Stem cell vaccine immunizes lab mice against multiple cancers

February 15, 2018

Stanford University researchers report that injecting mice with inactivated induced pluripotent stem cells (iPSCs) launched a strong immune response against breast, lung, and skin cancers. The vaccine also prevented relapses in animals that had tumors removed. The work appears in the journal Cell Stem Cell on Feb. 15.

iPSCs are generated from adult cells genetically reprogrammed to mimic embryonic stem cells' ability to become any type of cell in the body.

In the study, 75 mice received versions of the iPSC vaccine created from iPSCs that have been inactivated by irradiation. Within four weeks, 70 percent of the vaccinated mice fully rejected newly introduced breast cancer cells, while the remaining 30 percent had significantly smaller tumors. The effectiveness of the iPSC vaccine was also validated for lung and skin cancers.

Lead author Joseph C. Wu at Stanford's Cardiovascular Institute and Institute for Stem Cell Biology and Regenerative Medicine and colleagues found that a large amount of the antigens present on iPSCs are also present on cancer cells. When lab mice were vaccinated with iPSCs, their immune systems built an immune response to the antigens on the iPSCs. Because of key similarities between the iPSCs and cancer cells, the animals simultaneously built an immune response against cancer.

The iPSCs seemed to "prime their immune systems to eradicate tumor cells," Wu says.

To be effective, anti-cancer vaccines must introduce one or more antigens into the body that activate T cells or produce antibodies capable of recognizing and binding to antigens on the surfaces of cancer cells.

One of the biggest challenges for cancer immunotherapies is the limited number of antigens that can be presented to the immune system at a given time. The Stanford study uses an animal's own cells to create an iPSC-based cancer vaccine that simultaneously targets multiple tumor antigens. Using whole iPSCs eliminates the need to identify the most optimal antigen to target in a particular type of cancer.

"We present the immune system with a larger number of tumor antigens found in iPSCs, which makes our approach less susceptible to immune evasion by cancer cells," Wu says. The researchers also combined iPSCs with an immunity booster--a snippet of bacterial DNA called CpG that has been deemed safe in human trials. Stanford oncologist and study co-author Ronald Levy previously found CpG to be a potent tumor-fighting agent.

In the future, a patient's skin or blood cells may be re-programmed into iPSCs and administered as an anti-cancer vaccine or as a follow-up booster after surgery, chemotherapy, or radiation therapy.

"What surprised us most was the effectiveness of the iPSC vaccine in re-activating the immune system to target cancer," Wu says. "This approach may have clinical potential to prevent tumor recurrence or target distant metastases."
-end-
This work was supported by the California Institute of Regenerative Medicine (CIRM) and the National Institutes of Health (NIH).

Cell Stem Cell, Kooreman and Kim et al.: "Autologous iPSC-Based Vaccines Elicit Anti-tumor Responses In Vivo" http://www.cell.com/cell-stem-cell/fulltext/S1934-5909(18)30016-X

Cell Stem Cell (@CellStemCell), published by Cell Press, is a monthly journal that publishes research reports describing novel results of unusual significance in all areas of stem cell research. Each issue also contains a wide variety of review and analysis articles covering topics relevant to stem cell research ranging from basic biological advances to ethical, policy, and funding issues. Visit: http://www.cell.com/cell-stem-cell. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.