“…Similar to what was observed in cases of chemo-resistance against DNA damaging agents, miRNAs are involved in the activation of TGF-β signaling in cells treated with anti-metabolites and anti-microtubule drugs. Examples of miRNA regulators of TGF-β signaling include miR-423-5p, miR-552, and miR-17–92 cluster (miR-17, miR-18a, miR-19a, miR-19b, miR-20a and miR-92a) in prostate cancer, colorectal cancer, and pancreatic cancer ( Cioffi et al, 2015 ; Zhao et al, 2019 ; Shan et al, 2020 ). Intriguingly, TGF-β/SMAD signaling activation directly induced G1 cell-cycle arrest in SCC cells, leading to the entry of tumor-propagating cancer cells (TPCs) into quiescence, which protected cancer cells from DNA damage caused by 5-FU treatment by adopting a condensed heterochromatic state ( Brown et al, 2017 ).…”