Biology subjects

Laing, S.

Publications and source records attributed to Laing, S..

4 recordsLinked to original sources

bioRxiv2023

cMYC-mediated immune repression is reversed by inhibition of H3K9/H3K27 methylation maintenance

Aberrant cMYC activity is a key driver of cancer, involved in several hallmark processes. Alongside the canonical hallmark of proliferation, cMYC represses immune signalling in a cell-intrinsic manner. The histone methyltransferases EZH2 and G9a interact with cMYC to modulate gene expression, including repression of immune genes via H3K27 and H3K9 histone methylation. Analyses of 565 cell lines derived from solid cancers demonstrated that greater cMYC-G9a/EZH2-mediated repression correlates with lower immune gene scores in a cell-intrinsic manner (innate, Type I and Type II IFN response), an effect most evident in MYC-amplified cell lines. In ovarian high-grade serous carcinoma (HGSC) cell lines and an in vivo murine model of HGSC, HKMTi-1-005, an inhibitor of H3K27/H3K9 methylation maintenance, relieved cMYC-G9a/EZH2 repression whilst inducing an immune response. A 7-gene immune signature (7ISG), related to viral mimicry signalling, is at the core of the HGSC immune response to HKMTi-1-005. In MYC-amplified HGSC patients, a low 7ISG score was associated with poor survival. Additionally, MYC-amplified cell lines were significantly more sensitive to HKMTi-1-005, whilst a low 7ISG score was associated with greater HKMTi-1-005 sensitivity, effects that were independent of canonical cMYC transcriptional activation. Examining the effects of HKMTi-1-005 treatment in a MYC-deregulated lung adenocarcinoma (LuAd) revealed induction of an immune response in vitro and prolonged survival in vivo. This suggests that inhibition of H3K27/H3K9 methylation maintenance will have efficacy in cMYC-deregulated tumours with low 7ISG scores, via disruption of cMYC-mediated repression of cell autonomous immune signalling and induction of an anti-tumour immune response. Statement of significanceOver 70% of cancers are cMYC-deregulated. We show that inhibition of H3K27/H3K9 methylation maintenance relieves cMYC-dependent immune repression and prolongs survival of animal tumour models, suggesting a novel approach to treating cMYC-deregulated tumours.

cancer biology↗

bioRxiv2023

γδ T cells impair airway macrophage differentiation in lung adenocarcinoma

Protecting mucosal barriers, {gamma}{delta} T cells hold promise for the development of new cancer immunotherapies. In mice, {gamma}{delta} T cells can largely be segregated into CD27+ and CD27- cells, and their functions are modulated by interactions with surrounding cells. However, which cells communicate directly with {gamma}{delta} T cells in lung adenocarcinoma remains unknown. To address this, we combined flow cytometry, confocal microscopy, and scRNA-seq, using an autochthonous genetically engineered mouse model and different {gamma}{delta} T cell-deficient settings. We found that {gamma}{delta} T cells were increased in tumour-bearing lungs, with an altered phenotype. CD27- and CD27+ {gamma}{delta} T cells differed in their localisation and interactions including their tropism for macrophages. Overall, we propose a model where CD27+ {gamma}{delta} T cells undermine the differentiation of tumour-associated macrophages into airway macrophages, fostering a negative outcome in lung adenocarcinoma. Determining its translatability to human health may offer new avenues for immunotherapeutic strategies. SummaryGuardians of pulmonary homeostasis, {gamma}{delta} T cells remain enigmatic regarding their role in lung adenocarcinoma. Raffo-Iraolagoitia et al. report that a subset of {gamma}{delta} T cells impairs the differentiation of tumour-associated macrophages into airway macrophages, relevant for the outcome of lung adenocarcinoma. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/557344v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@e679f7org.highwire.dtl.DTLVardef@15152dforg.highwire.dtl.DTLVardef@17eaa5org.highwire.dtl.DTLVardef@2e0e47_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

ERBB signalling contributes to immune evasion in KRAS-driven lung adenocarcinoma

Immunotherapy is increasingly viewed as treatment of choice for lung cancer, however, clinical responses to immune checkpoint blockade remain highly unpredictable and are largely transient. A deeper mechanistic understanding of the dynamics of tumour:immune interactions is needed to drive rational development of improved treatment strategies. Progress is hampered by a paucity of autochthonous model systems in which to interrogate the 2-way interactions of immune responses to evolving tumours and vice-versa. Specifically, commonly used genetically engineered mouse models typically lack the genetic diversity needed to drive an adaptive immune response. APOBEC mutagenesis signatures are prominent in lung cancer and APOBEC activity is predicted to drive immune visibility through Cytidine deaminase activity, coupled with inaccurate DNA-repair responses. We therefore generated a CRE-inducible APOBEC3B allele, interbred with multiple oncogenic drivers of lung adenocarcinoma, and used the resulting mice to investigate the response to PD1 blockade at single cell resolution. SIGNIFICANCE Using our novel immune-visible model of KRas-driven autochthonous lung adenocarcinoma, we uncovered a surprising increase in tumour-cell expression of EGFR/ERBB ligands following treatment with -PD1 and present evidence that transient ERBB blockade can restore immune surveillance in KRas mutant LuAd and combine effectively with immune checkpoint blockade.

cancer biology↗

bioRxiv2023

Optimisation of sample preparation from primary mouse tissue to maintain RNA integrity for methods examining translational control

Protein output of different mRNAs can vary by two orders of magnitude therefore it is critical to understand the processes that control gene expression that operate at the level of translation. Translatome-wide techniques such as polysome profiling and ribosome profiling are key methods for determining translations rates occurring on specific mRNAs. These techniques are now widely used in cell lines; however, they are underutilised in tissues and cancer models. Ribonuclease (RNase) expression is often found to be higher in complex primary tissues in comparison to cell lines. Methods used to preserve RNA during lysis often use denaturing conditions which needs to be avoided when requiring to maintain the interaction and position of the ribosome with the mRNA. Here we detail the cell lysis conditions that produce high quality RNA from several different tissues covering a range of endogenous RNase expression levels. We highlight the importance of RNA integrity for accurate determination of the global translation status of the cell as determined by polysome gradients and discuss key aspects to optimise for accurate assessment of the translatome from primary mouse tissue.

molecular biology↗