Therapeutic gene for anaerobic tissue targeting delivery and selectivity stabilization expression method and its application

Abstract

The invention belongs to biology technical field, concretely relates to a method for realizing a therapeutic gene on anaerobic tissue targeting delivery and selectivity stabilization expression. According to the invention, a prokaryotic bacteria nitroso reductase promoter PnirB induced by prokaryotes anaerobe is taken as composition of a therapeutic gene promoter, anaerobic targeting bacteria, low copy plasmid and the like, so that therapeutic gene enables an specific expression under low oxygen or hypoxia environment in vivo and in vitro. The method for realizing the therapeutic gene on the anaerobic tissue targeting delivery and selectivity stabilization expression is effectively treating the anaerobic tissue diseases containing tumor, or treating the anaerobic tissue diseases comprising tumor by combining other chemical medicaments and traditional Chinese medicines, and can be used for preparing antitumor drugs.

Description

Technical field [0001] The invention belongs to the field of genetic engineering biotechnology, and specifically relates to methods and applications for targeted delivery and selective stable expression of therapeutic genes in anaerobic tissues. Background technique [0002] Tumor gene therapy can fundamentally compensate for the abnormality of gene expression caused by the occurrence and development of tumors and correct the disorder of tumors at the gene level, so it has broad application prospects. However, there are still some bottlenecks in tumor gene therapy. For example, in the case of systemic drug delivery, how to make the transferred therapeutic gene be restricted to high-level and high-specific expression within the solid tumor or the entire tumor environment. Is it not expressed in other normal tissues to effectively eliminate or reduce the possible side effects of therapeutic genes? This technical difficulty limits the practical application of gene therapy in the tr...

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Problems solved by technology

However, there are still some problems in the above-mentioned gene therapy expression system: for example, (1) the stability of the plasmid vector for gene expression in vivo is poor and easy to be lost; (2) although tumor tissue-targeting bacteria are highly concentrated in tumor tissue enriched and have better tumor targeting, but this does not mean that they are not distributed or absent in other normal tissues, for example, Salmonella typhimurium (Salmonella typhimurium) exists in the liver and spleen, therefore, the therapeutic gene It will be expressed in normal tissues, resulting in non-tumor tissue-specific expression of therapeutic genes, resulting in in vivo toxicity; (3) In most previous studies, the expression level of therapeutic genes in vivo is low, and conventional protein cannot be used Electrophoresis and Western blot (Western blot) methods for detection of target therapeutic gene expression [Weth R et al., 2001, Cancer Gene Therapy 8: 599-611; Li YH et al., 2001, International Journal of Cancer 94: 438-443; Pawelek JM et al. , 1997, Cancer Research 57: 4537-4544; Liu SC et al., 2002, Gene Therapy 9: 291-306; Nemunaitis J et al., 2003, Cancer Gene Therapy 10: 737-744]

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