736 Treatment with decitabine (DAC) induces the expression of stemness markers, PD-L1 and NY-ESO-1 in colorectal cancer

Abstract

Colorectal cancer (CRC) is a leading cause of cancer related deaths. Epigenetic silencing of numerous tumor suppressor genes by promoter region hypermethylation has been found in a variety of cancers including CRC. The chemotherapeutic drug decitabine (DAC) is a strong inducer of DNA demethylation. Primary cancer cells are known to express stemness markers as an escape pathway of treatment. Moreover, immunoregulatory genes can be inactivated in these cells by methylation of promoter CpG islands. Both mechanisms are known to play crucial roles in tumor progression. In this study, we investigated the effect of DAC on the expression of stemness markers, Programmed cell death ligand (PD-L1) and New York esophageal squamous cell carcinoma 1 (NY-ESO-1) in a metastatic (1872 Col) and a primary (1076 Col) colorectal cancer cell lines isolated from patients' tumor tissues.