As an important part of tumor microenvironment, neutrophils are poorly understood due to their spatiotemporal heterogeneity in tumorigenesis. Here we defined, at single-cell resolution, CD44-CXCR2- neutrophils as tumor-specific neutrophils (tsNeus) in both mouse and human gastric cancer (GC). We uncovered a Hippo regulon in neutrophils with unique YAP signature genes (e.g., ICAM1, CD14, EGR1) distinct from those identified in epithelial and/or cancer cells. Importantly, knockout of YAP/TAZ in neutrophils impaired their differentiation into CD54+ tsNeus and reduced their antitumor activity, leading to accelerated GC progression. Moreover, the relative amounts of CD54+ tsNeus were found to be negatively associated with GC progression and positively associated with patient survival. Interestingly, GC patients receiving neoadjuvant chemotherapy had increased numbers of CD54+ tsNeus. Furthermore, pharmacologically enhancing YAP activity selectively activated neutrophils to suppress refractory GC, with no significant inflammation-related side effects. Thus, our work characterized tumor-specific neutrophils in GC and revealed an essential role of YAP/TAZ-CD54 axis in tsNeus, opening a new possibility to develop neutrophil-based antitumor therapeutics.
Humans ; Animals ; Mice ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Stomach Neoplasms/pathology* ; Neutrophils/pathology* ; Signal Transduction/genetics* ; YAP-Signaling Proteins ; Tumor Microenvironment ; Hyaluronan Receptors/genetics*

OBJECTIVE To explore downstream regulatory pathway of microRNA-21 (miR-21) in colon cancer cells (RKO) through detecting miR-21 and its target PDCD4, and the influence of miR-21 regulation on the sensitivity of RKO cells to 5-fluorouracil (5-FU). METHODS 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the effect of 5-FU on the viability of RKO cells with knockout of miR-21 or high expression of PDCD4. Real-time was used to determine the expression of PDCD4, ABCC5 and CD44 in RKO cell after knockout of miR-21. RESULTS MTT assay reveals that the IC50 of 5-FU in RKO-WT cells (52.82 ± 0.06 umol/L) was about 67% higher than in miR-21 knockout cells (32.23 ± 0.05 umol/L) (P < 0.05), and the apoptosis ratio elevated after knockout of miR-21. High expression of PDCD4, a target gene of miR-21, can negatively regulate the expression of ABC transporter ABCC5 and the stem cell marker CD44. CONCLUSION MiR-21 can mediate the drug resistance to 5-FU by inhibiting its target PDCD4, which can regulate the expression of ABCC5 and CD44 genes.
ATP Binding Cassette Transporter, Sub-Family G, Member 5 ; ATP-Binding Cassette Transporters ; genetics ; Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis Regulatory Proteins ; physiology ; Cell Line, Tumor ; Colonic Neoplasms ; drug therapy ; pathology ; Drug Resistance, Neoplasm ; Fluorouracil ; pharmacology ; Humans ; Hyaluronan Receptors ; genetics ; Lipoproteins ; genetics ; MicroRNAs ; physiology ; RNA-Binding Proteins ; physiology

OBJECTIVE: To investigate the effect of gene silencing of Bmi-1 on proliferation regulation of CD44+ nasopharyngeal carcinoma cancer stem-like cells (CSC-LCs). METHOD: The sequence-specific short hairpin RNA lentivirus targeting at human Bmi-1 gene (LV-Bmi-1shRNA) was constructed and was used to infect CD44+ nasopharyngeal carcinoma cells which were sorted by flow cytometry. A lentiviral which included a random sequence was also designed to serve as a negative control. We employed fluorescence microscope and flow cytometry to detect infection efficiency; real-time PCR was used to detect Bmi-1 and its downstream gene while each protein expression level was confirmed by western blotting protocol; CCK-8 proliferation assay was applied to measure proliferation capacity; tumor spheroid assay was used to evaluate the self-renewal capacity. Colony formation assay was used to measure cell colony formation capability; flow cytometry analyzed cell cycle distribution. RESULT: The constructed LV-Bmi-1shRNA successfully infected into the CD44+ nasopharyngeal carcinoma cells. The infection efficiency could reach above 95%; LV-Bmi-lshRNA effectively inhibited Bmi-1 mRNA and protein expression, while the downstream gene p16INK4a and p14ARF mRNA as well as protein expression level were upregulated (P < 0.05). Notablely, the proliferation, colony formation, self-renewal capabilities of the experimental group decreased significantly (P < 0.05). In addition, the cell cycle arrested at the G0-G1 phase. CONCLUSION Gene silencing of Bmi-1 inhibited the proliferation, colony formation and self-renewal capabilities of the CD44+ nasopharyngeal carcinoma CSC-LCs, inhibited the cell cycle processes, which may mediate through Bmi1-p16INK4a/p14ARF-p53 pathway. Our experimental results indicated that Bmi-1 gene may play an important role in the maintenance of the stem cell-like characteristics of CD44+ nasopharyngeal carcinoma cells. Bmi-1 gene may be a potential new target for the treatment of nasopharyng al carcinoma in the future.
Carcinoma ; Cell Cycle ; Cell Division ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Gene Silencing ; Humans ; Hyaluronan Receptors ; metabolism ; Lentivirus ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Neoplastic Stem Cells ; cytology ; Polycomb Repressive Complex 1 ; genetics ; RNA, Messenger ; RNA, Small Interfering ; Tumor Suppressor Protein p14ARF ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo investigate the effect of tricostantin A (TSA) on self-renewal of breast cancer stem cells and explore the mechanisms.

METHODSBreast cancer cell lines MDA-MB-468, MDA-MB-231, MCF-7 and SKBR3 were cultured in suspension and treated with different concentrations of TSA for 7 days, using 0.1% DMSO as the control. Secondary mammosphere formation efficiency and percentage of CD44(+)/CD24(-) sub-population in the primary mammospheres were used to evaluate the effects of TSA on self-renewal of breast cancer stem cells. The breast cancer stem cell surface marker CD44(+)/CD24(-) and the percentage of apoptosis in the primary mammospheres were assayed using flow cytometry. The mRNA expressions of Nanog, Sox2 and Oct4 in the primary mammospheres were assayed with quantitative PCR.

RESULTSTSA at both 100 and 500 nmol/L, but not at 10 nmol/L, partially inhibited the self-renewal of breast cancer stem cells from the 4 cell lines. TSA at 500 nmol/L induced cell apoptosis in the primary mammospheres. TSA down-regulated the mRNA expression of Nanog and Sox2 in the primary mammospheres.

CONCLUSIONTSA can partially inhibit the self-renewal of breast cancer stem cells through a mechanism involving the down-regulation of Nanog and Sox2 expression, indicating the value of combined treatments with low-dose TSA and other anticancer drugs to achieve maximum inhibition of breast cancer stem cell self-renewal. The core transcriptional factor of embryonic stem cells Nanog and Sox2 can be potential targets of anticancer therapy.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Breast Neoplasms ; metabolism ; pathology ; CD24 Antigen ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Down-Regulation ; Female ; Histone Deacetylase Inhibitors ; administration & dosage ; pharmacology ; Homeodomain Proteins ; genetics ; metabolism ; Humans ; Hyaluronan Receptors ; metabolism ; Hydroxamic Acids ; administration & dosage ; pharmacology ; Nanog Homeobox Protein ; Neoplastic Stem Cells ; metabolism ; pathology ; RNA, Messenger ; metabolism ; SOXB1 Transcription Factors ; genetics ; metabolism

OBJECTIVETo investigate the influence of down-regulating Smoothened (SMO) gene expression through short hairpin RNA (shRNA) on the proliferation of breast cancer stem cells.

METHODSHuman SMO shRNA was designed, synthesized chemically, and transfected into MCF-7 cells to down-regulate SMO gene. By using G418, stable cells with down-regulated SMO were selected. In vitro proliferation of these cells was measured by CCK8 assay. The proportion of CD44(+)/CD24(-) cells was detected by flow cytometry and the mammospheres formation was determined by suspension sphere culture. The expression of SMO, GLI1 and Oct4 was detected by Western blot. In vivo, the volume of tumor was measured every 3 days and the expression of SMO, GLI1 and Oct4 detected by Western blot.

RESULTSIn vitro, the cells were transfected with SMO-shRNA and selected by G418 after 21 days. SMO-shRNA effectively down-regulated the expression of SMO gene and protein, and inhibited the proliferation of MCF-7 and markedly reduced the proportion of CD44(+)/CD24(-) cells and mammospheres. In vivo, SMO-shRNA treatment of MCF-7 significantly inhibited the volume of tumor. The positive rate of SMO in negative control and SMO-shRNA group was 5/5 and 2/5, respectively. The expression of SMO, GLI1 and Oct4 in different groups were 0.72 ± 0.17 and 0.21 ± 0.09, 1.21 ± 0.21 and 0.47 ± 0.12, 0.83 ± 0.13 and 0.25 ± 0.07. SMO, GLI1 and Oct4 down-regulation significantly suppressed at protein levels (P < 0.05).

CONCLUSIONThe shRNA by chemical synthesis can effectively down-regulate SMO gene expression and inhibit the proliferation of breast cancer stem cells.

Animals ; Cell Proliferation ; Down-Regulation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Hyaluronan Receptors ; metabolism ; MCF-7 Cells ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Neoplastic Stem Cells ; pathology ; Octamer Transcription Factor-3 ; metabolism ; RNA, Small Interfering ; genetics ; Receptors, G-Protein-Coupled ; genetics ; metabolism ; Smoothened Receptor ; Transcription Factors ; metabolism ; Transfection ; Tumor Burden ; Zinc Finger Protein GLI1

OBJECTIVE: To study the correlation of CD44 with epithelial-mesenchymal transition(EMT) and metastasis in nasopharyngeal cancer cells, and explore the possible mechanism of CD44 regulates EMT and metastasis in nasopharyngeal cancer cells. METHOD: The CD44 and EMT-associated proteins in 5-8F and 6-10B nasopharyngeal cancer cell lines were assayed by Western blotting. The erasion trace test was performed to observe the migratory ability of 5-8F and 6-10B nasopharyngeal cancer cells. Using lipid-mediated DNA transfection technique, the low metastatic nasopharyngeal cancer cells 6-10B were transfected in vitro with plasmid which contained CD44 gene, and then new nasopharyngeal cancer cells were obtained. The CD44 and EMT-associated proteins in 6-10B, empty vector transfected and CD44-transfected cells were assayed by Western blotting. The erasion trace test was performed to observe the alteration of migratory ability of nasopharyngeal cancer cells before and after CD44 transfection. RESULT: The expression of CD44 and EMT-associated protein MMP-9 in 5-8F was higher than that in 6-10B, but EMT-associated protein E-Cadherin in 5-8F was lower than that in 6-10B. The migratory ability of 5-8F was higher than that of 6-10B. The expression of CD44 and MMP-9 were significantly higher in the CD44-transfected nasopharyngeal cancer cells than in the control groups. Compared with control groups, the migratory ability of CD44-transfected nasopharyngeal cancer cells was significantly increased. CONCLUSION CD44 positively regulates the metastatic ability of nasopharyngeal cancer cells, which is relevant to the process of EMT.
Carcinoma ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Humans ; Hyaluronan Receptors ; genetics ; metabolism ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; metabolism ; pathology ; Neoplasm Metastasis ; Transfection

OBJECTIVETo explore the expression of ezrin protein in human non-small cell lung cancer (NSCLC) tissues and lung cancer cell lines, and the association between the expression of ezrin protein and the expression of E-cadherin and CD44V6 proteins.

METHODSThe expression of ezrin protein and mRNA in lung cancer cell lines was detected by RT-PCR and Western blotting. Ezrin, E-cadherin and CD44V6 were detected by immunohistochemical SP staining in tumor tissues from 150 lung cancer cases and in adjacent normal lung tissues from 30 patients. Furthermore, the expression of ezrin in 30 freshly-taken NSCLC tissues was also detected by Western blot.

RESULTSThe expression of ezrin protein and mRNA was up-regulated in highly metastatic human lung cancer. The positive rate of ezrin, E-cadherin and CD44V6 expression in the lung cancer was 61.3%, 54.0% and 58.7%, respectively. The up-regulation of ezrin expression was significantly correlated with lymph node metastasis, but not correlated with age, sex, tumor size, histological type, clinical TNM system and pathological grade. Western blot analysis showed that the level of ezrin in the NSCLC tissues was significantly higher than that in the normal tissues (t = 5.013, P < 0.01). Survival analysis showed that the 5-year survival rate of patients with negative ezrin expression was 29.3%, significantly higher than that of patients with positive ezrin expression (15.2%, χ(2) = 4.128, P = 0.042). Multivariate Cox regression analysis showed that ezrin expression (RR = 3.012, P = 0.047) and lymph node metastasis (RR = 4.827, P = 0.035) were significantly independent prognostic factors for patients with lung cancer. Furthermore, a negative correlation was observed between the expressions of ezrin and E-cadherin in lung cancer, and a positive correlation between the expressions of ezrin and CD44V6 in lung cancer.

CONCLUSIONSEzrin, E-cadherin and CD44V6 play an important role in the regulation of growth and meastasis of lung cancer. Combined detection of ezrin, E-cadherin and CD44V6 expression is helpful in evaluating the metastasis and prognosis of non-small cell lung cancer.

Adult ; Aged ; Cadherins ; metabolism ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; Cell Line, Tumor ; Cytoskeletal Proteins ; genetics ; metabolism ; Female ; Humans ; Hyaluronan Receptors ; metabolism ; Lung Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; RNA, Messenger ; metabolism ; Survival Rate ; Up-Regulation

Adolescent ; Antigens, CD20 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Burkitt Lymphoma ; drug therapy ; metabolism ; pathology ; surgery ; Child ; Child, Preschool ; Cyclophosphamide ; therapeutic use ; DNA-Binding Proteins ; metabolism ; Doxorubicin ; therapeutic use ; Female ; Follow-Up Studies ; Genes, myc ; Humans ; Hyaluronan Receptors ; metabolism ; Ki-67 Antigen ; metabolism ; Lymphoma, Large B-Cell, Diffuse ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Male ; Neoplasm Staging ; Neprilysin ; metabolism ; Peritoneal Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Prednisone ; therapeutic use ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-bcl-6 ; Stomach Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Translocation, Genetic ; Vincristine ; therapeutic use

OBJECTIVETo evaluate the impact of a new CD44 variant on invasion of human breast cancer cell line MCF-7, and its possible mechanisms.

METHODSThe full length cDNA encoding CD44v17 was obtained from the total RNA isolated from the MCF-7/ADR cells by reverse transcript-polymerase chain reaction (RT-PCR) and subcloned into pMD19-T vector. The CD44v17 gene sequence and reading frame were confirmed by two restriction enzymes and nucleotide sequencing, and then inserted into the eukaryotic expression vector pcDNA3.1. The pcDNA3.1-CD44v17 was transfected into MCF-7 cells by Lipofectamine. The changes of MMP-2 and MMP-9 expression at gene and protein levels were detected by RT-PCR and gelatin zymography, respectively. The number of the cells through the artificial matrix membrane in every group was counted to compare the change of the invasive ability regulated by CD44 variant. The ERK and p-ERK were investigated by Western blotting to approach the molecular mechanisms of MMP-2 and MMP-9 expression regulated by CD44 variant.

RESULTSThe new gene sequence was successfully cloned into recombinant vector pcDNA3.1 and identified by the two restriction enzymes. It was confirmed that the reconstructed plasmid contained the sequence of CD44 gene variant which was composed of 1 to 4 exons, 16 to 17 exons, and 1 to 205 bases of 18 exons. The new gene sequence was sent to NCBI for publication and obtained the registered number FJ216964. The up-regulated levels of the CD44 gene mRNA and protein were respectively detected by RT-PCR and flow cytometry in MCF-7 cells transfected with pcDNA3.1-CD44v17. The invasiveness of the cells and the activity of MMP-2 and MMP-9 were clearly activated by hyaluronic acid (HA) treatment and blocked by CD44 neutralizing antibody. Pretreated MCF-7/CD44v17 cells with the neutralizing antibody against CD44 and the inhibitor of MAPKs signaling pathway strongly block the expression of p-ERK.

CONCLUSIONA new CD44 gene variant has been found in adriamycin-resistant human breast cancer MCF-7/ADR cells. The expression vector pcDNA3.1-CD44v17 has been cloned and constructed successfully. HA can be integrated with CD44 variant and then regulates the expression of MMP-2 and MMP-9, which increases the invasion ability of MCF-7 cells through the Ras/MAPK signaling pathway.

Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Genetic Vectors ; Humans ; Hyaluronan Receptors ; genetics ; metabolism ; Hyaluronic Acid ; pharmacology ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Neoplasm Invasiveness ; Phosphorylation ; Plasmids ; Protein Isoforms ; RNA, Messenger ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Signal Transduction ; Transfection

The aim of this study was to investigate the apoptosis-inducing effect of anti-CD44 monoclonal antibody IM7 on chronic myeloid leukemia (CML) stem/progenitor cells in vitro and to explore its possible mechanism. Leukemic stem/progenitor cells (LSPCs) expressing CD34(+), CD38(-) and CD123(+) were isolated from bone marrow (BM) cells of 20 patients with newly-diagnosed chronic myeloid leukemia by using EasySep(TM) magnetic beads. The percentage of apoptotic CML-LSPCs was assayed by Annexin-V/PI staining; the expression changes of c-myc and NF-kappaB mRNA were detected by real-time quantitative PCR (RQ-PCR) and RT-PCR; the NF-kappaB activity was detected by NF-kappaB Activation Nuclear Translocation Assay Kit; the BCL-2 protein expression was determined in the Western blot method. The results showed that the IM7 effectively induced apoptosis of CML-LSPCs; the mean percentage of early apoptotic cells significantly increased, as compared with the untreated control CML-LSPCs cells 12.58 +/- 2.84% vs 5.42 +/- 1.84% (p < 0.05). The c-myc, NF-kappaB mRNA expressions were down-regulated as compared with the control group (0.65 +/- 0.10 vs 1.00, 0.42 +/- 0.21 vs 1.00, respectively) (p < 0.01) by RQ-PCR and (0.49 +/- 0.09 vs 0.60 +/- 0.12, 0.47 +/- 0.11 vs 0.67 +/- 0.08, respectively)(p < 0.01) by RT-PCR. The BCL-2 protein level in CML-LSPCs treated with IM7 also decreased as compared with the control group (p < 0.01). In addition, the depression of NF-kappaB activity was observed through fluorescence microscope. It is concluded that the anti-CD44 monoclonal antibody IM7 effectively induces apoptosis of CML-LSPCs through down-regulating c-myc and bcl-2 mRNA expression, and decreasing NF-kappaB activity in CML-LSPCs.
Antibodies, Monoclonal ; pharmacology ; Apoptosis ; drug effects ; genetics ; Humans ; Hyaluronan Receptors ; immunology ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; metabolism ; NF-kappa B ; metabolism ; Neoplastic Stem Cells ; drug effects ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Tumor Cells, Cultured