Molecular Cancer Therapeutics最新文献

Despite recent advances in the treatment of fibroblast growth factor receptor 3 (FGFR3)-altered metastatic urothelial carcinoma, there is no approved precision therapy that selectively targets FGFR3 while sparing other FGFR isoforms. Dabogratinib (TYRA-300)-a rationally designed selective FGFR3 inhibitor-was evaluated in vitro and in vivo. We also report three patient cases from the ongoing first-in-human, phase I/II SURF301 study (NCT05544552). Dabogratinib elicited a dose-dependent reduction in downstream signaling across three bladder cancer cell lines harboring an FGFR3 fusion, mutation, or gatekeeper resistance mutation. In a xenograft model driven by an FGFR3S249C-activating mutation, dabogratinib treatment resulted in dose-dependent tumor growth inhibition with tumor regression observed at the highest doses. These preclinical findings are supported by the three case reports from the SURF301 study, which demonstrate early clinical activity in patients with advanced metastatic urothelial carcinoma with an FGFR3 fusion or activating mutation.

A fundamental goal of cancer research is to translate preclinical findings into advances in clinical disease management. In preclinical investigations of anticancer therapeutics, the choices of the model, assay, and endpoint selected are critical in this process. If the model or assay is poorly chosen or the data inappropriately analyzed, preclinical findings can lead to inadequate conclusions that can negatively affect the ability to translate findings from the laboratory to the clinic. The present review discusses the pros and cons of preclinical models, assays, and endpoints commonly used in cancer therapeutic assessment evaluations.

Immune checkpoint inhibitors (ICI) have improved the prognosis of patients with non-small cell lung cancer (NSCLC), but the cure rate remains low because tolerant persister cancer cells can survive within the tumor during ICI treatment. We have previously reported that plasminogen activator inhibitor-1 (PAI-1) is involved in tolerance acquisition to osimertinib in EGFR-mutated NSCLC. This study aimed to examine the role of PAI-1 in ICI tolerance and whether PAI-1 may be a therapeutic target to overcome this tolerance. In a mouse subcutaneous tumor model using Lewis lung carcinoma or KLN205 cells, cancer cells surviving within the tumor 7 days after anti-PD-1 (aPD-1) antibody treatment were defined as aPD-1 antibody-tolerant persister cells (aPD-1-TP). PAI-1 and mesenchymal gene expression levels were higher in aPD-1-TPs than in control cells. IHC analyses showed higher numbers of tumor-associated macrophages, expression of PD-L1 in cancer cells, and degree of angiogenesis. In contrast, the number of tumor-infiltrating lymphocytes was lower in aPD-1 antibody-tolerant tumors than in control tumors. Combination treatment with an aPD-1 antibody and the PAI-1 inhibitor, TM5614 decreased mesenchymal gene expression, PD-L1 expression, tumor-associated macrophage numbers, and angiogenesis and increased tumor-infiltrating lymphocyte counts in tolerant tumors. Furthermore, it resulted in prolonged inhibition of tumor growth. In conclusion, this study underscores the involvement of PAI-1 in the survival of aPD-1-TPs via epithelial-mesenchymal transition and alteration of the tumor microenvironment. Combination treatment with an aPD-1 antibody and TM5614 can be a new therapeutic strategy for NSCLC.

The c-Met receptor tyrosine kinase, encoded by the MET proto-oncogene, plays a critical role in embryogenesis, tissue regeneration, and carcinogenesis. It is predominantly expressed in neoplastic cells and is essential for tumor growth and metastasis, making it a prime target for antibody-drug conjugates (ADC). In this study, we developed a new ADC, HRA00129-C004, which consists of a specifically designed humanized anti-c-Met mAb conjugated to a potent topoisomerase I inhibitor through a cleavable linker. We systematically assessed the pharmacologic properties, pharmacokinetics, and safety profiles of HRA00129-C004 in a series of preclinical models. Our studies demonstrated that HRA00129-C004 selectively binds to c-Met proteins, is internalized into lysosomes, and releases its payload. This process leads to DNA damage and apoptosis in multiple c-Met-expressing cancer cell lines and exhibits strong antitumor activities in both cell line- and patient-derived xenografts. Furthermore, HRA00129-C004 showed stability in circulation and had a favorable safety profile in cynomolgus monkeys. In summary, HRA00129-C004 is a superior c-Met ADC with relatively low affinity to c-Met, efficient internalization, and a strong bystander effect. It is currently being investigated in a phase I clinical trial for patients with advanced solid tumors.

We previously used a myoblast model of fusion-positive rhabdomyosarcoma (FP-RMS) to show that FGF8, a PAX3-FOXO1 (P3F) transcriptional target, is required for P3F-driven tumorigenicity and, when aberrantly expressed, can maintain tumorigenicity in P3F-independent recurrent tumors. We report in this study that FGF8, FGFR1, and FGFR4 are often highly expressed in FP-RMS tumors. High FGF8 expression in FP-RMS cells is associated with high sensitivity to an FGFR4 inhibitor and a pan-FGFR inhibitor. Although downregulating FGF8 resulted in loss of sensitivity to these inhibitors, FGF8 upregulation in myoblasts decreased FGFR4 expression and sensitized the cells to an FGFR1 inhibitor and a pan-FGFR inhibitor. FGF8 downregulation of FGFR4 expression was reverted by inhibitors of FGFR1, MEK, or ERK, thus defining a signaling pathway by which FGF8 mediates this regulatory effect. Finally, high FGF8 expression in P3F-independent recurrent tumors was attributable to a rearrangement of viral long terminal repeat (LTR) sequences into the FGF8 3' untranslated region, resulting in increased FGF8 mRNA stability. These findings indicate that FGF8 exerts oncogenic effects in FP-RMS via FGFR4 and may exert oncogenic effects in P3F-independent relapses via FGFR1. Our study reveals the functional significance of FGF8 in FP-RMS and provides a rationale for preclinical studies of FGFR inhibitors in FP-RMS.

Since its discovery more than 30 years ago, our understanding of the function of CD248 (also known as endosialin or TEM1) as a therapeutic target has evolved, and CD248 is now recognized as a potentially valuable target for therapeutics directed toward sarcomas and fibrotic diseases. The current study reviews the literature related to CD248 and examines CD248 expression across various models including patient-derived xenografts, patient-derived cell lines (pdmr.cancer.gov/), and large cell line collections, including the Cell Line Encyclopedia (CCLE) and the GDSC-MGH-Sanger. CD248 is highly and selectively expressed by sarcomas and by pericytes in tumor vasculature and wound-healing vasculature. It is a component of a multi-protein complex which connects various cell types into tissue structure. Multiple therapeutic approaches are being investigated to take advantage of CD248 in the treatment of sarcomas and fibrotic diseases. Endosialin/CD248/TEM1 is a promising biological target that remains poorly explored in cancer therapy. Importantly, CD248 is overexpressed in several human solid tumors and absent in most normal adult tissues, making it a suitable and potentially safe target for radioimmunotherapy, particularly in Ewing's sarcoma xenograft models.

Interleukin-15 (IL-15) potentiates NK and T cell immunity and has huge potential for tumor immunotherapy. However, the clinical prospects of IL-15 has been hindered by poor pharmacokinetics and systemic immune-related toxicities. Here we report the development of a novel CD122-biased IL-15 mutein, V0013, generated by the truncating four C-terminal amino acids (I111, N112, T113 and S114) of IL-15. V0013 retains the overall cytokine structure and has intact binding to the critical CD122 receptor subunit, but exhibits significantly reduced overall potency. In vivo, V0013 demonstrates a prolonged half-life, improved safety and sustained pharmacodynamic effects. As a single agent, V0013 effectively promotes NK cell-driven anti-tumor immunity and enhances therapeutic efficacy of antibodies. Further mechanistic studies reveal that the interaction with specific receptor subunits dictates the function and potency of IL-15 mutein. CD122 is essential for IL-15-mediated signaling and prescribes its preference to NK and memory CD8+ T cells. Compared to an IL-15 mutein with similar attenuation but markedly weaker CD122 binding (weak-β IL-15), V0013 more closely resembles WT IL-15 functions, driving superior NK cell proliferation and survival. In a tumor model engrafted with T cells, V0013 selectively enhances memory but not naïve CD8+ T cells in tumor, leading to enhanced tumor inhibition compared to weak-β IL-15. RNAseq analysis further elucidates the critical role of CD122 in IL-15 signaling, and demonstrates that the mutein retaining intact CD122 binding elicits strong anti-tumor immunity. These findings support the therapeutic potential of the attenuated CD122-biased IL-15 mutein therapy for cancer and other diseases.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor characterized by a high relapse rate, limited treatment options, and a poor prognosis. Delta-like ligand 3 (DLL3) has emerged as a promising target for SCLC. Notably, CAR T cells that use the variable domain of heavy-chain-only antibodies (VHH) demonstrate superior efficacy compared to their ScFv counterparts. However, the therapeutic effectiveness of anti-DLL3 VHH-CAR T cells has yet to be fully explored. To leverage the therapeutic potential of VHHs, we first immunized alpacas and screened for anti-DLL3 VHHs using yeast display. Then, 1-B12 and 5 identified the positive clones and compared them based on their affinity, specificity, and cytotoxicity in CAR T cell models. Moreover, 1-B12 was selected as the humanized sequence due to its higher affinity, greater specificity, and stronger cytotoxicity. Finally, the functionality of the four humanized VHH-CAR T cells from the 1-B12 sequence was evaluated through in vitro assays that measured cytokine production and cytotoxicity, followed by in vivo studies to assess their antitumor efficacy. The anti-DLL3 VHHs exhibited strong affinity, specificity, and cytotoxicity in CAR T cell models. Notably, the HM-CAR T cells exhibited robust cytokine secretion and cytotoxic activity against tumor cells. Moreover, these HM-CAR T cells demonstrated significant antitumor efficacy in vivo. This study highlights effective strategies for developing DLL3-specific VHHs and their application in CAR T therapy, which supports their clinical potential as a promising immunotherapeutic approach for cancers that express DLL3.

The methyl CpG-binding protein 2 (MECP2) gene has copy-number gain in a number of human cancers and functions as an oncogene through an unusual epigenetic mechanism. We explored the possibility that MECP2 might be a therapeutic target and whether its epigenetic mode of action is amenable to specific therapy. Constitutively expressed or inducible lentiviral short hairpin RNA directed at MECP2 in human triple-negative breast cancer (TNBC) cell lines with high or low level of MECP2 protein were grown as xenografts to assess oncogene addiction. We next evaluated the effect of DNA methylation inhibitors or histone deacetylase inhibitors on monolayer or soft agar growth of isogenic human mammary epithelial cells with or without MECP2 overexpression and xenograft growth of MECP2-dependent or MECP2-independent human TNBC or lung cancer cell lines. We then investigated the mechanism of MECP2-induced activation of the MAPK pathway and assessed the effect of drug treatment. Human cancer cell lines with MECP2 overexpression show MECP2 dependence, and epigenetic drugs are effective in these models. Activated RAS and other activators of the MAPK pathway caused resistance to these therapies, giving insight into their novel mode of action and demonstrating specificity. The kinase PAK3 is important for MECP2-mediated induction of the MAPK pathway, is modulated by epigenetic drugs affecting MECP2 action as expected, and may itself be a therapeutic target for MECP2-driven cancers. These preclinical studies show that tumors overexpressing MECP2 might benefit from epigenetic therapy targeting MECP2 function and demonstrate a novel mechanism of action for these drugs.

Ewing sarcoma (ES) is a rare and aggressive pediatric malignancy with limited therapeutic options, particularly for relapsed or refractory cases, highlighting the urgent need for innovative treatment strategies. In this study, we identify endoplasmic reticulum stress (ERS) and the unfolded protein response (UPR) as critical therapeutic vulnerabilities in ES and introduce 4-(heptyloxy)phenol (AC-45594) as a novel small-molecule agent that exploits these stress pathways. AC-45594 selectively inhibited the growth of ES cells among thirteen cancer and six non-cancerous cell lines, demonstrating marked tumor specificity. Structure-activity relationship studies revealed that both the phenolic hydroxyl group and an optimal alkoxy chain length (7-9 carbon atoms) are essential for its activity. Mechanistically, AC-45594 induces ERS, activates UPR, and drives a shift from adaptive to terminal stress signaling, culminating in apoptosis of ES cells. Proteomic and gene expression analyses further supported selective activation of proapoptotic UPR signaling. These findings establish ERS and UPR as actionable targets in ES and position AC-45594 as a first-in-class compound capable of selectively inducing stress-driven cell death. This work lays the foundation for a new class of therapeutics targeting maladaptive stress responses in pediatric sarcomas and potentially other hard-to-treat cancers.