Surgical treatment of preauricular fistulas: a 12-year single-center clinical observation.

OBJECTIVE: This study aimed to assess the effects of surgical timing and approach on operative duration, postoperative suture removal time, and postoperative recurrence rate in the management of preauricular fistula. A 12-year single-center clinical observation was conducted to analyze the potential effects of different surgical strategies on these critical outcomes. METHODS: The clinical data from 576 (782 ears) patients who underwent surgical resection for preauricular fistulas were examined in this retrospective study. The patients were classified into various groups based on differences in operative duration, surgical techniques and the use of intraoperative magnifying equipment. Furthermore, the specific data on operative duration, postoperative suture removal time, and postoperative recurrence rate were also recorded. RESULTS: The average operative duration for 782 ears and the average time required for postoperative suture removal were determined to be (34.57 ± 4.25) min and (3.62 ± 0.76) days, respectively. Among the cases examined, recurrence occurred in 13 ears, but all of them were cured after a second surgery, resulting in a recurrence rate of 1.67% (13/782). Interestingly, the operative and postoperative suture removal time was prolonged during the infection period (P < 0.05). The postoperative recurrence rate was significantly higher in the absence of magnifying equipment, as compared to those with the use of a microscope with 2.5× magnification (P < 0.05). No statistically significant differences were noted in the recurrence rate when comparing different anesthesia methods and types of surgical incisions, as well as the intraoperative use of methylene blue, and partial removal of cartilage of the pedicle (P > 0.05). CONCLUSION: The use of methylene blue, partial removal of the cartilage of the pedicle, and surgical incision during preauricular fistula resection did not affect the operative duration, postoperative suture removal time, and postoperative recurrence rate. Therefore, surgeons can select their preferred approaches based on their individual practices and patient-specific situations. However, the use of magnifying equipment during surgery is associated with a reduced risk of recurrence.

Application of the CRISPR/Cas9-based gene editing technique in basic research, diagnosis, and therapy of cancer.

The 2020 Nobel Prize in Chemistry was awarded to Emmanuelle Charpentier and Jennifer Doudna for the development of the Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease9 (CRISPR/Cas9) gene editing technology that provided new tools for precise gene editing. It is possible to target any genomic locus virtually using only a complex nuclease protein with short RNA as a site-specific endonuclease. Since cancer is caused by genomic changes in tumor cells, CRISPR/Cas9 can be used in the field of cancer research to edit genomes for exploration of the mechanisms of tumorigenesis and development. In recent years, the CRISPR/Cas9 system has been increasingly used in cancer research and treatment and remarkable results have been achieved. In this review, we introduced the mechanism and development of the CRISPR/Cas9-based gene editing system. Furthermore, we summarized current applications of this technique for basic research, diagnosis and therapy of cancer. Moreover, the potential applications of CRISPR/Cas9 in new emerging hotspots of oncology research were discussed, and the challenges and future directions were highlighted.

Epidemiological Analysis of 1234 Cases of Laryngeal Cancer in Shanxi Province, China.

BACKGROUND: Laryngeal cancer is a common malignancy of the head and neck, especially in northern China, including Shanxi province. This study intends to describe the epidemiological characteristics of laryngeal cancer in Shanxi Province, China, in order to support prevention and treatment efforts. METHODS: Retrospective analysis of the medical records of patients diagnosed with laryngeal cancer in hospitals in Shanxi Province from 2008 to 2012. RESULTS: The average annual incidence rate of laryngeal cancer in Shanxi province from 2008 to 2012 was 0.70/105, the Chinese population standardized incidence rate was 0.57/105 and the world population standardized incidence rate was 0.60/105. The city with the highest incidence of laryngeal cancer in Shanxi Province is Taiyuan, followed by Yangquan, and the lowest incidence are Yuncheng and Jincheng. The cases included 723 farmers (58.6%), 338 workers (27.4%), 95 government cadres (7.7%), 35 unemployed individuals (2.8%), 30 teachers (2.4%) and 13 individuals with other occupations (1.1%). The incidence of laryngeal cancer in rural areas was 0.78/105, while urban areas was 0.60/105. Of 1006 patients with smoking and drinking status reported, there were 238 both smoking and drinking (23.7%), 491 only smoking but not drinking (48.8%), 4 only drinking but not smoking (0.4%), 273 both not smoking and not drinking (27.1%) (P<0.001), and there were 695 males smoking (95.3%), 34 females smoking (4.7%) (P<0.001). Of 879 patients for whom the primary cancer location was known, 406 cases (46.2%) were supraglottic and 428 cases (48.7%) were glottic. Among 1009 patients with known pathological classification, the vast majority had squamous cell carcinoma (992 cases, 98.3%). CONCLUSIONS: To sum up, the incidence of laryngeal cancer in Shanxi Province exhibited a relatively stable trend from 2008 to 2012, and the incidence is higher in men than in women in all years. The high percentage of smokers in this study underscores the importance of smoking as a risk factor for laryngeal cancer, whereas rates of drinking did not appear to be linked. Incidence of laryngeal cancer was higher in rural areas than in urban areas, a pattern that differs from other regions of China and internationally.

Petroleum extract of Farfarae Flos alleviates nasal symptoms by regulating the Th1-Th2 cytokine balance in a mouse model of Allergic Rhinitis.

Farfarae Flos is a traditional Chinese medicine that has long been used to treat allergies. In this study, we aimed to investigate the effect of a petroleum extract of Farfarae Flos (PEFF) in a mouse model of allergic rhinitis (AR) and to explore the underlying molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with ovalbumin (OVA). PEFF was administered intranasally and AR nasal symptoms were assessed on a semi-quantitative scale according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The mechanism of action of PEFF was evaluated by histological analysis of nasal mucosa architecture and inflammatory status; ELISA-based quantification of serum OVA-specific IgE, interferon-γ (IFN-γ), and interleukin-4 (IL-4) concentrations; and immunohistochemical and western blot analysis of T-bet and GATA3 protein expression in nasal mucosa and spleen tissues. The results showed intranasal administration of PEFF alleviated AR symptom scores and reduced both the infiltration of inflammatory cells and tissue damage in the nasal mucosa. PEFF significantly decreased serum concentrations of OVA-specific IgE (P<0.01) and IL-4 (P<0.05) and significantly increased IFN-γ (P<0.01). PEFF also upregulated the expression of T-bet protein (P<0.05) but downregulated GATA3 protein (P<0.05) in nasal mucosa and spleen tissues. In conclusion, PEFF effectively reduces AR nasal symptoms and serum IgE levels in a mouse model and may act by correcting the imbalance between Th1 and Th2 responses.

AlloDriver: a method for the identification and analysis of cancer driver targets.

Identifying the variants that alter protein function is a promising strategy for deciphering the biological consequences of somatic mutations during tumorigenesis, which could provide novel targets for the development of cancer therapies. Here, based on our previously developed method, we present a strategy called AlloDriver that identifies cancer driver genes/proteins as possible targets from mutations. AlloDriver utilizes structural and dynamic features to prioritize potentially functional genes/proteins in individual cancers via mapping mutations generated from clinical cancer samples to allosteric/orthosteric sites derived from three-dimensional protein structures. This strategy exhibits desirable performance in the reemergence of known cancer driver mutations and genes/proteins from clinical samples. Significantly, the practicability of AlloDriver to discover novel cancer driver proteins in head and neck squamous cell carcinoma (HNSC) was tested in a real case of human protein tyrosine phosphatase, receptor type K (PTPRK) through a L1143F driver mutation located at the allosteric site of PTPRK, which was experimentally validated by cell proliferation assay. AlloDriver is expected to help to uncover innovative molecular mechanisms of tumorigenesis by perturbing proteins and to discover novel targets based on cancer driver mutations. The AlloDriver is freely available to all users at http://mdl.shsmu.edu.cn/ALD.

circPARD3 drives malignant progression and chemoresistance of laryngeal squamous cell carcinoma by inhibiting autophagy through the PRKCI-Akt-mTOR pathway.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) is the second most common malignant tumor in head and neck. Autophagy and circular RNAs (circRNAs) play critical roles in cancer progression and chemoresistance. However, the function and mechanism of circRNA in autophagy regulation of LSCC remain unclear. METHODS: The autophagy-suppressive circRNA circPARD3 was identified via RNA sequencing of 107 LSCC tissues and paired adjacent normal mucosal (ANM) tissues and high-content screening. RT-PCR, Sanger sequencing, qPCR and fluorescence in situ hybridization were performed to detect circPARD3 expression and subcellular localization. Biological functions of circPARD3 were assessed by proliferation, migration, invasion, autophagic flux, and chemoresistance assays using in vitro and in vivo models. The mechanism of circPARD3 was investigated by RNA immunoprecipitation, RNA pulldown, luciferase reporter assays, western blotting and immunohistochemical staining. RESULTS: Autophagy was inhibited in LSCC, and circPARD3 was upregulated in the LSCC tissues (n = 100, p < 0.001). High circPARD3 level was associated with advanced T stages (p < 0.05), N stages (p = 0.001), clinical stages (p < 0.001), poor differentiation degree (p = 0.025), and poor prognosis (p = 0.002) of LSCC patients (n = 100). Functionally, circPARD3 inhibited autophagy and promoted LSCC cell proliferation, migration, invasion and chemoresistance. We further revealed that activation of the PRKCI-Akt-mTOR pathway through sponging miR-145-5p was the main mechanism of circPARD3 inhibited autophagy, promoting LSCC progression and chemoresistance. CONCLUSION: Our study reveals that the novel autophagy-suppressive circPARD3 promotes LSCC progression and chemoresistance through the PRKCI-Akt-mTOR pathway, providing new insights into circRNA-mediated autophagy regulation and potential biomarker and target for LSCC treatment.

Circular RNA circCORO1C promotes laryngeal squamous cell carcinoma progression by modulating the let-7c-5p/PBX3 axis.

BACKGROUND: Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor of the head and neck. LSCC patients have seriously impaired vocal, respiratory, and swallowing functions with poor prognosis. Circular RNA (circRNA) has attracted great attention in cancer research. However, the expression patterns and roles of circRNAs in LSCC remain largely unknown. METHODS: RNA sequencing was performed on 57 pairs of LSCC and matched adjacent normal mucosa tissues to construct circRNA, miRNA, and mRNA expression profiles. RT-PCR, qPCR, Sanger sequencing, and FISH were undertaken to study the expression, localization, and clinical significance of circCORO1C in LSCC tissues and cells. The functions of circCORO1C in LSCC were investigated by RNAi-mediated knockdown, proliferation analysis, EdU staining, colony formation assay, Transwell assay, and apoptosis analysis. The regulatory mechanisms among circCORO1C, let-7c-5p, and PBX3 were investigated by luciferase assay, RNA immunoprecipitation, western blotting, and immunohistochemistry. RESULTS: circCORO1C was highly expressed in LSCC tissues and cells, and this high expression was closely associated with the malignant progression and poor prognosis of LSCC. Knockdown of circCORO1C inhibited the proliferation, migration, invasion, and in vivo tumorigenesis of LSCC cells. Mechanistic studies revealed that circCORO1C competitively bound to let-7c-5p and prevented it from decreasing the level of PBX3, which promoted the epithelial-mesenchymal transition and finally facilitated the malignant progression of LSCC. CONCLUSIONS: circCORO1C has an oncogenic role in LSCC progression and may serve as a novel target for LSCC therapy. circCORO1C expression has the potential to serve as a novel diagnostic and prognostic biomarker for LSCC detection.

MicroRNA-27b Modulates Inflammatory Response and Apoptosis during Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis poses a significant global health threat. MicroRNAs play an important role in regulating host anti-mycobacterial defense; however, their role in apoptosis-mediated mycobacterial elimination and inflammatory response remains unclear. In this study, we explored the role of microRNA-27b (miR-27b) in murine macrophage responses to M. tuberculosis infection. We uncovered that the TLR-2/MyD88/NF-κB signaling pathway induced the expression of miR-27b and miR-27b suppressed the production of proinflammatory factors and the activity of NF-κB, thereby avoiding an excessive inflammation during M. tuberculosis infection. Luciferase reporter assay and Western blotting showed that miR-27b directly targeted Bcl-2-associated athanogene 2 (Bag2) in macrophages. Overexpression of Bag2 reversed miR-27b-mediated inhibition of the production of proinflammatory factors. In addition, miR-27b increased p53-dependent cell apoptosis and the production of reactive oxygen species and decreased the bacterial burden. We also showed that Bag2 interacts with p53 and negatively regulates its activity, thereby controlling cell apoptosis and facilitating bacterial survival. In summary, we revealed a novel role of the miR-27b/Bag2 axis in the regulation of inflammatory response and apoptosis and provide a potential molecular host defense mechanism against mycobacteria.

Promoter Methylation-Regulated miR-145-5p Inhibits Laryngeal Squamous Cell Carcinoma Progression by Targeting FSCN1.

Laryngeal squamous cell carcinoma (LSCC) is a common form of head and neck cancer with poor prognosis. However, the mechanism underlying the pathogenesis of LSCC remains unclear. Here, we demonstrated increased expression of fascin actin-bundling protein 1 (FSCN1) and decreased expression of microRNA-145-5p (miR-145-5p) in a clinical cohort of LSCC. Luciferase assay revealed that miR-145-5p is a negative regulator of FSCN1. Importantly, low miR-145-5p expression was correlated with TNM (tumor, node, metastasis) status and metastasis. Moreover, cases with low miR-145-5p/high FSCN1 expression showed poor prognosis, and these characteristics together served as independent prognostic indicators of survival. Gain- and loss-of-function studies showed that miR-145-5p overexpression or FSCN1 knockdown inhibited LSCC migration, invasion, and growth by suppressing the epithelial-mesenchymal transition along with inducing cell-cycle arrest and apoptosis. Additionally, hypermethylation of the miR-145-5p promoter suggested that repression of miR-145-5p arises through epigenetic inactivation. LSCC tumor growth in vivo could be inhibited by using miR-145-5p agomir or FSCN1 small interfering RNA (siRNA), which highlights the potential for clinical translation. Collectively, our findings indicate that miR-145-5p plays critical roles in inhibiting the progression of LSCC by suppressing FSCN1. Both miR-145-5p and FSCN1 are important potential prognostic markers and therapeutic targets for LSCC.

Uncovering the anticancer mechanism of petroleum extracts of Farfarae Flos against Lewis lung cancer by metabolomics and network pharmacology analysis.

Lung cancer shows the highest incidence rate in the world. Thus, it has become increasingly important to find therapeutic drugs to treat lung cancer. Farfarae Flos (FF) has been used in traditional Chinese medicine to treat pulmonary diseases such as cough, bronchitis and asthmatic disorders. In this study, the anti-proliferation effects of petroleum extracts of FF (PEFF) on Lewis lung cancer cells and the corresponding mechanisms were studied using cell metabolomics. Fifteen differential metabolites in the cell extracts and the corresponding medium related to the anti-proliferation effect of PEFF were identified, which were probably involved in pyruvate metabolism and glycine, serine and threonine metabolism. For the cellular uptake compounds in PEFF, six metabolites derived from two prototype compounds were also tentatively identified by UHPLC-Q-Orbitrap high-resolution MS. Network pharmacology analysis demonstrated that the anti-proliferation mechanism of PEFF was also probably related to the target genes, including, Aurora-A, glutathione S-transferase Mu 1 (GSTM1), glutathione S-transferase P 1 (GSTP1), progesterone receptor and heme oxygenase-1 (HO-1), and further associated with the proteoglycans and PI3K/Akt signaling pathway. Cell metabolomics and network pharmacology analysis provided a holistic method to investigate the anti-proliferation mechanisms of PEFF. However, further studies were still needed to validate the potential target genes, pathways and active compounds in PEFF.

Identification of miR-145-5p-Centered Competing Endogenous RNA Network in Laryngeal Squamous Cell Carcinoma.

This study intends to investigate the transcriptional regulatory role of miR-145-5p in laryngeal squamous cell carcinoma (LSCC). LSCC cell line TU-177 is transfected with miR-145-5p mimics, generating miR-145-5p-overexpression LSCC cells. Whole transcriptome microarrays are used to investigate the differentially expressed lncRNAs, circRNAs, mRNAs, and miRNAs. The target genes of miRNAs are predicted and performed functional annotation. Additionally, the circRNAs, lncRNAs, and mRNAs that interact with miRNAs are predicted, and then the competing endogenous RNAs (ceRNAs) are predicted. Microarray analysis identifies 26 miRNAs, 248 mRNAs, 1118 lncRNAs, and 382 circRNAs differentially expressed in miR-145-5p overexpressed LSCC cells. Overall, 675 target genes are identified for the differentially expressed miRNAs, which involved in cell adhesion associated gene ontology (GO) terms, and MAPK and FoxO signaling pathways. The up-regulated mRNAs involved in the pathway of ABC transporters, while the down-regulated mRNAs involved in pathway of olfactory transduction. Moreover, 149 ceRNAs are predicted, which are associated with apoptosis, Wnt pathway, and metabolic pathway. Furthermore, qPCR results confirm that miR-145-5p affects expression of lncRNAs, miRNAs, mRNAs, and circRNAs in LSCC cells. Collectively, miR-145-5p may be inhibits LSCC progression via ceRNA-mediated pathways, such as WNT2B-miR-145-5p-NONHSAT127539.2, CASP10-miR-145-5p-NONHSAT127539.2, CASP10-miR-145-5p-circ_0003519, and TPO-miR-145-5p-circ_0003519.

Mass Spectrometric Analysis Identifies AIMP1 and LTA4H as FSCN1-Binding Proteins in Laryngeal Squamous Cell Carcinoma.

Dysregulation of fascin actin-bundling protein 1 (FSCN1) enhances cell proliferation, invasion, and motility in laryngeal squamous cell carcinoma (LSCC), while the mechanism remains unclear. Here, co-immunoprecipitation and mass spectrometry is utilized to identify potential FSCN1-binding proteins. Functional annotation of FSCN1-binding proteins are performed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Furthermore, the protein-protein interaction network of FSNC1-binding proteins is constructed and the interactions between FSCN1 and novel identified interacting proteins AIMP1 and LTA4H are validated. Moreover, the expression and functional role of AIMP1 and LTA4H in LSCC are investigated. A total of 123 proteins are identified as potential FSCN1-binding proteins, and functional annotation shows that FSCN1-binding proteins are significantly enriched in carcinogenic processes, such as filopodium assembly-regulation and GTPase activity. Co-IP/western blotting and immunofluorescence confirm that AIMP1 and LTA4H bind and colocalize with FSCN1. Furthermore, both AIMP1 and LTA4H are upregulated in LSCC tissues, and knockdown of AIMP1 or LTA4H inhibits LSCC cell proliferation, migration, and invasion. Collectively, the identification of FSCN1-binding partners enhances understanding of the mechanism of FSCN1-mediated malignant phenotypes, and these findings indicate that FSCN1 binds to AIMP1 and LTA4H might promote the progression of LSCC.

Unphosphorylated STAT1 represses apoptosis in macrophages during Mycobacteriumtuberculosis infection.

In murine macrophages infected with Mycobacterium tuberculosis (Mtb), the level of phosphorylated STAT1 (P-STAT1), which drives the expression of many pro-apoptosis genes, increases quickly but then declines over a period of hours. By contrast, infection induces a continued increase in the level of unphosphorylated STAT1 that persists for several days. Here, we found that the level of unphosphorylated STAT1 correlated with the intracellular bacterial burden during the later stages of infection. To investigate the significance of a high level of unphosphorylated STAT1, we increased its concentration exogenously, and found that the apoptosis rate induced by Mtb was sufficiently decreased. Further experiments confirmed that unphosphorylated STAT1 affects the expression of several immune-associated genes and lessens the sensitivity of macrophages to CD95 (FAS)-mediated apoptosis during Mtb infection. Furthermore, we characterized 149 proteins that interacted with unphosphorylated STAT1 and the interactome network. The cooperation between unphosphorylated STAT1 and STAT3 results in downregulation of CD95 expression. Additionally, we verified that unphosphorylated STAT1 and IFIT1 competed for binding to eEF1A. Taken together, our data show that the role of unphosphorylated STAT1 differs from that of P-STAT1, and represses apoptosis in macrophages to promote immune evasion during Mtb infection.

Mass spectrometry-based proteomic analysis of FSCN1-interacting proteins in laryngeal squamous cell carcinoma cells.

Fascin actin-bundling protein 1 (FSCN1) is an evolutionarily conserved actin-bundling protein that plays a critical role in cell migration, motility, adhesion, and cellular interactions. Although multiple clinical studies have implicated the expression of FSCN1 in laryngeal squamous cell carcinoma (LSCC) progression, the precise mechanism of FSCN1 in the process has not been clearly elucidated. To define FSCN1 function, we characterized FSCN1­interacting proteins in two cell lines by immunoprecipitation followed by mass spectrometry (MS). After data filtering, 119 proteins with expression in both the Hep-2 and TU-177 cell samples were identified as FSCN1-interacting partners. With in-depth bioinformatics analysis, we linked FSCN1 to critical cellular processes including cell adhesion, glycolysis/gluconeogenesis, regulation of protein ubiquitination, ribosomal RNA processing, and small molecule metabolism. We discuss the interactions between FSCN1 and some of the newly validated partners. The identification of these potential partners of FSCN1 expands our knowledge of the FSCN1 interactome and provides a valuable resource for understanding the functions of this protein in LSCC progression.

Whole-Transcriptome Analysis of CD133+CD144+ Cancer Stem Cells Derived from Human Laryngeal Squamous Cell Carcinoma Cells.

BACKGROUND/AIMS: CD133+CD44+ cancer stem cells previously isolated from laryngeal squamous cell carcinoma (LSCC) cell lines showed strong malignancy and tumorigenicity. However, the molecular mechanism underlying the enhanced malignancy remained unclear. METHODS: Cell proliferation assay, spheroid-formation experiment, RNA sequencing (RNA-seq), miRNA-seq, bioinformatic analysis, quantitative real-time PCR, migration assay, invasion assay, and luciferase reporter assay were used to identify differentially expressed mRNAs, lncRNAs, circRNAs and miRNAs, construct transcription regulatory network, and investigate functional roles and mechanism of circRNA in CD133+CD44+ laryngeal cancer stem cells. RESULTS: Differentially expressed genes in TDP cells were mainly enriched in the biological processes of cell differentiation, regulation of autophagy, negative regulation of cell death, regulation of cell growth, response to hypoxia, telomere maintenance, cellular response to gamma radiation, and regulation of apoptotic signaling, which are closely related to the malignant features of tumor cells. We constructed the regulatory network of differentially expressed circRNAs, miRNAs and mRNAs. qPCR findings for the expression of key genes in the network were consistent with the sequencing data. Moreover, our data revealed that circRNA hg19_circ_0005033 promotes proliferation, migration, invasion, and chemotherapy resistance of laryngeal cancer stem cells. CONCLUSIONS: This study provides potential biomarkers and targets for LSCC diagnosis and therapy, and provide important evidences for the heterogeneity of LSCC cells at the transcription level.

SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway.

BACKGROUND/AIMS: Self-renewal is one of the most important features of embryonic stem (ES) cells. SC1 is a small molecule modulator that effectively maintains the self-renewal of mouse ES cells in the absence of leukemia inhibitory factor (LIF), serum and feeder cells. However, the mechanism by which SC1 maintains the undifferentiated state of mouse ES cells remains unclear. METHODS: In this study, microarray and small RNA deep-sequencing experiments were performed on mouse ES cells treated with or without SC1 to identify the key genes and microRNAs that contributed to self-renewal. RESULTS: SC1 regulates the expressions of pluripotency and differentiation factors, and antagonizes the retinoic acid (RA)-induced differentiation in the presence or absence of LIF. SC1 inhibits the MEK/ERK pathway through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and pathway reporting experiments. Small RNA deep-sequencing revealed that SC1 significantly modulates the expression of multiple microRNAs with crucial functions in ES cells. The expression of miR124-3p is upregulated in SC1-treated ES cells, which significantly inhibits the MEK/ERK pathway by targeting Grb2, Sos2 and Egr1. CONCLUSION: SC1 enhances the self-renewal capacity of mouse ES cells by modulating the expression of key regulatory genes and pluripotency-associated microRNAs. SC1 significantly upregulates miR124-3p expression to further inhibit the MEK/ ERK pathway by targeting Grb2, Sos2 and Egr1.

Vitamin C enhances Nanog expression via activation of the JAK/STAT signaling pathway.

Vitamin C (Vc), also known as ascorbic acid, is involved in many important metabolic and physiological reactions in the body. Here, we report that Vc enhances the expression of Nanog and inhibits retinoic acid-induced differentiation of embryonic stem cells. We investigated Vc regulation of Nanog through Janus kinase/signal transducer and activator of transcription pathway using cell signaling pathway profiling systems, and further confirmed by specific pathway inhibition. Using overexpression and knockdown strategies, we demonstrated that STAT2 is a new positive regulator of Nanog and is activated by phosphorylation following Vc treatment. In addition, site mutation analysis identified that STAT2 physically occupies the Nanog promoter, which was confirmed by chromatin immunoprecipitation and electrophoretic mobility shift assays. Taken together, our data suggest a role for Vc in Nanog regulation networks and reveal a novel role for STAT2 in regulating Nanog expression.

E-cadherin is critical for SC1-induced colony growth of F9 embryonic carcinoma cells.

BACKGROUND: Colony morphology of embryonic stem (ES) cells contributes to the maintenance of undifferentiated ES cells. Small molecule 3,4-dihydropy-rimido[4,5-d]pyrimidine (SC1), an inhibitor of ERK1- and RasGAP-dependent signaling pathways, can maintain the compact colony morphology of ES cells. However, information on the influence of SC1 on cell morphological change remains lacking. METHODS: In this study, mouse ES cells J1 and embryonic carcinoma (EC) cells F9 were cultured in SC1-containing medium to determine the effect of SC1 on cell morphology. RESULTS: SC1 promotes a more compact morphology of J1 mouse ES cells and induces colony growth of F9 EC cells. Furthermore, the cell adhesion protein E-cadherin is a downstream target of SC1, and E-cadherin is critical for SC1-mediated colony growth of F9 EC cells. CONCLUSIONS: SC1 maintains and induces compact colony morphology of pluripotent cells, and its downstream target, E-cadherin, is involved in the colony phenotype of F9 EC cells. These results explored the potential role of SC1 in morphological change and gene expression in pluripotent cells.