Stem Cell Research



Stem Cell Research

Introduction

With over 700 mIRNAs genes identified experimentally in the human genome and a plethora of computationally predicted mRNA targets, these small RNAs are thought to have a central role in diverse cellular and developmental processes. Aberrant expression of micro RNAs can lead to human diseases, including cancer. Several studies have confirmed that miRNAs regulate cellular functions such as cell proliferation and apoptosis. Furthermore, these non-coding RNAs can control cellular identity and mediate differentiation. Understanding the mechanism of action of miRNAs in various biological contexts is critical in uncovering their exact roles in modulating gene expression. To study miRNAs, the study of two systems as models in which people could explore miRNA function, Stem cells and Cancer will be carried out in the assignment. In addition to cancer as a model system, the usage of pluripotent human Embryonic Stem Cells as another model for understanding the role of miRNAs in stem cell maintenance and differentiation will be also carried out in the research. Therefore, all the issues and aspects related to stem cell research will be discussed in detail.

Discussion

The growth and development of a multi-cellular organism must be tightly coordinated with both its reproductive program and the environment. Deregulation of the signaling pathways that regulate cell division can lead to uncontrolled cell proliferation, which lies at the root of many cancers, as well as other human disorders. Research in model organisms has provided a powerful means for dissecting the genetic basis of cell proliferation. For example, the study of yeast has allowed for extensive analysis of cell cycle checkpoints and chromosome maintenance, while research in multi-cellular organisms such as Drosophila melanogaster and Caenorhabditis elegans has allowed for insights into the control of cellular proliferation within the context of specific tissues, and has advanced the understanding of mechanisms relevant to tissue invasion and metastasis as well as maintenance of the stem cell niche (Albert, 1981, 451).

There are a number of features that make the soil-dwelling nematode C. elegans ideal for genetic studies: it has a short life cycle (approximately three days at 20°C); the primarily hermaphroditic populations of C. elegans (which are XX and reproduce clonally) allow for rapid expansion of a population while maintaining genetic homogeneity despite the organism's diploidy; the ability to induce the formation of XO males (which reproduce sexually with XX “females”) facilitates genetic analyses. The C. elegans genome, which consists of nearly 20, 000 genes spanning five diploid autosomes, and, a sixth X chromosome, has been sequenced, and, characterized and the entire cell lineage of the hermaphrodite worm has been documented, allowing for detailed investigations of cell fate determination. These studies are further facilitated by the transparency of the C. elegans cuticle allowing easy manipulation of the organism as well as the observation of transgenic markers such as GFP in vivo. Studies in C. elegans were pivotal in the understanding of cell cycle control, as the discovery of the conserved cul-1 family of genes represented the first identification of genes required for exit ...