title: On formation of melanosomes in a cultured melanoma line.
abstract: Melanosomes are present in abundant numbers in HPM-73 melanoma cells maintained in surum-containing cultures. However, withholding of serum for 3 days caused severe retardation of development of these organelles. Addition of chondroitin-4-sulphate (0.4 mg/ml) to serum-containing culture media for 3 days resulted in greater numbers of premelanosomes and melanosomes relative to mitochondria. The same amount of chrondroitin-4-sulphate (0.4 mg/ml) added to serum-free cultures also resulted in an increased ratio of premelanosomes and melanosomes to mitochondria but, within the 3-day period many of these organelles did not attain the pattern of maturity evident in melanoma cells reared in serum-supplemented media. By exploitation of slowed rates of development of melanosomes in cultures (especially, but not exclusively, in serum-free samples) it was possible to examine various early developmental forms of these organelles. It was found that in this cell line mitochondria appear to be involved in the process of melanosome formation.
mesh_terms: D002460:Cell Line; D002809:Chondroitin Sulfates / Q000494:pharmacology; D003470:Culture Media; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000648:ultrastructure; D008543:Melanins / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism / Q000648:ultrastructure; D008547:Melanophores / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D009024:Morphogenesis / Q000187:drug effects
chemical_list: D003470:Culture Media; D008543:Melanins; D002809:Chondroitin Sulfates