Inverse correlation between PD-L1 expression and LGR5 expression in tumor budding of stage II/III colorectal cancer
Annals of Diagnostic Pathology
Sato, K;Uehara, T;Nakajima, T;Iwaya, M;Miyagawa, Y;Watanabe, T;Ota, H;
| DOI: 10.1016/j.anndiagpath.2021.151739
We investigated the expression of LGR5, the most robust and reliable known cancer stem cell (CSC) marker of colorectal cancer, and PD-L1 in tumor budding (TB), as well as clinicopathological features. Tissue microarrays (TMAs) were generated from TB samples from 32 stage II/III colorectal adenocarcinoma patients, and LGR5 expression in TMAs was evaluated by RNAscope, an extremely sensitive RNA in situ hybridization technique. LGR5 expression was significantly lower in the PD-L1-positive group than in the PD-L1-negative group (P = 0.0256). In the PD-L1-positive group, the tumor-infiltrating lymphocytes (TILs) score tended to be higher while the TNM stage was lower compared with the PD-L1 negative group (P = 0.0822 and P = 0.0765, respectively). There was no significant difference in Overall Survival between the PD-L1-positive and PD-L1-negative groups (log-rank test, P = 0.8218). This study showed that PD-L1-positive patients are a unique population with low LGR5 expression, and that LGR5-positive cells may be a promising therapeutic target in PD-L1-negative patients.
Expression profile of intestinal stem cell and cancer stem cell markers in gastric cancers with submucosal invasion
Pathology, research and practice
Kim, HS;Song, HJ;Kim, HU;Jeong, IH;Koh, HM;Shin, JH;Jang, BG;
PMID: 33450435 | DOI: 10.1016/j.prp.2020.153336
Cancer stem cells (CSCs) are believed to be responsible for tumor growth, invasion, and metastasis. Submucosal invasion, which greatly enhances metastasis risk, is a critical step in gastric cancer (GC) progression. To identify stem cell-related markers associated with submucosal invasion and lymph node (LN) metastasis in GCs, we investigated the expression of candidate CSC markers (CD133, CD44, and ALDH1A) and intestinal stem cell (ISC) markers (EPHB2, OLFM4, and LGR5) in early GCs that manifested submucosal invasion. We discovered that EPHB2 and LGR5 expression was frequently confined to the basal area of the lamina propria (basal pattern) in mucosal cancer, and the proportion of stem cell marker-positive cells substantially increased during submucosal invasion. CD44 expression showed a focal pattern, ALDH1A was predominantly expressed diffusely, and there was no expansion of CD44 or ALDH1A expression in the submucosal cancer cells. Unexpectedly, no CSC markers showed any associations with LN metastasis, and only loss of EPHB2 expression was associated with increased LN metastasis. Treatment of RSPO2, a niche factor, along with Wnt 3a, to GC cells led to increased EPHB2 and LGR5 mRNA levels. RNA in situ hybridization confirmed specific RSPO2 expression in the smooth muscle cells of the muscularis mucosa, suggesting that RSPO2 is responsible for the increased expression of ISC markers in GC cells at the basal areas. In summary, no stem cell markers were associated with increased LN metastasis in early GCs. Conversely, isolated EPHB2 expression was associated with lower LN metastasis. EPHB2 and LGR5 showed a basal distribution pattern along with enhanced expression in submucosal invading cells in early GCs, which was induced by a niche factor, RSPO2, from the muscularis mucosa.
Pereira B, Amaral AL, Dias A, Mendes N, Muncan V, Silva AR, Thibert C, Radu AG, David L, M�ximo V, van den Brink GR, Billaud M, Almeida R
PMID: 32052574 | DOI: 10.15252/embr.201948938
Intestinal stem cells (ISCs) fuel the lifelong self-renewal of the intestinal tract and are paramount for epithelial repair. In this context, the Wnt pathway component LGR5 is the most consensual ISC marker to date. Still, the effort to better understand ISC identity and regulation remains a challenge. We have generated a Mex3a knockout mouse model and show that this RNA-binding protein is crucial for the maintenance of the Lgr5+ ISC pool, as its absence disrupts epithelial turnover during postnatal development and stereotypical organoid maturation ex vivo. Transcriptomic profiling of intestinal crypts reveals that Mex3a deletion induces the peroxisome proliferator-activated receptor (PPAR) pathway, along with a decrease in Wnt signalling and loss of the Lgr5+ stem cell signature. Furthermore, we identify PPAR? activity as a molecular intermediate of MEX3A-mediated regulation. We also show that high PPAR? signalling impairs Lgr5+ ISC function, thus uncovering a new layer of post-transcriptional regulation that critically contributes to intestinal homeostasis
Overexpression of Cancer-Associated Stem Cell Gene OLFM4 in the Colonic Epithelium of Patients With Primary Sclerosing Cholangitis
Inflammatory bowel diseases
Neyazi, M;Bharadwaj, SS;Bullers, S;Varenyiova, Z;Oxford IBD Cohort Study Investigators, ;Travis, S;Arancibia-Cárcamo, CV;Powrie, F;Geremia, A;
PMID: 33570127 | DOI: 10.1093/ibd/izab025
To examine immune-epithelial interactions and their impact on epithelial transformation in primary sclerosing cholangitis-associated ulcerative colitis (PSC-UC) using patient-derived colonic epithelial organoid cultures (EpOCs). The EpOCs were originated from colonic biopsies from patients with PSC-UC (n = 12), patients with UC (n = 14), and control patients (n = 10) and stimulated with cytokines previously associated with intestinal inflammation (interferon (IFN) γ and interleukin (IL)-22). Markers of cytokine downstream pathways, stemness, and pluripotency were analyzed by real-time quantitative polymerase chain reaction and immunofluorescence. The OLFM4 expression in situ was assessed by RNAscope and immunohistochemistry. A distinct expression of stem cell-associated genes was observed in EpOCs derived from patients with PSC-UC, with lower expression of the classical stem-cell marker LGR5 and overexpression of OLFM4, previously associated with pluripotency and early stages of neoplastic transformation in the gastrointestinal and biliary tracts. High levels of OLFM4 were also found ex vivo in colonic biopsies from patients with PSC-UC. In addition, IFNγ stimulation resulted in the downregulation of LGR5 in EpOCs, whereas higher expression of OLFM4 was observed after IL-22 stimulation. Interestingly, expression of the IL-22 receptor, IL22RA1, was induced by IFNγ, suggesting that a complex interplay between these cytokines may contribute to carcinogenesis in PSC-UC. Higher expression of OLFM4, a cancer stemness gene induced by IL-22, is present in PSC-UC, suggesting that IL-22 responses may result in alterations of the intestinal stem-cell niche in these patients.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Schaaf, CR;Polkoff, KM;Carter, A;Stewart, AS;Sheahan, B;Freund, J;Ginzel, J;Snyder, JC;Roper, J;Piedrahita, JA;Gonzalez, LM;
PMID: 37159340 | DOI: 10.1096/fj.202300223R
Intestinal epithelial stem cells (ISCs) are responsible for intestinal epithelial barrier renewal; thereby, ISCs play a critical role in intestinal pathophysiology research. While transgenic ISC reporter mice are available, advanced translational studies lack a large animal model. This study validates ISC isolation in a new porcine Leucine Rich Repeat Containing G Protein-Coupled Receptor 5 (LGR5) reporter line and demonstrates the use of these pigs as a novel colorectal cancer (CRC) model. We applied histology, immunofluorescence, fluorescence-activated cell sorting, flow cytometry, gene expression quantification, and 3D organoid cultures to whole tissue and single cells from the duodenum, jejunum, ileum, and colon of LGR5-H2B-GFP and wild-type pigs. Ileum and colon LGR5-H2B-GFP, healthy human, and murine biopsies were compared by mRNA fluorescent in situ hybridization (FISH). To model CRC, adenomatous polyposis coli (APC) mutation was induced by CRISPR/Cas9 editing in porcine LGR5-H2B-GFP colonoids. Crypt-base, green fluorescent protein (GFP) expressing cells co-localized with ISC biomarkers. LGR5-H2B-GFPhi cells had significantly higher LGR5 expression (p < .01) and enteroid forming efficiency (p < .0001) compared with LGR5-H2B-GFPmed/lo/neg cells. Using FISH, similar LGR5, OLFM4, HOPX, LYZ, and SOX9 expression was identified between human and LGR5-H2B-GFP pig crypt-base cells. LGR5-H2B-GFP/APCnull colonoids had cystic growth in WNT/R-spondin-depleted media and significantly upregulated WNT/β-catenin target gene expression (p < .05). LGR5+ ISCs are reproducibly isolated in LGR5-H2B-GFP pigs and used to model CRC in an organoid platform. The known anatomical and physiologic similarities between pig and human, and those shown by crypt-base FISH, underscore the significance of this novel LGR5-H2B-GFP pig to translational ISC research.
A constant pool of Lgr5+ intestinal stem cells is required for intestinal homeostasis
Tan, SH;Phuah, P;Tan, LT;Yada, S;Goh, J;Tomaz, LB;Chua, M;Wong, E;Lee, B;Barker, N;
PMID: 33503423 | DOI: 10.1016/j.celrep.2020.108633
Lgr5+ crypt base columnar cells, the operational intestinal stem cells (ISCs), are thought to be dispensable for small intestinal (SI) homeostasis. Using a Lgr5-2A-DTR (diphtheria toxin receptor) model, which ablates Lgr5+ cells with near-complete efficiency and retains endogenous levels of Lgr5 expression, we show that persistent depletion of Lgr5+ ISCs in fact compromises SI epithelial integrity and reduces epithelial turnover in vivo. In vitro, Lgr5-2A-DTR SI organoids are unable to establish or survive when Lgr5+ ISCs are continuously eliminated by adding DT to the media. However, transient exposure to DT at the start of culture allows organoids to form, and the rate of outgrowth reduces with the increasing length of DT presence. Our results indicate that intestinal homeostasis requires a constant pool of Lgr5+ ISCs, which is supplied by rapidly reprogrammed non-Lgr5+ crypt populations when preexisting Lgr5+ ISCs are ablated.
New Stable Cell Lines Derived from the Proximal and Distal Intestine of Rainbow Trout (Oncorhynchus mykiss) Retain Several Properties Observed In Vivo
Pasquariello, R;Verdile, N;Pavlovic, R;Panseri, S;Schirmer, K;Brevini, TAL;Gandolfi, F;
PMID: 34205481 | DOI: 10.3390/cells10061555
We derived two novel cell lines from rainbow trout (RT) proximal (RTpi-MI) and distal intestine (RTdi-MI) and compared them with the previously established continuous cell line RTgutGC. Intestinal stem cells, differentiating and differentiated epithelial cells, and connective cells were found in all cell lines. The cell lines formed a polarized barrier, which was not permeable to large molecules and absorbed proline and glucose. High seeding density induced their differentiation into more mature phenotypes, as indicated by the downregulation of intestinal stem cell-related genes (i.e., sox9, hopx and lgr5), whereas alkaline phosphatase activity was upregulated. Other enterocyte markers (i.e., sglt1 and pept1), however, were not regulated as expected. In all cell lines, the presence of a mixed population of epithelial and stromal cells was characterized for the first time. The expression by the stromal component of lgr5, a stem cell niche regulatory molecule, may explain why these lines proliferate stably in vitro. Although most parameters were conserved among the three cell lines, some significant differences were observed, suggesting that characteristics typical of each tract are partly conserved in vitro as well.
ZNRF3 and RNF43 cooperate to safeguard metabolic liver zonation and hepatocyte proliferation
Sun, T;Annunziato, S;Bergling, S;Sheng, C;Orsini, V;Forcella, P;Pikiolek, M;Kancherla, V;Holwerda, S;Imanci, D;Wu, F;Meylan, LC;Puehringer, LF;Waldt, A;Oertli, M;Schuierer, S;Terracciano, LM;Reinker, S;Ruffner, H;Bouwmeester, T;Sailer, AW;George, E;Roma, G;de Weck, A;Piscuoglio, S;Lohmann, F;Naumann, U;Liberali, P;Cong, F;Tchorz, JS;
PMID: 34129813 | DOI: 10.1016/j.stem.2021.05.013
AXIN2 and LGR5 mark intestinal stem cells (ISCs) that require WNT/β-Catenin signaling for constant homeostatic proliferation. In contrast, AXIN2/LGR5+ pericentral hepatocytes show low proliferation rates despite a WNT/β-Catenin activity gradient required for metabolic liver zonation. The mechanisms restricting proliferation in AXIN2+ hepatocytes and metabolic gene expression in AXIN2+ ISCs remained elusive. We now show that restricted chromatin accessibility in ISCs prevents the expression of β-Catenin-regulated metabolic enzymes, whereas fine-tuning of WNT/β-Catenin activity by ZNRF3 and RNF43 restricts proliferation in chromatin-permissive AXIN2+ hepatocytes, while preserving metabolic function. ZNRF3 deletion promotes hepatocyte proliferation, which in turn becomes limited by RNF43 upregulation. Concomitant deletion of RNF43 in ZNRF3 mutant mice results in metabolic reprogramming of periportal hepatocytes and induces clonal expansion in a subset of hepatocytes, ultimately promoting liver tumors. Together, ZNRF3 and RNF43 cooperate to safeguard liver homeostasis by spatially and temporally restricting WNT/β-Catenin activity, balancing metabolic function and hepatocyte proliferation.
Epithelium-derived Indian Hedgehog restricts stromal expression of ErbB family members that drive colonic tumor cell proliferation
Westendorp, F;Karpus, ON;Koelink, PJ;Vermeulen, JLM;Meisner, S;Koster, J;Büller, NVJA;Wildenberg, ME;Muncan, V;van den Brink, GR;
PMID: 33479497 | DOI: 10.1038/s41388-020-01633-0
Indian Hedgehog (Ihh) is a morphogen expressed by epithelial cells in the small intestine and colon that signals in a paracrine manner to gp38+ stromal cells. The loss of Ihh signaling results in increased epithelial proliferation, lengthening and multiplication of intestinal crypts and the activation of a stromal cell immune response. How Ihh controls epithelial proliferation through the stroma and how it affects colorectal cancer development remains poorly defined. To study the influence of Ihh signaling on the earliest stage of colorectal carcinogenesis, we used a well characterized mouse model in which both alleles of the Adenoma Polyposis Coli (Apc) gene could be inducibly deleted, leading to instant transformation of the colonic epithelium to an adenomatous phenotype. Concurrent deletion of Ihh from the adenomatous colonic epithelium of Apc inducible double mutant mice resulted in a remarkable increase in the hyperproliferative epithelial phenotype and increased accumulation of Lgr5+ stem cells. Transcriptional profiling of sorted colonic gp38+ fibroblasts showed upregulation of three ErbB pathway ligands (EREG, BTC, and NRG1) in Apc-/-Ihh-/- double mutant mice. We found that recombinant EREG, BTC, and NRG1 but not Lgr5 ligand R-Spondin promoted growth and proliferation of Apc double mutant colonic organoids. Thus, the loss of Ihh enhances Apc-driven colonic adenomagenesis via upregulation of ErbB pathway family members in colonic stromal cells. Our findings highlight the critical role of epithelium-derived Indian Hedgehog as a stromal tumor suppressor in the intestine.