Document Type: Research Articles
Department of Biochemistry and Molecular Biology, VNU University of Science, Vietnam National University, Vietnam.
Unit of Therapeutic Chemistry and Pharmacognosy, University of Mons (UMONS), Belgium.
Institute of Chemistry and Environment, High Command of Chemistry, Ministry of National Defense, Vietnam.
The Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Vietnam National University, Vietnam.
Background: Ricin has been reported as a potential chemical for cancer treatment. However, so far, the application
of ricin in cancer treatment is very limited because of its non-specificity. Methods: In this study, ricin were conjugated/
encapsulated with DOTAP/DOPE liposome to form ricin-liposome complexes (ricin-lipososme1, ricin-liposome2,
ricin-liposome3 and ricin-liposome4). Characteristics of ricin-liposome complexes were analyzed and their effects on
survival, apoptosis, migration, invasion and tumor formation of SKMEL-28 melanoma cells were examined by carrying
out the MTT assay, apoptosis assay, scratch wound healing assay, invasion assay and soft-agar colony formation assay,
respectively. Results: Ricin-liposome complexes had even size-distribution with average size of around 340 nm. These
ricin-liposome complexes were able to penetrate into the cells via endocytosis with the highest ability of the ricinliposome3.
It also showed that ricin-liposome3 expressed very high toxicity with the IC50 of 62.4 ng/mL and followed
by ricin-liposome4 (286.4 mg/mL), ricin-liposome2 (417.5 ng/mL), and ricin-liposome1 (604.3 ng/mL) to SKMEL-28
cells at 36 hours post treatment. At the concentrations of IC10 (10.1 ng/mL), ricin-liposome3 strongly induced necrosis
and apoptosis of SKMEL-28 cells up to 25.6% and 11.4%, respectively. Moreover, ricin-liposome3 expressed great
anticancer properties by decreasing the migration, invasion and tumor formation abilities of SKMEL-28 cells of 7.5
folds, 4.3 folds and 5.9 folds, respectively, compared with those of control SKMEL-28 cells. Conclusion: The obtained
results from our study suggest that although ricin is listed as one of the most poisonous substances in nature, it can be
used in the complex forms with liposome to increase its specificity to apply in treatment of melanoma and other cancers.