Development of a genetic material transfer approach for gene therapy

Ayaz, Şerife
This thesis is focused on the development of a gene delivery system, especially for the purpose of DNA vaccination. DNA expression vectors have the potential to be useful therapeutics for a wide variety of applications. A carrier system was designed to realize the delivery of genes to cells and the promotion of controlled adequate expression in the target cells. The low gene delivery efficiency observed with systems composed of polyplexes is mainly due to low stability of polycation e.g polyethylenimine-DNA complexes and inability of most of the complexes to the reach nucleus after entering the cells. The encapsulation of polyethylenimine-DNA complexes inside the alginate microspheres was expected to provide protection from nuclease-based attack, thereby, increasing the stability of the complex and also to achieve controlled release of the complex at the target tissue. In this study, controlled release of complexes from alginate microspheres was studied with DNA staining. In Tris-HCl buffer, the release of PEI-DNA complexes were completed in 48 h, however in cell culture medium (DMEM) 18 % of complexes were released in 48 h because of presence of Ca+2 ions in DMEM. Also, in order to provide mucosal gene delivery for mucosal immunization polyethylene glycol (PEG) was introduced into the composition of microspheres and the two systems were compared in terms of release kinetics of the complexes. In the presence of PEG, release of PEI-DNA complexes from alginate microspheres in the cell culture medium (DMEM) were enhanced and 50 % of PEI-DNA were released from the microspheres in 48 h. To understand the effect of the PEG on the surface of microspheres zeta potential analysis and microscopic examination were carried out. By increasing percentage of PEG (0, 15, 30, 50) in microspheres, less negative zeta potential value were measured. Mucoadhesion of alginate and


Cloning and characterization of industrially important alpha-galactosidase genes from the human pathogen aspergillus fumigatus
Söyler, U. Betül; Ögel, Zümrüt Begüm; Department of Food Engineering (2004)
In this study, molecular cloning studies were performed on the a-galactosidase genes of Aspergillus fumigatus IMI 385708. This organism is an opportunistic saprophytic fungus and a human pathogen, mainly affecting immunocompromised patients. A. fumigatus is a thermotolerant fungus and can efficiently produce thermostable a-galactosidase. Two different cloning strategies were undertaken in this study. A. fumigatus cDNA library, prepared previously, was screened with three different probes. No net results wer...
A novel approach for small sample size family-based association studies: sequential tests
İlk Dağ, Özlem; Dungul, Dilay Ciglidag; ÖZDAĞ, Hilal; İLK, HAKKI GÖKHAN (Springer Science and Business Media LLC, 2011-08-01)
In this paper, we propose a sequential probability ratio test (SPRT) to overcome the problem of limited samples in studies related to complex genetic diseases. The results of this novel approach are compared with the ones obtained from the traditional transmission disequilibrium test (TDT) on simulated data. Although TDT classifies single-nucleotide polymorphisms (SNPs) to only two groups (SNPs associated with the disease and the others), SPRT has the flexibility of assigning SNPs to a third group, that is,...
Novel BRCA2 pathogenic genotype and breast cancer phenotype discordance in monozygotic triplets
Duzkale, Neslihan; EYERCİ, NİLNUR; Oksuzoglu, Berna; Teker, Taner; Kandemir, Olcay (Elsevier BV, 2020-04-01)
BRCA1/2 genes with high-penetrance are tumor suppressor and tumor susceptibility genes that play important roles in the homologous recombination mechanism in DNA repair and increase breast cancer risk. Variants in BRCA1 or BRCA2 are the main causes of familial and early-onset breast cancer. This study investigated pathogenic variant belonging to the BRCA2 gene splice region in monozygotic triplets. A 44-year-old woman was diagnosed with breast cancer when she was 32 years old. Her monozygotic sister had a h...
Identification and analysis of genomic regions with large between-population differentiation in humans
Myles, S.; Tang, K.; Somel, Mehmet; Green, R. E.; Kelso, J.; Stoneking, M. (Wiley, 2008-01-01)
The primary aim of genetic association and linkage studies is to identify genetic variants that contribute to phenotypic variation within human populations. Since the overwhelming majority of human genetic variation is found within populations, these methods are expected to be effective and can likely be extrapolated from one human population to another. However, they may lack power in detecting the genetic variants that contribute to phenotypes that differ greatly between human populations. Phenotypes that...
Functional characterization of microrna-125b expression in MCF7 breast cancer cell line
Tuna, Serkan; Erson Bensan, Ayşe Elif; Department of Biology (2010)
microRNA dependent gene expression regulation has roles in diverse processes such as differentiation, proliferation and apoptosis. Therefore, deregulated miRNA expression has functional importance for various diseases, including cancer. miR-125b is among the commonly downregulated miRNAs in breast cancer cells . Therefore we aimed to characterize the effects of miR-125b expression in MCF7 breast cancer cell line (BCCL) to better understand its roles in tumorigenesis. Here, we investigated mir-125 family mem...
Citation Formats
Ş. Ayaz, “Development of a genetic material transfer approach for gene therapy,” M.S. - Master of Science, Middle East Technical University, 2005.