Gambogic acid induces growth inhibition and differentiation via upregulation of p21waf1/cip1 expression in acute myeloid leukemia cells

AbstractGambogic acid (GA) is the major active ingredient of gamboges, a brownish to orange resin product from Garcinia hanburyi tree in Southeast Asia. This compound exhibits anti-cancer effect on solid tumors. In this study, we investigated the effects of GA on the growth and differentiation of acute myeloid leukemia cells by growth-inhibition detection, morphological changes observation, nitroblue tetrazolium reduction, and the expression of the relative cell-surface differentiation markers. The results showed that GA could inhibit cell growth and promote differentiation in U937 and HL-60 cells. In addition, GA upregulated the expression of p21waf1/cip1 in the two cell lines. Finally, downregulating the p21waf1/cip1 expression with small interfering RNA partially blocked GA-induced cell growth inhibition and differentiation. These results of this study revealed that GA may be used as one of the investigational drugs for acute myeloid leukemia.Keywords:: gambogic acidacute myeloid leukemiagrowth inhibitiondifferentiationp21waf1/cip1 AcknowledgmentsThis work was supported by the National Natural Science Foundation of China (81001451), Program for Changjiang Scholars and Innovative Research Team in University (IRT1193), the Project Program of State Key Laboratory of Natural Medicines, China Pharmaceutical University (No. JKGZ201101), and the National Science & Technology Major Project (No. 2012ZX09304-001).Notes1. Yan Chen and Hui Hui contributed equally to this work.