Cancer Stem Cells (CSCs): key player of radiotherapy resistance and its clinical significance.

Cancer stem cells (CSCs) are self-renewing and slow-multiplying micro subpopulations in tumor microenvironments. CSCs contribute to cancer's resistance to radiation (including radiation) and other treatments. CSCs control the heterogeneity of the tumor. It alters the tumor's microenvironment cellular singling and promotes epithelial-to-mesenchymal transition (EMT). Current research decodes the role of extracellular vesicles (EVs) (exosomes a subpopulation of EVs) and CSCs interlink in radiation resistance. Exosomes are plasma membrane-originating subpopulations of extracellular vesicles. It is secreted by several cells. It is related to cellular communication and messenger of health and multiple pathological complications via its biological active cargo (DNA, RNA, protein, lipid, and glycan), which is capable of transforming recipient cells' nature. The molecular signatures of CSCs and CSC-derived exosomes are the primary targets for developing diagnostic markers and therapeutics. This review discusses cancer stem cells, radioresistance-mediated CSCs development, EMT associated with CSCs, the role of exosomes in radioresistance development, the current state of radiation therapy, and the use of CSCs and CSCs derived exosomes biomolecules as a clinical screening biomarker for cancer. This review gives new researchers a reason to keep an eye on the next phase of scientific research into cancer therapies that will help mankind.