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Bevan, C. L.

Publications and source records attributed to Bevan, C. L..

6 recordsLinked to original sources

Chromatin signalling pathways and FANCE amplification affect ATR inhibitor sensitivity in metastatic breast cancer

Metastatic breast cancer remains incurable, as many patients develop therapy resistance. Loss of ATM/p53 increases reliance on the ATR pathway, positioning ATR inhibitors (ATRi) as promising therapeutics. However, targeting a single pathway often leads to resistance due to tumour heterogeneity or alternative signalling mechanisms. Here, we combine chromatin-enrichment proteomics and phospho-proteomics with genome sequencing data in the ATRi-sensitive triple negative breast cancer (TNBC) cell line MDA-MB-453 to map adaptive responses to the ATR inhibitor AZD6738. We identify chromatin-associated activation of survival pathways, including AKT1, RPTOR (mTORC1), CDK4/5, and OGFR, alongside hyperphosphorylation of MKI67, SAFB2, and CHD4, indicating ATRi sensitivity. Complementary siRNA screening of DNA damage response (DDR) genes reveals that amplification of Fanconi anaemia (FA) pathway gene FANCE increases sensitivity to AZD6738. Analysis of breast cancer datasets highlights frequent FANCE amplification in metastatic patients, particularly in circulating tumour cells. Strikingly, pharmacological inhibition of the FA pathway (UBE2T/FANCL-IN-1) synergises with AZD6738. Together, our findings define adaptive resistance mechanisms to ATR inhibition and nominate FA pathway blockade as a rational combination strategy. Overall, our work provides fundamental insight into the complexity of DDR in metastatic breast cancer and offers a platform for mechanistic investigation, which can be exploited in cancer therapy.

cancer biology↗

The antiviral potential of the antiandrogen enzalutamide and the viral-androgen interplay in seasonal coronaviruses

The sex disparity in COVID-19 outcomes with males generally faring worse than females has been associated with the androgen-regulated expression of the protease TMPRSS2 and the cell receptor ACE2 in the lung and fueled interest in antiandrogens as potential antivirals. In this study, we explored enzalutamide, an antiandrogen used commonly against prostate cancer, as a potential antiviral against the human coronaviruses which cause seasonal respiratory infections (HCoV-NL63, -229E, and -OC43). Using lentivirus-pseudotyped and authentic HCoV, we report that enzalutamide reduced 229E and NL63 entry and replication in both TMPRSS2- and non-expressing immortalised cells, suggesting a TMPRSS2-independent mechanism. However, no effect was observed against OC43. To decipher this distinction, we performed RNA-sequencing analysis on 229E-and OC43- infected primary human airway cells. Our results show a significant induction of androgen-responsive genes by 229E compared to OC43 at 24 and 72h post-infection. The virus-mediated effect to AR signaling was further confirmed with a consensus androgen response element (ARE)-driven luciferase assay in androgen-depleted MRC-5 cells. Specifically, 229E induced luciferase reporter activity in the presence and absence of the synthetic androgen mibolerone, while OC43 inhibited induction. These findings highlight a complex interplay between viral infections and androgen signaling, offering insights for potential antiviral interventions.

microbiology↗

Detection of YAP1 and AR-V7 mRNA for Prostate Cancer prognosis using an ISFET Lab-On-Chip platform

Prostate cancer (PCa) is the second most common cause of male cancer-related death worldwide. The gold standard of treatment for advanced PCa is androgen deprivation therapy (ADT). However, eventual failure of ADT is common and leads to lethal metastatic castration resistant PCa (mCRPC). As such, the detection of relevant biomarkers in the blood for drug resistance in mCRPC patients could lead to personalized treatment options. mRNA detection is often limited by the low specificity of qPCR assays which are restricted to specialised laboratories. Here, we present a novel reversetranscription loop-mediated isothermal amplification (RT-LAMP) assay and have demonstrated its capability for sensitive detection of AR-V7 and YAP1 RNA (3x101 RNA copies per reaction). This work presents a foundation for the detection of circulating mRNA in PCa on a non-invasive Lab-on-chip (LoC) device for use at point-of-care. This technique was implemented onto a Lab-on-Chip platform integrating an array of chemical sensors (ion-sensitive field-effect transistors - ISFETs) for real-time detection of RNA. Detection of RNA presence was achieved through the translation of chemical signals into electrical readouts. Validation of this technique was conducted with rapid detection (<15 min) of extracted RNA from prostate cancer cell lines 22Rv1s and DU145s.

bioengineering↗

The CDK7 inhibitor CT7001 (Samuraciclib) targets proliferation pathways to inhibit advanced prostate cancer

BackgroundCurrent strategies to inhibit the androgen receptor (AR) are circumvented in castration-resistant prostate cancer (CRPC). Cyclin-dependent kinase 7 (CDK7) promotes AR signalling, in addition to established roles in cell cycle and global transcription regulation, together, providing a rationale for its therapeutic targeting in CRPC. MethodsThe antitumour activity of CT7001, an orally bioavailable CDK7 inhibitor, was investigated across CRPC models in vitro and in xenograft models in vivo. Cell-based assays and transcriptomic analyses of treated xenografts were employed to investigate the mechanism driving activity of CT7001, alone and in combination with the antiandrogen enzalutamide. ResultsCT7001 selectively engages with CDK7 in prostate cancer cells, causing inhibition of proliferation and cell cycle arrest. Activation of p53, induction of apoptosis, and suppression of transcription mediated by full-length and constitutively active AR splice variants contribute to antitumour efficacy in vitro. Oral administration of CT7001 represses growth of CRPC xenografts and significantly augments growth inhibition achieved by enzalutamide. Transcriptome analyses of treated xenografts indicate cell cycle and AR inhibition as the mode of action of CT7001 in vivo. ConclusionsThis study supports CDK7 inhibition as a strategy to target deregulated cell proliferation and demonstrates CT7001 is a promising CRPC therapeutic, alone or in combination with AR-targeting compounds.

molecular biology↗

A suite of activity-based probes to dissect the KLK activome in drug-resistant prostate cancer

Kallikrein-related peptidases (KLKs) are a family of secreted serine proteases, which form a network - the KLK activome - with an important role in proteolysis and signaling. In prostate cancer (PCa), increased KLK activity promotes tumor growth and metastasis through multiple biochemical pathways, and specific quantification and tracking of changes in the KLK activome could contribute to validation of KLKs as potential drug targets. Herein we report a technology platform based on novel activity-based probes (ABPs) and inhibitors with unprecedented potency and selectivity enabling simultaneous orthogonal analysis of KLK2, KLK3 and KLK14 activity in hormone-responsive PCa cell lines and tumor homogenates. Using selective inhibitors and multiplexed fluorescent activity-based protein profiling (ABPP) we dissect the KLK activome in PCa cells and show that increased KLK14 activity leads to a migratory phenotype. Furthermore, using biotinylated ABPs we show that active KLK molecules are secreted into the bone microenvironment by PCa cells following stimulation by osteoblasts suggesting KLK-mediated signaling mechanisms could contribute to PCa metastasis to bone. Together our findings show that ABPP is a powerful approach to dissect dysregulation of the KLK activome as a promising and previously underappreciated therapeutic target in advanced PCa.

biochemistry↗

Genome-wide analyses of transcription factors and co-regulators across seven cohorts identified reduced PPARGC1A expression as a driver of prostate cancer progression

Defining altered transcription factor (TF) and coregulators that are oncogenic drivers remains a challenge, in part because of the multitude of TFs and coregulators. We addressed this challenge by using bootstrap approaches to test how expression, copy number alterations or mutation of TFs (n = 2662), coactivators (COA; n= 766); corepressor (COR; n = 599); mixed function coregulators (MIXED; n = 511) varied across seven prostate cancer (PCa) cohorts (three of localized and four advanced disease). COAS, CORS, MIXED and TFs all displayed significant down-regulated expression (q.value < 0.1) and correlated with protein expression ({rho} 0.4 to 0.55). Stringent expression filtering identified commonly altered TFs and coregulators including well-established (e.g. ERG) and underexplored (e.g. PPARGC1A, encodes PGC1) in localized PCa. Reduced PPARGC1A expression significantly associated with worse disease-free survival in two cohorts of localized PCa. Stable PGC1 knockdown in LNCaP cells increased growth rates and invasiveness and RNA-Seq revealed a profound basal impact on gene expression (~2300 genes; FDR < 0.05, logFC > 1.5), but only modestly impacted PPAR{gamma} responses. GSEA analyses of the PGC1 transcriptome revealed that it significantly altered the AR-dependent transcriptome, and was enriched for epigenetic modifiers. PGC1-dependent genes were overlapped with PGC1-ChIP-Seq genes and significantly associated in TCGA with higher grade tumors and worse disease-free survival. Together these data demonstrate an approach to identify cancer-driver coregulators in cancer and that PGC1 expression is clinically significant yet underexplored coregulator in aggressive early stage PCa.

cancer biology↗