The role of proteasome inhibitor MG132 in cisplatin resistant ovarian cancer

Platinum based combined chemotherapy have been proved to be the most effective drugs for the ovarian cancer treatment, but it is difficult to treat cisplatin resistant ovarian cancer. Carbobenzoxy-L-leucy-L-Leucyl-L-Leucinal (MG132) is a reversible tripeptide aldehyde proteasome inhibitor, the purpose of this study was to observe the effect of MG132 on cisplatin resistant ovarian cancer SKOV3 cell and OVCAR-3 cell the expression of autophagy and apoptosis related factors. The cells were divided into four groups: control, MG132, cisplatin, MG132 and cisplatin combination groups. Cell growth was detected by cell counting kit-8 (CCK-8) assay. The apoptotic rates of cells and the cell cycle were detected by a flow cytometer (FCM). The Beclin1, Light chain 3 (LC3) and Caspase3 was detected by western blotting and reverse transcription-polymerase chain reaction (RT-PCR). Detection of apoptotic bodies by 4,6-Diamidino-2-phenylindole dihydrochloride (DAPI) staining. CCK-8 assay demonstrated that cell survival rate in the combination groups was lower than monotherapy group. FCM showed that apoptotic rates in the combination groups was higher than monotherapy group (p < 0.05). Western blotting and RT-PCR detected that Beclin1, LC3 and Caspase3 in the combination group were higher than monotherapy group (p < 0.05). DAPI staining showed the production of apoptotic bodies in the combination group and MG132 group. In conclusion, MG132 can inhibit the growth of cisplatin resistant ovarian cancer SKOV3 and OVCAR-3 cells, its inhibitory effect is related to apoptosis and autophagy, and it is expected to be a synergistic antitumor effect with cisplatin.

MG132; Cisplatin; Resistant ovarian cancer; Apoptosis; Autophagy

[1] Siegel RL, Miller KD, Jemal A. Cancer statistics, 2017. CA: A Cancer Journal for Clinicians. 2017; 67: 7–30.

[2] Maringe C, Walters S, Butler J, Coleman MP, Hacker N, Hanna L, et al. Stage at diagnosis and ovarian cancer survival: evidence from the international cancer benchmarking partnership. Gynecologic Oncology. 2012; 127: 75–82.

[3] Chan JK, Chow S, Bhowmik S, Mann A, Kapp DS, Coleman RL. Metastatic gynecologic malignancies: advances in treatment and management. Clinical & Experimental Metastasis. 2018; 35: 521–533.

[4] Tossetta G, Fantone S, Montanari E, Marzioni D, Goteri G. Role of NRF2 in ovarian cancer. Antioxidants. 2022; 11: 663.

[5] Jarome TJ, Devulapalli RK. The ubiquitin-proteasome system and memory: moving beyond protein degradation. The Neuroscientist. 2018; 24: 639–651.

[6] Zwickl P, Voges D, Baumeister W. The proteasome: a macromolecular assembly designed for controlled proteolysis. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences. 1999; 354: 1501–1511.

[7] Konstantinova IM, Tsimokha AS, Mittenberg AG. Role of proteasomes in cellular regulation. International Review of Cell and Molecular Biology. 2008; 36: 59–124.

[8] Klionsky DJ. The molecular machinery of autophagy: unanswered questions. Journal of Cell Science. 2005; 118: 7–18.

[9] Lu K, den Brave F, Jentsch S. Pathway choice between proteasomal and autophagic degradation. Autophagy. 2017; 13: 1799–1800.

[10] Herman-Antosiewicz A, Johnson DE and Singh SV. Sulforaphane causes autophagy to inhibit release of cytochrome C and apoptosis in human prostate cancer cells. Cancer Research. 2006; 66: 5828–5835.

[11] Liang XH, Jackson S, Seaman M, Brown K, Kempkes B, Hibshoosh H, et al. Induction of autophagy and inhibition of tumorigenesis by Beclin 1. Nature. 1999; 402: 672–676.

[12] Liang XH, Kleeman LK, Jiang HH, Gordon G, Goldman JE, Berry G, et al. Protection against fatal sindbis virus encephalitis by Beclin, a novel Bcl-2-interacting protein. Journal of Virology. 1998; 72: 8586–8596.

[13] Kabeya Y. LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing. The EMBO Journal. 2000; 19: 5720–5728.

[14] Wu J, Dang Y, Su W, Liu C, Ma H, Shan Y, et al. Molecular cloning and characterization of rat LC3a and LC3B—two novel markers of au-tophagosome. Biochemical and Biophysical Research Communications. 2006; 339: 437–442.

[15] Lichter DI, Danaee H, Pickard MD, Tayber O, Sintchak M, Shi H, et al. Sequence analysis of beta-subunit genes of the 20S proteasome in patients with relapsed multiple myeloma treated with bortezomib or dexamethasone. Blood. 2012; 120: 4513–4516.

[16] Liebermann DA, Hoffman B, Vesely D. P53 induced growth arrest versus apoptosis and its modulation by survival cytokines. Cell Cycle. 2007; 6: 166–170.

[17] Goldberg AL. Development of proteasome inhibitors as research tools and cancer drugs. Journal of Cell Biology. 2012; 199: 583–588.

[18] Laussmann MA, Passante E, Düssmann H, Rauen JA, Würstle ML, Delgado ME, et al. Proteasome inhibition can induce an autophagy-dependent apical activation of caspase-8. Cell Death & Differentiation. 2011; 18: 1584–1597.

[19] Campagna R, Bacchetti T, Salvolini E, Pozzi V, Molinelli E, Brisigotti V, et al. Paraoxonase-2 silencing enhances sensitivity of A375 melanoma cells to treatment with cisplatin. Antioxidants. 2020; 9: 1238.

[20] Guo N, Peng Z, Zhang J. Proteasome inhibitor MG132 enhances sensitivity to cisplatin on ovarian carcinoma cells in vitro and in vivo. International Journal of Gynecologic Cancer. 2016; 26: 839–844.

[21] Wang J, Zhou J, Wu GS. Bim protein degradation contributes to cisplatin resistance. Journal of Biological Chemistry. 2011; 286: 22384–22392.

[22] Tenev T, Marani M, McNeish I, Lemoine NR. Pro-caspase-3 overexpression sensitises ovarian cancer cells to proteasome inhibitors. Cell Death and Differentiation. 2001; 8: 256–320.