Biology subjects

Dale, S.

Publications and source records attributed to Dale, S..

5 recordsLinked to original sources

bioRxiv2026

EGFR INHIBITION PROMOTES ENTEROENDOCRINE CELL DIFFERENTIATION CONTRIBUTING TO TREATMENT-ASSOCIATED DIARRHEA

Enteroendocrine cells (EECs) are specialized sensors of the gastrointestinal (GI) epithelium that regulate gut function and systemic metabolism through hormone secretion. The molecular pathways directing intestinal stem cell (ISC) differentiation into EECs are incompletely understood due, in part, to their rarity. We sought to identify novel regulators of human EEC differentiation using a high-throughput screen of FDA-approved drugs and human duodenal organoids. Two epidermal growth factor receptor inhibitors (EGFRi) commonly used in cancer therapy and known to cause GI side effects, erlotinib and lapatinib, emerged as strong inducers of EEC differentiation, dramatically increasing chromogranin A (CHGA) expression compared to controls, while maintaining ISC function and organoid growth. EGFRi-treated organoids revealed robust and broad upregulation of EEC hormones, including serotonin (5HT), motilin (MLN), and somatostatin (SST), among others. In agreement with these findings, analysis of a patient cohort with lung cancer revealed an association with erlotinib use and increased circulating levels of the above EEC hormones compared to matched controls. Supporting a direct effect of EGFRi on EEC differentiation, mice treated with erlotinib demonstrated increased EEC numbers and hormones and showed EGFRi-associated diarrhea (EAD), a limiting side effect of these medications. Mechanistically, EGFRi induced upregulation of interferon (IFN) signaling targets during early ISC-to-EEC differentiation. Consistent with this, inhibition of Signal Transducer and Activator of Transcription 1 (STAT1) attenuated EGFRi-induced EEC differentiation. These findings provide important insight into EEC differentiation that could inform treatment strategies for EAD, metabolic diseases, and GI diseases. Brief SummaryInhibition of EGFR signaling promotes human ISC-to-EEC differentiation through activation of STAT1 signaling.

cell biology↗

bioRxiv2025

Vascular smooth muscle cell atherosclerosis trajectories characterized at single cell resolution identify causal transcriptomic and epigenomic mechanisms of disease risk

Vascular smooth muscle cells (SMC) contribute to heritable coronary artery disease (CAD) risk and undergo complex cell state transitions to multiple disease related phenotypes. To investigate the genetic basis of SMC state trajectories that underlie the SMC component of CAD causality we have developed a dense timecourse single cell transcriptomic and epigenetic map of atherosclerosis in a murine disease animal model. Cellular trajectories were derived from the temporal data and probabilistic fate modeling with Waddington-Optimal Transport (WOT). We created transcription factor (TF) centered regulons mapped across the developmental timeline and through network-based prioritization with WOT predicted TFs and in silico TF perturbation, identified key drivers of cell state changes associated with EMT, vascular development, and circadian clock functions. Integration of mouse disease data with human CAD genetic findings identified transition SMC phenotypes that mediate disease risk and point to causal disease mechanisms. Parallel studies using knockout of the validated CAD gene Tcf21 revealed its impact on SMC transition cellular phenotypes and disease risk genes, due in part to a role regulating the transition of SMC precursor cells in the secondary heart field. Together, these studies characterize atherosclerosis trajectories at single cell resolution and identify genetic causal transcriptomic and epigenomic mechanisms of CAD risk.

genomics↗

bioRxiv2023

Tipifarnib potentiates the antitumor effects of PI3Kα inhibition in PIK3CA- and HRAS-dysregulated HNSCC via convergent inhibition of mTOR activity

Outcomes for patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) are poor, with median overall survival ranging from 6 to 18 months. For those who progress on standard of care (chemo)immunotherapy, treatment options are limited, necessitating the development of rational therapeutic strategies. Toward this end, we targeted the key HNSCC drivers PI3K-mTOR and HRAS via the combination of tipifarnib, a farnesyltransferase inhibitor, and alpelisib, a PI3K inhibitor, in multiple molecularly defined subsets of HNSCC. We find that tipifarnib synergizes with alpelisib at the level of mTOR in PI3K-or HRAS-dependent HNSCCs, leading to marked cytotoxicity in vitro and tumor regression in vivo. Based on these findings, we have launched the KURRENT-HN trial to evaluate the effectiveness of this combination in PIK3CA-mutant/amplified and/or HRAS-overexpressing R/M HNSCC. Preliminary evidence supports the clinical activity of this molecular biomarker-driven combination therapy. SignificanceBacked by strong mechanistic rationale, the combination of alpelisib and tipifarnib has the potential to benefit >45% of R/M HNSCC patients. By blocking feedback reactivation of mTORC1, tipifarnib may prevent adaptive resistance to additional targeted therapies, thereby enhancing their clinical utility.

cancer biology↗

bioRxiv2019

Robotic microscopy for everyone: the OpenFlexure Microscope

Optical microscopes are an essential tool for both the detection of disease in clinics, and for scientific analysis. However, in much of the world access to high-performance microscopy is limited by both the upfront cost and maintenance cost of the equipment. Here we present an open-source, 3D-printed, and fully-automated laboratory microscope, with motorised sample positioning and focus control. The microscope is highly customisable, with a number of options readily available including trans- and epi-illumination, polarisation contrast imaging, and epi-florescence imaging. The OpenFlexure Microscope has been designed to enable low-volume manufacturing and maintenance by local personnel, vastly increasing accessibility. We have produced over 100 microscopes in Tanzania and Kenya for educational, scientific, and clinical applications, demonstrating that local manufacturing can be a viable alternative to international supply chains that can often be costly, slow, and unreliable.

microbiology↗

bioRxiv2019

Comparative Analysis of In Vitro Responses and Regeneration Between Diverse Bioenergy Sorghum Genotypes

Sorghum has been considered a recalcitrant plant in vitro, and suffers from a lack of regeneration protocols that function broadly and efficiently across a range of genotypes. This study was initiated to identify differential genotype-in vitro protocol responses across a range of bioenergy sorghum bioenergy parental lines, in order to characterize response profiles for use in future genetic studies. Seven bioenergy sorghum genotypes were compared, along with the common grain sorghum genotype Tx430, for their in vitro regeneration responses using two different in vitro protocols, LG and WU. All genotypes displayed some level of response during in vitro culture with both protocols. Distinct genotype-protocol responses were observed, with the WU protocol significantly better for plantlet regeneration. All bioenergy genotypes, with the exception of Chinese Amber, performed as well, if not better than Tx430, with Rio and PI329311 the top regenerating lines. Genotypes displayed protocol-dependent, differential phenolic exudation responses, as indicated by medium browning. During the callus induction phase, genotypes prone to medium browning exhibited a response on WU medium which was either equal or greater than on LG medium, with Pink Kafir and PI329311 the most prone to medium browning. Genotype- and protocol-dependent albino plantlet regeneration was also noted, with three of the bioenergy genotypes showing albino plantlet regeneration. Grassl, Rio and Pink Kafir were susceptible to albino plantlet regeneration, with the response strongly associated with the WU protocol. Pink Kafir displayed the highest albino formation, with close to 25% of regenerating explants forming albino plantlets.

plant biology↗