Using the venom from 312 honeybees and bumblebees, Dr. Ciara Duffy and colleagues, tested the effect of the venom on the clinical subtypes of breast cancer, including triple-negative breast cancer, which has limited treatment options. Their results revealed that honeybee venom rapidly destroyed triple-negative breast cancer and HER2-enriched breast cancer cells.
According to Dr. Duffy, the aim of the research was to investigate the anti-cancer properties of honeybee venom, and a component compound, melittin, on different types of breast cancer cells.
They tested honeybee venom on normal breast cells, and cells from the clinical subtypes of breast cancer: hormone receptor positive, HER2-enriched, and triple-negative breast cancer.
They also tested a very small, positively charged peptide in honeybee venom called melittin, which they could reproduce synthetically, and found that the synthetic product mirrored the majority of the anti-cancer effects of honeybee venom.
They reported that both honeybee venom and melittin significantly, selectively and rapidly reduced the viability of triple-negative breast cancer and HER2-enriched breast cancer cells.
A specific concentration of honeybee venom can induce 100% cancer cell death, while having minimal effects on normal cells.
They found that melittin can completely destroy cancer cell membranes within 60 minutes.
Melittin in honeybee venom also had another remarkable effect; within 20 minutes, melittin was able to substantially reduce the chemical messages of cancer cells that are essential to cancer cell growth and cell division.
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. They 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 tumor growth in mice.
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.
She found that the European honeybee in Australia, Ireland and England produced almost identical effects in breast cancer compared to normal cells. However, bumblebee venom was unable to induce cell death even at very high concentrations.
One of the first reports of the effects of bee venom was published in Nature in 1950, where the venom reduced the growth of tumors in plants. However, Dr. Duffy said it was only in the past two decades that interest grew substantially into the effects of honeybee venom on different cancers.
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.
References: Duffy, C., Sorolla, A., Wang, E. et al. Honeybee venom and melittin suppress growth factor receptor activation in HER2-enriched and triple-negative breast cancer. npj Precis. Onc. 4, 24 (2020). https://doi.org/10.1038/s41698-020-00129-0 link: https://www.nature.com/articles/s41698-020-00129-0