Tan Xuemei, Ye Hua, Yang Kai, Chen Dan, Tang Hong
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China; Email:
Zhonghua Kou Qiang Yi Xue Za Zhi. 2015 Jul;50(7):392-8.
To investigate the expression and circadian rhythm variation of biological clock gene Per1 and cell cycle genes p53, CyclinD1, cyclin-dependent kinases (CDK1), CyclinB1 in different stages of carcinogenesis in buccal mucosa and its relationship with the development of buccal mucosa carcinoma.
Ninety golden hamsters were housed under 12 hours light-12 hours dark cycles, and the model of buccal squamous cell carcinoma was established by using the dimethylbenzanthracene (DMBA) to smear the golden hamster buccal mucosa. Before the DMBA was used and after DMBA was used 6 weeks and 14 weeks respectively, the golden hamsters were sacrificed at 6 different time points (5 rats per time point) within 24 hour, including 4, 8, 12, 16, 20 and 24 hour after lights onset (HALO), and the normal buccal mucosa, precancerous lesions and cancer tissue were obtained, respectively. HE stained sections were prepared to observe the canceration of each tissue. Real time RT-PCR was used to detect the mRNA expression of Per1, p53, CyclinD1, CDK1 and CyclinB1, and a cosine analysis method was applied to determine the circadian rhythm variation of Per1, p53, CyclinD1, CDK1 and CyclinB1 mRNA expression, which were characterized by median, amplitude and acrophase.
The expression of Per1, p53, CDK1 and CyclinD1 mRNA in 6 different time points within 24 hours in the tissues of three different stages of carcinogenesis had circadian rhythm, respectively. However, the CyclinB1 mRNA was expressed with circadian rhythm just in normal and cancer tissue (P < 0.05), while in precancerous lesions the circadian rhythm was in disorder (P > 0.05). As the development of carcinoma, the median of Per1 and p53 mRNA expression were significantly decreased (P < 0.05), yet the median of CDK1, CyclinB1 and CyclinD1 mRNA expression were significantly increased (P < 0.05). The amplitude of Per1, p53 and CyclinD1 mRNA expression was significantly decreased as the development of carcinoma (P < 0.05), however the amplitude of CDK1 mRNA expression was significantly increased (P < 0.05). In addition, there was no significant difference in the amplitude of CyclinB1 mRNA expression. The time that the peak expression value of Per1 and CDK1 mRNA appeared (Acrophase) in precancerous lesions was remarkably earlier than that in normal tissues, but the acrophase of p53 and CyclinD1 mRNA expression was remarkably delayed. Moreover, the acrophase of CDK1 and CyclinB1 mRNA expression in cancer tissues was obviously earlier than that in normal tissues, yet there was no significant variation in acrophase of Per1, p53, CyclinD1 mRNA expression between normal tissues and cancer tissues.
The circadian rhythm of clock gene Per1 and cell cycle genes p53, CyclinD1, CDK1, CyclinB1 expression remarkably varied with the occurrence and development of carcinoma. Further research into the interaction between circadian and cell cycle of two cycle activity and relationship with the carcinogenesis may providenew ideas and methods of individual treatment and the mechanism of carcinogenesis.
探讨生物钟基因Per1及细胞周期基因p53、CyclinD1、细胞周期蛋白依赖性激酶（CDK1）、CyclinB1在颊黏膜癌变不同阶段的表达及昼夜节律变化，及其与颊黏膜癌发生发展的关系。
将90只金黄地鼠饲养于12小时光照-12小时黑暗周期环境中，采用二甲基苯并蒽（DMBA）涂抹金黄地鼠颊黏膜建立颊黏膜鳞状细胞癌模型。分别于使用DMBA前及使用DMBA后6周、14周，在24小时内的6个不同时间点（每个时间点5只大鼠）处死金黄地鼠，包括光照开始后4、8、12、16、20和24小时（HALO），分别获取正常颊黏膜、癌前病变及癌组织。制备HE染色切片观察各组织的癌变情况。采用实时RT-PCR检测Per1、p53、CyclinD1、CDK1和CyclinB1的mRNA表达，并应用余弦分析法确定Per1、p53、CyclinD1、CDK1和CyclinB1 mRNA表达的昼夜节律变化，以中位数、振幅和峰值相位进行表征。
致癌过程三个不同阶段组织中，Per1、p53、CDK1和CyclinD1 mRNA在24小时内6个不同时间点的表达均具有昼夜节律。然而，CyclinB1 mRNA仅在正常组织和癌组织中有昼夜节律表达（P<0.05），在癌前病变中昼夜节律紊乱（P>0.05）。随着癌的发展，Per1和p53 mRNA表达的中位数显著降低（P<0.05），而CDK1、CyclinB1和CyclinD1 mRNA表达的中位数显著升高（P<0.05）。随着癌的发展，Per1、p53和CyclinD1 mRNA表达的振幅显著降低（P<0.05），而CDK1 mRNA表达的振幅显著升高（P<0.05）。此外，CyclinB1 mRNA表达的振幅无显著差异。癌前病变中Per1和CDK1 mRNA表达峰值出现的时间（峰值相位）明显早于正常组织，但p53和CyclinD1 mRNA表达的峰值相位明显延迟。此外，癌组织中CDK1和CyclinB1 mRNA表达的峰值相位明显早于正常组织，但正常组织与癌组织中Per1、p53、CyclinD1 mRNA表达的峰值相位无显著差异。
生物钟基因Per1及细胞周期基因p53、CyclinD1、CDK1、CyclinB1表达的昼夜节律随癌的发生发展显著变化。进一步研究昼夜节律与细胞周期二者活动的相互作用及其与致癌作用的关系，可能为个体化治疗及致癌机制提供新的思路和方法。
