DISSECTING THE CONTRIBUTION OF THE HISTONE DEMETHYLASE LSD1 IN RETINOIC ACID-INDUCED DIFFERENTIATION OF APL CELLS

Acute promyelocytic leukemia (APL) is a cytogenetically distinct subtype of acute myeloid leukemia, characterized by the chromosomal translocation t(15;17) that involves the retinoic acid receptor (RAR) gene and leads to the production of the fusion protein PML-RAR\u3b1. In the past it has been successfully treated with all- trans retinoic acid at high doses to differentiate the leukemic blast. The fusion protein indeed retains the capability to binds DNA with an even stronger affinity and recruits repressive co-factors, making the cells insensitive to physiological concentrations of retinoic acid. In the last few years, also the lysine-specific demethylase (LSD1) protein has emerged as important target for the epigenetic therapy of cancer. We found that both pharmacological inhibition and knock down of LSD1 are able to sensitize NB4 cells - a cells line derived from an APL patient - to lower (physiological) doses of retinoic acid (RA) causing growth arrest and differentiation without degradation of the fusion protein. In order to elucidate the role of LSD1 in this mechanism, we characterized the LSD1 genomic distribution in acute myeloid leukemia by ChIP-seq experiment and performed RNA-seq and ChIP-seq for H3K4me1/me2/me3 and H3K27ac in all the four treatments (DMSO as control, RA low, RA high, LSD1 inhibition and cotreatment of LSD1 inhibitor and RA low). Results of RNA-seq analyses show significant changes in gene expression only after co-treatment (RAlow + LSD1i) and RA high, in line with experimental evidence of phenotype. Moreover, in addition to an high overlap between genes expressed in both co-treatment and RAhigh, we observe a significative number of cotreatment-specific expressed genes that suggest a putative synergistic and stronger effect of the cotreatment compare to the retinoic acid high alone. In parallel, the data on histone modifications obtained through ChIP-seq experiments show a significant increase of the di-metylation of H3K4 after treatment with inhibitor. This mainly occurs in regions marked with peaks of LSD1 and associated with genes involved in cell differentiation (genes over- expressed in co-treatment, but not in other single treatments). In the same regions we observe the presence of H3K27 acetylation after treatment with retinoic acid but not after LSD1 inhibition. Only after treatment with both drugs the regions acquire the two histone marks, and we can observe an effective phenotype of differentiation, correlating with the observed change in gene expression. An hypothesis might be that there are regulatory regions linked by LSD1, which undergo a kind of \u201cpre-mark\u201d in histone modifications after treatment with the inhibitor (gain of H3K4me2) or with retinoic acid (gain of H3K27ac), which is necessary but not sufficient to determine a change in expression, found only after co-treatment in the simultaneous presence of both epigenetic modifications. Overall the combination of the LSD1 inhibition and RA low bypasses the block of PML-RAR fusion protein activating a different pathway of genes compared to RA high with stronger effects on the differentiation of the cells. Taken together our results contribute to understand the role of LSD1 in the RA- induced differentiation of leukemic cells, suggest new therapeutic strategies for the intervention in APL and potentially other leukemias, and highlight the importance of combination therapies as new potent weapon in the cancer treatments

Reliability of Early Fetal Echocardiography for Congenital Heart Disease Detection: A Preliminary Experience and Outcome Analysis of 102 Fetuses to Demonstrate the Value of a Clinical Flow-Chart Designed for At-Risk Pregnancy Management

Early fetal echocardiography (EFEC) is a fetal cardiac ultrasound analysis performed between the 12th and 16th week of pregnancy (compared with the usual 18-22 weeks). In the last 10 years, the introduction of “aneuploidy sonographic markers” in screening for cardiac defects has led to a shift from late second to end of the first trimester or beginning of the second trimester of pregnancy for specialist fetal echocardiography. In this prospective study, early obstetric screening was performed between January 2014 and October 2015, using “aneuploidy sonographic markers” following SIEOG Guidelines 2014. These parameters were then collected and strategically combined in an evaluation score to select the group of pregnancies for performing EFEC, in accordance with the American Society of Echocardiography guidelines for fetal Echocardiography. All second-level examinations were performed transabdominally using a 3D convex volumetric probe with frequency range of 4-8 MHz (Accuvix – Samsung). The outcome data included transabdominal fetal echocardiography from 18 weeks to term and after birth. Overall, 99 pregnant women in the first trimester underwent EFEC (95 singleton and 4 twin pregnancies). Specifically, 30 fetuses were evaluated for extra-cardiac anomalies evidenced by obstetric screening (30%), 25 for family history of congenital heart diseases (25%), 8 for family history of genetic-linked diseases (8%), 4 for heart diseases suspected by obstetric screening (4%) and 19 by normal screening (19%). Was detected 11 (10.7%) CHD, when EFEC detected CHD, were compared to those performed later in pregnancy (18 weeks GA-term), a high degree of diagnosis correspondence was evidenced. The higher sensitivity value of EFEC vs late-FE, in comparison with the post-natal value, coupled with the high EFEC specificity shown vs both the end points, enabled us to consider it as a really reliable diagnostic technology, at least in perienced hands. The introduction of a key combination of the more sensitive obstetric and cardiologic variables should facilitate the formulation of a possible flow-chart as a guide for CHD at-risk pregnancies

Inclusion of new 5-fluorouracil amphiphilic derivatives in liposome formulation for cancer treatment

Correction for 'Inclusion of new 5-fluorouracil amphiphilic derivatives in liposome formulation for cancer treatment' by M. Petaccia et al., Med. Chem. Commun., 2015, 6, 1639–1642

Capacidad antimicrobiana de fitoproteasas autóctonas sobre cepas bacterianas patógenas de importancia clínica y alimentaria

Los productos naturales y las drogas relacionadas son usados en el tratamiento del 87% de las enfermedades que afectan al hombre inclusive en las infecciones bacterianas, en cáncer y en desórdenes inmunológicos. Es así que muchos países en desarrollo basan su medicina popular en compuestos obtenidos a partir de plantas. A diferencia de los animales, las plantas carecen de sistema inmunológico y la respuesta inmunitaria de ellas comprende mensajeros químicos sistémicos que se distribuyen por toda la planta. En los últimos años se ha reportado el aislamiento de diferentes tipos de proteínas vegetales con actividad antimicrobiana, entre ellas quitinasas, β-1,3-glucanasas, defensinas, tioninas, inhibidores de proteasas e incluso enzimas proteolíticas (Rojas et al., 2006). En consecuencia, la búsqueda de nuevas fuentes de agentes antimicrobianos se hace imprescindible, dado el creciente aumento de la resistencia de microorganismos a los antibióticos tradicionales. En este contexto, la investigación en compuestos biológicamente activos de origen natural resulta de gran interés. Se ha observado que algunas proteasas están involucradas en procesos de inhibición del crecimiento bacteriano (Guevara et al., 2004) y es por eso que el objetivo de este trabajo es determinar la capacidad antimicrobiana in vitro de dos endopeptidasas autóctonas frente a distintas cepas patógenas de importancia clínica y alimentaria. Se purificaron los extractos crudos de látex de frutos de Araujia hortorum y de frutos maduros de Salpichroa origanifolia. La actividad antimicrobiana de las fracciones purificadas fue ensayada sobre cepas seleccionadas de Staphylococcus aureus, Salmonella enteritidis, Escherichia coli, Serratia marcescen y Kebsiella pneumoniae. El ensayo in vitro se realizó incubando las proteasas en medio de cultivo líquido (caldo tripteína soja) a 37ºC frente a las distintas cepas bacterianas. El seguimiento de la cinética de crecimiento bacteriano en ausencia o en presencia del compuesto antimicrobiano se realizó midiendo la turbidez a 650 nm durante 20 hs de incubación, en un espectrofotómetro GeneQuant. El porcentaje de inhibición se calculó como el cociente entre las mediciones de DO con y sin peptidasa. Como conclusión podemos afirmar que las endopeptidasas cisteínicas presentes en Araujia hortorum (araujaína) demostraron actividad antimicrobiana frente Salmonella enteritidis (90% de inhibición) y en menor grado frente a Escherichia coli (25%). En el caso de las aspartil peptidasas de Salpichroa origanifolia (salpichroína), se observó un 95% de inhibición frente a cepas de Staphylococcus aureus, Klebsiella pneumoniae, Serratia marcescens y en menor grado de Escherichia coli (75%). Estos resultados podrían contribuir al desarrollo de nuevos agentes antimicrobianos en el área de salud, además de tener aplicación en la industria de los alimentos y/o en el sector agronómico.Centro de Investigación de Proteínas Vegetale

Targeting the scaffolding role of LSD1 (KDM1A) poises acute myeloid leukemia cells for retinoic acid–induced differentiation

The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors. In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells, triggering degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knockout, but targeting LSD1 sensitizes them to physiological doses of RA without altering of PML-RAR levels, and extends survival of leukemic mice upon RA treatment. The combination of RA with LSD1 inhibition (or knockout) is also effective in other non-APL, acute myeloid leukemia (AML) cells. Nonenzymatic activities of LSD1 are essential to block differentiation, while RA with targeting of LSD1 releases a differentiation gene expression program, not strictly dependent on changes in histone H3K4 methylation. Integration of proteomic/epigenomic/mutational studies showed that LSD1 inhibitors alter the recruitment of LSD1-containing complexes to chromatin, inhibiting the interaction between LSD1 and the transcription factor GFI1

Microbiota derived short chain fatty acids promote histone crotonylation in the colon through histone deacetylases

The recently discovered histone post-translational modification crotonylation connects cellular metabolism to gene regulation. Its regulation and tissue-specific functions are poorly understood. We characterize histone crotonylation in intestinal epithelia and find that histone H3 crotonylation at lysine 18 is a surprisingly abundant modification in the small intestine crypt and colon, and is linked to gene regulation. We show that this modification is highly dynamic and regulated during the cell cycle. We identify class I histone deacetylases, HDAC1, HDAC2, and HDAC3, as major executors of histone decrotonylation. We show that known HDAC inhibitors, including the gut microbiota-derived butyrate, affect histone decrotonylation. Consistent with this, we find that depletion of the gut microbiota leads to a global change in histone crotonylation in the colon. Our results suggest that histone crotonylation connects chromatin to the gut microbiota, at least in part, via short-chain fatty acids and HDACs

Pilot study of the multicentre DISCHARGE trial: image quality and protocol adherence results of computed tomography and invasive coronary angiography (vol 30, pg 1997, 2020)

The original version of this article, published on 16 December 2019, unfortunately contained two mistakes.Cardiovascular Aspects of Radiolog

B2B relational with a quality approach

This report aims to evaluate the quality of relations between B2B companies in the competitive context of globalization through the application of a concrete case study between two Italian companies. The quality approach proposed by Alves et al. (2016) was taken into consideration to verify its applicability to understand whether the quality of the relationship has an impact on the success of jointly produced products. Experimental results suggest the possibility that the proposed method could be effective to assess quality of relations in interorganizational cooperation and that it can be useful to better analyze and understand the nature of relationships and to underline the aspects most related to power-dependence situations, which may compromise synergy between partners and negatively aspect the success of the alliance. However, further studies are needed to demonstrate the effectiveness of this methodology. The limit of this approach is represented by the lack of use weights in scoring of descriptors. Because, some descriptors or dimensions are probably more important than others, further studies have to be carried out to better analyze mutual relations of considered RC domains and respective features and understand their relative importance in determining the quality of business relationships. This report shows a real case study of two small Italian companies that have actually found the effectiveness of this approach to improve their partnership, obtaining benefits

Self-renewal of tumor cells : Epigenetic determinants of the cancer stem cell phenotype

Among the functional subpopulations that coexist within the tumor, 'cancer stem cells' are characterized by increased self-renewal and the ability to derive all of the other subpopulations of tumor cells ('bulk'). The functional heterogeneity among cancer stem cells and bulk cells must reflect distinct cellular epigenetic landscapes, but - due to the difficulty to isolate bona fide cancer stem cells with a high degree of purity - those different epigenetic landscapes, and the molecular mechanisms underlying them, remain largely unknown. Cues of intratumor phenotypic plasticity complicate the interpretation of the cancer stem cell phenotype: we contend that, however, the concept of cancer stem cell has crucial therapeutic implication, and remains a key target for the exploration of the cancer epigenome