There is growing awareness that a wide variety of synthetic and natural compounds that may be present in water sources, such as streams, wells, and ground water, may lead to adverse health effects, including increased cancer risk. Even low concentrations of these compounds are of concern, as they may have biological effects at concentrations of parts per billion or less. In particular, the presence of endocrine disrupting chemicals (EDCs) in the environment is under examination for potential adverse effects on human health, such as immune suppression, impaired fertility, and increased incidence of cancer, diabetes, and obesity. However, these compounds are often laborious and difficult to measure and thus are not commonly monitored. In addition, even if such compounds are detected, only the known compound itself is typically measured, neglecting its metabolites which are more likely to be found in water samples and retain endocrine disrupting activity.
Inventors at the NCI’s Laboratory of Receptor Biology and Gene Expression have developed a novel assay methodology for detecting EDCs in contaminated water. The assay utilizes fluorescently labeled nuclear steroid receptor constructs in a high-throughput, mammalian cell-based format. Detection and measurements are based on translocation of the fluorescent marker from the cytoplasm to the nucleus in the presence of a ligand that interacts with a specific steroid receptor. Overall, this assay has the capability to detect very low concentrations of EDCs in water or other liquid samples. The inventors have demonstrated proof of concept for this technology by testing for the presence of Glucocorticoid Receptor (GR), Androgen Receptor (AR), Estrogen Receptor (ER), Aryl hydrocarbon receptor (AhR), Progesterone Receptor (PR), and Thyroid Hormone Receptor (TR) activity in water samples. For example, NCI scientists screened water samples collected from 14 states in the US and found AR activity in 35% of samples, as well as previously unrecognized glucocorticoid (GC) activity in 27% of the samples. In particular, the compound androst-4-en-3,6-dione was identified in one of the samples. AR-dependent nuclear translocation and transcriptional activation was also confirmed for two AR-responsive genes, NKX3.1 and RHOU. Moreover, NKX3.1 is a homeobox gene frequently deleted in prostate cancers, and RHOU is implicated in epidermal growth factor receptor signaling and cell migration.
A product or service based on this technology could fulfill an unmet need for a high-throughput, rapid method for screening multiple water samples for contaminants with potential endocrine-disrupting activity. The NCI is seeking co-development partners and/or licensees for this technology as a product or service for detecting and screening for endocrine disrupting chemicals in water samples.
- High-throughput and rapid testing
- High sensitivity and selectivity
- Readily adaptable for use with a variety of endocrine receptor targets
- Can detect many EDC variants modified in the environment or other compounds that may act and interfere like EDCs
- Does not require a priori knowledge of the ligand chemical structure
- Water source testing
- Wastewater testing
- Drug ligand screening for agonistic and antagonistic activity
- Research tool to detect known and orphan receptor activity