PETCH-DB: a Portal for Exploring Tissue-specific and Complex disease-associated 5-Hydroxymethylcytosines

Epigenetic modifications play critical roles in gene regulation and disease pathobiology. Highly sensitive enabling technologies, including microarray- and sequencing-based approaches have allowed genome-wide profiling of cytosine modifications in DNAs in clinical samples to facilitate discovery of epigenetic biomarkers for disease diagnosis and prognosis. Historically, many previous studies, however, did not distinguish the most investigated 5-methylcytosines (5mC) from other modified cytosines, especially the biochemically stable 5-hydroxymethylcytosines (5hmC), which have been shown to have a distinct genomic distribution and regulatory role from 5mC. Notably, during the past several years, the 5hmC-Seal, a highly sensitive chemical labeling technique, has been demonstrated to be a powerful tool for genome-wide profiling of 5hmC in clinically feasible biospecimens (e.g. a few milliliter of plasma or serum). The 5hmC-Seal technique has been utilized by our team in biomarker discovery for human cancers and other complex diseases using circulating cell-free DNA (cfDNA), as well as the characterization of the first 5hmC Human Tissue Map. Convenient access to the accumulating 5hmC-Seal data will allow the research community to validate and re-use these results, potentially providing novel insights into epigenetic contribution to a range of human diseases. Here we introduce the PETCH-DB, an integrated database that was implemented to provide 5hmC-related results generated using the 5hmC-Seal technique. We aim the PETCH-DB to be a central portal, which will be available to the scientific community with regularly updated 5hmC data in clinical samples to reflect current advances in this field. Database URL http://petch-db.org/.

Predictors of prostate cancer screening among health fair participants

OBJECTIVES

Most previous studies of predictors for participation in prostate-specific antigen (PSA) screening for prostate cancer have been conducted in purposive samples or clinical settings. This population-based study identified factors associated with documented PSA screening among health fair participants.

STUDY DESIGN

Cross-sectional survey of 2098 Nebraskan men aged 35 years and older who participated in a health fair in central and eastern Nebraska in 1993.

METHODS

All participants were offered a PSA screening and a questionnaire to collect information on demographics, family medical history, lifestyle factors and self-perceived health status. Predictors of PSA screening were estimated by odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Men were more likely to accept the PSA screening if they were older than 50 years of age (OR=3.1; 2.4-3.9), had a higher income (OR=1.5; 1.1-2.1), were currently employed (OR=1.4; 1.0-2.5), perceived their health status as good (OR=1.1; 0.8-1.5) or excellent (OR=1.4; 1.0-2.1), and believed that they themselves, rather than physicians, should be responsible for their health (OR=1.3; 1.0-1.7). Compared with men aged 50-59 years, the ORs of participation were 0.8 (0.6-1.1) for age 60-69 years and 0.7 (0.5-1.1) for age 70+ years. Decision making was not related to education, marital status or body mass index. Predictors of screening remained unchanged when analysis was limited to men aged 50 years and over, whereas only high income and non-smoking status predicted participation among men younger than 50 years of age.

CONCLUSIONS

Age, income, employment status, perceived control of health and perceived heath status were related to participation in PSA screening for prostate cancer, particularly in men older than 50 years of age. Willingness to receive a PSA screening among men aged 50 years and over decreased with increasing age.