Nelfinavir induces cytotoxicity towards high-grade serous ovarian cancer cells, involving induction of the unfolded protein response, modulation of protein synthesis, DNA damage, lysosomal impairment, and potentiation of toxicity caused by proteasome inhibition

Abstract

High-grade serous ovarian cancer (HGSOC) is a significant cause of mortality among women worldwide. Traditional treatment consists of platinum-based therapy; however, rapid development of platinum resistance contributes to lower life expectancy, warranting newer therapies to supplement the current platinum-based protocol. Repurposing market-available drugs as cancer therapeutics is a cost- and time-effective way to avail new therapies to drug-resistant patients. The anti-HIV agent nelfinavir (NFV) has shown promising toxicity against various cancers; however, its role against HGSOC is unknown. Here, we studied the effect of NFV against HGSOC cells obtained from patients along disease progression and carrying different sensitivities to platinum. NFV triggered, independently of platinum sensitivity, a dose-dependent reduction of HGSOC cell number and viability, and a parallel increase in hypo-diploid DNA content. Moreover, a dose-dependent reduction of clonogenic survival of cells escaping the acute toxicity was indicative of long-term residual damage. In addition, dose- and time-dependent phosphorylation of gama-H2AX indicated NFV-mediated DNA damage, which was associated with decreased proliferation signals driven by the AKT and ERK pathways. NFV also mediated a dose-dependent increase in endoplasmic reticulum stress-related molecules associated with long-term inhibition of protein synthesis and concurrent cell death; such events were accompanied by a proapoptotic environment, signaled by increased phospho-eIF2-alpha, ATF4, and CHOP, increased Bax/Bcl-2 ratio, and cleaved executer caspase-7. Finally, we show that NFV potentiates the short-term cell cycle arrest and long-term toxicity caused by the proteasome inhibitor bortezomib. Overall, our in vitro study demonstrates that NFV can therapeutically target HGSOC cells of differential platinum sensitivities via several mechanisms, suggesting its prospective repurposing benefit considering its good safety profile.

Auranofin induces lethality driven by reactive oxygen species in high-grade serous ovarian cancer cells

“…We used a pair of cell lines termed PEO1 and PEO4 which have different sensitivities to platinum. For instance, we recently demonstrated that PEO4 cells are about ten times less sensitive to cisplatin than their PEO1 siblings obtained from the same patient earlier during disease evolution [15]. Despite the large difference in platinum sensitivity among the two cell lines (Figures 1A and 1B), both cellular types responded to increased concentrations of auranofin with similar impairment in wellbeing as denoted by the similar decrease in their vitality (Figures 2C and 2D).…”

“…PEO1 cells are epithelial ovarian cancer cells isolated from a patient after its first relapse 22 months following treatment with cisplatin, 5-fluorouracil, and chlorambucil, while the patient was still sensitive to platinum-based chemotherapy; PEO4 cells were subsequently isolated from the same patient after the second relapse in which the patient was no longer sensitive to the chemotherapy. These cell lines were histologically characterized in 1988 and sequenced in 2010 [29,30], whereas we authenticated them in 2020 based on their autosomal short-tandem repeats [15]. The cells were cultured in RPMI 1640 media (Mediatech, Manassas, VA, USA) supplemented with 5% fetal bovine serum (FBS) (Atlanta Biologicals, Lawrenceville, GA, USA), 5% bovine serum (Life Technologies, Auckland, New Zealand), 0.01 mg/mL of human insulin (Roche, Indianapolis, IN, USA), 10 mM HEPES (Corning, Corning, NY, USA), 100 IU penicillin (Mediatech), 100 μg/mL streptomycin (Mediatech), 2 mM L-Alanyl-L-Glutamine 6 (Glutagro TM , Corning) and 1 mM sodium pyruvate (Corning).…”

“…Cell cycle analysis was completed using the Muse® micro-capillary cytometer (Millipore). This method was described previously in detail [15].…”

“…For instance, our laboratory has shown that the antiprogesterone/anti-glucocorticoid agent mifepristone is efficient as upfront therapy or after cisplatin and/or paclitaxel therapy against ovarian cancer cells [5,[11][12][13][14]. We have also shown the efficacy of the HIV inhibitor nelfinavir against ovarian cancer cells sensitive or resistant to platinum [15]. Here, we are adding auranofin, a gold complex approved in 1985 to treat rheumatoid arthritis [16] to the list of anti-ovarian cancer drugs emerging from repurposing auranofin.…”

Drug repositioning and ovarian cancer, a study based on Mendelian randomisation analysis

“…Currently, there are many related reports on the role of drug repositioning in ovarian cancer treatment ( 4 , 5 ), such as lipid-lowering drug statins ( 6 ), glucose-lowering drug metformin ( 7 ), antiarrhythmic drug amiodarone ( 8 ), neuroprotective drugs ( 9 ), ACEI for hypertension ( 10 ), disulfiram for chronic alcoholism anti-inflammatory ( 11 , 12 ), anti-bacterial ( 13 , 14 ), anti-viral ( 15 ), and anti-parasitic drugs ( 16 , 17 ) as well as calcium-channel blockers ( 18 ), have all shown different anti-ovarian cancer effects. However, there were huge differences in the specific results.…”