Researchers at the Kimmel Cancer Center at the Johns Hopkins School of Medicine recently made a groundbreaking discovery on the nature of prostate cancer cells. While studying the structure of prostate cancer cells, these researchers found that these cells possess the ability to change their shape, and invade neighboring tissues and organs in the body, enabling metastasis as a result.
The fundamental aspect of their research included a focus on AIM1, a gene more commonly known as “absent in melanoma 1”, which encodes for the protein AIM1. Contrary to the abundance of this protein found in normal prostate cells, researchers observed that localized (non-metastatic) prostate cancer cells were deficient in AIM1 approximately 20-30 percent of the time, while metastasizing prostate cancer cells did not possess the AIM1 gene at an even higher frequency of 40 percent of the time.
Our curiosity leads us to question the role of AIM1 in a normal prostate cell, and the mechanism by which it contributes to the prostate cancer metastasis, which is what Dr. Vasan Yegnasubramanian and the team of researchers wished to inquire. They injected dyes into these cells to monitor the presence of AIM1 and studied three particular types of cells: normal prostate cells, localized prostate cancer cells, and metastatic prostate cancer cells. In the normal prostate cells, AIM1 protein was present along the borders of the cell and linked to a protein beta-actin, a constituent of the cytoskeleton of the prostate cell which enforces the rigidity of its shape. However, researchers discovered that AIM1 did not link with beta-actin in cancerous cells, especially metastasizing cells, therefore allowing them to be more flexible. In additions, cells lacking AIM1 tended to exert greater force on their surroundings, suggesting an ability to propel themselves through their surroundings. As a result, these cells pervade other organs and tissues throughout the body, causing a greater incidence of tumor growth across the body.
Although researchers have found that the AIM1 protein contributes to the enablement of prostate cancer cells to drift and induce tumors in other parts of the human body, researchers have yet to uncover exactly how these cells move into other tissues. While the physical and structural properties of a prostate cancer cell are still being studied by experts at the Bloomberg School of Public Health, the mechanisms behind these cells’ movement into the tissue are still known. Another question of how tumors are induced also comes into play: while researchers are aware that the shapeshifting prostate cancer cells are able to move and plant themselves in various locations, not much is known about how tumors arise. These researchers noticed in mice models that the shapeshifters were incapable of forming fully-fledged colonies of tumors on their own.
By further examining the nature of these metastasizing cells, these researchers hope to discover other factors that may be involved in the reduced presence of AIM1 in cancerous cells. Dr Steven An, a cellular mechanics expert, has taken the initiative to use quantitative single-cell analysis to explore the properties of a cell and its cytoskeleton. In the future, this team of researchers hopes to produce new drugs that potentially shut down the metastasis mechanisms of these cells, preventing their spread and creation of new tumors in the process.
- Newman, T. (2017, August 10). ‘Shapeshifting’ cancer cells promote metastasis.
- H. (2017, August 08). Prostate cancer cells become ‘shapeshifters’ to spread to distant organs.
- Vanessa Wasta/ Published September 30, 2017. (2017, August 11). Prostate cancer cells become ‘shape shifters’ to spread to other organs, study finds.
- National Cancer Institute. “Common Cancer Types.”