OBJECTIVE: To explore the effect of CXCR4 on the treatment response and prognosis of Carfilzomib (CFZ) in multiple myeloma. METHODS: Dataset GSE69078 based on microarray data from two CFZ-resistant MM cell lines and their corresponding parental cell lines (KMS11-KMS11/CFZ and KMS34-KMS34/CFZ) were downloaded from Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified, and Protein-protein interaction (PPI) network was established to identify the key genes involved in CFZ resistance acquisition. Finally, the prognostic roles of the CFZ risistance key genes in MM using MMRF-CoMMpass data study was verified. RESULTS: 44 up-regulated and 46 down-regulated DEGs were identified. Top 10 hub genes (CCND1, CXCR4, HGF, PECAM1, ID1, HEY1, TCF4, HIST1H4J, HIST1H2BD and HIST1H2BH) were identified via Protein-protein interaction (PPI) network analysis. The CoMMpass data showed that high CXCR4 expression showed correlation to relative higher relapse and progress rates and the overall survival was significant decreased in high CXCR4 patients (P=0.013). CONCLUSION CXCR4 perhaps plays a crucial role in CFZ acquired resistance, which might help identifying potential CFZ-sensitive patients before treatment and providing a new therapeutic target in CFZ-resistant MM.
Histones ; Humans ; Multiple Myeloma/genetics* ; Neoplasm Recurrence, Local ; Oligopeptides/therapeutic use* ; Prognosis ; Receptors, CXCR4

OBJECTIVEThis review focuses on the state-of-the-art of CXCL12/CXCR4 signaling axis in pancreatic cancer and its role in tumor progression.

DATA SOURCESRelevant articles published in English were identified by searching in Pubmed from 1997 to 2013, with keywords "CXCL12", "CXCR4" and "pancreatic cancer". Important references from selected articles were also retrieved.

STUDY SELECTIONArticles about CXCL12/CXCR4 signaling axis in pancreatic cancer and relevant mechanisms were selected.

RESULTSPancreatic cancer has been one of the most lethal human malignancies, with median survival less than one year and overall 5-year survival only 6%. Tumor cells from pancreatic cancer express high level of CXCR4. CXCL12, the ligand for CXCR4, is extensively secreted by neighboring stromal cells and other distant organs. CXCL12 primarily binds to CXCR4, induces intracellular signaling through several divergent pathways, which are involved in progression and metastasis of pancreatic cancer.

CONCLUSIONSCXCL12/CXCR4 signaling axis may play an important role in the communication between pancreatic cancer cells and their microenvironment, which may have effect on tumor proliferation, invasion, angiogenesis, metastasis and chemoresistance. CXCL12/CXCR4 signaling axis may serves as a novel therapeutic target for pancreatic cancer.

Chemokine CXCL12 ; genetics ; metabolism ; Humans ; Pancreatic Neoplasms ; genetics ; metabolism ; Receptors, CXCR4 ; genetics ; metabolism ; Signal Transduction ; genetics ; physiology

BACKGROUND: There is growing evidence that 5-fluorouracil (5-FU) combined with therapeutic trauma can effectively induce skin repigmentation in vitiligo patients who are unresponsive to conventional treatments. Previous studies have mainly focused on identifying the antimitotic activity of 5-FU for the treatment of skin cancer, but few studies have investigated its extra-genotoxic actions favoring melanocyte recruitment. METHODS: We utilized the full thickness excisional skin wound model in Dct-LacZ transgenic mice to dynamically assess the migration of melanocytes in the margins of wounds treated with or without 5-FU. The in-situ expression of CXCL12 was examined in the wound beds using immunofluorescence staining. Quantitative real-time polymerase chain reaction and Western blotting analyses were performed to detect the expression levels of CXCL12 mRNA and protein in primary mouse dermal fibroblasts treated with or without 5-FU. Transwell assays and fluorescein isothiocyanate (FITC)-phalloidin staining were used to observe cell migration and filamentous actin (F-actin) changes of melan-a murine melanocytes. RESULTS: Whole mount and cryosection X-gal staining showed that the cell numbers of LacZ-positive melanocytes were much higher in the margins of dorsal and tail skin wounds treated with 5-FU compared with the controls. Meanwhile, CXCL12 immunostaining was significantly increased in the dermal compartment of wounds treated with 5-FU (control vs. 5-FU, 22.47 ± 8.85 vs. 44.69 ± 5.97, P < 0.05). Moreover, 5-FU significantly upregulated the expression levels of CXCL12 mRNA (control vs. 5-FU, 1.00 ± 0.08 vs. 1.54 ± 0.06, P < 0.05) and protein (control vs. 5-FU, 1.00 ± 0.06 vs. 2.93 ± 0.10, P < 0.05) in cultured fibroblasts. Inhibition of the CXCL12/CXCR4 axis suppressed melanocyte migration in vitro using a CXCL12 small interfering RNA (siRNA) or a CXCR4 antagonist (AMD3100). CONCLUSION 5-FU possesses a pro-pigmentary activity through activation of the CXCL12/CXCR4 axis to drive the chemotactic migration of melanocytes.
Animals ; Cell Movement ; Cell Proliferation ; Chemokine CXCL12/genetics* ; Fibroblasts ; Fluorouracil/therapeutic use* ; Humans ; Mice ; RNA, Messenger ; Receptors, CXCR4

OBJECTIVETo obtain a specific antagonist of CXCR4, SDF-1P2G54 by mutating SDF-1 second proline (P) into glycin (G) and removing the α-helix of its C-terminal.

METHODSSDF-1p2g54 gene amplified by PCR was inserted into the vector pET-30a (+) and transformed into Escherichia coli (E. coli) strain BL21. After IPTG induction of E. coli, the expressed recombinant protein was purified with nickel-affinity chromatography column under denaturing conditions and refolded with gradient dilution and ultra-filtration. The chemotactic effect of SDF-1P2G54 on Jurkat cells and its antagonistic effect against SDF-1 were determined by transwell assay; flow cytometry was used to assay the ability of SDF-1P2G54 to induce calcium influx and CXCR4 internalization in MOLT4 cells.

RESULTSThe recombinant protein SDF-1P2G54 completely lost the functions to activate CXCR4 or to induce transmembrane migration of Jurkat cells and calcium influx in MOLT4 cells, but maintained a high affinity to CXCR4. SDF-1P2G54 effectively inhibited the chemotactic effect of wild-type SDF-1 to Jurkat cells, and induced rapid CXCR4 internalization in MOLT4 cells.

CONCLUSIONSDF-1P2G54 is a new antagonist of CXCR4 with a potential value as an effective inhibitor of HIV-1 infection, cancer metastasis or other major diseases.

Cell Line ; Chemokines, CXC ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Mutant Proteins ; biosynthesis ; genetics ; Receptors, CXCR4 ; antagonists & inhibitors ; Recombinant Proteins ; biosynthesis ; genetics

To construct the lentiviral RNA interference (RNAi) vector of rat CXCR4 gene, three target sequences were selected according to rat CXCR4 mRNA sequence, the complementary DNA contained both sense and antisense oligonucleotides were designed and synthesized. After phosphorylation and annealing, these double-strand DNA were cloned to Bgl II and Hind III sites of pSUPER. Then the product pRiCXCR4 was confirmed by electrophoresis and sequencing. Next, CXCR4 shRNA was cloned to a transfer vector of lentivirus, pNL-EGFP, and pNL-RiCXCR4-EGFP was produced. It was confirmed by digestion and sequencing that CXCR4 shRNA expression structure was correctly cloned to pSUPER and pNL-EGFP respectively. Three plasmids, pNL-RiCXCR4-EGFP, pHELPER and pVSVG were cotransfected into 293T to package lentivirus particles. The functional titer of obtained virus was determined by flow cytometry after transduction in 293T, the resulting functional titer of unconcentrated virus and concentrated virus were 6.4 x 10(4) TU/mL and 6.9 x 10(6) TU/mL respectively. After the rat mesenchymal stem cells (rMSCs) were transduced with the constructed lentiviral vectors, real-time RT-PCR, Western blotting and flow cytometry were used to evaluate the level of CXCR4 expression. Compared with control group, the CXCR4 mRNA expression were obviously suppressed in all three experimental groups (rMSCs-CXCR4a, rMSCs-CXCR4b, rMSCs-CXCR4c), especially the expression rate in rMSCs-CXCR4b group was reduced by 95.6%. The RNAi lentivirus vector of rat CXCR4 gene has been constructed successfully. This greatly facilitates the further studies such as evaluation the role of CXCR4 in rMSCs recruitment to damaged tissue.
Animals ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; metabolism ; Lentivirus ; genetics ; metabolism ; Mesenchymal Stromal Cells ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; Rats ; Receptors, CXCR4 ; genetics ; metabolism ; Transduction, Genetic

This study was aimed to investigate the effect of down-regulating the CXCR4 expression on cell cycle and cell apoptosis of human T-ALL Jurkat cells. The CXCR4 specific siRNA plasmid vector was constructed and then transfected into the cultured Jurkat cell line by DMRIE-C. The expression of CXCR4 mRNA was detected by RT-PCR, the cell distribution in cell cycle and cell apoptosis were determined by flow cytometry. The experiments were divided into 3 groups: group A (blank control), group B (non-silencing dsRNA as negative control) and group C (CXCR4 siRNA). The results showed that the expression level of CXCR4 mRNA in Jurkat cells transfected with CXCR4 siRNA (group C) decreased and cell proportion in G(0)/G(1) phase increased as compared with group A (56.9% +/- 1.4% vs 68.3% +/- 2.4% and 35.8% +/- 1.9% vs 18.1% +/- 1.2% respectively) (p < 0.01), cell proportion in G(2)/M and S phase decreased as compared with group A (19.8% +/- 1.7%, 44.4% +/- 2.1% vs 27.2% +/- 1.5%, 54.7% +/- 2.8% respectively) (p < 0.01). The apoptosis rate of Jurkat cells in group C increased as compared with group A (20.9% +/- 2.0% vs 3.13% +/- 0.9% respectively) (p < 0.01), and the comparison between group A and B showed no statistical difference. It is concluded that the CXCR4 specific siRNA can effectively down-regulate the CXCR4 mRNA expression, which induces the cell apoptosis and cell cycle arrest, thereby inhibits the Jurkat cell proliferation.
Apoptosis ; genetics ; Cell Cycle ; genetics ; Cell Proliferation ; Gene Expression Regulation, Leukemic ; Humans ; Jurkat Cells ; RNA Interference ; RNA, Small Interfering ; genetics ; Receptors, CXCR4 ; genetics

OBJECTIVETo study the clinical and laboratory characteristics of cases with warts, hypogammaglobulinemia, infections and myelokathexis (WHIM) syndrome.

METHODAn 11-year-old boy was diagnosed as WHIM syndrome and CXCR4 gene mutation analysis was performed.

RESULTSince 3 years of age, the patient had recurrent fever and persistent cough. Since 6 years of age, he had warts on his fingers, the warts increased gradually. His complete blood count showed: white blood cell (WBC) 0.65×10(9)/L, neutrophil 0.15×10(9)/L, hemoglobin 116 g/L, platelet 200×10(9)/L, reticulocyte 0.62%. Results of serum biochemical tests: total protein (TP) 72.2 g/L (reference value 60 - 80 g/L), albumin 20.4 g/L (reference value 20 - 35 g/L), gammaglobulin 20.4 g/L (reference value 20 - 35 g/L). IgG 5.56 g/L (reference value 7.51 - 15.6 g/L), IgA 0.48 g/L (reference value 0.82 - 4.53 g/L), IgM 0.29 g/L (reference value 0.46 - 3.04 g/L). Peripheral blood lymphocyte subsets: CD3(+)T lymphocyte 43.6% (reference value 64.01% - 75.95%), CD19(+)B lymphocyte 1.00% (reference value 9.02% - 14.1%). Bone marrow smears showed that many of the neutrophils had a reactive appearance, with cytoplasmic vacuolation. Most neutrophils had hypersegmentation with four or five nuclear lobules. In some cells, the filaments connecting the nuclear lobes were long. CXCR4 mutation was detected.

CONCLUSIONWHIM syndrome is a rare immunodeficiency disorder with an autosomal-dominant pattern of inheritance. The disease is less progressive, and may accompany the patients' whole life.

Agranulocytosis ; genetics ; pathology ; Amino Acid Sequence ; Child ; Humans ; Immunoglobulins ; blood ; Immunohistochemistry ; Immunologic Deficiency Syndromes ; genetics ; pathology ; Leukocyte Count ; Male ; Mutation ; Receptors, CXCR4 ; genetics ; Warts ; genetics ; pathology

This study was aimed to clone the gene coding mouse CXC chemokine receptor 4 (CXCR4), to construct the recombinant lentiviral vector carrying enhanced green fluorescence protein (EGFP) and to explore its expression in eukaryotic cells (293FT cells). The full length CXCR4 gene was cloned by RT-PCR using bone marrow cells from C57BL/6 mouse as template and inserted into PCR-Blunt vector. CXCR4 fragment was generated by digestion with restriction endonuclease and subcloned into a lentiviral vector to generate recombinant lentiviral vector LV-IRES-EGFP-CXCR4, which was co-transfected into 293FT cells together with envelope plasmid and packaging plasmid by lipofectamine 2000. Viruses were gathered and concentrated using ultracentrifuge, and then transfected into 293FT cells. Expression of EGFP was detected by fluorescent microscopy and flow cytometry (FCM). And the expression of CXCR4 protein was detected by Western blot. The results demonstrated that mouse CXCR4 gene was cloned and the lentiviral vector was successfully constructed. The lentiviral particles were correctly packaged, and the virus titers were above 10(8) TU/ml in the supernatant after concentration. Expression of EGFP was detected by fluorescent microscopy in the transfected 293FT cells, and the transfection efficacy > 95% was determined by FCM. Expression of CXCR4 protein detected by FCM and Western blot was significantly higher than that in control group. It is concluded that the CXCR4 gene along with the gene coding EGFP is successfully inserted into a lentiviral vector to construct a recombinant lentiviral vector, which can be expressed in eukaryotic cells.
Animals ; Cell Line ; Gene Expression ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; Humans ; Lentivirus ; genetics ; Mice ; Mice, Inbred C57BL ; Plasmids ; Receptors, CXCR4 ; genetics ; Transfection

The stromal cell-derived factor 1 (SDF-1) interacts with its receptor CXCR4 to transduction signals, playing important roles in most physiological and pathological processes. It is reported that CXCR4 is highly expressed in many kinds of hematological malignancies and closely related to the prognosis, drug resistance and relapse of diseases. The growth of tumor cells can be inhibited by the anti-SDF-1 antibody or anti- CXCR4 antibody, supporting a new way for the therapy against hematological malignancies. Their expression in relation with prognosis and drug resistance of hematological malignancies are summarized in this review.
Chemokine CXCL12 ; biosynthesis ; genetics ; Drug Resistance, Neoplasm ; genetics ; Hematologic Neoplasms ; metabolism ; pathology ; Humans ; Prognosis ; Receptors, CXCR4 ; biosynthesis ; genetics ; Signal Transduction ; Stromal Cells ; metabolism

OBJECTIVETo construct pBIFC-VN173-CXCR4 and pBIFC-VC155-NT21MP eukaryotic expression plasmids and to investigate the interaction of chemokine receptor 4 (CXCR4) and viral macrophage inflammatory protein-II(vMIP-II) N terminal 21 peptides (NT21MP) in living cells.

METHODSDNA fragment encoding NT21MP was chemically synthesized and inserted into BiFC eukaryotic expression vector pBIFC-VC155. The full length of CXCR4 DNA fragment was amplified by RT-PCR from SKBR (3) cells and inserted into BiFC eukaryotic expression plasmid pBIFC-VN173. Two recombinant vectors were identified by restriction enzyme digestion and DNA sequencing. The recombinant vectors were cotransfected into Africa green monkey kidney fibroblast COS-7 cells by using Lipofectamine 2000. The interaction of NT21MP and CXCR4 was detected by bimolecular fluorescence complementation (BiFC) assay.

RESULTSThe restriction enzyme digestion and DNA sequences and open read frames of two vectors were consistent with experiment design. The BiFC plasmids were successfully cotransfected into the target cells and expressed. The strong BiFC signals were detected in pBIFC-VN173-CXCR4 and pBIFC-VC155-NT21MP cotransfected cells and the fluorescence signal was located in the cytoplasm.

CONCLUSIONThe eukaryotic expression plasmids for BiFC assay are successfully constructed. The interaction of NT21MP and CXCR4 in living cells can be detected by using this technology.

Animals ; COS Cells ; Cercopithecus aethiops ; Chemokines ; genetics ; Cloning, Molecular ; Female ; Genetic Vectors ; Humans ; Plasmids ; genetics ; Receptors, CXCR4 ; genetics ; Transfection ; Tumor Cells, Cultured