Tsn, or Tudor-staphylococcal/micrococcal-like nuclease, is involved in miRNA decay. It promotes the degradation of miRNAs containing CA and/or UA dinucleotides, which is a process known as TumiD [1]. This function potentially impacts gene expression regulation as miRNAs are key regulators of protein-encoding transcripts.

Cellular TumiD requires the ATP-dependent RNA helicase UPF1, and UPF1 can dissociate miRNAs from their mRNA targets, making them more susceptible to TumiD. In T24 human urinary bladder cancer cells, UPF1 augments the degradation of about 50% of candidate TumiD targets. UPF1-augmented TumiD promotes the invasion of T24 cells by degrading anti-invasive miRNAs and up-regulating proinvasive proteins [1].

In conclusion, Tsn plays a crucial role in miRNA decay, which can influence gene expression. Its function in promoting the invasion of bladder cancer cells through miRNA-mediated pathways, as revealed by in vitro studies on T24 cells, provides insights into cancer-related biological processes. Understanding Tsn's role in miRNA decay may offer new perspectives on gene regulation and potential therapeutic targets in cancer.