To proliferate and spread throughout the human body, cancer cells require proteins that bind copper ions. Recent research on protein interactions and how they bind to metals in cancer-related proteins has identified potential new treatment targets.
Human cells require trace quantities of the element copper to fulfil important biological processes. According to research that show increased copper levels in tumour cells and blood serum from cancer patients, cancer cells require more copper than healthy cells. Furthermore, greater copper levels activate more copper-binding proteins.
“As a result, these proteins are extremely important to study when it comes to understanding cancer development, and deeper knowledge about them can lead to new targets for cancer treatment,” said Pernilla Wittung-Stafshede, Professor of Chemical Biology at Chalmers University of Technology in Sweden.
The majority of cancer-related fatalities are caused by metastases, or secondary tumours, which occur in many locations throughout the body, such as the liver or lungs. Memo1 is a protein that is part of the signalling networks that cancer cells utilise to develop and disseminate throughout the body. Previous study has revealed that inactivating the Memo1 gene in breast cancer cells reduces their potential to produce metastases.
Chalmers researchers sought to explore into the relationship between Memo1 and copper. The researchers tested the Memo1 protein’s capacity to bind copper ions in a series of test tube tests in a recent study published in the scientific journal PNAS. They observed that the protein exclusively binds the reduced form of copper. This is the most frequent type of copper ion in living cells. It’s a significant discovery because, while reduced copper is required by the body, it also contributes to redox processes that harm – or even kill – cells. The researchers discovered that when Memo1 interacted with copper, it inhibited the metal’s harmful redox reactions.
“This increases the danger that the tumour may become too reliant on copper, which might produce chemical reactions that are detrimental to cancer cells. We suspect that Memo1 shields cancer cells by binding copper when needed, allowing them to continue to survive and spread “According to Pernilla Wittung-Stafshede, one of the study’s primary authors.
Memo1 may also form a compound with Atox1, another copper-binding protein found in our cells, according to the researchers. It is a copper transporter inside human cells, and earlier study has revealed that Atox1, with the assistance of copper, contributes to the ability of breast cancer cells to travel and generate metastases.
Overall, the new study’s findings suggest that copper and copper-binding proteins may be potential cancer therapeutic targets. “We discovered how copper ions may move between the proteins Memo1 and Atox1 in test tubes, and when we investigated in breast cancer cells, we found that the two proteins were adjacent to each other in space.” Based on this, we conclude that copper exchange between these proteins can occur in cancer cells as well as test tubes and therefore be biologically relevant,” explains Pernilla Wittung-Stafshede. The researchers now seek to determine the copper ion binding sites in Memo1, as well as how the presence of copper impacts Memo1’s activity in cancer formation.
“By expanding our basic understanding of the role of copper-binding proteins in cancer cells, we open the door to novel therapies,” Pernilla Wittung-Stafshede stated.