Abstract
Purpose: :
To study the effect of various growth factors on the growth of conjunctival melanocytes.
Methods: :
Human conjunctival melanocytes were isolated with methods previously reported (Exp Eye Res. 84:655-662, 2007) and cultured in HU16 medium (F12 medium with 10% serum, bFGF, IBMX and cholera toxin). Early passages of conjunctival melanocytes were seeded into 12-well plates in HU16 medium, 24 hours later, the culture medium was replaced with HU16 medium without bFGF. Various growth factors at different concentrations were added into the medium, including basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), hepatocyte growth factor (all at 1-100 ng/ml) and transforming growth factor-β2 (TGF-β2, at 0.1-10 ng/ml). Culture media were replaced every 2 days. Six days later, cells were detached by trypsin-EDTA solution and counted. Conjunctival melanocytes cultured with HU16 medium without growth factor were used as the controls. All tests were run in triplicate.
Results: :
bFGF and HGF stimulated the growth of conjunctival melanocytes in a dose dependent manner. Cell number of melanocytes cultured with bFGF and HGF was 245 ± 34% and 167 ± 23% (mean ± SD) of the controls, respectively (P < 0.01 as compared with the control). TGF-β2 inhibited the growth of conjunctival melanocytes in a dose dependent manner. Cell number of melanocytes cultured with TGF-β2 was 76 ± 9% of the controls (P < 0.01). EGF did not have any effect on the growth of conjunctival melanocytes.
Conclusions: :
Growth modulation of conjunctival melanocytes by various growth factors is similar to that of the uveal melanocytes. HGF, bFGF stimulate and TGF-β2 inhibits the growth of conjunctival melanocytes, whereas EGF does not affect the growth of conjunctival melanocytes in vitro.
Keywords: melanocytes • conjunctiva • growth factors/growth factor receptors