By Riya Gandhi ‘22

The location of cancer stem cells in tumors has opened the door to the development of a variety of therapeutic applications. These cells are the future of oncology, and scientists still have much to uncover regarding their various uses in medical treatment. While cancer stem cells are treasure chests of opportunity and have wide scientific application, they are difficult to obtain. In a recent study, researchers at a medical school in Japan made a substantial contribution to our ever-growing wealth of knowledge regarding cancer by proposing a means by which colon cancer cells could be reprogrammed to express characteristics of cancer stem cells.

Under head researcher Kanji Hirashima, scientists from the Shinshu University School of Medicine generated cancer stem cells in vivo from colon cancer cells. First, the researchers cultured two colon cancer cells lines, known as LoVo and OUMS-23, in the same DMEM high glucose medium. After that, they treated 2105 colorectal cancer cells with Sendai virus vectors that had been dissociated using the enzyme trypsin and suspended in a reprogramming cocktail containing fibroblast medium. After the first six days of exposure, the researchers harvested these reprogrammed cells, identified them as the control group, and confirmed the presence of induced pluripotent stem cell-like colonies. Scientists then determined which cells tested positive for Tra-1-60, a monoclonal antibody, and cultured these cells in an embryonic stem medium. Those that resembled cancer stem cells underwent sorting using a magnet system; the researchers then extracted the cells’ RNA as a means to detect CSC markers. Afterwards, the researchers compared the gene expressions of the original and reprogrammed colon cancer cells, injected both original and reprogrammed cells into female mice, and observed subsequent tumor formation.

After analyzing the results, the researchers determined that the reprogrammed colon cancer cells displayed cancer stem cell properties, demonstrating the success of their previous reprogramming efforts. Further analysis also suggested that the microenvironment of the cells played a crucial role in whether or not the reprogrammed cells maintained the acquired stem cell-like characteristics over time. As a result of this breakthrough, scientists may soon be able to reprogram cancer cells in tumors into stem cells, which could prove vastly beneficial to multiple facets of the field of oncology.

References

1. K. Hirashima, et. al., Cell biological profiling of reprogrammed cancer stem cell-like colon cancer cells maintained in culture. Cell and Tissue Research (2018). doi: https://doi.org/10.1007/s00441-018-2933-8  
2. Image retrieved from: https://www.pexels.com/photo/adult-biology-chemical-chemist-356040/