Tissue factor expression in human pterygium.
OBJECTIVE
A pterygium shows tumor-like characteristics, such as proliferation, invasion, and epithelial-mesenchymal transition (EMT). Previous reports suggest that tissue factor (TF) expression is closely related to the EMT of tumor cells, and subsequent tumor development. In this study, we analyzed the expression and immunolocalization of TF in pterygial and normal conjunctival tissues of humans.


METHODS
Eight pterygia and three normal bulbar conjunctivas, surgically removed, were used in this study. Formalin-fixed, paraffin-embedded tissues were submitted for immunohistochemical analysis with anti-TF antibody. Double staining immunohistochemistry was performed to assess TF and alpha-smooth muscle actin (α-SMA) or epidermal growth factor receptor (EGFR) expression in the pterygia.


RESULTS
Immunoreactivity for TF was detected in all pterygial tissues examined. TF immunoreactivity was localized in the cytoplasm of basal, suprabasal, and superficial epithelial cells. The number of TF-immunopositive cells in pterygial epithelial cells was significantly higher than in normal conjunctival epithelial cells (p<0.001). TF immunoreactivity was detected in α-SMA-positive or -negative pterygial epithelial cells. EGFR immunoreactivity was detected in pterygial epithelium, which was colocalized with TF.


CONCLUSIONS
These results suggest that TF plays a potential role in the pathogenesis and development of a pterygium, and that TF expression might be involved through EMT-dependent and -independent pathways.
Laboratory of Ocular Cell Biology and Visual Science, Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Ryo
R
Ando
Satoru
S
Kase
Tsutomu
T
Ohashi
Zhenyu
Z
Dong
Junichi
J
Fukuhara
Atsuhiro
A
Kanda
Miyuki
M
Murata
Kousuke
K
Noda
Nobuyoshi
N
Kitaichi
Susumu
S
Ishida
D000199:Actins / Q000096:biosynthesis; D003228:Conjunctiva / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000473:pathology; D066246:ErbB Receptors / Q000096:biosynthesis; D005557:Formaldehyde / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008648:Mesoderm / Q000473:pathology; D008954:Models, Biological; D011625:Pterygium / Q000378:metabolism*; D015398:Signal Transduction; D013925:Thromboplastin / Q000096:biosynthesis*
D000199:Actins; D005557:Formaldehyde; D013925:Thromboplastin; D066246:ErbB Receptors
Br J Ophthalmol. 2007 Jul;91(7):958-61
17179165
J Mol Med (Berl). 2004 Mar;82(3):175-81
14752606
Nat Rev Mol Cell Biol. 2006 Feb;7(2):131-42
16493418
Ophthalmology. 2005 Jun;112(6):1023-30
15885787
Invest Ophthalmol Vis Sci. 2007 Apr;48(4):1511-7
17389479
Cancer Res. 2008 Dec 15;68(24):10068-76
19074872
Curr Opin Rheumatol. 2004 Nov;16(6):733-8
15577612
Br J Ophthalmol. 2007 Sep;91(9):1209-12
17360734
Br J Ophthalmol. 1997 Jun;81(6):493-6
9274415
Immunol Res. 2000;21(2-3):289-92
10852129
Am J Pathol. 2005 Aug;167(2):489-503
16049334
Pathophysiol Haemost Thromb. 2006;35(1-2):103-10
16855354
Graefes Arch Clin Exp Ophthalmol. 2001 Nov;239(11):865-71
11789868