Darinaparsin is a dimethylated arsenic linked to glutathione. It is cytotoxic to DU145, LNCaP, and PC3 prostate cancer cells (IC50s = 5-10 &#181M) and patient-derived primary prostate cancer cells (IC50s = 2.5-20 &#181M), as well as Jurkat T cell lymphoma and L540 Hodgkin lymphoma cells (IC50s = 2.7 and 1.3 &#181M, respectively). [1][2] It decreases the tumor-initiating subpopulation in DU145 and PC3 cells and halts the cell cycle in the G2/M phase. Darinaparsin decreases transcription of Gli-2, a transcription factor that mediates Sonic hedgehog signaling, when used at a concentration of 1.5 but not 3 &#181M. It decreases SHP1 phosphatase activity and increases ERK phosphorylation. [2] Darinaparsin reduces tumor growth in DU145 and PC3 prostate cancer mouse xenograft models when administered at a dose of 100 mg/kg every other day.[1]

Reference:
[1]. Bansal, N., Farley, N.J., Wu, L., et al. Darinaparsin inhibits prostate tumor-initiating cells and Du145 xenografts and is an inhibitor of hedgehog signaling. Mol. Cancer Ther. 14(1), 23-30 (2015).
[2]. Ravi, D., Bhalla, S., Gartenhaus, R.B., et al. The novel organic arsenical darinaparsin induces MAPK-mediated and SHP1-dependent cell death in T-cell lymphoma and Hodgkin lymphoma cells and human xenograft models. Clin. Cancer Res. 20(23), 6023-6033 (2014).