The combined use of 131I-labeled antibody and the hypoxic cytotoxin SR 4233 in vitro and in vivo
Abstract
Radioimmunotherapy is hindered by the slow penetration of antibody molecules into tumors. Cells that are poorly targeted by antibody, because of their distance from feeding blood vessels, receive the lowest radiation dose, and this problem is compounded if there are radioresistant hypoxic cells present. It would be desirable to combine radioimmunotherapy with an agent that is preferentially toxic to these cells. SR 4233 is a potent hypoxic cytotoxin, and it was combined with 131I-NR-LU-10 to treat LS174T human colon adenocarcinoma multicell spheroids and nude mouse xenografts for these studies. Under conditions of severe hypoxia (< 0.01% O2), 2 h of pretreatment or 18 h of simultaneous treatment with SR 4233 did not significantly enhance the effectiveness of 131I-NR-LU-10 in spheroids. However, under aerobic conditions with a 10% fraction of hypoxic cells, there was more toxicity than would be predicted from simple additivity. Xenografts treated with 131I-NR-LU-10 + SR 4233 had a growth delay that was significantly longer than that achieved with 131I-NR-LU-10 alone. In both spheroids and xenografts, combined treatment produced about 10 times more cell killing than 131I-NR-LU-10 alone. The lack of enhancement in spheroids under complete hypoxia suggests that SR 4233 does not sensitize hypoxic cells to radiation damage. The results with aerobic spheroids and in vivo, where a portion of the cells were hypoxic, could be explained by the targeting of different cell populations…
Read the paper
Related studies
- Combining in silico and in vitro approaches to identification of potent inhibitor against phospholipase A2 (PLA2)
- In silico and in vitro studies: investigating the chemical composition, DFT, molecular docking, and dynamic simulation of Satureja candidissima (Munby) Briq essential oil as a potential antibacterial agent
- Quercetin combined with ciprofloxacin and gentamicin inhibits biofilm formation and virulence in Staphylococcus aureus
- In silico study of the mechanism of action, pharmacokinetic and toxicological properties of some N-methylanthranilates and their analogs
- Anticonvulsant Effects of Citronellal, Daidzin, and Phytol, Possibly Through GABAA Receptor and Voltage-Gated Sodium Channel Interaction Pathways: In Vivo and In Silico Studies
- 2-Phenylcyclopropylmethylamine (PCPMA) Derivatives as D3R-Selective Ligands for 3D-QSAR, Docking and Molecular Dynamics Simulation Studies
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.