Maintaining RNA integrity in a homogeneous population of mammary epithelial cells isolated by Laser Capture Microdissection

Background: Laser-capture microdissection (LCM) that enables the isolation of specific cell populations from complex tissues under morphological control is increasingly used for subsequent gene expression studies in cell biology by methods such as real-time quantitative PCR (qPCR), microarrays and most recently by RNA-sequencing. Challenges are i) to select precisely and efficiently cells of interest and ii) to maintain RNA integrity. The mammary gland which is a complex and heterogeneous tissue, consists of multiple cell types, changing in relative proportion during its development and thus hampering gene expression profiling comparison on whole tissue between physiological stages. During lactation, mammary epithelial cells (MEC) are predominant. However several other cell types, including myoepithelial (MMC) and immune cells are present, making it difficult to precisely determine the specificity of gene expression to the cell type of origin. In this work, an optimized reliable procedure for producing RNA from alveolar epithelial cells isolated from frozen histological sections of lactating goat, sheep and cow mammary glands using an infrared-laser based Arcturus Veritas LCM (Applied Biosystems®) system has been developed. The following steps of the microdissection workflow: cryosectioning, staining, dehydration and harvesting of microdissected cells have been carefully considered and designed to ensure cell capture efficiency without compromising RNA integrity.[br/] Results: The best results were obtained when staining 8 μm-thick sections with Cresyl violet® (Ambion, Applied Biosystems®) and capturing microdissected cells during less than 2 hours before RNA extraction. In addition, particular attention was paid to animal preparation before biopsies or slaughtering (milking) and freezing of tissue blocks which were embedded in a cryoprotective compound before being immersed in isopentane. The amount of RNA thus obtained from ca.150 to 250 acini (300,000 to 600,000 μm2) ranges between 5 to 10 ng. RNA integrity number (RIN) was ca. 8.0 and selectivity of this LCM protocol was demonstrated through qPCR analyses for several alveolar cell specific genes, including LALBA (α-lactalbumin) and CSN1S2 (αs2-casein), as well as Krt14 (cytokeratin 14), CD3e and CD68 which are specific markers of MMC, lymphocytes and macrophages, respectively.[br/] Conclusions: RNAs isolated from MEC in this manner were of very good quality for subsequent linear amplification, thus making it possible to establish a referential gene expression profile of the healthy MEC, a useful platform for tumor biomarker discovery

Insulin-like growth factor (IGF)-I obliterates the pregnancy-associated protection against mammary carcinogenesis in rats: evidence that IGF-I enhances cancer progression through estrogen receptor-α activation via the mitogen-activated protein kinase pathway

INTRODUCTION: Pregnancy protects against breast cancer development in humans and rats. Parous rats have persistently reduced circulating levels of growth hormone, which may affect the activity of the growth hormone/insulin-like growth factor (IGF)-I axis. We investigated the effects of IGF-I on parity-associated protection against mammary cancer. METHODS: Three groups of rats were evaluated in the present study: IGF-I-treated parous rats; parous rats that did not receive IGF-I treatment; and age-matched virgin animals, which also did not receive IGF-I treatment. Approximately 60 days after N-methyl-N-nitrosourea injection, IGF-I treatment was discontinued and all of the animal groups were implanted with a silastic capsule containing 17β-estradiol and progesterone. The 17β-estradiol plus progesterone treatment continued for 135 days, after which the animals were killed. RESULTS: IGF-I treatment of parous rats increased mammary tumor incidence to 83%, as compared with 16% in parous rats treated with 17β-estradiol plus progesterone only. Tumor incidence and average number of tumors per animal did not differ between IGF-I-treated parous rats and age-matched virgin rats. At the time of N-methyl-N-nitrosourea exposure, DNA content was lowest but the α-lactalbumin concentration highest in the mammary glands of untreated parous rats in comparison with age-matched virgin and IGF-I-treated parous rats. The protein levels of estrogen receptor-α in the mammary gland was significantly higher in the age-matched virgin animals than in untreated parous and IGF-I-treated parous rats. Phosphorylation (activation) of the extracellular signal-regulated kinase-1/2 (ERK1/2) and expression of the progesterone receptor were both increased in IGF-I-treated parous rats, as compared with those in untreated parous and age-matched virgin rats. Expressions of cyclin D(1 )and transforming growth factor-β(3 )in the mammary gland were lower in the age-matched virgin rats than in the untreated parous and IGF-I-treated parous rats. CONCLUSION: We argue that tumor initiation (transformation and fixation of mutations) may be similar in parous and age-matched virgin animals, suggesting that the main differences in tumor formation lie in differences in tumor progression caused by the altered hormonal environment associated with parity. Furthermore, we provide evidence supporting the notion that tumor growth promotion seen in IGF-I-treated parous rats is caused by activation of estrogen receptor-α via the Raf/Ras/mitogen-activated protein kinase cascade

Competing for Public Resources: Higher Education and Academic Research in Europe. A Cross-Sectoral Perspective

The chapter focuses on the increasing cross-sectoral competition for public resources between various types of public sector institutions in Europe and its implications for future public funding for both higher education and academic research. It views the major models of the institution of the modern (Continental) university and the major types of the modern institution of the state, and of the welfare state in particular, as traditionally closely linked (following Kogan et al., 2000; Kogan and Hanney, 2000; Becher and Kogan, 1992). Historically, in the post-war period in Europe, the unprecedented growth of welfare states and state-funded public services was paralleled by the unprecedented growth of public universities. The massification and universalization of higher education in Europe coincided with the growth of the welfare state in general. Currently, both processes in higher education are in full swing across Europe while welfare states are under the most far-reaching restructuring in their postwar history. The major implication is the fierce competition for public resources, studied in this chapter from a cross-sectoral perspective, in which the future levels of public funding for higher education in tax-based European systems are highly dependent on social attitudes towards what higher education brings to society and the economy, relative to what other claimants to the public purse can bring to them

Leverage, profitability and the ownership structures of listed firms in China

The relationship between leverage, profitability and a firm’s ownership structure in China is investigated in this paper. It is an exploratory study based on all firms listed on the Shanghai and Shenzhen stock exchanges from 1999 to 2005. The results of the empirical analysis are reported in this paper. The most significant result is that foreign holdings are found to have a significant relationship with the leverage of listed firms in China. Whereas, somewhat unexpectedly, institutional ownership, through legal person holding companies, state ownership and private holdings are not found to have a significant relationship with the capital structure choices of firms in China. The results also suggest that some firm-specific factors that are relevant for explaining firm leverage generally referred to in studies in developed economies, such as profitability, growth opportunities, size and tax shields, are also relevant in China. The age of the firms and the industry to which they principally belong also has significant bearing. Yet direct government grants and the use of an internationally renowned auditing firm do not show a significant relationship

Markets Governing Corporations

In many East Asian economies, more competitive markets are starting to encourage firms to adopt practices benefiting shareholders, creditors and consumers and move from a relationship to a rules based business model. Prior to the crisis, weak market competition often facilitated poor corporate governance standards and risky corporate behaviour as much as did poor regulations and enforcement. However, corporate exposure to competition varies greatly across the region and in most East Asian economies markets need to be strengthened further before they provide optimal discipline on corporates' behaviour. Strengthening market forces are coming from many sources. Weak banking systems, ongoing prudential reforms and corporate restructuring are pressuring corporates to shift from bank to direct capital market financing. Trade and investment liberalisation, market deregulation and privatisation are increasing goods and services market competition, providing incentives for corporates to seek out the cheapest inputs and finance and adopt more professional management approaches. To succeed in this environment, companies need a rules based business framework and stronger internal governance. This chapter maps major trends in East Asian market dynamics and their impact on the region's traditional and emerging business models

Patients' preferences for adjuvant sorafenib after resection of renal cell carcinoma in the SORCE trial: what makes it worthwhile?

Background: We sought to determine the survival benefits that patients judged sufficient to warrant adjuvant therapy with sorafenib for 1 year, or for 3 years after resection of renal cell carcinoma in the SORCE trial. / Methods: SORCE participants from all sites in Australia and New Zealand, and selected sites in the UK, completed a validated preferences questionnaire at months 0, 3, 15, and 42 to elicit the minimum survival benefits they judged sufficient to warrant adjuvant sorafenib for 1 year (versus observation), or for 3 years (versus 1 year). The questionnaires used reference survival times of 5 and 15 years; and reference survival rates at 5 years of 65% and 85%. / Results: The 233 participants had a median age of 57 years (range 29–78) and 71% were male. For 1 year of sorafenib versus no adjuvant therapy, the median benefits in survival times judged sufficient to warrant treatment were an extra 9 months beyond 5 years and an extra 1 year beyond 15 years; the median benefit in survival rates were an extra 4% beyond 65% and an extra 3% beyond 85% at 5 years. For 3 years of sorafenib versus 1 year of sorafenib, the median benefit in survival time judged sufficient to warrant extended treatment was an extra 1 year beyond both 5 and 15 years. Participants randomly allocated to treatment with sorafenib judged larger benefits necessary than those allocated to placebo. Participants’ preferences were not associated with their baseline characteristics or the interval from randomisation. / Conclusion: Most participants judged an extra year of survival necessary to warrant 1 year of adjuvant sorafenib worthwhile, and an additional year of survival to warrant extending the duration of sorafenib from 1 to 3 years. Patients’ preferences are important in shared decision making. / SORCE trial clinical trials number: NCT00492258

Individualised Predictions of the Survival Benefit Due to Adjuvant Therapy in a Randomised Trial of Sorafenib after Nephrectomy for Localised Renal Cell Carcinoma

BACKGROUND: Little has been published regarding how doctors think and talk about prognosis and the potential benefits of adjuvant therapy. OBJECTIVE: We sought predictions of survival rates and survival times, for patients with and without adjuvant therapy, from the clinicians of patients participating in a randomised trial of adjuvant sorafenib after nephrectomy for renal cell carcinoma. METHODS: A subset of medical oncologists and urologists in the SORCE trial completed questionnaires eliciting their predictions of survival rates and survival times, with and without adjuvant sorafenib, for each of their participating patients. To compare predictions elicited as survival times versus survival rates, we transformed survival times to survival rates. To compare predicted benefits elicited as absolute improvements in rates and times, we transformed them into hazard ratios (HR), a measure of relative benefit.We postulated that a plausible benefit in overall survival (OS) should be smaller than that hypothesized for disease–free survival (DFS) in the trials original sample size justification (i.e. HR for OS should be ≥ 0.75). RESULTS: Sixty–one medical oncologists and 17 urologists completed questionnaires on 216 patients between 2007 and 2013. Predictions of survival without adjuvant sorafenib were similar whether elicited as survival rates or survival times (median 5–year survival rate of 61% vs 60%, p = 0.6). Predicted benefits of sorafenib were larger when elicited as improvements in survival rates than survival times (median HR 0.76 vs 0.83, p < 0.0001). The proportion of HR for predicted OS with sorafenib that reflected a plausible benefit (smaller effect of sorafenib on OS than hypothesized on DFS, i.e. HR ≥ 0.75) was 51% for survival rates, and 65% for survival times. CONCLUSIONS: The predicted benefits of adjuvant sorafenib were larger when elicited as improvements in survival rates than as survival times, and were often larger than the sample size justification for the trial. These potential biases should be considered when thinking and talking about individual patients in clinical practice, and when designing clinical trials