SQAP, an acyl sulfoquinovosyl derivative, suppresses expression of histone deacetylase and induces cell death of cancer cells under hypoxic conditions

Sulfoglycolipid, SQAP, is a radiosensitizing agent that makes tumor cells more sensitive to radiation therapy. A previous study revealed that SQAP induced the degradation of hypoxia-inducible factor-1 alpha (HIF-1 alpha) and inhibited angiogenesis in a hepatoma model mouse. Herein, we examined the biological activities of SQAP against hepatocarcinoma cells under low oxygen conditions. Cell growth inhibition of SQAP under hypoxic conditions was significantly higher than that under normoxic conditions. In addition, SQAP was found to impair the expression of histone deacetylase (HDAC) under low oxygen conditions. Our present data suggested that SQAP induced the degradation of HIF-1 alpha and then decreased the expression of HDAC1. Unlike known HDAC inhibitors, SQAP increased the acetylation level of histone in cells without inhibition of enzymatic activity of HDACs. Our data demonstrated hypoxia-specific unique properties of SQAP.

Automated summary

Sulfoglycolipid, SQAP, is a radiosensitizing agent that increases the sensitivity of tumor cells to radiation therapy. In low oxygen conditions, SQAP shows higher efficacy in inhibiting the growth of hepatocarcinoma cells and affecting the expression of key proteins.