Preface

The prospective isolation of primitive blood-forming cells along with depicting of transcriptional networks that control early cell fate decisions, and characterization of microenvironmental signals influencing differentiation pathways during normal hematopoiesis, have been critical to the construction of a hierarchical model for the hematopoietic development, that has served as a paradigm for a number of systems within vertebrate development. Hematopoietic stem cell research has been helpful to elucidate mechanisms that govern tissue regeneration, to give an insight into perspectives that may allow protection of the system during disease, to design lifesaving therapies, and to discover novel drug activities. This promising field is being accelerated by significant contributions in genomics, molecular biology, and technologies including fluorescent activated cell sorting and mouse engineering, that give us a more integrated view of the nature of stem cells .

This book, *Advances in Hematopoietic Stem Cell Research,* is devoted to current and inprogress scientific knowledge on basic aspects of these seminal cells and their therapeutic applications. The text consists of 20 chapters grouped into four sections: 1) Hematopoietic stem cell properties, 2) Regulation of hematopoietic stem cells, 3) Hematopoietic stem cells in aging and disease, and 4) Hematopoietic stem cell therapy.

The first section provides four comprehensive chapters on the functional characteristics and biological properties that make distinctive the conspicuous population of hematopoietic stem cells, including multipotency, self-renewal, quiescence and novel surface markers. Five chapters in the second section contain powerful information about intrinsic and extrinsic factors that determine cell fates in early development. The authors have discussed cellular and molecular aspects of the hematopoietic microenvironment within the bone marrow, and progress in searching of procedures to make the expansion of truly stem cells possible . Behavior of the stem and progenitor cells in aging and during disease is analyzed in the third section of this text, which highlights recent achievements in unraveling the role of primitive cells in the pathogenesis of hematological malignancies like leukemia.

Finally, to provide a comprehensive overview of the advancements in therapeutic applications of hematopoietic stem cells, a fourth section with five chapters addresses

#### XIV Preface

a number of diseases for which stem cell transplantation is the indicated therapy. Of special interest, has been the evaluation of quality and potency of stem and progenitor cells for therapy purposes. Substantial efforts to assemble the bridge between basic research and clinical applications are currently being recorded worldwide, and their review in this section may increase the interest for the book.

It is hoped that *Advances in Hematopoietic Stem Cell Research* will prove to be an enjoyable read and that it contributes to this area of Modern Medicine. This book is in effect a compilation of the latest advances resulted from the participation of distinguished and dedicated authors, experts in the field, to whom I am extremely thankful. I would like to acknowledge the terrific contribution of Maja Bozicevic in the professional editing of the book.

**Rosana Pelayo** 

Oncology Research Unit, Oncology Hospital, Mexican Institute for Social Security, Mexico City, Mexico
