Recent studies suggest that targeting transcriptional machinery can lead to potent and selective anticancer effects in cancers dependent on high and constant expression of certain transcription factors for growth and survival. Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of the CDK-activating kinase complex. Its function is required for both cell-cycle regulation and transcriptional control of gene expression. CDK7 has recently emerged as an attractive cancer target because its inhibition leads to decreased transcript levels of oncogenic transcription factors, especially those associated with super-enhancers. Here, we describe a selective CDK7 inhibitor SY-1365, which is currently in clinical trials in populations of patients with ovarian and breast cancer (NCT03134638). In vitro, SY-1365 inhibited cell growth of many different cancer types at nanomolar concentrations. SY-1365 treatment decreased MCL1 protein levels, and cancer cells with low BCL2L1 (BCL-XL) expression were found to be more sensitive to SY-1365. Transcriptional changes in acute myeloid leukemia (AML) cell lines were distinct from those following treatment with other transcriptional inhibitors. SY-1365 demonstrated substantial antitumor effects in multiple AML xenograft models as a single agent; SY-1365-induced growth inhibition was enhanced in combination with the BCL2 inhibitor venetoclax. Antitumor activity was also observed in xenograft models of ovarian cancer, suggesting the potential for exploring SY-1365 in the clinic in both hematologic and solid tumors. Our findings support targeting CDK7 as a new approach for treating transcriptionally addicted cancers. Significance: These findings demonstrate the molecular mechanism of action and potent antitumor activity of SY-1365, the first selective CDK7 inhibitor to enter clinical investigation.
Polycyclic xanthone natural products are a family of polyketides which are characterized by highly oxygenated, angular hexacyclic frameworks. In the last decade, this novel class of molecules has attracted noticeable attention from the synthetic and biological communities due to emerging reports of their potential use as antitumour agents. The aim of this article is to highlight the most recent developments of this subset of the xanthone family by detailing the innate challenges of the construction of this class of natural products, new synthetic approaches, and pharmacological data.
CDK7 has emerged
as an exciting target in oncology due to its roles
in two important processes that are misregulated in cancer cells:
cell cycle and transcription. This report describes the discovery
of SY-5609, a highly potent (sub-nM CDK7 Kd) and selective, orally available inhibitor of CDK7 that entered
the clinic in 2020 ( Identifier: NCT04247126). Structure-based design was leveraged to
obtain high selectivity (>4000-times the closest off target) and
slow
off-rate binding kinetics desirable for potent cellular activity.
Finally, incorporation of a phosphine oxide as an atypical hydrogen
bond acceptor helped provide the required potency and metabolic stability.
The development candidate SY-5609 displays potent inhibition
of CDK7 in cells and demonstrates strong efficacy in mouse xenograft
models when dosed as low as 2 mg/kg.
We report a novel ring contraction allowing the direct conversion of N-chlorolactams to their corresponding ring-contraction N-heterocycles upon photolysis. Results show that the rearrangement occurs with a variety of N-chlorolactams and that the greater the substitution at the migrating carbon, the greater the yield of product. Importantly, stereochemistry at the migrating carbon is conserved in the product. Rearranged products were isolated as their methyl carbamates in yields varying from 17% to 58%, with the major side product being the recyclable parent lactam.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.