1,045 Matching Annotations
  1. Mar 2021
    1. CRISPR-LMNA HDR assayU2OS were seeded in 6-well plates at 200 000 cells per well. Knockdown of PALB2 was performed 6–8 h later with 50 nM siRNA using Lipofectamine RNAiMAX (Invitrogen). Twenty-four hours post-transfection, 1.5 × 106 cells were pelleted for each condition and resuspended in 100 μL complete nucleofector solution (SE Cell Line 4D-Nucleofector™ X Kit, Lonza) to which 1μg of pCR2.1-mRuby2LMNAdonor, 1 μg of pX330-LMNAgRNA2, 1 μg of the peYFP-C1 empty vector or the indicated siRNA-resistant YFP-PALB2 construct, and 150 ρmol siRNA was added. Once transferred to a 100 ul Lonza certified cuvette, cells were transfected using the 4D-Nucleofector X-unit, program CM-104, resuspended in culture media and split into 2 60-mm dishes. One dish was harvested 24 h later for protein expression analysis as described above while cells from the other were trypsinised after 48 h for plating onto glass coverslips. Coverslips were fixed with 4% paraformaldehyde and cells analyzed for expression of mRuby2-LMNA (indicative of successful HR) by fluorescence microscopy (63×) a total of 72 h post-nucleofection. Data are represented as mean relative percentages ± SD of mRuby2-positive cells over the YFP-positive population from 3 independent experiments (total n >300 YFP-positive cells per condition).

      AssayGeneralClass: BAO:0003061 reporter protein

      AssayMaterialUsed: CLO:0009454 U-2 OS cell

      AssayDescription: U2OS cells were treated with PALB2 siRNA and synchronized to G1/S phase by double thymidine block. Cells were then co-transfected with peYFP-PALB2 expressing PALB2 variants (or empty vector), pCR2.1-mRuby2LMNAdonor, and pX330-LMNAgRNA, which generates mRuby2-Lamin A/C fusion if HDR is successful.

      AssayReadOutDescription: Mean relative percentages of mRuby2-positive cells over the YFP-positive population relative to the wild type condition.

      AssayRange: %

      AssayNormalRange: Not reported

      AssayAbnormalRange: <40%

      AssayIndeterminateRange: 41%-77%

      ValidationControlPathogenic: 1

      ValidationControlBenign: 3

      Replication: Three independent experiments, each with n > 300 YFP-positive cells per condition

      StatisticalAnalysisDescription: One-way ANOVA followed by Dunnett's post hoc analysis

    2. RAD51 foci assayHeLa cells were seeded on glass coverslips in 6-well plates at 225 000 cells per well. Knockdown of PALB2 was performed 18 h later with 50 nM PALB2 siRNA using Lipofectamine RNAiMAX (Invitrogen). After 5 h, cells were subjected to double thymidine block. Briefly, cells were treated with 2 mM thymidine for 18 h and release into fresh media for 9 h. Complementation using 800 ng of the peYFP-C1 empty vector or the indicated siRNA-resistant YFP-PALB2 construct was carried out with Lipofectamine 2000 during that release time. Then, cells were treated with 2 mM thymidine for 17 h and protected from light from this point on. After 2 h of release from the second block, cells were irradiated with 2 Gy and processed for immunofluorescence 4 h post-irradiation. Unless otherwise stated, all immunofluorescence dilutions were prepared in PBS and incubations performed at room temperature with intervening washes in PBS. Cell fixation was carried out by incubation with 4% paraformaldehyde for 10 min followed by 100% ice-cold methanol for 5 min at −20°C. This was succeeded by permeabilization in 0.2% Triton X-100 for 5 min and a quenching step using 0.1% sodium borohydride for 5 min. After blocking for 1 h in a solution containing 10% goat serum and 1% BSA, cells were incubated for 1 h with primary antibodies anti-RAD51 (1 :7000, B-bridge International, #70–001) and anti-cyclin A (1:400, BD Biosciences, #611268) diluted in 1% BSA. Secondary antibodies Alexa Fluor 568 goat anti-rabbit (Invitrogen, #A-11011) and Alexa Fluor 647 goat anti-mouse (Invitrogen, #A-21235) were diluted 1:1000 in 1% BSA and applied for 1 h. Nuclei were stained for 10 min with 1 μg/ml 4,6-diamidino-2-phenylindole (DAPI) prior to mounting onto slides with 90% glycerol containing 1 mg/ml paraphenylenediamine anti-fade reagent. Z-stack images were acquired on a Leica CTR 6000 microscope using a 63× oil immersion objective, then deconvolved and analyzed for RAD51 foci formation with Volocity software v6.0.1 (Perkin-Elmer Improvision). The number of RAD51 foci per cyclin A-positive cells expressing the indicated YFP-PALB2 constructs was scored using automatic spot counting by Volocity software and validated manually. Data from three independent trials (total n = 225 cells per condition) were analyzed for outliers using the ROUT method (Q = 1.0%) in GraphPad Prism v6.0 and the remaining were reported in a scatter dot plot. Intensity values, also provided by Volocity, of 500 RAD51 foci from a representative trial were normalized to the WT mean and reported in a scatter dot plot. Horizontal lines on the plots designate the mean values.

      AssayGeneralClass: BAO:0000450 fluorescence microscopy

      AssayMaterialUsed: CLO:0003684 HeLa cell

      AssayDescription: HeLa cells were treated with PALB2 siRNA and synchronized to G1/S phase by double thymidine block. Cells were then transfected with peYFP-PALB2 expressing PALB2 variants (or empty vector) and irradiated with 2 Gy. Four hours after irradiation, cells were subjected to immunofluorescence for RAD51 foci (where foci formation serves as marker of normal DNA damage repair function).

      AssayReadOutDescription: The number of RAD51 foci per cyclin A-positive cells expressing the indicated YFP-PALB2 constructs was scored and presented as percentage change relative to the wild type mean RAD51 foci number per cell.

      AssayRange: %

      AssayNormalRange: Not reported

      AssayAbnormalRange: Not reported

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 1

      ValidationControlBenign: 3

      Replication: Three independent experiments, each with 225 cells per condition

      StatisticalAnalysisDescription: Kruskal–Wallis test with Dunn's multiple comparison post-test

    3. Olaparib sensitivity assayFor the sensitivity assay in HeLa, 240 000 cells were seeded into one well of a six-well plate before being transfected 6–8 h later with 50 nM control or PALB2 siRNA using Lipofectamine RNAiMAX (Invitrogen). The next morning, cells were complemented with 800 ng of the peYFP-C1 empty vector or the indicated siRNA-resistant YFP-tagged PALB2 construct using Lipofectamine 2000 (Invitrogen) for 24 h and then seeded in triplicates into a Corning 3603 black-sided clear bottom 96-well microplate at a density of 3000 cells per well. The remaining cells were kept and stored at −80°C until processed for protein extraction and immunoblotting as described above. Once attached to the plate, cells were exposed to different concentrations of olaparib (Selleckchem, #S1060) ranging from 0 (DMSO) to 2.5 μM. After 3 days of treatment, nuclei were stained with Hoechst 33342 (Invitrogen) at 10 μg/ml in media for 45 min at 37°C. Images of entire wells were acquired at 4x with a Cytation 5 Cell Imaging Multi-Mode Reader followed by quantification of Hoechst-stained nuclei with the Gen5 Data Analysis Software v3.03 (BioTek Instruments). Cell viability was expressed as percentage of survival in olaparib-treated cells relative to vehicle (DMSO)-treated cells. Results represent the mean ± SD of at least 3 independent experiments, each performed in triplicate.

      AssayGeneralClass: BAO:0003009 cell viability assay

      AssayMaterialUsed: CLO:0003684 HeLa cell

      AssayDescription: HeLa cells were treated with PALB2 siRNA followed by transfection peYFP-PALB2 expressing PALB2 variants (or empty vector) and exposed to olaparib (2.5 µM) for 3 days. Nuclei were stained with Hoechst 33342 and measured as an indicator of cell viability.

      AssayReadOutDescription: Cell viability expressed as percentage of survival in olaparib-treated cells relative to vehicle (DMSO)-treated cells

      AssayRange: %

      AssayNormalRange: Not reported

      AssayAbnormalRange: Not reported

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 1

      ValidationControlBenign: 3

      Replication: At least 3 independent experiments, each performed in triplicate

      StatisticalAnalysisDescription: Kruskal–Wallis test with Dunn's multiple comparison post-test

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    1. To further assess the impact of the 5 selected VUS on PALB2, we examined whether they affected the accumulation of RAD51 at IR-induced DSBs by measuring the formation RAD51 foci.

      AssayGeneralClass: BAO:0000450 fluorescence microscopy

      AssayMaterialUsed: CLO:0003684 HeLa cell

      AssayDescription: Transient expression of wild type and variant PALB2 cDNA constructs in HeLa cells following PALB2 siRNA knockdown; exposure ionizing radiation induces DNA damage; RAD51 foci formation is measured by immunofluorescence microscopy 4 h after irradiation

      AssayReadOutDescription: Number of RAD51 foci per S-phase cell (determined by cyclin A detection)

      AssayRange: foci/cell

      AssayNormalRange: RAD51 foci numbers comparable to that of cells expressing wild type PALB2; no numeric threshold given

      AssayAbnormalRange: RAD51 foci numbers comparable to that of cells expressing empty vector; no numeric threshold given

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 0

      ValidationControlBenign: 0

      Replication: 3 independent experiments

      StatisticalAnalysisDescription: Not reported

    2. analyzed several PALB2 variants in their response to the ICL-inducing agent cisplatin

      AssayGeneralClass: BAO:0002805 cell proliferation assay

      AssayMaterialUsed: CLO:0037317 mouse embryonic stem cell line

      AssayDescription: Stable expression of wild type and variant PALB2 cDNA constructs in Trp53 and Palb2-null mouse cell line containing DR-GFP reporter; exposure to cisplatin for 48 h induces interstrand-crosslink DNA damage; cell survival is measured by FACS 24 h after cisplatin washout

      AssayReadOutDescription: Relative resistance to cisplatin represented as cell survival relative to wild type, which was set to 100%

      AssayRange: %

      AssayNormalRange: Cisplatin resistance levels comparable to that of cells expressing wild type PALB2; no numeric threshold given

      AssayAbnormalRange: Cisplatin resistance levels comparable to that of cells expressing empty vector; no numeric threshold given

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 2

      ValidationControlBenign: 2

      Replication: 2 independent experiments

      StatisticalAnalysisDescription: Not reported

    3. sensitivity to PARPi treatment using a cellular proliferation assay

      AssayGeneralClass: BAO:0002805 cell proliferation assay

      AssayMaterialUsed: CLO:0037317 mouse embryonic stem cell line

      AssayDescription: Stable expression of wild type and variant PALB2 cDNA constructs in Trp53 and Palb2-null mouse cell line containing DR-GFP reporter; exposure to PARP inhibitor Olaparib for 48 h inhibits end-joining mediated by PARP and sensitizes cells to DNA damage; cell survival is measured by FACS 24 h after Olaparib washout

      AssayReadOutDescription: Relative resistance to PARPi represented as cell survival relative to wild type, which was set to 100%

      AssayRange: %

      AssayNormalRange: PARPi resistance levels comparable to that of cells expressing wild type PALB2; no numeric threshold given

      AssayAbnormalRange: PARPi resistance levels ≤30% of wild type

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 12

      ValidationControlBenign: 9

      Replication: 2 independent experiments

      StatisticalAnalysisDescription: Not reported

    4. A cell-based functional assay for PALB2 variants

      AssayGeneralClass: BAO:0003061 reporter protein

      AssayMaterialUsed: CLO:0037317 mouse embryonic stem cell line

      AssayDescription: Stable expression of wild type and variant PALB2 cDNA constructs in Trp53 and Palb2-null mouse cell line containing DR-GFP reporter; I-SceI endonuclease introduces a double-stranded break in the reporter construct and efficient repair results in GFP expression, which is detected by flow cytometry

      AssayReadOutDescription: Relative homologous recombination (HR) efficiency represented as mean percentages of GFP-positive cells among the mCherry-positive cells relative to wild type, which was set to 100%

      AssayRange: %

      AssayNormalRange: HR levels comparable to that of cells expressing wild type PALB2; no numeric threshold given

      AssayAbnormalRange: HR levels ≤40% of wild type

      AssayIndeterminateRange: Not reported

      ValidationControlPathogenic: 12

      ValidationControlBenign: 9

      Replication: 2 independent experiments

      StatisticalAnalysisDescription: Not reported

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