Browsing by Subject "Gene amplification"

Filter results by typing the first few letters
Now showing 1 - 4 of 4
  • Thumbnail Image
    ItemOpen Access
    Endothelial progenitor cells display clonal restriction in multiple myeloma
    (BioMed Central Ltd., 2006) Braunstein, M.; Özçelik, T.; Baǧişlar, S.; Vakil, V.; Smith, E. L. P.; Dai, K.; Akyerli, C. B.; Batuman O. A.
    Background: In multiple myeloma (MM), increased neoangiogenesis contributes to tumor growth and disease progression. Increased levels of endothelial progenitor cells (EPCs) contribute to neoangiogenesis in MM, and, importantly, covary with disease activity and response to treatment. In order to understand the mechanisms responsible for increased EPC levels and neoangiogenic function in MM, we investigated whether these cells were clonal by determining X-chromosome inactivation (XCI) patterns in female patients by a human androgen receptor assay (HUMARA). In addition, EPCs and bone marrow cells were studied for the presence of clonotypic immunoglobulin heavy-chain (IGH) gene rearrangement, which indicates clonality in B cells; thus, its presence in EPCs would indicate a close genetic link between tumor cells in MM and endothelial cells that provide tumor neovascularization. Methods: A total of twenty-three consecutive patients who had not received chemotherapy were studied. Screening in 18 patients found that 11 displayed allelic AR in peripheral blood mononuclear cells, and these patients were further studied for XCI patterns in EPCs and hair root cells by HUMARA. In 2 patients whose EPCs were clonal by HUMARA, and in an additional 5 new patients, EPCs were studied for IGH gene rearrangement using PCR with family-specific primers for IGH variable genes (VH). Results: In 11 patients, analysis of EPCs by HUMARA revealed significant skewing (≥ 77% expression of a single allele) in 64% (n = 7). In 4 of these patients, XCI skewing was extreme (≥ 90% expression of a single allele). In contrast, XCI in hair root cells was random. Furthermore, PCR amplification with VH primers resulted in amplification of the same product in EPCs and bone marrow cells in 71 % (n = 5) of 7 patients, while no IGH rearrangement was found in EPCs from healthy controls. In addition, in patients with XCI skewing in EPCs, advanced age was associated with poorer clinical status, unlike patients whose EPCs had random XCI. Conclusion: Our results suggest that EPCs in at least a substantial subpopulation of MM patients are related to the neoplastic clone and that this is an important mechanism for upregulation of tumor neovascularization in MM. © 2006 Braunstein et al; licensee BioMed Central Ltd.
  • Thumbnail Image
    ItemOpen Access
    Lack of association between RNASEL Arg462Gln variant and the risk of breast cancer
    (International Institute of Anticancer Research, 2004) Sevinç, A.; Yannoukakos, D.; Konstantopoulou, I.; Manguoglu, E.; Lüleci, G.; Çolak, T.; Akyerli, C.; Çolakoglu, G.; Tez, M.; Sayek, I.; Gerassimos, V.; Nasioulas, G.; Papadopoulou, E.; Florentin, L.; Kontogianni, E.; Bozkurt, B.; Kocabas, N. A.; Karakaya, A. E.; Yulug, I. G.; Özçelik, T.
    Background: The RNASEL G1385A variant was recently found to be implicated in the development of prostate cancer. Considering the function of RNase L and the pleiotropic effects of mutations associated with cancer, we sought to investigate whether the RNASEL G1385A variant is a risk factor for breast cancer. Patients and Methods: A total of 453 breast cancer patients and 382 age- and sex-matched controls from Greece and Turkey were analyzed. Genotyping for the RNASEL G1385A variant was performed using an Amplification Refractory Mutation System (ARMS). Results: Statistical evaluation of the RNASEL G1385A genotype distribution among breast cancer patients and controls revealed no significant association between the presence of the risk genotype and the occurrence of breast cancer. Conclusion: Although an increasing number of studies report an association between the RNASEL G1385A variant and prostate cancer risk, this variant does not appear to be implicated in the development of breast cancer.
  • Thumbnail Image
    ItemOpen Access
    Multiplex systems for the amplification of short tandem repeat loci: evaluation of laser fluorescence detection
    (1997) Ricciardone, M. D.; Lins, A. M.; Schumm, J. W.; Holland, M. M.
    Short tandem repeat (STR) loci are ideal markers for personal identification and for genomic mapping. Two fluorescent multiplex systems, each designed for simultaneous PCR amplification of four polymorphic STR loci (HUMCSF1PO, HUMTPOX, HUMTH01 and HUMVWFA31, and HUMF13A01, HUMFESFPS, HUMBFXIII and HUMLIPOL), were evaluated on three laser fluorescence detection instruments. Concordant DNA typing results were obtained with all three detection methods. These fluorescent multiplex STR systems offer an accurate, reproducible and versatile method of DNA profiling that is well-suited for forensic identity testing and other genetic analyses.
  • Thumbnail Image
    ItemOpen Access
    Oligonucleotide-based label-free detection with optical microresonators: strategies and challenges
    (Royal Society of Chemistry, 2016) Toren, P.; Ozgur E.; Bayındır, Mehmet
    This review targets diversified oligonucleotide-based biodetection techniques, focusing on the use of microresonators of whispering gallery mode (WGM) type as optical biosensors mostly integrated with lab-on-a-chip systems. On-chip and microfluidics combined devices along with optical microresonators provide rapid, robust, reproducible and multiplexed biodetection abilities in considerably small volumes. We present a detailed overview of the studies conducted so far, including biodetection of various oligonucleotide biomarkers as well as deoxyribonucleic acids (DNAs), ribonucleic acids (RNAs) and proteins. We particularly advert to chemical surface modifications for specific and selective biosensing.