Project description:Recent studies reveal that a subset of cancers in various indications are dependent on high and constant expression of certain transcription factors for growth and survival, a phenomenon termed as transcriptional addiction. Therefore, targeting transcriptional machinery can potentially lead to potent and selective anticancer effects. CDK7 is the catalytic subunit of the CDK-activating kinase (CAK) complex. Its function is required for both cell cycle regulation and transcriptional control of gene expression. CDK7 has recently emerged as an attractive target in cancer since its inhibition leads to decrease of the transcript levels of oncogenic transcription factors, especially those associated with super-enhancers (SEs). Here we describe a first-in-class CDK7 inhibitor SY-1365, which covalently targets a cysteine outside the kinase domain, resulting in sustained, highly selective inhibition of CDK7. In vitro studies reveal that SY-1365 has potency in a wide range of cancer models with low micromolar IC50 values. Cancer cells with low BCL-XL expression are found to be more dependent on MCL1 for survival and therefore particularly sensitive towards SY-1365 treatment since SY-1365 downregulates MCL1 protein level. SY-1365 treatment induces distinct transcriptional changes in acute myeloid leukemia (AML) cell lines. SY-1365 also demonstrates substantial anti-tumor effects in multiple AML xenograft models. Additionally, combination treatment with venetoclax shows synergistic effects in AML models both in vitro and in vivo. Our findings support targeting CDK7 as a new approach for treating transcriptionally addicted cancers. SY-1365 is currently being assessed in a Phase I trial in adult patients (NCT03134638) We performed microarray based expression profiling to quantify transcriptional changes upon treatment with the CDK7 inhibitor, SY-1365 and to compare it to transcriptional changes induced by treatment with other transcriptional drugs JQ1 (BRD4 inhibitor), NVP2 (CDK9 inhibitor) and flavopiridol (pan-CDK inhibitor). We profiled a human acute myeloid leukemia (AML) cell line THP-1. Cells were treated with either DMSO, 100nm SY-1365, 25nM NVP2 , 250nM JQ1 or 200nM flavopiridol for two and six hours. All samples were prepared in biological triplicate.
Project description:Recent studies reveal that a subset of cancers in various indications are dependent on high and constant expression of certain transcription factors for growth and survival, a phenomenon termed as transcriptional addiction. Therefore, targeting transcriptional machinery can potentially lead to potent and selective anticancer effects. CDK7 is the catalytic subunit of the CDK-activating kinase (CAK) complex. Its function is required for both cell cycle regulation and transcriptional control of gene expression. CDK7 has recently emerged as an attractive target in cancer since its inhibition leads to decrease of the transcript levels of oncogenic transcription factors, especially those associated with super-enhancers (SEs). Here we describe a first-in-class CDK7 inhibitor SY-1365, which covalently targets a cysteine outside the kinase domain, resulting in sustained, highly selective inhibition of CDK7. In vitro studies reveal that SY-1365 has potency in a wide range of cancer models with low micromolar IC50 values. Cancer cells with low BCL-XL expression are found to be more dependent on MCL1 for survival and therefore particularly sensitive towards SY-1365 treatment since SY-1365 downregulates MCL1 protein level. SY-1365 treatment induces distinct transcriptional changes in acute myeloid leukemia (AML) cell lines. SY-1365 also demonstrates substantial anti-tumor effects in multiple AML xenograft models. Additionally, combination treatment with venetoclax shows synergistic effects in AML models both in vitro and in vivo. Our findings support targeting CDK7 as a new approach for treating transcriptionally addicted cancers. SY-1365 is currently being assessed in a Phase I trial in adult patients (NCT03134638)
Project description:AML cell lines were treated with either vehicle or SY-1425 (tamibarotene), a potent and selective agonist of retinoic acid receptor alpha (RARa), and assayed by microarray expression analysis.
Project description:GATA-2 is a master regulator of hematopoiesis which controls expression of multiple genes and is implicated in acute myeloid leukemia (AML). However, the molecular mechanism how GATA-2 deregulation causes leukemogenesis is still unclear. In this study, GATA-2 ChIP-squ analysis was conducted in Kasumi-3 AML cell line to identify GATA-2 target genes which play important roles in the pathogenesis of AML. ChIP with GATA-2 antibody was conducted in Kasumi-3 AML cell line and ChIP-seq profile was generated by deep sequencing.
Project description:Nucleostemin (NS; product of the GNL3 gene) is a nucleolar/nucleoplasm shuttling GTPase whose levels are high in stem cells while rapidly decreasing upon differentiation. NS levels are also high in several solid and hematological neoplasms, including acute myeloid leukemia (AML). While a role in telomere maintenance, response to stress stimuli and in favoring DNA repair has been proposed in solid cancers, little or no information is available as to the role of nucleostemin in AML. Here we investigate this issue with a proteomics approach. We use as a model system the OCI-AML 3 cell line harboring a heterozygous mutation at the NPM1 gene, which is the most frequent driver mutation in AML (approximately 30% of total AML cases). We show that NS is highly expressed in this cell line but, contrary to what previously shown in other cancers, its presence is dispensable for cell growth and viability. However, proteomics analysis of OCI-AML 3 cell line before and after nu-cleostemin (NS) silencing showed several effects in different biological functions as highlighted by ingenuity pathway analysis (IPA). In particular, we report an effect in down-regulating DNA repair through homologous recombination and we confirmed higher DNA damage rate in OCI-AML 3 cells when NS is depleted, which considerably increases upon stress induced by the topoisomerase II inhibitor etoposide.
Project description:Post-chemotherapy relapse presents a major unmet medical need in AML where treatment options are limited. We used gene expression profile from 32 AML cell lines to characterize expression difference between responder and non-responders to PIM inhibitors. Our results highlight the importance of STAT5 and MYC in rendering cancer cells sensitive to PIM inhibitors. All AML cell lines were purchased from either ATCC or DSMZ and cultured accordingly to vendorsM-bM-^@M-^Y protocols. Gene expression were measured from the cell lines using Affymetrix microarrays. Response to PIM inhibitors (IC50) was recorded for each cell line, and association between drug response and gene expression were analyzed.
Project description:Acute myeloid leukemia (AML) and acute T-lymphoblastic leukemia (T-ALL) maintain the undifferentiated phenotype and proliferative capacity of their respective cells of origin, hematopoietic stem/progenitor cells and immature thymocytes. The mechanisms that maintain these progenitor-like characteristics are poorly understood. We report that transcription factor Zfx is required for the development and propagation of experimental AML caused by MLL-AF9 fusion, and of T-ALL caused by Notch1 activation. In both leukemia types, Zfx activated progenitor-associated gene expression programs and prevented differentiation. Key Zfx target genes included mitochondrial enzymes Ptpmt1 and Idh2, whose overexpression partially rescued the propagation of Zfx-deficient AML. These studies identify a common mechanism that controls the cell-of-origin characteristics of acute leukemias derived from disparate lineages and transformation mechanisms. Analysis of genomic ZFX binding in the AML cell line NOMO-1 and the T-ALL cell line RPMI-8402
Project description:We performed MS to analyze the acetylation site of PPAR alpha via PPAR alpha antibody (Cat#GTX101098) . Samples used were mice hepatic cell line AML 12 treated with DMSO or mg149.