Brenda K. ColwellDr. Sheryl Fuller-Espie, associate professor of biology and student research assistants, Mukti Patel and Rosa Smith, have been developing an experimental method to study the effects that prove earthworm’s natural killer-like cells truly kill human target tumor cells.
From the research done here at Cabrini, Fuller-Espie was invited to attend the Eighth International Symposium on Earthworm Ecology in Krakow, Poland. She presented a poster and was a chairperson at one of the workshops called Earthworm Immunology. About 200 people were invited to attend the symposium from around the world.
Today, the research done at Cabrini is in the process of being reviewed for publication in the “European Journal of Soil Biology.”
“Our paper is very promising,” Fuller-Espie said. She feels that all the information, statistics and research are definitely there to prove that this new method truly works.
In their thesis, they use earthworm’s natural killer-like cells and human tumor cells called K562 that come from a patient with chronic myelogenous leukemia.
The tumor cells are killed when they interact with the earthworm’s natural killer-like cells, but if the natural killer-like cells are exposed to environmental pollutants, this killing effect is suppressed. A chemical compound called dimethylbenz[a]anthracene, referred to as DMBA, is very similar to some environmental pollutants called polycyclic aromatic hydrocarbons.
Earthworms have natural killer-like cells which can be extruded from their bodies when they come into contact with a buffer containing 5 percent ethanol. The cells are released from the earthworm’s dorsal pores, which separate the natural killer-like cells from the earthworm’s cavity so the experiments can be conducted on the cells released from the earthworm’s body.
DMBA is added to the cells after extrusion so it does not harm the earthworm in any way. Therefore, the earthworm is available to be used repeatedly with no effects. The natural killer-like cells that are extracted are treated with DMBA before being added to the target tumor cells, to study the effect of DMBA on the killing activity of the earthworm cells.
In Fuller-Espie’s research, she uses fluorescent dyes to distinguish which tumor cells have been killed and which cells are still alive. Therefore, the tumor cells that have been killed will fluoresce in a way that will be noticed compared to the unaffected tumor cells.
Counting the number of cells that are defined into each category after they have been mixed and settled is done by analyzing them on a flow cytometer. The flow cytometer then counts each cell and separates the cells by color, leading to a count and ratios of how many target tumor cells are killed by the natural killer-like cells.
The conclusions have been drawn that earthworm natural killer-like cells truly kill human target tumor cells and this immune response can be concealed out of the body following exposure to DMBA. The results are interpreted because of the colors and dyes taken up by the tumor cells.
“By having a program like this at Cabrini, students learn to think analytically on their feet. What Cabrini and the SET research facilities can do now compared to two years ago is amazing!” Dr. Fuller-Espie said.
