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1.
Gan To Kagaku Ryoho ; 50(13): 1453-1455, 2023 Dec.
Article in Japanese | MEDLINE | ID: mdl-38303305

ABSTRACT

Chemotherapy is the standard therapy for unresectable intrahepatic cholangiocarcinoma(ICC), but chemotherapy is not efficacious. Proton beam therapy(PBT)has been covered by Japanese health insurance for ICC since 2022, and the number of cases is expected to increase. In some cases, irradiation is difficult due to the close proximity of the gastrointestinal tract to the tumor. We report our management of a patient with ICC close to the gastrointestinal tract. The patient was a 69-year- old woman with a history of distal gastrectomy and Billroth-Ⅰ reconstruction for gastric cancer. A CT scan showed a tumor in liver S3; a biopsy revealed ICC. Because the tumor was in contact with the gastroduodenal anastomosis, we placed an absorbable spacer and performed PBT. After the treatment, the tumor shrank slightly. Although the liver is anatomically adjacent to the digestive tract, the placement of absorbable spacers facilitates performing PBT without adverse events, and is thus considered a useful treatment.


Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Proton Therapy , Female , Humans , Aged , Gastroenterostomy , Cholangiocarcinoma/radiotherapy , Cholangiocarcinoma/surgery , Cholangiocarcinoma/pathology , Bile Ducts, Intrahepatic/pathology , Bile Duct Neoplasms/radiotherapy , Bile Duct Neoplasms/surgery , Bile Duct Neoplasms/pathology
2.
Case Rep Obstet Gynecol ; 2021: 9980015, 2021.
Article in English | MEDLINE | ID: mdl-34211792

ABSTRACT

Streptococcal toxic shock syndrome (STSS) is a life-threatening illness mainly caused by invasive group A Streptococcus (GAS) infection. Herein, we report a case of a postmenopausal woman who developed STSS from an ascending vaginal GAS infection after cytocervical sampling. The patient complained of vaginal discharge, for which she underwent gynecological examination with vaginal sampling. The following day, there was onset of diarrhea and vomiting. After 7 days, she was admitted to our hospital with septic shock. Necrotizing enterocolitis was suspected and surgical intervention was performed; however, the patient was diagnosed with primary peritonitis and antibiotics were initiated. On day 2, GAS was suspected by blood cultures, and antibiotics were changed in consideration of STSS. On day 4, GAS was confirmed in blood, ascitic fluid, and vaginal swab specimens, and STSS caused by an ascending vaginal GAS infection was diagnosed. This case report indicates that STSS could occur following cytocervical sampling for vaginal discharge. If a woman has unexplained septic shock, especially with gastroenteritis symptoms, STSS should be considered as a differential diagnosis.

3.
Case Rep Obstet Gynecol ; 2020: 8857300, 2020.
Article in English | MEDLINE | ID: mdl-33133709

ABSTRACT

Uterine torsion is extremely rare in postmenopausal women. Total ischemia of the uterus may cause life-threatening conditions; hence, accurate diagnosis and surgical intervention are crucial. However, preoperative diagnosis is often challenging due to nonspecific clinical features and laboratory findings. We report a case of uterine torsion in a 73-year-old woman who presented with mild but gradually worsening intermittent abdominal pain. During a 5-day observation, repeated blood exams showed elevating serum muscle enzyme levels, lactate dehydrogenase (LDH), and creatinine kinase (CPK), in addition to nonspecific signs of inflammation. Computed tomography (CT) scans were obtained before and after the worsening of symptoms, which revealed changes in size and position of the enlarged uterus with a large leiomyoma, even within a 5-day interval. Based on these findings, the preoperative diagnosis was uterine torsion. Emergency surgery revealed a 540-degree torsion of the uterus at the cervix and uterine body junction. Total hysterectomy and bilateral salpingo-oophorectomy were performed. Plasma muscle enzyme levels normalized after surgery, and the patient recovered without complications. In conclusion, uterine torsion should be considered during differential diagnosis in elderly women with large leiomyoma, even when symptoms are mild. Elevating plasma muscle enzymes may be an indication of uterine torsion; hence, repeated laboratory works and CT scanning should be performed when symptoms progress. Comparison of CT images, taken before and after the worsening of symptoms, may also be relevant for diagnosis. Since uterine torsion may cause rapid deterioration and become life-threatening, early diagnosis and surgical intervention are crucial to avoid serious complications.

4.
Gynecol Oncol ; 155(2): 331-339, 2019 11.
Article in English | MEDLINE | ID: mdl-31493899

ABSTRACT

INTRODUCTION: PI3K pathway signaling has received attention as a molecular target in clear cell ovarian carcinoma (CCOC). MDM2 is one of the AKT effectors in the PI3K pathway, which binds to and degrades p53. In this study, we aimed to clarify the prognostic significance of PIK3CA and MDM2 expression, and potential therapeutic effect of a dual inhibition of the PI3K pathway and MDM2. MATERIALS AND METHODS: cDNA expression was evaluated by using microarray data using 75 samples of CCOC. DS-7423 (dual inhibitor of pan-PI3K and mTOR) and RG7112 (MDM2 inhibitor) were used on CCOC cell lines to evaluate cell proliferation, expression level of MDM2 related proteins, and apoptosis by MTT assay, western blotting, and flow cytometry. DS-7423 (3 mg/kg) and/or RG7112 (50 mg/kg) were orally administrated every day for three weeks, and the anti-tumor effect was evaluated using tumor xenografts, along with immunohistochemistry. RESULTS: Tumors with high expression of both PIK3CA and MDM2 showed significantly worse prognosis in expression array of 71 CCOCs (P = 0.013). Dual inhibition of the PI3K pathway by DS-7423 and MDM2 by RG7112 showed synergistic anti-proliferative effect in 4 CCOC cell lines without TP53 mutations. The combination therapy more robustly induced pro-apoptotic proteins (PUMA and cleaved PARP) with increase of sub G1 population and apoptotic cells, compared with either single agent alone. The combination therapy significantly reduced tumor volume in mice (P < 0.001 in OVISE, and P = 0.038 in RMG-I) without severe body weight loss. Immunohistochemistry from the xenograft tumors showed that the combination treatment significantly reduced vascularity and cell proliferation, with an increase of apoptotic cell death. CONCLUSION: A combination therapy targeting the PI3K pathway and MDM2 might be a promising therapeutic strategy in CCOC.


Subject(s)
Ovarian Neoplasms/drug therapy , Phosphoinositide-3 Kinase Inhibitors , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Adenine/analogs & derivatives , Adenine/pharmacology , Adenocarcinoma, Clear Cell , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Class I Phosphatidylinositol 3-Kinases , DNA, Complementary/metabolism , Female , Heterografts , Imidazolines/pharmacology , Mice, Nude , Neoplasm Transplantation/physiology , Ovarian Neoplasms/metabolism , Piperazines/pharmacology , Protein Kinase Inhibitors/pharmacology , RNA, Messenger/metabolism , RNA, Neoplasm/metabolism , Random Allocation
5.
BMC Cancer ; 16(1): 897, 2016 11 17.
Article in English | MEDLINE | ID: mdl-27855669

ABSTRACT

BACKGROUND: Previous studies have shown that the cell polarity protein partitioning defective 3 (Par3) plays an essential role in the formation of tight junctions and definition of apical-basal polarity. Aberrant function of this protein has been reported to be involved in epithelial-mesenchymal transition (EMT) and cancer invasion. The aim of this study was to examine the functional mechanism of Par3 in ovarian cancer. METHODS: First, we investigated the association between Par3 expression level and survival of 50 ovarian cancer patients. Next, we conducted an in vitro analysis of ovarian cancer cell lines, focusing on the cell line JHOC5, to investigate Par3 function. To investigate the function of Par3 in invasion, the IL-6/STAT3 pathway was analyzed upon Par3 knockdown with siRNA. The effect of siRNA treatment was assessed by qPCR, ELISA, and western blotting. Invasiveness and cell proliferation following treatment with siRNA against Par3 were investigated using Matrigel chamber, wound healing, and cell proliferation assays. RESULTS: Expression array data for ovarian cancer patient samples revealed low Par3 expression was significantly associated with good prognosis. Univariate analysis of clinicopathological factors revealed significant association between high Par3 levels and peritoneal dissemination at the time of diagnosis. Knockdown of Par3 in JHOC5 cells suppressed cell invasiveness, migration, and cell proliferation with deregulation of IL-6/STAT3 activity. CONCLUSION: Taken together, these results suggest that Par3 expression is likely involved in ovarian cancer progression, especially in peritoneal metastasis. The underlying mechanism may be that Par3 modulates IL-6 /STAT3 signaling. Here, we propose that the expression of Par3 in ovarian cancer may control disease outcome.


Subject(s)
Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Gene Expression Profiling/methods , Membrane Proteins/genetics , Membrane Proteins/metabolism , Oligonucleotide Array Sequence Analysis/methods , Ovarian Neoplasms/pathology , Peritoneal Neoplasms/secondary , Adaptor Proteins, Signal Transducing , Adult , Aged , Aged, 80 and over , Cell Line, Tumor , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , Interleukin-6/genetics , Interleukin-6/metabolism , Middle Aged , Neoplasm Invasiveness , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Peritoneal Neoplasms/genetics , Peritoneal Neoplasms/metabolism , Prognosis , STAT3 Transcription Factor/metabolism , Signal Transduction , Survival Analysis
6.
Oncotarget ; 7(46): 75328-75338, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27659536

ABSTRACT

MDM2, a ubiquitin ligase, suppresses wild type TP53 via proteasome-mediated degradation. We evaluated the prognostic and therapeutic value of MDM2 in ovarian clear cell carcinoma. MDM2 expression in ovarian cancer tissues was analyzed by microarray and real-time PCR, and its relationship with prognosis was evaluated by Kaplan-Meier method and log-rank test. The anti-tumor activities of MDM2 siRNA and the MDM2 inhibitor RG7112 were assessed by cell viability assay, western blotting, and flow cytometry. The anti-tumor effects of RG7112 in vivo were examined in a mouse xenograft model. MDM2 expression was significantly higher in clear cell carcinoma than in ovarian high-grade serous carcinoma (P = 0.0092) and normal tissues (P = 0.035). High MDM2 expression determined by microarray was significantly associated with poor progression-free survival and poor overall survival (P = 0.0002, and P = 0.0008, respectively). Notably, RG7112 significantly suppressed cell viability in clear cell carcinoma cell lines with wild type TP53. RG7112 also strongly induced apoptosis, increased TP53 phosphorylation, and stimulated expression of the proapoptotic protein PUMA. Similarly, siRNA knockdown of MDM2 induced apoptosis. Finally, RG7112 significantly reduced the tumor volume of xenografted RMG-I clear cell carcinoma cells (P = 0.033), and the density of microvessels (P = 0.011). Our results highlight the prognostic value of MDM2 expression in clear cell carcinoma. Thus, MDM2 inhibitors such as RG7112 may constitute a class of potential therapeutics.


Subject(s)
Adenocarcinoma, Clear Cell/genetics , Antineoplastic Agents/pharmacology , Ovarian Neoplasms/genetics , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Adenocarcinoma, Clear Cell/drug therapy , Adenocarcinoma, Clear Cell/metabolism , Adenocarcinoma, Clear Cell/mortality , Animals , Apoptosis/drug effects , Apoptosis/genetics , Cell Line, Tumor , Cell Survival/genetics , Disease Models, Animal , Female , Gene Expression , Humans , Hypoxia/drug therapy , Hypoxia/genetics , Hypoxia/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Imidazolines/pharmacology , Mice , Molecular Targeted Therapy , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/mortality , Prognosis , Proto-Oncogene Proteins c-mdm2/genetics , Proto-Oncogene Proteins c-mdm2/metabolism , Tumor Suppressor Protein p53/metabolism
8.
Gynecol Oncol ; 138(2): 323-31, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26033306

ABSTRACT

OBJECTIVE: We aimed to clarify whether dual inhibition of PI3K/MAPK and MAPK pathways synergistically suppresses cell growth in endometrial cancer cells. METHODS: We exposed a panel of 12 endometrial cancer cell lines to a PI3K/mTOR inhibitor (voxtalisib, SAR245409) and/or a MEK inhibitor (pimasertib). The effect of each drug singly or in combination was evaluated by MTT assay, flow cytometry, and immunoblotting. Combination indexes (CIs) were calculated using the Chou-Talalay method to evaluate the synergy. RESULTS: The IC50 values for SAR245409 and pimasertib varied from 0.5 µM to 7 µM and from 0.1 µM to >20 µM, respectively. A combination of both compounds (1 µM SAR245409 and 30 nM pimasertib) caused a synergistic antitumor effect in 6 out of 12 endometrial cell lines (CI, 0.07-0.46). The synergistic effect was exclusively observed in 6 pimasertib-sensitive cell lines (IC50 of pimasertib, ≤5 µM). We found that 30 nM pimasertib, a concentration much lower than the IC50 for each cell line, was sufficient to cause a synergistic effect with SAR245409. Flow cytometric analysis showed that this combination significantly increased the population of G1 cells. However, a combination of rapamycin (an mTOR inhibitor) and pimasertib did not induce a synergistic effect in endometrial cancer cells, except for HEC-1B cells. CONCLUSIONS: The combination of a PI3K/mTOR inhibitor and a MEK inhibitor induced a synergistic antitumor effect in certain endometrial cancer cells. This study underscores the importance of using optimized doses of antitumor agents, singly or in combination, in treating endometrial cancer.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Endometrial Neoplasms/drug therapy , Niacinamide/analogs & derivatives , Protein Kinase Inhibitors/pharmacology , Quinoxalines/pharmacology , Sulfonamides/pharmacology , Cell Growth Processes/drug effects , Cell Line, Tumor , Drug Synergism , Endometrial Neoplasms/enzymology , Endometrial Neoplasms/metabolism , Female , Humans , MAP Kinase Kinase 1/antagonists & inhibitors , MAP Kinase Kinase 2/antagonists & inhibitors , MAP Kinase Signaling System/drug effects , Molecular Targeted Therapy , Niacinamide/administration & dosage , Niacinamide/pharmacology , Phosphoinositide-3 Kinase Inhibitors , Quinoxalines/administration & dosage , Sulfonamides/administration & dosage , TOR Serine-Threonine Kinases/antagonists & inhibitors
9.
PLoS One ; 10(6): e0128066, 2015.
Article in English | MEDLINE | ID: mdl-26043110

ABSTRACT

Ovarian clear cell carcinoma (CCC) is generally associated with chemoresistance and poor clinical outcome, even with early diagnosis; whereas high-grade serous carcinomas (SCs) and endometrioid carcinomas (ECs) are commonly chemosensitive at advanced stages. Although an integrated genomic analysis of SC has been performed, conclusive views on copy number and expression profiles for CCC are still limited. In this study, we performed single nucleotide polymorphism analysis with 57 epithelial ovarian cancers (31 CCCs, 14 SCs, and 12 ECs) and microarray expression analysis with 55 cancers (25 CCCs, 16 SCs, and 14 ECs). We then evaluated PIK3CA mutations and ARID1A expression in CCCs. SNP array analysis classified 13% of CCCs into a cluster with high frequency and focal range of copy number alterations (CNAs), significantly lower than for SCs (93%, P < 0.01) and ECs (50%, P = 0.017). The ratio of whole-arm to all CNAs was higher in CCCs (46.9%) than SCs (21.7%; P < 0.0001). SCs with loss of heterozygosity (LOH) of BRCA1 (85%) also had LOH of NF1 and TP53, and LOH of BRCA2 (62%) coexisted with LOH of RB1 and TP53. Microarray analysis classified CCCs into three clusters. One cluster (CCC-2, n = 10) showed more favorable prognosis than the CCC-1 and CCC-3 clusters (P = 0.041). Coexistent alterations of PIK3CA and ARID1A were more common in CCC-1 and CCC-3 (7/11, 64%) than in CCC-2 (0/10, 0%; P < 0.01). Being in cluster CCC-2 was an independent favorable prognostic factor in CCC. In conclusion, CCC was characterized by a high ratio of whole-arm CNAs; whereas CNAs in SC were mainly focal, but preferentially caused LOH of well-known tumor suppressor genes. As such, expression profiles might be useful for sub-classification of CCC, and might provide useful information on prognosis.


Subject(s)
Adenocarcinoma, Clear Cell/genetics , Adenocarcinoma, Clear Cell/pathology , Chromosome Aberrations , Gene Dosage , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Chromosomal Instability/genetics , Cluster Analysis , DNA Copy Number Variations/genetics , Female , Genes, Tumor Suppressor , Genotype , Humans , Loss of Heterozygosity , Polymorphism, Single Nucleotide/genetics , Prognosis , Treatment Outcome
10.
Gynecol Oncol ; 138(1): 174-80, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25913131

ABSTRACT

Radiation therapy is a key therapeutic strategy for endometrial carcinomas. However, biomarkers that predict radiosensitivity and drugs to enhance this sensitivity have not yet been established. We aimed to investigate the roles of TP53 and MAPK/PI3K pathways in endometrial carcinomas and to identify appropriate radiosensitizing therapeutics. D10 values (the irradiating dose required to reduce a cell population by 90%) were determined in eight endometrial cancer cell lines with known mutational statuses for TP53, PIK3CA, and KRAS. Cells were exposed to ionizing radiation (2-6Gy) and either a dual PI3K/mTOR inhibitor (NVP-BEZ235) or a MEK inhibitor (UO126), and their radiosensitizing effects were evaluated using clonogenic assays. The effects of silencing hypoxia-inducible factor-1 α (HIF-1α) expression with small interfering RNAs (siRNAs) were evaluated following exposure to ionizing radiation (2-3Gy). D10 values ranged from 2.0 to 3.1Gy in three cell lines expressing wild-type TP53 or from 3.3 to more than 6.0Gy in five cell lines expressing mutant TP53. NVP-BEZ235, but not UO126, significantly improved radiosensitivity through the suppression of HIF-1α/vascular endothelial growth factor-A expression. HIF-1α silencing significantly increased the induction of the sub-G1 population by ionizing radiation. Our study data suggest that TP53 mutation and PI3K pathway activation enhances radioresistance in endometrial carcinomas and that targeting the PI3K/mTOR or HIF-1α pathways could improve radiosensitivity.


Subject(s)
Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/radiotherapy , Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors , Phosphoinositide-3 Kinase Inhibitors , TOR Serine-Threonine Kinases/antagonists & inhibitors , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Butadienes/pharmacology , Carcinoma, Endometrioid/drug therapy , Carcinoma, Endometrioid/radiotherapy , Cell Line, Tumor , Enzyme Inhibitors/pharmacology , Female , Genes, p53 , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Imidazoles/pharmacology , Nitriles/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Quinolines/pharmacology , Radiation Tolerance/drug effects , TOR Serine-Threonine Kinases/metabolism , Vascular Endothelial Growth Factor A/metabolism
11.
BMC Cancer ; 14: 179, 2014 Mar 13.
Article in English | MEDLINE | ID: mdl-24625059

ABSTRACT

BACKGROUND: PTEN inactivation is the most frequent genetic aberration in endometrial cancer. One of the phosphatase-independent roles of PTEN is associated with homologous recombination (HR) in nucleus. Poly (ADP-ribose) polymerase (PARP) plays key roles in the repair of DNA single-strand breaks, and a PARP inhibitor induces synthetic lethality in cancer cells with HR deficiency. We examined the anti-tumor activity of olaparib, a PARP inhibitor, and its correlation between the sensitivity and status of PTEN in endometrial cancer cell lines. METHODS: The response to olaparib was evaluated using a clonogenic assay with SF50 values (concentration to inhibit cell survival to 50%) in 16 endometrial cancer cell lines. The effects of PTEN on the sensitivity to olaparib and ionizing radiation (IR) exposure were compared between parental HEC-6 (PTEN-null) and HEC-6 PTEN + (stably expressing wild-type PTEN) cells by clonogenic assay, foci formation of RAD51 and γH2AX, and induction of cleaved PARP. The effects of siRNA to PTEN were analyzed in cells with wild-type PTEN. RESULTS: The SF50 values were 100 nM or less in four (25%: sensitive) cell lines; whereas, SF50 values were 1,000 nM or more in four (25%: resistant) cell lines. PTEN mutations were not associated with sensitivity to olaparib (Mutant [n = 12]: 746 ± 838 nM; Wild-type [n = 4]: 215 ± 85 nM, p = 0.26 by Student's t test). RAD51 expression was observed broadly and was not associated with PTEN status in the 16 cell lines. The number of colonies in the clonogenic assay, the foci formation of RAD51 and γH2AX, and the induction of apoptosis were not affected by PTEN introduction in the HEC-6 PTEN + cells. The expression level of nuclear PTEN was not elevated within 24 h following IR in the HEC-6-PTEN + cells. In addition, knocking down PTEN by siRNA did not alter the sensitivity to olaparib in 2 cell lines with wild-type PTEN. CONCLUSIONS: Our results suggest that olaparib, a PARP inhibitor, is effective on certain endometrial cancer cell lines. Inactivation of PTEN might not affect the DNA repair function. Predictive biomarkers are warranted to utilize olaparib in endometrial cancer.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , Endometrial Neoplasms/drug therapy , Phthalazines/pharmacology , Piperazines/pharmacology , Cell Line, Tumor , Cell Proliferation/radiation effects , Endometrial Neoplasms/genetics , Endometrial Neoplasms/pathology , Female , Gene Expression Regulation, Neoplastic , Histones/metabolism , Humans , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Rad51 Recombinase/genetics , Rad51 Recombinase/metabolism , Radiation, Ionizing
12.
J Biomol Screen ; 18(3): 321-30, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23064887

ABSTRACT

The endocrine action of human (h) intestine-derived fibroblast growth factor 19 (hFGF19) toward liver cells necessitates a highly specific recognition system. We previously reported that at physiological concentrations (~30 pM), hFGF19 requires sulfated glycosaminoglycans (sGAGs) for its signaling via human FGF receptor 4 (hFGFR4) in the presence of a co-receptor, human ßKlotho (hKLB), thus establishing specific targeting. Here we report that the specificity of hFGF19 signaling is greatly altered in a mouse model system. In in vitro cellular systems, at concentrations achievable in transgenic animals and in pharmacologic animal experiments (1-100 nM), hFGF19 activates mouse (m)FGFR1c, mFGFR2c, and mFGFR3c but not mFGFR4 in the presence of mKLB and nonheparin authentic sGAGs. Furthermore, in the presence of hepatic sGAGs or heparin, nanomolar hFGF19 activates mFGFR4, even in the absence of co-expressed mKLB. Taken together, these results indicate that the sGAG-assisted receptor specificity of hFGF19 signaling achieved in experimental mouse systems differs greatly from that in physiological human systems. This suggests the function and mechanism of hFGF19 signaling identified using mouse systems should be reevaluated.


Subject(s)
Fibroblast Growth Factors/metabolism , Receptors, Cell Surface/metabolism , Animals , Cell Line, Tumor , Heparin/metabolism , Humans , Liver/metabolism , Mice , Mice, Transgenic , Receptor, Fibroblast Growth Factor, Type 4/metabolism , Signal Transduction
13.
J Biol Chem ; 286(30): 26418-23, 2011 Jul 29.
Article in English | MEDLINE | ID: mdl-21653700

ABSTRACT

Secreted from intestine, human fibroblast growth factor 19 (hFGF19) is an endocrine metabolic regulator that controls bile acid synthesis in the liver. Earlier studies have suggested that hFGF19 at 10-100 nM levels signals through FGF receptor 4 (FGFR4) in the presence of a co-receptor, betaKlotho, but its activity and receptor specificity at physiological concentrations (picomolar levels) remain unclear. Here we report that hFGF19 at picomolar levels require sulfated glycosaminoglycans (sGAGs), such as heparan sulfate, heparin, and chondroitin sulfates, for its signaling via human FGFR4 in the presence of human betaKlotho. Importantly, sGAGs isolated from liver are highly active in enhancing the picomolar hFGF19 signaling. At nanomolar levels, in contrast, hFGF19 activates all types of human FGFRs, i.e. FGFR1c, FGFR2c, FGFR3c, and FGFR4 in the co-presence of betaKlotho and heparin and activates FGFR4 even in the absence of betaKlotho. These results show that sGAGs play crucial roles in specific and sensitive hFGF19 signaling via FGF receptors and suggest that hepatic sGAGs are involved in the highly potent and specific signaling of picomolar hFGF19 through FGFR4 and betaKlotho. The results further suggest that hFGF19 at pathological concentrations may evoke aberrant signaling through various FGF receptors.


Subject(s)
Fibroblast Growth Factors/metabolism , Glycosaminoglycans/metabolism , Liver/metabolism , Membrane Proteins/metabolism , Receptor, Fibroblast Growth Factor, Type 4/metabolism , Signal Transduction/physiology , Animals , Cattle , Cell Line , Fibroblast Growth Factors/genetics , Glycosaminoglycans/chemistry , Glycosaminoglycans/isolation & purification , Glycosaminoglycans/pharmacology , Humans , Klotho Proteins , Membrane Proteins/genetics , Receptor, Fibroblast Growth Factor, Type 4/genetics , Signal Transduction/drug effects
14.
Mol Endocrinol ; 22(4): 1006-14, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18187602

ABSTRACT

Fibroblast growth factor (FGF) 21, a structural relative of FGF23 that regulates phosphate homeostasis, is a regulator of insulin-independent glucose transport in adipocytes and plays a role in the regulation of body weight. It also regulates ketogenesis and adaptive responses to starvation. We report that in a reconstituted receptor activation assay system using BaF3 cells, which do not endogenously express any type of FGF receptor (FGFR) or heparan sulfate proteoglycan, FGF21 alone does not activate FGFRs and that betaKlotho is required for FGF21 to activate two specific FGFR subtypes: FGFR1c and FGFR3c. Coexpression of betaKlotho and FGFR1c on BaF3 cells enabled FGF21, but not FGF23, to activate receptor signaling. Conversely, coexpression of FGFR1c and Klotho, a protein related to betaKlotho, enabled FGF23 but not FGF21 to activate receptor signaling, indicating that expression of betaKlotho/Klotho confers target cell specificity on FGF21/FGF23. In all of these cases, heparin enhanced the activation but was not essential. In 3T3-L1 adipocytes, up-regulation of glucose transporter (GLUT) expression by FGF21 was associated with expression of betaKlotho, which was absent in undifferentiated 3T3-L1 fibroblasts. It is thus suggested that betaKlotho expression is a crucial determinant of the FGF21 specificity of the target cells upon which it acts in an endocrine fashion.


Subject(s)
Fibroblast Growth Factors/pharmacology , Glucuronidase/metabolism , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Receptor, Fibroblast Growth Factor, Type 3/metabolism , 3T3-L1 Cells , Animals , Fibroblast Growth Factor-23 , Gene Expression/drug effects , Glucose Transport Proteins, Facilitative/genetics , Glucose Transport Proteins, Facilitative/metabolism , Glucuronidase/genetics , Immunoblotting , Klotho Proteins , Mice , Protein Binding , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, Fibroblast Growth Factor, Type 1/genetics , Receptor, Fibroblast Growth Factor, Type 3/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction
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