Phosphorylated c-Src in the nucleus is associated with improved patient outcome in ER-positive breast cancer

Elevated c-Src protein expression has been shown in breast cancer and <i>in vitro</i> evidence suggests a role in endocrine resistance. To investigate whether c-Src is involved in endocrine resistance, we examined the expression of both total and activated c-Src in human breast cancer specimens from a cohort of oestrogen receptor (ER)-positive tamoxifen-treated breast cancer patients. Tissue microarray technology was employed to analyse 262 tumour specimens taken before tamoxifen treatment. Immunohistochemistry using total c-Src and activated c-Src antibodies was performed. Kaplan–Meier survival curves were constructed and log-rank test were performed. High level of nuclear activated Src was significantly associated with improved overall survival (<i>P</i>=0.047) and lower recurrence rates on tamoxifen (<i>P</i>=0.02). Improved patient outcome was only seen with activated Src in the nucleus. Nuclear activated Src expression was significantly associated with node-negative disease and a lower NPI (<i>P</i><0.05). On subgroup analysis, only ER-positive/progesterone receptor (PgR)-positive tumours were associated with improved survival (<i>P</i>=0.004). This shows that c-Src activity is increased in breast cancer and that activated Src within the nucleus of ER-positive tumours predicts an improved outcome. In ER/PgR-positive disease, activated Src kinase does not appear to be involved in <i>de novo</i> endocrine resistance. Further study is required in ER-negative breast cancer as this may represent a cohort in which it is associated with poor outcome

On line clinical reasoning assessment with Script Concordance test in urology: results of a French pilot study

BACKGROUND: The Script Concordance test (SC) test is an assessment tool that measures the capacity to solve ill-defined problems, that is, reasoning in a context of uncertainty. This study assesses the feasibility, reliability and validity of the SC test made available on the Web to French urologists. METHODS: A 97 items SC test was developed based on major educational objectives of French urology training programmes. A secure Web site was created with two sequential modules: a) The first one for the reference panel to elaborate the scoring system; b) The second for candidates with different levels of experience in urology: Board certified urologists, chief-residents, residents, medical students. All participants were recruited on a voluntary basis. Statistical analysis included descriptive statistics of the participants' scores and factorial analysis of variance (ANOVA) to study differences between groups' means. Reliability was evaluated with Cronbach's alpha coefficient. RESULTS: The on line SC test has been operational since June 2004. Twenty-six faculty members constituted the reference panel. During the following 10 months, 207 participants took the test online (124 urologists, 29 chief-residents, 38 residents, 16 students). No technical problem was encountered. Forty-five percent of the participants completed the test partially only. Differences between the means scores for the 4 groups were statistically significant (P = 0.0123). The Bonferroni post-hoc correction indicated that significant differences were present between students and chief-residents, between students and urologists. There were no differences between chief-residents and urologists. Reliability coefficient was 0.734 for the total group of participants. CONCLUSION: Feasibility of Web-based SC test was proved successful by the large number of participants who participated in a few months. This Web site has permitted to quickly confirm reliability of the SC test and develop strategy to improve construct validity of the test when applied in the field of urology. Nevertheless, optimisation of the SC test content, with a smaller number of items will be necessary. Virtual medical education initiative such as this SC test delivered on the Internet warrants consideration in the current context of national pre-residency certification examination in France

Improving teaching on an inpatient pediatrics service: a retrospective analysis of a program change

Background: The traditional role of the faculty inpatient attending providing clinical care and effectively teaching residents and medical students is threatened by increasing documentation requirements, pressures to increase clinical productivity, and insufficient funding available for medical education. In order to sustain and improve clinical education on a general pediatric inpatient service, we instituted a comprehensive program change. Our program consisted of creating detailed job descriptions, setting clear expectations, and providing salary support for faculty inpatient attending physicians serving in clinical and educational roles. This study was aimed at assessing the impact of this program change on the learners’ perceptions of their faculty attending physicians and learners’ experiences on the inpatient rotations. Methods: We analyzed resident and medical student electronic evaluations of both clinical and teaching faculty attending physician characteristics, as well as resident evaluations of an inpatient rotation experience. We compared the proportions of “superior” ratings versus all other ratings prior to the educational intervention (2005–2006, baseline) with the two subsequent years post intervention (2006–2007, year 1; 2007–2008, year 2). We also compared medical student scores on a comprehensive National Board of Medical Examiners clinical subject examination pre and post intervention. Results: When compared to the baseline year, pediatric residents were more likely to rate as superior the quality of didactic teaching (OR=1.7 [1.0-2.8] year 1; OR=2.0 [1.1-3.5] year 2) and attendings’ appeal as a role model (OR=1.9 [1.1-3.3] year 2). Residents were also more likely to rate as superior the quality of feedback and evaluation they received from the attending (OR=2.1 [1.2-3.7] year 1; OR=3.9 [2.2-7.1] year 2). Similar improvements were also noted in medical student evaluations of faculty attendings. Most notably, medical students were significantly more likely to rate feedback on their data gathering and physical examination skills as superior (OR=4.2 [2.0-8.6] year 1; OR=6.4 [3.0-13.6] year 2). Conclusions: A comprehensive program which includes clear role descriptions along with faculty expectations, as well as salary support for faculty in clinical and educational roles, can improve resident and medical student experiences on a general pediatric inpatient service. The authors provide sufficient detail to replicate this program to other settings.JH Libraries Open Access Promotion Fun

Elevated c-Src is linked to altered cell–matrix adhesion rather than proliferation in KM12C human colorectal cancer cells

Elevated expression and/or activity of c-Src, the prototype of the Src family of protein tyrosine kinases, is associated with the development of human colon cancer. However, despite the known pleiotropic effects of these kinases in promoting (a) cell growth downstream of growth factor receptors, and (b) the dynamic regulation of integrin adhesions in fibroblast model systems, their precise role in epithelial cancer cells is unknown. Here we addressed whether elevated expression and activity of cellular Src alters cell proliferation and/or cell–matrix adhesion in cancer cells from the Fidler model of colorectal metastasis. Although elevated Src correlates with ability to metastasise to the liver after intrasplenic injection, we found that this was not linked to enhanced growth, either in vitro or in vivo as sub-cutaneous tumours. However, elevated Src was associated with enhanced attachment to extracellular matrix. In addition, adhesion to fibronectin, was suppressed by agents that inhibited Src activity, while enforced elevation of Src in non-metastatic cells was sufficient to stimulate adhesion to fibronectin and enhanced assembly of adhesion complexes, without influencing cell growth. Thus, we conclude that one role of elevated Src in human colon cancer cells is to modulate integrin-dependent cell–matrix attachment and formation of adhesion structures, which may, in turn, influence cell motility and integrin-dependent cellular responses

Src tyrosine kinase augments taxotere-induced apoptosis through enhanced expression and phosphorylation of Bcl-2

Activation of Src, which has an intrinsic protein tyrosine kinase activity, has been demonstrated in many human tumours, such as colorectal and breast cancers, and is closely associated with the pathogenesis and metastatic potential of these cancers. In this study, we have examined the effect of activated Src on the sensitivity to taxotere, an anticancer drug targeting microtubules, using v-src-transfected HAG-1 human gall bladder epithelial cells. As compared with parental HAG-1 cell line, v-src-transfected HAG/src3-1 cells became 5.9 and 7.0-fold sensitive to taxotere for 2 and 24-h exposure, respectively. By contrast, HAG-1 cells transfected with activated Ras, which acts downstream of Src, acquired approximately 2.5∼4.8-fold taxotere resistance. The taxotere sensitivity in HAG/src3-1 cells was reversed, if not completely, by herbimycin A, a specific inhibitor of Src family protein tyrosine kinase, indicating that Src protein tyrosine kinase augments sensitivity to taxotere. Treatment of HAG/src3-1 cells with taxotere resulted in phosphorylation of Bcl-2 and subsequent induction of apoptotic cell death, whereas neither Bcl-2 phosphorylation nor apoptosis occurred in parental or c-H-ras-transfected HAG-1 cells. Interestingly, the Bcl-2 protein is overexpressed in v-src-transfected cell line, compared to those in parental or Ras-transfected cell line. Treatment of HAG/src3-1 cells with herbimycin A significantly reduced the expression and phosphorylation of Bcl-2, and abrogated taxotere-induced apoptosis, suggesting a potential role for Src protein tyrosine kinase in the taxotere-induced apoptotic events. H-7, a protein kinase C inhibitor and wortmannin, a phosphatidylinositol-3 kinase (PI-3 kinase) inhibitor, neither altered taxotere sensitivity nor inhibited taxotere-induced apoptosis in these cells. These data indicate that the ability of activated Src to increase taxotere sensitivity would be mediated by apoptotic events occurring through Src to downstream signal transduction pathways toward Bcl-2 phosphorylation, but not by activated Ras, PI-3 kinase or protein kinase C

Breast cancer patients' clinical outcome measures are associated with Src kinase family member expression

<p>BACKGROUND: This study determined mRNA expression levels for Src kinase family (SFK) members in breast tissue specimens and assessed protein expression levels of prominent SFK members in invasive breast cancer to establish associations with clinical outcome. Ki67 was investigated to determine association between SFK members and proliferation.</p> <p>METHODS: The mRNA expression levels were assessed for eight SFK members by quantitative real-time PCR. Immunohistochemistry was performed for c-Src, Lyn, Lck and Ki67.</p> <p>RESULTS: mRNA expression was quantified in all tissue samples. SRC and LYN were the most highly expressed in malignant tissue. LCK was more highly expressed in oestrogen receptor (ER)-negative, compared with ER-positive tumours. High cytoplasmic Src kinase protein expression was significantly associated with decreased disease-specific survival. Lyn was not associated with survival at any cellular location. High membrane Lck expression was significantly associated with improved survival. Ki67 expression correlated with tumour grade and nuclear c-Src, but was not associated with survival.</p> <p>CONCLUSIONS: All eight SFK members were expressed in different breast tissues. Src kinase was highest expressed in breast cancer and had a negative impact on disease-specific survival. Membrane expression of Lck was associated with improved clinical outcome. High expression of Src kinase correlated with high proliferation.</p&gt

Cellular processes of v-Src transformation revealed by gene profiling of primary cells - Implications for human cancer

<p>Abstract</p> <p>Background</p> <p>Cell transformation by the Src tyrosine kinase is characterized by extensive changes in gene expression. In this study, we took advantage of several strains of the Rous sarcoma virus (RSV) to characterize the patterns of v-Src-dependent gene expression in two different primary cell types, namely chicken embryo fibroblasts (CEF) and chicken neuroretinal (CNR) cells. We identified a common set of v-Src regulated genes and assessed if their expression is associated with disease-free survival using several independent human tumor data sets.</p> <p>Methods</p> <p>CEF and CNR cells were infected with transforming, non-transforming, and temperature sensitive mutants of RSV to identify the patterns of gene expression in response to v-Src-transformation. Microarray analysis was used to measure changes in gene expression and to define a common set of v-Src regulated genes (CSR genes) in CEF and CNR cells. A clustering enrichment regime using the CSR genes and two independent breast tumor data-sets was used to identify a 42-gene aggressive tumor gene signature. The aggressive gene signature was tested for its prognostic value by conducting survival analyses on six additional tumor data sets.</p> <p>Results</p> <p>The analysis of CEF and CNR cells revealed that cell transformation by v-Src alters the expression of 6% of the protein coding genes of the genome. A common set of 175 v-Src regulated genes (CSR genes) was regulated in both CEF and CNR cells. Within the CSR gene set, a group of 42 v-Src inducible genes was associated with reduced disease- and metastasis-free survival in several independent patient cohorts with breast or lung cancer. Gene classes represented within this group include DNA replication, cell cycle, the DNA damage and stress responses, and blood vessel morphogenesis.</p> <p>Conclusion</p> <p>By studying the v-Src-dependent changes in gene expression in two types of primary cells, we identified a set of 42 inducible genes associated with poor prognosis in breast and lung cancer. The identification of these genes provides a set of biomarkers of aggressive tumor behavior and a framework for the study of cancer cells characterized by elevated Src kinase activity.</p

A Novel Peptide Derived from Human Apolipoprotein E Is an Inhibitor of Tumor Growth and Ocular Angiogenesis

Angiogenesis is a hallmark of tumor development and metastasis and now a validated target for cancer treatment. We previously reported that a novel dimer peptide (apoEdp) derived from the receptor binding region of human apolipoprotein E (apoE) inhibits virus-induced angiogenesis. However, its role in tumor anti-angiogenesis is unknown. This study demonstrates that apoEdp has anti-angiogenic property in vivo through reduction of tumor growth in a mouse model and ocular angiogenesis in a rabbit eye model. Our in vitro studies show that apoEdp inhibits human umbilical vein endothelial cell proliferation, migration, invasion and capillary tube formation. We document that apoEdp inhibits vascular endothelial growth factor-induced Flk-1 activation as well as downstream signaling pathways that involve c-Src, Akt, eNOS, FAK, and ERK1/2. These in vitro data suggest potential sites of the apoE dipeptide inhibition that could occur in vivo