Researchers undertake search for vaccine for cancer

Shooting up is one of the best things you can do to stay healthy.

No, not heroin; think more along the lines of vaccines.

These drugs give you a high unmatched by any illicit substance: staying alive. One little poke, and you're safe from an extended stay in bed, a hospital visit, or worse.

They can protect you from mumps, measles, meningitis. And Dr. Jill Slansky and Dr. John Kappler are trying to expand that list to include a biggie: cancer.

"The point of this projects is to try and take antigens associated with tumors and to alter them in some way to make it a better antigen for stimulating the immune system," explained Kappler.

Simplified, it's like this: the cells in the body and those from the outside—and diseases—are on two different teams, and each team has a different jersey. The body's defense can tell who to fight off based on jersey color.

Here's the tricky thing about cancer: Its antigen, or "jersey," is similar enough to the body's that the immune system thinks they're on the same side, and leaves the cancer alone.
Slansky and Keppler are trying to change that.

"We're using peptides [the bases of protein] to stimulate a specific response," said Slansky, "the part of the response that won't be directed to non-cancer cells. [The response] is toward cancer, is the idea there."

"We're using an insect-cell-based vaccine," Slansky said. "It's a system that expresses proteins at a really high level, and since its foreign, we can get a really good non-specific response."

The problem with the cancer cells is that they're similar enough to avoid detection by the immune system. But if you stimulate the immune system too much, it starts attacking everything, and you get an autoimmune disease.

"In lab animals, it's working well. We're really excited about how it's working so far. We'd like to take it to next level," Slansky said. "We're considering a clinical trial in pet dogs, because dogs also get cancer."

There'd be a big difference in the vaccines of normal diseases and the cancer ones, if the team's research pays off. It wouldn't be one of those shots that you get as a kid and never have to worry about again.

"We would only vaccinate an at-risk population, like if there's a family history of cancer, or a genetic risk," Keppler said. "Vaccinating everyone, that's a much bigger project. When immunizing for people who have had cancer, you know who to give it to."

Cancer isn't contagious. You can't cough and give someone colon cancer. So vaccinating the entire population, when a vast majority will never have the disease, according to Keppler, may be pointless.

"Out of 100 actual at-risk patients, maybe only one would actually get cancer," Keppler said.

So what's the use of making a vaccine if it wouldn't even be given to everyone?

"In some cases, after surgery there are still cancer cells left," Slansky said. "It would be a way of removing what's left over from chemo or surgery."

"The most practical thing would be a therapeutical vaccine, and use that to prevent reoccurrence," Keppler said.

In the end, the question of how the vaccine will be used isn't the main issue: It's developing it in the first place.

"The statistics are not so great," said Keppler. "It's a hope, right? There are no sure bets in cancer."

"I started my career with Nixon's war on cancer, and how we were going to cure it by pumping a lot of money into it," Keppler said. "Here we are, 40 years later, and we still haven't cured it. It's a really tough problem."

"I know there are people who have someone they want to use this for, right now," Slansky said. "For now, we'll keep plugging away."