Melanization of Bomirski hamster amelanotic melanoma cells (Ab line) depends on the type of culture medium

Abstract

Introduction. The effect of melanogenesis intensity on melanoma biology remains an open question, and the biological differences between melanotic and amelanotic melanoma cells have not yet been satisfactorily documented. As a result, the melanization of melanoma cells in in vitro cultures is not considered among experimental procedures. The aim of this study was to investigate the effect of the medium used to culture Bomirski amelanotic Ab melanoma cells on the melanogenesis process. Material and methods. Amelanotic melanoma cells (Ab) were cultured in two media recommended for in vitro melanoma cell cultures, RPMI and DMEM. The melanization was evaluated by determining the melanin and tyrosinase presence in the cells using spectrophotometrical and western blot methods, respectively. Changes in Ab melanoma cells' ultrastructure were determined using electron microscopy (EM). Results. The medium with higher level of tyrosine (DMEM) induced significant melanization of amelanotic melanoma cells (Ab) after only 24 h, while the RPMI medium, with a lower level of tyrosine, weakly affected melanin production. Melanization of Ab cells was paralleled by an increase in the amount of tyrosinase protein. Induced melanization was easily observed on EM-micrographs in the form of newly formed melanosomes containing melanin pigment. Melanosomes at stages from one (I) to four (IV) were observed. Conclusions. Culture medium has an important effect on the in vitro biology of amelanotic melanoma cells, since it can affect the rate of cellular melanization. The appropriate medium should be carefully selected, taking into account the known biology of the melanoma cells being used.

Melanization as unfavorable factor in amelanotic melanoma cell biology

“…2009). The presence of tyrosinase protein was confirmed in both Ab and B16F10 melanoma cells (Skoniecka et al 2018). Our observation did not confirm Kreider and Schmoyer's results which showed that ongoing melanization in B16 cells decreased proliferation in a significant way (Kreider and Schmoyer 1975).…”

“…Ab cells in DMEM were the amelanotic melanoma cells which exhibited the most darkening. The presence of melanin granules and tyrosinase activation were observed in Ab cells cultured in DMEM in our earlier studies (Skoniecka et al 2018). Morphological changes, decreasing cell numbers and significant displacement of cells from all cell cycle phases to the subG0/G1 fraction indicated Ab cell death.…”

“…The heterogenous reaction of amelanotic melanoma cells to Ltyrosine-induced melanization stressed that the lack of melanin may be the result of a different mechanism. Additionally, our previous results documented that Ab and B16F10 cells have an active tyrosinase, the basic enzyme of melanogenesis, while A375 do not (Skoniecka et al 2018). According to Kudugunti et al, the selective toxicity of some substances on amelanotic cells depends on the tyrosinase functionality (Kudugunti et al 2010).…”

Recurrent Amelanotic Melanoma of Nasal Cavity: Biological Variability and Unpredictable Behavior of Mucosal Melanoma. A Case Report

“…It is important to emphasize the possible chemotherapeutics and radiotherapy effect on melanogenesis, basic process for melanoma cells thus changing the tumor cells biology. 11,12 Vierne et al . reported an histologically different, mainly amelanotic mandibular metastasis 16 years after adjuvant radiotherapy treatment for primary cutaneous melanoma.…”