before, during and after neoadjuvant treatment. We found major transcriptomic changes during treatment with upregulation of immune, stromal and oncogenic pathways. Genetic data revealed that clonal sweeps through treatment were rare. Imaging mass cytometry and T cell receptor sequencing revealed remodeling of the tumor microenvironment during treatment. The presence of genetic immune escape, a less-cytotoxic T cell phenotype and a lack of clonal T cell expansions were linked to poor treatment response. In summary, there were widespread transcriptional and environmental changes through treatment, with limited clonal replacement, suggestive of phenotypic plasticity.

Inhalable TPGS/DPPC Micelles Coloaded with Curcumin and Icariin for Targeted Lung Cancer Therapy

Lung cancer, particularly NSCLC, poses a major therapeutic challenge due to drug resistance and the poor aqueous solubility of chemotherapeutic agents, limiting treatment efficacy. This study investigates inhalable micelles for the codelivery of curcumin (CUR) and icariin (ICA), two hydrophobic bioactive compounds with anticancer potential, as a targeted therapeutic approach for NSCLC. The optimized micellar formulation (9:1 TPGS/DPPC) yielded nanomicelles (∼18 nm) with high encapsulation efficiency (∼90%) and a zeta potential of -1.24 mV, demonstrating stability for pulmonary administration. In vitro cytotoxicity studies demonstrated enhanced anticancer activity of CUR- and ICA-loaded micelles against A549 lung cancer cells (IC50 = 3.0 μg/mL), lower than doxorubicin (30 μg/mL), suggesting enhanced cytotoxic potential. Additionally, DPPH assays confirmed that encapsulation preserved curcumin's functionality. Aerosolization studies demonstrated a high fine particle fraction (67 ± 3%) and emitted fraction (95 ± 1.0%), confirming the micelles' suitability for deep lung deposition and effective pulmonary drug delivery. These findings highlight the potential of CUR- and ICA-loaded micelles as an inhalable NSCLC treatment, requiring further preclinical investigation.

Rare Subset of T Cells Form Heterotypic Clusters with Circulating Tumor Cells to Foster Cancer Metastasis

The immune ecosystem is central to maintaining effective defensive responses. However, how immune cells in the periphery blood interact with circulating tumor cells (CTCs) - seeds of metastasis - remains largely understudied. Here, our analysis of the blood specimens (N=1,529) from patients with advanced breast cancer revealed that over 75% of the CTC-positive blood specimens contained heterotypic CTC clusters with CD45 + white blood cells (WBCs). Detection of CTC-WBC clusters correlates with breast cancer subtypes (triple negative and luminal B), racial groups (Black), and decreased survival rates. Flow cytometry and ImageStream analyses revealed diverse WBC composition of heterotypic CTC-WBC clusters, including overrepresented T cells and underrepresented neutrophils. Most strikingly, a rare subset of CD4 and CD8 double positive T (DPT) cells showed an up to 140-fold enrichment in the CTC clusters versus its frequency in WBCs. DPT cells shared part of the profiles with CD4 + T cells and others with CD8 + T cells but exhibited unique features of T cell exhaustion and immune suppression with higher expression of TIM-3 and PD-1. Single-cell RNA sequencing and genetic perturbation studies further pinpointed the integrin VLA4 (α4β1) in DPT cells and its ligand VCAM1 in tumor cells as essential mediators of heterotypic WBC-CTC clusters. Neoadjuvant administration of anti-α4 (VLA4) neutralizing antibodies markedly blocked CTC-DPT cell clustering and inhibited metastasis for extended survival in preclinical mouse models in vivo . These findings uncover a pivotal role of rare DPT cells with immune suppressive features in fostering cancer dissemination through direct interactive clustering with CTCs. It lays a foundation for developing innovative biomarkers and therapeutic strategies to prevent and target cancer metastasis, ultimately benefiting cancer care.

Brief summary

Our findings uncover a fostering role of immune-suppressive T cells in contact with circulating tumor cells and identify therapeutic approaches to eliminate devastating cancer metastasis.

Therapeutic potential and mechanistic insights of silibinin targeting cancer-associated fibroblasts in colorectal cancer

Objective

This study aims to elucidate the role of SB in inhibiting CRC progression by targeting CAFs and elucidating the underlying mechanisms.

Methods

In this study, a spontaneous CRC model induced by AOM/DSS was used to evaluate the effects of SB on CAFs. Mice were treated with SB, and tumor burden was assessed by colon length. CAFs were isolated post-treatment for transcriptomic analysis to identify differentially expressed genes, with molecular docking providing in silico evidence of SB's binding to target proteins. CAFs changes were further examined through HE staining, IHC, and assays for cell viability, colony formation, and migration. Integrated bioinformatic analysis elucidated the mechanistic role of SB in CAFs-mediated CRC progression.

Results

In vivo studies showed that SB effectively reduced POSTN and α-SMA protein levels in CAFs in AOM/DSS-induced CRC mice. Consistently, in vitro experiments demonstrated that SB significantly decreased both protein and mRNA levels of α-SMA and POSTN in fibroblasts (colonic myofibroblast CCD-18Co cell lines.) co-cultured with CRC cell lines (human colorectal adenocarcinoma SW480 and RKO cell lines). SB also inhibited proliferation, colony formation, and migration of CCD-18Co cells. Transcriptomic and integrated bioinformatic analyses further suggested that SB exerts therapeutic effects on CAFs in CRC by modulating key target pathways.

Conclusion

These results demonstrated that SB holds promise as a therapeutic agent for targeting CAFs in CRC. This study advances our understanding of SB's mechanisms, particularly its inhibitory effects on CAFs proliferation, colony formation, and migration.

Identification of the specific characteristics of neuroendocrine prostate cancer: Immune status, hub genes and treatment

Castration-resistant prostate cancer (CRPC) marks the advanced phase of prostate malignancy, manifested through two principal subtypes: castration-resistant adenocarcinoma (CRPC-adeno) and neuroendocrine prostate cancer (NEPC). This study aims to identify unique central regulatory genes, assess the immunological landscape, and explore potential therapeutic strategies specifically tailored to NEPC. We discovered 1444 differentially expressed genes (DEGs) distinguishing between the two cancer types and identified 12 critical hub genes. Notably, CHST1, MPPED2, and RIPPLY3 emerged as closely associated with the immune cell infiltration pattern, establishing them as top candidates. Prognostic analysis highlighted the potential critical roles of CHST1 and MPPED2 in prostate cancer development, findings corroborated through in vitro and in vivo assays. Moreover, we validated the functions and expression levels of CHST1, MPPED2, and RIPPLY3 in NEPC using cell lines, animal models and human tissues. In the final step, we found that imatinib might be the drug specific to NEPC, which was further confirmed by in vitro cell assay. Our results revealed the clinical characteristics, molecular features, immune cell infiltration pattern in CRPC-adeno and NEPC, and identified and confirmed CHST1, MPPED2, and RIPPLY3 as the critical genes in the development in prostate cancer and NEPC. We also predicted and validated imatinib as the potential specific drugs to NEPC.

Copper in melanoma: At the crossroad of protumorigenic and anticancer roles

Copper is an essential micronutrient that is a cofactor for various enzymes involved in multiple cellular processes. Melanoma patients have high serum copper levels, and elevated copper concentrations are found in melanoma tumors. Copper influences the activity of several melanoma-related proteins involved in cell survival, proliferation, pigmentation, angiogenesis, and metastasis. Targeting these processes with copper chelators has shown efficacy in reducing tumor growth and overcoming drug resistance. In contrast, excessive copper can also have detrimental effects when imported into melanoma cells. Multiple distinct cellular effects of copper overload, including the induction of different types of cell death, have been reported. Cuproptosis, a novel type of copper-dependent cell death, has been recently described and is associated with the metabolic phenotype. Melanoma cells can switch between glycolysis and oxidative phosphorylation, which are crucial for tumor growth and drug resistance. In this respect, metabolic plasticity might be exploited for the use of copper-delivery strategies, including repurposing of disulfiram, which is approved for the treatment of noncancer patients. In addition, the development of nanomedicines can improve the targeted delivery of copper to melanoma cells and enable the use of these drugs alone or in combination as copper has been shown to complement targeted therapy and immunotherapy in melanoma cells. However, further research is needed to explore the specific mechanisms of both copper restriction and excess copper-induced processes and determine effective biomarkers for predicting treatment sensitivity in melanoma patients. In this review, we discuss the dual role of copper in melanoma biology.

Elevated serum levels of GPX4, NDUFS4, PRDX5, and TXNRD2 as predictive biomarkers for castration resistance in prostate cancer patients: an exploratory study

BACKGROUND

Prostate cancer (PCa) is a heterogeneous disease affecting over 14% of the male population worldwide. Although patients often respond positively to initial treatments within the first 2-3 years, many eventually develop a more lethal form of the disease known as castration-resistant PCa (CRPC). At present, no biomarkers that predict the onset of CRPC are available. This study aims to provide insights into the diagnosis and prediction of CRPC emergence.

METHODS

Protein expression dynamics were analysed in drug (androgen receptor inhibitor)-tolerant persister (DTP) and drug withdrawal cells using proteomics to identify potential biomarkers. These biomarkers were subsequently validated using a mouse model, 180-paired carcinoma/benign tissues, and 482 serum samples. Five machine learning algorithms were employed to build clinical prediction models, wherein the SHapley Additive exPlanation (SHAP) framework was used to interpret the best-performing model. Moreover, three regression models were developed to determine the Time from initial PCa diagnosis to CRPC development (TPC) in patients.

RESULTS

We identified that the protein expression levels of GPX4, NDUFS4, PRDX5, and TXNRD2 were significantly upregulated in PCa patients, particularly in those with CRPC. Among the tested machine learning models, the random forest and extreme gradient boosting models performed best on tissue and serum cohorts, achieving AUCs of 0.958 and 0.988, respectively. In addition, a significant inverse correlation was observed between TPC and serum levels of these four biomarkers. This correlation was formulated in three regression models, which achieved the smallest mean absolute error of 1.903 on independent datasets for predicting CRPC emergence.

CONCLUSION

Our study provides new insights into the role of DTP cells in CRPC development. The quad protein panel identified in our study, along with the post hoc and intrinsically explainable prediction models, may serve as a convenient and real-time prognostic tool, addressing the current lack of clinical biomarkers for CRPC.

The development and potent antitumor efficacy of CD44/CD133 dual-targeting IL7Rα-armored CAR-T cells against glioblastoma

Tumor heterogeneity and an immunosuppressive microenvironment pose significant challenges for immunotherapy against solid tumors, particularly glioblastoma multiforme (GBM). Recent studies have highlighted the crucial role of glioma stem cells (GSCs) in tumor recurrence and therapeutic resistance. In this context, we developed a tandem chimeric antigen receptor (CAR)-T cell targeting CD44 and CD133 (PROM1), containing a truncated IL-7 receptor alpha intracellular domain (Δ7R) between the CD28 costimulatory receptor and the CD3ζ signaling chain (Tanζ-T28-Δ7R). Our target identification and validation were carried out using GSCs, samples from GBM patients, and the corresponding sequencing data. The antitumor efficacy of CAR-T cells was evaluated in patient-derived GSCs, intracranial xenograft models, patient-derived xenograft models, and glioblastoma organoids (GBOs). Single-cell RNA sequencing and mass cytometry were used to determine the immune phenotypes of CAR-T cells. We showed that locoregionally administered Tanζ-T28-Δ7R CAR-T cells induced long-term tumor regression with the desired safety outcomes. Patient-derived autologous Tanζ-T28-Δ7R CAR-T cells showed robust antitumor activity against GBOs. Our pre-clinical data has demonstrated the translational potential of Tanζ-T28-Δ7R CAR-T cell against GBM.

Advances in the Development of Ferroptosis-Inducing Agents for Cancer Treatment

Cancer is the main leading cause of death worldwide and poses a great threat to human life and health. Although pharmacological treatment with chemotherapy and immunotherapy is the main therapeutic strategy for cancer patients, there are still many shortcomings during the treatment such as incomplete killing of cancer cells and development of drug resistance. Emerging evidence indicates the promise of inducing ferroptosis for cancer treatment, particularly for eliminating aggressive malignancies that are resistant to conventional therapies. This review covers recent advances in important regulatory targets in the ferroptosis metabolic pathway and ferroptosis inducers (focusing mainly on the last 3 years) to delineate their design, mechanisms of action, and anticancer applications. To date, many compounds, including inhibitors, degraders, and active molecules from traditional Chinese medicine, have been demonstrated to have ferroptosis-inducing activity by targeting the different biomolecules in the ferroptosis pathway. However, strictly defined ferroptosis inducers have not yet been approved for clinical use; therefore, the discovery of new highly active, less toxic, and selective compounds remains the goal of further research in the coming years.

Poly(ARTEMA), a novel artesunate-based polymer induces ferroptosis in breast cancer cells

Ferroptosis, a form of non-apoptotic cell death, is emerging as a promising strategy for cancer therapy. Artesunate (ART), an extract obtained from the traditional Chinese medicine Qinghaosu, has been shown to exhibit anti-cancer activity by inducing ferroptosis in cancer cells. While previous research has focused on incorporating ART monomer into drug delivery systems for enhanced cancer targeting, this study presents 2-methacryloyloxyethyl ART polymer (poly(ARTEMA)), a novel polymer synthesized from ART for the first time. Our goal was evaluation of poly(ARTEMA) anticancer potential on breast cancer cells. First, we synthesized ARTEMA using esterification followed by its polymerization using the reversible addition-fragmentation chain transfer (RAFT) polymerization method. We evaluated its mechanism of action, focusing on two key pathways: temperature-triggered singlet oxygen generation and ferrous ions (Fe2+) release, both of which contribute to ferroptosis. Our results demonstrate that poly(ARTEMA) selectively generates singlet oxygen and Fe2+ due to the endoperoxide crosslinks, leading to cell death in breast cancer cells. We also investigated the anti-cancer potential of poly(ARTEMA) on breast cancer cells with and without a ferroptosis inhibitor. The IC50 values were 125 µM for the MCF-7 cancer cell line and 300 µM for the normal MCF-10 cell line, indicating enhanced toxicity toward cancer cell lines. These findings suggested that poly(ARTEMA) induces ferroptosis in cancer cells and may serve as a promising candidate for cancer therapy with minimal cytotoxicity. To the best of our knowledge, this report may be the first that successfully synthesized poly(ARTEMA) using ART, with its anticancer potential evaluation.

Dual role of interferon-gamma in the response of melanoma patients to immunotherapy with immune checkpoint inhibitors

Interferon-gamma (IFN-γ) is a cytokine produced mainly by immune cells and can affect cancer cells by modulating the activity of multiple signaling pathways, including the canonical Janus-activated kinase/signal transducer and activator of transcription (JAK/STAT) cascade. In melanoma, IFN-γ can exert both anticancer effects associated with cell-cycle arrest and cell death induction and protumorigenic activity related to immune evasion leading to melanoma progression. Notably, IFN-γ plays a crucial role in the response of melanoma patients to immunotherapy with immune checkpoint inhibitors (ICIs), which are currently used in the clinic. As these agents target programmed death-1 (PD-1) and its ligand (PD-L1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) and lymphocyte-activation gene 3 (LAG-3), they are designed to restore the antimelanoma immune response. In this respect, IFN-γ produced by cells in the tumor microenvironment in response to ICIs has a beneficial influence on both immune and melanoma cells by increasing antigen presentation, recruiting additional T-cells to the tumor site, and inducing direct antiproliferative effects and apoptosis in melanoma cells. Therefore, IFN-γ itself and IFN-γ-related gene signatures during the response to ICIs can constitute biomarkers or predictors of the clinical outcome of melanoma patients treated with ICIs. However, owing to its multifaceted roles, IFN-γ can also contribute to developing mechanisms associated with the acquisition of resistance to ICIs. These mechanisms can be associated with either decreased IFN-γ levels in the tumor microenvironment or diminished responsiveness to IFN-γ due to changes in the melanoma phenotypes associated with affected activity of other signaling pathways or genetic alterations e.g., in JAK, which restricts the ability of melanoma cells to respond to IFN-γ. In this respect, the influence of IFN-γ on melanoma-specific regulators of the dynamic plasticity of the cell phenotype, including microphthalmia-associated transcription factor (MITF) and nerve growth factor receptor (NGFR)/CD271 can affect the clinical efficacy of ICIs. This review comprehensively discusses the role of IFN-γ in the response of melanoma patients to ICIs with respect to its positive influence and role in IFN-γ-related mechanisms of resistance to ICIs as well as the potential use of predictive markers on the basis of IFN-γ levels and signatures of IFN-γ-dependent genes.

Tumor microenvironment: recent advances in understanding and its role in modulating cancer therapies

Tumor microenvironment (TME) denotes the non-cancerous cells and components presented in the tumor, including molecules produced and released by them. Interactions between cancer cells, immune cells, stromal cells, and the extracellular matrix within the TME create a dynamic ecosystem that can either promote or hinder tumor growth and spread. The TME plays a pivotal role in either promoting or inhibiting tumor growth and dissemination, making it a critical factor to consider in the development of effective cancer therapies. Understanding the intricate interplay within the TME is crucial for devising effective cancer therapies. Combination therapies involving inhibitors of immune checkpoint blockade (ICB), and/or chemotherapy now offer new approaches for cancer therapy. However, it remains uncertain how to best utilize these strategies in the context of the complex tumor microenvironment. Oncogene-driven changes in tumor cell metabolism can impact the TME to limit immune responses and present barriers to cancer therapy. Cellular and acellular components in tumor microenvironment can reprogram tumor initiation, growth, invasion, metastasis, and response to therapies. Components in the TME can reprogram tumor behavior and influence responses to treatments, facilitating immune evasion, nutrient deprivation, and therapeutic resistance. Moreover, the TME can influence angiogenesis, promoting the formation of blood vessels that sustain tumor growth. Notably, the TME facilitates immune evasion, establishes a nutrient-deprived milieu, and induces therapeutic resistance, hindering treatment efficacy. A paradigm shift from a cancer-centric model to a TME-centric one has revolutionized cancer research and treatment. However, effectively targeting specific cells or pathways within the TME remains a challenge, as the complexity of the TME poses hurdles in designing precise and effective therapies. This review highlights challenges in targeting the tumor microenvironment to achieve therapeutic efficacy; explore new approaches and technologies to better decipher the tumor microenvironment; and discuss strategies to intervene in the tumor microenvironment and maximize therapeutic benefits.

KLF4 promotes a KRT13+ hillock-like state in squamous lung cancer

Lung squamous cell carcinoma (LUSC) is basal-like subtype of lung cancer with limited treatment options. While prior studies have identified tumor-propagating cell states in squamous tumors, the broader landscape of intra-tumoral heterogeneity within LUSC remains poorly understood. Here, we employ Sox2-driven mouse models, organoid cultures, and single-cell transcriptomic analyses to uncover previously unrecognized levels of cell fate diversity within LUSC. Specifically, we identify a KRT13+ hillock-like population of slower-dividing tumor cells characterized by immunomodulatory gene expression signatures. The tumor hillock-like state is conserved across multiple animal models and is present in the majority of human LUSCs as well as head and neck and esophageal squamous tumors. Our findings shed light on the cellular origins of lung hillock-like states: normal club cells give rise to tumors with luminal hillock-like populations, while basal-like tumor-propagating cells transition into basal hillock-like states, resembling homeostatic cellular responses to lung injury. Mechanistically, we identify KLF4 as a key transcriptional regulator of the hillock-like state, both necessary and sufficient to induce KRT13 expression. Together, these results provide new molecular insights into cell fate plasticity that underlies intra-tumoral heterogeneity in LUSC, offering potential avenues for new therapeutic strategies.

Endothelial OX40 activation facilitates tumor cell escape from T cell surveillance through S1P/YAP-mediated angiogenesis

Understanding the complexity of the tumor microenvironment is vital for improving immunotherapy outcomes. Here, we report that the T cell costimulatory molecule OX40 was highly expressed in tumor endothelial cells (ECs) and was negatively associated with the prognosis of patients, which is irrelevant to T cell activation. Analysis of conditional OX40 loss- and gain-of-function transgenic mice showed that OX40 signal in ECs counteracted the antitumor effects produced in T cells by promoting angiogenesis. Mechanistically, leucine-rich repeat-containing GPCR5 (Lgr5+ ) cancer stem cells induced OX40 expression in tumor ECs via EGF/STAT3 signaling. Activated OX40 interacted with Spns lysolipid transporter 2 (Spns2), obstructing the export of sphingosine 1-phosphate (S1P) and resulting in S1P intracellular accumulation. Increased S1P directly bound to Yes 1-associated protein (YAP), disrupting its interaction with large tumor suppressor kinase 1 (LATS1) and promoting YAP nuclear translocation. Finally, the YAP inhibitor verteporfin enhanced the antitumor effects of the OX40 agonist. Together, these findings reveal an unexpected protumor role of OX40 in ECs, highlighting the effect of nonimmune cell compartments on immunotherapy.

Cancer stem cells: Masters of all traits

Cancer is a heterogeneous disease, which contributes to its rapid progression and therapeutic failure. Besides interpatient tumor heterogeneity, tumors within a single patient can present with a heterogeneous mix of genetically and phenotypically distinct subclones. These unique subclones can significantly impact the traits of cancer. With the plasticity that intratumoral heterogeneity provides, cancers can easily adapt to changes in their microenvironment and therapeutic exposure. Indeed, tumor cells dynamically shift between a more differentiated, rapidly proliferating state with limited tumorigenic potential and a cancer stem cell (CSC)-like state that resembles undifferentiated cellular precursors and is associated with high tumorigenicity. In this context, CSCs are functionally located at the apex of the tumor hierarchy, contributing to the initiation, maintenance, and progression of tumors, as they also represent the subpopulation of tumor cells most resistant to conventional anti-cancer therapies. Although the CSC model is well established, it is constantly evolving and being reshaped by advancing knowledge on the roles of CSCs in different cancer types. Here, we review the current evidence of how CSCs play a pivotal role in providing the many traits of aggressive tumors while simultaneously evading immunosurveillance and anti-cancer therapy in several cancer types. We discuss the key traits and characteristics of CSCs to provide updated insights into CSC biology and highlight its implications for therapeutic development and improved treatment of aggressive cancers.

An update on cancer stem cell survival pathways involved in chemoresistance in triple-negative breast cancer

Triple-negative breast cancer (TNBC) presents a formidable global health challenge, marked by its aggressive behavior and significant treatment resistance. This subtype, devoid of estrogen, progesterone, and HER2 receptors, largely relies on breast cancer stem cells (BCSCs) for its progression, metastasis, and recurrence. BCSCs, characterized by their self-renewal capacity and resistance to conventional therapies, exploit key surface markers and critical signaling pathways like Wnt, Hedgehog, Notch, TGF-β, PI3K/AKT/mTOR and Hippo-YAP/TAZ to thrive. Their adaptability is underscored by mechanisms including drug efflux and enhanced DNA repair, contributing to poor prognosis and high recurrence rates. The tumor microenvironment (TME) further facilitates BCSC survival through complex interactions with stromal and immune cells. Emerging therapeutic strategies targeting BCSCs - ranging from immunotherapy and nanoparticle-based drug delivery systems to gene-editing technologies - aim to disrupt these resistant cells. Additionally, innovative approaches focusing on exosome-mediated signaling and metabolic reprogramming show promise in overcoming chemoresistance. By elucidating the distinct characteristics of BCSCs and their role in TNBC, researchers are paving the way for novel treatments that may effectively eradicate these resilient cells, mitigate metastasis, and ultimately improve patient outcomes. This review highlights the urgent need for targeted strategies that address the unique biology of BCSCs in the pursuit of more effective therapeutic interventions for TNBC.

The emerging landscape and future perspective of SCLC transformation: From molecular mechanisms to therapeutic strategies

Small-cell lung cancer (SCLC) is featured by high malignancy and undesirable prognosis. Transformed SCLC shares several common grounds but differ in biological behavior, molecular mechanism and therapeutic options from typical SCLC. SCLC transformation exerts indispensable role in drug resistance among patients with non-small cell lung cancer (NSCLC) upon various treatment modalities. Two hypotheses have been raised to account for SCLC transformation. It develops mostly in EGFR-mutant adenocarcinoma, and can also occur in ALK or ROS1 mutant patients, and EGFR-wildtype adenocarcinoma. Effective biomarkers for early detection, and therapeutic strategies are vital for improving survival for patients undergoing SCLC transformation. This review summarizes the emerging landscape in transformed SCLC, including its origin, molecular mechanisms, approaches for early detection and corresponding therapeutic options, in a bid to gain a comprehensive insight of this recalcitrant and tricky disease. More importantly, we also discuss challenges that lie ahead and future perspectives on this aggressive malignancy.

Metabolic pathway activation and immune microenvironment features in non-small cell lung cancer: insights from single-cell transcriptomics

Introduction

In this study, we aim to provide a deep understanding of the tumor microenvironment (TME) and its metabolic characteristics in non-small cell lung cancer (NSCLC) through single-cell RNA sequencing (scRNAseq) data obtained from public databases. Given that lung cancer is a leading cause of cancer-related deaths globally and NSCLC accounts for the majority of lung cancer cases, understanding the relationship between TME and metabolic pathways in NSCLC is crucial for developing new treatment strategies.

Methods

Finally, machine learning algorithms were employed to construct a risk signature with strong predictive power across multiple independent cohorts. After quality control, 29,053 cells were retained, and PCA along with UMAP techniques were used to distinguish 13 primary cell subpopulations. Four highly activated metabolic pathways were identified within malignant cell subpopulations, which were further divided into seven distinct subgroups showing significant differences in differentiation potential and metabolic activity. WGCNA was utilized to identify gene modules and hub genes closely associated with these four metabolic pathways.

Results

Our analysis showed that DEGs between tumor and normal tissues were predominantly enriched in immune response and cell adhesion pathways. The comprehensive examination of our model revealed substantial variations in clinical and pathological characteristics, enriched pathways, cancer hallmarks, and immune infiltration scores between high-risk and low-risk groups. Wet lab experiments validated the role of KRT6B in NSCLC, demonstrating that KRT6B expression is elevated and it stimulates the proliferation of cancer cells.

Discussion

These observations not only enhance our understanding of metabolic reprogramming and its biological functions in NSCLC but also provide new perspectives for early detection, prognostic evaluation, and targeted therapy. However, future research should further explore the specific mechanisms of these metabolic pathways and their application potentials in clinical practice.

The landscape of cell lineage tracing

Cell fate changes play a crucial role in the processes of natural development, disease progression, and the efficacy of therapeutic interventions. The definition of the various types of cell fate changes, including cell expansion, differentiation, transdifferentiation, dedifferentiation, reprogramming, and state transitions, represents a complex and evolving field of research known as cell lineage tracing. This review will systematically introduce the research history and progress in this field, which can be broadly divided into two parts: prospective tracing and retrospective tracing. The initial section encompasses an array of methodologies pertaining to isotope labeling, transient fluorescent tracers, non-fluorescent transient tracers, non-fluorescent genetic markers, fluorescent protein, genetic marker delivery, genetic recombination, exogenous DNA barcodes, CRISPR-Cas9 mediated DNA barcodes, and base editor-mediated DNA barcodes. The second part of the review covers genetic mosaicism, genomic DNA alteration, TCR/BCR, DNA methylation, and mitochondrial DNA mutation. In the final section, we will address the principal challenges and prospective avenues of enquiry in the field of cell lineage tracing, with a particular focus on the sequencing techniques and mathematical models pertinent to single-cell genetic lineage tracing, and the value of pursuing a more comprehensive investigation at both the spatial and temporal levels in the study of cell lineage tracing.

Cancer stem cells and niches: challenges in immunotherapy resistance

Cancer stem cells (CSCs) are central to tumor progression, metastasis, immune evasion, and therapeutic resistance. Characterized by remarkable self-renewal and adaptability, CSCs can transition dynamically between stem-like and differentiated states in response to external stimuli, a process termed "CSC plasticity." This adaptability underpins their resilience to therapies, including immune checkpoint inhibitors and adoptive cell therapies (ACT). Beyond intrinsic properties, CSCs reside in a specialized microenvironment-the CSC niche-which provides immune-privileged protection, sustains their stemness, and fosters immune suppression. This review highlights the critical role of CSCs and their niche in driving immunotherapy resistance, emphasizing the need for integrative approaches to overcome these challenges.

Cell fusion as a driver of metastasis: re-evaluating an old hypothesis in the age of cancer heterogeneity

Numerous studies have investigated the molecular mechanisms and signalling pathways underlying cancer metastasis, as there is still no effective treatment for this terminal stage of the disease. However, the exact processes that enable primary cancer cells to acquire a metastatic phenotype remain unclear. Increasing attention has been focused on the fusion of cancer cells with myeloid cells, a phenomenon that may result in hybrid cells, so-called Tumour Hybrid Cells (THCs), with enhanced migratory, angiogenic, immune evasion, colonisation, and metastatic properties. This process has been shown to potentially drive tumour progression, drug resistance, and cancer recurrence. In this review, we explore the potential mechanisms that govern cancer cell fusion, the molecular mediators involved, the metastatic characteristics acquired by fusion-derived hybrids, and their clinical significance in human cancer. Additionally, we discuss emerging pharmacological strategies aimed at targeting fusogenic molecules as a means to prevent metastatic dissemination.

FoxA1/2-dependent epigenomic reprogramming drives lineage switching in lung adenocarcinoma

The ability of cancer cells to undergo identity changes (i.e., lineage plasticity) plays a key role in tumor progression and response to therapy. Loss of the pulmonary lineage specifier NKX2-1 in KRAS-driven lung adenocarcinoma (LUAD) enhances tumor progression and causes a FoxA1/2-dependent pulmonary-to-gastric lineage switch. However, the mechanisms by which FoxA1/2 activate a latent gastric identity in the lung remain largely unknown. Here, we show that FoxA1/2 reprogram the epigenetic landscape of gastric-specific genes after NKX2-1 loss in mouse models by facilitating ten-eleven translocation (TET)2/3 recruitment, DNA demethylation, histone 3 lysine 27 acetylation (H3K27ac) deposition, and three-dimensional (3D) chromatin interactions. FoxA1/2-mediated DNA methylation changes are highly conserved in human endodermal development and in progression of human lung and pancreatic neoplasia. Furthermore, oncogenic signaling is required for specific elements of FoxA1/2-dependent epigenetic reprogramming. This work demonstrates the role of FoxA1/2 in rewiring the DNA methylation and 3D chromatin landscape of NKX2-1-negative LUAD to drive cancer cell lineage switching.

Micro-physiological system of human lung: The current status and application to drug discovery

Various attempts have been made to elucidate the mechanisms of human lung development, its physiological functions, and diseases, in the hope of new drug discovery. Recent technological advancements in experimental animals, cell culture, gene editing, and analytical methods have provided new insights and therapeutic strategies. However, the results obtained from animal experiments are often inconsistent with those obtained from human data because of reproducibility issues caused by structural and physiological differences between mice and humans. In addition, it is not possible to accurately reproduce the internal environment of the human lung structure using conventional two-dimensional (2D) or three-dimensional (3D) cell culture methods. As a result, the micro-physiological system (MPS) technology, such as "lung-on-a-chip" that can culture human cells in a state close to human body environment have been developed, and its applications to disease models, toxicological studies, and drug discovery are accelerated worldwide. Here, we focus on the mimetics of the lung, including "lung-on-a-chip" technology, and review their recent progress, achievements and challenges. Finally, we discuss the role of these chips in drug discovery for refractory lung diseases.

Leveraging epigenetic alterations in pancreatic ductal adenocarcinoma for clinical applications

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by late detection and poor prognosis. Recent research highlights the pivotal role of epigenetic alterations in driving PDAC development and progression. These changes, in conjunction with genetic mutations, contribute to the intricate molecular landscape of the disease. Specific modifications in DNA methylation, histone marks, and non-coding RNAs are emerging as robust predictors of disease progression and patient survival, offering the potential for more precise prognostic tools compared to conventional clinical staging. Moreover, the detection of epigenetic alterations in blood and other non-invasive samples holds promise for earlier diagnosis and improved management of PDAC. This review comprehensively summarises current epigenetic research in PDAC and identifies persisting challenges. These include the complex nature of epigenetic profiles, tumour heterogeneity, limited access to early-stage samples, and the need for highly sensitive liquid biopsy technologies. Addressing these challenges requires the standardisation of methodologies, integration of multi-omics data, and leveraging advanced computational tools such as machine learning and artificial intelligence. While resource-intensive, these efforts are essential for unravelling the functional consequences of epigenetic changes and translating this knowledge into clinical applications. By overcoming these hurdles, epigenetic research has the potential to revolutionise the management of PDAC and improve patient outcomes.

FLT3 is associated with dendritic cell infiltration, tertiary lymphoid structure construction, and predict response to checkpoint inhibitors immunotherapy in solid cancers

The crosstalk between cancers and the immune microenvironment plays a critical role in malignant progression. FMS-like tyrosine kinase 3 (FLT3) is a frequently mutated gene in acute myeloid leukemia (AML). However, its role in solid cancers remains poorly understood. We analyzed the frequency of FLT3 alterations, its mRNA expression levels, and its prognostic implications across multiple cancer types. Additionally, we explored genes co-expressed with FLT3 and performed gene ontology analysis to identify associated biological processes. We also examined the relationship between FLT3 expression and markers of various immune cells, tertiary lymphoid structures (TLSs), and epithelial-mesenchymal transition. Furthermore, we validated these findings in our own cohort of hepatocellular carcinoma (HCC) patients. We found that FLT3 alteration and expression were both significantly upregulated in AML and were associated with poor prognosis, which is opposite to its role in solid cancers. The genes co-expressed with FLT3 in solid cancers were correlated with the regulation of the immune microenvironment. FLT3 was positively correlated with the formation of TLSs in only solid cancers, which was especially relevant to central memory T cells. We also found that FLT3 was positively correlated with the infiltration of NK cells, B cells, and DCs. It also positively correlated with the occurrence of apoptosis in solid cancers, but exhibited opposite roles in AML. The structural factors of the TLSs were positively correlated with FLT3 in solid cancers, but exhibited a negative correlation in AML. Meanwhile, we further validated the above conclusions in our own HCC cohort and demonstrated that FLT3 could serve as a predictive indicator of PD-1 treatment efficacy in HCC. In summary, the role of FLT3 is different in AML and solid cancers. FLT3 is associated with dendritic cell infiltration, tertiary lymphoid structure construction, and predict response to checkpoint inhibitors immunotherapy in HCC.

Systematic analysis of the transcriptional landscape of melanoma reveals drug-target expression plasticity

Metastatic melanoma originates from melanocytes of the skin. Melanoma metastasis results in poor treatment prognosis for patients and is associated with epigenetic and transcriptional changes that reflect the developmental program of melanocyte differentiation from neural crest stem cells. Several studies have explored melanoma transcriptional heterogeneity using microarray, bulk and single-cell RNA-sequencing technologies to derive data-driven models of the transcriptional-state change which occurs during melanoma progression. No study has systematically examined how different models of melanoma progression derived from different data types, technologies and biological conditions compare. Here, we perform a cross-sectional study to identify averaging effects of bulk-based studies that mask and distort apparent melanoma transcriptional heterogeneity; we describe new transcriptionally distinct melanoma cell states, identify differential co-expression of genes between studies and examine the effects of predicted drug susceptibilities of different cell states between studies. Importantly, we observe considerable variability in drug-target gene expression between studies, indicating potential transcriptional plasticity of melanoma to down-regulate these drug targets and thereby circumvent treatment. Overall, observed differences in gene co-expression and predicted drug susceptibility between studies suggest bulk-based transcriptional measurements do not reliably gauge heterogeneity and that melanoma transcriptional plasticity is greater than described when studies are considered in isolation.

Resistance mechanisms to immune checkpoint inhibitors: updated insights

The last decade has witnessed unprecedented succusses with the use of immune checkpoint inhibitors in treating cancer. Nevertheless, the proportion of patients who respond favorably to the treatment remained rather modest, partially due to treatment resistance. This has fueled a wave of research into potential mechanisms of resistance to immune checkpoint inhibitors which can be classified into primary resistance or acquired resistance after an initial response. In the current review, we summarize what is known so far about the mechanisms of resistance in terms of being tumor-intrinsic or tumor-extrinsic taking into account the multimodal crosstalk between the tumor, immune system compartment and other host-related factors.

Dual-Enzyme-Instructed Peptide Self-Assembly to Boost Immunogenic Cell Death by Coordinating Intracellular Calcium Overload and Chemotherapy

The concept of immunogenic cell death (ICD) induced by chemotherapy as a potential synergistic modality for cancer immunotherapy has been widely discussed. Unfortunately, most chemotherapeutic agents failed to dictate effective ICD responses due to their defects in inducing potent ICD signaling. Here, we report a dual-enzyme-instructed peptide self-assembly platform of CPMC (CPT-GFFpY-PLGVRK-Caps) that cooperatively utilizes camptothecin (CPT) and capsaicin (Caps) to promote ICD and engage systemic adaptive immunity for tumor rejection. Although CPT and Caps respectively prevent tumor progression by inhibiting type-I DNA topoisomerase and activating transient receptor potential cation channel subfamily V member 1 (TRPV1) for intracellular calcium overload, neither alone effectively stimulates sufficient ICD signaling to meet immunotherapeutic needs. CPMC, sequentially allowing an active Caps derivative of VRK-Caps and CPT to release extracellularly and intracellularly, can synergize two distinct apoptosis pathways stimulated by Caps and CPT to increase tumor immunogenicity and elicit systemic T-cell-based immunity. Consequently, CPMC facilitates the generation of improved tumor-specific cytotoxic T-cell responses and sustained immunological memory, successfully suppressing both primary and distant tumors. Moreover, CPMC can render tumors susceptible to PD-L1 blockade and synergize with an antiprogrammed cell death-ligand 1 (aPDL1) antibody for tumor inhibition. Combining two cancer chemotherapeutic drugs with low ICD-stimulating capacity using a peptide self-assembly strategy was demonstrated to boost ICD responses and potentiate cancer immunotherapy.

Aidi injection inhibits the migration and invasion of gefitinib-resistant lung adenocarcinoma cells by regulating the PLAT/FAK/AKT pathway

BACKGROUND

With extended gefitinib treatment, the therapeutic effect in some non-small cell lung cancer (NSCLC) patients declined with the development of drug resistance. Aidi injection (ADI) is utilized in various cancers as a traditional Chinese medicine prescription. This study explores the molecular mechanism by which ADI, when combined with gefitinib, attenuates gefitinib resistance in PC9GR NSCLC cells.

METHODS

In vitro and in vivo pharmacological experiments were conducted in PC9GR cells and NSG mice with PC9GR cell-derived tumors, respectively. The molecular mechanism of ADI was further studied using whole-transcriptome sequencing technology. Bioinformatics and molecular biology methods were employed to validate the critical targets of ADI.

RESULTS

Firstly, ADI treatment alone and combined with gefitinib significantly inhibited the proliferation, migration, and invasion of PC9GR cells. Then, whole-transcriptome sequencing and bioinformatics analysis revealed that PLAT is a key target for the increased efficacy of ADI combined with gefitinib. Additionally, ADI downregulates the expression of PLAT, TNC, ITGB3, p-AKT, p-PI3K, and p-FAK. ADI inhibits the migration and invasion of PC9GR cells by regulating the PLAT/FAK/AKT pathway.

CONCLUSIONS

Aidi injection inhibits the migration and invasion of gefitinib-resistant lung adenocarcinoma cells by regulating the PLAT/FAK/AKT pathway. This study provides essential evidence for elucidating the mechanism of ADI in synergistic therapy for lung cancer.

Intratumor heterogeneity of EGFR expression mediates targeted therapy resistance and formation of drug tolerant microenvironment

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are commonly used to treat non-small cell lung cancers with EGFR mutations, but drug resistance often emerges. Intratumor heterogeneity is a known cause of targeted therapy resistance and is considered a major factor in treatment failure. This study identifies clones of EGFR-mutant non-small cell lung tumors expressing low levels of both wild-type and mutant EGFR protein. These EGFR-low cells are intrinsically more tolerant to EGFR inhibitors, more invasive, and exhibit an epithelial-to-mesenchymal-like phenotype compared to their EGFR-high counterparts. The EGFR-low cells secrete Transforming growth factor beta (TGFβ) family cytokines, leading to increased recruitment of cancer-associated fibroblasts and immune suppression, thus contributing to the drug-tolerant tumor microenvironment. Notably, pharmacological induction of EGFR using epigenetic inhibitors sensitizes the resistant cells to EGFR inhibition. These findings suggest that intrinsic drug resistance can be prevented or reversed using combination therapies.

Mechanisms of Regulation of Cell Fate in Breast Development and Cancer

This chapter focuses on the mechanisms of regulation of cell fate in breast development, occurring mainly after birth, as well as in breast cancer. First, we will review how the microenvironment of the breast, as well as external cues, plays a crucial role in mammary gland cell specification and will describe how it has been shown to reprogram non-mammary cells into mammary epithelial cells. Then we will focus on the transcription factors and master regulators which have been established to be determinant for basal (BC) and luminal cell (LC) identity, and will describe the experiments of ectopic expression or loss of function of these transcription factors which demonstrated that they were crucial for cell fate. We will also discuss how master regulators are involved in the fate choice of LCs between estrogen receptor (ER)-positive cells and ER- cells, which will give rise to alveolar cells upon pregnancy and lactation. We will describe how oncogene expression induces reprogramming and change of fate of mammary epithelial cells before tumor appearance, which could be an essential step in tumorigenesis. Finally, we will describe the involvement of master regulators of mammary epithelial cells in breast cancer.

LKB1 inactivation promotes epigenetic remodeling-induced lineage plasticity and antiandrogen resistance in prostate cancer

Epigenetic regulation profoundly influences the fate of cancer cells and their capacity to switch between lineages by modulating essential gene expression, thereby shaping tumor heterogeneity and therapy response. In castration-resistant prostate cancer (CRPC), the intricacies behind androgen receptor (AR)-independent lineage plasticity remain unclear, leading to a scarcity of effective clinical treatments. Utilizing single-cell RNA sequencing on both human and mouse prostate cancer samples, combined with whole-genome bisulfite sequencing and multiple genetically engineered mouse models, we investigated the molecular mechanism of AR-independent lineage plasticity and uncovered a potential therapeutic strategy. Single-cell transcriptomic profiling of human prostate cancers, both pre- and post-androgen deprivation therapy, revealed an association between liver kinase B1 (LKB1) pathway inactivation and AR independence. LKB1 inactivation led to AR-independent lineage plasticity and global DNA hypomethylation during prostate cancer progression. Importantly, the pharmacological inhibition of TET enzymes and supplementation with S-adenosyl methionine were found to effectively suppress AR-independent prostate cancer growth. These insights shed light on the mechanism driving AR-independent lineage plasticity and propose a potential therapeutic strategy by targeting DNA hypomethylation in AR-independent CRPC.

Screening and in vitro Biological Evaluation of Novel Multiple Tyrosine Kinases Inhibitors as Promising Anticancer Agents

BACKGROUND

Tyrosine kinases have emerged as key stimulatory drivers in several cancer-related pathways. This is particularly evident in non-small cell lung cancer with regulating cell growth and apoptosis and so on. Tyrosine kinase inhibitors (TKI) are one breakthrough option that could improve the life quality of cancer patients.

OBJECTIVE

This study aims to find more effective tyrosine kinase inhibitors.

METHODS

In this study, natural products from TargetMol that may be the potential TKI for lung cancer were screened through structure-based virtual screening and experimental validation. Moreover, the binding between the hit compounds and tyrosine kinase was explored.

RESULTS

From the study findings, Gramicidin and Tannic acid have strong interactions with the four tyrosine kinases (ALK, TRK, MET, and ABL), and this could significantly inhibit the viability of A549 cells in a concentrationdependent manner.

CONCLUSION

These findings indicated that Gramicidin and Tannic acid might be potential multiple TKI and are promising anticancer agents that call for further study.

BRAFV600 and ErbB inhibitors directly activate GCN2 in an off-target manner to limit cancer cell proliferation

Targeted kinase inhibitors are well known for their promiscuity and off-target effects. Herein, we define an off-target effect in which several clinical BRAFV600 inhibitors, including the widely used dabrafenib and encorafenib, interact directly with GCN2 to activate the Integrated Stress Response and ATF4. Blocking this off-target effect by co-drugging with a GCN2 inhibitor in A375 melanoma cells causes enhancement rather than suppression of cancer cell outgrowth, suggesting that the off-target activation of GCN2 is detrimental to these cells. This result is mirrored in PC9 lung cancer cells treated with erlotinib, an EGFR inhibitor, that shares the same off-target activation of GCN2. Using an in silico kinase inhibitor screen, we identified dozens of FDA-approved drugs that appear to share this off-target activation of GCN2 and ATF4. Thus, GCN2 activation may modulate the therapeutic efficacy of some kinase inhibitors, depending on the cancer context.

Cytotoxic effects of bee venom-loaded ZIF-8 nanoparticles on thyroid cancer cells: a promising strategy for targeted therapy

Thyroid cancer continues to be a notable health issue, requiring the creation of novel treatment methods to enhance patient results. The objective of this study is to investigate the potential of utilizing bee venom (BV)-loaded zeolitic imidazolate framework-8 (ZIF-8) nanoparticles as a novel strategy for specifically targeting and treating medullary thyroid cancer cells. Due to their wide surface area and configurable pore size, ZIF-8 nanoparticles are ideal for drug delivery. Bee venom's cytotoxic capabilities are used in ZIF-8 nanoparticles to target thyroid cancer cells more effectively. ZIF-8 nanoparticles containing bee venom were tested on TT medullary thyroid cancer cell lines. The effects of these nanoparticles on cell viability, proliferation, and apoptosis were investigated. IC50 value at 24 h for BV-ZIF-8 nanoparticles in TT medullary thyroid carcinoma cells was determined to be 17.19 µg/mL, while the IC50 value at 48 h was determined to be 16.39 µg/mL. It has been demonstrated that nanoparticle treatment upregulates the Bax and caspase-3 genes while downregulating the Bcl-2, CCND1, and CDK4 genes. Additionally, it was observed that oxidative stress was triggered in the nanoparticle-treated group. Furthermore, an examination of its mechanisms was conducted, with a specific emphasis on the modulation of critical signaling pathways that are implicated in the progression of cancer. In thyroid cancer cells, ZIF-8 nanoparticles infused with bee venom promote programmed cell death and impair key biological processes.

Exosome-delivered NR2F1-AS1 and NR2F1 drive phenotypic transition from dormancy to proliferation in treatment-resistant prostate cancer via stabilizing hormonal receptors

Cancer cells acquire the ability to reprogram their phenotype in response to targeted therapies, yet the transition from dormancy to proliferation in drug-resistant cancers remains poorly understood. In prostate cancer, we utilized high-plasticity mouse models and enzalutamide-resistant (ENZ-R) cellular models to elucidate NR2F1 as a key factor in lineage transition and ENZ resistance. Depletion of NR2F1 drives ENZ-R cells into a relative dormancy state, characterized by reduced proliferation and heightened drug resistance, while NR2F1 overexpression yields contrasting outcomes. Transcriptional sequencing analysis of NR2F1-silenced prostate cancer cells and tissues from the Cancer Genome Atlas-prostate cancer and SU2C cohorts indicated exosomes as the most enriched cell component, with pathways implicated in steroid hormone biosynthesis and drug metabolism. Moreover, NR2F1-AS1 forms a complex with SRSF1 to upregulate NR2F1 expression, facilitating its binding with ESR1 to sustain hormonal receptor expression and enhance proliferation in ENZ-R cells. Furthermore, HnRNPA2B1 interacts with NR2F1 and NR2F1-AS1, assisting their packaging into exosomes, wherein exosomal NR2F1 and NR2F1-AS1 promote the proliferation of dormant ENZ-R cells. Our works offer novel insights into the reawaking of dormant drug-resistant cancer cells governed by NR2F1 upregulation triggered by exosome-derived NR2F1-AS1 and NR2F1, suggesting therapeutic potential for phenotype reversal.

Heterogeneity-driven phenotypic plasticity and treatment response in branched-organoid models of pancreatic ductal adenocarcinoma

In patients with pancreatic ductal adenocarcinoma (PDAC), intratumoural and intertumoural heterogeneity increases chemoresistance and mortality rates. However, such morphological and phenotypic diversities are not typically captured by organoid models of PDAC. Here we show that branched organoids embedded in collagen gels can recapitulate the phenotypic landscape seen in murine and human PDAC, that the pronounced molecular and morphological intratumoural and intertumoural heterogeneity of organoids is governed by defined transcriptional programmes (notably, epithelial-to-mesenchymal plasticity), and that different organoid phenotypes represent distinct tumour-cell states with unique biological features in vivo. We also show that phenotype-specific therapeutic vulnerabilities and modes of treatment-induced phenotype reprogramming can be captured in phenotypic heterogeneity maps. Our methodology and analyses of tumour-cell heterogeneity in PDAC may guide the development of phenotype-targeted treatment strategies.

Cellular and molecular aspects of drug resistance in cancers

OBJECTIVES

Cancer drug resistance is a multifaceted phenomenon. The present review article aims to comprehensively analyze the cellular and molecular aspects of drug resistance in cancer and the strategies employed to overcome it.

EVIDENCE ACQUISITION

A systematic search of relevant literature was conducted using electronic databases such as PubMed, Scopus, and Web of Science using appropriate key words. Original research articles and secondary literature were taken into consideration in reviewing the development in the field.

RESULTS AND CONCLUSIONS

Cancer drug resistance is a pervasive challenge that causes many treatments to fail therapeutically. Despite notable advances in cancer treatment, resistance to traditional chemotherapeutic agents and novel targeted medications remains a formidable hurdle in cancer therapy leading to cancer relapse and mortality. Indeed, a majority of patients with metastatic cancer experience are compromised on treatment efficacy because of drug resistance. The multifaceted nature of drug resistance encompasses various factors, such as tumor heterogeneity, growth kinetics, immune system, microenvironment, physical barriers, and the emergence of undruggable cancer drivers. Additionally, alterations in drug influx/efflux transporters, DNA repair mechanisms, and apoptotic pathways further contribute to resistance, which may manifest as either innate or acquired traits, occurring prior to or following therapeutic intervention. Several strategies such as combination therapy, targeted therapy, development of P-gp inhibitors, PROTACs and epigenetic modulators are developed to overcome cancer drug resistance. The management of drug resistance is compounded by the patient and tumor heterogeneity coupled with cancer's ability to evade treatment. Gaining further insight into the mechanisms underlying medication resistance is imperative for the development of effective therapeutic interventions and improved patient outcomes.

Advances in Understanding Drug Resistance Mechanisms and Innovative Clinical Treatments for Melanoma

OPINION STATEMENT

Melanoma, a highly invasive skin cancer resulting from melanocyte malignant transformation, is the third most common skin malignancy. Despite accounting for only 4% to 5% of all skin malignancies, it is responsible for 80% of skin cancer-related deaths. Targeted therapies and immune checkpoint inhibitors have improved survival rates, yet drug resistance remains a major challenge. In this review, I explore the latest research progress on melanoma drug resistance mechanisms and clinical treatment methods. This aims to provide insights for more effective treatment strategies and improve patient prognosis and quality of life. I also discuss potential strategies to overcome drug resistance based on the latest scientific findings, with a particular focus on the complex and multi-factorial drug resistance mechanisms of melanomas, including genetic mutations, epigenetic changes, and tumor microenvironment factors. Understanding these mechanisms is crucial for developing new drugs and combination therapies targeting drug-resistant tumors. Analyzing complex drug resistance pathways paves the way for personalized medical approaches, which is expected to provide enlightenment on breaking through drug resistance barriers and enhancing the effectiveness of melanoma treatment.

Recent research progress on microRNAs from mesenchymal stem cell-derived exosomes for tumor therapy: A review

ABSTRACT

Mesenchymal stem cells (MSCs) are a class of protocells that can differentiate into various cell types and have robust replication and renewal capabilities. MSCs secrete various nutritional factors to regulate the microenvironment of tumor tissues. The mechanism by which they inhibit or promote tumor growth may be closely related to MSC-derived exosomes (MSC-Exo). However, the role of MSC-Exo vesicles in tumors remains controversial. This review discusses the potential applications of microRNAs in exosomes derived from MSCs in treating tumors.

Clues into Wnt cell surface signalosomes and its biogenesis

Wnt morphogens induce signaling via binding their extracellular receptors. Here, we discuss several recent structural studies showing how Wnts engage their receptors frizzled (FZD) and low-density lipoprotein receptor-related protein 5/6 (LRP5/6), how Cachd1 has been shown as an alternative initiator of Wnt signaling, and how lipidated Wnt may be produced and secreted from the cell.

Targeting the gut and tumor microbiome in cancer treatment resistance

Therapy resistance represents a significant challenge in oncology, occurring in various therapeutic approaches. Recently, animal models and an increasing set of clinical trials highlight the crucial impact of the gut and tumor microbiome on treatment response. The intestinal microbiome contributes to cancer initiation, progression, and formation of distant metastasis. In addition, tumor-associated microbiota is considered a critical player in influencing tumor microenvironments and regulating local immune processes. Intriguingly, numerous studies have successfully identified pathogens within the gut and tumor microbiome that might be linked to a poor response to different therapeutic modalities. The unfavorable microbial composition with the presence of specific microbes participates in cancer resistance and progression via several mechanisms, including upregulation of oncogenic pathways, macrophage polarization reprogramming, metabolism of chemotherapeutic compounds, autophagy pathway modulation, enhanced DNA damage repair, inactivation of a proapoptotic cascade, and bacterial secretion of extracellular vesicles, promoting the processes in the metastatic cascade. Targeted elimination of specific intratumoral bacteria appears to enhance treatment response. However, broad-spectrum antibiotic pretreatment is mostly connected to reduced efficacy due to gut dysbiosis and lower diversity. Mounting evidence supports the potential of microbiota modulation by probiotics and fecal microbiota transplantation to improve intestinal dysbiosis and increase microbial diversity, leading to enhanced treatment efficacy while mitigating adverse effects. In this context, further research concerning the identification of clinically relevant microbiome signatures followed by microbiota-targeted strategies presents a promising approach to overcoming immunotherapy and chemotherapy resistance in refractory patients, improving their outcomes.

Peptides as innovative strategies to combat drug resistance in cancer therapy

Drug resistance is the leading cause of treatment failure in patients with cancer. Thus, innovative therapeutic strategies are required to overcome this critical challenge and improve patient outcomes. In this review, we examine the potential of peptide-based therapies to combat drug resistance in cancer. We highlight the unique strategies and mechanisms that can be explored by using peptides, including their ability to selectively target tumours, facilitate drug delivery into cancer cells, and inhibit key intracellular proteins that drive cancer progression and resistance. Peptides offer a promising approach to overcoming both intrinsic and adaptative cancer resistance against chemotherapy, targeted therapies, and biologics.

Antihyperlipidemic drug rosuvastatin suppressed tumor progression and potentiated chemosensitivity by downregulating CCNA2 in lung adenocarcinoma

Rosuvastatin (RSV) is widely used to treat hyperlipidemia and hypercholesterolemia and is recommended for the primary and secondary prevention of cardiovascular diseases (CVD). In this study, we aimed to explore its action and mechanism in lung adenocarcinoma (LUAD) therapy. Lewis and CMT64 cell-based murine subcutaneous LUAD models were employed to explore the effects of RSV monotherapy combined with cisplatin and gemcitabine. Human lung fibroblasts and human LUAD cell lines were used to assess the effects of RSV on normal and LUAD cells. Bioinformatics and RNA interference were used to observe the contribution of cyclin A2 (CCNA2) knockdown to RSV inhibition and to improve chemosensitivity in LUAD. RSV significantly suppressed grafted tumor growth in a murine subcutaneous LUAD model and exhibited synergistic anti-tumor activity with cisplatin and gemcitabine. In vitro and in vivo experiments demonstrated that RSV impaired the proliferation and migration of cancer cells while showing little inhibition of normal lung cells. RNA interference and CCK8 detection preliminarily indicated that RSV inhibited tumor growth and enhanced the chemosensitivity to cisplatin and gemcitabine by downregulating CCNA2. RSV suppressed LUAD progression and enhanced chemosensitivity to cisplatin and gemcitabine by downregulating CCNA2, which should be prior consideration for the treatment of LUAD, especially for patients co-diagnosed with hyperlipidemia and hypercholesterolemia.