Regulation of EGFR Protein Stability by the HECT-type Ubiquitin Ligase SMURF2

Epidermal growth factor receptor (EGFR) is overexpressed in a variety of epithelial tumors and is considered to be an important therapeutic target. Although gene amplification is responsible for EGFR overexpression in certain human malignancies including lung and head and neck cancers, additional molecular mechanisms are likely. Here, we report a novel interaction of EGFR with an HECT-type ubiquitin ligase SMURF2, which can ubiquitinate, but stabilize EGFR by protecting it from c-Cbl-mediated degradation. Conversely, small interfering RNA (siRNA)-mediated knockdown of SMURF2 destabilized EGFR, induced an autophagic response and reduced the clonogenic survival of EGFR-expressing cancer cell lines, with minimal effects on EGFR-negative cancer cells, normal fibroblasts, and normal epithelial cells. UMSCC74B head and neck squamous cancer cells, which form aggressive tumors in nudemice, significantly lost in vivo tumor-forming ability on siRNA-mediated SMURF2 knockdown. Gene expressionmicroarray data from 443 lung adenocarcinoma patients, and tissue microarray data from 67 such patients, showed a strong correlation of expression between EGFR and SMURF2 at the messenger RNA and protein levels, respectively. Our findings suggest that SMURF2-mediated protective ubiquitination of EGFR may be responsible for EGFR overexpression in certain tumors and support targeting SMURF2-EGFR interaction as a novel therapeutic approach in treating EGFR-addicted tumors.     

Staff attitudes towards institutionalised dementia residents

Aim. To explore the attitudes of staff caring for institutionalised dementia residents and the variables associated with these attitudes. Methods. Fourteen nursing homes and one hospital‐based geriatric ward in Bergen, Norway were surveyed, using the translation of an Approach to Dementia Questionnaire. The study population (n = 291) was a mixture of registered nurses, auxiliary nurses, nursing assistants and non‐trained aides. Design. Survey. Results. Significant differences in hope and person‐centred attitudes were identified in this study. Nursing assistants, compared with registered nurses (p = 0·02), had significantly lower hope attitudes· Staff over 50 years of age reported significantly lower hope attitudes (p = 0·01) than those under 40 years of age. Staff with 10 and fewer years of work experience reported significantly lower hope attitudes (p = 0·02) than those with more than 10 years of experience. Nurses with specialised training in geriatrics, psychiatry or dementia care had significantly higher hope attitudes, compared with nurses without any special training (p = 0·04). The person‐centred attitude was lower among participants who were over 50 years old, compared with their counterparts under the age of 40 (p ≤ 0·01). Discussion. Education, age, work experience, care unit size and specialised training are associated with differences in attitudes. We recommend that employers be proactive in encouraging and facilitating staff development by offering further training that aims to impart more positive attitudes. Relevance to clinical practice. Improvements in staff competency levels will be more important in the future, as a result of the forecasted increase in the percentage of the population who will suffer from dementia and reside in nursing homes.     

Effect of epidermal growth factor receptor inhibitor class in the treatment of head and neck cancer with concurrent radiochemotherapy in vivo.

PURPOSE: To optimally integrate epidermal growth factor receptor (EGFR) inhibitors into the clinical treatment of head and neck cancer, two important questions must be answered: (a) does EGFR inhibition add to the effects of radiochemotherapy, and (b) if so, which method of inhibiting EGFR is superior (an EGFR antibody versus a small molecule tyrosine kinase inhibitor)? We designed an in vivo study to address these questions. EXPERIMENTAL DESIGN: Nude mice with UMSCC-1 head and neck cancer xenografts received either single, double, or triple agent therapy with an EGFR inhibitor (either cetuximab or gefitinib), gemcitabine, and/or radiation for 3 weeks. Tumor volumes and animal weights were measured for up to 15 weeks. Immunoblotting and immunofluorescent staining were done on tumors treated with either cetuximab or gefitinib alone. RESULTS: The addition of an EGFR inhibitor significantly delayed the tumor volume doubling time, from a median of 40 days with radiochemotherapy (gemcitabine and radiation) alone, to 106 days with cetuximab and 66 days with gefitinib (both P < 0.005). Cetuximab resulted in significantly less weight loss than gefitinib. Immunoblot analysis and immunofluorescent staining of tumors show that although levels of phosphorylated AKT and extracellular signal-regulated kinase were decreased similarly in response to cetuximab or gefitinib, cetuximab caused prolonged suppression of pEGFR, pSTAT3, and Bcl(XL) compared with gefitinib. CONCLUSIONS: EGFR inhibition, particularly with cetuximab, improves the effectiveness of radiochemotherapy in this model of head and neck cancer. The correlation of response with prolonged suppression of EGFR, STAT3, and Bcl(XL) offers the possibility that these may be candidate biomarkers for response.     

Active surveillance to determine the impact of methicillin-resistant Staphylococcus aureus colonization on patients in intensive care units of a Veterans Affairs Medical Center.

OBJECTIVE: The impact of methicillin-resistant Staphylococcus aureus (MRSA) colonization on mortality has not been well characterized. We sought to describe the impact of MRSA colonization on patients admitted to intensive care units (ICUs) in the Birmingham Veterans Affairs Medical Center (VAMC). METHODS: We conducted a retrospective cohort study of ICU patients at the Birmingham VAMC during 2005 to evaluate the predictors of MRSA colonization and determine its effect on clinical outcomes. Surveillance cultures for MRSA were performed on admission to the ICU and weekly thereafter. Clinical findings, the incidence of MRSA infection, and mortality within 3 months after ICU admission were recorded. Predictors of mortality and S. aureus colonization were determined using multivariable models. RESULTS: S. aureus colonization was present in 97 (23.3%) of 416 patients screened, of whom 67 (16.1%) were colonized with methicillin-susceptible S. aureus (MSSA) and 30 (7.2%) with MRSA. All-cause mortality at 3 months among MRSA-colonized patients was significantly greater than that among MSSA-colonized patients (46.7% vs 19.4%; P = .009). MRSA colonization was an independent predictor of death (adjusted odds ratio [OR], 3.7 [95% confidence interval [CI], 1.5-8.9]; P = .003) and onset of MRSA infection after hospital discharge (adjusted OR, 7.6 [95% CI, 2.48-23.2]; P < .001). Risk factors for MRSA colonization included recent antibiotic use (adjusted OR, 4.8 [95% CI, 1.9-12.2]; P = .001) and dialysis (adjusted OR, 18.9 [95% CI, 2.1-167.8]; P = .008). CONCLUSIONS: Among ICU patients, MRSA colonization is associated with subsequent MRSA infection and an all-cause mortality that is greater than that for MSSA colonization. Active surveillance for MRSA colonization may identify individuals at risk for these adverse outcomes. Prospective studies of outcomes in MRSA-colonized patients may better define the role of programs for active MRSA surveillance.     

Endoluminal reconstruction of the arterial wall with endothelial cell/glue matrix reduces restenosis in an atherosclerotic rabbit

OBJECTIVES: The objectives of this study were 1) to improve the attachment of reimplanted endothelial cells (EC) using a fibrin glue, and 2) to assess the impact of endothelial reseeding on restenosis eight weeks after balloon angioplasty. BACKGROUND: A possible mechanism contributing to restenosis after balloon angioplasty is the loss of the EC lining. Previous attempts to reseed EC had little effect due to rapid loss of the seeded cells. METHODS: Twelve atherosclerotic rabbits were subjected to angioplasty of iliac arteries and reseeding procedure. One iliac artery was subjected to EC/glue reconstruction and a contralateral site to EC seeding without glue. The animals were sacrificed after 4 h. In another series 12 rabbits were treated in the same fashion and were restudied at eight weeks. Additionally, in 10 animals one iliac was subjected to glue treatment, and another served as control. RESULTS: Histological examination demonstrated the ability of this method to reattach the EC/glue matrix circumferentially to 68.0 +/- 6.7% of the arterial wall in comparison with 13.5 +/- 3.9% reattachment after EC seeding. Morphometry at eight weeks showed that the lumen area was significantly greater in the EC/glue group (1.23 +/- 0.35 mm2) than in the EC seeding alone (0.65 +/- 0.02 mm2) and 0.72 +/- 0.41 mm2 in the glue group. This was principally accounted for by the statistically significant differences in the intimal area (0.76 +/- 0.18 mm vs. 1.25 +/-0.26 mm2 and 1.01 +/- 0.53 mm2, respectively). CONCLUSIONS: The attachment of EC after angioplasty can be greatly improved with fibrin glue matrix. The near 70% endothelial coverage achieved by this method resulted in a significant reduction of restenosis in atherosclerotic rabbit.     

The impact of financing and quality changes on health care demand in Niger

This paper assesses the demand effects of a cost recovery and quality improvement pilot study conducted in Niger in 1993. Direct user charges and indirect insurance payments were implemented in government health care facilities in different parts of the country, and were preceded or accompanied by quality changes in these facilities. Decision-making by patients is modelled as a three-stage process of reporting an illness, seeking treatment and choice of provider; and multinomial nested logit techniques are used to estimate the parameters of the decision-tree. Overall, the results give a reasonably favourable impression of the policy changes. In neither case is there evidence of serious reductions in access or increases in cost. Particularly notable is that despite an increase in formal user charges, the observed decline in rates of visits is statistically insignificant, suggesting the success of measures to improve quality of health care in public facilities. The observed increase in the probability of formal visits in the district with indirect payments is also striking. Both contrast with the control region of Illela, where neither user charges were introduced nor were any efforts made to improve quality. The data suggest that higher utilization of formal care, probably due to improvements in quality, outweighed the decrease in utilization that may have come about due to introduction of cost recovery, so that the net effect of the policy changes was an increase in utilization. Quality considerations appear to be important in ensuring the long-term success of cost sharing.