Journal of Experimental & Clinical Cancer Research最新文献

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is critical for innate immunity, as it detects cytoplasmic DNA and drives type I interferon signaling. Pharmacological stimulation of this pathway has been recognized as a valuable approach for cancer immunotherapy, especially when used together with immune checkpoint inhibitors (ICIs). Preclinical studies have demonstrated synergistic antitumor effects of cGAS-STING agonists and ICIs across various tumor models, while early-phase clinical trials are exploring their safety and efficacy in patients. Nonetheless, intrinsic tumor resistance, an immunosuppressive tumor microenvironment (TME), and therapy-associated immune toxicities continue to pose substantial obstacles to clinical application. In this review, we provide an overview of the present status of cGAS-STING agonists, emphasizing preclinical and clinical advances in combination therapy with ICIs, and discusses the challenges and future directions to optimize efficacy, improve safety, and expand the therapeutic potential of this strategy in oncology.

Chemoresistance remains a major challenge in addressing T-cell lymphoblastic lymphoma/leukemia (T-LBL/ALL), underscoring the necessity for novel strategies to unravel the molecular factors driving resistance. Through transcriptomic profiling, circBPTF was found to be markedly overexpressed in chemoresistant samples. Further functional experiments demonstrated that BPTF-665aa, the protein product of circBPTF, plays a pivotal role in mediating resistance. Notably, BPTF-665aa prevents the ubiquitination degradation of full-length BPTF, and promotes chromatin accessibility at key promoter sites, such as that of c-Myc promter 2 (P2), facilitating transcriptional activation crucial for cellular survival and proliferation under therapeutic stress. Structural studies confirmed the motifs of BPTF-665aa, including the Plant Homeodomain (PHD) finger and Bromodomain, essential for its chromatin remodeling function. HY-B0509 was identified as a small-molecule inhibitor of BPTF-665aa, with molecular docking and dynamics simulations showing stable binding to critical residues within the protein's active site. Overall, this study introduces a new mechanism where circBPTF affects chromatin accessibility, causing chemoresistance, making BPTF-665aa as a potential therapeutic target for treating T-LBL/ALLs.

Background: HPV-negative (-) head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous cancer characterized by high mutational burden, an immunosuppressive microenvironment, and poor response to standard therapies. These features highlight the urgent need for novel and more effective treatment strategies.

Methods: Drug sensitivity prediction was performed using integrated datasets from TCGA, GDSC, and CCLE. To assess the therapeutic potential and underlying mechanisms of combining the CDK inhibitor AZD5438 with the MEK1/2 inhibitor PD0325901, we employed a comprehensive panel of HNSCC models, including established cell lines, orthotopic mouse tumor models, and patient-derived organoids (PDOs). Lipid nanoparticles (LNPs) were engineered to co-deliver both agents into the same cancer cell populations. The tumor secretome was profiled using biotinylation coupled with liquid chromatography-mass spectrometry (LC-MS). Molecular alterations were examined by immunofluorescence, immunohistochemistry, ELISA, flow cytometry, and Western blot.

Results: Our bioinformatics analysis identified AZD5438 and PD0325901 as two of thirteen candidate drugs whose sensitivity is consistently associated with the five most frequently mutated genes in HPV (-) HNSCC. Notably, among these candidates, AZD5438 and PD0325901 exhibited the lowest correlation in their sensitivity profiles, suggesting complementary mechanisms of action. In experimental models, the combination of AZD5438 and PD0325901 not only outperformed either monotherapy in suppressing tumor growth but also augmented CD8⁺ T cell-mediated antitumor immunity by promoting caspase-8/gasdermin E-dependent pyroptosis. Furthermore, in both orthotopic tumor-bearing mice and PDOs, the LNP-encapsulated drug combination produced significantly greater therapeutic efficacy compared with the free drug formulation.

Conclusions: Our findings indicate that the combination of AZD5438 and PD0325901 holds therapeutic potential for the treatment of HPV (-) HNSCC, particularly in tumors with a high mutational burden. By targeting complementary pathways, this combination may improve treatment outcomes in this aggressive cancer subtype.

Embryonic Transcription Factors (TFs) are often reactivated in cancer, driving developmental gene programs that support phenotypic plasticity. Metabolic adaptation fuels this plasticity by supplying energy and molecular building blocks for growth. RUNX2, the master regulator of bone morphogenesis, is ectopically expressed in epithelial cancer, promoting metastasis through trans-differentiation processes like Epithelial-to-Mesenchymal Transition (EMT) and osteomimicry. By combining omics data with functional validation, we demonstrated that RUNX2 drives cancer cell metabolic rewiring by repressing mitochondrial respiration while promoting anabolic processes. We showed that RUNX2 upregulates key genes of lipid biosynthesis by regulating and cooperating with SREBP1. In vivo expression analysis in thyroid and breast cancer patients confirmed that lipid metabolism and SREBF1 expression are associated with increased metastatic potential and clinical aggressiveness. These findings emphasize the RUNX2 role in cancer plasticity and indicate metabolic adaptation as an integral part of the trans-differentiation program induced by this TF during cancer progression.

Background: TCRαβ⁺ double negative T cells (DNT) have recently gained attention for their antitumor activity. Adoptive DNT therapy has emerged as a promising cancer immunotherapy due to its potent cytotoxic function and lack of graft-versus-host-disease. However, the intrinsic mechanisms regulating DNT antitumor functions remain unclear.

Methods: Signaling lymphocytic activation molecule factor 7 (SLAMF7) expression in murine and human DNT were evaluated. The antitumor activities were compared between SLAMF7⁺ and SLAMF7^- DNT both in vivo and in vitro. Further, metabolomics analysis was performed to reveal the underlying mechanism by which SLAMF7 promotes DNT antitumor cytotoxicity.

Results: The expression of SLAMF7 was markedly increased on DNT upon activation. SLAMF7⁺ DNT exhibited superior antitumor capacity both in vitro and in vivo compared with SLAMF7^- DNT. Mechanistically, SLAMF7 enhanced antitumor activity through ligand-independent and ligand-dependent dual manners. Firstly, SLAMF7 could upregulate GPT2/SLC1A5-mediated glutamine metabolism by activating ERK signaling pathway in DNT, thereby supporting mitochondrial fitness, increasing ATP production, enhancing the expression of effector molecules such as granzyme B and perforin, and promoting antitumor activity of DNT against tumor cells independent of homotypic ligand-receptor interactions. Secondly, DNT showed superior antitumor cytotoxicity against SLAMF7-expressing tumor cells because SLAMF7-SLAMF7 interaction between DNT and SLAMF7-expressing tumor cells promoted DNT cell degranulation. Furthermore, SLAMF7 was also highly expressed in human DNT, and its dual antitumor roles in human DNT were also validated.

Conclusions: SLAMF7 is a key regulator of DNT-mediated cytotoxicity and a promising target for improving DNT cell function in cancer therapy.

Background: Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer with limited therapeutic options. Although cisplatin is recommended as a first-line treatment, its clinical efficacy is hindered by the rapid development of drug resistance, highlighting the urgent need for effective strategies to overcome cisplatin resistance.

Methods: We established a NEPC mouse allograft model and performed RNA sequencing to identify genes associated with cisplatin resistance. The role of CCL5 in tumor-stromal crosstalk was investigated using immunofluorescence, ELISA assays, co-culture assays, and CCL5 knockout mice. Mechanistic studies were conducted to explore CCL5/CCR5-mediated signaling pathways. The therapeutic efficacy of cisplatin combined with maraviroc, an FDA-approved CCR5 antagonist, was evaluated in vitro using NEPC cell lines and patient-derived organoids, and in vivo using NEPC mouse models.

Results: Here, we identify a tumor-stromal interaction mediated by the CCL5/CCR5 axis that drives cisplatin resistance in NEPC. Cisplatin-induced DNA damage promotes a cGAS-STING-dependent senescence program in cancer-associated fibroblasts (CAFs), resulting in the secretion of CCL5, a key senescence-associated secretory phenotype factor. CCL5 from CAFs binds to CCR5 on tumor cells, promoting the formation of a CCR5/β-arrestin1/p85 complex that activates the PI3K/AKT pathway. This activation enhances DNA repair, protecting tumor cells from cisplatin-induced apoptosis. Pharmacologic inhibition of the CCL5/CCR5 pathway using maraviroc, an FDA-approved CCR5 antagonist, sensitizes NEPC cells to cisplatin treatment and significantly prolongs survival in NEPC mouse models.

Conclusions: Our findings identify the CCL5/CCR5 axis as a key mediator of tumor-stromal crosstalk driving cisplatin resistance in NEPC. Mechanistically, CAF-derived CCL5 activates AKT signaling in tumor cells by promoting the formation of the CCR5/β-arrestin1/p85 complex. Targeting this pathway with maraviroc in combination with cisplatin offers a promising therapeutic strategy for overcoming drug resistance in NEPC.

Background: Resistant mutations and amplification of the epidermal growth factor receptor (EGFR), followed by the upregulation of its translated protein undermines the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in EGFR-mutant lung adenocarcinoma (LUAD). This underscores that promoting EGFR protein degradation may be a promising strategy for treatment.

Methods: Ubiquitin ligases database analysis identified NEDD4L as a mediator of EGFR proteasomal degradation, which was further confirmed by qPCR, western blot, immunofluorescence staining and CO-IP. The upstream regulatory role of FOXM1 on NEDD4L was elucidated through bioinformatics analyses and validated using dual luciferase reporter assay, ChIP, qPCR, western blot and immunohistochemistry. Virtual screening and molecular docking were used to identify inhibitors of FOXM1. Functional studies and therapeutic strategies were conducted using gain- and loss-of-function assays, and evaluated through in vitro and in vivo experiments.

Results: We identified the E3 ubiquitin ligase NEDD4L that targets both wild-type EGFR and osimertinib-sensitive/resistant EGFR mutants for proteasomal degradation, thereby effectively inhibiting EGFR-driven LUAD growth. We found FOXM1 as a critical upstream transcription factor that binds to the promoter of NEDD4L and represses its expression, further promoting tumor growth and osimertinib resistance in LUAD by increasing EGFR protein level. High FOXM1 expression correlates with low NEDD4L expression in LUAD patients, which is associated with poor clinical outcomes. Notably, we further identified that verteporfin, an FDA-approved small molecule drug, as a FOXM1 inhibitor. Verteporfin suppresses FOXM1 to upregulate NEDD4L expression and facilitate EGFR proteasomal degradation, thereby inhibiting EGFR-driven LUAD growth and overcoming osimertinib resistance. Remarkably, the combination of verteporfin and osimertinib shows an additively inhibitory effect on EGFR-mutated LUAD growth compared to monotherapy, both in post-TKI resistance and upfront treatment settings.

Conclusions: This study demonstrates that FOXM1/NEDD4L axis impairs EGFR proteasomal degradation, thus contributing to EGFR-driven LUAD growth and osimertinib resistance. Combination therapy incorporating NEDD4L activation may represent a new valued therapeutic strategy for EGFR-driven LUAD and osimertinib resistance.

Background: Malignant pleural mesothelioma (MPM) responds poorly to chemotherapy and is a highly progressive malignancy with a median survival time of only 6-9 months. Therefore, the development of anti-MPM tumor agents with high efficacy and low toxicity is urgent and addresses an unmet need for MPM patients.

Methods: Medicinal chemistry synthesis of small molecules based on the FL118 drug platform were further comparatively investigated using multiple MPM and osteosarcoma cell/tumor in vitro and/or in vivo models. The method includes cell viability assay, Western blot analysis, colony formation assay, immunocytochemical staining, β-galactosidase senescence staining, flow cytometry, DNA fragmentation cell death detection, vector-free CRISPR-Cas9-mediated gene knockout, bioinformatic analysis, FL496 efficacy determination using severe combined immunodeficiency (SCID) mice with human MPM tumor, and immunohistochemistry (IHC) analysis of MPM tumors.

Results: Here, we report that we identified a novel FL118-derived small molecule (FL496). FL496 appears to be strikingly more effective in inhibiting MPM tumor growth in MPM tumor animal models than the currently most prevalent pemetrexed-cisplatin combination in the clinic. The treatment of MPM cells with FL496 rapidly induced p53 and p21 accumulation, and Rb and p-Rb inhibition, which were associated with MPM cell senescence and G₁/G₀ arrest and apoptosis. Knockout (KO) of the TP53/p53 gene decreased the ability of FL496 to inhibit MPM cell growth (i.e., increase FL496 IC₅₀ values) and colony formation. FL496-treated MPM cells resulted in strong inhibition of the expression of survivin, Mcl-1, Bcl-2, Bcl-XL, and the induction of active caspase-3, cleaved PARP, and PUMA, which were further confirmed using MPM tumor tissues via IHC analysis. High survivin in MPM patients' tumors is associated with poor patient survival. Similar to FL118, FL496 treatment reduces DDX5 expression in MPM cells, but FL496 is more potent than FL118 in inhibiting MPM cell growth. Therefore, the mechanism of action (MOA) of FL496 overlaps with, but is likely beyond the scope of FL118 MOA, which needs further investigation.

Conclusions: Together, these results indicate that FL496 is a promising anti-MPM small molecule, and its high anti-MPM potential is worthy of being further explored as a monotherapeutic agent to treat MPM patients in clinical trials.

Background: Acute myeloid leukemia (AML) remains a challenging hematological malignancy, with chemoresistance contributing significantly to treatment failure and relapse. The bone marrow microenvironment, particularly mesenchymal stem cells (MSCs), plays a critical role in AML cell survival and drug resistance. Although previous studies have extensively explored the MSCs differentiation, the regulatory role of the adipogenically differentiated MSCs on AML cells during co-culture remains unclear.

Methods: An indirect co-culture model was established to evaluate the impact of MSCs on the drug sensitivity of AML cells. Based on the comparable chemosensitivity trends observed among THP-1, U937, and HL-60 cells, THP-1 were selected for subsequent experiments due to their stable growth characteristics and well-established utilization. Metabolic alterations between co-cultured and monocultured THP-1 were profiled using nuclear magnetic resonance spectroscopy. Concurrently, RNA sequencing was conducted to identify differentially expressed genes and enriched signaling pathways between co-cultured and monocultured THP-1. To validate the pathway alterations identified by transcriptomic analysis, the Akt inhibitor MK-2206 was applied, and its effects were evaluated by western blotting and cell viability assays.

Results: The results demonstrated that AML cells co-cultured with adipogenic MSCs were less sensitive to daunorubicin and cytarabine in both in vitro and in vivo. Subsequent metabolomics analysis revealed significant alternative metabolic processes in AML cells following co-culture, specifically in the glycolysis, glutamine metabolism and lipid metabolism. Further transcriptomic profiling identified key differentially expressed genes and signaling pathways, with PI3K/Akt signaling pathway activation emerging as a contributor to the reduced chemotherapy sensitivity. Furthermore, elevated levels of IL-6 in the co-culture system suggested a role for cytokine-mediated signaling in promoting a protective microenvironment.

Conclusions: This work demonstrates that the adipogenically differentiated MSCs enhance the survival and chemoresistance of AML cells by modulating metabolic and signaling pathways. It provides integrated insights into the microenvironment-driven mechanisms of AML drug resistance and presents potential therapeutic targets to enhance treatment efficacy.