Biosynthesis and secretory pathway of basement membrane molecules by salivary gland carcinoma cells.

生物合成的基底膜分子（BELF）和纤连蛋白在体外测定在两个不同的人类细胞系统，ACC 2和ACC 3，建立从腺样囊性癌的唾液腺，通过使用免疫荧光和共聚焦显微镜。当细胞贴壁铺展在培养皿上时，IV型胶原、层粘连蛋白、硫酸乙酰肝素蛋白多糖、巢蛋白和纤维连接蛋白的免疫荧光首先在细胞质中弥散出现，然后在核周区转变为粗颗粒聚集。随着集落的形成，这些信号存在于细胞外空间中，最初在附着细胞的基底面，因此在侧向细胞间隙中。细胞形成汇合单层后，细胞外信号开始下降，与细胞内信号的再现成反比。乙酰肝素酶和其他酶在Bcl3开始合成时免疫定位于细胞核。它们的信号迁移到细胞质中，然后聚集在核周区。最后，它们在细胞间隙中与Bceptin共定位。光镜和电镜下免疫组化显示，胶原凝胶培养的细胞形成球形集落，空泡状结构，含Bcl3。结果表明，腺样囊性癌的实质细胞合成这五种细胞外基质分子，将它们分泌到细胞外环境中，并重塑细胞外沉积物。提示腺样囊性癌的特征性间质结构是由肿瘤细胞分泌和降解基底膜分子和纤维连接蛋白引起的。

Biosynthesis of basement membrane molecules (BMMs) and fibronectin was determined in vitro in the two different human cell systems, ACC2 and ACC3, established from adenoid cystic carcinomas of the salivary gland by using immunofluorescence and confocal microscopy. When the cells were attached and spread on dishes, fine granular immunofluorescence for type IV collagen, laminin, heparan sulfate proteoglycan, entactin, and fibronectin first appeared diffusely in the cytoplasm, and then they changed into aggregation of coarse granules in the perinuclear area. With formation of colonies, these signals were present in the extracellular space, initially in the basal aspect of attached cells and consequently in the lateral intercellular space. After the cells formed a confluent monolayr, extracellular signals started to decrease in the reverse proportion of reappearance of intracellular ones. Heparanase and other enzymes were immunolocalized in the nuclei when BMMs were started to be synthesized. Their signals migrated to the cytoplasm and were later condensed in the perinuclear area. Finally, they were co-localized with BMMs in the intercellular spaces. When cultured in collagen gel, the cells formed spherical colonies with vacuolar structures containing BMMs, that was shown by light and electron microscopic immunohistochemistry. The results indicated that the parenchymal cells of adenoid cystic carcinoma synthesize these five extracellular matrix molecules, secrete them into the extracellular milieu, and remodel the extracellular deposits. It is hence suggested that the characteristic stromal architecture of adenoid cystic carcinoma, represented by stromal pseudocysts, is resulted from their own secretion and enzymatic degradation of the basement membrane molecules and fibronectin by the tumor cells.