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1.
Gynecol Oncol ; 156(2): 308-314, 2020 02.
Article in English | MEDLINE | ID: mdl-31822399

ABSTRACT

BACKGROUND: Selinexor is an oral inhibitor of the nuclear export protein Exportin 1 (XPO1) with demonstrated antitumor activity in solid and hematological malignancies. We evaluated the efficacy and safety of selinexor in heavily pretreated, recurrent gynecological malignancies. METHODS: In this phase 2 trial, patients received selinexor (35 or 50 mg/m2 twice-weekly [BIW] or 50 mg/m2 once-weekly [QW]) in 4-week cycles. Primary endpoint was disease control rate (DCR) including complete response (CR), partial response (PR) or stable disease (SD) ≥12 weeks. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety. RESULTS: 114 patients with ovarian (N = 66), endometrial (N = 23) or cervical (N = 25) cancer were enrolled. Median number of prior regimens for ovarian, endometrial and cervical cancer was 6 (1-11), 2 (1-5), and 3 (1-6) respectively. DCR was 30% (ovarian 30%; endometrial 35%; cervical 24%), which included confirmed PRs in 8%, 9%, and 4% of patients with ovarian, endometrial, and cervical cancer respectively. Median PFS and OS for patients with ovarian, endometrial and cervical cancer were 2.6, 2.8 and 1.4 months, and 7.3, 7.0, and 5.0 months, respectively. Common Grade 3/4 adverse events (AEs) were thrombocytopenia (17%), fatigue (14%), anemia (10%), nausea (9%) and hyponatremia (9%). Patients with ovarian cancer receiving 50 mg/m2 QW had fewer high-grade AEs with similar efficacy as BIW treatment. CONCLUSIONS: Selinexor demonstrated single-agent activity and disease control in patients with heavily pretreated ovarian and endometrial cancers. Side effects were a function of dose level and treatment frequency, similar to previous reports, reversible and mitigated with supportive care.


Subject(s)
Genital Neoplasms, Female/drug therapy , Hydrazines/administration & dosage , Karyopherins/antagonists & inhibitors , Neoplasm Recurrence, Local/drug therapy , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Triazoles/administration & dosage , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Genital Neoplasms, Female/metabolism , Genital Neoplasms, Female/pathology , Humans , Hydrazines/adverse effects , Karyopherins/metabolism , Middle Aged , Neoplasm Grading , Neoplasm Recurrence, Local/pathology , Progression-Free Survival , Receptors, Cytoplasmic and Nuclear/metabolism , Triazoles/adverse effects , Exportin 1 Protein
2.
Leukemia ; 31(1): 143-150, 2017 01.
Article in English | MEDLINE | ID: mdl-27211268

ABSTRACT

Acute myeloid leukemia (AML) is a clonal hematologic malignant disease of developing myeloid cells that have acquired aberrant survival, uncontrolled proliferation and a block in normal hematopoietic cell differentiation. Standard chemotherapy often induces remissions in AML patients, but the disease frequently relapses due to incomplete targeting of leukemia-initiating cells (LICs), emphasizing the need for novel effective treatments. Exportin 1 (XPO1)-mediated nuclear export, which is inhibited by the drug selinexor, is an attractive new therapeutic target in AML. Selinexor has shown impressive activity in Phase I/II clinical trials for AML. Here we report the anti-leukemic efficacy and tolerability of KPT-8602, a second-generation XPO1 inhibitor. KPT-8602 demonstrates substantially reduced brain penetration compared to selinexor, with resultant attenuation of the central nervous system mediated side effects of anorexia and weight loss. Due to its improved tolerability profile, KPT-8602 can be given daily compared to the two or three times weekly regimen of selinexor, and exhibits greater anti-leukemic efficacy against both leukemic blasts and LICs in AML patient-derived xenograft models. Importantly, normal hematopoietic stem and progenitor cell (HSPC) frequency is not significantly reduced by KPT-8602, providing a therapeutic window for elimination of relapse-driving LICs while sparing normal HSPCs. These findings strongly endorse clinical testing of KPT-8602 in patients with relapsed and refractory AML.


Subject(s)
Active Transport, Cell Nucleus/drug effects , Karyopherins/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Blast Crisis/drug therapy , Blast Crisis/pathology , Carcinogenesis/drug effects , Carcinogenesis/pathology , Hematopoietic Stem Cells/drug effects , Heterografts , Humans , Hydrazines , Leukemia, Myeloid, Acute/pathology , Mice , Triazoles , Exportin 1 Protein
3.
Leukemia ; 30(12): 2364-2372, 2016 12.
Article in English | MEDLINE | ID: mdl-27323910

ABSTRACT

The nuclear export receptor, Exportin 1 (XPO1), mediates transport of growth-regulatory proteins, including tumor suppressors, and is overactive in many cancers, including chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML) and aggressive lymphomas. Oral selective inhibitor of nuclear export (SINE) compounds that block XPO1 function were recently identified and hold promise as a new therapeutic paradigm in many neoplasms. One of these compounds, KPT-330 (selinexor), has made progress in Phase I/II clinical trials, but systemic toxicities limit its administration to twice-per-week and requiring supportive care. We designed a new generation SINE compound, KPT-8602, with a similar mechanism of XPO1 inhibition and potency but considerably improved tolerability. Efficacy of KPT-8602 was evaluated in preclinical animal models of hematological malignancies, including CLL and AML. KPT-8602 shows similar in vitro potency compared with KPT-330 but lower central nervous system penetration, which resulted in enhanced tolerability, even when dosed daily, and improved survival in CLL and AML murine models compared with KPT-330. KPT-8602 is a promising compound for further development in hematological malignancies and other cancers in which upregulation of XPO1 is seen. The wider therapeutic window of KPT-8602 may also allow increased on-target efficacy leading to even more efficacious combinations with other targeted anticancer therapies.


Subject(s)
Antineoplastic Agents/therapeutic use , Hematologic Neoplasms/drug therapy , Karyopherins/antagonists & inhibitors , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Animals , Hematologic Neoplasms/mortality , Hematologic Neoplasms/pathology , Heterografts , Humans , Mice , Neoplasm Invasiveness , Survival Rate , Treatment Outcome , Exportin 1 Protein
4.
Leukemia ; 30(1): 190-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26202935

ABSTRACT

Currently available combination chemotherapy for acute myeloid leukemia (AML) often fails to result in long-term remissions, emphasizing the need for novel therapeutic strategies. We reasoned that targeted inhibition of a prominent nuclear exporter, XPO1/CRM1, could eradicate self-renewing leukemia-initiating cells (LICs) whose survival depends on timely XPO1-mediated transport of specific protein and RNA cargoes. Using an immunosuppressed mouse model bearing primary patient-derived AML cells, we demonstrate that selinexor (KPT-330), an oral antagonist of XPO1 that is currently in clinical trials, has strong activity against primary AML cells while sparing normal stem and progenitor cells. Importantly, limiting dilution transplantation assays showed that this cytotoxic activity is not limited to the rapidly proliferating bulk population of leukemic cells but extends to the LICs, whose inherent drug resistance and unrestricted self-renewal capacity has been implicated in the difficulty of curing AML patients with conventional chemotherapy alone.


Subject(s)
Hydrazines/pharmacology , Karyopherins/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Neoplastic Stem Cells/drug effects , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Triazoles/pharmacology , Animals , Humans , Immunosuppression Therapy , Leukemia, Myeloid, Acute/pathology , Mice , Xenograft Model Antitumor Assays , Exportin 1 Protein
5.
Br J Cancer ; 111(2): 281-91, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-24946002

ABSTRACT

BACKGROUND: We investigated the biologic and pharmacologic activities of a chromosome region maintenance 1 (CRM1) inhibitor against human non-small cell lung cancer (NSCLC) cells both in vitro and in vivo. METHODS: The in vitro and in vivo effects of a novel CRM1 inhibitor (KPT-330) for a large number of anticancer parameters were evaluated using a large panel of 11 NSCLC cell lines containing different key driver mutations. Mice bearing human NSCLC xenografts were treated with KPT-330, and tumour growth was assessed. RESULTS: KPT-330 inhibited proliferation and induced cell cycle arrest and apoptosis-related proteins in 11 NSCLC cells lines. Moreover, the combination of KPT-330 with cisplatin synergistically enhanced the cell kill of the NSCLC cells in vitro. Human NSCLC tumours growing in immunodeficient mice were markedly inhibited by KPT-330. Also, KPT-330 was effective even against NSCLC cells with a transforming mutation of either exon 20 of EGFR, TP53, phosphatase and tensin homologue, RAS or PIK3CA, suggesting the drug might be effective against a variety of lung cancers irrespective of their driver mutation. CONCLUSIONS: Our results support clinical testing of KPT-330 as a novel therapeutic strategy for NSCLC.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Hydrazines/pharmacology , Lung Neoplasms/drug therapy , Triazoles/pharmacology , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Growth Processes/drug effects , Cell Line, Tumor , Cisplatin/pharmacology , G1 Phase/drug effects , Genes, p53 , Humans , Karyopherins/antagonists & inhibitors , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Male , Mice , Mice, Inbred NOD , Mice, SCID , Mutation , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Xenograft Model Antitumor Assays , Exportin 1 Protein
7.
Leukemia ; 28(1): 155-65, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23588715

ABSTRACT

The key nuclear export protein CRM1/XPO1 may represent a promising novel therapeutic target in human multiple myeloma (MM). Here we showed that chromosome region maintenance 1 (CRM1) is highly expressed in patients with MM, plasma cell leukemia cells and increased in patient cells resistant to bortezomib treatment. CRM1 expression also correlates with increased lytic bone and shorter survival. Importantly, CRM1 knockdown inhibits MM cell viability. Novel, oral, irreversible selective inhibitors of nuclear export (SINEs) targeting CRM1 (KPT-185, KPT-330) induce cytotoxicity against MM cells (ED50<200 nM), alone and cocultured with bone marrow stromal cells (BMSCs) or osteoclasts (OC). SINEs trigger nuclear accumulation of multiple CRM1 cargo tumor suppressor proteins followed by growth arrest and apoptosis in MM cells. They further block c-myc, Mcl-1, and nuclear factor κB (NF-κB) activity. SINEs induce proteasome-dependent CRM1 protein degradation; concurrently, they upregulate CRM1, p53-targeted, apoptosis-related, anti-inflammatory and stress-related gene transcripts in MM cells. In SCID mice with diffuse human MM bone lesions, SINEs show strong anti-MM activity, inhibit MM-induced bone lysis and prolong survival. Moreover, SINEs directly impair osteoclastogenesis and bone resorption via blockade of RANKL-induced NF-κB and NFATc1, with minimal impact on osteoblasts and BMSCs. These results support clinical development of SINE CRM1 antagonists to improve patient outcome in MM.


Subject(s)
Karyopherins/antagonists & inhibitors , Multiple Myeloma/therapy , Osteoclasts/pathology , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Humans , Multiple Myeloma/pathology , Exportin 1 Protein
8.
Leukemia ; 27(12): 2357-65, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23752175

ABSTRACT

RNA interference screening identified XPO1 (exportin 1) among the 55 most vulnerable targets in multiple myeloma (MM). XPO1 encodes CRM1, a nuclear export protein. XPO1 expression increases with MM disease progression. Patients with MM have a higher expression of XPO1 compared with normal plasma cells (P<0.04) and to patients with monoclonal gammopathy of undetermined significance/smoldering MM (P<0.0001). The highest XPO1 level was found in human MM cell lines (HMCLs). A selective inhibitor of nuclear export compound KPT-276 specifically and irreversibly inhibits the nuclear export function of XPO1. The viability of 12 HMCLs treated with KTP-276 was significantly reduced. KPT-276 also actively induced apoptosis in primary MM patient samples. In gene expression analyses, two genes of probable relevance were dysregulated by KPT-276: cell division cycle 25 homolog A (CDC25A) and bromodomain-containing protein 4 (BRD4), both of which are associated with c-MYC pathway. Western blotting and reverse transcription-PCR confirm that c-MYC, CDC25A and BRD4 are all downregulated after treatment with KPT-276. KPT-276 reduced monoclonal spikes in the Vk*MYC transgenic MM mouse model, and inhibited tumor growth in a xenograft MM mouse model. A phase I clinical trial of an analog of KPT-276 is ongoing in hematological malignancies including MM.


Subject(s)
Acrylamides/pharmacology , Biological Transport/drug effects , Cell Nucleus/drug effects , Genome-Wide Association Study , Karyopherins/genetics , Multiple Myeloma/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Thiazoles/pharmacology , Animals , Cell Line, Tumor , Cell Nucleus/metabolism , Gene Expression Profiling , Humans , Karyopherins/drug effects , Mice , RNA Interference , Receptors, Cytoplasmic and Nuclear/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Xenograft Model Antitumor Assays , Exportin 1 Protein
9.
Leukemia ; 27(1): 66-74, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22847027

ABSTRACT

Drugs that target the chief mediator of nuclear export, chromosome region maintenance 1 protein (CRM1) have potential as therapeutics for leukemia, but existing CRM1 inhibitors show variable potencies and a broad range of cytotoxic effects. Here, we report the structural analysis and antileukemic activity of a new generation of small-molecule inhibitors of CRM1. Designated selective inhibitors of nuclear export (SINE), these compounds were developed using molecular modeling to screen a small virtual library of compounds against the nuclear export signal (NES) groove of CRM1. The 2.2-Å crystal structure of the CRM1-Ran-RanBP1 complex bound to KPT-251, a representative molecule of this class of inhibitors, shows that the drug occupies part of the groove in CRM1 that is usually occupied by the NES, but penetrates much deeper into the groove and blocks CRM1-directed protein export. SINE inhibitors exhibit potent antileukemic activity, inducing apoptosis at nanomolar concentrations in a panel of 14 human acute myeloid leukemia (AML) cell lines representing different molecular subtypes of the disease. When administered orally to immunodeficient mice engrafted with human AML cells, KPT-251 had potent antileukemic activity with negligible toxicity to normal hematopoietic cells. Thus, KPT-SINE CRM1 antagonists represent a novel class of drugs that warrant further testing in AML patients.


Subject(s)
Active Transport, Cell Nucleus/drug effects , Antineoplastic Agents/pharmacology , Karyopherins/chemistry , Leukemia, Myeloid, Acute/drug therapy , Nuclear Export Signals , Nuclear Proteins/metabolism , Receptors, Cytoplasmic and Nuclear/chemistry , ran GTP-Binding Protein/metabolism , Animals , Antineoplastic Agents/chemistry , Apoptosis , Blotting, Western , Cell Cycle , Cell Nucleus/metabolism , Cell Proliferation , Cells, Cultured , Crystallization , Crystallography, X-Ray , Female , Hematopoietic Stem Cells , Humans , Interleukin Receptor Common gamma Subunit/physiology , Karyopherins/metabolism , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Mice , Mice, Inbred NOD , Mice, SCID , Nuclear Proteins/chemistry , Protein Binding , Receptors, Cytoplasmic and Nuclear/metabolism , Small Molecule Libraries , Xenograft Model Antitumor Assays , ran GTP-Binding Protein/chemistry , Exportin 1 Protein
10.
Arch Dis Child ; 94(9): 690-2, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19531528

ABSTRACT

OBJECTIVE: To determine the aetiologies and clinical characteristics of infants with fever and a bulging fontanelle. DESIGN: The medical records of all febrile infants with a bulging fontanelle who underwent a lumbar puncture from January 2000 to February 2008 in Assaf Harofeh Medical Center, a university affiliated hospital in central Israel, were identified. RESULTS: 153 patients met the inclusion criteria. The male to female ratio was 100:53; age range was 3-11 months with a mean age of 5.6 (SD 1.8) months and a median age of 5 months. Cerebrospinal fluid pleocytosis was found in 42 cases (27.3%), including one case of bacterial meningitis (0.6%). Other leading diagnoses were aseptic meningitis (26.7%), upper respiratory tract infection (18.3%), viral disease not otherwise specified (15.6%), roseola infantum (8.5%) and acute otitis media (6.5%). Appearance on admission was described as good to excellent in 113 (73.8%) infants, none of whom had bacterial meningitis. 32 had aseptic meningitis and 17 had other bacterial disease (pneumonia, acute otitis media, pyelonephritis, bacteraemia, shigella or salmonella gastroenteritis). All the latter had, upon admission, symptoms, signs, laboratory tests or imaging studies suggesting a bacterial aetiology. CONCLUSIONS: In this large cohort, all infants who appeared well on admission and had normal clinical, laboratory and imaging studies had benign (non-bacterial) disease. In an infant who appears well and has no evidence of bacterial disease, it is reasonable to observe the infant and withhold lumbar puncture. Prospective studies should be carried out to confirm this approach.


Subject(s)
Bone Diseases, Infectious/etiology , Cranial Fontanelles , Fever/etiology , Patient Selection , Spinal Puncture , Bone Diseases, Infectious/diagnosis , Chi-Square Distribution , Exanthema Subitum/cerebrospinal fluid , Exanthema Subitum/complications , Female , Humans , Infant , Leukocytosis/cerebrospinal fluid , Leukocytosis/complications , Male , Meningitis, Aseptic/cerebrospinal fluid , Meningitis, Aseptic/complications , Meningitis, Bacterial/cerebrospinal fluid , Meningitis, Bacterial/complications , Otitis Media/cerebrospinal fluid , Otitis Media/complications , Respiratory Tract Infections/cerebrospinal fluid , Respiratory Tract Infections/complications , Retrospective Studies , Risk Assessment/methods , Virus Diseases/cerebrospinal fluid , Virus Diseases/complications
11.
Med Res Rev ; 21(5): 472-83, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11579443

ABSTRACT

G-protein-coupled receptors (GPCRs) are a large and functionally diverse protein superfamily, which form a seven transmembrane (TM) helices bundle with alternating extra-cellular and intracellular loops. GPCRs are considered to be one of the most important groups of drug targets because they are involved in a broad range of body functions and processes and are related to major diseases. In this paper we present a new technology, named PREDICT, for modeling the 3D structure of any GPCR from its amino acid sequence. This approach takes into account both internal protein properties (i.e., the amino acid sequence) and the properties of the membrane environment. Unlike competing approaches, the new technology does not rely on the single known structure of rhodopsin, and is thus capable of predicting novel GPCR conformations. We demonstrate the capabilities of PREDICT in reproducing the known experimental structure of rhodopsin. In principle, PREDICT-generated models offer new opportunities for structure-based drug discovery towards GPCR targets.


Subject(s)
GTP-Binding Proteins/chemistry , Models, Structural , Receptors, Cell Surface/chemistry , Amino Acid Sequence , Animals , Drug Design , Humans , Protein Conformation
12.
Vitam Horm ; 63: 63-90, 2001.
Article in English | MEDLINE | ID: mdl-11358118

ABSTRACT

Gonadotropin releasing hormone (GnRH), the first key hormone of reproduction, is synthesized and secreted from the hypothalamus in a pulsatile manner and stimulates pituitary gonadotrophs (5-10% of the pituitary cells) to synthesize and release gonadotropin luteinizing hormone (LH) and follicle stimulating hormone (FSH). Gonadotrophs consist of 60% multihormonal cells (LH+FSH) and 18% LH- and 22% FSH-containing cells. LH and FSH, members of the glycoprotein hormone family, stimulate spermatogenesis, folliculogenesis, and ovulation. Although GnRH plays a pivotal role in gonadotropin synthesis and release, other factors such as gonadal steroids and gonadal peptides exert positive and negative feedback mechanisms, which affect GnRH actions. GnRH actions include activation of phosphoinositide turnover as well as phospholipase D and A2, mobilization and influx of Ca2+, activation of protein kinase C (PKC) and mitogen-activated protein kinase (MAPK). A complex crosstalk between the above messenger molecules mediates the diverse actions of GnRH. Understanding the signaling mechanisms involved in GnRH actions is the basis for our understanding of basic reproductive functions in general and gonadotropin synthesis and release in particular.


Subject(s)
Gonadotropins/physiology , Receptors, LHRH/physiology , Animals , Arachidonic Acid/physiology , Calcium/physiology , Gene Expression , Gonadotropins/genetics , Gonadotropins/metabolism , Humans , Phosphatidylinositols/metabolism , Phospholipases/metabolism , Pituitary Gland/physiology , Protein Kinase C/physiology , Receptors, LHRH/chemistry , Signal Transduction/physiology , Structure-Activity Relationship
13.
Ann Endocrinol (Paris) ; 60(2): 79-88, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10456177

ABSTRACT

The purpose of this review is to update the information concerning the intracellular effect of GnRH. Binding of GnRH to a G-protein coupled receptor leads to stimulation of Gq and/or G11 protein and to activation of phospholipase C beta. Inositol 1-4-5-triphosphate and early diacylylycerol are the second messengers required for conventional protein kinase C activation. Activation of phospholipase A2 and phospholipase D are also involved, as demonstrated by the liberation of Arachidonic Acid and Phosphatidic Acid. Pituitary cells also express atypical protein kinase C isoforms which mode of activation is not known. Hypothesis concerning transcriptional regulation are presented.


Subject(s)
Cell Membrane/metabolism , Cell Nucleus/metabolism , Receptors, LHRH/physiology , Signal Transduction , Animals , GTP-Binding Proteins/physiology , Gonadotropin-Releasing Hormone/metabolism , Humans , Phospholipases/metabolism , Protein Kinases/metabolism , Receptors, LHRH/chemistry
14.
Front Neuroendocrinol ; 19(1): 1-19, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9465287

ABSTRACT

Gonadotropin-releasing hormone (GnRH), the first key hormone of reproduction, is synthesized in the hypothalamus and is released in a pulsatile manner to stimulate pituitary gonadotrope-luteinizing hormone (LH) and follicle-stimulating hormone (FSH) synthesis and release. Gonadotropes represent only about 10% of pituitary cells and are divided into monohormonal cells (18% LH and 22% FSH cells) and 60% multihormonal (LH + FSH) cells. GnRH binds to a specific seven transmembrane domain receptor which is coupled to Gq and activates sequentially different phospholipases to provide Ca2+ and lipid-derived messenger molecules. Initially, phospholipase C is activated, followed by activation of both phospholipase A2 (PLA2) and phospholipase D (PLD). Generation of the second messengers inositol 1,4,5-trisphosphate and diacylglycerol (DAG) lead to mobilization of intracellular pools of Ca2+ and activation of protein kinase C (PKC). Early DAG and Ca2+, derived via enhanced phosphoinositide turnover, might be involved in rapid activation of selective Ca(2+)-dependent, conventional PKC isoforms (cPKC). On the other hand, late DAG, derived from phosphatidic acid (PA) via PLD, may activate Ca(2+)-independent novel PKC isoforms (nPKC). In addition, arachidonic acid (AA) which is liberated by activated PLA2, might also support selective activation of PKC isoforms (PKCs) with or without other cofactors. Differential cross-talk of Ca2+, AA, and selective PKCs might generate a compartmentalized signal transduction cascade to downstream elements which are activated during the neurohormone action. Among those elements is the mitogen-activated protein kinase (MAPK) cascade which is activated by GnRH in a PKC-, Ca(2+)-, and protein tyrosine kinase (PTK)-dependent fashion. Transcriptional regulation can be mediated by the activation of transcription factors such as c-fos by MAPK. Indeed, GnRH activates the expression of both c-jun and c-fos which might participate in gene regulation via the formation of AP-1. The signaling cascade leading to gonadotropin (LH and FSH) gene regulation by GnRH is still not known and might involve the above-mentioned cascades. AA and selective lipoxygenase products such as leukotriene C4 also participate in GnRH action, possibly by cross-talk with PKCs, or by an autocrine/paracrine amplification cycle. A complex combinatorial, spatial and temporal cross-talk of the above messenger molecules seems to mediate the diverse effects elicited by GnRH, the first key hormone of the reproductive cycle.


Subject(s)
Calcium/physiology , Protein Kinase C/physiology , Receptors, LHRH/physiology , Signal Transduction/physiology , Animals , Gonadotropin-Releasing Hormone/physiology , Humans , Receptors, LHRH/chemistry , Structure-Activity Relationship
15.
Endocrinology ; 138(4): 1673-82, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9075730

ABSTRACT

The mechanism of mitogen-activated protein kinase (MAPK, ERK) stimulation by the GnRH analog [D-Trp6]GnRH (GnRH-a) was investigated in the gonadotroph-derived alphaT3-1 cell line. GnRH-a as well as the protein kinase C (PKC) activator 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulated a sustained response of MAPK activity, whereas epidermal growth factor (EGF) stimulated a transient response. MAPK kinase (MEK) is also activated by GnRH-a, but in a transient manner. GnRH-a and TPA apparently activated mainly the MAPK isoform ERK1, as revealed by Mono-Q fast protein liquid chromatography followed by Western blotting as well as by gel kinase assay. GnRH-a and TPA stimulated the tyrosine phosphorylation of several proteins, and this effect as well as the stimulation of MAPK activity were inhibited by the PKC inhibitor GF 109203X. Similarly, down-regulation of TPA-sensitive PKC subspecies nearly abolished the effect of GnRH-a and TPA on MAPK activity. Furthermore, the protein tyrosine kinase (PTK) inhibitor genistein inhibited protein tyrosine phosphorylation and reduced GnRH-a-stimulated MAPK activity by 50%, suggesting the participation of genistein-sensitive and insensitive pathways in GnRH-a action. Although Ca2+ ionophores have only a marginal stimulatory effect, the removal of Ca2+ markedly reduced MAPK activation by GnRH-a and TPA, but had no effect on GnRH-a and TPA stimulation of protein tyrosine phosphorylation. Interestingly, the removal of Ca2+ also partly inhibited the activation of MAPK by EGF and vanadate/H2O2. Thus, a calcium-dependent component(s) downstream of PKC and PTK might also participate in MAPK activation. Elevation of cAMP by forskolin exerted partial inhibition on EGF, but not on TPA or GnRH-a action, suggesting that MEK activators other than Raf-1 might be involved in GnRH action. We conclude that Ca2+, PTK, and PKC participate in the activation of MAPK by GnRH-a, with Ca2+ being necessary downstream to PKC and PTK.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Calcium/metabolism , Gonadotropin-Releasing Hormone/analogs & derivatives , Pituitary Gland, Anterior/enzymology , Protein Kinase C/metabolism , Animals , Cyclic AMP/metabolism , Enzyme Activation , Gonadotropin-Releasing Hormone/metabolism , Ionomycin/pharmacology , Isoenzymes/metabolism , Mitogen-Activated Protein Kinase 1 , Mitogen-Activated Protein Kinase Kinases , Phosphorylation , Pituitary Gland, Anterior/cytology , Protein Kinases/metabolism , Protein-Tyrosine Kinases/metabolism , Tetradecanoylphorbol Acetate/pharmacology , Triptorelin Pamoate , Virulence Factors, Bordetella/pharmacology
16.
Cell Mol Neurobiol ; 15(5): 527-44, 1995 Oct.
Article in English | MEDLINE | ID: mdl-8719039

ABSTRACT

1. The decapeptide neurohormone gonadotropin releasing hormone (GnRH) is the first key hormone of the reproductive system. Produced in the hypothalamus, GnRH is released in a pulsatile manner into the hypophysial portal system to reach the anterior pituitary and stimulates the release and synthesis of the gonadotropin hormones LH and FSH. GnRH, a Ca2+ mobilizing ligand, binds to its respective binding protein, which is a member of the seven transmembrane domain receptor family and activates a G-protein (Gq). 2. The alpha subunit of Gq triggers enhanced phosphoinositide turnover and the elevation of multiple second messengers required for gonadotropin release and biosynthesis. 3. The messenger molecules IP3, diacylglycerol, Ca2+, protein kinase C, arachidonic acid and leukotriene C4 cross-talk in a complex networks of signaling, culminating in gonadotropin release and gene expression.


Subject(s)
Arachidonic Acid/metabolism , Calcium/metabolism , Gonadotropin-Releasing Hormone/physiology , Protein Kinase C/metabolism , Receptors, LHRH/physiology , Second Messenger Systems , Signal Transduction , Animals , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Follicle Stimulating Hormone/metabolism , GTP-Binding Proteins/metabolism , Humans , Luteinizing Hormone/metabolism , Models, Neurological , Phosphatidylinositols/metabolism
17.
J Consult Clin Psychol ; 57(3): 365-71, 1989 Jun.
Article in English | MEDLINE | ID: mdl-2738209

ABSTRACT

Two studies were conducted in which pain and negative moods during labor were examined in relation to two key, independent variables: instructions to monitor labor contractions given to parturients on admission to the labor service and attendance at LaMaze (childbirth preparation) classes. In Study 1 (N = 48) pain and negative moods showed a sharp decline at Stage 2 (active labor) for women told to monitor and those who had attended classes; there was no decline for the control group. In Study 2 (N = 29), women attending LaMaze classes reported a similar decline in pain during active labor and were more energetic and less tired at admission. Of the three different mechanisms used to derive hypotheses, schema-directed coping provided the best account for the decline in pain and distress during active labor. A second mechanism, accurate expectations, seemed to account for the enhanced energy at the point of admission, in anticipation of birth.


Subject(s)
Adaptation, Psychological , Attitude to Health , Obstetric Labor Complications/psychology , Pain/psychology , Adolescent , Adult , Female , Humans , Pain Measurement , Pregnancy , Uterine Contraction
19.
Neurology ; 34(3): 378-80, 1984 Mar.
Article in English | MEDLINE | ID: mdl-6322046

ABSTRACT

Beta-endorphin-like immunoreactivity (i beta-EP) was measured in the CSF at myelography of 24 patients suspected of vertebral disk disease. Patients made several ratings of mood and pain for the 24 hours preceding myelography. Composite scores for pain, negative mood, and positive mood were derived by factor analysis. Pain Factor scores were negatively correlated with i beta-EP (r = -0.59, p less than 0.001), indicating a possible role for i beta-EP in the perception of the severity of pain. No significant correlation was shown between Positive or Negative Mood Factor scores and CSF i beta-EP. A physiologic indicator of pain severity is discussed.


Subject(s)
Endorphins/cerebrospinal fluid , Pain/cerebrospinal fluid , Emotions , Humans , Intervertebral Disc , Spinal Diseases/cerebrospinal fluid , Spinal Diseases/physiopathology , beta-Endorphin
20.
J Behav Med ; 6(4): 405-19, 1983 Dec.
Article in English | MEDLINE | ID: mdl-6668606

ABSTRACT

The present study investigated the correlation between cancer pain severity and mood states, and addressed methodological issues involved in measuring the association between these groups of variables. Five monthly interviews were administered to 95 cancer pain patients; each interview contained four measures of pain severity and the Profile of Mood States (POMS). The relationships between the two sets of variables were assessed using both interindividual (cross-sectional) and intraindividual (within-subject) methods of correlational analysis. Both types of analyses suggested small but significant positive correlations between the pain measures and negative mood states, and inverse correlations between pain and positive mood. The data also indicated that patients reported high levels of pain but reported little mood disturbance. In addressing methodological issues, the study clarified conceptual and computational differences between the two types of correlational analyses and indicated the appropriate applications of each method.


Subject(s)
Affective Symptoms/psychology , Neoplasms/physiopathology , Pain/psychology , Female , Humans , Male , Middle Aged , Pain Management , Psychological Tests , Sick Role
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