HDAC Inhibitors Induce HLA Class I Molecules through the SOX10-IRF1 Axis in Clear Cell Sarcoma Cells

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Clear cell sarcoma (CCS) is a rare cancer with a poor prognosis.
• Immune checkpoint inhibitors (ICIs) show limited efficacy in CCS.
• Previous research suggests histone deacetylase (HDAC) inhibitors can enhance melanoma immunogenicity.

Purpose of the Study:

• To investigate if HDAC inhibition can improve ICI efficacy in CCS.
• To explore the role of the SOX10-IRF1 pathway in HDAC-mediated immunogenicity in CCS.
• To identify potential novel therapeutic strategies for CCS and melanoma.

Main Methods:

• Inhibition of HDAC in CCS cells.
• Small interfering RNA (siRNA) mediated suppression of SOX10.
• Knockdown of IRF1.
• Analysis of HLA class I and PD-L1 expression.

Main Results:

• HDAC inhibition induced HLA class I expression in CCS cells via IRF1.
• SOX10 suppression also led to increased HLA class I expression.
• Specific inhibition of HDAC1/3 upregulated PD-L1 expression in concert with SOX10 suppression.
• IRF1 knockdown diminished PD-L1 induction.

Conclusions:

• HDAC inhibition, particularly of HDAC1/3, increases CCS and melanoma immunogenicity.
• This mechanism involves the SOX10-IRF1 pathway and PD-L1 upregulation.
• HDAC inhibitors represent a potential novel strategy for combination therapy with ICIs in CCS and melanoma.