Introduction:

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy with limited treatment options so far. Possible treatments are usually studied in monolayer cell-culture based in vitro models. In vitro models, such as spheroids, that better resemble the tumor structure and mimic cell-cell interactions affecting treatment response, are preferable. While spheroid formation in ACC cell lines has already proven successful, spheroid formation out of human primary ACC tissue has not succeeded yet.

Methods:

Five human primary ACC cell cultures were used for spheroid formation. 5.000–20.000 cells were plated into a low adherence plate prohibiting cell attachment, followed by incubation on a shaking plate for 72 hours. Spheroid size, cortisol secretion and mitotane sensitivity were determined.

Results:

Spheroid formation was successful in three out of five human ACC tissues (60%). Here we present data of one human ACC spheroid that has been in culture for 134 days. Over time, spheroid size increased 4.7-fold from 4.608µm² to 21.691µm². Cortisol production by the tumor spheroid and mitotane sensitivity did not change (day 7: IC₅₀ 13µM, day 134: IC₅₀ 11µM) during the culturing period.

Conclusion:

ACC spheroid culturing was feasible in 60% of the patients, and in one case even up to 134 days, with culturing time not affecting cortisol production nor mitotane sensitivity, indicating stable spheroid cells over time. The possibility to culture ACC spheroids can provide a suitable in vitro ACC model to improve understanding of both the disease and possible new therapies.