MMP-9: A Game-Changing Indicator in Melanoma Treatment?
"Discover how MMP-9 levels could predict the effectiveness of BRAF inhibitors in melanoma patients, offering new hope for personalized cancer therapy."
Melanoma treatment has undergone a revolution in the last decade, thanks to the introduction of immune checkpoint inhibitors and selective tyrosine kinase inhibitors like BRAF and MEK inhibitors. These advancements have significantly improved progression-free survival (PFS) and overall survival (OS) for many patients. Despite these promising results, a considerable number of patients still develop resistance, highlighting the need for more effective biomarkers to guide treatment decisions.
One area of particular interest is the role of matrix metalloproteinases (MMPs), especially MMP-9, in melanoma progression. MMP-9 promotes melanoma's invasiveness and spread by breaking down the extracellular matrix. Its expression is influenced by multiple molecular pathways, epigenetic events, and aberrant activation of signaling pathways like Ras-Raf-MEK-ERK and PI3K/PTEN/AKT/mTOR. Identifying reliable markers that correlate with treatment response remains a critical challenge.
The study by Salemi et al. (2018) explores the potential of MMP-9 as a predictive marker for response to BRAF inhibitors in melanoma patients with the BRAFV600E mutation. This mutation, the most common alteration observed in melanoma, is associated with MMP-9 overexpression. The researchers investigated whether MMP-9 levels, combined with circulating-free DNA analysis, could provide valuable insights into treatment efficacy and patient outcomes.
How Was MMP-9 Evaluated in Melanoma Patients?

The study involved a detailed evaluation of MMP-9 in melanoma cells following treatment with dabrafenib, a BRAF inhibitor. The in vitro findings were then validated using data from 26 melanoma patients. Among these patients, 14 were treated with a BRAF inhibitor alone, while 12 received a combination of BRAF and MEK inhibitors. Researchers used ELISA assays and droplet digital PCR to measure MMP-9 serum levels and circulating-free DNA BRAFV600E mutation, respectively.
- In vitro Analysis: MMP-9 and pEKR1-2 were statistically down-regulated in melanoma cells after treatment with dabrafenib.
- Circulating-Free DNA: The BRAFV600E mutation was detected in 11 out of 26 melanoma patients, showing higher levels of MMP-9 compared to those with undetectable BRAFV600E mutation.
- Survival Rates: Higher levels of MMP-9 and circulating-free DNA BRAFV600E mutation were associated with lower PFS and OS.
- Therapy Monitoring: MMP-9 significantly decreased at T1 and T2, but not at T-last, for patients with detectable circulating-free DNA BRAFV600E mutation.
What Does This Mean for Melanoma Patients?
In conclusion, the study highlights that high levels of MMP-9 and circulating-free DNA BRAFV600E mutation are associated with poorer progression-free survival (PFS) and overall survival (OS). MMP-9 may serve as a promising indicator of response to BRAF inhibitors when combined with the detection of BRAFV600E mutation. Further research is needed to validate these findings and explore the potential of MMP-9 as a therapeutic target in melanoma.