H1FOO-DD promotes efficiency and uniformity in reprogramming to naive pluripotency.

Heterogeneity among both primed and naive pluripotent stem cell lines remains a major unresolved problem. Here we show that expressing the maternal-specific linker histone H1FOO fused to a destabilizing domain (H1FOO-DD), together with OCT4, SOX2, KLF4, and LMYC, in human somatic cells improves the quality of reprogramming to both primed and naive pluripotency. H1FOO-DD expression was associated with altered chromatin accessibility around pluripotency genes and with suppression of the innate immune response. Notably, H1FOO-DD generates naive induced pluripotent stem cells with lower variation in transcriptome and methylome among clones and a more uniform and superior differentiation potency. Furthermore, we elucidated that upregulation of FKBP1A, driven by these five factors, plays a key role in H1FOO-DD-mediated reprogramming.

Assessing the distribution of cancer stem cells in tumorspheres.

Cancer Stem Cells presumably drive tumor growth and resistance to conventional cancer treatments. From a previous computational model, we inferred that these cells are not uniformly distributed in the bulk of a tumorsphere. To confirm this result, we cultivated tumorspheres enriched in stem cells, and performed immunofluorescent detection of the stemness marker SOX2 using confocal microscopy. In this article, we present an image processing method that reconstructs the amount and location of the Cancer Stem Cells in the spheroids. Its advantage is the use of a statistical criterion to classify the cells in Stem and Differentiated, instead of setting an arbitrary threshold. Moreover, the analysis of the experimental images presented in this work agrees with the results from our computational models, thus enforcing the notion that the distribution of Cancer Stem Cells in a tumorsphere is non-homogeneous. Additionally, the method presented here provides a useful tool for analyzing any image in which different kinds of cells are stained with different markers.

Genomic context sensitizes regulatory elements to genetic disruption.

Genomic context critically modulates regulatory function but is difficult to manipulate systematically. The murine insulin-like growth factor 2 (Igf2)/H19 locus is a paradigmatic model of enhancer selectivity, whereby CTCF occupancy at an imprinting control region directs downstream enhancers to activate either H19 or Igf2. We used synthetic regulatory genomics to repeatedly replace the native locus with 157-kb payloads, and we systematically dissected its architecture. Enhancer deletion and ectopic delivery revealed previously uncharacterized long-range regulatory dependencies at the native locus. Exchanging the H19 enhancer cluster with the Sox2 locus control region (LCR) showed that the H19 enhancers relied on their native surroundings while the Sox2 LCR functioned autonomously. Analysis of regulatory DNA actuation across cell types revealed that these enhancer clusters typify broader classes of context sensitivity genome wide. These results show that unexpected dependencies influence even well-studied loci, and our approach permits large-scale manipulation of complete loci to investigate the relationship between regulatory architecture and function.

Basal differentiation and expression status of SOX2 and KLF4 in basal layers are prognostic factors for disease-specific survival in oral squamous cell carcinoma.

BACKGROUND: Basal differentiation in oral squamous cell carcinoma is usually detected at invasive sites. However, its significance as a prognostic value has been poorly investigated. METHODS: COL17 was selected as a basal differentiation marker because of its stable expression in the basal-like cells of oral squamous cell carcinoma. Sixty-five cases of oral squamous cell carcinoma were subclassified into COL17-high (30 cases) and -low (35 cases) types, and the prognostic value was analyzed by Cox regression analysis. In addition, the stem cell markers such as SOX2, KLF4, MYC as well as the stem cell-related markers BMI1, EZH2, and YAP and its paralog TAZ, were immunohistochemically analyzed. Their prognostic values were investigated along with their COL17 status by Cox regression analysis. RESULTS: No significant difference was observed between the COL17-high and -low groups in the disease-specific survival and recurrence-free survival in oral squamous cell carcinoma. When the COL17-high and -low categories were combined with the SOX2, KLF4, EZH2, or YAP/TAZ status in the basal layers, together with gender and age as covariates, the hazard ratios reached 3.3, 3.7, 2.8, and 3.1, respectively. In addition, multivariate analysis, including COL17, SOX2, and KLF4, with gender and age as covariates, showed a significantly poor prognosis for disease-specific survival. CONCLUSION: Based on the relatively high hazard ratios, it is indicated that basal differentiation and the expression status of SOX2 and KLF4 in the basal layers are prognostic factors for oral squamous cell carcinoma.

Identification of MUC1-C as a Target for Suppressing Progression of Head and Neck Squamous Cell Carcinomas.

The MUC1-C protein is aberrantly expressed in adenocarcinomas of epithelial barrier tissues and contributes to their progression. Less is known about involvement of MUC1-C in the pathogenesis of squamous cell carcinomas (SCC). Here, we report that the MUC1 gene is upregulated in advanced head and neck SCCs (HNSCC). Studies of HNSCC cell lines demonstrate that the MUC1-C subunit regulates expression of (i) RIG-I and MDA5 pattern recognition receptors, (ii) STAT1 and IFN regulatory factors, and (iii) downstream IFN-stimulated genes. MUC1-C integrates chronic activation of the STAT1 inflammatory pathway with induction of the ∆Np63 and SOX2 genes that are aberrantly expressed in HNSCCs. In extending those dependencies, we demonstrate that MUC1-C is necessary for NOTCH3 expression, self-renewal capacity, and tumorigenicity. The findings that MUC1 associates with ∆Np63, SOX2 and NOTCH3 expression by single-cell RNA sequencing analysis further indicate that MUC1-C drives the HNSCC stem cell state and is a target for suppressing HNSCC progression. SIGNIFICANCE: This work reports a previously unrecognized role for MUC1-C in driving STAT1-mediated chronic inflammation with the progression of HNSCC and identifies MUC1-C as a druggable target for advanced HNSCC treatment.

TATA-binding associated factors have distinct roles during early mammalian development.

Early embryonic development is a finely orchestrated process that requires precise regulation of gene expression coordinated with morphogenetic events. TATA-box binding protein-associated factors (TAFs), integral components of transcription initiation coactivators like TFIID and SAGA, play a crucial role in this intricate process. Here we show that disruptions in TAF5, TAF12 and TAF13 individually lead to embryonic lethality in the mouse, resulting in overlapping yet distinct phenotypes. Taf5 and Taf12 mutant embryos exhibited a failure to implant post-blastocyst formation, and Taf5 mutants have aberrant lineage specification within the inner cell mass. In contrast, Taf13 mutant embryos successfully implant and form egg-cylinder stages but fail to initiate gastrulation. Strikingly, we observed a depletion of pluripotency factors in TAF13-deficient embryos, including OCT4, NANOG and SOX2, highlighting an indispensable role of TAF13 in maintaining pluripotency. Transcriptomic analysis revealed distinct gene targets affected by the loss of TAF5, TAF12 and TAF13. Thus, we propose that TAF5, TAF12 and TAF13 convey locus specificity to the TFIID complex throughout the mouse genome.

Early neural specification of stem cells is mediated by a set of SOX2-dependent neural-associated enhancers.

SOX2 is a transcription factor involved in the regulatory network maintaining the pluripotency of embryonic stem cells in culture as well as in early embryos. In addition, SOX2 plays a pivotal role in neural stem cell formation and neurogenesis. How SOX2 can serve both processes has remained elusive. Here, we identified a set of SOX2-dependent neural-associated enhancers required for neural lineage priming. They form a distinct subgroup (1,898) among 8,531 OCT4/SOX2/NANOG-bound enhancers characterized by enhanced SOX2 binding and chromatin accessibility. Activation of these enhancers is triggered by neural induction of wild-type cells or by default in Smad4-ablated cells resistant to mesoderm induction and is antagonized by mesodermal transcription factors via Sox2 repression. Our data provide mechanistic insight into the transition from the pluripotency state to the early neural fate and into the regulation of early neural versus mesodermal specification in embryonic stem cells and embryos.

Hyaluronic Acid Prevents Fusion of Brain Tumor-Derived Spheroids and Selectively Alters Their Gene Expression Profile.

Hyaluronic acid (HA), a major glycosaminoglycan of the brain extracellular matrix, modulates cell behaviors through binding its receptor, Cd44. In this study, we assessed the influence of HA on high-grade brain tumors in vitro. The model comprised cell cultures derived from six rodent carcinogen-induced brain tumors, forming 3D spheroids prone to spontaneous fusion. Supplementation of the standard culture medium with 0.25% HA significantly inhibited the fusion rates, preserving the shape and size uniformity of spheroids. The 3D cultures were assigned to two groups; a Cd44lo group had a tenfold decreased relative expression of Cd44 than another (Cd44hi) group. In addition, these two groups differed by expression levels of Sox2 transcription factor; the correlation analysis revealed a tight negative association for Cd44 and Sox2. Transcriptomic responses of spheroids to HA exposure also depended on Cd44 expression levels, from subtle in Cd44lo to more pronounced and specific in Cd44hi, involving cell cycle progression, PI3K/AKT/mTOR pathway activation, and multidrug resistance genes. The potential HA-induced increase in brain tumor 3D models' resistance to anticancer drug therapy should be taken into account when designing preclinical studies using HA scaffold-based models. The property of HA to prevent the fusion of brain-derived spheroids can be employed in CNS regenerative medicine and experimental oncology to ensure the production of uniform, controllably fusing neurospheres when creating more accurate in vitro brain models.

Reversal of Postnatal Brain Astrocytes and Ependymal Cells towards a Progenitor Phenotype in Culture.

Astrocytes and ependymal cells have been reported to be able to switch from a mature cell identity towards that of a neural stem/progenitor cell. Astrocytes are widely scattered in the brain where they exert multiple functions and are routinely targeted for in vitro and in vivo reprogramming. Ependymal cells serve more specialized functions, lining the ventricles and the central canal, and are multiciliated, epithelial-like cells that, in the spinal cord, act as bi-potent progenitors in response to injury. Here, we isolate or generate ependymal cells and post-mitotic astrocytes, respectively, from the lateral ventricles of the mouse brain and we investigate their capacity to reverse towards a progenitor-like identity in culture. Inhibition of the GSK3 and TGFß pathways facilitates the switch of mature astrocytes to Sox2-expressing, mitotic cells that generate oligodendrocytes. Although this medium allows for the expansion of quiescent NSCs, isolated from live rats by "milking of the brain", it does not fully reverse astrocytes towards the bona fide NSC identity; this is a failure correlated with a concomitant lack of neurogenic activity. Ependymal cells could be induced to enter mitosis either via exposure to neuraminidase-dependent stress or by culturing them in the presence of FGF2 and EGF. Overall, our data confirm that astrocytes and ependymal cells retain a high capacity to reverse to a progenitor identity and set up a simple and highly controlled platform for the elucidation of the molecular mechanisms that regulate this reversal.

The tale of SOX2: Focusing on lncRNA regulation in cancer progression and therapy.

Long non-coding RNAs (lncRNAs) have emerged as influential contributors to diverse cellular processes, which regulate gene function and expression via multiple mechanistic pathways. Therefore, it is essential to exploit the structures and interactions of lncRNAs to comprehend their mechanistic functions within cells. A growing body of evidence has revealed that deregulated lncRNAs are involved in multiple regulations of malignant events including cell proliferation, growth, invasion, and metabolism. SRY-related high mobility group box (SOX)2, a well-recognized member of the SOX family, is commonly overexpressed in various types of cancer, contributing to tumor progression and maintenance of stemness. Emerging studies have shown that lncRNAs interact with SOX2 to remarkably contribute to carcinogenesis and disease states. This review elaborates on the crosstalk between the intricate and complicated functions of lncRNAs and SOX2 in the context of malignant diseases. We elucidate distinct molecular mechanisms that contribute to the onset/advancement of cancer, indicating that lncRNAs/SOX2 axes hold immense promise for potential therapeutic targets. Furthermore, we delve into the modalities of emerging feasible treatment options for targeting lncRNAs, highlighting the limitations of such therapies and providing novel insights into further ameliorations of targeted strategies of lncRNAs to promote the clinical implications. Translating current discoveries into clinical applications could ultimately boost improved survival and prognosis of cancer patients.

A Low Dose of Rapamycin Promotes Hair Cell Differentiation by Enriching SOX2+ Progenitors in the Neonatal Mouse Inner Ear Organoids.

PURPOSE: To investigate the impact of rapamycin on the differentiation of hair cells. METHODS: Murine cochlear organoids were derived from cochlear progenitor cells. Different concentrations of rapamycin were added into the culture medium at different proliferation and differentiation stages. RESULTS: Rapamycin exhibited a concentration-dependent reduction in the proliferation of these inner ear organoids. Nevertheless, organoids subjected to a 10-nM dose of rapamycin demonstrated a markedly increased proportion of hair cells. Furthermore, rapamycin significantly upregulated the expression of markers associated with both hair cells and supporting cells, including ATOH1, MYO7A, and SOX2. Mechanistic studies revealed that rapamycin preferentially suppressed cells without Sox2 expression during the initial proliferation stage, thereby augmenting and refining the population of SOX2+ progenitors. These enriched progenitors were predisposed to differentiate into hair cells during the later stages of organoid development. Conversely, the use of the mTOR activator MHY 1485 demonstrated opposing effects. CONCLUSION: Our findings underscore a practical strategy for enhancing the generation of inner ear organoids with a low dose of rapamycin, achieved by enriching SOX2+ progenitors in an in vitro setting.

SUMO-dependent transcriptional repression by Sox2 inhibits the proliferation of neural stem cells.

Sox2 is known for its roles in maintaining the stem cell state of embryonic stem cells and neural stem cells. In particular, it has been shown to slow the proliferation of these cell types. It is also known for its effects as an activating transcription factor. Despite this, analysis of published studies shows that it represses as many genes as it activates. Here, we identify a new set of target genes that Sox2 represses in neural stem cells. These genes are associated with centrosomes, centromeres and other aspects of cell cycle control. In addition, we show that SUMOylation of Sox2 is necessary for the repression of these genes and for its repressive effects on cell proliferation. Together, these data suggest that SUMO-dependent repression of this group of target genes is responsible for the role of Sox2 in regulating the proliferation of neural stem cells.

STIM1/SOX2 proteins are co-expressed in the tumor and microenvironmental stromal cells of pancreatic ductal adenocarcinoma and ampullary carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) and ampullary carcinoma (AAC) are lethal malignancies with modest benefits from surgery. SOX2 and STIM1 have been linked to anticancer activity in several human malignancies. This study included 94 tumor cases: 48 primary PDAC, 25 metastatic PDAC, and 21 primary AAC with corresponding non-tumor tissue. All cases were immunohistochemically stained for STIM1 and SOX2 and results were correlated with clinicopathologic data, patient survival, and BCL2 immunostaining results. Results revealed that STIM1 and SOX2 epithelial/stromal expressions were significantly higher in PDAC and AAC in comparison to the control groups. STIM1 and SOX2 expressions were positively correlated in the primary and metastatic PDAC (P = 0.016 and, P = 0.001, respectively). However, their expressions were not significantly associated with BCL2 expression. SOX2 epithelial/stromal expressions were positively correlated with the large tumor size in the primary AAC group (P = 0.052, P = 0.044, respectively). STIM1 stromal and SOX2 epithelial over-expressions had a bad prognostic impact on the overall survival of AAC (P = 0.002 and P = 0.001, respectively). Therefore, STIM1 and SOX2 co-expression in tumor cells and intra-tumoral stroma could contribute to the development of PDAC and AAC. STIM1/SOX2 expression is linked to a bad prognosis in AAC.

SOX2 Expression Does Not Guarantee Cancer Stem Cell-like Characteristics in Lung Adenocarcinoma.

Effectively targeting cancer stemness is essential for successful cancer therapy. Recent studies have revealed that SOX2, a pluripotent stem cell factor, significantly contributes to cancer stem cell (CSC)-like characteristics closely associated with cancer malignancy. However, its contradictory impact on patient survival in specific cancer types, including lung adenocarcinoma (LUAD), underscores the need for more comprehensive research to clarify its functional effect on cancer stemness. In this study, we demonstrate that SOX2 is not universally required for the regulation of CSC-like properties in LUAD. We generated SOX2 knockouts in A549, H358, and HCC827 LUAD cells using the CRISPR/Cas9 system. Our results reveal unchanged CSC characteristics, including sustained proliferation, tumor sphere formation, invasion, migration, and therapy resistance, compared to normal cells. Conversely, SOX2 knockdown using conditional shRNA targeting SOX2, significantly reduced CSC traits. However, these loss-of-function effects were not rescued by SOX2 resistant to shRNA, underscoring the potential for SOX2 protein level-independent results in prior siRNA- or shRNA-based research. Ultimately, our findings demonstrate that SOX2 is not absolutely essential in LUAD cancer cells. This emphasizes the necessity of considering cancer subtype-dependent and context-dependent factors when targeting SOX2 overexpression as a potential therapeutic vulnerability in diverse cancers.

Diagnosis of verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) using CK17, SOX2 and GATA3 immunohistochemistry.

AIMS: Verruciform acanthotic vulvar intra-epithelial neoplasia (vaVIN) is an HPV-independent, p53 wild-type lesion with distinct morphology and documented risk of recurrence and cancer progression. vaVIN is rare, and prospective distinction from non-neoplastic hyperplastic lesions can be difficult. CK17, SOX2 and GATA3 immunohistochemistry has emerging value in the diagnosis of HPV-independent lesions, particularly differentiated VIN. We aimed to test the combined value of these markers in the diagnosis of vaVIN versus its non-neoplastic differentials in the vulva. METHODS AND RESULTS: CK17, SOX2 and GATA3 immunohistochemistry was evaluated on 16 vaVINs and 34 mimickers (verruciform xanthoma, lichen simplex chronicus, lichen sclerosus, psoriasis, pseudo-epitheliomatous hyperplasia). CK17 was scored as 3+ = full-thickness, 2+ = partial-thickness, 1+ = patchy, 0 = absent; SOX2 as 3+ = strong staining ≥ 10% cells, 2+ = moderate, 1 + =weak, 0 = staining in < 10% cells; and GATA3 as pattern 0 = loss in < 25% basal cells, 1 = loss in 25-75% basal cells, 2 = loss in > 75% basal cells. For analysis, results were recorded as positive (CK17 = 3+, SOX2 = 3+, GATA3 = patterns 1/2) or negative (CK17 = 2+/1+/0, SOX2 = 2+/1+/0, GATA3 = pattern 0). CK17, SOX2 and GATA3 positivity was documented in 81, 75 and 58% vaVINs, respectively, versus 32, 17 and 22% of non-neoplastic mimickers, respectively; ≥ 2 marker positivity conferred 83 sensitivity, 88 specificity and 86% accuracy in vaVIN diagnosis. Compared to vaVIN, SOX2 and GATA3 were differentially expressed in lichen sclerosus, lichen simplex chronicus and pseudo-epitheliomatous hyperplasia, whereas CK17 was differentially expressed in verruciform xanthoma and adjacent normal mucosa. CONCLUSIONS: CK17, SOX2 and GATA3 can be useful in the diagnosis of vaVIN and its distinction from hyperplastic non-neoplastic vulvar lesions. Although CK17 has higher sensitivity, SOX2 and GATA3 are more specific, and the combination of all markers shows optimal diagnostic accuracy.

E3 ubiquitin ligase RNF180 impairs IPO4/SOX2 complex stability and inhibits SOX2-mediated malignancy in ovarian cancer.

RING finger protein 180 (RNF180), an E3 ubiquitin ligase, is thought to be a tumor suppressor gene. However, the detailed mechanism of its effect on ovarian cancer (OV) has not been elucidated. Importin 4 (IPO4) which belongs to transport protein is reported to have cancer-promoting effects on OV. Here, we explored the potential signaling pathways related to RNF180 and IPO4. It was first verified that RNF180 is downregulated and IPO4 is upregulated in OV. By overexpressing or knocking down RNF180 in OV cells, we confirmed that RNF180 inhibited the malignant behaviors of OV cells both in vitro and in vivo. Bioinformatics analysis and proteomics experiments found that RNF180 could interact with IPO4 and promote the degradation of IPO4 through ubiquitination. In addition, overexpression of IPO4 removed the inhibitory effect of RNF180 on OV. We subsequently found that IPO4 could bind to the oncogene Sex determining Region Y-box 2 (SOX2). Knockdown of IPO4 in OV cells decreased SOX2 protein level in nucleus and promoted cyclin-dependent kinase inhibitory protein-1 (p21) expression. Overexpression of RNF180 also inhibited the expression of SOX2 in nucleus. All these results indicated that RNF180 inhibited the nuclear translocation of SOX2 by promoting ubiquitination of IPO4, which ultimately promoted the expression of p21 and then suppressed the progression of OV. This study verified the tumor suppressor effect of RNF180 on OV, elucidated the mechanism of the molecule network related to RNF180 and IPO4 in OV and identified for OV.

The impact of LncRNA-SOX2-OT/let-7c-3p/SKP2 Axis on head and neck squamous cell carcinoma progression: Insights from bioinformatics analysis and experimental validation.

BACKGROUND: LncRNA SRY-box transcription factor 2 overlapping transcript (SOX2-OT) is linked to multiple cancers, but its specific role and mechanism in head and neck squamous cell carcinoma (HNSCC) remain poorly understood. METHODS: We harnessed clinical data and HNSCC transcriptome profiles from UCSC Xena, TCGA, and GEO databases. Employing various algorithms, we assessed the correlation between SOX2-OT expression and the HNSCC immune microenvironment. Differential expression analysis identified immune-enriched miRNAs (DEmiRNAs) and mRNAs (DEmRNAs). Utilizing miRanda, miRWalk, and Cytoscape, we constructed a ceRNA network encompassing SOX2-OT, DEmiRNAs, and DEmRNAs. A Sankey diagram visualized pivotal SOX2-OT-miRNA-mRNA-pathways. Functional assays validated SOX2-OT silencing effects in HNSCC cells. Luciferase reporter assays verified SOX2-OT/let-7c-3p/SKP2 relationships. Additionally, a xenograft mouse model revealed SOX2-OT's impact on xenograft growth and lung metastasis. RESULTS: SOX2-OT expression demonstrated a predominantly positive correlation with B lineage and VTCN1, while manifesting a negative correlation with Neutrophil and CD47 in HNSCC tissues. We discerned a ceRNA network comprising 65 DEmiRNAs and 116 DEmRNAs, while a protein-protein interaction (PPI) network revealed 97 protein nodes among DEmRNAs. Notably, the Sankey diagram spotlighted six key DEmRNAs intricately linked to the SOX2-OT-regulated DEmiRNAs immune-related pathway. Experimental assays established that SOX2-OT silencing exerted inhibitory effects on cell proliferation, migration, tumor growth, and lung metastasis within HNSCC cells, both in vitro and in vivo. We identified let-7c-3p as a target miRNA of SOX2-OT and SKP2 as a target mRNA of let-7c-3p. CONCLUSIONS: Our study establishes the critical SOX2-OT/let-7c-3p/SKP2 axis as a pivotal regulator of HNSCC tumorigenesis and metastasis.

Highly cooperative chimeric super-SOX induces naive pluripotency across species.

Our understanding of pluripotency remains limited: iPSC generation has only been established for a few model species, pluripotent stem cell lines exhibit inconsistent developmental potential, and germline transmission has only been demonstrated for mice and rats. By swapping structural elements between Sox2 and Sox17, we built a chimeric super-SOX factor, Sox2-17, that enhanced iPSC generation in five tested species: mouse, human, cynomolgus monkey, cow, and pig. A swap of alanine to valine at the interface between Sox2 and Oct4 delivered a gain of function by stabilizing Sox2/Oct4 dimerization on DNA, enabling generation of high-quality OSKM iPSCs capable of supporting the development of healthy all-iPSC mice. Sox2/Oct4 dimerization emerged as the core driver of naive pluripotency with its levels diminished upon priming. Transient overexpression of the SK cocktail (Sox+Klf4) restored the dimerization and boosted the developmental potential of pluripotent stem cells across species, providing a universal method for naive reset in mammals.

SOX2 promotes a cancer stem cell-like phenotype and local spreading in oral squamous cell carcinoma.

Emerging evidence shows that oral squamous cell carcinoma (OSCC) invasiveness can be attributed to a small subpopulation of cancer stem cells (CSCs) in the bulk of the tumor. However, the presence of CSCs in the OSCC close resection margins is still poorly unexplored. Here, we found that BMI1, CD44, SOX2, OCT4, UBE2C, CXCR4 CSCs marker genes are significantly upregulated, while IGF1-R, KLF4, ALDH1A1, CD133, FAM3C are downregulated in the tumor core vs healthy mucosa of 24 patients with OSCC. Among these, SOX2 appears also upregulated in the tumor close margin vs healthy mucosa and this significantly correlates with tumor size and lymph node compromise. In vitro analyses in CAL27 and SCC15 tongue squamous cell carcinoma cell lines, show that SOX2 transient knockdown i) promotes the mesenchymal-to-epithelial transition, ii) smooths the invasiveness, iii) attenuates the 3D tumor sphere-forming capacity, and iv) partially increases the sensitivity to cisplatin treatment. Overall, our study highlights that the OSCC close margins can retain CSC-specific markers. Notably, SOX2 may represent a useful CSCs marker to predict a more aggressive phenotype and a suitable target to prevent local invasiveness.

Multifaceted SOX2-chromatin interaction underpins pluripotency progression in early embryos.

Pioneer transcription factors (TFs), such as OCT4 and SOX2, play crucial roles in pluripotency regulation. However, the master TF-governed pluripotency regulatory circuitry was largely inferred from cultured cells. In this work, we investigated SOX2 binding from embryonic day 3.5 (E3.5) to E7.5 in the mouse. In E3.5 inner cell mass (ICM), SOX2 regulates the ICM-trophectoderm program but is dispensable for opening global enhancers. Instead, SOX2 occupies preaccessible enhancers in part opened by early-stage expressing TFs TFAP2C and NR5A2. SOX2 then widely redistributes when cells adopt naive and formative pluripotency by opening enhancers or poising them for rapid future activation. Hence, multifaceted pioneer TF-enhancer interaction underpins pluripotency progression in embryos, including a distinctive state in E3.5 ICM that bridges totipotency and pluripotency.