The Role of Cancer Stem Cells in Malignancies: Properties, Function and Origin

Nowadays, the advancement of researcher's knowledge in the field of stem cell biology and its key role in the creation of complex multicellular organisms, the importance of stem cells in the development of tumors has become more significant. It has been suggested that cells with stem cell characteristics called cancer stem cells (CSCs) are involved in the development and spread of human cancers.
The objective of this review is to consider the properties of CSCs, function, origin and the difference between CSCs and stem cells.
In this review the search was done in electronic and scientific databases including Scopus, PubMed, Google scholar, Medline and ISI. The related papers were used.
CSCs are a subpopulation in tumors that have the ability to self-renewal and produce heterogeneous lines of cancer-producing tumor cells.
CSCs are proposed to persist in tumors as a distinct population and they are core of tumor. They cause relapse and metastasis by giving rise to new tumors. Also it has been demonstrated that CSCs are the cause of chemotherapy resistance.
It has been shown that CSCs or tumor-initiating cells are the main cause of cancer resistance and relapse. Therefore, the advancement of CSC-based therapies has created a new hope for increasing survival and improving the quality of life in cancer patients. So, the ability to isolate and characterize these cells leads to the production of new drugs targeting CSCs.