As Duffy explained: “I began with collecting Perth honeybee venom. Perth bees are some of the healthiest in the world. The bees were put to sleep with carbon dioxide and kept on ice before the venom barb was pulled out from the abdomen of the bee and the venom extracted by careful dissection.” In addition to the bees from Western Australia, she also tested the venom of honeybees and bumblebees from England and Ireland.
Seen at left is the effect of melittin – which can be reproduced synthetically – on three different cell types: normal fibroblast cells, HER2-enriched and triple-negative breast cancer cells (© Nature). Used in the right concentration, the effects of melittin were found to be “extremely potent,” destroying the cancer cells within an hour, with limited harm to the surrounding normal cells. Duffy discovered that the melittin had another remarkable effect: within 20 minutes it reduced substantially the chemical messaging that is essential for cancer cell growth and cell division. Interestingly, the bumblebee venom, which does not contain melittin, elicited minimal death in breast cancer cells.
Duffy (seen below right, © Harry Parker Institute) went one step further and answered the question: “Can these compounds found in nature be used in conjunction with chemically synthesized drugs to boost the anti-cancer effects?” They discovered that a combination of melittin and a chemotherapy drug called docetaxel was extremely effective in reducing tumour growth in mice.
Peter Klinken, chief scientist for Western Australia, enthused: “This is an incredibly exciting observation that melittin can suppress the growth of deadly breast cancer cells. It provides another wonderful example of where compounds in nature can be used to treat human diseases.” Alex Swarbrick from Sydney was more cautious: “It’s very early days. Many compounds can kill a breast cancer cell in a dish or in a mouse. But there’s a long way to go from those discoveries to something that can change clinical practice.”