The WSB1 Gene Is Involved in Pancreatic Cancer Progression

Pancreatic cancer cells generate metastases because they can survive the stress imposed by the new environment of the host tissue. To mimic this process, pancreatic cancer cells which are not stressed in standard culture conditions are injected into nude mice. Because they develop xenografts, they should have developed adequate stress response. Characterizing that response might provide new strategies to interfere with pancreatic cancer metastasis.In the human pancreatic cancer cell lines Panc-1, Mia-PaCa2, Capan-1, Capan-2 and BxPC3, we used Affymetrix DNA microarrays to compare the expressions of 22.000 genes in vitro and in the corresponding xenografts. We identified 228 genes overexpressed in xenografts and characterized the implication of one of them, WSB1, in the control of apoptosis and cell proliferation. WSB1 generates 3 alternatively spliced transcripts encoding distinct protein isoforms. In xenografts and in human pancreatic tumors, global expression of WSB1 mRNA is modestly increased whereas isoform 3 is strongly overexpressed and isoforms 1 and 2 are down-regulated. Treating Mia-PaCa2 cells with stress-inducing agents induced similar changes. Whereas retrovirus-forced expression of WSB1 isoforms 1 and 2 promoted cell growth and sensitized the cells to gemcitabine- and doxorubicin-induced apoptosis, WSB1 isoform 3 expression reduced cell proliferation and enhanced resistance to apoptosis, showing that stress-induced modulation of WSB1 alternative splicing increases resistance to apoptosis of pancreatic cancer cells.Data on WSB1 regulation support the hypothesis that activation of stress-response mechanisms helps cancer cells establishing metastases and suggest relevance to cancer development of other genes overexpressed in xenografts

Recherche de gènes de réponse au stress et leur implication dans les pathologies pancréatiques

Le laboratoire étudie les mécanismes de réponse au stress au cours des maladies pancréatiques, en particulier l adénocarcinome et la pancréatite aiguë. Nous pensons qu une cellule cancéreuse ne formera une métastase que si elle est capable de résister au stress induit par le nouvel environnement auquel elle sera exposée. Pour identifier les gènes impliqués dans ce mécanisme, nous avons injecté des lignées pancréatiques chez la souris nude et sélectionné les gènes surexprimés dans les xénogreffes. Parmi ceux-ci figure le gène WSB1 dont l expression des trois isoformes est modulée, non seulement dans les xénogreffes mais aussi in vitro en réponse au stress. Son originalité vient du fait que l expression est régulée par une réorientation majeure de l épissage alternatif en faveur de l isoforme 3. Cela a pour effet de ralentir la prolifération cellulaire mais aussi de faciliter la résistance à l apoptose induite par deux agents de himiothérapie, ce qui pourrait contribuer à la progression des tumeurs pancréatiques. L analyse de l expression des trois isoformes dans des adénocarcinomes pancréatiques humains supporte cette idée puisque l isoforme 3 y est largement prédominante. Un second projet concerne la relation entre autophagie et pancréatite aiguë. La pancréatite est associée à des modifications morphologiques ressemblant à des vacuoles autophagiques. Nous avons montré que VMP1, protéine induite au cours de la pancréatite aiguë, ainsi que TP53INP2 (paralogue de TP53INP1 également induite au cours de la pancréatite), sont nécessaires à la formation des vacuoles autophagiques. Ces observations suggèrent une implication de l autophagie dans le développement de la pancréatite.The main objective of our laboratory is to study stress response mechanisms during pancreatic disease, especially pancreatic adenocarcinoma and acute pancreatitis. We made the hypothesis that pancreatic cancer metastases occur only if they can survive the stress imposed by the new environment of the host tissue. In order to identify the genes involved in this process, we injected pancreatic cancer cells into nude mice and identified genes overexpressed in the xenografts. WSB1 was one of them. It showed the same altered expression in vitro under stress conditions. Interestingly, this gene is expressed as three different splice variants and expression of soform 3 was enhanced under stress conditions. This resulted in reduced cell proliferation and facilitated resistance to apoptosis induced by two chemotherapeutic agents, which could contribute to pancreatic tumor growth. Analyzing the expression of the three isoforms in human pancreatic adenocarcinomas supported this hypothesis since isoform 3 was found largely prevalent. The second part of the work addresses the relationship between autophagy and acute pancreatitis. Pancreatitis is associated with morphological changes in pancreatic cells reminding of autophagic conditions, such as vacuole formation. We showed that VMP1, a protein induced during acute pancreatitis, and TP53INP2 (paralogue of TP53INP1, also induced during pancreatitis), were necessary for the formation of autophagic vacuoles. These observations suggest that autophagy is actually involved in the development of pancreatitis.AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSudocFranceF

Prospective evaluation of Ga-68-DOTATATE PET/CT in limited disease neuroendocrine tumours and/or elevated serum neuroendocrine biomarkers

International audienceContextThe Ga-68-labelled somatostatin analogues (Ga-68-DOTA-SSAs) is becoming popular as an important diagnostic tool in neuroendocrine tumours as evidenced by a growing number of reports detailing institutional experience with various DOTA peptides. However, only few prospective studies have compared Ga-68-DOTA-SSAs and somatostatin receptor scintigraphy (SRS) in gastroenteropancreatic neuroendocrine tumours (GEP-NETs) and pulmonary neuroendocrine tumours. ObjectiveThe aim of our prospective study was to perform head-to-head comparison between Ga-68-DOTATATE PET/CT and standard imaging work-up (SI) that included multiphasic CT, liver MRI and SRS using single photon emission computed tomography. DesignIn this prospective study, the patients were enrolled only if they met any of the following inclusion criteria: (i) initial staging of a NETs without distant metastases on SI or neuroendocrine tumour with unknown primary on SI; (ii) restaging of NETs that could be treated by focused therapeutic interventions; (iii) elevated serum neuroendocrine hormones or peptides. The exclusion criteria was grade 3 GEP-NETs. ResultsThirty-two patients were enrolled in the study. Eleven patients (6 pancreas, 4 ileum, 1 duodenal) were included for initial evaluation and staging of NETs, 8 patients (5 pancreas, 1 ileal, 1 lung, 1 duodenal gastrinoma) for restaging, and 13 patients for elevated serum neuroendocrine biomarkers (5 ectopic Cushing's syndrome, 5 organic hypoglycaemia, 1 patient each with elevated vasoactive inhibitory peptide, chromogranin A and neuron-specific enolase). Ga-68-DOTATATE PET/CT detected more primary tumours than SRS (15/18 vs 10/18: P=.074). The missed tumours on Ga-68-DOTATATE PET/CT were located in the lung in two cases and duodenum in one case. For other anatomical regions (nodal and distant metastasis), no statistical difference was observed between imaging modalities using Ga-68-DOTATATE PET/CT and SRS. Overall, Ga-68-DOTATATE PET/CT+CT+MRI detected 31/33 of the involved regions (including primaries) (29 and 22 for Ga-68-DOTATATE and SRS, respectively). ConclusionOur study shows that Ga-68-DOTATATE PET/CT detected similar number of sites than combination of SRS, liver MRI and thoraco-abdominopelvic CT on region-based analysis. Ga-68-DOTATATE PET/CT missed half of primary lung carcinoids with ectopic Cushing's syndrome

Lymph node thyroglobulin in the diagnosis of metastases of thyroid carcinoma with the thyroid in situ: A prospective intraoperative study

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Quality of life, clinical outcomes and safety of early prophylactic ă levothyroxine administration in patients with Graves' hyperthyroidism ă undergoing radioiodine therapy: a randomized controlled study

International audienceObjective: While radioiodine therapy is commonly used for treating ă Graves' disease, a prolonged and clinical hypothyroidism may result in ă disabling symptoms leading to deterioration of quality of life (QoL) of ă patients. Introducing levothyroxine (LT4) treatment in the early ă post-therapeutic period may be an interesting approach to limit this ă phenomenon. ă Methods: A multicenter, prospective, open-label randomized controlled ă trial enrolled 94 patients with Graves' hyperthyroidism randomly ă assigned to the experimental group (n=46) (group A: early prophylactic ă LT4 treatment) or the control group (n=48) (group B: standard ă follow-up). The primary endpoint was the 6-month QoL. The secondary ă endpoints were other QoL scores such as Graves' ophthalmopathy (GO) ă outcomes, thyroid function tests and safety. ă Results: The primary endpoint at 6 months was achieved: the mental ă composite score (MCS) of Short Form 36 (SF-36) was significantly higher ă in group A compared to group B (P=0.009). Four other dimension scores of ă the SF-36 and four dimension scores of the thyroid-specific ă patient-reportedoutcome (ThyPRO) significantly differed between the two ă groups, indicating better QoL in group A. After adjustment for ă variables, the early LT4 administration strategy was found as an ă independent factor for only two scores of SF-36: the MCS and the general ă health (GH) score. There were no differences in GO, final thyroid status ă and changes in the anti-TSH receptor antibodies (TRAbs) levels between ă the two groups. No adverse cardiovascular event was reported. ă Conclusion: Early LT4 administration post-radioactive iodine (RAI) could ă represent a safe potential benefit for patients with regard to QoL. The ă optimal strategy taking into account administered RAI activities and LT4 ă treatment dosage and timing remains to be determined