Molecular bases of cancer: new tools for diagnosis, prognosis and treatment

Curso docente.Peer Reviewe

Regulation of Cu/Zn-superoxide dismutase expression via the phosphatidylinositol 3 kinase/Akt pathway and nuclear factor-κB

11 pages, 9 figures.Aerobic cells adjust the expression of antioxidant enzymes to maintain reactive oxygen species within tolerable levels. In addition, phosphatidylinositol 3 kinase (PI3K) and its downstream protein kinase effector Akt adapt cells to survive in the presence of oxidative stress. Here we provide evidence for an association between these two defense systems via transcriptional regulation of Cu/Zn-superoxide dismutase (Cu/Zn-SOD). PC12 pheochromocytoma cells expressing active Akt1 exhibit lower ROS levels in response to hydrogen peroxide, as determined with the superoxide-sensitive probe hydroethidine. Transfection of constitutive or 4-hydroxytamoxifen-inducible versions of Akt1 results in higher messenger RNA and protein levels of Cu/Zn-SOD. Luciferase reporter constructs, carrying different length fragments of the human sod1 gene promoter, have identified a region between -552 and -355 that is targeted by PI3K and Akt and that contains a putative site of regulation by nuclear factor-kappaB (NF-kappaB). Nerve growth factor (NGF) and Akt augment the transactivating activity and produce higher nuclear levels of p65-NF-kappaB. Electrophoretic mobility shift assays indicate that the putative NF-kappaB regulatory sequence binds p65-NF-kappaB more efficiently in nuclear extracts from these cells. A dominant-negative mutant of IkappaBalpha further demonstrates that the PI3K/Akt axis targets the sod1 promoter at the level of the newly characterized NF-kappaB site. These results illustrate a new mechanism by which the PI3K/Akt pathway protects cells against oxidative stress, involving the upregulation of Cu/Zn-SOD gene expression, and the results identify NF-kappaB as a key mediator in the regulation of this gene.This work was supported by Grants SAF2001-0545 from Ministry of Science and Technology and 08.5/0048/2001 from Comunidad Autónoma of Madrid.Peer reviewe

Empleo de Trefoil Factor-Family 3 (TFF3) en el pronóstico de pacientes diagnosticados con cáncer colorrectal

Peer reviewedUniversidad Autónoma de Madrid, Fundación para la Investigación Biomédica del Hospital Universitario de la Paz, Consejo Superior de Investigaciones CientíficasT3 Traducción de patente europe

GSE4, a small dyskerin- and GSE24.2-related peptide, induces telomerase activity, cell proliferation and reduces DNA damage, oxidative stress and cell senescence in dyskerin mutant cells

Dyskeratosis congenita is an inherited disease caused by mutations in genes coding for telomeric components. It was previously reported that expression of a dyskerin-derived peptide, GSE24.2, increases telomerase activity, regulates gene expression and decreases DNA damage and oxidative stress in dyskeratosis congenita patient cells. The biological activity of short peptides derived from GSE24.2 was tested and one of them, GSE4, that probed to be active, was further characterized in this article. Expression of this eleven amino acids long peptide increased telomerase activity and reduced DNA damage, oxidative stress and cell senescence in dyskerin-mutated cells. GSE4 expression also activated c-myc and TERT promoters and increase of c-myc, TERT and TERC expression. The level of biological activity of GSE4 was similar to that obtained by GSE24.2 expression. Incorporation of a dyskerin nuclear localization signal to GSE24.2 did not change its activity on promoter regulation and DNA damage protection. However, incorporation of a signal that increases the rate of nucleolar localization impaired GSE24.2 activity. Incorporation of the dyskerin nuclear localization signal to GSE4 did not alter its biological activity. Mutation of the Aspartic Acid residue that is conserved in the pseudouridine synthase domain present in GSE4 did not impair its activity, except for the repression of c-myc promoter activity and the decrease of c-myc, TERT and TERC gene expression in dyskerin-mutated cells. These results indicated that GSE4 could be of great therapeutic interest for treatment of dyskeratosis congenita patients.This work was supported by grants PI1401495 (supported by FEDER funds) and ER15PR07ACC114/757 (Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III. Spain), 201320E075 (Consejo Superior de Investigaciones Científicas) and IPT-2012-0674- 090000 (Ministerio de Economía y Competitividad. Spain). CM-G is supported by the CIBER de Enfermedades Raras.Peer Reviewe

CHK1 expression in gastric cancer is modulated by p53 and RB1/E2F1: implications in chemo/radiotherapy response

This work is licensed under a Creative Commons Attribution 4.0 International License.-- et al.Radiation has a limited but relevant role in the adjuvant therapy of gastric cancer (GC) patients. Since Chk1 plays a critical function in cellular response to genotoxic agents, we aimed to analyze the role of Chk1 in GC as a biomarker for radiotherapy resistance. We analyzed Chk1 expression in AGS and MKN45 human GC cell lines by RT-QPCR and WB and in a small cohort of human patient's samples. We demonstrated that Chk1 overexpression specifically increases resistance to radiation in GC cells. Accordingly, abrogation of Chk1 activity with UCN-01 and its expression with shChk1 increased sensitivity to bleomycin and radiation. Furthermore, when we assessed Chk1 expression in human samples, we found a correlation between nuclear Chk1 accumulation and a decrease in progression free survival. Moreover, using a luciferase assay we found that Chk1's expression is controlled by p53 and RB/E2F1 at the transcriptional level. Additionally, we present preliminary data suggesting a posttranscriptional regulation mechanism, involving miR-195 and miR-503, which are inversely correlated with expression of Chk1 in radioresistant cells. In conclusion, Chk1/microRNA axis is involved in resistance to radiation in GC, and suggests Chk1 as a potential tool for optimal stratification of patients susceptible to receive adjuvant radiotherapy after surgery.This work was supported by Instituto de Salud Carlos III–Fondo de Investigación Sanitaria (PS09/1988 to ISP; PI11-00949, pI014-1495 and Feder Funds to RP); Comunidad Autónoma de Madrid-Universidad Autónoma de Madrid (CCG10-UAM/BIO-5871 to ISP); Fundación Leticia Castillejo Castillo and Ministerio de Ciencia e Innovación (SAF2012-30862 to RSP), Spain. JBI was supported by a fellowship from Catedra Isaac Costero, funded by Banco Santander UAM and is a doctoral student from a double doctorate program in Molecular Biosciences (UAM) and in Biomedical Sciences, (UNAM) and received fellowship CVU:607546 from CONACYT.Peer Reviewe

Liberación de sustancias en células senescentes

La invención trata de nanodispositivos para la liberación controlada de sustancias que comprenden un soporte recubierto por oligosacáridos, donde dichos oligosacáridos comprenden al menos 3 unidades de monosacáridos, y donde al menos uno de los monosacáridos es galactosa. Estos nanodispositivos liberan su carga de manera específica en células senescentes. La invención también recoge su procedimiento de obtención y sus usosPeer reviewedUniversidad Politécnica de Valencia, Consejo Superior de Investigaciones Científicas, Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, Centro de Investigación Biomédica en Red de Enfermedades Rara

Evidence of telomere attrition and a potential role for DNA damage in systemic sclerosis

[Background]: To investigate the role of cell senescence in systemic sclerosis (SSc), we analyzed telomere shortening (TS) in SSc patients and the effect of targeting DNA damage in the bleomycin model of skin fibrosis. [Results]: Telomere length (TL) in blood leukocytes of 174 SSc patients and 68 healthy controls was measured by Southern blot, and we found shorter age-standardized TL in SSc patients compared to healthy controls. TL was shorter in SSc patients with ILD compared to those without ILD and in anti-topoisomerase I positive compared to anti-centromere positive patients. To analyze the potential role of DNA damage in skin fibrosis, we evaluated the effects of the DNA protective GSE4 peptide in the bleomycin mouse model of scleroderma and the fibrotic response of cultured human dermal fibroblasts. Administration of GSE4-nanoparticles attenuated bleomycin-induced skin fibrosis as measured by Masson’s staining of collagen and reduced Acta2 and Ctgf mRNA expression, whereas transduction of dermal fibroblasts with a lentiviral GSE4 expression vector reduced COL1A1, ACTA2 and CTGF gene expression after stimulation with bleomycin or TGF-β, in parallel to a reduction of the phospho-histone H2A.X marker of DNA damage. [Conclusions]: SSc is associated with TS, particularly in patients with lung disease or anti-topoisomerase I antibodies. Administration of GSE4 peptide attenuated experimental skin fibrosis and reduced fibroblast expression of profibrotic factors, supporting a role for oxidative DNA damage in scleroderma.The authors received financial support from Fondo de Investigación Sanitaria, Instituto de Salud Carlos III (PI19/01129, PI20/00335, and RIER network RD16/0012 RETICS program), co-financed by the European Regional Development Fund (FEDER)

Shorter telomere length is associated with COVID-19 hospitalization and with persistence of radiographic lung abnormalities

Background Age and comorbidity are the main determinants of COVID-19 outcome. Shorter leukocyte telomere length (TL), a hallmark of biological aging, has been associated with worse COVID-19 outcomes. We sought to determine TL in patients with severe COVID-19 requiring hospitalization to analyze whether clinical outcomes and post-COVID-19 manifestations are associated with shorter TL. Results We analyzed 251 patients with PCR-confirmed COVID-19, hospitalized in the first months of the pandemics. We determined TL in PBL at admission by quantitative-PCR (qPCR) analysis in patients. A healthy cohort from the same area with a similar age range (n = 169) was used to calculate TL Z-scores. After hospital discharge, 144 COVID-19 survivors were followed-up for persistent COVID-19 manifestations. A second TL determination was performed in a smaller group of 63 patients 1 year later and compared with baseline TL. Hospitalized COVID-19 patients had a decreased baseline age-adjusted TL Z-score compared to the reference group. No differences in Z-scores were observed in patients with different COVID-19 outcomes, classified as WHO ordinal scores. In 144 patients, followed for a median of 8 months, post-COVID manifestations were not associated to differences in TL. Persistence of lung radiographic abnormalities was associated with shorter baseline TL. In patients with a second TL determination, further telomere shortening (TS) was observed in 35% and telomere lengthening in 49%. Patients with further TS had suffered a more severe disease. Conclusion Shorter TL is associated with COVID-19 hospitalization but not with hospital clinical outcomes nor with persistent post-COVID-19 manifestations. Delayed resolution of radiographic lung abnormalities was also associated with shorter TL.This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology. Authors also received financial support from Fondo de Investigación Sanitaria, Instituto de Salud Carlos III (PI19/01129, COV20/00181, and RICOR RD21/0002) co-financed by the European Regional Development Fund (FEDER). MR.Peer reviewe

Next-generation sequencing in bone marrow failure syndromes and isolated cytopenias: experience of the spanish network on bone marrow failure sundromes

© 2021 the Author(s).Inherited bone marrow failure syndromes (IBMFSs) are a group of congenital rare diseases characterized by bone marrow failure, congenital anomalies, high genetic heterogeneity, and predisposition to cancer. Appropriate treatment and cancer surveillance ideally depend on the identification of the mutated gene. A next-generation sequencing (NGS) panel of genes could be 1 initial genetic screening test to be carried out in a comprehensive study of IBMFSs, allowing molecular detection in affected patients. We designed 2 NGS panels of IBMFS genes: version 1 included 129 genes and version 2 involved 145 genes. The cohort included a total of 204 patients with suspected IBMFSs without molecular diagnosis. Capture-based targeted sequencing covered > 99% of the target regions of 145 genes, with more than 20 independent reads. No differences were seen between the 2 versions of the panel. The NGS tool allowed a total of 91 patients to be diagnosed, with an overall molecular diagnostic rate of 44%. Among the 167 patients with classified IBMFSs, 81 patients (48%) were diagnosed. Unclassified IBMFSs involved a total of 37 patients, of whom 9 patients (24%) were diagnosed. The preexisting diagnosis of 6 clinically classified patients (6%) was amended, implying a change of therapy for some of them. Our NGS IBMFS gene panel assay is a useful tool in the molecular diagnosis of IBMFSs and a reasonable option as the first tier genetic test in these disorders

The Nobel Prize in Physiology or Medicine 2009 "for telomere biology" and its relevance to cancer and related diseases

Editorial.-- El pdf es la versión post-print.Peer Reviewe