Transcriptome analysis of a FACS-sorted human intersitial cells of Cajal (ICC) [array]

Interstitial cells of Cajal (ICC) are electrical pacemakers and mediators of neuromuscular neurotransmission in the gastrointestinal tract. Gastrointestinal stromal tumors (GIST) arise within the ICC lineage due to activating KIT/PDGFRA mutations. In this study we developed a method for isolation of human ICC by immunolabeling and fluorescence-activated cell sorting (FACS). Briefly, human gastric musculature was dissociated and incubated with antibodies against CD45, FCER1A, CD11B, KIT, and CD34. ICC (defined as HP-KIT+CD34- cells), NOT ICC (defined as HP-KIT-CD34- cells), and hematopoietic (HP) cells (defined as HP+ cells) were isolated using FACS. Microarray was performed on ICC, NOT ICC, HP+ cells, and unfractionated gastric tunica muscularis. This study utilized micorarray for the phenotypic characterization of FACS-sorted human ICC, allowing comparison of ICC to other cells of the gastric musculature, including GIST. De-identified human gastric tissues obtained as surgical excess tissue from patients undergoing bariatric operations. This study utilized oligonucleotide microarray analysis to characterize the transcriptome of FACS-sorted human ICC. Total RNA from ICC, NOT ICC, HP+ cells, and unfractionated gastric tunica muscularis was isolated. Oligonucleotide microarray studies were performed using Affymetrix GeneChip Human Genome U133 Plus 2.0 array.