Expression of high amounts of the CD117 molecule in a case of B-cell non-Hodgkin's lymphoma carrying the t(14:18) translocation

Abstract

The c-kit proto-oncogen (CD117) has been described to be present in normal and neoplastic hemopoietic cells including both myeloid and lymphoid lineages. Among the normal lymphoid cells CD117 expression would be restricted to a small subset of NK-cells, and to early T-cell precursors and it is not expressed by normal B-cells. Regarding chronic lymphoproliferative disorders the only data provided up to now suggests that CD117 expression is restricted to cases of Hodgkin's disease and anaplastic large-cell lymphoma. In the present paper we describe a case of a B-cell chronic lymphoproliferative disorder carrying the t(14:18) translocation as demonstrated by molecular studies, in which the flow cytometric immunophenotypic analysis of both peripheral blood and bone marrow samples revealed the expression of high amounts of the CD117 antigen in the surface of the clonal B-cell population. Further studies are necessary to explore both the functional role of c-kit expression in the neoplastic B-cells from this patient and its potential utility for the diagnosis and follow-up of patients with B-cell non-Hodgkin's lymphoma.

ARG tyrosine kinase activity is inhibited by STI571

“…In addition to ABL, tyrosine kinases known to be activated in leukemias include KIT, FLT3, JAK2, PDGF␤R, and ARG. 9,10,12,[19][20][21][22] Second, there have been many recent advances in the understanding and development of drugs that inhibit tyrosine kinases. For example the tyrphostin AG-490 was shown to induce apoptosis of acute lymphoblastic leukemia cells by inhibiting the JAK2 tyrosine kinase, 23 and the anticancer agent SU5416 is being tested in clinical trials as a potent inhibitor of VEGF signaling through the FLK-1 receptor, a receptor tyrosine kinase involved in tumor angiogenesis.…”

Diagnostic Algorithm of Common Mature B-Cell Lymphomas by Immunohistochemistry

“…CD117 is very rarely expressed in B-cell lymphomas. 71 Cyclin D1, a hallmark for MCL, is expressed in 30% to 35% of PCMs and in 0% to 17% of plasmacytomas. 9,72,73 As summarized in Table 2, the combination of BCL1, CD19, CD45, CD56, and CD117 is sufficient to distinguish PCs derived from PCMs and/or plasmacytomas from B-cell lymphomas, even in cases in which there is exuberant plasmacytic differentiation.…”

Recent advances in the understanding of mastocytosis: the role of KIT mutations*

“…Expression of the Kit protein has been reported in both normal cells [e.g. haematopoietic progenitors (Simmons et al, 1994), normal mature MC (Metcalfe, 2005), Cajal cells (Huizinga et al, 1995), melanocytes (Halaban et al, 1993), and germ cells (Strohmeyer et al, 1995)] and neoplastic cells from gastrointestinal stromal tumours (GIST) (Andersson et al, 2002), seminomas (Strohmeyer et al, 1995), small cell lung cancer (Sekido et al, 1991), colon cancer (Toyota et al, 1993), neuroblastoma (Beck et al, 1995), breast cancer (Hines et al, 1995), acute myeloid leukaemia (AML) (Bene et al, 1998), T-cell acute lymphoblastic leukaemia (ALL) (Bene et al, 1998), multiple myeloma (Escribano et al, 1998b), myelodysplastic syndromes (MDS) , myeloproliferative disorders (MPD) (Nakata et al, 1995), B-cell non-Hodgkin lymphoma (Bravo et al, 2000) and B-cell precursor ALL (Bene et al, 1998). In normal cells, Kit has been shown to play a major role in haematopoiesis (in the differentiation of erythroid, lymphoid, megakaryocytic and myeloid precursors) (Nocka et al, 1989), gametogenesis (Kissel et al, 2000), MC development and function (Metcalfe, 2005;Valent et al, 2005), melanogenesis (Nocka et al, 1989;Halaban et al, 1993) and gastrointestinal function (Miettinen & Lasota, 2005).…”