Published online Sep 26, 2015. doi: 10.4252/wjsc.v7.i8.1078
Peer-review started: January 24, 2015
First decision: March 6, 2015
Revised: June 27, 2015
Accepted: August 20, 2015
Article in press: August 21, 2015
Published online: September 26, 2015
Processing time: 244 Days and 15.5 Hours
A small subset of cancer cells that act as tumor initiating cells or cancer stem cells (CSCs) maintain self-renewal and growth promoting capabilities of cancer and are responsible for drug/treatment resistance, tumor recurrence and metastasis. Due to their potential clinical importance, many researchers have put their efforts over decades to unravel the molecular mechanisms that regulate CSCs functions. MicroRNAs (miRNAs) which are 21-23 nucleotide long, endogenous non-coding RNAs, regulate gene expression through gene silencing at post-transcriptional level by binding to the 3’-untranslated regions or the open reading frames of target genes, thereby result in target mRNA degradation or its translational repression and serve important role in several cellular, physiological and developmental processes. Aberrant miRNAs expression and their implication in CSCs regulation by controlling asymmetric cell division, drug/treatment resistance and metastasis make miRNAs a tool of great therapeutic potential against cancer. Recent advancements on the biological complexities of CSCs, modulation in CSCs properties by miRNA network and development of miRNA based treatment strategies specifically targeting the CSCs as an attractive therapeutic targets for clinical application are being critically analysed.
Core tip: Cancer stem cells (CSCs) which are believed to be the prerequisite for metastasis and tumor recurrence, are endowed with ability to undergo symmetric cell division, capacity for self-renewability, long term proliferation and resistance to anti-neoplasic therapeutic drugs. Regulatory characteristics of microRNAs (miRNAs) which are the clusters of non-coding RNA molecules, include widespread changes in gene expression through gene silencing at post-transcriptional level and are dysregulated in human cancer. Over the past two decades, miRNAs have gained widespread attention due to their involvement in acquisition of stem cell-like properties, regulation and reprogramming by cancer cells during cancer progression. Many studies are coming up which document miRNAs as novel therapeutic tool in targeting CSCs functions, sensitizing them to apoptotic effects of anti-cancer drugs, and reducing tumor burden with no relapse in current clinical settings.