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1.
Adv Mater ; 36(28): e2313328, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38561634

ABSTRACT

Whether intentionally generating acoustic waves or attempting to mitigate unwanted noise, sound control is an area of challenge and opportunity. This study investigates traditional fabrics as emitters and suppressors of sound. When attached to a single strand of a piezoelectric fiber actuator, a silk fabric emits up to 70 dB of sound. Despite the complex fabric structure, vibrometer measurements reveal behavior reminiscent of a classical thin plate. Fabric pore size relative to the viscous boundary layer thickness is found-through comparative fabric analysis-to influence acoustic-emission efficiency. Sound suppression is demonstrated using two distinct mechanisms. In the first, direct acoustic interference is shown to reduce sound by up to 37 dB. The second relies on pacifying the fabric vibrations by the piezoelectric fiber, reducing the amplitude of vibration waves by 95% and attenuating the transmitted sound by up to 75%. Interestingly, this vibration-mediated suppression in principle reduces sound in an unlimited volume. It also allows the acoustic reflectivity of the fabric to be dynamically controlled, increasing by up to 68%. The sound emission and suppression efficiency of a 130 µm silk fabric presents opportunities for sound control in a variety of applications ranging from apparel to transportation to architecture.

2.
Acta Psychiatr Scand ; 148(6): 538-552, 2023 12.
Article in English | MEDLINE | ID: mdl-37899506

ABSTRACT

BACKGROUND: Up to 30% of patients with a diagnosis of treatment-resistant psychosis remain symptomatic despite an optimal trial with the gold standard treatment, clozapine. Emerging evidence suggests the clinical utility of long-acting injections (LAI) in such clinical scenarios. In this study, we aimed to describe clozapine augmentation with LAIs in an inner London hospital and explore the literature on the clinical effectiveness of this treatment modality. METHODS: Patients prescribed clozapine, who were commenced on a LAI between 2007 and 2023 by the United Kingdom's largest mental health trust, were identified from electronic patient records. First, routine clinical data were used to describe the use, effectiveness, and safety of this augmentation strategy. Second, we conducted a literature search up to 1st June 2023 to identify published studies describing clinical outcomes after clozapine augmentation with a LAI. Clinical outcomes were collated and presented in a table, including hospitalisation rates and quantitative clinical assessments using validated scales. RESULTS: Of the 1248 patients prescribed clozapine in SLaM, three patients (0.2%) received augmentation with the following LAIs: olanzapine embonate, paliperidone palmitate and pipotiazine palmitate. This treatment strategy was clinically effective and generally well tolerated in all three cases. Twelve published studies between 2010 and 2022 were included in the review. Eight distinct LAIs were reported (4 first and 4 second generation antipsychotics), with risperidone and paliperidone most widely studied. All the identified studies were observational including mirror-image studies, case series and case reports. Duration of follow up varied from 3 months to 3 years. There was evidence that the use of LAIs with clozapine can significantly reduce clinical symptoms, hospitalisation rates and bed days. No serious adverse effects were reported. CONCLUSION: This preliminary evidence suggests clinical utility of LAIs in alleviating residual symptoms and subsequently reducing hospitalisation rates in patients optimised on clozapine treatment. The current study warrants further investigations including a randomised controlled study to establish the clinical efficacy, tolerability, and place in therapy of this treatment modality.


Subject(s)
Antipsychotic Agents , Clozapine , Schizophrenia , Humans , Antipsychotic Agents/pharmacology , Antipsychotic Agents/therapeutic use , Clozapine/adverse effects , Schizophrenia/drug therapy , Schizophrenia/chemically induced , Risperidone/therapeutic use , Paliperidone Palmitate/therapeutic use , Delayed-Action Preparations/therapeutic use
3.
Adv Mater ; 34(19): e2201081, 2022 May.
Article in English | MEDLINE | ID: mdl-35278246

ABSTRACT

Electronic fabrics necessitate both electrical conductivity and, like any textile, elastic recovery. Achieving both requirements on the scale of a single fiber remains an unmet need. Here, two approaches for achieving conductive fibers (107 S m-1 ) reaching 50% elongation while maintaining minimal change in resistance (<0.5%) in embedded metallic electrodes are introduced. The first approach involves inducing a buckling instability in a metal microwire within a cavity of a thermally drawn elastomer fiber. The second approach relies on twisting an elastomer fiber to yield helical metal electrodes embedded in a stretchable yarn. The scalability of both approaches is illustrated in apparatuses for continuous buckling and twisting that yield tens of meters of elastic conducting fibers. Through experimental and analytical methods, it is elucidated how geometric parameters, such as buckling pre-strain and helical angle, as well as materials choice, control not only the fiber's elasticity but also its Young's modulus. Links between mechanical and electrical properties are exposed. The resulting fibers are used to construct elastic fabrics that contain diodes, by weaving and knitting, thus demonstrating the scalable fabrication of conformable and stretchable antennas that support optical data transmission.

4.
Int J Mol Sci ; 22(4)2021 Feb 08.
Article in English | MEDLINE | ID: mdl-33567533

ABSTRACT

Transformed epithelial cells can activate programs of epithelial plasticity and switch from a sessile, epithelial phenotype to a motile, mesenchymal phenotype. This process is linked to the acquisition of an invasive phenotype and the formation of distant metastases. The development of compounds that block the acquisition of an invasive phenotype or revert the invasive mesenchymal phenotype into a more differentiated epithelial phenotype represent a promising anticancer strategy. In a high-throughput assay based on E-cadherin (re)induction and the inhibition of tumor cell invasion, 44,475 low molecular weight (LMW) compounds were screened. The screening resulted in the identification of candidate compounds from the PROAM02 class. Selected LMW compounds activated E-cadherin promoter activity and inhibited cancer cell invasion in multiple metastatic human cancer cell lines. The intraperitoneal administration of selected LMW compounds reduced the tumor burden in human prostate and breast cancer in vivo mouse models. Moreover, selected LMW compounds decreased the intra-bone growth of xenografted human prostate cancer cells. This study describes the identification of the PROAM02 class of small molecules that can be exploited to reduce cancer cell invasion and metastases. Further clinical evaluation of selected candidate inhibitors is warranted to address their safety, bioavailability and antitumor efficacy in the management of patients with aggressive cancers.


Subject(s)
Breast Neoplasms/pathology , Cell Movement , Drug Discovery , Gene Expression Regulation, Neoplastic/drug effects , Prostatic Neoplasms/pathology , Small Molecule Libraries/pharmacology , Animals , Apoptosis , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Cell Proliferation , Female , High-Throughput Screening Assays , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
5.
Asia Pac Psychiatry ; 12(3): e12403, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32830438

ABSTRACT

To facilitate the understanding of pregabalin and optimize its clinical usage in Hong Kong, an expert panel (11 psychiatrists, one family physician and one anesthesiologist) experienced in treating anxiety and somatic symptoms was invited to establish a set of consensus statements based on several discussion areas. A non-systematic literature search for relevant articles was conducted. The panelists addressed the discussion areas by sharing their clinical experience and available literature in a couple of meetings. At the last meeting, consensus statements derived from the proceedings were discussed and finalized. A total of 11 statements were ultimately accepted by panel voting based on their practicability of recommendation in Hong Kong. These statements are aimed to act as a practical reference for local clinicians when they consider prescribing pregabalin in different clinical situations.


Subject(s)
Calcium Channel Blockers/therapeutic use , Consensus , Practice Guidelines as Topic , Pregabalin/therapeutic use , Psychiatry/standards , Hong Kong , Humans , Neuropharmacology/standards , Practice Guidelines as Topic/standards , Psychopharmacology/standards
6.
ANZ J Surg ; 90(3): 251-256, 2020 03.
Article in English | MEDLINE | ID: mdl-30776854

ABSTRACT

BACKGROUND: This study aims to establish compliance levels to prescription guidelines among Australian surgeons in the use of antibiotics in the surgical management of appendicitis. The secondary outcomes are predictors of post-operative infective complications; surgical site infection (SSI) and intra-abdominal abscess (IAA) at 30 days. METHODS: A multi-centre, prospective, observational study was conducted over a period of 2 months with a 30-day follow-up. Patients were eligible for recruitment if they underwent appendicectomy for suspected appendicitis. Antibiotics prescription practices were recorded and compared to national guidelines. RESULTS: A total of 1189 patients were recruited across 27 centres; 1081 (92.1%) patients were given prophylactic antibiotics at the time of appendicectomy. Patients with gangrenous appendicitis were more likely to receive prophylactic antibiotics (98.9%); lower rates of use were seen in the non-appendicitis group (85.7%). A total of 619 (53.3%) patients received antibiotics in the post-operative period. Despite recommendations, 300 (44.3%) patients with simple appendicitis received post-operative antibiotics. Only six (2.9%) patients with complicated appendicitis did not receive antibiotics. Overall, SSI and IAA rates were 1.9% and 2.7%, respectively. Aboriginal and Torres Strait Islanders (P = 0.02) and patients with converted operations (P = 0.001) were more likely to have a SSI. Patients with complicated appendicitis and those operated on by a consultant were more likely to increase the odds of IAA (odds ratio 3.8 and 5.1, respectively). CONCLUSION: This broad-based study shows mixed compliance with antibiotic guidelines in the surgical management of appendicitis in Australia. The use of post-operative antibiotics in patients with simple appendicitis should be a target for antimicrobial stewardship programmes to prevent antibiotic over-utilization.


Subject(s)
Abdominal Abscess/prevention & control , Anti-Bacterial Agents/therapeutic use , Appendectomy , Appendicitis/drug therapy , Appendicitis/surgery , Drug Prescriptions/standards , Emergency Treatment , Guideline Adherence/statistics & numerical data , Postoperative Complications/prevention & control , Surgical Wound Infection/prevention & control , Abdominal Abscess/epidemiology , Adolescent , Adult , Aged , Australia , Child , Female , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Prospective Studies , Surgical Wound Infection/epidemiology , Young Adult
7.
Methods Mol Biol ; 1786: 81-102, 2018.
Article in English | MEDLINE | ID: mdl-29786788

ABSTRACT

Current treatments of advanced prostate cancer only marginally increase overall survival and can be regarded as predominantly palliative. Hence, there is an urgent need for novel therapeutic strategies for the treatment of primary tumors and, more importantly perhaps, for the prevention of tumor progression and metastasis formation. Clinically relevant preclinical models are therefore urgently needed. An ideal, clinically relevant preclinical model would mimic the genetic and phenotypic changes that occur at the different stages of human prostate cancer progression and subsequent metastasis. In this chapter, transplantable xenograft prostate cancer models are described, in which human prostate cancer cells are transplanted into host animals (e.g., immune-deficient mice). Cancer cells can be administered to the small laboratory animals in various ways, including inoculation of the prostate tumor cells subcutaneously, at the anatomical site of origin (orthotopically), or at the metastatic site. In addition, we describe imaging methods suitable for small laboratory animals with emphasis on optical imaging (bioluminescence and fluorescence).


Subject(s)
Neoplasm Transplantation , Optical Imaging , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Whole Body Imaging , Animals , Cell Line, Tumor , Disease Models, Animal , Heterografts , Humans , Luminescent Measurements/methods , Male , Mice , Multimodal Imaging/methods , Optical Imaging/methods , Whole Body Imaging/methods
8.
Asia Pac J Clin Oncol ; 14(2): e175-e180, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29115720

ABSTRACT

AIM: This study examined pathological quality-of-surgery indicators in laparoscopic and open rectal cancer resection specimens. METHODS: Retrospective analysis of consecutive, prospectively recorded laparoscopic (LR) or open (OR) resections for rectal cancer. Indicators included integrity of the perirectal fascial envelope, circumferential margin clearance, lymph node yield and distal margin clearance. RESULTS: Between January 2007 and December 2013, 168 LR and 189 OR were performed. Univariate analysis showed that the presence of tumor within 1 mm of the circumferential margin was lower in LR (13/168 vs 28/189 cases, P = 0.039) as was a distal margin of clearance of < 1 cm (3/165 vs 12/186, P = 0.032). There was no difference in the surgical disruption of the fascial envelope (P = 0.091) or the percentage of specimens with a lymph node yield < 12 (P = 0.576) between the LR and OR groups. Multivariate analysis did not reveal any significant differences in pathological outcomes. CONCLUSION: With careful case selection, laparoscopic surgery has similar pathological outcomes to open surgery for rectal cancer.


Subject(s)
Laparoscopy/methods , Rectal Neoplasms/surgery , Aged , Female , Humans , Male , Prospective Studies , Rectal Neoplasms/pathology , Retrospective Studies , Treatment Outcome
9.
PLoS One ; 11(7): e0159531, 2016.
Article in English | MEDLINE | ID: mdl-27427904

ABSTRACT

Transcription factors have an important role in cancer but are difficult targets for the development of tumour therapies. These factors include the Ets family, and in this study Elk3 that is activated by Ras oncogene /Erk signalling, and is involved in angiogenesis, malignant progression and epithelial-mesenchymal type processes. We previously described the identification and in-vitro characterisation of an inhibitor of Ras / Erk activation of Elk3 that also affects microtubules, XRP44X. We now report an initial characterisation of the effects of XRP44X in-vivo on tumour growth and metastasis in three preclinical models mouse models, subcutaneous xenografts, intra-cardiac injection-bone metastasis and the TRAMP transgenic mouse model of prostate cancer progression. XRP44X inhibits tumour growth and metastasis, with limited toxicity. Tumours from XRP44X-treated animals have decreased expression of genes containing Elk3-like binding motifs in their promoters, Elk3 protein and phosphorylated Elk3, suggesting that perhaps XRP44X acts in part by inhibiting the activity of Elk3. Further studies are now warranted to develop XRP44X for tumour therapy.


Subject(s)
Antineoplastic Agents/pharmacology , Bone Neoplasms/drug therapy , Gene Expression Regulation, Neoplastic , Piperazines/pharmacology , Prostatic Neoplasms/drug therapy , Proto-Oncogene Proteins c-ets/antagonists & inhibitors , Pyrazoles/pharmacology , Animals , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Cell Line, Tumor , Drug Evaluation, Preclinical , Female , Genes, ras/drug effects , Heart Ventricles/metabolism , Heart Ventricles/pathology , Injections, Subcutaneous , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Mice, Transgenic , Microtubules/drug effects , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/genetics , Mitogen-Activated Protein Kinase 3/metabolism , Neuroglia/drug effects , Neuroglia/metabolism , Neuroglia/pathology , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Proto-Oncogene Proteins c-ets/genetics , Proto-Oncogene Proteins c-ets/metabolism , Rats , Signal Transduction , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
10.
Prostate ; 75(8): 815-24, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25663076

ABSTRACT

BACKGROUND: The inflammatory tumor microenvironment, and more specifically the tumor-associated macrophages, plays an essential role in the development and progression of prostate cancer towards metastatic bone disease. Tumors are often characterized by a leaky vasculature, which - combined with the prolonged circulation kinetics of liposomes - leads to efficient tumor localization of these drug carriers, via the so-called enhanced permeability and retention (EPR) -effect. In this study, we evaluated the utility of targeted, liposomal drug delivery of the glucocorticoid dexamethasone in a model of prostate cancer bone metastases. METHODS: Tumor-bearing Balb-c nu/nu mice were treated intravenously with 0.2-1.0-5.0 mg/kg/week free- and liposomal DEX for 3-4 weeks and tumor growth was monitored by bioluminescent imaging. RESULTS: Intravenously administered liposomes localize efficiently to bone metastases in vivo and treatment of established bone metastases with (liposomal) dexamethasone resulted in a significant inhibition of tumor growth up to 26 days after initiation of treatment. Furthermore, 1.0 mg/kg liposomal dexamethasone significantly outperformed 1.0 mg/kg free dexamethasone, and was found to be well-tolerated at clinically-relevant dosages that display potent anti-tumor efficacy. CONCLUSIONS: Liposomal delivery of the glucocorticoid dexamethasone inhibits the growth of malignant bone lesions. We believe that liposomal encapsulation of dexamethasone offers a promising new treatment option for advanced, metastatic prostate cancer which supports further clinical evaluation.


Subject(s)
Antineoplastic Agents, Hormonal/administration & dosage , Bone Neoplasms/prevention & control , Bone Neoplasms/secondary , Dexamethasone/administration & dosage , Drug Delivery Systems/methods , Prostatic Neoplasms/drug therapy , Animals , Bone Neoplasms/pathology , Cell Line, Tumor , Humans , Liposomes , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Prostatic Neoplasms/pathology , Rats , Rats, Sprague-Dawley
11.
J Pathol ; 235(5): 745-59, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25421310

ABSTRACT

Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the most frequently occurring histological subtypes of breast cancer, accounting for 80-90% and 10-15% of the total cases, respectively. At the time of diagnosis and surgical resection of the primary tumour, most patients do not have clinical signs of metastases, but bone micrometastases may already be present. Our aim was to develop a novel preclinical ILC model of spontaneous bone micrometastasis. We used murine invasive lobular breast carcinoma cells (KEP) that were generated by targeted deletion of E-cadherin and p53 in a conditional K14cre;Cdh1((F/F));Trp53((F/F)) mouse model of de novo mammary tumour formation. After surgical resection of the growing orthotopically implanted KEP cells, distant metastases were formed. In contrast to other orthotopic breast cancer models, KEP cells readily formed skeletal metastases with minimal lung involvement. Continuous treatment with SD-208 (60 mg/kg per day), an orally available TGFß receptor I kinase inhibitor, increased the tumour growth at the primary site and increased the number of distant metastases. Furthermore, when SD-208 treatment was started after surgical resection of the orthotopic tumour, increased bone colonisation was also observed (versus vehicle). Both our in vitro and in vivo data show that SD-208 treatment reduced TGFß signalling, inhibited apoptosis, and increased proliferation. In conclusion, we have demonstrated that orthotopic implantation of murine ILC cells represent a new breast cancer model of minimal residual disease in vivo, which comprises key steps of the metastatic cascade. The cancer cells are sensitive to the anti-tumour effects of TGFß. Our in vivo model is ideally suited for functional studies and evaluation of new pharmacological intervention strategies that may target one or more steps along the metastatic cascade of events.


Subject(s)
Bone Neoplasms/secondary , Breast Neoplasms/pathology , Carcinoma, Lobular/secondary , Mammary Neoplasms, Experimental/pathology , Protein Kinase Inhibitors/toxicity , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pteridines/toxicity , Receptors, Transforming Growth Factor beta/antagonists & inhibitors , Animals , Apoptosis/drug effects , Bone Neoplasms/enzymology , Bone Neoplasms/genetics , Breast Neoplasms/chemically induced , Breast Neoplasms/enzymology , Breast Neoplasms/genetics , Carcinoma, Lobular/chemically induced , Carcinoma, Lobular/enzymology , Carcinoma, Lobular/genetics , Cdh1 Proteins/deficiency , Cdh1 Proteins/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Mammary Neoplasms, Experimental/chemically induced , Mammary Neoplasms, Experimental/enzymology , Mammary Neoplasms, Experimental/genetics , Mice, Knockout , Neoplasm Micrometastasis , Protein Serine-Threonine Kinases/metabolism , Receptor, Transforming Growth Factor-beta Type I , Receptors, Transforming Growth Factor beta/metabolism , Signal Transduction/drug effects , Time Factors , Transfection , Tumor Burden/drug effects , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics
12.
Oncotarget ; 5(19): 8986-94, 2014 Oct 15.
Article in English | MEDLINE | ID: mdl-25344861

ABSTRACT

Cancer cells with stem or progenitor properties play a pivotal role in the initiation, recurrence and metastatic potential of solid tumors, including those of the human prostate. Cancer stem cells are generally more resistant to conventional therapies thus requiring the characterization of key pathways involved in the formation and/or maintenance of this malignant cellular subpopulation. To this end, we identified Glycogen Synthase Kinase-3ß (GSK-3ß) as a crucial kinase for the maintenance of prostate cancer stem/progenitor-like cells and pharmacologic inhibition of GSK-3ß dramatically decreased the size of this cellular subpopulation. This was paralleled by impaired clonogenicity, decreased migratory potential and dramatic morphological changes. In line with our in vitro observations, treatment with a GSK-3ß inhibitor leads to a complete loss of tumorigenicity and a decrease in metastatic potential in preclinical in vivo models. These observed anti-tumor effects appear to be largely Wnt-independent as simultaneous Wnt inhibition does not reverse the observed antitumor effects of GSK-3ß blockage. We found that GSK-3ß activity is linked to cytoskeletal protein F-actin and inhibition of GSK-3ß leads to disturbance of F-actin polymerization. This may underlie the dramatic effects of GSK-3ß inhibition on prostate cancer migration. Furthermore, GSK-3ß inhibition led to strongly decreased expression of several integrin types including the cancer stem cell-associated α2ß1 integrin. Taken together, our mechanistic observations highlight the importance of GSK-3ß activity in prostate cancer stemness and may facilitate the development of novel therapy for advanced prostate cancer.


Subject(s)
Glycogen Synthase Kinase 3/antagonists & inhibitors , Neoplasm Metastasis/pathology , Neoplastic Stem Cells/cytology , Prostatic Neoplasms/pathology , Actins/metabolism , Animals , Cell Line, Tumor , Cell Movement , Cell Proliferation/drug effects , Glycogen Synthase Kinase 3 beta , Humans , Integrin alpha2beta1/biosynthesis , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Prostatic Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Protein Multimerization/drug effects , Wnt Proteins/antagonists & inhibitors , Wnt Signaling Pathway/drug effects
13.
PLoS One ; 9(9): e108464, 2014.
Article in English | MEDLINE | ID: mdl-25247809

ABSTRACT

Low survival rates of metastatic cancers emphasize the need for a drug that can prevent and/or treat metastatic cancer. αv integrins are involved in essential processes for tumor growth and metastasis and targeting of αv integrins has been shown to decrease angiogenesis, tumor growth and metastasis. In this study, the role of αv integrin and its potential as a drug target in bladder cancer was investigated. Treatment with an αv integrin antagonist as well as knockdown of αv integrin in the bladder carcinoma cell lines, resulted in reduced malignancy in vitro, as illustrated by decreased proliferative, migratory and clonogenic capacity. The CDH1/CDH2 ratio increased, indicating a shift towards a more epithelial phenotype. This shift appeared to be associated with downregulation of EMT-inducing transcription factors including SNAI2. The expression levels of the self-renewal genes NANOG and BMI1 decreased as well as the number of cells with high Aldehyde Dehydrogenase activity. In addition, self-renewal ability decreased as measured with the urosphere assay. In line with these observations, knockdown or treatment of αv integrins resulted in decreased metastatic growth in preclinical in vivo models as assessed by bioluminescence imaging. In conclusion, we show that αv integrins are involved in migration, EMT and maintenance of Aldehyde Dehydrogenase activity in bladder cancer cells. Targeting of αv integrins might be a promising approach for treatment and/or prevention of metastatic bladder cancer.


Subject(s)
Carcinoma, Transitional Cell/pathology , Genetic Vectors/pharmacology , Integrin alphaV/drug effects , Molecular Targeted Therapy , Neoplasm Proteins/antagonists & inhibitors , RNA Interference , RNA, Small Interfering/pharmacology , Receptors, Vitronectin/antagonists & inhibitors , Urinary Bladder Neoplasms/pathology , Aldehyde Dehydrogenase/biosynthesis , Aldehyde Dehydrogenase/genetics , Animals , Cell Adhesion/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Self Renewal/drug effects , Epithelial-Mesenchymal Transition/drug effects , Female , Gene Expression Regulation, Neoplastic/drug effects , Heart , Humans , Integrin alphaV/physiology , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , Neoplasm Transplantation/methods , Papilloma/pathology , Receptors, Vitronectin/physiology , Tibia , Transcription Factors/biosynthesis , Transcription Factors/genetics , Transduction, Genetic , Tumor Stem Cell Assay , Xenograft Model Antitumor Assays
14.
Am J Pathol ; 179(5): 2559-68, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21907176

ABSTRACT

Integrins participate in multiple cellular processes, including cell adhesion, migration, proliferation, survival, and the activation of growth factor receptors. Recent studies have shown that expression of αv integrins is elevated in the prostate cancer stem/progenitor cell subpopulation compared with more differentiated, committed precursors. Here, we examine the functional role of αv integrin receptor expression in the acquisition of a metastatic stem/progenitor phenotype in human prostate cancer. Stable knockdown of αv integrins expression in PC-3M-Pro4 prostate cancer cells coincided with a significant decrease of prostate cancer stem/progenitor cell characteristics (α2 integrin, CD44, and ALDH(hi)) and decreased expression of invasion-associated genes Snail, Snail2, and Twist. Consistent with these observations, αv-knockdown strongly inhibited the clonogenic and migratory potentials of human prostate cancer cells in vitro and significantly decreased tumorigenicity and metastatic ability in preclinical models of orthotopic growth and bone metastasis. Our data indicate that integrin αv expression is functionally involved in the maintenance of a highly migratory, mesenchymal cellular phenotype as well as the acquisition of a stem/progenitor phenotype in human prostate cancer cells with metastasis-initiating capacity.


Subject(s)
Integrin alphaV/metabolism , Neoplastic Stem Cells/metabolism , Prostatic Neoplasms/metabolism , Animals , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Cell Movement , Cell Transformation, Neoplastic/metabolism , Gene Knockdown Techniques , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Neoplasm Metastasis , Neoplasm Transplantation , Phenotype , Tumor Stem Cell Assay , Up-Regulation
15.
Clin Exp Metastasis ; 28(7): 615-25, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21647815

ABSTRACT

High aldehyde dehydrogenase (ALDH) activity can be used to identify tumor-initiating and metastasis-initiating cells in various human carcinomas, including prostate cancer. To date, the functional importance of ALDH enzymes in prostate carcinogenesis, progression and metastasis has remained elusive. Previously we identified strong expression of ALDH7A1 in human prostate cancer cell lines, primary tumors and matched bone metastases. In this study, we evaluated whether ALDH7A1 is required for the acquisition of a metastatic stem/progenitor cell phenotype in human prostate cancer. Knockdown of ALDH7A1 expression resulted in a decrease of the α2(hi)/αv(hi)/CD44(+) stem/progenitor cell subpopulation in the human prostate cancer cell line PC-3M-Pro4. In addition, ALDH7A1 knockdown significantly inhibited the clonogenic and migratory ability of human prostate cancer cells in vitro. Furthermore, a number of genes/factors involved in migration, invasion and metastasis were affected including transcription factors (snail, snail2, and twist) and osteopontin, an ECM molecule involved in metastasis. Knockdown of ALDH7A1 resulted in decreased intra-bone growth and inhibited experimentally induced (bone) metastasis, while intra-prostatic growth was not affected. In line with these observations, evidence is presented that TGF-ß, a key player in cancer invasiveness and bone metastasis, strongly induced ALDH activity while BMP7 (an antagonist of TGF-ß signaling) down-regulated ALDH activity. Our findings show, for the first time, that the ALDH7A1 enzyme is functionally involved in the formation of bone metastases and that the effect appeared dependent on the microenvironment, i.e., bone versus prostate.


Subject(s)
Aldehyde Dehydrogenase/metabolism , Bone Neoplasms/secondary , Neoplasm Metastasis/pathology , Prostatic Neoplasms/metabolism , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Cell Line, Tumor , Disease Progression , Epithelial-Mesenchymal Transition , Humans , Male , Prostatic Neoplasms/pathology
16.
Neoplasia ; 13(6): 516-25, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21677875

ABSTRACT

Acquisition of an invasive phenotype by cancer cells is a requirement for bone metastasis. Transformed epithelial cells can switch to a motile, mesenchymal phenotype by epithelial-mesenchymal transition (EMT). Recently, it has been shown that EMT is functionally linked to prostate cancer stem cells, which are not only critically involved in prostate cancer maintenance but also in bone metastasis. We showed that treatment with the non-peptide α(v)-integrin antagonist GLPG0187 dose-dependently increased the E-cadherin/vimentin ratio, rendering the cells a more epithelial, sessile phenotype. In addition, GLPG0187 dose-dependently diminished the size of the aldehyde dehydrogenase high subpopulation of prostate cancer cells, suggesting that α(v)-integrin plays an important role in maintaining the prostate cancer stem/progenitor pool. Our data show that GLPG0187 is a potent inhibitor of osteoclastic bone resorption and angiogenesis in vitro and in vivo. Real-time bioluminescent imaging in preclinical models of prostate cancer demonstrated that blocking α(v)-integrins by GLPG0187 markedly reduced their metastatic tumor growth according to preventive and curative protocols. Bone tumor burden was significantly lower in the preventive protocol. In addition, the number of bone metastases/mouse was significantly inhibited. In the curative protocol, the progression of bone metastases and the formation of new bone metastases during the treatment period was significantly inhibited. In conclusion, we demonstrate that targeting of integrins by GLPG0187 can inhibit the de novo formation and progression of bone metastases in prostate cancer by antitumor (including inhibition of EMT and the size of the prostate cancer stem cell population), antiresorptive, and antiangiogenic mechanisms.


Subject(s)
Antineoplastic Agents/pharmacology , Bone Neoplasms/prevention & control , Integrin alphaV/metabolism , Neoplastic Stem Cells/drug effects , Prostatic Neoplasms/drug therapy , Animals , Animals, Newborn , Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Epithelial-Mesenchymal Transition/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Immunohistochemistry , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplastic Stem Cells/metabolism , Neovascularization, Pathologic/prevention & control , Osteoclasts/drug effects , Osteoclasts/metabolism , Osteoclasts/pathology , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Reverse Transcriptase Polymerase Chain Reaction , Tumor Burden/drug effects , Tumor Microenvironment/drug effects , Twist-Related Protein 1/genetics , Xenograft Model Antitumor Assays
17.
Eur Urol ; 60(2): 337-43, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21616583

ABSTRACT

BACKGROUND: Bladder cancer is the fifth most common malignancy in the Western world and the second most frequently diagnosed genitourinary tumor. In the majority of cases, death from bladder cancer results from metastatic disease. Understanding the multistep process of carcinogenesis and metastasis in urothelial cancers is pivotal to the development of new therapeutic strategies. Molecular imaging of cancer growth and metastasis in preclinical models provides the essential link between cell-based experiments and clinical translation. OBJECTIVE: Develop preclinical models for sensitive bladder cancer cell tracking during tumor progression and metastasis. DESIGN, SETTING, AND PARTICIPANTS: A human transitional cell carcinoma UM-UC-3 cell line was generated that stably expresses luciferase 2 (UM-UC-3luc2), a mammalian codon-optimized firefly luciferase with superior expression. Preclinical models were developed with human UM-UC-3luc2 cells xenografted into the bladder (orthotopic model with metastases) or inoculated into the left cardiac ventricle (bone metastasis model) of immunocompromised mice. MEASUREMENTS: Noninvasive, sensitive bioluminescent imaging of human firefly luciferase 2-positive bladder cancer in mice using the IVIS100 imaging system. RESULTS AND LIMITATIONS: In the orthotopic model (intravesical inoculation), tumor growth could be followed directly after inoculation of UM-UC-3luc2 cells. Importantly, micrometastatic lesions originating from orthotopically implanted cancer cells could be detected in the locoregional lymph nodes and in distant organs. In addition, the superior bioluminescent indicator firefly luciferase 2 allows the detection and monitoring of micrometastatic lesions in real time after intracardiac inoculation of human bladder cancer cells in mice. The main disadvantage is the lack of T-cell immunity in the preclinical models. CONCLUSIONS: The new bioluminescence-based preclinical bladder cancer models enable superior, noninvasive, and real-time tracking of cancer cells, tumor progression, and micrometastasis. Because of the significant improvement in detection of small cell numbers, the presented models are ideally suited for functional studies dealing with minimal residual disease as well as real-time imaging of drug response.


Subject(s)
Bone Neoplasms/secondary , Carcinoma, Transitional Cell/secondary , Cell Tracking/methods , Luciferases, Firefly/biosynthesis , Luminescent Measurements , Lung Neoplasms/secondary , Urinary Bladder Neoplasms/pathology , Animals , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/metabolism , Cell Line, Tumor , Female , Humans , Luciferases, Firefly/genetics , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lymphatic Metastasis , Mice , Mice, Inbred BALB C , Mice, Nude , Time Factors , Transfection , Tumor Burden , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/metabolism
18.
Cancer Res ; 70(12): 5163-73, 2010 Jun 15.
Article in English | MEDLINE | ID: mdl-20516116

ABSTRACT

Metastatic progression of advanced prostate cancer is a major clinical problem. Identifying the cell(s) of origin in prostate cancer and its distant metastases may permit the development of more effective treatment and preventive therapies. In this study, aldehyde dehydrogenase (ALDH) activity was used as a basis to isolate and compare subpopulations of primary human prostate cancer cells and cell lines. ALDH-high prostate cancer cells displayed strongly elevated clonogenicity and migratory behavior in vitro. More strikingly, ALDH-high cells readily formed distant metastases with strongly enhanced tumor progression at both orthotopic and metastatic sites in preclinical models. Several ALDH isoforms were expressed in human prostate cancer cells and clinical specimens of primary prostate tumors with matched bone metastases. Our findings suggest that ALDH-based viable cell sorting can be used to identify and characterize tumor-initiating and, more importantly perhaps, metastasis-initiating cells in human prostate cancer.


Subject(s)
Aldehyde Dehydrogenase/metabolism , Bone Neoplasms/enzymology , Bone Neoplasms/secondary , Prostatic Neoplasms/enzymology , Prostatic Neoplasms/pathology , Animals , Biomarkers, Tumor/metabolism , Blotting, Western , Cell Line, Tumor , Cell Proliferation , Cell Transformation, Neoplastic , Disease Progression , Flow Cytometry , Humans , Immunoenzyme Techniques , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Prostate/enzymology , Prostate/pathology
19.
Article in English | MEDLINE | ID: mdl-16316716

ABSTRACT

PURPOSE: To evaluate clinical efficacy of clozapine in relation with its plasma level in a group of Chinese patients with treatment-resistant schizophrenia. In addition, the relationship between plasma level and side effects were examined. METHOD: Fifty-one patients with treatment-resistant schizophrenia were put on a fixed dose of clozapine at 300 mg/day for 6 weeks. Non-responders to week 6 received 500 mg/day in subsequent 6 weeks. Responders to week 6 continued to receive 300 mg/day. Clozapine plasma levels were checked at weeks 6 and 12. FINDINGS: No association was found between clozapine plasma level, response and side effects. Sodium valproate was found to elevate clozapine plasma level while lowering norclozapine/clozapine ratio. CONCLUSION: Clozapine plasma level was not found to be associated with response and side effect in Chinese treatment-resistant schizophrenic patients. Various explanations were postulated for the lack of relationship observed between clozapine plasma level and response in this population.


Subject(s)
Antipsychotic Agents/blood , Antipsychotic Agents/therapeutic use , Clozapine/blood , Clozapine/therapeutic use , Schizophrenia/blood , Schizophrenia/drug therapy , Adolescent , Adult , Aged , Anticonvulsants/administration & dosage , China/epidemiology , Chromatography, High Pressure Liquid/methods , Drug Interactions , Electrochemistry/methods , Female , Humans , Male , Middle Aged , ROC Curve , Sensitivity and Specificity , Statistics, Nonparametric , Time Factors , Valproic Acid/administration & dosage
20.
Anal Biochem ; 343(2): 263-7, 2005 Aug 15.
Article in English | MEDLINE | ID: mdl-15993373

ABSTRACT

An amperometric biosensor was constructed for analysis of human salivary phosphate without sample pretreatment. The biosensor was constructed by immobilizing pyruvate oxidase (PyOD) on a screen-printed electrode. The presence of phosphate in the sample causes the enzymatic generation of hydrogen peroxide (H(2)O(2)), which was monitored by a potentiostat and was in proportion to the concentration of human salivary phosphate. The sensor shows response within 2s after the addition of standard solution or sample and has a short recovery time (2 min). The time required for one measurement using this phosphate biosensor was 4 min, which was faster than the time required using a commercial phosphate testing kit (10 min). The sensor has a linear range from 7.5 to 625 microM phosphate with a detection limit of 3.6 microM. A total of 50 salivary samples were collected for the determination of phosphate. A good level of agreement (R(2)=0.9646) was found between a commercial phosphate testing kit and the phosphate sensor. This sensor maintained a high working stability (>85%) after 12h operation and required only a simple operation procedure. The amperometric biosensor using PyOD is a simple and accurate tool for rapid determinations of human salivary phosphate, and it explores the application of biosensors in oral and dental research and diagnosis.


Subject(s)
Biosensing Techniques/methods , Phosphates/analysis , Saliva/chemistry , Carbamates/chemistry , Electrochemistry , Enzymes, Immobilized/chemistry , Fluorocarbon Polymers/chemistry , Humans , Hydrogen Peroxide/chemistry , Phosphates/chemistry , Polyesters/chemistry , Pyruvate Oxidase/chemistry , Reagent Kits, Diagnostic , Reproducibility of Results , Time Factors
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