For Affymetrix microarray analysis, total RNA was isolated from
NK, PT1 and PT3 cell lines using Trizol (Invitrogen, Carlsbad, CA) according to the manufacturer’s protocol. After treatment with 5 U/μg of RNase-free DNase I at 37°C for 1 hour, all the samples were frozen in and sent to University of Iowa DNA facility for microarray analysis. After cDNA synthesis, samples were applied to a Human Genome GeneChip HG-U133A (Affymetrix Inc. Santa Clara, CA). Array filtering and significant expressed gene identification Microarray AZD6738 research buy data in the form of CEL files were imported into BRB ArrayTools developed by Dr. Richard Simon and Amy Peng Lamhttp://linus.nci.nih.gov/BRB-ArrayTools.html. HG-U133A microarray raw expression intensities of NK, PT1, and PT3 data were scaled to a target intensity of 100 units, normalized independently, using the robust multichip average (RMA) algorithm for the quantification of the expression level of target genes, Selleckchem BIBW2992 and passed by the filtering and subletting
criteria with any one absent (A) or marginal call (M). Genes that had more than 50% missing data across all observations were excluded from the analysis. Also, we selected those genes with an expression level of ≥ 20 in ≥ 25% of samples. Fold change has been transformed
based on log2(PT1/NK), log2(PT3/NK), log2(PT3/PT1), log2(PT3/non-PT3), respectively. Fold change above 2.0 was defined as differentially expressed genes between two cell lines, where it is meet fold >2 SD (above 97% confidence). Real-time quantitative PCR Validation of differential expressed genes was done by real-time Anacetrapib quantitative PCR (RT-qPCR). RT-qPCR assays were performed using the Applied Biosystems 7500 Systems (Applied Biosystems, USA). Each sample was run in triplicate to ensure quantitative accuracy. We used Human Universal ProbeLibrary from Roche Applied Science. Assay specificity was attained through the combination of specific primers designed from ProbeFinderhttps://www.roche-applied-science.com) web-based software. Seven genes, plus two reference genes, with their specific primers, and PCR product size information for real-time quantitative PCR validation are listed in Table4. Table 4 Primer information for real-time qPCR.