oa Editorial [Hot Topic: The Medicinal Chemistry of Ubiquitin-Proteasome Pathway (UPP) and Its Relevance in Drug Discovery (Guest Editor: Yongqiang Zhu)]

In this issue of Current Topics in Medicinal Chemistry, we highlight several aspects of the medicinal chemistry of ubiquitin- proteasome pathway (UPP) and its relevance in drug discovery by collecting comprehensive reviews from several experts working in this field. More than 80% normal and abnormal intracellular proteins were degraded by UPP. A growing body of evidence suggested that derangements of UPP could lead to many disorders, such as malignancies, neurodegenerative diseases and possible systematic autoimmunity. Due to making fundamental breakthroughs in understanding the function of this essential pathway, three distinguished scientists won the 2004 Nobel Prize in Chemistry. This pathway was clinically validated as an effective target for cancer therapy since the first proteasome inhibitor bortezomib was approved for the treatment of multiple myeloma by FDA in 2003. Nowadays, several inhibitors are being investigated in Phase I and II for the treatment of several types of tumors. Furthermore, many compounds are being discovered and developed as candidates for the treatment of other diseases, such as diabetes, Parkinson's disease (PD) and Alzheimer disease (AD). I would like to express my sincere appreciation to all the authors for their outstanding contributions. I also thank Dr. Allen Reitz, Editor-in-Chief, for inviting me to prepare this special issue of Current Topics in Medicinal Chemistry and great thanks are also owned to Dr. Rhoda Weber Joseph for his help during my preparation of this issue. I hope that this issue will be an informative contribution to the field and will represent an important reference work for the medicinal chemists involved in ubiquitin-proteasome pathway.