Parkinson E K, Grabham P, Emmerson A
Carcinogenesis. 1983;4(7):857-61. doi: 10.1093/carcin/4.7.857.
We have studied the action of phorbol, 12-myristate, 13-acetate (PMA) on human keratinocytes grown with lethally-irradiated 3T3 cells using medium supplemented with hydrocortisone, cholera toxin and epidermal growth factor. Normal keratinocyte cultures show a heterogeneous response to PMA; 90-93% of the colony-forming cells lose their colony-forming ability and form cornified envelopes when treated for 24 h with doses of 100 nM or less, but the remainder are resistant to doses of 1000 nM. The resistant cells are the precursors of the sensitive ones and heterogeneity is restored to those cells and their progeny after 8 days culture in the absence of PMA. Cultures of 3 squamous cell carcinoma lines, a SV40-transformed human keratinocyte line, and three clones of these lines were found to contain 3-17 times more PMA-resistant keratinocytes than the normal strains, and the size of the PMA-resistant fraction in each line was inversely related to the competence of that line to lose colony-forming efficiency when placed in suspension culture (which is the first detectable change in an ordered programme of events resembling terminal differentiation of the keratinocyte). The number of cells with cornified envelopes in surface cultures of normal human keratinocytes increased from approximately 3% in control cultures to approximately 70% in those treated for 6 days with 100 nM PMA. The transformed human keratinocyte cultures showed a 3-25-fold smaller increase in cornified envelope formation when treated with 100 nM PMA, and the increase in envelope formation by each line when exposed to this dose of PMA was related to the competence of that line to lose cloning efficiency in suspension culture. No relationship was found between the ability of any human keratinocyte strain or line we studied to metabolically inactivate PMA and their resulting response to the compound. The results are discussed in relation to the mechanism of action of PMA as a promoter of epidermal carcinogenesis.
我们使用添加了氢化可的松、霍乱毒素和表皮生长因子的培养基，研究了佛波醇12 -肉豆蔻酸酯13 -乙酸酯（PMA）对与经致死剂量照射的3T3细胞共同培养的人角质形成细胞的作用。正常角质形成细胞培养物对PMA表现出异质性反应；当用100 nM或更低剂量处理24小时时，90 - 93%的集落形成细胞丧失其集落形成能力并形成角质化包膜，但其余细胞对1000 nM剂量具有抗性。抗性细胞是敏感细胞的前体，在无PMA的情况下培养8天后，这些细胞及其后代恢复了异质性。发现3个鳞状细胞癌系、一个SV40转化的人角质形成细胞系以及这些系的3个克隆培养物中，PMA抗性角质形成细胞比正常菌株多3 - 17倍，并且每个系中PMA抗性部分的大小与该系在悬浮培养中丧失集落形成效率的能力（这是类似于角质形成细胞终末分化的有序事件程序中第一个可检测到的变化）呈负相关。正常人角质形成细胞表面培养物中具有角质化包膜的细胞数量从对照培养物中的约3%增加到用100 nM PMA处理6天的培养物中的约70%。用l00 nM PMA处理时，转化的人角质形成细胞培养物中角质化包膜形成的增加幅度小3 - 25倍，并且每个系在暴露于该剂量PMA时包膜形成的增加与该系在悬浮培养中丧失克隆效率的能力相关联。我们研究的任何人类角质形成细胞株或系代谢灭活PMA的能力与其对该化合物的反应之间均未发现相关性。结合PMA作为表皮癌发生促进剂的作用机制对结果进行了讨论。
