The melanoma origin of cell lines obtained from the axillary lymph node (mel Kas, mel Pet, and mel Lap from patients with a verified diagnosis) was confirmed by the detection of the Melan A melanocyte marker expression. A hyperdiploid (2n+) for the mel Kas line; near-diploid (2n), and in some cells near-tertaploid (4n), and even hypo-octaploid (8n) set (172–179 chromosomes) in the mel Pet cell line; and a hypotetraploid (4n−) for the mel Lap line were detected by karyotypic analysis. All three cell lines are tumorigenic; however, mel Pet demonstrates tumor growth in Balb/c nude mice only in the presence of matrigel. All three lines showed a high expression of TUBB3 and PD-L1 markers, while ERa was low (minimum for mel Pet). Significant differences in the expression level were shown for the Cyt molecular marker. In the transplantation of cells to Balb/c nude mice, a stable expression level is observed only for TUBB3. For the rest of the markers, a decrease in their expression level of varying degrees was noted when the cells were growing in solid tumors in vivo. Mutations were detected in oncogenes (BRAF, EZH2, KIT, KRAS, NRAS, ROS1) and tumor suppressor genes (CDKN2A, FAT4, KMT2C, LRP1B, PTEN, PTPRB, TP53). The detailed characterization of the cell lines makes them valuable for various scientific and regulatory experiments, particularly those involving preclinical data on antiproliferative drugs for malignant melanoma or investigations into melanoma cell properties and progression.

Optimizing the composition of an agroinfiltration solution is one way to boost the efficiency of the transient expression of the target protein in plants b

The use of cytokines as anticancer drugs is limited due to their toxicity. It is possible to reduce toxicity and to increase the therapeutic index by using cytokines in the form of conjugates with antibodies – immunocytokines. The results of preclinical studies have shown increased efficacy and reduced toxicity of various immunocytokines compared to the original, unconjugated cytokines. The potential of immunocytokines as anticancer agents is currently being studied in clinical trials. The therapeutic efficacy of immunocytokines depends on their physicochemical parameters, which determine the in vivo biodistribution, and biological activity as a result of the mechanisms of the antibody action and cytokine sites incorporated in the design. There is a need for methods that allow to assess the biological activity of both individual sites and the entire immunocytokine molecule when characterizing immunocytokines at an early stage of research.This review considers the existing approaches for assessing the biological activity of immunocytokines in vitro in the course of preclinical studies, such as monolayer cultures, reporter cell lines, co-cultures, three-dimensional (3D) tumor models. Monolayer cultures are sufficient to confirm the mechanism of action of separate sites of immunocytokines used in the design, and the “gold standard” test systems for determining the specific biological activity of the cytokine and the effector functions of the antibody site remain in demand. Commercial reporter cell lines remain an alternative option for assessing the biological activity of cytokine and antibody sites at the level of activation of signaling pathways. Co-cultures of tumor and effector cells make it possible to evaluate the cytotoxic and immunomodulatory effects of antibody and cytokine sites without using 3D cultivation methods. The use of 3D tumor models makes it possible to replace several tests for the biological activity of separate sites of immunocytokines conducted on monolayer cultures and co-cultures with one comprehensive study, however, such models require significant time and material costs.

Background. Plasma circulating tumor DNA (ctDNA) is a potential marker for tumor process monitoring. However, the feasibility of using mouse syngeneic subcutaneous melanoma model to assess ctDNA levels remains unclear.Aim. To evaluate the feasibility of ctDNA detection in mouse B16-F10 melanoma model using droplet digital polymerase chain reaction (ddPCR).Materials and methods. We developed and validated a ddPCR assay to quantify plasma ctDNA from B16-F10 cells. To form experimental tumors, C57Bl6 mice were inoculated with B16-F10 cells. On the first, 7th, 14th , 21st days after tumor inoculation blood was collected by retroorbital sinus puncture. ctDNA was extracted from blood plasma. On the 21st day after tumor inoculation mice were sacrificed.Results. We validated a ddPCR assay to quantify plasma ctDNA in B16-F10 melanoma syngeneic model in C57Bl6 mice. The assay linear range was 0.5–32 copies/ul, R2 = 0.997. The empirical limit of detection of ctDNA was 1 copy/ul in 5 ng normal tissue genomic DNA background. The coefficient of variation values ranged from 44.5 % (1 copy/ul) to 16.6 % (16 copies/ul). Plasma ctDNA was detected on 21st day after tumor inoculation in B16-F10 melanoma syngeneic subcutaneous model (p = 0.004). ctDNA concentration positively correlated with tumor volume (ρ = 0.95, p = 0.05) and total circulating DNA concentration (ρ = 1, p = 0.0).Conclusion. B16-F10 melanoma syngeneic subcutaneous model in C57Bl6 mice can be used to monitor cDNA in studies of new approaches for melanoma treatment.