Ptak Anna, Gut Patrycja, Błachuta Małgorzata, Rak Agnieszka, Gregoraszczuk Ewa Ł
Department of Physiology and Toxicology of Reproduction, Institute of Zoology, Jagiellonian University, 30-060 Kraków, Ingardena 6, Poland.
Toxicol Lett. 2009 Oct 28;190(2):187-92. doi: 10.1016/j.toxlet.2009.07.013. Epub 2009 Jul 18.
Our previously published data showed that 260h of exposure to 3,4-diOH-PCB3 decreased proliferation in the MCF-7 cell line. In the present study, we sought to determine whether this is due to action on the SHBG/cAMP/PKA system, activation of which can inhibit cell proliferation, or to direct inhibition of ERK1/2 phosphorylation. MCF-7 human breast cancer cells were treated for 72h with 4-monochlorobiphenyl (PCB3), 4'-hydroxy-4-monochlorobiphenyl (4-OH-PCB3) or 3'4'-dihydroxy-4-monochlorobiphenyl (3,4-diOH-PCB3) (300nM). After the completion of the treatment, cell proliferation was measured with a BrdU incorporation assay. SHBG, cAMP, PKA and ERK1/2 levels in the cells were determined via ELISA. PCB3 and 4-OH-PCB3 had no effect on extra- or intracellular SHBG levels, while a stimulation of SHBG intra- but not extracellular levels was noted in cells exposed to 3,4-diOH-PCB3. Both, pre- and co-incubation with SHBG decreased the proliferation of 3,4-diOH-PCB3-treated cells. Neither PCB3 nor its metabolite had an effect on the cAMP/PKA pathway. A decrease of both ERK1/2 forms was noted under the influence of 3,4-diOH-PCB3. In conclusion, the data presented clearly showed that the antiproliferative action of 3,4-diOH-PCB3 is not mediated by activation of the SHBG/AMP/PKA pathway, but many other plasma membrane receptors seem to be involved in the non-genomic action of 3,4-diOH-PCB3, and instead is due to direct inhibition of the ERK1/2 system.
我们之前发表的数据表明，暴露于3,4 - 二羟基多氯联苯3（3,4 - diOH - PCB3）260小时会降低MCF - 7细胞系的增殖。在本研究中，我们试图确定这是由于作用于性激素结合球蛋白/环磷酸腺苷/蛋白激酶A（SHBG/cAMP/PKA）系统（该系统的激活可抑制细胞增殖），还是由于直接抑制细胞外信号调节激酶1/2（ERK1/2）的磷酸化。MCF - 7人乳腺癌细胞用4 - 单氯联苯（PCB3）、4' - 羟基 - 4 - 单氯联苯（4 - OH - PCB3）或3'4' - 二羟基 - 4 - 单氯联苯（3,4 - diOH - PCB3）（300 nM）处理72小时。处理完成后，用BrdU掺入法检测细胞增殖。通过酶联免疫吸附测定（ELISA）法测定细胞中的SHBG、cAMP、PKA和ERK1/2水平。PCB3和4 - OH - PCB3对细胞外或细胞内SHBG水平均无影响，而在暴露于3,4 - diOH - PCB3的细胞中，观察到细胞内SHBG水平受到刺激，但细胞外SHBG水平未受影响。与SHBG预孵育和共孵育均降低了3,4 - diOH - PCB3处理细胞的增殖。PCB3及其代谢产物对cAMP/PKA途径均无影响。在3,4 - diOH - PCB3的影响下，观察到ERK1/2的两种形式均减少。总之，所呈现的数据清楚地表明，3,4 - diOH - PCB3的抗增殖作用不是由SHBG/环磷酸腺苷/蛋白激酶A（SHBG/AMP/PKA）途径的激活介导的，而是许多其他质膜受体似乎参与了3,4 - diOH - PCB3的非基因组作用，相反，其抗增殖作用是由于对ERK1/2系统的直接抑制。
