Effects of anticancer drugs and combination effects of anthracyclines on the hypoxic cells of head and neck cancer

: Head and neck cancer has hypoxic compartment. The hypoxic cells are resistant to anticancer drugs and thought to be one of the causes of recurrence. We examined effects of anticancer drugs on the hypoxic cells using HEp-2 human laryngeal cell line. Anticancer drugs, CDDP, peplomycin (PEP), 5-FU, THP-adriamycin (THP-ADR), and adriamycin (ADR), were incubated with cells in hypoxic condition (5% CO2 and 95% N2) for 72 hours. Drug effects were measured by proliferation rates (IC50). IC50 of PEP increased 22.89 folds in hypoxic cells. IC50 of CDDP and 5-FU also increased 1.86 and 2.27 folds respectively. However, IC50 of THP-ADR and ADR remained same in the hypoxic cells. It was proved that THP-ADR and ADR were effective for the hypoxic cells. The combination effect with THP-ADR and CDDP or PEP were more than additive against the hypoxic cells. It was suggested that the combination with THP-ADR and CDDP or PEP are effective for head and neck cancer which contains hypoxic cell compartment.