ETV5 i RUNX1, nous factors de transcripció implicats en la invasió miometrial del carcinoma endometrial

Actualment, en càncer d'endometri, està àmpliament acceptat el model dualístic que, atenent a bases morfològiques, diferencia tumors de tipus i o endometrioides dels de tipus ii o no endometrioides. La genètica molecular ha aportat dades que donen suport a aquest model dualístic de la tumorigènesi endometrial i algunes claus per a poder especular sobre la seqüència temporal de les alteracions moleculars que defineixen les rutes tumorigèniques. En els càncers endometrials endometrioides, o de tipus i, es coneixen alteracions majors, com poden ser el silenciament del gen PTEN, la inestabilitat de microsatèll. its associada a defectes en els gens reparadors de DNA, o mutacions al gen K-ras. Aquestes alteracions defineixen la progressió de l'endometri normal cap a la hiperplàsia i posteriorment cap al carcinoma. Recentment, l'ús de la tecnologia de microxips de cDNA per a identificar les diferències en els patrons d'expressió gènica entre els diferents tipus histològics de càncer d'endometri han permès la identificació de gens expressats diferencialment que podrien ajudar-nos a entendre les diferències en la biologia i el pronòstic clínic dels diferents histiotips tumorals. En el nostre laboratori hem aïllat i caracteritzat dos nous factors de transcripció, ETV5 i RUNX1, que estan associats amb els passos inicials de la infiltració miometrial en el càncer d'endometri endometrioide. Aquests estudis, i els d'altres gens implicats en el control de la mitosi com a mecanisme major de carcinogènesi en els càncers d'endometri no endometrioides, representen exemples de la utilitat dels estudis genètics amplis per a comprendre el procés de tumorigènesi i les rutes implicades en la patogènesi molecular del càncer d'endometri.A dualistic model, which has been established on a morphological basis and that differentiates type i endometrioid from type ii non-endometrioid endometrial cancer, is widely accepted. Molecular genetics have provided us with data supporting the dualistic model of endometrial tumorigenesis and with some clues to speculate about the sequence of the molecular alterations defining the tumorigenesis pathways. In type i endometrioid endometrial cancer, PTEN gene silencing, microsatellite instability associated with defects in DNA mismatch repair genes, or mutations in the K-ras gene are the known major alterations defining the progression from normal endometrium to hyperplasia and then on to carcinoma. Recently, cDNA microarray technology for identifying the differences in gene expression patterns between the histological types of endometrial cancer have permitted the identification of differentially expressed genes that could help us to understand differences in the biology and the clinical outcome between histiotypes. In our laboratory, we have recently isolated and characterized two new transcription factors, ETV5 and RUNX1, which expression appears to be associated with initial steps of myometrial infiltration in endometrioid endometrial carcinoma. These studies, as well as those on other genes involved in the mitotic checkpoint as a major mechanism of carcinogenesis in non-endometrioid endometrial cancer, represent examples of how useful large genetic screenings can be for understanding the tumorigenesis process and the future directions in the molecular pathogenesis of endometrial cancer

Allosteric modulation of NMDA receptors prevents the antibody effects of patients with anti-NMDAR encephalitis

Anti-N-Methyl-D-Aspartate Receptor (NMDAR) encephalitis is an immune-mediated disease characterized by a complex neuropsychiatric syndrome in association with an antibody-mediated decrease of NMDAR. About 85% of patients respond to immunotherapy (and removal of an associated tumor if it applies), but it often takes several months or more than 1 year for patients to recover. There are no complementary treatments, beyond immunotherapy, to accelerate this recovery. Previous studies showed that SGE-301, a synthetic analog of 24(S)-hydroxycholesterol, which is a potent, and selective positive allosteric modulator of NMDAR, reverted the memory deficit caused by phencyclidine (a non-competitive antagonist of NMDAR), and prevented the NMDAR dysfunction caused by patients' NMDAR antibodies in cultured neurons. An advantage of SGE-301 is that it is optimized for systemic delivery such that plasma and brain exposures are sufficient to modulate NMDAR activity. Here, we used SGE-301 to confirm that in cultured neurons it prevented the antibody-mediated reduction of receptors, and then we applied it to a previously reported mouse model of passive cerebroventricular transfer of patients' CSF antibodies. Four groups were established: mice receiving continuous (14-day) infusion of patients' or controls' CSF, treated with daily subcutaneous administration of SGE-301 or vehicle (no drug). The effects on memory were examined with the novel object location (NOL) test at different time points, and the effects on synaptic levels of NMDAR (assessed with confocal microscopy) and plasticity (long-term potentiation [LTP]) were examined in the hippocampus on day 18, which in this model corresponds to the last day of maximal clinical and synaptic alterations. As expected, mice infused with patients' CSF antibodies, but not those infused with controls' CSF, and treated with vehicle developed severe memory deficit without locomotor alteration, accompanied by a decrease of NMDAR clusters and impairment of LTP. All antibody-mediated pathogenic effects (memory, synaptic NMDAR, LTP) were prevented in the animals that were treated with SGE-301, despite that this compound did not antagonize antibody binding. Additional investigations on the potential mechanisms related to these SGE-301 effects showed that (1) in cultured neurons SGE-301 prolonged the decay time of NMDAR-dependent spontaneous excitatory postsynaptic currents suggesting a prolonged open time of the channel, and (2) it significantly decreased the internalization of antibody-bound receptors suggesting that additional, yet unclear mechanisms, contribute in keeping unchanged the surface NMDAR density. Overall, these findings suggest that SGE-301, or similar modulators of NMDAR, could potentially serve as complementary treatment for anti-NMDAR encephalitis and deserve future investigations

Thymoma and Autoimmune Encephalitis: Clinical Manifestations and Antibodies

To report the clinical, neuroimaging, and antibody associations in patients with autoimmune encephalitis (AE) and thymoma.A retrospective cohort study of 43 patients was conducted. Antibody determination and immunoprecipitation to characterize novel antigens were performed using reported techniques.Patients' median age was 52 years (range: 23-88 years). Forty (93%) had neuronal surface antibodies: gamma-aminobutyric acid receptor A (GABAAR) (15), amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) (13), contactin-associated protein-like 2 (CASPR2) (4), leucine-rich, glioma inactivated 1 (LGI1) (3), glycine receptor (GlyR) (3), and unknown antigens (2). Concurrent antibodies against intracellular antigens occurred in 13 (30%; 9 anti-collapsin response mediator protein 5 [CRMP5]) and were more frequent in anti-AMPAR encephalitis (54% vs 20%; p = 0.037). The most common clinical presentation was encephalitis with multiple T2/fluid-attenuated inversion recovery hyperintense lesions in 23 (53%) patients (15 GABAAR, 5 AMPAR, and 1 unknown neuropil antibody), followed by encephalitis with peripheral nerve hyperexcitability in 7 (16%; 4 CASPR2, 2 LGI1, and 1 unknown antibody), limbic encephalitis in 6 (14%; 4 AMPAR, 1 LGI1, and 1 antibody negative), progressive encephalomyelitis with rigidity and myoclonus in 4 (9%; 3 GlyR and 1 AMPAR antibodies), and encephalitis with normal MRI in 3 (7%; AMPAR antibodies). Anti-GABAAR encephalitis was more prevalent in Japanese patients compared with Caucasians and other ethnicities (61% vs 16%; p = 0.003). In anti-AMPAR encephalitis, 3/4 patients with poor and 0/6 with good outcome had concurrent CRMP5 antibodies (p = 0.033). Immunoprecipitation studies identified metabotropic glutamate receptor 3 antibodies that were additionally found in 5 patients (3 with and 2 without encephalitis).AE in patients with thymoma include several clinical-radiologic syndromes that vary according to the associated antibodies. Anti-GABAAR encephalitis was the most frequent AE and occurred more frequently in Japanese patients

Filamin A Binds to CCR2B and Regulates Its Internalization

The chemokine (C-C motif) receptor 2B (CCR2B) is one of the two isoforms of the receptor for monocyte chemoattractant protein-1 (CCL2), the major chemoattractant for monocytes, involved in an array of chronic inflammatory diseases. Employing the yeast two-hybrid system, we identified the actin-binding protein filamin A (FLNa) as a protein that associates with the carboxyl-terminal tail of CCR2B. Co-immunoprecipitation experiments and in vitro pull down assays demonstrated that FLNa binds constitutively to CCR2B. The colocalization of endogenous CCR2B and filamin A was detected at the surface and in internalized vesicles of THP-1 cells. In addition, CCR2B and FLNa were colocalized in lamellipodia structures of CCR2B-expressing A7 cells. Expression of the receptor in filamin-deficient M2 cells together with siRNA experiments knocking down FLNa in HEK293 cells, demonstrated that lack of FLNa delays the internalization of the receptor. Furthermore, depletion of FLNa in THP-1 monocytes by RNA interference reduced the migration of cells in response to MCP-1. Therefore, FLNa emerges as an important protein for controlling the internalization and spatial localization of the CCR2B receptor in different dynamic membrane structures

Targeting the NG2/CSPG4 Proteoglycan Retards Tumour Growth and Angiogenesis in Preclinical Models of GBM and Melanoma

Aberrant expression of the progenitor marker Neuron-glia 2 (NG2/CSPG4) or melanoma proteoglycan on cancer cells and angiogenic vasculature is associated with an aggressive disease course in several malignancies including glioblastoma multiforme (GBM) and melanoma. Thus, we investigated the mechanism of NG2 mediated malignant progression and its potential as a therapeutic target in clinically relevant GBM and melanoma animal models. Xenografting NG2 overexpressing GBM cell lines resulted in increased growth rate, angiogenesis and vascular permeability compared to control, NG2 negative tumours. The effect of abrogating NG2 function was investigated after intracerebral delivery of lentivirally encoded shRNAs targeting NG2 in patient GBM xenografts as well as in established subcutaneous A375 melanoma tumours. NG2 knockdown reduced melanoma proliferation and increased apoptosis and necrosis. Targeting NG2 in two heterogeneous GBM xenografts significantly reduced tumour growth and oedema levels, angiogenesis and normalised vascular function. Vascular normalisation resulted in increased tumour invasion and decreased apoptosis and necrosis. We conclude that NG2 promotes tumour progression by multiple mechanisms and represents an amenable target for cancer molecular therapy