High CXC Chemokine Receptor 4 Expression Research Articles

Expression and clinical value of CXCR4 in high grade gastroenteropancreatic neuroendocrine neoplasms.

CXC chemokine receptor 4 (CXCR4) is associated with the progression and metastasis of numerous malignant tumors. However, its relationship with Gastroenteropancreatic Neuroendocrine Neoplasms Grade 3 (GEP-NENs G3) is unclear. The aim of this study was to characterize the expression of CXCR4 in GEP-NENS and to explore the clinical and prognostic value of CXCR4. This study retrospectively collected clinical and pathological data from patients with GEP-NENs who receiving surgery in Qilu Hospital of Shandong University from January 2013 to April 2021, and obtained the overall survival of the patients based on follow-up. Immunohistochemistry (IHC) was performed on pathological paraffin sections to observe CXCR4 staining. Groups were made according to pathological findings. Kaplan-Meier (K-M) curve was used to evaluate prognosis. SPSS 26.0 was used for statistical analysis. 100 GEP-NENs G3 patients were enrolled in this study. There was a significant difference in primary sites (P=0.002), Ki-67 index (P<0.001), and Carcinoembryonic Antigen (CEA) elevation (P=0.008) between neuroendocrine tumor (NET) G3 and neuroendocrine carcinoma (NEC). CXCR4 was highly expressed only in tumors, low or no expressed in adjacent tissues (P<0.001). The expression level of CXCR4 in NEC was significantly higher than that in NET G3 (P=0.038). The K-M curves showed that there was no significant difference in overall survival between patients with high CXCR4 expression and patients with low CXCR4 expression, either in GEP-NEN G3 or NEC (P=0.920, P=0.842. respectively). Differential expression of CXCR4 was found between tumor and adjacent tissues and between NET G3 and NEC. Our results demonstrated that CXCR4 can be served as a new IHC diagnostic indicator in the diagnosis and differential diagnosis of GEP-NENs G3. Further studies with multi-center, large sample size and longer follow-up are needed to confirm the correlation between CXCR4 expression level and prognosis.

The Expression and Prognostic Significance of VEGF and CXCR4 in Gastric Cancer: Correlation with Angiogenesis, Lymphangiogenesis and Progression.

The cellular response to hypoxia includes the expression of hypoxia-inducible factor-1 (HIF-1) and its target genes: vascular endothelial growth factor (VEGF) and CXC chemokine receptor 4 (CXCR4). The aim of this study was to investigate the expression and prognostic significance of VEGF and CXCR4, which are responsible for angiogenesis and progression in gastric cancer. Twenty-eight gastric cancer patients were analyzed. The mRNA expression was examined in primary tumors and corresponding normal gastric mucosa by RT-PCR. The protein level was examined by immunohistochemistry staining. The high expression of VEGF and CXCR4 was found in 71.0 and 64.0% of tumors, respectively. The mean levels of VEGF and CXCR4 were upregulated in primary tumors compared to normal mucosa (p = 0.0007, p = 0.0052). A correlation between VEGF expression and tumor invasion (p = 0.0216) and stage (p = 0.0181) was found. CXCR4 expression correlated with lymph node metastases (p = 0.0237) and stage (p = 0.0054). The VEGF expression correlated with microvessel density (MVD) (p = 0.0491). The overall 3-year survival rate was 46.4% and correlated negatively with high CXCR4 mRNA expression (p = 0.0089). VEGF and CXCR4 play an important role in tumor progression. Their overexpression correlates with a bad prognosis and may improve high-risk patient selection, and these patients may obtain additional survival benefits if treated more aggressively.

CXCR4 overexpression: An indicator of poor survival and predictor of response to immunotherapy in patients with metastatic colorectal cancer.

3546 Background: CXC-chemokine receptor 4 (CXCR4) is a ubiquitous chemokine receptor activated by the CXCL12 ligand and is implicated in tumor invasion, metastasis, and immune cell (IC) trafficking. High CXCR4 expression is associated with poor prognosis in colorectal cancer (CRC). &lt; 10% of metastatic CRC cases harbor microsatellite instability (MSI-H) and demonstrate lower tumor mutation burden (TMB), decreased IC infiltration, and lack of response to current immunotherapy regimens. This study aims to interrogate the role of CXCR4 mRNA expression on the the tumor microenvironment (TME) and its prognostic and predictive value to tailor immunotherapeutic treatment strategies in CRC. Methods: A total of 15,026 CRC samples were analyzed using whole-exome sequencing, whole-transcriptome sequencing, and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Study cohort was stratified by CXCR4 mRNA expression levels in quartiles (Q1 (low) vs Q4 (high)). IC fraction was calculated by QuantiSeq, and real-world overall survival information was obtained from insurance claims data and calculated from tissue collection time to last day of contact. Statistical significance was determined using chi-square/Fisher-Exact and adjusted for multiple comparisons (q &lt; 0.05). Results: Samples obtained from metastatic sites showed higher CXCR4 mRNA expression than those from primary tumors (22.7 vs 18.6 median transcripts per million (TPM), p &lt; 0.001). CXCR4 mRNA expression was significantly lower in liver metastases than in non-liver metastases (21.2 vs 24.8 TPM, p &lt; 0.001). Median CXCR4 mRNA expression was highest in the consensus molecular subtypes 4 (33.3 TPM) and lowest in 3 (13.0 TPM, p &lt; 0.05). CXCR4 mRNA expression was positively associated with TMB-H, MSI-H/dMMR, and positive PD-L1 IHC status. In the TME, high CXCR4 mRNA expression was observed in tumors with a higher IC infiltration including B cells, M1/M2 macrophages, NK cells, CD8+ T cells and T-regs, regardless of MSI status. High CXCR4 mRNA expression in the primary tumor was associated with poor prognosis (HR 0.77, 95% CI 0.70-0.85; p &lt; 0.001), regardless of MSI-status. In metastatic tumors, low mRNA expression was correlated with improved survival (HR 0.89, 95% CI 0.80-0.99; p = 0.34); however, this did not reach statistical significance in the MSS cohort (HR 0.90, 95% CI 0.80-1.0; p = 0.06). Of note, high CXCR4 mRNA expression was associated with improved survival in all patients with CRC who received pembrolizumab (HR 2.12, 95% CI 1.16-3.91; p = 0.013). Conclusions: This is the largest clinical dataset to date demonstrating high CXCR4 expression as a predictor for poor survival in CRC. Furthermore, high CXCR4 expression was associated with improved outcome after checkpoint inhibition immunotherapy, indicating its strong potential as a predictive biomarker that could inform immunotherapeutic strategies in CRC.

Investigating CXCR4 expression of tumor cells and the vascular compartment: A multimodal approach.

The C-X-C chemokine receptor 4 (CXCR4) is G protein-coupled receptor that upon binding to its cognate ligand, can lead to tumor progression. Several CXCR4-targeted therapies are currently under investigation, and with it comes the need for imaging agents capable of accurate depiction of CXCR4 for therapeutic stratification and monitoring. PET agents enjoy the most success, but more cost-effective and radiation-free approaches such as ultrasound (US) imaging could represent an attractive alternative. In this work, we developed a targeted microbubble (MB) for imaging of vascular CXCR4 expression in cancer. A CXCR4-targeted MB was developed through incorporation of the T140 peptide into the MB shell. Binding properties of the T140-MB and control, non-targeted MB (NT-MB) were evaluated in MDA-MB-231 cells where CXCR4 expression was knocked-down (via shRNA) through optical imaging, and in the lymphoma tumor models U2932 and SuDHL8 (high and low CXCR4 expression, respectively) by US imaging. PET imaging of [18F]MCFB, a tumor-penetrating CXCR4-targeted small molecule, was used to provide whole-tumor CXCR4 readouts. CXCR4 expression and microvessel density were performed by immunohistochemistry analysis and western blot. T140-MB were formed with similar properties to NT-MB and accumulated sensitively and specifically in cells according to their CXCR4 expression. In NOD SCID mice, T140-MB persisted longer in tumors than NT-MB, indicative of target interaction, but showed no difference between U2932 and SuDHL8. In contrast, PET imaging with [18F]MCFB showed a marked difference in tumor uptake at 40–60 min post-injection between the two tumor models (p<0.05). Ex vivo analysis revealed that the large differences in CXCR4 expression between the two models are not reflected in the vascular compartment, where the MB are restricted; in fact, microvessel density and CXCR4 expression in the vasculature was comparable between U2932 and SuDHL8 tumors. In conclusion, we successfully developed a T140-MB that can be used for imaging CXCR4 expression in the tumor vasculature.

High CXCR4 expression in pancreatic ductal adenocarcinoma as characterized by an inflammatory tumor phenotype with potential implications for an immunotherapeutic approach.

4021 Background: Immunotherapy is considered ineffective in the majority of patients with pancreatic ductal adenocarcinoma (PDAC), a consequence of a highly immunosuppressive tumor microenvironment (TME). However, treatment induced inhibition of CXC chemokine receptor 4 (CXCR4) and programmed cell death protein-1 (PD-1) in the COMBAT trial caused T cell infiltration and tumor regression in a subset of PDAC patients. Elucidating a phenotype that predicts response is clinically relevant. We performed a comprehensive molecular landscape study in PDAC evaluating CXCR4 RNA expression. Methods: 3,647 PDAC specimens were centrally analysed. NextGen DNA sequencing (NextSeq, 592 gene panel or NovaSeq, whole-exome sequencing), whole-transcriptome RNA sequencing (NovaSeq) and immunohistochemistry (Caris Life Sciences, Phoenix, AZ) were performed. Gene expression is reported as TPM (Transcripts per million). Pathway gene enrichment analyses were done using GSEA (Subramaniam 2015, PNAS). Immune cell fraction was calculated by QuantiSeq (Finotello 2019, Genome Medicine). The cohort was stratified in quartiles according to CXCR4 RNA expression status. Results: Overall, CXCR4 expression was higher in primary tumors compared to distant metastasis (38 vs. 28 TPM, p &lt; 0.0001). CXCR4-high (top quartile: &gt; 59 TPMs), when compared to CXCR4-low (bottom quartile: &lt; 17 TPM) PDACs, were characterized by a high prevalence of mutations in signal transduction pathway genes (e.g. GNAS: 3.6 vs. 0.5%), an increased infiltration of immune cells (e.g. CD8+ T cells, M1 macrophages), and a higher expression of HLA-DRA and HLA-E (all p &lt; 0.0001). We detected an upregulation of CXCL9, CXCL10, CXCL12, CCL5, IDO1 and LAG3 in CXCR4-high compared to CXCR4-low tumors. In contrast, lower PD-L1 expression (17.4 vs. 13.1%, p = 0.02), genomic loss of heterozygosity (17.4 vs. 10.8%), and a lower frequency of gene amplifications in ERBB2 (2.1 vs. 0.1%), TNFRSF14 (2.0 vs. 0.1%), and TP53 (82 vs. 73%, all p &lt; 0.0001) were observed. Moreover, CXCR4-high expression was associated with a better survival (HR: 1.417, 95% CI [1.168-1.72], p &lt; 0.001). Conclusions: This is the first study comprehensively investigating the molecular landscape of PDACs according to CXCR4 RNA expression. High CXCR4 expression is associated with an improved survival and a pro-inflammatory phenotype that may identify a subset of tumors with greater responsiveness to immunotherapeutic approaches.

Prognostic and Predictive Role of CXC Chemokine Receptor 4 in Metastatic Colorectal Cancer Patients.

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. About 30% of patients present with metastatic disease involving predominantly the liver and a similar percentage will develop distant metastases later after removal of the primary tumor. In metastatic CRC, chemotherapies and biological drugs have prolonged survival for up to 30 months. However, there is a great need for biomarkers predictive of response and prognosis to optimize treatments. CXC chemokine receptor 4 (CXCR4) is a chemokine receptor; it binds to CXCL12 and plays a central role in colon cancer cells' growth and dissemination. CXCR4 was evaluated in CRC primary tissues by immunohistochemistry. Formalin-fixed, paraffin-embedded 4-μm tissue sections were immunostained using a biotin-streptavidin-peroxidase method and categorized into 2 semiquantitative classes: (i) absence of staining, ≤50% positive cells (negative/low) and (ii) >50% positive cells (high). Associations between clinic-pathologic variables and CXCR4 expression were evaluated using the χ test. The Kaplan-Meier product-limit method was applied to graph overall survival (OS). OS was defined as the time elapsed from diagnosis to death from any cause. Univariate analysis was carried out using the log-rank test. Cox proportional hazards regression was used to analyze the effect of several risk factors on OS. Seventy-eight primary adenocarcinomas were analyzed; 26 were categorized as negative/low and 52 as high. Age, sex, performance status, site of metastases, KRAS mutational status, type of first-line therapy, and a number of therapy lines did not correlate with CXCR4 expression. Although not significant (P=0.0533), high CXCR4 expression was more frequently localized on the right side of the colon. Significant correlations were detected with grading (P=0.0041) and response to first-line anti-epidermal growth factor receptors agents (P<0.0001), bevacizumab (P=0.0029), and chemotherapy alone (P=0.0260). At a median follow-up of 53 months, 77 deaths have been registered. Grading [hazard ratio (HR): 1.42; confidence interval (CI): 0.89-2.28; P<0.0001], KRAS mutational status (HR: 1.73; CI: 1.03-290; P=0.0133), response to first-line chemotherapy (HR: 3.39; CI: 2.10-5.48; P<0.0001), and CXCR4 expression (HR: 3.18; CI: 2.01-5.02; P<0.0001) showed prognostic power at univariate and multivariate analyses. In the present report, we show that CXCR4 expression on the primary tumor is an independent prognostic factor and correlates with response to first-line chemotherapy in metastatic CRC patients.

Suppression of the SDF‑1/CXCR4/β‑catenin axis contributes to bladder cancer cell growth inhibition invitro and invivo.

Previous studies have found that the activation of stromal cell‑derived factor‑1 (SDF‑1)/CXC chemokine receptor‑4 (CXCR4)/β‑catenin signaling is associated with biological malignant potential in cancers. However, its function has been rarely reported in the progression of bladder cancer (BCa). The aim of the present study was to investigate the association of SDF‑1/CXCR4 signaling and β‑catenin in regards to BCa cell proliferation, colony formation, migration and invasion. The methods used were MTS, colony formation, and Transwell migration and invasion assays which were performed in SW780 cells following treatment with the CXCR4 antagonist AMD3465, SDF‑1, the β‑catenin antagonist FH535, AMD3465+SDF‑1 or FH535+SDF‑1. The mRNA and protein levels were assayed by RT‑qPCR and western blotting, respectively. The effect of AMD3465 on SW780 cell xenograft growth invivo was evaluated using a nude mouse model. According to our results, human BCa SW780 cells were identified as having high expression of CXCR4 and β‑catenin. Subsequently, we found that both CXCR4 and β‑catenin antagonists could significantly inhibit the proliferation, colony formation, migration and invasion of SW780 cells. Notably, SDF‑1 could reverse the inhibitory effects of AMD3465 and FH535 on proliferation, colony formation, migration and invasion in SW780 cells. In AMD3465‑treated SW780 cells, the expression of c‑myc was significantly upregulated, and E‑cadherin was downregulated in the presence of SDF‑1. Furthermore, the tumor volume and average weight in the AMD3465‑treated group were evidently less than these parameters in the control group, indicating that AMD3465 can inhibit SW780 cell growth invivo. In conclusion, targeting the SDF‑1/CXCR4/β‑catenin axis may be a potential therapeutic target for suppressing BCa progression.

The CXCL12-CXCR4 axis promotes migration, invasiveness, and EMT in human papillary thyroid carcinoma B-CPAP cells via NF-κB signaling.

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-κB) signaling pathway, whereas BAY11-7082, an IκB 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-κB signaling pathway.

Gemcitabine induces epithelial-mesenchymal transition and promotes metastasis in cholangiocarcinoma through CXC chemokine ligand 12/CXC chemokine receptor 4 axis

Objective To explore the effect of gemcitabine (GEM) in cholangicocarcinoma cells on metastatic potential and epithelial-mesenchymal transition (EMT) through CXC chemokine ligand 12 (CXCL12)/CXC chemokine receptor 4 (CXCR4) axis. Methods The in vitro model was established using stromal cell derived factor 1 (SDF-1, 100 mg/ml) to activate the expression of CXCL12/CXCR4 biological axis in cholangicocarcinoma cells with a high CXCR4 expression. The proliferation rate was measured by methyl thiazol tetrazolium (MTT) method. Cholangicocarcinoma RBE cells were divided into control group and GEM group. Transwell chamber was used to observe the invasion and metastasis of the cells. Real-time quantitative polymerase chain reaction (Real-time PCR) was applied to detect the CXCR4, and Western blotting was used to detect the expression of CXCR4 and its downstream invasion and EMT related factors vascular endothelial growth factor C (VEGF-C), matrix metalloproteinase (MMP)-9, N-cadherin and E-cadherin. Results The cell survival rate in GEM group was significantly decreased (76.65%, 71.40%, and 52.25%; P<0.05). GEM promoted metastasis potential ability of cells (282.00±3.45 vs. 168.00±2.49), and promoted the overexpression of CXCR4 protein (0.965±0.163, 1.895±0.191, 3.975±0.120, 3.355±0.163, 3.572±0.198 and 6.154±0.113) in and mRNA (1.021±0.210, 2.442±0.556, 2.774±0.146, 2.961±0.275, 3.279±0.228 and 5.010±0.826), and also promoted the ability of metastasis [VEGF-C (3.250±0.212 vs. 1.025±0.318), MMP-9 (1.980±0.212 vs. 1.025±0.318)] and EMT [N-cadherin (2.162±0.254 vs. 1.025±0.318), E-cadherin (0.430±0.154 vs. 1.025±0.318), P<0.05]. Conclusion GEM may induce metastasis and EMT in cholangiocarcinoma through CXCL12/CXCR4 axis. Key words: Gemcitabine; Cholangiocarcinoma; CXC chemokine receptor 4; CXC chemokine ligand 12; Epithelial-mesenchymal transtion; Metastasis

A fully human CXCR4 antibody demonstrates diagnostic utility and therapeutic efficacy in solid tumor xenografts.

For physiologically important cancer therapeutic targets, use of non-invasive imaging for therapeutic guidance and monitoring may improve outcomes for treated patients. The CXC chemokine receptor 4 (CXCR4) is overexpressed in many cancers including non-small cell lung cancer (NSCLC) and triple negative breast cancer (TNBC). CXCR4 overexpression contributes to tumor growth, progression and metastasis. There are several CXCR4-targeted therapeutic agents currently in clinical trials. Since CXCR4 is also crucial for normal biological functions, its prolonged inhibition could lead to unwanted toxicities. While CXCR4-targeted imaging agents and inhibitors have been reported and evaluated independently, there are currently no studies demonstrating CXCR4-targeted imaging for therapeutic guidance.Monoclonal antibodies (mAbs) are commonly used for cancer therapy and imaging. Here, an 89Zr-labeled human CXCR4-mAb (89Zr-CXCR4-mAb) was evaluated for detection of CXCR4 expression with positron emission tomography (PET) while its native unmodified analogue was evaluated for therapy in relevant models of NSCLC and TNBC. In vitro and in vivo evaluation of 89Zr-CXCR4-mAb showed enhanced uptake in NSCLC xenografts with a high expression of CXCR4. It also had the ability to detect lymph node metastases in an experimental model of metastatic TNBC. Treatment of high and low CXCR4 expressing NSCLC and TNBC xenografts with CXCR4-mAb demonstrated a therapeutic response correlating with the expression of CXCR4. Considering the key role of CXCR4 in normal biological functions, our results suggest that combination of 89Zr-CXCR4-mAb-PET with non-radiolabeled mAb therapy may provide a precision medicine approach for selecting patients with tumors that are likely to be responsive to this treatment.

Expression of chemokine receptor CXCR4 is closely correlated with clinical outcome in human nasopharyngeal carcinoma.

The CXC chemokine receptor 4 (CXCR4) has been reported to be involved in the development and progression of nasopharyngeal carcinoma (NPC). However, the role of CXCR4 in clinical outcome and prognosis of NPC patients remains controversial. In the present study, we investigated and reviewed the expression of CXCR4 in NPC tissues and then analyzed the definitive role of CXCR4 in clinical outcome and prognosis. Here, we found that the expression level of CXCR4 was significantly higher in NPC cancer specimens (61/98) than that in paired non-tumor tissues (p < 0.001). Together with our pathological analysis, statistic analysis revealed that CXCR4 expression was indeed closely correlated with UICC stage (p = 0.000), N stage (p = 0.019), and metastasis (p = 0.000). Most importantly, the systematic review combined with our survival and multivariate analysis that revealed high expression of CXCR4 was obviously associated with poor overall survival (OS) (p = 0.000) and progression-free survival (PFS) (p = 0.000) and can act as an independent prognostic factor in NPC patients. In conclusion, this study suggests that CXCR4 is highly activated and expressed in the development of NPC and may be recommended as an indicator in the diagnosis of NPC. Thus, targeting of CXCR4 gene or protein could be used as a potential therapy for NPC.

VLA-4 and CXCR4 expression levels show contrasting prognostic impact (favorable and unfavorable, respectively) in acute myeloid leukemia

Very late antigen-4 (VLA-4) and CXC chemokine receptor 4 (CXCR4) perform critical roles in the adhesion of hematopoietic and leukemic stem cells to marrow stromal cells. This mechanism is associated with chemoresistance in patients with acute myeloid leukemia (AML). Here, we measured VLA-4 and CXCR4 expressions in leukemic myeloblasts to determine their prognostic implications. Using multicolor flow cytometry, positive VLA-4 and CXCR4 expressions were measured in leukemic myeloblasts in bone marrow aspirates that were obtained from newly diagnosed adult AML patients (n = 98). VLA-4 expression was higher in patients at favorable or intermediate cytogenetic risk than in patients at poor risk (p < 0.001 and p = 0.002, respectively), but CXCR4 expression was not significantly different. Among the 72 non-promyelocytic leukemia patients analyzed who received cytarabine + anthracycline-based induction chemotherapy, high VLA-4 expression was independently associated with a high probability of complete remission (p = 0.019) and superior relapse-free survival (RFS) (p < 0.001). However, high CXCR4 expression independently increased the probability of relapse (p = 0.002) and was associated with a shorter RFS (p = 0.006). When categorizing patients into three groups according to VLA-4 and CXCR4 expression levels, the group of high VLA-4 and low CXCR4 showed longer RFS (p = 0.001) and overall survival (OS) (p = 0.011) than the group of low VLA-4 or high CXCR4.

Close correlation between CXCR4 and VEGF expression and frequent CXCR7 expression in rhabdomyosarcoma.

CXC chemokine receptor 4 (CXCR4) expression is reportedly correlated with both vascular endothelial growth factor (VEGF) expression and poor prognosis in a variety of cancers. Its relation to CXC chemokine receptor 7 (CXCR7) is also noted in several malignancies, including rhabdomyosarcoma (RMS) cell lines. However, the correlations between these chemokine receptors and angiogenic factors have not yet been adequately investigated in RMS clinical specimens. By immunohistochemistry, we assessed CXCR4, CXCR7, CC chemokine receptor 6, CC chemokine receptor 7, VEGF expression, microvessel density, and MIB-1 labeling index in 82 formalin-fixed RMS specimens, including 34 primary alveolar RMS and 44 primary embryonal RMS (ERMS). Twenty-six frozen samples were available for investigation by quantitative reverse transcription polymerase chain reaction to detect the messenger RNA expression levels of these molecules. We also evaluated their significance with respect to clinicopathological factors and patient survival rates. Primary RMS showed high expression of CXCR7 (83.1%) regardless of the histologic subtype. High cytoplasmic CXCR4 and high VEGF expression revealed significant correlations in both ERMS and alveolar RMS (P = .0051 and P = .0003, respectively). By univariate analysis of ERMS cases, the tumors with high VEGF expression showed significantly poor prognoses (P = .0017). High VEGF expression also was the independent adverse prognostic factor for ERMS. Because CXCR4, CXCR7, and VEGF are widely expressed in RMS, the combination of these antagonists may provide a potential target for molecular therapy.

Expression of CXC chemokine receptor-4 and forkhead box 3 in neuroblastoma cells and response to chemotherapy.

Current evidence indicates that the abnormal expression of chemokines or their receptors, such as CXC chemokine receptor-4 (CXCR4), is positively correlated with the development, progression and metastasis of tumor cells. However, the role of CXCR4 in neuroblastoma and its response to chemotherapy remain largely unclear. In addition, forkhead box 3 (Foxp3), a transcription factor associated with T cell tolerance, is expressed in tumor cells and plays a role in the immune evasion of cancers. The present study aimed to examine the expression of CXCR4 and Foxp3 in the LAN-5 and SK-N-SH neuroblastoma cell lines. The effects of chemotherapy drugs, cyclophosphamide (CTX) and pirarubicin (THP), on the expression of these two genes were also investigated. Our findings indicated that CXCR4 and Foxp3 were highly expressed in LAN-5 and SK-N-SH cells. Following treatment with CTX and THP, the protein expression of CXCR4 in LAN-5 and SK-N-SH cells was significantly decreased (P<0.05). The expression of Foxp3 in LAN-5 cells was also significantly downregulated by CTX and THP treatment (P<0.05). Therefore, the high expression of CXCR4 and Foxp3 in LAN-5 and SK-N-SH cells and their subsequent downregulation following administration of the chemotherapy agents suggests that the chemokine receptors, CXCR4 and Foxp3, may be involved in the metastasis and tumor evasion of neuroblastoma. Further studies should investigate the expression of CXCR4 and Foxp3 in patient samples.

High CXC chemokine receptor 4 expression is an adverse prognostic factor in patients with clear-cell renal cell carcinoma

Background:Aberrant CXC chemokine receptor 4 (CXCR4) expressions in malignant tissues have been reported; however, its role in kidney cancer prognosis remains unknown. The aim of this study was to determine the prognostic value of CXCR4 expression in patients with clear-cell renal cell carcinoma (ccRCC).Methods:The study included 225 patients with ccRCC. The cohort was split into a training set (n=125) and a validation set (n=100). CXC chemokine receptor 4 expression was analysed by immunohistochemical staining and its correlations with clinicopathologic features and prognosis were evaluated.Results:CXCR4-staining intensity increased gradually accompanied with disease progression from TNM stages I to IV in 225 patients with ccRCC. Moreover, high CXCR4 expression indicated reduced overall survival (OS) in the training (P<0.001) and validation (P<0.001) sets, especially for patients with early-stage (TNM stage I+II) diseases. Furthermore, CXCR4 expression was identified as an independent prognostic factor for OS, and combining TNM stage with CXCR4 expression showed a better prognostic value for OS in both sets.Conclusions:High CXCR4 expression, an independent adverse prognostic factor, could be combined with TNM stage to generate a predictive nomogram for clinical outcome in patients with ccRCC.

The Prognostic Value of CXCR4 in Ovarian Cancer: A Meta-Analysis

ObjectiveRecent reports have shown that C-X-C chemokine receptor 4 (CXCR4) is expressed in ovarian cancer and plays an important role in metastasis. However, the prognostic value of CXCR4 in ovarian cancer remains controversial and has not been emphasized. The aim of this study is to evaluate the prognostic significance of CXCR4 in ovarian cancer by performing a meta-analysis.MethodsWe systematically searched for studies evaluating the relationship between CXCR4 expression and the outcome of ovarian cancer patients. Only articles in which CXCR4 expression was detected by immunohistochemical staining were included. Hazard ratios (HRs) and relative risk (RR) with 95% confidence intervals (CIs) were pooled as effect size (ES) across studies for overall survival (OS) and progression-free survival (PFS).ResultsA total of 729 patients from 7 studies (6 articles) were included in this meta-analysis. Our results showed that high CXCR4 expression was significantly associated with poor prognosis in terms of OS (ES, 2.81; 95% CI, 1.16–6.80; p = 0.022) and PFS (ES, 8.48; 95% CI, 2.13–33.70; p = 0.002) in ovarian cancer patients. The association between high CXCR4 expression and poor ovarian cancer prognosis in OS was also statistically significant in subgroups of Asian and III-IV patients constituting 70%.ConclusionsThe present meta-analysis indicated that high CXCR4 expression was associated with poor prognosis in ovarian cancer. More studies, especially larger scale and well-matched researches, are warranted to clarify the prognostic effect of CXCR4 on the outcome of ovarian cancer.

Clinical Significance of CXC Chemokine Receptor-4 and c-Met in Childhood Rhabdomyosarcoma

The CXC chemokine receptor-4 (CXCR4)/stromal-derived factor-1 and c-Met/hepatocyte growth factor axes promote the metastatic potential of rhabdomyosarcoma cell lines in experimental models, but no data are available on their role in rhabdomyosarcoma tumors. The expressions of CXCR4 and c-Met were evaluated in primary tumors and isolated tumor cells in marrow, and were correlated with clinicopathologic variables and survival. Forty patients with recently diagnosed rhabdomyosarcoma were retrospectively enrolled. CXCR4 and c-Met expression was investigated in primary tumors by immunohistochemistry, in isolated marrow-infiltrating tumor cells using double-label immunocytology. Results were expressed as the mean percentage of immunostained tumor cells. CXCR4 and c-Met were expressed in >/=5% of tumor cells from 40 of 40 tumors, with 14 of 40 cases showing >/=50% of immunostained tumor cells (high expression). High CXCR4 expression correlated with alveolar histology (P = 0.006), unfavorable primary site (P = 0.009), advanced group (P < 0.001), marrow involvement (P = 0.007), and shorter overall survival and event-free survival (P < 0.001); high c-Met expression correlated with alveolar histology (P = 0.005), advanced group (P = 0.04), and marrow involvement (P = 0.02). In patients with a positive diagnosis for isolated tumor cells in marrow (n = 16), a significant enrichment in the percentage of CXCR4-positive (P = 0.001) and c-Met-positive (P = 0.003) tumor cells was shown in marrow aspirates compared with the corresponding primary tumors. CXCR4 and c-Met are widely expressed in both rhabdomyosarcoma subtypes and, at higher levels, in isolated marrow-infiltrating tumor cells. High levels of expression are associated with unfavorable clinical features, tumor marrow involvement and, only for CXCR4, poor outcome. In rhabdomyosarcoma, CXCR4 and c-Met represent novel exploitable targets for disease-directed therapy.

Clinical significance of CXC chemokine receptor-4 (CXCR4) and c-Met in childhood rhabdomyosarcoma (RMS) tumors

9510 Background: Both CXCR4/SDF-1 and c-Met/HGF axes promote invasive growth of RMS cells in experimental models, but no data are available on their expression and significance in RMS tumors. Expression for CXCR4 and c-Met (and their ligands) was evaluated in primary RMS tumors and correlated with clinical features, marrow involvement at diagnosis, overall (OS) and progression-free survival (PFS). Methods: Forty newly diagnosed pts, aged 2–180 months (median 58), with embryonal (n. 20) or alveolar (n. 20) RMS admitted between 1994 and 2004 were retrospectively enrolled. The only selection criterion was availability of data on marrow involvement at diagnosis as assessed by cytomorphology and immunocytochemistry for MyoD1 and myogenin. Primary site was favorable (orbit, paratesticular, uterus/vagina) in 7 pts and unfavorable (all the others) in 33. Pts were entered as group I/II (n. 5), III (n. 28) or IV (n. 7) (IRS grouping system). Marrow was infiltrated at diagnosis in 16 pts. Treatment was according to Italian RMS protocols. Expression for CXCR4, SDF-1, c-Met and HGF proteins was investigated by immunohistochemistry. Three separate counts (each &gt;5,000 tumor cells) were performed without knowledge of clinical features and outcome; results expressed as mean percentage of immunostained tumor cells. Student t test, log-rank test, Kaplan-Meier survival analysis were applied. Institutional informed consent and ethical approval were obtained. Results: As of December 2006, median follow-up was 60 months, with 25 pts DF, 1 AWD and 14 DOD. CXCR4 and c-Met were expressed in =5% of tumor cells in all cases, but 14/40 tumors showed =50% tumor cell positivity (high expression) for either markers. High CXCR4 expression correlated with alveolar histology (p=0.006), unfavorable primary site (p=0.009), advanced group (p&lt;0.001), marrow involvement (p=0.007), shorter OS and PFS (p&lt;0.001). High c- Met expression with alveolar histology (p=0.005), advanced group (p=0.04), marrow involvement (p=0.02). SDF-1 and HGF were expressed by a lower percentage of tumor cells (1–95% of cells positive for the correspondent receptor). Conclusions: CXCR4/SDF-1 and c-Met/HGF pathways are clinically relevant in children with RMS and represent novel targets for disease-directed therapy. No significant financial relationships to disclose.

Overexpression of Both CXC Chemokine Receptor 4 and Vascular Endothelial Growth Factor Proteins Predicts Early Distant Relapse in Stage II-III Colorectal Cancer Patients

CXC chemokine receptor 4 (CXCR4) and vascular endothelial growth factor (VEGF) are implicated in the metastatic process of malignant tumors. However, no data are currently available on the biological relationship between these molecules in colorectal cancer. We studied whether CXCR4 and VEGF expression could predict relapse and evaluated in vitro the contribution of CXCR4 in promoting clonogenic growth, VEGF secretion, and intercellular adhesion molecule-1 (ICAM-1) expression of colorectal cancer cells. CXCR4 and VEGF were studied in colorectal cancer tissues and in Lovo, HT29, and SW620 colorectal cancer cell lines by immunohistochemistry. Correlations with baseline characteristics of patients and tumors were analyzed by chi2 test. VEGF secretion induced by CXCL12 was measured by ELISA. The effect of CXCL12 on ICAM-1 expression was evaluated by flow cytometry. Clonogenic growth induced by CXCL12 was determined by clonogenic assays. Functional effects induced by CXCL12 were prevented by the administration in vitro of AMD3100, a bicyclam noncompetitive antagonist of CXCR4. Seventy-two patients, seen between January 2003 and January 2004, were studied. CXCR4 was absent in 16 tumors (22.2%); it was expressed in < or = 50% of cells in 25 (34.7%) tumors and in >50% of cells in 31 (43.0%) tumors. VEGF was absent in 17 (23.6%) tumors; it was expressed in < or = 50% of cells in 16 (22.2%) tumors and in >50% of cells in 39 (54.2%) tumors. There was a significant association between CXCR4 expression and lymph nodal status (P = 0.0393). There were significant associations between VEGF and tumor invasion (P = 0.0386) and lymph nodal involvement (P = 0.0044). American Joint Committee on Cancer stage (P = 0.0016), VEGF expression (P = 0.0450), CXCR4 expression (P = 0.0428), and VEGF/CXCR4 expression (P = 0.0004) had a significant prognostic value for disease-free survival with univariate analysis. The predictive ability of the American Joint Committee on Cancer stage and of the concomitant and high expression of VEGF and CXCR4 was confirmed by multivariate analysis. Prognosis is particularly unfavorable for patients whose primary tumors express CXCR4 and VEGF in >50% of cells (median disease-free survival in relapsed patients, 5.8 months; hazard ratio of relapse, 8.23; 95% confidence interval, 7.24-14.29). In clonogenic assays, CXCL12 (20 ng/mL/d) significantly increased the number of clones in SW620, HT29, and Lovo cells at 7 and 14 days. Again, CXCL12 was able to stimulate VEGF secretion in SW620, HT29, and Lovo cells as well as up-regulated ICAM-1. These effects were prevented by the administration of AMD3100 (1 micromol/L). We have shown that concomitant and high expression of CXCR4 and VEGF is a strong and independent predictor of early distant relapse in colorectal cancer. CXCR4 triggers a plethora of phenomena, including stimulation of clonogenic growth, induction of VEGF release, and ICAM-1 up-regulation. These data support the inhibition of CXCR4 to prevent the development of colorectal cancer metastasis.

Relation between CXCR-4 expression, Flt3 mutations, and unfavorable prognosis of adult acute myeloid leukemia

AbstractRecently it was shown that, analogous to normal hematopoietic cells, the level of CXC chemokine receptor 4 (CXCR-4) expression on acute myeloid leukemia (AML) cells correlates with stromal cell derived factor-1 alpha (SDF-1)-induced chemotaxis. As we speculated that an anomalous organ distribution of AML cells could affect cell survival and thus result in an altered fraction surviving chemotherapy, we examined a possible correlation between patient prognosis and CXCR-4 expression in AML patients. We found that patients with a high CXCR-4 expression in the CD34+ subset had a significantly reduced survival and a higher probability of relapse, resulting in a median relapse-free survival (RFS) of only 8.3 months. CXCR-4 expression was significantly higher in fetal liver tyrosine kinase-3 (Flt3)/internal tandem duplication (ITD) AML than in Flt3/wild-type (wt) AML. Covariate analysis indicated that the prognostic significance of Flt3/ITDs with respect to RFS was no more apparent when analyzed in conjunction with the expression of CXCR-4 in the CD34+ subset, suggesting that the poor prognosis of Flt3/ITD AML might be subordinate to the increased CXCR-4 expression. Using a granulocyte colony-stimulating factor receptor (G-CSF-R)-expressing 32D cell line, we observed that SDF-1/CXCR-4 interaction is required for the survival of myeloid differentiating cells, and it also induces a block in G-CSF-induced myeloid differentiation. These data suggest that the SDF-1/CXCR-4 axis may influence therapy responsiveness and defines unfavorable prognosis in AML. (Blood. 2004;104:550-557)