GSK3β identified as a driver of drug resistance in BRAF mutant melanoma

A new research perspective was published in Oncotarget, Volume 16, on April 4, 2025, titled "GSK3β activation is a key driver of resistance to Raf inhibition in BRAF mutant melanoma cells."

In this work, first author Diana Crisan and corresponding author Abhijit Basu from the University Hospital Ulm led a team that presents experimental evidence pointing to the protein GSK3β as a key contributor to drug resistance in melanoma. Their findings suggest that GSK3β becomes increasingly active in cancer cells during treatment, helping them survive and adapt despite ongoing therapy with BRAF inhibitors.

Melanoma is a type of skin cancer in which nearly half of patients have mutations in the BRAF gene that accelerate tumor growth. While treatments targeting BRAF, known as BRAF inhibitors, initially work well, tumors often find ways to fight back. This research perspective explores how GSK3β, a protein involved in metabolism and cell survival, becomes more active in melanoma cells that develop resistance to BRAF inhibitors.

Researchers treated melanoma cells with a common BRAF mutation using Dabrafenib, a widely used BRAF inhibitor. Over time, the cancer cells developed resistance and showed a marked increase in GSK3β levels. This pattern was confirmed across multiple melanoma cell models, suggesting that the finding is consistent and reliable.

Importantly, the researchers observed that treating resistant cancer cells with a GSK3β inhibitor significantly reduced their growth. This result suggests that blocking this protein could restore sensitivity to treatment, highlighting GSK3β as a promising therapeutic target and supporting the idea of combining GSK3β inhibitors with existing melanoma therapies.

"Remarkably, treatment of BRAFi-resistant melanoma cells with the GSK3 inhibitor LY2090314 for three weeks could overcome resistance and significantly decreased melanoma cell growth, confirming the causal role of GSK3 activation for BRAFi resistance development."

The research perspective adds to ongoing efforts to understand and overcome melanoma drug resistance. It shows that resistance is not driven only by genetic mutations but may also involve adaptive changes in the cell's internal signaling and survival mechanisms. By identifying GSK3β as a potential contributor, the authors offer a new direction for improving the durability of targeted treatments in melanoma.

As research continues, GSK3β may be a critical factor in the long-term success of melanoma therapy, particularly for patients who have stopped responding to standard BRAF-targeted drugs.