Biological response of human esophageal squamous carcinoma cell line KYSE-150 to fractionated x-ray irradiation in vitro / 中华放射肿瘤学杂志

ABSTRACT

Objective To establish a radioresistant human cell line from esophageal squamous car-cinoma cells and detect the marker expression of cancer stem cells (CSCs). Methods A radioresistant hu-man esophageal squamous carcinoma cell line KYSE-150R was established by fractionated irradiation. Mor-phological changes from KYSE-150 to KYSE-150R were observed by phase- contrast microscopy. Karyotype analysis was performed by G-banding. The radiosensitivity of these two cell lines was assessed by colony for-marion assays. The cell cycle distribution was assayed by flow cytometry. CSCs markers of β-catenin and In-tegrin-β_1 were measured by Western Blot. Results The population doubling time of KYSE-150 and KYSE-150R were (23.62±0.23) hrand (25.90±0.55) hr, respectively (t =6.62,P=0.00). The numbers of chromosomes in KYSE-150R cells were increased and chromosome aberrations were observed. The SF_2, D_0, D_q and N values of KYSE-150R were all higher than those of KYSE-150. The ratio of D_0 values was 1.21. After irradiation, the number of S-phase cells of KYSE-150 increased from 45.35%±4.03% to 55.09%± 1.70% (t = -3.86,P=0.02) and G2/M phase cells decreased from 9.91%±3.83% to 1.15%±0.32% (t = 3.95, P = 0.02). However, no apparent change of cell cycle distribution for KYSE- 150R was observed. The expression levels of CSCs markers, β-catenin and Integrin-β_1 in KYSE-150R were about 2 times of those in KYSE-150. Conclusions The new cell line KYSE-150R is more radioresistant than its parental cell line KYSE-150. The CSCs in KYSE-150R is more than those in KYSE-150, which may suggest that CSCs is re-lated with the radioresistance.