Biology subjects

Cairns, M. J.

Publications and source records attributed to Cairns, M. J..

11 recordsLinked to original sources

bioRxiv2026

(E,E)-bisantrene suppresses MYC expression and displays anti-leukemic activity in acute myeloid leukemia

Background: Acute myeloid leukemia (AML) is genetically diverse with a high unmet clinical need for improved treatment options. Dysregulation of the transcription factor MYC plays a central role in AML progression and therapeutic resistance. (E,E)-bisantrene was recently found to inhibit MYC transcription and downstream activity via G-quadruplex DNA stabilization. This study aimed to evaluate the mechanism of action and preclinical activity of (E,E)-bisantrene in AML. Methods: The in vitro and in vivo activity of (E,E)-bisantrene was determined in a variety of AML models (cell lines, xenograft mouse models, and ex vivo human AML mononuclear cells). Transcriptomic, proteomic and phosphoproteomic analyses were performed after treatment with (E,E)-bisantrene. Analyses of -omics data to identify enriched pathways and upstream regulators were performed. Results: (E,E)-bisantrene demonstrated potent anti-proliferative activity across a panel of AML cell lines, inducing apoptosis and reducing S phase proportions. (E,E)-bisantrene significantly prolonged survival in cell- and patient-derived xenograft models of AML. Mechanistically, RNA-seq and proteomic analysis of MOLM13 and MV4-11 cells treated with (E,E)-bisantrene showed significant reductions in the activity of MYC and E2F, together with the cell cycle regulators CDK1/2/4/5. Transcript and protein levels of MYC were reduced in a dose- and time-dependent manner. TP53 and inflammation-associated transcript signatures were also observed. Conclusion: Anti-proliferative activity of (E,E)-bisantrene in preclinical AML models was associated with a downregulation of MYC, CDK1/2/4/5 and E2F. This study supports the ongoing clinical evaluation of (E,E)-bisantrene in AML where MYC is a clinically relevant driver of disease aggressiveness and therapy resistance.

cancer biology↗

bioRxiv2025

Neuroanatomical Correlates of Negative Symptoms in Schizophrenia

BackgroundSchizophrenia is characterized by widespread structural brain abnormalities, but associations between structural abnormalities and negative symptom severity are not well understood. Negative symptoms have been conceptualized in a hierarchical structure of two second-order dimensions--motivation and pleasure (MAP) and expression (EXP)--and five first-order domains: anhedonia, avolition, and asociality (MAP), and blunted affect and alogia (EXP). A better understanding of the neural circuitry underlying negative symptom dimensions and domains is important given their reported association with poor functional outcome and lack of available treatments. Study DesignThe meta-analysis included 1,591 individuals with schizophrenia across 16 samples with structural imaging and Scale for Assessment of Negative Symptoms data. The study generated correlations of cortical thickness and subcortical volumes with the negative symptom dimensions and domains. Study resultsNegative symptoms showed mainly negative associations with cortical thickness and subcortical volumes. The effect sizes were small but there was a pattern of associations in predominantly frontal lobe cortical thickness and limbic subcortical volumes. The regional correlation patterns of cortical thickness and subcortical volumes with symptom domains support the conceptualized hierarchical structure of negative symptoms: correlations of MAP domains were stronger with the MAP than EXP dimension, and vice versa. Exploratory analyses with receptor densities further supported the hierarchy. ConclusionOur findings reveal small but consistent associations between negative symptom dimensions and predominantly prefrontal region cortical thickness, and limbic region volumes. These findings advance our understanding of the network of anatomical regions that may contribute to the severity of negative symptoms in schizophrenia.

neuroscience↗

bioRxiv2025

Bisantrene potentiates tyrosine kinase inhibitor activity in clear cell renal cell carcinoma

Clear Cell Renal Cell Carcinoma (ccRCC) is the most prevalent kidney cancer and often develops resistance to standard therapies. This study aimed to assess if bisantrene, a multi-mechanistic agent with broad anticancer activity, can enhance the activity of standard of care ccRCC treatments. A panel of ccRCC cell lines were treated with bisantrene alone and in combination with common ccRCC drugs. Bisantrene showed moderate activity as a single agent, but strongly synergized with several ccRCC treatments, especially the tyrosine kinase inhibitors (TKIs) lenvatinib, pazopanib and cabozantinib. Cellular signaling pathways assessed by immunoblotting revealed the TKIs inhibit MET as well as downstream AKT and ERK signaling pathways as single agents. Combination of these TKIs with bisantrene was able to induce sustained downstream AKT inhibition and negate the rebound effect seen with TKI resistance. Overall, bisantrene shows promise as a new therapeutic agent for ccRCC in combination with TKIs.

cancer biology↗

bioRxiv2023

PI3K/mTOR is a therapeutically targetable genetic dependency in diffuse intrinsic pontine glioma

Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma - DIPG), are uniformly fatal brain tumors that lack effective pharmacological treatment. Analysis of pooled CRISPR-Cas9 loss-of-function gene deletion screen datasets, identified PIK3CA and MTOR as targetable molecular dependencies across DIPG patient derived models, highlighting the therapeutic potential of the blood-brain barrier penetrant PI3K/Akt/mTOR inhibitor paxalisib. At the human equivalent maximum tolerated dose, mice treated with paxalisib experienced systemic feedback resulting in increased blood glucose and insulin levels, commensurate with DIPG patients in Phase 1b clinical trials who experienced hyperglycemia/hyperinsulinemia. To exploit genetic dependences, but maintain compliance and benefit, we optimized a paxalisib treatment regimen that employed reduced dosing more frequently, in combination with the anti-hyperglycemic drug, metformin. Combining optimized dosing with metformin restored glucose homeostasis and decreased phosphorylation of the insulin receptor in vivo, a common mechanism of PI3K-inhibitor resistance, extending the survival of DIPG xenograft models. RNA sequencing and phosphoproteomic profiling of DIPG models treated with paxalisib identified increased calcium-activated PKC signaling. Using the brain penetrant PKC inhibitor, enzastaurin in combination with paxalisib, we synergistically extended the survival of orthotopic xenograft models, benefits further promoted by metformin; thus, identifying a clinically relevant DIPG combinatorial approach. Brief SummaryDiffuse intrinsic pontine glioma is a lethal childhood brain tumor. Here we identify PIK3CA as a genetic dependency targeted by the brain penetrant pan-PI3K-inhibitor paxalisib.

cancer biology↗

bioRxiv2021

RNA-seq, bioinformatic identification of potential MicroRNA-Like Small RNAs in the edible mushroom Agaricus bisporus and experimental approach for their validation

Although genomes from many edible mushrooms are sequenced, studies on fungal miRNAs are scarce. Most of the bioinformatic tools are designed for plants or animals but fungal miRNAs processing and expression share similarities and differences with both kingdoms. Moreover, since mushroom species such as Agaricus bisporus (white button mushroom) are frequently consumed as food, controversial discussions are still evaluating whether their miRNAs might or might not be assimilated, perhaps within extracellular vesicles (i.e exosomes). Therefore, the A. bisporus RNA-seq was studied in order to identify potential de novo miRNA-like small RNAs (milRNAs) that might allow their later detection in the diet. Results pointed to 1 already known and 37 de novo milRNAss. Three milRNAss were selected for RT-qPCR experiments. Precursors and mature milRNAs were found in the edible parts (caps and stipes) validating the predictions carried out in silico. When their potential gene targets were investigated, results pointed that mostly were involved in primary and secondary metabolic regulation. However, when human transcriptome is used as target, the results suggest that they might interfere with important biological processes related with cancer, infectious process and neurodegenerative diseases.

bioinformatics↗

bioRxiv2021

MicroRNA binding site variation is enriched inpsychiatric disorders

Psychiatric disorders and other complex traits have a polygenic architecture, often associated with dozens or even hundreds of independent genomic loci. As each of these have a relatively small influence on the trait, the dissection of their biological components is a non-trivial task. For psychiatric disorders in particular, the majority of associated loci lie within non-coding regions of the genome, suggesting that most of the genetic risk for disease originates from the disruption of regulatory sequences. While previously exploration of the heritability of these sequences has focused on variants that modify DNA elements, those that alter cis-acting RNA sequences, such as miRNA binding sites, are also likely to have a significant impact in these disorders. MiRNA have already been shown to be dysregulated in these disorders through both genetic and environmental influence, so it is reasonable to suspect their target genes may also be affected by common variation. In this study, we investigated the distribution of miRNA binding site variants (MBSVs) predicted to alter miRNA binding affinity in psychiatric disorders and observed significant enrichment in schizophrenia, depression, bipolar disorder, and anorexia nervosa. We also observed significant enrichment of MBSVs in genes targeted by several miRNA families, including miR-335-5p, miR-21-5p/590-5p, miR-361-5p, and miR-557 in both schizophrenia and depression, and nominally significant enrichment of MBSV for miR-323b-3p in schizophrenia. We also identified a significant association between MBSVs in gene sets involved in regulation of the synapse and synaptic depression in schizophrenia. While these observations support the role of miRNA in the pathophysiology of psychiatric disorders, we also observed significant association of MBSVs in other complex traits suggesting that MBSVs are an important class of regulatory variants that have functional implications for many disorders.

genetics↗

bioRxiv2020

Sex-Dependent Shared and Non-Shared Genetic Architecture Across Mood and Psychotic Disorders

BACKGROUNDSex differences in incidence and/or presentation of schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP) are pervasive. Previous evidence for shared genetic risk and sex differences in brain abnormalities across disorders suggest possible shared sex-dependent genetic risk. METHODSWe conducted the largest to date genome-wide genotype-by-sex (GxS) interaction of risk for these disorders, using 85,735 cases (33,403 SCZ, 19,924 BIP, 32,408 MDD) and 109,946 controls from the Psychiatric Genomics Consortium (PGC) and iPSYCH. RESULTSAcross disorders, genome-wide significant SNP-by-sex interaction was detected for a locus encompassing NKAIN2 (rs117780815; p=3.2x10-8), that interacts with sodium/potassium-transporting ATPase enzymes implicating neuronal excitability. Three additional loci showed evidence (p<1x10-6) for cross-disorder GxS interaction (rs7302529, p=1.6x10-7; rs73033497, p=8.8x10-7; rs7914279, p=6.4x10-7) implicating various functions. Gene-based analyses identified GxS interaction across disorders (p=8.97x10-7) with transcriptional inhibitor SLTM. Most significant in SCZ was a MOCOS gene locus (rs11665282; p=1.5x10-7), implicating vascular endothelial cells. Secondary analysis of the PGC-SCZ dataset detected an interaction (rs13265509; p=1.1x10-7) in a locus containing IDO2, a kynurenine pathway enzyme with immunoregulatory functions implicated in SCZ, BIP, and MDD. Pathway enrichment analysis detected significant GxS of genes regulating vascular endothelial growth factor (VEGF) receptor signaling in MDD (pFDR<0.05). CONCLUSIONSIn the largest genome-wide GxS analysis of mood and psychotic disorders to date, there was substantial genetic overlap between the sexes. However, significant sex-dependent effects were enriched for genes related to neuronal development, immune and vascular functions across and within SCZ, BIP, and MDD at the variant, gene, and pathway enrichment levels.

genetics↗

bioRxiv2020

Investigating the effect of glycaemic traits on the risk of psychiatric illness using Mendelian randomisation

Data from observational studies have suggested an involvement of abnormal glycaemic regulation in the pathophysiology of psychiatric illness. This may be an attractive target for clinical intervention as glycaemia can be modulated by both lifestyle factors and pharmacological agents. However, observational studies are inherently confounded, and therefore causal relationships cannot be reliably established. We employed genetic variants rigorously associated with three glycaemic traits (fasting glucose, fasting insulin, and glycated haemoglobin) as instrumental variables in a two-sample Mendelian randomisation analysis to investigate the causal effect of these measures on the risk for eight psychiatric disorders. A significant protective effect of a unit increase in fasting insulin levels was observed for anorexia nervosa after the application of multiple testing correction (OR = 0.48 [95% CI: 0.33-0.71] - inverse-variance weighted estimate. The relationship between fasting insulin and anorexia nervosa was supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between insulin levels and anorexia.

genetics↗

bioRxiv2019

Pairwise common variant meta-analyses of schizophrenia with other psychiatric disorders reveals shared and distinct gene and gene-set associations

The complex aetiology of schizophrenia is postulated to share factors with other psychiatric disorders. Recently, this has been supported by genome-wide association studies, with several psychiatric phenotypes displaying high genomic correlation with schizophrenia. We sought to investigate pleiotropy amongst the common variant genomics of schizophrenia and seven other psychiatric disorders using a multimarker test of association. Gene-based analysis of common variation revealed over 50 schizophrenia-associated genes shared with other psychiatric phenotypes; including bipolar disorder, major depressive disorder, ADHD, and autism spectrum disorder. In addition, we uncovered 78 genes significantly enriched with common variant associations for schizophrenia that were not linked to any of these seven disorders (P > 0.05). Transcriptomic imputation was then leveraged to investigate the functional significance of variation mapped to these genes, prioritising several interesting functional candidates. Pairwise meta-analysis of schizophrenia and each psychiatric phenotype further revealed 330 significantly associated genes (PMeta < 2.7 x 10-6) that were only nominally associated with each disorder individually (P < 0.05). Multivariable gene-set association suggested that common variation enrichment within biologically constrained genes observed for schizophrenia also occurs across several psychiatric phenotypes. These analyses consolidate the overlap between the genomic architecture of schizophrenia and other psychiatric disorders and uncovered several pleiotropic genes which warrant further investigation.\n\nAUTHOR SUMMARYSchizophrenia and other psychiatric disorders have many similarities, and this includes features of their overall genetic risk. Here, we investigate genes which may play a role in schizophrenia as well one or more of seven other psychiatric phenotypes and demonstrate that a number of them are pleiotropic and influence at least one other disorder. We also identify genes amongst the psychiatric disorders studied here which only show association with schizophrenia. Furthermore, we find a number of genes which were only significant when combining genetic association data from schizophrenia and one of the other seven disorders, suggesting there are shared genetic influences that are revealed through the power of joint analysis. This study identifies interesting novel shared (pleiotropic) genes in psychiatry which warrant future study.

genetics↗

bioRxiv2019

Pharmacological enrichment of polygenic risk for precision medicine in complex disorders

Individuals with complex disorders typically have a heritable burden of common variation that can be expressed as a polygenic risk score (PRS). While PRS has some predictive utility, it lacks the molecular specificity to be directly informative for clinical interventions. We therefore sought to develop a framework to quantify an individuals common variant enrichment in clinically actionable systems responsive to existing drugs. This was achieved with a metric designated the pharmagenic enrichment score (PES), which we demonstrate for individual SNP profiles in a cohort of cases with schizophrenia. A large proportion of these had elevated PES in one or more of eight clinically actionable gene-sets enriched with schizophrenia associated common variation. Notable candidates targeting these pathways included vitamins, insulin modulating agents, and protein kinase inhibitors with putative neuroprotective properties. Interestingly, elevated PES was also observed in individuals with otherwise low common variant burden. The biological saliency of PES profiles were observed directly through their impact on gene expression in a subset of the cohort with matched transcriptomic data, supporting our assertion that this framework can integrate an individuals common variant risk to inform personalised interventions, including drug repositioning, for complex disorders such as schizophrenia.

genetics↗

bioRxiv2018

The Medical Genome Reference Bank: Whole genomes and phenotype of 2,570 healthy elderly

Population health research is increasingly focused on the genetic determinants of healthy ageing, but there is no public resource of whole genome sequences and phenotype data from healthy elderly individuals. Here we describe the Medical Genome Reference Bank (MGRB), comprising whole genome sequence and phenotype of 2,570 elderly Australians depleted for cancer, cardiovascular disease, and dementia. We analysed the MGRB for single-nucleotide, indel and structural variation in the nuclear and mitochondrial genomes. Individuals in the MGRB had fewer disease-associated common and rare germline variants, relative to both cancer cases and the gnomAD and UK BioBank cohorts, consistent with risk depletion. Pervasive age-related somatic changes were correlated with grip strength in men, suggesting blood-derived whole genomes may also provide a biologic measure of age-related functional deterioration. The MGRB provides a broadly applicable reference cohort for clinical genetics and genomic association studies, and for understanding the genetics of healthy ageing. This research has been conducted using the UK Biobank Resource under Application Number 17984.

genomics↗