Cancer therapy New treatment approach against aggressive tumors

New approaches to cancer therapy discovered

The number of new cases of cancer in Germany has almost doubled since 1970. In addition to the surgical removal of the tumors are currently available as treatment options still radiation and chemotherapy available. However, researchers have now discovered entirely new approaches to cancer therapy.

Number of cancers is increasing

More and more people are suffering from cancer. According to the World Cancer Report of the International Agency for Research on Cancer (IARC), 20 million cancer cases could occur annually by 2025. Also in this country there are more and more new cancer cases. The number of new diagnoses has almost doubled in Germany since 1970. Patients are usually treated by surgery, chemotherapy and / or radiation. However, researchers have now discovered entirely new approaches to cancer therapy.

In addition to surgery, radiation and chemotherapy are currently available for the treatment of cancer. However, researchers have now discovered entirely new approaches to cancer therapy. (Image: auremar / fotolia.com)

Malignant vascular tumors with aggressive course

Angiosarcomas are rare malignant vascular tumors with an aggressive course. Currently available as treatment options in addition to the surgical removal of radiation and chemotherapy.

However, malignant vascular tumors have so far responded poorly to such therapies.

A team of cancer researchers from the University Medical Center Göttingen (UMG) has now discovered a fundamentally new approach, as current chemotherapy might be more effective against rare vascular tumors.

The scientists found that particularly aggressive angiosarcoma cells specifically activate a signaling pathway that makes the cells almost insensitive to lethal oxygen stress and thus extremely resistant to chemotherapy.

The research results were recently published in the journal "Clinical Cancer Research".

Altering tumor cells by medication

"We wanted to know if it is possible to change the tumor cells by medication so that they can be fought back by oxygen stress," explained Dr. med. Vivek Venkataramani, Department of Hematology and Medical Oncology and Department of Pathology of the UMG, in a statement.

He and his team of researchers have found a way to achieve exactly that, at least in the test tube: By combining the drug "pazopanib" with common chemotherapy, oxygen stress could be generated in the tumor cells and the cells effectively killed.

The active substance is already approved for use in tumor patients and could therefore very soon be used as a combination therapy with conventional chemotherapy in clinical trials in angiosarcoma patients, "said Prof. Dr. med. Philipp Ströbel, Director of the UMG Institute of Pathology and senior author of the publication.

After their discovery, the Göttingen scientists now want to explore further links to metabolic processes that regulate the cellular stress balance in tumors.

In the future, high-throughput screening will be carried out in collaboration with a pharmaceutical company in order to find new, and even better, substances that can be used to combat angiosarcomas and other tumors.

Background information: Oxygen stress

Oxygen plays a vital role in many metabolic processes in cells. The handling of oxygen can endanger cells but also in their function: Particularly reactive oxygen molecules, so-called radicals, can damage the cell walls and the DNA and destroy the cells even DNA.

Tumor cells suffer from high oxygen stress, but have found ways to deal with it. Tumors, which are very successful here, grow faster and are also less sensitive to chemotherapy.

Random observation

Their observation made the Göttingen researchers more by chance. Cultured tumor cells from angiosarcoma patients did not all look the same under the microscope.

Most tumor cells resembled normal vascular cells (more like "cobblestone") and also imitated vessels under specific conditions. In addition, there were few cells that looked like "spindle-shaped" connective tissue cells and behaved significantly more aggressive.

The research team succeeded in isolating the two cell types and then investigating them more closely.

For the first time, the Göttingen scientists have shown that not all cells in the angiosarcoma are identical: a small number of tumor cells lose certain important surface molecules, which play an important role in the formation and function of blood vessels.

These few tumor cells lose the ability to form vascular structures and thus become particularly aggressive.

Successful new therapeutic approaches

The researchers found that the loss of the surface molecule CD31 leads to the activation of a signaling pathway that not only makes the tumor cells much more aggressive, but also completely protects them from destruction by common chemotherapies.

"We were also able to regularly detect some tumor cells with low CD31 levels in tumor samples from patients with angiosarcoma," explained senior author Prof. Dr. med. Philipp Ströbel.

"We therefore believe that this is a generally important phenomenon that unfolds its full significance when patients need to be treated with chemo or radiation therapy. We are convinced that for successful new therapies especially this small cell population must be targeted. This strategy is very likely to be applicable to other tumors, "says the expert. (Ad)