Publications by authors named "Nelson J Dusetti"

Background: Pancreatic ductal adenocarcinoma (PDAC) has been widely studied at multiomics level. However, little is known about its specific ubiquitination, a major post-translational modification (PTM). As PTMs regulate the final function of any gene, we decided to establish the ubiquitination profiles of 60 PDAC.

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: Compare pancreatic ductal adenocarcinoma (PDAC), preclinical models, by their transcriptome and drug response landscapes to evaluate their complementarity. : Three paired PDAC preclinical models-patient-derived xenografts (PDX), xenograft-derived pancreatic organoids (XDPO) and xenograft-derived primary cell cultures (XDPCC)-were derived from 20 patients and analyzed at the transcriptomic and chemosensitivity level. Transcriptomic characterization was performed using the basal-like/classical subtyping and the PDAC molecular gradient (PAMG).

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Identifying critical factors involved in the metastatic progression of hepatocellular carcinoma (HCC) may offer important therapeutic opportunities. Here, we report that the proapoptotic stress response factor TP53INP1 is often selectively downregulated in advanced stage IV and metastatic human HCC tumors. Mechanistic investigations revealed that TP53INP1 downregulation in early-stage HCC cells promoted metastasis via DUSP10 phosphatase-mediated activation of the ERK pathway.

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Small noncoding miRNAs represent underexplored targets of genomic aberrations and emerging therapeutic targets. The 3q26.2 amplicon is among the most frequent genomic aberrations in multiple cancer lineages including ovarian and breast cancers.

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Previously, we identified the stress-induced chaperone, Hsp27, as highly overexpressed in castration-resistant prostate cancer and developed an Hsp27 inhibitor (OGX-427) currently tested in phase I/II clinical trials as a chemosensitizing agent in different cancers. To better understand the Hsp27 poorly-defined cytoprotective functions in cancers and increase the OGX-427 pharmacological safety, we established the Hsp27-protein interaction network using a yeast two-hybrid approach and identified 226 interaction partners. As an example, we showed that targeting Hsp27 interaction with TCTP, a partner protein identified in our screen increases therapy sensitivity, opening a new promising field of research for therapeutic approaches that could decrease or abolish toxicity for normal cells.

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Oxidative stress-induced sumoylation of TP53INP1 (tumor protein p53-induced nuclear protein 1) is essential to enhance the TP53 response. Sumoylation of TP53INP1 on the K113 residue, which is mediated by protein inhibitor of activated STAT 3 (PIAS3) and chromobox homolog 4 (CBX4) and removed by SUMO1/sentrin specific peptidase (SENP1, 2 and 6), favors its interaction with TP53 in the nucleus and enhances TP53-induced gene expression.

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Pancreatic ductal adenocarcinoma is one of the most intractable and fatal cancer. The decreased blood vessel density displayed by this tumor not only favors its resistance to chemotherapy but also participates in its aggressiveness due to the consequent high degree of hypoxia. It is indeed clear that hypoxia promotes selective pressure on malignant cells that must develop adaptive metabolic responses to reach their energetic and biosynthetic demands.

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Stress proteins of the pancreas, such as tumor protein 53-induced nuclear protein 1 (TP53INP1), are important factors in the invasion and metastasis of pancreatic cancer. TP53INP1 is a pro-apoptotic factor and is transcriptionally regulated in p53-dependent and -independent manners. A previous study proved that gemcitabine induces TP53INP1 expression in pancreatic cancer cells and the pancreatic cancer cell line (PANC-1).

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Tumor Protein 53-Induced Nuclear Protein 1 (TP53INP1) plays an important role during cell stress response in synergy with the potent "genome-keeper" p53. In human, the gene encoding TP53INP1 is expressed at very high level in some pathological situations, such as inflammation and prostate cancer (PC). TP53INP1 overexpression in PC seems to be a worse prognostic factor, particularly predictive of biological cancer relapse, making TP53INP1 a relevant specific target for molecular therapy of Castration Resistant (CR) PC.

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During the last couple decades, we have significantly advanced our understanding of mechanisms underlying the development of pancreatic ductual adenocarcinoma (PDAC). In the late 1990s into the early 2000s, a model of PDAC development and progression was developed as a multi-step process associated with the accumulation of somatic mutations. The correlation and association of these particular genetic aberrations with the establishment and progression of PDAC has revolutionized our understanding of this process.

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DNA damage triggers a phosphorylation-based signaling cascade known as the DNA damage response. p19INK4d, a member of the INK4 family of CDK4/6 inhibitors, has been reported to participate in the DNA damage response promoting DNA repair and cell survival. Here, we provide mechanistic insight into the activation mechanism of p19INK4d linked to the response to DNA damage.

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Background: Tumor protein 53-induced nuclear protein 1 (TP53INP1) is a proapoptotic protein involved in cell stress response. Whereas there is an overexpression of TP53INP1 in numerous tissues submitted to stress agents, TP53INP1 is down-expressed in stomach, pancreatic, and inflammation-mediated colic carcinomas. In medullary thyroid carcinomas, TP53INP1 overexpression correlates with poor prognosis.

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The p53-transcriptional target TP53INP1 is a potent stress-response protein promoting p53 activity. We previously showed that ectopic overexpression of TP53INP1 facilitates cell cycle arrest as well as cell death. Here we report a study investigating cell death in mice deficient for TP53INP1.

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To further characterize the molecular events supporting the tumor suppressor activity of Scrib in mammals, we aim to identify new binding partners. We isolated MCC, a recently identified binding partner for beta-catenin, as a new interacting protein for Scrib. MCC interacts with both Scrib and the NHERF1/NHERF2/Ezrin complex in a PDZ-dependent manner.

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p53 exerts its tumor suppressor function mainly through transcriptional induction of target genes involved in several processes, including cell cycle checkpoints, apoptosis, and regulation of cell redox status. p53 antioxidant function is dependent on its transcriptional activity and proceeds by sequential induction of antioxidant and proapoptotic targets. However, none of the thus far renowned p53 targets have proved able to abolish on their own the intracellular reactive oxygen species (ROS) accumulation caused by p53 deficiency, therefore pointing to the existence of other prominent and yet unknown p53 antioxidant targets.

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MicroRNAs (miRNAs) are small non-coding RNAs 19-24 nucleotides in length that regulate gene expression of target genes by translational repression. They regulate crucial processes such as development, proliferation, apoptosis, stress response and differentiation. Recent reports support a role for miRNAs in the initiation and progression of human malignancies; in particular, aberrant expression of miRNAs can contribute to carcinogenesis by promoting the expression of proto-oncogenes or by inhibiting the expression of tumor suppressor genes.

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Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease that shows minimal response to chemotherapy. Genetic changes involved in the progression of PDAC concern genes that encode proteins related to signal transduction networks. This fact reveals the importance in identifying the role and the relations between multiple signaling cascades in PDAC.

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Pancreatic cancer is a disease with an extremely poor prognosis. Tumor protein 53-induced nuclear protein 1 (TP53INP1) is a proapoptotic stress-induced p53 target gene. In this article, we show by immunohistochemical analysis that TP53INP1 expression is dramatically reduced in pancreatic ductal adenocarcinoma (PDAC) and this decrease occurs early during pancreatic cancer development.

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TP53INP1 is an alternatively spliced gene encoding two nuclear protein isoforms (TP53INP1alpha and TP53INP1beta), whose transcription is activated by p53. When overexpressed, both isoforms induce cell cycle arrest in G1 and enhance p53-mediated apoptosis. TP53INP1s also interact with the p53 gene and regulate p53 transcriptional activity.

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We describe the cloning and expression of the mouse gene interferon-inducible-protein 15 (IP15), whose activation is related to the acute phase of experimental pancreatitis. Analysis of its structure indicates that it encodes a putative transmembrane protein of 137 amino acids. This gene contains a predicted IFN-stimulable-response element.

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The TP53INP1 gene encodes two protein isoforms, TP53INP1alpha and TP53INP1beta, located into the nucleus. Their synthesis is increased during cellular stress by p53-mediated activation of transcription. Overexpression of these isoforms induces apoptosis, suggesting an involvement of TP53INP1s in p53-mediated cell death.

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The mouse stress-induced protein (SIP) mRNA is activated in the pancreas with acute pancreatitis and in several cell lines in response to various stress agents. The SIP gene is alternatively spliced, generating two proteins (SIP'8 and SIP27). Both proteins, located mainly in the nucleus, promote cell death when overexpressed in vitro.

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To characterize the emergency program set up by pancreatic cells in response to pancreatitis, we established the phenotype of the pancreatitis-affected pancreas by characterizing a large number of its transcripts. In this report, we describe the cloning, sequencing, and expression pattern of a new gene, named VMP1 (vacuole membrane protein 1). The VMP1 mRNA codes for a putative protein of 406 amino acids.

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