Activation of an actin signaling pathway in pre-malignant mammary epithelial cells by P-cadherin is essential for transformation

Alterations in the expression or function of cell adhesion molecules have been implicated in all steps of tumor progression. Among those, P-cadherin is highly enriched in basal-like breast carcinomas, playing a central role in cancer cell self-renewal, collective cell migration and invasion. To establish a clinically relevant platform for functional exploration of P-cadherin effectors in vivo, we generated a humanized P-cadherin Drosophila model. We report that actin nucleators, Mrtf and Srf, are main P-cadherin effectors in fly. We validated these findings in a human mammary epithelial cell line with conditional activation of the SRC oncogene. We show that, prior to promoting malignant phenotypes, SRC induces a transient increase in P-cadherin expression, which correlates with MRTF-A accumulation, its nuclear translocation and the upregulation of SRF target genes. Moreover, knocking down P-cadherin, or preventing F-actin polymerization, impairs SRF transcriptional activity. Furthermore, blocking MRTF-A nuclear translocation hampers proliferation, self-renewal and invasion. Thus, in addition to sustaining malignant phenotypes, P-cadherin can also play a major role in the early stages of breast carcinogenesis by promoting a transient boost of MRTF-A-SRF signaling through actin regulation.

Gastric cancer screening: a systematic review and meta-analysis

BACKGROUND AND AIMS

Gastric cancer (GC) screening is recommended in high-risk populations, although screening methods and intervals vary. In intermediate-risk populations, screening through esophagogastroduodenoscopy (EGD) may be considered depending on local resources. The aim of this study was to compare GC screening methods regarding effect on mortality, diagnostic yield and adherence.

METHODS

Systematic review and meta-analysis including studies evaluating population-based GC screening. Search was conducted in three online databases (MEDLINE, Scopus and clinicaltrials.gov), along with manual search.

RESULTS

Forty-four studies were included. Studies in upper gastrointestinal series (UGIS) demonstrated that GC screening was associated with significantly lower GC mortality rates (OR 0.63, 95% CI 0.55 - 0.73). Benefits on mortality were also found in EGD and serum pepsinogen (PG) studies. EGD was associated with significantly higher GC (0.55%, 95% CI 0.39 - 0.75%) and early-GC (EGC) detection rates (0.48%, 95% CI 0.34 - 0.65%) when compared to UGIS (GC 0.19%, 95% CI 0.10 - 0.31%; EGC 0.08%, 95% CI 0.04 - 0.13%) and PG (GC 0.10%, 95% CI 0.05 - 0.16%; EGC 0.10%, 95% CI 0.04 - 0.19%). Non-invasive methods tended to higher adherence rates when compared to EGD. Regardless of the screening method, individualized recruitment performed better.

DISCUSSION

Screening positively impacted GC mortality rates. EGD was associated with higher diagnostic yield, while UGIS and PG tended to higher adherence rates. Screening uptake was predominantly impacted by recruitment strategies independently of the adopted method.

Harter's self-perception profile for children adapted for use with young Portuguese students

This study of 260 Portuguese early adolescents (Grades 5 to 7; 11-14 years old) used a questionnaire which taps six different domains and was devised by Harter to evaluate the self-concepts of children and early adolescents in Grades 3 to 7. The Portuguese version has Cronbach coefficients alpha between .25 and .80. The results of factor analysis and correlational studies evidence a low differentiation of the dimensions of self-concept. Results of differential studies by sex and school grade indicate girls see themselves as better behaved than do boys and boys see themselves as significantly more athletically competent than do girls. Also, fifth graders see themselves as more competent in five domains of self-concept than do seventh graders.

Personal conceptions of intelligence: a developmental study in Portugal

The aim of this work is to present the results of a 2-yr. longitudinal study with a sample of 577 Portuguese high school students, observed twice, to study the intraindividual development of personal conceptions of intelligence during adolescence and its relation to school marks and to the causal dimension of controllability. Data, tested through LISREL structural equations, indicated school marks have an important role in the development of dynamic conceptions of intelligence during adolescence. These results were compared with those from other cultural contexts and were analysed in the context of Portuguese culture.