Hypoxia-Activated O6-Benzylguanine Prodrugs

缺氧激活的 O6-苄基鸟嘌呤前药

• 批准号: 8080493
• 负责人: ALAN CLAYTON SARTORELLI
• 金额: $ 28.5万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8080493
• 关键词: Active Sites; Alkylating Agents; Alkylation; Animals; Antineoplastic Agents; Area; Binding; Biochemical; Cancer Patient; Carmustine; Cell Fraction; Cells; Chemicals; Clinical; Clinical Trials; Cysteine; Cytosine; DNA; DNA lesion; Dacarbazine; Development; Diffusion; Dose; Drug Formulations; Drug-sensitive; Employment; Enzymes; Ethane; Evaluation; Experimental Neoplasms; FDA approved; Guanine; Human; Hydrazine; Hypoxia; In Vitro; Laboratories; Lead; Lomustine; Malignant Neoplasms; Measurement; Measures; Methodology; Mus; Myelosuppression; Neoplasms; Nitroreductases; Nitrosourea Compounds; Normal tissue morphology; O(6)-Methylguanine-DNA Methyltransferase; O(6)-benzylguanine; Oxygen; Patients; Pharmaceutical Preparations; Positioning Attribute; Procarbazine; Prodrugs; Proteins; Reaction; Relative (related person); Resistance; Site; Solid Neoplasm; Specificity; Staging; Streptozocin; System; Therapeutic; Tissues; Transplantation; Tumor Tissue; Water; adduct; alkyl group; analog; base; crosslink; cyclohexylchloroethylnitrosourea; cytotoxic; design; dosage; expectation; in vivo; inhibitor/antagonist; lead series; methyl group; neoplastic cell; nucleophilic substitution; public health relevance; repaired; resistance mechanism; temozolomide; tumor

DESCRIPTION (provided by applicant): Alkylating agent prodrugs that chloroethylate the O-6 position of DNA guanine include onrigin (cloretazine), an agent designed and synthesized in our laboratory, currently in late stage clinical trial; carmustine (BCNU) and temozolomide (TMZ), an FDA approved clinically used nitrosourea and methylating agent, respectively, and KS119, a sulfonylhydrazine prodrug selectively activated in hypoxic cells of solid tumors will be employed. The DNA lesion, produced by the cholorethylating agents, an alkylation of the O6-position of DNA guanine which leads to a G-C crosslink, is susceptible to repair by O6-alkylguanine-DNA alkyltransferase (AGT), a protein that transfers alkyl and methyl groups from the O-6 position of guanine to the AGT molecule. This action represents the primary mechanism of tumor and host tissue resistance to onrigin, KS119, BCNU, and TMZ. Non-toxic doses of systemic O6-BG have been shown in cancer patients to deplete the AGT content of tumors; this action also depletes AGT in normal tissue, sensitizing both tumor host tissues to BCNU used in combination. The depletion of AGT necessitates an 80% decrease in dosage of BCNU because of myelosuppression, leading to an ineffective antineoplastic level of this nitrosourea. The Specific Aims of this application are (a) the design and synthesis of formulatable O6-BG prodrugs containing a p-nitrobenzylcarbonyl trigger/linker activated selectively/preferentially by reducing enzymes in oxygen-deficient cells of solid tumors, thereby selectively depleting tumors of AGT while sparing oxygenated normal tissue; (b) evaluation of pretreatment of hypoxic and oxygenated tumor cells with O6-BG prodrugs in vitro followed by onrigin, KS119, BCNU, and TMZ; (c) evaluation in vivo of combinations of these agents with synthesized AGT inhibitors against a variety of transplanted human and murine tumors containing varied levels of AGT and (d) biochemical studies of the mechanism of action of the synthesized prodrugs The expectation is that solid tumors, resistant to the cytotoxic actions of O6-DNA guanine targeting agents because of constitutively high levels of AGT, will be selectively/preferentially depleted of the resistance inducing protein AGT by pretreatment with the O6-BG prodrug, leading to the conversion of chloroethylating/methylating agent resistant neoplasms to drug sensitive ones, thereby increasing the spectrum of malignancies that may derive benefit from onrigin, KS119, BCNU and TMZ. PUBLIC HEALTH RELEVANCE: The selective activation of AGT inhibitory prodrugs in oxygen-deficient tumor tissue enhance the antitumor potential of alkylating and methylating drugs that chloroethylate and methylate the O6-position of DNA guanine, as well as reverse the primary mechanism of resistance of this class of agents (i.e., alkylating agents targeting the O6-position of DNA guanine). The design, synthesis and characterization of new AGT inhibitory agents in concert with the continued development of specific known DNA O6-guanine targeting agents to use in combination may well prove to yield unique new treatments for a variety of currently non-responsive tumors.

描述（由申请人提供）：氯乙基的烷基化剂前药，DNA鸟嘌呤的O-6位置包括Onrigin（Cloretazine），这是一种在我们的实验室中设计和合成的剂，目前正在晚期临床试验中； Carmustine（BCNU）和Temozolomide（TMZ），FDA批准的临床使用的硝酸和甲基化剂，以及KS119（使用磺酰氢嗪在固体肿瘤的低氧细胞中选择性地激活的磺酰氢嗪前药。由胆碱甲基产生的DNA病变是DNA鸟嘌呤的O6位置的烷基化，导致G-C交叉链接的DNA斑点易于通过O6-烷基圭烷-DNA烷基转移酶（AGT）修复，这是一种将烷基和甲基从O-6中转移到O-6的位置的蛋白质。该作用代表了肿瘤和宿主组织抗对Onrigin，KS119，BCNU和TMZ的主要机制。在癌症患者中已显示出无毒的全身O6-BG剂量，以耗尽肿瘤的AGT含量。该作用还耗尽了正常组织中的AGT，将两个肿瘤宿主组织敏感到组合使用的BCNU。由于骨髓抑制，AGT的耗竭需要减少BCNU的剂量80％，从而导致该硝酸盐的抗肿瘤水平无效。该应用的具体目的是（a）含有含有P-硝基苯甲酰辅酶的可公式的O6-BG前药的设计和合成，通过减少固定性细胞的缺氧细胞中的氧气缺陷细胞中的氧气缺失，从而选择性地耗尽了蛋白质的氧化物，从而选择性地降低了氧气的氧气，从而选择性地/优先地激活了氧气，从而降低了氧气的氧化肿瘤，同时将氧气降低了氧气的氧化物。 （b）在体外用O6-BG前药对低氧和氧化肿瘤细胞进行预处理的评估，然后是Onrigin，KS119，BCNU和TMZ； (c) evaluation in vivo of combinations of these agents with synthesized AGT inhibitors against a variety of transplanted human and murine tumors containing varied levels of AGT and (d) biochemical studies of the mechanism of action of the synthesized prodrugs The expectation is that solid tumors, resistant to the cytotoxic actions of O6-DNA guanine targeting agents because of constitutively high levels of AGT将通过对O6-BG前药进行预处理选择性/优先耗尽诱导蛋白AGT的抗性，从而导致氯化/甲基化剂耐药性肿瘤转化为药物敏感的肿瘤，从而增加了可能受益于Onrigin，KS119，BCN的恶性肿瘤的光谱，从而增加了恶性肿瘤的光谱。 PUBLIC HEALTH RELEVANCE: The selective activation of AGT inhibitory prodrugs in oxygen-deficient tumor tissue enhance the antitumor potential of alkylating and methylating drugs that chloroethylate and methylate the O6-position of DNA guanine, as well as reverse the primary mechanism of resistance of this class of agents (i.e., alkylating agents targeting the O6-position of DNA guanine).新的AGT抑制剂的设计，合成和表征与用于组合使用的特定已知DNA O6-瓜氨酸靶向剂的持续开发很可能证明是为各种当前非反应性肿瘤提供独特的新处理。