Abstract
Abstract: :
Purpose: To test the hypothesis that adherence of conjunctival epithelial cells to laminin isoforms resident in conjunctival basement membrane elicits differential gene expression. Methods: Human conjunctival epithelial cells (the HC0597 virally transformed cell line) were cultured on plastic tissue culture plates coated with 10 ug/ml laminin-1, laminin-2, or laminin-10 for 24 hours. Cells were cultured in serum-free keratinocyte growth medium. Total RNA was isolated from cells adherent to each laminin isoform using the Qiagen RNeasy kit. cDNA expression array technology (Affymetrix HGU95 human gene chip) was subsequently used to analyze over 9,000 known genes and over 3,000 expressed sequenced tags (EST). Data was analyzed with the Affymetrix Data Mining Tool to identify genes exhibiting relative expression levels with greater than two-fold differences. Results: The mRNA expression levels of a number of genes differed by over two-fold dependent upon conjunctival epithelial cell adhesion to laminin isoforms. These genes included two angiogenesis modulators, angiopoietin I and VEGF. Genes associated with the cell cycle included cyclin C, cyclin D3, cyclin E1, cyclin G1, and cyclin B1 as well as cdc25c and cdc23. Several genes encoding for extracellular matrix proteins and adhesion molecules were also affected, including galectin-3, laminin alpha5 chain, collagen type VI, collagen type VIII, and alpha6 integrin. Conclusions: We have hypothesized that ocular surface epithelial cell adhesion to laminin isoforms may regulate cell proliferation, adhesion, and differentiation. Gene microarray analysis suggests that in human conjunctival epithelial cells in vitro, laminin-1, laminin-2, and laminin-10 may play roles in regulating angiogenic properties, cell cycle dynamics, cell adhesion, and cell signaling.
Keywords: conjunctiva • gene microarray • extracellular matrix