TY - JOUR
T1 - Co-localization of β1,6-branched oligosaccharides and coarse melanin in macrophage-melanoma fusion hybrids and human melanoma cells in vitro
AU - Rupani, Reena
AU - Handerson, Tamara
AU - Pawelek, John
PY - 2004/6
Y1 - 2004/6
N2 - Fusion hybrids between normal macrophages and Cloudman S91 melanoma cells were shown earlier to have increased metastatic potential, along with high expression of β1,6-N-acetylglucosaminyltransferase V and β1, 6-branched oligosaccharides. Curiously, hybrids, but not parental melanoma cells, also produced 'coarse melanin' - autophagic vesicles with multiple melanosomes. As β1,6-branched oligosaccharides were known to be associated with metastasis, and coarse melanin had been described in invasive human melanomas, we looked for potential relationships between the two. Using lectin- and immunohistochemistry, we analyzed cell lines producing coarse melanin for β1,6-branched oligosaccharides: gp100/pmel-17 (a melanosomal structural component) and CD63 (a late endosome/lysosome component associated with melanoma and certain other human cancers). Cell lines used in this study were (i) hybrid 94-H48, a highly metastatic, macrophage-melanoma experimental fusion hybrid; (ii) 6neo mouse melanoma cells, the weakly metastatic, parental fusion partner; and (iii) SKmel-23, a human melanoma cell line derived from a metastasis. Coarse melanin granules were prominent both in hybrids and in SKmel-23 cells, and co-localized with stains for β1,6-branched oligosaccharides, gp100/pmel 17, and CD63. This is the first report of this phenotype being expressed in vitro, although co-expression of β1, 6-branched oligosaccharides and coarse melanin was recently shown to be a common and pervasive characteristic in archival specimens of human melanomas, and was most prominent in metastases. The results suggest that pathways of melanogenesis in melanoma may differ significantly from those in normal melanocytes. In vitro expression of this phenotype provides new biological systems for more detailed analyses of its genesis and regulation at the molecular genetic level.
AB - Fusion hybrids between normal macrophages and Cloudman S91 melanoma cells were shown earlier to have increased metastatic potential, along with high expression of β1,6-N-acetylglucosaminyltransferase V and β1, 6-branched oligosaccharides. Curiously, hybrids, but not parental melanoma cells, also produced 'coarse melanin' - autophagic vesicles with multiple melanosomes. As β1,6-branched oligosaccharides were known to be associated with metastasis, and coarse melanin had been described in invasive human melanomas, we looked for potential relationships between the two. Using lectin- and immunohistochemistry, we analyzed cell lines producing coarse melanin for β1,6-branched oligosaccharides: gp100/pmel-17 (a melanosomal structural component) and CD63 (a late endosome/lysosome component associated with melanoma and certain other human cancers). Cell lines used in this study were (i) hybrid 94-H48, a highly metastatic, macrophage-melanoma experimental fusion hybrid; (ii) 6neo mouse melanoma cells, the weakly metastatic, parental fusion partner; and (iii) SKmel-23, a human melanoma cell line derived from a metastasis. Coarse melanin granules were prominent both in hybrids and in SKmel-23 cells, and co-localized with stains for β1,6-branched oligosaccharides, gp100/pmel 17, and CD63. This is the first report of this phenotype being expressed in vitro, although co-expression of β1, 6-branched oligosaccharides and coarse melanin was recently shown to be a common and pervasive characteristic in archival specimens of human melanomas, and was most prominent in metastases. The results suggest that pathways of melanogenesis in melanoma may differ significantly from those in normal melanocytes. In vitro expression of this phenotype provides new biological systems for more detailed analyses of its genesis and regulation at the molecular genetic level.
KW - Coarse melanin
KW - GnT-V
KW - In vitro models
KW - Melanoma
KW - Metastasis
UR - http://www.scopus.com/inward/record.url?scp=2642575686&partnerID=8YFLogxK
U2 - 10.1111/j.1600-0749.2004.00148.x
DO - 10.1111/j.1600-0749.2004.00148.x
M3 - Article
C2 - 15140074
AN - SCOPUS:2642575686
SN - 0893-5785
VL - 17
SP - 281
EP - 288
JO - Pigment Cell Research
JF - Pigment Cell Research
IS - 3
ER -