Efeito antitumoral da berberina em linhagem de células SK-MEL-28 de melanoma

Abstract

Melanoma is the most aggressive form of skin cancer, having high metastatic power, responsible for causing the majority (75%) of skin-related deaths. The metastatic power of tumor cells is a major challenge for therapeutic agents, since metastasis is the main cause of cancer-related death, due to cellular reprogramming, extravasation and invasive dissemination, promoting the growth of tumors in distant tissues. Berberine (BBR), an isoquinoline alkaloid, is a compound found in plants such as Coptis chinensis and Berberis aristata that has shown antitumor properties, in addition to decreasing the toxicity caused by chemotherapy. Thus, the objective of the study was to investigate the antitumor mechanisms of BBR in the human melanoma cell line SK-MEL-28. For this, cell viability was initially used by the MTT assay, in which SK-MEL-28 cells were treated at different concentrations of BBR (10, 25, 50, 75, 100, 150, 200 and 250 μM) and times (24, 48 and 72 hours) to determine the IC50. After that, analyzes of cell death, DNA damage index and cell cycle were performed, as well as quantification of proteins involved in apoptosis. Furthermore, analyzes of antioxidant activity, levels of reactive oxygen species (ROS) and cytokines were performed. Additionally, the ability to migrate was evaluated, as well as the activity and expression of components of the purinergic system against treatment with BBR and the concomitant or isolated use of the AMPK inhibitor (iAMPK). The results showed that BBR promotes a decrease in cell viability after 24 hours and the IC50 defined as 50 μM, causes an increase in the cellular DNA damage index, an increase in the number of cells with arrest in the G1/G0 phase of the cell cycle, increase in reactive oxygen species (ROS) and proteins linked to apoptosis in SK-MEL-28 cells. In addition, BBR induces apoptosis of melanoma cells and increases in anti- and pro-inflammatory cytokines. In addition, this compound influences the migration capacity, modifying the structure and adhesion of human melanoma cells, whereas iAMPK influences only the migration capacity. No changes were observed in the expression of NTPDase (CD39) and 5′-nucleotidase (CD73), but in 24 hours of treatment with BBR, there was an inhibition in the hydrolysis of ATP, ADP and AMP nucleotides. Finally, both iAMPK and BBR treatment concomitantly with iAMPK resulted in a reduction in nucleotide hydrolysis. It is important to emphasize that the results of this study are important, since human melanoma has a high metastatic capacity and mortality, which makes research with natural compounds an important ally of integrative medicine. We emphasize that in vivo studies such as clinical trials are needed to better demonstrate the effects of BBR, given the complexity of body metabolism.