To date, several multifunctional diagnostic and therapeutic nanostructures (NSs) have been developed by conjugating various imaging probes and targeting agents, including antibodies Abs/aptamers (Aps) and enzymes. The current investigation introduced an advanced and effective therapeutic nano-biosystem composed of gold nanoparticles (GNPs) conjugated with anti-EGFR monoclonal antibody cetuximab (Cet).

The GNPs were synthesized and conjugated with Cet. The physicochemical properties of the engineered nano-biosystem (GNP-Cet) were characterized. Then, its biological impacts, including cell viability and apoptosis, were evaluated in the colorectal cancer SW-480 cells. The apoptosis-related genes AKT, PTEN, and Caspase 3 expression were analyzed using real-time PCR.

The GNP-Cet nano-biosystem induced cytotoxicity and apoptosis in SW-480 cells. Besides, GNP-Cet was able to upregulate PTEN, caspase 3, and downregulate AKT, indicating their key influence in the induction of apoptosis and overcoming resistance to Cet in KRAs mutant SW-480 cancer cells.

Our findings revealed that the engineered nano-biosystem could inhibit cell proliferation and induce apoptosis in CRC cells resistant to anti-EGFR monoclonal antibodies. Thus, the GNP-Cet nano-biosystem can be considered a novel treatment modality for CRC and other solid tumors.