Assessment of stromal SCD-induced drug resistance of PDAC using 3D-printed zPDX model chips.

Lipid metabolism is extensively reprogrammed in pancreatic ductal adenocarcinoma (PDAC). Stearoyl-coenzyme A desaturase (SCD) is a critical lipid regulator that was unexplored in PDAC. Here, we characterized the existence of cancer-associated fibroblasts (CAFs) with high SCD expression, and revealed them as an unfavorable prognostic factor. Therefore, primary CAFs and pancreatic cancer cells were harvested and genetically labeled. The mixture of CAFs and cancer cells were co-injected into scd-/-; prkdc-/-, or hIGF1/INS-expressing zebrafish to generate patient-derived xenograft models (zPDX). The models were aligned in 3D-printed chips for semi-automatic drug administration and high-throughput scanning. The results showed that chaperoning of the SCD-high CAFs significantly improved the drug resistance of pancreatic cancer cells against gemcitabine and cisplatin, while the administration of SCD inhibitors neutralized the protective effect. Our studies revealed the prognostic and therapeutic value of stromal SCD in PDAC, and proposed the application of zPDX model chips for drug testing.

Evolutionary Trajectories of Primary and Metastatic Pancreatic Neuroendocrine Tumors Based on Genomic Variations.

Liver metastases are common in pancreatic neuroendocrine tumors (PanNETs) patients and they are considered a poor prognostic marker. This study aims to analyze the spatiotemporal patterns of genomic variations between primary and metastatic tumors, and to identify the key related biomolecular pathways. We performed next-generation sequencing on paired tissue specimens of primary PanNETs (n = 11) and liver metastases (n = 12). Low genomic heterogeneity between primary PanNETs and liver metastases was observed. Genomic analysis provided evidence that polyclonal seeding is a prevalent event during metastatic progression, and may be associated with the progression-free survival. Besides this, copy number variations of BRCA1/BRCA2 seem to be associated with better prognosis. Pathways analysis showed that pathways in cancer, DNA repair, and cell cycle regulation-related pathways were significantly enriched in primary PanNETs and liver metastases. The study has shown a high concordance of gene mutations between the primary tumor and its metastases and the shared gene mutations may occur during oncogenesis and predates liver metastasis, suggesting an earlier onset of metastasis in patients with PanNETs, providing novel insight into genetic changes in metastatic tumors of PanNETs.

Subpopulations of cancer-associated fibroblasts link the prognosis and metabolic features of pancreatic ductal adenocarcinoma.

Background: Cancer-associated fibroblasts (CAFs) are a vital constituent of the tumor microenvironment (TME) and have several activities, but the effect of CAF heterogeneity on the molecular features and clinical outcomes of pancreatic ductal adenocarcinoma (PDAC) remains unknown. Methods: An algorithm "scFrac" based on single-cell sequencing data from the Gene Expression Omnibus was introduced to emulate the enrichment of CAF subtypes in a TCGA-PDAC cohort and their prognostic influence, and confirmed by an external validation group (66 patients with PDAC) with multiplex immunohistochemistry staining. A comprehensive analysis including metabolic profile and transcription factor regulon activity was carried out among CAF subtypes. Results: Three distinct CAF populations were confirmed: myofibroblast (myCAF), inflammatory CAF (iCAF), and antigen-presenting CAF (apCAF). These subtypes expressed distinct metabolic profiles and transcriptional regulon activity. KEGG pathway annotation demonstrated that complement and coagulation cascades, as well as cytokine-cytokine receptor interaction were dominant in iCAFs, and pathways related to focal adhesion, and ECM-receptor interaction showed dominance in myCAFs, while antigen processing and presentation were the top enriched pathways in apCAFs. iCAFs trended to glycolysis with CREB3L1, EGR2 and SOX4 activation, whereas myCAFs depend on the tricarboxylic acid cycle and its derivatives with NRF2, CEBPD and YBX1 activation. iCAF is a protective factor associated with an inflammatory phenotype, but myCAF is an important factor in the poor prognosis of PDAC. Conclusions: We identified distinct molecular characteristics of 3 CAF subtypes in PDAC and plotted their metabolism profile. We introduced a novel algorism, scFrac, for exploring how CAF subgroups dysregulate cancer biology, and also shed a new therapeutic light on targeting the CAF subtype in TME.

PLK1/NF-κB feedforward circuit antagonizes the mono-ADP-ribosyltransferase activity of PARP10 and facilitates HCC progression.

Dysregulation of PARP10 has been implicated in various tumor types and plays a vital role in delaying hepatocellular carcinoma (HCC) progression. However, the mechanisms controlling the expression and activity of PARP10 in HCC remain mostly unknown. The crosstalk between PLK1, PARP10, and NF-κB pathway in HCC was determined by performing different in vitro and in vivo assays, including mass spectrometry, kinase, MARylation, chromatin immunoprecipitation, and luciferase reporter measurements. Functional examination was performed by using small chemical drug, cell culture, and mice HCC models. Correlation between PLK1, NF-κB, and PARP10 expression was determined by analyzing clinical samples of HCC patients with using immunohistochemistry. PLK1, an important regulator for cell mitosis, directly interacts with and phosphorylates PARP10 at T601. PARP10 phosphorylation at T601 significantly decreases its binding to NEMO and disrupts its inhibition to NEMO ubiquitination, thereby enhancing the transcription activity of NF-κB toward multiple target genes and promoting HCC development. In turn, NF-κB transcriptionally inhibits the PARP10 promoter activity and leads to its downregulation in HCC. Interestingly, PLK1 is mono-ADP-ribosylated by PARP10 and the MARylation of PLK1 significantly inhibits its kinase activity and oncogenic function in HCC. Clinically, the expression levels of PLK1 and phosphor-p65 show an inverse correlation with PARP10 expression in human HCC tissues. These findings are the first to uncover a PLK1/PARP10/NF-κB signaling circuit that underlies tumorigenesis and validate PLK1 inhibitors, alone or with NF-κB antagonists, as potential effective therapeutics for PARP10-expressing HCC.

Protective Effects of Bone Marrow-Derived Mesenchymal Stem Cells on Insulin Secretion and Inflammation in the Treatment of Severe Acute Pancreatitis in Rats.

OBJECTIVE: The present study aims to demonstrate the protective effect of bone marrow mesenchymal stem cells (bmMSCs) on transplanted islets and its potential therapeutic role of severe acute pancreatitis (SAP) in rat model. MATERIALS AND METHODS: Mesenchymal stem cells (MSCs) were isolated from 6 male SD rats, and were identified. The Islets isolated from 20 SD rats were evenly and randomly divided into co-culture group, and basic culture group (control group), in which the islets were cultured in DMEM/F12 medium, so as to compare the insulin secretion and stimulation index. Severe AP was induced in SD rats by retrograde injection of sodium taurocholate. Ninety rats were randomly and evenly assigned into 5 groups: control group (healthy rats), SAP group, tail vein injection group, intraperitoneal injection group and combined injection (tail vein + intraperitoneal) group. Rats were sacrificed on day 1, 2, and 3. The pancreatic tissues and blood were collected. The plasma levels of IL-10, IL-1ß, TNF-α, IL-6 were determined using ELISA. Pathologic changes of the pancreas were observed using HE staining, and the positioning of DAPI labeled bmMSCs in vivo were detected. RESULTS: Insulin secretion and the stimulation index of co-culture group were significantly higher than those of basic culture group (P < .05), after 7 and 14 days of culture. Inflammation, edema, hemorrhage and necrosis in each model of pancreatitis were reduced significantly in BMMSCs injection group as compared to SAP group (P < .05). Infused BMMSCs through combined injection indicated improved outcome than that of tail-vein injection or intraperitoneal injection alone. CONCLUSION: Co-culture of BMMSCs with transplanted islets prolongs the survival time of islets and maintains in vitro activity. In the rat model of SAP, combined injection of BMMSCs through tail vein and intraperitoneal significantly suppresses the inflammatory reaction and alleviates pancreatic injury in rat SAP model.