Probable aestivation burrows from the Eocene/Oligocene transition in south-eastern France and their palaeoenvironmental implications

International audienceEnigmatic biogenic structures are reported from the Palaeogene of south-eastern France in the Castellane-Blieux area (Alpes de Haute-Provence French Department). They occur at the Eocene/Oligocene transition at the top of the Marnes Bleues Formation, which corresponds to a clearly defined regressive sequence, where thick marls are overlain by lacustrine limestones or sandstones. The marls have abundant shallow marine fauna and the upper part of the Formation corresponds to a rapid transition to non-marine deposits. The studied structures exhibit three main morphologies: vertical shafts, furrows, and tunnels. They can also form dense clusters and cross-cut marginal marine crustacean burrows such as Psilonichnus. By comparison with modern and fossil examples, these trace fossils are interpreted as probably aestivation burrows. The possible trace-makers could be lungfish (in particular for the common vertical burrows) or amphibians (for the furrows and tunnels). The occurrence of these different aestivation burrows defines the border of a basin and probably indicates increasing droughts on the coastal plain. This could reflect the well-known development of arid conditions in south-eastern France at the beginning of the Oligocene

Le stratotype de la base de l’Etage Bathonien à Bas-Auran (Réserve Géologique de Haute Provence)

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Le GSSP du Bathonien à Bas Auran (réserve naturelle géologique de Haute-Provence, France)

Le Bathonien est le troisième étage du Jurassique moyen. Son nom dérive de la « Bath Oolithe », une formation définie près de Bath (Somerset, Angleterre). Mais, dans cette région, les niveaux condensés ne sont pas favorables pour définir le stratotype de l’étage. On ne peut pas sélectionner d’affleurements pouvant permettre de définir le stratotype de limite de l’étage. En France, trois coupes dans les environs de Bas Auran (Alpes de Haute-Provence, France) ont donc été proposées en 1967. En 1990, ces mêmes localités ont été présentées officiellement comme possible stratotype de la limite basale de l'étage (GSSP). Enfin en 2007, le GSSP a été formellement accepté par le « Bathonian Working Group » et, en 2008, par l’IUGS. Les coupes ont été levées dans les ravins du Bès, d'Auran et des Robines, près du hameau de Bas Auran (commune de Chaudon-Norante, Alpes de Haute-Provence). Elles montrent une alternance marno-calcaire, d'une épaisseur de 13 mètres environ, coiffée par une surface durcie (hard-ground), constituant le mur de la formation des Terres Noires. Les âges s’étendent de la sous-zone à Bomfordi (Zone à Parkinsoni, Bajocien supérieur) à la Sous-zone à Tenuiplicatus (Zone à Aurigerus, Bathonien inférieur). Des travaux récents ont permis de compléter et d’affiner les données existantes concernant les assemblages d’ammonoïdes, la sédimentologie et l'ichnologie. Les associations d’ammonoïdés, les microfossiles, le nannoplancton, les assemblages ichnologiques et surtout, l'absence de discontinuités notables, permettent de proposer la base du banc 71 de la coupe du Ravin du Bès comme stratotype de la limite inférieure du Bathonien. Atout non négligeable, Bas Auran se situe au sein de la Réserve Géologique de Haute-Provence, ce qui permet la sauvegarde de ce site, très facile d'accès. [ABSTRACT] The Bathonian is the third stage of the Middle Jurassic System. Its name derives from the “Bath Oolithe” formation, cropping out in the surroundings of Bath, in southern England. However, in this country, no outcrops make it possible define the stratotype of the Bathonian Stage, as the succession is taphonomically and stratigraphically condensed. The Ravin du Bès section at Bas Auran was thus suggested as the bounding stratotype in 1967. Only later, in 1990, this section was officially proposed as possible stratotype (G.S.S.P.) of the basal boundary of the Bathonian Stage. Lastly, in 2007 this G.S.S.P. was formally accepted by the Bathonian Working Group and, in 2008, the proposal was ratified by the I.U.G.S. Three sections were studied in the surroundings of the Bas Auran farm (Alpes de Haute-Provence, France). The succession is composed of marly and calcareous beds that alternate on nearly 13 metres, and is unconformably overlain by the “Terres Noires” Formation with a sharp hard ground at the lithostratigraphic boundary. The studied interval spans the Bomfordi Subzone (Parkinsoni Zone, late Bajocian) to the Tenuiplicatus Subzone (Aurigerus Zone, early Bathonian)

The stress phenotype makes cancer cells addicted to CDT2, a substrate receptor of the CRL4 ubiquitin ligase

CDT2/L2DTL/RAMP is one of the substrate receptors of the Cullin Ring Ubiquitin Ligase 4 that targets for ubiquitin mediated degradation a number of substrates, such as CDT1, p21 and CHK1, involved in the regulation of cell cycle and survival. Here we show that CDT2 depletion was alone able to induce the apoptotic death in 12/12 human cancer cell lines from different tissues, regardless of the mutation profile and CDT2 expression level. Cell death was associated to rereplication and to loss of CDT1 degradation. Conversely, CDT2 depletion did not affect non-transformed human cells, such as immortalized kidney, lung and breast cell lines, and primary cultures of endothelial cells and osteoblasts. The ectopic over-expression of an activated oncogene, such as the mutation-activated RAS or the amplified MET in non-transformed immortalized breast cell lines and primary human osteoblasts, respectively, made cells transformed in vitro, tumorigenic in vivo, and susceptible to CDT2 loss. The widespread effect of CDT2 depletion in different cancer cells suggests that CDT2 is not in a synthetic lethal interaction to a single specific pathway. CDT2 likely is a non-oncogene to which transformed cells become addicted because of their enhanced cellular stress, such as replicative stress and DNA damage

Prognostic Role of Serum Cytokeratin-19 Fragment (CYFRA 21-1) in Patients with Hepatocellular Carcinoma

Keratin 19 (K19) is a cancer stem cell marker expressed by a subpopulation of hepatocellular carcinoma (HCC), associated with tumor aggressiveness. We evaluated the prognostic value of serum K19 fragment (CYFRA 21-1), in comparison or in combination with alpha-fetoprotein (AFP) and protein induced by vitamin-K absence or antagonist-II (PIVKA-II), in patients with HCC. A total of 160 patients (28F/132M; median age 62, range 44-86 years) with a new diagnosis of HCC and available serum samples collected at tumor diagnosis were analyzed retrospectively. Median overall survival (OS) after HCC diagnosis was 35.1, 95% CI 27.1-70.5 months. Multivariate Cox regression analysis showed that CYFRA 21-1 > 2.7 ng/mL (hazard ratio (HR) = 3.39, p 20 ng/mL (HR = 2.27, p = 0.007), and PIVKA-II > 200 mAU/mL (HR = 2.17, p = 0.020) were independent predictors of OS. The combination of biomarkers positivity allowed us to stratify patients with HCC into four risk categories associated with a progressively lower survival probability (log-rank test, p < 0.001). CYFRA 21-1 resulted an independent prognostic factor of patients with HCC and its combination with AFP and PIVKA-II might be useful to tailor personalized treatment strategies