Engineered self-destructing Salmonella as a colorectal cancer cure

工程化的自毁性沙门氏菌作为结直肠癌的治疗方法

• 批准号: 7962999
• 负责人: Wei Kong
• 金额: $ 16.58万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7962999
• 关键词: Anaerobic Bacteria; Angiogenic Proteins; Apoptosis; Area; Aspartate; Attenuated; Bacteria; Biological Response Modifier Therapy; Cancer Etiology; Cell Death; Cells; Cessation of life; Chemoreceptors; Chemotherapy-Oncologic Procedure; Colorectal Cancer; Cytolysis; DNA Vaccines; Development; Diagnosis; Diffusion; Drug resistance; Engineering; Enzymes; Exhibits; Genes; Genetic; Human; Hypoxia; Immune; Immune response; Immune system; Implant; Individual; Lead; Legal patent; Malignant Neoplasms; Malignant neoplasm of lung; Micrometastasis; Morbidity - disease rate; Mus; Normal tissue morphology; Oncogenes; Organ; Outcome; Phenotype; Prodrugs; Protein Biosynthesis; Proteins; Protocols documentation; Radiation therapy; Recombinants; Resistance; Salmonella; Salmonella enterica; Salmonella typhimurium; Serine; Site; Solid Neoplasm; Survival Rate; System; Targeted Toxins; Technology; Therapeutic; Time; Tissues; Toxic effect; Tumor Necrosis Factor Ligand Superfamily Member 6; Tumor Tissue; United States; Virulence Factors; base; cancer cell; cancer therapy; chemotherapy; conventional therapy; cytotoxic; design; design and construction; gene therapy; improved; killings; mortality; neoplastic cell; novel; novel strategies; programs; promoter; public health relevance; research study; tumor; tumor eradication; tumor growth; vector

DESCRIPTION (provided by applicant): We have constructed the attenuated hyper-invasive Salmonella enterica serovar Typhimurium (hereinafter S. Typhimurium), that are attenuated, yet capable of synthesizing selected protein and harboring an improved DNA vaccine vector encoding a selected protein. The programmed self-destructing features designed into these S. Typhimurium strains allow release of the cell contents by cell lysis after bacteria accumulated in host tissues. This proposal was promoted by the idea that if the selected proteins are able to trigger tumor cell apoptosis, then the engineered self-destructing Salmonella could serve as a programmed "bio-time-bomb" to destroy tumor tissues by release of tumor killing materials after colonization in tumor tissues. Colorectal cancer is the second leading cause of cancer-related deaths in the United States (after lung cancer). A major challenge in treating cancer is the difficulty of bringing therapy to poorly perfused areas of solid tumors, which are often most resistant to chemo- and radiotherapy. Motile facultative S. Typhimurium strains, which are specifically attracted to compounds produced by quiescent cancer cells and could overcome the traditional therapeutic barrier. It is known that attenuated S. Typhimurium preferably target and penetrate into tumor tissue allowing to accumulate about 2,000-fold more in tumors than in other organs, where they could overcome diffusion limitations and attack quiescent cancer cells that are impervious to standard chemo- and radiotherapy. Therefore we wish to explore the potential to use the engineered self-destructing Salmonella as a colorectal cancer cure. Our objective is to design, construct and evaluate a novel inexpensive rapidly modifiable recombinant attenuated S. Typhimurium (RAS) delivery system that will be a "time bomb" with multiple functional biotherapy agents as an optimal colorectal cancer cure to overcome chemo- and radiotherapeutic resistance. The (RAS) delivery system with newly developed features will (i) be hyper- invasive, (ii) selectively synthesize bacterial serine and aspartate chemoreceptors to facilitate maximal colonization of tumor tissues, (iii) displays regulated delayed synthesis of S. Typhimurium T3SS effector SopE2 that stimulates innate immune responses, and (iv) exhibits regulated delayed lysis to efficiently deliver the bacterial virulence factor TlpA, that directed by Salmonella promoter preferentially activated inside tumors, to induce apoptosis in tumor cells, and an improved DNA vaccine vector encoding a tumor-specifically synthesized death ligand Fas to trigger tumor cell death and also to attract immune cells to attack tumor cells. This RAS delivery system will have features to render it completely safe for humans administered the engineered Salmonella and to be unable to persist in immunized individuals or survive if excreted. Furthermore, we believe that the designing, constructing and evaluating an engineered Salmonella-based cancer cure would represent a highly effective means to reduce systemic toxicity of cancer treatment and perhaps lead to eradication of tumors from the host. ) PUBLIC HEALTH RELEVANCE: The engineered self-destructing Salmonella could serve as a programmed "bio-time-bomb" to destroy tumor tissues by release of tumor killing materials after colonization in tumor tissues. The designing, constructing and evaluating an engineered Salmonella-based colorectal cancer cure would represent a highly effective means to overcome chemo- and radiotherapeutic resistance, to reduce systemic toxicity of cancer treatment and perhaps lead to eradication of tumors from the host.

描述(申请人提供)：我们已经构建了减毒的高侵袭性肠道沙门氏菌血清型鼠伤寒沙门氏菌(以下简称鼠伤寒沙门氏菌)，该减毒鼠伤寒沙门氏菌能够合成选定的蛋白，并携带编码选定蛋白的改进DNA疫苗载体。这些鼠伤寒沙门氏菌中设计的程序化自毁功能允许细菌在宿主组织中积累后，通过细胞裂解释放细胞内容物。这一提议的推动者认为，如果选定的蛋白质能够触发肿瘤细胞凋亡，那么工程化的自毁沙门氏菌可以作为一枚程序化的“生物定时炸弹”，通过在肿瘤组织中定植后释放肿瘤杀伤物质来摧毁肿瘤组织。在美国，结直肠癌是癌症相关死亡的第二大原因(仅次于肺癌)。治疗癌症的一个主要挑战是难以将治疗带到实体肿瘤的低血流区域，这些区域通常对化疗和放射治疗最具抵抗力。能活动的兼性鼠伤寒沙门氏菌，它能被静止的癌细胞产生的化合物所吸引，并能克服传统的治疗障碍。众所周知，减毒鼠伤寒沙门氏菌最好靶向并渗透到肿瘤组织中，使其在肿瘤中的积聚比在其他器官中多约2000倍，在其他器官中，它们可以克服扩散限制，攻击不受标准化疗和放射治疗影响的静止癌细胞。因此，我们希望探索利用基因工程自毁沙门氏菌治疗结直肠癌的可能性。我们的目标是设计、构建和评价一种新型廉价、可快速修饰的重组减毒伤寒沙门氏菌(RAS)递送系统，该系统将成为具有多种功能生物治疗药物的“定时炸弹”，作为克服化疗和放射治疗耐药性的最佳结直肠癌治疗方案。新开发的RAS递送系统将(I)超侵袭，(Ii)选择性地合成细菌丝氨酸和天冬氨酸化学受体，以促进肿瘤组织的最大限度定植，(Iii)显示受调控的鼠伤寒沙门氏菌T3SS效应子SopE2的延迟合成，刺激天然免疫反应，(Iv)受调控的延迟裂解，以有效地输送由沙门氏菌启动子引导的细菌毒力因子TLPA，在肿瘤内优先激活，以诱导肿瘤细胞凋亡，以及改进的DNA疫苗载体编码肿瘤特异性合成的死亡连接蛋白和Fas，以触发肿瘤细胞死亡，并吸引免疫细胞攻击肿瘤细胞。这种RAS递送系统将具有使其对人类完全安全的特点，使其对注射工程沙门氏菌的人类来说是完全安全的，并且无法在接种疫苗的个体身上存活或在排泄后存活。此外，我们相信，设计、构建和评估一种基于沙门氏菌的工程化癌症治疗方法将是一种非常有效的手段，可以减少癌症治疗的全身毒性，并可能导致肿瘤从宿主中根除。) 与公共卫生相关：经过改造的自毁沙门氏菌可以作为一枚程序化的“生物定时炸弹”，通过在肿瘤组织中定植后释放肿瘤杀伤物质来摧毁肿瘤组织。设计、构建和评价一种基于沙门氏菌的基因工程结直肠癌治疗方法将是克服化疗和放射治疗耐药性、减少肿瘤治疗的全身毒性以及可能导致肿瘤从宿主体内根除的一种高效手段。