MBL在结肠直肠癌中的基因分型

目的：MBL是补体激活凝集素途径的关键因素。MBL基因多态性影响MBL血清水平。结肠直肠癌患者血清MBL水平升高。低水平的MBL则预示着术后肺炎的发生，目前还不清楚此相关性是否与遗传相关。本实验分析调查了结肠直肠癌患者和健康对照者的MBL基因分型，评估基因分析和复发率、生存率之间潜在的相关性。方法：使用TaqMan基因分型分析法和实时定量PCR分析MBL基因的4个SNP、启动子区2个SNP、非编码区1个SNP；ELISA测定标本血清MBL含量。结果：所有标本中发现了8种不同的MBL单体型，它们在患者和健康者中出现频率几乎是完全一样的；YA/YA基因型与高水平的MBL相关，YO／YO与低水平的MBL水平相关，6种不同基因型CRC患者的MBL水平存在着明显不同。结论：MBL基因型与血清MBL浓度显薯相关（P〈0．0001）；突变型B，C，D和启动子单体型Y，X对MBL含量的影响起主要作用；MBL基因型和术后感染并发症没有明显相关性（P=0．33），与复发癌和存活时间也没有明显相关性（P=0．74）。因此，从基因水平还不能解释为何结肠直肠癌患者血清MBL水平增加。对比已经检测出的血清MBL水平，其基因型还不能预测结肠直肠癌患者的疾病进程。

MBL Genotypes in Colorectal Cancer

Objective： Mannan-binding lectin （MBL） is key factors of the lectin pathway of complement activation. Polymorphisms of the MBL-2 genes affect serum levels of MBL. In patients with colorectal cancer （CRC）, the MBL serum levels are increased and low MBL levels predict post-operative pneumonia. It is not known whether these associations are genetically based. In this study, the MBL genotypes are investigated in patients with CRC and healthy controls. The potential association between genetic profile and reeurrence and survival is evaluated. Methods： Four single-nucleotide polymorphisms （SNPs） of MBL, two SNPs of promoter region and one SNP of untranslated region were analysed using TaqMan assays. The concentration of MBL in the sera were detected by ELISA. Results： Eight different MBL haplotypes were found among the CRC patients and healthy individuals, The fi＇equency of each haplotype in the patients was not different from that in healthy controls, YA/YA genotype was associated with the highest MBL levels, and YO/YO and XA/YO with the lowest levels, a significant difference between the serum levels of MBL in the six genotypes. Conclusion： MBL genotype significantly assoeiated with MBL concentration in serum （P〈0.0001）. Variants B, C and D and the promoter haplotypes Y and X have dominant effects on the concentration of MBL. No significant association between MBL genotype and post-operative infectious complications （P=0.33）, recurrent cancer or survival （P=0.74） was found. Thus, the increased serum levels of MBL found in patients with CRC are not explained for by genetic profiles. In contrast to what has been demonstrated for serum levels of MBL, the genotypes do not predict disease eourse of the CRC patients.