RESUMO
Infectious hematopoietic necrosis virus (IHNV; n = 18) was identified in the Korean national surveillance program between February 2013 and April 2015, suggesting that IHNV is a major viral pathogen in cultured salmonids. By phylogeny analysis, we found that the JRt-Nagano and JRt-Shizuoka groups could each be further subdivided into three distinct subtypes. The Korean strains were genetically similar to Japanese isolates, suggesting introduction from Japan. Interestingly, the amino acid sequences of the middle glycoprotein gene show that distinct Korean subtypes have circulated, indicating that the settled IHNVs might be evolved stably in cultured salmonid farm environments.
Assuntos
Doenças dos Peixes/virologia , Vírus da Necrose Hematopoética Infecciosa/genética , Vírus da Necrose Hematopoética Infecciosa/isolamento & purificação , Infecções por Rhabdoviridae/veterinária , Sequência de Aminoácidos , Animais , Variação Genética , Genoma Viral , Genótipo , Vírus da Necrose Hematopoética Infecciosa/classificação , Filogenia , República da Coreia , Infecções por Rhabdoviridae/virologia , Salmonidae/crescimento & desenvolvimento , Salmonidae/virologia , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genéticaRESUMO
LATS2 is a tumor suppressor gene implicated in the control of cell growth and the cell cycle. Here, we investigated the post-transcriptional regulation of LATS2 expression by tristetraprolin (TTP). Our results show that the expression level of LATS2 is inversely correlated with TTP expression in human cancer cell lines. Overexpression of TTP reduced the expression level of LATS2. Conversely, treatment with small interfering RNA against TTP increased the expression level of LATS2 through stabilization of LATS2 mRNA and suppressed the proliferation of A549 human lung cancer cells. LATS2 mRNA contains AU-rich elements (AREs) within the 3'-untranslated region, and TTP destabilized a luciferase mRNA containing LATS2 ARE. In addition, RNA electrophoretic mobility shift assay revealed that TTP directly bound to the ARE of LATS2 mRNA. These results establish LATS2 mRNA as a physiological target of TTP and suggest the possibility that TTP controls cell growth through regulation of LATS2 mRNA stability.
Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas Serina-Treonina Quinases/metabolismo , Tristetraprolina/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Regiões 3' não Traduzidas , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Neoplasias Pulmonares/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Estabilidade de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Arsenic trioxide (As(2)O(3)) is a well-known and effective treatment that can result in clinical remission for patients diagnosed with acute promyelocytic leukemia (APL). The biologic efficacy of As(2)O(3) in APL and solid tumor cells has been explained through its actions on anti-proliferation, anti-angiogenesis, and apoptotic signaling pathways. We theorize that As(2)O(3) activates a pathway that disrupts microtubule dynamics forming abnormal, nonfunctioning mitotic spindles, thus preventing cellular division. In this study, we investigated how As(2)O(3) induces apoptosis by causing microtubule dysfunction. METHODS: Cultured NB4 cells were treated with As(2)O(3), paclitaxel, and vincristine. Flow cytometric analysis was then performed. An MTT assay was used to determine drug-mediated cytotoxicity. For tubulin polymerization assay, each polymerized or soluble tubulin was measured. Microtubule assembly-disassembly was measured using a tubulin polymerization kit. Cellular microtubules were also observed with fluorescence microscopy. RESULTS: As(2)O(3) treatment disrupted tubulin assembly resulting in dysfunctional microtubules that cause death in APL cells. As(2)O(3) markedly enhanced the amount of depolymerized microtubules. The number of microtubule posttranslational modifications on an individual tubulin decreased with As(2)O(3) concentration. Immunocytochemistry revealed changes in the cellular microtubule network and formation of polymerized microtubules in As(2)O(3)-treated cells. CONCLUSION: The microtubules alterations found with As(2)O(3) treatment suggest that As(2)O(3) increases the depolymerized forms of tubulin in cells and that this is potentially due to arsenite's negative effects on spindle dynamics.
RESUMO
Gefitinib (Iressa, ZD1839), a selective epidermal growth factor receptor tyrosine kinase inhibitor, inhibits growth, invasion and colony formation of various cancer cells. However, little is known about the effect of combination of gefitinib and arsenic trioxide (ATO) on differentiation of acute promyelocytic leukemia (APL). Therefore, we investigated whether gefitinib had any role in the ATO-induced differentiation of NB4 cells (APL cell line). Gefitinib induced the expression of differentiation markers including CD11b and CD14 in ATO-treated NB4 cells and facilitated ATO-induced morphologic changes and ROS generation. The results were evident that the combination of gefitinib and ATO could induce more effectively the functional differentiation of leukemic cells to macrophage-like cells. Moreover, the ERK pathway was necessary for the enhancement of gefitinib in ATO-induced differentiation, measured by CD11b and CD14 expression on NB4 cells. Therefore, our data indicated that gefitinib can play a potential role as an adjunctive differentiation agent in APL.