Cancer stem-like cells represent a population of tumour-initiating cells that lead to the relapse and
metastasis of
cancer. Conventional anti-
cancer therapeutic drugs are usually ineffective in eliminating the
cancer stem-like cells. Therefore, new drugs or therapeutic methods effectively targeting
cancer stem-like cells are in urgent need to successfully cure
cancer. Gamboge is a natural anti-
cancer medicine whose pharmacological effects are different from those of conventional chemotherapeutical drugs and they can kill some kinds of
cancer cells selectively. In this study, we identified a new gamboge derivative, Compound 2 (C2), which presents eminent suppression effects on
cancer cells. Interestingly, when compared with
cisplatin (CDDP), C2 effectively suppresses the growth of both
cancer stem-like cells and non-
cancer stem-like cells derived from
head and neck squamous cell carcinoma (
HNSCC), inhibiting the formation of tumour spheres and colony in vitro, resulting in the loss of expression of multiple cancer stem cell (CSC)-related molecules in
HNSCC. Treating with C2 effectively inhibited the growth of
HNSCC in BALB/C nude mice. Further investigation found that C2 notably inhibits the activation of epithelial
growth factor receptor and the phosphorylation of its downstream
protein kinase homo sapiens v-akt murine
thymoma viral oncogene homolog (AKT) in
HNSCC, resulting in down-regulation of multiple CSC-related molecules in
HNSCC. Our study has demonstrated that C2 effectively inhibits the stem-like property of
cancer stem-like cells in
HNSCC and may be a hopeful targeting
drug in
cancer therapy.