CD38 and chronic lymphocytic leukemia: a decade later

Abstract

This review highlights a decade of investigations into the role of CD38 in CLL. CD38 is accepted as a dependable marker of unfavorable prognosis and as an indicator of activation and proliferation of cells when tested. Leukemic clones with higher numbers of CD38 ؉ cells are more responsive to BCR signaling and are characterized by enhanced migration. In vitro activation through CD38 drives CLL proliferation and chemotaxis via a signaling pathway that includes ZAP-70 and ERK1/2. Finally, CD38 is under a polymorphic transcriptional control after external signals.Consequently, CD38 appears to be a global molecular bridge to the environment, promoting survival/proliferation over apoptosis. Together, this evidence contributes to the current view of CLL as a chronic disease in which the host's microenvironment promotes leukemic cell growth and also controls the sequential acquisition and accumulation of genetic alterations. This view relies on the existence of a set of surface molecules, including CD38, which support proliferation and survival of B cells on their way to and after neoplastic transformation. The second decade of studies on CD38 in CLL will tell if the molecule is an effective target for antibody-mediated therapy in this currently incurable leukemia. (Blood. 2011;118(13):3470-3478)The current view of chronic lymphocytic leukemia (CLL) is that of a disease characterized by a dynamic balance between cells circulating in the blood and cells located in permissive niches in lymphoid organs. 1 The former are primarily mature-looking small lymphocytes resistant to apoptosis, whereas the latter are composed of lymphocytes that undergo either proliferation or apoptosis according to the environment. 2 The heterogeneous clinical outcome of CLL patients is dictated, at least in part, by the nature of these microenvironmental signals and interactions that can promote or impair accumulation of genomic alterations. 3 Detailed immunophenotypic and genetic analyses of different neoplastic clones have led to the identification of a number of molecular markers, some of which are gaining relevance in clinical practice to predict disease outcome. [4][5][6][7] Cell surface CD38 is one of these markers.This review highlights a decade of investigations into the role of CD38 in CLL. An association between CD38 expression by CLL cells and a more aggressive clinical behavior was first reported in 1999 4 and confirmed by several subsequent studies. [8][9][10][11][12] Consequently, determination of the percentage of CD38-expressing cells within a clone has become part of the workup of CLL patients in many clinical centers, 13 and it is generally accepted that CD38 ϩ patients will have a shorter progression-free interval, require earlier and more frequent treatments, and ultimately die sooner. 4 The underlying question behind these clinical observations is why expression of this molecule on the cell surface would correlate with a worse clinical outcome. The most obvious possibility is that CD38 expression reflects events occurring in...

Transfusion Practices in the Era of Anti-CD38 Antibodies in the Treatment of Multiple Myeloma: A Mini Review

“…CD38 is a transmembrane glycoprotein with ectoenzymatic activity in the catabolism of extracellular nucleotides [11][12][13][14][15]. Other functions include receptor-mediated adhesion by interacting with CD31 or hyaluronic acid, regulation of migration, and signaling events [16].…”

Daratumumab granted breakthrough drug status

“…Furthermore, long-lived and/or MMinitiating cells from which MM plasma cells are derived are CD38 ++(high) CD19 -(negative) plasma cells that are either CD138 + or CD138 - [22,23], suggesting that these may in turn identify MM stem cells that are relatively resistant to therapy. Interestingly, CD38 expression in CLL is associated with a more aggressive clinical behaviour, as CD38+ patients have a shorter progression-free and overall survival [6]. In vitro studies have shown that interaction between CD38 and CD31 promotes the proliferation and survival of CLL cells both directly and through up-regulation of CD100 [24], which interacts with plexin-B1 on stromal cells and some subsets of T cells [25].…”

“…Functional CD38 appears as a dimer or a multimer [3] on the cytoplasmic side of the membrane, where its catalytic site is defined [4]. As a receptor, CD38 is preferentially localized in lipid rafts, microdomains of plasma membrane and is in close contact with the BCR complex and with other molecules (i.e., CXCR4) regulating signaling, homing, adhesion and migration [5,6]. Lipid raft localization and association with signaling complexes are prerequisites for signals mediated through CD38 to phosphorylate ERK1/2 and activate NF-kB [7,8].…”

Anti-CD38 Antibody Therapy: Windows of Opportunity Yielded by the Functional Characteristics of the Target Molecule

“…It is now generally accepted that CD38 + patients will have a shorter progression-free interval, require earlier and more frequent treatments, and ultimately die sooner. It remains undeniable that CD38 marks the majority of clinically more aggressive leukemic clones requiring treatment (19).…”