维甲酸对实验性大肠癌的逆转治疗作用

Reversale therapeutic effect of retinoic acid on experimental colonrectal cancer

目的;观察维甲酸(RA)对实验性大肠癌的逆转治疗作用。方法:应用维甲酸对大鼠大肠癌的诱发过程进行干预治疗,观察癌变率及增殖细胞核抗原(PCNA)和核仁组成区嗜银蛋白(AgNOR)的表达。结果:维甲酸治疗组(Ⅱ组)大肠癌的发生率显著低于未加维甲酸治疗的对照组(Ⅰ组)。在诱癌的中晚期PCNA指数及AgNOR数亦显著低于Ⅰ组(P<0.01)。Ⅰ、Ⅱ组的PCNA指数及AgNOR数显著高于未用诱癌剂的Ⅲ、Ⅳ组(P<0.01)。组内对比结果显示,Ⅰ组PCNA指数及AgNOR数有随着诱癌时间延长而增加的趋势,差异有显著性(P<0.05),而Ⅱ、Ⅲ、Ⅳ组内比较差异无显著性(P>0.05)。结论:维甲酸可完全或部分阻逆实验性大肠癌的癌变过程,降低其发生率,为临床应用维甲酸防治大肠癌提供了理论资料。

OBJECTIVE To study the reversal therapeutic effect of retinoic acid (RA) on experimental colonrectal cancer. METHODS Retinoic acid was applied to treat rat colonrectal cancer induced by dimethylhydrazine (DMH). The expression of proliferating cell nuclear antigen (PCNA) and nucleolar organizer region- associated protein (AgNOR) were studied. RESULTS It was showed that the incidence of colonrectal cancer was significantly lower in RA treated group (group Ⅱ2) than in untreated group (group Ⅰ). The PCNA indices and mean AgNOR count in group Ⅰ and group Ⅱ were significantly higher than in group Ⅲand group Ⅳ in which carcinogen was not given (P<0.01). The results also showed that there was a tendency in group Ⅰ that the longer of the stage induced by DMH, the higher of the PCNA and AgNOR index. But there was no significant difference in group Ⅱ , Ⅲ and Ⅳ(P>0.05). In the early stage there was no significant difference of the PCNA and AgNOR index between group Ⅰand group Ⅱ. But after the early stage the PCNA and AgNOR index in group Ⅱ were significantly lower than that in group I (P<0.01). CONCLUSIONS It is concluded that RA coald inhibit the carcinogenic effect of DMH and decrease the incidence of colonrectal cancer entirely or partially.