Browsing by Author "Silva, Verónica"
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Publication Administration of Secretome Derived from Human Mesenchymal Stem Cells Induces Hepatoprotective Effects in Models of Idiosyncratic Drug-Induced Liver Injury Caused by Amiodarone or Tamoxifen(2023) Huang, Ya-Lin; De Gregorio, Cristian; Silva, Verónica; Elorza, Álvaro; Léniz, Patricio; Aliaga, Víctor; Maracaja, Vinicius; Budini, Mauricio; Ezquer, Fernando; Ezquer, MarceloDrug-induced liver injury (DILI) is one of the leading causes of acute liver injury. While many factors may contribute to the susceptibility to DILI, obese patients with hepatic steatosis are particularly prone to suffer DILI. The secretome derived from mesenchymal stem cell has been shown to have hepatoprotective effects in diverse in vitro and in vivo models. In this study, we evaluate whether MSC secretome could improve DILI mediated by amiodarone (AMI) or tamoxifen (TMX). Hepatic HepG2 and HepaRG cells were incubated with AMI or TMX, alone or with the secretome of MSCs obtained from human adipose tissue. These studies demonstrate that coincubation of AMI or TMX with MSC secretome increases cell viability, prevents the activation of apoptosis pathways, and stimulates the expression of priming phase genes, leading to higher proliferation rates. As proof of concept, in a C57BL/6 mouse model of hepatic steatosis and chronic exposure to AMI, the MSC secretome was administered endovenously. In this study, liver injury was significantly attenuated, with a decrease in cell infiltration and stimulation of the regenerative response. The present results indicate that MSC secretome administration has the potential to be an adjunctive cell-free therapy to prevent liver failure derived from DILI caused by TMX or AMI.Item Caveolin-1-containing extracellular vesicles transport adhesion proteins and promote malignancy in breast cancer cell lines(Future Medicine Ltd, 2018) Campos, America; Salomon, Carlos; Bustos, Rocío; Díaz, Jorge; Martínez, Samuel; Silva, Verónica; Reyes, Constanza; Díaz-Valdivia, Natalia; Varas-Godoy, Manuel; Lobos-González, Lorena; Quest, AndrewBreast cancer is one of the most frequently diagnosed cancers and the leading cause of cancer-related deaths in women worldwide, whereby mortality is largely attributable to the development of distant metastasis. Caveolin-1 (CAV1) is a multifunctional membrane protein that is typically upregulated in the final stages of cancer and promotes migration and invasion of tumor cells. Elevated levels of CAV1 have been detected in extracellular vesicles (EVs) from advanced cancer patients. EVs are lipid enclosed vesicular structures that contain bioactive proteins, DNA and RNAs, which can be transferred to other cells and promote metastasis. Therefore, we hypothesized that CAV1 containing EVs released from breast cancer cells may enhance migration and invasion of recipient cells. EVs were purified from conditioned media of MDA-MB-231 wild-type (WT), MDA-MB-231 (shCAV1; possessing the plasmid pLKO.1 encoding a 'small hairpin' directed against CAV1) and MDA-MB-231 (shC) short hairpin control cells. Nanoparticle tracking analysis revealed an average particle size of 40-350 nm for all preparations. As anticipated, CAV1 was detected in MDA-MB-231 WT and shC EVs, but not in MDA-MB-231 (shCAV1) EVs. Mass spectrometry analysis revealed the presence of specific cell adhesion-related proteins, such as Cyr61, tenascin (TNC) and S100A9 only in WT and shC, but not in shCAV1 EVs. Importantly, EVs containing CAV1 promoted migration and invasion of cells lacking CAV1. We conclude that the presence of CAV1 in EVs from metastatic breast cancer cells is associated with enhanced migration and invasiveness of recipient cells in vitro, suggesting that intercellular communication promoted by EVs containing CAV1 will likely favor metastasis in vivo.Item Exosomes released upon mitochondrial ASncmtRNA knockdown reduce tumorigenic properties of malignant breast cancer cells.(Nature Publishing Group, 2020) Lobos-González, Lorena; Bustos, Rocío; Campos, América; Silva, Valeria; Silva, Verónica; Jeldes, Emanuel; Salomon, Carlos; Varas-Godoy, Manuel; Cáceres-Verschae, Albano; Durán, Eduardo; Vera, Tamara; Ezquer, Fernando; Ezquer, Marcelo; Burzio, Verónica; Villegas, JaimeDuring intercellular communication, cells release extracellular vesicles such as exosomes, which contain proteins, ncRNAs and mRNAs that can influence proliferation and/or trigger apoptosis in recipient cells, and have been proposed to play an essential role in promoting invasion of tumor cells and in the preparation of metastatic niches. Our group proposed the antisense non-coding mitochondrial RNA (ASncmtRNA) as a new target for cancer therapy. ASncmtRNA knockdown using an antisense oligonucleotide (ASO-1537S) causes massive death of tumor cells but not normal cells and strongly reduces metastasis in mice. In this work, we report that exosomes derived from ASO-1537S-treated MDA-MB-231 breast cancer cells (Exo-1537S) inhibits tumorigenesis of recipient cells, in contrast to exosomes derived from control-ASO-treated cells (Exo-C) which, in contrast, enhance these properties. Furthermore, an in vivo murine peritoneal carcinomatosis model showed that Exo-1537S injection reduced tumorigenicity compared to controls. Proteomic analysis revealed the presence of Lactadherin and VE-Cadherin in exosomes derived from untreated cells (Exo-WT) and Exo-C but not in Exo-1537S, and the latter displayed enrichment of proteasomal subunits. These results suggest a role for these proteins in modulation of tumorigenic properties of exosome-recipient cells. Our results shed light on the mechanisms through which ASncmtRNA knockdown affects the preparation of breast cancer metastatic niches in a peritoneal carcinomatosis model.Item Mitochondrial ncRNA targeting induces cell cycle arrest and tumor growth inhibition of MDA-MB-231 breast cancer cells through reduction of key cell cycle progression factors(2019) Fitzpatrick, Christopher; Bendek, Maximiliano F.; Briones, Macarena; Farfán, Nicole; Silva, Valeria A.; Nardocci, Gino; Montecino, Martín; Boland, Anne; Deleuze, Jean-Francois; Villegas, Jaime; Villota, Claudio; Silva, Verónica; Lobos-González, Lorena; Borgna, Vincenzo; Barrey, Eric; Burzio, Luis O.; Burzio, Verónica A.The family of long noncoding mitochondrial RNAs (ncmtRNAs), comprising sense (SncmtRNA), and antisense (ASncmtRNA-1 and ASncmtRNA-2) members, are differentially expressed according to cell proliferative status; SncmtRNA is expressed in all proliferating cells, while ASncmtRNAs are expressed in normal proliferating cells, but is downregulated in tumor cells. ASncmtRNA knockdown with an antisense oligonucleotide induces massive apoptosis in tumor cell lines, without affecting healthy cells. Apoptotic death is preceded by proliferation blockage, suggesting that these transcripts are involved in cell cycle regulation. Here, we show that ASncmtRNA knockdown induces cell death preceded by proliferative blockage in three different human breast cancer cell lines. This effect is mediated by downregulation of the key cell cycle progression factors cyclin B1, cyclin D1, CDK1, CDK4, and survivin, the latter also constituting an essential inhibitor of apoptosis, underlying additionally the onset of apoptosis. The treatment also induces an increase in the microRNA hsa-miR-4485-3p, whose sequence maps to ASncmtRNA-2 and transfection of MDA-MB-231 cells with a mimic of this miRNA induces cyclin B1 and D1 downregulation. Other miRNAs that are upregulated include nuclear-encoded hsa-miR-5096 and hsa-miR-3609, whose mimics downregulate CDK1. Our results suggest that ASncmtRNA targeting blocks tumor cell proliferation through reduction of essential cell cycle proteins, mediated by mitochondrial and nuclear miRNAs. This work adds to the elucidation of the molecular mechanisms behind cell cycle arrest preceding tumor cell apoptosis induced by ASncmtRNA knockdown. As proof-of-concept, we show that in vivo knockdown of ASncmtRNAs results in drastic inhibition of tumor growth in a xenograft model of MDA-MB-231 subcutaneous tumors, further supporting this approach for the development of new therapeutic strategies against breast cancer.Publication Paleodermatology: Dermatoscopic findings of "Niño del Plomo" an Incan mummy in Chile(2023) Catalán, Verónica; Castro, Mario; Cabrera, Raúl; Silva, Verónica; Castro, Alex; Lecaros, CristóbalPaleodermatology is a collaborative science that provides insights into the physiology and pathology of ancient populations as well as informs physicochemical properties currently relevant to dermatologic research. Mummification is a taphonomic process antagonistic to putrefaction characterized by dehydration and desiccation of soft tissues. Spontaneous natural mummification requires arid conditions, such as extreme temperatures, dryness, and hypoxia, to prevent cell autolysis, insects from laying eggs, and bacteria growing on the cadaver. Once skin is mummified, it is extremely resistant to decomposition and can remain unchanged for thousands of years. Very well-preserved micro- and ultrastructures have been observed in mummified skin.Item Targeting antisense mitochondrial noncoding RNAs induces bladder cancer cell death and inhibition of tumor growth through reduction of survival and invasion factors.(Ivyspring International Publisher, 2020) Borgna, Vincenzo; Lobos-González, Lorena; Guevara, Francisca; Landerer, Eduardo; Bendek, Maximiliano; Ávila, Rodolfo; Silva, Verónica; Villota, Claudio; Araya, Mariela; Rivas, Alexis; López, Constanza; Socías, Teresa; Castillo, Jorge; Alarcón, Luis; Burzio, Luis; Burzio, Verónica; Villegas, JaimeKnockdown of the antisense noncoding mitochondrial RNAs (ASncmtRNAs) induces apoptotic death of several human tumor cell lines, but not normal cells, supporting a selective therapy against different types of cancer. In this work, we evaluated the effects of knockdown of ASncmtRNAs on bladder cancer (BCa). We transfected the BCa cell lines UMUC-3, RT4 and T24 with the specific antisense oligonucleotide Andes-1537S, targeted to the human ASncmtRNAs. Knockdown induced a strong inhibition of cell proliferation and increase in cell death in all three cell lines. As observed in UMUC-3 cells, the treatment triggered apoptosis, evidenced by loss of mitochondrial membrane potential and Annexin V staining, along with activation of procaspase-3 and downregulation of the anti-apoptotic factors survivin and Bcl-xL. Treatment also inhibited cell invasion and spheroid formation together with inhibition of N-cadherin and MMP 11. In vivo treatment of subcutaneous xenograft UMUC-3 tumors in NOD/SCID mice with Andes-1537S induced inhibition of tumor growth as compared to saline control. Similarly, treatment of a high-grade bladder cancer PDX with Andes-1537S resulted in a strong inhibition of tumor growth. Our results suggest that ASncmtRNAs could be potent targets for bladder cancer as adjuvant therapy.