Li Ziyu

Promoter hypermethylation of p16 gene in pre- and post-operative plasma of patients with gastric adenocarcinoma

AbstractsObjective: To detect promoter hypermethylation of p16 gene in matched pre- and post-operative plasma of patients with gastric adenocarcinoma for evaluating the effectiveness of therapeutic intervention. Methods: Tissue samples, pre- and post-operative plasma of 84 patients were collected. Plasma of 15 healthy people was collected as control. After sodium-bisulfite treatment, extracted DNA was amplified for p16 promoter by methylation-specific polymerase chain reaction (MSP). The PCR products were detected by both gel-ethidium bromide electrophoresis and high performance liquid chromatogram (HPLC). Results: Among 84 patients, p16 hypermethylation was detected in 26 (31.0%) cancer tissues and 2 (0.02%) tumor-adjacent tissues and 12 (14.3%) pre-operative plasma, while negative in plasma of healthy people. For positive plasma cases, the paired tumor tissues were confirmed to be methylated. Within available 30 pairs of matched pre- and post-operative plasma, 6 pre-operative plasma was positive, and only 1 of 6 plasma remained hypermethylated after surgery. The results detected by HPLC exactly matched those by gel-electrophoresis. Conclusion: The alteration of status of p16 hypermethylation in post-operative plasma is considered the consequences of surgical intervention. Although p16 hypermethylation has no role in pre-operative staging of gastric cancer, detecting hypermethylated p16 in plasma could be utilized in monitoring patients after surgery.

联合检测术前与术后CEA CA19-9 CA72-4对不同分期胃癌根治术后复发的预测价值

目的 探讨联合检测术前、术后CEA、CA19-9、CA72-4等肿瘤标志物对不同分期胃癌根治术后复发的预测价值。 方法 回顾性分析北京大学肿瘤医院2002年1月至2007年3月收治的564例胃癌患者的临床资料及血清肿瘤标志物情况。所有患者均未行新辅助治疗，术前、术后均联合检测CEA、CA19-9、CA72-4等肿瘤标志物。分析CEA、CA19-9、CA72-4等肿瘤标志物与胃癌复发的关系。 结果 在Ⅰ、Ⅱ期胃癌患者中，CEA、CA19-9、CA72-4术前阳性的患者术后复发率分别为50.0%、24.1%、22.6%，而术后阳性的患者复发率分别为42.9%、21.7%、14.3%。在Ⅲ期胃癌患者中，CEA、CA19-9、CA72-4术前阳性的患者术后复发率分别为50.0%、55.2%、47.6%，而术后阳性的患者术后复发率分别为75.0%、66.7%、66.7%。多因素分析表明术前CEA增高是Ⅰ、Ⅱ期胃癌复发的独立影响因素，术后CA72-4增高是Ⅲ期胃癌复发的独立影响因素。 结论 对于Ⅰ、Ⅱ期胃癌，术前CEA水平是预测复发较好的因子；对于Ⅲ期胃癌，术后CA72-4水平的预测性较好。

CLINICOPATHOLOGICAL ANALYSIS OF 50 RECTAL CANCER CASES DIAGNOSED AS ADENOMA IN BIOPSY

Objective: To evaluate the clinicopathological characteristics of rectal cancer diagnosed as adenoma in biopsy. Methods: 50 rectal cancer cases diagnosed as adenoma in biopsy were analyzed retrospectively in this study by comparing the biopsy and postoperative pathology. Results: Among these 50 patients, biopsy pathology showed 26% (13/50) adenoma with mild dysplasia, 30% (15/50) adenoma with moderate dysplasia, and 44% (22/50) adenoma with severe dysplasia. In 8 cases, the adenomas were smaller than 2cm. On postoperatively surgical pathology, only 10 cases were carcinoma-in-situ, while 40 cases were invasive cancer. Conclusion: Special emphasis should be taken to biopsy-negative rectal adenomas and those smaller than 2cm.

IFN-γ regulates Fas/FasL expression in cholangio carcinoma cells

AbstractsObjective: To study the regulation of Fas receptor (Fas)/Fas ligand (FasL) expression by IFN-γ in cholangiocarcinoma cell lines. Methods: We studied the expressions of Fas and FasL gene in the human cholangiocarcinoma cell line QBC939 by RT-PCR, Western blot, and immunohistochemistry and their apoptosis effects on human T cell line Jurkat cell. At the same time, we investigated the regulative effect of IFN-γ on them. Results: Fas, FasL mRNA and protein were expressed by cholangiocarcinoma cells. We also found IFN-γ could up-regulate the expressions of these two genes. However, IFN-γ could also down-regulate the ability of them to make Jurkat cells apoptotic. With the increasing of dosage and time, the effect was enhanced. Conclusion: IFN-γ could regulate the expression of Fas and FasL in cholangiocarcinoma cells, and might influence the ability of cholangiocarcinoma to regulate immune escape. This study provides new theoretical basis for immunological therapy of cholangiocarcinoma.