尿核苷检测在结直肠癌诊断与手术治疗监测中的应用

Application of urinary nucleosides in the diagnosis and surgical monitoring of colorectal cancer

目的探讨尿核苷检测对结直肠癌的诊断价值及在手术治疗监测中的应用。方法采用反相高效液相色谱法检测经结肠镜与活检病理证实的52例结直肠癌患者术前1天与术后第8天尿中14种正常与修饰核苷水平,同时以62例健康人作为对照组,并与传统肿瘤标记物癌胚抗原(CEA),CA199,CA125,甲胎蛋白(AFP)相比较,探讨尿核苷与结直肠癌临床病理特征的关系。结果结直肠癌组14种核苷中假尿嘧啶核苷(Pseu),腺嘌呤核苷(A),胞嘧啶核苷(C),1甲基腺苷(m1A),1甲基次黄嘌呤核苷(m1I),3甲基尿苷+5甲基尿苷(mU),2,2二甲基鸟苷(m22G),次黄嘌呤核苷(I),1甲基鸟苷(m1G),N4乙酰胞苷(ac4C),6甲基腺苷(m6A)等11种核苷水平显著升高,与正常对照组相比差异具有统计学意义(P<0.05);通过主成分分析,76.9%(40/52)的结直肠癌患者被正确识别,敏感性与传统标记物CEA(38.5%),CA199(40.4%),CA125(15.4%),AFP(17.3%)相比差异有统计学意义(均P<0.01);Pseu与m1G的受试者操作特征曲线下面积分别达到0.896与0.816;对8种核苷(Pseu,m1A,m1I,m22G,I,m1G,ac4C,m6A)进行逐步判别分析,发现Pseu、m1G在判别分析中有统计学意义,建立判别函数Y正常人=-3.009+0.0272×Pseu+4.918×m1G,Y结直肠癌=-8.057+0.0667×Pseu+8.258×m1G;40例结直肠癌患者的Pseu,C,U(尿嘧啶核苷)

Objective To evaluate the value of urinary normal and modified nucleosides in diagnosis and surgical monitoring of colorectal cancer (CRC). Methods Between October 2002 and July 2003, 52 consecutive patients with pathological confirmed CRC were included in this study. Spontaneous urine samples were collected 1 d before and 8 d after surgery and 14 kinds of urinary nucleosides in the samples were determined by reversed-phase high-performance liquid chromatography (RP-HPLC) method. Another 62 healthy volunteers were also enrolled as controls. The routine clinical tumor markers, including serum CEA, CA199, CA125 and AFP levels of CRC patients were evaluated by electrochemical-luminescence immunoassay simultaneously. Results The mean levels of pseudouridine (Pseu), adenosine (A), cytidine (C), 1-methyladenosine (m1A), 1-methylinosine (m1I), 3-methyluridine+5-methyluridine (mU), 2,2-methylguanosine (m22G), inosine(I), 1-methylguanosine(m1G), N4-acetylcytidine(ac4C), N6-methyladenosine(m6A) among 14 kinds of determined urinary nucleosides in CRC group were much higher than those of controls(P<0.05). Based on principal component analysis, 76.9% of CRC patients were correctly identified, which was much higher than that of CEA(38.5%),CA199(40.4%), CA125 (15.4%), and AFP(17.3%)(P<0.01). ROC curve analysis of m1G, and Pseu showed good sensitivity-specificity profiles to CRC. Two classification equations, Y_~normal =-3.009+0.0272×Pseu+4.918×m1G and Y_~CRC =-8.057+0.0667×Pseu+8.258×m1G, were established by Bayes stepwise discriminate analysis for predicting carcinogenesis of CRC. The elevated levels of Pseu, C,U(uridine), m1A, m1I, m1G, ac4C, A, m22G dramatically decreased after curative resection of 40 cases of CRC. And our data also showed that the preoperative levels of Pseu, m1G, m1A and m22G were positively related with tumor size and the preoperative levels of m1A,m22G and ac4C were positively related with Duke′s staging of CRC(P<0.05). Conclusions Normal and modified urinary nucleosides may become additional tumor markers which are feasible in the clinical setting and will prove helpful in the diagnosis, management and follow-up of CRC, and Pseu and m1G may be more promising for clinical application.