Abstract: PURPOSE: To preliminarily explore the cytotoxicological responses of keratinocytes derived from human embryonic stem cells(K-hESCs) to drugs, and to provide a basis for the establishment of a new biosafety evaluation model. METHODS: CCK-8 assay was used to detect cell viability and cytotoxicity. The detection of pharmacological response was observed and compared when K-hESCs directly derived from human embryonic stem cells, human gingival epithelial cells (HGECs), and human immortalized oral epithelial cells (HIOECs) were treated with retinoic acid (RA), 5-fluorouracil(5-FU), dexamethasone(DEX), and penicillin G(PG). Statistical analysis was performed using SPSS 16.0 software package. RESULTS: After drugs were applied to HGECs, HIOEC and K-hESCs, the half inhibitory concentrations (IC₅₀) of RA was 6.1±0.03, 5.62±0.05 and 6.58±0.02, respectively. The IC₅₀ of 5-FU was 1.65±0.02,3.00±0.02 and 1.72±0.04, respectively. The IC₅₀ of DEX was 113.67±0.014,328±0.002 and 126.17±0.05, respectively. The IC₅₀ of PG was 2200±1.34,3795±2.42 and 2880±1.5, respectively. The IC₅₀ of the four drugs between HIOEC and HGECs had significant differences(P<0.05), but there was no significant difference in IC₅₀ between K-hESCs and HGECs(P>0.05). The IC₅₀ of K-hESCs and HIOEC also had significant differences(P<0.05). CONCLUSIONS: IC₅₀ of K-hESCs was closer to HGECs than HIOEC. It was speculated that K-hESCs could simulate the response of normal human cells in cytotoxicity study.

Key words: Human embryonic stem cells, Keratinocytes, Cytotoxicity