Ergosta-7,22-diene-2β,3α,9α-triol (EGDT) from Ganoderma lucidum inhibits nasopharyngeal carcinoma cells by blocking EGFR signaling pathway

Objective To investigate the efficacy and mechanism of EGDT against NPC cell lines. Methods MTT assay was used to assess cell proliferation inhibition of EGDT. The apoptotic induction and cell cycle arrest were detected by flow cytometry. Western blot was adopted to detect the protein levels. Quantitative Real-time PCR was used to determine the mRNA expressions. The NPC xenografts were established to evaluate the tumor growth inhibition of EGDT. Immunohistochemistry was applied to analyze the EGFR expression in the tumor tissues. Results EGDT showed proliferation inhibition on the NPC cell, induced G0/G1 phase arrest and cell apoptosis in vitro. EGDT decreased the protein and mRNA levels of EGFR and its downstream RAF/MEK/ERK and PI3K/AKT pathways in time- and dose-dependent manner. Furthermore, EGDT also showed a sound antitumor activity in NPC xenograft in vivo. Conclusion The treatment of EGDT displays EGFR and its mediated downstream signaling pathway blockade through decreasing the protein and mRNA levels, suggesting a promising strategy in treating human NPC.