The ZFHX1A gene is differentially autoregulated by its isoforms

The Zfhx1a gene expresses two different isoforms; the full length Zfhx1a-1 and a truncated isoform termed Zfhx1a-2 lacking the first exon. Deletion analysis of the Zfhx1a-1 promoter localized cell-specific repressors, and a proximal G-string that is critically required for transactivation. Transfection of Zfhx1a-1 cDNA, but not Zfhx1a-2, downregulates Zfhx1a-1 promoter activity. Mutation of an E2-box disrupted the binding of both Zfhx1a isoforms. Consistent with this, transfected Zfhx1a-1 does not regulate the transcriptional activity of the E-box mutated Zfhx1a-1 promoter. Competitive EMSAs and transfection assays show that Zfhx1a-2 can function as a dominant negative isoform since it is able to compete and displace Zfhx1a-1 from its binding site and overcome Zfhx1a-1 induced repression of the Zfhx1a-1 promoter in cells. Hence, the Zfhx1a-1 gene is autoregulated in part by negative feedback on its own promoter which is, in turn, modified by the availability of the negative dominant isoform Zfhx1a-2.Fil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Roqueiro, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Darling, Douglas S.. University of Louisville; Estados UnidosFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

Glypican-3 induces a mesenchymal to epithelial transition in human breast cancer cells

Breast cancer is the disease with the highest impact on global health, beingmetastasis the main cause of death. To metastasize, carcinoma cells must reactivate a latent program called epithelial-mesenchymal transition (EMT), through which epithelial cancer cells acquire mesenchymal-like traits.Glypican-3 (GPC3), a proteoglycan involved in the regulation of proliferationand survival, has been associated with cancer. In this study we observed thatthe expression of GPC3 is opposite to the invasive/metastatic ability of Hs578T,MDA-MB231, ZR-75-1 and MCF-7 human breast cancer cell lines. GPC3 silencingactivated growth, cell death resistance, migration, and invasive/metastatic capacity of MCF-7 cancer cells, while GPC3 overexpression inhibited these properties in MDA-MB231 tumor cell line. Moreover, silencing of GPC3 deepened the MCF-7 breast cancer cells mesenchymal characteristics, decreasing the expression of the epithelial marker E-Cadherin. On the other side, GPC3 overexpression induced the mesenchymal-epithelial transition (MET) of MDA-MB231 breast cancer cells, which re-expressed E-Cadherin and reduced the expression of vimentin and N-Cadherin.While GPC3 inhibited the canonical Wnt/β-Catenin pathway in the breast cancer cells, this inhibition did not have effect on E-Cadherin expression. We demonstrated that the transcriptional repressor of E-Cadherin - ZEB1 - is upregulated in GPC3 silenced MCF-7 cells, while it is downregulated when GPC3 was overexpressed in MDA-MB231 cells.We presented experimental evidences showing that GPC3 induces the E-Cadherinre-expression in MDA-MB231 cells through the downregulation of ZEB1.Our data indicate that GPC3 is an important regulator of EMT in breast cancer,and a potential target for procedures against breast cancer metastasisFil: Castillo, Lilian Fedra. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Tascón, Rocío Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Lago Huvelle, María Amparo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Novack, Gisela Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Llorens de Los Ríos, María Candelaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; ArgentinaFil: Ferreira Dos Santos, Ancély. Universidade de Sao Paulo; BrasilFil: Shortrede, Jorge Eduardo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Cabanillas, Ana Maria de Los A.. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Bal, Elisa Dora. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Labriola, Leticia. Universidade de Sao Paulo; BrasilFil: Peters, María Giselle. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; Argentin

Oxidative stress induces transcription of telomeric repeat-containing RNA (TERRA) by engaging PKA signaling and cytoskeleton dynamics

Long non-coding RNAs transcribed from telomeres, known as TERRA (telomeric repeat-containing RNA), are associated with telomere and genome stability. TERRA abundance responds to different cell stresses; however, no studies have focused on oxidative stress, condition that damages biomolecules and is involved in aging and disease. Since telomeres are prone to oxidative damage leading to their dysfunction, our objective was to characterize TERRAs and the mechanisms that control their expression. TERRA increased in cells exposed to H2O2 and reverted by antioxidant treatment. TERRAs are also induced in brown adipose tissue of mice exposed to cold, which raises mitochondrial ROS. In cells exposed to H2O2, ChIP showed that chromatin landscape was modified favoring telomere transcription. TERRAs interacted with HP1α/γ, proteins that were found recruited to subtelomeres. Since HP1γ interacts with the transcriptional machinery, TERRAs may stimulate their own expression by recruiting HP1γ to subtelomeres. TERRA induction reverted within 2 h after removal of H2O2 from culture medium, suggesting they have protective functions. This was supported by rapid TERRA induction following a second H2O2 challenge. PKA inhibitors H89 and PKI blocked TERRA increase by H2O2 or IBMX+Forskolin treatment, suggesting PKA signaling regulates TERRA induction. Treatment of cells with drugs that disturb cytoskeleton integrity or growing cells on surfaces of different stiffness known to generate differential cytoskeleton tension also modified TERRA levels and sensitized cells to lower H2O2 concentrations. In summary, we show that TERRAs are induced in response to oxidative stress and are regulated by PKA as well as by changes in cytoskeleton dynamics.Fil: Galigniana, Natalia Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Charó, Nancy Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Uranga, Romina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Piwien Pilipuk, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Novel DNA photocleavage properties of [Cr(NN)3]3+ complexes

The aim of this study was to investigate the ability of chromium(III) tris-diimine complexes, [Cr(NN)3]3+, to induce DNA photodamage and to examine its capability to impair the survival of irradiated bacteria with the purpose of using these compounds as photocleavage reagents. [Cr(NN)3]3+ complexes, where NN stands for the ligands: phen (1,10-phenanthroline), 5-Mephen, 4,7-diMephen, 3,4,7,8-tetraMephen, 5-Phphen and 5-Clphen were used for this purpose. Their properties of DNA photocleavage were investigated by electrophoretic studies and assays of the photosensitization of transformed bacteria. The results clearly indicate that [Cr(NN)3]3+ complexes promote the photocleavage of plasmid DNA with varied degrees of efficiency after 12 h of irradiation. The combination of DNA, [Cr(NN)3]3+ and light proved to be required to induce the breakdown of DNA. Irradiated plasmid DNA-[Cr(NN) 3]3+ association is also capable of impairing the transforming capacity of bacteria. These results provide evidence which confirms the responsibility and essential role of the excited state of [Cr(NN) 3]3+ for inducing damage. Moreover, assays of the photo sensitization of transformed bacterial suspensions suggest that Escherichia coli may be photo inactivated by irradiation in the presence of [Cr(NN) 3]3+ complexes.Fil: Toneatto, Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Lorenzatti, Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Arguello, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Frecuencia de mutaciones de Beta-Talasemia, en una población con pseudopoliglobulia y microcitosis de La Rioja

La hemoglobina es la proteína casi exclusivamente presente en los glóbulos rojos que permite el transporte de oxígeno desde los pulmones a todas los tejidos del organismo. Las mutaciones en la hemoglobina pueden llevar a una menor velocidad de la síntesis de la cadena de globina conocido con el nombre genérico de talasemias. Aun es muy escasa la información sobre la frecuencia de talasémicos en la población argentina, según las regiones geográficas y aun más escasa es la información en relación a la proporción de talasémicos mal o sub diagnosticados. Este estudio se diseñó para obtener información acerca delas mutaciones de β-talasemia más frecuentes en una población con características talasémicas, con o sin diagnóstico previo de la misma, en la ciudad de La Rioja, Argentina. Seleccionada entre julio y diciembre de 2012 entre los pacientes que asistieron al laboratorio privado Cortes Viñes. Se estudiaron las seis mutaciones más frecuentes de acuerdo al origen étnico de la población:CD39, IVSI-1, IVSI-6, IVSI-110, IVSII-1 e IVSII-745, utilizando PCR-ARMS múltiple. En 60 individuos estudiados identificamos 14 portadores de alguna mutación (23,3%). 7 pacientes con CD39 (11,7%), seis con IVSI-1(10%) y uno con IVSI-6 (1,7%). La frecuencia encontrada difiere ligeramente a las reportadas en las ciudades del centro del país, revelando un espectro diferente de migración en las provincias del noroeste. La información obtenida permite aproximarse al conocimiento de las β-talasemias en La Rioja, para contribuir a su diagnóstico,al asesoramiento o consejo genético para parejas en riesgo y al diagnóstico prenatal.Fil: Lozdan, Maricel. Universidad Nacional de la Rioja. Departamento de Cs. Exactas, Físicas y Naturales; ArgentinaFil: Rearte, Sergio N.. Universidad Nacional de la Rioja. Departamento de Cs. Exactas, Físicas y Naturales; ArgentinaFil: Milanesio, Antonella. Universidad Nacional de la Rioja. Departamento de Cs. Exactas, Físicas y Naturales; ArgentinaFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

New insights in the DNA-[Cr(phen)2(dppz)]3+ binding and photocleavage properties by the complex with an intercalating ligand

Due to the key role of DNA in cell life and pathological processes, the design of specific chemical nucleases, fic chemical nucleases, DNA probes and alkylating agents is an important research area for the development of new therapeutic agents and tools in Biochemistry. Hence, the interaction of small molecules with DNA has attracted in particular a great deal of attention. 27a great deal of attention. The aim of this study was to investigate the ability of [Cr(phen)2(dppz)]3+ to associate with DNA and to 282(dppz)]3+ to associate with DNA and to characterize it as photocleavage reagent for Photodynamic Therapy (PDT).Chromium(III) complex [Cr(phen)2(dppz)]3+, (dppz=dipyridophenazine, phen=1,10-phenanthroline), 302(dppz)]3+, (dppz=dipyridophenazine, phen=1,10-phenanthroline),where dppz is a planar bidentate ligand with an extended ¦Ð system, has been found to bind strongly 31¦Ð system, has been found to bind strongly to double strand oligonucleotides (ds-oligo) and plasmid DNA with intrinsic DNA binding constants, Kb, of 32ds-oligo) and plasmid DNA with intrinsic DNA binding constants, Kb, of (3.9¡À0.3)¡Á105 M−1 and (1.1¡À0.1)¡Á105 M−1, respectively. The binding properties to DNA were 335 M−1 and (1.1¡À0.1)¡Á105 M−1, respectively. The binding properties to DNA were investigated by UV¨Cvisible (UV¨CVis) absorption spectroscopy and electrophoretic studies. UV¨CVis absorption 34¨Cvisible (UV¨CVis) absorption spectroscopy and electrophoretic studies. UV¨CVis absorption data provide clearly that the chromium(III) complex interacts with DNA intercalatively. Competitive binding experiments show that the enhancement in the emission intensity of ethidium bromide (EthBr) in the presence of DNA was quenched by [Cr(phen)2(dppz)]3+, indicating that the Cr(III) complex displaces EthBr 372(dppz)]3+, indicating that the Cr(III) complex displaces EthBr from its binding site in plasmid DNA. Moreover, [Cr(phen)2(dppz)]3+, non-covalently bound to 382(dppz)]3+, non-covalently bound to DNA, promotes the photocleavage of plasmid DNA under 457 nm irradiation. We also found that the irradiated Cr(III)-plasmid DNA association is able to impair the transforming capacity of bacteria. These results provide evidence confirming the responsible and essential role of the excited state of [Cr(phen)2(dppz)]3+ for firming the responsible and essential role of the excited state of [Cr(phen)2(dppz)]3+ for damaging the DNA structure. The combination of DNA, [Cr(phen)2(dppz)]3+ and light, is necessary to induce damage. In addition, assays of the photosensitization of transformed bacterial suspensions suggest that Escherichia coli may be photoinactivated by irradiation in the presence of [Cr(phen)2(dppz)]3+. In sum, our may be photoinactivated by irradiation in the presence of [Cr(phen)2(dppz)]3+. In sum, our results allow us to postulate the [Cr(phen)2(dppz)]3+ complex as a very attractive candidate for DNA 2(dppz)]3+ complex as a very attractive candidate for DNA photocleavage with potential applications in Photodynamic Therapy (PDT).fic chemical nucleases, DNA probes and alkylating agents is an important research area for the development of new therapeutic agents and tools in Biochemistry. Hence, the interaction of small molecules with DNA has attracted in particular a great deal of attention. 27a great deal of attention. The aim of this study was to investigate the ability of [Cr(phen)2(dppz)]3+ to associate with DNA and to 282(dppz)]3+ to associate with DNA and to characterize it as photocleavage reagent for Photodynamic Therapy (PDT).Chromium(III) complex [Cr(phen)2(dppz)]3+, (dppz=dipyridophenazine, phen=1,10-phenanthroline), 302(dppz)]3+, (dppz=dipyridophenazine, phen=1,10-phenanthroline),where dppz is a planar bidentate ligand with an extended ¦Ð system, has been found to bind strongly 31¦Ð system, has been found to bind strongly to double strand oligonucleotides (ds-oligo) and plasmid DNA with intrinsic DNA binding constants, Kb, of 32ds-oligo) and plasmid DNA with intrinsic DNA binding constants, Kb, of (3.9¡À0.3)¡Á105 M−1 and (1.1¡À0.1)¡Á105 M−1, respectively. The binding properties to DNA were 335 M−1 and (1.1¡À0.1)¡Á105 M−1, respectively. The binding properties to DNA were investigated by UV¨Cvisible (UV¨CVis) absorption spectroscopy and electrophoretic studies. UV¨CVis absorption 34¨Cvisible (UV¨CVis) absorption spectroscopy and electrophoretic studies. UV¨CVis absorption data provide clearly that the chromium(III) complex interacts with DNA intercalatively. Competitive binding experiments show that the enhancement in the emission intensity of ethidium bromide (EthBr) in the presence of DNA was quenched by [Cr(phen)2(dppz)]3+, indicating that the Cr(III) complex displaces EthBr 372(dppz)]3+, indicating that the Cr(III) complex displaces EthBr from its binding site in plasmid DNA. Moreover, [Cr(phen)2(dppz)]3+, non-covalently bound to 382(dppz)]3+, non-covalently bound to DNA, promotes the photocleavage of plasmid DNA under 457 nm irradiation. We also found that the irradiated Cr(III)-plasmid DNA association is able to impair the transforming capacity of bacteria. These results provide evidence confirming the responsible and essential role of the excited state of [Cr(phen)2(dppz)]3+ for firming the responsible and essential role of the excited state of [Cr(phen)2(dppz)]3+ for damaging the DNA structure. The combination of DNA, [Cr(phen)2(dppz)]3+ and light, is necessary to induce damage. In addition, assays of the photosensitization of transformed bacterial suspensions suggest that Escherichia coli may be photoinactivated by irradiation in the presence of [Cr(phen)2(dppz)]3+. In sum, our may be photoinactivated by irradiation in the presence of [Cr(phen)2(dppz)]3+. In sum, our results allow us to postulate the [Cr(phen)2(dppz)]3+ complex as a very attractive candidate for DNA 2(dppz)]3+ complex as a very attractive candidate for DNA photocleavage with potential applications in Photodynamic Therapy (PDT).Fil: Toneatto, Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Boero, Rodolfo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Lorenzatti, Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Arguello, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin