Project description:To explore the transcriptional inhibition of the CDK7 inhibitor THZ1 in cervical cancer cells, we used gene expression miceoarray analysis to detect the gene expression profiles after THZ1 treatment in HeLa compared with negative control(DMSO). HeLa was trreated with 100 nM THZ1 or DMSO, and total RNA was extracted after treatment for 6 hours. Microarray analysis showed that massive oncogene transcripts, especially those associated with tumorigenesis, were preferential suppressed after THZ1 treatment.
Project description:The t(8;21) is one of the most frequent chromosomal translocations associated with acute myeloid leukemia (AML). We found that t(8;21) AML were extremely sensitive to THZ1, which triggered apoptosis after only 4 hr. We used precision nuclear run-on transcription sequencing (PROseq) to define the global effects of THZ1 and other CDK inhibitors on RNA polymerase II dynamics. Inhibition of CDK7 using THZ1 caused wide-spread loss of promoter-proximal paused RNA polymerase. This loss of 5’ pausing was associated with accumulation of polymerases in the body of a large number of genes. However, there were modest effects on genes regulated by “super-enhancers”. At the 3’ ends of genes, treatment with THZ1 suppressed RNA polymerase “read through” at the end of the last exon, which resembled a phenotype associated with a mutant RNA polymerase with slower elongation rates. Consistent with this hypothesis, polyA site-sequencing (PolyA-seq) did not detect differences in polyA sites after THZ1 treatment. PROseq analysis after short treatments with THZ1 suggested that these 3’ effects were due to altered CDK7 activity at the 5’ end of long genes, and were likely to be due to slower rates of elongation.
Project description:Developing a psoralen probe (PP)-based method for RNA tagging and RNA-protein complex (RP-complex) enrichment, isolating of both coding and noncoding RNAs from HeLa cells was achieved by PP enrichment. Exploring the type and relative distribution of the PP isolated RNAs by RNA-sequencing analysis. And dynamic investigation of RNA upon transcription inhibition by ActD treatment.
Project description:ChIP-seq analysis was performed in an adult T-cell leukemia/lymphoma cell line (TL-Om1) to analyze DNA bindings of RNA polymerase II (Pol II) after treatment with the THZ1 CDK7 inhibitor.
Project description:Purpose: To assess THZ1-induced global changes of transcriptome of Hh-driven cancer Methods: SMB56 or SMB56-shSufu cells were mouse hedgehog-driven medulloblastoma cell lines that are either responsive or resistant to SMO inhibitor (GDC-0449). They were treated with 0.1 uM THZ1 or DMSO for 8 hours. 1 uM GDC-0449 treated SMB56 cells were included as control. Gene expression profiles were generated by RNAseq, in duplicate, using Hiseq3000. The RNAseq reads were mapped to the hg19 reference genome using STAR (v2.5.3a). Expression levels for each sample were quantified to FPKM using Cufflinks (v2.2.1). Differential expression analysis was carried out using R package DESeq2 (v1.20.0) Results: Compared to GDC-0449 treatment in SMB56 cells, THZ1 induced a robust global transcriptional downregulation in both SMB56 and SMB56-shSufu cells. When we compared the top 2000 significantly downregulated genes between THZ1-treated SMB56 and SMB56-shSufu cells, we found they had ~70% in common. GSEA reveals Hh-target genes are enriched in DMSO treated cells versus THZ1-treated ones. Conclusions: CDK7 inhibition induced a robust and similar transcriptional downregulation in both SMB56 and SMB56-shSufu cells, with preferential targeting of Hh pathway transcriptional output.
Project description:Peripheral T-cell lymphomas (PTCL) are aggressive diseases with poor response to chemotherapy and dismal survival. Identification of effective strategies to target PTCL biology represents an urgent need. Here we report that PTCL are sensitive to transcription-targeting drugs, and, in particular, to THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7). The STAT-signaling pathway is highly vulnerable to THZ1 even in PTCL cells that carry the activating STAT3 mutation Y640F. In mutant cells, CDK7 inhibition decreases STAT3 chromatin binding and expression of highly transcribed target genes like MYC, PIM1, MCL1, CD30, IL2RA, CDC25A and IL4R. In surviving cells, THZ1 decreases the expression of STAT-regulated anti-apoptotic BH3 family members MCL1 and BCL-XL sensitizing PTCL cells to BH3 mimetic drugs. Accordingly, the combination of THZ1 and the BH3 mimetic obatoclax improves lymphoma growth control in a primary PTCL ex vivo culture and in two STAT3-mutant PTCL xenografts, delineating a potential targeted agent-based therapeutic option for these patients.
Project description:Microarray gene expression profiling was performed in an adult T-cell leukemia/lymphoma cell line (TL-Om1) to analyze genes regulated by the THZ1 CDK7 inhibitor.
Project description:Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancy and accounts for the majority of thyroid cancer-related deaths. Despite intensive research, there remains no effective treatment for patients with ATC. Here, we identify THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid cancer (PTC) cells, are exceptionally sensitive to CDK7 inhibition. Analyzing both gene expression profiles and super enhancer (SE) features reveals that the SE-mediated oncogenic transcriptional amplification renders the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays discovers a number of novel cancer genes of ATC, including PPP1R15A, SMG9 and KLF2. Inhibition of PPP1R15A with Guanabenz (GBZ) or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, GBZ or THZ1 treatment sensitizes ATC cells to conventional chemotherapy. Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.