Project description:Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and heterogeneous tumors presenting a wide spectrum of different clinical and biological characteristics. In these tumors, the histological evaluation is a crucial element of clinical management. Currently, tumor grading, determined by Ki-67 staining and mitotic counts, is the most reliable predictor of prognosis. This scoring method is time-consuming and a high reproducibility cannot be achieved. Novel approaches are needed to support histological evaluation and prognosis. In this study, starting from a microarray analysis, we defined the miRNAs signature for poorly differentiated NETs (G3) compared to well differentiated NETs (G1 and G2) consisting of 56 deregulated miRNAs. Moreover, we identified 8 miRNAs that were expressed in all GEP-NETs grades but at different level. Among these miRNAs, we found miR-96-5p that raised its expression levels from grade 1 to grade 3; inversely, its target FOXO1 was decrease from grade 1 to grade 3. Our results reveal that the miRNAs expression profile of GEP-NET correlates their expression with grading showing a potential advantage of miRNA quantification to aid clinicians in the classification of common GEP-NETs subtypes.
Project description:The aggressive clinical behavior of mantle cell lymphoma (MCL) is attributed to specific genetic and molecular mechanisms involved in its pathogenesis, mainly the t(11;14)(q13;q32) traslocation and cyclin D1 (CCND1) overexpression. Nevertheless, evidence of a certain degree of heterogeneity has been disclosed by gene expression profile (GEP) and (immuno)genetic/immunohistochemistry studies. AIM: To use a GEP approach in MCL cell line models.
Project description:GEP of the murine cell line BAL17 (BALB/c) BAL17- / BAL17VII-induced primary CNS lymphoma analysis. 5x10^5 cells were implanted into the brain of BALB/c wt mice and analyzed 21 and 28 days post implantation. The cell lines were also analyzed.
Project description:Expression profile of human GEP-NET tumors, including 113 fresh frozen biopsies of primary and metastatic tumours originating from pancreas (P-NET, 83 primary and 30 metastasis), 81 from small intestine (SI-NET, 44 primary and 37 metastasis), and 18 from rectum (RE-NET, 3 primary and 15 metastasis).
Project description:Somatostatin receptors are overexpressed in GEP-NETs and can be visualized in vivo by radiolabeled somatostatin-analogs.
During the last decades, conventional scintigraphy using 111In-DTPA-Octreotide (often named somatostatin receptor scintigraphy or SRS) was considered as the gold standard nuclear imaging technique in the evaluation of GEP-NETs. However, SRS may be suboptimal in this clinical setting because of the low intrinsic resolution of the technique and its selectivity for SST2 only. Its overall sensitivity is estimated to 60-70% (per lesion analysis), even when using the most recent SPECT-CT cameras. MRI have also a higher sensitivity than CT and SRS for the detection of liver metastases from GEP-NETs.
In recent years, positron emission tomography (PET) imaging, a high resolution and sensitive technology, has gained an increasing role in oncology. It has also been evaluated in GEP-NETs with somatostatin agonists (SSTa) radiolabelled with Gallium-68 [68Ga], a positron emitter with very promising results. Its diagnostic sensitivity is clearly superior to SRS and many European centers have already replaced SRS by [68Ga]-PET-SSTa.
Currently, three different [68Ga]-coupled peptides can be used in trials: DOTA-TOC, DOTA-TATE and DOTA-NOC with excellent affinities for SST2 (IC50: 2.5; 0.2 and 1.9 nM, respectively). Sensitivities of DOTA-TOC and DOTA-TATE PET/CT are quite similar.
[68Ga]-DOTANOC which also binds to SST5 was recently found to detect significantly more lesions than the SST2-specific radiotracer [68Ga]-DOTATATE in patients with GEP-NETs but this requires further evaluation.
It is therefore important to determine the interest of [68Ga]-DOTANOC combined with the standard diagnosis strategy in GEP-NETs and evaluate medicoeconomic impact of adding [68Ga]-DOTANOC in the work-up of patients.
The investigators hypothesis is that [68Ga]-DOTANOC will modify the management in at least 20% of patients in a more adapted way according to the 2012 ENETS guidelines in comparison to the decision based on the standard imaging work up (multiphasic WB CT, liver MRI and SRS).
110 patients will be included prospectively in 5 different French experienced centers (Marseille, Bordeaux, Toulouse, Paris, Clermond-Ferrand).
Project description:In this work, we compared gene expression profile (GEP) of K562 cells transduced with the retroviral vector LCALRins5IDN or LCALRdel52IDN with K562 cells transduced with LwtCALRIDN In order to unravel MPL-independent mechanisms underlying the effect of CALR mutations on MPN pathogenesis, we analysed the transcriptional changes induced by the CALRins5 or CALRdel52 overexpression in K562 cells, which lack MPL expression
Project description:Collagen, the most abundant organic compound of vertebrate organisms, is a supramolecular protein-made polymer. Details of its subtle post-translational maturation largely determine the mechanical properties of connective tissues. Its assembly requires massive, heterogeneous prolyl-4-hydroxylation (P4H), catalyzed by Prolyl-4-hydroxylases (P4HA1-3), providing thermostability to its elemental, triple helical building block. So far, there was no evidence of tissue-specific regulation of P4H, nor of a differential substrate repertoire of P4HAs. Here, the positional P4H profiles of collagen extracted from bone, skin, and tendon were compared, revealing lower hydroxylation of most GEP/GDP motifs in the tendon, across homeotherms. P4HA2 mRNA was found low in tendon. Invalidation of P4HA2, unlike decreased, generalized P4H activity, in the ATDC5 cellular model of collagen assembly, mimicked the tendon-related P4H profile. Therefore, P4HA2 has a better ability than other P4HAs to hydroxylate GEP/GDP motifs and the differential expression of P4HAs in tissues dictates the positional P4H profile of collagen, which participates in determining tissue specificities of its assembly.