Chitooligosaccharides promote radiosensitivity in colon cancer line SW480

• Published in: World journal of gastroenterology : WJG Vol. 22; no. 22; pp. 5193 - 5200
• Main Authors: Han, Fu-Shi, Yang, Shi-Jie, Lin, Mou-Bin, Chen, Ying-Qun, Yang, Ping, Xu, Jin-Ming
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 14.06.2016
• Subjects: Apoptosis - radiation effects; Basic Study; Cell Line, Tumor; Cell Proliferation - drug effects; Cell Survival - radiation effects; Chitin - analogs & derivatives; Chitin - pharmacology; Chitooligosaccharides;Cancer; colon;Radiotherapy;Radiosensitization;Apoptosis;Cell; Colonic Neoplasms - pathology; Colonic Neoplasms - radiotherapy; cycle; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; G2 Phase Cell Cycle Checkpoints - radiation effects; Humans; Radiation Tolerance - drug effects; Radiation-Sensitizing Agents - pharmacology; Radiosensitization; Radiotherapy; Cancer of colon; Chitooligosaccharides; Cell cycle; Apoptosis
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v22.i22.5193

AIM: To investigate the anti-proliferation and radiosensitization effect of chitooligosaccharides(COS) on human colon cancer cell line SW480.METHODS: SW480 cells were treated with 0, 1.0, 2.0, 3.0, 4.0 and 5.0 mg/m L of COS for 48 h. CCK-8 assay was employed to obtain the cell survival ratio of SW480 cells, and the anti-proliferation curve was observed with the inhibition ratio of COS on SW480 cells. The RAY + COS group was treated with 1.0 mg/m L of COS for 48 h, while both the RAY and RAY+COS groups were exposed to X-ray at 0, 1, 2, 4, 6 and 8 Gy, respectively. Clonogenic assay was used to analyze cell viability in the two groups at 10 d after treatment, and a cell survival curve was used to analyze the sensitization ratio of COS. The RAY group was exposed to X-ray at 6 Gy, while the RAY+COS group was treated with 1.0 mg/m L of COS for 48 h in advance and exposed to X-ray at 6 Gy. Flow cytometry was employed to detect cell cycle and apoptosis rate in the non-treatment group, as well as in the RAY and RAY + COS groups after 24 h of treatment.RESULTS: COS inhibited the proliferation of SW480 cells, and the inhibition rate positively correlated with the concentration of COS(P < 0.01). Cell viability decreased as radiation dose increased in the RAY and RAY+COS groups(P < 0.01). Cell viabilities in the RAY+COS group were lower than in the RAY group at all doses of X-ray exposure(P < 0.01), and the sensitization ratio of COS on SW480 cells was 1.39. Compared with the non-treatment group, there was a significant increase in apoptosis rate in both the RAYand RAY + COS groups; while the apoptosis rate in the RAY+COS group was significantly higher than in the RAY group(P < 0.01). In comparing these three groups, the percentage of G2/M phase in both the RAY and RAY + COS groups significantly increased, and the percentage of the S phase and G0/G1 phase was downregulated. Furthermore, the percentage in the G2/M phase was higher, and the percentage in the S phase and G0/G1 phase was lower in the RAY + COS group vs RAY group(P < 0.01). CONCLUSION: COS can inhibit the proliferation of SW480 cells and enhance the radiosensitization of SW480 cells, inducing apoptosis and G2/M phase arrest.