LW6

CAY10585, also known as LW6, was first identified and reported by a group scientists from Korea. LW8 was found to inhibits the accumulation of HIF-1alpha. LW6 decreased HIF-1alpha protein expression without affecting HIF-1beta expression. It was further found that LW8 promoted the degradation of wild type HIF-1alpha, but not of a DM-HIF-1alpha with modifications of P402A and P564A, at hydroxylation sites in the oxygen-dependent degradation domain (ODDD) . LW6 did not affect the activity of prolyl hydroxylase (PHD), but induced the expression of von Hippel-Lindau (VHL), which interacts with prolyl-hydroxylated HIF-1alpha for proteasomal degradation. In the presence of LW8, knockdown of VHL did not abolish HIF-1alpha protein accumulation, indicating that LW8 degraded HIF-1alpha via regulation of VHL expression. In mice carrying xenografts of human colon cancer HCT116 cells, LW8 demonstrated strong anti-tumor efficacy in vivo and caused a decrease in HIF-1alpha expression in frozen-tissue immunohistochemical staining. These data suggest that LW8 may be valuable in the development of a HIF-1alpha inhibitor for cancer treatment.