Immunological regulation of human cancer stem cells/cancer-initiating cells

Abstract

Recent cancer biology research has suggested that cancer stem cells/cancer-initiating cells (CSCs/CICs) exist in most tumor tissues. They show self renewal, differentiation, and, most importantly, tumorigenic potential. Thus, the possibility of regulating CSCs/CICs immunologically is highly intriguing. Our recent studies suggest that CSC/CIC-specific antigens, designated ‘cancer testis stem cell antigens’, are generally highly immunogenic, and should be useful for immunotherapeutic as well as prophylactic treatment of cancers. Since the clonal expansion of peripheral T lymphocytes is limited in vivo, immunological targeting of CSCs/CICs by cytotoxic T lymphocyte is thought to be the most rational and efficient approach for the treatment of and prophylaxis against cancers. In particular, cancer testis stem cell antigens might act as primordial tumor antigens in the basic immune surveillance mechanisms against tumors.