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Biology subjects

Grosche, S.

Publications and source records attributed to Grosche, S..

3 recordsLinked to original sources

DUSP4 knockdown in BRAF V600E mutant colorectal cancer induces cell cycle arrest and halts tumor growth

Oncogenic signaling in cancer cells is essential for proliferation, and its disruption, either through inhibition or overactivation, can provide therapeutic opportunities. Dual specificity phosphatase 4 (DUSP4), a negative regulator of the MAPK pathway that dephosphorylates ERK, has been proposed as a potential target; however, its therapeutic relevance has not been evaluated in vivo. In this study, we show that DUSP4 knock-down induces G1 cell cycle arrest and reduces proliferation in BRAFV600E-mutant and BRAF inhibitor-resistant colorectal cancer models, both in vitro and in vivo, and induces a rapid DUSP5-mediated adaptive response. While treatment achieved tumor stasis indicating disease control, it did not yield tumor regression, suggesting that DUSP4 may have limited efficacy as a monotherapy target in cancer.

genetics↗

Genetic dependencies associated with transcription factor activities in human cancer cell lines

Transcription factors (TFs) are key components of the aberrant transcriptional programs in cancer cells. In this study, we used TF activity (TFa), inferred from the downstream regulons as a potential biomarker to identify associated genetic vulnerabilities in cancer cells. Our linear model framework, integrating TFa and genome-wide CRISPR knockout datasets identified 1,770 candidate TFa-target pairs across different cancer types and assessed their survival impact in patient data. As a proof of concept, through inhibitor screens and genetic depletion assays in cell lines, we validated the dependency of cell lines on predicted targets linked to TEAD1, the most prominent TF from our analysis. Overall, these candidate pairs represent an attractive resource for early-stage targets and drug discovery programs in oncology.

bioinformatics↗

A Canal-Associated Neuron cAMP signalling pathway that regulates C. elegans larval development

Caenorhabditis elegans larval development requires the function of the two Canal-Associated Neurons (CANs): killing the CANs by laser microsurgery or disrupting their development by mutating the gene ceh-10 results in early larval arrest. How these cells promote larval development, however, remains a mystery. In screens for mutations that bypass CAN function, we identified the gene kin-29, which encodes a member of the Salt-Inducible Kinase (SIK) family and a component of a conserved pathway that regulates various C. elegans phenotypes. Like kin-29 loss, gain-of-function mutations in genes that may act upstream of kin-29 or growth in cyclic-AMP analogs bypassed ceh-10 larval arrest, suggesting that a conserved adenylyl cyclase/PKA pathway inhibits KIN-29 to promote larval development and that loss of CAN function results in dysregulation of KIN-29 and larval arrest. The adenylyl cyclase ACY-2 mediates CAN-dependent larval development: acy-2 mutant larvae arrested development with a similar phenotype to ceh-10 mutants, and the arrest phenotype was suppressed by mutations in kin-29. ACY-2 is predominantly expressed in the CANs, and we provide evidence that the acy-2 functions in the CANs to promote larval development. By contrast, cell-specific expression experiments suggest that kin-29 acts in both the hypodermis and neurons, but not in the CANs. Based on our findings, we propose that cAMP produced by ACY-2 in the CANs acts in neighboring neurons and hypodermal cells where it activates PKA and inhibits KIN-29 to promote larval development. We discuss how this conserved pathway could be partitioned between two cells.

developmental biology↗