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1.
Pathol Res Pract ; 241: 154243, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36481650

ABSTRACT

Prostate cancer diagnosis and early stratification is an important aspect to avoid undertreatment of high-risk prostate cancer patients. Major Vault Protein (MVP) has been proposed as a prognostic biomarker in prostate cancer. PTEN and the immune checkpoint protein B7-H3 interact with MVP and are important in prostate cancer progression and therapy response. We evaluated the expression of MVP by immunohistochemistry of tissue microarray samples from a retrospective cohort consisting of 119 prostate cancer patients. We correlated the protein expression of MVP with clinicopathological characteristics, and protein expression of androgen receptor (AR), PTEN, immune checkpoint proteins B7-H3 and PD-L1. We found MVP to be expressed in 53 % of prostate tumors, and correlated positively with biochemical recurrence (ρ = 0.211/p = 0.021). Furthermore, we found positive correlation of MVP expression with expression of AR (ρ = 0.244/p = 0.009) and the immune checkpoint protein B7-H3 (ρ = 0.200/p = 0.029), but not with PD-L1 (ρ = 0.152/p = 0.117) or PTEN expression (ρ = - 0.034/p = 0.721). Our findings support the notion that expression of MVP is associated with poor prognosis in prostate cancer. The correlation between MVP and immune checkpoint protein B7-H3 in prostate cancer suggests a role for MVP in immunoregulation and drug resistance.


Subject(s)
B7-H1 Antigen , Prostatic Neoplasms , Male , Humans , B7-H1 Antigen/metabolism , Immune Checkpoint Proteins , Retrospective Studies , Receptors, Androgen , Prostatic Neoplasms/pathology , Prognosis
2.
Cancers (Basel) ; 13(16)2021 Aug 19.
Article in English | MEDLINE | ID: mdl-34439316

ABSTRACT

This study undertook to predict biochemical recurrence (BCR) in prostate cancer patients after radical prostatectomy using serum biomarkers and clinical features. Three radical prostatectomy cohorts were used to build and validate a model of clinical variables and serum biomarkers to predict BCR. The Cox proportional hazard model with stepwise selection technique was used to develop the model. Model evaluation was quantified by the AUC, calibration, and decision curve analysis. Cross-validation techniques were used to prevent overfitting in the Irish training cohort, and the Austrian and Norwegian independent cohorts were used as validation cohorts. The integration of serum biomarkers with the clinical variables (AUC = 0.695) improved significantly the predictive ability of BCR compared to the clinical variables (AUC = 0.604) or biomarkers alone (AUC = 0.573). This model was well calibrated and demonstrated a significant improvement in the predictive ability in the Austrian and Norwegian validation cohorts (AUC of 0.724 and 0.606), compared to the clinical model (AUC of 0.665 and 0.511). This study shows that the pre-operative biomarker PEDF can improve the accuracy of the clinical factors to predict BCR. This model can be employed prior to treatment and could improve clinical decision making, impacting on patients' outcomes and quality of life.

3.
PLoS One ; 16(6): e0253828, 2021.
Article in English | MEDLINE | ID: mdl-34191854

ABSTRACT

The ß2-adrenergic receptor has been shown to be involved in neuroendocrine differentiation and to contribute to the development of aggressive prostate cancer. In this study we have investigated whether miR-196a plays a role in the regulation of the ß2-adrenergic receptor in the LNCaP prostate cancer cell line. Our results show that the expression of miR-196a is elevated in LNCaP prostate cancer cells with reduced levels of ß2-adrenergic receptor after stably transfection with three different shRNAs. Furthermore, treatment with ß-blockers showed that this upregulation is strictly related to the low levels of ß2-adrenergic receptor and not to the inhibition of the receptor signaling activity. Finally, we found that the reduced ability of LNCaP cells with low levels of ß2-adrenergic receptor to initiate neuroendocrine differentiation under androgen depletion conditions is mediated by miR-196a. In conclusion, this study provides the rational for a role of miR-196a in the ß2-adrenergic receptor mediated neuroendocrine differentiation of LNCaP prostate cancer cells.


Subject(s)
Gene Expression Regulation, Neoplastic , MicroRNAs/metabolism , Neuronal Outgrowth/genetics , Prostatic Neoplasms/genetics , Receptors, Adrenergic, beta-2/genetics , Adrenergic beta-2 Receptor Antagonists , Cell Line, Tumor , Gene Knockdown Techniques , Humans , Male , MicroRNAs/genetics , Neuronal Outgrowth/drug effects , Prostate/pathology , Prostatic Neoplasms/pathology , Receptors, Adrenergic, beta-2/metabolism , Up-Regulation
4.
Carcinogenesis ; 42(5): 685-693, 2021 05 28.
Article in English | MEDLINE | ID: mdl-33609362

ABSTRACT

The demographic shift toward an older population will increase the number of prostate cancer cases. A challenge in the treatment of prostate cancer is to avoid undertreatment of patients at high risk of progression following curative treatment. These men can benefit from early salvage treatment. An explorative cohort consisting of tissue from 16 patients who underwent radical prostatectomy, and were either alive or had died from prostate cancer within 10 years postsurgery, was analyzed by mass spectrometry analysis. Following proteomic and bioinformatic analyses, major vault protein (MVP) was identified as a putative prognostic biomarker. A publicly available tissue proteomics dataset and a retrospective cohort of 368 prostate cancer patients were used for validation. The prognostic value of the MVP was verified by scoring immunohistochemical staining of a tissue microarray. High level of MVP was associated with more than 4-fold higher risk for death from prostate cancer (hazard ratio = 4.41, 95% confidence interval: 1.45-13.38; P = 0.009) in a Cox proportional hazard models, adjusted for Cancer of the Prostate Risk Assessments Post-surgical (CAPRA-S) score and perineural invasion. Decision curve analyses suggested an improved standardized net benefit, ranging from 0.06 to 0.18, of adding MVP onto CAPRA-S score. This observation was confirmed by receiver operator characteristics curve analyses for the CAPRA-S score versus CAPRA-S and MVP score (area under the curve: 0.58 versus 0.73). From these analyses, one can infer that MVP levels in combination with CAPRA-S score might add onto established risk parameters to identify patients with lethal prostate cancer.


Subject(s)
Prostatic Neoplasms/genetics , Proteomics , Vault Ribonucleoprotein Particles/genetics , Biomarkers, Tumor/genetics , Fatal Outcome , Gene Expression Regulation, Neoplastic/genetics , Humans , Male , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/mortality , Prostatic Neoplasms/pathology
5.
Eur Urol Open Sci ; 21: 51-60, 2020 Oct.
Article in English | MEDLINE | ID: mdl-34337468

ABSTRACT

BACKGROUND: More accurate risk assessments are needed to improve prostate cancer management. OBJECTIVE: To identify blood-based protein biomarkers that provided prognostic information for risk stratification. DESIGN SETTING AND PARTICIPANTS: Mass spectrometry was used to identify biomarker candidates from blood, and validation studies were performed in four independent cohorts retrospectively collected between 1988 and 2015. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome objectives were progression-free survival, prostate cancer-specific survival (PCSS), and overall survival. Statistical analyses to assess survival and model performance were performed. RESULTS AND LIMITATION: Serum leucine-rich α-2-glycoprotein 1 (LRG1) was found to be elevated in fatal prostate cancer. LRG1 provided prognostic information independent of metastasis and increased the accuracy in predicting PCSS, particularly in the first 3 yr. A high LRG1 level is associated with an average of two-fold higher risk of disease-progression and mortality in both high-risk and metastatic patients. However, our study design, with a retrospective analysis of samples spanning several decades back, limits the assessment of the clinical utility of LRG1 in today's clinical practice. Thus, independent prospective studies are needed to establish LRG1 as a clinically useful biomarker for patient management. CONCLUSIONS: High blood levels of LRG1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer, and LRG1 increased the accuracy of risk stratification of prostate cancer patients. PATIENT SUMMARY: High blood levels of leucine-rich α-2-glycoprotein 1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer.

6.
Int J Cancer ; 146(1): 223-235, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31444972

ABSTRACT

Angiogenesis is necessary for tumor growth and has been targeted in breast cancer; however, it is unclear which patients will respond and benefit from antiangiogenic therapy. We report noninvasive monitoring of patient response to neoadjuvant chemotherapy given alone or in combination with anti-vascular endothelial growth factor (bevacizumab) in a randomized clinical trial. At four time points during neoadjuvant chemotherapy ± bevacizumab of receptor tyrosine-protein kinase erbB-2-negative breast cancers, we measured metabolites and inflammation-related markers in patient's serum. We report significant changes in the levels of several molecules induced by bevacizumab, the most prominent being an increase in pentraxin 3 (PTX3) and von Willebrand factor (VWF). Serum levels of AXL, VWF and pulmonary and activation-regulated cytokine (PARC/CCL18) reflected response to chemotherapy alone or in combination with bevacizumab. We further analyzed serum cytokines in relation to tumor characteristics such as gene expression, tumor metabolites and tumor infiltrating leukocytes. We found that VWF and growth-differentiation factor 15 tumor mRNA levels correlated with their respective serum protein levels suggesting that these cytokines may be produced by tumors and outflow to the bloodstream while influencing the tumor microenvironment locally. Finally, we used binomial logistic regression which allowed to predict patient's response using only 10 noninvasive biomarkers. Our study highlights the potential of monitoring circulating levels of cytokines and metabolites during breast cancer therapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/therapeutic use , Breast Neoplasms/drug therapy , Chemotherapy, Adjuvant , Inflammation Mediators/blood , Bevacizumab/administration & dosage , Biomarkers/metabolism , Breast Neoplasms/blood , Cytokines/blood , Female , Humans , Middle Aged , Neoadjuvant Therapy
7.
BMC Cancer ; 18(1): 739, 2018 Jul 13.
Article in English | MEDLINE | ID: mdl-30005623

ABSTRACT

BACKGROUND: The development of both chronic obstructive pulmonary disease (COPD) and lung cancer (LC) is influenced by smoking related chronic pulmonary inflammation caused by an excessive innate immune response to smoke exposure. In addition, the smoking induced formation of covalent bonds between the carcinogens and DNA and the accumulation of permanent somatic mutations in critical genes are important in the carcinogenic processes, and can also induce inflammatory responses. How chronic inflammation is mirrored by serum markers in COPD and LC and if these markers reflect prognosis in patients with LC is, however, largely unknown. METHODS: Serum levels of 18 markers reflecting inflammation, endothelial activation and extracellular matrix remodelling were analysed in 207 patients with non-small lung carcinoma (NSCLC) before surgery and 42 COPD patients. 56% of the LC patients also suffered from COPD. The serum samples were analysed by enzyme immunoassays. RESULTS: Serum levels of OPG, PTX3, AXL, ALCAM, sCD163, CD147, CatS and DLL1 were significantly higher in patients with COPD as compared to patients with LC. High sTNFR1 levels were associated with improved progression free survival (PFS) and overall survival (OS) in LC patients with (PFS hazard ratio (HR) 0.49, OS HR 0.33) and without COPD (OS HR 0.30). High levels of OPG were associated with improved PFS (HR 0.17) and OS (HR 0.14) for LC with COPD. CRP was significantly associated with overall survival regardless of COPD status. CONCLUSION: Several markers reflecting inflammation, endothelial activation and extracellular matrix remodelling are elevated in serum from patients with COPD compared to LC patients. Presence of COPD might influence the levels of circulating biomarkers. Some of these markers are also associated with prognosis.


Subject(s)
Endothelium, Vascular/physiology , Extracellular Matrix/physiology , Inflammation/complications , Lung Neoplasms/etiology , Pulmonary Disease, Chronic Obstructive/etiology , Adult , Aged , Biomarkers/blood , Female , Humans , Lung Neoplasms/blood , Lung Neoplasms/mortality , Male , Middle Aged , Prognosis , Pulmonary Disease, Chronic Obstructive/blood , Pulmonary Disease, Chronic Obstructive/mortality
9.
Br J Cancer ; 117(11): 1656-1664, 2017 Nov 21.
Article in English | MEDLINE | ID: mdl-28972967

ABSTRACT

BACKGROUND: Robust biomarkers that identify prostate cancer patients with high risk of recurrence will improve personalised cancer care. In this study, we investigated whether tissue metabolites detectable by high-resolution magic angle spinning magnetic resonance spectroscopy (HR-MAS MRS) were associated with recurrence following radical prostatectomy. METHODS: We performed a retrospective ex vivo study using HR-MAS MRS on tissue samples from 110 radical prostatectomy specimens obtained from three different Norwegian cohorts collected between 2002 and 2010. At the time of analysis, 50 patients had experienced prostate cancer recurrence. Associations between metabolites, clinicopathological variables, and recurrence-free survival were evaluated using Cox proportional hazards regression modelling, Kaplan-Meier survival analyses and concordance index (C-index). RESULTS: High intratumoural spermine and citrate concentrations were associated with longer recurrence-free survival, whereas high (total-choline+creatine)/spermine (tChoCre/Spm) and higher (total-choline+creatine)/citrate (tChoCre/Cit) ratios were associated with shorter time to recurrence. Spermine concentration and tChoCre/Spm were independently associated with recurrence in multivariate Cox proportional hazards modelling after adjusting for clinically relevant risk factors (C-index: 0.769; HR: 0.72; P=0.016 and C-index: 0.765; HR: 1.43; P=0.014, respectively). CONCLUSIONS: Spermine concentration and tChoCre/Spm ratio in prostatectomy specimens were independent prognostic markers of recurrence. These metabolites can be noninvasively measured in vivo and may thus offer predictive value to establish preoperative risk assessment nomograms.


Subject(s)
Neoplasm Recurrence, Local/metabolism , Prostatectomy , Prostatic Neoplasms/metabolism , Aged , Biomarkers, Tumor , Citric Acid/metabolism , Humans , Magnetic Resonance Spectroscopy , Male , Middle Aged , Neoplasm Recurrence, Local/diagnosis , Proportional Hazards Models , Prostatic Neoplasms/mortality , Prostatic Neoplasms/pathology , Prostatic Neoplasms/surgery , Retrospective Studies , Spermine/metabolism
10.
Clin Nutr ; 36(3): 672-679, 2017 06.
Article in English | MEDLINE | ID: mdl-27406859

ABSTRACT

BACKGROUND & AIMS: The effect of lycopene-containing foods in prostate cancer development remains undetermined. We tested whether a lycopene-rich tomato intervention could reduce the levels of prostate specific antigen (PSA) in prostate cancer patients. METHODS: Prior to their curative treatment, 79 patients with prostate cancer were randomized to a nutritional intervention with either 1) tomato products containing 30 mg lycopene per day; 2) tomato products plus selenium, omega-3 fatty acids, soy isoflavones, grape/pomegranate juice, and green/black tea (tomato-plus); or 3) control diet for 3 weeks. RESULTS: The main analysis, which included patients in all risk categories, did not reveal differences in changes of PSA-values between the intervention and control groups. Post-hoc, exploratory analyses within intermediate risk (n = 41) patients based on tumor classification and Gleason score post-surgery, revealed that median PSA decreased significantly in the tomato group as compared to controls (-2.9% and +6.5% respectively, p = 0.016). In separate post-hoc analyses, we observed that median PSA-values decreased by 1% in patients with the highest increases in plasma lycopene, selenium and C20:5 n-3 fatty acid, compared to an 8.5% increase in the patients with the lowest increase in lycopene, selenium and C20:5 n-3 fatty acid (p = 0.003). Also, PSA decreased in patients with the highest increase in lycopene alone (p = 0.009). CONCLUSIONS: Three week nutritional interventions with tomato-products alone or in combination with selenium and n-3 fatty acids lower PSA in patients with non-metastatic prostate cancer. Our observation suggests that the effect may depend on both aggressiveness of the disease and the blood levels of lycopene, selenium and omega-3 fatty acids.


Subject(s)
Carotenoids/administration & dosage , Prostate-Specific Antigen/blood , Prostatic Neoplasms/blood , Prostatic Neoplasms/diet therapy , Solanum lycopersicum/chemistry , Aged , Carotenoids/blood , Diet , Fatty Acids, Omega-3/administration & dosage , Fatty Acids, Omega-3/blood , Fruit and Vegetable Juices , Humans , Isoflavones/administration & dosage , Lycopene , Lythraceae/chemistry , Male , Middle Aged , Selenium/administration & dosage , Selenium/blood , Glycine max/chemistry , Vitis/chemistry
11.
Br J Nutr ; 108(12): 2138-47, 2012 Dec 28.
Article in English | MEDLINE | ID: mdl-22397815

ABSTRACT

Nutritionally relevant levels of genistein, the predominant isoflavone in soyabean associated with lower risk of prostate cancer (PCa), may modulate the expression of prostate tissue biomarkers associated with cancer prediction and progression. A phase 2 placebo-controlled, randomised, double-blind clinical trial was conducted in forty-seven Norwegian patients before prostatectomy. Intervention was 30 mg genistein or placebo capsules daily for 3-6 weeks. Luminal cells from malignant and benign glands were isolated with laser capture microdissection and the mRNA levels of androgen-related biomarkers (androgen receptor, NK3 homeobox 1, kallikrein-related peptide 4 (KLK4)) and cell cycle-related genes (p21 Waf1/Cip1 , p27 Kip1 , p53) were analysed with real-time semiquantitative PCR. Immunohistochemistry of androgen-, cell cycle-, proliferative- (Ki67 nuclear antigen), apoptotic- (B-cell CLL/lymphoma 2 (BCL-2) and BCL-2-associated X protein) and neuroendocrine differentiation-related biomarkers (neuron-specific enolase and cytoplasmic chromogranin A) was performed using tissue microarrays containing normal, Gleason grade 3 and grade 4 prostate tissues. There were no significant effects by genistein intervention on proliferation-, cell cycle-, apoptosis- or neuroendocrine biomarkers. Genistein intervention, however, significantly reduced the mRNA level of KLK4 in tumour cells (P = 0·033) and there was a non-significant reduction in androgen and cell cycle-related biomarkers, except for p27Kip1, whose expression in the nuclear compartment was increased. Genistein intervention modulated the expression of several biomarkers which may be related to PCa prediction and progression. The present study supports genistein as a chemopreventive agent in PCa. Further investigation is warranted in larger and longer-duration studies.


Subject(s)
Biomarkers, Tumor/analysis , Genistein/administration & dosage , Prostatic Neoplasms/chemistry , Prostatic Neoplasms/surgery , Androgens/genetics , Anticarcinogenic Agents , Apoptosis/genetics , Biomarkers, Tumor/genetics , Cell Cycle/genetics , Cell Proliferation , Double-Blind Method , Gene Expression/drug effects , Humans , Kallikreins/genetics , Male , Norway , Placebos , Prostate/pathology , Prostatectomy , Prostatic Neoplasms/pathology , RNA, Messenger/analysis , Receptors, Androgen/genetics , Tissue Array Analysis
12.
Nutr Cancer ; 63(6): 889-98, 2011.
Article in English | MEDLINE | ID: mdl-21714686

ABSTRACT

We conducted a placebo-controlled, block-randomized double-blind Phase 2 study to examine the effect of 30 mg synthetic genistein daily on serum and tissue biomarkers in patients with localized prostate cancer (CaP). Fifty-four study subjects were recruited and randomized to treatment with genistein (n = 23) or placebo (n = 24) for 3 to 6 wk prior to prostatectomy. Seven study subjects were noncompliant to the study protocol. Adverse events were few and mild. Serum prostate specific antigen (PSA) decreased by 7.8% in the genistein arm and increased by 4.4% in the placebo arm (P = 0.051). The PSA level was reduced in tumor tissue compared to normal tissue in the placebo arm. In the genistein arm, the PSA level in tumor and normal tissue was comparable. Total cholesterol was significantly lower in the genistein arm (P = 0.013). There were no significant effects on thyroid or sex hormones. Plasma concentrations of total genistein were on average 100-fold higher in the genistein arm after treatment (P < 0.001). Genistein at a dose that can be easily obtained from a diet rich in soy reduced the level of serum PSA in patients with localized CaP, without any effects on hormones. It was well tolerated and had a beneficial effect on blood cholesterol.


Subject(s)
Genistein/therapeutic use , Phytotherapy , Plant Extracts/therapeutic use , Prostatectomy , Prostatic Neoplasms/drug therapy , Biomarkers/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Diet , Double-Blind Method , Endpoint Determination , Genistein/blood , Humans , Immunohistochemistry , Male , Middle Aged , Prostatic Neoplasms/surgery , Glycine max/chemistry , Thyrotropin/blood
13.
Scand J Urol Nephrol ; 44(2): 76-83, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20059407

ABSTRACT

OBJECTIVE: To explore the use of two-dimensional gel electrophoresis (2DE) for analysing the proteome of clinically relevant tissue samples such as biopsies from transurethral resections of the bladder (TURB), by generating a Ta proteome map, possibly identifying technical or biological artefacts, and searching for biological subgroups associated with clinical data. MATERIAL AND METHODS: Biopsies from 23 patients were homogenized and the protein content was separated by 2DE. The gels were silver stained and scanned, and the resulting pictures were analysed for similarities in the spot pattern. RESULTS: A majority of 18 patients displayed a consistent protein expression profile and a Ta proteome map was constructed by averaging the grey value of each pixel in all 18 pictures. Spot detection was performed on a project proteome map (based on all 23 samples) and resulted in 1583 detected spots. 416 of these which were positively detected in all 18 "Ta-map" samples. Three patients displayed a pattern with some marked alterations to the majority profile, possibly artefacts of yet unknown heredity. One patient revealed a protein pattern deemed to constitute a separate group, later revealed as a blinded control from a T4 tumour. Only one sample was sparse in protein spots, probably containing mostly blood owing to inadequate sampling. No biological subgroups associated with clinical data were identified. CONCLUSIONS: A Ta proteome map was successfully created from TURB samples. Deviating protein expression profiles were identified, indicating a future potential to reveal biologically relevant subgroups in this or other stages of urothelial cell carcinomas.


Subject(s)
Proteomics , Urinary Bladder Neoplasms/genetics , Aged , Aged, 80 and over , Electrophoresis, Gel, Two-Dimensional , Female , Humans , Male , Middle Aged , Neoplasm Staging , Urinary Bladder Neoplasms/pathology
14.
J Biol Chem ; 278(29): 26750-6, 2003 Jul 18.
Article in English | MEDLINE | ID: mdl-12740381

ABSTRACT

Protein kinase A (PKA)-anchoring protein AKAP95 is localized to the nucleus in interphase, where it primarily associates with the nuclear matrix. A yeast two-hybrid screen for AKAP95 interaction partners identified the minichromosome maintenance (MCM) 2 protein, a component of the pre-replication complex. AKAP95-MCM2 interaction was mapped to residues 1-195 of AKAP95 and corroborated by glutathione S-transferase precipitation and immunoprecipitation from chromatin. Disruption of AKAP95-MCM2 interaction with an AKAP95-(1-195) peptide within HeLa cell nuclei abolishes initiation of DNA replication in G1 phase and the elongation phase of replication in vitro without affecting global nuclear organization or import. Disruption of the C-terminal zinc finger of AKAP95 reduces efficiency of replication initiation. Disruption of the PKA-binding domain does not impair replication in G1- or S-phase nuclei, whereas a PKA inhibitor affects the initiation but not the elongation phase of replication. Depleting AKAP95 from nuclei partially depletes MCM2 and abolishes replication. Recombinant AKAP95 restores intranuclear MCM2 and replication in a dose-dependent manner. Our results suggest a role of AKAP95 in DNA replication by providing a scaffold for MCM2.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , DNA Replication/physiology , DNA-Binding Proteins/metabolism , Nuclear Proteins/metabolism , Binding Sites , Cell Nucleus/metabolism , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , DNA-Binding Proteins/chemistry , Enzyme Inhibitors/pharmacology , G1 Phase , HeLa Cells , Humans , In Vitro Techniques , Intracellular Signaling Peptides and Proteins , Minichromosome Maintenance Complex Component 2 , Nuclear Proteins/chemistry , Protein Structure, Tertiary , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Two-Hybrid System Techniques
15.
EMBO Rep ; 3(5): 426-32, 2002 May.
Article in English | MEDLINE | ID: mdl-11964380

ABSTRACT

A-kinase (or PKA)-anchoring protein AKAP95 is a zinc-finger protein implicated in mitotic chromosome condensation by acting as a targeting molecule for the condensin complex. We have identified determinants of chromatin-binding, condensin-targeting and chromosome-condensation activities of AKAP95. Binding of AKAP95 to chromatin is conferred by residues 387-450 and requires zinc finger ZF1. Residues 525-569 are essential for condensation of AKAP95-free chromatin and condensin recruitment to chromosomes. Mutation of either zinc finger of AKAP95 abolishes condensation. However, ZF1 is dispensable for condensin targeting, whereas the C-terminal ZF2 is required. AKAP95 interacts with Xenopus XCAP-H condensin subunit in vitro and in vivo but not with the human hCAP-D2 subunit. The data illustrate the involvement of overlapping, but distinct, domains of AKAP95 for condensin recruitment and chromosome condensation and argue for a key role of ZF1 in chromosome condensation and ZF2 in condensin targeting. Moreover, condensin recruitment to chromatin is not sufficient to promote condensation.


Subject(s)
Adenosine Triphosphatases/metabolism , Chromosomes/metabolism , DNA-Binding Proteins/metabolism , Nuclear Proteins/metabolism , Animals , DNA-Binding Proteins/genetics , HeLa Cells , Humans , Intracellular Signaling Peptides and Proteins , Multiprotein Complexes , Mutation , Nuclear Proteins/genetics , Protein Structure, Tertiary , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Analysis, Protein , Sequence Deletion , Xenopus
16.
J Biol Chem ; 277(25): 22902-8, 2002 Jun 21.
Article in English | MEDLINE | ID: mdl-11943768

ABSTRACT

We have reported recently that mice overexpressing the forkhead/winged helix transcription factor FOXC2 are lean and show increased responsiveness to insulin due to sensitization of the beta-adrenergic cAMP-PKA(+) pathway and increased levels of the RI alpha subunit of cAMP-dependent protein kinase (PKA) (Cederberg, A., Grønning, L. M., Ahren, B., Taskén, K., Carlsson, P., and Enerbäck, S. (2001) Cell 106, 563-573). In this present study, we reveal that FOXC2 and a related factor, FOXD1, specifically activate the 1b promoter of the RI alpha gene in adipocytes and testicular Sertoli cells, respectively. By deletional mapping, we discovered two different mechanisms by which the Fox proteins activated expression from the RI alpha 1b promoter. In 3T3-L1 adipocytes, an upstream region represses promoter activity under basal conditions. Bandshift experiments indicate that overexpression of FOXC2 promotes the release of a potential repressor from this region. In Sertoli cells, sequences downstream of the transcription start sites mediate the activating effect of FOXD1, and protein kinase B alpha/Akt1 strongly induces this effect. Furthermore, we show that an inactive FOXD1 mutant lowers the cAMP-mediated induction of the RI alpha 1b reporter construct. In summary, winged helix transcription factors of the FOXC/FOXD families function as regulators of the RI alpha subunit of PKA and may integrate hormonal signals acting through protein kinase B and cAMP in a cell-specific manner.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Enzymologic , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins , Transcription Factors/metabolism , 3T3 Cells , Animals , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/chemistry , Enzyme Activation , Forkhead Transcription Factors , Genes, Reporter , Immunoblotting , Luciferases/metabolism , Male , Mice , Microscopy, Fluorescence , Models, Biological , Plasmids/metabolism , Promoter Regions, Genetic , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Protein Structure, Tertiary , Proto-Oncogene Proteins c-akt , Rats , Rats, Sprague-Dawley , Sertoli Cells/metabolism , Signal Transduction , Transfection
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