Melanoma is among the most molecularly diverse and clinically challenging cancers in oncology. Its rapid progression, capacity for metastasis, and remarkable ability to evade the immune system have made it a central focus of cancer biology and drug development for decades.
This article provides a practical overview of the most important melanoma cell lines used in skin cancer and immunotherapy research, what makes each one useful, and how to select the right model for your specific scientific question.
Why Melanoma Cell Line Selection Matters
Melanoma is not a single disease at the molecular level. Cutaneous melanoma, the type that arises from melanocytes in the skin, carries a distinct mutation landscape compared to uveal melanoma, which originates in the eye, or acral melanoma, which arises on the palms, soles, and nail beds.
Within cutaneous melanoma alone, roughly 50% of tumors carry the BRAF V600E mutation, while another 15 to 20% carry NRAS mutations, and approximately 15% carry NF1 alterations. These differences profoundly affect drug sensitivity, resistance pathways, and immune phenotype.
A cell line that mirrors the mutation you are studying will produce biologically meaningful results. One that does not will give you data that looks clean but tells you nothing useful about the clinical scenario you are trying to model.
Most Widely Used Human Melanoma Cell Lines
A375: The Standard BRAF V600E Human Model
A375 is a human cutaneous melanoma cell line derived from a metastatic lesion and is one of the most cited melanoma lines in the research literature. Its defining feature is a homozygous BRAF V600E mutation, which makes it highly relevant for studies on BRAF-targeted therapy.
A375 responds to BRAF inhibitors such as vemurafenib and dabrafenib, and it is routinely used to study both initial drug sensitivity and the mechanisms by which cells develop acquired resistance following treatment. The line is also used to generate vemurafenib-resistant derivatives in the laboratory by exposing parental cells to gradually increasing drug concentrations over several weeks, a strategy that produces resistance models with clinical relevance.
A375 engrafts reliably in immunodeficient mouse models, making it a practical choice for xenograft studies when a human BRAF-mutant tumor is needed in vivo.
SK-MEL Lines: A Diverse Family for Comparative Research
The SK-MEL series encompasses a range of human cutaneous melanoma cell lines derived at the Memorial Sloan Kettering Cancer Center from patients at various stages of disease. Because individual SK-MEL lines carry different mutation profiles, some BRAF-mutant, some NRAS-mutant, some wild-type for both, they are particularly useful for comparative studies where researchers want to examine how mutation status affects biological behavior or drug response.
SK-MEL-28 carries BRAF V600E and is used alongside A375 in BRAF inhibitor studies as a validation line. SK-MEL-1 and SK-MEL-2 are BRAF wild-type and NRAS-mutant, providing a contrasting background for studying MAPK pathway independence or NRAS-driven oncogenesis.
For immunotherapy research, the SK-MEL lines vary in their PD-L1 expression and HLA class I presentation, which allows researchers to investigate how genetic background shapes immune recognition and checkpoint inhibitor response.
M14: A Metastatic Melanoma Line with a Complicated History
M14 is a human melanoma cell line with a history worth knowing. It has been used in NCI-60 drug screening panels as a melanoma representative, but studies have established that it shares an identical STR fingerprint with the MDA-MB-435 cell line, which was originally characterized as a breast cancer line.
The current consensus treats M14 as a melanoma-derived line given its biological characteristics, but researchers should be aware of this historical complexity and exercise appropriate caution when interpreting or comparing data from studies that used it.
B16 and B16-F10: The Backbone of Mouse Melanoma Immunotherapy Research
For immunotherapy research requiring an immune-competent in vivo environment, the B16 family of murine melanoma cell lines is the most important tool in the field.
B16 was originally derived from a spontaneous melanoma in a C57BL/6 mouse. The B16-F10 subline was selected through multiple rounds of in vivo passaging for enhanced pulmonary metastatic potential, making it more aggressive and more metastasis-prone than the parental line.
Because B16-F10 is syngeneic with C57BL/6 mice, it can be implanted into immunocompetent animals while preserving a fully functional host immune system. This is what makes it indispensable for immunotherapy research. Studies testing checkpoint inhibitors, CAR-T cell therapies, combination immunotherapy regimens, and immune modulatory compounds all rely on syngeneic models precisely because the tumor-immune interaction cannot be studied in immunodeficient mice.
Uveal Melanoma Cell Lines: A Distinct Category
Uveal melanoma is biologically and clinically distinct from cutaneous melanoma. It arises in the choroid, ciliary body, or iris of the eye, carries a very different mutation landscape — primarily GNAQ and GNA11 mutations rather than BRAF or NRAS alterations — and has an extremely poor prognosis once it metastasizes, with no approved targeted therapy until recently.
The most commonly used uveal melanoma cell lines include MEL270, MEL290, 92.1, MEL202, OMM2.3, and OMM2.5.
MEL270 and its derivatives are among the most studied uveal melanoma lines and are used to model primary uveal disease. MEL270 and OMM2.5 were both derived from the same patient — MEL270 from the primary ocular tumor and OMM2.5 from a liver metastasis — making them a paired system for studying metastatic evolution in uveal melanoma.
Melanoma Cell Lines in Immunotherapy Research
The role of melanoma cell lines in immunotherapy research has expanded considerably since the clinical success of checkpoint inhibitors such as pembrolizumab and nivolumab. These agents block the PD-1/PD-L1 axis, relieving an inhibitory signal that tumors exploit to suppress T cell activity.
Understanding why some tumors respond to checkpoint inhibitors and others do not is one of the most active areas of current melanoma research, and melanoma cell lines are central to that work.
PD-L1 expression studies use melanoma cell lines to investigate what drives tumor PD-L1 upregulation. Both A375 and the SK-MEL series express variable PD-L1 levels, and interferon-gamma treatment can modulate this expression — providing a model for studying the adaptive immune resistance that tumors mount in response to T cell attack.
CTLA-4 and combination checkpoint blockade is studied in the B16-F10 model in vivo, where the relative resistance to anti-PD-1 monotherapy provides a useful platform for testing whether combination checkpoint blockade (anti-PD-1 plus anti-CTLA-4) or drug combinations can restore immune control.
CAR-T cell therapy research against melanoma has used xenograft models with A375 and other human lines in immunodeficient mice to evaluate tumor cell killing by engineered T cells, with DR5 expression status serving as one selection criterion for which lines are most appropriate for specific CAR designs.
Epigenetic reprogramming of immune phenotype is an active research focus. Compounds such as HDAC inhibitors (including entinostat) and BET inhibitors (including JQ1) alter the immune phenotype of melanoma cells , affecting HLA class I expression, PD-L1 levels, and antigen presentation, and the consequences of these changes are studied using both human melanoma lines and B16-F10 in vivo.
Practical Guidance: Matching Your Model to Your Question
The key decision points for melanoma cell line selection are:
Do you need a human or murine model? Human lines (A375, SK-MEL series, uveal lines) are essential for studying human mutation-specific biology and drug sensitivity. Murine syngeneic lines (B16-F10, YUMM) are required for any study where a functioning immune system is needed.
What is the mutation status you need to model? BRAF V600E: A375, SK-MEL-28, YUMM1.1. BRAF wild-type/NRAS-mutant: SK-MEL-2. GNAQ/GNA11-mutant (uveal): MEL270, 92.1, MEL202.
Is checkpoint inhibitor resistance part of your study? B16-F10 in C57BL/6 provides a model where checkpoint monotherapy shows limited efficacy, making it ideal for testing combination strategies. YUMM lines show greater checkpoint sensitivity and are better for studying initial response mechanisms.
Do you need metastatic behavior? B16-F10 has well-characterized pulmonary metastasis potential following intravenous injection. Human metastatic lines such as A2058 and 1205Lu are used in xenograft metastasis models.
Important Considerations When Working with Melanoma Cell Lines
Pigmentation status varies between lines. Some melanoma lines are highly pigmented and produce melanin, which can interfere with certain optical assays. A375, for example, is relatively low in pigmentation, while B16 cells are darkly pigmented due to active melanogenesis.
Resistance develops rapidly. Melanoma is notorious for developing resistance to BRAF inhibitors. If your study involves repeated or long-term drug exposure, monitor BRAF inhibitor sensitivity regularly and keep authenticated early-passage frozen stocks from which to restart if phenotypic drift occurs.
Authentication is essential. The history of the M14 line serves as a reminder that cell line identity should never be assumed. STR profiling should be performed on any melanoma line when it enters your lab and periodically thereafter.
Frequently Asked Questions
What are the most commonly used melanoma cell lines in research?
The most frequently used human melanoma cell lines are A375 and the SK-MEL series for cutaneous melanoma studies, and MEL270, 92.1, and MEL202 for uveal melanoma research. For in vivo immunotherapy studies using immune-competent models, B16-F10 in C57BL/6 mice is the standard syngeneic murine melanoma model.
What is the A375 melanoma cell line and what makes it useful?
A375 is a human cutaneous melanoma cell line derived from a metastatic lesion, carrying a homozygous BRAF V600E mutation. It is one of the most widely used melanoma lines for studying BRAF-targeted therapy.
What melanoma cell lines are best for immunotherapy research?
For in vivo immunotherapy research requiring an intact immune system, B16-F10 in C57BL/6 mice and YUMM lines are the primary choices. For in vitro immunotherapy studies, including PD-L1 expression analysis, T cell killing assays, and checkpoint pathway biology.
Final Thoughts
Melanoma cell lines have been central to some of the most significant advances in cancer therapy, from the development of BRAF inhibitors to the mechanistic understanding of checkpoint immunotherapy resistance. The key to getting the most out of these models is knowing what each line represents, what it does not represent, and how to interpret results in that context.
No single cell line captures the full complexity of human melanoma. Using multiple models — and being transparent about their limitations — produces more credible, reproducible, and translationally meaningful research.