Identification of differentially expressed genes in anagen dermal papilla by suppression subtractive hybridization.

Background: We constructed a cDNA subtractive library of dermal papilla cells (DPCs) in anagen with suppression subtractive hybridization (SSH) technique and clone differentially expressed genes related to DPCs in anagen.

Methods: Total mRNA was isolated from DPCs of anagen and telogen follicles. Moreover, single-strand (ss) and double-strand (ds) cDNAs were synthesized in turn using SMART PCR cDNA synthesis technology. ds cDNAs then were digested with Rsa I and divided into two groups, and ligated to the specific adaptor 1 and adaptor 2R, respectively. After cDNAs were hybridized with each other twice and underwent two rounds of nested PCR. PCR products were ligated with arms of T/A plasmid vectors to set up the subtractive library. Selected clones were demonstrated by reverse Northern blot and sequenced. The acquired sequence data were aligned against the Genbank nucleotide database.

Results: cDNA subtractive library of DPCs in anagen follicles was set up successfully with high subtractive efficiency. Thirty-five genes were identified in this study with 22 known functional genes and 13 unknown functional genes.

Conclusions: All results confirm the effectiveness and sensitivity of SSH in detecting differentially expressed genes from a small amount of clinical samples. Information about such alterations in gene expression could be useful for elucidating the genetic events in hair follicle growth regulation.