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

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 purposed to explore the expression of p57kip2 in the bone marrow of patients with de novo myelodysplastic syndrome (MDS) and its role in MDS pathogenesis, as well as the relationship between the expression of p57kip2 and SDF-1/CXCR4 signal. The expression of p57kip2 and CXCR4 in 67 de novo MDS patients was measured by real-time quantitative PCR. The percentage of CD34(+) cells in the bone marrow from MDS patients was measured by flow cytometry. 18 healthy volunteers were recruited for control. The effect of SDF-1 on p57kip2 expression in bone marrow mononuclear cell (BMMNC) from MDS or normal controls was investigated in vitro, and difference between them was compared. The results showed that low-risk MDS and high-risk MDS displayed a significant reduction of p57kip2 mRNA expression in BMMNC compared with that in control group (P < 0.001) and there was a negative correlation between p57kip2 expression and percentage of CD34(+) (r = -0.458, P < 0.001); the patients with abnormal karyotype showed lower expression of p57kip2 gene, compared to patients with normal karyotype (P = 0.045). Although the expression of CXCR4 had no difference between MDS patients and normal controls, a positive correlation between p57kip2 and CXCR4 in MDS patients was still found (r = 0.609, P < 0.001). Moreover, SDF-1 increased p57kip2 expression in normal BMMNC in dose-dependent manner, but BMMNC from MDS patients showed no response to SDF-1. SDF-1-induced p57 expression was blocked by AMD3100. It is concluded that the low expression of p57 gene in MDS may play a role in the pathogenesis of MDS. Furthermore, SDF-1-induced p57kip2 expression in BMMNC, and the decreasing response of BMMNC to SDF-1 may contribute to the low expression of p57kip2 in MDS patients.
Case-Control Studies ; Chemokine CXCL12 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p57 ; genetics ; metabolism ; Flow Cytometry ; Humans ; Myelodysplastic Syndromes ; genetics ; metabolism ; Receptors, CXCR4 ; metabolism

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 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

Cadherins ; metabolism ; Female ; Gene Expression Profiling ; Humans ; Inflammatory Breast Neoplasms ; genetics ; metabolism ; pathology ; NF-kappa B ; metabolism ; Receptor, ErbB-2 ; metabolism ; Receptor, Notch3 ; Receptors, CCR7 ; metabolism ; Receptors, CXCR4 ; metabolism ; Receptors, Notch ; metabolism

OBJECTIVETo investigate the expression of ALDH1, CXCR4 and E-cadherin in gastric carcinoma and their roles in lymphatic metastasis.

METHODSSurgical specimens from 127 cases of gastric carcinoma were examined for expressions of ALDH1, CXCR4 and E-cadherin immuohistochemistry with 60 adjacent tissues as control. The associations of ALDH1, CXCR4 and E-cadherin with the clinicopathological pfeatures, 5-year survival rate and lymph node metastasis of the patients were analyzed.

RESULTSALDH1, CXCR4 and E-cadherin were positive in 57.5% (73/127), 63.8% (81/127), and 36.2% (46/127) of the gastric carcinoma tissues, respectively, showing significant differences from the rates in the adjacent tissues (P<0.05). The expression of ALDH1 was significantly correlated with TNM stage and lymph node metastasis (P<0.05), CXCR4 was significantly correlated with the invasion depth, differentiation, TNM stage and lymph node metastasis of the tumor (P<0.05), and E-cadherin was significantly correlated with the invasion depth, differentiation and lymph node metastasis (P<0.05). The positivity rates of ALDH1, CXCR4 and E-cadherin were higher in cases with lymph node metastasis than in those without metastasis. E-cadherin expression was inversely correlated with ALDH1 and CXCR4 expression, and the latter two were positively correlated (P<0.001). Overexpressions of ALDH1 and CXCR4 and a decreased expression of E-cadherin were all related to a poor prognosis of the patients (P<0.05). The expressions ofALDH1, CXCR4 and E-cadherin were all independent prognostic factors of gastric carcinoma.

CONCLUSIONThe expressions of ALDH1, CXCR4 and E-cadherin are associated with the invasion, metastasis and prognosis of gastric carcinoma, and their combined detection provides important evidence for predicting the progression and prognosis of gastric carcinoma.

Cadherins ; genetics ; metabolism ; Carcinoma ; genetics ; metabolism ; Disease Progression ; Humans ; Isoenzymes ; genetics ; metabolism ; Lymphatic Metastasis ; Prognosis ; Receptors, CXCR4 ; genetics ; metabolism ; Retinal Dehydrogenase ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; Survival Rate

OBJECTIVE: To detected the mechanism of allergic rhinitis associated with asthma with bioinformatics methods. METHOD: GenMAPP software was used to analyze the expression profile of nasal mucosa of seasonal allergic rhinitis(SAR) and SAR associated with asthma of oligonucleotide microarray (Affymetrix HG-U133-plus2). One the first step,of differentially expressed genes screening were done, then differential gene database retrieval was established, at last pathway analysis was performed. RESULT: 689 genes out of 47 000 analyzed transcripts of nasal mucosa of SAR associated with asthma were differentially expressed at least 4-fold, in which 233 genes were up regulated and 456 genes were down regulated. These differential expression genes participate in 69 bio-pathways, in which the interaction pathway between cytokine and cytokine receptor was most. Chemotactic factor CXCL12 and its receptor CXCR4 expressed in SAR associated with asthma patients were up-regulated predominantly, compared with that in SAR patients. CONCLUSION Multiple pathways were involved in the development of SAR and SAR complicated with asthma. The CXCL12/CXCR4 axis might play a main role in the allergic airway diseases.
Asthma ; diagnosis ; genetics ; Chemokine CXCL12 ; metabolism ; Computational Biology ; Gene Expression Profiling ; Humans ; Oligonucleotide Array Sequence Analysis ; methods ; Receptors, CXCR4 ; metabolism ; Rhinitis, Allergic, Seasonal ; diagnosis ; genetics ; Software

OBJECTIVETo investigate the gene expression profiles in lung adenocarcinoma (LA), tumor adjacent tissue (TAT) and fetal lung tissue (FLT) by cDNA microarray technique.

METHODSTotal RNA from LA, TAT and FLT was extracted and purified. The cDNA was made by RT-PCR, and then labeled with Cy5 and Cy3 fluorescence as probes which were hybridized with the whole gene chips. Subsequently, the signal images were scanned by ScanArray 4000 fluorescence scanner and analyzed by Gene Pix PRO3.0.

RESULTSIn 4 cases with LA and TAT, 25 genes were screened out for differences in gene expression level, among which 3 were upregulated and 22 downregulated; in FLT and TAT cases, 316 genes were screened out, among which 192 were upregulated and 124 downregulated; 16 genes were found to be differentially expressed genes in common in LA, TAT and FLT, among which 12 were upregulated and 4 downregulated.

CONCLUSIONThe 25 differentially expressed genes in LA and TAT may be related to occurrence and development of lung cancer, while the 316 genes in FLT and TAT may be related to fetal developmental. The 16 differentially expressed genes may be related to the initiation of lung cancer.

Adenocarcinoma ; genetics ; metabolism ; Fetal Development ; genetics ; Fetus ; Gene Expression Profiling ; Humans ; Interleukin-6 ; metabolism ; Lung ; metabolism ; Lung Neoplasms ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; Oncogenes ; genetics ; Pyruvate Kinase ; metabolism ; Receptors, CXCR4 ; metabolism ; Thioredoxin-Disulfide Reductase ; metabolism

OBJECTIVETo construct mouse CXC chemokine receptor type 4 (Cxcr4) gene overexpressing lentiviral vector and to evaluate its biological effect on mouse mesenchymal stem cells (MSCs).

METHODSCxcr4 gene was amplified and subcloned into pCR-Blunt vector. Cxcr4 gene and enhanced green fluorescent protein (EGFP) gene expressed bicistronic recombinant lentiviral vector LV-CXCR4-IRES-EGFP and control vector LV-IRES-EGFP were constructed, respectively. Both plasmids were co-transfected into 293FT packaging cell line with packaging plasmid pSPAX2 and enveloping plasmid pMD.2G using Lipofectamine 2000 to produce lentiviral virus, respectively. The recombinant viruses were harvested and the virus titer was determined by limiting dilution. Mouse MSCs were infected with viral supernatant. EGFP expression was visualized using fluorescence microscope and efficiency of infection was determined by flow cytometry (FCM). Cell counting kit-8 (CCK-8) was applied in mixed lymphocyte reaction (MLR) to evaluate the suppressive effect of MSCs on mice splenocyte proliferation in vitro. Wound healing ability of MSCs was measured by scratch experiment and migration capacity by a chemotaxis assay using a transwell assay.

RESULTSThe Cxcr4 fragment was amplified by reverse transcription polymerase chain reaction (RT-PCR) and verified by DNA sequencing. The restriction enzyme digestion experiment demonstrated that the recombinant lentiviral vector LV-CXCR4-IRES-EGFP and the control vector LV-IRES-EGFP were successfully constructed. Expression of CXCR4 was detected by fluorescence microscopy, which indicated that the lentiviral particles expressing CXCR4 were packaged. Furthermore, expression of EGFP were detected by fluorescence microscopy in MSCs after infection and the expression of CXCR4 protein on MSCs surface in CXCR4-MSC group was significantly increased comparing to those in the control group(P < 0.05).CXCR4-MSCs group and the control group were (90.3 ± 3.37)% and (1.53 ± 0.34)%, respectively. Meanwhile, overexpression of CXCR4 had no effect on their capacity of immune regulation when co-cultured with splenocyte(P > 0.05). Moreover, overexpression of CXCR4 can not only accelerated the wound healing after scratch, but also enhanced the migration ability of cells in the transwell induced by high concentration of SDF-1 in a dose-dependent manner compared with the EGFP control group.

CONCLUSIONThe CXCR4 expressing lentiviral vector LV-CXCR4-IRES-EGFP was successfully constructed. The lentiviral vector can not only efficiently infect mouse MSCs, but also stably express CXCR4 in MSCs. The MSCs modified with CXCR4 have biological characteristic in vitro.

Animals ; Cell Line ; Genetic Vectors ; Lentivirus ; genetics ; Mesenchymal Stromal Cells ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Receptors, CXCR4 ; genetics