Copper is an essential element that plays a role in a variety of functions in biological systems.
A copper imbalance is a feature of many diseases, including cancer, in particular prostate cancer cells have been shown to accumulate more copper than normal cells.
The transport of copper in the blood occurs predominantly via carrier proteins, but a small amount is bound to low molecular weight species whose identity and roles in cellular delivery are poorly understood.
The aim of this systematic study, published in Metallomics, was to look at the effects of low molecular weight species, namely a select number of amino acids, on copper uptake in tumour cells.
The delivery of Cu-64 into tumour cells was first assessed by in vitro assays, which showed that whilst Cu-64 is not delivered as an amino acid complex, cell accumulation of Cu-64 is enhanced by L-cysteine or N-acetyl cysteine (NAC) influx into cells. Cu-64 in vivo whole body trafficking was then visualised by PET imaging with Cu-64, demonstrating that NAC pre-injection decreased Cu-64 accumulation in the DU145 tumour and in the brain.
Joanna Bartnicka, the first author of this work said that this study demonstrated the connection between the metabolism of copper and thiol amino acids in cancer cells, contributing to the area of copper biology which is still poorly understood. "With this study we also wanted to demonstrate the feasibility of PET imaging with positron-emitting metal isotopes to observe whole body trafficking of essential metals, such as copper. In this case, a PET metallomics approach was used to address the basic biology questions in vivo, providing a much more complex biological context than cell culture studies."