Stanford, California - A recent study from Stanford University tested the use of inactivated induced pluripotent stem cells (iPSs) for personalized cancer vaccines that could treat and even potentially prevent cancer. The study is still in the early phases and has only been implemented in mice modules, but shows promise for the potential to vaccinate patients against various types of cancer, including mesothelioma, melanoma, and breast cancer.
Induced pluripotent stem cells can be harvested from skin or blood samples and genetically treated to transform into a pluripotent stage. Pluripotent stem cells are considered “master cells,” since they can potentially be used to produce any cell or tissue in the body that needs to be repaired or fight diseases like cancer.
In this study, researchers realized that iPSs are superficially similar to tumor cells, as both the stem cells and cancer cells have similar proteins (epitopes) on their surfaces. Furthermore, both cells lack the structured mechanisms usually witnessed in mature cells’ abilities to grow and divide with control. For instance, part of the transformation of a normal, healthy cell into a cancerous cell is the sudden, rapid cell division after shedding the naturally occurring mechanisms that block such uncontrolled growth.
With this in mind, the researchers began to explore if the immune system could be primed to recognize dangerous cells and prevent their growth and development in the future by targeting the specific proteins the IPSs and cancer cells have in common.
The study used four different groups of mice to test the effects of the genetically matching IPSs with and without an adjuvant that would stimulate an immune response against control groups. After being vaccinated for four weeks with either a control solution or one of the stem cell solutions, all of the mice had breast cancer cells implanted.
Within a week, all of the mice had developed breast cancer tumors. The researchers discovered that while the tumors grew quickly in the control groups not treated with the stem cells, the tumors had shrunk in 7 of the 10 mice treated with the IPS and adjuvant solution. Two of the mice completely rejected the tumor growth and survived for one year after the cancer cells were introduced. The researchers repeated the study with mesothelioma and melanoma, finding similar results.
“This approach is particularly powerful because it allows us to expose the immune system to many different cancer-specific epitopes simultaneously,” Nigel Kooreman, one of the lead researchers, said. “Once activated, the immune system is on alert to target cancers as they develop throughout the body.”
The researchers hope to take this early-phase study to the next step and explore the effects of stem cells and immunotherapy on human cancers in a laboratory setting. Though there is still a lot of work ahead, the researchers envision a future where a simple blood sample can be used to make IPS cells, which can then be injected into an individual to prevent future cancers. Hopefully with more research, their vision can become a reality and help eliminate cancer.