Combining Type I Interferons and 5-Aza-2'-Deoxycitidine to Improve Anti-Tumor Response against Melanoma

Area of Science:

• Oncology
• Immunology
• Epigenetics

Background:

• Tumor resistance to interferon-alpha (IFN-I) is linked to epigenetic silencing of IFN-stimulated genes via DNA methylation.
• Melanoma exhibits resistance to IFN-I, necessitating novel therapeutic strategies.

Purpose of the Study:

• To investigate if co-administration of decitabine (DAC), a demethylating agent, with IFN-I can overcome resistance and enhance anti-melanoma effects.
• To evaluate the direct and immune-mediated anti-tumor effects of the combined DAC and IFN-I treatment in melanoma.

Main Methods:

• In vitro and in vivo studies using murine and human melanoma cells and spheroids.
• Assessment of cell growth, apoptosis, migration, and tumor architecture.
• Analysis of immune cell infiltration (CD8+ T cells, myeloid cells, regulatory T cells) in vivo and in vitro using microfluidic devices.

Main Results:

• Combined DAC/IFN-I treatment significantly inhibited melanoma cell growth, induced apoptosis, and reduced migration.
• Synergistic suppression of 3D melanoma spheroids and induction of the IFN-stimulated gene Mx1.
• In vivo, DAC/IFN-I promoted CD8+ T cell infiltration and inhibited immunosuppressive myeloid and regulatory T cell homing, enhancing adaptive immunity.

Conclusions:

• Decitabine and IFN-I synergize to exert direct anti-melanoma effects by restoring IFN-stimulated genes.
• The combination therapy also enhances anti-melanoma immunity by modulating the tumor microenvironment.
• DAC plus IFN-I represents a promising therapeutic strategy for melanoma, acting through both direct and immune-mediated mechanisms.