Melanogenesis is the
production of
melanin from
tyrosine by a series of
enzyme-catalyzed reactions, in which
tyrosinase and
DOPA oxidase play key
roles. The
melanin content in the
skin determines
skin pigmentation.
Abnormalities in
skin pigmentation lead to various
skin pigmentation disorders. Recent
research has shown that the expression of EMP2 is much lower in
melanoma than in normal
melanocytes, but its
role in
melanogenesis has not yet been elucidated. Therefore, we investigated the
role of EMP2 in the
melanogenesis of MNT1
human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during
melanogenesis in MNT1
melanoma cells by
gene silencing of EMP2.
Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2
siRNA in MNT1
cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2
gene was knocked out of the
cell line (EMP2
CRISPR/Cas9) by using a
CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2
CRISPR/Cas9
cell lines. Loss of EMP2 also reduced migration and invasion of MNT1
melanoma cells. In addition, the
melanosome transfer from the
melanocytes to
keratinocytes in the EMP2 KO
cells cocultured with
keratinocytes was reduced compared to the
cells in the control
coculture group. In conclusion, these results suggest that EMP2 is involved in
melanogenesis via the
regulation of TRP-2 expression.