Combination of TPF regimen and cinobufotalin inhibits proliferation and induces apoptosis in human hypopharyngeal and laryngeal squamous cell carcinoma cells

BACKGROUND: Hypopharyngeal squamous cell carcinoma and laryngeal squamous cell carcinoma have a potential risk of metastasis and local recurrence. It is urgent to determine novel effective therapy. METHODS: UMSCC5 and FADU cells were treated with TPF regimen (a mixture comprising paclitaxel, cisplatin, and 5-fluorouracil), cinobufotalin, and combination. Cell counting kit-8 (CCK-8), clone formation assays, and flow cytometry were performed to investigate whether combination of cinobufotalin and TPF can exhibit synergistic effects in reducing tumor growth. RESULTS: CCK-8 assay and IC(50) analysis showed that the TPF and cinobufotalin could suppress viability of UMSCC5 and FADU cells, implying the strong antitumor effect. The synergism between TPF and cinobufotalin was further verified by the CCK-8 and clone formation assays showing the TPF- and cinobufotalin-suppressed cell proliferation synergistically. Notably, flow cytometry showed that the combination also promoted apoptosis synergistically. CONCLUSION: TPF regimen combining cinobufotalin suppressed proliferation and promoted apoptosis synergistically in hypopharyngeal squamous cell carcinoma and laryngeal squamous cell carcinoma cells.