Role of microRNA in Normal and Malignant Hematopoiesis

Abstract

Epigenetic modifications in the recent era have received a lot of attention in a variety of diseases particularly cancer. They are defined as the modulation of gene expression by chromatin modification that does not involve DNA sequence alterations [1]. These modifications act either by altering the chromatin structure to deregulate gene expression or by the post-translational modification. Consequently, epigenetics control cell differentiation and function by “switching on” or “off” certain gene expressions, and a disruption of the normal epigenetic mechanism can lead to uncontrolled gene activation or silencing resulting into an altered homeostasis. Three main types of epigenetic processes which have been identified include DNA methylation, nucleosomal histone modifications, and post-translational alterations by the non-coding RNAs [2]. Prominent among these non-coding RNAs are microRNAs (miRNAs), which have recently emerged as important players in the regulation of normal hematopoietic cell development and differentiation as well as in malignant transformation. In this chapter, we have provided a comprehensive summary of the current knowledge on the role of miRNAs in normal and aberrant hematopoiesis with a focus on the clinical significance of the deranged miRNAs in some of the common hematological neoplasms.