| 摘要: | The purpose of this study was to investigate the chemopreventive effect of carotenoids on proliferating cell nuclear antigen (PCNA) and cyclin D1 expression in the betel quid extract (BQE)-induced hamster oral cancer and human KB cell models, respectively. In animal study, forty-one hamsters were divided into six groups and were treated with 0.3 mL of 0.5% of DMBA, BQE, α-tocopherol, β-carotene, lycopene, lutein, and a mixture of carotenoids for 12 weeks. After treatment, the pouches were excised and graded using an immunohistochemical assay of PCNA. In cell experiment, KB cells were cultured and evaluated the inhibitory effect of carotenoids (β-carotene, lycopene and lutein) on cell proliferation. Cyclin D1 and PCNA were evaluated as cell differentiation. In results, most of the animal lesions showed no overexpression of PCNA. However, in the dysplastic lesions, PCNA expressions of the β-carotene, lutein, lycopene, mixture, and vitamin E groups were less than that of the control group. In papilloma lesions, PCNA expressions of the β-carotene, mixture, and vitamin E groups were less severe than of the control group. PCNA expressions of vitamin E-treated group were less severe than that of the controlled group. No carcinoma was found in the lycopene and mixture groups. In cell study, all carotenoids exerted a significant inhibitory effect on KB cell proliferation. Although lycopene suppressed KB cell proliferation at G0/G1 phase with significant decrease of PCNA expression, -carotene and lutein possessed less inhibited effect and even elevated the cell proliferation at G2/M phase. These results indicate that differ carotenoids presented the various suppressive ability of PCNA and cyclin D1 expression in cell proliferation. In conclusion, carotenoids suppressed the carcinogenesis of induced hamster oral cancer and cancer cell line by acting as a suppressor for inhibiting the expression of PCNA and cyclin D1. |
