Expression Levels Of SOX2 Research Articles

Nicotine inhibits expression of Prrx1 in pituitary stem/progenitor cells through epigenetic regulation, leading to a delayed supply of growth-hormone-producing cells

ObjectiveNicotine, a toxic component of smoking, adversely affects animal growth and reproduction by decreasing secretion of anterior pituitary hormones. However, it has not been clarified whether nicotine inhibits the supply of endocrine cells in the pituitary gland. The present study investigated short- and long-term effects of persistent nicotine exposure on the pituitary glands of young animals. DesignThree-week-old male Wistar rats were exposed to nicotine (1 mg/kg body weight/day) for 7 days, and gene expression, cell numbers, and DNA methylation status were analyzed on the following day and 4 weeks after final treatments. ResultsThe expression level of the stem cell marker Sox2 was not changed by nicotine exposure throughout the experiment. On the other hand, nicotine inhibited expression of a progenitor cell marker, Prrx1, and growth hormone (Gh). Immunohistochemical analysis showed that the SOX2-positive cells positive for PRRX1 in nicotine-treated groups decreased to 61% (4-week-old) and 70% (8-week-old) of the saline-treated controls. In addition, the proportion of GH-positive cells in nicotine-treated group was 14% lower than that of saline-treated controls. Furthermore, first intron hypermethylation of Prrx1 was detected by a bisulfite sequence of genomic DNA from the anterior lobe of the rat pituitary gland. ConclusionsWe show that persistent nicotine exposure in young animals inhibits expression of Prrx1 in pituitary stem/progenitor cells through epigenetic regulation, leading to a delayed supply of GH-producing cells.

MiR-16 enhances miR-302/367-induced reprogramming and tumor suppression in breast cancer cells.

Overexpression of either miR-302 or miR-302/367 cluster induces reprogramming of cancer cells and exerts tumor-suppressive effects by induction of mesenchymal-to-epithelial transition, apoptosis and a less proliferative capacity. Several reports have described miR-16 as a tumor suppressor microRNA (miRNA). Here, we studied the impact of exogenous induction of miR-16 in MDA-MB-231 and SK-BR-3 breast cancer cells following overexpression of miR-302/367 cluster and investigated whether transfection of these cells by a mature miR-16 mimic could affect the reprogramming state of the cells and their tumorigenicity. miR-16 enhanced the expression levels of OCT4A, SOX2, and NANOG, generally known as transcription or pluripotency factors, and suppressed proliferation and invasiveness of these cells. Meanwhile, inhibition of miR-16 counteracted both the reprogramming effect and the antitumor function of miR-302/367 in the breast cancer cells. Current results indicate that miR-16 can work as an adjuvant to improve both cancer cell reprogramming and tumor-suppressive function of miR-302/367 cluster in MDA-MB-231 and SK-BR-3 cells, while its inhibition counteracts all of these effects. Combined application of miRNAs that share some common targets in cancer cell signaling pathways may provide new approaches for repression of multiple hallmarks of cancer.

MiRNA-137-mediated modulation of mitochondrial dynamics regulates human neural stem cell fate.

The role of miRNAs in determining human neural stem cell (NSC) fate remains elusive despite their high expression in the developing nervous system. In this study, we investigate the role of miR‐137, a brain‐enriched miRNA, in determining the fate of human induced pluripotent stem cells‐derived NSCs (hiNSCs). We show that ectopic expression of miR‐137 in hiNSCs reduces proliferation and accelerates neuronal differentiation and migration. TargetScan and MicroT‐CDS predict myocyte enhancer factor‐2A (MEF2A), a transcription factor that regulates peroxisome proliferator‐activated receptor‐gamma coactivator (PGC1α) transcription, as a target of miR‐137. Using a reporter assay, we validate MEF2A as a downstream target of miR‐137. Our results indicate that reduced levels of MEF2A reduce the transcription of PGC1α, which in turn impacts mitochondrial dynamics. Notably, miR‐137 accelerates mitochondrial biogenesis in a PGC1α independent manner by upregulating nuclear factor erythroid 2 (NFE2)‐related factor 2 (NRF2) and transcription factor A of mitochondria (TFAM). In addition, miR‐137 modulates mitochondrial dynamics by inducing mitochondrial fusion and fission events, resulting in increased mitochondrial content and activation of oxidative phosphorylation (OXPHOS) and oxygen consumption rate. Pluripotency transcription factors OCT4 and SOX2 are known to have binding sites in the promoter region of miR‐137 gene. Ectopic expression of miR‐137 elevates the expression levels of OCT4 and SOX2 in hiNSCs which establishes a feed‐forward self‐regulatory loop between miR‐137 and OCT4/SOX2. Our study provides novel molecular insights into NSC fate determination by miR‐137.

PI3K/AKT inhibition reverses R-CHOP resistance by destabilizing SOX2 in diffuse large B cell lymphoma.

Up to one-third of diffuse large B cell lymphoma (DLBCL) patients eventually develop resistance to R-CHOP regimen, while the remaining therapeutic options are limited. Thus, understanding the underlying mechanisms and developing therapeutic approaches are urgently needed.Methods: We generated two germinal center B cell-like (GCB) and activated B cell-like (ABC) subtype R-CHO resistant DLBCL cell lines, of which the tumor-initiating capacity was evaluated by serial-transplantation and stemness-associated features including CD34 and CD133 expression, side population and ALDH1 activity were detected by flow cytometry or immunoblotting. Expression profiles of these resistant cells were characterized by RNA sequencing. The susceptibility of resistant cells to different treatments was evaluated by in vitro CytoTox-glo assay and in tumor-bearing mice. The expression levels of SOX2, phos-AKT, CDK6 and FGFR1/2 were detected in 12 R-CHOP-resistant DLBCL clinical specimens by IHC.Results: The stem-like CSC proportion significantly increased in both resistant DLBCL subtypes. SOX2 expression level remarkably elevated in both resistant cell lines due to its phosphorylation by activated PI3K/AKT signaling, thus preventing ubiquitin-mediated degradation. Further, multiple factors, including BCR, integrins, chemokines and FGFR1/2 signaling, regulated PI3K/AKT activation. CDK6 in GCB subtype and FGFR1/2 in ABC subtype were SOX2 targets, whose inhibition potently re-sensitized resistant cells to R-CHOP treatment. More importantly, addition of PI3K inhibitor to R-CHOP completely suppressed the tumor growth of R-CHO-resistant DLBCL cells, most likely by converting CSCs to chemo-sensitive differentiated cells.Conclusions: The PI3K/AKT/SOX2 axis plays a critical role in R-CHOP resistance development and the pro-differentiation therapy against CSCs proposed in this study warrants further study in clinical trials for the treatment of resistant DLBCL.

Decreased Sox2 Messenger RNA Expression in Basal Cell Carcinoma.

Background:Sox2, zeb1, and p21 have been implicated in aggressive behavior of squamous cell carcinoma (SCC) and melanoma. However, their expression level in basal cell carcinoma (BCC) has not been elucidated. We hypothesized BCC, contrary to SCC, and melanoma, could be a suitable model to study mechanisms which attenuate tumor metastasis. The aim of this study was to examine the messenger RNA (mRNA) expression levels of sox2, zeb1, and p21 in BCC.Materials and Methods:Twenty-seven nonmetastatic BCC and twelve normal skin samples were evaluated using real-time reverse transcriptase polymerase chain reaction.Results:The stemness marker sox2 demonstrated marked down-regulation, but zeb1 and p21 showed no significant change.Conclusions:Here, we report a negative association between sox2 mRNA expression level and nonmetastatic BCC, thus, providing a likely explanation for the fact that normal skin is more reliant on sox2 than BCC. BCC may be using decreased sox2 mRNA to remain incognito from metastatic potential.

Effect of Maternal Age on Hippo Pathway Related Gene Expressions and Protein Localization Pattern in Human Embryos.

Objective The Hippo pathway plays an important role in embryo development, and separation of trophectoderm (TE) and inner cell mass (ICM) cell lines. Therefore, this study investigated effect of maternal age on activity of Hippo pathway in human embryos. Materials and Methods In this experimental study, the developed up embryos to the blastocyst stage and the embryos whose growth stopped at the morula stage were collected from women aged 20-30 years old (young group, 94 embryos) and >37 years (old group, 89 embryos). Expression of OCT4, SOX2, CDX2, GATA3, YAP genes and the relevant proteins, in the both groups were evaluated using respectively quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunofluorescence methods. Results There was no significant difference in the expression level of OCT4, SOX2, CDX2, GATA3 and YAP genes in blastocyst and morula stages, between the two groups. However, SOX2 and CDX2 gene expressions in morula stage embryos of the old group was statistically lower than that of the young group (P=0.007 and P=0.008, respectively). Additionally, in the embryos collected from women with >37 years of age, at the blastocyst stage, phospho-YAP (p-YAP) protein was found to be accumulated in the TE, but it was almost disappeared from the ICM. Additionally, in the old group, contrary to the expectation, YAP protein was expressed in the ICM, rather than TE. ConclusionThe results of this study showed that YAP and P-YAP among the Hippo signalling pathway may be altered by increasing age.

IGF-1-releasing PLGA nanoparticles modified 3D printed PCL scaffolds for cartilage tissue engineering

The aim of this study is to fabricate and test a 3D-printed PCL scaffold incorporating IGF-1-releasing PLGA nanoparticles for cartilage tissue engineering. IGF-1 loaded PLGA nanoparticles were produced by the double-emulsion method, and were incorporated onto 3D printed PCL scaffolds via PDA. Particle size, loading effciency (LE) and encapsulation effciency (EE) of the nanoparticles were examined. SEM, pore size, porosity, compression testing, contact angle, IGF-1 release kinetics of the composite scaffolds were also determined. For cell culture studies, CCK-8, Live/dead, MTT, GAG content and expression level of chondrocytes specific proteins and genes and HIF-1α were also tested. There was no difference of the nanoparticle size. And the LE and EE of IGF-1 in PLGA nanoparticles was about 5.53 ± 0.12% and 61.26 ± 2.71%, respectively. There was a slower, sustained release for all drug-loaded nanoparticles PLGA/PDA/PCL scaffolds. There was no difference of pore size, porosity, compressive strength of each scaffold. The contact angles PCL scaffolds were significant decreased when coated with PDA and PLGA nanoparticales. (p < .05) Live/dead staining showed more cells attached to the IGF-1 PLGA/PDA/PCL scaffolds. The CCK-8 and MTT assay showed higher cell proliferation and better biocompatibility of the IGF-1 PLGA/PDA/PCL scaffolds. (p < .05) GAG content, chondrogenic protein and gene expression level of SOX-9, COL-II, ACAN, and HIF pathway related gene (HIF-1α) were significantly higher in IGF-1 PLGA/PDA/PCL scaffolds group compared to other groups. (p < .05) IGF-1 PLGA/PDA/PCL scaffolds may be a better method for sustained IGF-1 administration and a promising scaffold for cartilage tissue engineering.

Histone H3K9 methylation is involved intemporomandibular joint osteoarthritis.

The morbidity of temporomandibular joint osteoarthritis (TMJOA) increases with age. Condylar articular cartilage degradation, which causes TMJOA, is known to be involved in articular chondrocyte metabolic imbalances in the temporomandibular joint (TMJ) and in other joints of the body. Epigenetic regulation, such as the chemical modification of DNA and histones, is implicated in cartilage homeostasis. However, few studies have been conducted on the epigenetic regulation of condylar articular cartilage degradation. The present study investigated the regulation of histone H3 lysine9 (H3K9) methylation and its effects on the pathogenesis of degenerative TMJ cartilage disorders. The histone H3K9 methylation level was decreased in degenerated condylar articular cartilage in aged mice. Treatment with chaetocin (a selective H3K9 methylation inhibitor) reduced cell viability and promoted caspase‑3/7 activity in ATDC5 mouse chondroprogenitor cells. The inhibition of H3K9 methylation increased matrix metalloproteinase (Mmp)1 and Mmp13 mRNA expression in these cells. Furthermore, the expression levels of Sox9 and collagenα1(II) (Col2a1) mRNA, which are anabolic factors for chondrogenic differentiation, were also decreased by treatment with chaetocin, which is an inhibitor of histone methyltransferases. These results indicated that histone H3K9 methylation regulates chondrocyte homeostasis in terms of cell growth, apoptosis and gene expression, and highlighted a possible future therapy option for TMJOA.

Differential expression of Sox9 protein and proteoglycans in the epiphyseal cartilage of bromocriptine-treated pregnant and lactating rats.

Several investigations have shown that pregnancy and lactation are able to induce elongation of long bone by altering epiphyseal cartilage function in a prolactin-dependent manner. Since the transcription factor Sox9 is of utmost importance for chondrocyte proliferation and differentiation and since bromocriptine, a dopaminergic D2 agonist widely used to suppress milk production, is known to disrupt the production and release of prolactin, we herein aimed to investigate whether pregnancy and lactation as well as bromocriptine could alter the expression of Sox9. Our immunohistochemical analysis showed that the Sox9 expression levels were markedly upregulated in the tibial proliferative zone of day 21 pregnant rats. In day 8 (early) and day 14 (mid) lactating rats, the Sox9 expression was enhanced only in the proliferative zone, but not in the resting and hypertrophic zones. There was no change in Sox9 expression in day 21 (late) lactating rats. Postweaning rats manifested a decreased Sox9 expression in the hypertrophic zone. Bromocriptine had no effect on Sox9 expression in the proliferative zone of day 21 pregnant rats; however, it completely prevented the Sox9 upregulation in those of early and mid-lactating rats. A differential response was observed in the proliferative and hypertrophic zones of late lactating rats, in which bromocriptine enhanced Sox9 expression. Further investigation of cartilaginous matrix revealed no change in proteoglycans accumulation in lactating rats. In conclusion, the upregulated Sox9 expression predominantly occurred in the proliferative zone during late pregnancy and early and mid-lactation, while the bromocriptine effects depended on the periods and epiphyseal zones.

Effects of combination TGF-B1 transfection and platelet rich plasma (PRP) on three-dimension chondrogenic differentiation of rabbit dental pulp-derived mesenchymal stem cells

ABSTRACT Aim: The aim of this study was to evaluate the effects of standard culture medium and chondrogenic differentiation medium with PRP on chondrogenic differentiation of rabbit dental pulp-derived mesenchymal stem cells (rabbit DPSCs) that are transfected with transforming growth factor-beta 1 (TGF-B1) gene, based on the hypothesis of TGF- B1 and PRP can be effective on the chondrogenesis of stem cells. Materials and Methods: Rabbit DPSCs were characterized by using flow cytometry, immunofluorescent staining, quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and differentiation tests. For the characterization, CD29, CD44 and CD45 mesenchymal cell markers were used. Rabbit DPSCs were transfected with TGF-B1 gene using electroporation technique in group 1; with PRP 10% in group 2; with chondrogenic medium in group 3; with both chondrogenic medium and PRP in group 4. DPSCs were cultured in medium with 10% inactive PRP in group 5, chondrogenic medium in group 6, chondrogenic medium with PRP 10% in group 7. SOX9, MMP13 and Aggrecan gene expression levels were evaluated in 3, 6, 12. and 24. days by qRT-PCR. Results: The expression levels of SOX9, MMP13 and Aggrecan were higher in group 2, 3 and group 7 in 3th day however in 24th day group 7 and group 2 were found higher. The expression levels changed by time-dependent. The extracellular matrix of the cells in experimental groups were positively stained with safranin O and toluidine blue. Conclusion: The combination in culture medium of TGF-B1 gene transfection and 10% PRP accelerates the chondrogenic differentiation of DPSCs.

Characterising a SOX2+ OLIG2+ glioma stem cell using Crispr-engineered fluorescent reporters in primary patient-derived GBM and DIPG cells.

Abstract Malignant glioma can be understood as a cancer stem cell disease. There is strong evidence that expression of a core set of neural stem cell master regulators is necessary and sufficient for tumour initiation in both adult and childhood disease subtypes, and across a range of underlying mutation signatures and expression profiles. We hypothesise that a double positive SOX2+ OLIG2+ progenitor is the cancer stem cell in H3K27M diffuse intrinsic pontine glioma (DIPG) and adult glioblastoma (GBM) alike. We present expression data in 4 patient-derived cell lines (2 adult GBM, 2 DIPG) in vitro and in a defined mutation mouse model of the H3K27M disease, demonstrating high expression levels of SOX2 and OLIG2 in serum-free culture and especially in the invasive tumour. We then demonstrate derivation of patient-derived human dual reporter lines, using a CRISPR targeting approach to add fluorescent reporters at the endogenous SOX2 and OLIG2 loci. With these tools, we aim to characterise the tumour-initiating potential of the SOX2+ OLIG2+ fraction. We further aim to identify cell surface markers whose expression is driven by this transcription program and which might represent targets for novel molecular therapies.

The expression level of SOX2 at the blastocyst stage regulates the developmental capacity of bovine embryos up to day-13 of in vitro culture.

Quality of in vitro-produced embryos is influenced by changes in gene expression in response to adverse conditions. Gene markers for predicting 'good embryos' do not exist at present. We propose that the expression of pluripotency markers OCT4-SOX2-NANOG in D9 (day 9) bovine demi-embryos correlated with development at D13 (day 13). Day 8 in vitro-produced blastocysts were split in two cloned halves, one half (D9) was subjected to analysis of pluripotency markers and the other was kept in culture until D13 of development. Embryo development was scored and correlated with its own status at D9 and assigned to one of two categories: G1, arrested/dead; or G2, development up to D13. SOX2 and NANOG expression levels were significantly higher in embryos from G1 and there was also negative correlation between SOX2 and embryo survival to D13 (G3; r = -0.37; P = 0.03). We observed a significant reduction in the expression of the three studied genes from D9 to D13. Furthermore, there was a correlation between the expression of pluripotency markers at D9 and embryo diameter and the expression of trophoblastic markers at D13 (TP1-EOMES-FGF4-CDX2-TKDP1). Finally, the quotient between the relative expression of SOX2 and OCT4 in the D9 blastocysts from G1 and G2 showed that embryos that were considered as competent (G2) had a quotient close to one, while the other group had a quotient of 2.3 due to a higher expression of SOX2. These results might indicate that overexpression of SOX2 at the blastocyst stage had a negative effect on the control of embryonic developmental potential.

Prostaglandin D2 synthase modulates macrophage activity and accumulation in injured peripheral nerves.

We have previously reported that prostaglandin D2 Synthase (L-PGDS) participates in peripheral nervous system (PNS) myelination during development. We now describe the role of L-PGDS in the resolution of PNS injury, similarly to other members of the prostaglandin synthase family, which are important for Wallerian degeneration (WD) and axonal regeneration. Our analyses show that L-PGDS expression is modulated after injury in both sciatic nerves and dorsal root ganglia neurons, indicating that it might play a role in the WD process. Accordingly, our data reveals that L-PGDS regulates macrophages phagocytic activity through a non-cell autonomous mechanism, allowing myelin debris clearance and favoring axonal regeneration and remyelination. In addition, L-PGDS also appear to control macrophages accumulation in injured nerves, possibly by regulating the blood-nerve barrier permeability and SOX2 expression levels in Schwann cells. Collectively, our results suggest that L-PGDS has multiple functions during nerve regeneration and remyelination. Based on the results of this study, we posit that L-PGDS acts as an anti-inflammatory agent in the late phases of WD, and cooperates in the resolution of the inflammatory response. Thus, pharmacological activation of the L-PGDS pathway might prove beneficial in resolving peripheral nerve injury.

TCGA Data Reveal a Transcriptomic Signature of Sox2 and Nanog Targets Associated with Survival in Head and Neck Cancer

Head and neck cancers represent a diverse group of tumors linked with HPV infection, alcohol and smoking that contribute to cancer morbidity and mortality globally. Sox2 and Nanog are transcription factors that maintain pluripotency in embryonic stem cells, and their individual expression has been associated with prognosis in head and neck tumors previously TCGA dataset containing 522 tumor samples with RNAseq data, clinical information (anatomically classified as 133 oral tongue, 117 laryngeal, 73 oral cavity, 63 floor of mouth, 45 tonsillar, 27 base of tongue and 70 other samples) and 44 normal samples with RNAseq data available was used to detect differentially expressed genes in head and neck tumors. The levels of each gene were then transformed to z-score per patient and classified as over- or underexpressed if those were 2 SD away from the mean. The expression levels were then correlated with survival in individual patients for all tumor combined. Subgroup analysis of oral tongue, laryngeal, oral cavity, floor of mouth, tonsillar cancers were carried out separately. A total of 233 genes were significantly correlated with survival in head and neck tumors ( < 0.01). This gene set was subsequently analyzed for enrichment of common pathway dysregulation or for enrichment of shared regulatory elements. The expression level of a set of a total of 15 genes that represent targets of Nanog and Sox2 was shown to either increase or decrease survival directly dependent on either up or downregulated expression levels. Of note, neither Nanog nor Sox2 expression levels individually impacted survival. Subgroup analysis revealed individualized prognostic signatures in each anatomic location, with an overlap of individual genes with Nanog and Sox2 targets signature ranging from 6.25-20%. We describe a prognostic signature in head and neck tumors derived from a TCGA data consisting of genes that represent targets of critical stem cell regulators Sox2 and Nanog. On a subgroup analysis, we also derived prognostic signatures for five anatomic locations and head and neck tumors with various ranges of overlap with Sox2 and Nanog targets signature. Pending validation in additional datasets, those represent an attractive target for further mechanistic evaluation in tumorigenesis in this group of tumors.

Evaluation of Polycaprolactone-Associated Human Nasal Chondrocytes as a Therapeutic Agent for Cartilage Repair

In this study, we manufactured a complex of human nasal septal cartilage (hNC) with polycaprolactone (PCL) for transplantation into cartilaginous skeletal defects and evaluated their characteristics. Nasal septum tissue was obtained from five patients aged ≥ 20years who were undergoing septoplasty. hNCs were isolated and subcultured for three passages in vitro. To formulate the cell-PCL complex, we used type I collagen as an adhesive between chondrocyte and PCL. Immunofluorescence staining, cell viability and growth in the hNC-PCL complex, and mycoplasma contamination were assessed. hNCs in PCL showed viability ≥ 70% and remained at these levels for 9h of incubation at 4°C. Immunostaining of the hNC-PCL complex also showed high expression levels of chondrocyte-specific protein, COL2A1, SOX9, and aggrecan during 24h of clinically applicable conditions. The hNC-PCL complex may be a valuable therapeutic agent for implantation into injured cartilage tissue, and can be used clinically to repair cartilaginous skeletal defects. From a clinical perspective, it is important to set the short duration of the implantation process to achieve effective functional implantation.

Induced Overexpression of THAP11 in Human Fibroblast Cells Enhances Expression of Key Pluripotency Genes

Background: THAP11 is a recently discovered pluripotency factor and described as an important gene that involved in embryonic stem cells self-renewal and embryo development, which works independently with other known pluripotency factors. We aimed to overexpressed the THAP11 gene in primary fibroblast cells to determine the effects of the THAP11 on these cells. Materials and Methods: The THAP11 gene was amplified using PCR followed by ligation into pCDH vector and lentiviral particle production in HEK293T cells by using psPAX2 and pMD2.G helper vectors. The human fibroblast cells were transduced using viral particles and after confirmation overexpression, the key pluripotency factors were estimated using real-time PCR and changes in proliferation rate was measured by the 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) test. Results: The overexpression of THAP11 in fibroblast cells leads to increase the expression level of Sox2, Oct4, Nanog and Klf4 as key pluripotency genes and a decrease in proliferation rate according to MTT results. Conclusion: Our results confirm that we are faced with a molecule with double features, which could be involved in pluripotency and proliferation suppressor simultaneously. It seems that the roles of THAP11 in pluripotency are so complex and attributed to other regulatory molecules.

Induced Overexpression of THAP11 in Human Fibroblast Cells Enhances Expression of Key Pluripotency Genes

Background: THAP11 is a recently discovered pluripotency factor and described as an important gene that involved in embryonic stem cells self-renewal and embryo development, which works independently with other known pluripotency factors. We aimed to overexpressed the THAP11 gene in primary fibroblast cells to determine the effects of the THAP11 on these cells. Materials and Methods: The THAP11 gene was amplified using PCR followed by ligation into pCDH vector and lentiviral particle production in HEK293T cells by using psPAX2 and pMD2.G helper vectors. The human fibroblast cells were transduced using viral particles and after confirmation overexpression, the key pluripotency factors were estimated using real-time PCR and changes in proliferation rate was measured by the 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) test. Results: The overexpression of THAP11 in fibroblast cells leads to increase the expression level of Sox2, Oct4, Nanog and Klf4 as key pluripotency genes and a decrease in proliferation rate according to MTT results. Conclusion: Our results confirm that we are faced with a molecule with double features, which could be involved in pluripotency and proliferation suppressor simultaneously. It seems that the roles of THAP11 in pluripotency are so complex and attributed to other regulatory molecules. [GMJ.2019;8:e1308]

Exosomes derived from liver cancer cells reprogram biological behaviors of LO2 cells by transferring Linc-ROR

ObjectiveExosomes have been described as a messenger between cells' communication and contain various information (lipids, proteins, mRNAs, microRNAs, LncRNAs). It has been proved that Linc-ROR was enriched in exosomes released by HepG2 cells. Our aim was to investigate whether exosomes released by HepG2 cells could affect the biological behaviors of LO2 cells and whether Linc-ROR played an important role in this process. MethodsExosomes-derived from HepG2 cells were isolated and characterized. Real-time PCR assessed expression level of Linc-ROR in specimens of cancerous tissues and carcinoma-adjacent tissues. The Linc-ROR expression level in HepG2, Huh7, SMMC-7721, Bel-7402, LO2 cells and exosomes was detected by real-time PCR. Knockdown the expression of Linc-ROR in HepG2 by using effective siRNA. Cell counting method was used to test LO2 cells proliferative activities. Flow cytometry was performed to quantify the apoptosis rates of LO2 cells cocultured with exosomes. The expression levels of OCT4, NANOG, SOX2, P53 and CD133 were assessed by western blot. ResultsLinc-ROR was enriched in exosomes released by HepG2 cells. Exosomes derived from HepG2 cells promoted the proliferation and suppressed the apoptosis of LO2 cells suffering nutrient deficiency. Knockdown the expression of Linc-ROR in HepG2 or LO2 cells could significantly impaired the exosomes' effects on LO2 cells. In addition, the long-term coculture with exosomes would obviously change the biological behaviors of LO2 cells. ConclusionsOur experiments indicated the HepG2 cells could transfer its Linc-ROR to the LO2 cells via exosomes, then influenced the recipient cells.

Abstract 5309: Inhibition of cancer stem-like cells in esophageal squamous cell carcinoma with SOCS-1 gene therapy

Abstract INTRODUCTION: Cancer stem-like cells are thought to be one of the causes of cancer initiation and progression. They are associated with the resistance to radiotherapy and chemotherapy for various types of tumor including esophageal squamous cell carcinoma (ESCC). Therefore, cancer stem-like cells are promising therapeutic targets of cancer. Suppressor of cytokine signaling-1 (SOCS-1) was identified as a negative regulator of various cytokine signaling. We have previously demonstrated that overexpression of SOCS-1 showed a potent anti-tumor effect on ESCC through inhibiting of the JAK/STAT signaling pathway. This study aimed to evaluate the anti-tumor effect of SOCS-1 gene therapy using adenoviral vector (AdSOCS-1) against cancer stem-like cells in ESCC. METHODS: ESCC cell lines were separated into aldehyde dehydrogenase (ALDH) positive and ALDH negative cells by ALDEFLOUR, and then sphere formation assays were performed. The inhibitory effects of AdSOCS-1 and AdLacZ on the sphere formation were evaluated using TE8, TE14 ESCC cell lines. The inhibition of sphere formation was also evaluated using ESCC cells obtained from ESCC PDX mice (ESCC8). Next, the expression of transcription factors associated with cancer stem-like cells in ESCC was evaluated by RT-PCR. The inhibitory effects on tumor formation by AdSOCS-1 were evaluated by tumorigenicity assay using TE8 xenograft mice. RESULTS: In the sphere formation assay, ALDH positive TE8 cells and TE14 cells represented strong sphere formation capacity. Compared with AdLacZ infected ALDH positive cells, sphere formation of AdSOCS-1 infected ALDH positive cells was significantly inhibited. The inhibition of sphere formation was also confirmed in ESCC cells obtained from ESCC8 PDX mouse tumor tissue. Interestingly, the expression level of Sox2, a critical stem cell factor regulated by STAT3, was also decreased by AdSOCS-1. Furthermore, AdSOCS-1 decreased the tumorigenic activity of the ALDH positive ESCC tumor cells. CONCLUSIONS: A potent anti-tumor effect of SOCS-1 gene therapy on ESCC may be partially explained by inhibiting the expression of a STAT3 regulated transcription factor critical for cancer stem-like cells. Citation Format: Ayumi Yamamoto, Eri Munekage, Satoshi Serada, Shigehiro Tsujii, Kosuke Hiramatsu, Minoru Fujimoto, Kazuhiro Hanazaki, Tetsuji Naka. Inhibition of cancer stem-like cells in esophageal squamous cell carcinoma with SOCS-1 gene therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5309.

Abstract 3677: Downregulation of FOXO3a by DNMT1 promotes breast cancer stem cell properties and tumorigenesis

Abstract Breast cancer stem cells (BCSCs) are tumor initiating cells that can self-renew and are highly tumorigenic and chemoresistant. Recent evidence indicated that FOXO3a plays an important role in regulating CSCs properties. However, the biologic function and detailed molecular mechanism of FOXO3a in BCSCs remains largely elusive. Here, we demonstrated that FOXO3a was hypermethylated and downregulated in breast cancer cells and tissues. Overexpression of FOXO3a potently attenuated the BCSCs properties in vitro and inhibited tumorigenesis in vivo, whereas knockdown of FOXO3a increased these properties. Further mechanistic investigation revealed that FOXO3a was functionally linked to the inhibition of the FOXM1/SOX2 pathway. Moreover, we found that SOX2 directly transactivated DNMT1 gene expression and then feedback inhibited FOXO3a expression. Clinically, we observed a significant inverse correlation between FOXO3a and FOXM1 or SOX2 expression levels. Loss of FOXO3a expression also predicted poor prognosis in breast cancer. In addition, we demonstrated that inhibition of DNMT activity suppressed tumor growth via regulating of FOXO3a/FOXM1/SOX2 signaling in breast cancer. Our findings suggest an important role of DNMT1/FOXO3a/FOXM1/SOX2 pathway in regulating BCSCs properties, identifying potential therapeutic targets for breast cancer. Keywords: breast cancer, cancer stem cell, FOXO3a, DNMT Note: This abstract was not presented at the meeting. Citation Format: Zhimin He, Hao Liu, Ying Song, Guopei Zheng. Downregulation of FOXO3a by DNMT1 promotes breast cancer stem cell properties and tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3677.