FOS, a Critical Downstream Mediator of PGR and EGF Signaling Necessary for Ovulatory Prostaglandins in the Human Ovary

Abstract Context Fos null mice failed to ovulate and form a corpus luteum (CL) even when given exogenous gonadotropins, suggesting that ovarian Fos expression is critical for successful ovulation and CL formation. However, little is known about FOS in the human ovary. Objectives To determine the expression, regulation, and function of FOS in human periovulatory follicles. Design/Participants Timed periovulatory follicles were obtained from normally cycling women. Granulosa/lutein cells were collected from in vitro fertilization patients. Main Outcome Measures The in vivo expression after human chorionic gonadotropin (hCG) administration and in vitro regulation of FOS, JUN, JUNB, and JUND was evaluated at the mRNA and protein level. Binding of progesterone receptor (PGR) and FOS to their target genes was assessed by chromatin immunoprecipitation analyses. Prostaglandin E2 (PGE2) and progesterone were measured. Results The expression of FOS, JUNB, and JUND drastically increased in ovulatory follicles after hCG administration. In human granulosa/lutein cell cultures, hCG increased the expression of FOS and JUN proteins. Inhibitors of PGR and epidermal growth factor (EGF) receptors reduced hCG-induced increases in the expression and phosphorylation of FOS. PGR bound to the FOS gene. A selective FOS inhibitor blocked hCG-induced increases in PGE2 and the expression of prostaglandin (PG) synthases and transporters (PTGES, SLCO2A1, and ABCC1). FOS bound to the promoter regions of these genes. Conclusions The increase of FOS/activator protein 1 in human periovulatory follicles after hCG administration is mediated by collaborative actions of PGR and EGF signaling and critical for the upregulated expression of key ovulatory genes required for the rise in ovulatory PG in human granulosa cells.

Download Full-text

c-Jun/c-Fos heterodimers regulate cellular genes via a newly identified class of methylated DNA sequence motifs

Nucleic Acids Research ◽

10.1093/nar/gkt1323 ◽

2013 ◽

Vol 42 (5) ◽

pp. 3059-3072 ◽

Cited By ~ 45

Author(s):

Montse Gustems ◽

Anne Woellmer ◽

Ulrich Rothbauer ◽

Sebastian H. Eck ◽

Thomas Wieland ◽

...

Keyword(s):

Transcription Factor ◽

Dna Sequence ◽

Epigenetic Silencing ◽

Activator Protein 1 ◽

Sequence Motifs ◽

Promoter Regions ◽

Barr Virus ◽

Dna Sequence Motifs

Abstract CpG methylation in mammalian DNA is known to interfere with gene expression by inhibiting the binding of transactivators to their cognate sequence motifs or recruiting proteins involved in gene repression. An Epstein–Barr virus-encoded transcription factor, Zta, was the first example of a sequence-specific transcription factor that preferentially recognizes and selectively binds DNA sequence motifs with methylated CpG residues, reverses epigenetic silencing and activates gene transcription. The DNA binding domain of Zta is homologous to c-Fos, a member of the cellular AP-1 (activator protein 1) transcription factor family, which regulates cell proliferation and survival, apoptosis, transformation and oncogenesis. We have identified a novel AP-1 binding site termed meAP-1, which contains a CpG dinucleotide. If methylated, meAP-1 sites are preferentially bound by the AP-1 heterodimer c-Jun/c-Fos in vitro and in cellular chromatin in vivo. In activated human primary B cells, c-Jun/c-Fos locates to these methylated elements in promoter regions of transcriptionally activated genes. Reminiscent of the viral Zta protein, c-Jun/c-Fos is the first identified cellular member of the AP-1 family of transactivators that can induce expression of genes with methylated, hence repressed promoters, reversing epigenetic silencing.

Download Full-text

Structure of the DNA-binding domain of the response regulator SaeR fromStaphylococcus aureus

Acta Crystallographica Section D Biological Crystallography ◽

10.1107/s1399004715010287 ◽

2015 ◽

Vol 71 (8) ◽

pp. 1768-1776 ◽

Cited By ~ 8

Author(s):

Xiaojiao Fan ◽

Xu Zhang ◽

Yuwei Zhu ◽

Liwen Niu ◽

Maikun Teng ◽

...

Keyword(s):

Dna Binding ◽

Target Genes ◽

Response Regulator ◽

Regulatory System ◽

Binding Domain ◽

Dna Binding Domain ◽

Promoter Regions ◽

Winged Helix

The SaeR/S two-component regulatory system is essential for controlling the expression of many virulence factors inStaphylococcus aureus. SaeR, a member of the OmpR/PhoB family, is a response regulator with an N-terminal regulatory domain and a C-terminal DNA-binding domain. In order to elucidate how SaeR binds to the promoter regions of target genes, the crystal structure of the DNA-binding domain of SaeR (SaeRDBD) was solved at 2.5 Å resolution. The structure reveals that SaeRDBDexists as a monomer and has the canonical winged helix–turn–helix module. EMSA experiments suggested that full-length SaeR can bind to the P1 promoter and that the binding affinity is higher than that of its C-terminal DNA-binding domain. Five key residues on the winged helix–turn–helix module were verified to be important for binding to the P1 promoterin vitroand for the physiological function of SaeRin vivo.

Download Full-text

Hypermethylation-mediated Transcriptional Silencing of lncRNA-SCARF1 Promotes Progression and Metastasis of Hepatocellular Carcinoma

10.21203/rs.3.rs-1110965/v1 ◽

2021 ◽

Author(s):

Boyi Liao ◽

Peiran Huang ◽

Xiangyu Zhang ◽

Xinyu Wang ◽

Kaiqian Zhou ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Dna Methylation ◽

Target Genes ◽

Malignant Tumors ◽

Aberrant Methylation ◽

Promoter Regions ◽

Migration Ability ◽

Downstream Target

Abstract Background: Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths. Recent studies have demonstrated that deregulation of long noncoding RNAs (lncRNAs), such as abnormal DNA methylation of promoter, is strongly associated with development and progression of diverse malignant tumors. This study investigated the mechanisms and changes in DNA methylation levels of promoter regions of HCC-specific lncRNAs, and alterations of downstream target genes.Methods: LncRNA expression profile data of 8 human HCC tissues and matched normal tissues were obtained. LncRNAs with aberrant methylation were identified through DNA methylation microarray. The biological functions of the lncRNAs were investigated through targeted knockdown of lncRNA-SCARF1 in vitro and in vivo. Furthermore, the downstream targets of lncRNA-SCARF1 were identified through ChIRP-MS.Results: LncRNA-SCARF1 was significantly down-regulated in HCC samples. Hypermethylation in the promoter of lnc-SCARF1 induced its down-regulation in HCC. Over-expression of lnc-SCARF1 inhibited the tumor proliferation and migration ability of HCC cells in vitro and in vivo. Furthermore, CUL9 was found to be a potential downstream target of lncRNA-SCARF1.Conclusion: LncRNA-SCARF1 regulates HCC progression by interacting with CUL9 and may serve as a prognostic biomarker or an effective therapeutic target in HCC.

Download Full-text

Seminal Plasma: Relevant for Fertility?

International Journal of Molecular Sciences ◽

10.3390/ijms22094368 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4368

Author(s):

Heriberto Rodriguez-Martinez ◽

Emilio A. Martinez ◽

Juan J. Calvete ◽

Fernando J. Peña Vega ◽

Jordi Roca

Keyword(s):

Seminal Plasma ◽

Current Knowledge ◽

Inorganic Ions ◽

Vitro Fertilization ◽

Dna And Rna ◽

Model Animal ◽

Sexual Glands ◽

Species Specific

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.

Download Full-text

Activation of MAT2A-RIP1 signaling axis reprograms monocytes in gastric cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-001364 ◽

2021 ◽

Vol 9 (2) ◽

pp. e001364

Author(s):

Yan Zhang ◽

Hui Yang ◽

Jun Zhao ◽

Ping Wan ◽

Ye Hu ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Metabolism ◽

Vital Role ◽

Methionine Metabolism ◽

Promoter Regions ◽

Normal Tissues ◽

Methionine Cycle

BackgroundThe activation of tumor-associated macrophages (TAMs) facilitates the progression of gastric cancer (GC). Cell metabolism reprogramming has been shown to play a vital role in the polarization of TAMs. However, the role of methionine metabolism in function of TAMs remains to be explored.MethodsMonocytes/macrophages were isolated from peripheral blood, tumor tissues or normal tissues from healthy donors or patients with GC. The role of methionine metabolism in the activation of TAMs was evaluated with both in vivo analyses and in vitro experiments. Pharmacological inhibition of the methionine cycle and modulation of key metabolic genes was employed, where molecular and biological analyses were performed.ResultsTAMs have increased methionine cycle activity that are mainly attributed to elevated methionine adenosyltransferase II alpha (MAT2A) levels. MAT2A modulates the activation and maintenance of the phenotype of TAMs and mediates the upregulation of RIP1 by increasing the histone H3K4 methylation (H3K4me3) at its promoter regions.ConclusionsOur data cast light on a novel mechanism by which methionine metabolism regulates the anti-inflammatory functions of monocytes in GC. MAT2A might be a potential therapeutic target for cancer cells as well as TAMs in GC.

Download Full-text

Prrx1 promotes stemness and angiogenesis via activating TGF-β/smad pathway and upregulating proangiogenic factors in glioma

Cell Death and Disease ◽

10.1038/s41419-021-03882-7 ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Zetao Chen ◽

Yihong Chen ◽

Yan Li ◽

Weidong Lian ◽

Kehong Zheng ◽

...

Keyword(s):

Stem Cells ◽

Therapeutic Strategy ◽

Critical Role ◽

Glioma Stem Cells ◽

Promoter Regions ◽

Aberrant Expression ◽

Smad Pathway ◽

Tgf Β1

AbstractGlioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.

Download Full-text

Circular RNA circSDHC serves as a sponge for miR-127-3p to promote the proliferation and metastasis of renal cell carcinoma via the CDKN3/E2F1 axis

Molecular Cancer ◽

10.1186/s12943-021-01314-w ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Junjie Cen ◽

Yanping Liang ◽

Yong Huang ◽

Yihui Pan ◽

Guannan Shu ◽

...

Keyword(s):

Renal Cell Carcinoma ◽

Cell Carcinoma ◽

Renal Cell ◽

Target Genes ◽

Expression Patterns ◽

Luciferase Reporter ◽

Circular Rnas ◽

Proliferation And Metastasis

Abstract Background There is increasing evidence that circular RNAs (circRNAs) have significant regulatory roles in cancer development and progression; however, the expression patterns and biological functions of circRNAs in renal cell carcinoma (RCC) remain largely elusive. Method Bioinformatics methods were applied to screen for circRNAs differentially expressed in RCC. Analysis of online circRNAs microarray datasets and our own patient cohort indicated that circSDHC (hsa_circ_0015004) had a potential oncogenic role in RCC. Subsequently, circSDHC expression was measured in RCC tissues and cell lines by qPCR assay, and the prognostic value of circSDHC evaluated. Further, a series of functional in vitro and in vivo experiments were conducted to assess the effects of circSDHC on RCC proliferation and metastasis. RNA pull-down assay, luciferase reporter and fluorescent in situ hybridization assays were used to confirm the interactions between circSDHC, miR-127-3p and its target genes. Results Clinically, high circSDHC expression was correlated with advanced TNM stage and poor survival in patients with RCC. Further, circSDHC promoted tumor cell proliferation and invasion, both in vivo and in vitro. Analysis of the mechanism underlying the effects of circSDHC in RCC demonstrated that it binds competitively to miR-127-3p and prevents its suppression of a downstream gene, CDKN3, and the E2F1 pathway, thereby leading to RCC malignant progression. Furthermore, knockdown of circSDHC caused decreased CDKN3 expression and E2F1 pathway inhibition, which could be rescued by treatment with an miR-127-3p inhibitor. Conclusion Our data indicates, for the first time, an essential role for the circSDHC/miR-127-3p/CDKN3/E2F1 axis in RCC progression. Thus, circSDHC has potential to be a new therapeutic target in patients with RCC.

Download Full-text

TMOD-15. EFFICACY OF THE MDM2 INHIBITOR KRT-232 IN GLIOBLASTOMA PATIENT-DERIVED XENOGRAFT MODELS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.966 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii231-ii231

Author(s):

Rachael Vaubel ◽

Ann Mladek ◽

Yu Zhao ◽

Shiv K Gupta ◽

Minjee Kim ◽

...

Keyword(s):

Target Genes ◽

Xenograft Model ◽

Culture Conditions ◽

Patient Derived Xenograft ◽

Fold Induction ◽

Extended Survival ◽

Mdm2 Amplification ◽

Mdm2 Inhibitor

Abstract Non-genotoxic reactivation of p53 by MDM2 inhibitors represents a promising therapeutic strategy for tumors with wild-type TP53, particularly tumors harboring MDM2 amplification. MDM2 controls p53 levels by targeting it for degradation, while disruption of the MDM2-p53 interaction causes rapid accumulation of p53 and activation of the p53 pathway. We examined the efficacy of the small molecule MDM2 inhibitor KRT-232, alone and in combination with radiation therapy (RT), in MDM2-amplified and/or p53 wildtype patient-derived xenograft (PDX) models of glioblastoma in vitro and in vivo. In vitro, glioblastoma PDX explant cultures showed sensitivity to KRT-232, both tumors with MDM2 amplification (GBM108 and G148) and non-amplified but TP53-wildtype lines (GBM10, GBM14, and GBM39), with IC50s ranging from 300-800 nM in FBS culture conditions. A TP53 p.F270C mutant PDX (GBM43) was inherently resistant, with IC50 >3000 nM. In the MDM2-amplified GBM108 line, KRT-232 led to a robust (5-6 fold) induction of p53-target genes p21, PUMA, and NOXA, with initiation of both apoptosis and senescence. Expression of p21 and PUMA was greater with KRT-232 in combination with RT (25-35 fold induction), while stable knock-down of p53 in GBM108 led to complete resistance to KRT-232. In contrast, GBM10 showed lower induction of p21 and PUMA (2-3 fold) and was more resistant to KRT-232. In an orthotopic GBM108 xenograft model, treatment with KRT-232 +/- RT for one week extended survival from 22 days (placebo) to 46 days (KRT-232 alone); combination KRT-232 + RT further extended survival (77 days) over RT alone (31 days). KRT-232 is an effective treatment in a subset of glioblastoma pre-clinical models alone and in combination with RT. Further studies are underway to understand the mechanisms conferring innate sensitivity or resistance to KRT-232.

Download Full-text

Ways into Understanding HIF Inhibition

Cancers ◽

10.3390/cancers13010159 ◽

2021 ◽

Vol 13 (1) ◽

pp. 159

Author(s):

Tina Schönberger ◽

Joachim Fandrey ◽

Katrin Prost-Fingerle

Keyword(s):

Protein Interactions ◽

Target Genes ◽

Protein Protein Interactions ◽

Low Oxygen ◽

Drug Candidates ◽

Open Questions ◽

Wide Range ◽

Hif Pathway

Hypoxia is a key characteristic of tumor tissue. Cancer cells adapt to low oxygen by activating hypoxia-inducible factors (HIFs), ensuring their survival and continued growth despite this hostile environment. Therefore, the inhibition of HIFs and their target genes is a promising and emerging field of cancer research. Several drug candidates target protein–protein interactions or transcription mechanisms of the HIF pathway in order to interfere with activation of this pathway, which is deregulated in a wide range of solid and liquid cancers. Although some inhibitors are already in clinical trials, open questions remain with respect to their modes of action. New imaging technologies using luminescent and fluorescent methods or nanobodies to complement widely used approaches such as chromatin immunoprecipitation may help to answer some of these questions. In this review, we aim to summarize current inhibitor classes targeting the HIF pathway and to provide an overview of in vitro and in vivo techniques that could improve the understanding of inhibitor mechanisms. Unravelling the distinct principles regarding how inhibitors work is an indispensable step for efficient clinical applications and safety of anticancer compounds.

Download Full-text

Genome-Wide Binding Analyses of HOXB1 Revealed a Novel DNA Binding Motif Associated with Gene Repression

Journal of Developmental Biology ◽

10.3390/jdb9010006 ◽

2021 ◽

Vol 9 (1) ◽

pp. 6

Author(s):

Narendra Pratap Singh ◽

Bony De Kumar ◽

Ariel Paulson ◽

Mark E. Parrish ◽

Carrie Scott ◽

...

Keyword(s):

Dna Binding ◽

Target Genes ◽

Embryonic Stem ◽

Binding Motif ◽

Binding Assays ◽

Histone Marks ◽

Genome Wide ◽

Hox Cofactors

Knowledge of the diverse DNA binding specificities of transcription factors is important for understanding their specific regulatory functions in animal development and evolution. We have examined the genome-wide binding properties of the mouse HOXB1 protein in embryonic stem cells differentiated into neural fates. Unexpectedly, only a small number of HOXB1 bound regions (7%) correlate with binding of the known HOX cofactors PBX and MEIS. In contrast, 22% of the HOXB1 binding peaks display co-occupancy with the transcriptional repressor REST. Analyses revealed that co-binding of HOXB1 with PBX correlates with active histone marks and high levels of expression, while co-occupancy with REST correlates with repressive histone marks and repression of the target genes. Analysis of HOXB1 bound regions uncovered enrichment of a novel 15 base pair HOXB1 binding motif HB1RE (HOXB1 response element). In vitro template binding assays showed that HOXB1, PBX1, and MEIS can bind to this motif. In vivo, this motif is sufficient for direct expression of a reporter gene and over-expression of HOXB1 selectively represses this activity. Our analyses suggest that HOXB1 has evolved an association with REST in gene regulation and the novel HB1RE motif contributes to HOXB1 function in part through a repressive role in gene expression.

Download Full-text