Kinugasa T, Kuroki M, Takeo H, Matsuo Y, Ohshima K, Yamashita Y, Shirakusa T, Matsuoka Y
Department of Surgery, School of Medicine, Fukuoka University, Japan.
Int J Cancer. 1998 Mar 30;76(1):148-53. doi: 10.1002/(sici)1097-0215(19980330)76:1<148::aid-ijc23>3.0.co;2-7.
Four human carcinoembryonic antigen (CEA) family members, CEA (CD66e), non-specific cross-reacting antigen (NCA, CD66c), biliary glycoprotein (BGP, CD66a) and CEA gene-family member 2 (CGM2), are expressed in normal mucosal epithelia of the colon. Expression of BGP and CGM2 has recently been demonstrated to be down-regulated in colorectal adenocarcinomas. We have now investigated the expression of the 4 CEA family antigens in gastric adenocarcinoma and carcinoma cell lines in comparison with adjacent normal gastric mucosa. The transcripts of the CEA, NCA and BGP genes evaluated by reverse transcription-polymerase chain reaction were detectable at various levels in all the gastric adenocarcinoma cell lines tested, while CGM2 mRNA was detectable in the cell lines of poorly differentiated but not of well-differentiated carcinomas. The levels of CEA mRNA in normal gastric mucosa were variable but mostly increased in adenocarcinomas. The sparse expression of NCA observed in the normal tissues was markedly up-regulated in the carcinomas. In contrast to previous findings on normal and cancerous colonic tissues, the transcripts of CGM2 were totally undetectable and those of BGP were recognized only marginally, if at all, in normal gastric mucosa, while both messages were detected at significant levels in most of the gastric adenocarcinomas. This was confirmed by in situ hybridization. Our findings indicate that expression of the CEA family antigens, particularly that of BGP and CGM2, is differently regulated in epithelial cells of the colon and the stomach.
四种人癌胚抗原（CEA）家族成员，即CEA（CD66e）、非特异性交叉反应抗原（NCA，CD66c）、胆汁糖蛋白（BGP，CD66a）和CEA基因家族成员2（CGM2），在结肠正常黏膜上皮中表达。最近已证实，BGP和CGM2的表达在结肠腺癌中下调。我们现在研究了4种CEA家族抗原在胃腺癌及癌细胞系中的表达情况，并与相邻正常胃黏膜进行了比较。通过逆转录-聚合酶链反应评估的CEA、NCA和BGP基因转录本在所有测试的胃腺癌细胞系中均能检测到不同水平的表达，而CGM2 mRNA仅在低分化而非高分化癌细胞系中可检测到。正常胃黏膜中CEA mRNA水平各异，但在腺癌中大多升高。在正常组织中观察到的NCA稀疏表达在癌组织中明显上调。与先前关于正常和癌性结肠组织的研究结果不同，CGM2转录本在正常胃黏膜中完全检测不到，BGP转录本即使能检测到也仅为微量，而在大多数胃腺癌中这两种转录本均能检测到显著水平。原位杂交证实了这一点。我们的研究结果表明，CEA家族抗原的表达，尤其是BGP和CGM2的表达，在结肠和胃的上皮细胞中受到不同的调控。
