Animal Studies: New Cancer Vaccine Bypasses Tumor Defenses

The world has learned many lessons over the past few years. One of these lessons is the importance of vaccines, which are capable of serving as prevention of illness as well as cure.

This concept also applies to cancer vaccines. Some experts are dubbing a relatively new field of medicine "the cancer miracle."

A new animal study published in Nature suggested that one new cancer vaccine could be about to change the game once more, providing protective immunity even against tumors with common escape mutations.

The cure for cancer is frequently held up as the gold standard of scientific progress in popular culture.

However, delivering on this demand has been challenging as "cancer" is a broad term that encompasses more than 200 different diseases, each with subtypes and variations as diverse as the people affected.

Dr. Matt Lam, Science Communications Manager at Worldwide Cancer Research, said that cancer is a complex disease for which there is no single cure.

Lam, who was not involved in the research, noted that each type and subtype of cancer necessitates a distinct approach to prevention, diagnosis, and treatment.

Lam added that the disease is highly adaptable as it can spread to other organs and it can become resistant to treatments that initially work.

Some researchers have been looking for a way to use the body's immune system to fight cancer, a technique known as immunotherapy.

In 2006, the world's first cancer vaccine was released, protecting against HPV-related diseases like cervical cancer and head and neck cancers, and recent years have seen the development of new and personalized vaccines for different types of cancers.

Not Without Flaws

The study suggested that most cancer vaccines target peptide antigens, which are specific protein cells expressed on the surface of tumors.

The cancer vaccines are all tailored to each disease and person.

The precise nature of each antigen and its ability to stimulate an immune response in the patient is too diverse to make a universal cancer vaccine sound.

The new vaccine, according to the research authors, induces a coordinated attack by diverse T cell and natural killer (NK) cell populations.

These are two of the human body's first-line defenses against disease, with NK cells being named for their ability to hunt down tumor cells without being primed by antigens.

The vaccine sends these cells into battle against MICA and MICB proteins, which are expressed by a variety of human cancers.

Until now, the vaccine has been merely mimicking what our bodies would do naturally when confronted with a tumor.

T and NK cells usually attack cancer by binding to MICA and MICB proteins on the tumor's surface, and the tumor usually responds by "slicing" or "cleaving" the affected proteins.

The new vaccine, however, prevents this.

The study suggested that vaccine-induced antibodies increase the density of MICA/B proteins on the surface of tumor cells by inhibiting proteolytic shedding, which, according to the paper, encourages T and NK cells to go in and launch a coordinated attack.

Although the vaccine has not yet been tested in humans, the researchers claim that it has shown efficacy and safety in mice and nonhuman primates.

The researchers emphasized that through the coordinated action of NK cells and CD4+ T cells, this vaccine maintains efficacy against tumors resistant to cytotoxic T cells.

The vaccine is also effective in a clinically significant setting: immunization after surgical removal of primary, highly metastatic tumors inhibits later metastasis growth.

The next step is to test the vaccine in human cancer patients, with a first-in-human clinical trial being planned.

The team warned that DNA damage enhances MICA/B expression by cancer cells, suggesting that the vaccine could be used in conjunction with radiation therapy.

Cancer Paradigms

Dr. Jason Fung, a nephrologist, told Global News in 2018 that they have gone through several cancer paradigms, so this comes down to a new approach.

The first paradigm was chemotherapy, radiation, and surgery, which worked to some extent; the second paradigm looked at cancer's genetic defects, which was a dead-end that cost a lot of money and took about 20 years.

With cancer vaccines, humankind is now in paradigm three.