Compounds found inside honeybee venom can help to tackle aggressive forms of breast cancer without putting healthy cells at risk, a new clinical study discovered.
Experts from the University of Western Australia used venom from 312 bees found in Perth, Western Australia, Ireland and England as part of the research.
Melittin, a new breakthrough
The team tested the effects of venom on different types of breast cancers that have limited treatment – they found it rapidly destroyed tumours and cancerous cells.
Before this study nobody had compared the effects of honeybee venom or a component of the venom called melittin on cancerous and normal cell types.
The Australian team found that the synthetic product mirrored the majority of the anti-cancer effects of honeybee venom.
It was able to ‘selectively and rapidly ‘reduced the viability of triple-negative breast cancer' as well as other cancerous cells.
Lead researcher, Dr Ciara Duffy, said melittin in the right concentrations can be used to completely destroy cancer cell membranes within 60 minutes.
Melittin in honeybee venom also had another remarkable effect; within 20 minutes, it was able to substantially reduce the chemical messages of cancer cells that are essential to cancer cell growth and cell division.
‘We looked at how honeybee venom and melittin affect the cancer signalling pathways,' said Duffy.
These pathways are the chemical messages that are fundamental for cancer cell growth and reproduction – finding pathways were quickly shut down with melittin.
‘Melittin modulated the signalling in breast cancer cells by suppressing the activation of the receptor that is commonly over expressed in triple-negative breast cancer,‘ Duffy explained.
‘It suppressed the activation of HER2 which is over-expressed in HER2-enriched breast cancer,‘ she said.
Western Australia's Chief Scientist, Professor Peter Klinken, described the synthesis of melittin as ‘incredibly exciting.'
‘It provides another wonderful example of where compounds in nature can be used to treat human diseases,' he said.
Melittin use with existing chemotherapies?
Dr Duffy also tested to see if melittin could be used with existing chemotherapy drugs as it forms pores, or holes, in breast cancer cell membranes, potentially enabling the entry of other treatments into the cancer cell to enhance cell death.
‘We found that melittin can be used with small molecules or chemotherapies, such as docetaxel, to treat highly-aggressive types of breast cancer. The combination of melittin and docetaxel was extremely efficient in reducing tumour growth in mice.‘
As part of the study Duffy and colleagues had to put bees to sleep with carbon dioxide and kept them on ice until the venom barb could be pulled out.
While there are 20,000 species of bees, Dr Duffy wanted to compare the effects of Perth honeybee venom to other honeybee populations in Ireland and England, as well as to the venom of bumblebees.
‘I found that the European honeybee in Australia, Ireland and England produced almost identical effects in breast cancer compared to normal cells,‘ she said.
However, bumblebee venom was unable to induce cell death even at very high concentrations.
In the future, studies will be required to formally assess the optimum method of delivery of melittin, as well as toxicities and maximum tolerated doses.