Abstract
Purpose: :
MicroRNAs (miRNAs) are small, single stranded RNAs that regulate gene expression by partial, complementary base pairing to specific messenger RNAs (mRNAs). The purpose of the study was to study the regulatory mechanisms mediated by miRNAs and their importance in human primary pterygium.
Methods: :
Human primary nasal pterygia and normal superotemporal bulbar conjunctival tissue of the same eye were collected in the context of conventional excision of pterygium with autotransplantation of conjunctiva. Expression of miRNAs and mRNAs was investigated using Affymetrix GeneChip miRNA Array (6703 probe sets, Affymetrix, Santa Clara, CA) and Affymetrix GeneChip Human Gene 1.0 ST Array offering whole-transcript coverage (28869 genes), respectively. Functional pathway analysis was performed using Ingenuity Pathway Analysis (Ingenuity Systems, Redwood City, CA).
Results: :
A molecular signature consisting of 31 human miRNAs and 290 mRNAs (|fold change|>=2, p-value<0.05, false discovery rate 20%) distinguished primary pterygium from normal conjunctival tissue. The differentially expressed miRNAs such as miR-200A, miR-200B, miR-LET71, miR203, miR20B, miR31, miR210, miR125A, miR361, and miR296 were identified to be involved in connective tissue disorders; inflammatory disease; cellular development, growth, and proliferation; and cell death. Among the differentially expressed mRNAs, members of conjunctival mucins (MUC13, MUC15, MUC21, and MUC20), carcinoembryonic antigen-related cell adhesion molecules (CEACAM1, CEACAM6, CEACAM7), and cytokeratins (KRT6 and KRT10) were significantly altered in pterygium. Overlay analysis of combined miRNA and mRNA expressions suggested that miR-200A might regulate the expression of PHD finger protein 6 (PHF6) and prostaglandin E synthase 3 (PTGES3).
Conclusions: :
This study is the first to identify a combined miRNA and mRNA gene expression profile of human primary pterygium, which may contribute to the understanding of pterygium pathogenesis.
Keywords: pterygium • gene microarray • gene/expression