CXCR4 Expression In Patients Research Articles

[68 Ga]Ga-CXCR4 PET/CT imaging in high-grade glioma for assessment of CXCR4 receptor expression

PurposeGliomas account for 75 % of primary malignant CNS tumors. High-grade glioma (CNS WHO grades 3 and 4) have an unfavorable treatment response and poor outcome. CXCR4 is a G protein-coupled receptor that plays an important part in the signaling pathway between cancer cells and tumor microenvironment. CXCR4 overexpression has been shown in a variety of cancers. In this study, we evaluate the potential value of [68Ga]Ga-Pentixafor as a PET/CT CXCR4-probe for in vivo assessment of CXCR4 expression in patients with high-grade glioma and its correlation with tumor grade. Materials and Methods[68Ga]Ga-CXCR4 PET/CT was performed in the prospective single-center study in treatment-naïve biopsy-proven patients with high-grade glioma. The acquired images were analyzed qualitatively and semi-quantitatively. ResultA total of 26 patients (mean age: 53.3±14.4 years, 11 women, 15 men) were enrolled. CNS WHO grade 3 pathology was seen in 19 % (5/26) of the sample. The patient-based sensitivity of 68Ga-CXCR4 was 96.2 %. Overall, 28 pathologic lesions were detected, leading to a lesion-based sensitivity of 96.4 %. The median (IQR) SUVmax of grade 4 lesions was substantially greater than the grade 3(3.03(2.5–3.7) vs. 1.51(1.2–1.8), p = 0.0145).). The highest tracer activity of organs −beside bladder as the main excretion reservoir-was in lymphoid tissue of Waldeyer’s ring (mean SUVmax: 7.41), and spleen (mean SUVmax: 6.62). ConclusionIn conclusion, this new application for [68Ga]Ga-Pentixafor PET tracer exhibits excellent visual and semi-quantitative diagnostic properties. Further studies are warranted.

CXCR4-directed PET/CT with [68 Ga]Ga-pentixafor in solid tumors—a comprehensive analysis of imaging findings and comparison with histopathology

BackgroundC-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in various solid cancers and can be targeted by CXCR4-directed molecular imaging. We aimed to characterize the in-vivo CXCR4 expression in patients affected with solid tumors, along with a comparison to ex-vivo findings.MethodsA total 142 patients with 23 different histologically proven solid tumors were imaged with CXCR4-directed PET/CT using [68 Ga]Ga-pentixafor (total number of scans, 152). A semi-quantitative analysis of the CXCR4-positive tumor burden including maximum standardized uptake values (SUVmax) and target-to-background ratios (TBR) using blood pool was conducted. In addition, we performed histopathological staining to determine the immuno-reactive score (IRS) from patients’ tumor tissue and investigated possible correlations with SUVmax (by providing Spearman’s rho ρ). Based on imaging, we also assessed the eligibility for CXCR4-targeted radioligand therapy or non-radioactive CXCR4 inhibitory treatment (defined as more than five CXCR4-avid target lesions [TL] with SUVmax above 10).ResultsOne hundred three of 152 (67.8%) scans showed discernible uptake above blood pool (TBR > 1) in 462 lesions (52 primary tumors and 410 metastases). Median TBR was 4.4 (1.05–24.98), thereby indicating high image contrast. The highest SUVmax was observed in ovarian cancer, followed by small cell lung cancer, desmoplastic small round cell tumor, and adrenocortical carcinoma. When comparing radiotracer accumulation between primary tumors and metastases for the entire cohort, comparable SUVmax was recorded (P > 0.999), except for pulmonal findings (P = 0.013), indicative for uniform CXCR4 expression among TL. For higher IRS, a weak, but statistically significant correlation with increased SUVmax was observed (ρ = 0.328; P = 0.018). In 42/103 (40.8%) scans, more than five TL were recorded, with 12/42 (28.6%) exhibiting SUVmax above 10, suggesting eligibility for CXCR4-targeted treatment in this subcohort.ConclusionsIn a whole-body tumor read-out, a substantial portion of prevalent solid tumors demonstrated increased and uniform [68 Ga]Ga-pentixafor uptake, along with high image contrast. We also observed a respective link between in- and ex-vivo CXCR4 expression, suggesting high specificity of the PET agent. Last, a fraction of patients with [68 Ga]Ga-pentixafor-positive tumor burden were rendered potentially suitable for CXCR4-directed therapy.

Investigation of spleen CXCR4 expression by [68Ga]Pentixafor PET in a cohort of 145 solid cancer patients

BackgroundThe chemokine receptor CXCR4 is frequently overexpressed and associated with adverse prognosis in most hematopoietic malignancies and solid cancers. Recently, CXCR4 molecular imaging using the CXCR4-specific positron emission tomography (PET) tracer Pentixafor ([68Ga]Pentixafor) has become a well-established method to non-invasively measure CXCR4 expression in vivo. In previous Pentixafor imaging studies, highly variable CXCR4 tracer uptake to the spleen was observed.ResultsWe investigated the hypothesis that enhanced spleen [68Ga]Pentixafor uptake and thus CXCR4 expression in patients with solid tumors would indicate an activated spleen state and/or an association with clinical and prognostic features and survival parameters. In this retrospective study, [68Ga]Pentixafor-PET images and patient records of 145 solid tumor patients representing 27 cancer entities were investigated for an association of spleen [68Ga]Pentixafor uptake and clinical characteristics and outcome. Based on this assessment, we did not observe differences in clinical outcomes, measured by progression-free survival, overall survival and remission status neither within the entire cohort nor within subgroups of adrenal cancer, desmoplastic small round cell tumor, neuroendocrine tumors, non-small cell lung cancer, small cell lung cancer and pancreatic adenocarcinoma patients. No tumor entity showed especially high levels of spleen [68Ga]Pentixafor uptake compared to others or a control cohort. However, when investigating laboratory parameters, there was a positive correlation of high spleen [68Ga]Pentixafor uptake with leukocyte and/or platelet counts in neuroendocrine tumors, non-small cell lung cancer and small cell lung cancer.ConclusionSpleen [68Ga]Pentixafor uptake was not associated with stage of disease and clinical outcomes in solid tumor patients. We identified positively associated platelet and/or leukocyte counts with spleen [68Ga]Pentixafor uptake in neuroendocrine tumors, non-small cell lung cancer and small cell lung cancer, suggesting that splenic CXCR4 expression could possibly play a role in systemic immunity/inflammation in some types of solid tumors or a subgroup of patients within solid tumor entities.

CXCR4 is a valuable poor prognostic marker for chronic lymphocytic leukemia

Background Chronic lymphocytic leukemia (CLL) is one of the common chronic lymphoproliferative disorders (lymphoid neoplasms). It is characterized by a progressive accumulation of functionally incompetent lymphocytes, which are usually monoclonal in origin. CLL is a heterogeneous disease; thus, in some cases, the disease progresses so slowly that treatment is not required, but in others, a more aggressive form of the disease develops. CXCR4 (CD184) is a chemokine and chemokine receptor pair playing critical roles in tumor genesis. It is overexpressed in many hematological malignancies including acute myeloid leukemia and non-Hodgkin's lymphoma and generally correlates with a poor prognosis. Aim To evaluate the clinical utility of CXCR4 expression in patients with CLL as a possible predictor of disease outcome. Patients and methods This is a prospective study conducted on 33 adult patients with newly diagnosed CLL. Expression of CXCR4 was determined by flow cytometry on either peripheral blood or bone marrow samples. Correlation with the course of the disease and the known CLL prognostic parameters was done initially and after 6 months of follow-up. Results CXCR4 expression was positively correlated with absolute lymphocytic count, Rai score, β2 microglobulin, and lactate dehydrogenase levels. It was negatively correlated with hemoglobin and platelet counts, overall response rate, and 6-month disease-free survival. Conclusion We conclude that CXCR4 is a valuable poor prognostic marker for CLL. Its higher level of expression is associated with inferior response to therapy and lower disease-free survival.

The FLT3-ITD mutation and the expression of its downstream signaling intermediates STAT5 and Pim-1 are positively correlated with CXCR4 expression in patients with acute myeloid leukemia

Chemokine ligand 12(CXCL12) mediates signaling through chemokine receptor 4(CXCR4), which is essential for the homing and maintenance of Hematopoietic stem cells (HSCs) in the bone marrow. FLT3-ITD mutations enhance cell migration toward CXCL12, providing a drug resistance mechanism underlying the poor effects of FLT3-ITD antagonists. However, the mechanism by which FLT3-ITD mutations regulate the CXCL12/CXCR4 axis remains unclear. We analyzed the relationship between CXCR4 expression and the FLT3-ITD mutation in 466 patients with de novo AML to clarify the effect of FLT3-ITD mutations on CXCR4 expression in patients with AML. Our results indicated a positive correlation between the FLT3-ITD mutant-type allelic ratio (FLT3-ITD MR) and the relative fluorescence intensity (RFI) of CXCR4 expression in patients with AML (r = 0.588, P ≤ 0.0001). Moreover, the levels of phospho(p)-STAT5, Pim-1 and CXCR4 proteins were positively correlated with the FLT3-ITD MR, and the mRNA levels of CXCR4 and Pim-1 which has been revealed as one of the first known target genes of STAT5, were upregulated with an increasing FLT3-ITD MR(P < 0.05). Therefore, FLT3-ITD mutations upregulate the expression of CXCR4 in patients with AML, and the downstream signaling intermediates STAT5 and Pim-1 are also involved in this phenomenon and subsequently contribute to chemotherapy resistance and disease relapse in patients with AML. However, the mechanism must be confirmed in further experiments. The combination of CXCR4 antagonists and FLT3 inhibitors may improve the sensitivity of AML cells to chemotherapy and overcome drug resistance.

Relationship of Circulating CXCR4+ EPC with Prognosis of Mild Traumatic Brain Injury Patients

To investigate the changes of circulating endothelial progenitor cells (EPCs) and stromal cell-derived factor-1α (SDF-1α)/CXCR4 expression in patients with mild traumatic brain injury (TBI) and the correlation between EPC level and the prognosis of mild TBI. 72 TBI patients (57 mild TBI, 15 moderate TBI patients) and 25 healthy subjects (control) were included. The number of circulating EPCs, CD34+, and CD133+ cells and the percentage of CXCR4+ cells in each cell population at 1,4,7,14,21 days after TBI were counted by flow cytometer. SDF-1α levels in serum were detected by ELISA assay. The patients were divided into poor and good prognosis groups based on Extended Glasgow Outcome Scale and Activity of Daily Living Scale at 3 months after TBI. Correlation analysis between each detected index and prognosis of mild TBI was performed. Moderate TBI patients have higher levels of SDF-1α and CXCR4 expression than mild TBI patients (P < 0.05). The percentage of CXCR4+ EPCs at day 7 post-TBI was significantly higher in mild TBI patients with poor prognosis than the ones with good prognosis (P < 0.05). HAMA and HAMD scores in mild TBI patients were significantly lower than moderate TBI patients (P < 0.05) in early term. The percentage of CXCR4+ EPCs at day 7 after TBI was significantly correlated with the prognosis outcome at 3 months. The mobilization of circulating EPCs can be induced in mild TBI. The expression of CXCR4+ in EPCs at 7 days after TBI reflects the short-term prognosis of brain injury, and could be a potential biological marker for prognosis prediction of mild TBI.

Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia.

Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [(68)Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche.

CXCR4 Protein Epitope Mimetic Antagonist POL5551 Disrupts Metastasis and Enhances Chemotherapy Effect in Triple-Negative Breast Cancer.

The SDF-1 receptor CXCR4 has been associated with early metastasis and poorer prognosis in breast cancers, especially the most aggressive triple-negative subtype. In line with previous reports, we found that tumoral CXCR4 expression in patients with locally advanced breast cancer was associated with increased metastases and rapid tumor progression. Moreover, high CXCR4 expression identified a group of bone marrow-disseminated tumor cells (DTC)-negative patients at high risk for metastasis and death. The protein epitope mimetic (PEM) POL5551, a novel CXCR4 antagonist, inhibited binding of SDF-1 to CXCR4, had no direct effects on tumor cell viability, but reduced migration of breast cancer cells in vitro. In two orthotopic models of triple-negative breast cancer, POL5551 had little inhibitory effect on primary tumor growth, but significantly reduced distant metastasis. When combined with eribulin, a chemotherapeutic microtubule inhibitor, POL5551 additively reduced metastasis and prolonged survival in mice after resection of the primary tumor compared with single-agent eribulin. Hypothesizing that POL5551 may mobilize tumor cells from their microenvironment and sensitize them to chemotherapy, we used a "chemotherapy framing" dosing strategy. When administered shortly before and after eribulin treatment, three doses of POL5551 with eribulin reduced bone and liver tumor burden more effectively than chemotherapy alone. These data suggest that sequenced administration of CXCR4 antagonists with cytotoxic chemotherapy synergize to reduce distant metastases.

In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma.

CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination and poor prognosis. We evaluated the novel CXCR4 probe [68Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [68Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [68Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [18F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34+ flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [68Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases.

Clinical significance of nuclear factor κB and chemokine receptor CXCR4 expression in patients with diffuse large B-cell lymphoma who received rituximab-based therapy.

Background/AimsThis study investigated the expression of nuclear factor κB (NF-κB) and the chemokine receptor (CXCR4) in patients with diffuse large B-cell lymphoma (DLBCL) who received rituximab-based therapy.MethodsSeventy patients with DLBCL and treated with rituximab-CHOP (R-CHOP) were included, and immunohistochemistry was performed to determine the expression of NF-κB (IκB kinase α, p50, and p100/p52) and CXCR4. To classify DLBCL cases as germinal center B-cell-like (GCB) and non-GCB, additional immunohistochemical expression of CD10, bcl-6, or MUM1 was used in this study. The expression was divided into two groups according to the intensity score (negative, 0 or 1+; positive, 2+ or 3+).ResultsThe median age of the patients was 66 years (range, 17 to 87), and 58.6% were male. Twenty-seven patients (38.6%) had stage III or IV disease at diagnosis. Twenty-three patients (32.9%) were categorized as high or high-intermediate risk according to their International Prognostic Indexs (IPIs). The overall incidence of bone marrow involvement was 5.7%. Rates of positive NF-κB and CXCR4 expression were 84.2% and 88.6%, respectively. High NF-κB expression was associated with CXCR4 expression (p = 0.002), and 56 patients (80.0%) showed coexpression. However, the expression of NF-κB or CXCR4 was not associated with overall survival and EFS. On multivariate analysis that included age, gender, performance status, stage, and the IPI, no significant association between the grade of NF-κB or CXCR4 expression and survival was observed.ConclusionsThe current study suggests that the tissue expression of NF-κB and CXCR4 may not be an independent prognostic marker in DLBCL patients treated with R-CHOP.

Prognostic value of CXCR4 expression in patients with clear cell renal cell carcinoma.

The expression of CXCR4 is implicated in the metastatic dissemination of different cancers. The information on its prognostic value has been very limited in clear cell renal cell carcinoma (ccRCC). Our objective was to explore the prognostic value of CXCR4 in ccRCC. 104 patients with a ccRCC were studied. There were 69 men and 35 women with an average age of 64.5 years old (range: 34-86 years). The CXCR4 expression was evaluated by immunohistochemistry. The follow-up varied from 12 to 184 months with a mean of 79.5 months. Kaplan-Meier with a log rank test was performed to compare overall survival and cancer-specific survival after surgery. Univariate and multivariate analyses were performed according to the Cox regression model. CXCR4 expression was found in 68/104 (65.4%) of tumor samples. CXCR4 expression was located in the nucleus in 55/68 (80.8%) cases while cytoplasm or membrane location was found in 13/68 (19.2%) cases. High expression was found in 25/68 (36.8%) cases. During follow-up, 39 patients died, of which 26 died of cancer. Kaplan-Meier analysis revealed that a high expression of CXCR4 was associated with a reduced overall survival (p=0.017) and cancer-specific survival (p=0.022). Univariate analysis indicated that a high expression of CXCR4 was a significant factor for a poorer overall survival (p=0.020) and cancer-specific survival (p=0.027). By multivariate analysis, a high expression of CXCR4 appeared to be an independent factor of overall survival (p=0.024) and cancer-specific survival (p=0.028). This study suggested that a high CXCR4 expression was correlated with a worse outcome for ccRCC patients.

The Prognostic Value of CXCR4 in Acute Myeloid Leukemia

CXC chemokine receptor (CXCR4) has been shown to be expressed in a subset of acute myeloid leukemia (AML) patients and is correlated with a poor prognosis. CXCR4 expression appears to be an independent prognostic factor for survival in a heterogeneous group of AML patients. To better assess its significance, we analyzed CXCR4 expression in a group of AML patients. The prognostic value of CXCR4 expression in 53 patients with AML presenting between 2003 and 2008 was analyzed. Formalin-fixed, paraffin-embedded bone marrow biopsy or clot sections were stained using immunohistochemical methods. CXCR4 was expressed in 26 patients (49.1%). A patient age of less than 60 years (P=0.023), achievement of complete remission after induction therapy (P<0.001), and no CXCR4 expression (P=0.010) were all associated with better progression-free survival (PFS). Among mutations of NPM1, CEBPA, FLT3 ITD, and FLT3 D835 and expression of CXCR4, only CXCR4 expression was associated with PFS (P=0.010; by log-rank test). By multivariate analysis, CXCR4 expression was an independent prognostic factor (P=0.001 for PFS and P=0.001 for overall survival). CXCR4 expression in patients with a normal karyotype was detected in 15 of 22 patients (68.2%, relative ratio 4.46, P=0.035). Expression of CXCR4 in normal-karyotype AML showed inferior PFS (median 2.0 vs. 10.7 mo, P=0.026) and had a trend toward inferior overall survival (median 10.8 vs. 14.0 mo, P=0.058). These results suggest that CXCR4 expression is associated with poor prognosis in patients with AML. Specifically, CXCR4 expression is common in normal-karyotype AML and is a marker of more aggressive disease in this population. CXCR4 expression could be incorporated into the risk assessment of patients with AML.

The Internal-Tandem-Duplication of Flt3 Mutations Augment Chemotaxis in Hematopoietic Cells by Blocking the Down-Regulation of Rho-Associated Kinase That Is Induced by SDF1/CXCR4 Signaling

Abstract 1319Internal Tandem Duplication mutations of the Flt3 gene (ITD-Flt3) and the deregulation of CXCR4 expression in patients with AML are associated with a poor prognosis (Rombouts et al. Blood 2004). ITD-Flt3 induces myeloproliferative disease with extramedullary infiltration in transplantation models, thereby suggesting that ITD-Flt3 can regulate the dissemination of leukemia cells. We have reported that ITD-Flt3 mutations enhance the migration of mouse hematopoietic cells toward SDF1 and modulate their homing in vivo (Fukuda et al. Blood 2005, Exp Hematology 2006). However, the molecular mechanism responsible for the aberrant migration of ITD-Flt3+ cells toward SDF1 remains unknown. A recent report has demonstrated that Rho-Associated Kinase (Rock) regulates the proliferation of ITD-Flt3+ hematopoietic cells (Mali et al. Cancer Cell 2012). In this report, we investigate the functional role of Rock1 in the aberrant hematopoietic cell migration induced by ITD-Flt3.The migration of Ba/F3 cells containing 3 different ITD-Flt3 variants (N51, N73, N78: ITD-Flt3+ cells) toward SDF1 (0–500 ng/ml) was significantly increased compared with Ba/F3 cells lacking ITD-Flt3 (wild-type Flt3+ cells; P<0.01, N=4). Moreover, the enhanced migration of the ITD-Flt3+ cells toward SDF1 was reduced with the treatment of the ITD-Flt3 inhibitor, CEP701, and the CXCR4 antagonist, AMD3100. CXCR4 expression levels in all ITD-Flt3+ cells were reduced compared with the wild-type Flt3+ cells (50±6% reduction), thereby indicating that the enhanced migration of the ITD-Flt3+ cells toward SDF1 is independent of CXCR4. The incubation of wild-type Flt3+ cells with the Rock inhibitors, Y27632 and H1152, reduced the migration toward SDF1 in a dose-dependent manner. Similarly, the shRNA specific for Rock1 significantly down-regulated the migration of the wild-type Flt3+ cells toward SDF1 (72±6% reduction, N=3, P<0.01). The addition of the Flt3-ligand (FL) toward SDF1 accentuated the migration of the wild-type Flt3+ cells compared with SDF1 alone, which was also inhibited by H1152. These data indicate that Rock activity is necessary for the cell migration toward SDF1 in the presence or absence of Flt3 signaling. However, Rock1 mRNA was down-regulated by treatment with 100ng/ml SDF1 in the wild-type Flt3+ cells (52±8% reduction, N=6, P<0.001). In contrast, the FL up-regulated Rock1 mRNA expression in wild-type Flt3+ cells in a dose-dependent manner (N=3, P<0.05). Similarly, ITD-Flt3 mutations enhanced Rock1 mRNA expression (2.1±0.5-, 2.2±0.2-, and 3.2±0.6-fold increases in N51, N73 and N78, respectively; P<0.05). The reduction of Rock1 mRNA induced by SDF1 in the wild-type Flt3+ cells was abrogated by the treatment with 10ng/ml of FL. Moreover, the addition of 100 ng/ml of FL to SDF1 enhanced Rock1 expression compared with the vehicle alone in the wild-type Flt3+ cells (55±19% increase, N=3, P<0.01), thereby indicating that Flt3 signaling antagonizes the SDF1-induced down-regulation of Rock1 expression. Similarly, Rock1 levels in the 3 different ITD-Flt3+ cells that migrated toward 100ng/ml of SDF1 were significantly higher compared with the wild-type Flt3+ cells that migrated toward SDF1 (2.2±0.5-, 4.2±1.1- and 1.4±0.2-fold increases in N51, N73 and N78, respectively; P<0.02). The incubation of the ITD-Flt3+ cells with Y27632 and H1152 lead to a reduction in the enhanced migration toward SDF1 in a dose-dependent manner. The shRNA specific for Rock1 significantly down-regulated the migration of the ITD-Flt3+ cells toward SDF1 (72±8% reduction, P<0.02), thereby indicating that Rock1 supports the enhanced cell migration toward SDF1 that is induced by ITD-Flt3. Although SDF1 enhanced the phosphorylation of MYPT1, a downstream substrate of Rock1, in both the wild-type Flt3+ and ITD-Flt3+ cells, the phosphorylation levels remained elevated until 4 hours in ITD-Flt3+ cells compared with the wild-type Flt3+ cells, in which the signal faded away earlier.Our data demonstrates that SDF1 down-regulates Rock1 expression in the absence of Flt3 signaling, while ITD-Flt3 mutations augment cell migration toward SDF1 by blocking the down-regulation of Rock1 that is induced by SDF1 signaling. Manipulating the SDF1/Rock1 axis that is modulated by ITD-Flt3 may be clinically beneficial for antagonizing the aberrant dissemination of AML cells in patients. Disclosures:No relevant conflicts of interest to declare.

Adiponectin promotes the migration of circulating angiogenic cells through p38-mediated induction of the CXCR4 receptor

AimsAdiponectin (adipo) and exercise training (ET) contribute to the maintenance of a normal vascular tone by influencing vascular NO bioavailability and concentration and function of circulating angiogenic cells (CAC). The molecular mechanisms are only partially understood. Aim of the present study was to elucidate the effects of adipo on CAC migration and the underlying signaling pathways. Furthermore, the impact of ET on adiponectin-mediated CAC migration was investigated. Methods and resultsCACs were isolated from peripheral blood and exposed to different adipo concentrations. Adipo (5μg/ml) enhanced the ability of CACs to migrate following an SDF-1 gradient by 345%. This was associated with a significant increase in CXCR4 expression on the surface of CACs as compared to control (10.1±1.5 vs. 33.2±4.5% CXCR4 positive cells, p<0.05). Adiponectin-induced CAC migration and CXCR4-upregulation were mediated through adipo-receptor 1 (AdipoR1) and blocked by an inhibitor of PI3-kinase, p38MAP kinase and NFκb. Adipo-stimulated migration of CACs, CXCR4 expression and p38MAPK-activation is impaired in patients with coronary artery disease (CAD). ET over 4weeks partially corrects adiponectin-stimulated CAC migration and CXCR4 expression in patients with CAD (n=10). No change was observed in the control group (n=10). ConclusionAdipo improves the migratory capacity of CACs in response to SDF1, partially through an upregulation of CXCR4. This is mediated through a pathway that involves binding of adipo to the AdipoR1 and subsequent PI3kinase/p38MAPK/ NFκb activation. In addition ET corrects the adiponectin responsiveness of CACs, and thereby might promote endogenous repair of damaged endothelium.

Clinical significance of nuclear kappa B and chemokine receptor CXCR4 expression in patients with diffuse large B-cell lymphoma.

e18533 Background: This study investigated the activation of nuclear factor kB (NFkB) and the chemokine receptor CXCR4 co-expression in patients with diffuse large B-cell lymphoma (DLBCL) who received rituximab-based therapy. Methods: Seventy patients with DLBCL and treated with rituximab-CHOP (RCHOP) were included. Tissue microarray blocks were created from 70 cases of DLBCL. Sections were stained with antibodies to IKKα, p-IkB, p50, p52, and CXCR4. To classify cases of DLBCL into GCB (germinal center B-cell-like) and non-GCB, additional immunohistochemical expression of CD10, bcl-6, or MUM1 has been used in this study. A numeric intensity score of 0-3 was assigned each case. Negative was scored if 0/+1 and positive was scored if 2+/3+. Results: The median age was 66.5 years (range, 17-87) and 58.6% were male. Twenty-seven patients (38.6%) had stage III and IV at diagnosis. Twenty-three patients (32.9%) were categorized as high or high-intermediate risk according to their IPI. The overall incidence of BM involvement was 5.7%. Positive expression for NFkB and CXCR4 were more than 80%. In NFkB and CXCR4 status, there are no significant difference between GCB and non-GCB. High NFkB expression is associated with CXCR4 expression and they are co-expressed in about two thirds of patients. With a median follow-up duration of 28.7 months (range, 0.1-76.1), the 5-year overall survival (OS) and event-free survival (EFS) rate was 67.4% and 79.8%, respectively. Neither NFkB nor CXCR4 were associated with DLBCL outcomes. Conclusions: In concolusion, none of the NFkB and CXCR4 expression profiles investigated in this study was found to be an independent prognostic marker for Korean patients with DLBCL. However, further studies on a larger scale are warranted to clarify the role of NFkB and CXCR4 as a prognostic marker.

Correlation between Chemokine Receptor CXCR4 Expression and Prognostic Factors in Patients with Prostate Cancer

PurposeWe evaluated the correlation between the expression of CXCR4 and prognostic factors in patients with prostate cancer.Materials and MethodsA total of 57 patients who had undergone surgery for prostate cancer were enrolled. Specimens were obtained before any treatment and were stained with antihuman CXCR4 antibody. The intensity of staining was graded as low or high. The age, pretreatment prostate-specific antigen (PSA) level, Gleason score, T stage, biochemical recurrence, local recurrence, and distant metastasis were compared according to the expression of CXCR4 in patients with prostate cancer.ResultsLocal recurrence was higher in the group with high expression, in 11 of 36 cases (30.6%), than in the group with low expression, in 1 of 21 cases (4.8%), with statistical significance (p=0.040). Distant metastasis was also associated with expression, occurring in 10 of 36 cases (27.8%) in the group with high expression and in 1 of 21 cases (4.8%) in the group with low expression (p=0.041). In the logistic regression test, CXCR4 expression was the only factor in determining local recurrence (p=0.016) and distant metastasis (0.022). Furthermore, the group with high CXCR4 expression showed significantly longer cancer-specific survival than did the low expression group (p=0.041). CXCR4 showed no association with age (p=0.881), pretreatment PSA level (p=0.584), Gleason score (p=0.640), T stage (p=0.967), or biochemical recurrence (p=0.081).ConclusionsThe high expression of CXCR4 was associated with local recurrence and distant metastasis. CXCR4 expression was shown to be a useful prognostic factor for patients with prostate cancer.

Prognostic significance of CXCR-4 expression in oral squamous cell carcinoma

We investigated the prognostic significance of CXC chemokine receptor CXCR-4 expression in patients with oral squamous cell carcinoma (OSCC) and its relationship with matrix metalloproteinase 2 (MMP-2), MMP-9, and Ki-67 expression. The CXCR-4, MMP-2, MMP-9, and Ki-67 expression was assessed immunohistochemically in 74 OSCC patients. The results were analyzed in connection with clinicopathologic factors. The CXCR-4 expression was positive in 45 cases and significantly correlated with lymph node metastasis (P = .037), MMP-9 expression (P = .025), and Ki-67 expression (P = .001). Univariate analysis showed that CXCR-4 expression, MMP-9 expression, Ki-67 expression, tumor size, lymph node metastasis, clinical stage, and recurrence positively correlated with prognosis. Multivariate analysis indicated that CXCR-4 expression was an independent prognostic factor for poor survival in patients with OSCC. Expression of CXCR-4 is a significant prognostic indicator for poor survival in patients with OSCC and correlates with expression of MMP-9 and Ki-67. The inhibition of CXCR-4 represents a possible molecular approach to the treatment of OSCC.

Chemokine receptor CXCR4 expression and prognosis in patients with metastatic prostate cancer

The chemokine receptor CXCR4 has been reported to be aberrantly expressed in human cancers and has also been shown to participate in the development of cancer metastasis. The present study was carried out to assess immunohistochemically the pattern of CXCR4 expression in patients with metastatic prostate cancer. We analyzed whether there may be an association between CXCR4 expression and prognosis. Fifty-two patients who received hormonal therapy were enrolled. Specimens were obtained from transperineal needle biopsy before treatment, and were stained with antihuman CXCR4 antibody. We also evaluated the pathological grade, extent of bony metastasis, clinical response to hormonal therapy, and patient prognosis. CXCR4 was detected in 94.2% patients. Its expression showed no association with pathological grade, extent of bony metastasis, or clinical response to hormonal therapy. Patients with a high expression of CXCR4 in tumors had poorer cancer-specific survival than those with low expression of CXCR4. CXCR4 expression is a useful prognostic factor for patients with metastatic prostate cancer treated with androgen-withdrawal therapy.

MP-17.04: Chemokine receptor CXCR4 expression and prognosis in patients with metastatic prostate cancer

Chemokine receptor CXCR4 has been reported to be aberrantly expressed in human cancers and also has been shown to participate in the development of cancer metastasis, including bone metastatic prostate cancer. This study was performed to assess, immunohistochemically, the pattern of CXCR4 expression in patients with metastatic prostate cancer.

Chemokine Receptor CXCR4 Expression in Patients With Melanoma and Colorectal Cancer Liver Metastases and the Association With Disease Outcome

To determine the role of chemokine receptor (CR) expression in patients with melanoma and colorectal cancer (CRC) liver metastases. Murine and in vitro models have identified CR as potential factors in organ-specific metastasis of multiple cancers. Chemokines via their respective receptors have been shown to promote cell migration to distant organs. Patients who underwent hepatic surgery for melanoma or CRC liver metastases were assessed. Screening cDNA microarrays of melanoma/CRC cell lines and tumor specimens were analyzed to identify CR. Microarray data were validated by quantitative real-time RT-PCR (qRT) in paraffin-embedded liver metastases. Migration assays and immunohistochemistry were performed to verify CR function and confirm CR expression, respectively. Microarray analysis identified CXCR4 as the most common CR expressed by both cancers. qRT demonstrated CXCR4 expression in 24 of 27 (89%) melanoma and 28 of 29 (97%) CRC liver metastases. In vitro treatment of melanoma or CRC cells with CXCL12, the ligand for CXCR4, significantly increased cell migration (P < 0.001). Low versus high CXCR4 expression in CRC liver metastases correlated with a significant difference in overall survival (median 27 months vs. 10 months, respectively; P = 0.036). In melanoma, low versus high CXCR4 expression in liver metastases demonstrated no difference in overall survival (median 11 months vs. 8 months, respectively; P = not significant). CXCR4 is expressed and functional on melanoma and CRC cells. The ligand for CXCR4 is highly expressed in liver and may specifically attract melanoma and CRC CXCR4 (+) cells. Quantitative analysis of CXCR4 gene expression in patients with liver metastases has prognostic significance for disease outcome.