Scientists are testing vaccine against colorectal cancer for the first time

Vaccination should help against colon cancer
Colorectal cancer is one of the three most common cancers in Germany. Around 26,000 Germans die every year. In Frankfurt am Main, doctors are now testing a vaccine to protect against certain types of colon cancer. Maybe the serum could even heal.

Vaccine could replace chemo
Colon cancer is the second most common malignancy in men and women in Germany. Nearly a fifth of those affected have a family history. Even people who suffer from inflammatory bowel disease such as ulcerative colitis and Crohn's disease are at increased risk. In addition, lack of exercise, smoking, alcohol consumption and malnutrition, such as a very high fat and meat diet, are among the factors that increase the risk of colon cancer. If diagnosed early, this cancer is often curable. If colorectal cancer is detected in patients, surgery and chemotherapy and / or radiation are often followed. This could possibly change something in the future. As the "world" reports in a recent article, doctors in Frankfurt am Main are testing a vaccine to protect against certain colon cancer types. The syringe could even replace the onerous chemotherapy if the tumor is already there.

Hone the power of the immune system
The aim of immunotherapy is therefore to sharpen the power of the immune system so that it can detect and overwhelm tumor cells early. For example, people who are at high risk for hereditary cancers could be saved from the disease. According to the "world", molecular biologists Magnus von Knebel Doeberitz from Heidelberg University Hospital and Matthias Kloor from the German Cancer Research Center have spent years working "to develop a vaccine that can be used against certain forms of colon cancer and possibly protect against the onset of the disease . "

Vaccine is currently being used in patients for the first time
Currently, this is being used for the first time in patients under the direction of oncologist Elke Jäger in the hospital Northwest in Frankfurt. Despite the early stage of clinical trials, it shows that "the vaccine actually activates the immune system of cancer patients as desired," says Magnus von Knebel Doeberitz. The researcher was recently honored with the Felix Burda Award 2015 in the category "Medicine and Science" together with his colleague and colleague. The expert explained that the idea that a vaccine could work against colorectal cancer goes back to the 1990s. Researchers in the US had recently identified those gene mutations that are the cause of one of the most common forms of hereditary colorectal cancer.

Genes for cell repair system fail
The so-called HNPCC / Lynch syndrome is reported to affect approximately five percent of all cases of colon cancer. This leads to a massive accumulation of errors in a part of the genetic material, which consists of frequent repetition sequences. The cause of this is the failure of an important cell repair system. "You have to imagine that this repair system in the cells repeatedly moves along the DNA and checks for molecular mismatches in the double strand. It constantly compares old and new mating constellations with each other, "said the scientist. If it encounters a mismatched pair, repair proteins are called into action, which will normally correct the errors immediately. However, in patients with the hereditary form of colorectal cancer, the genes for this repair system have failed, both in the paternal and in the maternal inherited gene.

Immune system eliminates cells that can lead to cancer
There is thus no longer any "backup copy" that the affected cells could access. Then the errors accumulate rapidly with each cell division. In the course of the process it should actually come to an explosive cell degeneration. "That's not the case, we owe our immune system," explained Magnus von Knebel Doeberitz. This often recognizes the genes derived from defective genes as "alien". Such labeled cells are then eliminated by the immune system before they can develop into precursors of a tumor. The researchers' approach starts at this point. They have been able to show that the immune system as a "cleaner" recognizes and destroys potential cell degeneration and is also active in patients with HNPCC / Lynch syndrome.

Despite genetic predisposition, some people do not get sick
"We were wondering how it's possible that about half of the people who have a genetic predisposition to hereditary colon cancer on both gene copies do not get the tumor in their lifetime," said Magnus von Knebel Doeberitz. This is all the more surprising, since it comes to the burgeoning degeneracy caused by the double failure much more often than previously thought. The scientists also came up with their idea in such cases because of the effective protection provided by the immune system. Patients who do not have hereditary colorectal cancer could benefit from it, but random mutations can lead to genetic errors. Magnus von Knebel Doeberitz estimates that about 15 percent of all patients with colorectal cancer could benefit from such a vaccine.

Vaccine is being tested on 22 patients in Frankfurt
During the years of laboratory work, the researchers were, among other things, the question of which of the many mutated genes, more specifically, which of them derived defective protein compounds or tumor antigens produce the strongest immune response. Finally, in collaboration with Peer Bork from the European Molecular Biology Laboratory (EMBL) in Heidelberg, they succeeded in identifying promising genetic target structures. In a next step, a number of corresponding tumor antigens could be predicted, which first had to take their impact in blood samples from colon cancer patients. In the final selection for the vaccine came then three antigens, which are now being tested in an optimal combination in the clinical "Micoryx" study in a total of 22 patients in Frankfurt.

Chemotherapy should be replaced by vaccination
"In addition to the effects, safety and tolerability of the inoculation approach are at the forefront in the early stages," explained Magnus von Knebel Doeberitz. The investigator explained that preliminary results suggest that the vaccine is very well tolerated and leads to the development of strong specific immune responses. If the positive results are confirmed, the next step could be to extend the clinical trial to a larger number of patients. The question of which survival advantage the new therapy offers can only then be answered. "Our goal is to replace the heavy-duty chemotherapy with a well-tolerated vaccine," said Knebel Doeberitz. (Ad)

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