MCF-7细胞在亚多层中细胞膜极性的变化

人乳腺癌细胞株MCF-7细胞于微孔滤膜上经较长时间培养后形成亚多层。表层细胞保持了单层MCF-7细胞所具有的形态学极性与膜极性特征。免疫酶细胞化学技术显示,97.5%的细胞表达了表面乳脂球膜抗原MAM-6,并且该抗原呈顶面极性分布。深层细胞没有面向培养液的游离面,缺乏形态学极性特征,仅??12.9%的细胞表达表面MAM-6,且呈无极性随机分布。深层细胞胞质的MAM-6免疫染色强度大于表层细胞。本研究结果提示,非对称性空间环境(由液相空间与固相空间构成)对于MCF-7细胞的膜极性的建立是必需的。

CHANGES OF MEMBRANE POLARITY OF MCF-7 CELLS IN SUB-MULTILAYER CULTURE

Sub-multilayer of MCF-7 cell,an esta-blished human breast carcinoma cell line,wasachieved by culturing the cells on milliporefilters for a long time.The superficial layercells maintained their membrane polarity fea-tures as MCF-7 cells in monolayers did.MAM-6,a human milk fat globule membraneantigen,was polarizedly distributed in apicaldomain of 97.5% superficial layer cells re-vealed by immunoperoxidase cytochemistry.Whereas,among the low layer cells,whichhad no free surface (apical domain) towardthe culture medium and did not show morph-ological polarity features,only 12.9% exp-ressd surface MAM-6 with weak immunope-roxidase staining and random distribution.But the immunostaining for detecting cyto-plasmic MAM-6 in low layer cells was stron-ger than that in superficial layer cells,indi-cating that the vectorial delivery and insertof MAM-6 carrying glycoprotein to the pla-sma membrane seemed to be stopped or decli-ned and became undirectional in the latersituation.The study demonstrates that anasymmetric spatial environment,which iscomposed of a liquid phase space and a solidphase space,is crucial for the establishmentof epithelial membrane polarity of MCF-7cells.