Researchers have developed cancer-fighting nanoparticles that may ship modern chemoimmunotherapy.
In keeping with a brand new research printed within the journal Nature Nanotechnology, researchers on the College of Pittsburgh have developed cancer-fighting nanoparticles that concurrently ship chemotherapy and a novel immunotherapy.
The brand new immunotherapy, which silences a gene concerned in immunosuppression, has been proven to be efficient in shrinking tumors in mouse fashions of colon and pancreatic most cancers when mixed with chemotherapy and packaged into nanoparticles.
“There are two modern points of our research: the invention of a brand new therapeutic goal and a brand new nanocarrier that could be very efficient in selective supply of immunotherapy and chemotherapeutic medication,” stated senior creator Music Li, M.D., Ph.D., professor of pharmaceutical sciences within the Pitt Faculty of Pharmacy and UPMC Hillman Most cancers Middle investigator. “I’m enthusiastic about this analysis as a result of it’s extremely translational. We don’t know but whether or not our method works in sufferers, however our findings counsel that there’s a lot of potential.”
Chemotherapy is a pillar of most cancers remedy, however residual most cancers cells can persist and trigger tumor relapse. This course of entails a lipid referred to as phosphatidylserine (PS), which is often discovered contained in the tumor cell membrane’s interior layer however migrates to the cell floor in response to chemotherapy medication. On the floor, PS acts as an immunosuppressant, defending the remaining most cancers cells from the immune system.
The Pitt researchers discovered that remedy with chemotherapy medication fluorouracil and oxoplatin (FuOXP)
led to elevated ranges of Xkr8, a protein that controls the distribution of PS on the cell membrane. This discovering steered that blocking Xkr8 would forestall most cancers cells from shunting PS to the cell floor, permitting immune cells to mop up most cancers cells that lingered after chemotherapy.
In an unbiased research that was not too long ago printed in Cell Reports, Yi-Nan Gong, Ph.D., assistant professor of immunology at Pitt, also identified Xkr8 as a novel therapeutic target to boost anti-tumor immune response.
Li and his team designed snippets of genetic code called short interference RNA (siRNA), which shuts down the production of specific proteins — in this case, Xkr8. After packaging siRNA and FuOXP together into dual-action nanoparticles, the next step was targeting them to tumors.
Nanoparticles are typically too large to cross intact blood vessels in healthy tissue, but they can reach cancer cells because tumors sometimes have poorly developed vessels with holes that allow them passage. But this tumor-targeting approach is limited because many human tumors do not have large enough holes for nanoparticles to pass through.
“Like a ferry carrying people from one side of the river to the other, we wanted to develop a mechanism that allows nanoparticles to cross intact blood vessels without relying on holes,” said Li.
To develop such a ferry, the researchers decorated the surface of the nanoparticles with chondroitin sulfate and PEG. These compounds help the nanoparticles target tumors and avoid healthy tissue by binding to cell receptors common on both tumor blood vessels and tumor cells and prolonging the length of time they remain in the bloodstream.
When injected into mice, about 10% of the nanoparticles made their way to their tumor — a significant improvement over most other nanocarrier platforms. A previous analysis of published research found that, on average, only 0.7% of nanoparticle doses reach their target.
The dual-action nanoparticles dramatically reduced the migration of immunosuppressing PS to the cell surface compared to nanoparticles containing the chemodrug FuOXP alone.
Next, the researchers tested their platform in mouse models of colon and pancreatic cancer. Animals treated with nanoparticles containing both FuOXP and siRNA had better tumor microenvironments with more cancer-fighting T cells and fewer immunosuppressive regulatory T cells than animals that received placebo or FuOXP doses.
As a result, mice that received the siRNA-FuOXP nanoparticles showed a dramatic decrease in tumor size compared to animals that received those carrying just one therapy.
According to Li, the study also pointed to the potential of combining the FuOXP-siRNA nanoparticles with another type of immunotherapy called checkpoint inhibitors. Immune checkpoints such as PD-1 act like brakes on the immune system, but checkpoint inhibitors work to release the brakes and help immune cells to fight cancer.
The researchers found that FuOXP nanoparticles with or without siRNA increased PD-1 expression. But when they added a PD-1 inhibitor drug, the combination therapy had drastic improvements in tumor growth and survival in mice.
With their sights set on translating their novel therapy to the clinic, the team is now looking to validate their findings with additional experiments and further evaluate potential side effects.
References: “Targeting Xkr8 via nanoparticle-mediated in situ co-delivery of siRNA and chemotherapy drugs for cancer immunochemotherapy” by Yuang Chen, Yixian Huang, Qinzhe Li, Zhangyi Luo, Ziqian Zhang, Haozhe Huang, Jingjing Sun, LinXinTian Zhang, Runzi Sun, Daniel J. Bain, James F. Conway, Binfeng Lu and Song Li, 24 November 2022, Nature Nanotechnology.
“Mobilizing phospholipids on tumor plasma membrane implicates phosphatidylserine externalization blockade for cancer immunotherapy” by Weihong Wang, Shaoxian Wu, Zhanpeng Cen, Yixin Zhang, Yuang Chen, Yixian Huang, Anthony R. Cillo, Joshua S. Prokopec, Giovanni Quarato, Dario A.A. Vignali, Jacob Stewart-Ornstein, Song Li, Binfeng Lu and Yi-Nan Gong, 1 November 2022, Cell Reports.
The study was funded by the National Institutes of Health.