Gastrointestinal cancer-associated fibroblasts expressing Junctional Adhesion Molecule-A are amenable to infection by oncolytic reovirus.

Gastrointestinal (GI) cancers are characterized by extensive tumor stroma that both promotes tumor progression and acts as a physical barrier for adjacent tumor cells, limiting the effect of current treatment modalities. Oncolytic virotherapy is currently investigated in clinical trials as a novel therapeutic agent for different malignancies of the GI tract, but it is largely unknown whether these viruses can also target the tumor stroma. Here, we investigated the tropism of two commonly studied OVs, adenovirus and reovirus, towards primary GI fibroblasts from human oesophageal, gastric, duodenal and pancreatic carcinomas (N = 36).

Targeting pancreatic cancer by TAK-981: a SUMOylation inhibitor that activates the immune system and blocks cancer cell cycle progression in a preclinical model.

Objective: Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all forms of chemotherapy and immunotherapy, leading to a 5-year survival rate of 9%. Our study aims to add novel small molecule therapeutics for the treatment of PDAC.

Design: We have studied whether TAK-981, a novel highly selective and potent small molecule inhibitor of the small ubiquitin like modifier (SUMO) activating enzyme E1 could be used to treat a preclinical syngeneic PDAC mouse model and we have studied the mode of action of TAK-981.

Targeting Endoglin Expressing Cells in the Tumor Microenvironment Does Not Inhibit Tumor Growth in a Pancreatic Cancer Mouse Model.

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal forms of cancer and is known to have low immunogenicity and an immunosuppressive microenvironment. It is also characterized by high accumulation of dense stroma, composed of mostly cancer-associated fibroblasts (CAFs). Multiple subsets of CAFs are described, with one of them expressing the transforming growth factor (TGF)-β co-receptor endoglin.

Adenoviral vaccines promote protective tissue-resident memory T cell populations against cancer.

Background: Adenoviral vectors emerged as important platforms for cancer immunotherapy. Vaccination with adenoviral vectors is promising in this respect, however, their specific mechanisms of action are not fully understood. Here, we assessed the development and maintenance of vaccine-induced tumor-specific CD8 T cells elicited upon immunization with adenoviral vectors.

Targeting Endoglin-Expressing Regulatory T Cells in the Tumor Microenvironment Enhances the Effect of PD1 Checkpoint Inhibitor Immunotherapy.

Purpose: Endoglin is a coreceptor for TGFβ ligands that is highly expressed on proliferating endothelial cells and other cells in the tumor microenvironment. Clinical studies have noted increased programmed cell death (PD)-1 expression on cytotoxic T cells in the peripheral blood of patients with cancer treated with TRC105, an endoglin-targeting antibody. In this study, we investigated the combination of endoglin antibodies (TRC105 and M1043) with an anti-PD1 antibody.

Endoglin: Beyond the Endothelium.

endoglin; CD105 TGF-β; BMP9; ALK-1; TRC105; tumor microenvironment.

Bidirectional tumor/stroma crosstalk promotes metastasis in mesenchymal colorectal cancer.

Patients with the mesenchymal subtype colorectal cancer (CRC) have a poor prognosis, in particular patients with stroma-rich tumors and aberrant SMAD4 expression. We hypothesized that interactions between SMAD4-deficient CRC cells and cancer-associated fibroblasts provide a biological explanation. In transwell invasion assays, fibroblasts increased the invasive capacity of SMAD4-deficient HT29 CRC cells, but not isogenic SMAD4-proficient HT29 cells.

Tumor-draining lymph nodes are pivotal in PD-1/PD-L1 checkpoint therapy.

PD-1/PD-L1 checkpoint therapy for cancer is commonly considered to act by reactivating T cells in the tumor microenvironment. Here, we present data from 2 mouse tumor models demonstrating an essential involvement of tumor-draining lymph nodes in PD-1 and PD-L1 therapeutic efficacy. Immune activation induced by checkpoint treatment was predominantly observed in the tumor-draining, but not nondraining, lymph nodes and was reflected in local accumulation of CD8+ T cells.

Mesenchymal stromal cells prevent progression of liver fibrosis in a novel zebrafish embryo model.

Chronic liver damage leads to the onset of fibrogenesis. Rodent models for liver fibrosis have been widely used, but are less suitable for screening purposes. Therefore the aim of our study was to design a novel model for liver fibrosis in zebrafish embryos, suitable for high throughput screening.

Endoglin Expression on Cancer-Associated Fibroblasts Regulates Invasion and Stimulates Colorectal Cancer Metastasis.

Purpose: Cancer-associated fibroblasts (CAF) are a major component of the colorectal cancer tumor microenvironment. CAFs play an important role in tumor progression and metastasis, partly through TGF-β signaling pathway. We investigated whether the TGF-β family coreceptor endoglin is involved in CAF-mediated invasion and metastasis.

Endoscopic Administration of Mesenchymal Stromal Cells Reduces Inflammation in Experimental Colitis.

Background: Mesenchymal stromal cells (MSCs) are a potential therapeutic modality in inflammatory bowel diseases (IBDs) because of their immunomodulatory and regenerative properties. However, when injected systemically, only a small portion of the cells, if any, reach the inflamed colon. In this study, we assessed whether endoscopic injections of MSCs into the intestinal wall of the inflamed colon affect the course of experimental colitis.

Combined inhibition of CDK and HDAC as a promising therapeutic strategy for both cutaneous and uveal metastatic melanoma.

Very little to no improvement in overall survival has been seen in patients with advanced non-resectable cutaneous melanoma or metastatic uveal melanoma in decades, highlighting the need for novel therapeutic options. In this study we investigated as a potential novel therapeutic intervention for both cutaneous and uveal melanoma patients a combination of the broad spectrum HDAC inhibitor quisinostat and pan-CDK inhibitor flavopiridol. Both drugs are currently in clinical trials reducing time from bench to bedside.

PD-L1 expression on malignant cells is no prerequisite for checkpoint therapy.

Immunotherapy with PD-1/PD-L1-blocking antibodies is clinically effective for several tumor types, but the mechanism is not fully understood. PD-L1 expression on tumor biopsies is generally regarded as an inclusion criterion for this cancer therapy. Here, we describe the PD-L1-blocking therapeutic responses of preclinical tumors in which PD-L1 expression was removed from cancer cells, but not from immune infiltrate.

Parenteral monofluorophosphate (MFP) is a more potent inducer of enamel fluorotic defects in neonatal hamster molars than sodium fluoride.

Supra-optimal intake of sodium fluoride (NaF) during early childhood results in formation of irreversible enamel defects. Monofluorophosphate (MFP) was considered as less toxic than NaF but equally cariostatic. We compared the potency of MFP and NaF to induce pre-eruptive sub-ameloblastic cysts and post-eruptive white spots and pits in developing hamster enamel.