2--deoxy-4--thiocytidine and Neoplasms

Challenges remain on the selection of patients who potentially respond to a class of drugs that target epigenetics for cancer treatment. This study aims to investigate TET2/DNMT3A mutations and antitumor activity of a novel epigenetic agent in multiple human cancer cell lines and animal models.. Seventeen cancer cell lines and multiple xenograft models bearing representative human solid tumors were subjected to 4'-thio-2'-deoxycytidine (T-dCyd) or control treatment. Gene mutations in cell lines were examined by whole exome and/or Sanger sequencing. Specific gene expression was measured in cells and xenograft tumor samples by Western blotting and immunohistochemistry. TET2/DNMT3A mutation status in 47,571 human tumor samples was analyzed at cBioPortal for Cancer Genomics.. Cell survival was significantly inhibited by T-dCyd in breast BT549, lung NCI-H23, melanoma SKMEL5 and renal ACHN cancer lines harboring deleterious TET2 and nonsynonymous DNMT3A mutations compared to 13 lines without such mutation pattern (P = 0.007). The treatment upregulated p21 and induced cell cycle arrest in NCI-H23 cells, and dramatically inhibited their xenograft tumor growth versus wildtype models. T-dCyd administrations led to a significant p21 increase and near eradication of tumor cells in the double-mutant xenografts by histological evaluation. TET2/DNMT3A was co-mutated in human lung, breast, skin and kidney cancers and frequently in angioimmunoblastic and peripheral T cell lymphomas and several types of leukemia.. Cell and animal models with concurrent mutations in TET2 and DNMT3A were sensitive to T-dCyd treatment. The mutations were detectable in human solid tumors and frequently occur in some hematological malignancies.

Topics: Animals; Biomarkers, Tumor; Cell Line, Tumor; Deoxycytidine; Dioxygenases; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3A; DNA-Binding Proteins; Female; HCT116 Cells; Humans; MCF-7 Cells; Mice; Mice, Nude; Mutation; Neoplasms; Proto-Oncogene Proteins; Thionucleosides; Xenograft Model Antitumor Assays