Background: All-trans retinoic acid(RA), an active metabolite of vitamin A, is widely used to induce cell differentiation. It has significant effects on growth and proliferation of epithelial cells. It also causes cell cycle arrest in G0/G1 phase and induces the apoptosis. cisplatin, a chemotherapy compound that cross-linking to DNA, and leads to apoptosis, it is commonly used for treatment of ovarian, head and neck, esophageal, gastric cancers and melanoma. Recent studies showed that RA enhances cytotoxic effects of cisplatin on melanoma and ovarian cancer. Our literature review showed that there is no previous study on the effect of RA in combination with cisplatin on esophageal cancer, hence current study conducted to investigate such combination treatment on esophageal derived cell, KYSE-30.

Materials and Methods: KYSE30 cell line was cultured in presence of different concentration of RA alone and in combination with cisplatin. Then, cell death was investigated by colonogenic assay and acridine orange/ ethedium bromide staining.

Results: The results showed that RA concentrations &ge15µM cause differentiation of KYSE30 to squamous cell morphology, while lower concentrations decreases the colony formation (p&le0.05). These effects were also observed in combination with cisplatin and RA. The best effects on cell death were observed in 10 µM of RA of combination with 5 and 10 µg/ml of cisplatin.

Conclusion: The results suggest that low concentration of RA in combination with cisplatin are more effective than cisplatin alone in terms of apoptosis and necrosis of esophageal cancer, KYSE-30.