Background <p>Globally, colorectal cancer (CRC) stands as the second most lethal malignancy. Chemotherapeutic drugs have shown some limitations, including systemic toxicity and non-specificity. Nanocarriers such as chitosan/gold nanoparticles (CS/Au NPs) facilitate drug localization at tumor sites, thereby reducing off-target adverse effects.</p> Methods <p>Doxorubicin-loaded CS/Au NPs were synthesized, and their physicochemical properties were analyzed using Fourier transform infrared (FT-IR) spectroscopy and dynamic light scattering (DLS). HCT116 cells were treated with both free doxorubicin and CS/Au-DOX NPs. In vitro cytotoxic effects were evaluated using the MTT assay. Additionally, apoptosis induction, cell cycle arrest, and cellular uptake assay were examined by flow cytometry. The scratch assay used to evaluate the effect of CS/Au-DOX NPs on the cell migration potential of HCT116, and the expression levels of CLMAT3 and ZNRD1-AS1 were determined by qRT-PCR.</p> Results <p>CS/Au-DOX NPs exhibited high encapsulation efficiency (78%) with favorable nanoscale properties, and were markedly more potent than free doxorubicin against HCT116 cells (IC₅₀ 0.5 vs. 3 µM). Flow cytometry revealed significant apoptosis induction, G2/M arrest, and enhanced cellular uptake in HCT116 following treatment with CS/Au-DOX NPs. These NPs also reduced the migration potential of CRC cells. In CRC tissues, CLMAT3 and ZNRD1-AS1 were upregulated, with CLMAT3 overexpression associated with lymph node metastasis, while both lncRNAs showed limited diagnostic value. Notably, CS/Au-DOX NPs downregulated CLMAT3 and ZNRD1-AS1 expression in HCT116 cells.</p> Conclusion <p>CS/Au-DOX NPs substantially enhanced the anticancer efficacy of DOX in the HCT116 cell line. Furthermore, CLMAT3 and ZNRD1-AS1 exhibited only limited utility as diagnostic biomarkers in CRC, suggesting that their clinical applicability in early detection may be restricted.</p>