Cellular and molecular gastroenterology and hepatology
Kim, TY;Kim, S;Kim, Y;Lee, YS;Lee, S;Lee, SH;Kweon, MN;
PMID: 34971821 | DOI: 10.1016/j.jcmgh.2021.12.015
Dietary signals are known to modulate stemness and tumorigenicity of intestinal progenitors; however, the impact of a high-fat diet (HFD) on the intestinal stem cell (ISC) niche and its association with colorectal cancer remains unclear. Thus, we aimed to investigate how a HFD affects the ISC niche and its regulatory factors.Mice were fed a purified diet (PD) or HFD for 2 months. The expression levels of ISC-related markers, ISC-supportive signals, and Wnt2b were assessed with real-time quantitative polymerase chain reaction, in situ hybridization, and immunofluorescence staining. RNA sequencing and metabolic function were analyzed in mesenchymal stromal cells (MSCs) from PD- and HFD-fed mice. Fecal microbiota were analyzed by 16s rRNA sequencing. Bile salt hydrolase activity and bile acid (BA) levels were measured.We found that expression of CD44 and Wnt signal-related genes was higher in the colonic crypts of HFD-fed mice than in those fed a PD. Within the ISC niche, MSCs were expanded and secreted predominant levels of Wnt2b in the colon of HFD-fed mice. Of note, increased energy metabolism and cancer-associated fibroblast (CAF)-like properties were found in the colonic MSCs of HFD-fed mice. Moreover, colonic MSCs from HFD-fed mice promoted the growth of tumorigenic properties and accelerated the expression of cancer stem cell (CSC)-related markers in colon organoids. In particular, production of primary and secondary BAs was increased through the expansion of bile salt hydrolase-encoding bacteria in HFD-fed mice. Most importantly, BAs-FXR interaction stimulated Wnt2b production in colonic CAF-like MSCs.HFD-induced colonic CAF-like MSCs play an indispensable role in balancing the properties of CSCs through activation of the BAs-FXR axis.
Experimental eye research
Bonnet, C;Ruiz, M;Gonzalez, S;Tseng, CH;Bourges, JL;Behar-Cohen, F;Deng, SX;
PMID: 36702232 | DOI: 10.1016/j.exer.2022.109337
Limbal epithelial stem/progenitor cells (LSCs) are adult stem cells located at the limbus, tightly regulated by their close microenvironment. It has been shown that Wnt signaling pathway is crucial for LSCs regulation. Previous differential gene profiling studies confirmed the preferential expression of specific Wnt ligands (WNT2, WNT6, WNT11, WNT16) and Wnt inhibitors (DKK1, SFRP5, WIF1, FRZB) in the limbal region compared to the cornea. Among all frizzled receptors, frizzled7 (Fzd7) was found to be preferentially expressed in the basal limbal epithelium. However, the exact localization of Wnt signaling molecules-producing cells in the limbus remains unknown. The current study aims to evaluate the in situ spatial expression of these 4 Wnt ligands, 4 Wnt inhibitors, and Fzd7. Wnt ligands, DKK1, and Fzd7 expression were scattered within the limbal epithelium, at a higher abundance in the basal layer than the superficial layer. SFRP5 expression was diffuse among the limbal epithelium, whereas WIF1 and FRZB expression was clustered at the basal limbal epithelial layer corresponding to the areas of high levels of Fzd7 expression. Quantitation of the fluorescence intensity showed that all 4 Wnt ligands, 3 Wnt inhibitors (WIF1, DKK1, FRZB), and Fzd7 were highly expressed at the basal layer of the limbus, then in a decreasing gradient toward the superficial layer (P < 0.05). The expression levels of all 4 Wnt ligands, FRZB, and Fzd7 in the basal epithelial layer were higher in the limbus than the central cornea (P < 0.05). All 4 Wnt ligands, 4 Wnt inhibitors, and Fzd7 were also highly expressed in the limbal stroma immediately below the epithelium but not in the cornea (P < 0.05). In addition, Fzd7 had a preferential expression in the superior limbus compared to other quadrants (P < 0.05). Taken together, the unique expression patterns of the Wnt molecules involved in the limbus suggests the involvement of both paracrine and autocrine effects in LSCs regulation, and a fine balance between Wnt activators and inhibitors to govern LSC fate.
Xue T, Wang WG, Zhou XY, Li XQ.
PMID: - | DOI: 10.1016/j.pathol.2018.08.011
Summary Programmed cell death ligand 1 (PD-L1) is upregulated in various types of haematological malignancies and is associated with immunosuppression. This study aimed to investigate the expression pattern of PD-L1 in Epstein–Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL). We retrospectively analysed clinicopathological characteristics in 30 cases of EBV-positive DLBCL and immunohistochemically evaluated the level of membrane bound PD-L1 protein. Twenty-eight cases expressed PD-L1 protein 15 of which showed an intense positive staining. In addition, we investigated the relationships between PD-L1 protein and PD-L1 mRNA and MYC, respectively. The expression level of PD-L1 protein was not fully parallel with PD-L1 mRNA, and no significant correlation was observed between PD-L1 protein and MYC. Notably, PD-L1 mRNA was at a low dosage, which indicated that there might be other mechanisms inducing the overexpression of membrane bound PD-L1 protein apart from genetic alterations. Furthermore, the low expression level of MYC may not interfere with the PD-L1 protein expression in EBV-positive DLBCL. In conclusion, overexpression of PD-L1 protein can be observed in EBV-positive DLBCL, and the level was non-parallel with both PD-L1 mRNA and MYC. Moreover, we emphasise that immunohistochemistry is a clinically reasonable method for screening formalin fixed, paraffin embedded (FFPE) tumour samples in this entity.
Guo L, Li W, Zhu X, Ling Y, Qiu T, Dong L, Fang Y, Yang H, Ying J.
PMID: 27390646 | DOI: 10.1186/s40064-016-2513-x
Abstract
PURPOSE:
To estimate the therapeutic potential of PD-L1 inhibition in breast cancer, we evaluated the prevalence and significance of PD-L1 protein expression with a validated antibody and CD274 gene alternation in a large cohort of triple negative breast cancer (TNBC) and correlated with clinicopathological data and patients overall survival.
METHODS:
Immunohistochemistry and in situ mRNA hybridization was used to detect PD-L1 protein and mRNA expression in tumor tissues from 183 TNBC patients respectively. Fluorescence in situ hybridization analysis was performed on PD-L1 strong expression samples to assess copy number on chromosome 9p24.1 of CD274 gene.
RESULTS:
Expression of PD-L1 by immune cells was observed in 4.9 % of TNBC, while expression by tumor cells accounted for 8.7 %. There was a high concordance in PD-L1 protein expression and PDL1 mRNA expression. Samples with PD-L1 strong expression were found to have a CD274 gene copy number gain. PD-L1 expression was correlated with higher tumor grade, but was independent of menopausal status, lymph nodes metastasis, histological subtype and tumor size. In addition, we used precise stratification of PD-L1 expression on tumor or immune cells of certain breast cancer subtype and suggested that patients with PD-L1 expression in basal-like tumors by immune cells or with CD274 gene copy number gain had a longer disease-specific overall survival.
CONCLUSIONS:
Our findings may promote the more precise analysis of PD-L1 expression in breast cancer and aid the selection of patients who may benefit from immune therapy.
Licenziato, L;Minoli, L;Ala, U;Marconato, L;Fanelli, A;Giannuzzi, D;De Maria, R;Iussich, S;Orlando, G;Bertoni, F;Aresu, L;
PMID: 36951124 | DOI: 10.1177/03009858231162209
Canine diffuse large B-cell lymphoma (cDLBCL) is characterized by high mortality and clinical heterogeneity. Although chemo-immunotherapy improves outcome, treatment response remains mainly unpredictable. To identify a set of immune-related genes aberrantly regulated and impacting the prognosis, we explored the immune landscape of cDLBCL by NanoString. The immune gene expression profile of 48 fully clinically characterized cDLBCLs treated with chemo-immunotherapy was analyzed with the NanoString nCounter Canine IO Panel using RNA extracted from tumor tissue paraffin blocks. A Cox proportional-hazards model was used to design a prognostic gene signature. The Cox model identified a 6-gene signature (IL2RB, BCL6, TXK, C2, CDKN2B, ITK) strongly associated with lymphoma-specific survival, from which a risk score was calculated. Dogs were assigned to high-risk or low-risk groups according to the median score. Thirty-nine genes were differentially expressed between the 2 groups. Gene set analysis highlighted an upregulation of genes involved in complement activation, cytotoxicity, and antigen processing in low-risk dogs compared with high-risk dogs, whereas genes associated with cell cycle were downregulated in dogs with a lower risk. In line with these results, cell type profiling suggested the abundance of natural killer and CD8+ cells in low-risk dogs compared with high-risk dogs. Furthermore, the prognostic power of the risk score was validated in an independent cohort of cDLBCL. In conclusion, the 6-gene-derived risk score represents a robust biomarker in predicting the prognosis in cDLBCL. Moreover, our results suggest that enhanced tumor antigen recognition and cytotoxic activity are crucial in achieving a more effective response to chemo-immunotherapy.
Filley A, Henriquez M, Bhowmik T, Tewari BN, Rao X, Wan J, Miller MA, Liu Y, Bentley RT, Dey M.
PMID: 29330750 | DOI: 10.1007/s11060-018-2753-4
Malignant glioma (MG), the most common primary brain tumor in adults, is extremely aggressive and uniformly fatal. Several treatment strategies have shown significant preclinical promise in murine models of glioma; however, none have produced meaningful clinicalresponses in human patients. We hypothesize that introduction of an additional preclinical animal model better approximating the complexity of human MG, particularly in interactions with host immune responses, will bridge the existing gap between these two stages of testing. Here, we characterize the immunologic landscape and gene expression profiles of spontaneous canine glioma and evaluate its potential for serving as such a translational model. RNA in situ hybridization, flowcytometry, and RNA sequencing were used to evaluate immune cell presence and gene expression in healthy and glioma-bearing canines. Similar to human MGs, canine gliomas demonstrated increased intratumoral immune cell infiltration (CD4+, CD8+ and CD4+Foxp3+ T cells). The peripheral blood of glioma-bearing dogs also contained a relatively greater proportion of CD4+Foxp3+ regulatory T cells and plasmacytoid dendritic cells. Tumors were strongly positive for PD-L1 expression and glioma-bearing animals also possessed a greater proportion of immune cells expressing the immune checkpoint receptors CTLA-4 and PD-1. Analysis of differentially expressed genes in our canine populations revealed several genetic changes paralleling those known to occur in human disease. Naturally occurring canine glioma has many characteristics closely resembling human disease, particularly with respect to genetic dysregulation and host immune responses to tumors, supporting its use as a translational model in the preclinical testing of prospective anti-glioma therapies proven successful in murine studies.
Coppock JD, Volaric AK, Mills AM, Gru AA.
PMID: 30075155 | DOI: 10.1016/j.humpath.2018.07.025
Targeted inhibition of programmed cell death-1 (PD-1) and its ligand (PD-L1) has emerged as first-line therapy for advanced non-small cell lung cancer. While patients with high PD-L1 expression have improved outcomes with anti-PD-1/PD-L1 directed therapies, use as a predictive biomarker is complicated by robust responses in some patients with low-level expression. Furthermore, reported PD-L1 levels in lung cancers vary widely and discrepancies exist with different antibodies. PD-L1 expression was thus compared by immunohistochemistry (IHC) versus RNA in situ hybridization (ISH) in 112 lung cancers by tissue microarray: 51 adenocarcinoma, 42 squamous cell carcinoma, 9 adenosquamous carcinoma, 5 carcinoid, 3 undifferentiated large-cell carcinoma, 1 large-cell neuroendocrine carcinoma, and 1 small cell carcinoma. At least 1% tumor cell staining was considered positive in each modality. A positive concordance of only 60% (67/112) was found between IHC and ISH. 50% (56/112) were positive by IHC and 50% (56/112) by ISH, however 20% (22/112) were ISH positive but IHC negative. Conversely, 21% (23/112) were IHC positive but ISH negative. There was no significant stratification of PD-L1 positivity by histologic subtype. A trend of more PD-L1 positive stage I cancers identified by ISH versus IHC was observed, however was not statistically significant [50% (27/54) by IHC and 64% (35/55) by ISH, P=.18]. No significant difference in survival was identified, with an average of 5.3months in IHC versus 5.2months in ISH positive cases. The results demonstrate discordance between PD-L1 RNA levels and protein expression in non-small cell lung cancers, warranting comparison as predictive biomarkers.
Wu S, Shi X, Sun J, Liu Y, Luo Y, Liang Z, Wang J, Zeng X.
PMID: 28145884 | DOI: 10.18632/oncotarget.14851
Abstract
BACKGROUND:
Lung adenocarcinoma (AD) is a common variant of non-small cell lung cancer (NSCLC). Programmed cell death protein 1/programmed cell death ligand 1 (PD1/PD-L1) are promising immunotherapy targets and its expression may be an important biomarker of predicting clinical response. In this study, we evaluated PD-L1 expression in conjunction with clinicopathological characteristics and outcomes in resected lung adenocarcinoma.
RESULTS:
This study included 133 cases of lung adenocarcinoma. PD-L1 expression rate in lung adenocarcinoma was 16.5% at the mRNA level and 13.5% at the protein level, and the kappa coefficient of the two examination methods was 0.824 (P = 0.219, highly correlated). PD-L1 was highly expressed in male patients and smokers with lung adenocarcinoma (P = 0.019 and 0.002, respectively), while no associations were identified between PD-L1 expression and age, tumor size, clinical stage, positive pleural invasion, lymph node metastasis, or therapy methods. Overexpression of PD-L1 was a significant indicator of shorter recurrence free survival time and overall survival (P = 0.000 and 0.000, respectively). Multivariate analysis revealed that PD-L1 expression was an independent risk factor for poor recurrence free survival and overall survival (P = 0.009 and 0.016, respectively).
MATERIALS AND METHODS:
Expression of PD-L1 was examined with immunohistochemistry, using the VENTANA PD-L1 (SP263) rabbit monoclonal antibody. mRNA levels of PD-L1 were evaluated using in situ hybridization.
CONCLUSIONS:
PD-L1 overexpression is more frequently observed in male patients and smokers in lung adenocarcinoma. PD-L1 expression is an indicator of worse prognosis in surgically resected lung adenocarcinoma patients.
Veterinary immunology and immunopathology
Murphy, JD;Shiomitsu, K;Milner, RJ;Lejeune, A;Ossiboff, RJ;Gell, JC;Axiak-Bechtel, S;
PMID: 36804838 | DOI: 10.1016/j.vetimm.2023.110560
Histiocytic sarcoma (HS) is an aggressive malignant neoplasm in dogs. Expression and prognostic significance of transforming growth factor beta (TGF-β), programmed death-ligand 1 (PD-L1), and T regulatory cells (Tregs) in HS is unknown. The goal of this study was to investigate the expression and prognostic significance of TGF-β, PD-L1, and FoxP3/CD25 in canine HS utilizing RNA in situ hybridization (RNAscope ). After validation was performed, RNAscope on formalin-fixed paraffin-embedded (FFPE) patient HS tissue samples was performed for all targets and expression quantified with HALO software image analysis. Cox proportional hazard model was conducted to investigate the association between survival time and each variable. Additionally, for categorical data, the Kaplan-Meier product-limit method was used to generate survival curves. TGF-β and PD-L1 mRNA expression was confirmed in the DH82 cell line by reverse transcription polymerase chain reaction (RT-PCR) and CD25 + FoxP3 + cells were detected by flow cytometry in peripheral blood. Once the RNAscope method was validated, TGF-β H-score and dots/cell and FoxP3 dots/cell were assessed in HS samples and found to be significantly correlated with survival. Moderate positive correlations were found between FoxP3 and PD-L1 H-score, percent staining area, and dots/cell, and FoxP3 and TGF-β dots/cell. In summary, RNAscope is a valid technique to detect TGF-β and PD-L1 expression and identify Tregs in canine HS FFPE tissues. Furthermore, canine HS expresses TGF-β and PD-L1. Increased TGF-β and FoxP3 correlated with worse prognosis. Prospective studies are warranted to further investigate TGF-β, PD-L1, and Tregs effect on prognosis.
Cellular and molecular gastroenterology and hepatology
Zhu, S;Rao, X;Qian, Y;Chen, J;Song, R;Yan, H;Yang, X;Hu, J;Wang, X;Han, Z;Zhu, Y;Liu, R;Jong-Leong Wong, J;McCaughan, GW;Zheng, X;
PMID: 35202885 | DOI: 10.1016/j.jcmgh.2022.02.010
The liver has complex interconnecting blood vessel and biliary networks, however how the vascular and biliary network form and regulate each other and liver function are not well understood. We aimed to examine the role of Heg in mammalian liver development and functional maintenance.Global (Heg-/-) or liver endothelial cell-specific deletion of Heg (Lyve1-Cre;Hegfl/fl ) mice were used to study the in vivo function of Heg in the liver. Carbon-ink anterograde and retrograde injection were used to visualize the 3-D patterning of liver portal and biliary networks, respectively. RNA sequencing, histology, molecular and biochemical assays were used to assess liver gene expression, protein distribution, liver injury response and function.Heg deficiency in liver endothelial cells led to a sparse liver vascular and biliary network. This network paucity does not compromise liver function under baseline conditions but did alter liver zonation. Molecular analysis revealed that endothelial Heg deficiency decreased expression of Wnt ligands/agonists including Wnt2, Wnt9b and Rspo3 in endothelial cells, which limits Axin2 mediated canonical Wnt signaling and the expression of cytochrome P450 enzymes in hepatocytes. Under chemical-induced stressed conditions, Heg-deficiency in liver endothelial cells protected mice from drug-induced liver injuries.Our study found that endothelial Heg is essential for the 3-D patterning of the liver vascular and indirectly regulates biliary networks and proper liver zonation via its regulation of Wnt ligand production in liver endothelial cells. The endothelial Heg-initiated changes of the liver metabolic zonation and metabolic enzyme expression in hepatocytes was functionally relevant to xenobiotic metabolism and drug induced liver toxicity.
Tretiakova M, Fulton R, Kocherginsky M, Long T, Ussakli C, Antic T, Gown A.
PMID: 29271413 | DOI: 10.1038/modpathol.2017.188
Therapy with anti-PD-L1 immune check-point inhibitors is approved for several cancers, including advanced urothelial carcinomas. PD-L1 prevalence estimates vary widely in bladder cancer, and lack of correlation between expression and clinical outcomes and immunotherapyresponse may be attributed to methodological differences of the immunohistochemical reagents and procedures. We characterized PD-L1 expression in 235 urothelial carcinomas including 79 matched pairs of primary and metastatic cancers using a panel of four PD-L1 immunoassays in comparison with RNAscope assay using PD-L1-specific probe (CD274). The antibody panel included three FDA-approved clones (22C3 for pembrolizumab, 28.8 for nivolumab, SP142 for atezolizumab), and a commonly used clone E1L3N. Manual scoring of tissue microarrays was performed in each of 235 tumors (624 tissue cores) and compared to an automated image analysis. Expression of PD-L1 in tumor cells by ≥1 marker was detected in 41/142 (28.9%) primary tumors, 13/77 (16.9%) lymph nodes, and 2/16 (12.5%) distant metastases. In positive cases, high PD-L1 expression (>50% cells) was detected in 34.1% primary and 46.7% metastases. Concordant PD-L1 expression status was present in 71/79 (89.9%) cases of matched primary and metastatic urothelial carcinomas. PD-L1 sensitivity ranked from highest to lowest as follows: RNAscope, clone 28.8, 22C3, E1L3N, and SP142. Pairwise concordance correlation coefficients between the four antibodies in 624 tissue cores ranged from 0.76 to 0.9 for tumor cells and from 0.30 to 0.85 for immune cells. RNA and protein expression levels showed moderate to high agreement (0.72-0.87). Intra-tumor expression heterogeneity was low for both protein and RNA assays (interclass correlation coefficients: 0.86-0.94). Manual scores were highly concordant with automated Aperio scores (0.94-0.97). A significant subset of 56/235 (23.8%) urothelial carcinomas stained positive for PD-L1 with high concordance between all four antibodies and RNA ISH assay. Despite some heterogeneity in staining, the overall results are highly concordant suggesting diagnostic equivalence of tested assays.
Journal of Oncology (2018)
Humphries MP, Hynes S, Bingham V, Cougot D, James J, Patel-Socha F, Parkes EE, Blayney JK, Rorke MA, Irwin GW, McArt DG, Kennedy RD, Mullan PB, McQuaid S, Salto-Tellez M, Buckley NE.
| DOI: 10.1155/2018/2937012
The role of PD-L1 as a prognostic and predictive biomarker is an area of great interest. However, there is a lack of consensus on how to deliver PD-L1 as a clinical biomarker. At the heart of this conundrum is the subjective scoring of PD-L1 IHC in most studies to date. Current standard scoring systems involve separation of epithelial and inflammatory cells and find clinical significance in different percentages of expression, e.g., above or below 1%. Clearly, an objective, reproducible and accurate approach to PD-L1 scoring would bring a degree of necessary consistency to this landscape. Using a systematic comparison of technologies and the application of QuPath, a digital pathology platform, we show that high PD-L1 expression is associated with improved clinical outcome in Triple Negative breast cancer in the context of standard of care (SoC) chemotherapy, consistent with previous findings. In addition, we demonstrate for the first time that high PD-L1 expression is also associated with better outcome in ER- disease as a whole including HER2+ breast cancer. We demonstrate the influence of antibody choice on quantification and clinical impact with the Ventana antibody (SP142) providing the most robust assay in our hands. Through sampling different regions of the tumour, we show that tumour rich regions display the greatest range of PD-L1 expression and this has the most clinical significance compared to stroma and lymphoid rich areas. Furthermore, we observe that both inflammatory and epithelial PD-L1 expression are associated with improved survival in the context of chemotherapy. Moreover, as seen with PD-L1 inhibitor studies, a low threshold of PD-L1 expression stratifies patient outcome. This emphasises the importance of using digital pathology and precise biomarker quantitation to achieve accurate and reproducible scores that can discriminate low PD-L1 expression.
