Effect of interferon-γand all-trans retinoic acid (ATRA) on the proliferation of and apoptosis in a human cutaneous squamous cell carcinoma cell line SCL-1 / 中华皮肤科杂志

ABSTRACT

Objective To investigate the in vitro effect of interferon-γ (IFN-γ) and ATRA on the morphological transition, proliferation of and apoptosis in a human cutaneous squamous cell carcinoma cell line SCL-1. Methods Cultured SCL-1 cells were divided into 6 groups to be treated with ATRA of 1 μmol/L, various concentrations ( 100, 500, 1000 U/ml) of IFN-γ, the combination of ATRA of 1 μmol/L and IFN-y of 1000 U/ml,respectively, or to remain untreated. MTT assay and flow cytometry were performed to evaluate the cell proliferation and apoptosis. The morphological features of apoptotic cells were observed by a transmission electron microscope (TEM) and inverted phase contrast microscope after 1% propidium iodide staining. Results IFN-γ could inhibit the proliferation of SCL-1 cells in a dose-dependent manner, and the most pronounced inhibitory effect was observed at a dose of 1000 U/ml . ATRA and IFN-γ induced an apoptosis in SCL-1 cells, and the early apoptosis rate was 4.84%, 11.96% and 18.71% in SCL-1 cells after treated with ATRA of 1 μmol/L, IFN-γ of 1000 U/ml and their combination, respectively. A series of morphological changes characteristic of apoptosis,such as bipolar changes, were observed in SCL-1 cells treated with ATRA and IFN-γ, with the presence of many early apoptotic cells, which showed a trend towards benign differentiation. Conclusions Within a certain concentration range, IFN-γcan promote the differentiation, but inhibit the proliferation of SCL-1 cells in a dose-dependent manner, and ATRA could enhance the effects of IFN-γ.