Interferon signaling promotes tolerance to chromosomal instability during metastatic evolution in renal cancer

Molecular routes to metastatic dissemination are critical determinants of aggressive cancers. Through in vivo CRISPR-Cas9 genome editing, we generated somatic mosaic genetically engineered models that faithfully recapitulate metastatic renal tumors. Disruption of 9p21 locus is an evolutionary driver to systemic disease through the rapid acquisition of complex karyotypes in cancer cells. Cross-species analysis revealed that recurrent patterns of copy number variations, including 21q loss and dysregulation of the interferon pathway, are major drivers of metastatic potential. In vitro and in vivo genomic engineering, leveraging loss-of-function studies, along with a model of partial trisomy of chromosome 21q, demonstrated a dosage-dependent effect of the interferon receptor genes cluster as an adaptive mechanism to deleterious chromosomal instability in metastatic progression. This work provides critical knowledge on drivers of renal cell carcinoma progression and defines the primary role of interferon signaling in constraining the propagation of aneuploid clones in cancer evolution.

Loss of ARID1A Promotes Epithelial-Mesenchymal Transition and Sensitizes Pancreatic Tumors to Proteotoxic Stress

Cellular dedifferentiation is a key mechanism driving cancer progression. Acquisition of mesenchymal features has been associated with drug resistance, poor prognosis, and disease relapse in many tumor types. Therefore, successful targeting of tumors harboring these characteristics is a priority in oncology practice. The SWItch/Sucrose non-fermentable (SWI/SNF) chromatin remodeling complex has also emerged as a critical player in tumor progression, leading to the identification of several SWI/SNF complex genes as potential disease biomarkers and targets of anticancer therapies. AT-rich interaction domain-containing protein 1A (ARID1A) is a component of SWI/SNF, and mutations in ARID1A represent one of the most frequent molecular alterations in human cancers. ARID1A mutations occur in approximately 10% of pancreatic ductal adenocarcinomas (PDAC), but whether these mutations confer a therapeutic opportunity remains unclear. Here, we demonstrate that loss of ARID1A promotes an epithelial-mesenchymal transition (EMT) phenotype and sensitizes PDAC cells to a clinical inhibitor of HSP90, NVP-AUY922, both in vitro and in vivo. Although loss of ARID1A alone did not significantly affect proliferative potential or rate of apoptosis, ARID1A-deficient cells were sensitized to HSP90 inhibition, potentially by promoting the degradation of intermediate filaments driving EMT, resulting in cell death. Our results describe a mechanistic link between ARID1A defects and a quasi-mesenchymal phenotype, suggesting that deleterious mutations in ARID1A associated with protein loss exhibit potential as a biomarker for patients with PDAC who may benefit by HSP90-targeting drugs treatment. SIGNIFICANCE: This study identifies ARID1A loss as a promising biomarker for the identification of PDAC tumors that are potentially responsive to treatment with proteotoxic agents.

Allosteric SHP2 Inhibitor, IACS-13909, Overcomes EGFR-Dependent and EGFR-Independent Resistance Mechanisms toward Osimertinib

Src homology 2 domain-containing phosphatase (SHP2) is a phosphatase that mediates signaling downstream of multiple receptor tyrosine kinases (RTK) and is required for full activation of the MAPK pathway. SHP2 inhibition has demonstrated tumor growth inhibition in RTK-activated cancers in preclinical studies. The long-term effectiveness of tyrosine kinase inhibitors such as the EGFR inhibitor (EGFRi), osimertinib, in non-small cell lung cancer (NSCLC) is limited by acquired resistance. Multiple clinically identified mechanisms underlie resistance to osimertinib, including mutations in EGFR that preclude drug binding as well as EGFR-independent activation of the MAPK pathway through alternate RTK (RTK-bypass). It has also been noted that frequently a tumor from a single patient harbors more than one resistance mechanism, and the plasticity between multiple resistance mechanisms could restrict the effectiveness of therapies targeting a single node of the oncogenic signaling network. Here, we report the discovery of IACS-13909, a specific and potent allosteric inhibitor of SHP2, that suppresses signaling through the MAPK pathway. IACS-13909 potently impeded proliferation of tumors harboring a broad spectrum of activated RTKs as the oncogenic driver. In EGFR-mutant osimertinib-resistant NSCLC models with EGFR-dependent and EGFR-independent resistance mechanisms, IACS-13909, administered as a single agent or in combination with osimertinib, potently suppressed tumor cell proliferation in vitro and caused tumor regression in vivo. Together, our findings provide preclinical evidence for using a SHP2 inhibitor as a therapeutic strategy in acquired EGFRi-resistant NSCLC. SIGNIFICANCE: These findings highlight the discovery of IACS-13909 as a potent, selective inhibitor of SHP2 with drug-like properties, and targeting SHP2 may serve as a therapeutic strategy to overcome tumor resistance to osimertinib.

pyNBS: a Python implementation for network-based stratification of tumor mutations

Summary

We present pyNBS: a modularized Python 2.7 implementation of the network-based stratification (NBS) algorithm for stratifying tumor somatic mutation profiles into molecularly and clinically relevant subtypes. In addition to release of the software, we benchmark its key parameters and provide a compact cancer reference network that increases the significance of tumor stratification using the NBS algorithm. The structure of the code exposes key steps of the algorithm to foster further collaborative development.

Availability and implementation

The package, along with examples and data, can be downloaded and installed from the URL https://github.com/idekerlab/pyNBS.

Predictive Signatures Inform the Effective Repurposing of Decitabine to Treat KRAS-Dependent Pancreatic Ductal Adenocarcinoma

Mutated KRAS protein is a pivotal tumor driver in pancreatic cancer. However, despite comprehensive efforts, effective therapeutics that can target oncogenic KRAS are still under investigation or awaiting clinical approval. Using a specific KRAS-dependent gene signature, we implemented a computer-assisted inspection of a drug-gene network to in silico repurpose drugs that work like inhibitors of oncogenic KRAS. We identified and validated decitabine, an FDA-approved drug, as a potent inhibitor of growth in pancreatic cancer cells and patient-derived xenograft models that showed KRAS dependency. Mechanistically, decitabine efficacy was linked to KRAS-driven dependency on nucleotide metabolism and its ability to specifically impair pyrimidine biosynthesis in KRAS-dependent tumors cells. These findings also showed that gene signatures related to KRAS dependency might be prospectively used to inform on decitabine sensitivity in a selected subset of patients with KRAS-mutated pancreatic cancer. Overall, the repurposing of decitabine emerged as an intriguing option for treating pancreatic tumors that are addicted to mutant KRAS, thus offering opportunities for improving the arsenal of therapeutics for this extremely deadly disease. SIGNIFICANCE: Decitabine is a promising drug for cancer cells dependent on RAS signaling.

[A follow-up study on the clinical characteristics among patients with diabetes mellitus combined with acute myocardial infarction]

Objective: To investigate the clinical characteristics of diabetic patients combined with acute myocardial infarction (AMI) and to compare the prognosis between diabetic and non- diabetic patients in 4-5 years after the onset of AMI. Methods: Followed the certain inclusive and exclusive criteria, a total of 420 patients with acute myocardial infarction were included and divided into diabetes group (group D) and non-diabetes group (group N) with numbers as 161 people and 259 respectively. Baseline data, clinical information, short-term outcome and long-term prognosis of the two groups were compared and analyzed. Results: Among the patients with diabetes, the average age was older (65.65±11.33 vs. 63.30±15.34), with fewer males (64.59% vs. 79.92%); and more likely to have other complications as hypertension (64.60% vs. 53.28%) or hyperlipidemia (42.24% vs. 26.25%). 59.29% of the patients in group D showed pathological changes in 3 major coronary arteries, which were significantly more than its counterpart (40.83%). The proportion of patients that had undergone the coronary artery bypass, grafting (11.11% vs. 5.31%) appeared also higher. There was no significant difference seen in the short-term outcomes between the two groups, but results from the long-term follow-up program showed that both the incidence of Major Adverse Cardiovascular Events (MACE) (50.67% vs. 27.72%) and the all-cause mortality (20.00% vs. 9.90%) in group D were higher than those appeared in group N (27.72%). Conclusions: Patients suffered from the combination of both diabetes and acute myocardial infarction appeared older in age, more in females, with more complications and the coronary artery lesions were more severe and wider. During hospitalization, no significant difference was seen regarding the short-term outcomes between the two groups but the results from long-term follow-up process showing that the risk of MACE events was significantly higher in patients with type2 diabetes.

A Fast and Flexible Framework for Network-Assisted Genomic Association

We present an accessible, fast, and customizable network propagation system for pathway boosting and interpretation of genome-wide association studies. This system-NAGA (Network Assisted Genomic Association)-taps the NDEx biological network resource to gain access to thousands of protein networks and select those most relevant and performative for a specific association study. The method works efficiently, completing genome-wide analysis in under 5 minutes on a modern laptop computer. We show that NAGA recovers many known disease genes from analysis of schizophrenia genetic data, and it substantially boosts associations with previously unappreciated genes such as amyloid beta precursor. On this and seven other gene-disease association tasks, NAGA outperforms conventional approaches in recovery of known disease genes and replicability of results. Protein interactions associated with disease are visualized and annotated in Cytoscape, which, in addition to standard programmatic interfaces, allows for downstream analysis.

Genomic Landscape of Appendiceal Neoplasms

Purpose

Appendiceal neoplasms are heterogeneous and are often treated with chemotherapy similarly to colorectal cancer (CRC). Genomic profiling was performed on 703 appendiceal cancer specimens to compare the mutation profiles of appendiceal subtypes to CRC and other cancers, with the ultimate aim to identify potential biomarkers and novel therapeutic targets.

Methods

Tumor specimens were submitted to a Clinical Laboratory Improvement Amendments-certified laboratory (Foundation Medicine, Cambridge, MA) for hybrid-capture-based sequencing of 3,769 exons from 315 cancer-related genes and 47 introns of 28 genes commonly rearranged in cancer. Interactions between genotype, histologic subtype, treatment, and overall survival (OS) were analyzed in a clinically annotated subset of 76 cases.

Results

There were five major histopathologic subtypes: mucinous adenocarcinomas (46%), adenocarcinomas (30%), goblet cell carcinoids (12%), pseudomyxoma peritonei (7.7%), and signet ring cell carcinomas (5.2%). KRAS (35% to 81%) and GNAS (8% to 72%) were the most frequent alterations in epithelial cancers; APC and TP53 mutations were significantly less frequent in appendiceal cancers relative to CRC. Low-grade and high-grade tumors were enriched for GNAS and TP53 mutations, respectively (both χ² P < .001). GNAS and TP53 were mutually exclusive (Bonferroni corrected P < .001). Tumor grade and TP53 mutation status independently predicted OS. The mutation status of GNAS and TP53 strongly predicted OS (median, 37.1 months for TP53 mutant v 75.8 GNAS-TP53 wild type v 115.5 GNAS mutant; log-rank P = .0031) and performed as well as grade in risk stratifying patients.

Conclusion

Epithelial appendiceal cancers and goblet cell carcinoids show differences in KRAS and GNAS mutation frequencies and have mutation profiles distinct from CRC. This study highlights the benefit of performing molecular profiling on rare tumors to identify prognostic and predictive biomarkers and new therapeutic targets.

Abstract 1310: Systematic evaluation of gene networks for discovery of disease genes

Gene networks are rapidly growing in size and number, raising the question of which networks are most appropriate for a particular application. Here, we evaluate 21 human genome-wide interaction networks for their ability to recover gene sets associated with 446 different diseases and 9 cancer hallmarks. While all networks have some ability in these recovery tasks, we observe a wide range of performance with STRING, GeneMANIA and GIANT networks having the best performance overall. A general tendency is that performance scales with network size, suggesting that new interaction discovery currently outweighs the detrimental effects of false positives. Correcting for size, we find that the DIP network provides the highest efficiency (value per interaction). Based on these results we create a parsimonious composite network with both high efficiency and absolute performance, which outperforms any single resource. This work provides a benchmark for selection of molecular networks in human disease research.

Citation Format: Justin K. Huang, Daniel E. Carlin, Michael K. Yu, Wei Zhang, Jason F. Kreisberg, Pablo Tamayo, Trey Ideker. Systematic evaluation of gene networks for discovery of disease genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1310.

Disruption of NSD1 in Head and Neck Cancer Promotes Favorable Chemotherapeutic Responses Linked to Hypomethylation

Human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) represents a distinct classification of cancer with worse expected outcomes. Of the 11 genes recurrently mutated in HNSCC, we identify a singular and substantial survival advantage for mutations in the gene encoding Nuclear Set Domain Containing Protein 1 (NSD1), a histone methyltransferase altered in approximately 10% of patients. This effect, a 55% decrease in risk of death in NSD1-mutated versus non-mutated patients, can be validated in an independent cohort. NSD1 alterations are strongly associated with widespread genome hypomethylation in the same tumors, to a degree not observed for any other mutated gene. To address whether NSD1 plays a causal role in these associations, we use CRISPR-Cas9 to disrupt NSD1 in HNSCC cell lines and find that this leads to substantial CpG hypomethylation and sensitivity to cisplatin, a standard chemotherapy in head and neck cancer, with a 40% to 50% decrease in the IC₅₀ value. Such results are reinforced by a survey of 1,001 cancer cell lines, in which loss-of-function NSD1 mutations have an average 23% decrease in cisplatin IC₅₀ value compared with cell lines with wild-type NSD1Significance: This study identifies a favorable subtype of HPV-negative HNSCC linked to NSD1 mutation, hypomethylation, and cisplatin sensitivity. Mol Cancer Ther; 17(7); 1585-94. ©2018 AACR.

Econazole induces increases in free intracellular Ca2+ concentrations in human osteosarcoma cells

Econazole is an antifungal drug with different in vitro effects. However, econazole's effect on osteoblast like cells is unknown. In human MG63 osteosarcoma cells, the effect of econazole on intracellular Ca2+ concentrations ([Ca2+]i) was explored by using fura-2. At a concentration of 0.1 μM, econazole started to cause a rise in [Ca2+]i in a concentration-dependent manner. Econazole-induced [Ca2+]i rise was reduced by 74% by removal of extracellular Ca2+. The econazole-induced Ca2+ influx was mediated via a nimodipine-sensitive pathway. In Ca2+ free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+ ATPase, caused a [Ca2+]i rise, after which the increasing effect of econazole on [Ca2+]i was abolished. Pretreatment of cells with econazole to deplete Ca2+ stores totally prevented thapsigargin from releasing Ca2+. U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate dependent Ca2+ mobilizer)-induced, but not econazoleinduced, [Ca2+]i rise. Econazole inhibited 76% of thapsigargin-induced store-operated Ca2+ entry. These findings suggest that in MG63 osteosarcoma cells, econazole increases [Ca2+]i by stimulating Ca2+ influx and Ca2+ release from the endoplasmic reticulum via a phospholipase C-independent manner. In contrast, econazole acts as a potent blocker of store-operated Ca2+ entry.

ERCC1 and TS Expression as Prognostic and Predictive Biomarkers in Metastatic Colon Cancer

In patients with metastatic colon cancer, response to first line chemotherapy is a strong predictor of overall survival (OS). Currently, oncologists lack diagnostic tests to determine which chemotherapy regimen offers the greatest chance for response in an individual patient. Here we present the results of gene expression analysis for two genes, ERCC1 and TS, measured with the commercially available ResponseDX: Colon assay (Response Genetics, Los Angeles, CA) in 41 patients with de novo metastatic colon cancer diagnosed between July 2008 and August 2013 at the University of California, San Diego. In addition ERCC1 and TS expression levels as determined by RNAseq and survival data for patients in TCGA were downloaded from the TCGA data portal. We found that patients with low expression of ERCC1 (n = 33) had significantly longer median OS (36.0 vs. 10.1 mo, HR 0.29, 95% CI .095 to .84, log-rank p = 9.0x10^-6) and median time to treatment to failure (TTF) following first line chemotherapy (14.1 vs. 2.4 mo, HR 0.17, 95% CI 0.048 to 0.58, log-rank p = 5.3x10^-4) relative to those with high expression (n = 4). After accounting for the covariates age, sex, tumor grade and ECOG performance status in a Cox proportional hazard model the association of low ERCC1 with longer OS (HR 0.18, 95% CI 0.14 to 0.26, p = 0.0448) and TTF (HR 0.16, 95% CI 0.14 to 0.21, p = 0.0053) remained significant. Patients with low TS expression (n = 29) had significantly longer median OS (36.0 vs. 14.8 mo, HR 0.25, 95% CI 0.074 to 0.82, log-rank p = 0.022) relative to those with high expression (n = 12). The combined low expression of ERCC1/TS was predictive of response in patients treated with FOLFOX (40% vs. 91%, RR 2.3, Fisher’s exact test p = 0.03, n = 27), but not with FOLFIRI (71% vs. 71%, RR 1.0, Fisher’s exact test p = 1, n = 14). Overall, these findings suggest that measurement of ERCC1 and TS expression has potential clinical utility in managing patients with metastatic colorectal cancer.

Light extraction efficiency enhancement of GaN-based light emitting diodes on n-GaN layer using a SiO2 photonic quasi-crystal overgrowth

In this paper, GaN-based LEDs with a SiO2 photonic quasi-crystal (PQC) pattern on an n-GaN layer by nano-imprint lithography (NIL) are fabricated and investigated. At a driving current of 20 mA on Transistor Outline (TO)-can package, the better light output power of LED III (d = 1.2 microm) was enhanced by a factor of 1.20. After 1000 h life test (55 degrees C/50 mA) condition, Normalized output power of LED with a SiO2 PQC pattern (LED III (d = 1.2 microm)) on an n-GaN layer only decreased by 5%. This results offer promising potential to enhance the light output power of commercial light-emitting devices using the technique of nano-imprint lithography.

Effect of Celecoxib on Ca2+Fluxes and Proliferation in MDCK Renal Tubular Cells

The effect of celecoxib on renal tubular cells is largely unexplored. In Madin Darby canine kidney (MDCK) cells, the effect of celecoxib on intracellular CaCa2+ concentration ([Ca2+]i) and proliferation was examined by using the Ca(2 +)-sensitive fluorescent dye fura-2 and the viability detecting fluorescent dye tetrazolium, respectively. Celecoxib (> or =1 micro M) caused an increase of [CaCa2+]i in a concentration-dependent manner. Celecoxib-induced [CaCa2+]i increase was partly reduced by removal of extracellular CaCa2+. Celecoxib-induced CaCa2+ influx was independently suggested by MnCa2+ influx-induced fura-2 fluorescence quench. In Ca(2 +)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2 +)-ATPase, caused a monophasic [CaCa2+]i increase, after which celecoxib only induced a tiny [CaCa2+]i increase; conversely, pretreatment with celecoxib completely inhibited thapsigargin-induced [CaCa2+]i increases. U73122, an inhibitor of phospholipase C, abolished ATP (but not celecoxib)-induced [CaCa2+]i increases. Overnight incubation with 1 or 10 micro M celecoxib decreased cell viability by 80% and 100%, respectively. These data indicate that celecoxib evokes a [CaCa2+]i increase in renal tubular cells by stimulating both extracellular CaCa2+ influx and intracellular CaCa2+ release and is highly toxic to renal tubular cells in vitro.

Melittin-induced [Ca2+]i increases and subsequent death in canine renal tubular cells

The effect of melittin on cytosolic free Ca2+ concentration ([Ca2+]i) and viability is largely unknown. This study examined whether melittin alters Ca2+ levels and causes Ca2+-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca2+]i and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Melittin at concentrations above 0.5 μM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 75% by removing extracellular Ca2+. The melittin-induced Ca2+ influx was also implicated by melittin-caused Mn2+ influx. After pretreatment with 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), melittin-induced Ca2+ release was inhibited; and conversely, melittin pretreatment abolished thapsigargin-induced Ca2+ release. At concentrations of 0.5–20 μM, melittin killed cells in a concentration-dependent manner. The cytotoxic effect of 0.5 μM melittin was nearly completely reversed by prechelating cytosolic Ca2+ with BAPTA. Melittin at 0.5–2 μM caused apoptosis as assessed by flow cytometry of propidium iodide staining. Collectively, in MDCK cells, melittin induced a [Ca2+]i rise by causing Ca2+ release from endoplasmic reticulum and Ca2+ influx from extracellular space. Furthermore, melittin can cause Ca2+-dependent cytotoxicity in a concentration-dependent manner.

Leiomyosarcoma in the nasopharynx: MR imaging findings

The MR imaging findings of a leiomyosarcoma arising from the nasopharynx are presented. To our knowledge, this is the first MR imaging description of this entity.

Squeeze maneuver: an easy way to manage radiological contrast-medium extravasation

BACKGROUND

Contrast-medium extravasation injuries may be self-limited to catastrophic. Adequate prophylactic measures are enforced when risk factors for extravasation are present, and prompt treatment can avoid serious complications.

PURPOSE

To describe the squeeze maneuver, an effective method for the treatment of symptomatic contrast-medium extravasation.

MATERIAL AND METHODS

Over a 3-month period, eight patients with >50 ml contrast-medium extravasation resulting in vascular compromise of the fingers were managed with the squeeze maneuver as follows. The intravenous catheter used for contrast-medium injection was removed, and the skin around the insertion site was cleaned with povidone-iodine. An 18-gauge needle was then used to puncture five to eight openings near the catheter insertion site as deeply as possible. We then began squeezing from the periphery of the swelling toward the needle holes. As the contrast medium drained, it was swabbed away with iodine-soaked cotton swabs.

RESULTS

In all eight patients, the maneuver was successful with immediate resolution of the vascular compromise.

CONCLUSION

The squeeze maneuver provides an easy way to manage radiological contrast-medium extravasation and can be performed immediately in the CT suite.

Effect of riluzole on Ca2+ movement and cytotoxicity in Madin-Darby canine kidney cells

Riluzole is a drug used in the treatment of amyotrophic lateral sclerosis; however, its in vitro action is unclear. In this study, the effect of riluzole on intracellular Ca2+ concentration ([Ca2+]i) in Madin-Darby canine kidney (MDCK) cells was investigated using the Ca2+ -sensitive fluorescent dye, fura-2. Riluzole (100-500 microM) caused a rapid and sustained increase of [Ca2+]i in a concentration-dependent manner (EC50 = 150 microM). Some 40 and 50% of this [Ca2+]i increase was prevented by the removal of extracellular Ca2+ and the addition of La3+, respectively, but was unchanged by dihydropyridines, verapamil and diltiazem. In Ca2+ -free medium, thapsigargin - an inhibitor of the endoplasmic reticulum (ER) Caz+ -ATPase--caused a monophasic [Ca2+]i increase, after which the increasing effect of riluzole on [Ca2+]i was attenuated by 70%; in addition, pre-treatment with riluzole abolished thapsigargin-induced [Ca2+]i increases. U73122, an inhibitor of phospholipase C (PLC), abolished ATP (but not riluzole)-induced [Ca2+]i increases. At concentrations of 250 and 500 microM, riluzole killed 40 and 95% cells, respectively. The cytotoxic effect of riluzole (250 microM) was unaltered by pre-chelating cytosolic Ca2+ with BAPTA. Collectively, in MDCK cells, riluzole rapidly increased [Ca2+]i by stimulating extracellular Ca2+ influx via an La3+ -sensitive pathway and intracellular Ca2+ release from the ER via, as yet, unidentified mechanisms. Furthermore, riluzole caused Ca2+ -unrelated cytotoxicity in a concentration-dependent manner.

Spectral karyotyping and fluorescence in situ hybridization analysis of de novo partial trisomy 7p (7p21.2-->pter) and partial monosomy 12q (12q24.33-->qter)

An 8-year-old boy presenting with hypotonia, moderate mental retardation, developmental delay, and psychomotor retardation is reported. Magnetic resonance imaging of the brain at age 3 years revealed a Dandy-Walker variant. Cytogenetic analysis of the peripheral blood revealed a derivative chromosome 12 with unknown additional material attached to the distal region of the long arm of chromosome 12. The parental karyotypes were normal. Spectral karyotyping (SKY) using the 24-color SKY probes and fluorescence in situ hybridization (FISH) using the specific 7p, 7q, 12p, and 12q telomeric probes confirmed a duplication of distal 7p and a deletion of terminal 12q. The karyotype of the proband was designated as 46,XY.ish der(12)t(7;12) (p21.2;q24. 33)(SKY+, 7pTEL+, 12qTEL-). The present case provides evidence for the association of partial trisomy 7p (7p21.2-->pter) and partial monosomy 12q (12q24.33-->qter) with a cerebellar malformation and the usefulness of SKY and FISH in the identification of a de novo aberrant chromosome resulting from an unbalanced translocation.

Direct transmission of the 18q- syndrome from mother to daughter

A 34-year-old mother presented moderate mental retardation, short stature, microcephaly, and characteristic facial dysmorphism. Her 12-year-old daughter manifested moderate mental retardation, short stature, microcephaly, dysplastic external ear canals, hearing impairment, and characteristic facial dysmorphism. Cytogenetic analysis of the family revealed a normal karyotype, 46,XY, in the father, and a 46,XX,del(18)(q22.2) karyotype in both mother and daughter. Molecular marker analysis determined direct transmission of the distal 18q deletion from mother to daughter. The present case provides evidence of fertility of the affected females and a mother-to-daughter direct transmission in the familial 18q- syndrome. Identification of affected females with the 18q- syndrome should include genetic counseling of possible direct transmission and consideration of birth control or prenatal genetic testing at reproductive age.

De novo satellited 21q associated with corpus callosum dysgenesis, colpocephaly, a concealed penis, congenital heart defects, and developmental delay

De novo satellited 21q associated with corpus callosum dysgenesis, colpocephaly, a concealed penis, congenital heart defects, and developmental delay: We present clinical and cytogenetic data on an infant with de novo satellited 21 q. A 3-month-old boy was found to have microcephaly, developmental delay, hypertelorism, down-slanting palpebral fissures, large low-set ears, a prominent nose, a broad philtrum, a concealed penis, interventricular septal defects, corpus callosum dysgenesis, colpocephaly, ventriculomegaly, and a de novo karyotype of 46,XY,21qs. Standard Ag-NOR staining and FISH studies confirmed a satellite and a deletion on the long arm of a chromosome 21. Quantitative-fluorescent polymerase chain reaction using the polymorphic small tandem repeat markers specific for chromosome 21 determined a maternal origin of the deletion and the breakpoint between D21S156 (21q22.1) (present) and D21S53 (21q22.3) (absent), centromeric to the known minimal holoprosencephaly critical region, D21S13-21qter. The present case provides evidence of the correlation of a distal region of chromosome 21 to the phenotypic effects of monosomy 21.

Effect of triethyltin on Ca2+ movement in Madin-Darby canine kidney cells

The effects of the environmental toxicant, triethyltin, on Ca2+ mobilization in Madin-Darby canine kidney (MDCK) cells have been examined. Triethyltin induced an increase in cytosolic free Ca2+ levels ([Ca2+]i) at concentrations larger than 2 microM in a concentration-dependent manner. Within 5 min, the [Ca2+]i signal was composed of a gradual rise and a sustained phase. The [Ca2+]i signal was partly reduced by removing extracellular Ca2+. In Ca(2+)-free medium, pretreatment with thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, reduced 50 microM triethyltin-induced [Ca2+]i increase by 80%. Conversely, pretreatment with triethyltin abolished thapsigargin-induced Ca2+ release. Pretreatment with U73122 (2 microM) to inhibit phospholipase C-coupled inositol 1,4,5-trisphosphate formations failed to alter 50 microM triethyltin-induced Ca2+ release. Incubation with triethyltin at a concentration (1 microM) that did not increase basal [Ca2+]i for 3 min did not alter ATP (10 microM)- and bradykinin (1 microM)-induced [Ca2+]i increases. Collectively, this study shows that triethyltin altered Ca2+ movement in renal tubular cells by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner, and by inducing Ca2+ influx.

Mechanism underlying histamine-induced intracellular Ca2+ movement in PC3 human prostate cancer cells

The effect of histamine on intracellular free Ca2+ levels ([Ca2+]i) in PC3 human prostate cancer cells and the underlying mechanism were evaluated using fura-2 as a Ca2+ dye. Histamine at concentrations between 0.1 and 50 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 1 microM. The [Ca2+]i response comprised an initial rise and a slow decay, which returned to baseline within 3 min. Extracellular Ca2+ removal inhibited 50% of the [Ca2+]i signal. In the absence of extracellular Ca2+, after cells were treated with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), 10 microM histamine did not increase [Ca2+]i. After pretreatment with 10 microM histamine in a Ca2+-free medium for several minutes, addition of 3 mM Ca2+ induced [Ca2+]i increases. Histamine (10 microM)-induced intracellular Ca2+ release was abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3- methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), and by 10 microM pyrilamine but was not altered by 50 microM cimetidine. Collectively, the present study shows that histamine induced [Ca2+]i transients in PC3 human prostate cancer cells by stimulating H1 histamine receptors leading to Ca2+ release from the endoplasmic reticulum in an inositol 1,4,5-trisphosphate-dependent manner, and by inducing Ca2+ entry.

The presynaptic particle web: ultrastructure, composition, dissolution, and reconstitution

We report the purification of a presynaptic "particle web" consisting of approximately 50 nm pyramidally shaped particles interconnected by approximately 100 nm spaced fibrils. This is the "presynaptic grid" described in early EM studies. It is completely soluble above pH 8, but reconstitutes after dialysis against pH 6. Interestingly, reconstituted particles orient and bind PSDs asymmetrically. Mass spectrometry of purified web components reveals major proteins involved in the exocytosis of synaptic vesicles and in membrane retrieval. Our data support the idea that the CNS synaptic junction is organized by transmembrane adhesion molecules interlinked in the synaptic cleft, connected via their intracytoplasmic domains to the presynaptic web on one side and to the postsynaptic density on the other. The CNS synaptic junction may therefore be conceptualized as a complicated macromolecular scaffold that isostatically bridges two closely aligned plasma membranes.

Mechanism of bifonazole-induced [Ca2+]i increases in MDCK renal tubular cells

The effect of the antifungal drug bifonazole on Ca2+ homeostasis in Madin Darby canine kidney (MDCK) cells was investigated. Cell suspensions were loaded with the Ca2+-sensitive dye fura-2, and the fluorescence changes were measured with a spectrofluorophotometer. At concentrations between 10-80 microM bifonazole increased cytosolic free Ca2+ levels ([Ca2+]i) in a concentration-dependent manner. The Ca2+ signals were partly inhibited by removing extracellular Ca2+. Bifonazole (40 microM) released Ca2+ from the store sensitive to 1 microM thapsigargin, an endopolasmic reticulum Ca2+ pump inhibitor. Bifonazole (40 microM) per se induced capacitative Ca2+ entry while reduced 1 microM thapsigargin-induced capacitative Ca2+ entry. Inositol 1,4,5-trisphosphate may be involved in bifonazole-induced Ca2+ release because inhibiting phospholipase C with 2 microM U73122 partly reduced the bifonazole response. Together, bifonazole increased [Ca2+]i in renal tubular cells by inducing intracellular Ca2+ release and extracellular Ca2+ influx.

Fendiline mobilizes intracellular Ca2+ in Chang liver cells

1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.

Dual effect of the antianginal drug fendiline on bladder female transitional carcinoma cells: mobilization of intracellular CA2+ and induction of cell death

The effect of fendiline, an antianginal drug, on cytosolic free Ca2+ levels ([Ca2+]i) in populations of bladder female transitional carcinoma (BFTC) cells was explored using fura-2 as a Ca2+ indicator. Fendiline at concentrations between 3 and 200 micromol/l increased [Ca2+]i in a concentration-dependent manner and the signal saturated at 100 micromol/l. The [Ca2+]i signal was biphasic, with an initial rise and a slow decay. Ca2+ removal inhibited the Ca2+ signal by about half in peak amplitude. Adding 3 mmol/l Ca2+ increased [Ca2+]i in cells pretreated with 100 micromol/l fendiline in Ca2+ -free medium, suggesting that fendiline induced Ca2+ influx via capacitative Ca2+ entry. In Ca2+ -free medium, pretreatment with 1 micromol/l thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete the endoplasmic reticulum Ca2+ store inhibited most of the 100 micromol/l fendiline-induced internal Ca2+ release; and conversely, pretreatment with 100 micromol/l fendiline partly inhibited 1 micromol/l thapsigargin-induced Ca2+ release. This indicates that the major internal Ca2+ store of fendiline-induced [Ca2+]i increases is located in the endoplasmic reticulum. The Ca2+ release induced by 100 micromol/l fendiline may be partly mediated by inositol 1,4,5-trisphosphate, because the [Ca2+]i increase was inhibited by 50% by inhibiting phospholipase C with 2 micromol/l U73122. Fendiline (100 micromol/l) decreased cell viability by 12-44% after being added to cells for 2- 30 min. Together, the findings indicate that in BFTC cells, fendiline exerts a dual effect: mobilization of intracellular Ca2+ and induction of cell death.

Mechanisms of diethylstilbestrol-induced calcium movement in MG63 human osteosarcoma cells

The effect of the estrogen diethylstilbestrol (DES) on cytosolic free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteoblasts was explored by using fura-2 as a Ca(2+) indicator. DES at concentrations between 5--20 microM induced an immediate increase in [Ca(2+)](i) in a concentration-dependent manner with an EC(50) of 10 microM. Removing extracellular Ca(2+) reduced the Ca(2+) signal by 70%. Pretreatment with 50 microM La(3+) or 10 microM of nifedipine, verapamil and diltiazem did not change 20 microM DES-induced [Ca(2+)](i) increases. Addition of 3 mM Ca(2+) increased [Ca(2+)](i) in cells pretreated with 20 microM DES in Ca(2+)-free medium. Pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) to deplete the endoplasmic reticulum Ca(2+) store partly inhibited 20 microM DES-induced Ca(2+) release, but addition of carbonylcyanide m-chlorophenylhydrazone (CCCP; a mitochondrial uncoupler) and thapsigargin together abolished DES-induced Ca(2+) release. Conversely, pretreatment with 20 microM DES abrogated CCCP- and thapsigargin-induced Ca(2+) release. Inhibition of phospholipase C activity with 2 microM U73122 did not alter 20 microM DES-induced Ca2+ release. Another estrogen 17beta-estradiol also increased [Ca(2+)](i) in a concentration-dependent manner with an EC50 of 7 microM. Together, the data indicate that in human osteoblasts, DES increased [Ca(2+)](i) via causing Ca(2+) release from both mitochondria and the endoplasmic reticulum in a phospholipase C-independent manner, and by causing Ca(2+) influx.

Fendiline, an anti-anginal drug, increases intracellular Ca2+ in PC3 human prostate cancer cells

BACKGROUND

The effects of the anti-anginal drug fendiline on intracellular Ca2+ concentrations ([Ca2+]i) in human PC3 prostate cancer cells were examined.

METHODS

[Ca2+]i was measured using the fluorescent dye fura-2.

RESULTS

Fendiline (0.5-100 microM) increased [Ca2+]i in a concentration-dependent manner. Ca2+ removal partly inhibited the Ca2+ signals. In Ca2+-free medium, pretreatment with 100 microM fendiline inhibited most of the [Ca2+]i increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), and pretreatment with thapsigargin abolished the fendiline-induced [Ca2+]i increases. Adding 3 mM Ca2+ increased [Ca2+]i in cells pretreated with 0.5-200 microM fendiline in Ca2+-free medium. Pretreatment with 1 microM U73122 to block the formation of inositol-1.4.5-trisphosphate (IP3) did not alter fendiline-induced internal Ca2+ release.

CONCLUSIONS

The anti-anginal drug fendiline induced internal Ca2+ release and external Ca2+ entry. Because prolonged increases in [Ca2+]i may lead to cell injury and death, the long-term effect of fendiline on the function of prostate cancer cells should be investigated.

Mechanism of estrogens-induced increases in intracellular Ca(2+) in PC3 human prostate cancer cells

BACKGROUND

The effect of estrogens (diethylstilbestrol [DES], 17 beta-estradiol) on intracellular Ca(2+) concentrations ([Ca(2+)](i)) in hormone-insensitive PC3 human prostate cancer cells was examined.

METHODS

[Ca(2+)](i) changes in suspended cells were measured by using the Ca(2+)-sensitive fluorescent dye fura-2.

RESULTS

Estrogens (1--20 microM) increased [Ca(2+)](i) concentration-dependently with DES being more potent. Ca(2+) removal inhibited 50 +/- 10% of the signal. In Ca(2+)-free medium, pretreatment with 20 microM estrogens abolished the [Ca(2+)](i) increases induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP, a mitochondrial uncoupler) and 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), but pretreatment with CCCP and thapsigargin did not alter DES-induced Ca(2+) release and partly inhibited 17 beta-estradiol-induced Ca(2+) release. Addition of 3 mM Ca(2+) increased [Ca(2+)](i) in cells pretreated with 1- 20 microM estrogens in Ca(2+)-free medium. Pretreatment with 1 microM U73122 to block phospholipase C-coupled inositol 1,4,5-trisphosphate formation did not alter estrogens-induced Ca(2+) release. The effect of 20 microM estrogen on [Ca(2+)](i) was not affected by pretreatment with 0.1 microM estrogens.

CONCLUSIONS

Estrogen induced significant Ca(2+) release and Ca(2+) influx in an inositol 1,4,5-trisphosphate-independent manner in PC3 cells. These effects of estrogens on Ca(2+) signaling appear to be nongenomic. Prostate 47:141-148, 2001.

In vitro effect of hyperbaric oxygen on the chemolysis of infective stones

BACKGROUND

In order to extend the feasibility of hyperbaric oxygen therapy in the urological field, the present study aimed to investigate the dissolution activity of human infective stones in UROCITRA solution under hyperbaric oxygen condition.

METHODS

The dissolution activity of 7 struvite and 11 mixed struvite and carbonate apatite stones in UROCITRA solution were studied under 2.5 atmosphere (atm) hyperbaric oxygen (HBO) status in a Sigma I N-124 monoplace chamber. Another 7 struvite and 10 mixed struvite and carbonate apatite stones were also studied under normal condition. Chemolysis was performed in a drip device with a 150-ml/hour continuous flow rate.

RESULTS

Under 2.5 atm HBO status, the PO2 of UROCITRA solution was 365 +/- 44 mmHg, which was significantly higher than that of tap water (113 +/- 62 mmHg) and UROCITRA solution (125 +/- 12 mmHg) under normobaric condition (p < 0.001). The decreases in the stone weight of struvite under normobaric condition were 31 +/- 8.8% after 2 h and 48 +/- 15% after 4 h of treatment. The HBO-enriched UROCITRA solution did not increase the dissolution activity as reflected by comparable decreases in the dried stone weight (31.2 +/- 14.6% and 54 +/- 19% at the 2nd and 4th post-treatment hours, respectively, p > 0.05). Similarly, there was no significant difference in the percent stone weight decrease of the mixed struvite and carbonate apatite stones under either HBO or normobaric condition. The dissolution responsiveness of struvite was significantly greater than that of the mixed struvite and carbonate apatite stones.

CONCLUSIONS

The chemolysis of struvite in UROCITRA solution is significantly greater than that of the mixed struvite and carbonate apatite stones. However, the UROCITRA solution enriched with HBO does not enhance the dissolution of infective stones.

Tamoxifen-induced Ca2+ mobilization in bladder female transitional carcinoma cells

This study examined the effect of tamoxifen, an anti-breast cancer drug, on Ca2+ handling in bladder female transitional cancer cells. Changes in cytosolic free Ca2+ levels were recorded by using the Ca2+-sensitive dye fura-2. In a dose-dependent manner, tamoxifen induced intracellular free Ca2+ concentrations ([Ca2+]i) increases between 5 and 20 microM with an EC50 of 10 microM. External Ca2+ removal reduced the response by 60+/-6%. Addition of 3 mM Ca2+ caused a [Ca2+]i increase after pretreatment with 10 microM tamoxifen in Ca2+-free medium. In Ca2+-free medium, pretreatment with 10 microM tamoxifen abolished the [Ca2+]i increase induced by 1 microM thapsigargin, an endoplasmic reticulum Ca2+ pump inhibitor. Conversely, pretreatment with 1 microM thapsigargin prevented tamoxifen from releasing more Ca2+. Inhibition of phospholipase C-dependent inositol 1,4,5-tris-phosphate formation with 2 microM U73122 did not alter 10 microM tamoxifen-induced Ca2+ release. The [Ca2+]i increase induced by 5 microM tamoxifen was not altered by 10 microM La3+, nifedipine, verapamil, and diltiazem. Collectively, it was found that tamoxifen increased [Ca2+]i in bladder cancer cells by releasing Ca2+ from the endoplasmic reticulum Ca2+ stores in a manner independent of phospholipase C activity, and by inducing Ca2+ entry from external medium.

Organizing principles of the axoglial apparatus

On axonal surfaces that flank the node of Ranvier and in overlying glial paranodal loops, proteins are arranged within circumscribed microdomains that defy explanation by conventional biosynthetic mechanisms. We postulate that the constraint of proteins to these loci is accomplished in part by discriminative membrane-embedded molecular sieves and diffusion barriers, which serve to organize and redistribute proteins after delivery by vesicular transport to neural cell plasma membranes. One sieve likely comprises a moveable, macromolecular scaffold of axonal and glial cell-derived transmembrane adhesion molecules and their associated cytoplasmic binding partners, located at the ends of each elongating myelin internode; this sieve contributes to restricting the sodium channel complexes to the node. We also anticipate the existence of a passive paranodal diffusion barrier at the myelin/noncompact membrane border, which prohibits protein diffusion out of contiguous paranodal membranes.

AM-404 elevates renal intracellular Ca(2+), questioning its selectivity as a pharmacological tool for investigating the anandamide transporter

The effect of N-(4-hydroxyphenyl)-arachidonamide (AM-404), a drug commonly used to inhibit the anandamide transporter, on intracellular free Ca(2+) levels ([Ca(2+)](i)) was studied in Madin Darby canine kidney (MDCK) cells. [Ca(2+)](i) was measured using fura-2 as a Ca(2+) indicator. Between 2 and 40 microM, AM-404 increased [Ca(2+)](i) in a concentration-dependent fashion with an EC(50) value of 20 microM. Removal of extracellular Ca(2+) abolished the [Ca(2+)](i) signals. The [Ca(2+)](i) increase was nearly abrogated by 10 microM La(3+), but was insensitive to 50 microM Ni(2+) and 10 microM of nifedipine, nimodipine, nicardipine, and verapamil. At a concentration that did not increase [Ca(2+)](i), AM-404 (1 microM) did not alter the [Ca(2+)](i) increases induced by 10 microM ATP and 1 microM bradykinin. AM-404 (5 microM) also increased [Ca(2+)](i) in Chang liver cells, PC3 human prostate cancer cells, BFTC human bladder cancer cells, and MG63 human osteoblast-like cells. Together, this study shows for the first time that AM-404 at concentrations commonly used to inhibit the anandamide transporter in various systems induced an increase in [Ca(2+)](i) in different cell types. The [Ca(2+)](i) increase was solely due to extracellular Ca(2+) influx. Thus caution must be exercised in using AM-404 as a selective inhibitor of the anandamide transporter.

Clomiphene, an Ovulation-Inducing Agent, Mobilizes Intracellular Ca2+ and Causes Extracellular Ca2+ Influx in Bladder Female Transitional Carcinoma Cells

BACKGROUND/METHODS

The effect of clomiphene, an ovulation-inducing agent, on cytosolic free Ca2+ levels ([Ca2+]i) in populations of BFTC human bladder cancer cells was explored by using fura-2 as a Ca2+ indicator.

RESULTS

Clomiphene at concentrations between 10 and 75 microM increased [Ca2+]i in a concentration-dependent manner and the signal saturated at 50 microM. The [Ca2+]i signal was biphasic with an initial rise and a slow decay. Ca2+ removal inhibited the Ca2+ signal by about 40-50% in maximum [Ca2+]i. Adding 3 mM Ca2+ increased [Ca2+]i in cells pretreated with 50 microM clomiphene in Ca2+-free medium, suggesting that clomiphene induced capacitative Ca2+ entry. In Ca2+-free medium, pretreatment with 50 microM brefeldin A (to disrupt the Golgi complex Ca2+ store), 1 microM thapsigargin (to inhibit the endoplasmic reticulum Ca2+ pump), and CCCP (to uncouple mitochondria) inhibited 85% of clomiphene-induced intracellular Ca2+ release. Conversely, pretreatment with 50 microM clomiphene in Ca2+-free medium abolished the [Ca2+]i increase induced by brefeldin, thapsigargin or CCCP. The intracellular Ca2+ release was unaltered by inhibiting formation of inositol-1,4,5-trisphosphate (IP3) with 2 mM 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122; a phospholipase C inhibitor).

CONCLUSION

The [Ca2+]i increase induced by 50 microM clomiphene was not affected by 10 microM of nifedipine, verapamil or diltiazem. Collectively, the results suggest that clomiphene releases intracellular Ca2+ in an IP3-independent manner and also activates extracellular Ca2+ influx.

Linoleamide, a brain lipid that induces sleep, increases cytosolic Ca2+ levels in MDCK renal tubular cells

Linoleamide is an endogenous lipid that has been shown to induce sleep in cats, rats and humans. However, its physiological function remains unclear. In this study the effect of linoleamide on cytosolic free Ca2+ concentrations ([Ca2+]i) in Madin Darby canine kidney (MDCK) tubular cells was examined, by using fura-2 as a Ca2+ probe. In a concentration-dependent manner, linoleamide induced increases in [Ca2+]i between 10-500 microM with an EC50 of 20 microM. The signal comprised a slow rise and a persistent phase, and was a result of internal Ca2+ release and external Ca2+ influx because it was partly inhibited by external Ca2+ removal. In Ca2+-free medium, depletion of the endoplasmic reticulum Ca2+ store with 1 microM thapsigargin abolished 100 microM linoleamide-induced internal Ca2+ release, and conversely, pretreatment with linoleamide prevented thapsigargin from releasing internal Ca2+. This demonstrates that the internal source of linoleamide-induced [Ca2+]i increase is located in the endoplasmic reticulum. This discharge of internal Ca2+ caused capacitative Ca2+ entry because after incubation with 100 microM linoleamide in Ca2+-free medium for 8 min readmission of 3 mM CaCl2 induced increases in [Ca2+]i. After the formation of inositol-1,4,5-trisphosphate (IP3) was blocked by the phospholipase C inhibitor U73122 (1 microM), linoleamide still induced an increase in [Ca2+]i but the shape of the increase was altered. Similar results were found for another sleep-inducing lipid 9,10-octadecenoamide. Together, the present study shows that the endogenous sleep-inducing lipid linoleamide was able to cause significant increases in [Ca2+]i in renal tubular cells, by releasing the endoplasmic reticulum Ca2+ store and triggering capacitative Ca2+ entry in a manner independent of IP3.

Annual changes in the clinical features of prostatic adenocarcinoma in Taiwan

OBJECTIVE

To determine, using a clinical and pathological database, the annual changes in the characteristics of adenocarcinoma of the prostate diagnosed in consecutive men in Taiwan.

PATIENTS AND METHODS

All prostatic adenocarcinomas newly diagnosed between 1991 and 1999 in our institution were analysed. Using logistic regression for dichotomous variables, the annual trends were assessed for changes in the percentage of T1c disease, incidental carcinoma, clinically localized disease and Gleason grade 4/5 cancers. The annual trends for changes in the pathological features of disease in patients treated by radical prostatectomy were also analysed.

RESULTS

The study included 694 patients; the median age at diagnosis increased significantly (P = 0.004) and there was a significant increase in clinical T1c disease (relative risk, RR, 1.142, P = 0.022). There were also significant decreases in incidental carcinomas (RR 0.789, P < 0.001), patients with a serum prostate-specific antigen (PSA) level of > 20 ng/mL (RR 0.848, P < 0.001) and with Gleason grade 4/5 tumours (RR 0.919, P = 0.005). There was no significant change in the percentage of clinically localized disease. Radical prostatectomy was undertaken in 179 men; the annual incidence of lymph node metastases decreased significantly (P = 0.035) and there was a significant 19% increase in the RR of having organ-confined disease (pT1-2N0M0) and a 19% decrease in Gleason grade 4/5 tumours.

CONCLUSIONS

These results may reflect the annual trends of prostate cancer in Taiwan in the period for which the PSA assay became available. The increasing application of PSA testing was associated with a significant increase in clinical T1c disease and decrease in incidental carcinoma. There was also a significant trend towards less aggressive cancers. Despite the dramatic increase in the annual detection rate, tumours were not detected at an earlier stage. However, for patients treated with radical prostatectomy, there was a significant change to earlier stage disease and fewer de-differentiated cancers.

Fluoxetine-induced Ca2+ signals in Madin-Darby canine kidney cells

The effect of fluoxetine on Ca2+ signaling in Madin-Darby canine kidney (MDCK) cells was investigated by using fura-2 as a Ca2+ probe. Fluoxetine increased [Ca2+]i concentration-dependently between 5 microM and 200 microM with an EC50 value of 40 microM. The response was reduced by external Ca2+ removal by 30%40%. In Ca2+-free medium pretreatment with 1 microM thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+ pump, abolished 100 microM fluoxetine-induced Ca2+ release. Addition of 3 mM Ca2+ to Ca2+-free medium increased [Ca2+]i when cells were pretreated with 100 microM fluoxetine. Suppression of 1,4,5-trisphosphate (IP3) formation by 2 microM U73122 (a phospholipase C inhibitor) did not affect 100 microM fluoxetine-induced Ca2+ release. Fluoxetine (5-100 microM) also increased [Ca2+]i in neutrophils, prostate cancer cells and bladder cancer cells from human and rat glioma cells.

Disulfide bond effects on protein stability: designed variants of Cucurbita maxima trypsin inhibitor-V

Attempts to increase protein stability by insertion of novel disulfide bonds have not always been successful. According to the two current models, cross-links enhance stability mainly through denatured state effects. We have investigated the effects of removal and addition of disulfide cross-links, protein flexibility in the vicinity of a cross-link, and disulfide loop size on the stability of Cucurbita maxima trypsin inhibitor-V (CMTI-V; 7 kD) by differential scanning calorimetry. CMTI-V offers the advantage of a large, flexible, and solvent-exposed loop not involved in extensive intra-molecular interactions. We have uncovered a negative correlation between retention time in hydrophobic column chromatography, a measure of protein hydrophobicity, and melting temperature (T(m)), an indicator of native state stabilization, for CMTI-V and its variants. In conjunction with the complete set of thermodynamic parameters of denaturation, this has led to the following deductions: (1) In the less stable, disulfide-removed C3S/C48S (Delta Delta G(d)(50 degrees C) = -4 kcal/mole; Delta T(m) = -22 degrees C), the native state is destabilized more than the denatured state; this also applies to the less-stable CMTI-V* (Delta Delta G(d)(50 degrees C) = -3 kcal/mole; Delta T(m) = -11 degrees C), in which the disulfide-containing loop is opened by specific hydrolysis of the Lys(44)-Asp(45) peptide bond; (2) In the less stable, disulfide-inserted E38C/W54C (Delta Delta G(d)(50 degrees C) = -1 kcal/mole; Delta T(m) = +2 degrees C), the denatured state is more stabilized than the native state; and (3) In the more stable, disulfide-engineered V42C/R52C (Delta Delta G(d)(50 degrees C) = +1 kcal/mole; Delta T(m) = +17 degrees C), the native state is more stabilized than the denatured state. These results show that a cross-link stabilizes both native and denatured states, and differential stabilization of the two states causes either loss or gain in protein stability. Removal of hydrogen bonds in the same flexible region of CMTI-V resulted in less destabilization despite larger changes in the enthalpy and entropy of denaturation. The effect of a cross-link on the denatured state of CMTI-V was estimated directly by means of a four-state thermodynamic cycle consisting of native and denatured states of CMTI-V and CMTI-V*. Overall, the results show that an enthalpy-entropy compensation accompanies disulfide bond effects and protein stabilization is profoundly modulated by altered hydrophobicity of both native and denatured states, altered flexibility near the cross-link, and residual structure in the denatured state.

p53 mutation and bcl-2 expression in transitional cell carcinoma of the urinary bladder

BACKGROUND

The purpose of our study was to examine the frequency of p53 mutation and bcl-2 expression in transitional cell carcinoma of the urinary bladder and their clinicopathologic correlates.

METHODS

A total of 137 patients who underwent transurethral resection for primary transitional cell bladder carcinomas were enrolled. The paraffin-embedded tissue blocks were recut and stained by monoclonal anti-p53 (DO7) and anti-bcl-2 (124) antibodies. The bcl-2 and p53 immunoreactivity was correlated to tumor grade and pathological stage.

RESULTS

p53 mutation was identified in 102 patients (78.5%). The mutation was most common in grade 3 tumors (95%) as compared to grade 2 (74%) and grade 1 (80%) tumors, but the difference was not statistically significant (p = 0.289). Stage pT2 tumors had higher incidence of p53 mutation (97%) as compared to pTa-1 tumors (71%, p = 0.0003). Only 17 tumors (13%) expressed bcl-2; the grade 3 tumors had significantly higher incidence of bcl-2 expression (p = 0.04). The bcl-2 expression was not related to pathological stage (p = 0.083). There was no interrelation between p53 mutation and bcl-2 expression (p = 0.97). Grade 3 tumors correlated well with invasive disease (p < 0.00001). When grade 2 tumors were evaluated separately, p53 mutation was positively correlated with disease invasion (p = 0.001).

CONCLUSIONS

Grade 3 tumor was the most important variable associated with tumor invasion in transitional cell carcinoma of the urinary bladder. p53 mutation was positively correlated with invasive disease. Grade 2 tumors with p53 mutation had greater probability of disease invasion. Expression of bcl-2 positively correlated with tumor grade but not pathological stage.

NPC-14686, a novel anti-inflammatory agent, increased intracellular Ca(2+) concentrations in MDCK renal tubular cells

The effect of NPC-14686 (Fmoc-L-homophenylalanine), a novel anti-inflammatory agent on intracellular free Ca(2+) concentrations ([Ca(2+)](i)) in Madin Darby canine kidney (MDCK) renal tubular cells, was investigated, using fura-2 as a Ca(2+) dye. At concentrations between 10 and 200 microM NPC-14686 increased [Ca(2+)](i) concentration dependently. The [Ca(2+)](i) signal comprised an initial rise and a sustained phase. Ca(2+) removal inhibited the Ca(2+) signals by 90%. In Ca(2+)-free medium, pretreatment with 100 microM NPC-14686 nearly abolished the [Ca(2+)](i) increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) and abolished the [Ca(2+)](i) increase induced by 2 microM carbonylcyanide m-chlorophenylhydrazone (CCCP) (a mitochondrial uncoupler). NPC-14686 (100 microM) induced a slight [Ca(2+)](i) increase after pretreatment with 2 microM CCCP and 1 microM thapsigargin. Addition of 3 mM Ca(2+) elicited a [Ca(2+)](i) increase in cells pretreated with 100 microM NPC-14686 in Ca(2+)-free medium. Inhibition of inositol-1,4,5-trisphosphate (IP(3)) production by suppressing phospholipase C with 2 microM U73122 did not alter NPC-14686-induced Ca(2+) release. Trypan blue exclusion revealed that incubation with 10 or 200 microM NPC-14686 for 1-30 min decreased cell viability by 10-20% concentration dependently. Collectively, the results demonstrate that, in MDCK tubular cells, NPC-14686 induced Ca(2+) release followed by Ca(2+) entry, with the latter playing a major role. NPC-14686 appears to release intracellular Ca(2+) in an IP(3)-uncoupled manner. NPC-14686 may be of mild cytotoxicity.

N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride) (W-7) causes increases in intracellular free Ca2+ levels in bladder female transitional carcinoma (BFTC) cells

The effect of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride) (W-7), a widely used calmodulin inhibitor, on intracellular free Ca2+ levels ([Ca2+]i) in bladder female transitional cancer (BFTC) cells was examined using fura-2 as a Ca2+ dye. W-7 (10-1000 microM) caused an increase in [Ca2+]i in a concentration-dependent manner with an EC50 of 75 microM. The [Ca2+]i response was composed of an initial rise and a sustained plateau without significant decaying during the measurement of 250 seconds. Extracellular Ca2+ removal dramatically decreased the Ca2+ signals by 50-90%. W-7 (100 microM) failed to induce a [Ca2+]i increase in Ca(2+)-free medium after pretreatment with thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor; conversely, W-7 pretreatment abolished the Ca2+ release induced by thapsigargin. Addition of 3 mM Ca2+ increased [Ca2+]i after preincubation with 100 microM W-7 in Ca(2+)-free medium. W-7-induced Ca2+ release was not altered by inhibiting phospholipase C with 2 microM 1-(6-((17b-3-methoxyestra-1,3,5 (10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) (U73122). Together, this study shows that W-7 caused [Ca2+]i increases in human bladder cancer cells by releasing intracellular Ca2+ from the endoplasmic reticulum and also by causing extracellular Ca2+ influx with the later playing a dominant role. The W-7-induced intracellular Ca2+ release was uncoupled to a prior elevation in intracellular levels of inositol 1,4,5-trisphosphate (IP3).

High-energy shock waves alter cytosolic calcium mobilization in single MDCK cells

The damaging effect of shock waves on intracellular calcium homeostasis in renal tubular cells has not been investigated previously. We have examined the effects of shock waves on Madin Darby canine kidney (MDCK) cells by determining the release of two cellular enzymes: glutamate oxalactate transferase (GOT) and lactate dehydrogenase (LDH); and both the basal cytosolic calcium concentration ([Ca2+]i) and the [Ca2+]i rises evoked by Ca2+-mobilizing agonists after shock wave exposure (SWE). Immediately but transiently after SWE, the release of GOT and LDH increased by 15 % and 5-fold, respectively, implicating cell membrane damage; and within 1-7 h after SWE, basal [Ca2+]i was elevated by 15-141%. In SWE-treated cells, the peak amplitude of the [Ca2+]i transients evoked by ATP, bradykinin, thapsigargin and 2,5-Di-(t-butyl)-1,4-hydroquinone (BHQ) was slightly altered, and the plateau amplitude was markedly elevated. The ATP and bradykinin receptors, the Ca2+ pump on the endoplasmic reticulum membrane, and the effector molecules involved in regulating the [Ca2+]i transients were slightly affected. Shock waves appeared to cause a mild impairment in the mechanisms responsible for the decay of the evoked [Ca2+]i rises.

Fatty acids enhanced tubermycin production by Pseudomonas strain 2HS

A new microbial isolate, Pseudomonas 2HS, produced trace amounts of a greenish-yellow pigment when grown aerobically in a 1% yeast extract medium at 30 degrees C and shaken at 250 rpm for 5 days. In contrast, cells produced more greenish-yellow pigment (2.16 mg/15 ml culture) when grown in the presence of 0.5% 12-hydroxyoctadecanoic acid (w/v). The greenish-yellow pigment was identified as phenazine-1-carboxylic acid (tubermycin B), and the Pseudomonas 2HS was identified as P. aeruginosa 2HS. This is the first report that 12-hydroxyoctadecanoic, ricinoleic and other fatty acids can enhance the production of phenazine-1-carboxylic acid by a Pseudomonas species.

Evaluation of optic disc changes in severe myopia

PURPOSE

To evaluate the changes in the optic nerve head in highly myopic subjects by means of confocal laser scanning opthalmoscope.

METHODS

Using laser scanning and a three-dimensional image analysis system, we studied 114 young (21.4 +/- 1.4 years), highly myopic subjects with refractive errors greater than -8.0 D and a control group of 29 subjects (18.9 +/- 1.2 years) with myopia of -3.0 D or less. Measurements included cycloplegic refraction, corneal curvature, biometric axial length, and morphometric values of the optic disc obtained with a laser scanning disc analyzer.

RESULTS

The optic disc area in highly myopic eyes was similar to that in mildly myopic eyes. However, regression analysis revealed that the optic disc area increased with axial length in subjects with severe myopia. The cup/disc ratio, the disc depth, the neuroretinal rim area, and the tilting of the disc were not significantly different between the severe and mild myopia groups.

CONCLUSIONS

These findings may be useful in further investigations of myopic progression and of the mechanisms responsible for the development of myopic complications.

Effects of bombesin on gut mucosal immunity in rats after thermal injury

BACKGROUND AND PURPOSE

Severe burns induce a disruption in gastrointestinal mucosal integrity and facilitate bacterial translocation (BT). Bombesin (BBS), a tetradecapeptide analogous to mammalian gastrin-releasing peptide, can induce the release of all gut hormones except secretin. This study examined the effects of BBS on mucosal immunity in rats after thermal injury.

METHODS

Forty-two Sprague-Dawley rats were divided into one sham control group and six burn groups. Burn groups were subjected to 35% total body surface area burn injury. One to 6 days after the injury, six animals (one from each group) were killed every 24 hours. Biliary secretory immunoglobulin A (SIgA), jejunal mucosal height, intestinal permeability, and BT to the mesenteric lymph nodes (MLNs), liver, and spleen were examined. In a second experiment, three groups of rats (6 in each) received either sham treatment and saline injection, or thermal injury and saline injection, or thermal injury and BBS injection. Twenty-four hours after burns or sham treatment, six animals (1 from each group) were killed. The biliary SIgA, jejunal mucosal height, and BT to the MLNs, liver, and spleen were examined.

RESULTS

The biliary SIgA decreased to one-seventh of normal levels 1 day after burn injury, and increased thereafter. The jejunal mucosal height decreased significantly to two-thirds of the normal value 1 day after burn injury. The intestinal mucosal permeability increased significantly to three times the normal level 2 days after the burn injury, and decreased thereafter. BBA significantly reduced the BT incidence and significantly increased the biliary SIgA and jejunal mucosal height 1 day after burn injury.

CONCLUSIONS

The results of this study show that, in rats, the intestinal permeability increased, the gut mucosal barrier failed, and the gut immunity deteriorated in the first few days after burn injury. BBS therapy helped to restore the postburn gut mucosal barrier in rats, by increasing biliary SIgA levels and the jejunal mucosal height.

Novel effects of gossypol, a chemical contraceptive in man: mobilization of internal Ca(2+) and activation of external Ca(2+) entry in intact cells

The effect of gossypol on Ca(2+) signaling in Madin Darby canine kidney (MDCK) cells was investigated by using fura-2 as a Ca(2+) probe. Gossypol evoked a rise in cytosolic free Ca(2+) levels ([Ca(2+)](i)) concentration-dependently between 2 and 20 microM. The response was decreased by external Ca(2+) removal. In Ca(2+)-free medium pretreatment with gossypol nearly abolished the [Ca(2+)](i) increase induced by carbonylcyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler, and thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+) pump; but pretreatment with CCCP and thapsigargin only partly inhibited gossypol-induced Ca(2+) release. Addition of 3 mM Ca(2+) induced a [Ca(2+)](i) increase after pretreatment with 5 microM gossypol in Ca(2+)-free medium. This Ca(2+) entry was decreased by 25 microM econazole, 50 microM SKF96365 and 40 microM aristolochic acid (a phospholipase A(2) inhibitor). Pretreatment with aristolochic acid inhibited 5 microM gossypol-induced internal Ca(2+) release by 55%, but suppression of phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3, 5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) had no effect. Gossypol (5 microM) also increased [Ca(2+)](i) in human bladder cancer cells and neutrophils. Collectively, we have found that gossypol increased [Ca(2+)](i) in MDCK cells by releasing Ca(2+) from multiple Ca(2+) stores in a manner independent of the production of inositol-1,4,5-trisphosphate, followed by Ca(2+) influx from external space.

NPC-15199, a novel anti-inflammatory agent, mobilizes intracellular Ca2+ in bladder female transitional carcinoma (BFTC) cells

This report demonstrates that NPC-15199 [(N-(9-fluorenylmethoxycarbonyl)L-leucine)], a novel anti-inflammatory agent, increases intracellular Ca2+ concentration ([Ca2+]i) in human bladder female transitional cancer (BFTC) cells. Using fura-2 as a Ca2+ probe, NPC-15199 (0.1-2 mM) was found to increase [Ca2+]i concentration-dependently. The response saturated at 2-5 mM NPC-15199. The [Ca2+]i increase comprised an initial rise, a slow decay, and a plateau. Ca2+ removal partly inhibited the Ca2+ signals. In Ca2+-free medium, pretreatment with 1 mM NPC-15199 abolished the [Ca2+]i increase induced by 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor); and after pretreatment with thapsigargin, NPC-15199-induced Ca2+ release was dramatically inhibited. This indicates that NPC-15199 released internal Ca2+ mostly from the endoplasmic reticulum. Adding 3 mM Ca2+ increased [Ca2+]i in cells pretreated with 1 mM NPC-15199 in Ca2+-free medium. Together, the findings suggest that in BFTC bladder cancer cells, NPC-15199 induced Ca2+ release from the endoplasmic reticulum and activating Ca2+ entry.