Increased in vitro growth capacity of tracheal epithelium exposed in vivo to 7, 12-dimethylbenz(a)anthracene.
Increased in vitro growth capacity of tracheal epithelium exposed in vivo to 7, 12-dimethylbenz(a)anthracene.
复制标题
体内暴露于 7, 12-二甲基苯并(a)蒽的气管上皮的体外生长能力增加。
作者：
A. Marchok;J. Rhoton;R. Griesemer;P. Nettesheim
将大鼠异位气管移植物在体内暴露于150或640 μ g的7，12-二甲基苯并（a）蒽（DMBA），持续2周，并在体外研究上皮细胞，试图确定肿瘤发展早期生长行为的变化。从暴露的气管以及一系列对照中制备外植体，并测量外植体的上皮生长速率。其次，研究了副产物作为原代培养物存活的能力及其在体外多次传代中存活的能力。在最初的种植过程中，生长率是迄今为止最大的外植体预暴露于150微米的DMBA。从外植体预暴露于640 microng DMBA的产物是稀疏的第一次种植，但在重复种植时，胰岛素和氢化可的松补充培养基中使用显着增加。在重复种植致癌物暴露的气管碎片过程中，生长的建立明显依赖于激素。对照外植体没有表现出这种激素依赖性。原代培养可以建立从只有三个6外植体预暴露于150 micron DMBA。这些外植体已开始在胰岛素和氢化可的松补充培养基。原代培养物成功传代培养。原代培养物也建立了五个外植体预暴露于640 microngDMBA和培养在补充琼脂糖的培养基。从每个外植体获得至少一个细胞系。为了建立和维持来自对照气管的原代培养物，需要含有氨基酸补充剂、丙酮酸钠和腐胺以及激素补充剂的富集培养基。然而，这些培养物不能传代培养。原代培养的致癌物暴露的外植体和随后开发的细胞系都表现出角化鳞状上皮的形态特征。这些特性包括：上皮样细胞形态、嗜橙色鳞状细胞的多层和脱落以及透明角质颗粒的存在。这些实验表明，气管上皮细胞在体内短时间暴露于致癌物质后，其体外生长能力显著增加。
Heterotopic tracheal transplants of rats were exposed in vivo to 150 or 640 microng of 7, 12-dimethylbenz(a)anthracene (DMBA) delivered over 2 weeks, and the epithelium was studied in vitro in an attempt to identify changes in growth behavior during early phases of neoplastic development. Explants were made from the exposed tracheas, as well as from a series of controls, and the rate of epithelial outgrowth from the explants was measured. Secondly, the capacity of the outgrowths to survive as primary cultures and their ability to survive multiple in vitro passages were studied. During the initial planting, the rate of outgrowth was by far the greatest from the explants preexposed to 150 microng DMBA. Outgrowth from explants preexposed to 640 microng DMBA was sparse during the first planting but increased markedly during repeated planting when insulin- and hydrocortisone-supplemented medium was used. Establishment of outgrowth during repeated planting of carcinogen-exposed tracheal pieces was clearly hormone dependent. Control explants did not exhibit this hormone dependency. Primary cultures could be established from only three of six explants preexposed to 150 microng DMBA. These explants had been initiated in insulin- and hydrocortisone-supplemented medium. The primary cultures were successfully subcultured. Primary cultures were also established from five of five explants preexposed to 640 microng DMBA and cultured in hormone-supplemented medium. At least one cell line was obtained from each of the explants. To establish and maintain primary cultures from control tracheas required an enriched medium containing amino acid supplements, sodium pyruvate, and putrescine, as well as the hormone supplements. However, such cultures could not be subcultured. The primary cultures from the carcinogen-exposed explants and the subsequently developed cell lines all exhibited morphological characteristics of keratinizing squamous epithelium. These characteristics include: epithelioid cell morphology, multilayering and sloughing of orangeophilic squamous cells, and the presence of keratohyalin granules. These experiments demonstrate a markedly increased in vitro growth capacity of tracheal epithelium after a short in vivo exposure to carcinogen.