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1.
Exp Mol Pathol ; 109: 1-15, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30953647

RESUMEN

Recent FDA approvals of immunotherapy for NSCLC provide patients new treatment options, and these approvals also highlight the importance of the immune response in cancer treatment. While immunotherapy provides patients a new treatment option, the therapy is effective in less than half of the treated patients. To attain greater insight into the tumor-immune microenvironment, NSCLC tumors were analyzed by IHC and RNA-seq. IHC was used to identify NSCLC tumors that contain low, moderate, or high levels of CD8+ positive cells as a manifestation of an active anti-tumor immune response. Gene expression analysis identified an emergent gene signature that is associated with high and moderate levels of CD8 in NSCLC. In addition, the NSCLC tumors also express a unique combination of genes that may indicate complex anti-tumor immune responses (INFG-related genes, STATs, CXCL9, OX40, PD-L1, PD-L2, IDO1, and CD47). Several NSCLC tumors also express the immune checkpoint PD-L1 and at least one additional immune inhibitory molecule (IDO1, PD-L2, or others), which may explain the lack of a therapeutic response to treatments that disrupt only one immune checkpoint pathway.


Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias Pulmonares/genética , Transducción de Señal/genética , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/inmunología , Biomarcadores de Tumor/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Análisis por Conglomerados , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Inmunoterapia/métodos , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/inmunología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/terapia , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Transducción de Señal/inmunología , Microambiente Tumoral/genética , Microambiente Tumoral/inmunología
2.
PLoS One ; 12(5): e0176989, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28562656

RESUMEN

Temporal isolation remains an understudied, and potentially under-appreciated, mechanism of reproductive isolation. Phenological differences have been discovered in populations of the pine white butterfly (Neophasia menapia), a typically univoltine species found throughout western North America. At two locations in the Coast Range of California there are two periods of adult emergence per year, one in early summer (July) and one in late summer/autumn (September/October). Differences in flight time are accompanied by differences in wing shape and pigmentation. Here we use a combination of population genomics and morphological analyses to assess the extent to which temporal isolation is able to limit gene flow between sympatric early and late flights. Not only did we detect both genetic and morphological differences between early and late flights at the two sites, we also found that the patterns of differentiation between the two flights were different at each location, suggesting an independent origin for the two sympatric flights. Additionally, we found no evidence that these sympatric flights originated via colonization from any of the other sampled localities. We discuss several potential hypotheses about the origin of these temporally isolated sympatric flights.


Asunto(s)
Mariposas Diurnas/genética , Animales , Mariposas Diurnas/anatomía & histología , California , Genética de Población , Pinus
3.
Mol Cancer Ther ; 15(7): 1746-56, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27196778

RESUMEN

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer that remains poorly understood at the molecular level. Comprehensive tumor profiling was performed to understand clinically actionable alterations in IBC. Targeted next-generation sequencing (NGS) and IHC were performed to identify activated pathways in IBC tumor tissues. siRNA studies examined the impact of IBC genomic variants in cellular models. IBC tumor tissues were further characterized for immune infiltration and immune checkpoint expression by IHC. Genomic analysis identified recurrent alterations in core biologic pathways, including activating and targetable variants in HER/PI3K/mTOR signaling. High rates of activating HER3 point mutations were discovered in IBC tumors. Cell line studies confirmed a role for mutant HER3 in IBC cell proliferation. Immunologic analysis revealed a subset of IBC tumors associated with high CD8(+)/PD-L1(+) lymphocyte infiltration. Immune infiltration positively correlated with an NGS-based estimate of neoantigen exposure derived from the somatic mutation rate and mutant allele frequency, iScore. Additionally, DNA mismatch repair alterations, which may contribute to higher iScores, occurred at greater frequency in tumors with higher immune infiltration. Our study identifies genomic alterations that mechanistically contribute to oncogenic signaling in IBC and provides a genetic basis for the selection of clinically relevant targeted and combination therapeutic strategies. Furthermore, an NGS-based estimate of neoantigen exposure developed in this study (iScore) may be a useful biomarker to predict immune infiltration in IBC and other cancers. The iScore may be associated with greater levels of response to immunotherapies, such as PD-L1/PD-1-targeted therapies. Mol Cancer Ther; 15(7); 1746-56. ©2016 AACR.


Asunto(s)
Antígeno B7-H1/metabolismo , Linfocitos T CD8-positivos/metabolismo , Regulación Neoplásica de la Expresión Génica , Genómica , Neoplasias Inflamatorias de la Mama/genética , Neoplasias Inflamatorias de la Mama/metabolismo , Linfocitos Infiltrantes de Tumor/metabolismo , Transducción de Señal , Linfocitos T CD8-positivos/inmunología , Línea Celular Tumoral , Análisis por Conglomerados , Biología Computacional/métodos , Femenino , Perfilación de la Expresión Génica , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Neoplasias Inflamatorias de la Mama/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Modelos Biológicos , Mutación , Tasa de Mutación , Fosfatidilinositol 3-Quinasas/metabolismo , ARN Interferente Pequeño/genética , Receptor ErbB-3/genética , Serina-Treonina Quinasas TOR/metabolismo
4.
Evolution ; 70(5): 1156-60, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27061297

RESUMEN

In their technical comment, Janz et al. take issue with our recent study examining the association between host breadth and diversification rates in the brush-footed butterflies (Lepidoptera: Nymphalidae) (Hamm and Fordyce 2015). Specifically, they are concerned that we misrepresent their "oscillation hypothesis" (OH) (Janz et al. 2006; Janz and Nylin 2008) and that one of our models was inadequate to test hypotheses regarding host breadth and diversification rate. Given our mutual interests in the macroevolutionary patterns of herbivorous insects, we appreciate the opportunity to respond to their concerns.


Asunto(s)
Mariposas Diurnas , Filogenia , Animales , Herbivoria
5.
J Insect Sci ; 162016.
Artículo en Inglés | MEDLINE | ID: mdl-27126962

RESUMEN

Members of the plant genus Selaginella (de Beauvois 1805) have few known insect herbivores even though they are considered by some to be 'living fossils', with extant taxa virtually indistinguishable from 300 Mya fossils. Butterflies are well-known herbivores, and the satyrs are among the most speciose of them despite having radiated ∼ 35 Mya ago. Nearly all satyrs feed on grass or sedges, but members of the Neotropical genus Euptychia Hübner 1818 feed on Selaginella; little is known about the degree to which this butterfly favors this ancient plant over those that its close relatives utilize. To advance our knowledge of Euptychia natural history, we conducted a series of experiments to examine oviposition preference and growth rates across a series of potential host plants on a Euptychia westwoodi population in Costa Rica. We found that Euptychia westwoodi Butler 1867 exhibit a strong preference to oviposit on Selaginella eurynota over the sympatric Selaginella arthritica, though they perform equally well as larvae on both plants. We did not observe oviposition on a sympatric grass that is commonly consumed by close relatives of E. westwoodi, and when larvae were offered the grass they refused to eat. These results suggest that E. westwoodi in Costa Rica exhibit a strong preference for Selaginella and may have lost the ability to feed on a locally abundant grass commonly used by other Satyrinae.


Asunto(s)
Mariposas Diurnas/fisiología , Selaginellaceae/parasitología , Animales , Mariposas Diurnas/crecimiento & desarrollo , Costa Rica , Herbivoria , Larva/crecimiento & desarrollo , Oviposición/fisiología
6.
Pharmacol Ther ; 151: 72-86, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25797698

RESUMEN

Epigenetics is a molecular phenomenon that pertains to heritable changes in gene expression that do not involve changes in the DNA sequence. Epigenetic modifications in a whole genome, known as the epigenome, play an essential role in the regulation of gene expression in both normal development and disease. Traditional epigenetic changes include DNA methylation and histone modifications. Recent evidence reveals that other players, such as non-coding RNAs, may have an epigenetic regulatory role. Aberrant epigenetic signaling is becoming to be known as a central component of human disease, and the reversible nature of the epigenetic modifications provides an exciting opportunity for the development of clinically relevant therapeutics. Current epigenetic therapies provide a clinical benefit through disrupting DNA methyltransferases or histone deacetylases. However, the emergence of next-generation epigenetic therapies provides an opportunity to more effectively disrupt epigenetic disease states. Novel epigenetic therapies may improve drug targeting and drug delivery, optimize dosing schedules, and improve the efficacy of preexisting treatment modalities (chemotherapy, radiation, and immunotherapy). This review discusses the epigenetic mechanisms that contribute to the disease, available epigenetic therapies, epigenetic therapies currently in development, and the potential future use of epigenetic therapeutics in a clinical setting.


Asunto(s)
Enfermedad/genética , Epigénesis Genética , Genoma Humano , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Ensayos Clínicos como Asunto , Islas de CpG , Citidina Desaminasa/metabolismo , Metilación de ADN , Metilasas de Modificación del ADN/antagonistas & inhibidores , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Humanos , Inmunoterapia , Transducción de Señal
7.
Evolution ; 69(3): 589-601, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25546268

RESUMEN

Herbivorous insects represent one of the most successful animal radiations known. They occupy a wide range of niches, feed on a great variety of plants, and are species rich; yet the factors that influence their diversification are poorly understood. Host breadth is often cited as a major factor influencing diversification, and, according to the Oscillation Hypothesis, shifts from generalist to specialist feeding states increase the diversification rate for a clade. We explored the relationship between host breadth and diversification within the Nymphalidae (Lepidoptera) and explicitly tested predictions of the Oscillation Hypothesis. We found strong evidence of diversification rate heterogeneity, but no difference in host breadth between clades with a higher diversification rate compared to their sisters. We also found some clades exhibited phylogenetic nonindependence in host breadth and these clades had lower host plant turnover than expected by chance, suggesting host breadth is evolutionarily constrained. Finally, we found that transitions among host breadth categories varied, but the likelihood of reductions in host breadth was greater than that of increases. Our results indicate host breadth is decoupled from diversification rate within the Nymphalidae, and that constraints on diet breadth might play an important role in the evolution of herbivorous insects.


Asunto(s)
Evolución Biológica , Mariposas Diurnas/clasificación , Herbivoria , Filogenia , Animales , Teorema de Bayes , Mariposas Diurnas/fisiología , Larva , Especificidad de la Especie
8.
Mol Ecol ; 23(19): 4871-85, 2014 10.
Artículo en Inglés | MEDLINE | ID: mdl-25156506

RESUMEN

Drosophila suzukii recently invaded North America and Europe. Populations in Hawaii, California, New York and Nova Scotia are polymorphic for Wolbachia, typically with <20% infection frequency. The Wolbachia in D. suzukii, denoted wSuz, is closely related to wRi, the variant prevalent in continental populations of D. simulans. wSuz is also nearly identical to Wolbachia found in D. subpulchrella, plausibly D. suzukii's sister species. This suggests vertical Wolbachia transmission through cladogenesis ('cladogenic transmission'). The widespread occurrence of 7-20% infection frequencies indicates a stable polymorphism. wSuz is imperfectly maternally transmitted, with wild infected females producing on average 5-10% uninfected progeny. As expected from its low frequency, wSuz produces no cytoplasmic incompatibility (CI), that is, no increased embryo mortality when infected males mate with uninfected females, and no appreciable sex-ratio distortion. The persistence of wSuz despite imperfect maternal transmission suggests positive fitness effects. Assuming a balance between selection and imperfect transmission, we expect a fitness advantage on the order of 20%. Unexpectedly, Wolbachia-infected females produce fewer progeny than do uninfected females. We do not yet understand the maintenance of wSuz in D. suzukii. The absence of detectable CI in D. suzukii and D. subpulchrella makes it unlikely that CI-based mechanisms could be used to control this species without transinfection using novel Wolbachia. Contrary to their reputation as horizontally transmitted reproductive parasites, many Wolbachia infections are acquired through introgression or cladogenesis and many cause no appreciable reproductive manipulation. Such infections, likely to be mutualistic, may be central to understanding the pervasiveness of Wolbachia among arthropods.


Asunto(s)
Drosophila/microbiología , Wolbachia/fisiología , Animales , Técnicas de Tipificación Bacteriana , ADN Mitocondrial/genética , Drosophila/clasificación , Drosophila/fisiología , Femenino , Fertilidad , Masculino , Tipificación de Secuencias Multilocus , Filogenia , Reproducción , Wolbachia/clasificación
9.
J Hered ; 105(1): 19-27, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24158752

RESUMEN

The modern delineation of taxonomic groups is often aided by analyses of molecular data, which can also help inform conservation biology. Two subspecies of the butterfly Neonympha mitchellii are classified as federally endangered in the United States: Neonympha mitchellii mitchellii, the Mitchell's satyr, and Neonympha mitchellii francisi, the Saint Francis's satyr. The recent discovery of additional disjunct populations of N. mitchellii in the southeastern US could have important implications for both legal protection and management decisions. We elucidated the relationships among 48 individuals representing 5 N. mitchellii populations using 6 molecular markers (5 nuclear and 1 mitochondrial) under a variety of analytical frameworks. Phylogenetic analysis resulted in moderately supported clades that corresponded with the geographic region where samples originated. Clustering analyses identified 3 groups, wherein the 2 named subspecies formed separate clusters. Coalescent analyses indicated evolutionary divergence between N. m. mitchellii and all other populations but weakly supported divergence among N. m. francisi and the recently discovered populations. Hence, the 2 currently accepted subspecies were clearly different from one another, but the recently discovered populations could not be completely distinguished from N. m. francisi or each other. We propose that N. m. mitchellii and N. m. francisi continue to be managed as separate endangered species.


Asunto(s)
Mariposas Diurnas/clasificación , Mariposas Diurnas/genética , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Animales , Evolución Biológica , Análisis por Conglomerados , Sitios Genéticos , Variación Genética , Haplotipos , Filogeografía , Análisis de Secuencia de ADN , Estados Unidos
10.
G3 (Bethesda) ; 3(12): 2257-71, 2013 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-24142924

RESUMEN

Drosophila suzukii Matsumura (spotted wing drosophila) has recently become a serious pest of a wide variety of fruit crops in the United States as well as in Europe, leading to substantial yearly crop losses. To enable basic and applied research of this important pest, we sequenced the D. suzukii genome to obtain a high-quality reference sequence. Here, we discuss the basic properties of the genome and transcriptome and describe patterns of genome evolution in D. suzukii and its close relatives. Our analyses and genome annotations are presented in a web portal, SpottedWingFlyBase, to facilitate public access.


Asunto(s)
Proteínas de Drosophila/genética , Drosophila/genética , Genoma de los Insectos , Animales , Evolución Biológica , Codón , Elementos Transponibles de ADN , Femenino , Expresión Génica , Internet , Masculino , Anotación de Secuencia Molecular , Filogenia , Transcriptoma , Navegador Web
11.
Childs Nerv Syst ; 29(11): 1977-83, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23999875

RESUMEN

PURPOSE: Malignant rhabdoid tumors (MRT) can occur in a variety of anatomical sites. The most frequent locations are the brain, where they are named atypical teratoid/rhabdoid tumors (AT/RT), and the kidney, where they are named rhabdoid tumors of the kidney (RTK). MRTs at all sites are recognized as the same entity due to their similar morphology, aggressive behavior, and a common genetic abnormality, an inactivating mutation of the SMARCB1/INI-1/hSNF5/BAF47 gene. We aim to investigate potential molecular differences between AT/RT and RTK. METHODS: We analyzed the microRNA (miRNA) and gene expression (GE) profiles of 10 RTK, 13 AT/RT, and 2 human MRT cell lines (G401-RTK and MON-AT/RT). Illumina V2 MicroRNA Chips (Illumina, Inc., CA, USA) were used for miRNA analysis, and Illumina HT-12 whole genome expression arrays were used for GE analysis. RESULTS: The distribution of p values from GE showed a significant difference between RTK and AT/RT, with 20 % of the genes having p values ≤0.05 and the principal component analysis of the GE data showed separation between RTK and AT/RT. However, the miRNA expression failed to identify the different tumor groups. Among the 122 genes significantly differentially expressed between AT/RT and RTK, we found both genes related to brain development (i.e., FABP7, 22-fold increase in AT/RT) and genes related to kidney development (i.e., TCF21, sixfold increase in RTK). CONCLUSION: Based on our results, we hypothesized that although MRT are indeed the same tumor, independent of the site of origin, the GE differences reflect the influence of microenvironment over tumor development.


Asunto(s)
Neoplasias Encefálicas/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias Renales/genética , MicroARNs/biosíntesis , Tumor Rabdoide/genética , Línea Celular Tumoral , Humanos , Bancos de Tejidos
12.
Childs Nerv Syst ; 29(1): 5-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23143003

RESUMEN

PURPOSE: Atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant central nervous system tumors that occur during infancy and early childhood. Their poor outcome and resistance to conventional chemotherapies and radiotherapy, urges the development of new therapies. Recent studies have evaluated the effects of histone deacetylase inhibitors (HDACi) as a new potential treatment for ATRTs. However, most HDACi act unselectively against all, or at least several, histone deacetylase (HDAC) family members. We hypothesized that specific HDAC family members are deregulated in ATRT and therefore a more selective class of HDACi would be beneficial to patients with ATRT. METHODS: To test our hypothesis, we evaluated the expression level of different HDAC family members in ATRTs. Eight ATRTs were compared to six medulloblastoma samples in regards to the level of expression of the 18 HDAC family members as determined by microarray gene expression profiling. RESULTS: HDAC1 was the only member of the HDAC family to be significantly differentially expressed in ATRTs (FC = 4.728; p value = 0.00003). CONCLUSIONS: A class of HDACi specifically targeting HDAC1 may allow for the desired therapeutic benefits with fewer side effects for children with ATRT.


Asunto(s)
Neoplasias del Sistema Nervioso Central/enzimología , Histona Desacetilasas/metabolismo , Tumor Rabdoide/enzimología , Teratoma/enzimología , Línea Celular Tumoral , Perfilación de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Tumor Rabdoide/patología , Teratoma/patología
13.
Drug Discov Today ; 16(13-14): 626-35, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21570477

RESUMEN

The future of drug design and the development of new therapeutics will rely on our ability to unravel the complexities of the epigenome in normal and disease states. Proper epigenetic regulation is essential for normal differentiation in embryogenesis and development. Conversely, abnormal epigenetic regulation is a feature of complex diseases, including cancer, diabetes, heart disease and other pathologies. Epigenetic therapies hold promise for a wide range of biological applications, from cancer treatment to the establishment of induced pluripotent stem cells. The creation of more specific and effective epigenetic therapies, however, requires a more complete understanding of epigenomic landscapes. Here, we give a historical overview of the epigenomics field and how epigenetic modifications can affect embryo development and disease etiology. We also discuss the impact of current and future epigenetic drugs.


Asunto(s)
Diseño de Fármacos , Epigénesis Genética , Epigenómica/métodos , Animales , Humanos
14.
BMC Cancer ; 10: 471, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20809981

RESUMEN

BACKGROUND: Chondrosarcomas are malignant cartilage tumors that do not respond to traditional chemotherapy or radiation. The 5-year survival rate of histologic grade III chondrosarcoma is less than 30%. An animal model of chondrosarcoma has been established--namely, the Swarm Rat Chondrosarcoma (SRC)--and shown to resemble the human disease. Previous studies with this model revealed that tumor microenvironment could significantly influence chondrosarcoma malignancy. METHODS: To examine the effect of the microenvironment, SRC tumors were initiated at different transplantation sites. Pyrosequencing assays were utilized to assess the DNA methylation of the tumors, and SAGE libraries were constructed and sequenced to determine the gene expression profiles of the tumors. Based on the gene expression analysis, subsequent functional assays were designed to determine the relevancy of the specific genes in the development and progression of the SRC. RESULTS: The site of transplantation had a significant impact on the epigenetic and gene expression profiles of SRC tumors. Our analyses revealed that SRC tumors were hypomethylated compared to control tissue, and that tumors at each transplantation site had a unique expression profile. Subsequent functional analysis of differentially expressed genes, albeit preliminary, provided some insight into the role that thymosin-ß4, c-fos, and CTGF may play in chondrosarcoma development and progression. CONCLUSION: This report describes the first global molecular characterization of the SRC model, and it demonstrates that the tumor microenvironment can induce epigenetic alterations and changes in gene expression in the SRC tumors. We documented changes in gene expression that accompany changes in tumor phenotype, and these gene expression changes provide insight into the pathways that may play a role in the development and progression of chondrosarcoma. Furthermore, specific functional analysis indicates that thymosin-ß4 may have a role in chondrosarcoma metastasis.


Asunto(s)
Biomarcadores de Tumor/genética , Condrosarcoma/genética , Epigénesis Genética , Perfilación de la Expresión Génica , Neoplasias Pulmonares/etiología , Tibia/patología , Animales , Biomarcadores de Tumor/metabolismo , Western Blotting , Cartílago/metabolismo , Cartílago/patología , Condrosarcoma/metabolismo , Condrosarcoma/patología , Factor de Crecimiento del Tejido Conjuntivo/genética , Factor de Crecimiento del Tejido Conjuntivo/metabolismo , Metilación de ADN , Genes fos/fisiología , Humanos , Inyecciones Subcutáneas , Neoplasias Pulmonares/secundario , Masculino , Ratones , Ratones Desnudos , Análisis de Secuencia por Matrices de Oligonucleótidos , Fenotipo , Ratas , Ratas Sprague-Dawley , Timosina/genética , Timosina/metabolismo , Tibia/metabolismo , Células Tumorales Cultivadas/trasplante
15.
PLoS One ; 4(12): e8340, 2009 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-20019818

RESUMEN

Abnormal patterns of DNA methylation are observed in several types of human cancer. While localized DNA methylation of CpG islands has been associated with gene silencing, the effect that genome-wide loss of methylation has on tumorigenesis is not completely known. To examine its effect on tumorigenesis, we induced DNA demethylation in a rat model of human chondrosarcoma using 5-aza-2-deoxycytidine. Rat specific pyrosequencing assays were utilized to assess the methylation levels in both LINEs and satellite DNA sequences following 5-aza-2-deoxycytidine treatment. Loss of DNA methylation was accompanied by an increase in invasiveness of the rat chondrosarcoma cells, in vitro, as well as by an increase in tumor growth in vivo. Subsequent microarray analysis provided insight into the gene expression changes that result from 5-aza-2-deoxycytidine induced DNA demethylation. In particular, two genes that may function in tumorigenesis, sox-2 and midkine, were expressed at low levels in control cells but upon 5-aza-2-deoxycytidine treatment these genes became overexpressed. Promoter region DNA analysis revealed that these genes were methylated in control cells but became demethylated following 5-aza-2-deoxycytidine treatment. Following withdrawal of 5-aza-2-deoxycytidine, the rat chondrosarcoma cells reestablished global DNA methylation levels that were comparable to that of control cells. Concurrently, invasiveness of the rat chondrosarcoma cells, in vitro, decreased to a level indistinguishable to that of control cells. Taken together these experiments demonstrate that global DNA hypomethylation induced by 5-aza-2-deoxycytidine may promote specific aspects of tumorigenesis in rat chondrosarcoma cells.


Asunto(s)
Azacitidina/análogos & derivados , Condrosarcoma/genética , Condrosarcoma/patología , Metilación de ADN/efectos de los fármacos , Animales , Azacitidina/farmacología , Línea Celular Tumoral , Citocinas/genética , Citocinas/metabolismo , Decitabina , Epigénesis Genética/efectos de los fármacos , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Elementos de Nucleótido Esparcido Largo/genética , Ratones , Repeticiones de Microsatélite/genética , Midkina , Invasividad Neoplásica/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Ratas , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Análisis de Secuencia de ADN , Ensayos Antitumor por Modelo de Xenoinjerto
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