摘要
目的探讨宫颈癌细胞中叶酸对DNA甲基转移酶1（DNMT1）和甲基化CpG岛结合蛋白2（MeCP2）表达的调节作用。方法采用体外实验研究方法，对宫颈癌细胞caski（HPV16阳性）和C33A（HPV阴性）进行不同浓度（10、50、100、500、750、1000μg／ml）叶酸干预，分别采用Westernblot和real．timePCR方法检测两种细胞中DNMT1和MeCP2蛋白的表达量和mRNA水平。结果随着叶酸水平的升高，两种细胞的生长抑制率（C33A：r=0．984，P〈0．001；Caski：r=0．978，P=0．002）和凋亡率（C33A：r=0．989，P〈0．001；Caski：r=0．994，P〈0．001）均逐渐上升，DNMTl蛋白表达（C33A：r=－0．914，P〈0．001；Caski：r=－0．859，P=0．003）及MeCP2蛋白表达（C33A：r=－0．830，P=0．005；Caski：r=－0．981，P〈0，001）均呈逐渐降低趋势，而DNMTl和MeCP2mRNA的Q比值在两种细胞中的变化均无统计学意义（P〉0．05）。相同叶酸浓度下，DNMTl蛋白和mRNA表达水平在Caski细胞均较C33A细胞为高，而MeCP2蛋白和mRNA表达水平则在C33A细胞较Caski细胞普遍为高。结论补充叶酸可有效抑制宫颈癌细胞的增殖，促进凋亡，逆转DNMTl和MeCP2蛋白的异常表达；HPVl6感染与DNMTl功能异常对宫颈癌的发生可能有协同效应。
Objective To explore the effects of folate on the expression of DNA methyltransferase 1 （DNMT1） and methyl-CpG-bingding protein 2 （MeCP2） in cervical cancer cell lines. Methods Experimental study was carried out in vitro. Human cervical cancer cell lines, including C33A cell with HPV negative and Caski cell with HPV16 positive, were treated with different concentration of folate. The expression of DNMT1 and MeCP2 protein （by Western blot） and mRNA （by real-time PCR） were then detected in the two cell lines. Results It was found that supplement of folate was able to reduce the cell proliferation in C33A cell （r=0.984, P〈0.001 ） and Caski cell （r=0.978, P=0.002）, as well as induced the cell apoptosis （C33A： r=0.989, P〈0.001 ; Caski： r=0.994, P〈0.001）. Results showed that the expression levels of DNMT1 protein （C33A： r=-0.914, P〈 0.001 ; Caski： r =-0.859, P= 0.003） and MeCP2 protein （C33A： r =-0.830, P= 0.005 ; Caski： r=-0.981, P〈0.001 ） decreased gradually with the increase of folate concentrations, but the expression of DNMT1 and MeCP2 mRNA was not observed in Caski or C33A cell. When at the same levels of folate, the expression of DNMT1 protein or mRNA was higher in Caski cell than in C33A cell. However, the expression of MeCP2 protein or mRNA was higher in C33A cell than in Caski cell.Conclusion Our finding indicated that adequate foleta could effectively inhibit the proliferation of cervical cancer cells and facilitate their apoptosis in vitro, thus would reverse the aberration protein expression of DNMT1 and MeCP2. That there might be a synergistic action between HPV16 infection and parafunction of DNMT1 in cervical cancer,being noticed.
出处
《中华流行病学杂志》
CAS
CSCD
北大核心
2013年第2期173-177,共5页
Chinese Journal of Epidemiology
基金
基金项目：国家自然科学基金（30872166,81273157）
山西省自然科学基金（2008011075-1）
