Stromal cell-derived factor-1 enhances motility and integrin up-regulation through CXCR4, ERK and NF-kappaB-dependent pathway in human lung cancer cells.
ABSTRACT The chemokine stromal-derived factor-1alpha (SDF-1alpha) and its receptor, CXCR4, play a crucial role in adhesion and migration of human cancer cells. Integrins are the major adhesive molecules in mammalian cells. Here we found that SDF-1alpha increased the migration and cell surface expression of beta1 or beta3 integrin in human lung cancer cells (A549 cells). CXCR4-neutralizing antibody, CXCR4 specific inhibitor (AMD3100) or small interfering RNA against CXCR4 inhibited the SDF-1alpha-induced increase in the migration of lung cancer cells. Stimulation of cells with SDF-1alpha caused an increase in extracellular signal regulated kinase (ERK) phosphorylation in a time-dependent manner. In addition, treatment of A549 cells with ERK inhibitor (PD98059), NF-kappaB inhibitor (PDTC) or IkappaB protease inhibitor (TPCK) inhibited SDF-1alpha-induced cells migration and integrins expression. Treatment of A549 cells with SDF-1alpha induced IkappaB kinase alpha/beta (IKK alpha/beta) phosphorylation, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 Ser(536) phosphorylation, and kappaB-luciferase activity. The SDF-1alpha-mediated increases in IKK alpha/beta phosphorylation, p65 Ser(536) phosphorylation, and kappaB-luciferase activity were inhibited by PD98059 and ERK2 mutant. Taken together, these results suggest that SDF-1alpha acts through CXCR4 to activate ERK, which in turn activates IKKalpha/beta and NF-kappaB, resulting in the activations of beta1 and beta3 integrins and contributing the migration of lung cancer cell.
- SourceAvailable from: Eitan Lunenfeld[Show abstract] [Hide abstract]
ABSTRACT: Glial cell line-derived neurotrophic factor (GDNF) regulates spermatogonial stem cell (SSC) maintenance. In the present study, we examined the levels and the cellular origin of GDNF in mouse testes during age-development, and the capacity of GDNF to induce migration of enriched GFR-α1 positive cells in vitro. The involvement of MAP kinase (MEK) and NF-kB signal pathways were examined. Our results show high levels of GDNF in testicular tissue of one-week-old mice which significantly decreased with age when examined by ELISA, real time PCR (qPCR) and immunofluorescence staining (IF) analysis. GDNF receptor (GFR-α1) expression was similar to GDNF when examined by qPCR analysis. Only Sertoli cell cultures (SCs) from one-week-old mice produced GDNF compared to SCs from older mice. However, peritubular cells from all the examined ages did not produce GDNF. The addition of recombinant GDNF (rGDNF) or supernatant from SCs from one-week-old mice to GFR-α1 positive cells induced their migration in vitro. This effect was significantly reduced by the addition of inhibitors to MEK (PD98059, U0126), NF-kB (PDTC) and IkB protease inhibitor (TPCK). Our results show for the first time the capacity of rGDNF and supernatant from SCs to induce migration of enriched GFR-α1 positive cells, and the possible involvement of MEK, NF-kB and IkB in this process. This study may suggest a novel role for GDNF in the regulation SSC niches and spermatogenesis.Differentiation 08/2013; 86(1-2):38-47. DOI:10.1016/j.diff.2013.06.005 · 2.84 Impact Factor
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ABSTRACT: Despite successful preclinical testing carried out through the use of subcutaneous xenografted tumors, many anti-cancer agents have gone on to fail in human trials. One potential factor accounting for this discrepancy may relate to the inadequacy of the commonly employed preclinical models to recapitulate the human disease, particularly when it comes to discovery of agents that are effective against advanced disease. Herein, we report the characterization of a NSCLC model and an exploration of the impact that a CXCR4 inhibitor, AMD3100, had on NCI-H1299-derived metastasis. These cells express a variety of metastasis-promoting factors, hence we selected them for a study of their metastatic colonization potential. To accomplish this, luciferase-expressing H1299 (H1299-luc2) cells were inoculated into athymic mice via the intracardiac route. This strategy produced adrenal, bone, ovarian, and pancreatic metastases, sites commonly involved in human metastatic NSCLC. Notably, micro-computed tomography and histological evaluation of the skeletal lesions revealed the presence of extensive osteolysis. To investigate the potential role of CXCR4 in mediating metastatic colonization of tissues, AMD3100 was administered to mice inoculated with H1299-luc2 cells. While this treatment did not appreciably alter the frequency of metastatic colonization, it was able to slow the growth of macrometastases. This model, recapitulating some of the events seen in late-stage human NSCLC, may prove useful in the evaluation of new therapies targeting metastatic disease.01/2015; 2(3):263-71.
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ABSTRACT: Kidney fibrosis is the final common pathway for virtually every type of chronic kidney disease (CKD) and is a consequence of a prolonged healing response that follows tissue inflammation. Chronic kidney inflammation ultimately leads to progressive tissue injury and scarring / fibrosis. Several pathways have been implicated in the progression of kidney fibrosis. In this study, we demonstrate that G-protein coupled chemokine receptor CXCR4 is significantly upregulated following renal injury and sustained activation of Cxcr4 expression augments fibrotic response. We demonstrate that following unilateral ureteral obstruction (UO) both gene and protein expression of Cxcr4 is highly upregulated in tubular cells of the nephron. The increased Cxcr4 expression in tubules correlates with their increased dedifferentiated state leading to an increased mRNA expression of Pdgfα, Tgfβ1 and concurrently loss of Bmp7. Ablating tubular Cxcr4 attenuates UO-mediated fibrotic response that correlates with a significant reduction in Pdgfα, Tgfβ1 levels and preservation of Bmp7 expression after UO. Furthermore, Cxcr4+ immune cells infiltrate the obstructed kidney and further up-regulate their Cxcr4 expression. Genetic ablation of Cxcr4 from macrophages is protective against UO-induced fibrosis. There is also reduced total kidney TGFβ1 that correlates with reduced SMAD activation and αSma levels. We conclude that chronic high Cxcr4 expression in multiple effector cell types can contribute to the pathogenesis of renal fibrosis by altering their biological profile. This study has uncovered a novel cross-talk between Cxcr4-Tgfβ1 and Bmp7 pathways and may provide novel targets for interrupting the progression of fibrosis. Copyright © 2014, American Journal of Physiology - Renal Physiology.American journal of physiology. Renal physiology 12/2014; 308(5):ajprenal.00146.2014. DOI:10.1152/ajprenal.00146.2014 · 3.30 Impact Factor