Establishment of melanoma primary cultures from patient tumor samples

The use of patient-derived primary cell cultures in cancer preclinical assays, including drug screens and genotoxic studies, has increased in recent years. However, their translational value is constrained by several limitations, including variability that can be caused by the culture conditions. Here, we show that the medium composition commonly used to propagate primary melanoma cultures has limited their representability of their tumor of origin and their cellular plasticity, and modified their sensitivity to therapy. Indeed, we established and compared cultures from different melanoma patients propagated in parallel in low-tyrosine (Ham’s F10) or in high-tyrosine (Ham’s F10 supplemented with tyrosine or RPMI1640 or DMEM). Tyrosine is the precursor of melanin biosynthesis, a process particularly active in differentiated melanocytes and melanoma cells. We identified that growing primary melanoma cultures in low-tyrosine medium allows the maintenance of a clinically-relevant highly differentiated melanoma state. These cultures with highly differentiated features in high tyrosine media can be early drifted away to a less differentiated state or can be even lost through the entry into a senescence-like state. Our group establishes melanoma cultures (protocol design and optimization) including primary cultures. We have a culture unit with adequate infrastructure dedicated to cell culture and adheres to rigorous quality control programs that has established more than 150 primary lines and cultures of normal and tumour cells (mainly melanomas). We share our cell cultures with some 80 research teams around the world. Our current melanoma cultures (patient-derived cultures known as MM lines) were crucial and very relevant in several studies that identified regulatory networks underlying melanoma states, mechanisms and regulators of phenotype switching, translation and metabolic reprogramming mechanisms and signatures associated with resistance to therapy (Wouters et al., Nature Cell Biology 2020, Verfaillie et al., Nature Communications 2015, Corre et al., Nature Communications 2018, Rapino et al., Nature 2018, Janssen et al., Cell Death Discovery 2019, Rambow et al., Cell 2018). These melanoma cultures are available at Applied Biological Materials (abm) and CancerTools. https://www.cancertools.org/cell-lines/161602