Rebekka Johanna Sabine Salzmann – Secondment at the Medical University of Vienna (MUW).

• Post by: fantom
• 16 July 2026
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During my time in the Merkel lab in Vienna, I investigated lipid metabolism in anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL). ALK-positive ALCL cells are known to be deficient in squalene monooxygenase, an enzyme involved in the cholesterol synthesis pathway. Squalene monooxygenase normally converts squalene into 2,3-oxidosqualene, an intermediate step in de novo cholesterol synthesis. Loss of this enzyme leads to the accumulation of squalene and makes these tumor cells dependent on cholesterol uptake from their environment.

Since cholesterol is essential for cell growth, proliferation and membrane integrity, I was interested in the lipid composition of different ALCL models and whether interaction with macrophages can alter the lipid profile of ALK-positive ALCL cells. For this, I used the Folch method to extract lipids from human cells and then analyzed them using thin-layer chromatography (TLC), a method that separates lipids based on their polarity. I analyzed Karpas299 and SupM2 cells after co-culture with THP-1-derived M2-like macrophages. In addition, I compared untreated different ALCL cell lines, ALK-positive as well as ALK-negative.

To verify that THP-1 macrophages provide cholesterol to ALK-positive ALCL cells through secretion, THP-1-derived macrophages were fed with fluorescently labelled cholesterol and subsequently co-cultured with ALK-positive ALCL cells. After only a few hours, fluorescent cholesterol had been taken up by the ALK-positive ALCL cells, located mostly in.

Beyond the scientific work, I really enjoyed the change of routine and learning a new technique in a different laboratory environment. Moreover, I had the chance to meet and collaborate with colleagues from the FANTOM network and the former ALKATRAS network, as well as to reconnect with researchers I had met during my first secondment in Gerda Eggers lab.