Benzo(a)pyrene-DNA adduct formation and removal in mouse epidermis in vivo and in vitro: relationship of DNA binding to initiation of skin carcinogenesis.
Benzo(a)pyrene-DNA adduct formation and removal in mouse epidermis in vivo and in vitro: relationship of DNA binding to initiation of skin carcinogenesis.
复制标题
体内和体外小鼠表皮苯并（a）芘-DNA 加合物的形成和去除：DNA 结合与皮肤癌发生的关系。
作者：
J. Nakayama;S. Yuspa;M. Poirier
通过酶联免疫吸附测定，使用对体内与脱氧鸟苷形成的主要苯并（a）芘（BP）加合物具有特异性的抗血清来监测局部暴露于初始剂量 BP 的 BALB/c 小鼠表皮以及体外暴露于 BP 或 BP 的 BALB/c 小鼠角质形成细胞中 DNA 结合产物的形成和去除。 其活化衍生物。在小鼠表皮 DNA 中，抗体可识别产物的形成在 50 至 250 nmol BP 剂量之间成比例增加，分别产生 2.3 至 6.0 fmol/微克 DNA，并在 1000 至 1500 nmol 剂量之间达到 10 至 11 fmol/微克 DNA 的平台。抗体可识别的加合物大约占总 BP-DNA 结合的一半，因为通过酶联免疫吸附测定，250 nmol 剂量的 [3H]BP 产生 6 fmol/微克 DNA，通过放射性标记产生 12.9 fmol/微克 DNA。在暴露于 500 nmol BP 的小鼠表皮 DNA 中监测了反式-(7R)-N2-(10-[7 β, 8 α, 9 α-三羟基-7,8,9,10-四氢苯并(a)芘]-基)-脱氧鸟苷加合物的去除，尽管没有对 在皮肤上，24小时内形成的加合物大约有一半在3天后被去除，到一周结束时仅剩下10%。还在培养的小鼠角质形成细胞中研究了 BP-DNA 的结合和去除，其中可以通过调节培养基的 Ca2+ 浓度来选择性地研究增殖的基底细胞和终末分化细胞。 BP剂量反应研究表明，在不同成熟状态的细胞中，BP-DNA加合物水平相似。大于 10 至 11 fmol/微克（体内获得的最高值）的加合物形成与广泛的细胞毒性和细胞死亡相关。在可监测 DNA 合成稀释或细胞损失的条件下，跟踪培养物中加合物去除的动力学。这些实验的结果表明，在分化群体中，BP-DNA加合物的初始去除速度更快，尽管在两个群体中，50%的加合物在24小时内被去除。对Ca2+诱导的终末分化具有抗性的病灶的形成先前已被认为与培养的角质形成细胞中的致癌物处理有关。暴露于产生低细胞毒性的浓度的BP或抗二醇环氧化物，产生与所用化合物的剂量和形成的DNA加合物的数量成比例的分化改变灶的频率。
An antiserum specific for the major benzo(a)pyrene (BP) adduct formed with deoxyguanosine in vivo has been used by enzyme-linked immunosorbent assay to monitor the formation and removal of DNA-bound products in BALB/c mouse epidermis exposed topically to initiating doses of BP and in BALB/c mouse keratinocytes exposed in vitro to BP or its activated derivatives. In mouse epidermal DNA, formation of antibody-recognizable products increased proportionally between doses of 50 and 250 nmol of BP, giving 2.3 to 6.0 fmol/micrograms of DNA, respectively, and reached a plateau of 10 to 11 fmol/micrograms of DNA at doses between 1000 and 1500 nmol. Antibody-recognizable adducts comprised roughly one-half of the total BP-DNA binding, since a 250-nmol dose of [3H]BP yielded 6 fmol/micrograms of DNA by enzyme-linked immunosorbent assay and 12.9 fmol/micrograms of DNA by radiolabeling. Removal of trans-(7R)-N2-(10-[7 beta, 8 alpha, 9 alpha-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene]-yl)-deoxyguanosine adducts was monitored in epidermal DNA of mice exposed to 500 nmol of BP and, although no correction was approximated for DNA turnover in the skin, about one-half of the adducts formed by 24 hr were removed 3 days later, and only 10% remained at the end of a week. BP-DNA binding and removal were also studied in cultured mouse keratinocytes, where proliferating basal cells and terminally differentiating cells can be selectively studied by modulating the Ca2+ concentration of the medium. BP dose-response studies showed that, in cells of different maturation states, BP-DNA adduct levels were similar. Adduct formation greater than 10 to 11 fmol/micrograms (the highest obtained in vivo) was associated with extensive cytotoxicity and cell death. The kinetics of adduct removal was followed in culture under conditions in which dilution by DNA synthesis or cell loss could be monitored. Results of these experiments suggested that initial removal of BP-DNA adducts was more rapid in the differentiating population although, in both populations, 50% of the adduct was removed by 24 hr. The formation of foci resistant to Ca2+-induced terminal differentiation has been associated previously with carcinogen treatment in cultured keratinocytes. Exposure to BP or the antidiol-epoxide, at concentrations producing low cytotoxicity, yielded frequencies of differentiation-altered foci proportional to the dose of the compound used and to the number of DNA adducts formed.
短期器官培养和体内小鼠和大鼠皮肤对苯并[a]芘的代谢和激活。
影响因子：
5.1
作者：
Weston,A;Grover,PL;Sims,P
通讯作者：
Sims,P