A comparison of normal and cancer stem cells revealed that the cancer stem cells are unusually trapped at an early stage of development, according to NCI scientists.
The investigators isolated tumor-initiating cells (TICs) from primary human glioblastomas and compared them to human and mouse normal stem cells (NSCs) at various developmental stages.
The research team found that the TICs isolated from an adult patient are more similar to early embryonic stem cells than to later embryonic or adult-derived stem cells. Specifically, the TICs appear to be stuck at this early developmental stage, at least in part, due to epigenetic repression of bone morphogenic protein receptor 1B (BMPR1B) expression mediated through a polycomb repressive complex, they noted.
BMPs are known to mediate proliferation, differentiation, and apoptosis in NSCs. The scientists showed that forced expression of the silenced BMPR1B restored normal differentiation capacity to the isolated TICs, halting further cell division and inducing terminal differentiation.
The research is published in the January issue of Cancer Cell.