Photodynamic Therapy for Prostate Cancer

前列腺癌的光动力疗法

基本信息

批准号：
6623450
负责人：
GANG ZHENG
金额：
$ 15.85万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-04-02 至 2005-03-31
项目状态：
已结题

项目摘要

The overall objective of this project is to develop bacteriochlorophyll- carotenoid based molecular beacons (BChl-MB) as prostate cancer (CaP)-specific photosensitizers for photodynamic therapy (PDT). The basic concept underlying this proposal is depicted in Figure 1. We propose to synthesize a molecular beacon (MB) consisting of any antisense oligodeoxynucleotide (AS-ON) sequence complementary to an mRNA specific for the target cancer cells. The MB contains a single- stranded DNA that can form a stem-loop structure. The loop sequence is an AS-ON. The stem is formed by the annealing of two complementary arm sequences that are on either side of the loop sequence. A dye (D) is attached to the end of one arm and a quencher (Q) is similarly attached to the other end. Proximity of D and Q quenches fluorescence and photoreactivity of the dye by energy transfer. In the presence of the tumor specific mRNA, the MB hybridizes with the mRNA, disrupting the hydrogen bonds of the stem. The quencher is removed from the immediate vicinity of the dyne. Upon irradiating with light, the dye emits fluorescence and generates cytotoxic singlet oxygen. The beacon serves both as a directed photodynamic therapy (PDT) agent and as a tumor specific diagnostic agent. We are proposing to synthesize BCh1-Mbs [in Fig. 1 D= bacteriochlorophyll (BCh1), Q= carotenoid (Car)] containing stem-loop AS-ON sequence targeted at the DD3 mRNA.. We have selected DD3 as the molecular target because it is one of the most CaP- specific genes described to date and is highly over-expressed in CaP. Such MB based PDT agents should be CaP-specific. We will focus on the synthesis of the BChl-MB that can hybridize with DD3 mRNA resulting in the significant increase of the fluorescence and the singlet oxygen production. We will develop cell-specific peptides as delivery reagents fort Bchl-MB and confirm that this agent reaches the target sites. Finally, we will validate the concept of MB based PDT agents in two human prostate cancer cell lines. Finally, we will validate the concept of MB based PDT agents in tow human prostate cancer cell lines, LNCaP (over-expressing DD3) and DU145 (not expressing DD3).

该项目的总体目标是开发基于细菌叶绿素-类胡萝卜素的分子信标（BChl-MB）作为用于光动力疗法（PDT）的前列腺癌（CaP）特异性光敏剂。该提议的基本概念如图 1 所示。我们建议合成一种分子信标 (MB)，该分子信标由与靶癌细胞特异性 mRNA 互补的任何反义寡脱氧核苷酸 (AS-ON) 序列组成。 MB含有可形成茎环结构的单链DNA。循环序列是 AS-ON。茎由环序列两侧的两个互补臂序列退火形成。染料 (D) 连接到一个臂的末端，猝灭剂 (Q) 类似地连接到另一端。 D 和 Q 的接近通过能量转移猝灭染料的荧光和光反应性。在肿瘤特异性 mRNA 存在的情况下，MB 与 mRNA 杂交，破坏茎的氢键。从达因附近去除猝灭剂。在光照射下，染料发出荧光并产生细胞毒性单线态氧。该信标既可用作定向光动力治疗（PDT）剂，又可用作肿瘤特异性诊断剂。我们建议合成含有针对 DD3 mRNA 的茎环 AS-ON 序列的 BCh1-Mbs [图 1 中 D= 细菌叶绿素 (BCh1)，Q= 类胡萝卜素 (Car)]。我们选择 DD3 作为分子靶标因为它是迄今为止描述的最具 CaP 特异性的基因之一，并且在 CaP 中高度过度表达。这种基于 MB 的 PDT 药物应该是 CaP 特异性的。我们将重点关注可与 DD3 mRNA 杂交的 BChl-MB 的合成，从而显着增加荧光和单线态氧的产生。我们将开发细胞特异性肽作为 Bchl-MB 的递送试剂，并确认该试剂到达目标位点。最后，我们将在两种人类前列腺癌细胞系中验证基于 MB 的 PDT 药物的概念。最后，我们将在两种人类前列腺癌细胞系 LNCaP（过度表达 DD3）和 DU145（不表达 DD3）中验证基于 MB 的 PDT 药物的概念。