Evolutionary adaptation of probiotics in the gut: selection pressures, optimization strategies, and regulatory challenges.

Probiotics and live bacterial therapeutics are garnering increased attention for use in human health and have the potential to revolutionise the treatment of gastrointestinal diseases. However, a pervasive feature of bacteria that must be considered in the design of safe and effective probiotics and live bacterial therapeutics is their capacity for rapid evolution, both at the individual (epi)genetic level and in terms of population dynamics. Here we summarise gastrointestinal-specific evolution of bacteria, focussing on genetic and population levels of adaptation to factors such as carbon source availability, environmental stressors, and interactions with the native microbiome.

Discovery of WEE1 Kinase Inhibitors with Potent Activity against Patient-Derived, Metastatic Colorectal Cancer Organoids.

A library of potent WEE1 kinase inhibitors was synthesized based on the discontinued frontrunner clinical candidate AZD1775 (), many of which were more selective for WEE1 over an undesirable off-target of , the kinase PLK1. When tested against patient-derived organoids (PDOs) grown from -mutated colorectal cancer (CRC) peritoneal metastases, (IC value of 62 nM) exhibited stronger efficacy than (IC value of 120 nM) and the best-in-class clinical candidate ZN-c3 (IC value of 127 nM). Against primary CRC PDOs with -WT, significantly enhanced DNA damage, replication stress and apoptosis compared to , as well as demonstrated high selectivity over patient-matched normal healthy colon PDOs, highlighting a potential therapeutic window for cancer treatment.

Towards Understanding Tumour Colonisation by Probiotic Bacterium Nissle 1917.

The last decade has seen a rapid increase in studies utilising a genetically modified probiotic, Nissle 1917 (EcN), as a chassis for cancer treatment and detection. This approach relies on the ability of EcN to home to and selectively colonise tumours over normal tissue, a characteristic common to some bacteria that is thought to result from the low-oxygen, nutrient-rich and immune-privileged niche the tumour provides. Pre-clinical studies have used genetically modified EcN to deliver therapeutic payloads that show efficacy in reducing tumour burden as a result of high-tumour and low off-target colonisation.

Engineering tumor-colonizing E. coli Nissle 1917 for detection and treatment of colorectal neoplasia.

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment. Here, first, we demonstrate selective colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition and orthotopic models of CRC.

Generation and assessment of cytokine-induced killer cells for the treatment of colorectal cancer liver metastases.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Cytokine-induced killer (CIK) cells are an adoptive immunotherapy reported to have strong anti-tumour activity across a range of cancers. They are a heterogeneous mix of lymphoid cells generated by culturing human peripheral blood mononuclear cells with cytokines and monoclonal antibodies in vitro.

Advancing translational research for colorectal immuno-oncology.

Colorectal cancer (CRC) is a common and deadly disease. Unfortunately, immune checkpoint inhibitors (ICIs) fail to elicit effective anti-tumour responses in the vast majority of CRC patients. Patients that are most likely to respond are those with DNA mismatch repair deficient (dMMR) and microsatellite instability (MSI) disease.

Engineered bacteria detect tumor DNA.

Synthetic biology has developed sophisticated cellular biosensors to detect and respond to human disease. However, biosensors have not yet been engineered to detect specific extracellular DNA sequences and mutations. Here, we engineered naturally competent to detect donor DNA from the genomes of colorectal cancer (CRC) cells, organoids, and tumors.

Colorectal cancer detection and treatment with engineered probiotics.

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment strategies. Here, we demonstrate the phenomenon of selective, long-term colonization of colorectal adenomas after oral delivery of probiotic Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition. We show that, after oral administration, adenomas can be monitored over time by recovering EcN from stool.

The Antianginal Drug Perhexiline Displays Cytotoxicity against Colorectal Cancer Cells In Vitro: A Potential for Drug Repurposing.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Perhexiline, a prophylactic anti-anginal drug, has been reported to have anti-tumour effects both in vitro and in vivo. Perhexiline as used clinically is a 50:50 racemic mixture ((R)-P) of (-) and (+) enantiomers.

The Origin and Contribution of Cancer-Associated Fibroblasts in Colorectal Carcinogenesis.

Background & Aims: Cancer-associated fibroblasts (CAFs) play an important role in colorectal cancer (CRC) progression and predict poor prognosis in CRC patients. However, the cellular origins of CAFs remain unknown, making it challenging to therapeutically target these cells. Here, we aimed to identify the origins and contribution of colorectal CAFs associated with poor prognosis.

Portal Vein Injection of Colorectal Cancer Organoids to Study the Liver Metastasis Stroma.

Hepatic metastasis of colorectal cancer (CRC) is a leading cause of cancer-related death. Cancer-associated fibroblasts (CAFs), a major component of the tumor microenvironment, play a crucial role in metastatic CRC progression and predict poor patient prognosis. However, there is a lack of satisfactory mouse models to study the crosstalk between metastatic cancer cells and CAFs.

Delineating proinflammatory microenvironmental signals by ex vivo modeling of the immature intestinal stroma.

The intestinal stroma provides an important microenvironment for immune cell activation. The perturbation of this tightly regulated process can lead to excessive inflammation. We know that upregulated Toll-like receptor 4 (TLR4) in the intestinal epithelium plays a key role in the inflammatory condition of preterm infants, such as necrotizing enterocolitis (NEC).

Stromal DLK1 promotes proliferation and inhibits differentiation of the intestinal epithelium during development.

The stem/progenitor cells of the developing intestine are biologically distinct from their adult counterparts. Here, we examine the microenvironmental cues that regulate the embryonic stem/progenitor population, focusing on the role of Notch pathway factor delta-like protein-1 (DLK1). mRNA-seq analyses of intestinal mesenchymal cells (IMCs) collected from embryonic day 14.

The Balance of Stromal BMP Signaling Mediated by GREM1 and ISLR Drives Colorectal Carcinogenesis.

Background & Aims: Cancer-associated fibroblasts (CAFs), key constituents of the tumor microenvironment, either promote or restrain tumor growth. Attempts to therapeutically target CAFs have been hampered by our incomplete understanding of these functionally heterogeneous cells. Key growth factors in the intestinal epithelial niche, bone morphogenetic proteins (BMPs), also play a critical role in colorectal cancer (CRC) progression.

Medium-throughput Drug Screening of Patient-derived Organoids from Colorectal Peritoneal Metastases to Direct Personalized Therapy.

Purpose: Patients with colorectal cancer with peritoneal metastases (CRPMs) have limited treatment options and the lowest colorectal cancer survival rates. We aimed to determine whether organoid testing could help guide precision treatment for patients with CRPMs, as the clinical utility of prospective, functional drug screening including nonstandard agents is unknown.

Experimental Design: CRPM organoids (peritonoids) isolated from patients underwent parallel next-generation sequencing and medium-throughput drug panel testing to identify specific drug sensitivities for each patient.

Genetic editing of colonic organoids provides a molecularly distinct and orthotopic preclinical model of serrated carcinogenesis.

Objective: Serrated colorectal cancer (CRC) accounts for approximately 25% of cases and includes tumours that are among the most treatment resistant and with worst outcomes. This CRC subtype is associated with activating mutations in the mitogen-activated kinase pathway gene, , and epigenetic modifications termed the CpG Island Methylator Phenotype, leading to epigenetic silencing of key tumour suppressor genes. It is still not clear which (epi-)genetic changes are most important in neoplastic progression and we begin to address this knowledge gap herein.

CD10-positive myoepithelial cells are usually prominent around in situ lobular neoplasia of the breast and much less prominent or absent in DCIS.

Aims: To study the relationship between the neoplastic cells of in situ lobular neoplasia (ILN) and ductal carcinoma in situ (DCIS) and the surrounding CD10-positive myoepithelial cells.

Materials And Methods: Twenty consecutive cases of ILN and 51 of DCIS were stained for CD10 using the immunoperoxidase technique. The presence of CD10-positive cells was assessed semiquantitatively on a scale of 0-3 where 0 indicates their absence and 3 indicates the presence of multiple layers, which can be focal.

The role of iron in the skin and cutaneous wound healing.

In this review article we discuss current knowledge about iron in the skin and the cutaneous wound healing process. Iron plays a key role in both oxidative stress and photo-induced skin damage. The main causes of oxidative stress in the skin include reactive oxygen species (ROS) generated in the skin by ultraviolet (UVA) 320-400 nm portion of the UVA spectrum and biologically available iron.

Genome-wide identification of miR-200 targets reveals a regulatory network controlling cell invasion.

The microRNAs of the miR-200 family maintain the central characteristics of epithelia and inhibit tumor cell motility and invasiveness. Using the Ago-HITS-CLIP technology for transcriptome-wide identification of direct microRNA targets in living cells, along with extensive validation to verify the reliability of the approach, we have identified hundreds of miR-200a and miR-200b targets, providing insights into general features of miRNA target site selection. Gene ontology analysis revealed a predominant effect of miR-200 targets in widespread coordinate control of actin cytoskeleton dynamics.

Regulation of the neuronal transcription factor NPAS4 by REST and microRNAs.

NPAS4 is a brain restricted, activity-induced transcription factor which regulates the expression of inhibitory synapse genes to control homeostatic excitatory/inhibitory balance in neurons. NPAS4 is required for normal social interaction and contextual memory formation in mice. Protein and mRNA expression of NPAS4 is tightly coupled to neuronal depolarization and most prevalent in the cortical and hippocampal regions in the brain, however the precise mechanisms by which the NPAS4 gene is controlled remain unexplored.

Counter-regulation of alpha- and beta-synuclein expression at the transcriptional level.

Alpha-synuclein is a cytosolic protein associated with a range of diseases including Parkinson's disease. In these diseases alpha-synuclein aggregates and this is believed to play a causative role in disease progression. Alpha-synuclein aggregation has been suggested to be caused by increased expression levels and has also been suggested to be countered by increased beta-synuclein expression.

Epigenetic modulation of the miR-200 family is associated with transition to a breast cancer stem-cell-like state.

The miR-200 family is a key regulator of the epithelial-mesenchymal transition, however, its role in controlling the transition between cancer stem-cell-like and non-stem-cell-like phenotypes is not well understood. We utilized immortalized human mammary epithelial (HMLE) cells to investigate the regulation of the miR-200 family during their conversion to a stem-like phenotype. HMLE cells were found to be capable of spontaneous conversion from a non-stem to a stem-like phenotype and this conversion was accompanied by the loss of miR-200 expression.

ZEB1 drives prometastatic actin cytoskeletal remodeling by downregulating miR-34a expression.

Metastatic cancer is extremely difficult to treat, and the presence of metastases greatly reduces a cancer patient's likelihood of long-term survival. The ZEB1 transcriptional repressor promotes metastasis through downregulation of microRNAs (miRs) that are strong inducers of epithelial differentiation and inhibitors of stem cell factors. Given that each miR can target multiple genes with diverse functions, we posited that the prometastatic network controlled by ZEB1 extends beyond these processes.

Prion protein expression alters APP cleavage without interaction with BACE-1.

The prion protein (PrP) and the beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE-1) are both copper binding proteins, but are associated with two separate neurodegenerative diseases. The role of BACE-1 in the formation of beta-amyloid has made it a major target in attempts to reduce the formation of beta-amyloid in Alzheimer's diseases. However, the suggestion that PrP, normally associated with prion diseases, binds to BACE-1 and reduces its activity has led to the suggestion that the study of this interaction could be of considerable importance to Alzheimer's disease.