Platelet-Derived {miR}-126-3p Directly Targets {AKT}2 and Exerts Anti-Tumor Effects in Breast Cancer Cells: Further Insights in Platelet-Cancer Interplay

Among the surrounding cells influencing tumor biology, platelets are recognized as novel players as they release microvesicles (MVs) that, once delivered to cancer cells, modulate signaling pathways related to cell growth and dissemination. We have previously shown that physiological delivery of platelet MVs enriched in miR-126 exerted anti-tumor effects in different breast cancer (BC) cell lines. Here, we seek further insight by identifying AKT2 kinase as a novel miR-126-3p direct target, as assessed by bioinformatic analysis and validated by luciferase assay. Both ectopic expression and platelet MV-mediated delivery of miR-126-3p downregulated AKT2 expression, thus suppressing proliferating and invading properties, in either triple negative (BT549 cells) or less aggressive Luminal A (MCF-7 cells) BC subtypes. Accordingly, as shown by bioinformatic analysis, both high miR-126 and low AKT2 levels were associated with favorable long-term prognosis in BC patients. Our results, together with the literature data, indicate that miR-126-3p exerts suppressor activity by specifically targeting components of the PIK3/AKT signaling cascade. Therefore, management of platelet-derived MV production and selective delivery of miR-126-3p to tumor cells may represent a useful tool in multimodal therapeutic approaches in BC patients

Comparing continuous treatment matching methods in policy evaluation

The paper evaluates the statistical properties of two different matching estimators in the case of continuous treatment, using a Montecarlo experiment. The traditional generalized propensity score matching estimator is compared whit a new two steps matching estimator for the continuous treatment case, recently developed (Adorno, Bernini, Pellegrini, 2007). It compares treatment and control units similar in terms of their observable characteristics in both selection processes (the participation decision and the treatment level assignment), where the generalized propensity score matching estimator collapses the two processes into one single step matching. The results show that the two steps estimator has better finite sample properties if some institutional rules define the level of treatment with respect to the characteristics of treated units

Do Capital Subsidies Affect Growth in the Tourism Industry?

The Italian literature on the evaluations of the impact of L. 488/1992 public subsidies deals with the estimation of treatment effects on manufacturing firms, while at now the impact on tourism firms has been never investigated. The aim of the paper is to evaluate the causal effect of L. 488 policy intervention to tourism industry in the case of a continuous treatment, exploring the impact of differences in treatment level on tourism firms performance. A new estimation approach is used (Adorno, Bernini and Pellegrini; 2007) for the evaluation of the effects of a continuous treatment based on a two-step matching method: in the first step, treated and not treated units are matched on the basis of a propensity score function; in the second step, among matched units in the first step, another matching procedure pair units with similar treatment level. The impact of L.488 on tourism firms is evaluated with respect to the main performance variables

THE IMPACT OF CAPITAL SUBSIDIES: NEW ESTIMATIONS UNDER CONTINUOUS TREATMENT

[ARTICOLO

The Impact of Capital Subsidies: New Estimations under Continuous Treatment

Most of the relevant literature on the evaluation of the impact of public subsidies to private firms deals with the estimation of causal effects of a binary treatment. However, several policies allow for different levels of subsidies, depending on the investment project, the firm dimension, the region and also on the firms’ choice. The aim of the paper is to evaluate the causal effect of a policy intervention in the case of a continuous treatment, exploring the impact of differences in treatment level on policy outcome. As an empirical application, we estimated the impact of subsidies allocated by L. 488/1992, the main regional policy in Italy, in the southern regions of the country in the period 1996-2000. We compare two estimation methods: a parametric method, based on a more traditional DID estimator adapted to the continuous treatment case, and a non parametric estimator, based on a novel two-step matching method developed in our recent work (Adorno, Bernini and Pellegrini, 2007a). On average, our results support the conclusions derived from methods based on the binary treatment: subsidies have a positive and often statistically significant effect on employment, fixed assets and turnover. However, the strong heterogeneity of the treatment outcome with respect to different levels of treatment is highlighted. We find that higher the level of incentive, higher the policy effect until a certain point, from which the marginal impact decreases. The results are robust to changes in the estimation method.continuous treatment, matching estimator, industrial policy evaluation, subsidies to capital accumulation