The sonic hedgehog signaling pathway is reactivated in human renal cell carcinoma and plays orchestral role in tumor growth

<p>Abstract</p> <p>Background</p> <p>Human clear cell renal cell carcinoma (CRCC) remains resistant to therapies. Recent advances in Hypoxia Inducible Factors (HIF) molecular network led to targeted therapies, but unfortunately with only limited clinical significance. Elucidating the molecular processes involved in kidney tumorigenesis and resistance is central to the development of improved therapies, not only for kidney cancer but for many, if not all, cancer types. The oncogenic PI3K/Akt, NF-kB and MAPK pathways are critical for tumorigenesis. The sonic hedgehog (SHH) signaling pathway is crucial to normal development.</p> <p>Results</p> <p>By quantitative RT-PCR and immunoblot, we report that the SHH signaling pathway is constitutively reactivated in tumors independently of the von Hippel-Lindau (VHL) tumor suppressor gene expression which is inactivated in the majority of CRCC. The inhibition of the SHH signaling pathway by the specific inhibitor cyclopamine abolished CRCC cell growth as assessed by cell counting, BrdU incorporation studies, fluorescence-activated cell sorting and β-galactosidase staining. Importantly, inhibition of the SHH pathway induced tumor regression in nude mice through inhibition of cell proliferation and neo-vascularization, and induction of apoptosis but not senescence assessed by in vivo studies, immunoblot and immunohistochemistry. Gli1, cyclin D1, Pax2, Lim1, VEGF, and TGF-β were exclusively expressed in tumors and were shown to be regulated by SHH, as evidenced by immunoblot after SHH inhibition. Using specific inhibitors and immunoblot, the activation of the oncogenic PI3K/Akt, NF-kB and MAPK pathways was decreased by SHH inhibition.</p> <p>Conclusions</p> <p>These findings support targeting SHH for the treatment of CRCC and pave the way for innovative and additional investigations in a broad range of cancers.</p

A modular magnetic anastomotic device for minimally invasive digestive anastomosis: proof of concept and preliminary data in the pig model

Background: The aim of our study was to assess the feasibility of minimally invasive digestive anastomosis using a modular flexible magnetic anastomotic device made up of a set of two flexible chains of magnetic elements. The assembly possesses a non-deployed linear configuration which allows it to be introduced through a dedicated small-sized applicator into the bowel where it takes the deployed form. A centering suture allows the mating between the two parts to be controlled in order to include the viscerotomy between the two magnetic rings and the connected viscera. Methods and procedures: Eight pigs were involved in a 2-week survival experimental study. In five colorectal anastomoses, the proximal device was inserted by a percutaneous endoscopic technique, and the colon was divided below the magnet. The distal magnet was delivered transanally to connect with the proximal magnet. In three jejunojejunostomies, the first magnetic chain was injected in its linear configuration through a small enterotomy. Once delivered, the device self-assembled into a ring shape. A second magnet was injected more distally through the same port. The centering sutures were tied together extracorporeally and, using a knot pusher, magnets were connected. Ex vivo strain testing to determine the compression force delivered by the magnetic device, burst pressure of the anastomosis, and histology were performed. Results : Mean operative time including endoscopy was 69.2±21.9min, and average time to full patency was 5days for colorectal anastomosis. Operative times for jejunojejunostomies were 125, 80, and 35min, respectively. The postoperative period was uneventful. Burst pressure of all anastomoses was ≥110mmHg. Mean strain force to detach the devices was 6.1±0.98 and 12.88±1.34N in colorectal and jejunojejunal connections, respectively. Pathology showed a mild-to-moderate inflammation score. Conclusions: The modular magnetic system showed enormous potential to create minimally invasive digestive anastomoses, and may represent an alternative to stapled anastomoses, being easy to deliver, effective, and low cost

SMARCB1 regulates a TFCP2L1-MYC transcriptional switch promoting renal medullary carcinoma transformation and ferroptosis resistance

Renal medullary carcinoma (RMC) is an aggressive tumour driven by bi-allelic loss of SMARCB1 and tightly associated with sickle cell trait. However, the cell-of-origin and oncogenic mechanism remain poorly understood. Using single-cell sequencing of human RMC, we defined transformation of thick ascending limb (TAL) cells into an epithelial-mesenchymal gradient of RMC cells associated with loss of renal epithelial transcription factors TFCP2L1, HOXB9 and MITF and gain of MYC and NFE2L2-associated oncogenic and ferroptosis resistance programs. We describe the molecular basis for this transcriptional switch that is reversed by SMARCB1 re-expression repressing the oncogenic and ferroptosis resistance programs leading to ferroptotic cell death. Ferroptosis resistance links TAL cell survival with the high extracellular medullar iron concentrations associated with sickle cell trait, an environment propitious to the mutagenic events associated with RMC development. This unique environment may explain why RMC is the only SMARCB1-deficient tumour arising from epithelial cells, differentiating RMC from rhabdoid tumours arising from neural crest cells

Dietary polyphenol supplementation prevents alterations of spatial navigation in middle-aged mice

Spatial learning and memory deficits associated with hippocampal synaptic plasticity impairments are commonly observed during aging. Besides, the beneficial role of dietary polyphenols has been suggested as potential functional food candidates to prevent this memory decline. Indeed, polyphenols could potentiate the signaling pathways of synaptic plasticity underlying learning and memory. In this study, spatial learning deficits of middle-aged mice were first highlighted and characterized according to their navigation patterns in the Morris water maze task. An eight-week polyphenol-enriched diet, containing a polyphenol-rich extract from grape and blueberry (PEGB; from the Neurophenols Consortium) with high contents of flavonoids, stilbenes and phenolic acids, was then successful in reversing these age-induced effects. The use of spatial strategies was indeed delayed with aging whereas a polyphenol supplementation could promote the occurrence of spatial strategies. These behavioral results were associated with neurobiological changes: while the expression of hippocampal calmodulin kinase II (CaMKII) mRNA levels was reduced in middle-aged animals, the polyphenol-enriched diet could rescue them. Besides, an increased expression of nerve growth neurotrophic factor (NGF) mRNA levels was also observed in supplemented adult and middle-aged mice. Thus these data suggest that supplementation with polyphenols could be an efficient nutritional way to prevent age-induced cognitive decline

Recherche de nouveaux facteurs pronostiques et thérapeutiques dans le carcinome à cellules rénales humain

RESUME : Le cancer du rein, correspondant dans 90% des cas à un carcinome à cellules rénales (CCR), est d incidence croissante et de mauvais pronostic. Malgré l amélioration récente de la prise en charge thérapeutique des CCR métastatiques (anti-angiogéniques), il convient de préciser les critères pronostiques et de développer de nouvelles thérapies combinées et plus spécifiques. Nous avons étudié le mécanisme d action de la protéine apparentée à l hormone parathyroïdienne (PTHrP) exprimée dans 90% des CCR et son interaction avec d autres voies de signalisation. Nos études in vitro et in vivo ont mis en évidence que la PTHrP a des propriétés anti-apoptotique via la stimulation de la voie PI3K/Akt, avec une activation spécifique du facteur de transcription Nuclear Factor kappaB (NF B). La voie NF B est impliquée dans la résistance intrinsèque du CCR à l apoptose, indépendamment du statut du gène suppresseur de tumeur von Hippel-Lindau (VHL), souvent inactivé dans des CCR. Sur une puce à tissus de 249 CCR humains (suivi de 12-22 ans), l expression immunohistochimique de pAkt et pNF B (phosphorylés) est corrélée au type histologique (cellules claires). L augmentation de l expression de pAkt est corrélée au grade de Fuhrman et à une diminution de la survie globale et sans récidive. Par contre, l expression nucléaire de pNF B est plus importante si la tumeur est de petite taille et de stade localisé avec une meilleure survie sans récidive. Cependant, ces 2 facteurs ne sont pas indépendants. Les voies PTHrP/PI3K/Akt et NF B sont impliquées dans la croissance et la survie du CCR humain, ouvrant de nouvelles perspectives pronostiques mais également thérapeutiques dans cette pathologie.SUMMARY: Incidence of renal cell carcinoma (RCC) is increasing with a pejorative prognosis. It accounts for more than 90% of adult renal neoplasms. Despite the recent major improvements in the treatment of metastatic RCC (anti-angiogenic drugs), ones needs to precise prognostic factors and to develop more specific and combined targeted therapies. The aim of our project was to determine the implication of parathyroid hormone-related protein (PTHrP), expressed in 90% of RCC and its interaction with the other known signaling pathways involved in carcinogenesis. We identified the role of PTHrP in controlling tumor cell survival in vitro and in vivo. PTHrP acts through the PI3K/Akt pathway leading to the specific activation of Nuclear Factor kappaB (NF B). The NF B pathway is involved in the intrinsic resistance of RCC to apoptosis, with no influence of von Hippel-Lindau (VHL) tumor suppressor gene expression., often inactivated in RCC. We built up a tissue-microarray containing 249 human RCC with 12 to 22 years of clinical follow-up. Clear cell RCC showed increased pAkt and pNF B (phosphorylated) immunoreactivity. Increased expression of pAkt was significantly associated with Fuhrman grade and reduced survival. Increased expression of pNF B was correlated with small and localized tumor with best recurrence free survival. These two prognostic factors were not found to be independent for patient survival. This report provides the strong implication of PTHrP/PI3K/Akt and NF B pathways in renal growth and survival of RCC, as promising prognostic and therapeutic.STRASBOURG-Medecine (674822101) / SudocSudocFranceF

Tumeur maligne ou kératokyste ? A propos d’un cas

La découverte radiologique fortuite d’une lésion radiotransparente envahissant les maxillaires représente souvent un défit diagnostique pour le clinicien. Cet article présente le cas d’un patient adressé initialement pour une tumeur maligne. Les étapes de la prise en charge sont détaillées depuis la consultation jusqu’au diagnostic final de kératokyste. Toutes les étapes du traitement sont présentées et les différentes possibilités thérapeutiques envisagées. Le diagnostic clinique et radiologique entre une tumeur maligne et un kératokyste est parfois difficile ; pour cette raison, le kératokyste odontogène est de plus en plus considéré comme une néoplasie kystique bénigne

Enantiomer separation of N-protected amino acids by non-aqueous capillary electrophoresis and high-performance liquid chromatography with tert.-butyl carbamoylated quinine in either the background electrolyte or the stationary phase

A non-aqueous CE method was developed for evaluating the chiral discrimination potential of cinchona alkaloids and different kinds of carbamoylated derivatives of quinine and quinidine type chiral selectors towards acidic analytes, in particular a series of various Bz (benzoyl), DNB (3,5-dinitrobenzoyl) and DNZ (3,5-dinitrobenzyloxycarbonyl) amino acid derivatives. In this study, the enantioselectivity values obtained in non-aqueous CE with tert-butyl carbamoylated quinine as chiral additive have been compared with the values found for the same series of selectands in HPLC using the same selector immobilized onto silica as chiral stationary phase. Similarly to the background electrolyte used in CE an ethanol-methanol mixture (60:40, v/v) containing 100 mM octanoic acid and 12.5 mM ammonia has been selected as HPLC mobile phase. Under these conditions, a good correlation (r=0.954) between the enantioselectivities observed with the two techniques has been obtained. Thus the non-aqueous CE method can be applied as a screening tool for the rapid evaluation of the chiral discrimination potential of a large set of newly developed chiral selectors derived from quinine and related alkaloids. (C) 2002 Elsevier Science B.V. All rights reserved

Sarcomatoid Dedifferentiation in Renal Cell Carcinoma: From Novel Molecular Insights to New Clinical Opportunities

Sarcomatoid features in renal cell carcinoma (RCC) have long been associated with dismal prognosis and poor response to therapy, while biological mechanisms underpinning sarcomatoid dedifferentiation remained obscure. Several efforts have been conducted to break down the molecular profile of sarcomatoid RCC and investigate different targeted therapeutic approaches. Mutations enriched for in sarcomatoid RCC involve, notably, TP53, BAP1, cell cycle, and chromatin-remodeling genes. The immunological landscape of these tumors is also gradually being uncovered, showing frequent expression of programmed cell death ligand-1 (PD-L1) and high levels of tumor-infiltrating lymphocytes. These features may be major determinants for the activity of immune checkpoint inhibitors in this population, which has been confirmed by retrospective studies and subgroup analyses of large randomized phase 3 trials. Combinations based on PD-1/PD-L1 inhibition have demonstrated response rates and complete responses in &gt;50% and &gt;10% of patients in the first-line metastatic setting, respectively, with median overall survival exceeding two years. This remarkable improvement in outcomes effectively establishes immune checkpoint inhibitor combinations as a new standard of care in patients with sarcomatoid RCC. New research fields, including epigenetic regulations and tumor&ndash;microenvironment interactions, may further sharpen understanding of sarcomatoid RCC and advance therapeutic developments