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. 2012 Apr;93(2):104-14.
doi: 10.1111/j.1365-2613.2011.00800.x. Epub 2012 Jan 5.

Deregulation of the CXCL12/CXCR4 axis in methotrexate chemotherapy-induced damage and recovery of the bone marrow microenvironment

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Deregulation of the CXCL12/CXCR4 axis in methotrexate chemotherapy-induced damage and recovery of the bone marrow microenvironment

Kristen R Georgiou et al. Int J Exp Pathol. 2012 Apr.

Abstract

Cancer chemotherapy disrupts the bone marrow (BM) microenvironment affecting steady-state proliferation, differentiation and maintenance of haematopoietic (HSC) and stromal stem and progenitor cells; yet the underlying mechanisms and recovery potential of chemotherapy-induced myelosuppression and bone loss remain unclear. While the CXCL12/CXCR4 chemotactic axis has been demonstrated to be critical in maintaining interactions between cells of the two lineages and progenitor cell homing to regions of need upon injury, whether it is involved in chemotherapy-induced BM damage and repair is not clear. Here, a rat model of chemotherapy treatment with the commonly used antimetabolite methotrexate (MTX) (five once-daily injections at 0.75 mg/kg/day) was used to investigate potential roles of CXCL12/CXCR4 axis in damage and recovery of the BM cell pool. Methotrexate treatment reduced marrow cellularity, which was accompanied by altered CXCL12 protein levels (increased in blood plasma but decreased in BM) and reduced CXCR4 mRNA expression in BM HSC cells. Accompanying the lower marrow CXCL12 protein levels (despite its increased mRNA expression in stromal cells) was increased gene and protein levels of metalloproteinase MMP-9 in bone and BM. Furthermore, recombinant MMP-9 was able to degrade CXCL12 in vitro. These findings suggest that MTX chemotherapy transiently alters BM cellularity and composition and that the reduced cellularity may be associated with increased MMP-9 expression and deregulated CXCL12/CXCR4 chemotactic signalling.

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Figures

Figure 1
Figure 1
Methotrexate (MTX)-induced changes to bone marrow (BM) cellularity and recovery following short-term MTX treatment. (a) H&E-stained histology section of tibial diaphyseal BM in a control rat. (b) Histology of H&E-stained section from a rat 6 days after initial dose of 0.75 mg/kg MTX. Scale bar 100 μM. (c) Total BM cellularity expressed as total mononuclear cells × 106 cells/ml. (d) Ex vivo granulocyte/macrophage-lineage colony formation with BM cells isolated from rats over the MTX time-course. Different superscript letters denote means significantly different from each other P < 0.05.
Figure 2
Figure 2
Changes in receptor CXCR4 mRNA expression over the methotrexate chemotherapy-induced damage/recovery time-course. Quantitative RT-PCR relative gene expression analysis relative to endogenous control Cyclophilin A with RNA isolated from bone marrow (BM) non-adherent cells (a), whole peripheral blood specimens (b) and BM stromal cells (c). Different superscript letters denote means significantly different from each other P < 0.05.
Figure 3
Figure 3
Methotrexate (MTX) chemotherapy-induced changes in chemokine CXCL12 protein and mRNA expression. CXCL12 protein levels (ng/ml) were determined by ELISA in bone marrow (BM) supernatant (a) and in peripheral blood plasma (b) from MTX-treated and untreated control rats. (c) Quantitative RT-PCR relative gene expression analysis of CXCL12 in RNA isolated from BM stromal cells from normal and MTX-treated rats at different time-points. Different superscript letters denote means significantly different from each other P < 0.05.
Figure 4
Figure 4
Methotrexate (MTX) chemotherapy-induced changes in MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression and activity of MMP-9 in degrading recombinant CXCL12 in vitro. Quantitative RT-PCR relative gene expression analysis of MMP-9 in RNA isolated from whole metaphyseal bone (a) and from whole peripheral blood specimens (b). Protein levels (ng/ml) over the MTX time-course were determined by ELISA for MMP-9 (c) and for the naturally occurring MMP-9 inhibitor TIMP-1 (d) in bone marrow supernatant from control and days 6, 9 and 14 after MTX treatment. (e) Assessment by Western blot showing CXCL12 recombinant protein is partially degraded after in vitro incubation with MMP-9 recombinant protein for 8 h. Different superscript letters denote means significantly different from each other P < 0.05.
Figure 5
Figure 5
Effects of exogenous CXCL12 protein on differentiation potential of bone marrow cells isolated from normal rats. (a) Ex vivo granulocyte/macrophage-lineage colony formation assay; (b) Ex vivo colony formation-fibroblast assay.

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References

    1. Abd-Allah AR, Al-Majed AA, Al-Yahya AA, Fouda SI, Al-Shabana OA. L-Carnitine halts apoptosis and myelosuppression induced by carboplatin in rat bone marrow cell cultures (BMC) Arch. Toxicol. 2005;79:406–413. - PubMed
    1. Ahmed SF, Wallace WH, Kelnar CJ. An anthropometric study of children during intensive chemotherapy for acute lymphoblastic leukaemia. Horm. Res. 1997;48:178–183. - PubMed
    1. Athanassiadou F, Tragiannidis A, Rousso I, et al. Bone mineral density in survivors of childhood acute lymphoblastic leukemia. Turk. J. Pediatr. 2006;48:101–104. - PubMed
    1. Balabanian K, Lagane B, Infantino S, et al. The chemokine SDF-1/CXCL12 binds to and signals through the orphan receptor RDC1 in T lymphocytes. J. Biol. Chem. 2005;280:35760–35766. - PubMed
    1. Banfi A, Podesta M, Fazzuoli L, et al. High-dose chemotherapy shows a dose-dependent toxicity to bone marrow progenitors: a mechanism for post-bone marrow transplantation osteopenia. Cancer. 2001;92:2419–2428. - PubMed

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