parp 1 inhibitor olaparib  (MedChemExpress)

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: PAK1 regulates homologous recombination (HR) repair and olaparib sensitivity in ovarian cancer cells. (A, B) HR (A) and non-homologous end-joining (NHEJ) (B) repair efficiencies in control and PAK1-depleted HEK293T cells, evaluated using HR and NHEJ reporter systems. Data were presented as mean ± standard error of the mean from three independent experiments. (C) Western blotting analysis of PAK2 and PAK3 in control and PAK2/PAK3-depleted HEK293T cells. (D – G) HR (D, F) and NHEJ (E, G) repair efficiencies in control and PAK2/PAK3-depleted HEK293T cells, evaluated using HR and NHEJ reporter systems. (H, I) Cell cycle distribution in control and PAK1-depleted Ovcar8 cells, analyzed by flow cytometry. (J, K) RAD51 foci formation in Ovcar8 cells treated with 10 μM olaparib for 24 h: (J) representative images and (K) quantification. More than 200 cells were analyzed per experiment. (L, N) The survival of control or PAK1-depleted Ovcar8 (L) and SKOV-3 (N) cells, assessed by colony formation assay. (M, O) Phosphorylation of CHK1 in control or PAK1-depleted Ovcar8 (M) and SKOV-3 (O) cells, treated with 10 μM olaparib for 6 h. (P, Q) The survival of control, (P) PAK2-depleted, or (Q) PAK3-depleted Ovcar8 cells, assessed by colony formation assay. Error bars represent the standard error of the mean from three independent experiments. Scale bars = 50 μm.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Homologous Recombination, Non-Homologous End Joining, Control, Western Blot, Flow Cytometry, Colony Assay, Phospho-proteomics

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: PAK1 regulates homologous recombination (HR) repair and olaparib sensitivity dependent on its kinase activity. PAK1-depleted cells were transfected with wild-type PAK1 or the K299R kinase mutant for 24 h. (A) Western blotting analysis of PAK1 and CHK1 phosphorylation in transfected Ovcar8 cells treated with 10 μM olaparib for 6 h. (B) The survival of transfected Ovcar8 cells treated with different concentrations of olaparib for 2 weeks, assessed by colony formation assay. (C) HR activity in transfected HEK293T cells co-transfected with HR reporter plasmids, followed by HR assay after 48 h. (D, E) RAD51 foci formation in transfected Ovcar8 cells treated with 10 μM olaparib for 24 h: (D) representative images and (E) quantification. Over 200 cells were analyzed in each experiment. Error bars represent the standard error of the mean from three independent experiments.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Homologous Recombination, Activity Assay, Transfection, Mutagenesis, Western Blot, Phospho-proteomics, Colony Assay

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: PAK1 inhibition enhances the efficiency of olaparib in ovarian cancer cells. (A) Western blotting analysis of PAK1 and CHK1 phosphorylation in Ovcar8 cells treated with 10 μM olaparib, 10 μM IPA-3, or their combination for 6 h. (B) Homologous recombination (HR) efficiency in HEK293T cells transfected with HR reporter plasmids, treated with olaparib, IPA-3, or both, followed by HR assay. (C, D) RAD51 foci formation in Ovcar8 cells treated with olaparib, IPA-3, or their combination for 24 h: (C) representative images and (D) quantification. More than 200 cells were analyzed per experiment. (E, F) The survival of Ovcar8 (E) and SKOV-3 (F) cells treated with olaparib alone or in combination with IPA-3, assessed by colony formation assay. Error bars represent the standard error of the mean from three independent experiments. Statistical significance was determined by a two-tailed t -test, with P -values < 0.05 considered significant.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Inhibition, Western Blot, Phospho-proteomics, Homologous Recombination, Transfection, Colony Assay, Two Tailed Test

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: PAK1 inhibition promotes olaparib-induced replication stress and DNA damage. (A, B) DNA fiber assay for the length of CIdU (red) tracks in Ovcar8 cells treated with olaparib, IPA-3, or their combination for 6 h: (A) representative images and (B) quantification. Data were expressed as mean ± standard deviation, analyzed by a two-tailed unpaired t -test. (C, D) Immunoblot analysis of chromatin and soluble fractions of Ovcar8 cells treated with olaparib, IPA-3, or both for 6 h, probing for the indicated antibodies (C), or IPOND (isolation of proteins on nascent DNA) analysis of RPA1 and RPA2 at replication forks (D). (E, F) γ-H2AX foci formation in Ovcar8 cells treated with olaparib, IPA-3, or their combination for 24 h: (E) representative images and (F) quantification. More than 100 cells were counted per experiment. (G) RNA sequencing analysis of Ovcar8 cells treated with olaparib and IPA-3. Differentially expressed genes were classified based on fold change ≥ 1.5 or ≤ 0.5, with P < 0.05. (H) Biological process analysis of up- and down-regulated genes in the combination treatment compared with IPA-3 alone. (I, J) GSEA of up- and down-regulated genes in the combination treatment compared with IPA-3 alone. (K) The heatmap displaying up-regulated genes associated with DNA repair. (L) The quantitative real-time PCR showed the up-regulated genes associated with DNA repair. Error bars represent the standard error of the mean from three independent experiments. Statistical significance was determined by a two-tailed t -test. Two-sided P -values < 0.05 were considered significant. Scale bars = 50 μm.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Inhibition, Standard Deviation, Two Tailed Test, Western Blot, Isolation, RNA Sequencing, Real-time Polymerase Chain Reaction

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: Combination of IPA-3 and olaparib synergistically suppresses ovarian cancer xenograft tumor growth. OVCAR8 and SKOV-3 cells were subcutaneously implanted into NOD-SCID mice, and the animals were treated with control (DMSO), IPA-3 (10 mg/kg), olaparib (50 mg/kg), or their combination (intraperitoneally, 3 days × 6 times). (A, B, L, M) Serum AST and ALT were measured for Ovcar8 (A, B) and SKOV-3 (L, M) xenografts. (C, D, N, O) Tumor images and growth curves for Ovcar8 (C, D) and SKOV-3 (N, O) xenografts. Data were expressed as mean ± standard error of the mean from five independent samples. Statistical significance was assessed by a two-tailed unpaired t -test. (E–K, P – V ) Hematoxylin-eosin, Ki-67, γ-H2AX, and cleaved caspase-3 staining in tumor tissues, evaluated by immunohistochemistry for Ovcar8 (E–K) and SKOV-3 (P–V) xenografts. Quantification is shown in the corresponding panels. Images of 10 random fields per section were analyzed using ImageJ software. Scale bars = 50 μm. Statistical analysis was performed using a two-tailed t -test and two-way ANOVA. P -values < 0.05 were considered significant.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Control, Two Tailed Test, Staining, Immunohistochemistry, Software

Journal: Genes & Diseases

Article Title: PAK1 inhibition synergistically enhances the anti-tumor efficacy of PARP inhibitors in ovarian cancers

doi: 10.1016/j.gendis.2025.101887

Figure Lengend Snippet: Combination of IPA-3 and olaparib synergistically suppresses ovarian cancer cells' growth in patient-derived organoid and patient-derived xenograft models. (A, B, D, E) Ovarian cancer organoids were treated with IPA-3 (200 nM), olaparib (200 nM), or both for 3 days. Representative bright-field images and quantitative analysis are shown. (C, F) Western blotting analysis of CHK1 phosphorylation and cleaved caspase-3 in ovarian cancer organoids treated with IPA-3 (200 nM), olaparib (200 nM), or both for 3 days. (G, H) Patient-derived xenograft models were established by transplanting tumor tissues into 6-week-old female BALB/c nude mice. Mice were treated with DMSO, IPA-3 (10 mg/kg), olaparib (50 mg/kg), or their combination. Tumor images (G) and growth curves (H) are shown. (I–O) Immunohistochemical analysis of hematoxylin-eosin, cleaved caspase-3, γ-H2AX, and Ki-67 levels in tumor tissues. Quantification of staining is shown in (K), (M), and (O). Data were represented as mean ± standard deviation. Images of 10 random fields per section were recorded for analysis. Statistical significance was assessed using a two-tailed t -test and a two-way ANOVA. P -values < 0.05 were considered significant. Scale bars = 50 μm.

Article Snippet: Chlorodeoxyuridine (Cidu), 5-iodo-2′-deoxyuridine (Idu), and the PAK1 inhibitor IPA-3 were sourced from MedChemExpress, while the PARP inhibitor olaparib was acquired from TargetMol.

Techniques: Derivative Assay, Western Blot, Phospho-proteomics, Immunohistochemical staining, Staining, Standard Deviation, Two Tailed Test

Journal: bioRxiv

Article Title: ZNF423 depletion induces the integrated stress response and represents a potential vulnerability in NF1-associated MPNST

doi: 10.64898/2026.03.03.709360

Figure Lengend Snippet: (A-B) Volcano plots of whole-transcriptome differentially expressed genes (DEGs) identified by RNAseq in ST88-14 and NF90.8 cells following siRNA-mediated depletion of ZNF423 ( n =3) compared to control ( n =3). Dashed vertical lines reflect log 2 FC of −1 and 1. Dashed horizontal line reflects false discovery rate (FDR) of 0.05. Downregulated genes with log 2 FC≤-1 and -log 10 adjusted p-value above FDR threshold are denoted in blue. Upregulated genes log 2 FC≥1 and -log 10 adjusted p-value above FDR threshold are denoted in red. Raw RNAseq hit counts for ZNF423 in NF90.8 cells transfected with control siRNA ( n =3) or siZNF423 ( n =3). P-values represent unpaired, two-tailed t-tests between groups. (C) Venn diagram showing overlap of significantly downregulated DEGs common among ST88-14 and NF90.8 cell lines. Downregulated DEGs were defined as log 2 FC≥-1 and adjusted p-value of ≤0.05. (D) Dot plot of top enriched Hallmark gene signatures of shared downregulated genes (FDR≤0.05). (E) Venn diagram showing overlap of significantly upregulated DEGs common among ST88-14 and NF90.8 cell lines. Upregulated DEGs were defined as log 2 FC≥1 and adjusted p-value of ≤0.05. (F) Dot plot of top enriched Hallmark gene signatures of shared upregulated genes (FDR≤0.05). (G-H) Volcano plots of differentially expressed transcription factors and kinases in ST88-14 and NF90.8 cells following siRNA-mediated depletion of ZNF423 compared to control. (I-J) Immunoblots showing cleavage of PARP, ATF3, ATF4 and ZNF423 protein expression following siRNA-mediated depletion of ZNF423 ( n =3) compared to controls ( n =3). GAPDH serves as loading control. Protein expression was normalized to total protein and quantified using ImageJ. Error bars reflect SEM. P-values represent unpaired, two-tailed t test with Welch’s correction. ****=p-value ≤0.0001, ***=p-value≤0.001, **=p-value≤0.01, *=p-value≤0.05, ns=not significant.

Article Snippet: PARP inhibitor olaparib (HY-10162, MedChemExpress) was dissolved in 100% DMSO and stored as a 10μM stock at −20°C until use.

Techniques: RNA sequencing, Control, Transfection, Two Tailed Test, Western Blot, Expressing

Journal: bioRxiv

Article Title: ZNF423 depletion induces the integrated stress response and represents a potential vulnerability in NF1-associated MPNST

doi: 10.64898/2026.03.03.709360

Figure Lengend Snippet: (A-B) Immunoblots showing increased protein levels of γH2A.x following siRNA-mediated depletion of ZNF423 ( n =3) compared to control ( n =3). GAPDH serves as loading control. Protein expression was normalized to total protein and quantified using ImageJ. Error bars reflect SEM. P-values represent unpaired, two-tailed t test with Welch’s correction. (C) Immunofluorescence staining for phosphorylated γH2A.x in ST88-14 cells (10x) following ZNF423 knockdown. DAPI stained nuclei are in blue, and phosphorylated γH2A.x positive cells are shown in green. Scale bars represent 240μm. (D-E) CellTiter-Glo viability assays were used to generate dose response curves for four MPNST cell lines treated with doxorubicin or ifosfamide. IC₅₀ values were calculated using nonlinear regression (log[inhibitor] vs. normalized response, variable slope model). Error bars reflect SEM. (F) Representative phase-contrast images of ST88-14 cells showing enhanced growth inhibition following combined ZNF423 knockdown and treatment with doxorubicin or ifosfamide compared to scrambled controls. Scale bars represent 360μm. (G-H) Quantification of cell viability by CellTiter-Glo assay following ZNF423 depletion in combination with doxorubicin or ifosfamide treatment ( n =6). P-values represent two-way ANOVA with Tukey’s multiple comparisons tests across groups. Error bars reflect SEM. (I) Dose-response curves for three MPNST cell lines treated with the PARP inhibitor olaparib. IC₅₀ values were calculated using nonlinear regression (log[inhibitor] vs. normalized response, variable slope model). Error bars reflect SEM. (J) Representative images showing enhanced growth inhibition following ZNF423 siRNA-mediated knockdown combined with olaparib treatment. Scale bars, 360μm. (K-M) Quantification of cell viability by CellTiter-Glo assay following combined ZNF423 depletion and PARP inhibitor treatment ( n =6). P-values represent two-way ANOVA with Tukey’s multiple comparisons tests across groups. Error bars reflect SEM. (N) Immunoblots of JH-2-002 cells showing increased γH2A.x following ZNF423 knockdown and treatment with olaparib. ****=p-value ≤0.0001, ***=p-value≤0.001, **=p-value≤0.01, *=p-value≤0.05, ns=not significant.

Article Snippet: PARP inhibitor olaparib (HY-10162, MedChemExpress) was dissolved in 100% DMSO and stored as a 10μM stock at −20°C until use.

Techniques: Western Blot, Control, Expressing, Two Tailed Test, Immunofluorescence, Staining, Knockdown, Inhibition, Glo Assay

Journal: bioRxiv

Article Title: The SF3B1 inhibitor pladienolide B massively inhibits DNA damage signaling and repair and counteracts resistance to platinum salts in Non-Small Cell Lung Cancer

doi: 10.64898/2026.02.17.706284

Figure Lengend Snippet: (a) Quantification of DSB-induced homologous recombination in H1299 clones stably expressing the pDR-GFP (pBL174) plasmid. When these cells are transfected with the pBL133 plasmid encoding the I-SceI restriction enzyme, efficient recombination restores a functional GFP coding sequence. (b) H1299-pBL174 cells were transfected with pcDNA3.1 or pBL133 for 24 hours and treated (pBL133+PDB) or not (pBL133) with 5 nM pladienolide B during 48 additional hours. Left panels: representative FL1-H versus FSC-H dot plots of GFP-positive (FL1-H +) and –negative (FL1-H -) cells. Right panel: GFP-positive cells (%). Mean ± SD. n = 3. Unpaired t test. ** p<0.01, ns: not significant. (c) A549 LUAD cells stably expressing the pBL230 plasmid were generated. This plasmid contains genes encoding the membrane antigens CD4 and CD8. CD8 is not expressed as it is in inverted orientation, and CD4 is not expressed because it is too far from the promoter. Two cleavage sites for I-SceI are present in non-coding sequences, which are in direct orientation generating cohesive ends between the two sites. When two DSBs are produced by I-SceI, rejoining of the DNA ends by exclusion or inversion leads to the expression of CD4 or CD8, respectively. (d) Quantification of DNA repair by c-NHEJ in A549-pBL230 clones transfected with either pcDNA3.1 or pBL133 plasmid and treated or not with 5 nM pladienolide B for 24 or 48 hours. Left panel: western blotting of I-SceI-HA in transfected cells treated or not with pladienolide B for 48 hours. Right panel: CD4-positive cells (%). Mean ± SD. n = 3. Mann-Whitney t test. * p< 0.05. (e) G2PCC in H460R cells treated or not with 5 nM pladienolide B for indicated times. Left panels: representative images of G2PCC showing chromosome breaks and exchanges. Right panels: quantification of the number of breaks or exchanges per 100 G2PCC. Mann-Whitney t test. * p< 0.05, ** p<0.01, ns: not significant. (f) Clonogenic survival assay. H460S or H460R cells were treated or not with 1 nM pladienolide B for 10 days in the presence or absence of 5 µM BO2 a RAD51 inhibitor, which was the only drug removed after 24 hours treatment, 10 µM 6-OH-DOPA, a RAD52 inhibitor, or 10 µM olaparib, a PARP1/2 inhibitor. The number of colonies obtained in non treated condition was arbitrarily assigned to 100% survival. Mann-Whitney t test. * p< 0.05, ** p<0.01, *** p< 0.001, **** p<0.0001.

Article Snippet: These drugs included 10 μM olaparib, a PARP1/2 inhibitor (cat. #S1060, Selleckchem), 10 μM 6-OH-DOPA, a RAD52 inhibitor (cat. # H2380, Sigma Aldrich) or 5 μM BO2, a RAD51 inhibitor (cat. # SML0364, Sigma Aldrich) which was the only drug removed after 24 hours treatment.

Techniques: Homologous Recombination, Clone Assay, Stable Transfection, Expressing, Plasmid Preparation, Transfection, Functional Assay, Sequencing, Generated, Membrane, Produced, Western Blot, MANN-WHITNEY, Clonogenic Cell Survival Assay