OBJECTIVE: To isolate tumor stem-like cells from human epithelial ovarian cancer SKOV3 cells and explore their role in the formation of vascularization mimicry (VM). METHODS: SKOV3 cells were passaged to the 7th generation by suspension culture in serum-free medium, and the percentages of CD133- and CD117-positive cells in the 1st, 3rd, 5th and 7th generations were analyzed using flow cytometry. The proliferative activity of the cells sorted from the 7th generation SKOV3 cells was assessed with colony formation assay. A three-dimensional cell culture model was established to compare the ability of VM formation between the sorted cells and the parental SKOV3 cells. The expression levels of matrix metalloproteinases-2 (MMP-2) and MMP-9 in the two groups were detected using real-time PCR and Western blotting. RESULTS: Some SKOV3 cells formed typical cell spheres with suspension growth in serum-free medium and were passaged to the 7th generation. Flow cytometry revealed that the percentage of CD133-positive cells increased with cell passaging. The cloning efficiency of the sorted cells was significantly higher than that of the parental SKOV3 cells (50.33% 5.33%, < 0.001). The VM formation ability of the sorted cells was stronger than that of the parental SKOV3 cells in the three-dimensional cell culture system. RT-PCR and Western blotting showed that the expression levels of MMP-2 and MMP-9 were significantly higher in the 7th passage cells than in the parental cells ( < 0.05). CONCLUSIONS The sorted cells from SKOV3 cells cultured in serum-free medium exhibit biological properties of tumor stem cells with strong VM formation ability, suggesting their role in VM formation.
Carcinoma, Ovarian Epithelial ; pathology ; Cell Line, Tumor ; Cell Movement ; Female ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Neoplastic Stem Cells ; cytology ; Neovascularization, Pathologic ; pathology ; Ovarian Neoplasms ; pathology

Cancer stem cells (CSCs) have tumor initiation, self-renewal, metastasis and chemo-resistance properties in various tumors including colorectal cancer. Targeting of CSCs may be essential to prevent relapse of tumors after chemotherapy. Phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) signals are central regulators of cell growth, proliferation, differentiation, and apoptosis. These pathways are related to colorectal tumorigenesis. This study focused on PI3K and mTOR pathways by inhibition which initiate differentiation of SW620 derived CSCs and investigated its effect on tumor progression. By using rapamycin, LY294002, and NVP-BEZ235, respectively, PI3K and mTOR signals were blocked independently or dually in colorectal CSCs. Colorectal CSCs gained their differentiation property and lost their stemness properties most significantly in dual-blocked CSCs. After treated with anti-cancer drug (paclitaxel) on the differentiated CSCs cell viability, self-renewal ability and differentiation status were analyzed. As a result dual-blocking group has most enhanced sensitivity for anti-cancer drug. Xenograft tumorigenesis assay by using immunodeficiency mice also shows that dual-inhibited group more effectively increased drug sensitivity and suppressed tumor growth compared to single-inhibited groups. Therefore it could have potent anti-cancer effects that dual-blocking of PI3K and mTOR induces differentiation and improves chemotherapeutic effects on SW620 human colorectal CSCs.
AC133 Antigen/genetics/metabolism ; Animals ; Antineoplastic Agents/pharmacology/therapeutic use ; Cell Differentiation/*drug effects ; Cell Line, Tumor ; Cell Survival/drug effects ; Chromones/pharmacology/therapeutic use ; Colorectal Neoplasms/drug therapy/metabolism/pathology ; Humans ; Imidazoles/pharmacology/therapeutic use ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Morpholines/pharmacology/therapeutic use ; Neoplastic Stem Cells/cytology/drug effects/metabolism ; Paclitaxel/pharmacology/therapeutic use ; Phosphatidylinositol 3-Kinases/*antagonists & inhibitors/metabolism ; Quinolines/pharmacology/therapeutic use ; SOXB1 Transcription Factors/genetics/metabolism ; Signal Transduction/*drug effects ; Sirolimus/pharmacology/therapeutic use ; TOR Serine-Threonine Kinases/*antagonists & inhibitors/metabolism ; Xenograft Model Antitumor Assays

Acute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-β in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-β promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.
Acute Disease ; Adolescent ; Adult ; Angiogenesis Inducing Agents ; immunology ; metabolism ; pharmacology ; Angiopoietin-1 ; genetics ; immunology ; pharmacology ; Angiopoietin-2 ; genetics ; immunology ; pharmacology ; Antineoplastic Agents ; therapeutic use ; Female ; Gene Expression Regulation, Neoplastic ; Graft vs Host Disease ; genetics ; immunology ; pathology ; Hematopoietic Stem Cell Transplantation ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; immunology ; Humans ; Leukemia, Myeloid ; genetics ; immunology ; pathology ; therapy ; Lymphoma, Non-Hodgkin ; genetics ; immunology ; pathology ; therapy ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; immunology ; pathology ; therapy ; Retrospective Studies ; Signal Transduction ; Transplantation, Homologous ; Tumor Necrosis Factor-alpha ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics ; immunology

OBJECTIVETo investigate the effect of Emodin combined with 3'-azido-3'-deoxythymidine (AZT) on the proliferation and apoptosis of concentrated leukemia stem cells (CLSC)-human acute myeloid leukemia KG-la cells and expression of BCL-2, NF-κB and TGF-β.

METHODSThe tumor stem cell-like subpopulation in human leukemia cell line KG-1a was enriched with 5-fluorouracil (5-FU). The CD34⁺ CD38⁻ subpopulation in the KG-1a cells was detected with flow cytometry, the cell proliferation was detected by MTT method to study the of Emodin and AZT in the CLSC. The cell apoptosis was analyzed by flow cytometry. The expression of NF-κB, BCL-2 and TGF-β mRNA and proteins were measured with RT-PCR and Western blot respectively.

RESULTSAs compared with cells treated with mentioned above drugs alone, the inhibition of proliferation potential and apoptosis rate of cells in combination group markedly increase with time and concentration dependent member (P < 0.01), the expression of NF-κB, BCL-2 and TGF-β mRNA and proteins decreased.

CONCLUSIONEmodin combined AZT can synergistically inhibit the proliferation, induce cell apoptosis, and down regulate the expression of NF-κB, BCL-2 and TGF-β mRNA and proteins in the CLSC, the possible mechanism of synergistic effect may be associated with inhibiton of BCL-2 activation and down-regulation of the expression of NF-κB, and TGF-β.

Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Emodin ; pharmacology ; Humans ; Leukemia ; NF-kappa B p50 Subunit ; metabolism ; Neoplastic Stem Cells ; cytology ; drug effects ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Zidovudine ; pharmacology

OBJECTIVETo explore the biological mechanisms underlying Angelica sindsis polysaccharide (ASP) -induced aging of human-derived leukemia stem cells (LSCs) in vitro.

METHODAcute myelogenous leukemia stem cells were isolated by magnetic activated cell sorting (MACS). The ability of LSC proliferation treated by various concentration of ASP(20-80 mg · L(-1)) in vitro for 48 hours were tested using cell counting Kit-8 ( CCK8) , colony forming were evaluated by methylcellulose CFU assay. The ultra structure changes of AML CD34+ CD38- cells were analyzed by transmission electron microscopy. The aging cells were detected with senescence-β-galactosidase Kit staining. Expression of aging-related p53, p21, p16, Rb mRNA and P16, Rb, CDK4 and Cyclin E protein were detected by quantitative reverse transcription polymerase chain reaction( qRT-PCR) and Western blotting, respectively.

RESULTThe purity of the CD34 + CD38 - cells is (91.15 ± 2.41)% after sorted and showed good morphology. The proliferation of LSC was exhibited significantly concentration-dependent inhibited after exposure to various concentration of ASP. Treated by 40 mg · L(-1) ASP for 48 hours, the percentage of positive cells stained by SA-β-Gal was dramatically increased (P < 0.01) and the colony-formed ability has been weakened (P < 0.01). The observation of ultrastructure showed that cell heterochromatin condensation and fragmentation, mitochondrial swelling, lysosomes increased in number. Aging-related p53, p21, p16, Rb and P16, Rb were up-regulated, protein regulatory cell-cycle CDK4 and Cyclin E were down-regulated. ASP may induce the senescence of LSCs effectively in vitro, P16-Rb cell signaling pathway play a significant role in this process.

CONCLUSIONASP can induce human leukemia stem cell senescence in vitro, the mechanism involved may be related to ASP regulation P16-Rb signaling pathways.

Angelica sinensis ; chemistry ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; genetics ; metabolism ; Cells, Cultured ; Cellular Senescence ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Leukemic ; drug effects ; Humans ; Leukemia ; drug therapy ; genetics ; metabolism ; physiopathology ; Neoplastic Stem Cells ; cytology ; drug effects ; Polysaccharides ; pharmacology ; Signal Transduction ; drug effects

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

PURPOSE: Cancer stem cells have recently been thought to be closely related to tumor development and reoccurrence. It may be a promising way to cure malignant glioma by using glioma stem cell-targeted dendritic cells as a tumor vaccine. In this study, we explored whether pulsing dendritic cells with antigens of glioma stem cells was a potent way to induce specific cytotoxic T lymphocytes and anti-tumor immunity. MATERIALS AND METHODS: Cancer stem cells were cultured from glioma cell line U251. Lysate of glioma stem cells was obtained by the repeated freezing and thawing method. Dendritic cells (DCs) were induced and cultured from the murine bone marrow cells, the biological characteristics were detected by electron microscope and flow cytometry. The DC vaccine was obtained by mixing DCs with lysate of glioma stem cells. The DC vaccine was charactirizated through the mixed lymphocyte responses and cell killing experiment in vitro. Level of interferon-gamma (IFN-gamma) in the supernatant was checked by ELISA. RESULTS: After stimulation of lysate of glioma stem cell, expression of surface molecules of DC was up-regulated, including CD80, CD86, CD11C and MHC-II. DCs pulsed with lysate of glioma stem cells were more effective than the control group in stimulating original glioma cells-specific cytotoxic T lymphocytes responses, killing glioma cells and boosting the secretion of IFN-gamma in vitro. CONCLUSION: The results demonstrated DCs loaded with antigens derived from glioma stem cells can effectively stimulate naive T cells to form specific cytotoxic T cells, kill glioma cells cultured in vitro.
Animals ; Antigens, Neoplasm/immunology ; Apoptosis ; Brain Neoplasms/*therapy ; Cancer Vaccines/*therapeutic use ; Cell Line, Tumor ; Cell Proliferation ; Dendritic Cells/*cytology ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Glioma/*therapy ; Humans ; Interferon-gamma/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Neoplastic Stem Cells/*cytology ; T-Lymphocytes, Cytotoxic/immunology

Multiparametric flow cytometry (MFC) allows discrimination between normal and neoplastic plasma cells (NeoPCs) within the bone marrow plasma cell (BMPC) compartment. This study sought to characterize immunophenotypes and quantitate the proportion of NeoPCs in BMPCs to diagnose plasma cell myeoma (PCM) and evaluate the prognostic impact of this method. We analyzed the MFC data of the bone marrow aspirates of 76 patients with PCM and 33 patients with reactive plasmacytosis. MFC analysis was performed using three combinations: CD38/CD138/-/CD45; CD56/CD20/CD138/CD19; and CD27/CD28/CD138/CD117. The plasma cells of patients with reactive plasmacytosis demonstrated normal immunophenotypic patterns. Aberrant marker expression was observed in NeoPCs, with negative CD19 expression observed in 100% of cases, CD56+ in 73.7%, CD117+ in 15.2%, CD27- in 10.5%, CD20+ in 9.2%, and CD28+ in 1.3%. In PCM patients, more than 20% of NeoPCs/BMPCs were significantly associated with factors suggestive of poor clinical outcomes. Patients who were CD27- or CD56+/CD27-, demonstrated shorter overall survival than patients of other CD56/CD27 combinations. Our results support the clinical value of immunophenotyping and quantifying NeoPCs in PCM patients. This strategy could help to reveal poor prognostic categories and delineate surrogate markers for risk stratification in PCM patients.
Adult ; Aged ; Aged, 80 and over ; Antigens, CD27/metabolism ; Antigens, CD56/metabolism ; Asian Continental Ancestry Group ; Bone Marrow Cells/*cytology/metabolism ; Female ; Flow Cytometry ; Humans ; *Immunophenotyping ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Multiple Myeloma/metabolism/mortality/*pathology ; Neoplasm Staging ; Neoplastic Stem Cells/*cytology/metabolism ; Prognosis ; Republic of Korea ; Risk Factors

OBJECTIVETo dynamically investigate the morphology of human gastric cancer SGC-7901 cell clones, and then compare the tumorigenic ability of different clones in order to identify the tumor stem cell clones.

METHODSClones derived from gastric cancer SGC-7901 cells were assessed by morphological observation, and the clone formation rate and proportion of each clone were calculated. The expression of CD44 and CDX2 in different clones was detected by immunofluorescence microscopy and Western blot. Furthermore, different clones were isolated and cultured, and their self-renewal property was assayed. Cells of different clones were subcutaneously inoculated into nude mice and the tumorigenic ability of each group was determined.

RESULTSClones derived from gastric cancer SGC-7901 cells had three types, i.e. clones of tight, transitional and loose types. The total clone formation rate was (9.80 ± 1.07)%, and the proportion of tight, transitional and loose type clones was 10.2%, 56.0% and 33.8%, respectively. The results of immunofluorescence microscopic examination showed that the signal of CD44 was significantly stronger in the tight clones than in the transitional and loose clones, however, the signal of CDX2 was weakest in the tight colonies. The results of Western blot were consistent with that of immunofluorescence microscopic observation. SGC-7901 cells of tight clones possessed strong ability of self-renewal and in vivo tumorigenicity in the nude mice.

CONCLUSIONSGC-7901 cell clones vary in morphology and differentiation, and the tight type clones may include rich gastric cancer stem cells.

Animals ; CDX2 Transcription Factor ; Cell Differentiation ; Cell Line, Tumor ; Cell Proliferation ; Clone Cells ; classification ; Female ; Homeodomain Proteins ; metabolism ; Humans ; Hyaluronan Receptors ; metabolism ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Neoplastic Stem Cells ; cytology ; metabolism ; Random Allocation ; Stomach Neoplasms ; metabolism ; pathology

OBJECTIVETo detect the inhibitory effect of all-trans retinoic acid(ATRA) on breast cancer stem cells (CSCs).

METHODSThe inhibitory effect of ATRA on MCF-7 and SK-BR-3 cell lines was analyzed using a Cell Counting Kit-8 (CCK-8). The proportion of CD44(+)CD24(-) tumor cells of the two cell lines were measured before and after the ATRA treatment, and the role of ATRA in the regulation of CSC self-renewing ability was evaluated with a tumor sphere assay. The tumor spheres were grown in an adherent culture to evaluate the ATRA-induced differentiation of breast cancer stem cells.

RESULTSATRA effectively inhibited the unsorted cells and stem cells, but the CSCs were more sensitive to ATRA. At a concentration of 10(-6) mol/L, the inhibitory rate of MCF-7 unsorted cells and stem cells were (8.66 ± 1.06)% and (21.09 ± 3.25)%, respectively (P = 0.004). For SK-BR-3 cells, the rates were (39.19 ± 1.47)% and (51.22 ± 2.80)%, respectively (P = 0.005). The self-renewing ability of the CSCs was impaired by ATRA at a concentration of 10(-6) mol/L. The rate of MCF-7 and SK-BR-3 stem cells to form tumor sphere was 5.2% (5/96) and 13.5% (13/96), respectively. For the control group, it was 86.5% (83/96) and 93.8% (90/96), respectively (P < 0.001). ATRA also promoted the CD44(+)CD24(-) subpopulation to differentiate. SK-BR-3 stem cells were grown in an adherent culture. After using ATRA, the proportion of CD44(+)CD24(-) cells was (48.1 ± 2.5)% and that of the control group was (86.6 ± 2.5)% (P < 0.001).

CONCLUSIONSATRA effectively inhibits breast NCSCs and CSCs, but CSCs are more sensitive to ATRA. ATRA impairs the self-renewing ability of CSCs and promotes CSCs to differentiate.

Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; metabolism ; pathology ; CD24 Antigen ; metabolism ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Female ; Humans ; Hyaluronan Receptors ; metabolism ; Neoplastic Stem Cells ; cytology ; drug effects ; Tretinoin ; pharmacology