Mesnil M, Montesano R, Yamasaki H
Exp Cell Res. 1986 Aug;165(2):391-402. doi: 10.1016/0014-4827(86)90593-8.
Gap-junctional intercellular communication of transformed and non-transformed rat liver epithelial cell lines was compared using a dye transfer method in the presence and absence of 12-O-tetradecanoylphorbol 13-acetate (TPA). Whereas non-transformed cells (IAR 20, non-tumorigenic in newborn rats and in nude mice) showed very high communication capacity throughout a culture period of 3 weeks, transformed cells (IAR 6-1, tumorigenic in newborn rats and in nude mice) were less able to communicate. Similar correlation between intercellular communication and expression of transformed phenotypes were also found in newly cloned epithelial cell lines, IAR 27E and IAR 27F. When TPA was added to culture medium at 100 ng/ml, intercellular communication in all lines tested was reduced within 60 min. However, communications recovered completely from the effect within 10 h after addition of TPA. Further addition of TPA to the cultures every 24 h for 3 weeks had no effect on intercellular communication (measured 30 min after each TPA addition), suggesting that a single application of TPA made these cells refractory to further doses. A known stimulator of gap-junctional communication, db-cAMP, also increased dye transfer in IAR 20 and IAR 6-1 cells. TPA added to db-cAMP-treated cultures of IAR 20 and IAR 6-1 cells inhibited intercellular communication, suggesting that cAMP is not an antagonist of the effect of TPA on intercellular communication in these cell lines. These results are in sharp contrast to those obtained with the fibroblast cell line BALB/c 3T3, in which db-cAMP antagonized TPA effect and inhibition by TPA of intercellular communication was transient only when administered during their growth phase, and was stable and continuous when TPA was applied at confluence, and suggest that TPA may not be an effective tumour promoter in rat liver.
采用染料转移法，在添加和不添加12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）的情况下，比较了转化和未转化的大鼠肝上皮细胞系的间隙连接细胞间通讯。未转化细胞（IAR 20，在新生大鼠和裸鼠中无致瘤性）在3周的培养期内显示出非常高的通讯能力，而转化细胞（IAR 6 - 1，在新生大鼠和裸鼠中具有致瘤性）的通讯能力较弱。在新克隆的上皮细胞系IAR 27E和IAR 27F中也发现了细胞间通讯与转化表型表达之间的类似相关性。当向培养基中添加100 ng/ml的TPA时，所有测试细胞系的细胞间通讯在60分钟内均降低。然而，在添加TPA后10小时内，通讯完全从该效应中恢复。每24小时向培养物中进一步添加TPA持续3周，对细胞间通讯没有影响（每次添加TPA后30分钟测量），这表明单次应用TPA使这些细胞对进一步的剂量产生了抗性。一种已知的间隙连接通讯刺激剂db - cAMP，也增加了IAR 20和IAR 6 - 1细胞中的染料转移。添加到经db - cAMP处理的IAR 20和IAR 6 - 1细胞培养物中的TPA抑制了细胞间通讯，这表明cAMP不是TPA对这些细胞系中细胞间通讯作用的拮抗剂。这些结果与用成纤维细胞系BALB/c 3T3获得的结果形成鲜明对比，在BALB/c 3T3细胞系中，db - cAMP拮抗TPA的作用，并且仅在其生长阶段给予TPA时，TPA对细胞间通讯的抑制是短暂的，而当在汇合时应用TPA时，抑制是稳定且持续的，这表明TPA在大鼠肝脏中可能不是一种有效的肿瘤促进剂。
