Overexpression of Insulin-like growth factor-binding protein-2 in pterygium body fibroblasts.
OBJECTIVE
To examine the expression pattern of insulin-like growth factor-binding protein (IGFBP)-2 in cultured primary pterygium fibroblasts and compare it with expression in normal conjunctival fibroblasts.


METHODS
Profile of gene expression by normal conjunctival and primary pterygium fibroblasts was performed by using a cDNA microarray. The overexpression of IGFBP-2 thus identified was further confirmed by RT-PCR and Western blot analysis of cultured cells and by immunohistochemistry on primary pterygium and normal conjunctival tissue sections.


RESULTS
A dramatically increased expression of IGFBP-2 mRNA was demonstrated in cDNA microarray membranes from two different pterygium fibroblasts. This finding was confirmed by RT-PCR in four additional different pterygium fibroblasts and by Western blot analysis of their culture supernatants. Immunohistochemistry of frozen sections from primary pterygium demonstrated increased staining in extracellular matrix of the stroma, compared with that of the normal conjunctiva. IGFBP-2 was also found in goblet cells of both normal conjunctival and pterygium epithelia.


CONCLUSIONS
The increased expression of IGFBP-2 mRNA and protein in pterygium fibroblasts is further strong evidence to support the transformed phenotype of these cells and helps explain why there is increased growth of fibrovascular tissue. This phenotype may be used as a marker to assess the malignant nature of pterygium growth and recurrence.
Solomon
Abraham
A
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Essen, Essen, Germany.
Grueterich
Martin
M
Li
De-Quan
DQ
Meller
Daniel
D
Lee
Sao-Bing
SB
Tseng
Scheffer C G
SC
D015153:Blotting, Western; D002478:Cells, Cultured; D003228:Conjunctiva / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D006801:Humans; D007124:Immunoenzyme Techniques; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis / Q000235:genetics*; D008875:Middle Aged; D011625:Pterygium / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D018971:Insulin-Like Growth Factor Binding Protein 2; D012333:RNA, Messenger