Wong Y W, Chew J, Yang H, Tan D T H, Beuerman R
Singapore Eye Research Institute, c/o Singapore National Eye Centre, 11 Third Hospital Avenue, level 6, Singapore.
Br J Ophthalmol. 2006 Jun;90(6):769-72. doi: 10.1136/bjo.2005.087486. Epub 2006 Feb 17.
Pterygium is a fibrovascular overgrowth from the conjunctiva onto the cornea. The pathogenesis of this common ocular surface disorder is not well understood and the only treatment is surgical removal.
DNA microarray analysis of primary pterygium tissue was carried out using uninvolved conjunctiva tissue as a comparison for gene expression levels. Real time polymerase chain reaction (PCR) was used to verify the mRNA level of expression for genes changed in pterygium. Western blot analysis and immunohistochemistry showed protein expression levels and the tissue distribution.
Microarray analysis revealed that mRNA levels of a number of genes were changed in primary pterygium. In particular the gene for insulin-like growth factor binding protein-3, (IGFBP3), which modulates the effects of insulin-like growth factor on cells was significantly decreased. Both the message and protein expression of IGFBP3 in pterygium were decreased compared to normal, uninvolved conjunctiva.
Decreased levels of IGFBP3 protein have been strongly correlated with the presence of cancer. Identification of the low level of expression of IGFBP3 in pterygium suggests that the pathway controlling cell proliferation has lost an important control mechanism, which may explain the continued growth of pterygium.
翼状胬肉是一种从结膜向角膜生长的纤维血管组织增生。这种常见眼表疾病的发病机制尚不清楚，唯一的治疗方法是手术切除。
以未受累的结膜组织作为对照，对原发性翼状胬肉组织进行DNA微阵列分析，以检测基因表达水平。采用实时聚合酶链反应（PCR）验证翼状胬肉中发生变化的基因的mRNA表达水平。蛋白质印迹分析和免疫组织化学显示蛋白质表达水平及组织分布情况。
微阵列分析显示，原发性翼状胬肉中多个基因的mRNA水平发生了变化。特别是调节胰岛素样生长因子对细胞作用的胰岛素样生长因子结合蛋白-3（IGFBP3）基因显著降低。与正常未受累结膜相比，翼状胬肉中IGFBP3的信使核糖核酸和蛋白质表达均降低。
IGFBP3蛋白水平降低与癌症的发生密切相关。翼状胬肉中IGFBP3表达水平较低，表明控制细胞增殖的途径失去了一种重要的控制机制，这可能解释了翼状胬肉的持续生长。
