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Sample GSM5065117

Query DataSets for GSM5065117

Status

Public on Oct 13, 2021

Title

ChIP-seq LucKD Veh Rep1 H3K27ac

Sample type

SRA

Source name

MCF-7

Organism

Homo sapiens

Characteristics

cell line: MCF-7
genotype: LucKD
treatment: Vehicle
biological replicate: Replicate1
antibody: H3K27ac

Treatment protocol

Prior to all experiments, MCF-7 cells were grown for 3 days in phenol red-free MEM Eagle medium supplemented with 5% charcoal-dextran-treated calf serum (CDCS). For experiments, cells were treated with 100 nM E2 or vehicle (ethanol) for 40 minutes.

Growth protocol

MCF-7 cell lines were obtained from the ATCC used for ChIP and proliferation assays described herein. MCF-7 cells were maintained in Minimum Essential Medium Eagle supplemented with 5% calf serum.

Extracted molecule

genomic DNA

Extraction protocol

MCF-7 cells were seeded at ~3 x 106 cells per 15 cm diameter plate and treated as described above. The cells were cross-linked with 1% paraformaldehyde in PBS for 10 minutes at 37°C and quenched in 125 mM glycine in PBS for 5 minutes at 4°C. The cells were then collected and lysed in Farnham lysis buffer (5 mM PIPES pH 8.0, 85 mM KCl, 0.5% NP-40, 1 mM DTT, and 1x RCPIC). A crude nuclear pellet was collected by centrifugation, resuspended in lysis buffer (1% SDS, 10 mM EDTA, 50 mM Tris-HCl, pH 7.9, 1 mM DTT, and 1x RCPIC), and incubated on ice for 10 minutes. The chromatin was sheared at 4°C by sonication using a Bioruptor UC200 at the high setting for four 5-minute cycles of 30 seconds on and 60 seconds off to generate chromatin fragments of ~300 bp in length. The soluble chromatin was diluted 1:10 with dilution buffer (20 mM Tris-HCl, pH 7.9, 0.5% Triton X-100, 2 mM EDTA, 150 mM NaCl, 1 mM DTT and 1x RCPIC) and pre-cleared with protein A agarose beads. The pre-cleared supernatant was used in immunoprecipitation reactions with antibodies against the factor of interest or with rabbit IgG as a control. The immunoprecipitated material was washed once with low salt wash buffer (20 mM Tris-HCl, pH 7.9, 2 mM EDTA, 125 mM NaCl, 0.05% SDS, 1% Triton X-100, 1 mM aprotinin, and 1 mM leupetin), once with high-salt wash buffer (20 mM Tris-HCl, pH 7.9, 2 mM EDTA, 500 mM NaCl, 0.05% SDS, 1% Triton X-100, 1 mM aprotinin, and 1 mM leupetin), once with LiCl wash buffer (10 mM Tris-HCl, pH 7.9, 1 mM EDTA, 250 mM LiCl, 1% NP-40, 1% sodium deoxycholate, 1 mM aprotinin, and 1 mM leupetin), and once with 1x Tris-EDTA (TE). The immunoprecipitated material was eluted in elution buffer (100 mM NaHCO3, 1% SDS) and was then digested with proteinase K and RNase H to remove protein and RNA, respectively. The immunoprecipitated genomic DNA was then extracted with phenol:chloroform:isoamyl alcohol and precipitated with ethanol. The immunoprecipitated DNA was purified further using the MinElute PCR Purification Kit from Qiagen.
After purification, 50 ng of ChIP’d DNA for each condition was used to generate libraries for sequencing, as previously described {Robertson, 2007 #41}, with some modifications. Briefly, the DNA was end-repaired and a single “A”-base overhang was added using the Klenow fragment of E. coli DNA polymerase. The A-modified DNA was ligated with Ilumina sequencing adaptors using the Illumina TruSeq DNA Sample Prep Kit. The ligated DNA (250 ± 25 bp) was size-selected by agarose gel electrophoresis and extraction, amplified by PCR, and purified using AmPure beads (Beckman Coulter). The final libraries were subjected to QC (size, purity, adapter contamination) and sequenced using an Illumina HiSeq 2000 per the manufacturer’s instructions.

Library strategy

ChIP-Seq

Library source

genomic

Library selection

ChIP

Instrument model

Illumina HiSeq 2000

Description

ChIP-enriched DNA from MCF-7 cells in vehicle treated condition
ChIP-seq_LucKD_Veh_H3K27ac.narrowPeak.gz

Data processing

The ChIP-seq reads were aligned to the hg19 human reference genome using the Bowtie software package (Langmead et al, 2009) .
Mapped reads were further converted to (1) “bed” files for later Metagene and read-density analyses and (2) “wiggle” files counting reads in non-overlapping 200-bp windows across the genome for presentation as genome browser tracks by using the BEDTools software package (Quinlan et al, 2010).
Genome_build: hg19
Supplementary_files_format_and_content: bed

Submission date

Feb 04, 2021

Last update date

Oct 13, 2021

Contact name

W. Lee Kraus

E-mail(s)

[email protected]

Organization name

UT Southwestern Medical Center

Street address

5323 Harry Hines Blvd.