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

OBJECTIVE: To investigate the effect of Piwil2-induced cancer stem-like cell (Piwil2-iCSC)-derived exosomes on the proliferation,migration and invasion of human umbilical cord blood-derived mesenchymal stem cells (hucMSCs). METHODS: Piwil2-iCSC-derived exosomes were isolated by ultracentrifugation and identified using transmission electron microscopy,nanoparticle tracking analysis and Western blotting.Exosome uptake assay was used to identify the pathway that Piwil2-iCSCderived exosomes utilized.HucMSCs were divided into control group,PBS intervention group and exosome intervention group,and CCK-8 assay,wound healing assay,Transwell assay,Western blotting and cell karyotype analysis were used to observe the proliferation,migration,invasion,expression levels of MMP2 and MMP9 proteins,and chromosome structure of hucMSCs. RESULTS: The diameter of Piwil2-iCSC-derived exosomes ranged from 50 nm to 100 nm,and most of them were oval or spherical capsules rich in CD9,CD63 and Piwil2 proteins.Exosomal uptake assay showed that the exosomes executed theirs functions after entering the cells.Compared with the control cells and PBS-treated cells,hucMSCs treated with the exosomes showed significantly increased number of proliferating cells (<0.05) with accelerated healing rate (<0.05 at 24 h;<0.01 at 48 h),increased invasive cells (<0.01),enhanced protein expressions of MMP2(<0.05 PBS group;<0.01 control group) and MMP9(<0.05),but their karyotype still remained 46XY without any abnormalities. CONCLUSIONS Piwil2-iCSC-derived exosomes can promote the proliferation,migration and invasion but does not cause cancer-like heterogeneity changes in hucMSCs.
Argonaute Proteins ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Exosomes ; physiology ; Fetal Blood ; cytology ; Humans ; Karyotyping ; Mesenchymal Stem Cells ; pathology ; Neoplasm Invasiveness ; Neoplastic Stem Cells ; Umbilical Cord ; Wound Healing

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

BRG1 (Brahma-related gene 1, BRG1) is the ATPase subunit of SWI/SNF chromatin remodeling complexes, which plays an important role in cell cycle regulation, DNA repair and tumor development. Unlike the evidence as tumor suppressor genes in the past reports, latest researches show that BRG1 plays an important role in sustaining the growth of leukemia cells in acute myeloid leukemia, and these effects on normal hematopoietic stem cells are dispensable. Further studies of the role and mechanism of BRG1 in acute myeloid leukemia will contribute to the development of a new and promising targeted therapy strategy. This article reviews the role of BRG1 on leukemia cells and leukemia stem cells in AML and discusses the related mechanism, which providing some reference for the targeted treatment strategy of AML.
Chromatin ; Chromatin Assembly and Disassembly ; DNA Helicases ; genetics ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Neoplastic Stem Cells ; cytology ; Nuclear Proteins ; genetics ; Transcription Factors ; genetics

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

In this study, we aimed to investigate the influences of conditioned medium from human umbilical vein endothelial cells (HUVEC) on cancer stem cell phenotype of human hepatoma cells. HUVEC and human hepatoma cells (MHCC97H) were cultured, respectively, and then the MHCC97H cells were co-cultured with conditioned medium from HUVEC (EC-CM) with Transwell system. Anti-cancer drug sensitivity, colony-formation, migration/invasion ability, expression of cancer stem cell marker and sphere formation were performed to determine the cancer stem cell phenotype in MHCC97H cells. We found that MHCC97H cells co-cultured with EC-CM exhibited significantly higher colony-formation ability and lower sensitivity of anti-cancer drugs 5-FU and Cis. Transwell assay showed that treatment with EC-CM obviously increased migration and invasion of MHCC97H cells. Moreover, increased sphere forming capability and expression of CD133 in MHCC97H cells were observed after co-cultured with EC-CM. These results suggested that EC-CM could promote cancer stem cell phenotype of hepatoma cells.
Antineoplastic Agents ; pharmacology ; Carcinoma, Hepatocellular ; Cell Line, Tumor ; Coculture Techniques ; Culture Media, Conditioned ; Fluorouracil ; pharmacology ; Human Umbilical Vein Endothelial Cells ; chemistry ; Humans ; Liver Neoplasms ; Neoplastic Stem Cells ; cytology ; Phenotype

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

OBJECTIVETo study the cell morphology change in dormancy and proliferation stage of colorectal cancer stem cells in order to provide reference to the treatment of colorectal cancer.

METHODSThe subpopulation of EpCAM(high)/CD44(+)/CD133(+) was isolated from fresh colorectal cancer tissues. These cells were tested by xenograft assay in NOD/SCID nude mice. Colorectal cancer stem cells underwent three-dimensional culture, and the growth curve of stem cells was drawn by WST-1. The expression of P27 and Ki-67 was examined by flow cytometry to understand the phase of dormancy and proliferation of colorectal cancer stem cells. Then the morphological differences of colorectal cancer stem cells between dormant and proliferation stages were recognized by immunofluorescence staining of actin.

RESULTSThe percentage of EpCAM(high)/CD44(+)/CD133(+) was 1.6%, and the subpopulation was confirmed to be colorectal cancer stem cells by means of the experiment of tumorigenicity in vivo. The growth curve of colorectal cancer stem cells was "S" type. Colorectal cancer stem cells grew slowly in the first three days. The expression of P27 was gradually up-regulated, and the level of Ki-67 was very low. These cells remained quiescence, which was the so-called dormancy. The expression of Ki-67 of colorectal cancer stem cells was at high level since the fourth day, and the P27 level was very low. According to the growth curve, this period belonged to the proliferative stage of colorectal cancer stem cells. On immunofluorescence staining, colorectal cancer stem cells with high level of P27 were round, large, and few pseudopodium, but no obvious death was found. These cells showed characteristics of dormancy. In contrast, the stem cells with high level of Ki-67 had much pseudopodium, showing proliferation and invasion.

CONCLUSIONSCancer recurrence and metastasis may be associated with the change of growth state of cancer stem cells. Colorectal cancer stem cells in the proliferation stage show greater proliferative and invasive ability as compared to the dormancy stage, which provides a new perspective for the treatment of colorectal cancer, and recurrence and metastasis of other tumors.

Animals ; Antigens, CD ; Antigens, Neoplasm ; Cell Adhesion Molecules ; Cell Cycle Checkpoints ; Cell Proliferation ; Cell Shape ; Colorectal Neoplasms ; Epithelial Cell Adhesion Molecule ; Glycoproteins ; Mice ; Mice, Inbred NOD ; Mice, Nude ; Mice, SCID ; Neoplasm Recurrence, Local ; Neoplastic Stem Cells ; cytology