Vezanje proteina CTCF i BORIS na promotor gena TOP2A u stanicama Cal 27 ; Binding of CTCF and BORIS to TOP2A promoter in Cal 27 cells

Topoizomeraza IIα (kodirana genom TOP2A) je enzim neophodan za preživljavanje stanica. Razina tog enzima je često povišena u zloćudnim tumorima i povezuje se sa osjetljivošću stanica na citotoksične lijekove. Protein CTCF i njegov paralog BORIS, koji se ispoljava samo u subpopulaciji spermatocita te aberantno u brojnim tumorima, imaju važnu ulogu u uspostavljanju i održavanju metilacije DNK i regulaciji transkripcije brojnih gena. S obzirom da se ova dva proteina mogu vezati na ista mjesta u genomu, ali imaju različitu ulogu u regulaciji transkripcije, cilj ovog rada bio je utvrditi da li se oni vežu na promotor gena TOP2A. Tretmanom 3- aminobenzamidom sam potaknula ispoljavanje proteina BORIS u stanicama Cal 27 te metodom kromatinske imunoprecipitacije pokazala da se proteini CTCF i BORIS vežu na navedeni promotor. Rezultati ovog istraživanja će olakšati upoznavanje uloge ovih proteina u regulaciji transkripcije gena TOP2A i primjenjivosti njezine modulacije u nalaženju novih pristupa u liječenju tumora. ; The enzyme topoisomerase IIα (encoded by TOP2A) is essential for cell survival. Its expression is often upregulated in malignant tumors and has been implicated in cellular sensitivity to cytotoxic drugs. Protein CTCF and its paralogue BORIS, which is normally expressed only in a subpopulation of spermatocytes and aberrantly in various tumors, have important roles in the establishment and maintenance of DNA methylation and transcriptional regulation. Since those two proteins bind to the same DNA motifs, but have different roles in transcriptional regulation, the aim of this study was to investigate their association with the TOP2A promoter. With an 3-aminobenzamide treatment I have induced BORIS in Cal 27 cells and by chromatin immunoprecipitation demonstrated that CTCF and BORIS bind to the TOP2A promoter. Results of this study facilitate further investigation of their role in the regulation of TOP2A transcription and the applicability of its modulation in the therapy of malignant tumors.