基于AR和Jak2/Stat3信号通路对异甘草素多靶点触控抑制前列腺癌作用的分子机制研究

Prostate cancer (PCa) is the most common male malignancy. PCa currently lack effective treatments and medicines. There lies defects in single targeted drugs, while multi-targeted drugs maybe more effective in affecting the whole complex system in cells. Trying to introduce a concept of computer technology called "multi-touch", by means of comparison, our group hypothesized that Chinese herbal compound may have some component (ingredient), which can simultaneously target multiple proteins, regulate multiple signaling pathways and inhibit tumor growth in a “multi-touch” way. We supposed that small molecule active natural products can also simultaneously touch multiple pathways to inhibit the proliferation or induce apoptosis of tumor cells under the combining effect. According to this hypothesis, we have screened isoliquiritigenin (ISL) from Chinese herbal compound PC-SPES—once used as a treatment of PCa, which showed activity in inhibiting the proliferation of PCa cells. We found ISL can regulate AR and Jak2/Stat3 in the same time, which may be a potential molecule to inhibit the growth of PCa in a “multi-touch” way. To confirm this conjecture, we aim to observe the activity of ISL in inhiting proliferation of PCa cells in vitro and tumor growth in vivo. Furthermore we will study the target of ISL in AR and Jak2/Stat3 multiple signal pathways to explain its multi-touch molecular mechanism of the inhibition of PCa. The study will provide experimental evidence and theoretical foundation for seeking PCa multi-targeted drugs.

前列腺癌（PCa）是男性常见恶性肿瘤，目前尚缺乏高效的治疗药物。单一靶点药物尚存在缺陷，多靶点药物较单一靶点药物能更有效影响细胞的复杂系统。课题组引用计算机技术“多点触控”概念，提出中药复方中存在某一组分（成分）能同时接触多个靶蛋白调控多个信号通路的多靶点触控抑制肿瘤生长的假说，设想小分子活性天然产物能同时触控多个信号通路，综合作用达到抑制肿瘤细胞增殖或诱导调亡。根据这个假说，我们从治疗PCa的复方PC-SPES中筛选了抑制PCa细胞增殖的异甘草素（ISL）。ISL能同时调控AR和Jak2/Stat3多条信号通路，可能是一种多靶点触控抑制前列腺癌的潜在分子。为证实这一猜想，我们将考察ISL体内外抑制PCa细胞增殖及肿瘤生长的活性，探讨ISL对AR和Jak2/Stat3多信号通路的作用，以阐释其多靶点触控抑制前列腺癌作用的分子机制。本研究将为寻找治疗PCa的多靶点药物提供实验依据和理论基础

异甘草素是从中药甘草中提取的天然查尔酮类化合物。课题组前期从治疗前列腺癌的复方PC-SPES入手，筛选出其中能抑制前列腺癌细胞增殖的有效成分异甘草素。异甘草素（25-50μM）体外能抑制前列腺癌细胞的增殖，诱导细胞凋亡；体内能有效抑制前列腺癌细胞PC-3裸鼠移植瘤的生长。对激素依赖性前列腺癌细胞LNCaP，异甘草素能显著下调雄激素受体AR的表达，以及下游受AR调控的前列腺特异性抗原PSA的表达；对激素非依赖性前列腺癌细胞PC-3、22RV1，异甘草素能阻滞细胞周期于G2/M期。结合本课题中提出的“多靶点触控”的概念，我们采用了基因芯片技术，利用转录组学的数据来支持“多靶点触控”的假设。结果表明异甘草素使前列腺癌细胞中与细胞周期、DNA损伤以及细胞凋亡信号通路相关的多个基因表达显著改变，比如周期依赖性蛋白CDK1、凋亡相关蛋白Bax等；另外针对激素依赖性前列腺癌细胞LNCaP，异甘草素的作用主要体现在对甾体激素合成和雄激素受体信号通路的调节，比如醛酮还原酶AKR1C1和AKR1C2，雄激素受体AR。进一步的分子机制研究表明异甘草素通过下调CDK1及其复合物cyclin B1-CDK1使细胞周期阻滞于G2/M期；同时异甘草素对激素合成网络的整体调节，尤其是上调AKR1C1和AKR1C2，促使雄激素受体高亲和力的配体二氢睾酮DHT还原为低亲和力配体雄烷二醇3α-diol和3β-diol，下调AR转录活性，从而达到抑制前列腺癌细胞增殖的作用。综上所述，异甘草素是通过同时调控细胞周期、激素合成和雄激素受体等多个信号通路发挥抗前列腺癌的作用。本研究有助于寻找抗前列腺癌的多靶点小分子药物，为其提供实验依据和理论基础。