PhD Scientific Days 2020

Pathology and Oncology I. Lectures

Assessment of Demethylation in Pituitary Neuroendocrine Tumor (Pitnet) Reveals Decitabine as a Potential Therapeutic Option

Előadó neve

Borbála, Szabó, MSc

Előadó munkahelye

Semmelweis University

Előadó telefonszáma

06202220078

Előadó e-mail címe

szaboborbala92@gmail.com

Az előadás címe

Assessment of Demethylation in Pituitary Neuroendocrine Tumor (Pitnet) Reveals Decitabine as a Potential Therapeutic Option

Szerző(k) neve és munkahelye

Borbála Szabó1, Kinga Németh2, Katalin Mészáros2, Nikolette Szücs1, Sándor Czirják3, Lilla Reiniger4, Attila Patócs2,5, Henriett Butz2,5
12nd Department of Internal Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary
2Hereditary Endocrine Tumors Research Group, Hungarian Academy of Sciences and Semmelweis University, Hungary
3National Institute of Clinical Neurosciences, Budapest, Hungary
41st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
5Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary

Szekció

Pathology and Oncology I. Lectures

Language of the presentation

Hungarian

Section, first choice

Pathology and Oncology

Section, second choice

Neurosciences

Összefoglaló szövege

Introduction: The altered DNA methylation of certain genes in Pituitary Neuroendocrine Tumors (PitNETs) are well known. However little information is available regarding global methylation changes and especially the process of demethylation. Influencing global methylation-demethylation could be a potential new therapeutic option, particularly in clinically non-functional PitNETs.
Aim: Therefore our aim was to investigate the role of demethylation in PitNET by in vitro funcional assays and on human PitNET samples.
Materials and Methods: Effect of decitabine, an FDA approved demethylation agent was investigated on GH3 and RC-4B/C pituitary tumor cell lines in vitro by viablitity and proliferation assays. Gene expression of DNA Methyl-transferase (DNMT1), methyl-cytosine dioxygenases (TET1-3) and ubiquitin-like with PHD and ring finger domain (UHRF1-2) were investigated by RT-qPCR. 5-hydroxymethylcytisone (5hmC), UHRF1-2 protein and Ki-67 were assessed by immunohistochemistry on 44 fresh frozen pituitary adenoma tissues (29 gonadotroph, 12 somatotroph, 3 corticotroph) as well. Additionally, 5-methylcytosine (5mC) and 5hmC level were also determined by liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS).
Results: Decitabine significantly decreased 5mC and increased 5hmC in pituitary tumor cells parallel with decreased proliferation and viability. UHRF1-2 were also altered upon decitabine treatment in vitro. Interestingly, in PitNET tissue samples 5hmC was gradually decreased in samples with higher Ki-67 index. In samples with different histology UHRF2 showed different expression, while UHRF1 showed gradually increase in expression in adenoma samples with higher Ki-67 index. Additionally, UHRF2 positively correlated with 5hmC level in pitNET tissues and both UHRF1 and UHRF2 showed significant positive correlation with DNMT1 and TET1-3 expression.
Conclusion: Our results showed that methylation-demethylation process (5hmC, DNMT1, TET1-3 and UHRF1-2) is closely linked to proliferative behaviour of PitNETs both in vitro and on human samples. Altering global 5mC and 5hmC level can be a potential, new therapeutic target in therapy resistant pituitary tumors.

Additional Information

Doctoral School of Clinical Medicine
Program: Hormonal Regulations
Supervisor: Henriett Butz
e-mail: szaboborbala92@gmail.com

Bemutatás módja

Szóbeli

Kind

Szabad

Status

elfogadva

Accepted presentation method

szóbeli

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

4135

Start

11:05

End

11:20

Authors (legacy)

Borbála Szabó1, Kinga Németh2, Katalin Mészáros2, Nikolette Szücs1, Sándor Czirják3, Lilla Reiniger4, Attila Patócs2,5, Henriett Butz2,5
12nd Department of Internal Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary
2Hereditary Endocrine Tumors Research Group, Hungarian Academy of Sciences and Semmelweis University, Hungary
3National Institute of Clinical Neurosciences, Budapest, Hungary
41st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
5Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary