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Ludwig Cancer Research had a stall at the Aylesbury relay for life event in Aylesbury Rugby Club on Saturday 5th July 2014.
Deficiency of factor-inhibiting HIF creates a tumor-promoting immune microenvironment
Hypoxia signaling influences tumor development through both cell-intrinsic and -extrinsic pathways. Inhibiting hypoxia-inducible factor (HIF) function has recently been approved as a cancer treatment strategy. Hence, it is important to understand how regulators of HIF may affect tumor growth under physiological conditions. Here we report that in aging mice factor-inhibiting HIF (FIH), one of the most studied negative regulators of HIF, is a haploinsufficient suppressor of spontaneous B cell lymphomas, particular pulmonary B cell lymphomas. FIH deficiency alters immune composition in aged mice and creates a tumor-supportive immune environment demonstrated in syngeneic mouse tumor models. Mechanistically, FIH-defective myeloid cells acquire tumor-supportive properties in response to signals secreted by cancer cells or produced in the tumor microenvironment with enhanced arginase expression and cytokine-directed migration. Together, these data demonstrate that under physiological conditions, FIH plays a key role in maintaining immune homeostasis and can suppress tumorigenesis through a cell-extrinsic pathway.
Characterising the Behaviour of a Structured PDE Model of the Cell Cycle in Contrast to a Corresponding ODE System.
Experimental results have shown that anti-cancer therapies, such as radiotherapy and chemotherapy, can modulate the cell cycle and generate cell cycle phase-dependent responses. As a result, obtaining a detailed understanding of the cell cycle is one possible path towards improving the efficacy of many of these therapies. Here, we consider a basic structured partial differential equation (PDE) model for cell progression through the cell cycle, and derive expressions for key quantities, such as the population growth rate and cell phase proportions. These quantities are shown to be periodic and, as such, we compare the PDE model to a corresponding ordinary differential equation (ODE) model in which the parameters are linked by ensuring that the long-term ODE behaviour agrees with the average PDE behaviour. By design, we find that the ODE model does an excellent job of representing the mean dynamics of the PDE model within just a few cell cycles. However, by probing the parameter space we find cases in which this mean behaviour is not a good measure of the PDE population growth. Our analytical comparison of two caricature models (one PDE and one ODE system) provides insight into cases in which the simple ODE model is an appropriate approximation to the PDE model.
Continuous Indexing of Fibrosis (CIF): improving the assessment and classification of MPN patients.
The grading of fibrosis in myeloproliferative neoplasms (MPN) is an important component of disease classification, prognostication and monitoring. However, current fibrosis grading systems are only semi-quantitative and fail to fully capture sample heterogeneity. To improve the quantitation of reticulin fibrosis, we developed a machine learning approach using bone marrow trephine (BMT) samples (n = 107) from patients diagnosed with MPN or a reactive marrow. The resulting Continuous Indexing of Fibrosis (CIF) enhances the detection and monitoring of fibrosis within BMTs, and aids MPN subtyping. When combined with megakaryocyte feature analysis, CIF discriminates between the frequently challenging differential diagnosis of essential thrombocythemia (ET) and pre-fibrotic myelofibrosis with high predictive accuracy [area under the curve = 0.94]. CIF also shows promise in the identification of MPN patients at risk of disease progression; analysis of samples from 35 patients diagnosed with ET and enrolled in the Primary Thrombocythemia-1 trial identified features predictive of post-ET myelofibrosis (area under the curve = 0.77). In addition to these clinical applications, automated analysis of fibrosis has clear potential to further refine disease classification boundaries and inform future studies of the micro-environmental factors driving disease initiation and progression in MPN and other stem cell disorders.
Early mucosal responses following a randomised controlled human inhaled infection with attenuated Mycobacterium bovis BCG
Abstract The development of an effective vaccine against Mycobacterium tuberculosis is hampered by an incomplete understanding of immunoprotective mechanisms. We utilise an aerosol human challenge model using attenuated Mycobacterium bovis BCG, in BCG-naïve UK adults. The primary endpoint of this study (NCT03912207) was to characterise the early immune responses induced by aerosol BCG infection, the secondary endpoint was to identify immune markers associated with in-vitro protection. Blinded volunteers were randomised to inhale 1 × 107 CFU aerosolised BCG or 0.9% saline (20:6); and sequentially allocated to bronchoscopy at day 2 or 7 post-inhalation (10 BCG, 3 saline each timepoint). In the bronchoalveolar lavage post-aerosol BCG infection, there was an increase in frequency of eosinophils, neutrophils, NK cells and Donor-Unrestricted T cells at day 7, and the frequency of antigen presenting cells decreased at day 7 compared with day 2. The frequency of interferon-gamma+ BCG-specific CD4+ T cells increased in the BAL and peaked in the blood at day 7 post-BCG infection compared to day 2. BAL cells at day 2 and day 7 upregulated gene pathways related to phagocytosis, MHC-II antigen loading, T cell activation and proliferation. BCG’s lack of key virulence factors and its failure to induce granulomas, may mean the observed immune responses do not fully recapitulate Mycobacterium tuberculosis infection. However, human infection models can provide unique insights into early immune mechanisms, informing vaccine design for complex pathogens.
Chromothripsis-associated chromosome 21 amplification orchestrates transformation to blast-phase MPN through targetable overexpression of DYRK1A
Abstract Chromothripsis, the chaotic shattering and repair of chromosomes, is common in cancer. Whether chromothripsis generates actionable therapeutic targets remains an open question. In a cohort of 64 patients in blast phase of a myeloproliferative neoplasm (BP-MPN), we describe recurrent amplification of a region of chromosome 21q (‘chr. 21amp’) in 25%, driven by chromothripsis in a third of these cases. We report that chr. 21amp BP-MPN has a particularly aggressive and treatment-resistant phenotype. DYRK1A, a serine threonine kinase, is the only gene in the 2.7-megabase minimally amplified region that showed both increased expression and chromatin accessibility compared with non-chr. 21amp BP-MPN controls. DYRK1A is a central node at the nexus of multiple cellular functions critical for BP-MPN development and is essential for BP-MPN cell proliferation in vitro and in vivo, and represents a druggable axis. Collectively, these findings define chr. 21amp as a prognostic biomarker in BP-MPN, and link chromothripsis to a therapeutic target.
Impact of Long-Term Chemotherapy on Outcomes in Pancreatic Ductal Adenocarcinoma: A Real-World UK Multi-Centre Study
Background: We reviewed outcomes of short and long-term chemotherapy with or without breaks in pancreatic ductal adenocarcinoma (PDAC) patients. Methods: PDAC patients receiving ≥3 chemotherapy cycles between 2019 and 2024 at three institutions were included. Progression-free survival after first-line chemotherapy (PFS1), overall survival (OS) and best overall response (BOR) to chemotherapy were assessed using the Wilcoxon test, Kaplan–Meier test, and univariate and multivariate Cox regression models. Results: We screened 237 patients, and 135 patients met the study criteria. Among these patients, 25 had resectable disease, and 110 had unresectable/metastatic disease (13% borderline resectable (BRPC), 20% locally advanced (LAPC), 10% localised developing metastases, 57% de novo metastatic). Ten patients (7%) underwent genetic profiling; KRAS aberrations (N = 4), actionable PLAB2/BRCA2/FGFR2 mutations (N = 3), ATM/BRIP1 alteration (N = 1). Two patients were managed with PARP inhibitors after receiving multiple lines of chemotherapy. Median PFS1 and OS were concordant with the published literature, but select patient groups achieved prolonged survival outcomes. Among the 36 BRPC/LAPC patients, we observed >1-year PFS1 in 9 (25%) patients and >2-year OS in 3 (8%) patients. Among the 63 de novo metastatic patients, we observed >1-year PFS1 and >2-year OS in 6 (10%) patients. Among patients with localised disease, smoking history was a poor prognostic factor with respect to OS (p = 0.03). Improved PFS1 and OS was associated with ≥6 cycles of first-line chemotherapy, its duration of ≥3.66 months, and local treatment after first chemotherapy (p < 0.05 for all). Stereotactic body radiotherapy following first-line chemotherapy was delivered in N = 6 (27%) and N = 1 (7%) of patients with LAPC and BRPC, respectively. Chemotherapy interruption duration, but not number, was associated with PFS1 and OS only in the localised cohort (p < 0.05). In patients with de novo metastatic disease, prevalence of type 2 diabetes was adversely associated with OS (p = 0.03). Improved PFS and OS was associated with ≥6 cycles of first-line chemotherapy, its duration of ≥4.37 months, and BOR to it (only in this cohort) (p < 0.05 for all). A favourable OS was associated with >1 line of chemotherapy (p = 0.003). Conclusion: Despite challenges, extended chemotherapy and multiple treatment lines may improve survival, with localised treatments benefiting select patients.
Novel H-2Db-restricted CD8 epitope derived from mouse MAGE-type antigen P1A mediates antitumor immunity in C57BL/6 mice.
BackgroundMelanoma antigen gene (MAGE)-type antigens are promising targets for cancer immunotherapy as they are expressed in cancer cells but not in normal tissues, except for male germline cells. The mouse P1A antigen shares this MAGE-type expression pattern and has been used as a target antigen in preclinical tumor models aiming to induce antitumor CD8+ T-cell responses. However, so far only one MHC I-restricted P1A epitope has been identified. It is presented by H-2Ld in mice of the H-2d genetic background such as DBA/2 and BALB/c. Given the availability of multiple genetically altered strains of mice in the C57BL/6 background, it would be useful to define P1A T-cell epitopes presented by the H-2b haplotype, to facilitate more refined mechanistic studies.MethodsWe employed a heterologous prime-boost vaccination strategy based on a chimpanzee adenovirus (ChAdOx1) and a modified vaccinia Ankara (MVA) encoding P1A, to induce P1A-specific T-cell responses in C57BL/6 mice. Vaccine-induced responses were measured by intracellular cytokine staining and multiparameter flow cytometry. We mapped the immunogenic CD8 epitope and cloned the cognate T-cell receptor (TCR), which we used for adoptive cell therapy.ResultsChAdOx1/MVA-P1A vaccination induces a strong P1A-specific CD8+ T-cell response in C57BL/6 mice. This response is directed against a single 9-amino acid peptide with sequence FAVVTTSFL, corresponding to P1A amino acids 43-51. It is presented by H-2Db. P1A vaccination, especially with ChAdOx1 administered intramuscularly and MVA delivered intravenously, protected mice against P1A-expressing EL4 (EL4.P1A) tumor cell challenge. We identified and cloned four TCRs that are specific for the H-2Db-restricted P1A43-51 peptide. T cells transduced with these TCRs recognized EL4.P1A but not MC38.P1A and B16F10.P1A tumor cells, likely due to differences in the proteasome subtypes present in these cells. Adoptive transfer of these T cells in mice bearing EL4.P1A tumors reduced tumor growth and increased survival.ConclusionsWe identified the first CD8+ T-cell epitope of the MAGE-type P1A tumor antigen presented in the H-2b background. This opens new perspectives for mechanistic studies dissecting MAGE-type specific antitumor immunity, making use of the wealth of genetically altered mouse strains available in the C57BL/6 background. This should facilitate the advancement of specific cancer immunotherapies.
A Langendorff-heart discovery pipeline demonstrates cardiomyocyte targeting by extracellular vesicles functionalized with beta-blockers using click-chemistry.
Extracellular vesicles (EVs) are widely explored as vehicles for delivering therapeutic or experimental cargo to cardiomyocytes. Efforts to improve EV bioavailability in the heart, and reduce their off-target actions, require screening methods that can replicate the physiological and anatomical barriers present in the myocardium. Additionally, discovery pipelines must exercise control over EV dosage and timing, and provide a means of assessing cargo incorporation into cardiomyocytes specifically. These criteria are not generally met by experiments on cultured cells or animals. Here, we present a Langendorff-heart discovery pipeline that combines the strengths of in vivo and in vitro approaches. Langendorff-mode perfusion enables controlled exposure of beating hearts to re-circulated EVs. Following perfusion, cardiomyocytes can be isolated enzymatically for analysis, such as imaging. We tested this discovery pipeline by functionalizing EVs with beta-blockers (atenolol, metoprolol) using click-chemistry and incorporating the fluorescent protein NeonGreen2 to track the fate of EV cargo. Fluorescence in cardiomyocytes, including their nuclear regions, increased after Langendorff-treatment with beta-blocker decorated EVs, but only if these contained NeonGreen2, implicating the fluorescent cargo as the source of signal. Superior binding efficacy of beta-blockers was confirmed by referencing to the substantially lower signals obtained using wild-type EVs or EVs presenting myomaker or myomixer proteins, motifs that modestly enrich cardiac EV uptake in mice. Our findings demonstrate successful cardiomyocyte targeting using EVs decorated with beta-receptor binders. We propose the Langendorff-perfused heart as an intermediate step - nested between in vitro characterisation and animal testing - in discovery pipelines for seeking improved cardiac-specific EV designs.
Ferrofluid Droplet Chains in Thermotropic Nematic Liquid Crystals.
Dispersing ferrofluids in liquid crystals (LCs) produces unique systems which possess magnetic functionality and novel phenomena such as droplet chaining. This work reports the formation of ferrofluid droplet chains facilitated by the topological defects within the LC director field, induced by the dispersed ferrofluid. The translational and rotational motion of these chains could be controlled via application of external magnetic fields. The process of the droplet chain formation in LCs can be stabilized by the addition of surfactants. The magnetic colloidal particles in the ferrofluid located at the interface between the ferrofluid and the LC are arranged so that a boundary layer was formed. The velocities and boundary layer thickness values of ferrofluid droplet chains in nematic 5CB (4-Cyano-4'-pentylbiphenyl) were investigated for varying average droplet sizes and number of droplets in a chain. The creation and behaviour of ferrofluid droplet chains in 5CB with the addition of the surfactant polysorbate 60 (Tween-60) and without, was comparatively investigated. The integration of liquid crystals and ferrofluids along with the incorporation of functional materials facilitates the innovative development of advanced materials for future applications.
Delineating Mpl-dependent and -independent phenotypes of Jak2 V617F- positive MPNs in vivo.
The Jak2 V617F mutation stands as the main driver of myeloproliferative neoplasms (MPNs) by constitutively activating signaling of several type I cytokine receptors, namely those for erythropoietin (EpoR), thrombopoietin (TpoR), and Granulocyte Colony Stimulating Factor (G-CSFR). Among these, TpoR assumes a pivotal role in hematopoietic stem cell renewal and differentiation, being positioned as a key driver of MPNs alongside mutated Jak2. However, the impact of TpoR/MPL absence in the context of Jak2 V617F in vivo has been explored only through a transgenic Jak2 V617F mouse model, where regulation of Jak2 expression does not depend on its natural promoter. In this study, we use a novel mouse model expressing Jak2 V617F under its endogenous promoter at the heterozygous state within a Mpl knock-out background. Our findings indicate that erythrocytosis, leukocytosis and moderate splenomegaly with mild spleen peri-vascular fibrosis persist even in the absence of Mpl expression. Notably, the inherent growth-stimulating effect induced by Jak2 V617F remains consistent across diverse early hematopoietic progenitor populations in the absence of Mpl but is reduced at the stem cell level and does not allow clonal expansion in competitive transplantation. Our results delineate Mpl-dependent and -independent phenotypes induced by Jak2 V617F and confirm that inhibiting Mpl expression at the stem cell level negates the long-term advantage of the mutant clone. Consequently, while MPL emerges as a major player in Jak2 V617F positive MPNs, our study underscores that it is not the exclusive contributor, broadening the spectrum for therapeutic intervention.
Discovery of an LSD1 PROTAC degrader.
Aberrant expression of lysine-specific demethylase 1 (LSD1) has been implicated in various cancers, including acute myeloid leukemia (AML). Recent studies have revealed both catalytic and noncatalytic oncogenic functions of LSD1, which cannot be effectively addressed by traditional small-molecule inhibitors. Therefore, to remove LSD1 and mitigate its oncogenic activity, we utilized the proteolysis-targeting chimera (PROTAC) approach and developed an LSD1 PROTAC degrader MS9117, which recruits the E3 ligase cereblon (CRBN). MS9117 induces LSD1 degradation in a concentration-, time-, CRBN-, and proteasome-dependent manner. Importantly, MS9117 effectively degrades LSD1 and demonstrates superior antiproliferative effects in AML cells, compared to the existing pharmacological LSD1 inhibitors. Furthermore, MS9117 also sensitized nonacute promyelocytic leukemia AML cells to all-trans retinoic acid treatment. Moreover, we developed two negative controls of MS9117, MS9117N1 and MS9117N2, which do not degrade LSD1 or inhibit leukemia cell growth, further confirming the mechanism of action of MS9117. Overall, MS9117 serves as a valuable chemical tool and a potential therapeutic to target both the catalytic and scaffolding functions of LSD1. With several LSD1 inhibitors already in clinical development, the LSD1 degraders such as MS9117 offer an additional option for future clinical studies.