In:
Frontiers in Oncology, Frontiers Media SA, Vol. 11 ( 2022-1-27)
Abstract:
Cyclin-dependent kinases (CDKs) that have critical roles in RNA polymerase II (Pol II)-mediated gene transcription are emerging as therapeutic targets in cancer. We have previously shown that THZ1, a covalent inhibitor of CDKs 7/12/13, leads to cytotoxicity in MYCN -amplified neuroblastoma through the downregulation of super-enhancer-associated transcriptional upregulation. Here we determined the effects of YKL-5-124, a novel covalent inhibitor with greater selectivity for CDK7 in neuroblastoma cells. Experimental Design We tested YKL-5-124 in MYCN -amplified and nonamplified neuroblastoma cells individually and in combination with other inhibitors in cell line and animal models. Cell viability, target validation, effects on cell cycle and transcription were analyzed. Results CDK7 inhibition with YKL-5-124 did not lead to significant cell death, but resulted in aberrant cell cycle progression especially in MYCN -amplified cells. Unlike THZ1, YKL-5-124 had minimal effects on Pol II C-terminal domain phosphorylation, but significantly inhibited that of the CDK1 and CDK2 cell cycle kinases. Combining YKL-5-124 with the BRD4 inhibitor JQ1 resulted in synergistic cytotoxicity. A distinct MYCN -gene expression signature associated with resistance to BRD4 inhibition was suppressed with the combination. The synergy between YKL-5-124 and JQ1 translated into significant tumor regression in cell line and patient-derived xenograft mouse models of neuroblastoma. Conclusions The combination of CDK7 and BRD4 inhibition provides a therapeutic option for neuroblastoma and suggests that the addition of YKL-5-124 could improve the therapeutic efficacy of JQ1 and delay resistance to BRD4 inhibition.
Type of Medium:
Online Resource
ISSN:
2234-943X
DOI:
10.3389/fonc.2021.773186
DOI:
10.3389/fonc.2021.773186.s001
DOI:
10.3389/fonc.2021.773186.s002
DOI:
10.3389/fonc.2021.773186.s003
DOI:
10.3389/fonc.2021.773186.s004
Language:
Unknown
Publisher:
Frontiers Media SA
Publication Date:
2022
detail.hit.zdb_id:
2649216-7
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