In vitro activity: Icilin (also known as AG-3-5 or AG 3-5) is a synthetic CMR1/TRPM8 (transient receptor potential M8) super-cooling agent/agonist that is 2.5-fold more efficacious and nearly 200-fold more potent than the reference cold thermosensory agonist, l-menthol. Icilin induces sensations of intense cold when applied orally in humans, and induces 'wet dog shakes', a behavioral marker of cold sensation, when given to rats. Icilin should serve as the reference cold nociceptive agonist For TRP-type ion channels in the future. Icilin down-regulated the expression of cell cycle signature genes and caused G1 arrest in PC-3 prostate cancer cells. Icilin inactivates a small regulatory module controlling the cell cycle in prostate cancer cells. This study might provide insight into the development of cell cycle-targeted cancer therapeutics.

Kinase Assay: Icilin (also known as AG-3-5 or AG 3-5) is a synthetic CMR1/TRPM8 (transient receptor potential M8) super-cooling agent/agonist that is 2.5-fold more efficacious and nearly 200-fold more potent than the reference cold thermosensory agonist, l-menthol.

Cell Assay: icilin, a super-cooling agent, down-regulated the expression of cell cycle signature genes and caused G1 arrest in PC-3 prostate cancer cells. icilin affected cell cycle-related transcriptional modules and identified E2F1 transcription factor as a target master regulator of icilin. icilin reduced the activity and expression levels of E2F1. Icilin concentration-response curves were significantly shifted to the right when pH was lowered from 7.3 to 6.9, whereas those with menthol were unaltered in solutions of pH 6.1. Icilin modulated the expression level of various cell cycle regulators at transcription or post-translational levels. In addition, icilin activated JNK and p38 kinase pathways, but not ERK.