Yorkshire Cancer Research

l-Tryptophan (Trp) is an essential amino acid catabolised through the kynurenine pathway, which is mediated by the enzymes indoleamine-2,3-dioxygenase 1 (IDO1), IDO2, or Trp-2,3-deoxygenase. In cancer, IDO1 acts as an immune checkpoint, suppressing effector T cell function. Yet, direct inhibition of IDO1 has had limited success in clinical trials. Therefore, alternative approaches to Trp metabolism therapeutic targeting are needed. We screened a library of 597 natural products (NPs) or NP derivatives for their effect on kynurenine production in triple-negative breast cancer cells. This revealed 24 candidate inhibitors of kynurenine production. Among them, artemether, a member of the artemisinin family of anti-malarial drugs, suppressed kynurenine production, likely via an endoperoxide bridge-dependent mechanism. The Euphorbia factor L9 (EFL9) inhibited kynurenine production, likely via a C7-benzoylation-dependent mechanism. Neither artemether nor EFL9 affected JAK/STAT signalling or IDO1 levels. Targeted metabolomics and molecular docking analyses demonstrated that artemether suppressed kynurenine production through heme sequestration and potential interactions with the IDO1 heme-binding pocket A. EFL9 affected Trp metabolism through heme-independent mechanisms and resulted in changes in purine and amino acid metabolism and the cellular redox balance. Notably, ouabain, a regulator of IDO1 levels, and linrodostat, a clinically approved IDO1 inhibitor, revealed distinct metabolic profiles, with ouabain and EFL9 showing the largest overlap. Importantly, the kynurenine-suppressing activities of artemether and EFL9 were observed in non-transformed primary mammary epithelial cells and also lung cancer cells. Overall, our findings set the foundation for future studies exploring the use of artemether or EFL9 as novel Trp metabolism-targeting therapeutics.

Estrogen receptor-positive (ER+) breast cancer carries a lifelong risk of recurrence and disease progression, with hypoxia-associated transcriptional signatures linked to poor prognosis and therapy resistance. While the effects of hypoxia on tumour progression are well studied, the impact on ERα epigenomic regulation remains poorly characterised. Here, we demonstrate that activation of hypoxia-inducible factors (HIFs) dramatically remodels ERα chromatin localisation in ER+ breast cancer cells. Transcripts of genes located near hypoxia-induced ERα binding sites are significantly associated with reduced recurrence-free survival in breast cancer patients. Transcriptomic profiling under hypoxic conditions (1% oxygen), with and without ERα depletion by fulvestrant, revealed a hypoxia-induced, ERα-dependent gene expression programme, including upregulation of epithelial sodium channel (ENaC) regulatory subunits that results in acquired sensitivity to the ENaC inhibitor amiloride. Notably, this transcriptional response is spatially correlated with the epithelial-to-mesenchymal hallmark in patient tumours. Our findings establish an interdependence between ERα signalling and the hypoxic response, and present functional evidence that ERα reprogramming offers novel therapeutic opportunities that bypass the need to directly target the hypoxic response.

Immune checkpoint blockade has yet to produce robust anti-cancer responses for prostate cancer. Sialyltransferases have been shown across several solid tumours, including breast, melanoma, colorectal and prostate to promote immune suppression by synthesising sialoglycans, which act as ligands for Siglec receptors. We report that ST3 beta-galactoside alpha-2,3-sialyltransferase 1 (ST3Gal1) levels negatively correlate with androgen signalling in prostate tumours. We demonstrate that ST3Gal1 plays an important role in modulating tumour immune evasion through the synthesises of sialoglycans with the capacity to engage the Siglec-7 and Siglec-9 immunoreceptors preventing immune clearance of cancer cells. Here, we provide evidence of the expression of Siglec-7/9 ligands and their respective immunoreceptors in prostate tumours. These interactions can be modulated by enzalutamide and may maintain immune suppression in enzalutamide treated tumours. We conclude that the activity of ST3Gal1 is critical to prostate cancer anti-tumour immunity and provide rationale for the use of glyco-immune checkpoint targeting therapies in advanced prostate cancer.

Advance care planning and tools can help you ask patients with a life-limiting illness what is important to them

Lipid traits have been inconsistently linked to risk of non-Hodgkin lymphoma (NHL). We examined the association of genetically predicted lipid traits with risk of diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), and marginal zone lymphoma (MZL) using Mendelian randomization (MR) analysis. Genome-wide association study data from the InterLymph Consortium were available for 2,661 DLBCLs, 2,179 CLLs, 2,142 FLs, 824 MZLs, and 6,221 controls. SNPs associated (P < 5 × 10-8) with high-density lipoprotein (HDL, n = 164), low-density lipoprotein (LDL, n = 137), total cholesterol (TC, n = 161), and triglycerides (TG, n = 123) were used as instrumental variables (IV), explaining 14.6%, 27.7%, 16.8%, and 12.8% of phenotypic variation, respectively. Associations between each lipid trait and NHL subtype were calculated using the MR inverse variance-weighted method, estimating odds ratios (OR) per standard deviation and 95% confidence intervals (CI). HDL was positively associated with DLBCL (OR = 1.14; 95% CI, 1.00-1.30) and MZL (OR = 1.09; 95% CI, 1.01-1.18), while TG was inversely associated with MZL risk (OR = 0.90; 95% CI, 0.83-0.99), all at nominal significance (P < 0.05). A positive trend was observed for HDL with FL risk (OR = 1.08; 95% CI, 0.99-1.19; P = 0.087). No associations were noteworthy after adjusting for multiple testing. We did not find evidence of a clear or strong association of these lipid traits with the most common NHL subtypes. While these IVs have been previously linked to other cancers, our findings do not support any causal associations with these NHL subtypes. Our results suggest that prior reported inverse associations of lipid traits are not likely to be causal and could represent reverse causality or confounding.

Aim Early access to palliative care can improve patients’ signs and symptoms and reduce hospital admissions. In the UK many palliative care referrals are made in the last weeks and days of life, which indicates there are barriers to timely integration. This study aims to understand the barriers to timely integration of palliative care for people with cancer and establish the level of patient information provision.Method The study involved three stages: a literature review to identify barriers to referral, an audit of patient information resources available in adult oncology services across Yorkshire and Humber, and a critique of the identified information resources.Findings The literature review identified patient misconceptions about palliative care as a barrier to engagement with services. The regional audit found that information about palliative care is not widely available to cancer patients and the information provided does not address the misconceptions reported in the literature.Conclusion There is a need to improve information for cancer patients that addresses known misconceptions about palliative care and to make this widely available in oncology departments. This information could support earlier integration of palliative care alongside oncology management by improving understanding of when and how palliative care may benefit patients.

A successful prostate cancer must be capable of changing its phenotype in response to a variety of microenvironmental influences, such as adaptation to treatment or successful proliferation at a particular metastatic site. New cell phenotypes emerge by selection from the large, genotypically heterogeneous pool of candidate cells present within any tumor mass, including a distinct stem cell-like population. In such a multicellular model of human prostate cancer, flexible responses are primarily governed not only by de novo mutations but appear to be dominated by a combination of epigenetic controls, whose application results in treatment resistance and tumor relapse. Detailed studies of these individual cell populations have resulted in an epigenetic model for epithelial cell differentiation, which is also instructive in explaining the reported high and inevitable relapse rates of human prostate cancers to a multitude of treatment types.

Prostate cancers have a justified reputation as one of the most heterogeneous human tumours. Indeed, there are some who consider that advanced and castration-resistant prostate cancers are incurable, as a direct result of this heterogeneity. However, tumour heterogeneity can be defined in different ways. To a clinician, prostate cancer is a number of different diseases, the treatments for which remain equally heterogeneous and uncertain. To the pathologist, the histopathological appearances of the tumours are notoriously heterogeneous. Indeed, the genius of Donald Gleason in the 1960s was to devise a classification system designed to take into account the heterogeneity of the tumours both individually and in the whole prostate context. To the cell biologist, a prostate tumour consists of multiple epithelial cell types, inter-mingled with various fibroblasts, neuroendocrine cells, endothelial cells, macrophages and lymphocytes, all of which interact to influence treatment responses in a patient-specific manner. Finally, genetic analyses of prostate cancers have been compromised by the variable gene rearrangements and paucity of activating mutations observed, even in large numbers of patient tumours with consistent clinical diagnoses and/or outcomes. Research into familial susceptibility has even generated the least tractable outcome of such studies: the genetic loci are of low penetrance and are of course heterogeneous. By fractionating the tumour (and patient-matched non-malignant tissues) heterogeneity can be resolved, revealing homogeneous markers of patient outcomes.