Combined use of green tea and quercetin in prostate cancer

绿茶和槲皮素联合使用治疗前列腺癌

基本信息

批准号：
8215640
负责人：
Susanne Margarete Henning
金额：
$ 7.7万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-01-25 至 2012-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8215640
关键词：
Animals Apoptosis Biological Availability Catechol O-Methyltransferase Catechols Cell Culture Techniques Cell Proliferation Cells Chemicals Chemoprevention Chemopreventive Agent Chromosomes, Human, Pair 10 Cytosine DNA Methyltransferase DNA Modification Methylases Detection Development Diagnosis Diagnostic Neoplasm Staging Diet Enzymes Epidemiology Epigallocatechin Gallate Flavonoids Gene Expression Green tea Health Health Benefit High Pressure Liquid Chromatography Human Immunohistochemistry In Vitro Incubated Induction of Apoptosis Kidney Knockout Mice LNCaP Laboratories Lead Liver Lung Malignant neoplasm of prostate Measures Metabolism Methylation Mus Operative Surgical Procedures P-Glycoprotein P-Glycoproteins PC3 cell line PTEN gene Pattern Phase Play Preventive Prostate Prostatic Neoplasms Publications Quercetin Role SCID Mice Structure Tea Testing Time Tissues Transgenic Organisms Tumor Suppressor Proteins Tumor Tissue Tumor Volume Tumor Weights Tumor stage Urine Water Western Blotting Work Xenograft procedure base cancer cell cell growth drinking water enzyme activity epicatechin epicatechin gallate fruits and vegetables gallocatechol in vivo inhibitor/antagonist mRNA Expression men mouse model novel polyphenol prostate cancer prevention protein expression serum PSA tumor tumor growth tumor xenograft

项目摘要

DESCRIPTION (provided by applicant): The anticarcinogenic activity of green tea has been demonstrated in many epidemiological, animal and cell culture studies. The main green tea polyphenols (GTPs) in brewed green tea (GT) responsible for the health benefits are epigallocatechin gallate (EGCG) and epigallocatechin (EGC), with smaller amounts of epicatechin (EC) and epicatechin gallate (ECG). Their limited bioavailability and high metabolism (conjugation and methylation) may decrease the potential of GT in chemoprevention. We determined that 50 percent or more of GTPs in human prostate tissue and urine is found in methylated form and that methylation significantly decreased the anticarcinogenic activity of EGCG. Catechol-O-methyltransferase (COMT) is the enzyme responsible for methylation of polyphenols with a catechol structure. Catechol-compounds such as EGCG and quercetin, a natural flavonoid occurring in many fruits and vegetable, inhibit COMT activity in prostate cancer cells (LNCaP). Co-treatment of quercetin and EGCG enhanced the COMT inhibitory effect, decreased EGCG methylation and increased EGCG bioavailability significantly. Therefore it is our hypothesis that co-treatment with quercetin and green tea will increase the chemopreventive activity of GT by inhibiting EGCG methylation and increasing the bioavailability in prostate cancer (CaP). We will test our hypothesis and investigate the mechanism using two different mouse models: A) by treating severe combined immunodeficient (SCID) mice inoculated with LNCaP xenograft tumors with green tea (GT) alone, GT and 0.2% quercetin (Q)-diet, GT+0.4%Q-diet, 0.2%Q-diet alone, 0.4%Q-diet alone or water control; and B) by treating transgenic phosphatase and tensin homolog deleted on chromosome 10 (PTEN) knock out mice with GT alone, Q alone and GT+ Q together using the concentration shown to be most effective for SCID mice. Lack of the tumor suppressor PTEN in the mouse prostate recapitulates many of the pathological features of CaP development in humans. To determine the chemopreventive activity we will measure tumor weight and volume, tumor stage, and cell proliferation, apoptosis by immunohistochemistry. Tumor tissue will be used to measure COMT and 5- cytosine DNA methyltransferase 1 (DNMT1) enzyme activity as well as protein and gene expression using Western blot and quantitative real-time PCR. Multidrug resistance proteins (MRP) may play a role in the increase in bioavailability of EGCG by co-treatment with quercetin. Therefore we will also determine protein and gene expression of MRP1 and MRP2 in tumor tissue. The effect on bioavailability will be determined by analysis of tea polyphenols, quercetin and their metabolites in tumor tissue, liver, lung, and kidney by high performance liquid chromatography and coularray electrochemical detection. This novel combination of natural complementary and alternative agents utilizes the ability of quercetin to reduce the methylation of GTPs and increase their bioavailability at the same time. This novel treatment will retain the non-toxic character of green tea and at the same time increase its activity in chemoprevention of CaP.

描述（由申请人提供）：在许多流行病学，动物和细胞培养研究中已经证明了绿茶的抗癌活性。负责健康益处的酿造绿茶（GT）中的主要绿茶多酚（GTP）是Epigallocatechin Gallate（EGCG）和epigallocatechin（EGC），较少的Epicatechin（EC）（EC）和埃泊酸酯（Epicatechin）和Epicatechin（ECG）（ECG）。它们有限的生物利用度和高代谢（结合和甲基化）可能会降低GT在化学预防中的潜力。我们确定人类前列腺组织和尿液中50％或更多的GTP以甲基化形式发现，并且甲基化显着降低了EGCG的抗癌活性。 Catechol-O-甲基转移酶（COMT）是负责具有儿茶酚结构的多酚甲基化的酶。 Catechol-Compound（例如EGCG和槲皮素）是一种天然类黄酮，在许多水果和蔬菜中发生，抑制了前列腺癌细胞中COMT活性（LNCAP）。槲皮素和EGCG的共同治疗增强了COMT抑制作用，EGCG甲基化降低，EGCG生物利用度显着提高。因此，我们的假设是，与槲皮素和绿茶的共同治疗将通过抑制EGCG甲基化并增加前列腺癌（CAP）的生物利用度来增加GT的化学预防活性。我们将使用两种不同的小鼠模型来检验我们的假设并研究机制：a）通过治疗与单独使用绿茶（GT）接种的严重组合免疫缺陷（SCID）小鼠，与LNCAP异种移植肿瘤接种，GT和0.2％槲皮素（Q）-Diet，GT+0.4％Q-DIET，0.4％Q-Diet，0.4％Q-Diet，0.4％Q-DIET，0.4％Q-DAWER CONTROTION，或0.4％Q-Diet，或0.4％Q-dietect，或Q-Dietect，或Q-Dietect，或0.4％q-dietect; b）通过在单独使用GT的染色体10（PTEN）上处理转基因磷酸酶和Tensin同源物，单独使用GT，单独使用Q和GT+ Q敲出小鼠，并使用对SCID小鼠最有效的浓度一起将小鼠一起。小鼠前列腺中缺乏肿瘤抑制剂PTEN概括了人类CAP发育的许多病理特征。为了确定化学预防活性，我们将测量肿瘤的体重和体积，肿瘤分期和细胞增殖，通过免疫组织化学的凋亡。肿瘤组织将用于测量使用Western印迹和定量实时PCR的蛋白质和蛋白质和基因表达的COMT和5-胞嘧啶DNA DNA甲基转移酶1（DNMT1）酶。多药耐药蛋白（MRP）可能通过与槲皮素共同治疗EGCG的生物利用度提高。因此，我们还将确定肿瘤组织中MRP1和MRP2的蛋白质和基因表达。对生物利用度的影响将通过对肿瘤组织，肝脏，肺和肾脏中的茶多酚，槲皮素及其代谢产物的分析来确定，高性能液相色谱和coularray电化学检测。这种自然互补剂和替代剂的新型组合利用槲皮素降低GTP的甲基化并同时增加其生物利用度的能力。这种新颖的治疗方法将保留绿茶的无毒特征，同时增加其在CAP化学预防中的活性。