Levels Of Oct4 Research Articles

ALDH2 promotes cancer stemness and metastasis in colorectal cancer through activating β-catenin signaling.

Colorectal cancer (CRC) is the primary cause of death from gastrointestinal cancers. Aldehyde dehydrogenase 2 (ALDH2), a crucial mitochondrial enzyme for the oxidative pathway of alcohol metabolism, plays a dual role in cancer progression. In some cancers, it is tumor suppressive; in others, it drives cancer progression. However, whether targeting ALDH2 has any therapeutic implications or prognostic value in CRC is still unclear. Here, we investigated the role of ALDH2 in CRC progression by targeting its enzymatic activity rather than gene expression. We found that inhibiting ALDH2 by CVT-10216 and daidzein significantly decrease migration and stemness properties of both DLD-1 and HCT 116 cells, whereas activating ALDH2 by Alda-1 enhances migration rate. Concomitantly, ALDH2 inhibition by both CVT-10216 and daidzein downregulates the mRNA levels of fibronectin, snail, twist, MMP7, CD44, c-Myc, SOX2, and OCT-4, which are oncogenic in the advanced stage of CRC. Furthermore, Gene Set Enrichment Analysis (GSEA) on ALDH2 co-expressed genes from The Cancer Genome Atlas (TCGA) revealed that MYC target gene sets are upregulated. We found that ALDH2 inhibition decreased the nuclear protein levels of pGSK3β serine 9 and c-Myc. This suggests that ALDH2 probably targets β-catenin signaling in CRC cells. Together, our results demonstrate the prognostic value of ALDH2 in CRC as it regulates both CRC stemness and migration. Our findings also propose that the plant-derived isoflavone daidzein could be a potential chemotherapeutic drug targeting ALDH2 in CRC.

Impact of the Stimulation and Inhibition of NAD<sup>+</sup> Biosynthesis on the Maintenance of Pluripotency in Mouse Embryonic Stem Cells

Nicotinamide adenine dinucleotide (NAD+) plays a key role in cellular metabolism and signaling. In recent years, evidence has accumulated that NAD+-dependent processes are involved in the regulation of pluripotency and differentiation of mammalian embryonic stem cells. The major means to maintain NAD+ levels in mammalian cells is through its biosynthesis from various forms of vitamin B3. In this study, we examined how stimulation and inhibition of NAD+ biosynthesis affect the maintenance of the pluripotency of mouse embryonic stem cells E14 Tg2a (E14 cells). The pluripotency status of E14 cells was assessed by immunocytochemical and immunoblotting analysis using antibodies to the pluripotency factor Oct4, as well as by staining for alkaline phosphatase. Using NMR spectroscopy, we have found that the concentration of NAD+ in pluripotent E14 cells cultured in the presence of LIF is about 4 nmol/mg, and it remains unchanged after induction of differentiation with retinoic acid. We have also demonstrated that pharmacological stimulation of NAD+ biosynthesis by nicotinamide riboside increases the level of intracellular NAD+ by 20%, but it does not affect the maintenance of pluripotency in E14 cells. Moreover, under conditions of critical depletion of NAD+ pool by Nampt inhibition with FK866 E14 cells maintained pluripotency, though the expression level of Oct4 was decreased.

Sodium selenite preserves rBM-MSCs’ stemness, differentiation potential, and immunophenotype and protects them against oxidative stress via activation of the Nrf2 signaling pathway

BackgroundThe physiological level of reactive oxygen species (ROS) is necessary for many cellular functions. However, during the in-vitro manipulations, cells face a high level of ROS, leading to reduced cell quality. Preventing this abnormal ROS level is a challenging task. Hence, here we evaluated the effect of sodium selenite supplementation on the antioxidant potential, stemness capacity, and differentiation of rat-derived Bone Marrow MSCs (rBM-MSCs) and planned to check our hypothesis on the molecular pathways and networks linked to sodium selenite’s antioxidant properties.MethodsMTT assay was used to assess the rBM-MSCs cells’ viability following sodium selenite supplementation (concentrations of: 0.001, 0.01, 0.1, 1, 10 µM). The expression level of OCT-4, NANOG, and SIRT1 was explored using qPCR. The adipocyte differentiation capacity of MSCs was checked after Sodium Selenite treatment. The DCFH-DA assay was used to determine intracellular ROS levels. Sodium selenite-related expression of HIF-1α, GPX, SOD, TrxR, p-AKT, Nrf2, and p38 markers was determined using western blot. Significant findings were investigated by the String tool to picture the probable molecular network.ResultsMedia supplemented with 0.1 µM sodium selenite helped to preserve rBM-MSCs multipotency and keep their surface markers presentation; this also reduced the ROS level and improved the rBM-MSCs’ antioxidant and stemness capacity. We observed enhanced viability and reduced senescence for rBM-MSCs. Moreover, sodium selenite helped in rBM-MSCs cytoprotection by regulating the expression of HIF-1 of AKT, Nrf2, SOD, GPX, and TrxR markers.ConclusionsWe showed that sodium selenite could help protect MSCs during in-vitro manipulations, probably via the Nrf2 pathway.

Supplementing culture medium with the weak acid, 5,5-dimethyl-2,4-oxazolidinedione (DMO) limits the developmentof aneuploid mouse embryos through a Trp53-dependent mechanism.

This study was designed to determine if DMO limits in vitro development of aneuploid-enriched mouse embryos by activating a Trp53-dependent mechanism. Mouse cleavage-stage embryos were treated with reversine to induce aneuploidy or vehicle to generate controls, and then cultured in media supplemented with DMO to reduce the pH of the culture media. Embryo morphology was assessed by phase microscopy. Cell number, mitotic figures, and apoptotic bodies were revealed by staining fixed embryos with DAPI. mRNA levels of Trp53, Oct-4, and Cdx2 were monitored by quantitative polymerase chain reactions (qPCRs). The effect of Trp53 on the expression of Oct-4 and Cdx2 was assessed by depleting Trp53 using Trp53 siRNA. Aneuploid-enriched late-stage blastocysts were morphologically indistinguishable from control blastocysts but had fewer cells and reduced mRNA levels of Oct-4 and Cdx2. Adding 1mM DMO to the culture media during the 8-cell to blastocyst transition reduced the formation of aneuploid-enriched late-stage blastocysts but not control blastocysts and further suppressed the levels of Oct-4 and Cdx2 mRNA. Trp53 RNA levels in aneuploid-enriched embryos that were exposed to DMO were > twofold higher than controls, and Trp53 siRNA levels reduced the levels of Trp53 and increased levels of Oct-4 and Cdx2 mRNA by > twofold. These studies suggest that the development of morphologically normal aneuploid-enriched mouse blastocysts can be inhibited by adding low amounts of DMO to the culture media, which results in elevated levels of Trp53 mRNA that suppresses Oct-4 and Cdx2 expression.

Chemokine CCL2 Activates Hypoxia Response Factors Regulating Pluripotency and Directed Endothelial Differentiation of Human Pluripotent Stem Cells

Human pluripotent stem cell (PSC) research is currently focused on selecting conditions and growth factors that better mimic preimplantation development and germ cell differentiation, which is important for disease modeling using PSC. Previously, it was shown that in the presence of the chemokine CCL2, human PSCs acquire properties attributable for preimplantation blastomeres, namely, they activate the JAK-STAT3 signalling pathway and increase the mRNA level of the hypoxic response genes. However, CCL2 is practically not used in the human PSCs cultivation, and its effect is described in a single study. We continued to study the CCL2 effect on human PSC and showed that human embryonic and induced pluripotent stem cells cultured with CCL2 have an increased protein level of the oxygen-dependent subunits HIF1A and HIF2A, which are necessary to trigger the hypoxic response, as well as elevated protein levels of the key pluripotency transcription factors OCT4, NANOG, KLF4, SOX2, and TFCP2L1. In addition, the presence of CCL2 had a positive effect on directed endothelial differentiation, accelerating the maturation of progenitors and enhancing the angiogenic potential of differentiated derivatives.

Inhibition of PIM Kinases Promotes Neuroblastoma Cell Differentiation to a Neuronal Phenotype

BackgroundNeuroblastoma arises from aberrancies in neural stem cell differentiation. PIM kinases contribute to cancer formation, but their precise role in neuroblastoma tumorigenesis is poorly understood. In the current study, we evaluated the effects of PIM kinase inhibition on neuroblastoma differentiation. MethodsVersteeg database query assessed the correlation between PIM gene expression and the expression of neuronal stemness markers and relapse free survival. PIM kinases were inhibited with AZD1208. Viability, proliferation, motility were measured in established neuroblastoma cells lines and high-risk neuroblastoma patient-derived xenografts (PDXs). qPCR and flow cytometry detected changes in neuronal stemness marker expression after AZD1208 treatment. ResultsDatabase query showed increased levels of PIM1, PIM2, or PIM3 gene expression were associated with higher risk of recurrent or progressive neuroblastoma. Increased levels of PIM1 were associated with lower relapse free survival rates. Higher levels of PIM1 correlated with lower levels of neuronal stemness markers OCT4, NANOG, and SOX2. Treatment with AZD1208 resulted in increased expression of neuronal stemness markers. ConclusionsInhibition of PIM kinases differentiated neuroblastoma cancer cells toward a neuronal phenotype. Differentiation is a key component of preventing neuroblastoma relapse or recurrence and PIM kinase inhibition provides a potential new therapeutic strategy for this disease.

The prognostic effect of immunohistochemical staining rates in patients with non-muscle-invasive bladder cancer.

Despite the follow-up protocols developed in non-muscle-invasive bladder cancer patients, progression and recurrence could not be prevented. We aimed to investigate whether proteins such as OCT-4, CD47, p53, Ki-67, and Survivin, which increase in bladder cancer cells, can be used as prognostic markers for patients with non-muscle-invasive bladder cancer. The study included a total of 89 patients with newly diagnosed non-muscle-invasive bladder cancer between January 2015 and December 2020. Levels of OCT-4, CD47, p53, Kİ-67, and Survivin proteins in cancer cells were determined with a semi-quantitative immunohistochemical experiment. Pathological data and survival rates were compared according to the staining rates. Data obtained in the study were analyzed statistically with SPSS 22.0 (SPSS, Chicago, IL, USA). The mean age of the patients was 64.25 ± 9.91 years, and the median follow-up period was 55 months. Recurrence rate was determined to be 36% (n = 32), and the rate of progression at 40.4% (n = 36). The staining rates were stronger for each marker in the progression group and advanced-stage tumors (p < 0.001). The findings of the multivariate analysis carried out as part of the study showed that older age and higher tumor stage were independent risk factors for recurrence-free survival (HR = 1.048 and 7.074, respectively; P = 0.02). Also, higher tumor stages, diameters, and grades were associated with reduced progression-free survival (HR = 0.105, 0.395, 0.225, respectively; P < 0.05). Although immunohistochemical staining rates are promising, it is more appropriate to use tumor characteristics when assessing survival rate in patients with non-muscle-invasive bladder cancer.

The Role of Box A of HMGB1 in Enhancing Stem Cell Properties of Human Mesenchymal Cells: A Novel Approach for the Pursuit of Anti-aging Therapy.

Box A is a highly conserved DNA-binding domain of high-mobility group box 1 (HMGB1) and has been shown to reverse senescence and aging features in many cell models. We investigated whether the activation of box A can influence stem cell properties. Human dermal papilla (DP) cells and primary human white pre-adipocytes (HWPc) were employed as mesenchymal cell models. Box A-overexpressing plasmids were used to induce cellular box A expression. mRNA and protein levels of stemness markers POU class 5 homeobox 1 pseudogene 5 (OCT4, HGNC: 9221), Nanog homeobox (NANOG, HGNC: 20857), and SRY-box transcription factor 2 (SOX2, HGNC:11195) in DP cells and HWPc were measured by real-time polymerase chain reaction and immunofluorescence analysis, respectively. Transfection efficiency of box A-overexpressing plasmid was 80% and 50% in DP cells and HWPc, respectively. The proliferative rate of both cell types significantly increased 72 h after transfection. Levels of OCT4, NANOG and SOX2 mRNA and protein expression were significantly increased in box A-transfected DP cells and HWPc compared to empty plasmid-transfected cells. Immunofluorescence analysis confirmed the induction of OCT4, NANOG and SOX2 protein expression in response to box A in DP cells and HWPc. OCT4 and SOX2 were expressed in both the nuclear and cytoplasmic compartments, while NANOG was intensely located in the nucleus of box A-transfected cells. Our findings suggest that box A may potentially enhance stemness, which may have significant benefits in improving stem cell function due to aging processes and disease. This research may have implications for regenerative medicine applications.

Inhibitory Effect and Mechanism of Ursolic Acid on Cisplatin-Induced Resistance and Stemness in Human Lung Cancer A549 Cells.

The survival rate of lung cancer patients remains low largely due to chemotherapy resistance during treatment, and cancer stem cells (CSCs) may hold the key to targeting this resistance. Cisplatin is a chemotherapy drug commonly used in cancer treatment, yet the mechanisms of intrinsic cisplatin resistance have not yet been determined because lung CSCs are hard to identify. In this paper, we proposed a mechanism relating to the function of ursolic acid (UA), a new drug, in reversing the cisplatin resistance of lung cancer cells regulated by CSCs. Human lung cancer cell line A549 was selected as the model cell and treated to become a cisplatin-resistant lung cancer cell line (A549-CisR), which was less sensitive to cisplatin and showed an enhanced capability of tumor sphere formation. Furthermore, in the A549-CisR cell line expression, levels of pluripotent stem cell transcription factors Oct-4, Sox-2, and c-Myc were increased, and activation of the Jak2/Stat3 signaling pathway was promoted. When UA was applied to the cisplatin-resistant cells, levels of the pluripotent stem cell transcription factors were restrained by the inhibition of the Jak2/Stat3 signaling pathway, which reduced the enrichment of tumor stem cells, and in turn, reversed cisplatin resistance in lung cancer cells. Hence, as a potential antitumor drug, UA may be able to inhibit the enrichment of the lung CSC population by inhibiting the activation of the Jak2-Stat3 pathway and preventing the resistance of lung cancer cells to cisplatin.

Knockdown of CENPU inhibits cervical cancer cell migration and stemness through the FOXM1/Wnt/β-catenin pathway

Currently, the clinical outcome of cervical cancer (CC) is still undesirable, and it is urgent to explore more treatment strategies for CC. In this study, the effects of CENPU on migration and stemness of CC was studied. The CENPU expression were retrieved from The Cancer Genome Atlas (TCGA). The effects of CENPU on the viability and proliferation of cells were evaluated by CCK-8 assay and colony formation assay. Wound healing assay and invasion assay were chosen to assess migration and invasion of cells. Tumorsphere-forming assay was applied for testing the stemness. Western blot analysis was applied for assessing the level of CENPU, Nanog, Oct4, FOXM1, β-catenin, c-myc and MMP-7. The tumor sizes and volumes were also measured. The TCGA data and WB assay suggested that CENPU was upregulated in CC. CENPU knockdown would inhibit the viability of CC cells and prohibit the migration and invasion of cells. Tumorsphere-forming assay and WB results suggested that CENPU silencing decreased the sphere formation rate and the expression of Nanog and Oct4. Moreover, CENPU knockdown suppressed the expression of FOXM1, β-catenin, c-myc and MMP-7 by WB. In vivo study demonstrated that CENPU knockdown inhibited the growth of CC, indicated by reduced sizes and volumes of CC. In summary, our results suggested that knockdown of CENPU inhibited CC migration and stemness through the FOXM1/Wnt/β-catenin pathway.

SENP1 induced protein deSUMO modification increased the chemotherapy sensitivity of endometrial cancer side population cells

Objective: To inhibit the stemness maintenance potential of endometrial cancer and increase the sensitivity of endometrial cancer side population cells to chemotherapy drugs by inducing extensive deSUMOylation modification of proteins. Methods: Flow cytometry was used to sort and culture CD133(+) CD44(+) KLE endometrial cancer cell clone spheres. Protein expression level of small ubiquitin-related modifier 1 (SUMO1) and two stemness maintenance genes of tumor side population cells, octamer binding transcription factor-4 (Oct4) and sex determining region Y-box2 (Sox2), were detected by western blotting method. Lentivirus-mediated Sentrin/SUMO-specific proteases 1 (SENP1) gene was stably transfected into KLE side population cells. Western blotting was used to detect the protein expressions of SENP1, SUMO1, Oct4 and Sox2. The clone formation rate was compared between KLE side population cells with or without SENP1 overexpression. Flow cytometry was applied to detect cell cycle changes. 3-(4, 5-Dimethylthiazole-2)-2, 5-diphenyl-tetrazolium bromide (MTT) experiment and flow cytometry apoptosis method were used to detect the chemosensitivity of the side population of endometrial cancer cells to cisplatin. Tumor-bearing mouse models of endometrial cancer were established to detect the effect of SENP1 overexpression on the chemotherapy sensitivity of cisplatin. Results: Compared with CD133(-)CD44(-) KLE cells, CD133(+) CD44(+) KLE side population cells could form clonal spheres and express higher levels of SUMO1, Oct4 and Sox2 proteins (P<0.05). Compared with KLE side population cells that were not transfected with SENP1 gene, the expression level of SENP1 protein in KLE side population cells overexpressing SUMO1、Oct4 and Sox2 were lower. The clonal sphere formation rate was reduced from (25.67±5.44)% to (7.46±1.42)%, and cell cycle shifted from G(0)/G(1) phase to G(2) phase. IC(50) of cisplatin decreased from (55.46±6.14) μg/ml to (11.55±3.12) μg/ml, and cell apoptosis rate increased from (9.76±2.09)% to (16.79±3.44)%. Overexpression of SENP1 could reduce the tumorigenesis rate of KLE side population cells in vivo and increase their chemotherapy sensitivity to cisplatin (P<0.05). Conclusion: Overexpression of SENP1 can induce protein deSUMOylation modification, inhibit the stemness maintenance potential of endometrial cancer side population cells, and enhance their chemotherapy sensitivity, which provides a new reference for gene therapy of endometrial cancer.

Integration of metabolomics and transcriptomics to reveal ferroptosis is involved in Tripterygium wilfordii polyglycoside tablet-induced testicular injury

Ethnopharmacological relevanceTripterygium wilfordii polyglycoside tablet (TWP), a traditional Chinese medicine preparation, has multiple pharmacological properties, including anti-inflammatory, immune-modulatory and anti-proliferative activities. However, the reproductive toxicity of TWP greatly limits its clinical application and the mechanism of TWP-induced reproductive toxicity is not fully understood yet. Aim of the studyThis study was designed to explore the mechanism of TWP-induced testis injury in male rats. Materials and methodsThe mechanism underlying TWP-induced rat testicular injury was firstly investigated by integration of metabolomics and transcriptomics. Meanwhile, histopathological analysis, Western blot and RT-qPCR were performed to confirm the damaging effects and mechanisms of TWP on rat testis. ResultsHistopathological analysis revealed that TWP had significant testicular damage, which severely reduced the testis's tubular diameter and epithelium height. Further, TWP caused the protein level of ZO-1, CLDN11, PLZF, and OCT4 significantly downregulate, suggesting the blood-testis barrier function and spermatogenesis were damaged. Differentially expressed genes (DEGs), including 4952 upregulated and 2626 downregulated, were found in TWP-exposed testis compared to the normal group. Moreover, 77 changed metabolites were identified from testis samples. With integrated analysis of DEGs and changed metabolites, we found that glutathione metabolism and ferroptosis played an essential role in testicular injury. Additionally, the levels of ferroptosis-related protein GPX4, SLC7A11, and NRF2 were significantly downregulated, and the protein level of 4-HNE, a leading product of lipid peroxidation and oxidative stress, was upregulated. The changes in ferroptosis-related genes indicated that TWP might promote ferroptosis in rat testis. ConclusionThese results suggested that ferroptosis was involved in the testicular damage caused by TWP, which might provide a new strategy to alleviate TWP- induced testicular injury.

Cyclosporin A Promotes Invasion and Migration of Extravillous Trophoblast Cells Derived from Human-Induced Pluripotent Stem Cells and Human Embryonic Stem Cells.

Extravillous trophoblast (EVT) cells play an essential role in the maternal-fetal interaction. Although abnormal development and function of EVT cells, including impaired migration and invasion capability, are believed to be etiologically linked to severe pregnancy disorders including pre-eclampsia, the associated molecular mechanisms are not clear due to the lack of an appropriate cell model in vitro. Cyclosporin A (CsA) is a macrolide immunosuppressant and also used in clinic to improve pregnancy outcomes. However, whether CsA has any effects on the function of EVT cells has not been well investigated. In this study, we induced differentiation of human-induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) into EVT cells (hiPSC-EVT and hESC-EVT cells, respectively) by Y27632, neuregulin-1 (NRG1), A83-01, and matrigel, and collected these derived EVT cells by flow cytometry for sorting cells positive for double human leukocyte antigen-G (HLA-G) and Cytokeratin7 (KRT7), both of which are EVT markers. We then investigated the effects of CsA on the invasion and migration of these derived EVT cells. We found that the hiPSC-EVT and hESC-EVT cells expressed high levels of the EVT markers such as KRT7, integrin alpha 5 (ITGA5), and HLA-G but low levels of OCT4, a stem cell marker, and that CsA significantly promoted the invasion and migration of hiPSC-EVT and hESC-EVT cells compared with HTR-8/SVneo cells. These results represent a possible cell model for studying the function of EVT cells and mechanism of pregnancy-related disorders associated with EVT. In addition, CsA may be used to treat pregnancy complications in clinic associated with deficient EVT function.

Increased ammonium in culture medium may promote cellular apoptosis and negatively affect pluripotency of human blastocysts.

To determine the association between ammonium concentration in culture medium and blastocyst development and to assess the influence of increased ammonium concentration on the expression of Bax, Bcl-2 and Oct4. A total of 254 cleavage-stage embryos were individually cultured in 30μL G2-plus medium on Day 3, and then culture media samples were collected on Day 5 for ammonium concentration determination immediately after evaluating the embryos morphology. Poor-quality blastocysts (combined score of CC) were used for gene expression analysis. The blastocyst formation rate, good-quality blastocyst rate and relative expression levels of Bax, Bcl-2 and Oct4 were analyzed. Based on receiver operating characteristic curve, the cutoff value of ammonium concentration produced by embryos was 16.07μmol/L (AUC = 0.722, 95% CI 0.637-0.807; P = 0.000), so all embryos were assigned to two groups according to the cutoff value: normal group (< 16.07μmol/L) and increased group (≥ 16.07μmol/L). There was a significant difference in blastocyst formation rate (80.5% vs 59.0%, P < 0.01) between normal group and increased group, as well as for good-quality blastocyst rate (21.0% vs 3.4%, P < 0.01). A significantly higher expression level of Bax (P < 0.05) and considerably lower expression level of Oct4 (P < 0.01) were observed in increased group compared to normal group. Our data demonstrated for the first time that increased ammonium concentration in culture medium may promote cellular apoptosis and negatively affect pluripotency of human blastocyst.

Gene Analysis of Cancer Stem Cells in Thyroid Cancer

<i>Objective </i>Recurrence and drug resistance in different thyroid cancer in the clinic are associated with tumor stem cells. To investigate the differences in transcript levels of tumor stem cell-associated genes in different thyroid cancer cell lines and their correlation with tumor pathways for identifing factors affecting thyroid cancer progression. <i>Methods </i>Wound healing assay was performed to analyze cell migration; to compare the transcript levels of tumor stem cell related genes CD133, OCT4, ABCG2, ALDH2, Nanog, CD44, CD24, EMT and thyroid specific genes in different thyroid cancer cell lines; to analyze the correlation between the above genes and tumor pathways and the correlation between genes using R software GSVA package combined with TCGA database. <i>Results</i> Wound healing results showed that thyroid cancer cell lines TPC-1 and ATC healed faster than normal cells. qPCR showed significantly different expression of EGFR, CD44, CD24 and ABCG2 in ATC and TPC-1 compared to Nthy-ori 3-1. EGFR and ABCG2 were highly expressed in ATC cell lines, while CD24 gene was highly expressed in TPC -1; TTF2 was significantly low expressed in both ATC and TPC-1 cell lines. Correlation analysis showed that ABCG2 and OCT4 were negatively correlated with inflammatory response, ALDH2 with P53 signaling pathway, CD24 with ECM degradation and P53 signaling pathway, Nanog with MYC target gene pathway, and CD44 with reactive oxygen species (ROS) gene upregulation in thyroid cancer; EGFR was positively correlated with TGFB signaling pathway. The genes ALDH2, ABCG2 and CD44 were significantly and positively correlated with TPO and TG. <i>Conclusion </i>The transcriptional levels of tumor stem cell genes differed greatly among different types of thyroid cancer and were significantly associated with tumor signaling pathways. It may be related to signaling pathways that exacerbate the development of thyroid cancer.

Oct4 promoted proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in colon cancer cells by activating the SCF/c-Kit signaling pathway

ABSTRACT Octamer-binding transcription factor 4 (Oct4) is closely related to the occurrence and development of cancer. In the present study, we paid a special interest in exploring the effect of Oct4 on colon cancer (CC) proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) and its molecular mechanism. Immunohistochemistry (IHC) was used to detect the expression level of Oct4 in colon tissue of patients with colon cancer. Oct4 overexpression vector pcDNA-Oct4 was used to stably express Oct4 in human colon cancer cells HT29 and SW480. Cell counting kit-8 (CCK-8) assay was used to detect the cell proliferation. The invasion and migration abilities were observed by transwell and wound healing assays. The expression of EMT relate genes were observed by Western blot. We found that Oct4 was up-regulated in human colon cancer tissues than that in paracancerous tissues. The proliferation, migration, and invasion of HT29 and SW480 cells was significantly induced by transfection of pcDNA-Oct4. Furthermore, Oct4 overexpression enhanced EMT of CC cells, characterized by the increased expression of vimentin, Twist, and Snail, as well as decreased expression of E-cadherin. Mechanistically, Oct4 overexpression activated stem cell factor (SCF)/c-Kit signaling pathway in CC cells, and the SCF/c-Kit signaling inhibitor imatinib reversed pro-oncogenic effects of Oct4. These finding provide an insight into the potential of Oct4 for CC diagnosis and therapy.

MafA-positive insulin-producing cells derived from rat adipose stem cells are efficient in glucose hemostasis in vitro

Objective: MafA has been recognized as a specific pancreatic β-cells activator for Insulin expression. This study investigated the changes in glucose transport and consumption by MafA-positive Insulin-producing cells resulting from the differentiation of rat adipose tissue-derived mesenchymal stem cells. Methods: Adipose tissue-derived mesenchymal stem cells were differentiated into Insulin-producing cells in a 14-day protocol using nicotinamide and ITS. The ability to produce Insulin was confirmed by adipogenesis differentiation capacity and expression of Oct4, Nanog, and Sox2. Insulin and Glucagon concentrations in Insulin-producing cells were determined by ELISA. The ability of Insulin-producing cells for the presence of MafA, Glut2, ENO1, and IGF-I receptor genes was determined by Western blotting analysis. The amounts of Glucokinase and Pyruvate Carboxylase activities were measured by Fluorometric and Colorimetric methods, respectively. Results: The un-differentiated cells showed a promising capacity to differentiate toward adipocytes. The adipose tissue mesenchymal stem cells revealed significantly elevated levels of Oct4, Nanog, and Sox2 compared to differentiated adipocytes. The cells that differentiated into Insulin-producing cells secreted considerably more Insulin and Glucagon than undifferentiated cells.

Granulosa Cell Conditioned Medium Enhances The Rate of Mouse Oocyte In Vitro Maturation and Embryo Formation.

In vitro maturation (IVM) and cryopreservation of oocytes are two important parts of assisted reproductive technology (ART), but their efficacy is low. This study aimed to improve the quality of in vitro vitrified-warmed maturated oocytes using granulosa cell conditioned medium (GCCM). In the experimental study, fresh/non-vitrified and vitrified-warmed mouse germinal vesicle (GV) oocytes (as F and V) were In vitro maturated using basal medium (BM) and also BM supplemented with 50% GCCM as treated groups (GM), and categorized as FBM, FGM, VBM and VGM groups, respectively. The rate of successful IVM (MII oocyte formation), mitochondrial membrane potential and the viability of MII oocytes were determined using inverted microscopy, JC-1 and trypan blue staining. Then, the rate of In vitro fertilization (IVF) and subsequent two-cell embryo formation was calculated. Finally, the expression levels of Oct4, Sox2, Cdk-2, Gdf9, Integrin beta1 and Igf2 were analyzed using real-time polymerase chain reaction (PCR) in MII oocytes and two-cell embryos. These analyses showed that GCCM significantly increased the IVM rate, oocyte meiotic resumption and mitochondrial membrane potential (P<0.05). In addition, the rate of IVF and two-cell embryo formation was significantly higher in FGM and VGM compared to FBM and VBM (P<0.05). Interestingly, GCCM significantly affected the expression of the studied genes. Our findings suggest that GCCM might be useful for improving the efficiency of IVM and the subsequent IVF outcomes.

Effects of Combined Action of Neutron and Proton Radiation on the Pool of Breast Cancer Stem Cells and Expression of Stemness Genes In Vitro.

Radiation response of cancer stem cells was studied in two breast cancer cell lines: luminal A (MCF-7) and triple negative (MDA-MB-231) subtypes. The relative number of CD44+CD24-/low cancer stem cells of the MCF-7 line increased by 1.7 times under the influence of γ-irradiation at a dose of 4 Gy (p=0.047 in comparison with the control). However, no significant changes were found in the relative number of cancer stem cells and the expression level of OCT4, NANOG, and SOX2 genes after neutron, proton beam irradiation or their combined action at a total equieffective dose of 4 Gy in comparison with the control in both cell lines. The absolute number of cancer stem cells decreased under the influence of neutron or proton radiation in comparison with the control (p<0.05 for both cell lines). At the same time, the effects of sequential exposures to neutron and proton radiation on the size of the cancer stem cell pool depended on the molecular subtype of cancer cells. Additive interaction was observed for MCF-7 line and antagonistic one for MDA-MB-231 line (coefficients of synergism were 0.96 and 0.45, respectively).

Determining the expression levels of CSF-1 and OCT4, CREM-1, and protamine in testicular biopsies of adult Klinefelter patients: Their possible correlation with spermatogenesis.

Klinefelter syndrome (KS) is the most prevalent genetic disorder of infertile males. This study aimed to determine in Klinefelter patients (KS) the expression levels of spermatogenic markers and testicular growth factors that might predict spermatogenesis based on conventional testicular sperm extraction (TESE). The expression levels of the pre-meiotic (OCT4, CD9, GFR-α1, α-6-INTEGRIN, SALL4, C-KIT), meiotic (CREM-1), and post-meiotic (protamine) markers, as well as the colony stimulating factor-1 (CSF-1) were examined in testicular biopsies with and without mature sperm of KS and normal karyotype of azoospermic patients (AZO) with complete spermatogenesis. In the biopsies of AZO, the expression levels (fold of expression compared to the PPI of the same sample) of OCT4 were 9.68± 7.93, CREM 42.78± 28.22, CSF-1 3.07 ± 3.19, and protamine 78498.12 ± 73214.40. Biopsies from KS included 7 with sperm and 17 without sperm. Among the biopsies with sperm, the expression levels of OCT4 were 7.27± 9.29, CREM 3.13± 7.89, CSF-1 35.5 ± 48.01, and protamine 902.97 ± 2365.92. In 14 biopsies without sperm, we found low expression levels of OCT4, CREM and CSF-1, and no expression of protamine. However, in three of the biopsies without sperm that highly expressed OCT4 and CSF-1, the expression levels of CREM-1 and protamine were high. These results may be used for further consulting with patients considering repeating conventional TESE or micro TESE and cryopreservation for possible future in-vitro spermatogenesis.