Published online Jun 26, 2020. doi: 10.4252/wjsc.v12.i6.406
Peer-review started: January 16, 2020
First decision: April 7, 2020
Revised: April 29, 2020
Accepted: May 27, 2020
Article in press: May 27, 2020
Published online: June 26, 2020
Since the first publication regarding the existence of stem cells in cancer [cancer stem cells (CSCs)] in 1994, many studies have been published providing in-depth information about their biology and function. This research has paved the way in terms of appreciating the role of CSCs in tumour aggressiveness, progression, recurrence and resistance to cancer therapy. Targeting CSCs for cancer therapy has still not progressed to a sufficient degree, particularly in terms of exploring the mechanism of dynamic interconversion between CSCs and non-CSCs. Besides the CSC scenario, the problem of cancer dissemination has been analyzed in-depth with the identification and isolation of microRNAs (miRs), which are now considered to be compelling molecular markers in the diagnosis and prognosis of tumours in general and specifically in patients with non-small cell lung cancer. Paracrine release of miRs via “exosomes” (small membrane vesicles (30-100 nm), the derivation of which lies in the luminal membranes of multi-vesicular bodies) released by fusion with the cell membrane is gaining popularity. Whether exosomes play a significant role in maintaining a dynamic equilibrium state between CSCs and non-CSCs and their mechanism of activity is as yet unknown. Future studies on CSC-related exosomes will provide new perspectives for precision-targeted treatment strategies.
Core tip: The role of cancer stem cells (CSCs) in tumour aggressiveness, progression, recurrence and resistance to cancer therapy is well appreciated. However, therapeutic strategies to target CSCs for cancer therapy has still not progressed sufficiently, particularly in terms of exploring the mechanism of dynamic interconversion between CSCs and non-CSCs. Similar to other cells, CSCs also release exosomes loaded with microRNAs (miRs) as part of their paracrine activity. Our review focusses on the exosomal payload of miRs released by cancer cells and their role in the diagnosis as well as prognosis of lung cancer patients.