RESUMEN
An understanding of differential gene expression in highly metastatic osteosarcoma could provide gene targets for treatment of metastases. We compared gene expression profiles of high- (LM7) and low- (LM2) metastatic SaOS2-derived cell lines in an in vitro tissue culture model and examined several differentially regulated genes in vivo in a murine orthotopic xenograft model. We hypothesized an orthotopic inoculation of LM2 and LM7 cells would establish a primary lesion and the gene expression profile of cells grafted in this fashion would resemble the gene expression profile observed in an in vitro model. Thirty-five days after inoculation, animals were euthanized and both tibiae were harvested and rapidly frozen in liquid nitrogen. Human-specific GAPDH mRNA was present in two of four tibias inoculated with LM2 cells and three of four tibias inoculated with LM7 cells. Tibiae displaying the presence of human cells were assayed by semiquantitative reverse transcriptase polymerase chain reaction. We observed poor correspondence of in vitro to in vivo gene expression for either cell line. Accordingly, in vitro osteosarcoma gene expression data must be interpreted with caution until confirmed in vivo. Our orthotopic injection model allowed in vivo study of differential gene expression between these two cell lines but did not show radiographic evidence of an established primary lesion.
Asunto(s)
Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Regulación Neoplásica de la Expresión Génica/fisiología , Osteosarcoma/metabolismo , Osteosarcoma/patología , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Regulación hacia Abajo/genética , Perfilación de la Expresión Génica , Humanos , Ratones , Análisis de Secuencia por Matrices de Oligonucleótidos , Trasplante HeterólogoAsunto(s)
Clavícula/lesiones , Disnea/etiología , Fútbol Americano/lesiones , Fracturas Óseas/diagnóstico , Luxaciones Articulares/diagnóstico , Articulación Esternoclavicular/lesiones , Accidentes por Caídas , Asma/complicaciones , Traumatismos en Atletas/complicaciones , Niño , Fracturas Óseas/etiología , Fracturas Óseas/terapia , Humanos , Luxaciones Articulares/etiología , Luxaciones Articulares/terapia , Masculino , RecurrenciaRESUMEN
Primary cultures of granule cells (GC) from rat cerebellar cortex were used to determine whether bioelectric activity, via a Ca(2+)/calmodulin-dependent kinase (CaMK) signaling cascade, modulates expression and exon selection in the inositol trisphosphate receptor type 1 (IP(3)R1). IP(3)R1 contains or lacks three exons (S1, S2, and S3) that are regulated in a regionally and temporally specific manner. The neuronal, or long, form of IP(3)R1 is distinguished from peripheral tissues by inclusion of the S2 exon. Although previous studies indicated that IP(3)R1 are undetectable in the cerebellar granular layer in vivo, receptor protein and mRNA are induced in cultured GC grown in medium supplemented with 25 mM KCl or NMDA, two trophic agents that promote long-term survival, compared with GC grown in 5 mM KCl. IP(3)R1 induction in response to 25 mM KCl or NMDA is attenuated by coaddition of voltage-sensitive calcium channel or NMDA receptor antagonists, respectively. Actinomycin D, CaMK, and calcineurin antagonists likewise suppress induction. Unlike the major variants of IP(3)R1 in Purkinje neurons, which lack S1 and S3, GC grown with trophic agents express mRNA containing these exons. Both neuronal types contain S2. Evidence obtained using mutant mice with Purkinje cell lesions, laser-microdissected GC neurons from slices, and explant cultures indicates that GC predominantly express the S1-containing variant of IP(3)R1 in vivo.