Unravelling the molecular landscape of endometrial cancer subtypes: insights from multi-omics analysis.

BACKGROUND: Endometrial cancer (EC) as one of the most common gynecologic malignancies is increasing in incidence during the past 10 years. Genome-Wide Association Studies (GWAS) extended to metabolic and protein phenotypes inspired us to employ multi-omics methods to analyze the causal relationships of plasma metabolites and proteins with EC to advance our understanding of EC biology and pave the way for more targeted approaches to its diagnosis and treatment by comparing the molecular profiles of different EC subtypes. METHODS: Two-sample Mendelian randomization (MR) was performed to investigate the effects of plasma metabolites and proteins on risks of different subtypes of EC (endometrioid and non-endometrioid). Pathway analysis, transcriptomic analysis, and network analysis were further employed to illustrate gene-protein-metabolites interactions underlying the pathogenesis of distinct EC histological types. RESULTS: We identified 66 causal relationships between plasma metabolites and endometrioid EC, and 132 causal relationships between plasma proteins and endometrioid EC. Additionally, 40 causal relationships between plasma metabolites and non-endometrioid EC, and 125 causal relationships between plasma proteins and non-endometrioid EC were observed. Substantial differences were observed between endometrioid and non-endometrioid histological types of EC at both the metabolite and protein levels. We identified 7 overlapping proteins (RGMA, NRXN2, EVA1C, SLC14A1, SLC6A14, SCUBE1, FGF8) in endometrioid subtype and 6 overlapping proteins (IL32, GRB7, L1CAM, CCL25, GGT2, PSG5) in non-endometrioid subtype and network analysis of above proteins and metabolites to identify coregulated nodes. CONCLUSIONS: Our findings observed substantial differences between endometrioid and non-endometrioid EC at the metabolite and protein levels, providing novel insights into gene-protein-metabolites interactions that could influence future EC treatments.

Fibroblast growth factor-21 alleviates proteasome injury via activation of autophagy flux in Parkinson's disease.

Parkinson's disease (PD) is one of the most common and complex Neurodegeneration, with an inherited metabolic disorder. Fibroblast growth factor 21 (FGF21), an endocrine hormone that belongs to the fibroblast growth factor superfamily, plays an extensive role in metabolic regulation. However, our understandings of the specific function and mechanisms of FGF21 on PD are still quite limited. Here, we aimed to elucidate the actions and the underlying mechanisms of FGF21 on dopaminergic neurodegeneration using cellular models of parkinsonism. To investigate the effects of FGF21 on dopaminergic neurodegeneration in vitro, proteasome impairment models of PD were utilized. Human dopaminergic neuroblastoma SH-SY5Y cells were treated with the proteasome inhibitor lactacystin (5 µmol/L) for 12 h, then with 50 ng/ml FGF-21 with or without 5 mmol/L of 3-methyladenine.The cells were dissected to assess alterations in autophagy using immunofluorescence, immunoblotting and electron microscopy assays. Our data indicate that FGF21 prevents dopaminergic neuron loss and shows beneficial effects against proteasome impairment induced PD syndrome, indicating it might be a potent candidate for developing novel drugs to deal with PD.

Triage method for endometrial biopsy in postmenopausal women: a multicenter retrospective cohort study.

OBJECTIVE: To identify the optimal triage procedure for endometrial biopsies in postmenopausal women. METHODS: The clinical information of 470 postmenopausal women with endometrial biopsy results and postmenopausal bleeding (PMB) and/or transvaginal ultrasonography (TVU) abnormalities were collected at the gynecology departments of four general hospitals from March 2021 to March 2022. In the validation cohort, 112 women with TVU abnormalities who underwent endometrial biopsy at Xiangya hospital between May 2022 and May 2023 were enrolled. The endpoint was the final diagnosis based on hysteroscopy reports and biopsy pathology results. The sensitivity, specificity, positive predictive value, and negative predictive value were compared among the three triage methods. A nomogram prediction model was developed and validated. RESULTS: Referring women with TVU abnormalities for endometrial biopsy identified 100% malignant/premalignant lesions despite low specificity (19.7%). Among women with measurable endometrial thickness (ET), we suggest that the ET cutoff value for biopsy referral should be ≥4 mm. The PMB (odds ratio [OR], 3.241; 95% confidence interval [CI], 1.073-9.789), diabetes (OR, 10.915; 95% CI, 3.389-35.156), and endometrial thickness (OR, 1.277; 95% CI, 1.156-1.409) were independent predictive factors for endometrial (pre)malignancy. A nomogram prediction model was constructed (area under curve [AUC] = 0.802, 95% CI: 0.715 to 0.889). The ideal cutoff point was 22.5, with a sensitivity of 100.0% and a specificity of 15.7%. The external validation achieved an AUC of 0.798 (95% CI, 0.685-0.911). CONCLUSIONS: It was possible to refer all postmenopausal women with TVU abnormity (ET ≥ 4 mm or other abnormal findings) for endometrial biopsy. Among women with TVU abnormalities, a nomogram was constructed, and a score greater than 22.5 suggested the need for referral for endometrial biopsy, while a score less than 22.5 suggested that regular follow-up was required, further improving the triage procedure.

Preemptive QP001, a fast-acting meloxicam formulation, provides analgesia and reduces opioid consumption following abdominal surgery: a randomized controlled trial.

BACKGROUND: QP001, a novel meloxicam formulation, has been developed to manage moderate to severe postoperative pain. This study aimed to evaluate the efficacy and safety of QP001 injections for moderate to severe pain following abdominal surgery. METHOD: This prospective, multicenter, randomized, double-blind, placebo-controlled clinical trial enlisted patients experiencing moderate to severe pain following abdominal surgery. These patients were randomized to receive either QP001 injections (30 mg or 60 mg) or a placebo pre-surgery. The primary efficacy endpoint was the total morphine consumption within 24 h after the first administration. RESULTS: A total of 108 patients were enrolled, and 106 patients completed the study. The total morphine consumption in the QP001 30 mg group and 60 mg group, versus placebo group, were significantly lower over the following 24 h (5.11[5.46] vs 8.86[7.67], P = 0.011; 3.11[3.08] vs 8.86[7.67], P < 0.001), respectively. The total morphine consumption in the QP001 30 mg and 60 mg groups, versus placebo group, was also significantly decreased over the following 48 h, including the 24-48 h period (P ≤ 0.001). The QP001 30 mg and 60 mg groups, versus placebo, showed a significant decrease in the area under the curve for pain intensity-time as well as a significant decrease in the effective pressing times of the analgesic pump over the 24 h and 48 h periods (P < 0.05). The QP001 groups, versus placebo, show no significant different in Adverse Events or Adverse Drug Reactions (P > 0.05). CONCLUSION: Preoperative/preemptive QP001 provides analgesia and reduces opioid consumption in patients with moderate to severe pain following abdominal surgery, while maintaining a favorable safety profile.

Minimally invasive approaches for the early detection of endometrial cancer.

Endometrial cancer (EC) is one of the most common gynecologic cancers and its incidence is rising globally. Although advanced EC has a poor prognosis; diagnosing EC at an earlier stage could improve long-term patient outcomes. However, there is no consensus on the early detection strategies for EC and the current diagnostic practices such as transvaginal ultrasound, hysteroscopy and endometrial biopsy are invasive, costly and low in specificity. Thus, accurate and less invasive screening tests that detect EC in women with early stages of the disease are needed. Current research has revolutionized novel EC early detection methodologies in many aspects. This review aims to comprehensively characterizes minimally invasive screening techniques that can be applied to EC in the future, and fully demonstrate their potential in the early detection of EC.

Breast-conserving in centrally located breast cancer patients confirmed safe by SEER based study.

BACKGROUND: Due to the lack of high-level data, there is still controversy over the oncological safety of breast conservation in patients with centrally located breast cancer. This study aimed to assess the safety of breast-conserving surgery in patients with centrally located breast cancer based on the data from the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: We collected data for all cases diagnosed with breast cancer who underwent breast-conserving surgery from 2012-2014 in the SEER database. The primary outcome of our study was disease-specific survival (DSS) and overall survival (OS). The PSM was used to eliminate the effects of non-random statistics. Chi-square test, Kaplan-Meier method and Cox proportional hazards regression model on univariate and multivariate analysis were used to analyze the data. RESULTS: Data from 79,214 patients who had undergone breast-conserving surgery were analyzed in this study, including those with breast cancer in the central region (n=3,128) and outside the central region (n=76,086). The DSS of central breast cancer patients and outside the central breast cancer patients was 58.1 months versus 58.0 months (P>0.05), respectively, while the OS of the 2 groups was 58.0 months versus 58.0 months (P>0.05), respectively. CONCLUSIONS: Breast cancer in the central region should not be contraindicated for breast conserving surgery and breast-conserving surgery can benefit a wider range of patients.

The efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in people with abdominal and pelvic cancer: A systematic review and meta-analysis based on 23 randomized studies.

BACKGROUND AND AIMS: We evaluated the efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in patients with abdominal or pelvic cancer. METHODS: We searched the Cochrane Library, PubMed, EMBASE, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases up to August 2019. We also hand searched the citation lists of included studies and previous systematic reviews identified to identify further relevant trials. The primary outcome was the incidence of chemoradiotherapy-induced diarrhea of all grades. The secondary outcomes were improvement of antidiarrheal medication use, stool form (Bristol scale), response rate, and adverse events (AEs). Diarrhea was graded according to the Common Toxicity Criteria system. Two reviewers assessed trial quality and extracted data independently. The included studies were analyzed using Review Manager ver. 5.2. RESULTS: Twenty-three randomized, placebo-controlled studies (N = 2570 participants) were included in the efficacy assessment. The incidence of all diarrhea (risk ratio [RR] 0.16; 95% confidence interval [CI] 0.51-0.73), grade ≥ 3 diarrhea (RR 0.36; 95% CI 0.18-0.72), and grade ≥ 2 diarrhea (RR 0.65; 95% CI 0.54-0.78), but not that of grade ≤ 2 diarrhea (RR 1.07; 95% CI 0.95-1.21), was significantly reduced in the probiotics compared to the placebo groups. No significant increase in the incidence of AEs was found in the probiotics group, although four studies reported a variety of AEs. CONCLUSIONS: Probiotics prevented chemoradiotherapy-induced diarrhea, particularly high-grade diarrhea. Probiotics rarely cause AEs.

miR-30b protects nigrostriatal dopaminergic neurons from MPP(+)-induced neurotoxicity via SNCA.

OBJECTIVE: To explore the function of miR-30b in pathogenesis of Parkinson's disease (PD) and its underlying molecular mechanism. MATERIALS AND METHODS: We used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPP(+)) as a tool for constructing the PD cell model, using miR-30b mimics or inhibitors to manipulate miR-30b level for an experimental model of acquisition. The cell viability of SH-SY5Y was detected by CCK, and luciferase was used to screen the binding of target genes. The protein levels of SNCA were measured by Western blot. Then, we investigate the changes in pro- and anti-apoptotic markers with or without miR-30b treatment. RESULTS: There was a significant low expression of MiR-30b in MPP(+)-induced cells. SH-SY5Y cell viability was rescued by MiR-30b overexpression. Luciferase experiments showed that MiR-30b may bind to the 3'-UTR side of SNCA and inhibited its expression. By Western blot, the SNCA level was markedly decreased by miR-30b. miR-30b attenuated the upregulation of Bax and the depletion of Bcl-2 induced by MPP(+).

Evaluation of Clinical Outcome and Risk Factors for Recurrence after Pelvic Reconstruction of Pelvic Organ Prolapse with Implanted Mesh or Biological Grafts: A Single-Blind Randomized Trial.

BACKGROUND: There are few studies on the relative factors related to postoperative recurrence. OBJECTIVES: To compare the outcomes of pelvic floor reconstruction involving Herniamesh mesh and biological grafts and to investigate the correlative factors of postoperative recurrence. METHOD: Two hundred and thirty-two patients were randomly divided into 2 groups: Herniamesh mesh group (117) and biological graft group (115). Follow-ups for 6 months and 1 year after the surgery. The primary outcomes were recurrence, perioperative complications. Secondary outcome was a questionnaire about the life habits associated with relapse. RESULTS: The recurrence rate at 6 months or 1 year did not differ substantially between the 2 groups (p = 0.787 and 0.968, respectively). Adverse events occurred with significantly different frequencies over 1 year (p = 0.005). Twelve factors were investigated and analyzed by logistic regression analysis. It showed that recurrence had a strong association with a long-term vegetarian diet (OR 0.283, 95% CI 0.117-0.683), long-term soybean product diet (OR 8.010, 95% CI 2.514-25.523), and vaginal intercourse (OR 5.154, 95% CI 1.461-18.184). CONCLUSIONS: The surgical recurrence rate for the mesh was similar to biological grafts at short-term follow-up. Eating soy products often and vaginal intercourse after surgery can reduce recurrence.

PCAF-mediated acetylation of Lin28B increases let-7 biogenesis in lung adenocarcinoma H1299 cells.

BACKGROUND: Lin28B and its paralog Lin28A are small RNA binding proteins that have similar inhibitory effects, although they target separate steps in the maturation of let-7 miRNAs in mammalian cells. Because Lin28B participates in the promotion and development of tumors mostly by blocking the let-7 tumor suppressor family members, we sought to explore the associated mechanisms to gain insights into how Lin28B might be decreased in human cancer cells to increase let-7 levels and reverse malignancy. RESULTS: We demonstrated that the histone acetyltransferase PCAF, via its cold shock domain, directly interacts with and subsequently acetylates Lin28B in lung adenocarcinoma-derived H1299 cells. RT-qPCR assays showed that both let-7a-1 and let-7g were increased in PCAF-transfected H1299 cells. Lin28B is acetylated by ectopic PCAF and translocates from the nucleus to the cytoplasm in H1299 cells. CONCLUSIONS: The effects of acetylated Lin28B on let-7a-1 and let-7g are similar to that of stable knockdown of Lin28B in H1299 cells. The new role of PCAF in mediating Lin28B acetylation and the specific release of its target microRNAs in H1299 cells may shed light on the potential application of let-7 in the clinical treatment of lung cancer patients.

CRIF1 enhances p53 activity via the chromatin remodeler SNF5 in the HCT116 colon cancer cell lines.

CR6-interacting factor 1 (CRIF1) is ubiquitously expressed in human tissues. CRIF1 was first identified as a Gadd45γ (also known as CR6)-interacting protein, and it was also identified in a human colon cancer cell line stably transformed with p53. These results suggested that CRIF1 functions in the nucleus with p53 and Gadd45 family proteins in the suppression of cell growth and tumor development. Here, we found that CRIF1 could be recruited to a specific region in the promoter of the p53 gene, eliciting an increase in the mRNA and protein levels of p53 as well as p53 functional target genes. These functions required CRIF1 to interact with SNF5. CRIF1 was further recruited to the upstream promoter region of the p53 gene to suppress cell cycle progression in HCT116 cells. To our knowledge, this is the first evidence indicating that SNF5 is indispensable for CRIF1-enhanced p53 activity and its function in the suppression of cell cycle arrest in human cancer cells.

Histone deacetylase 4 increases progressive epithelial ovarian cancer cells via repression of p21 on fibrillar collagen matrices.

Histone deacetylase (HDAC) 4 is an emerging target in cancer therapeutics, but little is known about the function of HDAC4 in gynecologic malignancies. Therefore we investigated the mechanism of HDAC4 promoting the proliferation of epithelial ovarian cancer cells (OV). In this study, we observed that the proliferation of cells with HDAC4 inhibitor Trichostatin A (TSA) treatment was markedly decreased, Further, we showed that epithelial ovarian cancer tissues with stage III/IV had higher HDAC4 expression, compared to that with stage I/II. We examined first that the HDAC4 expression was increased in response to fibrillar collagen matrices. In addition, we found that HDAC4 was retained in the nucleus by regulation of PP1α, which regulated HDAC4 cellular fraction via phosphorylation of HDAC4. In addition, we found that HDAC4 bound to Sp1 in epithelial ovarian cancer cells. Finally, ovarian cancer cell line OVCAR3 was evaluated via gain/loss-of-function of HDAC4 by either overexpression of HDCA4 or knock-down of HDAC4 with shRNA. We examined both protein and mRNA of p21 by western blotting and qPCR. We performed analysis of colony formation in matrigel and migration by ECIS. Our results suggest that the accumulation of HDAC4 induced by fibrillar collagen matrices in the nucleus via co-localization of PP1α, leads to repression of the mRNA/protein of p21 and in turn promotes the proliferation and migration of epithelial ovarian cancer cells.

C/EBPα negatively regulates SIRT7 expression via recruiting HDAC3 to the upstream-promoter of hepatocellular carcinoma cells.

Mammalian Sirtuin proteins (SIRTs) are homologs of yeast Sir2, and characterized as class III histone deacetylases of NAD(+) dependence. Unlike their lower counterparts that are directly involved in the extending of lifespan, mammalian SIRTs mainly function in metabolism and cellular homeostasis, among them, SIRT7 is the least understood. SIRT7 is localized in the nucleus and rich in nucleoli associated with RNA polymerase I, and correlated with cell proliferation. In contrast, SIRT7 has recently been demonstrated to specifically deacetylate H3K18ac in the chromatin, and in most cases represses proliferation. Although MicroRNA as miR-125b has been reported to down-regulate SIRT7 by binding to its 3'UTR, however, how SIRT7 gene is regulated remains unclear. Here, we identified the transcription initiation site of human SIRT7 gene at the upstream 23rd A nucleotide respective to the translational codon, and the SIRT7 is a TATA-less and initiator-less gene. The sequences in the upstream region between -256 and -129 bp are identical with important functions in the three species detected. A C/EBPα responding element is found that binds both C/EBPα and C/EBPß in vitro. We showed TSA induced SIRT7 gene transcription and only the HDAC3, but not its catalytic domain depleted mutant, interacted with C/EBPα to occupy the C/EBPα element and repressed SIRT7 gene in the hepatocellular carcinoma cells. To our knowledge, this is the first report on the regulation mechanism of SIRT7 gene, in which, HDAC3 collaborated with C/EBPα to occupy its responding element in the upstream region of SIRT7 gene and repressed its expression in human cells.

S-phase cell cycle arrest, apoptosis, and molecular mechanisms of aplasia ras homolog member I-induced human ovarian cancer SKOV3 cell lines.

OBJECTIVE: Aplasia Ras homolog member I (ARHI) is associated with human ovarian cancer (HOC) growth and proliferation; however, the mechanisms are unclear. The purpose of this study was to investigate ARHI effects in HOC SKOV3 cells. METHODS: We transfected SKOV3 cells with PIRES2-EGFP-ARHI and measured growth inhibition rates, cell cycle distribution, apoptosis rates, and expression of P-STAT3 (phosphorylated signal transduction and activators of transcription 3) and P-ERK (phosphorylated extracellular signal regulated protein kinase). RESULTS: Our data showed significant inhibition of growth, significantly increased S-phase arrest and apoptosis rates, and reduction of P-STAT3 and P-ERK1/2 expression levels. CONCLUSIONS: We propose the mechanism may involve ARHI-induced phosphorylation of ERK1/2 and STAT3 protein kinases, thereby blocking proliferation signaling pathways, to induce HOC SKOV3 apoptosis.

Reversible acetylation of Lin28 mediated by PCAF and SIRT1.

Lin28 is a small RNA-binding protein that plays an important role in regulating developmental timing, stem cell reprogramming, and oncogenesis. However, the significance of the effect of post-translational modifications on Lin28 activity is not fully understood. In this study, we demonstrated that PCAF directly interacted with and acetylated Lin28. We also showed that the acetylation of Lin28 can be specifically reversed by the deacetylase SIRT1. These findings suggest that the PCAF/SIRT1 balance plays an important role in regulating Lin28 activity. Furthermore, we found that the cold shock domain of Lin28 is the major target of PCAF-mediated acetylation, which leads to a severe reduction in the Lin28 protein levels and an increase in the level of mature let-7a. This study provides the first demonstration that post-translational modification regulates Lin28 activity during let-7a biogenesis and sheds light on the regulation of Lin28 in ES cells and carcinogenesis.

The impact of R213 mutation on p53-mediated p21 activity.

p53 is a transcriptional regulator in the nucleus that functions as a tumor suppressor and its mutations are frequently found in human tumors. It has been reported that p53 with R213Q mutation is exist in certain tumor cell lines and its methylation on R213 as well. However, the mechanisms and consequences of these modifications on p53 function are not fully understood. Mutations of p53 at R213Q (R/Q) and R213K (R/K) were respectively constructed and transfected into the p53 null H1299 cells. As shown in luciferase reporter assays, either R/Q or R/K disrupted the efficiency of p53 transactivation. EMSA and ChIP assays revealed that these mutants were less efficient in targeting the consensus binding sequences of p53 in the regulatory region of p21 gene. In addition, R/Q and R/K mutants attenuated the expression of p21 gene and counteracted the p53 mediated G1/S arrest to deliver a normal cell cycle progression as in the mock H1299 cells. Through this study, we have provided the first evidence on the pivotal role of arginine 213 that determines the p53 mediated functions of p21 in human cancer cells.

Adaptive changes in autophagy after UPS impairment in Parkinson's disease.

AIM: Ubiquitin-proteasome system (UPS) and autophagosome-lysosome pathway (ALP) are the most important machineries responsible for protein degradation in Parkinson's disease (PD). The aim of this study is to investigate the adaptive alterations in autophagy upon proteasome inhibition in dopaminergic neurons in vitro and in vivo. METHODS: Human dopaminergic neuroblastoma SH-SY5Y cells were treated with the proteasome inhibitor lactacystin (5 µmol/L) for 5, 12, or 24 h. The expression of autophagy-related proteins in the cells was detected with immunoblotting. UPS-impaired mouse model of PD was established by microinjection of lactacystin (2 µg) into the left hemisphere of C57BL/6 mice that were sacrificed 2 or 4 weeks later. The midbrain tissues were dissected to assess alterations in autophagy using immunofluorescence, immunoblotting and electron microscopy assays. RESULTS: Both in SH-SY5Y cells and in the midbrain of UPS-impaired mouse model of PD, treatment with lactacystin significantly increased the expression levels of LC3-I/II and Beclin 1, and reduced the levels of p-mTOR, mTOR and p62/SQSTM1. Furthermore, lactacystin treatment in UPS-impaired mouse model of PD caused significant loss of TH-positive neurons in the substantia nigra, and dramatically increased the number of autophagosomes in the left TH-positive neurons. CONCLUSION: Inhibition of UPS by lactacystin in dopaminergic neurons activates another protein degradation system, the ALP, which includes both the mTOR signaling pathway and Beclin 1-associated pathway.

Fibrillar type I collagen matrices enhance metastasis/invasion of ovarian epithelial cancer via ß1 integrin and PTEN signals.

OBJECTIVE: This study investigated the involvement of fibrillar collagen in remodeling extracellular matrices (ECM) and its significant impact on the metastasis/invasion of epithelial ovarian cancer cells via ß1 integrin/phosphatase and tensin homolog (PTEN) signaling. MATERIALS/METHODS: Normal ovarian surface epithelium tissues (n = 13), ovarian cancer tissues (n = 28), ovarian cancer cell lines, and a 3-dimensional model of fibrillar type I collagen that mimicked pathological ECM in vivo were used in the study. We explored the specific mechanisms behind ECM remodeling and the cellular signals that affected the invasion of ovarian cancer cells. RESULTS: The data showed that increased ß1 integrin expression in ovarian cancer cells led to enhance migration/invasion of ovarian cancer cells via regulation of PTEN/protein kinase B (Akt) signal in response to fibrillar type I collagen matrices. Low PTEN activity corresponded to the following: (1) increased PTEN degradation and (2) phosphorylation of PTEN. Decreased protein phosphatase 2A activity was detected in ovarian cancer. Protein phosphatase 2A might play a role in enhancing the progression of ovarian cancer through regulating PTEN/Akt signal. CONCLUSION: These findings indicate that fibrillar type I collagen, by modulating integrin-PTEN/PI3K/Akt signaling pathway in remodeling ECM, is very important in affecting the invasion of aggressive ovarian cancer cells. Moreover, these data provide direct evidence for pathological ECM remodeling and cell signaling networks involved in the invasion of ovarian cancer cells.

Differential effects of AdOx on gene expression in P19 embryonal carcinoma cells.

BACKGROUND: Pluripotent cells maintain a unique gene expression pattern and specific chromatin signature. In this study, we explored the effect of the methyltransferase inhibitor adenosine dialdehyde (AdOx) on pluripotency maintenance and gene expression in P19 embryonal carcinoma cells. RESULTS: After AdOx treatment, the pluripotency-related gene network became disordered, and the early developmental genes were released from the repression. Remarkably, AdOx caused contrasting effects on the expression of two key pluripotency genes, nanog and oct3/4, with the reduction of the repressive histone marks H3K27me3, H3K9me3 and H3K9me2 only in the nanog gene. CONCLUSIONS: Key pluripotency genes were controlled by different mechanisms, including the differential enrichment of repressive histone methylation marks. These data provided novel clues regarding the critical role of histone methylation in the maintenance of pluripotency and the determination of cell fate in P19 pluripotent cells.