Abstract: To efficiently identify and select a clone from clones of induced pluripotent stem cells (iPS cell) having low tumor formation rate in vivo when allowed to differentiate and transplanted in a living body, iPS cells of the clones are induced to differentiate, undifferentiated cells among the cells after the induction of differentiation are detected, and a clone having the content of the undifferentiated cell below a control is selected.

Abstract: The present invention relates to a probe for selecting ES cells, which characteristically contains one of DNAs having base sequences depicted in SEQ ID Nos; 1, 2, 3, 4, 5, 6, 7 and 8, or DNAs having base sequences depicted in SEQ ID Nos; 9, 11, 13, 15, 17, 19, 21, 23 and 41 and a screening method of ES cell using this probe. Preparation of a probe for selecting ES cells becomes feasible by identifying plural gene with ES cell-specific expressions (ECAT genes) and using the information of the base sequences of these gene groups. Efficient selection of ES cell enables supply of a large amount of ES cell expected to be applicable to regenerative medicine.

Abstract: [Object] To provide a technology for production of safer iPS cells and to provide a more efficient technology for culturing iPS cells. [Solving Means] Induced pluripotent stem cells are produced from human somatic cells by co-culturing human somatic cells having a reprogrammed nucleus with human cells as feeder cells. Induced pluripotent stem cells are produced from somatic cells by co-culturing somatic cells having a reprogrammed nucleus with autologous cells as feeder cells. Induced pluripotent stem cells are cultured with culture supernatant of somatic cells.

Abstract: The present invention relates to a nuclear reprogramming factor having an action of reprogramming a differentiated somatic cell to derive an induced pluripotent stem (iPS) cell. The present invention also relates to the aforementioned iPS cells, methods of generating and maintaining iPS cells, and methods of using iPS cells, including screening and testing methods as well as methods of stem cell therapy. The present invention also relates to somatic cells derived by inducing differentiation of the aforementioned iPS cells.

Abstract: Reprogramming substances capable of substituting for Klf4, selected from the group consisting of members of the IRX family (e.g., IRX6), members of the GLIS family (e.g., GLIS1), members of the PTX family (e.g., PITX2), DMRTB1, and nucleic acids that encode the same, are provided. Also provided are a method of producing iPS cells, comprising the step of introducing into a somatic cell both one or more kinds of the above-described nuclear reprogramming substances and a substance capable of inducing iPS cells from a somatic cell when combined with Klf4. Still also provided are iPS cells comprising an extraneous nucleic acid that encodes any one of the above-described nuclear reprogramming substances, that can be obtained by the method, and a method of producing somatic cells by inducing the iPS cells to differentiate.

Abstract: The present invention relates to a nuclear reprogramming factor having an action of reprogramming a differentiated somatic cell to derive an induced pluripotent stem (iPS) cell. The present invention also relates to the aforementioned iPS cells, methods of generating and maintaining iPS cells, and methods of using iPS cells, including screening and testing methods as well as methods of stem cell therapy. The present invention also relates to somatic cells derived by inducing differentiation of the aforementioned iPS cells.

Abstract: There is provided a nuclear reprogramming factor for a somatic cell, which comprises a gene product of each of the following three kinds of genes: an Oct family gene, a Klf family gene, and a Myc family gene, as a means for inducing reprogramming of a differentiated cell to conveniently and highly reproducibly establish an induced pluripotent stem cell having pluripotency and growth ability similar to those of ES cells without using embryo or ES cell.

Abstract: The present invention relates to a method for producing mammalian induced pluripotent stem cells, comprising introducing mammal-derived reprogramming factors comprising Oct3/4 and Nanog, or nucleic acids encoding Oct3/4 and Nanog, into mammal-derived somatic cells and thereby inducing induced pluripotent stem cells from the somatic cells, wherein the reprogramming factors comprise neither Sox2 nor nucleic acid encoding Sox2.

Abstract: The present invention provides a method of improving the efficiency of establishment of induced pluripotent stem (iPS) cells, comprising inhibiting the p53 function in the step of somatic cell nuclear reprogramming. The inhibition of p53 function is achieved by bringing a substance selected from the group consisting of (1) chemical inhibitors of p53, (2) dominant negative mutants of p53 and nucleic acids that encode the same, (3) siRNAs and shRNAs against p53 and DNAs that encode the same, and (4) p53 pathway inhibitors, into contact with a somatic cell, and the like. The present invention also provides an agent for improving the efficiency of establishment of iPS cells, the agent comprising an inhibitor of p53 function, particularly (1) chemical inhibitors of p53, (2) dominant negative mutants of p53 and nucleic acids that encode the same, (3) siRNAs and shRNAs against p53 and DNAs that encode the same, and (4) p53 pathway inhibitors.

Abstract: The present invention provides a method of producing induced pluripotent stem (iPS) cells, comprising bringing a nuclear reprogramming substance into contact with dental pulp stem cells. By using dental pulp stem cells as a source of somatic cells, the efficiency of establishment of human iPS cells by transfer of 3 or 4 factors can be improved dramatically. Additionally, dental pulp stem cells are easily available because they can be isolated and prepared from extracted wisdom teeth and teeth extracted because of periodontal disease and the like, so that they can be used widely as a source of somatic cells for iPS cell banks.

Abstract: In order to provide a therapeutic agent for nerve injury which contains iPS-derived neural stem cells and has low or no risk of side effects, as well as a method for treating a nerve injury using the iPS cells, by efficiently establishing in vivo the iPS-derived neural stem having low or no risk of tumor formation, neurospheres are formed following formation of embryoid bodies from the iPS cells, and a clone whose ratio of cells in which the promoter of Nanog gene is activated is 0.01% or less is selected, and the clone is administered to a patient suffering from the nerve injury.

Abstract: The present invention provides a screening method for somatic cell nuclear reprogramming substances, which comprises (a) a step for bringing into contact with each other a somatic cell comprising a gene wherein a marker gene is present at a position permitting expression control by the expression control region of an ECAT gene, and a test substance, and (b) a step following the aforementioned step (a), for determining the presence or absence of the emergence of cells expressing the marker gene, and selecting a test substance allowing the emergence of the cells as a somatic cell nuclear reprogramming substance candidate, and the like.

Abstract: It is an object of the present invention to provide a method for efficiently preparing blood cells, such as mature megakaryocytes and platelets, from iPS cells in an in vitro culture system. The present invention provides a sac-like structure enclosing hematopoietic progenitor cells, which is obtained by inoculating iPS cells onto feeder cells and then culturing the iPS cells under conditions suitable for inducing the differentiation of hematopoietic progenitor cells. Moreover, the present invention also provides a method for producing various types of blood cells, which comprises culturing hematopoietic progenitor cells enclosed in the sac-like structure under conditions suitable for inducing the differentiation of blood cells. Furthermore, the present invention also provides a method for producing various types of blood cells, particularly megakaryocytes and platelets, without involving the sac-like structure.

Abstract: Provided is a method of improving the efficiency of establishment of induced pluripotent stem cells, comprising culturing somatic cells under hypoxic conditions in the step of nuclear reprogramming thereof.

Abstract: Provided is a method of preparing an induced pluripotent stem cell (iPS cell) deprived of a reprogramming gene, including providing an iPS cell having an expression vector wherein a loxP sequence is placed on each of the 5? and 3? sides of the reprogramming gene or a vector component necessary for the replication of the reprogramming gene in the same orientation, and treating the IPS cell with Cre recombinase. Also provided are an iPS cell deprived of a reprogramming gene, as obtained by the method, and a use of the iPS cell as a cell source for producing somatic cells.

Abstract: This invention provides a method of producing an induced pluripotent stem cell comprising the step of introducing at least one kind of non-viral expression vector (more preferably a plasmid vector) incorporating at least one gene that encodes a reprogramming factor into a somatic cell. An induced pluripotent stem cell wherein no exogenous genes induced is integrated into the cellular genome is also provided.

Abstract: The present invention relates to an ES cell detection marker containing a polynucleotide derived from any one of ECAT15-1 gene, ECAT15-2 gene, ECAT16 gene, Rnf17 gene and LOC380905(TDRD4) gene.

Abstract: The present invention relates to a nuclear reprogramming factor having an action of reprogramming a differentiated somatic cell to derive an induced pluripotent stem (iPS) cell. The present invention also relates to the aforementioned iPS cells, methods of generating and maintaining iPS cells, and methods of using iPS cells, including screening and testing methods as well as methods of stem cell therapy. The present invention also relates to somatic cells derived by inducing differentiation of the aforementioned iPS cells.

Abstract: The present invention relates to a nuclear reprogramming factor having an action of reprogramming a differentiated somatic cell to derive an induced pluripotent stem (iPS) cell. The present invention also relates to the aforementioned iPS cells, methods of generating and maintaining iPS cells, and methods of using iPS cells, including screening and testing methods as well as methods of stem cell therapy. The present invention also relates to somatic cells derived by inducing differentiation of the aforementioned iPS cells.

Abstract: A method of preparing induced pluripotent stem cells, comprising a nuclear reprogramming step with a nuclear reprogramming factor in the presence of miRNA, wherein said miRNA has a property of providing a higher nuclear reprogramming efficiency in the presence of said miRNA than in the absence thereof.