Gene expression analysis of human middle ear cholesteatoma using complementary DNA arrays

Abstract

Objective: To identify genes regulated in human cholesteatoma compared with normal skin tissue using complementary DNA arrays.

Study design: In vitro analysis.

Methods: Eight cholesteatoma and retroauricular skin samples were obtained from the same patients during surgery. Upregulated and downregulated genes were highlighted using complementary DNA arrays for screening. Reverse transcriptase-polymerase chain reaction and immunohistochemical staining were performed to confirm the results of the complementary DNA array.

Results: Twelve genes were found to be induced or upregulated in cholesteatoma compared with skin samples. These included genes involved in cell proliferation and differentiation (eg, calgranulin A, calgranulin B, psoriasin, thymosin beta-10) and cell invasion (eg, cathepsin C, cathepsin D, cathepsin H). Analyses by means of reverse transcription-polymerase chain reaction showed enhanced expression of several genes including calgranulin A, calgranulin B, psoriasin, thymosin beta-10, cathepsin C, cathepsin D, and cathepsin H in cholesteatoma, supporting the findings from the gene array. In addition, it was verified by immunohistochemical analysis that the expressions of Calgranulin A, Calgranulin B, and Cathepsin D were mainly located in cholesteatoma epithelium.

Conclusion: The observed alteration in gene expression may play a role in various mechanisms of pathogenesis in cholesteatoma.