Colorectal cancer cells with the BRAF(V600E) mutation are addicted to the ERK1/2 pathway for growth factor-independent survival and repression of BIM.

The RAF-mitogen-activated protein kinase kinase 1/2-extracellular signal-regulated kinase 1/2 (RAF-MEK1/2-ERK1/2) pathway is activated in many human tumours and can protect cells against growth factor deprivation; however, most such studies have relied upon overexpression of RAF or MEK constructs that are not found in tumours. Here we show that expression of the endogenous BRAF(V600E) allele in mouse embryonic fibroblasts from conditional knock-in transgenic mice activates ERK1/2, represses the BH3-only protein BIM and protects cells from growth factor withdrawal. Human colorectal cancer (CRC) cell lines harbouring BRAF(V600E) are growth factor independent for the activation of ERK1/2 and survival. However, treatment with the MEK1/2 inhibitors U0126, PD184352 or the novel clinical candidate AZD6244 (ARRY-142886) overcomes growth factor independence, causing CRC cell death. BIM is de-phosphorylated and upregulated following MEK1/2 inhibition in all CRC cell lines studied and knockdown of BIM reduces cell death, indicating that repression of BIM is a major part of the ability of BRAF(V600E) to confer growth factor-independent survival. We conclude that a single endogenous BRAF(V600E) allele is sufficient to repress BIM and prevent death arising from growth factor withdrawal, and CRC cells with BRAF(V600E) mutations are addicted to the ERK1/2 pathway for repression of BIM and growth factor-independent survival.

Inhibition of COX-2 with NS-398 decreases colon cancer cell motility through blocking epidermal growth factor receptor transactivation: possibilities for combination therapy.

UNLABELLED: The use of non-steroidal anti-inflammatory drugs has proved of great interest in the prevention and treatment of colorectal cancer, although their precise mechanisms of action remain unclear. Overexpression of cyclooxygenase-2 (COX-2) and subsequent prostaglandin production promote metastasis and have been shown to increase cell motility in vitro. OBJECTIVE: We have aimed to elucidate whether specific inhibition of COX-2 with NS-398 (NS-398 is a selective inhibitor of COX-2) would be able to inhibit motility of colorectal cancer cells and whether this was modulated through epidermal growth factor receptor (EGFR) transactivation. MATERIALS AND METHODS: A transwell filter assay was used to study cell motility. Expression of COX-2, EGFR phosphorylation and prostaglandin E(2) (PGE(2)) receptors were assessed by Western blot analysis and reverse transcriptase-polymerase chain reaction. PGE(2) concentrations after NS-398 treatment were estimated by enzyme immunoassay. RESULTS: Treatment with NS-398 significantly reduced PGE(2) levels and reduced cell migration in the HT29 and HCA7 colorectal carcinoma cell lines and this effect was rescued by addition of PGE(2). Furthermore, specific inhibition of COX-2 with NS-398 reduced EGFR phosphorylation in colorectal cancer cells. Direct inhibition of EGFR activity with AG1478 reduced PGE(2)-stimulated motility, clearly demonstrating that PGE(2 )acts via the EGFR-signalling pathway. The novel combination of NS-398 and AG1478 dramatically reduced migration of colorectal cancer cells. CONCLUSION: The data presented indicate that the use of NS-398 in chemoprevention and adjuvant therapy for colorectal cancer may work in part, through the inhibition of cell motility. Furthermore, our data suggest that the combined use of non-steroidal anti-inflammatory drugs with EGFR antagonists could be explored further for future use in the clinic.

Modelling 5-year functional outcome in a major traumatic injury survivor cohort.

AIM: To estimate associations between possible predictors of functional disability outcome at 5 years in a working adult population cohort of survivors of major traumatic injury and to develop a prognostic model of outcome. DESIGN: Population based retrospective cohort study. POPULATION: Persons who had experienced major traumatic injury (Injury Seventy Score >15) in the area of the former Yorkshire Regional Health Authority during the period 30 September 1988 to 1 October 1989 and who survived for 5 years (average 5.3 years). METHODS: The same interviewer saw each survivor at their home and used the OPCS Adult Disability Schedule to ascertain levels of functional disability. Disability scores for each survivor were then combined in accordance with the OPCS guidance to calculate a level of disability between 0 (no disability) to 10 (maximum disability). The OPCS level was then dichotomised with a cut-point at 4/5. Possible predictor and confounding variables from pre-injury, injury and post-injury periods were modelled in a logistic regression to identify those that predicted outcome level. Two reduced models were developed to allow early prognosis of late outcome. RESULTS: The full model correctly classified 91% of observed outcomes. Inpatient length of stay OR 1.031 (95% CI 1.014,1.048) per day predicted poorer 5-year outcome; Glasgow Coma Score OR 0.790(0.629,0.992) per 1 point increase; stay in Intensive Care Unit OR 0.931 (0.877,0.987) per day; attainment of degree-level education OR 0.014 (0.000,0.707); single civil status OR 0.110 (0.013,0.908); being taken initially to a hospital with a neurosurgical facility OR 0.064(0.010,0.420); being in paid work during the 2 weeks before index injury OR 0.093(0.009,0.969) predicted better 5-year disability outcome. Two reduced models were constructed that included a simple set of variables, one of these models excluded any rehabilitation variables but still correctly classified 85% of the observed outcomes. CONCLUSION: As well as level of traumatic brain injury (TBI) and total inpatient stay, Pre-injury educational attainment and employment, civil status, immediate care in a hospital with a neurosurgical facility and stay in an Intensive Care Unit determined 5-year outcome. It is possible to efficiently predict outcome at an early stage. Previous work on predictors of disablement have suffered from large selection and attrition biases.

Prospects in NSAID-derived chemoprevention of colorectal cancer.

There is strong evidence for an important role for increased COX (cyclo-oxygenase)-2 expression and PG (prostaglandin) E2 production in colorectal tumorigenesis. PGE(2) acts through four E-prostanoid receptors (EP1-4). COX-2 has therefore become a target for the potential chemoprevention and therapy of colorectal cancer. However, any therapeutic/preventive strategy has the potential to have an impact on physiological processes and hence result in side effects. General COX (COX-1 and -2) inhibition by traditional NSAIDs (non-steroidal anti-inflammatory drugs), such as aspirin, although chemopreventive, has some side effects, as do some conventional COX-2-selective NSAIDs. As PGE2 is thought to be the major PG species responsible for promoting colorectal tumorigenesis, research is being directed to a number of protein targets downstream of COX-2 that might allow the selective inhibition of the tumour-promoting activities of PGE2, while minimizing the associated adverse events. The PGE synthases and E-prostanoid receptors (EP1-4) have therefore recently attracted considerable interest as potential novel targets for the prevention/therapy of colorectal cancer. Selective (and possibly combinatorial) inhibition of the synthesis and signalling of those PGs most highly associated with colorectal tumorigenesis may have some advantages over COX-2-selective inhibitors.

The epidemiology of disability and occupation handicap resulting from major traumatic injury.

PURPOSE: To assess the prevalence of disability and handicap among survivors of major traumatic injury (injury severity score > 15) using a prospective population based cohort study design. The study was set in the former Yorkshire Health Region. SUBJECTS/METHODS: A cohort of 367 individuals identified as having received and survived major traumatic injury during the 12 month period October 1988-September 1989. OPCS disability scores and employment status at 5 years post injury were established through structured face-to-face interviews. RESULTS: Three hundred and four (84% response. 89% adjusted response) individuals were interviewed. Seventy-seven percent of these were male and they had a mean age (SEM) of 30.8 (1.06) years. Injuries were caused by road traffic accidents in 68% of the cases and were primarily orthopaedic and neurological in nature. At 5 years post injury 81.2% of individuals had some form of measurable disability principally relating to locomotion, behaviour, continence and intellectual functioning consistent with injury type. A third had an OPCS disability score of 5 or greater and approximately 1 in 12 were in the most severe categories of OPCS scores of 9-10 necessitating dependency on formal or informal carer assistance. Whilst five of the eight sub-scales of the SF36 showed correlation in severity proportion, general health perception and energy/vitality were higher in those with increasing disability as measured by the OPCS scale. Of those between the ages of 16-64 nearly half (49%) were not in paid employment at the time of follow up. CONCLUSION: A high prevalence of severe permanent disability, work disability and occupation handicap has been identified in a cohort of mainly young adult males following major traumatic injury resulting from road traffic accidents. Progress in accident prevention, injury reduction and the management of patients with serious injuries should be measured not only in terms of reduced mortality from such events but also in the long term disability and quality of life sequelea of survivors.

Variation in clinical decision making is a partial explanation for geographical variation in lower extremity amputation rates.

BACKGROUND: Rates of lower extremity amputation vary significantly both between and within countries. The variation does not appear to support differences in need as an explanation. This study set out to see if variations in clinical decision making might contribute to the explanation. METHODS: Based on an extensive audit database of lower extremity amputations and revascularization operations, a decision model was produced. Drawing on items in this model allowed the selection of six clinical cases that differed in their probability of having amputation as the outcome. Two cases had 80 per cent or more, two cases had 45--55 per cent and two cases had 20 per cent or less probability of amputation. Each of ten consultant vascular surgeons looked at these cases without knowledge of their probability of outcome and decided on amputation or revascularization. RESULTS: Overall the chance-adjusted level of agreement (kappa coefficient) between the decisions made by ten surgeons on the six clinical cases and the actual outcome was 0.46, indicating a moderate level of agreement. The kappa coefficient for individual surgeons showed complete agreement (kappa = 1) for four, substantial agreement (kappa = 0.66) for four, fair agreement (kappa = 0.32) for one and no agreement other than at a chance level (kappa = 0) for one surgeon. CONCLUSION: Variations in the clinical decisions made by vascular surgeons given the same patient are likely to explain at least a part of the observed geographical variation in rates of lower extremity amputation. Consensus guidelines may enable more consistent decision making for this problem.

Metaplastic breast carcinoma metastatic to the lung mimicking a primary chondroid lesion: report of a case with cytohistologic correlation.

This case study illustrates the unusual morphologic findings of a metastatic breast carcinoma to the lung. The tumor showed chondromatous differentiation and mimicked a primary chondroid lesion of the lung on fine-needle aspiration and needle core biopsy. The patient was a 59-year-old woman with a previous history of stage II carcinoma of the breast, which had been reported as "poorly differentiated, infiltrating ductal carcinoma," with two of 13 axillary lymph nodes showing metastatic ductal carcinoma. The pathology report received from the outside institution contained no mention of metaplastic components, and because the new pulmonary lesion was a peripherally located, well-circumscribed mass found incidentally on abdominal computed tomography scan in the lower lung field cuts, pulmonary chondroid hamartoma was initially postulated as a preliminary diagnosis. However, on review of the outside glass slide material from a prior lumpectomy, chondromatous differentiation was identified and a final diagnosis of metaplastic carcinoma of the breast with pulmonary metastasis was made. To the best of our knowledge, this is the only reported case of a metastasis of metaplastic breast carcinoma initially identified from fine-needle aspiration biopsy. The importance of recognizing and reporting metaplastic elements in primary breast tumors is discussed, and the value of direct morphologic comparison of cytologic material to prior histology is emphasized.