Abstract: Tissue stem cells are responsible for the maintenance and regeneration of mammalian organs, tissues, and cells, including those of humans. Convenient methods for specific and accurate counting of human and animal stem cells are needed for a wide array of applications, including but not limited to cell research, medicine, stem cell medicine, gene therapy, pharmaceutical and biopharmaceutical drug development, cell and tissue biomanufacturing and bioengineering, and environmental toxicology. The invention is mathematical algorithms that can be used to compute the tissue stem cell-specific fraction of any cell preparation, including human, from the input of the cell population doubling time of a cell preparation during culture.

Abstract: Herein, we describe a direct in vitro method that identifies agents that are toxic against natural human tissue stem cells. We provide a novel schedule for culturing any cell population containing homologous tissue stem cells that allows the number and cell kinetics of tissue stem cells, transient cells, and terminally differentiated cells within the population to be monitored. Using the passage schedule together with determination of a growth curve for the population, one can determine whether or not an agent is toxic to tissue stem cells, or to transient cells and/or terminal cells. The same method can also be used to identify agents that act positively on tissue stem cells and the other specific cell types.

Abstract: Herein, we describe a direct in vitro method that identifies agents that are toxic against natural human tissue stem cells. We provide a novel schedule for culturing any cell population containing homologous tissue stem cells that allows the number and cell kinetics of tissue stem cells, transient cells, and terminally differentiated cells within the population to be monitored. Using the passage schedule together with determination of a growth curve for the population, one can determine whether or not an agent is toxic to tissue stem cells, or to transient cells and/or terminal cells. The same method can also be used to identify agents that act positively on tissue stem cells and the other specific cell types.

Abstract: This invention provides methods of determining the number and percent of tissue specific stem cells (TSSCs) in a sample of cells, a population of cells or a sample of tissue. The methods rely on detecting the pattern-specific asymmetric localization of asymmetric self-renewal associated (ASRA) proteins or cell cycle specific proteins (CSSP) in cell undergoing asymmetrical self-renewal, which is a characteristic of TSSCs. The methods can be applied to any situations in which the percent of TSSC is desired such as laboratory research on adult stem cells, in drug development tests, prognostic indicator and therapeutic index, as a diagnostic and prognostic indicator and in monitoring TSSC expansion, e.g., in cell manufacturing processes.

Abstract: The present invention is directed to methods for readily propagating somatic pancreatic precursor cells. The methods comprise isolating cells from intact pancreatic samples and enhancing guanine nucleotide (GNP) biosynthesis in cultures comprising these cells, thereby expanding guanine nucleotide pools. This in turn conditionally suppresses asymmetric cell kinetics in the cells, thereby generating pancreatic precursor cells.

Abstract: Embodied herein are methods of reprogramming somatic cells or tissue stem cells to a more multipotent state or even a pluripotent state, the methods do not involve gene transfer of master transcription factor genes/proteins. The methods are also useful for rapid and efficient cloning of induced pluripotent stem cells after gene transfer of master transcription factor genes/proteins.

Abstract: The present invention is directed to methods for readily generating hepatocyte precursor cell lines that retain hepatocyte-specific functions after extensive in vitro culturing. The methods comprise isolating and culturing hepatocyte precursor cell lines under permissive culture conditions that suppress asymmetric cell kinetics and allow exponential growth of the precursor cells, followed by transferring the hepatocyte precursor cell lines to non-permissive culture conditions that allow expression of asymmetric cell kinetics and induce expression of hepatocyte-specific characteristics.

Abstract: This invention provides methods of determining the number and percent of tissue specific stem cells (TSSCs) in a sample of cells, a population of cells or a sample of tissue. The methods rely on detecting the pattern-specific asymmetric localization of asymmetric self-renewal associated (ASRA) proteins or cell cycle specific proteins (CSSP) in cell undergoing asymmetrical self-renewal, which is a characteristic of TSSCs. The methods can be applied to any situations in which the percent of TSSC is desired such as laboratory research on adult stem cells, in drug development tests, prognostic indicator and therapeutic index, as a diagnostic and prognostic indicator and in monitoring TSSC expansion, e.g., in cell manufacturing processes.

Abstract: Embodied herein are methods of reprogramming somatic cells or tissue stem cells to a more multipotent state or even a pluripotent state, the methods do not involve gene transfer of master transcription factor genes/proteins. The methods are also useful for rapid and efficient cloning of induced pluripotent stem cells after gene transfer of master transcription factor genes/proteins.

Abstract: The present invention is directed to unique properties of stem cells, including methods to identify stem cell markers by identifying molecules associated specifically with chromosomes in stem cells. More particularly, we have discovered that somatic stem cells repeatedly inherit an entire complement of chromosomes that contain the same parental template DNA strands from one generation to the next. The present invention also provides methods related to diagnosis, prognosis, and treatments for cancer and aging in mammalian tissus, including human.

Abstract: The present invention is directed to nucleic acid sequences whose expression is associated with different cell states, including nucleic acid sequences whose expression is induced at least 100-fold, or alternatively upregulated, in cells exhibiting asymmetric self-renewal relative to other cells. The invention is also directed to nucleic acid sequences whose expression is induced at least 100-fold, or alternatively upregulated, in cells exhibiting symmetric self-renewal relative to other cells.

Abstract: The present invention is directed to methods for readily propagating somatic liver stem cells. The methods comprise enhancing guanine nucleotide (GNP) biosynthesis, thereby expanding guanine nucleotide pools. This in turn conditionally suppresses asymmetric cell kinetics in the explanted cells. The methods of the invention include pharmacological methods and genetic methods. For example, the resulting cultured somatic liver stem cells can be used for a variety of applications including cell replacement therapies, gene therapies, drug discovery applications, and tissue engineering applications, such as the generation of artificial liver.

Abstract: The present invention is directed to methods for readily generating hepatocyte precursor cell lines that retain hepatocyte-specific functions after extensive in vitro culturing. The methods comprise isolating and culturing hepatocyte precursor cell lines under permissive culture conditions that suppress asymmetric cell kinetics and allow exponential growth of the precursor cells, followed by transferring the hepatocyte precursor cell lines to non-permissive culture conditions that allow expression of asymmetric cell kinetics and induce expression of hepatocyte-specific characteristics.

Abstract: The present invention is directed to methods for readily propagating somatic hair follicle stem cells or melanocyte stem cells. The methods comprise enhancing guanine nucleotide (GNP) biosynthesis, thereby expanding guanine nucleotide pools. This in turn conditionally suppresses asymmetric cell kinetics in the explanted cells. The methods of the invention include pharmacological methods and genetic methods. For example, the resulting cultured somatic hair follicle stem cells can be used for a variety of applications including cell replacement therapies such as hair transplants, gene therapies, and tissue engineering applications, such as the generation of artificial skin and skin regeneration strategies including skin grafts.

Abstract: The present invention is directed to methods for readily generating hepatocyte precursor cell lines that retain hepatocyte-specific functions after extensive in vitro culturing. The methods comprise isolating and culturing hepatocyte precursor cell lines under permissive culture conditions that suppress asymmetric cell kinetics and allow exponential growth of the precursor cells, followed by transferring the hepatocyte precursor cell lines to non-permissive culture conditions that allow expression of asymmetric cell kinetics and induce expression of hepatocyte-specific characteristics.

Abstract: The present invention is directed to nucleic acid sequences whose expression is associated with different cell states, including nucleic acid sequences whose expression is induced at least 100-fold, or alternatively upregulated, in cells exhibiting asymmetric self-renewal relative to other cells. The invention is also directed to nucleic acid sequences whose expression is induced at least 100-fold, or alternatively upregulated, in cells exhibiting symmetric self-renewal relative to other cells.

Abstract: The present invention is directed to methods for readily generating hepatocyte precursor cell lines that retain hepatocyte-specific functions after extensive in vitro culturing. The methods comprise isolating and culturing hepatocyte precursor cell lines under permissive culture conditions that suppress asymmetric cell kinetics and allow exponential growth of the precursor cells, followed by transferring the hepatocyte precursor cell lines to non-permissive culture conditions that allow expression of asymmetric cell kinetics and induce expression of hepatocyte-specific characteristics.

Abstract: The present invention is directed to methods for readily propagating somatic tissue stem cells ex vivo. The methods comprise enhancing guanine nucleotide (GNP) biosynthesis, thereby expanding guanine nucleotide pools. This in turn conditionally suppresses asymmetric cell kinetics in the explanted tissue cells. The methods of the invention include pharmacological methods and genetic methods. The resulting cultured somatic stem cells can be used for a variety of applications including cell replacement therapies such as bone marrow transplants, gene therapies, tissue engineering, and in vitro organogenesis.

Abstract: This invention provides a novel murine cultured cell line which is derived from primary mouse embryo fibroblasts and which exhibits inducer-regulated growth kinetics. The cell line has the potential to grow either linearly or exponentially depending on exposure to an appropriate inducing agent. A corresponding cell line that does not respond to the inducing agent is also provided. The paired cell line system provides a valuable research tool for the development of therapeutic agents that target cells exhibiting deregulated growth kinetics, and also enables the identification of potential carcinogenic agents that alter stem cell renewal kinetics.