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Melanoma-Derived iPCCs Show Differential Tumorigenicity and Therapy Response
Mathias Bernhardt1, Daniel Novak1, Yassen Assenov2
1Skin Cancer Unit (G300), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Department of Dermatology, Venereology and Allergology, University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg, 68167 Mannheim, Germany.
Abstract:
A point mutation in the BRAF gene, leading to a constitutively active form of the protein, is present in 45%-60% of patients and acts as a key driver in melanoma. Shortly after therapy induction, resistance to MAPK pathway-specific inhibitors develops, indicating that pathway inhibition is circumvented by epigenetic mechanisms. Here, we mimicked epigenetic modifications in melanoma cells by reprogramming them into metastable induced pluripotent cancer cells (iPCCs) with the ability to terminally differentiate into non-tumorigenic lineages. iPCCs and their differentiated progeny were characterized by an increased resistance against targeted therapies, although the cells harbor the same oncogenic mutations and signaling activity as the parental melanoma cells. Furthermore, induction of a pluripotent state allowed the melanoma-derived cells to acquire a non-tumorigenic cell fate, further suggesting that tumorigenicity is influenced by the cell state.
Insights
Melanoma cells reprogrammed into induced pluripotent cancer cells (iPCCs) exhibit resistance to targeted therapies. This suggests that cell state, not just mutations, influences tumorigenicity and treatment response in BRAF-mutated melanoma.
Area of Science:
- Oncology
- Cancer Biology
- Epigenetics
Background:
- BRAF mutations drive 45%-60% of melanomas, leading to constitutive pathway activation.
- Resistance to MAPK inhibitors develops rapidly, often via epigenetic mechanisms bypassing direct pathway inhibition.
Purpose of the Study:
- To investigate the role of epigenetic modifications and cell state in melanoma drug resistance.
- To explore the potential of reprogramming melanoma cells into a pluripotent state.
Main Methods:
- Melanoma cells were reprogrammed into metastable induced pluripotent cancer cells (iPCCs).
- iPCCs were induced to terminally differentiate into non-tumorigenic lineages.
- Therapeutic resistance of iPCCs and their progeny was assessed against targeted therapies.
Main Results:
- Reprogrammed iPCCs and their differentiated progeny showed increased resistance to targeted therapies.
- This resistance persisted despite harboring the same oncogenic BRAF mutations and signaling activity as parental melanoma cells.
- Induction of pluripotency enabled melanoma cells to acquire a non-tumorigenic cell fate.
Conclusions:
- Cellular state and epigenetic modifications significantly influence melanoma's response to targeted therapies.
- Targeted therapy resistance in melanoma may be circumvented by altering the cell's epigenetic state.
- Tumorigenicity is plastic and influenced by the cell's developmental state, offering new therapeutic avenues.