Kallikrein gene regulation in hormone-dependent cancer cell lines

摘要: Hormone-dependent cancers (HDCs), such as those of the prostate, ovary, breast and endometrium, share characteristics that indicate similar underlying mechanisms carcinogenesis. Through steroid hormone signalling on "down-stream" target genes, growth, development progression HDCs are regulated. One family highly expressed in regulated by hormones, tissue kallikreins (KLKs). The KLKs a multigene serine proteases involved physiological processes blood pressure regulation, inflammation, tumour via hydrolysis specific substrates. Although KLK gene is clearly implicated tumourigenesis, precise roles played these genes largely unknown. Additionally, except for androgen-responsive KLK2 KLK3, their hormonal regulation yet to be identified. initial focus this thesis was examine kallikreins, KLK1 KLK4, estradiol progesterone endometrial cancer cell lines. From studies, KLK4 expression T47D cells therefore, remaining studies further at transcriptional level. An overview results obtained detailed below. Human K1 hK4 protein levels were increased 10 nmol/L benzoate, progesterone, or combination two, over 48 hours line, KLE. However, same treatments resulted no change hK1 lines, HEC1A HEC1B (only analysed). Progesterone treatment (0-100 nmol/L) 24 clear increase mRNA dose T47D. with 0-48 hr, rapid 2 hr which sustained hr. Further analysis latter antiprogesterone, RU486, hours, an observable decrease 1 µmol/L RU486. estrogen not analysed, data supported premise progesterone-responsive. two suggests transcription directly coupled perhaps through receptor (PR) binding progesterone-responsive regions within promoter far "up-stream" regions. Thus, following performed. To test hypothesis, initiation site (TIS) 5' flanking interrogated. Primer extension RACE identified TIS 78 bp putative ATG translation Korkmaz et al. (2001). This transcript consists only four exons, thus excludes pre/pro signal peptide. TATA-box present -25 -30 TIS, number consensus motifs Sp1 half-sites It possible sites basal gene. response element (PRE) Basal observed proximal region when luciferase reporter transfected into did induce added system, however, inhibitory expression. could contain functional EREs but PREs. In keeping some ER identified, PR obvious region. PRE assembled vitro, vivo, assessed electromobility shift assays chromatin immunoprecipitation (EMSAs ChIPs), respectively. successfully competed out antibody androgen antibody, confirms specificity PRE-PR complex. recruited onto off cyclic fashion. strongly suggest represents one core components complex gene, presumably also contributes Moreover, coordination between cells, thus, provide model system study events vivo.