A laboratory study published in 2021 is circulating again online after social posts highlighted its counterintuitive approach: using a hydrogel to turn differentiated cancer cells into cells with cancer-stem-cell traits.
Researchers at Hokkaido University and Japan's National Cancer Center Research Institute reported in Nature Biomedical Engineering that a double-network hydrogel rapidly reprogrammed tumor cells in laboratory experiments. The method gives researchers a way to produce more of a rare, treatment-resistant cancer-cell population for laboratory study and drug screening. It does not treat patients or make healthy stem cells.
Cancer stem cells can be resistant to chemotherapy and radiotherapy and have been linked to recurrence. Because they occur in small numbers, they can be difficult to identify and study.
The gel induced stem-like traits within 24 hours
The double-network gel combines two chemical networks and holds a large amount of water, giving it soft, wet properties that resemble biological tissue. The researchers tested whether that environment could act as a niche that induces stemness in cancer cells.
Within 24 hours, cells on the gel formed spheroids and showed elevated levels of the stemness genes Sox2, Oct3/4 and Nanog. The result appeared across six human cancer cell lines representing brain, uterine, lung, colon and bladder cancers, plus sarcoma. The researchers also observed the effect in brain cancer cells taken from patients with glioblastoma.
The study included an animal experiment to test whether the gel-induced cells behaved like cancer stem cells. Human brain cancer cells cultured on the double-network gel were more tumorigenic after injection into the brains of immunodeficient mice than cells grown on single-network gels.
The team also identified biological signals involved in the process. Calcium-channel receptors and the protein osteopontin were necessary for the gel-mediated induction of stemness in brain cancer cells, according to the paper.
A research tool, not a cancer treatment
In another experiment, patient-derived brain cancer cells grown on the gel expressed platelet-derived growth factor receptors. A targeted inhibitor of those receptors eradicated the gel-induced cancer stem cells in culture.
That result does not show that the hydrogel or inhibitor treats cancer in people. Instead, it illustrates the platform's proposed use: generating cancer stem cells consistently enough to investigate their biology and screen potential drugs against them.
A joint release from Hokkaido University and the National Cancer Center Research Institute said the researchers hoped the method could eventually support cancer diagnosis, drug development and personalized medicine. Those remain prospective applications.
The date is an important part of the story. The paper was published March 29, 2021, and the university announced it the following day. The current attention reflects renewed circulation of that laboratory finding, not a newly reported clinical breakthrough.
