1 National Institute of Genetic Engineering, Genetics and Biotechnology, Medical Biotechnology Research Institute, Department of Molecular Medicine, Karaj, Iran

Background: Due to the heterogeneity of breast cancer, most advanced-stage patients are resistant to therapy. Disruption of SUMOylation, a post-translational modification, is linked to breast cancer.
Objective: This study aimed to assess the impact of thymoquinone nanoparticles (Liposomal-TQ), an anti-cancer
drug, combined with doxorubicin (DXR), the most effective chemotherapeutic drug used to treat breast cancer, on
the expression of SENP2 and SENP6, two major components involved in the SUMOylation process, in normal and
cancerous breast cell lines.
Materials and Methods:  The MCF7 cell line, a breast cancer cell line, and MCF10, a non-tumor epithelial cell line, were
separately treated with Liposomal-TQ and DXR. Cell viability and cell migration were assessed using MTT and scratch
tests. Apoptosis analysis was performed using annexin-V/PI staining. Gene expression analysis of SENP2 and SENP6 was
conducted using quantitative real-time PCR (RT-qPCR). Additionally, the scratch test evaluated the anti-cell migratory
effect of Liposomal-TQ.

Results: The findings obtained from RT-qPCR analysis indicated a significant increase in the expression of SENP2 and
SENP6 genes in the TQ and DXR treatment groups compared to the control group in MCF7 but not in MCF10 cell lines
(p-value < 0.05). Also, after 24 hours of treatment of MCF7 and MCF10 cells with liposomal-TQ, late apoptotic cells
were significantly increased compared to the control and liposome groups (p-value < 0.0001) and compared to the control group, both DXR and Liposomal-TQ dramatically reduced the migratory ability of breast cancer cells (p-value = 0.001
and p-value = 0.001, respectively)
Conclusion:  Our study indicated that Liposomal-TQ promotes apoptosis in breast cancer cells and inhibits cell migration
ability. These findings enhance our understanding of the role of Liposomal-TQ in the carcinogenic activities of SENP2
and SENP6 in the SUMOylation pathway of breast cancer.