Purpose There is a critical need for population-based prospective cohort studies because they follow individuals before the onset of disease, allowing for studies that can identify biomarkers and disease-modifying effects, and thereby contributing to systems epidemiology. Participants This paper describes the design and baseline characteristics of an intensively examined subpopulation of the LifeLines cohort in the Netherlands. In this unique subcohort, LifeLines DEEP, we included 1539 participants aged 18 years and older. Findings to date We collected additional blood (n=1387), exhaled air (n=1425) and faecal samples (n=1248), and elicited responses to gastrointestinal health questionnaires (n=1176) for analysis of the genome, epigenome, transcriptome, microbiome, metabolome and other biological levels. Here, we provide an overview of the different data layers in LifeLines DEEP and present baseline characteristics of the study population including food intake and quality of life. We also describe how the LifeLines DEEP cohort allows for the detailed investigation of genetic, genomic and metabolic variation for a wide range of phenotypic outcomes. Finally, we examine the determinants of gastrointestinal health, an area of particular interest to us that can be addressed by LifeLines DEEP. Future plans We have established a cohort of which multiple data levels allow for the integrative analysis of populations for translation of this information into biomarkers for disease, and which will offer new insights into disease mechanisms and prevention.

There is a critical need for population-based prospective cohort studies because they follow individuals before the onset of disease, allowing for studies that can identify biomarkers and disease-modifying effects and thereby contributing to systems epidemiology. This paper describes the design and baseline characteristics of an intensively examined subpopulation of the LifeLines cohort in the Netherlands. For this unique sub-cohort, LifeLines DEEP, additional blood (n=1387), exhaled air (n=1425), fecal samples (n=1248) and gastrointestinal health questionnaires (n=1176) were collected for analysis of the genome, epigenome, transcriptome, microbiome, metabolome and other biological levels. Here, we provide an overview of the different data layers in LifeLines DEEP and present baseline characteristics of the study population including food intake and quality of life. We also describe how the LifeLines DEEP cohort allows for the detailed investigation of genetic, genomic and metabolic variation on a wealth of phenotypic outcomes. Finally, we examine the determinants of gastrointestinal health, an area of particular interest to us that can be addressed by LifeLines DEEP.

VEGF-A is the most potent angiogenic factor in tumour angiogenesis. Its effects are mediated via two receptors VEGFR-1 and VEGFR-2. Primary aim of our study was to examine the expression of VEGFR-1 in breast cancer and its correlation to VEGF expression, lymph node status, tumour size, histological grade, and hormone receptor status. To examine the VEGFR-1 and VEGF expressions in tumour and surrounding tissue of 51 breast cancer patients, and in healthy breast tissue of 30 benign breast diseases patients, we used three-step immunohistochemical staining. VEGFR-1 and VEGF expressions were significantly increased in breast cancer tumour in relation to surrounding tissue (P < 0.01), and the VEGF expression was significantly increased in lymph node positive breast cancer patients (P < 0.01). VEGFR-1 and VEGF expressions were significantly higher in breast cancer tumour compared with healthy breast tissue (P < 0.01). Significant correlation between VEGF and VEGFR-1 expressions was found (P < 0.05). No significant correlations between VEGF and VEGFR-1 expressions and tumour size, histological grade, and hormone receptor status were found. Increased expression of VEGFR-1 and VEGF in breast cancer tumour and significant correlation between these proteins suggest the possible role of VEGF/VEGFR-1 signalization in breast cancer development, although VEGFR-1 potential prognostic value was not confirmed.