Heparanase: a universal immunotherapeutic target in human cancers

Heparanase has been identified as a particularly important player in metastasis, and its expression directly correlates with the metastatic spread of various tumors. Ideal targets for immunotherapy are gene products that are silenced in normal tissues but overexpressed in cancer, and that are directly involved in tumor cell survival and progression. Metastasis is the culmination of neoplastic progression. The importance of the role of heparanase in metastasis implies that immune escape by downregulation of heparanase expression could reduce the mortality of the cancer. These characteristics of heparanase make it an attractive universal target for cancer immunotherapy. Here, we review current knowledge about heparanase and its involvement in tumor metastasis, with an emphasis on recent results from heparanase-targeted cancer immunotherapy studies.