Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 31
Filter
1.
Acta Gastroenterol Belg ; 86(2): 371-373, 2023.
Article in English | MEDLINE | ID: mdl-37428174

ABSTRACT

Immunotherapy is becoming more and more relevant in the treatment of advanced melanoma. Proper management of its side effects can prevent severe complications. We describe the case of a 73-year-old patient with severe refractory colitis secondary to immunotherapy. The patient has been treated for 6 months with Nivolumab, an anti-PD-1, as adjuvant therapy for locally advanced melanoma. He was admitted to the hospital with a deteriorating general condition associated with severe diarrhea and rectal bleeding for 3 weeks. Despite three lines of treatment (high dose corticosteroids, infliximab, mycophenolate mofetil), the patient still presented clinical and endoscopic colitis, with additional infectious complications. The patient required surgical management for total colectomy. In this article we present one of the rare cases of autoimmune colitis that did not respond to various immunosuppressive treatments and required surgery.


Subject(s)
Colitis , Melanoma , Male , Humans , Aged , Immune Checkpoint Inhibitors/therapeutic use , Melanoma/drug therapy , Melanoma/surgery , Colitis/etiology , Immunosuppressive Agents/therapeutic use , Colectomy
2.
Acta Clin Belg ; 77(6): 897-905, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34789066

ABSTRACT

INTRODUCTION: Abiraterone acetate + prednisone (AAP) and docetaxel have proven their efficacy in the treatment of patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) in clinical trials. However, real-world data are scarce. The goal of this study is to evaluate real-world data on the efficacy and safety of these therapies in mHSPC patients. PATIENTS AND METHODS: Records of 93 patients from 21 different centres were retrospectively reviewed. Primary and secondary endpoints were radiographic and PSA progression-free survival (RPFS - PSA-PFS) and cancer specific and overall survival (CSS - OS), respectively. Adverse events (AEs) were evaluated according to the Common Terminology Criteria for Adverse Events version 5.0. Differences in oncological outcome and AEs were evaluated between three treatment groups: ADT only (N=26) - ADT + AAP (N=48) - ADT + docetaxel (N=19). Survival analysis was performed using Kaplan-Meier statistics. RESULTS: Median RPFS was 13 months (95% confidence interval [CI]: 9-17) for ADT only, 21 months (95% CI: 19-23) for ADT + AAP and 12 months (95% CI: 11-14) for ADT + docetaxel (p = 0.004). The 1-year PSA-PFS, CSS and OS were 73.5%, 90.7% and 88.7%, respectively, with no significant differences between the three groups. Adverse events of grade 3 or higher were not observed more frequently. CONCLUSION: Retrospective real-world data show a significantly longer RPFS for mHSPC patients treated with ADT + AAP compared to ADT only or ADT + docetaxel at short-term follow-up. This can aid in counselling of mHSPC patients in daily clinical practice.


Subject(s)
Abiraterone Acetate , Prostatic Neoplasms , Male , Humans , Abiraterone Acetate/therapeutic use , Docetaxel/therapeutic use , Androgen Antagonists/therapeutic use , Retrospective Studies , Prednisone/therapeutic use , Prostate-Specific Antigen/therapeutic use , Belgium/epidemiology , Data Analysis , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/pathology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Hormones/therapeutic use , Treatment Outcome
3.
Clin Immunol ; 216: 108463, 2020 07.
Article in English | MEDLINE | ID: mdl-32437923

ABSTRACT

OBJECTIVES: Patients with Crohn's disease often produce antibodies against flagellated intestinal bacteria. There are mixed data as to whether such antibodies are present in patients with spondyloarthritis. Our objectives were to evaluate for the presence of antibodies against intestinal organisms in children with enthesitis related arthritis (ERA). METHODS: Children with ERA and healthy controls were recruited at three sites. Sera were plated on a nitrocellulose array and incubated with labelled antibodies to human IgA and IgG. RESULTS: At UAB, patients and controls had similar antibody levels against the majority of the bacteria selected, with the exception of increased IgA antibodies among ERA patients against Prevotella oralis (1231 [IQR 750, 2566] versus 706 [IQR 428, 1106], p = .007.) These findings were partially validated at a second but not at a third site. CONCLUSIONS: ERA patients may produce increased IgA antibodies against P. oralis. The possible significance of this finding bears further exploration.


Subject(s)
Antigens, Bacterial/blood , Antigens, Bacterial/immunology , Arthritis, Juvenile/blood , Arthritis, Juvenile/immunology , Prevotella/immunology , Arthritis, Juvenile/microbiology , Child , Crohn Disease/immunology , Crohn Disease/microbiology , Female , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Male
4.
Eur J Immunol ; 46(5): 1162-7, 2016 05.
Article in English | MEDLINE | ID: mdl-26840377

ABSTRACT

It has been shown that while commensal bacteria promote Th1, Th17 and Treg cells in lamina propria (LP) in steady-state conditions, they suppress mucosal Th2 cells. However, it is still unclear whether there are specific commensal organisms down-regulating Th2 responses, and the mechanism involved. Here we demonstrate that commensal A4 bacteria, a member of the Lachnospiraceae family, which produce an immunodominant microbiota CBir1 antigen, inhibits LP Th2-cell development. When transferred into the intestines of RAG(-/-) mice, CBir1-specific T cells developed predominately towards Th1 cells and Th17 cells, but to a lesser extent into Th2 cells. The addition of A4 bacterial lysates to CD4(+) T-cell cultures inhibited production of IL-4. A4 bacteria stimulated dendritic cell production of TGF-ß, and blockade of TGF-ß abrogated A4 bacteria inhibition of Th2-cell development in vitro and in vivo. Collectively, our data show that A4 bacteria inhibit Th2-cell differentiation by inducing dendritic cell production of TGF-ß.


Subject(s)
Dendritic Cells/immunology , Gram-Positive Bacteria/immunology , Mucous Membrane/immunology , Symbiosis , Th2 Cells/immunology , Transforming Growth Factor beta/immunology , Animals , Cell Differentiation , Cells, Cultured , Gram-Positive Bacteria/chemistry , Interleukin-4/biosynthesis , Interleukin-4/immunology , Lymphocyte Activation , Mice , Mucous Membrane/microbiology , Th1 Cells/immunology , Th17 Cells/immunology , Th2 Cells/physiology , Transforming Growth Factor beta/biosynthesis
5.
J Allergy Clin Immunol ; 136(5): 1378-86.e1-5, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26014812

ABSTRACT

BACKGROUND: Although immune responses directed against antigens from the intestinal microbiota are observed in certain diseases, the normal human adaptive immune response to intestinal microbiota is poorly defined. OBJECTIVE: Our goal was to assess the adaptive immune response to the intestinal microbiota present in 143 healthy adults and compare this response with the response observed in 52 children and their mothers at risk of having allergic disease. METHODS: Human serum was collected from adults and children followed from birth to 7 years of age, and the serum IgG response to a panel of intestinal microbiota antigens was assessed by using a novel protein microarray. RESULTS: Nearly every subject tested, regardless of health status, had serum IgG that recognized a common set of antigens. Seroreactivity to the panel of antigens was significantly lower in atopic adults. Healthy infants expressed the highest level of IgG seroreactivity to intestinal microbiota antigens. This adaptive response developed between 6 and 12 months of age and peaked around 2 years of age. Low IgG responses to certain clusters of microbiota antigens during infancy were associated with allergy development during childhood. CONCLUSIONS: There is an observed perturbation of the adaptive response to antigens from the microbiota in allergic subjects. These perturbations are observable even in childhood, suggesting that optimal stimulation of the adaptive immune system by the microbiota might be needed to prevent certain immune-mediated diseases.


Subject(s)
Antigens, Bacterial/immunology , Gastrointestinal Microbiome/immunology , Hypersensitivity/immunology , Intestines/immunology , Adaptive Immunity , Adult , Child , Child, Preschool , Female , Humans , Immunoglobulin G/blood , Infant , Infant, Newborn , Intestines/microbiology , Male , Microarray Analysis
6.
Eur J Immunol ; 44(3): 673-82, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24293139

ABSTRACT

Commensal flora plays an important role in the development of the mucosal immune system and in maintaining intestinal homeostasis. However, the mechanisms involved in regulation of host-microbiota interaction are still not completely understood. In this study, we examined how microbiota and intestinal inflammatory conditions regulate host microRNA expression and observed lower microRNA-107 (miR-107) expression in the inflamed intestines of colitic mice, compared with that in normal control mice. miR-107 was predominantly reduced in epithelial cells and CD11c(+) myeloid cells including dendritic cells and macrophages in the inflamed intestines. We demonstrate that IL-6, IFN-γ, and TNF-α downregulated, whereas TGF-ß promoted, miR-107 expression. In addition, miR-107 expression was higher in the intestines of germ-free mice than in mice housed under specific pathogen-free conditions, and the presence of microbiota downregulated miR-107 expression in DCs and macrophages in a MyD88- and NF-κB-dependent manner. We determined that the ectopic expression of miR-107 specifically repressed the expression of IL-23p19, a key molecule in innate immune responses to commensal bacteria. We concluded that regulation of miR-107 by intestinal microbiota and proinflammatory cytokine serve as an important pathway for maintaining intestinal homeostasis.


Subject(s)
Interleukin-23 Subunit p19/genetics , Intestinal Mucosa/metabolism , Intestines/microbiology , MicroRNAs/genetics , Microbiota , Myeloid Cells/metabolism , Animals , Bacteria/immunology , Bacteria/metabolism , Base Pairing , Base Sequence , Colitis/genetics , Colitis/immunology , Cytokines/metabolism , Cytokines/pharmacology , Dendritic Cells/drug effects , Dendritic Cells/immunology , Dendritic Cells/metabolism , Gene Expression Regulation , Inflammation Mediators/metabolism , Inflammation Mediators/pharmacology , Interleukin-23 Subunit p19/chemistry , Interleukin-23 Subunit p19/metabolism , Intestines/immunology , Ligands , Macrophages/drug effects , Macrophages/immunology , Macrophages/metabolism , Mice , Mice, Transgenic , MicroRNAs/chemistry , Myeloid Cells/drug effects , Myeloid Cells/immunology , Toll-Like Receptors/metabolism
7.
Support Care Cancer ; 21(12): 3483-90, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23955094

ABSTRACT

PURPOSE: To study the treatment patterns, effectiveness and safety of zoledronic acid (ZOL) beyond 2 years of therapy, given the paucity of data on long-term treatment in daily clinical practice. METHODS: Patients with multiple myeloma (MM) or solid tumor bone metastases (STM) and at least 24 months of regular q3-4w ZOL therapy were followed prospectively for an additional 18 months beyond the 24 months required for study entry. End-points included ZOL exposure, incidence of skeletal related events (SRE), and safety. RESULTS: In all, 298 evaluable patients were enrolled. The mean continuation rate of ZOL was 90.6%. Exposure to ZOL decreased with time in all patients, but was lower (50.0% vs. 67.6%; p<0.001) and with higher discontinuation rates (incidence rate ratio [IRR]=1.95; p=0.002) in MM compared to the STM group. ZOL suppressed the rate of SREs similarly during the study as compared to before inclusion (0.12 vs. 0.13 events per person-year; p=0.7). At 18 months, 84.5% remained SRE-free. In STM patients, persistent ZOL therapy was associated with lower SRE risk (hazard ratio [HR]=0.42; p=0.01), but not in MM. Renal deterioration occurred in 3.7% and osteonecrosis of the jaw (ONJ) developed in 6.0%, with dental trauma increasing ONJ risk (HR=4.67; p=0.002). CONCLUSIONS: Beyond 2 years of therapy, treatment patterns of ZOL were heterogeneous and SRE rates were low. The safety profile of ZOL was acceptable, and interrupting ZOL in patients with solid tumors was associated with a higher risk of SREs.


Subject(s)
Bone Density Conservation Agents/administration & dosage , Bone Neoplasms/drug therapy , Bone Neoplasms/secondary , Diphosphonates/administration & dosage , Imidazoles/administration & dosage , Multiple Myeloma/drug therapy , Adult , Aged , Aged, 80 and over , Bone Density Conservation Agents/adverse effects , Diphosphonates/adverse effects , Drug Administration Schedule , Female , Humans , Imidazoles/adverse effects , Male , Middle Aged , Prospective Studies , Zoledronic Acid
8.
Acta Clin Belg ; 68(2): 120-3, 2013.
Article in English | MEDLINE | ID: mdl-23967721

ABSTRACT

Haemangiopericytoma is a rare tumor of vascular origin. We report the case of patient with severe refractory anaemia due to peripheral destruction of red blood cells by spleen metastases. Anaemia was successfully treated by splenectomy. Afterwards, our patient developed liver and lung metastases and was treated, in a clinical trial, with gefitinib that stabilised the disease during nine years. These interesting features are discussed.


Subject(s)
Anemia/etiology , Hemangiopericytoma/pathology , Lung Neoplasms/secondary , Shoulder , Splenic Neoplasms/secondary , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Combined Modality Therapy , Diagnosis, Differential , Disease Progression , Female , Hemangiopericytoma/diagnosis , Hemangiopericytoma/drug therapy , Hemangiopericytoma/surgery , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/drug therapy , Magnetic Resonance Imaging , Splenectomy , Splenic Neoplasms/diagnosis , Splenic Neoplasms/drug therapy , Splenic Neoplasms/surgery , Tomography, X-Ray Computed
9.
Br J Cancer ; 103(12): 1815-21, 2010 Dec 07.
Article in English | MEDLINE | ID: mdl-21063408

ABSTRACT

BACKGROUND: half of anticancer drugs are predominantly excreted in urine. Dosage adjustment in renal insufficiency (RI) is, therefore, a crucial issue. Moreover, patients with abnormal renal function are at high risk for drug-induced nephrotoxicity. The Belgian Renal Insufficiency and Anticancer Medications (BIRMA) study investigated the prevalence of RI in cancer patients, and the profile/dosing of anticancer drugs prescribed. METHODS: primary end point: to estimate the prevalence of abnormal glomerular filtration rate (GFR; estimated with the abbreviated Modification of Diet in Renal Disease formula) and RI in cancer patient. Secondary end point: to describe the profile of anticancer drugs prescribed (dose reduction/nephrotoxicity). Data were collected for patients presenting at one of the seven Belgian BIRMA centres in March 2006. RESULTS: a total of 1218 patients were included. The prevalence of elevated SCR (> or =1.2 mg per 100 ml) was 14.9%, but 64.0% had a GFR<90 ml min(-1) per 1.73 m(2). In all, 78.6% of treated patients (n=1087) were receiving at least one drug needing dosage adjustment and 78.1% received at least one nephrotoxic drug. In all, 56.5% of RI patients receiving chemotherapy requiring dose reduction in case of RI did not receive dose adjustment. CONCLUSIONS: the RI is highly frequent in cancer patients. In all, 80% of the patients receive potentially nephrotoxic drugs and/or for which dosage must be adjusted in RI. Oncologists should check the appropriate dose of chemotherapeutic drugs in relation to renal function before prescribing.


Subject(s)
Antineoplastic Agents/adverse effects , Neoplasms/drug therapy , Renal Insufficiency/physiopathology , Adult , Aged , Anemia/etiology , Antineoplastic Agents/administration & dosage , Bone Neoplasms/secondary , Creatinine/blood , Female , Glomerular Filtration Rate/drug effects , Humans , Kidney/drug effects , Male , Middle Aged , Multivariate Analysis , Neoplasms/physiopathology , Renal Insufficiency/chemically induced
11.
Ann Oncol ; 19(3): 598-599, 2008 Mar.
Article in English | MEDLINE | ID: mdl-32560013
12.
Acta Clin Belg ; 62(4): 223-9, 2007.
Article in English | MEDLINE | ID: mdl-17849693

ABSTRACT

In an effort to map the use of interleukin-2 (IL-2) treatment in patients with clear cell renal cell cancer (RCC) in Belgian hospitals, 44 cases were registered from 9 hospitals between February 2003 and June 2006. It was demonstrated that the majority of these patients were treated with subcutaneous (SC) IL-2. Other methods such as the inhalation of the drug in case of intrathoracic disease or high dose intravenous (IV) administration were much less frequent (3 and 0 cases in this registry, respectively). The results of antitumour activity (around 16% partial response-absence of complete responses) and toxicity of this drug correlate with observations from the literature with the SC administration. In view of the poor results and tolerance with the currently used cytokines (IL-2 or interferon-alfa), much hope is directed towards the development of the novel targeted drugs like sunitinib or sorafenib used alone or in combination with cytokines in this disease.


Subject(s)
Antineoplastic Agents/administration & dosage , Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/secondary , Interleukin-2/administration & dosage , Aged , Aged, 80 and over , Belgium , Drug Utilization/statistics & numerical data , Female , Humans , Male , Middle Aged , Practice Patterns, Physicians'/statistics & numerical data , Registries , Retrospective Studies , Treatment Outcome
13.
Inflamm Bowel Dis ; 13(10): 1191-201, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17712838

ABSTRACT

BACKGROUND: Serologic expression cloning has identified flagellins of the intestinal microbiota as immunodominant antigens in experimental colitis in mice and in individuals with Crohn's disease (CD). The present study was done to identify the microbial source of such flagellins. METHODS: Using a variety of isolation and culture approaches, a number of previously unknown flagellated bacteria were isolated. Based on 16S ribosomal DNA sequences, these bacteria fall into the family Lachnospiraceae of the phylum Firmicutes. RESULTS: Serum IgG from patients with CD and from mice with colitis reacted to the flagellins of these bacteria, and only their flagellins, whereas serum IgG from controls did not. The sequence of these flagellins demonstrate conserved amino- and carboxy-terminal domains that cluster phylogenetically and have a predicted 3D structure similar to Salmonella fliC, including an intact TLR5 binding site. The flagellin of 1 of these bacteria was likely O-glycosylated. CONCLUSIONS: The conserved immune response in both mouse and human to these previously unknown flagellins of the microbiota indicate that they play an important role in host-microbe interactions in the intestine.


Subject(s)
Antigens, Bacterial/immunology , Bacteria/metabolism , Cecum/microbiology , Crohn Disease/etiology , DNA, Bacterial/genetics , Flagellin/genetics , Animals , Bacteria/genetics , Bacteria/immunology , Blotting, Western , Cells, Cultured , Cloning, Molecular , Crohn Disease/genetics , Crohn Disease/immunology , Female , Flagellin/immunology , Humans , Intestinal Mucosa/microbiology , Mice , Mice, Inbred C3H , Phylogeny , Polymerase Chain Reaction , Rabbits , Sequence Analysis, DNA
14.
Ann Oncol ; 18(4): 738-44, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17208931

ABSTRACT

BACKGROUND: To assess the safety and preliminary efficacy of concurrent radiotherapy, capecitabine, and cetuximab in the preoperative treatment of patients with rectal cancer. PATIENTS AND METHODS: Forty patients with rectal cancer (T3-T4, and/or N+, endorectal ultrasound) received preoperative radiotherapy (1.8 Gy, 5 days/week for 5 weeks, total dose 45 Gy, three-dimensional conformal technique) in combination with cetuximab [initial dose 400 mg/m(2) intravenous given 1 week before the beginning of radiation followed by 250 mg/m(2)/week for 5 weeks] and capecitabine for the duration of radiotherapy (650 mg/m(2) orally twice daily, first dose level; 825 mg/m(2) twice daily, second dose level). RESULTS: Four and six patients were treated at the first and second dose level of capecitabine, respectively. No dose-limiting toxicity occurred. Thirty additional patients were treated with capecitabine at 825 mg/m(2) twice daily. The most frequent grade 1/2 side-effects were acneiform rash (87%), diarrhea (65%), and fatigue (57%). Grade 3 diarrhea was found in 15%. Three grade 4 toxic effects were recorded: one myocardial infarction, one pulmonary embolism, and one pulmonary infection with sepsis. Two patients (5%) had a pathological complete response. CONCLUSIONS: Preoperative radiotherapy in combination with capecitabine and cetuximab is feasible with some patients achieving pathological downstaging.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Radiotherapy, Conformal/methods , Rectal Neoplasms/therapy , Adult , Aged , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Capecitabine , Cetuximab , Combined Modality Therapy , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Deoxycytidine/analogs & derivatives , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Fluorouracil/analogs & derivatives , Humans , Male , Middle Aged
15.
Sarcoma ; 2006: 56282, 2006.
Article in English | MEDLINE | ID: mdl-17496996

ABSTRACT

Purpose. To evaluate the activity and safety of ecteinascidin (ET-743) in pretreated patients with advanced or metastatic soft tissue and bone sarcoma. Patients or subjects. Eighty-nine patients received ET-743 as a 24-hour continuous infusion at a dose of 900-1500 mug/m(2) every 3 weeks. Results. We observed one complete remission, 5 partial remissions, one minimal response, and 16 patients with a disease stabilization of 6 months or more. The objective response rate was 6.7% and the clinical benefit rate at 3 and 6 months was 37.7% and 23.4%, respectively. Responses were noted in patients with lipo-, leiomyo-, osteo-, and myogenic sarcoma, with a median duration of 9.85 months. Toxicity mainly involved an asymptomatic elevation of transaminases and neutropenia. Estimated 1- and 2-year survival rates were 39.4% and 15.8%. Median overall survival was 8.25 months. Discussion. This retrospective analysis confirms that ET-743 induces objective responses and progression arrest in a clinically relevant proportion of patients.

16.
Ann Oncol ; 16(12): 1898-905, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16219623

ABSTRACT

BACKGROUND: Preoperative radiotherapy has been shown to decrease the local recurrence rate of patients with locally advanced rectal cancer. Capecitabine and oxaliplatin are both active anticancer agents in the treatment of patients with advanced colorectal cancer and have radiosensitizing properties. Therefore, these drugs would be expected to improve effectiveness of preoperative radiotherapy in terms of local control and prevention of distant metastases. PATIENTS AND METHODS: Forty patients with rectal cancer (T3-T4 and/or N+) received radiotherapy (1.8 Gy, 5 days a week over 5 weeks, total dose 45 Gy, 3D conformational technique) in combination with intravenous oxaliplatin 50 mg/m2 once weekly for 5 weeks and oral capecitabine 825 mg/m2 twice daily on each day of radiation. Surgery was performed 6-8 weeks after completion of radiotherapy. The main end points were safety and efficacy as assessed by the pathological complete response (pCR). RESULTS: The most frequent grade 3/4 adverse event was diarrhea, occurring in 30% of patients. pCR was found in five (14%) patients. According to Dworak's classification, good regression was found in six (18%) additional patients. CONCLUSIONS: Combination of preoperative radiotherapy with capecitabine and oxaliplatin is feasible for downstaging rectal cancer.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Preoperative Care , Rectal Neoplasms/drug therapy , Rectal Neoplasms/radiotherapy , Adenocarcinoma/drug therapy , Adenocarcinoma/radiotherapy , Adenocarcinoma/surgery , Administration, Oral , Adult , Aged , Aged, 80 and over , Capecitabine , Combined Modality Therapy , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Female , Fluorouracil/analogs & derivatives , Humans , Injections, Intravenous , Liver Neoplasms/secondary , Liver Neoplasms/therapy , Male , Maximum Tolerated Dose , Middle Aged , Neoplasm Staging , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Rectal Neoplasms/surgery , Treatment Outcome
17.
Trends Endocrinol Metab ; 15(8): 383-92, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15380810

ABSTRACT

Hypothalamic gonadotropin releasing hormone (GnRH I) and its pituitary receptor are responsible for the CNS regulation of reproduction. However, a second GnRH (GnRH II) is also expressed in humans and a gene that resembles the GnRH II receptor in fish has been identified in humans and monkeys. The amino-acid sequence of this newly identified, seven-transmembrane, G-protein-coupled receptor in monkeys differs from the human GnRH I receptor by having a C-terminal, cytoplasmic tail. GnRH II is approximately 400-fold more potent at GnRH II receptors than GnRH I receptors. GnRH I directly inhibits proliferation of human tumor cells, and GnRH II and its receptor might have a similar role. Limited progress has been made, however, because of difficulty translating the mRNA that encodes the human GnRH II receptor. Nevertheless, such receptors are likely to exist in humans because GnRH II is more inhibitory to tumor cell replication than GnRH I, and GnRH I and GnRH II have reciprocal effects on human decidual stromal cells in culture. The focus of this review is the identity of a possible translatable, functional GnRH II receptor in humans. The two possibilities considered are either that GnRH II receptor mRNA is expressed that encodes either 5 or 7 transmembrane domains or that a GnRH II-responsive complex is formed by the GnRH I receptor and fragments derived from the GnRH II receptor.


Subject(s)
Receptors, LHRH/physiology , Amino Acid Sequence , Animals , Humans , Molecular Sequence Data , Peptide Fragments/metabolism , Receptors, LHRH/chemistry , Receptors, LHRH/genetics
18.
Eur J Cancer ; 40(12): 1855-61, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15288287

ABSTRACT

This study was initiated to evaluate the efficacy of luteinizing hormone-releasing hormone (LH-RH) agonists in protecting premenopausal patients against the adverse gynaecological effects induced by tamoxifen. Between January 1998 and January 2000, 85 premenopausal breast cancer patients were included in this prospective study. All were to receive LH-RH agonists and tamoxifen for a minimum of two years. All patients underwent a pretreatment gynaecological evaluation and annual follow-up. Bone density was also measured at the start of treatment and then after 2, 3 and 4 years. Pretreatment evaluation revealed 2 polyps. At one and two years of follow-up, no abnormal symptoms were noted and echographic findings were normal. At three years of follow-up, a polyp associated with adnexal masses was discovered. Histology revealed ovarian and endometrial metastases of infiltrating lobular breast carcinoma. Bone density evaluation after 2, 3 and 4 years of treatment showed no significant bone loss. LH-RH agonists offer safe protection against the gynaecological side-effects of tamoxifen in premenopausal breast cancer patients.


Subject(s)
Antineoplastic Agents, Hormonal/adverse effects , Breast Neoplasms/drug therapy , Genital Diseases, Female/prevention & control , Gonadotropin-Releasing Hormone/agonists , Tamoxifen/adverse effects , Adult , Bone Density/drug effects , Female , Genital Diseases, Female/chemically induced , Humans , Premenopause , Prospective Studies
19.
BMC Cell Biol ; 2: 21, 2001.
Article in English | MEDLINE | ID: mdl-11716781

ABSTRACT

BACKGROUND: Luteinizing hormone secreted by the anterior pituitary gland regulates gonadal function. Luteinizing hormone secretion is regulated both by alterations in gonadotrope responsiveness to hypothalamic gonadotropin releasing hormone and by alterations in gonadotropin releasing hormone secretion. The mechanisms that determine gonadotrope responsiveness are unknown but may involve regulators of G protein signaling (RGSs). These proteins act by antagonizing or abbreviating interaction of Galpha proteins with effectors such as phospholipase Cbeta. Previously, we reported that gonadotropin releasing hormone-stimulated second messenger inositol trisphosphate production was inhibited when RGS3 and gonadotropin releasing hormone receptor cDNAs were co-transfected into the COS cell line. Here, we present evidence for RGS3 inhibition of gonadotropin releasing hormone-induced luteinizing hormone secretion from cultured rat pituitary cells. RESULTS: A truncated version of RGS3 (RGS3T = RGS3 314-519) inhibited gonadotropin releasing hormone-stimulated inositol trisphosphate production more potently than did RSG3 in gonadotropin releasing hormone receptor-bearing COS cells. An RSG3/glutathione-S-transferase fusion protein bound more 35S-Gqalpha than any other member of the G protein family tested. Adenoviral-mediated RGS3 gene transfer in pituitary gonadotropes inhibited gonadotropin releasing hormone-stimulated luteinizing hormone secretion in a dose-related fashion. Adeno-RGS3 also inhibited gonadotropin releasing hormone stimulated 3H-inositol phosphate accumulation, consistent with a molecular site of action at the Gqalpha protein. CONCLUSIONS: RGS3 inhibits gonadotropin releasing hormone-stimulated second messenger production (inositol trisphosphate) as well as luteinizing hormone secretion from rat pituitary gonadotropes apparently by binding and suppressing the transduction properties of Gqalpha protein function. A version of RGS3 that is amino-terminally truncated is even more potent than intact RGS3 at inhibiting gonadotropin releasing hormone-stimulated inositol trisphosphate production.


Subject(s)
GTP-Binding Proteins , GTPase-Activating Proteins , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Luteinizing Hormone/metabolism , Pituitary Gland, Anterior/metabolism , RGS Proteins/physiology , Repressor Proteins , Animals , COS Cells , Calcium Signaling , Cells, Cultured , Female , Heterotrimeric GTP-Binding Proteins/metabolism , Inositol 1,4,5-Trisphosphate/metabolism , RGS Proteins/genetics , Rats , Receptors, LHRH/metabolism , Sequence Deletion
20.
Biochem Biophys Res Commun ; 282(4): 1012-8, 2001 Apr 13.
Article in English | MEDLINE | ID: mdl-11352653

ABSTRACT

Mammalian gonadotropin-releasing hormone (GnRH I) is a hypothalamic decapeptide that stimulates gonadotropic hormone secretion upon interaction with its membrane receptors (type I) on pituitary cells, thereby governing reproductive processes. A second releasing hormone (GnRH II) expressed in mammals was shown earlier to be expressed in nonmammals and to have its own receptor. Here we demonstrate that a second receptor (type II) gene is present in the human genome, and report the cloning and characterization of its cDNA from monkeys. The cDNA encodes a G-protein-coupled/7 transmembrane receptor having a C-terminal cytoplasmic tail; it resembles more closely the type II receptors of amphibians and fish (approximately 55% identity) than it does the type I receptor of humans (approximately 39%). The GnRH type II receptor proved to be experimentally functional with, and specific for, GnRH II. GnRH receptor type II RNA is expressed ubiquitously in human tissues. This is the first report of a GnRH type II receptor in mammals. Its identification will permit exploration of its role in regulating gonadotropin secretion, female sexual behavior, and tumor cell growth.


Subject(s)
Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/metabolism , Receptors, LHRH/genetics , Amino Acid Sequence , Animals , COS Cells , Cloning, Molecular , Humans , Macaca mulatta , Molecular Sequence Data , RNA, Messenger/biosynthesis , Receptors, LHRH/biosynthesis , Receptors, LHRH/physiology , Sequence Homology, Amino Acid , Tissue Distribution , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...