Endocrine Abstracts

Introduction: In vitro monolayer cell cultures are not able to faithfully model the biological features of the three dimensional (3D) structure of solid tumours. There are limited information about the applicability of 3D cell culturing methods for modeling of tumours of endocrine organs.

Aim: The aim of our work was the establishment and characterization of three-dimensional in vitro models of various endocrine tumour cells in order to test their applicability for evaluation of pathomechanisms of tumorigenesis.

Materials and methods: Induction of spheroid formation of tumor cell lines of pituitary (RC4-B/C, GH3), adrenal cortex (H295R) and adrenal medulla (PC12) cell lines were performed using serum-free defined medium (SFDM), ultra-low attachment plate (ULA), hanging drop culturing method and matrigel. AlamarBlue and Trypan Blue assays were used to examine cell proliferation and cell viability. Pharmacological treatment (mitotane, itaconate and glutaminase inhibitor) were applied for studying cell proliferation. Severe combined immundeficient mice (SCID) were used for xenograft formation of H295R cells. In vitro and in vivo hormone production was assessed by HLPC-MS/MS.3D culture models were compared both to 2D and xenografts models.

Results: While pituitary adenoma cells did not form 3D cultures, in vitro spheroid induction of H295R cells were successful by three different methods. PC12 cells (chromaffin cells) formed 3D spheroids using serum-free defined media (SFDM). 3D culturing resulted in changes in cell viability, proliferation compared to 2D monolayer cultures. Interestingly, hormone producing of H295R cells was higher in 3D cultures compared to monolayer cultured cells, similarly to the in vivo model.

Conclusion: Based on the phenotype features and biological characteristics (viability, proliferation and hormone production), in vitro 3D culture represents a better model of endocrine tumors compared to monolayer culturing. Therapeutic options of neuroendocrine tumours are limited, therefore establishing a new, cheap, easy handling in vitro model could help to better understand the pathogenesis and to identify novel therapeutical approaches for these tumors.

Grants and financial support: This work has been funded by Semmelweis Innovation Found (STIA_19) to Henriett Butz, National Program of Bionics (Program Medical Bionics lead by Attila Patócs) and grant received from National Research and Innovation Office (grant NKFIH K125231 to AP). Henriett Butz is a recipient of Bolyai Research Fellowship of Hungarian Academy of Sciences and ÚNKP-18-4-SE-8 New National Excellence Program of The Ministry of Human Capacities. Kinga Nemeth is a recipient ofNew National Excellence Program of The Ministry of Human Capacities.