Project description:In a forward genetic screen, we have previously identified a null mutant of Cdk12 that results in alterations in actin dynamics, the axon initial segment and electrophysiology in Drosophila melanogaster. To decipher how Cdk12 may be having these effects, we extracted RNA from pooled Drosophila heads and compared Cdk12-null mutants to controls at the transcriptome level.
Project description:To identify potential targets of co-regulation by DnaA and Rok, we compared the transcriptional profiles of dnaA null, rok null, and dnaA null rok null mutants. Because a dnaA null mutant requires an oriC- strain background, we used an oriC- oriN+ background for all strains, to allow direct comparisons.
Project description:We describe the epigenetic profiling of the H3K9me2 and HP1a in Drosophila third instar larvae before and after CDK12 depletion by RNA interference (RNAi). Here we show that CDK12 regulates heterochromatin dynamics in Drosophila chromosomes. Depletion of CDK12 induces the increased HP1a and H3K9me2 binding profile on the coding region of euchromatic genes, with the X chromosome being the most affected. These results are consistent with the polytene chromosome immunostaining pattern of HP1a and H3K9me2 after CDK12 knockdown in our initial cytological observations, which show that CDK12 depletion induce heterochromatin spreading on euchromatic arms, especially on the X chromosome. This study describes a novel role of the CDK12 complex in controlling the epigenetic transition between euchromatin and heterochromatin. Examination of the genome-wide H3K9me2 and HP1a binding profile in wildtype larvae (WT) and CDK12-depleted larvae (CDK12-KD). Examination of the genome-wide CDK12 binding profile in wildtype larvae (WT). Twelve independent immunoprecipitations were conducted for each antibody. Two biological replicates were performed.
Project description:Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a unique molecular subtype of metastatic castration resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer development—either alone, or in the context of other genetic alterations—and whether CDK12-mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with p53 inactivation, but negatively associated with Pten inactivation—similar to what is seen in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent p53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten-null prostate cancer mouse model abrogates tumor growth. Bigenic CDK12 and p53 loss allografts represent a new syngeneic model for the study of prostate cancer. Cdk12-null organoids (either with or without p53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and paralog-based synthetic lethality is a promising strategy for treating CDK12 mutant mCRPC.
Project description:Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a unique molecular subtype of metastatic castration resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer development—either alone, or in the context of other genetic alterations—and whether CDK12-mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with p53 inactivation, but negatively associated with Pten inactivation—similar to what is seen in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent p53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten-null prostate cancer mouse model abrogates tumor growth. Bigenic CDK12 and p53 loss allografts represent a new syngeneic model for the study of prostate cancer. Cdk12-null organoids (either with or without p53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and paralog-based synthetic lethality is a promising strategy for treating CDK12 mutant mCRPC.
Project description:Transcriptional profiling of 3 day old virgin male and female adults comparing control male Drosophila melanogaster (MDM) versus male D sechellia (MDS) and comparing control female Drosophila melanogaster (FDM) versus female D sechellia (FDS). Goal was to determine why D sechellia is tolerant to octanoïc acid, the major toxic compound of Morinda citrifolia fruit
Project description:To identify potential targets of co-regulation by DnaA and Rok, we compared the transcriptional profiles of dnaA null, rok null, and dnaA null rok null mutants. Because a dnaA null mutant requires an oriC- strain background, we used an oriC- oriN+ background for all strains, to allow direct comparisons. We compared biological triplicates for each of the following strains: dnaA null (CAL2074), rok null (CAS196), dnaA null rok null (CAS192), and dnaA+ rok+ (CAL2083; control).