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Biology subjects

Lulka, H.

Publications and source records attributed to Lulka, H..

4 recordsLinked to original sources

Minute virus of mice is oncolytic for pancreatic cancer cells with mesenchymal phenotype

Pancreatic cancer will soon become the second cause of death by cancer in Western countries. The main barrier to increase the survival of patients with this disease requires the development of novel and efficient therapeutic strategies, that better consider tumor biology. Oncolytic viruses are quickly moving toward the forefront of medicines for the management of cancer. Among them, the fibrotropic minute virus of mice prototype (MVMp) preferentially infects migrating and undifferentiated cells, that highly resemble poorly differentiated, basal-like, pancreatic tumors showing the worst clinical outcome. Thus, we hypothesized that MVMp may specifically target the most aggressive subtype of pancreatic cancer cells. We report here that MVMp specifically infects, replicates in and kills pancreatic cancer cells from murine and human origin with a mesenchymal, basal-like profile, while sparing cancer cells with an epithelial phenotype. In vivo, MVMp shows oncolytic activity in experimental tumors with mesenchymal phenotype only, and shows increased antitumoral efficacy in immune competent models. Collectively, we demonstrate herein for the first time that MVMp is specific and oncolytic for pancreatic tumors with mesenchymal, basal-like profile, paving the way for precision medicine opportunities for the management of the most aggressive and lethal form of this disease.

cancer biology↗

The Loss of the E3 ubiquitin ligase TRIP12 inhibits Pancreatic Acinar Cell Plasticity and Tumor Cell Metastatic Capacity

Background & AimsAlthough specialized and dedicated to the production of digestive enzymes, pancreatic acinar cells harbor a high plasticity and are able to modify their identity. They undergo reversible acinar-to-ductal cell metaplasia (ADM) through epigenetic silencing of the acinar lineage gene program mainly controlled by PTF1a (Pancreas Transcription Factor 1a). ADM becomes irreversible in the presence of oncogenic Kras mutations and leads to the formation of preneoplastic lesions. We investigated the role of the E3 ubiquitin ligase Thyroid hormone Receptor Interacting Protein 12 (TRIP12), involved in PTF1a degradation, in pancreatic carcinogenesis. MethodsWe used genetically engineered mouse models of pancreas-selective Trip12 deletion, mutant Kras (G12D) and mutant Trp53 (R172H). We performed RNA sequencing analysis from acinar cells and cell lines derived from mice models tumors. We investigated the impact of TRIP12 deficiency on acute pancreatitis, tumor formation and metastasis development. ResultsTRIP12 is overexpressed in human pancreatic preneoplastic lesions and tumors. We show that a conditional deletion of TRIP12 in the pancreas during murine embryogenesis alters pancreas homeostasis and acinar cell genes expression patterns in adults. EGF induced-ADM is suppressed in TRIP12-depleted pancreatic acini. In vivo, a loss of TRIP12 prevents acini to develop ADM in response to pancreatic injury, the formation of Kras-induced pancreatic preneoplastic lesions, and impairs tumors and metastasis formation in the presence of mutated Trp53. TRIP12 is required for Claudin18.2 isoform expression in pancreatic tumors cells. ConclusionsOur study identifies TRIP12 as a novel regulator of acinar fate in the adult pancreas with an important dual role in pancreatic carcinogenesis, in initiation steps and in metastatic behavior of tumor cells. SynopsisThis study shows that Thyroid hormone Receptor Interacting Protein 12 plays an important dual role in the initiation steps and invasion of pancreatic carcinogenesis. Moreover, expression of TRIP12 switches on the expression of Claudin-18, a targetable biomarker of pancreatic tumors.

cancer biology↗

Preclinical development of non-viral gene therapy for patients with advanced pancreatic cancer

Pancreatic ductal adenocarcinoma remains one of the greatest challenges in oncology for which therapeutic intervention is urgently needed. We demonstrated that the intratumoral gene transfer of somatostatin receptor 2, to combat tumor aggressiveness, or of deoxycytidine kinase and uridylate monophosphate kinase, to sensitize to gemcitabine chemotherapy, has antitumoral potential. Here, we describe the development of CYL-02 non-viral gene-therapy product, that comprises a DNA-plasmid encoding for the three aforementioned genes complexed with PolyEthylEnimine (22 kDa). In this work, we performed preclinical toxicology, biodistribution and therapeutic activity studies of CYL-02 in experimental models of pancreatic cancer. We demonstrated the safety of CYL-02 and defined the maximal tolerated dose in two animal species. CYL-02 co-administrated with gemcitabine did not increase gemcitabine toxicity. Biodistribution studies revealed that CYL-02 is rapidly cleared from blood following intravenous administration, and sequestered in tumors following intratumoral injection. CYL-02 drives the expression of therapeutic genes in cancer cells and strongly sensitizes tumor cells to gemcitabine, with significant inhibition of tumor cells dissemination. This study was instrumental for the later use of CYL-02 in patients with advanced pancreatic cancer, demonstrating that rigorous and thorough preclinical investigations are informative for the clinical transfer of gene therapy against pancreatic cancer. GRAPHICAL ABSTRACT

cancer biology↗

The antitumoral activity of TLR7 ligands is corrupted by the microenvironment of pancreatic tumors

Toll like receptors are key players in the innate immune system. Recent studies have suggested that they may impact the growth of pancreatic cancer, a disease with no cure. Among them, Toll like receptor-7 shows promise for therapy but may also promote tumor growth. Thus, we aimed to better understand the mechanism of action of Toll like receptor-7 ligands in pancreatic cancer, to open the door for clinical applications. In vitro, Toll like receptor-7 ligands strongly inhibit the proliferation and induce cell death by apoptosis of pancreatic cancer cells. In vivo, while Toll like receptor-7 agonists significantly delay the growth of aggressive tumors engrafted in immunodeficient mice, they instead surprisingly promote tumor growth and accelerate animal death in immunocompetent models. Molecular investigations revealed that Toll like receptor-7 agonists strongly increase the number of tumor-promoting macrophages to drive pancreatic tumorigenesis in immunocompetent mice. This is in stark contrast with Toll like receptor-7 ligands great potential to inhibit pancreatic cancer cell proliferation in vitro and tumor growth in vivo in immunosuppressed models. Collectively, our findings shine a light on the duality of action of Toll like receptor-7 agonists in experimental cancer models, and calls into question their use for pancreatic cancer therapy.

cancer biology↗