Lysophosphatidic acid improves development of porcine somatic cell nuclear transfer embryos.

This study was conducted to investigate whether lysophosphatidic acid (LPA) could improve the development of porcine somatic cell nuclear transfer (SCNT) embryos. Porcine SCNT-derived embryos were cultured in chemically defined polyvinyl alcohol (PVA)-based porcine zygote medium (PZM)-4 without or with LPA, and the development, cell proliferation potential, apoptosis, and expression levels of pluripotent markers were evaluated. LPA significantly increased the rates of cleavage and blastocyst formation compared to those seen in the LPA un-treatment (control) group. The expression levels of embryonic development-related genes (IGF2R, PCNA and CDH1) were higher (p < 0.05) in the LPA treatment group than in the control group. LPA significantly increased the numbers of total, inner cell mass and EdU (5-ethynyl-2'-deoxyuridine)-positive cells in porcine SCNT blastocysts compared to those seen in the control group. TUNEL assay showed that LPA significantly reduced the apoptosis rate in porcine SCNT-derived embryos; this was confirmed by decreases (p < 0.05) in the expression levels of pro-apoptotic genes, BAX and CASP3, and an increase (p < 0.05) in the expression level of the anti-apoptotic gene, BCL2L1. In addition, LPA significantly increased Oct4 expression at the gene and protein levels. Together, our data suggest that LPA improves the quality and development of porcine SCNT-derived embryos by reducing apoptosis and enhancing cell proliferation and pluripotency.

Anti-cancer activity of secreted aspartyl proteinase protein from Candida tropicalis on human cervical cancer HeLa cells.

Cervical cancer is the fourth leading cause of cancer-related death in women worldwide. Microbial products are valuable sources of anti-cancer drugs. The aim of this study was to isolate secreted aspartyl proteinase protein from Candida tropicalis, investigate its inhibitory effect on human cervical cancer HeLa cells, and analyze the expression profiling of selected nuclear stem cell-associated transcription factors. The presence of secreted aspartyl proteinase protein was confirmed by the expression of SAP2 and SAP4 genes in C. tropicalis during the yeast-hyphae transition phase. The enzyme was purified and characterized using the aqueous two-phase system purification method, as well as proteolytic activity and the Bradford and micro-Kjeldahl methods, respectively. The in vitro anti-cancer properties of secreted aspartyl proteinase protein were evaluated by MTT assay, microscopic image analysis, nitric oxide (NO) scavenging activity assay, intracellular reactive oxygen species (ROS) production assay, and RT-qPCR. The isolated C. tropicalis secreted aspartyl proteinase protein exhibited proteinase activity with values ranging from 93.72 to 130.70 µg/mL and 89.88-127.72 µg/mL according to the Bradford and micro-Kjeldahl methods, respectively. Secreted aspartyl proteinase showed effective cytotoxicity in HeLa cell line leading to significant morphological changes. Additionally, it exhibited increased free radical scavenging activity compared to the untreated control group, as evidenced by nitrite inhibition. ROS production increased in HeLa cells exposed to secreted aspartyl proteinase. The expression levels of the nuclear stem cell-associated transcription factors octamer-binding transcription factor 4 (OCT4), sex determining region Y-box 2 (SOX2), and Nanog homeobox (NANOG) were significantly downregulated in the HeLa cells treated with secreted aspartyl proteinase. Secreted aspartyl proteinase protein may be a promising anti-cancer agent, as it effectively affects gene expression and may ultimately reduce the development and progression of cervical cancer. Targeting the genes related to nuclear stem cell-associated transcription factors may provide a novel amenable to cancer treatment.

Suppress the cell growth of cancer stem-like cells (NTERA-2) using Sox2-Oct4 decoy oligodeoxynucleotide-encapsulated niosomes-zinc hybrid nanocarriers under X-irradiation.

Sox2 and Oct4 dysregulations could significantly increase in the cancer stem cell (CSC) population in some cancer cells and resistance to common treatments. In this study, the synergistic effects of Sox2-Oct4 decoy oligodeoxynucleotides-encapsulated Niosomes-zinc hybrid nanocarriers along with X-irradiation conditions as a combinational therapy tool were investigated in the treatment of cancer-like stem cells (NTERA-2). The NTERA-2 cell line known as a cancer-like stem cell line was used in this investigation. Sox2-Oct4 decoy oligodeoxynucleotides were designed based on the sequence of the Sox2 promoter and synthesized. Physicochemical characteristics of ODNs-encapsulated niosomes-zinc hybrid nanocarriers (NISM@BSA-DEC-Zn) investigated with FT-IR, DLS, FESEM, and ODNs release kinetic estimation assays. Further investigations such as hemolysis, uptake, cell viability, apoptosis, cell cycle, and scratch repair tests were performed. All the above assays were completed with and without X-ray exposure conditions (fractionated 2Gy). Physicochemical characteristics results showed that the Niosomes-Zn nanocarriers were successfully synthesized. NISM@BSA-DEC-Zn was efficiently taken up by NTERA-2 cells and significantly inhibited cell growth, increased apoptosis, and reduced cell migration in both conditions (with and without X-ray exposure). Furthermore, NISM@BSA-DEC-Zn treatment resulted in G1 and G2/M cell cycle arrest without and with X-irradiation, respectively. The prepared nanocarrier system can be a promising tool for drug delivery in cancer treatment. Decoy ODN strategy along with zinc nanoparticles could increase the sensitivity of cancer cells toward irradiation, which has the potential for combinational cancer therapies.

Evaluation of the Effects of Opium on the Expression of SOX2 and OCT4 in Wistar Rat Bladder.

BACKGROUND: Bladder cancer is a malignancy greatly affected by behavioral habits. The aim of this study was to examine the effect of opium on changes in the expression of OCT4 and SOX2 in the bladder tissue of rats. METHOD: Thirty six rats were divided into six groups: 24 rats in the addicted group received morphine and opium for 4 months with 12 rats in the control group. Blood testing was done for the evaluation of CBC, MDA, and TAC. The bladder tissue was removed and checked by histopathological examination. All total RNA was extracted, then cDNAs were synthesized and the OCT4 and SOX2 gene expressions were evaluated by Real-time PCR. RESULTS: The OCT4 mRNA expression level in the opium group of rats was significantly increased compared to the control group (13.5 and 6.8 fold in males and females respectively). Also, in the morphine group, similar augmentation was detected (3.8 and 6.7 fold in males and females respectively). The SOX2 mRNA over-expression level was seen in the morphine group of both genders as compared to the control group (3.7 and 4.2 fold in male and female respectively) but in the opium group, enhancement of mRNA level was seen only in males (6.6 fold). Opium increases both OCT4 and SOX2 expression more than morphine in male rats, but in female rats, SOX2 is increased more by morphine. CONCLUSION: Over expression of OCT4 and SOX2 was observed in rats treated with opium and morphine. Increased OCT4 and SOX2 expression was seen in opium-treated male rats, but in female rats, SOX2 was increased more by morphine.

LINC00662 Promotes Aggressive Traits by Modulating OCT4 Expression through miR-335-5p in Gallbladder Cancer Cells.

Long non-coding RNAs (lncRNAs) are nucleotide sequences that participate in different biological processes and are associated with different pathologies, including cancer. Long intergenic non-protein-coding RNA 662 (LINC00662) has been reported to be involved in different cancers, including colorectal, prostate, and breast cancer. However, its role in gallbladder cancer has not yet been described. In this article, we hypothesize that LINC00662 has an important role in the acquisition of aggressiveness traits such as a stem-like phenotype, invasion, and chemoresistance in gallbladder cancer. Here, we show that LINC00662 is associated with larger tumor size and lymph node metastasis in patients with gallbladder cancer. Furthermore, we show that the overexpression of LINC00662 promotes an increase in CD133+/CD44+ cell populations and the expression of stemness-associated genes. LINC00662 promotes greater invasive capacity and the expression of genes associated with epithelial-mesenchymal transition. In addition, the expression of LINC00662 promotes resistance to cisplatin and 5-fluorouracil, associated with increased expression of chemoresistance-related ATP-binding cassette (ABC) transporters in gallbladder cancer (GBC) cell lines. Finally, we show that the mechanism by which LINC00662 exerts its function is through a decrease in microRNA 335-5p (miR-335-5p) and an increase in octamer-binding transcription factor 4 (OCT4) in GBC cells. Thus, our data allow us to propose LINC00662 as a biomarker of poor prognosis and a potential therapeutic target for patients with GBC.

The primitive endoderm supports lineage plasticity to enable regulative development.

Mammalian blastocyst formation involves the specification of the trophectoderm followed by the differentiation of the inner cell mass into embryonic epiblast and extra-embryonic primitive endoderm (PrE). During this time, the embryo maintains a window of plasticity and can redirect its cellular fate when challenged experimentally. In this context, we found that the PrE alone was sufficient to regenerate a complete blastocyst and continue post-implantation development. We identify an in vitro population similar to the early PrE in vivo that exhibits the same embryonic and extra-embryonic potency and can form complete stem cell-based embryo models, termed blastoids. Commitment in the PrE is suppressed by JAK/STAT signaling, collaborating with OCT4 and the sustained expression of a subset of pluripotency-related transcription factors that safeguard an enhancer landscape permissive for multi-lineage differentiation. Our observations support the notion that transcription factor persistence underlies plasticity in regulative development and highlight the importance of the PrE in perturbed development.

The Oct4-related PouV gene, pou5f3, mediates isthmus development in zebrafish by directly and dynamically regulating pax2a.

Using a transgenic zebrafish line harboring a heat-inducible dominant-interference pou5f3 gene (en-pou5f3), we reported that this PouV gene is involved in isthmus development at the midbrain-hindbrain boundary (MHB), which patterns the midbrain and cerebellum. Importantly, the functions of pou5f3 reportedly differ before and after the end of gastrulation. In the present study, we examined in detail the effects of en-pou5f3 induction on isthmus development during embryogenesis. When en-pou5f3 was induced around the end of gastrulation (bud stage), the isthmus was abrogated or deformed by the end of somitogenesis (24 hours post-fertilization). At this stage, the expression of MHB markers -- such as pax2a, fgf8a, wnt1, and gbx2 -- was absent in embryos lacking the isthmus structure, whereas it was present, although severely distorted, in embryos with a deformed isthmus. We further found that, after en-pou5f3 induction at late gastrulation, pax2a, fgf8a, and wnt1 were immediately and irreversibly downregulated, whereas the expression of en2a and gbx2 was reduced only weakly and slowly. Induction of en-pou5f3 at early somite stages also immediately downregulated MHB genes, particularly pax2a, but their expression was restored later. Overall, the data suggested that pou5f3 directly upregulates at least pax2a and possibly fgf8a and wnt1, which function in parallel in establishing the MHB, and that the role of pou5f3 dynamically changes around the end of gastrulation. We next examined the transcriptional regulation of pax2a using both in vitro and in vivo reporter analyses; the results showed that two upstream 1.0-kb regions with sequences conserved among vertebrates specifically drove transcription at the MHB. These reporter analyses confirmed that development of the isthmic organizer is regulated by PouV through direct regulation of pax2/pax2a in vertebrate embryos.

Expression of Pluripotency Factors OCT4 and LIN28 Correlates with Survival Outcome in Lung Adenocarcinoma.

Background and Objectives: Lung adenocarcinoma is a leading cause of cancer-related mortality despite recent therapeutic advances. Cancer stem cells have gained increasing attention due to their ability to induce cancer cell proliferation through self-renewal and differentiation into multiple cell lineages. OCT4 and LIN28 (and their homologs A and B) have been identified as key regulators of pluripotency in mammalian embryonic (ES) and induced stem (IS) cells, and they are the crucial regulators of cancer progression. However, their exact role in lung adenocarcinoma has not yet been clarified. Materials and Methods: The aim of this study was to explore the role of the pluripotency factors OCT4 and LIN28 in a cohort of surgically resected human lung adenocarcinomas to reveal possible biomarkers for lung adenocarcinoma prognosis and potential therapeutic targets. The expressions of OCT4, LIN28A and LIN28B were analyzed in formalin-fixed, paraffin-embedded tissue samples from 96 patients with lung adenocarcinoma by immunohistochemistry. The results were analyzed with clinicopathologic parameters and were related to the prognosis of patients. Results: Higher OCT4 expression was related to an improved 5-year overall survival (OS) rate (p < 0.001). Nuclear LIN28B expression was lower in stage I and II tumors (p < 0.05) compared to advanced stage tumors. LIN28B cytoplasmic expression was associated with 5-year OS rates not only in univariate (p < 0.005), but also in multivariate analysis (where age, gender, histopathological subtype and stage were used as cofactors, p < 0.01 HR = 2.592). Patients with lower LIN28B expression showed improved 5-year OS rates compared to patients with increased LIN28B expression. Conclusions: Our findings indicate that OCT4 and LIN28B are implicated in lung adenocarcinoma progression and prognosis outcome; thus, they serve as promising prognostic biomarkers and putative therapeutic targets in lung adenocarcinomas.

Pseudogene OCT4-pg5 upregulates OCT4B expression to promote bladder cancer progression by competing with miR-145-5p.

Bladder cancer (BC) is one of the most common malignant neoplasms worldwide. Competing endogenous RNA (ceRNA) networks may identify potential biomarkers associated with the progression and prognosis of BC. The OCT4-pg5/miR-145-5p/OCT4B ceRNA network was found to be related to the progression and prognosis of BC. OCT4-pg5 expression was significantly higher in BC cell lines than in normal bladder cells, with OCT4-pg5 expression correlating with OCT4B expression and advanced tumor grade. Overexpression of OCT4-pg5 and OCT4B promoted the proliferation and invasion of BC cells, whereas miR-145-5p suppressed these activities. The 3' untranslated region (3'UTR) of OCT4-pg5 competed for miR-145-5p, thereby increasing OCT4B expression. In addition, OCT4-pg5 promoted epithelial-mesenchymal transition (EMT) by activating the Wnt/ß-catenin pathway and upregulating the expression of matrix metalloproteinases (MMPs) 2 and 9 as well as the transcription factors zinc finger E-box binding homeobox (ZEB) 1 and 2. Elevated expression of OCT4-pg5 and OCT4B reduced the sensitivity of BC cells to cisplatin by reducing apoptosis and increasing the proportion of cells in G1. The OCT4-pg5/miR-145-5p/OCT4B axis promotes the progression of BC by inducing EMT via the Wnt/ß-catenin pathway and enhances cisplatin resistance. This axis may represent a therapeutic target in patients with BC.

Oncogenic Role of SATB2 In Vitro: Regulator of Pluripotency, Self-Renewal, and Epithelial-Mesenchymal Transition in Prostate Cancer.

Special AT-rich sequence binding protein-2 (SATB2) is a nuclear matrix protein that binds to nuclear attachment regions and is involved in chromatin remodeling and transcription regulation. In stem cells, it regulates the expression of genes required for maintaining pluripotency and self-renewal and epithelial-mesenchymal transition (EMT). In this study, we examined the oncogenic role of SATB2 in prostate cancer and assessed whether overexpression of SATB2 in human normal prostate epithelial cells (PrECs) induces properties of cancer stem cells (CSCs). The results demonstrate that SATB2 is highly expressed in prostate cancer cell lines and CSCs, but not in PrECs. Overexpression of SATB2 in PrECs induces cellular transformation which was evident by the formation of colonies in soft agar and spheroids in suspension. Overexpression of SATB2 in PrECs also resulted in induction of stem cell markers (CD44 and CD133), pluripotency-maintaining transcription factors (cMYC, OCT4, SOX2, KLF4, and NANOG), CADHERIN switch, and EMT-related transcription factors. Chromatin immunoprecipitation assay demonstrated that SATB2 can directly bind to promoters of BCL-2, BSP, NANOG, MYC, XIAP, KLF4, and HOXA2, suggesting SATB2 is capable of directly regulating pluripotency/self-renewal, cell survival, and proliferation. Since prostate CSCs play a crucial role in cancer initiation, progression, and metastasis, we also examined the effects of SATB2 knockdown on stemness. SATB2 knockdown in prostate CSCs inhibited spheroid formation, cell viability, colony formation, cell motility, migration, and invasion compared to their scrambled control groups. SATB2 knockdown in CSCs also upregulated the expression of E-CADHERIN and inhibited the expression of N-CADHERIN, SNAIL, SLUG, and ZEB1. The expression of SATB2 was significantly higher in prostate adenocarcinoma compared to normal tissues. Overall, our data suggest that SATB2 acts as an oncogenic factor where it is capable of inducing malignant changes in PrECs by inducing CSC characteristics.

Blastocyst-like Structures in the Peripheral Retina of Young Adult Beagles.

In this immunohistological study on the peripheral retina of 3-year-old beagle dogs, excised retina specimens were immunostained with antibodies against nestin, Oct4, Nanog, Sox2, CDX2, cytokeratin 18 (CK 18), RPE65, and YAP1, as well as hematoxylin and DAPI, two nuclear stains. Our findings revealed solitary cysts of various sizes in the inner retina. Intriguingly, a mass of small round cells with scant cytoplasms was observed in the cavity of small cysts, while many disorganized cells partially occupied the cavity of the large cysts. The small cysts were strongly positive for nestin, Oct4, Nanog, Sox2, CDX2, CK18, and YAP1. RPE65-positive cells were exclusively observed in the tissue surrounding the cysts. Since RPE65 is a specific marker of retinal pigment epithelial (RPE) cells, the surrounding cells of the peripheral cysts were presumably derived from RPE cells that migrated intraretinally. In the small cysts, intense positive staining for nestin, a marker of retinal stem cells, seemed to indicate that they were derived from retinal stem cells. The morphology and positive staining for markers of blastocyst and RPE cells indicated that the small cysts may have formed structures resembling the blastocyst, possibly caused by the interaction between retinal stem cells and migrated RPE cells.

Dissecting gene activation and chromatin remodeling dynamics in single human cells undergoing reprogramming.

During cell fate transitions, cells remodel their transcriptome, chromatin, and epigenome; however, it has been difficult to determine the temporal dynamics and cause-effect relationship between these changes at the single-cell level. Here, we employ the heterokaryon-mediated reprogramming system as a single-cell model to dissect key temporal events during early stages of pluripotency conversion using super-resolution imaging. We reveal that, following heterokaryon formation, the somatic nucleus undergoes global chromatin decompaction and removal of repressive histone modifications H3K9me3 and H3K27me3 without acquisition of active modifications H3K4me3 and H3K9ac. The pluripotency gene OCT4 (POU5F1) shows nascent and mature RNA transcription within the first 24 h after cell fusion without requiring an initial open chromatin configuration at its locus. NANOG, conversely, has significant nascent RNA transcription only at 48 h after cell fusion but, strikingly, exhibits genomic reopening early on. These findings suggest that the temporal relationship between chromatin compaction and gene activation during cellular reprogramming is gene context dependent.

Oct4 redox sensitivity potentiates reprogramming and differentiation.

The transcription factor Oct4/Pou5f1 is a component of the regulatory circuitry governing pluripotency and is widely used to induce pluripotency from somatic cells. Here we used domain swapping and mutagenesis to study Oct4's reprogramming ability, identifying a redox-sensitive DNA binding domain, cysteine residue (Cys48), as a key determinant of reprogramming and differentiation. Oct4 Cys48 sensitizes the protein to oxidative inhibition of DNA binding activity and promotes oxidation-mediated protein ubiquitylation. Pou5f1 C48S point mutation has little effect on undifferentiated embryonic stem cells (ESCs) but upon retinoic acid (RA) treatment causes retention of Oct4 expression, deregulated gene expression, and aberrant differentiation. Pou5f1 C48S ESCs also form less differentiated teratomas and contribute poorly to adult somatic tissues. Finally, we describe Pou5f1 C48S (Janky) mice, which in the homozygous condition are severely developmentally restricted after E4.5. Rare animals bypassing this restriction appear normal at birth but are sterile. Collectively, these findings uncover a novel Oct4 redox mechanism involved in both entry into and exit from pluripotency.

Integrative analysis of the lncRNA-miRNA-mRNA interactions in smooth muscle cell phenotypic transitions.

Objectives: We previously found that the pluripotency factor OCT4 is reactivated in smooth muscle cells (SMC) in human and mouse atherosclerotic plaques and plays an atheroprotective role. Loss of OCT4 in SMC in vitro was associated with decreases in SMC migration. However, molecular mechanisms responsible for atheroprotective SMC-OCT4-dependent effects remain unknown. Methods: Since studies in embryonic stem cells demonstrated that OCT4 regulates long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), making them candidates for OCT4 effect mediators, we applied an in vitro approach to investigate the interactions between OCT4-regulated lncRNAs, mRNAs, and miRNAs in SMC. We used OCT4 deficient mouse aortic SMC (MASMC) treated with the pro-atherogenic oxidized phospholipid POVPC, which, as we previously demonstrated, suppresses SMC contractile markers and induces SMC migration. Differential expression of lncRNAs, mRNAs, and miRNAs was obtained by lncRNA/mRNA expression array and small-RNA microarray. Long non-coding RNA to mRNA associations were predicted based on their genomic proximity and association with vascular diseases. Given a recently discovered crosstalk between miRNA and lncRNA, we also investigated the association of miRNAs with upregulated/downregulated lncRNA-mRNA pairs. Results: POVPC treatment in SMC resulted in upregulating genes related to the axon guidance and focal adhesion pathways. Knockdown of Oct4 resulted in differential regulation of pathways associated with phagocytosis. Importantly, these results were consistent with our data showing that OCT4 deficiency attenuated POVPC-induced SMC migration and led to increased phagocytosis. Next, we identified several up- or downregulated lncRNA associated with upregulation of the specific mRNA unique for the OCT4 deficient SMC, including upregulation of ENSMUST00000140952-Hoxb5/6 and ENSMUST00000155531-Zfp652 along with downregulation of ENSMUST00000173605-Parp9 and, ENSMUST00000137236-Zmym1. Finally, we found that many of the downregulated miRNAs were associated with cell migration, including miR-196a-1 and miR-10a, targets of upregulated ENSMUST00000140952, and miR-155 and miR-122, targets of upregulated ENSMUST00000155531. Oppositely, the upregulated miRNAs were anti-migratory and pro-phagocytic, such as miR-10a/b and miR-15a/b, targets of downregulated ENSMUST00000173605, and miR-146a/b and miR-15b targets of ENSMUST00000137236. Conclusion: Our integrative analyses of the lncRNA-miRNA-mRNA interactions in SMC indicated novel potential OCT4-dependent mechanisms that may play a role in SMC phenotypic transitions.

E2F1-regulated USP5 contributes to the tumorigenic capacity of glioma stem cells through the maintenance of OCT4 stability.

Mesenchymal glioma stem cells (MES GSCs) are a subpopulation of cells in glioblastoma (GBM) that contribute to a worse prognosis owing to their highly aggressive nature and resistance to radiation therapy. Here, OCT4 is characterized as a critical factor in sustaining the stemness phenotype of MES GSC. We find that OCT4 is expressed intensively in MES GSC and is intimately associated with poor prognosis, moreover, OCT4 depletion leads to diminished invasive capacity and impairment of the stem phenotype in MES GSC. Subsequently, we demonstrated that USP5 is a deubiquitinating enzyme which directly interacts with OCT4 and preserves OCT4 stability through its deubiquitination. USP5 was additionally proven to be aberrantly over-expressed in MES GSCs, and its depletion resulted in a noticeable diminution of OCT4 and consequently a reduced self-renewal and tumorigenic capacity of MES GSCs, which can be substantially restored by ectopic expression of OCT4. In addition, we detected the dominant molecule that regulates USP5 transcription, E2F1, with dual luciferase reporter gene analysis. In combination, targeting the E2F1-USP5-OCT4 axis is a potentially emerging strategy for the therapy of GBM.

Oct4 controls basement membrane development during human embryogenesis.

Basement membranes (BMs) are sheet-like structures of extracellular matrix (ECM) that provide structural support for many tissues and play a central role in signaling. They are key regulators of cell behavior and tissue functions, and defects in their assembly or composition are involved in numerous human diseases. Due to the differences between human and animal embryogenesis, ethical concerns, legal constraints, the scarcity of human tissue material, and the inaccessibility of the in vivo condition, BM regulation during human embryo development has remained elusive. Using the post-implantation amniotic sac embryoid (PASE), we delineate BM assembly upon post-implantation development and BM disassembly during primitive streak (PS) cell dissemination. Further, we show that the transcription factor Oct4 regulates the expression of BM structural components and receptors and controls BM development by regulating Akt signaling and the small GTPase Rac1. These results represent a relevant step toward a more comprehensive understanding of early human development.

The expanding roles of Nr6a1 in development and evolution.

The Nuclear Receptor (NR) family of transcriptional regulators possess the ability to sense signalling molecules and directly couple that to a transcriptional response. While this large class of proteins are united by sequence and structural homology, individual NR functional output varies greatly depending on their expression, ligand selectivity and DNA binding sequence specificity. Many NRs have remained somewhat enigmatic, with the absence of a defined ligand categorising them as orphan nuclear receptors. One example is Nuclear Receptor subfamily 6 group A member 1 (Nr6a1), an orphan nuclear receptor that has no close evolutionary homologs and thus is alone in subfamily 6. Nonetheless, Nr6a1 has emerged as an important player in the regulation of key pluripotency and developmental genes, as functionally critical for mid-gestational developmental progression and as a possible molecular target for driving evolutionary change in animal body plan. Here, we review the current knowledge on this enigmatic nuclear receptor and how it impacts development and evolution.

Oct4 activates IL-17A to orchestrate M2 macrophage polarization and cervical cancer metastasis.

BACKGROUND: Cervical cancer is a common malignant tumor in the female. Interleukin (IL)-17A is a proinflammatory factor and exerts a vital function in inflammatory diseases and cancers. M2 macrophage has been confirmed to promote tumor development. Nevertheless, it is not yet known whether IL-17A facilitates cervical cancer development by inducing M2 macrophage polarization. Therefore, this study was conducted to investigate the regulatory effect of IL-17A on M2 macrophage polarization and the underlying mechanism in cervical cancer development. METHODS: RT-qPCR was utilized for testing IL-17A expression in cancer tissues and cells. Flow cytometry was applied to evaluate the M1 or M2 macrophage polarization. Cell proliferative, migratory, and invasive capabilities were measured through colony formation and transwell assays. ChIP and luciferase reporter assays were applied to determine the interaction between IL-17A and octamer-binding transcription factor 4 (OCT4). RESULTS: IL-17A expression and concentration were high in metastatic tissues and cells of cervical cancer. IL-17A was found to facilitate M2 macrophage polarization in cervical cancer. Furthermore, IL-17A facilitated the macrophage-mediated promotion of cervical cancer cell proliferative, migratory, and invasive capabilities. Mechanistic assays manifested that Oct4 binds to and transcriptionally activated IL-17A in cervical cancer cells. Furthermore, Oct4 promoted cervical cancer cell malignant phenotype and M2 macrophage polarization by activating the p38 pathway that, in turn, upregulated IL-17A. Additionally, in vivo experiments confirmed that Oct4 knockdown reduced tumor growth and metastasis. CONCLUSION: Oct4 triggers IL-17A to facilitate the polarization of M2 macrophages, which promotes cervical cancer cell metastasis.

Txnip regulates the Oct4-mediated pluripotency circuitry via metabolic changes upon differentiation.

Thioredoxin interacting protein (Txnip) is a stress-responsive factor regulating Trx1 for redox balance and involved in diverse cellular processes including proliferation, differentiation, apoptosis, inflammation, and metabolism. However, the biological role of Txnip function in stem cell pluripotency has yet to be investigated. Here, we reveal the novel functions of mouse Txnip in cellular reprogramming and differentiation onset by involving in glucose-mediated histone acetylation and the regulation of Oct4, which is a fundamental component of the molecular circuitry underlying pluripotency. During reprogramming or PSC differentiation process, cellular metabolic and chromatin remodeling occur in order to change its cellular fate. Txnip knockout promotes induced pluripotency but hinders initial differentiation by activating pluripotency factors and promoting glycolysis. This alteration affects the intracellular levels of acetyl-coA, a final product of enhanced glycolysis, resulting in sustained histone acetylation on active PSC gene regions. Moreover, Txnip directly interacts with Oct4, thereby repressing its activity and consequently deregulating Oct4 target gene transcriptions. Our work suggests that control of Txnip expression is crucial for cell fate transitions by modulating the entry and exit of pluripotency.

Correlation analysis of cancer stem cell marker CD133 and human endogenous retrovirus (HERV)-K env in SKOV3 ovarian cancer cells.

BACKGROUND: Human endogenous retrovirus (HERV)-K is a type of retrovirus that is present in the human genome, and its expression is usually silenced in healthy tissues. The precise mechanism by which HERV-K env influences cancer stemness is not fully understood, but it has been suggested that HERV-K env may activate various signaling pathways that promote stemness traits in cancer cells. OBJECTIVE: To establish the connection between HERV-K env expression and cancer stemness in ovarian cancer cells, we carried out correlation analyses between HERV-K env and the cancer stem cell (CSC) marker known as the cluster of differentiation 133 (CD133) gene in SKOV3 ovarian cancer cells. METHOD: To perform correlation analysis between HERV-K env and CSCs, ovarian cancer cells were cultured in a medium designed for cancer stem cell induction. The expression of HERV-K env and CD133 genes was verified using quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Additionally, the expression of stemness-related markers, such as OCT-4 and Nanog, was also confirmed using RT-qPCR. RESULTS: In the stem cell induction medium, the number of tumorsphere-type SKOV3 cells increased, and the expression of CD133 and HERV-K env genes was up-regulated. Additionally, other stemness-related markers like OCT-4 and Nanog also exhibited increased expression when cultured in the cancer stem cell induction medium. However, when HERV-K env knockout (KO) SKOV3 cells were cultured in the same cancer stem cell induction medium, there was a significant decrease in the number of tumorsphere-type cells compared to mock SKOV3 cells subjected to the same conditions. Furthermore, the expression of CD133, Nanog, and OCT-4 did not show a significant increase in HERV-K env KO SKOV3 cells compared to mock SKOV3 cells cultured in the same cancer stem cell induction medium. CONCLUSION: These findings indicate that the expression of HERV-K env increased in SKOV3 cells when cultured in cancer stem cell induction media, and cancer stem cell induction was inhibited by KO of HERV-K env in SKOV3 cells. These results suggest a strong association between HERV-K env and stemness in SKOV3 ovarian cancer cells.