Year: 2012
Type: dissertation
Abstract: BTG2, a member of antiproliferative gene family BTG/TOB, has been implicated in cell cycle regulation, normal development and tumor suppression.However, the underlying mechanism(s) by which BTG2 regulates these processes is still unclear.Previously, it has been shown that BTG2 expression is either completely lost or downregulated in human breast cancers.Herein, I found that BTG2 protects human mammary epithelial cells from oxidative stress due to hydrogen peroxide (H 2 O 2 ) and other oxidants, namely, nickel acetate and paraquat.Further, I showed that BTG2mediated protection against oxidative stress in human breast epithelial cells is BRCA1 independent but requires the antioxidant-response transcription factor NFE2L2.The cytoprotective role of BTG2 is partly mediated by up-regulating the activity of key antioxidant enzymes including catalase, superoxide dismutase (SOD) 1, SOD2, and glutathione peroxidase, which are also NFE2L2-depedent.Additionally, I showed that BTG2 increases the transcriptional activity of the antioxidant transcriptional factor, NFE2L2.Furthermore, our immunoprecipitation results indicate that BTG2 is a binding partner of NFE2L2; with this physical interaction being facilitated by Box B, a short highly conserved amino acid motif characteristic of BTG2/TOB family proteins, Fornace, Dr. Vicente Notario and Dr. Rabindra Roy for their valuable time and constructive critique that has helped me to complete and present my final form of this thesis.Finally, I would like to thank my parents as well as my friends for their unconditional love, support and encouragement throughout this process.vi List of abbreviations CHAPTER I ATMataxia telangiectasia mutated ARE -antioxidant response element BRCA1 -breast cancer susceptibility gene 1 BRCA2 -breast cancer susceptibility gene 2 BTG2 -B-cell translocation gene 2 CAF1 -chromatin assembly factor 1 CDC -centers for disease control and prevention CNC -cap n'collar D3T -1,2-dithiole-3-thione ER -estrogen receptor GSH -glutathione, reduced form GSSG -glutathione, oxidized form GST -glutathione S-transferase GPx -glutathione peroxidase H 2 O 2 -hydrogen peroxide Keap1 -kelch-like ECH-associated protein 1 KO -knockout LOH -loss of heterozygosity MT477 -thiopyrano[2,3-c]quinoline NCI -national cancer institute NFE2L2 -nuclear factor (erythroid-derived 2)-like 2 NGF -nerve growth factor PC3 -pheochromocytoma cell 3 PEITC -phenethyl isothiocyanate PKC -protein kinase C pRb -retinoblastoma protein, phosphorylated ROS -reactive oxygen species SNP -single nucleotide polymorphism SOD -superoxide dismutase SRC-1 -steroid receptor co-activator 1 TIS21 -tetradecanoyl phorbol acetate-inducible sequence 21 TOB -transducers of ErbB2 TP53 -tumor protein 53 TSG -tumor suppressor gene CHAPTER II BrdU -5-bromo-2'-deoxyuridine ChIP -chromatin immunoprecipitation vii DMEM -Dulbecco's Modified Eagle medium DMSO -Dimethylsulfoxide DN-NFE2L2 -dominant negative nuclear factor (erythroid-derived 2)-like 2 FCS -fetal calf serum HO-1 -heme oxygenase 1 IgG -immunoglobulin G IP -immunoprecipitation MTT-3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide NQO1 -NAD(P)H dehydrogenase [quinone] 1 RT-PCR -semi-quantitative reverse transcriptase polymerase chain reaction SEM -standard error of the mean siRNA -small interfering RNA wt -wild-type CHAPTER III AR -androgen receptor HoxB9 -homeobox protein B9 mRNA -messenger RNA PICK1-protein kinase Calpha (PKCalpha)-binding protein PRMT1 -protein arginine N-methyltransferase 1 CHAPTER IV BER -base excision repair OGG1 -8-oxoguanine glycosylase OCT1 -octamer transcription factor 1 CHAPTER V DMBA -7,12-dimethylbenzanthracene TMA -tissue microarray analysis viii
Author: Tejaswita M. Karve
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: Georgetown University
OpenAlex ID: W1920699916