Non-stem cell lineages as an alternative origin of intestinal tumorigenesis in the context of inflammation.

According to conventional views, colon cancer originates from stem cells. However, inflammation, a key risk factor for colon cancer, has been shown to suppress intestinal stemness. Here, we used Paneth cells as a model to assess the capacity of differentiated lineages to trigger tumorigenesis in the context of inflammation in mice.

Intestinal stem cells: guardians of homeostasis in health and aging amid environmental challenges.

The intestinal epithelium is the first line of defense and acts as an interface between the vast microbial world within the gastrointestinal tract and the body's internal milieu. The intestinal epithelium not only facilitates nutrient absorption but also plays a key role in defending against pathogens and regulating the immune system. Central to maintaining a healthy epithelium are intestinal stem cells (ISCs), which are essential for replenishing the intestinal epithelium throughout an individual's lifespan.

Combined inhibition of MTAP and MAT2a mimics synthetic lethality in tumor models via PRMT5 inhibition.

Homozygous 5'-methylthioadenosine phosphorylase (MTAP) deletions occur in approximately 15% of human cancers. Co-deletion of MTAP and methionine adenosyltransferase 2 alpha (MAT2a) induces a synthetic lethal phenotype involving protein arginine methyltransferase 5 (PRMT5) inhibition. MAT2a inhibitors are now in clinical trials for genotypic MTAP cancers, however the MTAP genotype represents fewer than 2% of human colorectal cancers (CRCs), limiting the utility of MAT2a inhibitors in these and other MTAP cancers.

The origin of intestinal cancer in the context of inflammation.

According to conventional views, colon cancer originates from stem cells. However, inflammation, a key risk factor for colon cancer, was shown to suppress intestinal stemness. Here, we employed Paneth cells (PCs) as a model to assess the capacity of differentiated lineages to trigger tumorigenesis in the context of inflammation.

EOGT enables residual Notch signaling in mouse intestinal cells lacking POFUT1.

Notch signaling determines cell fates in mouse intestine. Notch receptors contain multiple epidermal growth factor-like (EGF) repeats modified by O-glycans that regulate Notch signaling. Conditional deletion of protein O-fucosyltransferase 1 (Pofut1) substantially reduces Notch signaling and markedly perturbs lineage development in mouse intestine.

Intestinal stem cell aging at single-cell resolution: Transcriptional perturbations alter cell developmental trajectory reversed by gerotherapeutics.

The intestinal epithelium consists of cells derived from continuously cycling Lgr5 intestinal stem cells (Lgr5 ISCs) that mature developmentally in an ordered fashion as the cells progress along the crypt-luminal axis. Perturbed function of Lgr5 ISCs with aging is documented, but the consequent impact on overall mucosal homeostasis has not been defined. Using single-cell RNA sequencing, the progressive maturation of progeny was dissected in the mouse intestine, which revealed that transcriptional reprogramming with aging in Lgr5 ISCs retarded the maturation of cells in their progression along the crypt-luminal axis.

Paneth cells as the origin of intestinal cancer in the context of inflammation.

Paneth cells (PCs), responsible for the secretion of antimicrobial peptides in the small intestine and for niche support to crypt-base columnar stem cells (CBCs), have been shown to respond to inflammation by dedifferentiating into stem-like cells in order to sustain a regenerative response. Therefore, PCs may represent the cells-of-origin of intestinal cancer in the context of inflammation. To test this hypothesis, we targeted and mutations in Paneth cells by Cre-Lox technology and modelled inflammation by dextran sodium sulfate (DSS) administration.

Transition state analogue of MTAP extends lifespan of APC mice.

A mouse model of human Familial Adenomatous Polyposis responds favorably to pharmacological inhibition of 5'-methylthioadenosine phosphorylase (MTAP). Methylthio-DADMe-Immucillin-A (MTDIA) is an orally available, transition state analogue inhibitor of MTAP. 5'-Methylthioadenosine (MTA), the substrate for MTAP, is formed in polyamine synthesis and is recycled by MTAP to S-adenosyl-L-methionine (SAM) via salvage pathways.

Effects of Diet Choice on Stem Cell Function Necessitate Clarity in Selection and Reporting.

Augenlicht and colleagues raise concerns about the impact of diet on stem cell regulation and call for more careful reporting on dietary conditions used in mouse studies on this topic. We agree that specific conditions for animal housing and care should be reported, and we encourage this in our STAR Methods guidelines for all papers. However, moving forward we will require more detailed reporting on dietary information for mouse studies where the main scientific focus concerns stem cell functions, and especially metabolism.

Vitamin D and the nutritional environment in functions of intestinal stem cells: Implications for tumorigenesis and prevention.

Sporadic colon cancer accounts for ∼80% of CRC, with high incidence in western societies strongly linked to dietary patterns. The only mouse model for sporadic CRC results from feeding mice a purified rodent western-style diet (NWD1), establishing mouse intake of several common nutrients that mimic for each its level consumed in western populations at higher risk for colon cancer (higher fat, lower vitamin D, calcium, methyl donors and fiber). This causes sporadic colon and small intestinal tumors at an incidence and frequency similar to that of humans.

The nutritional environment determines which and how intestinal stem cells contribute to homeostasis and tumorigenesis.

Sporadic colon cancer accounts for approximately 80% of colorectal cancer (CRC) with high incidence in Western societies strongly linked to long-term dietary patterns. A unique mouse model for sporadic CRC results from feeding a purified rodent Western-style diet (NWD1) recapitulating intake for the mouse of common nutrient risk factors each at its level consumed in higher risk Western populations. This causes sporadic large and small intestinal tumors in wild-type mice at an incidence and frequency similar to that in humans.

Environmental Impact on Intestinal Stem Cell Functions in Mucosal Homeostasis and Tumorigenesis.

Multiple cell compartments at or near the base of the intestinal crypt have been identified as contributing intestinal stem cells for homeostasis of the rapidly turning over intestinal mucosa and cells that can initiate tumor development upon appropriate genetic changes. There is a strong literature establishing the importance of the frequently dividing Lgr5+ crypt base columnar cells as the fundamental cell in providing these stem cell-associated functions, but there are also clear data that more quiescent cells from other compartments can be mobilized to provide these stem cell functions upon compromise of Lgr5+ cells. We review the data that vitamin D, a pleiotropic hormone, is essential for Lgr5 stem cell functions by signaling through the vitamin D receptor.

Calcium and 1,25-dihydroxyvitamin D3 modulate genes of immune and inflammatory pathways in the human colon: a human crossover trial.

Background: A high dietary calcium intake with adequate vitamin D status has been linked to lower colorectal cancer risk, but the mechanisms of these effects are poorly understood.

Objective: The objective of this study was to elucidate the effects of a Western-style diet (WD) and supplemental calcium and/or 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the colorectal mucosa.

Design: We conducted 2 crossover trials to define molecular pathways in the human colorectum altered by 1) a 4-wk WD supplemented with and without 2 g calcium carbonate/d and 2) a 4-wk WD supplemented with 1,25(OH)2D3 (0.

Real time analysis of metabolic profile in ex vivo mouse intestinal crypt organoid cultures.

The small intestinal mucosa exhibits a repetitive architecture organized into two fundamental structures: villi, projecting into the intestinal lumen and composed of mature enterocytes, goblet cells and enteroendocrine cells; and crypts, residing proximal to the submucosa and the muscularis, harboring adult stem and progenitor cells and mature Paneth cells, as well as stromal and immune cells of the crypt microenvironment. Until the last few years, in vitro studies of small intestine was limited to cell lines derived from either benign or malignant tumors, and did not represent the physiology of normal intestinal epithelia and the influence of the microenvironment in which they reside. Here, we demonstrate a method adapted from Sato et al.

Vitamin D is a determinant of mouse intestinal Lgr5 stem cell functions.

Lgr5+ intestinal crypt base columnar cells function as stem cells whose progeny populate the villi, and Lgr5+ cells in which Apc is inactivated can give rise to tumors. Surprisingly, these Lgr5+ stem cell properties were abrogated by the lower dietary vitamin D and calcium in a semi-purified diet that promotes both genetically initiated and sporadic intestinal tumors. Inactivation of the vitamin D receptor in Lgr5+ cells established that compromise of Lgr5 stem cell function was a rapid, cell autonomous effect of signaling through the vitamin D receptor.

The intestinal epithelial cell differentiation marker intestinal alkaline phosphatase (ALPi) is selectively induced by histone deacetylase inhibitors (HDACi) in colon cancer cells in a Kruppel-like factor 5 (KLF5)-dependent manner.

The histone deacetylase inhibitor (HDACi) sodium butyrate promotes differentiation of colon cancer cells as evidenced by induced expression and enzyme activity of the differentiation marker intestinal alkaline phosphatase (ALPi). Screening of a panel of 33 colon cancer cell lines identified cell lines sensitive (42%) and resistant (58%) to butyrate induction of ALP activity. This differential sensitivity was similarly evident following treatment with the structurally distinct HDACi, MS-275.

Circulating soluble cytokine receptors and colorectal cancer risk.

Background: Soluble cytokine receptors and receptor antagonist of proinflammatory cytokines can modify cytokine signaling and may affect cancer risk.

Methods: In a case-cohort study nested within the Women's Health Initiative cohort of postmenopausal women, we assessed the associations of plasma levels of interleukin (IL)-1 receptor antagonist (IL-1Ra) and the soluble receptors of IL-1 (sIL-1R2), IL-6 (sIL-6R and sgp130), and TNF (sTNFR1 and sTNFR2) with risk of colorectal cancer in 433 cases and 821 subcohort subjects. Baseline levels of estradiol, insulin, leptin, IL-6, and TNF-α measured previously were also available for data analysis.

Mucus enhances gut homeostasis and oral tolerance by delivering immunoregulatory signals.

A dense mucus layer in the large intestine prevents inflammation by shielding the underlying epithelium from luminal bacteria and food antigens. This mucus barrier is organized around the hyperglycosylated mucin MUC2. Here we show that the small intestine has a porous mucus layer, which permitted the uptake of MUC2 by antigen-sampling dendritic cells (DCs).

The effect of lung cancer on cytokine expression in peripheral blood mononuclear cells.

The purpose of this study is to evaluate cytokine expression by peripheral blood mononuclear cells (PBMC) from stage I lung cancer patients and to confirm these expression patterns by exposing PBMCs to lung cancer cells in vitro. Five altered cytokines in stage I lung cancer patients (CCL3, IL8, IL1β, CXCL10, sIL2Rα) were identified in plasma from subjects (n = 15) before and after resection using a 30-plex panel protein assay. Gene expression studies using quantitative RT-qPCR were performed on PBMCs from stage I lung cancer patients (n = 62) before and after resection, and compared to non-cancer patients (n = 32) before and after surgery for benign disease.

Abdominal obesity, independent from caloric intake, accounts for the development of intestinal tumors in Apc(1638N/+) female mice.

To determine whether visceral fat (VF), independent of other confounders, is causally linked to intestinal tumorigenesis, we surgically removed visceral fat in Apc(1638/N+) mice. At 15 weeks of age, male and female Apc(1638/N+) mice were randomized to one of three groups: ad libitum, visceral fat removal (VF-) and ad libitum fed, or caloric restriction, and were studied for effects on tumorigenesis and survival. As compared with ad libitum, VF- and caloric restriction reduced macroadenomas to a similar extent (P < 0.

Dietary cholecalciferol and calcium levels in a Western-style defined rodent diet alter energy metabolism and inflammatory responses in mice.

Male and female C57Bl6 mice were fed a control AIN76A diet, a new Western-style diet (NWD1) reflecting dietary patterns linked to elevated colon cancer incidence (higher fat, lower cholecalciferol, calcium, methyl donors, fiber), or NWD1 with elevated cholecalciferol and calcium (NWD2) from weaning. After 24 wk, serum 25-hydroxyvitamin D [25(OH)D] decreased by >80% in the NWD1 group compared with controls, but with no alteration in serum calcium or bone mineral density. The decreased serum 25(OH)D was prevented in the NWD2 group.

Intrinsic mitochondrial membrane potential and associated tumor phenotype are independent of MUC1 over-expression.

We have established previously that minor subpopulations of cells with stable differences in their intrinsic mitochondrial membrane potential (Δψm) exist within populations of mammary and colonic carcinoma cells and that these differences in Δψm are linked to tumorigenic phenotypes consistent with increased probability of participating in tumor progression. However, the mechanism(s) involved in generating and maintaining stable differences in intrinsic Δψm and how they are linked to phenotype are unclear. Because the mucin 1 (MUC1) oncoprotein is over-expressed in many cancers, with the cytoplasmic C-terminal fragment (MUC1 C-ter) and its integration into the outer mitochondrial membrane linked to tumorigenic phenotypes similar to those of cells with elevated intrinsic Δψm, we investigated whether endogenous differences in MUC1 levels were linked to stable differences in intrinsic Δψm and/or to the tumor phenotypes associated with the intrinsic Δψm.