7852

CXCR4

The CXC chemokine receptor 4 (CXCR4) contributes to the metastasis of human breast cancer cells. The CXCR4 COOH-terminal domain (CTD) seems to play a major role in regulating receptor desensitization and down-regulation. We expressed either wild-type CXCR4 (CXCR4-WT) or CTD-truncated CXCR4 (CXCR4-DeltaCTD) in MCF-7 human mammary carcinoma cells to determine whether the CTD is involved in CXCR4-modulated proliferation of mammary carcinoma cells. CXCR4-WT-transduced MCF-7 cells (MCF-7/CXCR4-WT cells) do not differ from vector-transduced MCF-7 control cells in morphology or growth rate. However, CXCR4-DeltaCTD-transduced MCF-7 cells (MCF-7/CXCR4-DeltaCTD cells) exhibit a higher growth rate and altered morphology, potentially indicating an epithelial-to-mesenchymal transition. Furthermore, extracellular signal-regulated kinase (ERK) activation and cell motility are increased in these cells. Ligand induces receptor association with beta-arrestin for both CXCR4-WT and CXCR4-DeltaCTD in these MCF-7 cells. Overexpressed CXCR4-WT localizes predominantly to the cell surface in unstimulated cells, whereas a significant portion of overexpressed CXCR4-DeltaCTD resides intracellularly in recycling endosomes. Analysis with human oligomicroarray, Western blot, and immunohistochemistry showed that E-cadherin and Zonula occludens are down-regulated in MCF-7/CXCR4-DeltaCTD cells. The array analysis also indicates that mesenchymal marker proteins and certain growth factor receptors are up-regulated in MCF-7/CXCR4-DeltaCTD cells. These observations suggest that (a) the overexpression of CXCR4-DeltaCTD leads to a gain-of-function of CXCR4-mediated signaling and (b) the CTD of CXCR4-WT may perform a feedback repressor function in this signaling pathway. These data will contribute to our understanding of how CXCR4-DeltaCTD may promote progression of breast tumors to metastatic lesions.

Stromal cell-derived factor 1alpha (SDF-1alpha) and its receptor CXCR4 have been implicated in the tumorigenesis, proliferation, and lymph node metastasis of cancer. Here, we report that highly invasive squamous cell carcinoma (SCC) cells with a spindle cell morphology show a strong expression of both SDF-1alpha and CXCR4. CXCR4 expression and cell migratory activity were further up-regulated by treatment with SDF-1alpha or TGF-beta1 in these cells. When epithelial-mesenchymal transition (EMT) was induced by Snail over-expression in SCC cells with an epithelial phenotype, an increased expression of SDF-1alpha was observed. Furthermore, SDF-1alpha and TGF-beta1 up-regulated the expression of CXCR4 and cell migratory activity in these cells. These results indicate that SDF-1alpha and CXCR4 expressions are possible markers of highly-invasive SCC and regulated by EMT.

AIMS: Determination of prognostic parameters that are predictive of survival of gastric cancer (GC) may allow better identification of patients who could benefit from current chemotherapy regimens. To assess the correlation between tumour progression and epithelial-mesenchymal transition (EMT), we assayed the expression levels of selected molecules involved in EMT [CD44, transforming growth factor (TGF)-alpha, cyclooxygenase-2 (COX-2), matrix metalloproteinase (MMP)-7, MMP-9 and C-X-C chemokine receptor (CXCR4)], and correlated these with overall patient survival (OS) and disease stage. METHODS AND RESULTS: Medical records and pathological biopsy results of 137 patients with GC were evaluated retrospectively. Spearman's correlation analysis showed that expression of CXCR4 was correlated significantly with the expression of all other proteins studied. In contrast, COX-2 expression correlated significantly with the expression of only MMP-7 (P = 0.011), MMP-9 (P = 0.015) and CXCR4 (P = 0.013). We observed significant negative correlations between OS and the expression of TGF-alpha (P = 0.017), COX-2 (P < 0.001), CXCR4 (P = 0.010), MMP-7 (P = 0.020) and MMP-9 (P = 0.015). On multivariate analysis, only COX-2 was an independent prognostic factor for OS [hazard ratio (HR) = 3.34; 95% confidence interval (CI): 1.43-9.75; P = 0.002). CONCLUSIONS: COX-2, TGF-alpha, MMP-7, MMP-9 and CXCR4 are associated with poor OS in gastric cancer.CI - (c) 2012 Blackwell Publishing Ltd.

OBJECTIVE: To evaluate the expression of CXCR4, its ligand SDF-1, beta-catenin and E-cadherin throughout the local tumor microenvironment of prostate cancer. PATIENTS AND METHODS: A total of 64 prostate cancer specimens, 24 frozen and 40 paraffin-embedded sections, were obtained from patients treated with radical prostatectomy for clinically localized cancer. Real-time RT-PCR was used for mRNA quantification of CXCR4 and SDF-1 in the tumor center (T), tumor front (F) and distant peritumoral tissue (D). Immunohistochemical analysis was used to investigate the expression patterns of CXCR4, E-cadherin and beta-catenin. Clinical records of these patients were studied for follow-up data, and the prognostic value of these molecules' expression was statistically assessed. RESULTS: CXCR4 mRNA and protein were significantly increased at the tumor front as compared to distant tissue or tumor center. In comparison, SDF-1 mRNA level gradually increased from the tumor center to the distant peritumoral tissue. High CXCR4 at the tumor front was associated with high Gleason score. Low SDF-1 at the tumor front was associated with locally advanced cancer and disease recurrence. Moreover, high CXCR4 staining at the tumor front and increased cytosolic E-cadherin expression in the same location was associated with locally advanced disease. CONCLUSIONS: CXCR4 seems overexpressed at the tumor front of prostate tumors, where it potentially promotes cell migration toward the SDF-1 centrifugal attracting gradient, as well as epithelial-mesenchymal transition. High CXCR4 and low SDF-1 levels at tumor front were both associated with adverse histological features.

Stromal cell-derived factor 1 (SDF-1) and its receptor, CXCR4, play an important role in angiogenesis and are associated with tumor progression. This study aimed to investigate the role of SDF-1/CXCR4-mediated epithelial-mesenchymal transition (EMT) and the progression of colorectal cancer (CRC) as well as the underlying mechanisms. The data showed that expression of CXCR4 and beta-catenin mRNA and protein was significantly higher in CRC tissues than in distant normal tissues. CXCR4 expression was associated with beta-catenin expression in CRC tissues, whereas high CXCR4 expression was strongly associated with low E-cadherin, high N-cadherin, and high vimentin expression, suggesting a cross talk between the SDF-1/CXCR4 axis and Wnt/beta-catenin signaling pathway in CRC. In vitro, SDF-1 induced CXCR4-positive colorectal cancer cell invasion and EMT by activation of the Wnt/beta-catenin signaling pathway. In contrast, SDF-1/CXCR4 axis activation-induced colorectal cancer invasion and EMT was effectively inhibited by the Wnt signaling pathway inhibitor Dickkopf-1. In conclusion, CXCR4-promoted CRC progression and EMT were regulated by the Wnt/beta-catenin signaling pathway. Thus, targeting of the SDF-1/CXCR4 axis could have clinical applications in suppressing CRC progression.CI - Copyright (c) 2014 Elsevier Ireland Ltd. All rights reserved.

The aim of the present study was to examine the role of protease-activated receptor-1 (PAR1)-stimulated platelet activation in the epithelial-mesenchymal transition (EMT) and migration of colon cancer cells, and to identify the underlying mechanisms. TFLLR-NH2, a PAR1 agonist, was used to activate platelets and the platelet supernatants were used to treat the SW620 colon cancer cell line. expression of E-cadherin and vimentin on SW620 cells was detected by immunofluorescence and western blotting, and the level of the transforming growth factor beta1 (TGF-beta1) was measured using ELISA following the activation of platelets by TFLLR-NH2. miR-200b expression was detected using quantitative PCR in SW620 cells. In order to investigate the chemotactic ability of the SW620 cells, the expression of CXC chemokine receptor type 4 (CXCR4) was measured by flow cytometry. Transwell migration assays were performed following exposure of the cells to the supernatant of PAR1-activated platelets. SW620 cells cultured in the supernatant of TFLLR-NH2-activated platelets upregulated E-cadherin expression and downregulated the vimentin expression. In the in vitro platelet culture system, a TFLLR-NH2 dose-dependent increase of secreted TGF-beta1 was detected in the supernatant. The activation of PAR1 on the platelets led to the inhibition of miR-200b expression in the SW620 cells that were cultured in platelet-conditioned media. The number of SW620 cells that penetrated through the Transwell membrane increased with the dose of TFLLR-NH2 used to treat the platelets. The percentage of CXCR4-positive SW620 cells was significantly higher when they were exposed to the supernatant of platelets cultured for 24 h with PAR1 agonist than when cultured in non-conditioned media (40.89 +/- 6.74 vs. 3.47 +/- 1.40%, P < 0.01). Platelet activation with a PAR1 agonist triggered TGF-beta secretion, which induced EMT of SW620 human colon cancer cells via the downregulation of miR-200b expression, and activated platelets had a chemotactic effect on colon cancer cells mediated by the upregulation of CXCR4 on the cell surface.

Metastasis is the main reason for lung cancer-related mortality, but little is known about specific determinants of successful dissemination from primary tumors and metastasis initiation. Here, we show that CD133(+)/CXCR4(+) cancer-initiating cells (CIC) directly isolated from patient-derived xenografts (PDX) of non-small cell lung cancer are endowed with superior ability to seed and initiate metastasis at distant organs. We additionally report that CXCR4 inhibition successfully prevents the increase of cisplatin-resistant CD133(+)/CXCR4(+) cells in residual tumors and their metastatization. Immunophenotypic analysis of lung tumor cells intravenously injected or spontaneously disseminated to murine lungs demonstrated the survival advantage and increased colonization ability of a specific subset of CD133(+)/CXCR4(+) with reduced expression of epithelial cell adhesion molecule (EpCAM(-)), which also shows the greatest in vitro invasive potential. We next prove that recovered disseminated cells from lungs of PDX-bearing mice enriched for CD133(+)/CXCR4(+)/EpCAM(-) CICs are highly tumorigenic and metastatic. Importantly, microenvironment stimuli eliciting epithelial-to-mesenchymal transition, including signals from cancer-associated fibroblasts, are able to increase the dissemination potential of lung cancer cells through the generation of the CD133(+)/CXCR4(+)/EpCAM(-) subset. These findings also have correlates in patient samples where disseminating CICs are enriched in metastatic lymph nodes (20-fold, P = 0.006) and their detection in primary tumors is correlated with poor clinical outcome (disease-free survival: P = 0.03; overall survival: P = 0.05). Overall, these results highlight the importance of specific cellular subsets in the metastatic process, the need for in-depth characterization of disseminating tumor cells, and the potential of therapeutic strategies targeting both primary tumor and tumor-microenvironment interactions.CI - (c)2015 American Association for cancer Research.

The Nef-M1 peptide competes effectively with the natural ligand of CXC chemokine receptor 4 (CXCR4), stromal cell-derived factor 1-alpha, to induce apoptosis and inhibit growth in colon cancer (CRC) and breast cancer (BC). Its role in tumor angiogenesis, and epithelial-to-mesenchymal transition (EMT) regulation, key steps involved in tumor growth and metastasis, are unknown. We evaluated the angioinhibitory effect of Nef-M1 peptide and examined its role in the inhibition of EMT in these cancers. Colon (HT29) and breast (MDA-MB231) cancer cells expressing CXCR4 were studied in vitro and in xenograft tumors propagated in severe combined immunodeficient mice. The mice were treated intraperitoneally with Nef-M1 or scrambled amino acid sequence of Nef-M1 (sNef-M1) peptide, a negative control, starting at the time of tumor implantation. Sections from tumors were evaluated for tumor angiogenesis, as measured by microvessel density (MVD) based on immunostaining of endothelial markers. In vitro tumor angiogenesis was assessed by treating human umbilical vein endothelial cells with conditioned media from the tumor cell lines. A BC cell line (MDA-MB 468) which does not express CXCR4 was used to study the actions of Nef-M1 peptide. Western blot and immunofluorescence analyses assessed the effect of Nef-M1 on tumor angiogenesis and EMT in both tumors and cancer cells. Metastatic lesions of CRC and BC expressed more CXCR4 than primary lesions. It was also found that tumors from mice treated with sNef-M1 had well established vascularity, while Nef-M1 treated tumors had very poor vascularization. Indeed, the mean MVD was lower in tumors from Nef-M1 treated mice than in sNef-M1 treated tumors. Nef-M1 treated tumor has poor morphology and loss of endothelial integrity. Although conditioned medium from CRC or BC cells supported HUVEC tube formation, the conditioned medium from Nef-M1 treated CRC or BC cells did not support tube formation. Western blot analyses revealed that Nef-M1 effectively suppressed the expression of VEGF-A in CRC and BC cells and tumors. This suggests that Nef-M1 treated CRC and BC cells are more consistent with E-cadherin signature, and thus appears more epithelial in nature. Our data indicate that Nef-M1 peptide inhibits tumor angiogenesis and the oncogenic EMT process. Targeting the chemokine receptor, CXCR4, mediated pathways using Nef-M1 may prove to be a novel therapeutic approach for CRC and BC.

Colorectal cancer (CRC) is the most commonly diagnosed cancer worldwide, and over 50% of patients will develop hepatic metastasis during the course of their disease. CXCR4 and its ligand, stromal cell-derived factor 1alpha (SDF-1alpha)/chemokine (C-X-C motif) ligand 12 (CXCL12) have been revealed as regulatory molecules involved in the spreading and progression of a variety of tumors. Here we have shown that lipopolysaccharides (LPS) promoted the migratory capacity of colon cancer cells in vivo and in vitro, which correlated with the activation of SDF-1alpha/CXCR4 axis and epithelial-mesenchymal transition (EMT) occurrence. Additionally, we found that LPS-induced CXCR4 expression and EMT through NF-kappaB signaling pathway activation. And inhibition of NF-kappaB pathway, which recovered the epithelial phenotype and attenuated CXCR4 expression, inhibited cell migratory capacity. Clinically, high levels of CXCR4 always correlated with metastasis and poor prognosis of CRC patients. In conclusion, LPS participate in the whole process of hepatic metastasis of CRC, not only causing liver damage resulting in the production of SDF-1alpha, but also enhancing the invasive potential of CRC cells by promoting CXCR4 expression and EMT occurrence, which would contribute to the enhancement of cell migration and invasion.

Metastasis is the major cause of death in patients with non-small cell lung cancer (NSCLC), and epithelial-mesenchymal transition (EMT) has been observed to be one of the key regulators of metastasis in certain cancers as it confers an invasive phenotype. CD133 is a widely used cancer stem cell (CSC) marker, and CD133-positive cancer cells are thought to be tumor-initiating cells with CSC characteristics, while CXCR4, a stromal-derived-factor-1 specific chemokine receptor, is highly expressed in NSCLC tissues and participates in cancer progression by regulating cell anti-apoptosis. We previously demonstrated that CXCR4 promotes NSCLC chemoresistance by upregulating CYP1B1, however, the relationship of CD133, CXCR4 and EMT processes in NSCLC metastasis are unclear. In this study, we detected a CD133 and CXCR4 high expression in tissue specimens from 64 NSCLC patients by immunohistochemistry, of which CD133 and CXCR4 were found to be positively associated with metastatic NSCLC patients. CD133 was found to promote NSCLC tumorigenesis and mediated the expression of CXCR4. Furthermore, CD133/CXCR4 co-expression was found to be an independent prognostic factor as shown by univariate and multivariate Cox regression analysis, and was observed to regulate the expression of EMT-related molecules and transcriptional factors in NSCLC. In addition, our results showed that E-cadherin and Vimentin were simultaneously downregulated and upregulated, in CD133+CXCR4+ A549 cells, respectively. While E-cadherin was upregulated and Vimentin was downregulated in metastatic NSCLC patients. Vimentin expression was also observed to have a positive correlation with CD133/CXCR4 co-expression in NSCLC patients and survival analysis results suggested that Vimentin high expression might be significantly associated with poor survival rates of the patients. Thus, these results suggest that the CD133/CXCR4/EMT axis may be a prognostic marker and may provide novel targets for combinational therapies in the treatment of NSCLC.

OBJECTIVES: Compelling evidence demonstrates that CXC-chemokine receptor 4 (CXCR4) is involved in tumor invasion, angiogenesis, metastasis, and resistance to chemotherapy in addition to being one of the coreceptors for T-tropic human immunodeficiency virus entry into T cells. However, it remains controversial as to how to identify functionally activated CXCR4 in tumor biopsies, which would assist in determining which patients may benefit from potential CXCR4-targeted therapy. MATERIALS AND METHODS: Immunohistochemistry (IHC) staining on archival tissues of patients with non-small-cell lung cancer (NSCLC) was used to detect a panel of biomarkers, including phospho-ERK1/2, phospho-AKT, and E-cadherin, which are relevant to downstream signaling of CXCR4 and epithelial to mesenchymal transition (EMT). We also examined whether subcellular localization of CXCR4 could help define possible activation of CXCR4. RESULTS: A total of 94 primary tumor tissue samples from patients with NSCLC were included. Sixty-six patients had both cytomembranous and nuclear staining of CXCR4, 22 had solely nuclear staining, 5 had solely cytomembranous staining, and 1 had negative staining. Cytoplasmic location of CXCR4 with or without nuclear location was associated with loss of the epithelial marker E-cadherin (P = .0015) and activation of ERK1/2 (P = .0121) and AKT (P = .0024), suggesting EMT in these tumors; whereas tumors with only nuclear location of CXCR4 were more indolent and preserved an epithelial phenotype. CONCLUSIONS: Our study suggests that different subcellular localization of CXCR4 may be associated with different activation states; cytoplasmic CXCR4 seems to correlate with biomarker changes associated with EMT in NSCLC.CI - Copyright (c) 2016 Elsevier Inc. All rights reserved.

Neuroendocrine tumors (NETs) metastasize to the skeleton in approximately 20% of patients. We have previously shown that the epithelial-mesenchymal transition (EMT) regulates the NET osteotropism and that CXCR4 overexpression predicts bone spreading. Here, we unravel the molecular mechanisms linking the activation of the CXCL12/CXCR4 axis to the bone colonization of NETs using cell lines representative of pancreatic (BON1, CM, QGP1), intestinal (CNDT 2.5), and bronchial origin (H727). By combining flow cytometry and ELISA, BON1, CM and QGP1 cells were defined as CXCR4high/CXCL12low, while H727 and CNDT 2.5 were CXCR4low/CXCL12high. CXCL12 was inert on cell proliferation, but significantly increased the in vitro osteotropism of CXCR4high/CXCL12low cells, as assessed by transwell assays with or without Matrigel membranes. In these cells, CXCL12 induced in vitro a marked EMT-like transcriptional shift with acquirement of a mesenchymal shape. The nuclei of CXCR4high/CXCL12low NET cells were typically enriched in non-phosphorylated CXCR4, particularly upon agonist stimulation. Silencing of CXCR4 via siRNA prevented the CXCL12-induced EMT in CXCR4high/CXCL12low NET cell lines resulting in the abrogation of both migration and transcriptional mesenchymal patterns. Our data suggest that CXCL12 conveys EMT-promoting signals in NET cells through CXCR4, which in turn regulates transcriptional, morphologic and functional modifications resulting in enhanced in vitro osteotropism of NET cells. Unique functions of CXCR4 may be segregated in relation to its subcellular localization and may acquire potential relevance in future in vivo studies.

The molecular mechanism underlying gastric cancer (GC) invasion and metastasis is still poorly understood. In this study, we tried to investigate the roles of CXCR4 and CXCR2 signalings in gastric cancer metastasis. A highly invasive gastric cancer cell model was established. Chemokines receptors were profiled to search for the accountable ones. Then the underlying molecular mechanism was investigated using both in vitro and in vivo techniques, and the clinical relevance of CXCR4 and CXCR2 expression was studied in gastric cancer samples. CXCR4 and CXCR2 were highly expressed in a high invasive gastric cancer cell model and in gastric cancer tissues. Overexpression of CXCR4 and CXCR2 was associated with more advanced tumor stage and poorer survival for GC patients. CXCR4 and CXCR2 expression strongly correlated with each other in the way that CXCR2 expression changed accordingly with the activity of CXCR4 signaling and CXCR4 expression also changed in agreement with CXCR2 activity. Further studies demonstrated CXCR4 and CXCR2 can both activated NF-kappaB and STAT3 signaling, while NF-kappaBp65 can then transcriptionally activate CXCR4 and STAT3 can activate CXCR2 expression. This crosstalk between CXCR4 and CXCR2 contributed to EMT, migration and invasion of gastric cancer. Finally, Co-inhibition of CXCR4 and CXCR2 is more effective in reducing gastric cancer metastasis. Our results demonstrated that CXCR4 and CXCR2 cross-activate each other to promote the metastasis of gastric cancer.

CXC chemokine receptor 4 (CXCR4) is associated with poor clinical outcomes and decreased survival in hepatocellular carcinoma (HCC). In the present study, we targeted CXCR4 by CRISPR/Cas9 in HepG2 cells and observed the effects both in vitro and in vivo. The results indicated that after targeting CXCR4 the expression of CXCR4 was significantly decreased and the cell proliferation was inhibited. Clonogenicity and scratch cell migration assays indicated that specific downregulation of CXCR4 inhibited cell migration. This disruption of CXCR4 led to less invasiveness, the genes related to epithelial-mesenchymal transition (EMT) and cell self-renewal were also affected. Moreover, sensitivity to the anticancer drug cisplatin was significantly increased in vitro by the downregulation of CXCR4. The results of the in vivo study showed that the growth volumes were significantly smaller in neoplasms derived from CXCR4-downregulated HepG2 cells compared to those derived from wild-type cells. These results showed that targeting CXCR4 by CRISPR/Cas9 could inhibit proliferation, migration and invasion, reversed EMT, increased chemosensitivity and decrease the malignancy of HCC in vitro and in vivo.

BACKGROUND: Ferritin plays a central role in the intracellular iron metabolism; the molecule is a nanocage of 24 subunits of the heavy and light types. The heavy subunit (FHC) is provided of a ferroxidase activity and thus performs the key transformation of iron in a non-toxic form. Recently, it has been shown that FHC is also involved in additional not iron-related critical pathways including, among the others, p53 regulation, modulation of oncomiRNAs expression and chemokine signalling. epithelial to mesenchymal transition (EMT) is a cellular mechanism by which the cell acquires a fibroblast-like phenotype along with a decreased adhesion and augmented motility. In this work we have focused our attention on the role of the FHC on EMT induction in the human cell lines MCF-7 and H460 to elucidate the underlying molecular mechanisms. METHODS: Targeted silencing of the FHC was performed by lentiviral-driven shRNA strategy. Reconstitution of the FHC gene product was obtained by full length FHC cDNA transfection with Lipofectamine 2000. MTT and cell count assays were used to evaluate cell viability and proliferation; cell migration capability was assayed by the wound-healing assay and transwell strategy. Quantification of the CXCR4 surface expression was performed by flow cytometry. RESULTS: Experimental data indicated that FHC-silenced MCF-7 and H460 cells (MCF-7(shFHC), H460(shFHC)) acquire a mesenchymal phenotype, accompanied by a significant enhancement of their migratory and proliferative capacity. This shift is coupled to an increase in ROS production and by an activation of the CXCR4/CXCL12 signalling pathway. We present experimental data indicating that the cytosolic increase in ROS levels is responsible for the enhanced proliferation of FHC-silenced cells, while the higher migration rate is attributable to a dysregulation of the CXCR4/CXCL12 axis. CONCLUSIONS: Our findings indicate that induction of EMT, increased migration and survival depend, in MCF-7 and H460 cells, on the release of FHC control on two pathways, namely the iron/ROS metabolism and CXCR4/CXCL12 axis. Besides constituting a further confirmation of the multifunctional nature of FHC, this data also suggest that the analysis of FHC amount/function might be an important additional tool to predict tumor aggressiveness.

BACKGROUND: Recent studies have indicated that microRNAs (miRNAs) are closely related to lung cancer. However, the effects of miR-1246 on lung cancer are still elusive. In this study, we aimed to explore the molecular mechanisms of miR-1246 in lung cancer. MATERIALS AND METHODS: Using RT-qPCR assay, we analyzed the expression of miR-1246 in lung cancer cell lines and lung epithelial cell line. Using Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell, RT-qPCR and western blot assays, we investigated cell viability, apoptosis, invasion and epithelial mesenchymal transition (EMT) process. Using luciferase reporter assay, we confirmed a target of miR-1246. Using western blot assay, we detected the protein mechanisms of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signal pathways. RESULTS: Our results showed that miR-1246 was down-regulated in lung cancer cell lines (A549, H1650 and H1299) compared to in lung epithelial cell line (16HBE14o). MiR-1246 overexpression remarkably inhibited cell invasion as well as up-regulated E-cadherin expression and down-regulated N-cadherin, Vimentin, ZEB1 and Snail expressions in A549 cells. Further studies have confirmed CXCR4 as a target gene of miR-1246, and CXCR4 silence significantly abolished the promotion effect of miR-1246 suppression on cell invasion and EMT process in A549 cells. Besides, miR-1246 blocked JAK/STAT and PI3K/AKT signal pathways by regulation of CXCR4. CONCLUSIONS: These results demonstrated that miR-1246 inhibited cell invasion and EMT process by targeting CXCR4 and blocking JAK/STAT and PI3K/AKT signal pathways in lung cancer cells.

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy involving local and distant metastasis. It is known that CXC chemokine ligand 12 (CXCL12) interacts specifically with CXC chemokine receptor 4 (CXCR4) to guide the migration of PTC cells. However, the signaling pathway downstream of the CXCL12-CXCR4 axis in PTC is not fully understood. In the present study, high expression of CXCR4 was detected in 38 out of 82 specimens of PTC, and the expression level of CXCR4 significantly correlated with the stage of PTC. Additionally, the roles of the CXCL12-CXCR4 axis in the migration, invasion, and epithelial-mesenchymal transition (EMT) of B-CPAP cells were investigated in vitro. The motility and invasiveness were significantly enhanced in CXCR4-overexpressing B-CPAP cells with CXCL12 treatment. Moreover, the CXCL12-CXCR4 axis promoted the EMT process, as evidenced by a decreased level of E-cadherin and increased expressions of N-cadherin and vimentin. Furthermore, the CXCL12-CXCR4 axis activated the nuclear factor kappa-B (NF-kappaB) signaling pathway, whereas BAY11-7082, an IkappaB phosphorylation inhibitor, counteracted CXCL12-CXCR4-induced migration, invasion, and EMT processes in B-CPAP cells. In conclusion, the CXCL12-CXCR4 axis promotes the migration, invasion, and EMT processes in B-CPAP cells, at least partly, by activating the NF-kappaB signaling pathway.

We have earlier found abnormal expression of the mitochondrial ribosomal protein S18-2 (MRPS18-2, S18-2) in endometrial cancer, compared to the expression in hyperplasia and in normal endometrium. Here we report that expression of S18-2 was increased with disease progression in clinical specimens of prostate cancer (PCa). The level of induction of epithelial to mesenchymal cell transition (EMT) correlated with the expression level of S18-2 in PCa cell lines. Moreover, cells acquired increased ability of migration upon S18-2 overexpression, as was evaluated in zebrafish embryo model and in trans-well assay. We found that this is due to increased CXCR4 cell surface expression. Neutralizing CXCR4 protein or abrogating S18-2 expression in cells significantly reduced their migratory ability directed toward CXCL12. The mRNA expression of TWIST2, encoding one of transcription factors that induce EMT upon CXCR4 increase, positively correlated with the S18-2 protein level. Together, these data suggest that the S18-2 protein induces EMT through the TWIST2/E-cadherin signalling and, consequently, CXCR4-mediated migration of PCa cells.

CXCR4 has been shown to play a key role in the metastasis of non-small cell lung cancer (NSCLC). And CXCR may be associated with the Hippo-Yes kinase-associated protein (YAP) pathway, thus involving in the occurrence and progression of NSCLC. This study aims to investigate the effect of CXCR4 inhibition on epithelial-mesenchymal transition (EMT), invasion and migration of NSCLC cells via the Hippo-YAP pathway. QRT-PCR and Western blot were employed to detect CXCR4 expression in NSCLC cell lines. A549 and H1299 cells were treated with WZ811 (0, 10, 30, and 50 microM), and A549 cells were also divided into the Control, WZ811, YAP siRNA, and WZ811 + YAP groups. Wound-healing, Transwell assay, immunofluorescent staining, and a luciferase reporter gene assay were performed in this experiment. Compared with human bronchial epithelial (HBE) cells, CXCR4 expression was up-regulated in NSCLC cell lines. WZ811 increased E-cadherin; decreased expression of Twist, vimentin, Snail, p-YAP, CTGF, and BIRC5; blocked GTIIC reporter activity; and reduced migration and invasion of A549 cells, all in a dose-dependent manner. YAP siRNA had a similar effect to WZ811 by inhibiting EMT, invasion and migration of A549 cells. However, compared with A549 cells in the YAP siRNA and WZ811 groups, cells in the WZ811 + YAP group showed a dramatically enhanced EMT phenotype as well as invasion and migration abilities. Inhibition of CXCR4 may reduce EMT, invasion and migration of NSCLC cells, thereby providing a new therapeutic target for NSCLC.CI - (c) 2018 International Federation for Cell Biology.

Extra-medullary disease (EMD) in multiple myeloma (MM) is associated with poor prognosis and resistance to chemotherapy. However, molecular alterations that lead to EMD have not been well defined. We developed bone marrow (BM)- and EMD-prone MM syngeneic cell lines; identified that epithelial-to-mesenchymal transition (EMT) transcriptional patterns were significantly enriched in both clones compared to parental cells, together with higher levels of CXCR4 protein; and demonstrated that CXCR4 enhanced the acquisition of an EMT-like phenotype in MM cells with a phenotypic conversion for invasion, leading to higher bone metastasis and EMD dissemination in vivo. In contrast, CXCR4 silencing led to inhibited tumor growth and reduced survival. Ulocuplumab, a monoclonal anti-CXCR4 antibody, inhibited MM cell dissemination, supported by suppression of the CXCR4-driven EMT-like phenotype. These results suggest that targeting CXCR4 may act as a regulator of EMD through EMT-like transcriptional modulation, thus representing a potential therapeutic strategy to prevent MM disease progression.CI - Copyright (c) 2015 The Authors. Published by Elsevier Inc. All rights reserved.