Journal: Clinical cancer research : an official journal of the American Association for Cancer Research

Article Title: Talazoparib is a Potent Radiosensitizer in Small Cell Lung Cancer Cell Lines and Xenografts

doi: 10.1158/1078-0432.CCR-18-0401

Figure Lengend Snippet: A. Western blot of tumor PAR with increasing concentrations of talazoparib with or without radiation demonstrates a dose dependent reduction in PAR polymerization. Relative lane intensities normalized to actin control are reported below. B. Western blots performed on nuclear soluble and nuclear chromatin-bound fractions show a dose dependent increase in chromatin-bound PARP1 (PARP trapping) by talazoparib with no change in soluble nuclear fraction of PARP1. Co-treatment with 0.01% methylmethane sulfate (MMS) was performed to allow detection of PARP trapping by inducing DNA damage.

Article Snippet: Enzyme-linked immunosorbent assay (ELISA) was performed using the PARP in vivo Pharmacodynamic Assay II Kit (Trevigen).

Techniques: Western Blot, Control

Journal: Clinical cancer research : an official journal of the American Association for Cancer Research

Article Title: Talazoparib is a Potent Radiosensitizer in Small Cell Lung Cancer Cell Lines and Xenografts

doi: 10.1158/1078-0432.CCR-18-0401

Figure Lengend Snippet: A. Western blots of tumor PAR in NCI-H446 after 1 hour of 200 nM talazoparib or 1.6 uM veliparib show similar levels of inhibition of PAR polymerization in whole cell lysates. Levels of inhibition remained similar after mock irradiation and 6 Gy radiation. B. Mean and SD of quantified PAR levels after treatment with 200 nM talazoparib or 1.6 uM veliparib, performed over 3 replicates without irradiation, shows no statistical difference between the tested concentrations. Lane intensities, expressed as percentage of DMSO control, were quantified between bands at 100 kDa and 200 kDa and normalized to actin loading control. C. Talazoparib at 200 nM causes greater PARP trapping (chromatin-bound PARP1) in NCI-H446 cells than veliparib at 1.6 uM. Co-treatment with 0.01% methylmethane sulfate (MMS) was performed to allow detection of PARP trapping by inducing DNA damage. D. Clonogenic survival assay of NCI-H446 shows significant radiosensitization at 200 nM talazoparib but not at 1.6 uM of veliparib. E. Clonogenic survival assay of NCI-H82 shows significant radiosensitization of NCI-H82 at 20 nM talazoparib but not with concentrations of veliparib up to 800 nM. Error bars represent standard deviation.

Article Snippet: Enzyme-linked immunosorbent assay (ELISA) was performed using the PARP in vivo Pharmacodynamic Assay II Kit (Trevigen).

Techniques: Western Blot, Inhibition, Irradiation, Control, Clonogenic Cell Survival Assay, Standard Deviation

Journal: Clinical cancer research : an official journal of the American Association for Cancer Research

Article Title: Talazoparib is a Potent Radiosensitizer in Small Cell Lung Cancer Cell Lines and Xenografts

doi: 10.1158/1078-0432.CCR-18-0401

Figure Lengend Snippet: A. Immunostaining of gH2AX nuclear foci after treatment with PARP inhibitor and radiation shows more foci in cells treated with talazoparib compared to veliparib or DMSO control both with and without 6 Gy IR. Talazoparib was applied for 24 hours prior to IR, fresh media was applied one hour after IR, and fixing and staining was performed 24 hours after IR (see pulse dosing below). Slides were scanned with a 40X/0.95NA objective. B. Experiment timeline and violin plot of gH2AX foci per nuclei, performed over 2 independent experiments. The number of nuclei analyzed was >3000 in each group. Cells were either treated with 48 hours of continuous drug and irradiated 24 hours into treatment prior to fixing and staining, or were alternatively changed into fresh media one hour after irradiation (pulse dosing). Mean counts of gH2AX nuclei per cell are represented as a dot within each violin. All comparisons among drug treatments and doses of radiation were statistically significant using the Mann-Whitney tests and Bonferroni adjustment for multiple comparisons.

Article Snippet: Enzyme-linked immunosorbent assay (ELISA) was performed using the PARP in vivo Pharmacodynamic Assay II Kit (Trevigen).

Techniques: Immunostaining, Control, Staining, Irradiation, MANN-WHITNEY