Cellular senescence contributes to a variety of pathologies associated with aging and is implicated as a cellular state in which cancer cells can survive treatment. Reported senolytic drug treatments act through varying molecular mechanisms, but heterogeneous efficacy across the diverse contexts of cellular senescence indicates a need for predictive biomarkers of senolytic activity. Using multi-parametric analyses of commonly reported molecular features of the senescent phenotype, we assayed a variety of models, including malignant and nonmalignant cells, using several triggers of senescence induction and found little univariate predictive power of these traditional senescence markers to identify senolytic drug sensitivity.
View Article and Find Full Text PDFThe master regulator of the DNA damage response, the transcription factor p53, orchestrates multiple downstream responses and coordinates repair processes. In response to double-strand DNA breaks, p53 exhibits pulses of expression, but how it achieves temporal coordination of downstream responses remains unclear. Here, we show that p53's posttranslational modification state is altered between its first and second pulses of expression.
View Article and Find Full Text PDFCyclin-dependent kinase 7, along with cyclin H and MAT1, forms the CDK-activating complex (CAK), which directs cell cycle progression via T-loop phosphorylation of cell cycle CDKs. Pharmacological inhibition of CDK7 leads to selective anti-cancer effects in cellular and in vivo models, motivating several ongoing clinical investigations of this target. Current CDK7 inhibitors are either reversible or covalent inhibitors of its catalytic activity.
View Article and Find Full Text PDFDetermining the balance between DNA double strand break repair (DSBR) pathways is essential for understanding treatment response in cancer. We report a method for simultaneously measuring non-homologous end joining (NHEJ), homologous recombination (HR), and microhomology-mediated end joining (MMEJ). Using this method, we show that patient-derived glioblastoma (GBM) samples with acquired temozolomide (TMZ) resistance display elevated HR and MMEJ activity, suggesting that these pathways contribute to treatment resistance.
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