改进MSP法对肿瘤患者血清DNA的探测

Detection of serum DNA in cancer patient by modified MSP

目的 寻找一种切实可行的检测方法及肿瘤的生物标志物。方法 用改良的Herman新方法对111例不同癌症患者的血清及部分组织进行了p16异常甲基化检测,同时对55例患者检测突变K-ras基因作为比较。结果 各期住院患者血清及癌组织p16异常甲基化均在50％左右,与正常人及非恶性肿瘤对照组比较差异有显著性(P<0.05)。早期癌血清与组织无明显差异。晚期癌症患者阳性率明显上升(P<0.05);术后20 d基本消失。突变K-ras基因的阳性率仅为30％,较前者明显为低,如二者联合应用可提高阳性率13％。结论 改进MSP法检测血清中异常甲基化是一种行之有效的方法,与突变K-ras基因检测联合应用,则效果更好。

Objective To develop a new method and a kind of biomarker to indicate the cancer burden of patients. Method Modified Herman's new test--Methylation Specific Polymerase Chain Reaction (MSP) was used to detect serum and cancer tissue of 111 cases of different kinds of cancers for p16 abnormal methylation,at the same time to detect the mutant K-ras gene in 55 patients for comparison.Results The methylated p16 positive rate was about 50% in serum or cancer tissue of the patients, being significandy different from that of the controls (P < 0.05), whereas there was no difference between cancer and its neighbouring tissue, and between serum of the early cancer stage patients and their cancer tissue.The positive rate increased along with the progression of cancer. Twenty days after operation, it nearly disappeared. The positive rate of mutant K-ras was only 30%, which was much lower than that of the former one. Combining these two tests, the positive rate would be elevated by 13% . Conclusion Applying modified MSP to detect the p16 methylation combined with mutant K-ras detection in serum of cancer patients would be a very useful method.