96 research outputs found
United States: Sexual Behavior in Association with Human Papilloma Virus Vaccination in Young Girls
The first human Papilloma virus (HPV) vaccine was approved in the United States in 2006 with the potential to reduce cervical cancer and genital warts. Since then, its efficacy in preventing HPV-related cancers in both males and females has been promising. Despite CDC recommendations, opponents of the vaccine assert that vaccinating preadolescents and adolescents will increase their sexual activity, as well as overtly condone risky sexual behavior. We analyzed clinic data of 499 adolescents with a mean age of 16 years to explore whether vaccination led to change in sexual behavior after one year. Our results showed no statistically significant difference in either initiation of sexual activity or change in sexual behavior when compared to peers, therefore refuting the assertion that this method of preventative healthcare promotes promiscuity. Thus, we conclude that teenage sexual behavior is linked more closely to ethics, morality, and other socio-cultural phenomena rather than HPV vaccine itself
No Significant Change in Sexual Behavior in Association with Human Papilloma Virus Vaccination in Young Girls
The first human Papilloma virus (HPV) vaccine was approved in the United States in 2006 with the potential to reduce cervical cancer and genital warts. Since then, its efficacy in preventing HPV-related cancers in both males and females has been promising. Despite CDC recommendations, opponents of the vaccine assert that vaccinating pre-adolescents and adolescents will increase their sexual activity, as well as overtly condone risky sexual behavior. We analyzed clinic data of 499 adolescents with a mean age of 16 years to explore whether vaccination led to change in sexual behavior after one year. Our results showed no statistically significant difference in either initiation of sexual activity or change in sexual behavior when compared to peers, therefore refuting the assertion that this method of preventative healthcare promotes promiscuity. Thus, we conclude that teenage sexual behavior is linked more closely to ethics, morality, and other socio-cultural phenomena rather than HPV vaccine itself
Cause and Consequences of Genetic and Epigenetic Alterations in Human Cancer
Both genetic and epigenetic changes contribute to development of human cancer. Oncogenomics has primarily focused on understanding the genetic basis of neoplasia, with less emphasis being placed on the role of epigenetics in tumourigenesis. Genomic alterations in cancer vary between the different types and stages, tissues and individuals. Moreover, genomic change ranges from single nucleotide mutations to gross chromosomal aneuploidy; which may or may not be associated with underlying genomic instability. Collectively, genomic alterations result in widespread deregulation of gene expression profiles and the disruption of signalling networks that control proliferation and cellular functions. In addition to changes in DNA and chromosomes, it has become evident that oncogenomic processes can be profoundly influenced by epigenetic mechanisms. DNA methylation is one of the key epigenetic factors involved in regulation of gene expression and genomic stability, and is biologically necessary for the maintenance of many cellular functions. While there has been considerable progress in understanding the impact of genetic and epigenetic mechanisms in tumourigenesis, there has been little consideration of the importance of the interplay between these two processes. In this review we summarize current understanding of the role of genetic and epigenetic alterations in human cancer. In addition we consider the associated interactions of genetic and epigenetic processes in tumour onset and progression. Furthermore, we provide a model of tumourigenesis that addresses the combined impact of both epigenetic and genetic alterations in cancer cells
Centrosome amplification in chondrosarcomas: A primary cell culture and cryopreserved tumor sample study
The genetics background underlying the aggressiveness of chondrosarcoma (CS) is poorly understood. One possible cause of malignant transformation is chromosomal instability, which involves an error in mitotic segregation due to numerical and/or functional abnormalities of centrosomes. The present study aimed to evaluate centrosome amplification in cryopreserved samples of tumor tissue from patients with CS. An analysis was performed on 3 primary cultures of tumors from patients who underwent surgery between January 2012 and December 2012 at the Department of Orthopedics at the Barretos Cancer Hospital (Barretos, Brazil). Additionally, cryopreserved tumor specimens were analyzed from 10 patients. The data were assessed using immunocytochemistry and immunohistochemistry staining techniques with monoclonal antibody anti-gamma-tubulin. A total of 4 samples of CS cultured cells were obtained from 3 patients. A recurrence of a histological grade III tumor was detected in a female patient with Ollier's syndrome. The other 2 cases were grade I and III. The incidence of centrosome amplification in the primary cultures ranged from 15-64% of the cells. Whereas control cultured fibroblasts showed baseline levels of 4% amplified cells. For the cryopreserved specimens, two independent observers analyzed each sample and counted the cells stained with.-tubulin, verifying the percentage of affected cells to be a mean of 14%, with the number of clusters ranging between 0-6 per slide. In conclusion, centrosome amplification was found to be a consistent biological feature of CS and may underlie chromosomal instability in this tumor.info:eu-repo/semantics/publishedVersio
Modulation by decitabine of gene expression and growth of osteosarcoma U2OS cells in vitro and in xenografts: Identification of apoptotic genes as targets for demethylation
<p>Abstract</p> <p>Background</p> <p>Methylation-mediated silencing of genes is one epigenetic mechanism implicated in cancer. Studies regarding the role of modulation of gene expression utilizing inhibitors of DNA methylation, such as decitabine, in osteosarcoma (OS) have been limited. A biological understanding of the overall effects of decitabine in OS is important because this particular agent is currently undergoing clinical trials. The objective of this study was to measure the response of the OS cell line, U2OS, to decitabine treatment both <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p>Microarray expression profiling was used to distinguish decitabine-dependent changes in gene expression in U2OS cells, and to identify responsive loci with demethylated CpG promoter regions. U2OS xenografts were established under the sub-renal capsule of immune-deficient mice to study the effect of decitabine <it>in vivo </it>on tumor growth and differentiation. Reduced nuclear methylation levels could be detected in xenografts derived from treated mice by immunohistochemistry utilizing a 5-methylcytidine antibody. Decitabine treatment reduced tumor xenograft size significantly (p < 0.05). Histological analysis of treated U2OS xenograft sections revealed a lower mitotic activity (p < 0.0001), increased bone matrix production (p < 0.0001), and a higher number of apoptotic cells (p = 0.0329). Microarray expression profiling of U2OS cultured cells showed that decitabine treatment caused a significant induction (p < 0.0025) in the expression of 88 genes. Thirteen had a ≥2-fold change, 11 of which had CpG-island-associated promoters. Interestingly, 6 of these 11 were pro-apoptotic genes and decitabine resulted in a significant induction of cell death in U2OS cells <it>in vitro </it>(p < 0.05). The 6 pro-apoptotic genes (<it>GADD45A</it>, <it>HSPA9B</it>, <it>PAWR</it>, <it>PDCD5</it>, <it>NFKBIA</it>, and <it>TNFAIP3</it>) were also induced to ≥2-fold <it>in vivo</it>. Quantitative methylation pyrosequencing confirmed that the tested pro-apoptotic genes had CpG-island DNA demethylationas a result of U2OS decitabine treatment both <it>in vitro </it>and in xenografts</p> <p>Conclusion</p> <p>These data provide new insights regarding the use of epigenetic modifiers in OS, and have important implications for therapeutic trials involving demethylation drugs. Collectively, these data have provided biological evidence that one mode of action of decitabine may be the induction of apoptosis utilizing promoter-CpG demethylation of specific effectors in cell death pathways in OS.</p
Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics
Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is poor, with five year osteosarcoma survival rates in people not having improved in decades. For dogs, one year survival rates are only around ~45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human osteosarcoma. Finally, the current position of canine osteosarcoma genetic research is discussed and areas for additional work within the canine population are identified
Mutations causing medullary cystic kidney disease type 1 lie in a large VNTR in MUC1 missed by massively parallel sequencing
Although genetic lesions responsible for some mendelian disorders can be rapidly discovered through massively parallel sequencing of whole genomes or exomes, not all diseases readily yield to such efforts. We describe the illustrative case of the simple mendelian disorder medullary cystic kidney disease type 1 (MCKD1), mapped more than a decade ago to a 2-Mb region on chromosome 1. Ultimately, only by cloning, capillary sequencing and de novo assembly did we find that each of six families with MCKD1 harbors an equivalent but apparently independently arising mutation in sequence markedly under-represented in massively parallel sequencing data: the insertion of a single cytosine in one copy (but a different copy in each family) of the repeat unit comprising the extremely long (~1.5–5 kb), GC-rich (>80%) coding variable-number tandem repeat (VNTR) sequence in the MUC1 gene encoding mucin 1. These results provide a cautionary tale about the challenges in identifying the genes responsible for mendelian, let alone more complex, disorders through massively parallel sequencing.National Institutes of Health (U.S.) (Intramural Research Program)National Human Genome Research Institute (U.S.)Charles University (program UNCE 204011)Charles University (program PRVOUK-P24/LF1/3)Czech Republic. Ministry of Education, Youth, and Sports (grant NT13116-4/2012)Czech Republic. Ministry of Health (grant NT13116-4/2012)Czech Republic. Ministry of Health (grant LH12015)National Institutes of Health (U.S.) (Harvard Digestive Diseases Center, grant DK34854
In Vitro Analysis of Integrated Global High-Resolution DNA Methylation Profiling with Genomic Imbalance and Gene Expression in Osteosarcoma
Genetic and epigenetic changes contribute to deregulation of gene expression and development of human cancer. Changes in DNA methylation are key epigenetic factors regulating gene expression and genomic stability. Recent progress in microarray technologies resulted in developments of high resolution platforms for profiling of genetic, epigenetic and gene expression changes. OS is a pediatric bone tumor with characteristically high level of numerical and structural chromosomal changes. Furthermore, little is known about DNA methylation changes in OS. Our objective was to develop an integrative approach for analysis of high-resolution epigenomic, genomic, and gene expression profiles in order to identify functional epi/genomic differences between OS cell lines and normal human osteoblasts. A combination of Affymetrix Promoter Tilling Arrays for DNA methylation, Agilent array-CGH platform for genomic imbalance and Affymetrix Gene 1.0 platform for gene expression analysis was used. As a result, an integrative high-resolution approach for interrogation of genome-wide tumour-specific changes in DNA methylation was developed. This approach was used to provide the first genomic DNA methylation maps, and to identify and validate genes with aberrant DNA methylation in OS cell lines. This first integrative analysis of global cancer-related changes in DNA methylation, genomic imbalance, and gene expression has provided comprehensive evidence of the cumulative roles of epigenetic and genetic mechanisms in deregulation of gene expression networks
Genome-wide methylation and expression profiling identifies promoter characteristics affecting demethylation-induced gene up-regulation in melanoma
Rapid Selection and Proliferation of CD133(+) Cells from Cancer Cell Lines: Chemotherapeutic Implications
Cancer stem cells (CSCs) are considered a subset of the bulk tumor responsible for initiating and maintaining the disease. Several surface cellular markers have been recently used to identify CSCs. Among those is CD133, which is expressed by hematopoietic progenitor cells as well as embryonic stem cells and various cancers. We have recently isolated and cultured CD133 positive [CD133(+)] cells from various cancer cell lines using a NASA developed Hydrodynamic Focusing Bioreactor (HFB) (Celdyne, Houston, TX). For comparison, another bioreactor, the rotary cell culture system (RCCS) manufactured by Synthecon (Houston, TX) was used. Both the HFB and the RCCS bioreactors simulate aspects of hypogravity. In our study, the HFB increased CD133(+) cell growth from various cell lines compared to the RCCS vessel and to normal gravity control. We observed a (+)15-fold proliferation of the CD133(+) cellular fraction with cancer cells that were cultured for 7-days at optimized conditions. The RCCS vessel instead yielded a (−)4.8-fold decrease in the CD133(+)cellular fraction respect to the HFB after 7-days of culture. Interestingly, we also found that the hypogravity environment of the HFB greatly sensitized the CD133(+) cancer cells, which are normally resistant to chemo treatment, to become susceptible to various chemotherapeutic agents, paving the way to less toxic and more effective chemotherapeutic treatment in patients. To be able to test the efficacy of cytotoxic agents in vitro prior to their use in clinical setting on cancer cells as well as on cancer stem cells may pave the way to more effective chemotherapeutic strategies in patients. This could be an important advancement in the therapeutic options of oncologic patients, allowing for more targeted and personalized chemotherapy regimens as well as for higher response rates
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