Differential Response of Progesterone Receptor Isoforms in Hormone-Dependent and -Independent Facilitation of Female Sexual Receptivity

Abstract Neurobehavioral effects of progesterone are mediated primarily by its interaction with neural progesterone receptors (PRs), expressed as PR-A and PR-B protein isoforms. Whereas the expression of two isoforms in the neural tissues is suggestive of their selective cellular responses and modulation of distinct subsets of PR-induced target genes, the role of individual isoforms in brain and behavior is unknown. We have previously demonstrated a critical role for PRs as transcriptional mediators of progesterone (ligand-dependent), and dopamine (ligand-independent)-facilitated female reproductive behavior in female mice lacking both the isoforms of PR. To further elucidate the selective contribution of the individual PR isoforms in female sexual receptive behavior, we used the recently generated PR-A and PR-B isoform-specific null mutant mice. We present evidence for differential responses of each isoform to progesterone and dopamine agonist, SKF 81297 (SKF), and demonstrate a key role for PR-A isoform in both hormone-dependent and -independent facilitation of sexual receptive behavior. Interestingly, whereas both the isoforms were essential for SKF-facilitated sexual behavior, PR-A appeared to play a more important role in the 8-bromo-cAMP-facilitated lordosis response, raising the possibility of distinct intracellular signaling pathways mediating the responses. Finally, we also demonstrate that antiprogestin, RU38486, was an effective inhibitor of PR-A-mediated, progesterone-dependent, but not SKF or 8-bromo-cAMP-dependent sexual receptivity. The data reveal the selective contributions of individual isoforms to the signaling pathways mediating female reproductive behavior.

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Engineering combinatorial and dynamic decoders using synthetic immediate-early genes

10.1101/2019.12.17.880179 ◽

2019 ◽

Author(s):

Pavithran T. Ravindran ◽

Maxwell Z. Wilson ◽

Siddhartha G. Jena ◽

Jared E. Toettcher

Keyword(s):

Growth Factor ◽

Signaling Pathways ◽

Intracellular Signaling ◽

Target Genes ◽

Immediate Early Genes ◽

Immediate Early Gene ◽

Early Gene ◽

Immediate Early ◽

Specific Target ◽

Early Genes

AbstractFor tissues to grow and function properly, cells must coordinate actions such as proliferation, differentiation and apoptosis. This coordination is achieved in part by the activation of intracellular signaling pathways that trigger the expression of context-specific target genes. While the function of these natural circuits has been actively studied, synthetic biology provides additional powerful tools for deconstructing, repurposing, and designing novel signal-decoding circuits. Here we report the construction of synthetic immediate-early genes (synIEGs), target genes of the Erk signaling pathway that implement complex, user-defined regulation and can be monitored through the use of live-cell biosensors to track transcription and translation. We demonstrate the power and flexibility of this approach by confirming Erk duration-sensing by the FOS immediate-early gene, elucidating how the BTG2 gene is regulated by transcriptional activation and translational repression after growth-factor stimulation, and by designing a synthetic immediate-early gene that responds with AND-gate logic to the combined presence of growth factor and DNA damage stimuli. Our work paves the way to defining the molecular circuits that link signaling pathways to specific target genes, highlighting an important role for post-transcriptional regulation in signal decoding that may be masked by analyses of RNA abundance alone.

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Phosphorylated Progesterone Receptor Isoforms Mediate Opposing Stem Cell and Proliferative Breast Cancer Cell Fates

Endocrinology ◽

10.1210/en.2018-00990 ◽

2018 ◽

Vol 160 (2) ◽

pp. 430-446 ◽

Cited By ~ 14

Author(s):

Thu H Truong ◽

Amy R Dwyer ◽

Caroline H Diep ◽

Hsiangyu Hu ◽

Kyla M Hagen ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cell ◽

Cancer Progression ◽

Target Genes ◽

Progesterone Receptors ◽

Late Recurrence ◽

Luminal Breast Cancer ◽

Clear Understanding ◽

Progesterone Receptor Isoforms ◽

Advanced Tumor

Abstract Progesterone receptors (PRs) are key modifiers of estrogen receptor (ER) target genes and drivers of luminal breast cancer progression. Total PR expression, rather than isoform-specific PR expression, is measured in breast tumors as an indicator of functional ER. We identified phenotypic differences between PR-A and PR-B in luminal breast cancer models with a focus on tumorsphere biology. Our findings indicated that PR-A is a dominant driver of cancer stem cell (CSC) expansion in T47D models, and PR-B is a potent driver of anchorage-independent proliferation. PR-A+ tumorspheres were enriched for aldehyde dehydrogenase (ALDH) activity, CD44+/CD24−, and CD49f+/CD24− cell populations relative to PR-B+ tumorspheres. Progestin promoted heightened expression of known CSC-associated target genes in PR-A+ but not PR-B+ cells cultured as tumorspheres. We report robust phosphorylation of PR-A relative to PR-B Ser294 and found that this residue is required for PR-A–induced expression of CSC-associated genes and CSC behavior. Cells expressing PR-A S294A exhibited impaired CSC phenotypes but heightened anchorage-independent cell proliferation. The PR target gene and coactivator, FOXO1, promoted PR phosphorylation and tumorsphere formation. The FOXO1 inhibitor (AS1842856) alone or combined with onapristone (PR antagonist), blunted phosphorylated PR, and tumorsphere formation in PR-A+ and PR-B+ T47D, MCF7, and BT474 models. Our data revealed unique isoform-specific functions of phosphorylated PRs as modulators of distinct and opposing pathways relevant to mechanisms of late recurrence. A clear understanding of PR isoforms, phosphorylation events, and the role of cofactors could lead to novel biomarkers of advanced tumor behavior and reveal new approaches to pharmacologically target CSCs in luminal breast cancer.

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Distinct effects of thrombopoietin depending on a threshold level of activated Mpl in BaF-3 cells

Journal of Cell Science ◽

10.1242/jcs.115.11.2329 ◽

2002 ◽

Vol 115 (11) ◽

pp. 2329-2337

Author(s):

Gaël A. Millot ◽

William Vainchenker ◽

Dominique Duménil ◽

Fédor Svinarchuk

Keyword(s):

Signaling Pathways ◽

Intracellular Signaling ◽

Kinase Inhibitors ◽

Critical Role ◽

Threshold Level ◽

Pi3k Pathway ◽

Mitogen Activated Protein Kinase ◽

Activation Level ◽

Low Levels ◽

In Cells

Thrombopoietin (TPO) plays a critical role in megakaryopoiesis through binding to its receptor Mpl. This involves activation of various intracellular signaling pathways, including phosphoinositide 3-kinase (PI3K) and the mitogen-activated protein kinase (MAPK) pathways. Their precise role in TPO-mediated proliferation, survival and differentiation is not fully understood. In the present study, we show that TPO induces different biological responses in Mpl-transduced BaF-3 cells, depending on the cell surface density of Mpl and the resulting activation level of signaling pathways. TPO mediates cell proliferation in cells expressing high levels of Mpl but only mediates survival without proliferation in cells expressing low levels of the receptor. By using the kinase inhibitors PD98059 and LY294002,we further showed that the activation level of the PI3K and MAPK p42/44 pathways is a determining factor for the proliferative effect. In cells expressing low levels of Mpl, the survival effect was strongly dependent on the activation level of the PI3K/AKT, but not the MAPK p42/44 pathway. Moreover, this effect was correlated with the phosphorylation level of BAD but not with the expression level of Bcl-XL. However, PI3K pathway inhibition did not increase apoptosis when BaF-3 cells proliferated in response to TPO, indicating a compensating mechanism from other Mpl signaling pathways in this case.

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Regulation of the germinal center and humoral immunity by interleukin-21

Journal of Experimental Medicine ◽

10.1084/jem.20191638 ◽

2019 ◽

Vol 217 (1) ◽

Cited By ~ 9

Author(s):

Stuart G. Tangye ◽

Cindy S. Ma

Keyword(s):

Humoral Immunity ◽

Immune Cells ◽

Germinal Center ◽

Intracellular Signaling ◽

Cell Activation ◽

Target Genes ◽

Critical Role ◽

Loss Of Function ◽

Receptor Complexes

Cytokines play critical roles in regulating the development, survival, differentiation, and function of immune cells. Cytokines exert their function by binding specific receptor complexes on the surface of immune cells and activating intracellular signaling pathways, thereby resulting in induction of specific transcription factors and regulated expression of target genes. While the function of cytokines is often fundamental for the generation of robust and effective immunity following infection or vaccination, aberrant production or function of cytokines can underpin immunopathology. IL-21 is a pleiotropic cytokine produced predominantly by CD4+ T cells. Gene-targeting studies in mice, in vitro analyses of human and murine lymphocytes, and the recent discoveries and analyses of humans with germline loss-of-function mutations in IL21 or IL21R have revealed diverse roles of IL-21 in immune regulation and effector function. This review will focus on recent advances in IL-21 biology that have highlighted its critical role in T cell–dependent B cell activation, germinal center reactions, and humoral immunity and how impaired responses to, or production of, IL-21 can lead to immune dysregulation.

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Overview of the signaling pathways involved in metastasis: An intriguing story-tale of the metastatic journey of ovarian cancer cells

Cellular and Molecular Biology ◽

10.14715/cmb/2021.67.3.34 ◽

2021 ◽

Vol 67 (3) ◽

pp. 212-223

Author(s):

Rukset Attar ◽

Tahira Panah ◽

Mirna Azalea Romero ◽

Ishmuratova Margarita Yulaevna ◽

Maria Gazouli ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Signaling Pathways ◽

Intracellular Signaling ◽

Cancer Metastasis ◽

Scientific Evidence ◽

Critical Role ◽

Signaling Cascades ◽

Ovarian Cancer Cells ◽

Term Survival

Wealth of information has revolutionized our understanding related to the genetics and functional genomics of this heterogeneous disease. Keeping in view the heterogeneity of ovarian cancer, long-term survival might be achieved by translation of recently emerging mechanistic insights at the cellular and molecular levels to personalize individual strategies for treatment and to identify biomarkers for early detection. Importantly, the motility and invasive properties of ovarian cancer cells are driven by a repertoire of signaling cascades, many components of which have been experimentally verified as therapeutic targets in preclinical models as well as in clinical trials. Scientific evidence garnered over decades of research has deconvoluted the highly intricate intertwined network of intracellular signaling pathways which played fundamental role in carcinogenesis and metastasis. In this review we have provided a compendium of myriad of signaling cascades which have been documented to play critical role in the progression and metastasis of ovarian cancer. We have partitioned this multi-component review into different sections to individually discuss and summarize the roles of TGF/SMAD, JAK/STAT, Wnt/?-Catenin, NOTCH, SHH/GLI, mTORC1/mTORC2, VEGFR and Hippo/YAP pathways in ovarian cancer metastasis.

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The Interplay Between Tumor Suppressor p53 and Hypoxia Signaling Pathways in Cancer

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.648808 ◽

2021 ◽

Vol 9 ◽

Author(s):

Cen Zhang ◽

Juan Liu ◽

Jianming Wang ◽

Tianliang Zhang ◽

Dandan Xu ◽

...

Keyword(s):

Tumor Suppressor ◽

Signaling Pathways ◽

Cancer Progression ◽

Target Genes ◽

Critical Role ◽

Hypoxia Inducible Factor ◽

Metabolic Reprogramming ◽

Tissue Type ◽

Mutant P53 ◽

P53 Signaling

Hypoxia is a hallmark of solid tumors and plays a critical role in different steps of tumor progression, including proliferation, survival, angiogenesis, metastasis, metabolic reprogramming, and stemness of cancer cells. Activation of the hypoxia-inducible factor (HIF) signaling plays a critical role in regulating hypoxic responses in tumors. As a key tumor suppressor and transcription factor, p53 responds to a wide variety of stress signals, including hypoxia, and selectively transcribes its target genes to regulate various cellular responses to exert its function in tumor suppression. Studies have demonstrated a close but complex interplay between hypoxia and p53 signaling pathways. The p53 levels and activities can be regulated by the hypoxia and HIF signaling differently depending on the cell/tissue type and the severity and duration of hypoxia. On the other hand, p53 regulates the hypoxia and HIF signaling at multiple levels. Many tumor-associated mutant p53 proteins display gain-of-function (GOF) oncogenic activities to promote cancer progression. Emerging evidence has also shown that GOF mutant p53 can promote cancer progression through its interplay with the hypoxia and HIF signaling pathway. In this review, we summarize our current understanding of the interplay between the hypoxia and p53 signaling pathways, its impact upon cancer progression, and its potential application in cancer therapy.

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