Su Zhi Hong, Li Ji Cheng
Department of Lymphology, Institute of Cell Biology, Zhejiang University, Hangzhou 310031, China.
Shi Yan Sheng Wu Xue Bao. 2003 Oct;36(5):325-9.
Techniques such as DNA extraction from paraffin-embedded tissues, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), ordinary silver stain, Envision immunohistochemistry and Leica-Qwin computer imaging techniques were used to study microsatellite instability (MSI) and loss of heterozygosity (LOH) of locus D17S396 at the 17th chromosome of Chinese patients and their influence on the expression of gene nm23H1, and to clarify the relationship between the genetic instability of gene nm23H1 and the development of colon cancer, which may provide experimental basis for clinical treatment. In our experiments, the frequency of MSI, LOH and nm23H1 protein reacted positive of 30 cases of colon cancer were 26.67%, 20.00% and 53.33% respectively. In tumor node metastasis (TNM) staging, the positive frequency of MSI (43.75%) and nm23H1 protein (81.25%) in stage I + II were more than those (MSI 7.14%, p < 0.05 and nm23H1 21.43%, p < 0.01) in stage III + IV, while the frequency of LOH (35.71%), which had a rising trend along with the Duke's staging increasing, was higher than that of LOH (6.25%, p < 0.05) in stage I + II. The positive frequency of nm23H1 protein in the group of tubular adenocarcinoma (60.00%) was distinctively higher than that in the group of mucoid adenocarcinoma (20.00%, p < 0.01), showing a rising trend along with the increase of the differentiation degree of tubular adenocarcinoma. Furthermore, the positive frequency of nm23H1 protein in MSI positive group was also higher than MSI negative group (p < 0.05). And there was no difference in nm23H1 protein expression analyzed by computer imaging techniques. The results of experiments indicated that both MSI and LOH controlled the development of sporadic colon cancer independently in different paths. LOH occurred mostly in the late period of sporadic colon cancer and endowed with it a high aggressive and poor prognosis. In contrast, MSI was an early period molecule marker of sporadic colon cancer. Increasing the amount of nm23H1 protein expression could effectively restrain colon cancer metastasis and improved prognosis of sporadic colon cancer patients.
采用从石蜡包埋组织中提取DNA、聚合酶链反应-单链构象多态性（PCR-SSCP）、普通银染、Envision免疫组化及Leica-Qwin计算机图像分析技术等，研究中国结肠癌患者第17号染色体上D17S396位点的微卫星不稳定性（MSI）及杂合性缺失（LOH），以及它们对nm23H1基因表达的影响，以阐明nm23H1基因的遗传不稳定性与结肠癌发生发展的关系，为临床治疗提供实验依据。本实验中，30例结肠癌患者的MSI、LOH及nm23H1蛋白阳性率分别为26.67%、20.00%和53.33%。在肿瘤-淋巴结-转移（TNM）分期中，Ⅰ+Ⅱ期的MSI阳性率（43.75%）和nm23H1蛋白阳性率（81.25%）高于Ⅲ+Ⅳ期（MSI 7.14%，p<0.05；nm23H1 21.43%，p<0.01），而LOH发生率（35.71%）随Duke分期增加呈上升趋势，高于Ⅰ+Ⅱ期（6.25%，p<0.05）。管状腺癌组nm23H1蛋白阳性率（60.00%）明显高于黏液腺癌组（20.00%，p<0.01），且随管状腺癌分化程度增加呈上升趋势。此外，MSI阳性组nm23H1蛋白阳性率也高于MSI阴性组（p<0.05）。计算机图像分析技术分析nm23H1蛋白表达无差异。实验结果表明，MSI和LOH均以不同途径独立控制散发性结肠癌的发生发展。LOH多发生于散发性结肠癌晚期，使其具有高侵袭性和预后不良。相反，MSI是散发性结肠癌的早期分子标志物。增加nm23H1蛋白表达量可有效抑制结肠癌转移，改善散发性结肠癌患者预后。
