PhD Scientific Days 2022

Budapest, 6-7 July 2022

Pathology and Oncology III. (Poster discussion will take place in the Aula during the Coffee Break)

Investigating the effect of extracellular matrix on adrenocortical carcinoma tumour behaviour

Text of the abstract

Introduction. Extracellular matrix (ECM) represents an important survival signal for tumour cells. However, there is scarce information about the role of ECM in adrenocortical carcinoma (ACC) behaviour. In our previous work, we developed an innovative model in which we combined tumour spheres with extracellular matrix.
Aim. To investigate the role of ECM on ACC behaviour.
Materials and methods. In vitro monolayer (2D) and 3D adrenocortical tumor cell (H295R, SW-13) cultures were generated using matrigel matrix and in vivo ACC xenograft model was developed in SCID mice. In vitro functional assays (proliferation, dead cell ratio and migration) were applied. In vitro and in vivo cortisol production was detected by HPLC-MS/MS. RNA sequencing was used to investigate global transcriptome changes in all three models (2D, 3D and xenograft) with or without mitotane treatment.
Results. While cell proliferation was significantly lower, hormone production increased in in vitro 3D model compared to monolayer cultures. Upon mitotane treatment dead cell ratio was increased and inhibition of hormone secretion was significantly higher in 2D compared 3D model. Changes in both cell proliferation and hormone production were more similar between in vitro 3D and xenograft models compared to 2D culture.
Transcriptome sequencing revealed differences in steroid biosynthesis, metabolism and extracellular matrix-related signaling.
Changes in transcription factor (NR0B1, CXCR4, ABCG2) expression and hedgehog signalling which are implicated in adrenal cell differentiation were detected in in vivo xenografts compared to in vitro models. Stem cell marker KLF4 was significantly induced in 3D and xenograft models while it was unchanged in 2D cultures. CTNNB1 expression while significantly decreased in monolayer cultures following mitotane, it exhibited no change in 3D or xenograft model. As CTNNB1 expression negatively correlates with patient survival, our findings highlight the clinical relevance of our tumor model on therapy response assessment.
Conclusion. There is significant difference between in vitro ACC 2D and 3D tumor model characteristics and mitotane therapy response. By the assessment of cell proliferation, differentiation, dead cell ratio, hormone production our 3D model represents a better in vitro model for ACC.
Funding: NKFI-FK 135065, Bolyai Research Fellowshi (NLP-p17).