胃癌单克隆抗体MG系列相应抗原在人胚胎组织中的表达

作者用ABC免疫组化方法观察了鼠抗人胃癌单克降抗体MG 7.MG 9,MGd1相应抗原在不同胎龄胎儿(10～40周)多种组织中的表达及其消长过程。胎儿组织用10％缓冲福尔马林或1.33mol/L多聚甲醛或0.0087 mol/L苦味酸混合固定液固定,石蜡包埋,部分胎儿组织同时作冰冻切片染色。结果发现:MG7,MG9,MGd1均与14～36周胎儿食管上皮表层细胞、15～32周胎儿结肠上皮表面上皮细胞及部分胎胃上皮呈不同程度的阳性反应。抗原表达随胎龄变化:第14周见于食管上皮,第15周见于结肠上皮,表达较弱,第20～24周表达最强,第28周以后表达逐渐减弱,足月胎儿抗原表达完全消失。这组抗体相应抗原在任何时期的胎儿肝、胆囊、胰腺、小肠、心肌、肺、气管、肾、肾上腺、骨骼肌、皮肤等组织均无表达,仅与2例接近成熟的胎儿胸腺小体呈强阳性反应。由于本组抗体相应抗原仅在胃癌、食管癌、结肠癌及其相应胎儿组织中表达,而在正常人胃、食管、结肠等组织表达阴性,推测它们是一组与胃癌相关的消化道癌胚共同抗原。

Expression of Gastric Cancer Associated Antigens in Human Fetal Tis- sues Detected by Monoclonal Antibodies MG7, MG 9 and MGd1

The expression of gastric cancer - associated antigens was observed in tissues from human fetus of various gestational ages (10 - 40 weeks) by means of biotin avidin pcroxidasc immunohislochcmical assay. Sections of snap-frozen tissues were fixed in 10% neutral buffered formaldehyde or in 1.33mol 1 paraformaldehyde 0.0087 mol/1 picric acid The corresponding antigens of MG7, MG9 and MGd 1 were detected in the supcrfidal cpithclia of most esophagal, colon- rectal specimens and in two fetal stomaches as well as Hassall's corpuscles. The distribution of MG 7 Ag, MG9- Ag, MGd 1 Ag was similar in fetal tissues, the staining intensity of MG7, MGd 1 being stronger than that of MG7 in esophagus, but similar in the gastric and colon rectal cpithclia The corresponding antigens of MG7.MG9 and MGdl came to appear since 14 th-15th week of pregnancy, expressed strongly in 20th - 24th week, decreased in the last trimester of pregnancy, and disappeared after birth. They could not be detected in fetal liver, gall bladder, bile ducts, pancreas, small intestine of different stages, lung, trachea, kidney, spleen, adrenal gland and skin, muscle etc. The results suggest thai the corresponding antigens of MG7, MG9,MGd 1 may be a new group of gastric cancer associated gastrointestinal oncofetal antigens.