CXC motif chemokine receptor 4 gene polymorphism and cancer risk

Effect of SDF-1 and CXCR4 gene variants on the development of diabetic kidney disease

Diabetic kidney disease (DKD) is the gradual loss of renal function occurring in patients with diabetes. Stromal cell-derived factor-1 (SDF-1, encoded by SDF-1 gene) is a chemokine that binds to its receptor, CXCR4, to mediate many aspects of renal biology. To test the potential impact of SDF-1/CXCR4 gene variations on the risk for DKD, single-nucleotide polymorphisms (SNPs) of SDF-1/CXCR4 genes were genotyped in 388 DKD patients and 335 DKD-free diabetic controls. Among 6 SNPs examined, we demonstrated that rs1801157 of SDF-1 gene was associated with an increased risk for DKD (GA vs GG, AOR=2.252, p=0.035; GA+AA vs GG, AOR=2.156, p=0.036). Further stratification revealed that the correlation of rs1801157 with DKD was particularly detected in diabetic patients with early CKD but not in those with severe renal impairment. Instead, another SNP of SDF-1 gene, rs266085, was found in association with the advanced form of DKD (TC vs TT, AOR=2.106, p=0.027; TC+CC vs TT, AOR=2.130, p=0.019), indicating differential impacts of SDF-1 gene polymorphisms on the progressive loss of renal function in diabetic patients. Moreover, preliminary survey of public gene expression datasets showed that rs1801157 and rs266085 modulated SDF-1 expression in many human tissues, and SDF-1/CXCR4 levels were elevated in renal tissues of DKD patients. These data suggest that allele-specific expression of SDF-1 gene may influence DKD progression.

The potential crosstalk genes and molecular mechanisms between glioblastoma and periodontitis

Despite clinical and epidemiological evidence suggestive of a link between glioblastoma (GBM) and periodontitis (PD), the shared mechanisms of gene regulation remain elusive. In this study, we identify differentially expressed genes (DEGs) that overlap between the GEO datasets GSE4290 [GBM] and GSE10334 [PD]. Functional enrichment analysis was conducted, and key modules were identified using protein-protein interaction (PPI) network and weighted gene co-expression network analysis (WGCNA). The expression levels of CXCR4, LY96, and C3 were found to be significantly elevated in both the test dataset and external validation dataset, making them key crosstalk genes. Additionally, immune cell landscape analysis revealed elevated expression levels of multiple immune cells in GBM and PD compared to controls, with the key crosstalk genes negatively associated with Macrophages M2. FLI1 was identified as a potential key transcription factor (TF) regulating the three key crosstalk genes, with increased expression in the full dataset. These findings contribute to our understanding of the immune and inflammatory aspects of the comorbidity mechanism between GBM and PD.

Allelic variants and immunostaining profile in CXCL12/CXCR4 axis: An investigation of association with prognosis in prostate cancer

Prostate cancer (PCa) is the malignant neoplasm that most commonly affects men and is an important cause of death. It can be detected by changes in serum levels of Prostate Specific Antigen (PSA) and digital rectal examination, but often symptoms do not appear until advanced stages and metastases. The C-X-C Motif Chemokine Ligand 12/C-X-C Motif Chemokine Receptor 4 (CXCL12/CXCR4) axis acts in cell migration and may be involved in the metastatic process. In this context, the aim of this study was to evaluate the allelic variants rs1801157 (CXCL12) and rs2228014 (CXCR4) and the immunostaining of CXCR4 protein as candidates for prognostic markers in PCa. Samples (n = 60) were divided according to prognostic parameters (with and without metastasis at diagnosis) in tree groups: better prognosis, worse prognosis with metastasis at diagnosis and worse prognosis without metastasis at diagnosis, and immunostaining was evaluated by indirect immunohistochemistry, considering tumoral and adjacent tissues from the same patient (n = 120). A significant association was found between the C allele of rs2228014 (CXCR4) and the extraprostatic extension. For CXCR4 immunostaining a weak labeling and a cytoplasmic localization predominated, as well as a significant difference between malignant versus adjacent tissue, with higher protein expression in the malignant tissue. A significant association was found between CXCR4 tumor immunostaining with TNM staging (T2b-T2c) and PSA level (> 20 ng/mL). None of the allelic variants affected CXCR4 immunostaining. Prognostic groups did not differ in allelic variant frequency or immunostaining profile. Findings suggest that CXCR4 receptor may be one of the ways to worsen the prognosis of prostatic cancer.

Gene Variations of Chemokine and Chemokine Receptor CXCL12/CXCR4 in Lung Cancer

Lung cancer is the most common type of cancer in the world and about 1 million people die from lung cancer every year in the world. Inflammation is an important factor in the onset, progression and metastasis of lung cancer. The most important regulators of inflammation are chemokines and chemokine receptors. Chemokines induce the proliferation of cancer cells and prevent their apoptosis. Chemokines may indirectly affect tumor growth by inducing growth and release of angiogenic factors from cells in the tumor microenvironment. CXCL12/CXCR4 are chemokine and chemokine receptors predicted to be involved in lung cancer pathogenesis. This study aimed to determine the relationship between CXCL12/CXCR4 gene variations and CXCL12 serum levels in disease pathogenesis in lung cancer. For this purpose, DNA samples isolated from 90 lung cancer patients (36 squamous cell carcinomas, 18 small cell carcinomas and 36 adenocarcinomas) and 90 control individuals were genotyped by PCR-RFLP method for CXCL12 (rs1801157) and CXCR4 (rs2228014). CXCL12 protein levels were determined from serum samples by the enzyme-linked immuno-sorbent assay (ELISA) method. Results were evaluated using IBM SPSS Statistics 21 software and FINNETI program. As a result, there was no significant difference between the genotype frequencies of the CXCL12 rs1801157 variant and the risk of lung cancer (P = 0.396). CXCR4 rs2228014 genotypes were significantly associated with lung cancer risk (P < 0.001). Lung cancer patients had significantly elevated serum CXCL12 levels than controls (P < 0.001). In conclusion, the rs2228014 variants localized on the chemokine receptors CXCR4 gene was found to be closely related to lung cancer risk.

Correlation between single nucleotide polymorphisms in CXCR4 microRNA binding site and the susceptibility to knee osteoarthritis in Han Chinese population

Background

This study aimed to investigate the relationship between single nucleotide polymorphisms (SNPs) at the microRNA target sequence in CXCR4 and the susceptibility to knee osteoarthritis (KOA).

Methods

A total of 305 patients with KOA and 305 healthy controls were recruited into this study. The genotypes of CXCR4 rs1804029 and rs17848060 loci were analyzed.

Results

The susceptibility to KOA of CXCR4 rs1804029 G allele carriers was 1.33 times (95% CI: 1.09‐1.54, P = .006) that of T allele carriers. The KOA susceptibility in individuals carrying T allele at CXCR4 rs17848060 locus was 1.38 times that of individuals carrying A allele (95% CI: 1.17‐1.57, P < .001). The G allele at CXCR4 rs1804029 locus was the target of hsa‐miR‐146a‐3p, while the A allele at CXCR4 rs17848060 locus could be targeted by hsa‐miR‐20a‐3p. The plasma level of hsa‐miR‐146a‐3p was lower in rs1804029 G allele carriers than T allele carriers (P < .001), whereas plasma level of hsa‐miR‐20a‐3p was higher in rs17848060 T allele carriers than A allele carriers (P < .001).

Conclusion

The SNPs at rs1804029 and rs17848060 loci in CXCR4 were significantly associated with the susceptibility to KOA in Han Chinese population.

Identification of Key Biomarkers and Potential Molecular Mechanisms in Renal Cell Carcinoma by Bioinformatics Analysis

Renal cell carcinoma (RCC) is the most common form of kidney cancer, caused by renal epithelial cells. RCC remains to be a challenging public health problem worldwide. Metastases that are resistant to radiotherapy and chemotherapy are the major cause of death from cancer. However, the underlying molecular mechanism regulating the metastasis of RCC is poorly known. Publicly available databases of RCC were obtained from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified using GEO2R analysis, whereas the Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed by Gene Set Enrichment Analysis (GSEA) and Metascape. Protein-protein interaction (PPI) network of DEGs was analyzed by STRING online database, and Cytoscape software was used for visualizing PPI network. Survival analysis of hub genes was conducted using GEPIA online database. The expression levels of hub genes were investigated from The Human Protein Atlas online database and GEPIA online database. Finally, the comparative toxicogenomics database (CTD; http://ctdbase.org) was used to identify hub genes associated with tumor or metastasis. We identified 229 DEGs comprising 135 downregulated genes and 94 upregulated genes. Functional analysis revealed that these DEGs were associates with cell recognition, regulation of immune, negative regulation of adaptive immune response, and other functions. And these DEGs mainly related to P53 signaling pathway, cytokine-cytokine receptor interaction, Natural killer cell mediated cytotoxicity, and other pathways are involved. Ten genes were identified as hub genes through module analyses in the PPI network. Finally, survival analysis of 10 hub genes was conducted, which showed that the MMP2 (matrix metallo peptidase 2), DCN, COL4A1, CASR (calcium sensing receptor), GPR4 (G protein-coupled receptor 4), UTS2 (urotensin 2), and LDLR (low density lipoprotein receptor) genes were significant for survival. In this study, the DEGs between RCC and metastatic RCC were analyzed, which assist us in systematically understanding the pathogeny underlying metastasis of RCC. The MMP2, DCN, COL4A1, CASR, GPR4, UTS2, and LDLR genes might be used as potential targets to improve diagnosis and immunotherapy biomarkers for RCC.

Silibinin efficacy in a rat model of pulmonary arterial hypertension using monocrotaline and chronic hypoxia

Background

C-X-C chemokine receptor type 4 (CXCR4) may be involved in the development of pulmonary arterial hypertension (PAH). CXCR4 inhibitor AMD3100 was described to have a positive effect on the prevention of pulmonary arterial muscularization in PAH models. Silibinin is a traditional medicine that has an antagonistic effect on CXCR4. We investigated the effect of silibinin using rat models of PAH.

Methods

PAH was induced by a single subcutaneous injection of monocrotaline. The rats were maintained in a chronic hypoxic condition (10% O₂) with or without silibinin. To evaluate the efficacy of silibinin on PAH, right ventricular systolic pressure (RVSP), Fulton index (weight ratio of right ventricle to the left ventricle and septum), percent medial wall thickness (% MT), and vascular occlusion score (VOS) were measured and calculated. Immunohistochemical analysis was performed targeting CXCR4 and c-Kit. Reverse transcription-quantitative polymerase chain reaction was performed for the stem cell markers CXCR4, stromal cell derived factor-1 (SDF-1), c-Kit, and stem cell factor (SCF), and the inflammatory markers monocyte chemoattractant protein 1 (MCP1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα). Statistical analyses were performed using t-test and one-way analysis of variance with Bonferroni’s post hoc test.

Results

Silibinin treatment for 1 week reduced RVSP and Fulton index. Treatment for 2 weeks reduced RVSP, Fulton index, % MT, and VOS, as well as downregulating the expression of CXCR4, SDF-1, and TNFα in pulmonary arteries. In contrast, treatment for 3 weeks failed to ameliorate PAH. The time-course study demonstrated that RVSP, Fulton index, % MT, and VOS gradually increased over time, with a decrease in the expression of CXCR4 and TNFα occurring after 2 weeks of PAH development. After 3 weeks, SDF-1, c-Kit, and SCF began to decrease and, after 5 weeks, MCP1 and IL-6 gradually accumulated.

Conclusions

The CXCR4 inhibitor silibinin can ameliorate PAH, possibly through the suppression of the CXCR4/SDF-1 axis, until the point where PAH becomes a severe and irreversible condition. Silibinin results in reduced pulmonary arterial pressure and delays pulmonary arteriolar occlusion and pulmonary vascular remodeling.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1041-y) contains supplementary material, which is available to authorized users.

Involvement of CXCR4 in Normal and Abnormal Development

CXC motif chemokine receptor type 4 (CXCR4) is associated with normal and abnormal development, including oncogenesis. The ligand of CXCR4 is stromal cell-derived factor (SDF), also known as CXC motif ligand (CXCL) 12. Through the SDF-1/CXCR4 axis, both homing and migration of hematopoietic (stem) cells are regulated through niches in the bone marrow. Outside of the bone marrow, however, SDF-1 can recruit CXCR4-positive cells from the bone marrow. SDF/CXCR4 has been implicated in the maintenance and/or differentiation of stemness, and tissue-derived stem cells can be associated with SDF-1 and CXCR4 activity. CXCR4 plays a role in multiple pathways involved in carcinogenesis and other pathologies. Here, we summarize reports detailing the functions of CXCR4. We address the molecular signature of CXCR4 and how this molecule and cells expressing it are involved in either normal (maintaining stemness or inducing differentiation) or abnormal (developing cancer and other pathologies) events. As a constituent of stem cells, the SDF-1/CXCR4 axis influences downstream signal transduction and the cell microenvironment.

Targeting CXC motif chemokine receptor 4 inhibits the proliferation, migration and angiogenesis of lung cancer cells

An increasing volume of data indicates that disrupting the interaction between CXC motif chemokine receptor 4 (CXCR4) and its specific ligand, CXC motif chemokine 12 (CXCL12), may reduce tumor growth and metastasis. However, the translation from bench to bedside must be performed with extreme caution, as the CXCR4/CXCL12 axis is crucial for the normal development and maintenance of tissues and organs. In the present study, Cell Counting Kit-8 and Transwell migration assays were used to detect in vitro proliferation and chemotaxis of CXCR4-expressing A549 cells, a cell strain originating from human non-small-cell lung cancer (NSCLC), with or without the presence of AMD3100, a small-molecule inhibitor specific to CXCR4 signaling. In a xenograft model established by injecting nude mice with A549 cells, tumor growth, CXCR4 expression and microvessel density (MVD) in the tumor mass were determined through tumor size measurements and immunohistochemical staining following intraperitoneal administration of AMD3100 or vehicle. The results demonstrated that CXCR4 blockade inhibited the proliferation of A549 cells and their migration towards CXCL12 in vitro. Tumor growth, CXCR4 expression and MVD were markedly reduced in nude mice treated with AMD3100 compared with mice treated with the vehicle. In conclusion, the present data demonstrated that CXCR4 targeting impaired NSCLC cell growth, angiogenesis and metastatic spread, indicating that it may represent a novel treatment strategy for NSCLC.

CXCL12 chemokine and CXCR4 receptor: association with susceptibility and prognostic markers in triple negative breast cancer

CXCL12/CXCR4 signaling has been implicated in breast carcinogenesis, and genetic polymorphisms in these molecules have been associated with different types of cancer. The present study analyzed genetic polymorphisms in CXCL12 (rs1801157, G > A) and CXCR4 (rs2228014, C > T) and CXCR4 immunostaining in tumor tissues from patients with triple negative breast cancer (TNBC) aiming to evaluate their possible role in its' susceptibility and prognosis. Genetic polymorphisms were analyzed in 59 TNBC patients and 150 control women; age-adjusted logistic regression showed no association when variants were considered in isolation; however, a statistically significant interaction was noted for heterozygosis for both allelic variants increasing the odds for TNBC (CXCL12-GA by CXCR4-CT: OR 7.23; 95% CI 1.15-45.41; p = 0.035). CXCL12 polymorphism was correlated negatively with proliferation index (Ki67) (Tau-b = - 0.406; p = 0.006). CXCR4 immunostaining was evaluated in 37 TNBC patients (22 with paired tumor-normal adjacent tissue). CXCR4 was detected more intensely in cell cytoplasm than in membrane, and was more expressed in tumor than in normal adjacent tissues, although not statistically significant. CXCR4 expression on the membrane of tumor cells was correlated positively with histopathological grade (Tau-b = 0.271; p = 0.036) and negatively with lymph node metastasis (Tau-b = - 0.478; p = 0.036). The present study indicates that CXCL12 and CXCR4 polymorphisms and CXCR4 immunostaining might have susceptibility and prognostic roles in TNBC pathogenesis.

Genetic variation of CXCR4 and risk of coronary artery disease: epidemiological study and functional validation of CRISPR/Cas9 system

Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, while coronary artery disease (CAD) account for a large part of CVDs. Vascular CXCR4 could limit atherosclerosis by maintaining arterial integrity. Here, we conducted a population-based, case-control study to evaluate the associations of common genetic variation within the CXCR4 gene (rs2228014, rs117600832, rs2471859, and rs2322864) with CAD risk in a Chinese population. We found that CXCR4 rs2228014 was significantly associated with 1.29-fold increased risk of CAD (A vs G: OR = 1.29; 95% CI = 1.07–1.55; P = 0.007). The subjects with genotype AA (OR = 1.98; 95% CI = 1.03–3.81; P = 0.041) and AG (OR = 1.27; 95% CI = 1.02–1.58; P = 0.030) have higher risk of CAD, compared with those with genotype GG. Furthermore, both in the CAD patients with diabetes and those without diabetes, rs2228014 was significantly associated with increased risk of CAD (P < 0.05). Additionally, we also validated the significant association for rs2322864 (C vs T: OR = 1.20; 95% CI = 1.00–1.44; P = 0.046). Knockout of CXCR4 gene could significantly impair the capacity of cholesterol efflux (P < 0.01). These findings strongly suggest that CXCR4 polymorphisms might contribute to CAD susceptibility, and the exact biological mechanism awaits further research.