Georgia Southern graduate student Alexandria “Allie” Griffis has found promising results in experiments testing drugs against prostate cancer cells implanted in zebrafish embryos and is hoping to translate these results to other forms of cancer.
In her unpublished thesis, Griffis cites previous research from Georgia Southern's lab as the basis for her experiments. This previous research identified a protein, Integrin Alpha 6 (ITGA6), as an influential adhesion molecule in some cancer development and metastasis (the migration of cancer cells from a primary tumor to surrounding tissue). The results of the previous study showed correlations between increased expression of ITGA6 and increased migration of cancer cells.
The experiment that Griffis performed tested the effects of two drugs, Cucurbitacin B and Silmitasertib, to see if they would increase or decrease the amount of ITGA6 present in the prostate cancer cells and therefore increase or decrease cancer metastasis.
Cucurbitacin B
https://pubchem.ncbi.nlm.nih.gov/compound/Cucurbitacin-B
Silmitasertib
https://pubchem.ncbi.nlm.nih.gov/compound/Silmitasertib#section=InChIKey
A Walk Through Cell the Culture Lab: The Process
The prostate cancer cells are carefully harvested from the Liquid Nitrogen Storage Dewar where they are kept at temperatures below -180 degrees Celsius, and thawed in a warm 37-degree Celsius bath. Once thawed these cells are piped into a flask with a culture medium that supplies nutrients to the cells. The cells are transferred to microscope viewing slides, washed multiple times, and labeled with a red dye so their migration can be viewed.
This process can take weeks and requires a sterile environment and careful handling of the cells.
“It's weird to say that I have to make healthy cancer cells but they do have to be healthy,” said Griffis. She says that without thriving cells, these tests would not be possible.
After the cells grow to cover a certain amount of the slide, the culture medium is replaced with a concentration of both Cucurbitacin B and Silmitaseratib. The prostate cancer cells are then injected into the zebrafish embryos, each batch including 200-300 embryos, which are then incubated.
Over time, Griffis observed significantly decreased levels of ITGA6 and cancer metastasis in the zebrafish embryos that were injected with the treated cancer cells compared to the control group.
Figure 1. ITGA6 expression in PC3 cells dosed with Silmitasertib. Panel A shows
ITGA6 expression (green fluorescence) in 0.02% DMSO control cells. Panel B
shows ITGA6 expression in cells dosed with 5 uM of Silmitasertib. Panel C shows
ITGA6 expression in cells dosed with 10 uM of Silmitasertib. Panel D shows ITGA6
expression in cells dosed with 25 uM of Silmitasertib that showed the least amount of
expression. (Provided by Alexandria Griffis)
The Long and Winding Road to Results
The path to obtaining usable results was long and arduous according to Griffis. “The most difficult thing was trying to get the drug concentrations right,” she said.
Translating the experimental process of testing the drugs on just the cells in the lab to implanting them into the embryos and having them survive, proved to be challenging.
The complexity of lab science often follows this path of trial and error, and it is often costly. A milliliter vial of these chemicals can cost up to 500$, Griffis said, “You need several of them… We’re talking thousands of dollars”
Which some might say is a steep price to pay for results that couldn’t have been guaranteed. There was research out there that had tested the drugs, but the effects had not been confirmed yet. “It was just a hunch,” said Griffis. A hunch that just so happened to be correct.
And the Research Continues…
After Griffis graduates, she will spend the summer continuing the development of this research and teaching other scientists how to perform experiments in the cell culture lab. She hopes to continue working towards translating these results to other forms of cancer such as lung and breast cancer.
Griffis says she is unsure about the future possibility of a complete cure for cancer. But she does believe that it is possible to stop cancer metastasis, the cause of 90% of cancer deaths, and her research aims to do just that.