Abstract:
The present invention provides a bacterium belonging to the genus Bifidobacterium, by which DNA coding for a protein having an antitumor activity or DNA coding for a protein having the activity of converting a precursor of an antitumor substance into the antitumor substance is delivered to tumor tissues specifically under anaerobic conditions thereby expressing the protein encoded by the DNA, as well as a pharmaceutical composition comprising said anaerobic bacterium.
Abstract:
The present invention provides a shuttle vector for a microorganism of the genus Bifidobacterium (BM) and Escherichia coli having a wide host range and a large copy number in BM and capable of highly expressing a desired protein when used as an expression vector; an expression vector capable of expressing a desired gene in BM by use of the shuttle vector; BM transformed with the expression vector; and an antitumor agent comprising the BM as an active ingredient. It comprises a pTB6-derived region portion comprising a replication origin (oriV)-repB region of pTB6 but not comprising MembB, MobA, OrfI, and oriT regions of pTB6 and an Escherichia coli-derived plasmid portion comprising a replication origin (Puc Ori) region of Escherichia coli but having deleted DNA encoding an N-terminal region of an ampicillin resistance gene (ampR) expression product β-lactamase.
Abstract:
The present invention provides a shuttle vector for a microorganism of the genus Bifidobacterium (BM) and Escherichia coli having a wide host range and a large copy number in BM and capable of highly expressing a desired protein when used as an expression vector; an expression vector capable of expressing a desired gene in BM by use of the shuttle vector; BM transformed with the expression vector; and an antitumor agent comprising the BM as an active ingredient. It comprises a pTB6-derived region portion comprising a replication origin (oriV)-repB region of pTB6 but not comprising MembB, MobA, OrfI, and oriT regions of pTB6 and an Escherichia coli-derived plasmid portion comprising a replication origin (oriC) region of Escherichia coli but having deleted DNA encoding an N-terminal region of an ampicillin resistance gene (ampR) expression product β-lactamase, and constitute a shuttle vector for Escherichia coli with a BM having an average copy number of 6 to 30.
Abstract:
An object of the present invention is to provide a method of efficiently constructing a gene delivery carrier having a favorable activity and expression efficiency of a protein expressed by a gene introduced by transformation. Moreover, an object of the present invention is to provide a pharmaceutical composition comprising a gene delivery carrier constructed by the construction method and a therapeutic agent for solid tumor comprising the resistant bacterium. The objects of the present invention have been attained by a gene delivery carrier consisting of an anaerobic microorganism capable of growing in a tumor tissue in an anaerobic environment and capable of expressing (A) a protein having an antitumor activity or (B) a protein having an activity of converting an antitumor substance precursor to an antitumor substance, wherein DNA encoding the protein of interest is allowed to further comprise, on the 5′-terminal side thereof, a DNA fragment comprising a nucleotide sequence encoding a peptide consisting of an amino acid sequence from the 1st to at least 4th amino acids at the N-terminus of a histone-like DNA-binding protein.
Abstract:
The present invention provides a method for producing a cytosine deaminase (CD)-expressing, 5-fluorouracil (5-FU)-resistant microorganism which can grow in anaerobic tumor tissues, can express CD, and has a resistance to 5-FU at a concentration that is at least effective for antitumor activity. More specifically, the method is a method (A) comprising performing subculture or acclimation culture of a CD-expressing microorganism which can grow in anaerobic tumor tissues, in the presence of 5-fluorocytosine (5-FC), or a method (B) comprising (1) performing subculture or acclimation culture of a microorganism which can grow in anaerobic tumor tissues and does not express CD, in the presence of 5-FU to produce a 5-FU-resistant microorganism and (2) transforming the 5-FU-resistant microorganism by introducing a CD gene. The present invention also provides the CD-expressing, 5-FU-resistant microorganism and a pharmaceutical composition comprising the microorganism.
Abstract:
An object of the present invention is to provide a method of efficiently constructing a gene delivery carrier having a favorable activity and expression efficiency of a protein expressed by a gene introduced by transformation. Moreover, an object of the present invention is to provide a pharmaceutical composition comprising a gene delivery carrier constructed by the construction method and a therapeutic agent for solid tumor comprising the resistant bacterium. The objects of the present invention have been attained by a gene delivery carrier consisting of an anaerobic microorganism capable of growing in a tumor tissue in an anaerobic environment and capable of expressing (A) a protein having an antitumor activity or (B) a protein having an activity of converting an antitumor substance precursor to an antitumor substance, wherein DNA encoding the protein of interest is allowed to further comprise, on the 5′-terminal side thereof, a DNA fragment comprising a nucleotide sequence encoding a peptide consisting of an amino acid sequence from the 1st to at least 4th amino acids at the N-terminus of a histone-like DNA-binding protein.
Abstract:
The present invention provides an obligately anaerobic lactic acid bacterium having no risk of causing side effects in normal tissue and promising as a safe therapeutic agent and a gene transporter for a disease that is in an anaerobic environment such as a solid tumor, a preparation method therefor, and an expression vector useful in the preparation method. The obligately anaerobic lactic acid bacterium of the present invention has been artificially mutated from being facultatively anaerobic to being obligately anaerobic and, furthermore, is capable of being transformed by an expression vector having introduced thereinto a gene for expressing an active protein useful for the treatment of a disease that is in an anaerobic environment. Furthermore, the expression vector of the present invention functions in an obligately anaerobic lactic acid bacterium and contains a Lactobacillus-derived plasmid replication protein gene (Rep), a secretion signal sequence (PslpA-SSartP) comprising a Lactobacillus-derived s-layer gene promoter and a Lactobacillus-derived PrtP protein secretion signal, and one or more selection marker genes. The expression vector of the present invention enables producing an extremely safe and excellent therapeutic agent and gene transporting microorganism for a disease that is in an anaerobic environment.
Abstract:
The present invention provides an obligately anaerobic lactic acid bacterium having no risk of causing side effects in normal tissue and promising as a safe therapeutic agent and a gene transporter for a disease that is in an anaerobic environment such as a solid tumor, a preparation method therefor, and an expression vector useful in the preparation method. The obligately anaerobic lactic acid bacterium of the present invention has been artificially mutated from being facultatively anaerobic to being obligately anaerobic and, furthermore, is capable of being transformed by an expression vector having introduced thereinto a gene for expressing an active protein useful for the treatment of a disease that is in an anaerobic environment. Furthermore, the expression vector of the present invention functions in an obligately anaerobic lactic acid bacterium and contains a Lactobacillus-derived plasmid replication protein gene (Rep), a secretion signal sequence (PslpA-SSartP) comprising a Lactobacillus-derived s-layer gene promoter and a Lactobacillus-derived PrtP protein secretion signal, and one or more selection marker genes. The expression vector of the present invention enables producing an extremely safe and excellent therapeutic agent and gene transporting microorganism for a disease that is in an anaerobic environment.
Abstract:
The present invention provides a bacterium belonging to the genus Bifidobacterium, by which DNA coding for a protein having an antitumor activity or DNA coding for a protein having the activity of converting a precursor of an antitumor substance into the antitumor substance is delivered to tumor tissues specifically under anaerobic conditions thereby expressing the protein encoded by the DNA, as well as a pharmaceutical composition comprising said anaerobic bacterium.