The present invention generally provides methods and compositions for transdifferentiation of an animal cell from a first non-pluripotent cell fate to a second non-pluripotent cell fate. Also provided are methods and compositions for the transdifferentiation of an animal cell from a non-pluripotent mesodermal, endodermal, or ectodermal cell fate to a different non-pluripotent mesodermal, endodermal, or ectodermal cell fate.

A method of preparing a population of iPS cells including (i) expressing one or more Yamanaka factors selected from Oct3/4, Sox2, Klf4, Myc, Nanog and Lin28, and reducing the amount and/or activity of Menin (Men1) in a population of target cells, and (ii) optionally isolating the iPS cells from the target cell population; and a method of enhanced differentiation of a first cell into a somatic cell of a tissue of interest, including (i) treating a cell with a differentiation factor of the tissue of interest, and (ii) reducing the amount and/or activity of Menin (Men1) in a population of target cells.

The present invention provides compositions and methods for reprogramming somatic cells using purified RNA preparations comprising single-strand mRNA encoding an iPS cell induction factor. The purified RNA preparations are preferably substantially free of RNA contaminant molecules that: i) would activate an immune response in the somatic cells, ii) would decrease expression of the single-stranded mRNA in the somatic cells, and/or iii) active RNA sensors in the somatic cells. In certain embodiments, the purified RNA preparations are substantially free of partial mRNAs, double-stranded RNAs, un-capped RNA molecules, and/or single-stranded run-on mRNAs.

An in vitro co-culture system comprising cancer-associated fibroblasts (CAFs) and cancer cells for producing and maintaining cancer stem cells and uses thereof for identifying agents capable of reducing cancer cell stemness. Also disclosed herein are a paracrine network through which CAFs facilitate production and/or maintenance of cancer stem cells and the use of components of such a paracrine network for prognosis purposes and for identifying cancer patients who are likely to respond to certain treatment.

Reprogramming allows the “conversion” of any mature or somatic cell of the human or animal body into a pluripotent stem cell. Reprogramming can be performed through the introduction of exogenous factors, usually transcription factors, into the mature cell. This process allows the production of induced pluripotent stem cells without the use of embryos, with the advantage that they can be produced from an individual to return/re-implant to the same individual. The inventors have developed a method of transient expression of exogenous reprogramming factors using a transient vector, wherein the vector is a closed linear DNA. Surprisingly, pluripotent stem cells developed in this manner are stable and closer in phenotype to natural stem cells such as ESCs.

Method for expanding stemness and differentiation potential of pluripotent cells. The invention is based on the finding that increasing micro RNA-203 levels in induced pluripotent stem (iPSCs) or embryonic stem (ESCs) cells improves the quality cell fate potential and ability of these cells to differentiate into multiple cell lineages and to reach further maturation properties without interfering with their self-renewal properties. This effect is mediated through the mi R-203-dependent control of de novo DNA methyltransferases Dnmt3a and Dnmt3b, which in turn regulate the methylation landscape of pluripotent cells. The effect can be achieved by overexpression of micro RNA-203 or by adding micro RNA-203 or analogues thereof to the cell culture medium and can be observed using a variety of cellular and in vivo models. The generated cells are naïve pluripotent cells with an improved capacity to differentiate, that can be used to obtain more efficiently differentiated and mature cells proficient for regenerative medicine strategies.

The disclosure provides methods and compositions useful for obtaining induced stem cells, methods of making and use thereof.

The present invention provides an induced pluripotent stem (iPS) cell, or population of iPS cells, wherein the cell or cells giving rise to the iPS cell(s) are obtained from human postpartum tissue or cells, wherein the iPS cell(s) have increased levels of one or more factors selected from Group I: an Oct family member, a Sox family member, a Klf family member, a Myc family member, Nanog, Lin28, and combinations thereof. The present invention also provides differentiated cells derived from the cells of the invention and compositions, including pharmaceutical compositions comprising the cells of the invention. The invention further provides uses of the cells of the invention, e.g., in the treatment of a subject suffering from a disease of disorder. The invention additionally provides methods of generating iPS cell(s) from postpartum tissue, such as the cells of the invention.

The preset invention relates to a novel super-enhancer-bound Ash2l/OSN complex that can drive enhance activation, govern pluripotency network and stemness circuitry, and a reprogramming system or method through the regulation of this super-enhancer, Ash2l, to modulate pluripotency and cell fates. Ash2l directly binds to super-enhancers of several stemness genes to regulate pluripotency and self-renewal in pluripotent stem cells. Ash2l recruits Oct4/Sox2/Nanog (OSN) to form Ash2l/OSN complex at the super-enhancers of Jarid2, Nanog, Sox2, and Oct4, and further drives enhancer activation, upregulation of stemness genes, and maintains the pluripotent circuitry. Ash2l knockdown abrogates the OSN recruitment to all super-enhancers and further hinders the enhancer activation. In addition, CRISPRi/dCas9-mediated blocking of Ash2l-binding motifs at these super-enhancers also prevents OSN recruitment and enhancer activation, validating that Ash2l directly binds to super-enhancers and initiates the pluripotency network. Transfection of Ash2l with W118A mutation to disrupt Ash2l-Oct4 interaction fails to rescue Ash2l-driven enhancer activation and pluripotent gene upregulation in Ash2l-depleted pluripotent stem cells.

The present invention generally provides methods and compositions for transdifferentiation of an animal cell from a first non-pluripotent cell fate to a second non-pluripotent cell fate. Also provided are methods and compositions for the transdifferentiation of an animal cell from a non-pluripotent mesodermal, endodermal, or ectodermal cell fate to a different non-pluripotent mesodermal, endodermal, or ectodermal cell fate.