de Vasconcellos JF, Laranjeira ABA, Zanchin NIT, Otubo R, Vaz TH, Cardoso AA, Brandalise SR, Yunes JA. Increased CCL2 and IL-8 in the bone marrow microenvironment in acute lymphoblastic leukemia.
Pediatr Blood Cancer 2011;
56:568-77. [PMID:
21298741 DOI:
10.1002/pbc.22941]
[Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 11/02/2010] [Indexed: 02/01/2023]
Abstract
BACKGROUND
The interactions of acute lymphoblastic leukemia (ALL) blasts with bone marrow (BM) stromal cells have a positive impact on leukemia cell survival. In the present study, we proposed to identify and investigate the role of molecules critically involved in leukemia--microenvironment crosstalk.
PROCEDURE
Gene expression profiling analyses of BM mesenchymal stem cells (BMMSC) were performed following stimulation by ALL cells. CCL2 and IL-8 plasma levels were evaluated from ALL patients and controls. Expression of the CCL2 and IL-8 receptors in ALL was determined by RT-PCR. The biological effects of CCL2, IL-8 or its neutralizing antibodies in primary precursor-B ALL and BMMSC cells were evaluated using in vitro assays.
RESULTS
Leukemia stimulation of BMMSC upregulated the expression of several inflammatory chemokines, including CCL2 and IL-8. The BM plasma levels of CCL2 and IL-8 in children at diagnosis were significantly higher than in healthy controls (P < 0.001). Functional studies revealed that CCL2 and IL-8 enhanced the capacity of BMMSC to support adhesion of ALL cells. CCL2 and IL-8 were also found to enhance BMMSC survival and to increase their proliferation. ALL cells were not directly affected by CCL2 or IL-8.
CONCLUSIONS
The leukemic BM microenvironment had increased levels of CCL2 and IL-8. These chemokines are known to have suppressive effects in normal hematopoiesis. Our data indicate that CCL2 and IL-8 have a positive impact on BMMSC survival, proliferation, and adhesiveness to ALL cells. Leukemia-associated CCL2 and IL-8 upregulation may represent one possible mechanism of microenvironment perversion in favor of ALL cells.
Collapse