Abstract Gold nanoparticles have gained increasing interest because of their unique optical properties. Among different shapes of nanoparticles, gold nanoparticles (Au-NPs) with non-spherical shape, such as gold nanorods (Au-NR), are gaining particular attention for various applications because of their facile synthesis and modification. They can be conjugated with different molecules for biomedical applications, such as tumor imaging and therapy. Previously, we have shown that small sized Au-NPs possess distinct effects depending on the treatment modality; they protect against x-ray induced apoptosis while enhancing apoptosis induced by ultrasound and helium based cold atmospheric plasma. Therefore, this study is intended to investigate the effects of Au-NR, on x-ray (2.5 Gy) induced apoptosis as well as mediating molecular pathways in MOLT 4 cells in-vitro. The effect of Au-NR on x-ray induced apoptosis was determined by observing the changes in intracellular reactive oxygen species (ROS) formation and apoptotic signalling pathways. The results indicate that cells pre-treated with 10 nm size of Au-NR at a dose of 0.1 and 0.5 μg significantly enhanced apoptosis. Typical morphological changes were observed by using Giemsa staining which shows the enhanced apoptotic cell death in combination treatment. Loss of mitochondrial membrane potential, glutathione and intracellular calcium ion level was significantly enhanced; observed by using flow cytometry. Furthermore, western blot analysis was employed to determine the expression of caspase-3, and Bcl-2 family proteins. In this study we have shown for the first time that in combination treatment, Au-NR significantly enhanced the low dose of x-ray-induced apoptotic cell death. Our finding indicates that the combination treatment of cancer will be emerged as a critical approach to achieve remarkable anticancer effects. Citation Format: Paras Jawaid, Mati Ur Rehman, Azhar Hussain Rajabali, Ather Enam. Redox modulation by gold nanorods enhances radiosensitivity in MOLT 4 cells abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4639.
Jawaid et al. (Fri,) studied this question.