New Insights into Breast Cancer Treatment: DNA Methyltransferase Inhibitors and Immunotherapy

Strategic Insights -

Researchers from Daegu Catholic University have published a study on the effects of DNA methyltransferase (DNMT) inhibitors and immunotherapy on major histocompatibility complex class-I (MHC-I) gene methylation in triple-negative breast cancer (TNBC). The study analyzed data from The Cancer Genome Atlas (TCGA) and found an inverse correlation between DNA methylation and expression of MHC-I. The researchers also observed that the effects of DNMT inhibitors and programmed cell death-ligand 1 (PD-L1) inhibitor were different depending on the TNBC cell lines and the types of drugs used.

Key Takeaways:

  • The study highlights the importance of MHC-I gene expression in TNBC, with implications for cancer immunotherapy.
  • DNMT inhibitors, such as Decitabine and Zebularine, can increase MHC-I expression in certain TNBC cell lines.
  • PD-L1 inhibitor, such as Atezolizumab, can also increase MHC-I expression in some TNBC cell lines, but the effects are cell-line specific.
  • The study suggests that a combination of DNMT inhibitors and PD-L1 inhibitor may be needed to target MHC-I expression in TNBC.
  • The results of the study have implications for the development of new cancer therapies and highlight the need for further research into the mechanisms of MHC-I gene regulation.

Statistics:

  • The study analyzed data from 16 TNBC cell lines.
  • 10 of the cell lines showed increased MHC-I expression after treatment with DNMT inhibitors.
  • 6 of the cell lines showed increased MHC-I expression after treatment with PD-L1 inhibitor.
  • The study found an inverse correlation between DNA methylation and expression of MHC-I in the TCGA dataset.

Sources:

  • Jeong YY, Lee NR, Oh HK. Regulation of major histocompatibility complex class-I (MHC-I) gene methylation using DNA methyltransferase inhibitor and PD-L1 inhibitor in triple negative breast cancer. Discover Oncology, 2025,16(1):1-17. doi: 10.1007/s12672-025-03591-z
  • NewsRx. Reports on Breast Cancer Findings from Daegu Catholic University Provide New Insights. Immunotherapy Weekly, October 15, 2025; p 852.