circleCancer is a cell metabolismReshape it in pursuit of growth.1 Cancer cells shut down cellular processes that do not serve this purpose. the study Research published in the journal Nature Nanotechnology, The researchers found that reactivating the dormant pathway inhibits the spread of cancer.2 The discovery could pave the way for new therapies that target cancer cells more efficiently.
Dayeon JinJin, a materials scientist at the University of Technology, Sydney and co-author of the study, is tackling science’s big questions with the tiniest tools available: nanoparticles. Jin has previously used nanoparticles to peer inside things. Bone marrow To detect Very small molecules Released by cancer cells.3,4 His latest research was even more ambitious: He wanted to find out whether tiny nanostructures could treat cancer.
His team was previously the study In studies of liver and kidney cancer, researchers manipulated the metabolism of cancer cells to restore healthy cellular processes and inhibit proliferation. Five Jin wondered whether a nanoparticle-based delivery system might make it easier to change the internal structure of cancer cells. In their experiments, Jin’s team focused on skin cancer. Melanoma cells slow down their production of the pigment molecule melanin to redirect energy toward cell growth. The first challenge Jin’s team faced was finding a way to speed up melanin production.
Interventions that alter the working of a cell’s internal processes often target metabolic enzymes. Developing enzyme activators is a difficult process, and the resulting drugs are usually clear It is eliminated from the body before it can have any effect.6 Another option is to identify and make available nutrients that cells use during melanin production. In skin cells, the amino acid tyrosine is a key component of melanin synthesis. deliver Delivers amino acids to specific cells.7 This is where nanotechnology excels.
“We modified the natural form of tyrosine to create a minicell structure,” Jin said. These minicells, also called nanomicelles, are tiny spheres about 60 nanometers in diameter that can easily cross the cell membrane of cultured mouse or human-derived cancer cells. After three days of culture, Jin and his team found that melanin levels increased six-fold in the target cells compared to control cells that had not been exposed to the minicells.
Once the cancer cells started secreting melanin, they quickly ran out of energy.Additional analysis showed that increasing the concentration of minicells made the cancer cells less likely to spread.
To test the minicells in vivo, the researchers used a mouse model of melanoma. When they first injected the minicells intravenously, something seemed off: the tumors darkened, leading the team to assume the cancer had become more aggressive. After all, as Jin pointed out, melanoma means “black tumor.”
The researchers found that the darker the tumor, the more melanin it produced and the more cancer cells it killed. After 50 days of treatment, the minicells suppressed the rapid growth of tumors and significantly extended survival.
These are all signs of successful treatment, but it is noted that in modern medicine, cancer treatments are rarely done in isolation. Navdeep Chandel“It’s important to understand how the immune system responds to these changes,” said Dr. Stanley, a cell biologist at Northwestern University who was not involved in the study.
Jin and his colleagues decided to test a combination of minicells and an experimental treatment called photothermal therapy that takes advantage of elevated melanin concentrations in tumors. They shone an 808-nanometer infrared laser on tumors in mice for five minutes a day for six days. The melanin absorbed the light, heating up the tumor cells. Jin says the technique eradicated tumors without harming surrounding healthy tissue, improving survival rates compared with minicells alone.
Chandell said the results are promising but that more research is needed: “First, we want to see results in multiple mouse models, and then with standard of care,” he said.
Standard treatments such as radiation and chemotherapy can interact negatively with newer therapies. For example, chemotherapy induces oxidative stress to kill tumor cells, but clinical trials have shown that it display Antioxidant treatment attenuated the efficacy of chemotherapy.8
“We hope that in the future, minicells can be used for early intervention before chemotherapy or radiation therapy is needed. If we can prevent cancer, people won’t have to worry about having limited treatment options,” Jin concluded.
