Anticarcinogenic Effect of ITCs Against Prostate Cancer

ITCs 对前列腺癌的抗癌作用

• 批准号: 6776402
• 负责人: Shivendra Singh
• 金额: $ 32.95万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-14 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6776402
• 关键词: affinity chromatography; analog; apoptosis; athymic mouse; biological products; biotechnology; cancer prevention; cell growth regulation; chemical structure function; chemoprevention; cyclin dependent kinase; cysteine endopeptidases; drug design /synthesis /production; drug screening /evaluation; enzyme activity; enzyme induction /repression; glutathione; high performance liquid chromatography; isothiocyanates; mitogen activated protein kinase; neoplasm /cancer chemotherapy; neoplastic process; prohormone convertase; prostate neoplasms; statistics /biometry; transfection

DESCRIPTION (provided by applicant): This translational research project is based on the premise that isothiocyanates (ITCs; R-N=C=S) may be used to inhibit onset and/or progression of human prostate cancer, which is a serious public health concern especially for elderly men. Based on our preliminary data, we hypothesize that ITCs will be highly effective in suppressing growth of human prostate cancer cells due to their ability to (a) induce apoptosis involving activation of caspases and extraeellular signal-regulated kinases 1/2 (ERKI/2), and (b) arrest cells in G2/M phase by reducing the activity of the cyclin-dependent kinase1 (Cdk1)/cyclinB kinase complex. An interesting corollary to the above hypothesis is that the antiproliferative activity of the ITCs is significantly affected not only by chemical modification in their terminal R-group and alkyl chain length but also because of their reactivity with glutathione (GSH). We propose to test the above mentioned hypotheses through studies in following specific aims: Specific Aim 1: Determine the effects of the ITC analogues with varying terminal R-group and or alkyl chain length on proliferation, apoptosis induction and cell cycle distribution in PC-3 and LNCaP human prostate cancer cells, and a normal prostate epithelial cell line (PrEC). These studies will not only provide insights into the crucial structure-activity relationship but also identify the most effective natural ITC analogue for mechanistic and in vivo efficacy studies for specific aims 2-5. Among the ITC analogs screened to date in our preliminary studies, phenethy-ITC (PEITC) appears most promising due to its strong growth suppressive activity against cultured human prostate cancer cells. Studies for specific aims 2 through 5 will focus on PEITC if this agent is superior to other ITC analogues in terms of greater cytotoxicity to prostate cancer cells and lack of an effect on proliferation of normal prostate epithelial cell line, Specific Aim 2: Determine the impact of GSH conjugation on antiproliferative activity of ITCs using PC-3 and LNCaP cells. This objective will be achieved by (a) determining the effect of overexpression of Pi class GSH transferase (hGSTP1-1), through stable transfection in prostate cancer cells, on antiproliferative activity of the ITC, and (b) determining the effect of ethacrynic acid, an inhibitor of GST activity, on antiproliferative activity of the ITC against prostate cancer ceils. Specific Aim 3: Define the mechanism(s) of lTC-induced apoptosis using cultured PC-3 and LNCaP cells. In this specific aim, studies are designed to determine the role of caspases and ERKs and their associated signaling pathways in ITC-induced apoptosis. Specific Aim 4: Define the mechanism(s) of lTC-induced G2/M arrest using PC-3 and LNCaP. Specifically, studies are designed to test the hypothesis that G2/M arrest in ITC treated prostate cancer cells is attributable to reduced activity of the Cdk1/cyclinB kinase complex due to increased ubiquitin-proteasome mediated degradation of dual-specificity phosphatases Cdc25B and Cdc25C, and possibly Cdk1. Specific Aim 5: Determine the effect of oral administration of ITC on growth of PC-3 and LNCaP human prostate cancer xenografts in vivo in nude mice. The effect of the ITC administration will be assessed in terms of xenograft growth and tumor regression. Studies are also planned to determine whether ITC treatment leads to a sustained suppression of tumor growth even after cessation of its administration. Tumors from the vehicle treated control and ITC treated mice will be examined to determine the extent to which ITC-induced molecular changes observed in cells (aims 3 and 4) correlate with its effect in vivo. Studies proposed in this application may lead to identification of an ITC analogue that can be used to delay onset and/or progression of human prostate cancer.

描述（由申请人提供）：该转化研究项目基于以下前提：异硫氰酸盐（ITCS; r-n = C = S）可用于抑制人类前列腺癌的发作和/或进展，这是一个严重的公共卫生问题对于老年人。根据我们的初步数据，我们假设ITC由于能力（a）诱导凋亡涉及caspase激活的凋亡和细胞外信号调节激酶1/2（ERKI/2）的能力，在抑制人前列腺癌细胞的生长方面非常有效。 ，（b）通过降低细胞周期蛋白依赖性激酶1（CDK1）/Cyclinb激酶复合物的活性，在G2/M期间停止细胞。上述假设的一个有趣的推论是，ITC的抗增殖活性不仅受到其末端R组和烷基链长度的化学修饰的影响，而且还因为它们与谷胱甘肽（GSH）的反应性。我们建议通过研究以下特定目的来检验上述假设：具体目标1：确定具有不同末端R组和 /或烷基链长度对PC-3中PC-3中的ITC类似物的影响和 /或烷基链长度对增殖，凋亡诱导和细胞周期分布的影响。和LNCAP人前列腺癌细胞以及正常的前列腺上皮细胞系（PREC）。这些研究不仅将提供有关关键结构活性关系的见解，而且还将确定针对特定目标2-5的机械和体内功效研究的最有效的天然ITC类似物。在我们的初步研究中筛选的ITC类似物中，由于对培养的人类前列腺癌细胞的强烈生长抑制活性，是否其最有前途的策略ITC（PEITC）似乎是最有前途的。对于特定目标2至5的研究，如果该试剂优于其他ITC类似物，就对前列腺癌细胞的更大细胞毒性而优于其他ITC类似物，并且对正常前列腺上皮细胞系的增殖缺乏影响，请确定影响：确定影响。使用PC-3和LNCAP细胞对ITC的抗增殖活性的GSH结合。该目标将通过（a）确定PI类GSH转移酶（HGSTP1-1）的过表达，通过前列腺癌细胞中的稳定转染，对ITC的抗增殖活性的影响，以及（b）确定乙二醇酸的效果。 ，一种GST活性的抑制剂，对ITC对前列腺癌天花板的抗增殖活性。特定目标3：使用培养的PC-3和LNCAP细胞定义LTC诱导的凋亡的机制。在这个具体目的中，研究旨在确定胱天蛋白酶和ERK及其相关信号通路在ITC诱导的凋亡中的作用。特定目标4：使用PC-3和LNCAP定义LTC诱导的G2/M停滞的机理。具体而言，研究旨在检验以下假设：ITC处理的前列腺癌细胞中的G2/M停滞归因于CDK1/Cyclinb激酶复合物的活性降低，这是由于泛素 - 蛋白酶体介导的双特异性磷酸酶CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B和CDC25B，以及可能是CDK1。具体目标5：确定ITC口服给药对裸鼠体内PC-3和LNCAP人前列腺异种移植物的生长的影响。 ITC给药的效果将根据异种移植生长和肿瘤回归评估。还计划确定即使停止给药后，ITC治疗是否会导致肿瘤生长的持续抑制。将检查来自媒介物处理对照和ITC处理的小鼠的肿瘤，以确定ITC诱导的分子变化在细胞中观察到的分子变化的程度（目标3和4）与其在体内的作用相关。在此应用中提出的研究可能导致鉴定ITC类似物，该类似物可用于延迟人类前列腺癌的发作和/或进展。