Human Genetics Laboratory, Department of Zoology, Osmania University, Hyderabad, India.
Int J Gynecol Cancer. 2012 May;22(4):553-60. doi: 10.1097/IGC.0b013e31823fa90c.
To determine the alterations of tumor suppressor gene p16INK4A in human ovarian cancers to explore the possibilities of identifying potential minimally invasive markers in blood of the patients, which could help in the clinical practice as a diagnostic and prognostic marker.
Ovarian cancer tissue and corresponding blood samples were collected from patients (n = 50). The promoter methylation and mutation status of p16 gene in blood and ovarian tissue DNA was then assessed using methylation-specific polymerase chain reaction and denaturing high-performance liquid chromatography along with DNA sequencing method. In addition, the protein expression in ovarian cancer tissue samples was detected by immunostaining method using monoclonal antibodies against p16.
Methylation of p16 was observed in 56% (28/50) of the cases. The data showed concordance in promoter methylation status of p16 gene between the tumor tissue and the corresponding blood DNA samples of the patients with ovarian cancer. There was a weak statistical agreement (Kendall tau b = +0.31), and a perfect correspondence was observed in 50% of the cases. The p16 mutations were comparatively low, revealing only 2 variations among the samples analyzed. The percentage of protein expression was inversely correlated with the p16 gene promoter methylation.
This study demonstrates that the p16 gene plays a role in the progression of human ovarian cancers and the blood DNA methylation of p16 gene promoter region is a weak predictor of tumor tissue methylation status.
确定抑癌基因 p16INK4A 在人卵巢癌中的改变，探索在患者血液中鉴定潜在微创标志物的可能性，这有助于作为临床诊断和预后标志物。
收集 50 例患者的卵巢癌组织和相应的血液样本。然后使用甲基化特异性聚合酶链反应和变性高效液相色谱法以及 DNA 测序法评估血液和卵巢组织 DNA 中 p16 基因的启动子甲基化和突变状态。此外，使用针对 p16 的单克隆抗体通过免疫染色法检测卵巢癌组织样本中的蛋白表达。
在 56%（28/50）的病例中观察到 p16 的甲基化。数据显示卵巢癌患者肿瘤组织和相应血液 DNA 样本中 p16 基因启动子甲基化状态一致。存在弱统计学一致性（Kendall tau b = +0.31），并且在 50%的病例中观察到完全一致。p16 突变率较低，分析的样本中仅发现 2 种变异。蛋白表达率与 p16 基因启动子甲基化呈负相关。
本研究表明，p16 基因在人卵巢癌的进展中起作用，p16 基因启动子区域的血液 DNA 甲基化是肿瘤组织甲基化状态的弱预测因子。
