INVESTIGATION ON THE ROLE OF MICAL2 IN MALIGNANT PLEURAL MESOTHELIOMA

Malignant pleural mesothelioma (MPM) is an aggressive cancer with poor prognosis, classified in three hystological subtypes: epithelioid, sarcomatoid, and biphasic. MPM is characterized by the concomitant presence of epithelioid and sarcomatoid (mesenchymal) features; Sarcomatoid type is associated to worse prognosis, suggesting a role of epithelial-mesenchymal transition (EMT) in this dual phenotype (Fassina et al. 2012). EMT is a process by which a polarized epithelial cell undergoes a series of biochemical changes and that results in an elongated and highly migratory mesenchymal phenotype. These changes include the alteration of cell-cell and cell-matrix adhesions and, profound cytoskeletal reorganization, that confer to the cell the ability to move within the extracellular matrix and migrate away from the epithelial layer, in which it originated. Important regulators of cytoskeleton dynamics are the MICAL proteins, a family of monooxygenases able to modify actin. In this way, MICALs may control basic cell phenomena such as adhesion, motility, proliferation/differentiation. In particular, we focused our attention on a member of this family, MICAL2, because studies have shown that MICAL2 is the only family proteins member constitutive active, suggesting that its deregulation might be sufficient to derange its function. Since, in silico analysis show that MICAL2 is expressed in several types of cancer and overexpressed in MPM, we made the hypothesis that its abnormal expression may promote MPM progression. Furthermore our data have shown that MICAL2 was expressed in MPM patients and its expression levels positively correlated with mesothelin (MSLN), an MPM marker, and vimentin (VIM), an EMT marker. To investigate the role of MICAL2 in MPM we used as model MPM cells: the spindle-shaped, MERO-14 and, the mixed epithelial-mesenchymal shaped MERO-25 cell lines, to induce a stable MICAL2 knock-down. MICAL2 abatement in MERO14 cells induces a phenotypic change: from mesenchymal-shape to more epithelial one. Furthermore, our results have shown that the expression levels of SNAI1 and SNAI2 (two EMT-transcription factors), VIM and MSLN, were decreased in MICAL2 knock down (MIC2KD) cells. Furthermore, the expression of SNAI1 and SNAI2 positively correlate with MICAL2 mRNA levels. These findings suggested that MICAL2 could be implicated in EMT process. Our results showed that MERO-14 MIC2KD cells exhibited decreased cell proliferation, adhesion, motility and invasion compared to control cell lines. Moreover, studies suggested that MICAL2 could be an important player in the exosome-release pathway, since some MICAL family membersvare known to interact with the Rab proteins, key regulators of vesicular trafficking and consequently, involved in also in exosomes release. Exosomal markers in kidney cancer 786-O cells-conditioned medium have been identified. Their secretion rate was increased under hypoxia, but exosomal markers were absent in 786-O MIC2KD cells conditioned medium, suggesting that the abatement of MICAL2 may affect also the exosome release. Overall our in vitro preliminary data showed that MICAL2 participate in controlling MPM cells proliferation, adhesion, motility, and exocytosis, probably because it is involved in the regulation of EMT process. Further investigatigation are needed to evaluate MICAL2 as target for anti-cancer therapy

Natural Phytochemicals in the Treatment and Prevention of Dementia: An Overview

The word dementia describes a class of heterogeneous diseases which etiopathogenetic mechanisms are not well understood. There are different types of dementia, among which, Alzheimer’s disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) are the more common. Currently approved pharmacological treatments for most forms of dementia seem to act only on symptoms without having profound disease-modifying effects. Thus, alternative strategies capable of preventing the progressive loss of specific neuronal populations are urgently required. In particular, the attention of researchers has been focused on phytochemical compounds that have shown antioxidative, anti-amyloidogenic, anti-inflammatory and anti-apoptotic properties and that could represent important resources in the discovery of drug candidates against dementia. In this review, we summarize the neuroprotective effects of the main phytochemicals belonging to the polyphenol, isothiocyanate, alkaloid and cannabinoid families in the prevention and treatment of the most common kinds of dementia. We believe that natural phytochemicals may represent a promising sources of alternative medicine, at least in association with therapies approved to date for dementia

Cannabidiol Modulates the Expression of Alzheimer’s Disease-Related Genes in Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have emerged as a promising tool for the treatment of several neurodegenerative disorders, including Alzheimer’s disease (AD). The main neuropathological hallmarks of AD are senile plaques, composed of amyloid beta (Aβ), and neurofibrillary tangles, formed by hyperphosphorylated tau. However, current therapies for AD have shown limited efficacy. In this study, we evaluated whether pre-treatment with cannabidiol (CBD), at 5 μM concentration, modulated the transcriptional profile of MSCs derived from gingiva (GMSCs) in order to improve their therapeutic potential, by performing a transcriptomic analysis by the next-generation sequencing (NGS) platform. By comparing the expression profiles between GMSCs treated with CBD (CBD-GMSCs) and control GMSCs (CTR-GMSCs), we found that CBD led to the downregulation of genes linked to AD, including genes coding for the kinases responsible of tau phosphorylation and for the secretases involved in Aβ generation. In parallel, immunocytochemistry analysis has shown that CBD inhibited the expression of GSK3β, a central player in AD pathogenesis, by promoting PI3K/Akt signalling. In order to understand through which receptor CBD exerted these effects, we have performed pre-treatments with receptor antagonists for the cannabinoid receptors (SR141716A and AM630) or for the vanilloid receptor 1 (TRPVI). Here, we have proved that TRPV1 was able to mediate the modulatory effect of CBD on the PI3K/Akt/GSK3β axis. In conclusion, we have found that pre-treatment with CBD prevented the expression of proteins potentially involved in tau phosphorylation and Aβ production in GMSCs. Therefore, we suggested that GMSCs preconditioned with CBD possess a molecular profile that might be more beneficial for the treatment of AD

SILENCING MICAL2 REPRESSES HUMAN CANCER CELL GROWTH AND INVASION INDUCING MESENCHYMAL TO EPITHELIAL TRANSITION

MICAL (Molecules Interacting with CasL)2 belongs to an evolutionarily conserved family of proteins that catalyze actin oxidation-reduction reactions destabilizing F-actin in cytoskeletal dynamics. Here we show for the first time that MICAL2 mRNA is significantly over-expressed in aggressive, poorly differentiated/ undifferentiated, primary gastric and renal human epithelial cancers. Immunohistochemistry showed MICAL2- positive cells on the cancer invasive front and in metastasizing cancer cells inside emboli, but not at sites of metastasis, suggesting MICAL2 expression was “on” in a subpopulation of primary cancer cells seemingly detaching from the tissue of origin, enter emboli and travel to distant sites, to be turned “off” once homing at the metastatic site occurred. In vitro, MICAL2 knock-down was clearly associated with induction of mesenchymal to epithelial transition, causing reduction of viability and loss of motility and invasion properties of human cancer cells. Moreover, expression of MICAL2 cDNA in MICAL2-depleted cells induced epithelial to mesenchymal transition. All together our data indicate MICAL2 over-expression is associated with cancer progression and metastatic disease. MICAL2 might be an important regulator of epithelial to mesenchymal transition and therefore a promising target for anti-metastatic therapy