Analysis of a National Programme for Selective Internal Radiation Therapy for Colorectal Cancer Liver Metastases.

AIMS: Patients with chemotherapy-refractory colorectal cancer liver metastases have limited therapeutic options. Selective internal radiation therapy (SIRT) delivers yttrium 90 microspheres as a minimally invasive procedure. This prospective, single-arm, observational, service-evaluation study was part of National Health Service England Commissioning through Evaluation. METHODS: Patients eligible for treatment had histologically confirmed carcinoma with liver-only/liver-dominant metastases with clinical progression during or following oxaliplatin-based and irinotecan-based chemotherapy. All patients received SIRT plus standard of care. The primary outcome was overall survival; secondary outcomes included safety, progression-free survival (PFS) and liver-specific PFS (LPFS). RESULTS: Between December 2013 and March 2017, 399 patients were treated in 10 centres with a median follow-up of 14.3 months (95% confidence interval 9.2-19.4). The median overall survival was 7.6 months (95% confidence interval 6.9-8.3). The median PFS and LPFS were 3.0 months (95% confidence interval 2.8-3.1) and 3.7 months (95% confidence interval 3.2-4.3), respectively. During the follow-up period, 143 patients experienced an adverse event and 8% of the events were grade 3. CONCLUSION: Survival estimates from this pragmatic study show clinical outcomes attainable in the National Health Service comparable with previously published data. This study shows the value of a registry-based commissioning model to aid national commissioning decisions for highly specialist cancer treatments.

Structure-function analysis of a novel member of the LIV-1 subfamily of zinc transporters, ZIP14.

Here, we report the first investigation of a novel member of the LZT (LIV-1 subfamily of ZIP zinc Transporters) subfamily of zinc influx transporters. LZT subfamily sequences all contain a unique and highly conserved metalloprotease motif (HEXPHEXGD) in transmembrane domain V with both histidine residues essential for zinc transport by ZIP (Zrt-, Irt-like Proteins) transporters. We investigate here whether ZIP14 (SLC39A14), lacking the initial histidine in this motif, is still able to transport zinc. We demonstrate that this plasma membrane located glycosylated protein functions as a zinc influx transporter in a temperature-dependant manner.

Heat shock proteins in cultured human keratinocytes and fibroblasts.

Heat shock induces in cells the synthesis of specific proteins called heat-shock proteins. We have compared the induction of these proteins in human keratinocytes, skin fibroblasts, and a human epithelial tumor cell line following exposure to weak and strong inducing agents (heat, cadmium sulphate, and sodium arsenite). The induction of heat shock proteins was measured in cells by one-dimensional gel electrophoresis of [35S] methionine-labeled proteins and by immunofluorescence using a specific HSP72 monoclonal antibody. Both HSP90 and HSP116 were constitutively expressed in these cell types. Exposure of these cells to weak inducing agents such as heat or cadmium sulphate resulted in the synthesis of HSP72 and HSP90, whereas HSP28 and HSP116 synthesis was detected in keratinocytes and fibroblasts following exposure to the strong inducing agent sodium arsenite. In addition, sodium arsenite induced the synthesis of HSP46 in human keratinocytes. Immunofluorescence demonstrated a rapid and reversible accumulation of the 72-kD heat shock protein within the nucleolus of heat-stressed human keratinocytes and fibroblasts.

Hormonal and metabolic control of proteolysis.

Proteolysis in heart muscle is regulated by hormonal and metabolic factors. In the absence of insulin, protein degradation accelerated, autophagic vacuoles appeared within the heart and latency of lysosomal enzymes decreased. Addition of insulin prevented or reversed these changes. Provision of leucine inhibited proteolysis in control hearts. Addition of the products of transamination and oxidative decarboxylation of leucine, isoleucine and valine had similar inhibitory effects. Protein degradation was inhibited in ischaemic or anoxic hearts, but latency of lysosomal enzymes was decreased. Inhibition of degradation in energy-poor tissue may represent both an energy-requirement for proteolysis and inhibition by accumulation of metabolic products, such as lactate.

Signal transduction in myocardial hypertrophy.

Transduction of stretch of the ventricular wall into accelerated growth and ultimately hypertrophy of cardiac muscle cells is a cyclic AMP (cAMP) dependent phenomenon. When stretch was induced in isolated perfused rat hearts by an increase in aortic pressure from 60 to 120 mmHg, protein synthesis was accelerated during the second hour of perfusion. Only a brief exposure to higher aortic pressure (2 min) was required to elicit this effect. Elevation of aortic pressure also increased cAMP content. Other interventions that increased cAMP content such as glucagon increased second hour rates of protein synthesis. Stretch of the ventricular wall had a more rapid effect on ribosome formation. During the first hour of perfusion, increased aortic pressure raised rates of 60S ribosomal subunit formation by 38% in the absence of added insulin and 35% in the presence of the hormone. Ribosome formation was also accelerated by addition of glucagon. The muscarinic cholinergic agonist, methacholine blocked the effects of elevated aortic pressure on protein synthesis, ribosome formation, and cAMP content. These studies indicate that stretch of the ventricular wall is transduced into greater cAMP content and that this intracellular messenger is one of the substances responsible for accelerated ribosome formation and protein synthesis.

Isolated heart perfusion techniques for rapid screening of myocardial preservation methods. Anoxia versus ischemia.

Isolated nonworking and working heart preparations are described and recent modifications that increase their reliability and scope are reviewed. Isolated perfused tissues are superior to other models for screening myocardial preservation techniques. The metabolic and functional differences between anoxia and ischemia are stressed, myocardial glycolysis is reviewed, and from basic studies potentially fruitful avenues for investigation of myocardial preservation techniques are outlined. Better application of available knowledge of myocardial metabolism could further reduce the risks of cardiac operation.

In vitro reconstruction of human skin: The use of skin equivalents as potential indicators of cutaneous toxicity.

A three-dimensional reconstruction of living skin-the skin equivalent-has been modified to accept materials that can be applied topically to the skin. Using an irritant gel containing 10% benzoyl peroxide, changes in the skin equivalent model were investigated. Histologically, epidermal necrosis and vacuolar change were observed within 4-6 hr after topical application. Using skin equivalents prelabelled with [(3)H]arachidonic acid, studies involving direct measurement using HPLC and radioimmunoassay have indicated the release of potent lipoxygenase products, such as leukotriene B(4) and 15-hydroxyeicosa-tetraenoic acid. These preliminary results suggest that the skin equivalent may prove to be a useful in vitro model for the prediction of cutaneous toxicity of topically applied substances.

Induction of heat shock proteins as a measure of chemical cytotoxicity.

Exposure of human keratinocytes to non-lethal heat shock treatment (43 degrees C for 90 min) followed by a recovery period of 2 hr at 37 degrees C resulted in the rapid accumulation of two proteins with polypeptide molecular weights of 72 and 90 kDa. Exposure of human keratinocytes to sodium arsenite (10-200 mug/ml) for 90 min at 37 degrees C resulted in the synthesis of proteins with polypeptide molecular weights of 110, 90, 72, 46 and 28 kDa. The 72 kDa heat- or sodium arsenite-induced protein was identified by immunoprecipitation as the 72 kDa heat shock protein. In contrast, the human epithelial tumour cell line (A431) synthesized only the 72 and 28 kDa heat shock proteins in response to arsenite treatment with all other stress proteins being expressed constitutively. General protein synthesis was inhibited in cells exposed to elevated temperature or sodium arsenite. Using immunofluorescence a rapid and reversible accumulation of the 72 kDa heat shock protein was demonstrated within the nucleolus of heat stressed human fibroblasts and keratinocytes.

Aortic perfusion pressure and protein synthesis.

The effect of increased pressure load on cardiac protein synthesis has been studied in Langendorff preparations and working hearts supplied glucose as substrate. During the second hour of perfusion, elevation of perfusion pressure from 60 to 120 mmHg in Langendorff preparations accelerated protein synthesis by approximately 40% while induction of cardiac work and development of a systolic pressure of 145 mmHg increased synthesis by 22%, as compared to a Langendorff preparation perfused at 60 mmHg. In Langendorff preparations, increased perfusion pressure still accelerated protein synthesis when a drain was placed in the ventricle and intraventricular pressure development was prevented or when the heart was arrested with tetrodotoxin and the ventricle drained. These results suggest that the enhancement of protein synthesis with a pressure load may be induced by passive stretch of the cardiac muscle cell secondary to increased perfusion pressure.

Cellular aspects of cardiac failure.

Intracellular signaling systems that are involved in growth of cardiac myocytes and that are modified in congestive heart failure include the alpha 1- and beta-adrenergic systems and angiotensin II. These systems include G-protein-linked hormone receptors and their membrane enzyme including adenylyl cyclase and phospholipase C. In addition, membrane enzymes, and adenylyl cyclase in particular, respond directly to stretch of the cell membrane with an increase in cAMP formation. Furthermore, interactions between stretch and hormonal stimuli can potentiate each other and result in enhanced signal generation.