Would cancer stem cells affect the future investment in stem cell therapy.

The common goal within the overwhelming interests in stem cell research is to safely translate the science to patients. Although there are various methods by which this goal can be reached, this editorial emphasizes the safety of mesenchymal stem cell (MSC) transplant and possible confounds by the growing information on cancer stem cells (CSCs). There are several ongoing clinical trials with MSCs and their interactions with CSCs need to be examined. The rapid knowledge on MSCs and CSCs has now collided with regards to the safe treatment of MSCs. The information discussed on MSCs can be extrapolated to other stem cells with similar phenotype and functions such as placenta stem cells. MSCs are attractive for cell therapy, mainly due to reduced ethical concerns, ease in expansion and reduced ability to be transformed. Also, MSCs can exert both immune suppressor and tissue regeneration simultaneously. It is expected that any clinical trial with MSCs will take precaution to ensure that the cells are not transformed. However, going forward, the different centers should be aware that MSCs might undergo oncogenic events, especially as undifferentiated cells or early differentiated cells. Another major concern for MSC therapy is their ability to promote tumor growth and perhaps, to protect CSCs by altered immune responses. These issues are discussed in light of a large number of undiagnosed cancers.