Bloomlinnet9115
Most currently available three-dimensional melanoma models have either focused on simplicity or were optimized for physiological relevance. Accordingly, these paradigms have been either composed of malignant cells only or they were sophisticated human skin equivalents featuring multiple cell types and skin-like organization. Here, an intermediate spheroid-based assay system is presented, which uses tri-cultures of human CCD-1137Sk fibroblasts, HaCaT keratinocytes, and SK-MEL-28 melanoma cells. Being made of cell lines, these spheroids can be reliably reproduced without any special equipment using standard culture procedures, and they feature different aspects of skin and early stage melanoma. Therefore, this kind of model can be useful for lead-compound testing or addressing fundamental principles of early melanoma formation.Researchers often aim to incorporate microenvironmental variables such as the dimensionality and composition of the extracellular matrix into their cell-based assays. A technical challenge created by introduction of these variables is quantification of single-cell measurements and control of environmental reproducibility. Here, we detail a methodology to quantify viability and proliferation of melanoma cells in 3D collagen-based culture platforms by automated microscopy and 3D image analysis to yield robust, high-throughput results of single-cell responses to drug treatment.Three-dimensional (3D) cell culture has allowed a deeper understanding of complex pathological and physiological processes, overcoming some of the limitations of 2D cell culture on plastic and avoiding the costs and ethical issues related to experiments involving animals. Here we describe a protocol to embed single melanoma cells alone or together with primary human lymphatic endothelial cells in a 3D cross-linked matrix, to investigate the invasion and molecular crosstalk between these two cell types, respectively. After fixation and staining with antibodies and fluorescent conjugates, phenotypic changes in both cell types can be specifically analyzed by confocal microscopy.Lymph node invasion by tumor cells is an important process in the progression of melanoma and is a poor prognostic factor for patients with this cancer. Before they are able to spread to regional lymph nodes, though, melanoma cells must first adhere to lymphatic endothelium and transmigrate into the lymphatic vasculature. In order to study melanoma cell adhesion to lymphatic endothelial cells and the factors that regulate this process, we have developed an in vitro flow cytometry-based assay to measure melanoma cell attachment to lymphatic endothelial cells. This assay will be a useful tool for investigating the interactions that take place between melanoma cells and lymphatic endothelial cells during the adhesion process.Tumor-associated macrophages (TAMs) are one of most important components of the tumor microenvironment. Although many assays have been developed to differentiate monocytes into macrophages (Mϕ) for studying the biology of TAMs in vitro, little is known whether the macrophages induced by these approaches can recapitulate the biology of TAMs present in the tumor microenvironment. We have developed a novel assay to differentiate human monocytes into TAMs using modified melanoma-conditioned medium, which is derived from the concentrated tumor cell culture medium. Characterization of these modified melanoma-conditioned medium-induced macrophages (MCMI-Mϕ) by multiple flow cytometry, Luminex, microarray, and immunohistochemistry analyses indicates that MCMI-Mϕ are phenotypically and functionally highly similar to the TAMs present in the tumor microenvironment.Within the adaptive and innate immune system, effector lymphocytes known as cytotoxic T cells (CTLs) or natural killer (NK) cells play an essential role in host defense against tumor cells and virally infected cells. Here we describe a flow cytometry-based method to quantify CTLs or NK cell cytotoxic activity against melanoma cells. In this assay, spleen cells, peripheral blood mononuclear cells (PBMCs), or purified NK cell preparations are co-incubated at different ratios with a target tumor cell line. The target cells are pre-labeled with a fluorescent dye to allow their discrimination from the effector cells. After the incubation period, killed target cells are identified by a nucleic acid stain, which specifically permeates dead cells. This method is amenable to both diagnostic and research applications.Glutamine is a major substrate for biosynthesis. It contributes to multiple pathways required for cell proliferation, supports antioxidant defense via glutathione synthesis, and sustains the tricarboxylic acid (TCA) cycle through anaplerosis. Glutamine-fueled anaplerosis and related biosynthesis can be studied in detail in melanoma using stable isotope (13C) labeling followed by gas chromatography-mass spectrometry (GC-MS) analysis of metabolite amounts and labeling. Detailed protocols for the assay of polar metabolites (including amino acids, TCA cycle, and glycolysis metabolites) and fatty acids by these methods following cell treatment with 13C-glutamine or 13C-glucose are presented.Cancer cells have deregulated metabolism that can contribute to the unique metabolic makeup of the tumor microenvironment. This can be variable between patients, and it is important to understand these differences since they potentially can affect therapy response. Here we discuss a method of processing and assaying metabolism from direct ex vivo murine and human tumor samples using seahorse extracellular flux analysis. This provides real-time profiling of oxidative versus glycolytic metabolism and can help infer the metabolic status of the tumor microenvironment.Melanoma cells have high glycolytic capacity. Glucose uptake is a key rate-limiting step in glucose utilization. Here we describe a simple protocol for measuring direct glucose uptake in living melanoma cells by flow cytometry.Cell migration is a critical process involved in morphogenesis, inflammation, and cancer metastasis. BTK pathway inhibitor Wound healing assay is a simple, non-expensive, and highly reproducible method to study cancer cell migration in vitro. It is based on the observation that cells growing in a monolayer migrate to re-establish cell contacts after the development of an artificial wound. The assay involves creation of a wound in a monolayer, image acquisition during wound closure, and comparison of migrated area at initial and final time points.