Limitation and challenges in using pancreatic cancer-derived organoids as a preclinical tool

Pancreatic ductal adenocarcinoma (PDAC) is a dismaldisease with a fast evolution and unpredictable treatmentresponse. Nowadays, FOLFIRINOX and gemcitabine are the preferred treatments with a response rateof 33% and 11%, respectively. This poor patient responsehas been associated with an inefficient/non-personalizedtreatment allocation. Consequently, developing a rapidand efficient preclinical tool to test tumor drug sensitivityfor each patient is hugely needed. Biopsy patient-derivedorganoid (PDO) appears to be a promising tool for devel-oping individualized treatments for patients with PDAC.Several PDO-based platforms are in development world-wide as a guide to optimize therapy by directing tailored treatments.Fil: Fraunhoffer Navarro, Nicolas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Aix-Marseille University; FranciaFil: Abuelafia, Analía Meilerman. Aix-Marseille University; FranciaFil: Dusetti, Nelson. Aix-Marseille University; FranciaFil: Iovanna, Juan Lucio. Aix-Marseille University; Franci

Expression of POU2F3 Transcription Factor Control Inflammation, Immunological Recruitment and Metastasis of Pancreatic Cancer in Mice

International audienceTUFT cells have been described as strong modulators of inflammatory cells in several tissues including pancreas. TUFT cells, also known as DCLK1+ cells, are dependent of the transcriptional factor POU2F3. Several works report DCLK1+ cells in early stages of PDAC development suggesting an important role of TUFT cells in PDAC development. Therefore, we developed a mice model (PDX1-Cre;KrasG12D;Ink4afl/fl), known as PKI model, deficient or not of POU2F3. In this animal model, deficiency of POU2F3 results in the absence of TUFT cells in PDAC as expected. Although, tumor development and growth are not significantly influenced, the development of liver metastasis was almost completely inhibited in POU2F3-deficient mice. Surprisingly, the absence of metastasis was associated with a higher expression of epithelial-to-mesenchymal transition markers, but to a lower inflammatory microenvironment suggesting that inflammation influences metastasis production more than epithelial-to-mesenchymal transition in this animal model. We can conclude that POU2F3 could be a new therapeutic target for control PDAC progression

Targeting REG3β limits pancreatic ductal adenocarcinoma progression through CTGF downregulation

The crosstalk between the transformed tumoral cells and their microenvironment is a key aspect for pancreatic ductal adenocarcinoma (PDAC) progression. This molecular dialog is intensively studied because it may result in an efficient therapeutic target. Contrary to this near microenvironment, the stromal portion in direct contact with the transformed cells, a far microenvironment, placed at the periphery of the tumor mass, produces factors signaling tumors. Among these factors, REG3β, produced by this part of the pancreas, is an important factor in promoting tumor progression. This paper demonstrated that targeting REG3β protein with specific antibodies limits the PDAC tumor growth in an orthotopic, syngeneic mice model induced by injection of Panc02 cells. Then, we showed that CTGF is over-expressed in response to REG3β in PDAC-derived cells. Moreover, inactivation of REG3β by treating tumors with anti-REG3β antibodies results in a strong decrease of CTGF in PDAC tumors. Lastly, we demonstrated that forced expression of CTGF in xenografted Panc02 cells abolishes the therapeutic effect of the anti-REG3β antibody treatment. Altogether, these results indicate that the effect of REG3β in promoting PDAC progression is mediated by CTGF over-activation. Thus, REG3β is a promising therapeutic target to treat PDAC with an original rationale. In conclusion, we demonstrated that the far microenvironment is essential for PDAC progression by producing active secretory factors, and some of them could be used as therapeutic targets.This work was supported by La Ligue Contre le Cancer, INCa, Canceropole PACA, and INSERM

Long-term apoptosis-related protein expression in the diabetic mouse ovary.

Emerging evidence has shown that oocytes from diabetic ovaries exhibit delayed maturation, mitochondrial dysfunction and meiotic defects, which are related increased apoptosis. The main objective of the present study was to analyze the apoptosis pathways activated during follicular loss at multiple time points in a diabetic mouse model. Twenty BALB/c mice were used in this study, and diabetes mellitus was induced by streptozotocin injection. Three diabetic and two control animals were sacrificed on days 15, 20, 70 and 80 posttreatment. The ovaries were then removed; one was used for follicular counting, TUNEL, immunohistochemistry and immunofluorescence, while the other was used for Western blot analysis. The proteins studied were BAX, BCL2, t-BID, FAS, FASL, active caspase 8, active caspase 9 and active caspase 3. Follicular apoptosis decreased over time, with the highest values observed at 15 days posttreatment. Granulosa cells were positive for active caspase 3, which showed constant expression levels at all time points. FAS, FASL, t-BID and active caspase 8 showed strong cytoplasmic immunostaining in the oocytes and granulosa cells of the diabetic mice, with significant increases observed at 15, 20 and 70 days posttreatment. BAX expression was slightly higher in the diabetic mouse ovaries than in the control ovaries at 15, 20 and 70 days posttreatment, whereas the highest active caspase 9 expression was at observed 20 days posttreatment. Low BCL2 protein levels were detected in the diabetic mouse ovaries at all time points. This study describes for the first time the behavior of apoptosis-related proteins in the diabetic mouse ovary and shows not only that the FAS/FASL pathway contributes to follicular loss but also that antral follicles are the most affected

Priming therapy by targeting enhancer-initiated pathways in patient-derived pancreatic cancer cells

International audienceBACKGROUND: Systems biology leveraging multi-OMICs technologies, is rapidly advancing development of precision therapies and matching patients to targeted therapies, leading to improved responses. A new pillar of precision oncology lies in the power of chemogenomics to discover drugs that sensitizes malignant cells to other therapies. Here, we test a chemogenomic approach using epigenomic inhibitors (epidrugs) to reset patterns of gene expression driving the malignant behavior of pancreatic tumors. METHODS: We tested a targeted library of ten epidrugs targeting regulators of enhancers and super-enhancers on reprogramming gene expression networks in seventeen patient-derived primary pancreatic cancer cell cultures (PDPCCs), of both basal and classical subtypes. We subsequently evaluated the ability of these epidrugs to sensitize pancreatic cancer cells to five chemotherapeutic drugs that are clinically used for this malignancy. FINDINGS: To comprehend the impact of epidrug priming at the molecular level, we evaluated the effect of each epidrugs at the transcriptomic level of PDPCCs. The activating epidrugs showed a higher number of upregulated genes than the repressive epidrugs (χ(2) test p-value <0.01). Furthermore, we developed a classifier using the baseline transcriptome of epidrug-primed-chemosensitized PDPCCs to predict the best epidrug-priming regime to a given chemotherapy. Six signatures with a significant association with the chemosensitization centroid (R ≤ -0.80; p-value < 0.01) were identified and validated in a subset of PDPCCs. INTERPRETATION: We conclude that targeting enhancer-initiated pathways in patient-derived primary cells, represents a promising approach for developing new therapies for human pancreatic cancer. FUNDING: This work was supported by INCa (Grants number 2018-078 to ND and 2018- 079 to JI), Canceropole PACA (ND), Amidex Foundation (ND), and INSERM (JI)