Synergistic antiproliferative and pro-apoptotic activity of dacarbazine combined with 2-aminoethyl dihydrogen phosphate in melanoma cells

Cutaneous melanoma is an aggressive malignancy characterized by high metastatic potential and resistance to conventional chemotherapeutic regimens. Dacarbazine, an alkylating agent historically used as a first-line drug, exhibits limited clinical efficacy due to the rapid emergence of chemoresistance and concentration-dependent toxicity. The development of rational pharmacological combinations capable of enhancing dacarbazine's cytotoxic potential while reducing collateral damage to healthy cells represents an important therapeutic goal. This study investigated the pharmacodynamic interaction between dacarbazine and the monophosphate ester 2-aminoethyl dihydrogen phosphate (2-AEH₂P), a metabolic modulator with antiproliferative and pro-apoptotic properties, in human (SK-MEL-28) and murine (B16-F10) melanoma cells. Normal fibroblasts (FN1 and L929) were used as non-tumor controls. Cells were treated with both compounds individually and in combination. Cytotoxicity, morphology, cell cycle progression, proliferative activity, mitochondrial membrane potential and apoptosis-related markers were evaluated by MTT assay, microscopy, and flow cytometry. The combined treatment demonstrated a synergistic pharmacological effect, producing greater antiproliferative and pro-apoptotic responses than either compound alone, while maintaining selectivity toward melanoma cells. This was associated with cell cycle arrest in the G2/M phase, reduced proliferative index, and increased expression of caspases, p53, and Bad, alongside downregulation of Bcl-2. In summary, the dacarbazine-2-AEH₂P combination exhibits synergistic pharmacodynamic activity that enhances cytotoxicity through coordinated modulation of proliferative and apoptotic pathways. These findings highlight its potential as a promising strategy to improve chemotherapeutic efficacy and overcome resistance in melanoma treatment.