Role of the RANKL/RANK system in the induction of interleukin-8 (IL-8) in B chronic lymphocytic leukemia (B-CLL) cells.
B chronic lymphocytic leukemia (B-CLL) cells express several members of the tumor necrosis factor (TNF) family, such as CD40L, CD30L, and TRAIL. By using the cDNA microarray technology, B-CLL samples were found to overexpress receptor activator of nuclear factor kB (NF-kB) ligand (RANKL), as compared to normal CD19(+) B cells. These findings were validated at the protein level by Western blot and flow cytometry analyses. Moreover, unlike primary normal B cells, leukemic B-CLL cells showed surface expression of RANK, the cognate transmembrane receptor of RANKL. When added in vitro to B-CLL cultures, either alone or in association with chlorambucil or fludarabine, recombinant RANKL did not significantly modulate cell viability, and it minimally affected the IL-8 expression/release. On the other hand, treatment with RANK-Fc chimera potently upregulated the release of IL-8 in the B-CLL culture supernatants, suggesting involvement of reverse signaling through transmembrane RANKL in IL-8 induction. In turn, exposure of B-CLL cells to recombinant IL-8 significantly decreased spontaneous apoptosis as well as chlorambucil- and fludarabine-mediated cytoxicity in B-CLL cells. Since IL-8 has been implicated in progression of B-CLL disease, our findings suggest that, by upregulating IL-8, the RANKL/RANK system may contribute to the pathogenesis of B-CLL.
Secchiero
Paola
P
Department of Morphology and Embryology, Human Anatomy Section, University of Ferrara, Via Fossato di Mortara 66, Ferrara, Italy. secchier@mail.umbi.umd.edu
Corallini
Federica
F
Barbarotto
Elisa
E
Melloni
Elisabetta
E
di Iasio
Maria Grazia
MG
Tiribelli
Mario
M
Zauli
Giorgio
G
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002699:Chlorambucil / Q000494:pharmacology; D005434:Flow Cytometry; D015870:Gene Expression / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics; D007375:Interleukin-1 / Q000494:pharmacology; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000235:genetics; D014740:Vidarabine / Q000031:analogs & derivatives / Q000494:pharmacology
D000970:Antineoplastic Agents; D002352:Carrier Proteins; D006023:Glycoproteins; D007074:Immunoglobulin G; D007375:Interleukin-1; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C105190:TNFRSF10A protein, human; C505686:TNFRSF11A protein, human; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; D002699:Chlorambucil; D014740:Vidarabine; C024352:fludarabine