摘要目的 通过检测结直肠腺癌中神经内分泌(NE)细胞微卫星改变和p53基因突变,探讨结直肠腺癌中NE细胞的克隆性起源.方法 采用激光捕获显微切割(LCM)技术,应用DNA抽提和全基因组扩增,在全基因组范围内选取26个微卫星位点,使用聚合酶链反应-单链构象多态性(PCR-SSCP)-银染色检测30例伴NE分化的结直肠腺癌中腺癌细胞和NE细胞的微卫星不稳定(MSI)、杂合性缺失(LOH)改变情况,联合PCR测序检测p53基因突变发生情况.结果 30例样本MSI总发生率为16.9％,LOH总发生率为8.5％,腺癌细胞与NE细胞的MSI和LOH发生率差异无统计学意义.30例样本中6例微卫星改变完全一致,23例微卫星改变一致性大于不一致性,1例微卫星改变一致性与不一致性相同.微卫星改变一致性与不一致性的差异有统计学意义(t=11.138,P=0.000).p53基因突变发生率为16.7％,腺癌细胞与NE细胞发生一致性改变.结论 结直肠腺癌中腺癌细胞与NE细胞具有相似的微卫星改变和完全一致的p53基因突变,推测两种细胞起源具有一致性.

abstractsObjective To study the possible clonal origin of neuroendocrine cells in colorectal adenocarcinoma.Methods Twenty-six microsatellite loci were screened using laser capture microdissection,DNA extraction and whole genome amplification.Microsatellite instability (MSI) and loss of heterozygosity (LOH) in adenocarcinoma cells and neuroendocrine cells amongst 30 cases of colorectal carcinoma with neuroendocrine differentiation were detected using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)-silver staining.The mutation status of p53 was evaluated by PCR-sequencing.The clonal origin of neuroendocrine cells in colorectal adenocarcinoma was determined.Results Amongst the 30 cases studied,the prevalence of MSI was 16.9％ while that of LOH was 8.5％.The rate showed no statistically significant difference between adenocarcinoma cells and neuroendocrine cells.In 6 cases,the microsatellite alteration was entirely consistent.In 23 cases,the rate of microsatellite alteration consistency was greater than that of inconsistency.In 1 case,the consistency and inconsistency rates were identical.There was statistically significant difference between consistency and inconsistency of microsatellite alteration.The prevalence of p53 mutation was 16.7％ which was the same for both adenocarcinoma cells and neuroendocrine cells.Conclusions Adenocarcinoma cells and neuroendocrine cells in colorectal adenocarcinoma with neuroendocrine differentiation have similar biologic changes.It is likely that they are of identical origin.