Differentiation and Tumorigenicity of Human Malignant Melanocytes in Relation to Their Culture Conditions23

Abstract

The effects of variations in the concentrations of L-cystine (Cys), L-methionine (Met), and L-glutamine (Glu) on the establishment of melanocyte cell lines obtained from a primary tumor and its metastasis in the same patient were studied. The special role of Glu was also studied in 4 lymph node metastases from other patients. Differentiation in vitro was dependent on the culture conditions, as assessed by morphologic and biochemical studies. Karyologic expression, doubling time, cloning efficiency, and tumorigenicity in nude BALB/c mice varied widely among the cell lines. Cys was an indispensable amino acid and Glu was not. Met and Glu were implicated in melanogenesis. From these observations arose the question of the accuracy of comparative results, concerning differentiation and tumorigenicity, that had been collected for cell lines obtained under different culture conditions.

In vitro modulation of the metastatic phenotype. I. Analysis of differentiation forms of the B16 melanoma expressing Met-72 determinants and metastatic activity

“…Although these results contrast what might be expected based on our in vitro findings, similar findings have been observed by others [4] with human malignant melanoma grown in nude mice. Although these results contrast what might be expected based on our in vitro findings, similar findings have been observed by others [4] with human malignant melanoma grown in nude mice.…”

“…It is clear that a number of in vitro growth conditions can influence the growth and differentiation of tumor cells [4,5,19,24,28,29,35]. Any similarity in mechanisms affecting differentiation in previous reports and those observed in our system are at present unknown.…”

“…Recent studies have now shown that although many cell lines are considered representative of a given differentiation form, a number of culture conditions can influence the growth, differentiation and phenotype of a variety of different cell lines [5,35], including melanoma [4,19,28,29]. These variable conditions along with the continual tendency of tumor cell populations to undergo cellular diversification and phenotypic drift [16,36] have complicated efforts to assign biological behavior to each of the multiple morphological forms obtained from primary tumors and their metastases.…”

Establishment and characterization of human ocular melanoma cell lines

“…In this report we describe 5 different, original, permanent cell lines obtained from the 3 kinds of ocular melanoma. Our rcsults indicate substantial differences in the behavior of malignant nielanocytes obtained from 3 primary uveal tumors, in particular when these are compared to our 18 established cell lines derived from primary cutaneous melanomas (Aubert et al, 1980b(Aubert et al, , 1984 and the 3 new ones reported here. The biological characteristics of conjunctival melanomas do not differ significantly from those of cutaneous melanomas (Bernardino et al, 1976).…”

The natural history of a family of transplantable melanomas in hamsters

“…Melanomas are favorite models for such studies, as their cells contain easily recognized markers of differentiation, such as melanin, tyrosinase, or the formation of cell processes. They were found to differentiate spontaneously in vitro [139][140][141] or under the influence of MSH [142][143][144], cAMP [145], theophylline [143,146,147], colcemid and arabinofurasonylcytosine [148], anthracycline antibiotics [149], dimethyl sulfoxide and phorbol esters [150][151][152], retinoids [153], guanosine triphosphate [154], tritiated thymidine [155], and polyamine antimetabolites [156]. Among the instances of melanoma cell differentiation in vitro, the case of the Ab melanoma is most peculiar because the cells, which are completely amelanotic in vivo, melanize heavily during a few days in a standard in vitro condition, without any additional treatment.…”