Mesenchymal stem cells (MSCs) are attractive candidates for clinical repair or regeneration of damaged tissues. Oct4 and Sox2, which are essential transcription factors for pluripotency and self-renewal, are naturally expressed in MSCs at low levels in early passages, and their levels gradually decrease as the passage number increases. Therefore, to improve MSC proliferation and stemness, we introduced human Oct4 and Sox2 for conferring higher expansion and differentiation capabilities. The Oct4-IRES-Sox2 vector was transfected into human adipose tissue MSCs (ATMSCs) by liposomal transfection and used directly. Oct4 and Sox2 were successfully transfected into ATMSCs, and we confirmed maintenance of MSC surface markers without alterations in both red fluorescent protein (RFP) (control) and Oct4/Sox2-ATMSCs. Enhanced proliferative activity of Oct4/Sox2-ATMSCs was shown by WST-1 assay, and this result was further confirmed by cell counting using trypan blue exclusion for a long period. In addition, FACs cell cycle analysis showed that there was a reduction in the fraction of Oct4/Sox2-ATMSCs in G1 with a concomitant increase in the fraction of cells in S, compared with RFP-ATMSCs. Increased levels of cyclin D1 were also seen in Oct4/Sox2-ATMSCs, indicating acceleration in the transition of cells from G1 to S phase. Furthermore, Oct4/Sox2-overexpressing ATMSCs showed higher differentiation abilities for adipocytes or osteoblasts than controls. The markers of adipogenic or osteogenic differentiation were also upregulated by Oct4/Sox2 overexpression. The improvement in cell proliferation and differentiation using Oct4/Sox2 expression in ATMSCs may be a useful method for expanding the population and increasing the stemness of ATMSCs.
Adipose Tissue/cytology ; *Cell Differentiation ; *Cell Proliferation ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells/cytology/*metabolism/physiology ; Octamer Transcription Factor-3/genetics/*metabolism ; SOXB1 Transcription Factors/genetics/*metabolism

Animals ; Astrocytes ; cytology ; Cell Differentiation ; Cellular Reprogramming ; Induced Pluripotent Stem Cells ; cytology ; Kruppel-Like Transcription Factors ; genetics ; metabolism ; Mice ; Neurons ; cytology ; Octamer Transcription Factor-3 ; genetics ; metabolism

With the increasing use of culture-expanded mesenchymal stromal cells (MSCs) for cell therapies, factors that regulate the cellular characteristics of MSCs have been of major interest. Oxygen concentration has been shown to influence the functions of MSCs, as well as other normal and malignant stem cells. However, the underlying mechanisms of hypoxic responses and the precise role of hypoxia-inducible factor-1alpha (Hif-1alpha), the master regulatory protein of hypoxia, in MSCs remain unclear, due to the limited span of Hif-1alpha stabilization and the complex network of hypoxic responses. In this study, to further define the significance of Hif-1alpha in MSC function during their self-renewal and terminal differentiation, we established adult bone marrow (BM)-derived MSCs that are able to sustain high level expression of ubiquitin-resistant Hif-1alpha during such long-term biological processes. Using this model, we show that the stabilization of Hif-1alpha proteins exerts a selective influence on colony-forming mesenchymal progenitors promoting their self-renewal and proliferation, without affecting the proliferation of the MSC mass population. Moreover, Hif-1alpha stabilization in MSCs led to the induction of pluripotent genes (oct-4 and klf-4) and the inhibition of their terminal differentiation into osteogenic and adipogenic lineages. These results provide insights into the previously unrecognized roles of Hif-1alpha proteins in maintaining the primitive state of primary MSCs and on the cellular heterogeneities in hypoxic responses among MSC populations.
*Cell Differentiation ; Cell Proliferation ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics/*metabolism ; Kruppel-Like Transcription Factors/genetics/metabolism ; Mesenchymal Stromal Cells/cytology/*metabolism/physiology ; Octamer Transcription Factor-3/genetics/metabolism ; Protein Stability

BACKGROUNDMultidrug resistance (MDR) is a main reason for paclitaxel (TAX) treatment failure. Indirubin-3'-monoxime (IRO) and Matrine are traditional Chinese medicines, which may reverse the resistance of tumor cells to some chemotherapy drugs, but the relationship between paclitaxel resistance and Matrine is still unclear. The aim of this study was to explore the potential molecular mechanism of IRO and Matrine in reversal of TAX resistance.

METHODSIn this study, MTT assay was used to measure the non-cytotoxic dosage of IRO and Matrine on NCI-H520/TAX25 cells and determine the reversal extent of TAX resistance under non-toxic doses. In addition, RT-PCR and Western blotting were used to evaluate the mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 cells using semi-quantitative methods.

RESULTSThere was no obvious inhibition on sensitive cell strains and drug-resistant strains, when the final concentration was at lest 4 µmol/L for IRO and 100 µmol/L for Matrine. So 4 µmol/L of IRO and 100 µmol/L of Matrine were considered as the reversal dosage. When 4 µmol/L of IRO or 100 µmol/L of Matrine were used together with TAX, the sensitivity to TAX increased evidently in NCI-H520/TAX2 cells; the reversal rate of IRO and Matrine was about 1.92 (43.56/22.6 nmol/L) and 1.74 (43.56/25.0 nmol/L), respectively. The mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 decreased significantly (P < 0.05) after addition of IRO or Matrine in TAX treatment, compared to that of TAX treatment alone.

CONCLUSIONThe decrease in both mRNA expression and protein level of survivin, Oct-4, and Sox-2 might be the molecular mechanism, by which IRO and Matrine mediate the reversal of TAX resistance.

Alkaloids ; pharmacology ; Blotting, Western ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Humans ; Indoles ; pharmacology ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Octamer Transcription Factor-3 ; genetics ; metabolism ; Oximes ; pharmacology ; Paclitaxel ; pharmacology ; Quinolizines ; pharmacology ; SOXB1 Transcription Factors ; genetics ; metabolism

Embryonic stem cell is promising for regenerative medicine. However, its application is hampered by the utilization of eggs in most established methods. Recently, a new pluripotent stem cell establishing method was reported that, mouse and human differentiated cells could be induced reprogrammed into a pluripotent state by expressing exogenetic stem factors such as Oct4, Sox2, et al, through retroviral transduction. This approach avoiding egg use is a great breakthrough not only in stem cell technology but also present theory hypothesis of reprogramming. Here these works were reviewed in this article. Both the mechanism of induced reprogramming and the prospects of induced pluripotent stem cells were discussed.
Animals ; Cell Differentiation ; genetics ; Cells, Cultured ; Cellular Reprogramming ; drug effects ; genetics ; Humans ; Octamer Transcription Factor-3 ; metabolism ; Pluripotent Stem Cells ; cytology ; Retroviridae ; genetics ; SOXB1 Transcription Factors ; metabolism ; Transduction, Genetic

OBJECTIVETo explore the effects of bisphenol A (BPA) exposure on toxicity characteristic and OCT4 and SOX2 gene expression of mouse embryonic stem cells (mESC).

METHODSmESC were cultured, and treated with the doses of 10(-8), 10(-7), 10(-6), 10(-5), 10(-4) mol/L respectively of BPA and DMSO (the solvent control group)for 24 hours, and three groups of cells were treated with the same method. The morphological changes of mESC in the control and exposure groups were observed through an inverted microscope. Cell counting kit 8 (CCK8) was used to detect the effects of BPA on proliferation of mESC, and based on the results, the half inhibitory concentration (IC50) was calculated. Real-time fluorescent quantitative polymerase chain reaction (RT-QPCR) and western blotting were used to detect the expression of OCT4 and SOX2.

RESULTSBPA had certain toxicity on mESC, the treatment of BPA significantly increased cell toxicity in a concentration-dependent manner, and the IC50 was 4.3×10(-4) mol/L, combined with the BPA exposure concentration of the environment and the related literature, eventually taking the five concentrations of 10(-8), 10(-7), 10(-6), 10(-5), 10(-4) mol/L as the experimental groups. The mESC morphology were effected after the treatment of BPA for 24 h, compared with the control group, the number of cells decreased, appearing some floating cells, and the cell cloning became irregular and differentiation in the higher concentration groups. The OCT4 mRNA expression level in the 10(-7) mol/L (1.146 ± 0.087), 10(-6) mol/L (1.156 ± 0.030), 10(-5) mol/L (1.158 ± 0.103) and the 10(-4) mol/L (1.374 ± 0.053) dose group were all significantly higher than the control group (1.000 ± 0.000) (t values were -2.384, -2.953, -3.203, -4.021 respectively, P value all < 0.05). Meanwhile, the SOX2 mRNA expression level in the 10(-4) mol/L (1.113 ± 0.052) were higher than the control group (1.000 ± 0.000) (t value was -2.765, P value < 0.05). Moreover, the OCT4 protein expression level in the 10(-5) mol/L (1.360 ± 0.168) and 10(-4) mol/L (1.602 ± 0.151) were all significantly higher than the control group (1.000 ± 0.000) (t values were -3.538, -4.002 respectively, P value all < 0.05), while no obvious change of the SOX2 protein expression level was detected in all treated groups.

CONCLUSIONBPA in a certain dose range could upregulate the expression of OCT4 gene in mouse embryonic stem cells while had no significant effect on the expression of SOX2 gene.

Animals ; Benzhydryl Compounds ; toxicity ; Cells, Cultured ; Embryonic Stem Cells ; drug effects ; metabolism ; Gene Expression ; Mice ; Octamer Transcription Factor-3 ; genetics ; Phenols ; toxicity ; SOXB1 Transcription Factors ; genetics ; Signal Transduction ; drug effects

Antigens ; immunology ; Antigens, Neoplasm ; drug effects ; immunology ; metabolism ; Gallbladder Neoplasms ; immunology ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Neoplastic Stem Cells ; immunology ; Octamer Transcription Factor-3 ; genetics ; metabolism ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Tumor Cells, Cultured

The somatic cells can be induced into ES-like stem cells when retrovirally infected the defined transcription factors including Oct4, Sox2, Klf4 and c-Myc. These ES-like cells are named induced pluripotent stem (iPS) cells and this method is called iPS technology. Until the end of 2009, iPS cell lines have been generated in various animal species, such as mouse, human, rhesus monkey, rat and pig. Mouse iPS cells are also used to generate chimera mice and viable mice through the tetraploid complementation. Although iPS cells are extremely similar to ES cells in both morphology and growth features, to generate iPS cells do need the defined culture procedures. Based on the update global iPS technology development and the iPS studies in our laboratory, this paper focused on the establishment of iPS cell lines and improvement of iPS cell culture condition.
Animals ; Cell Culture Techniques ; methods ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; metabolism ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Kruppel-Like Transcription Factors ; genetics ; metabolism ; Octamer Transcription Factor-3 ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; SOXB1 Transcription Factors ; genetics ; metabolism ; Transcription Factors ; genetics ; metabolism

OBJECTIVE: To determine on the expression of prostate stem cell antigen (PCSA )and Oct-4 and detect their clinicopathological significance in benign and malignant lesions of the stomach. METHODS: EnVision immunohistochemistry for assaying the expression of PSCA and Oct-4 was used in paraffin-embedded sections from specimens of primary foci (n = 58) and metastatic foci of regional lymph nodes (n = 36) of gastric cancer, peritumoral tissues (n = 20), and benign lesions of the stomach (n = 80). RESULTS The positive rates of PSCA and Oct-4 were significantly higher in gastric cancer than those in peritumoral tissues and benign lesions (P<0.05 or P<0.01).The positive cases of PSCA and Oct-4 in peritumoral tissues and benign lesions showed mild- to severe-atypical hyperplasia. No difference of the positive rate of PSCA and Oct-4 was found between the primary foci and the metastatic foci of gastric cancer(P > 0.05). The positive rates of PSCA and Oct-4 were significantly lower in infiltrating depth T(1) to approximately T(2), non-metastasis of lymph nodes, metastasis of lymph nodes N1 site, and non-metastasis of distant organs than those in infiltrating depth T(3) to approximately T(4), metastasis of lymph nodes, metastasis of lymph node N(2) to approximately N(3) site, and metastasis of distant organs(P < 0.05 or P < 0.01).Conclusion The expressive levels of PSCA and Oct-4 might be related to the invasive potential, metastasis of lymph nodes, and distant organs, it suggested the expressions levels of PSCA and Oct-4 might be important markers for reflecting the biological behaviors and prognosis of gastric cancer.
Adenocarcinoma ; metabolism ; pathology ; Adult ; Aged ; Antigens, Neoplasm ; Biomarkers, Tumor ; Female ; GPI-Linked Proteins ; Humans ; Male ; Membrane Glycoproteins ; biosynthesis ; genetics ; Middle Aged ; Neoplasm Proteins ; biosynthesis ; genetics ; Octamer Transcription Factor-3 ; biosynthesis ; genetics ; Prognosis ; Stomach Neoplasms ; metabolism ; pathology

Increasing evidence suggests that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. Additionally, it is becoming apparent that cyclooxygenase (COX) signaling is associated with canine mammary tumor development. The goals of the present study were to investigate COX-2 expression patterns and their effect on CSC-mediated tumor initiation in primary canine mammary tissues and tumorsphere models using immunohistochemistry. Patterns of COX-2, CD44, octamer-binding transcription factor (Oct)-3/4, and epidermal growth factor receptor (EGFR) expression were examined in malignant mammary tumor (MMT) samples and analyzed in terms of clinicopathological characteristics. COX-2 and Oct-3/4 expression was higher in MMTs compared to other histological samples with heterogeneous patterns. In MMTs, COX-2 expression correlated with tumor malignancy features. Significant associations between COX-2, CD44, and EGFR were observed in low-differentiated MMTs. Comparative analysis showed that the levels of COX-2, CD44, and Oct-3/4 expression varied significantly among TSs of three histological grades. Enhanced COX-2 staining was consistently observed in TSs. Similar levels of staining intensity were found for CD44 and Oct-3/4, but EGFR expression was weak. Our findings indicate the potential role of COX-2 in CSC-mediated tumor initiation, and suggest that COX-2 inhibition may help treat canine mammary tumors by targeting CSCs.
Animals ; Antigens, CD44/genetics/metabolism ; Biomarkers, Tumor/genetics/metabolism ; Cell Transformation, Neoplastic/*genetics/metabolism ; Cyclooxygenase 2/*genetics/metabolism ; Dog Diseases/*genetics/metabolism ; Dogs ; Female ; Immunohistochemistry/veterinary ; Mammary Neoplasms, Animal/*genetics/metabolism ; Mammary Neoplasms, Experimental/*genetics/metabolism ; Neoplastic Stem Cells/*metabolism ; Octamer Transcription Factor-3/genetics/metabolism ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Retrospective Studies