Researchers make progress on preventive vaccine for cancer

New research out of Stanford University suggests that it may be possible to harness an individual’s own cells to prevent or fight certain cancers.

Nigel Kooreman, MD, of Stanford University and one of the study authors, said there have been attempts at a stem cell vaccine before using genetically engineered pluripotent cells that overexpress an inflammatory stimulant (GM-CSF). However, this study is the first to show efficacy in using induced pluripotent stem cells (iPSCs) to activate the immune system in targeting multiple types of cancer, he said.

“We show that our approach is effective in preventing cancer development, but also preventing tumor recurrence after tumor resection,” Kooreman said. “Unlike previous reports, our approach does not require genetically engineered iPSCs to make them trigger an immune response. This makes our approach more easily generalizable, and takes out the potential hazard of using genetically engineered cells.”

The study, published in Cell, investigated the use of iPSCs in combination with an immunostimulant agent to create a vaccine to activate the immune system in targeting the proteins on iPSCs. The rationale behind the vaccine is the overlap in proteins that are present on cancer cells, as well as iPSCs, according to the study. “Because of this overlap, we can activate the immune system to target the proteins on the iPSCs which in turn primes it to attack cancer cells with the same set of proteins,” Kooreman said.

There is a two-fold message that clinicians should take from the report, according to Kooreman. One is that the vaccine could be a prophylactic treatment for high-risk patients when they reach an age to be vulnerable to certain cancers, like those caused by genetic mutations. The vaccine could provide an immune booster that targets cancer cells or provides memory immunity against future cancers.

“Key implications of such a vaccine would be that people would not develop cancer at all or the onset of cancer would be delayed,” Kooreman said.

The other is the use of the vaccine as an adjuvant therapy alongside established cancer treatments like surgery, chemotherapy, and radiation. The vaccine in this case would be used to re-activate the immune system to target remnant cancer cells, he says.

“In this situation, you could develop the vaccine at the moment the patient presents with cancer,” Kooreman said. “At the time of initiating cancer treatment, you would also have the vaccine available to provide the immune system with an extra boost to fight the cancer at a time when the cancer is most vulnerable.”

As for what types of cancers the vaccine could target, Kooreman said the possibilities are endless.

“Looking at our RNA-sequencing data, we found an overlap in gene expression between iPSCs and a large number of cancer-related genes,” he said. “These findings would suggest that our vaccine could be used on a large number of cancers, if not all.”
The research team is now looking at performing in-vitro experiments using human samples, but Kooreman said pre-clinical safety studies could take several more years.

“We hope that our vaccine might become an addition to the current standard in cancer treatment and help the patient’s own immune system in targeting remnant cancer cells,” Kooreman said. “In addition, we see the potential of this vaccine as a prophylactic treatment in high risk patients for the development of cancer. These patients could be vaccinated and this would hopefully protect them against the development of cancer.”