CycT, an abbreviation that could refer to either cyclopamine tartrate or CyclinT1/T2, has significant biological implications. Cyclopamine tartrate is a water-soluble derivative of cyclopamine, a natural inhibitor of the hedgehog (Hh) signaling pathway. The Hh pathway is crucial in development and is often aberrantly activated in cancers [1,3,4,5]. CyclinT1/T2 is related to the Cyclin-dependent kinase 9 (CDK9), which is essential for RNA Polymerase II transcription in processes like development, differentiation, and cell fate responses [2].

Regarding cyclopamine tartrate, in two mouse models of basal cell carcinomas (K14cre:Ptch1(neo/neo) and K14cre:SmoM2(YFP)), daily topical application of CycT for 21 days led to tumor shrinkage and decreased expression of Hh target genes, indicating its effectiveness in inhibiting Hh-signaling-mediated carcinogenesis [1]. In non-small cell lung cancer (NSCLC) mouse models, CycT strongly suppressed the growth of subcutaneously and orthotopically implanted NSCLC xenografts. It reduced heme synthesis and degradation, suppressed oxygen consumption in mitochondria, decreased levels of proteins related to heme synthesis, uptake, and oxidative phosphorylation, as well as regulators promoting oxidative phosphorylation (OXPHOS) like MYC and MCL1, and alleviated tumor hypoxia. These effects seem to be independent of hedgehog signaling [4].

In conclusion, as cyclopamine tartrate, CycT has anti-cancer properties, particularly in basal cell carcinomas and NSCLC, by inhibiting Hh signaling-mediated carcinogenesis, heme metabolism, and OXPHOS. As CyclinT1/T2, it is involved in important transcriptional processes. The study of CycT in mouse models has provided valuable insights into its role in cancer-related biological processes, potentially paving the way for new cancer treatment strategies.