Cancer is one of the leading causes of death in industrial countries. Malignant tumors invade and destroy adjacent tissues. A group of tumor cells are resistant to chemotherapy and radiation therapy and can spread to distant sites to seed metastases. Thus, there is still a large unmet need for new therapeutic options.
As tumors consist of the body’s own cells, they are better tolerated by the immune system than other invasive agents such as pathogens. Moreover, tumors can actively suppress the immune system. Recent therapeutic approaches aim to break the immune system’s tolerance against tumor cells, thus enabling eradication of the tumor by the immune system. This concept, however, relies on the existence or induction of tumor-specific immune cells.
Certain tumor stem cells express the molecule ABCB5 on their surface. This molecule could potentially serve as a basis for immunotherapies. By targeting ABCB5 on tumor stem cells – either directly by specific antibodies or indirectly by boosting or inducing a specific cellular immune response against ABCB5 – new therapeutic options might arise for patients not or only poorly responding to available therapies.