Study of Diagnostic Oncogene Analysis of Gastric Carcinoma

目的：本研究的目的是明确胃癌中杂合性缺失（洛）的确切频率，并探讨一些临床病理因素与洛的相关性。为胃癌转移的研究提供了重要的信息。材料和方法：肿瘤和配对的正常粘膜组织从手术切除的标本中获得。根据标准蛋白酶K消化和酚-氯仿提取法提取基因组DNA。采用聚合酶链反应-单链构象多态性（PCR-SSCP）方法，对14 q32的等位基因缺失进行了检测，检测的微卫星标记为D14 S65、D14 S68、D14 S62、D14 S267和D14 S250。结果：所有胃癌病例的平均信息率为42.7%。在所检测的5个位点中，D14 S65位点的洛丢失发生率最高（61%）。在其他位点中，D14 S68、D14562、D14 S267和D14 S250的洛合性丢失率分别为61%、52%、41%和26%。胃癌洛缺失程度与淋巴结转移及淋巴管浸润密切相关。结论首次报道14 q32等位基因缺失与胃癌淋巴道转移有关。这些发现不仅可能成为胃癌淋巴道转移的分子研究的立足点，而且可能导致进展期胃癌的精确诊断。

OBJECTIVE : The purpose of this study was to determine the precise frequency of loss of heterozygosity (LOH) and to define the correlation between some clinicopathological factors and LOH in gastric carcinoma. It might lead to some important informations useful for study of metastasis of gastric carcinoma. MATERIALS AND METHODS : Tumor and paired normal mucosal tissues were obtained from surgically resected specimens. Genomic DNA was extracted according to the standard proteinase K digestion and phenol-chloroform extraction method. Allelic deletions on 14q32 were assessed with a PCR (polymerase Chain Reaction)-SSCP (single-strand conformation polymorphism) method using following five microsatellite markers : D14S65, D14S68, D14S62, D14S267, and D14S250. RESULTS : The average rate of informative data was 42.7% in all cases of gastric carcinomas analyzed. The highest incidence (61%) of LOH was observed at the D14S65 locus within the five loci examined. As for the other loci, LOH was recognized in 61% at Dl 4S68, 52% at D14562, 41% at D14S267, and 26% at D14S250. There was a significant correlation between the extent of LOH and both of lymphatic invasion and lymph node metastasis of gastric carcinoma. CONCLUSIONS We firstly reported that allelic deletion at 14q32 associated with lymphatic spread of gastric carcinoma. These findings might not only become a foothold for molecular studies on lymphatic spread of cancer and also lead to precise diagnosis of advanced disease in gastric cancer.