Site of breast cancer metastasis is independent of single nutrient levels.

Cancer metastasis is a major contributor to patient morbidity and mortality, yet the factors that determine the organs where cancers can metastasize are incompletely understood. In this study, we quantify the absolute levels of over 100 nutrients available across multiple tissues in mice and investigate how this relates to the ability of breast cancer cells to grow in different organs. We engineered breast cancer cells with broad metastatic potential to be auxotrophic for specific nutrients and assessed their ability to colonize different organs.

Novel modes of oestrogen receptor agonism and antagonism by hydroxylated and chlorinated biphenyls, revealed by conformation-specific peptide recognition patterns.

Because of the concern about environmental chemicals with oestrogenic and anti-oestrogenic effects, there is a need to construct biosensors for classifying such chemicals according to their effect on oestrogen receptor conformation. The conformation of the ligand-binding domains (LBD) of oestrogen receptor-alpha and -beta determine their transcription regulation activity. Some ligands, i.

An electrochemical sensor based on the human estrogen receptor ligand binding domain.

Three different conformations of the ligand binding domain of the human estrogen receptor (ER-LBD) are observed for the native state when binding an agonist and when binding an antagonist. By conjugating ER-LBD conformation specific peptides to CdS nanoparticles, the three different states can be identified by anodic stripping voltammetry. This electrochemical sensor can detect and distinguish the binding of different ligands to the human estrogen receptor.

Femtomolar electrochemical detection of DNA targets using metal sulfide nanoparticles.

A new electrochemical DNA sensor providing detection capabilities down to 100 attomol of target DNA has been developed. The method applies CdS, ZnS, and PbS nanoparticles conjugated with short DNA sequences which are immobilized via hybridization with complementary sequences on a gold surface. When the DNA target is added, it can be identified by ousting the existing hybridization between one of the DNA-nanoparticle conjugates and the surface DNA.

Quantum-dot/aptamer-based ultrasensitive multi-analyte electrochemical biosensor.

The coupling of aptamers with the coding and amplification features of inorganic nanocrystals is shown for the first time to offer a highly sensitive and selective simultaneous bioelectronic detection of several protein targets. This is accomplished in a single-step displacement assay in connection to a self-assembled monolayer of several thiolated aptamers conjugated to proteins carrying different inorganic nanocrystals. Electrochemical stripping detection of the nondisplaced nanocrystal tracers results in a remarkably low (attomole) detection limit, that is, significantly lower than those of existing aptamer biosensors.