Cell-SELEX-based selection of ssDNA aptamers for specifically targeting BRAF V600E-mutated melanoma

Malignant melanoma is regarded as the most aggressive form of skin cancer, and is responsible for most death caused by skin cancer. BRAF mutations occur in approximately 40-50% of melanomas, with V600E being the most common mutation. Testing for BRAF mutations and targeted therapy have markedly improved long-term survival for patients with BRAF-mutated melanoma. Here, we report two aptamers, CH1 and CH5 generated by Cell-SELEX, against BRAF V600E-mutated human melanoma cells A375. The two aptamers exhibited high affinity to target cells with low dissociation constants (K_d) in the nanomolar range. Furthermore, the binding of two aptamers to target cells was independent of incubation temperature, and their molecular targets were demonstrated to be membrane proteins on the cell surface. We also demonstrated that aptamer CH1 was able to bind to metastatic colorectal cancer cells harboring BRAF V600E mutation, indicating a relationship between aptamer CH1 and BRAF V600E-related metastatic cancer. Owing to the structure stability and high selectivity to BRAF V600E-mutated targeting cells, aptamer CH1 holds great potential as a molecular probe for the detection of BRAF V600E-mutated metastatic melanoma.