Mutations inhibiting KDM4B drive ALT activation in ATRX-mutated glioblastomas.

Alternative Lengthening of Telomeres (ALT) is a telomere maintenance pathway utilised in 15% of cancers. ALT cancers are strongly associated with inactivating mutations in ATRX; yet loss of ATRX alone is insufficient to trigger ALT, suggesting that additional cooperating factors are involved. We identify H3.3G34R and IDH1/2 mutations as two such factors in ATRX-mutated glioblastomas. Both mutations are capable of inactivating histone demethylases, and we identify KDM4B as the key demethylase inactivated in ALT. Mouse embryonic stem cells inactivated for ATRX, TP53, TERT and KDM4B (KDM4B knockout or H3.3G34R) show characteristic features of ALT. Conversely, KDM4B over-expression in ALT cancer cells abrogates ALT-associated features. In this work, we demonstrate that inactivation of KDM4B, through H3.3G34R or IDH1/2 mutations, acts in tandem with ATRX mutations to promote ALT in glioblastomas.

Health survey of employees regularly using 3D printers.

Background: 3D printers emit potentially hazardous ultrafine particles and volatile organic compounds. Workers using 3D printing technologies may be at risk of respiratory illness from occupational exposure. Aims: To assess whether 3D printing is associated with health effects in occupational users. Methods: This was a preliminary survey. Workers in 17 companies using 3D printing, including commercial prototyping businesses, educational institutions and public libraries, in the Greater Toronto Area, Canada, were asked to complete survey questionnaires concerning demographic, occupational and health information. Associations between self-reported health history variables and occupational characteristics were examined by chi-square and Fisher's exact tests. Results: Among 46 surveyed workers, 27 (59% of participants) reported having respiratory symptoms at least once per week in the past year. Working more than 40 h per week with 3D printers was significantly associated with having been given a respiratory-related diagnosis (asthma or allergic rhinitis) (P < 0.05). We observed a wide variation in occupational hygiene practices in the 17 printing workplaces that we surveyed. Conclusions: Our finding of frequently reported respiratory symptoms suggests a need for additional studies on exposed workers in this field.

Collapsin response mediator protein-1 (CRMP1) acts as an invasion and metastasis suppressor of prostate cancer via its suppression of epithelial-mesenchymal transition and remodeling of actin cytoskeleton organization.

The cancer cells can acquire migration and invasion capacities during the metastasis process through the developmental regulatory program epithelial-mesenchymal-transition (EMT), and through its reverse process mesenchymal-epithelial transition cancer cells can recolonize at distant metastatic sites. Among the multifaceted effects exerted by this program, reorganization of actin cytoskeleton is the key mechanical drive for the invasive properties gained by cancer cells. Collapsin response mediator protein-1 (CRMP1) is a cytosolic phosphoprotein and originally characterized as the mediator of semaphorin 3A signaling involved in axon differentiation during neural development. Here we report that CRMP1 can act as a suppressor of tumorigenicity and metastasis in prostate cancer cells. We demonstrated that CRMP1 exhibited a decreased expression pattern in high-grade prostate cancer tissues and many prostate cancer cell lines, and its downregulation in cancer cells was attributed to histone deacetylation and direct repression of its gene by the EMT regulator Snail. Functional analyses revealed that CRMP1 suppressed EMT in prostate cancer cells, as its knockdown could trigger EMT and enhance in vitro invasion capacity, whereas its overexpression could inhibit EMT and suppress both in vitro invasion and in vivo metastasis capacities of prostate cancer cells. Moreover, CRMP1 overexpression could significantly confer resistance to EMT induced by Snail or transforming growth factor-ß1 in prostatic epithelial cells and prostate cancer cells. Finally, we demonstrated that CRMP1 could associate with actin and WAVE1, an activator of actin nucleation complex Arp2/3, and also its knockdown could stabilize F-actin and trigger the formation of stress fibers in prostate cancer cells. Together, our study shows that CRMP1 acts an EMT and metastasis suppressor in prostate cancer cells via its regulation of actin polymerization and also suggests that targeting the CRMP1-actin signaling in actin organization could be a potential strategy for management of prostate cancer metastasis.

Establishment of a novel immortalized human prostatic epithelial cell line stably expressing androgen receptor and its application for the functional screening of androgen receptor modulators.

In this study, we developed a human prostatic epithelial cell line BPH-1-AR stably expressing AR by lentiviral transduction. Characterization by immunoblot and RT-PCR showed that AR was stably expressed in all representative BPH-1-AR clones. Androgen treatment induced a secretory differentiation phenotype in BPH-1-AR cells but suppressed their cell proliferation. Treatments with AR agonists induced transactivation of a transfected PSA-gene promoter reporter in BPH-1-AR cells, whereas this transactivation was suppressed by an AR antagonist flutamide, indicating that the transduced AR in BPH-1-AR cells was functional. Finally, we utilized BPH-1-AR cells to evaluate the androgenic activities and growth effects of five newly developed non-steroidal compounds. Results showed that these compounds showed androgenic activities and growth-inhibitory effects on BPH-1-AR cells. Our results showed that BPH-1-AR cell line would be a valuable in vitro model for the study of androgen-regulated processes in prostatic epithelial cells and identification of compounds with AR-modulating activities.

Orphan nuclear receptor estrogen-related receptor-beta suppresses in vitro and in vivo growth of prostate cancer cells via p21(WAF1/CIP1) induction and as a potential therapeutic target in prostate cancer.

Recent studies indicate that estrogen-related receptors (ERRs) are involved in similar estrogen receptor (ER) regulatory pathways and play roles in energy and lipid metabolism. Here, we analysed the functional role of ERRbeta in prostate cancer cell growth regulation in an androgen-sensitive and androgen-insensitive prostate cancer cell lines. ERRbeta was expressed in normal human prostates, but exhibited a reduced expression in prostate cancer lesions. Stable ERRbeta expression suppressed significantly cell proliferation and tumorigenicity of LNCaP and DU145 cells, accompanied by an S-phase suppression and increased p21 expression. Reporter and chromatin immunoprecipitation assays showed that ERRbeta could directly transactivate p21 gene promoter, which could be further enhanced by peroxisome proliferator-activated receptor-gamma coactivator-1alpha. Truncation analysis showed that ERRbeta-mediated p21 transactivation and prostate cancer cell growth inhibition required intact DNA-binding domain and AF2 domains in ERRbeta. Interestingly, ERRbeta displayed a cell cycle associated downregulated expression pattern in ERRbeta-transduced and non-transduced cells. Finally, we showed that ERRbeta-mediated growth inhibition could be potentiated by an ERRbeta/gamma agonist DY131. Knockdown of ERRbeta by RNA interference could reduce the DY131-induced growth inhibition in prostate cancer cells. Taken together, our findings indicate that ERRbeta performs a tumor suppressing function in prostate cancer cells, and targeting ERRbeta could be a potential therapeutic strategy for prostate cancer.

A national study of the epidemiology of pneumococcal disease among hospitalised patients in Singapore: 1995 to 2004.

INTRODUCTION: Infections with Streptococcus pneumoniae cause significant morbidity and mortality. In this study, we describe the epidemiology of pneumococcal disease based on hospitalisation rates for all age groups in Singapore. This is important for evaluating prevention and control strategies of pneumococcal disease. METHODS: We conducted a retrospective study of hospitalisation cases admitted to all public and private hospitals from 1995 to 2004. 4,275 hospitalisation records were extracted, based on the International Classification of Diseases, Ninth Revision (ICD-9) codes for pneumococcal disease. We analysed the demographics, type of pneumococcal disease, length of stay and case fatality of these cases. RESULTS: Our study showed that the mean annual hospitalisation rate for pneumococcal disease was 10.9 per 100,000 population from 1995 to 2004. The mean annual hospitalisation rate was highest in the young and the elderly. CONCLUSION: Baseline information on the epidemiology of pneumococcal disease is important for the formulation and evaluation of a national prevention and control programme.

The relaxant effect of urocortin in rat pulmonary arteries.

Urocortin is a potent vasodilator, which plays physiological or pathophysiological roles in systemic circulation. However, little is known about its action on pulmonary circulation. The present study was aimed to characterize some cellular mechanisms underlying the relaxant effect of urocortin in isolated rat pulmonary arteries. Changes in isometric tension were measured on small vessel myographs. Urocortin inhibited U46619-induced contraction with reduction of the maximal response. Urocortin-induced relaxation was independent of the presence of endothelium. Inhibitors of nitric oxide (NO)-dependent dilator, NG-nitro-L-arginine methyl ester or 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one, did not affect the relaxation. Astressin (100-500 nM), a corticotropin-releasing factor (CRF) receptor antagonist and KT5720, a protein kinase A (PKA) inhibitor reduced urocortin-induced relaxation. Urocortin produced less relaxant effect in 30 mM K+- than U46619-contracted arterial rings. Urocortin did not reduce CaCl2-induced contraction in 60 mM K+-containing solution. Ba2+ (100-500 microM) but not other K+ channel blockers reduced the relaxant responses to urocortin. Urocortin also relaxed the rings preconstricted by phorbol 12,13-diacetae in normal Krebs solution while this relaxation was less in a Ca2+-free solution. Our results show that urocortin relaxed rat pulmonary arteries via CRF receptor-mediated and PKA-dependent but endothelium/NO or voltage-gated Ca2+ channel-independent mechanisms. Stimulation of Ba2+-sensitive K+ channel may contribute to urocortin-induced relaxation. Finally, urocortin relaxed pulmonary arteries partly via inhibition of a PKC-dependent contractile mechanism.

MRI of neonatal encephalopathy.

We present the magnetic resonance imaging (MRI) findings in neonatal encephalopathy, including hypoxic-ischaemic encephalopathy, perinatal/neonatal stroke, metabolic encephalopathy from inborn errors of metabolism, congenital central nervous system infections and birth trauma. The applications of advanced MRI techniques, such as diffusion-weighted imaging and magnetic resonance spectroscopy are emphasized.

Brain morphological abnormality in schizophrenia is independent of country of origin.

OBJECTIVE: The disorder schizophrenia has a worldwide prevalence of 1% and is generally associated with lateral cerebral ventricular enlargement. Whether there is a relationship between these two findings is unclear but has aetiological relevance. METHOD: Consecutively admitted Chinese patients (n = 19) with first episode of schizophrenia and healthy community volunteers (n = 29) underwent magnetic resonance imaging brain scan. The groups were balanced for age, sex, best social class and handedness. These patients were similar on clinical and socio-demographic indices to those who declined participation (n = 15). Semi-automated volumetric analysis of whole brain volume, cortical grey matter, cerebrospinal fluid, sulci and lateral ventricles was performed. RESULTS: Chinese patients in their first episode of schizophrenia have significant enlargement of lateral ventricles. CONCLUSION: Brain morphological abnormality in schizophrenia is present regardless of the country of origin. The importance of genes in driving normal brain development and stable prevalence suggests that aetiology may favour genes over environment.

CT in acute mesenteric ischaemia.

Enhanced computed tomography (CT) is frequently performed for possible bowel ischaemia. It has the distinct advantage of possible detection of the causes of ischaemia. Radiologists therefore need to be familiar with the spectrum of diagnostic CT signs. We present the CT imaging findings in surgically proven cases of small bowel ischaemia. In addition to signs pertaining to the underlying aetiological pathology, bowel dilatation, bowel wall thickening, mural gas, occlusion of mesenteric vessels, ascites and infarct of other abdominal organs were observed.

Persistent adrenal enhancement may be the earliest CT sign of significant hypovolaemic shock.

AIM: To report two cases of intense and persistent adrenal enhancement on computed tomography (CT) examinations of the abdomen. MATERIALS AND METHODS: Two patients presented with septic shock, one due to pyogenic liver abscess and the other strangulated obturator hernia with gangrenous bowel. Both patients were resuscitated with fluid before undergoing unenhanced and enhanced CT. RESULTS: In both patients intravascular volume was not reduced as evident by normal calibre of the aorta and inferior vena cava. One patient had abnormal enhancement pattern in the liver and kidneys, suggesting hypoperfusion. The other patient had normal enhancement pattern of the other abdominal viscera. Both patient subsequently died with multi-organ failure. CONCLUSION: We propose that adrenal enhancement may be a sign of hyperperfusion in early stage of shock due to the crucial role of the adrenal glands in this clinical situation. This may not persist with further circulatory compromise due to vasoconstriction. If confirmed, its recognition has potential value of identifying a therapeutic window before irreversible shock set in.

Prostate targeting: PSP94 gene promoter/enhancer region directed prostate tissue-specific expression in a transgenic mouse prostate cancer model.

To date, only a few prostate-specific vector genes have been tested for prostate targeting in gene therapy of prostate cancer (CaP). Current clinical trials of gene therapy of CaP utilize the only two available vector genes with a combination of a rat probasin promoter and a human PSA promoter sequence in an adenovirus vector to target CaP. There is an urgent need to establish additional vector gene systems to sustain and propagate the current research. Since PSP94 (prostate secretory protein of 94 amino acids) is one of the three most abundant proteins secreted from the human prostate and is generally considered to be prostate tissue-specific in both human and rodents, we performed a transgenic experiment to assess the promoter/enhancer region of PSP94 gene-directed prostate targeting. Firstly, a series of progressive deletion mutants of a 3.84 kb PSP94 gene promoter/enhancer region (including parts of the intron 1 sequence) linked with a reporter LacZ gene was constructed and assessed in vitro in cell culture. Next, transgenic mice were generated with two transgene constructs using the SV40 early region (Tag oncogene) as a selection marker. PSP94 gene promoter/enhancer region-directed SV40 Tag expression specifically in the mouse was demonstrated in three breeding lines (A, B, C, n = 374) by immunohistochemistry staining of Tag expression. Specific targeting to the prostate in the PSP94 gene-directed transgenic CaP model was characterized histologically by correlation of SV40 Tag-induced tumorigenesis (tumor grading) with puberty and age (10-32 weeks). Prostatic hyperplasia was observed as early as 10 weeks of age, with subsequent emergence of prostatic intraepithelial neoplasia (PIN) and eventually high grade carcinoma in the prostate. The PSP94 transgenic mouse CaP model was further characterized by its tumor progression and metastatic tendency at 20 weeks of age and also by its responsiveness and refractoriness to androgen manipulation. This study indicates that the PSP94 gene promoter/enhancer has the potential for prostate specific targeting and may ultimately be of use in gene therapy of CaP.

Imaging of peripheral PNET: common and uncommon locations.

AIM: We present the imaging features of peripheral primitive neuroectodermal tumour (PNET) in eight children, highlighting the unusual locations of this tumour in three children. MATERIALS AND METHODS: At presentation, the tumours were studied with magnetic resonance imaging (MRI; n = 6), computed tomography (CT; n = 7) and ultrasound (US; n = 1). The diagnoses were confirmed histologically (n = 8), immunohistochemically (n = 8), by cytogenetics (n = 3) and electron microscopy (n = 1). Correlation with gross pathology, histology, treatment and outcome were obtained. RESULTS: The tumours were located in the chest wall (n = 2), shoulder, pelvis, small bowel mesentery, adrenal gland, dura mater and skin and subcutaneous tissue of the abdominal wall (n = 1 each). Peripheral PNET arising from the small bowel mesentery, adrenal gland and dura mater have not been previously reported in the English literature. The tumours were mainly large (mean size: 10.6 cm) and infiltrative. All tumours were heterogeneously hyperintense on T2-weighted MRI, heterogeneously iso/hypodense on CT and had variable contrast enhancement. Most tumours were heterogeneously hypointense to muscle on T1-weighted MRI. US showed a hypoechoic mass with a cystic component. CONCLUSION: Peripheral PNET can occur in unusual locations. The clinical and imaging features of peripheral PNET are non-specific, making tissue diagnosis essential. PNET should be included in the differential diagnosis of aggressive soft tissue tumours in children.

H-type tracheo-oesophageal fistula: appearance on three-dimensional computed tomography and virtual bronchoscopy.

H-type tracheo-oesophageal fistula (TOF) is a rare type of fistula without oesophageal atresia. The symptoms are usually present at birth, but the diagnosis is often delayed. Traditionally, contrast oesophagography and/or fiberoptic bronchoscopy are used to confirm the diagnosis. We describe the imaging features of a case of H-type TOF seen on three-dimensional computed tomography and virtual bronchoscopy and the usefulness of these techniques in pre-operative evaluation.

Detection of mRNA expression of gonadotropin-releasing hormone and its receptor in normal and neoplastic rat prostates.

Hypothalamic gonadotropin-releasing hormone (GnRH) plays a central role in the regulation of the mammalian reproductive systems as a releasing hormone of pituitary gonadotropins. However, a number of studies have shown that GnRH or its receptor are also expressed in some reproductive organs including prostate gland, mammary gland, ovary and placenta, tumors and tumor cell lines derived from these organs, suggesting that this peptide hormone may have other extrapituitary functions in addition to its role as a gonadotropin-releasing hormone. Moreover, it has been demonstrated that GnRH analogs exert some direct inhibitory effects on the proliferation of human and rat prostate cancer cells, probably mediated by its own specific receptors expressed in these tumor cells. In the present study, we investigated the mRNA expression of GnRH and its receptor in normal Noble rat prostate gland, and in three rat models of prostate cancer including the sex hormone-induced Noble rat model, an androgen-independent Noble rat prostatic tumor (AIT) and Dunning rat prostatic adenocarcinomas by RT-PCR and Southern blot analyses. The results showed that GnRH mRNA was expressed in the normal, hormone-treated and neoplastic rat prostates, in addition to its positive control expression in the hypothalamus, whereas its receptor was only detected in the androgen-dependent Dunning R3327H tumor. The detection of both GnRH and its receptor in the androgen-dependent Dunning R3327H tumor tissue suggests that this peptide hormone may have some autocrine and paracrine regulatory functions in this tumor. However, the gene expression of GnRH receptor was not detected in two androgen-independent Dunning tumor sublines and the Noble rat prostatic tumor, AIT, suggesting that the expression of GnRH receptor is lost or down-regulated in the prostatic tumors during the progression to a hormone-independent phenotype.