RESUMEN
PURPOSE: The heavy subunit of the iron storage protein ferritin (FHC) is essential for the intracellular iron metabolism and, at the same time, it represents a central hub of iron-independent pathways, such as cell proliferation, angiogenesis, p53 regulation, chemokine signalling, stem cell expansion, miRNAs expression. In this work we have explored the ability of FHC to modulate gene expression in K562 cells, through the up-regulation of the lncRNA H19 and its cognate miR-675. MATERIALS AND METHODS: Targeted silencing of FHC was performed by lentiviral-driven shRNA strategy. FHC reconstitution was obtained by full length FHC cDNA transfection with Lipofectamine 2000. ROS amounts were determined with the redox-sensitive probe H2DCFDA. H19, miR-675, miR-107, Twist1, ID3, EPHB6, GNS, ANK1 and SMAD6 mRNA amounts were quantified by Taqman assay and qPCR analysis. RESULTS: FHC silencing in K562 cells modulates gene expression through the up-regulation of the lncRNA H19 and its cognate miR-675. Experimental findings demonstrate that the molecular mechanism underlying this phenomenon is represented by an FHC knock-down-triggered increase in reactive oxygen species (ROS) production. CONCLUSIONS: In this paper we uncover a so far not described function of the ferritin heavy subunit in the control of lncRNA pathways.
Asunto(s)
Ferritinas/genética , MicroARNs/genética , ARN Largo no Codificante/genética , ARN Interferente Pequeño/genética , Regulación hacia Arriba , Redes Reguladoras de Genes , Silenciador del Gen , Humanos , Células K562 , Lípidos/farmacología , Oxidorreductasas , Especies Reactivas de Oxígeno/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
The serum- and glucocorticoid-regulated kinase (Sgk1) is essential for hormonal regulation of epithelial sodium channel-mediated sodium transport and is involved in the transduction of growth factor-dependent cell survival and proliferation signals. Growing evidence now points to Sgk1 as a key element in the development and/or progression of human cancer. To gain insight into the mechanisms through which Sgk1 regulates cell proliferation, we adopted a proteomic approach to identify up- or downregulated proteins after Sgk1-specific RNA silencing. Among several proteins, the abundance of which was found to be up- or downregulated upon Sgk1 silencing, we focused our attention of RAN-binding protein 1 (RANBP1), a major effector of the GTPase RAN. We report that Sgk1-dependent regulation of RANBP1 has functional consequences on both mitotic microtubule activity and taxol sensitivity of cancer cells.
Asunto(s)
Carcinoma/genética , Carcinoma/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Resistencia a Antineoplásicos/genética , Proteínas Inmediatas-Precoces/metabolismo , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Transcripción Genética , Apoptosis/efectos de los fármacos , Apoptosis/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Humanos , Paclitaxel/farmacología , Fosforilación , Proteómica , Interferencia de ARN , Factor de Transcripción Sp1/metabolismoRESUMEN
Periostin (POSTN), an osteoblast-specific secreted protein known to be associated with cell adhesion activity for bone formation and development by the epithelial cell-derived tumors, leads to a significant enhancement in angiogenesis and tumorigenesis. At present, little is known about the mechanisms underlying its transcriptional control either in physiological or neoplastic conditions. In this study we demonstrate that the ability of the human POSTN promoter to drive transcription mostly depends on the activity of YingYang-1 (YY1) zinc finger transcription factor. YY1, whose regulatory role in biology includes, besides transcriptional control, also chromatin remodeling, DNA damage repair and tumorigenesis, acts as a strong negative modulator of the POSTN expression. We retain that the identification of the functional role of YY1 in the transcriptional control of the human POSTN gene adds new insights in the studies focused on gene expression in normal and transformed cells.