The cells were collected, spun down and added SDS lysis buffer, and then incubated on ice. The DNA was sonicated (5 pulses for 10 s, chilled on ice for 50 s) to shear it into 200-1000 base pairs. Once the sheared DNA was diluted into ChIP Bortezomib in vivo buffer a pellet was obtain by centrifugation. The assay requires two negative controls. The first control was transcriptionally inactivated DNA that was used for the PCR reaction, and the second control was

transcriptionally active DNA without antibody for immuno-precipitation. The immuno-precipitating Sp1 antibody was added to the DNA and incubated overnight. PCR (Polymerase Chain Reaction) was done in order to amplify the DNA that was bound to the immunoprecipitated histones. The primers used for amplification were design using OligoPerfect PXD101 chemical structure Primer Design Program (Invitrogen) and are as follows: A17 1F 5′-TGGAGCAAATGTGCATTCAG-3′, A17 1R 5′-GCATTTGGTTCAGGGTCCTA-3′, A17 2F 5′- GTGGGCATCAAGACAAAGGA-3′, A17 2R 5′-CTTCCTGGACGCAGACGTA-3′, A17 3F 5′-GAGCCTGGCGGTAGAATCTT-3′, A17 3R 5′-TACCGACTCCACCTCTCTGG-3′. Once amplified, the PCR product was tested by electrophoresis

on a 2% agarose gel containing 0.01% ethidium bromide. The results were visualized using DualLite Trans-illuminator machine (Fisher). The ChIP assay was performed under normoxic conditions. Real-time PCR Quantitative RT-PCR was performed using real-time PCR with the SYBR Green reporter. The RNA was isolated from the cell cultures by using the Absolutely RNA Miniprep Kit (Stratagene). RNA yield was determined with OD260 nm. RNA was reverse transcribed to complementary DNA using the M-MLV RT protocol (Invitrogen). Quantitative RT-PCR was selleck inhibitor performed after stabilizing the RNA. The kit used for RT-PCR was a SYBR Green PCR master kit HDAC inhibitor with the appropriate forward and reverse primers (Invitrogen), which were optimized to the desired concentration (10 nM). The instrument used for this experiment was ABI 7000 PCR machine (Applied Biosystems). Each sample was tested three times. The primers used for this experiment are in Table 1. Human TATA-box binding protein was used as an internal

control. Table 1 The primers used for real time polymerase chain reaction Gene GenBank accession number Sequence HIF-1α NM024359 5′-CGTTCCTTCGATCAGTTGTC -3′     5′-TCAGTGGTGGCAGTGGTAGT -3′ ADAM17 NM003183 5′-ACTCTGAGGACAGTTAACCAAACC-3′     5′-AGTAAAAGGAGCCAATACCACAAG-3′ Sp1 NM138473 5′-AAACATATCAAAGACCCACCAGAAT-3′     5′-ATATTGGTGGTAATAAGGGCTGAA-3′ TBP NM003194 5′-TGCACAGGAGCCAAGAGTGAA-3′     5′-CACATCACAGCTCCCCACCA-3′ ADAM17, a disintegrin and a metalloproteinase-17; HIF-1α, hypoxia inducible factor-1 alpha; Sp1, specificity transcription protein -1; TBP, TATA-binding protein. Western blot Proteins were extracted from the cell culture and the added in 500 μL lysis buffer with 1% protease inhibitor cocktail (1 mM phenylmethylsulfonyl fluoride-PMSF, 1 μg/mL aprotinin and 1 μg/mL pepstatin A).