中国癌症杂志 ›› 2015, Vol. 25 ›› Issue (1): 19-24.doi: 10.3969/j.issn.1007-3969.2015.01.004

• 论著 • 上一篇    下一篇

宫颈上皮内瘤变和宫颈癌中LMX1A和PAX1基因甲基化的定量分析

陈蔚1,杨慧娟1,徐军2,朱昊平3   

  1. 1. 复旦大学附属肿瘤医院妇瘤科,复旦大学上海医学院肿瘤学系,上海 200032 ;
    2. 复旦大学附属闵行医院妇产科,上海 201199 ;
    3. 上海市计划生育科学研究所,上海 200032
  • 出版日期:2015-01-30 发布日期:2015-05-08
  • 通信作者: 徐军 E-mail:xujun1958@hotmail.com
  • 基金资助:
    上海市卫生局科研课题计划(20114152)。

Quantitative analysis of LMX1A and PAX1 gene methylation in cervical cancer and cervical intraepithelial neoplasia

CHEN Wei1, YANG Huijuan1, XU Jun2, ZHU Haoping3   

  1. 1.Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China; 2.Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai 201199, China; 3.Shanghai Institute of Planned Parenthood Research, Shanghai 200032, China
  • Published:2015-01-30 Online:2015-05-08
  • Contact: XU Jun E-mail: xujun1958@hotmail.com

摘要:
背景与目的:
DNA甲基化是宫颈上皮癌变过程中常见的表观遗传改变。本研究旨在检测同源盒转录因子1ɑ(LMX1A)基因和配对盒基因家族PAX1基因在浸润性宫颈鳞癌(invasive cervical cancers,ICC)组织中的甲基化水平,评估其作为分子标志物用于区分各级别宫颈病变的潜在临床价值。方法:在32例低级别宫颈上皮内瘤变(low-grade cervical intraepithelial neoplasia,LG-CIN)、34例高级别宫颈上皮内瘤变(high-grade cervical intraepithelial neoplasia,HG-CIN)、27例ICC病变宫颈组织和28例慢性宫颈炎为正常对照组(negative for intraepithelial lesion or malignancy,NLM)中,采用巢式PCR和焦硫酸测序(pyrosequencing)技术定量分析LMX1A基因的6个位点和PAX1基因的9个位点的甲基化。并通过受试者工作特征曲线下面积(receiver operating characteristic curve,ROC)的计算获得上述基因的甲基化检测用于诊断各级别宫颈病变的准确性。结果:宫颈癌中的LMX1A基因6个位点的甲基化平均水平为14.36%,明显高于HG-CIN病变的4.70%、LG-CIN病变的5.05%和NLM的4.53%(P<0.01)。宫颈癌中PAX1基因9个位点的甲基化平均水平为41.97%,明显高于HG-CIN的10.21%(P<0.01);而后者又明显高于LG-CIN的5.55%和NLM的4.92%(P<0.01)。检测LMX1A基因甲基化和PAX1基因甲基化水平鉴别宫颈癌的ROC曲线下面积分别为0.603(P=0.104)和0.883(P<0.001)。经ROC曲线下面积计算获得最佳PAX1基因甲基化水平的界定值为20.50%,其诊断浸润性宫颈癌的灵敏度为81%、特异度为93%。当PAX1基因甲基化水平界定值为9.58%时,其检测浸润性宫颈癌的灵敏度为89%、特异度为84%。结论:定量分析宫颈组织中的PAX1基因甲基化将有可能作为分子标志物用于浸润癌的鉴别诊断,而LMX1A基因的甲基化检测临床价值有限。

关键词: 宫颈癌, 宫颈上皮内瘤变, DNA甲基化, LMX1A基因, PAX1基因

Abstract:
Background and purpose: DNA methylation is a common epigenetic alteration in cervical carcinogenesis. The aim of this study was to measure the levels of LMX1A and PAX1 gene methylation in cervical cancer and precursors and to identify their potential in clinical application. Methods: Cervical specimens were collected from 121 female patients including 27 cases with invasive cervical cancers (ICC), 34 cases with high-grade cervical intraepithelial neoplasia (HG-CIN), 32 cases with low-grade cervical intraepithelial neoplasia (LG-CIN) and 28 cases with chronic cervicitis as normal controls (NLM). DNA methylations of the LMX1A and PAX1 gene were quantified using the techniques of nest PCR and pyrosequencing. The mean methylation values of the 6 gene loci on the LMX1A gene and the 9 gene loci on the PAX1 gene were respectively calculated for a given sample. Receiver operating characteristic (ROC) curve was used to evaluate the accuracy of gene methylation analysis to discriminate the cervical diseases. Results: The mean methylation value of the LMX1A gene in ICC was 14.36%, which was significantly higher than those in HG-CIN (4.70%), LG-CIN (5.05%) and NLM (4.53%) (P<0.01). The mean methylation value of the PAX1 gene in ICC was 41.97%, which was significantly higher than those in HG-CIN (10.21%), LG-CIN (5.55%) and NLM (4.92%) (P<0.01). The area under the ROC curve (AUC) was 0.603 for LMX1A gene methylation, and was 0.883 for PAX1 gene methylation, to discriminate ICC from HG-CIN, LGCIN, and NLM (P=0.104 and <0.001, respectively). The optimal cut-off value for PAX1 gene methylation was set at 20.50% with the sensitivity of 81% and with the specificity of 93%. If the cut-off value was set at 9.58%, the sensitivity and the specificity of PAX1 gene methylation were 89% and 84% respectively. Conclusion: Quantitative analysis of the PAX1 gene methylation in cervical tissue might be helpful to differentiate invasive cancers from precursors, while the clinical application of the LMX1A gene methylation was limited.

Key words: Cervical cancer, Cervical intraepithelial neoplasia, DNA methylation, LMX1A gene, PAX1 gene