Project description:Pancreatic Ductal Adenocarcinoma (PDA) is a critical health issue in cancer field with little new therapeutic options. Several evidences support an implication of intra-tumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within pathophysiology and clinical course of PDA, mainly through tumor recurrence and neuropathic pain, remains unknown neglecting a putative therapeutic window. Here, we report that intra-tumoral microenvironment is a mediator of PDA Associated Neural Remodeling (PANR). With laser capture microdissection of stromal/tumoral compartment from human PDA followed by cDNA based microarray analyses we highlighted numerous factors expressed by stromal compartment that could impact on neuroplastic changes; among them, the Slit2/Robo axon guidance pathway. Using co-culture in vitro, we showed that stromal secreted Slit2 increases DRG neurite outgrowth and Schwann cells migration/proliferation by modulating N-Cadherin/β-Catenin signaling. Importantly, Slit2/Robo signaling inhibition disrupts this stromal/neural connection. Finally, we revealed in vivo that Slit2 expression is correlated with neural remodeling within Human and mouse PDA. These results demonstrate the implication of microenvironment, through secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of stromal/neural compartment dialogue by using Slit2/Robo pathway inhibitors for treatment of pancreatic cancer recurrence and associated pain.
Project description:Pancreatic Ductal Adenocarcinoma (PDA) is a critical health issue in cancer field with little new therapeutic options. Several evidences support an implication of intra-tumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within pathophysiology and clinical course of PDA, mainly through tumor recurrence and neuropathic pain, remains unknown neglecting a putative therapeutic window. Here, we report that intra-tumoral microenvironment is a mediator of PDA Associated Neural Remodeling (PANR). With laser capture microdissection of stromal/tumoral compartment from human PDA followed by cDNA based microarray analyses we highlighted numerous factors expressed by stromal compartment that could impact on neuroplastic changes; among them, the Slit2/Robo axon guidance pathway. Using co-culture in vitro, we showed that stromal secreted Slit2 increases DRG neurite outgrowth and Schwann cells migration/proliferation by modulating N-Cadherin/β-Catenin signaling. Importantly, Slit2/Robo signaling inhibition disrupts this stromal/neural connection. Finally, we revealed in vivo that Slit2 expression is correlated with neural remodeling within Human and mouse PDA. These results demonstrate the implication of microenvironment, through secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of stromal/neural compartment dialogue by using Slit2/Robo pathway inhibitors for treatment of pancreatic cancer recurrence and associated pain. Freshly frozen tissue samples of PDACs were obtained from patients who underwent surgery. Patients underwent hemipancreaticoduodenectomy or distal pancreatectomy. No distant metastases were revealed at initial diagnosis. Histological examination confirmed diagnosis of PDAC in all cases. Prior to surgery all patients had signed an informed consent form that had been approved by the local ethics committee. Frozen sections were obtained from tissue samples of three tumors. After a brief staining sections were dehydrated and epithelial and stromal compartment has been microdissected using the PALM system. The microdissected material was immediately dissolute in a buffer containing β-mercaptoethanol and RNA carrier, and frozen before RNA extraction. Fifteen ug of total RNA was converted to biotinylated cRNA and hybridised to a human oligonucleotide array U133 Plus 2.0 (Genechip, Affymetrix, Santa Clara, CA).
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.