| 1. |
- Colombo, Diego, et al.
(författare)
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Caffeic acid phenethyl ester targets ubiquitin-specific protease 8 and synergizes with cisplatin in endometrioid ovarian carcinoma cells
- 2022
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Ingår i: Biochemical Pharmacology. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0006-2952 .- 1356-1839 .- 1873-2968. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- Deubiquitinases (DUBs) mediate the removal of ubiquitin from diverse proteins that participate in the regulation of cell survival, DNA damage repair, apoptosis and drug resistance. Previous studies have shown an association between activation of cell survival pathways and platinum-drug resistance in ovarian carcinoma cell lines. Among the strategies available to inhibit DUBs, curcumin derivatives appear promising, thus we hypothesized their use to enhance the efficacy of cisplatin in ovarian carcinoma preclinical models. The caffeic acid phenethyl ester (CAPE), inhibited ubiquitin-specific protease 8 (USP8), but not proteasomal DUBs in cell-free assays. When CAPE was combined with cisplatin in nine cell lines representative of various histotypes a synergistic effect was observed in TOV112D cells and in the cisplatin-resistant IGROV-1/Pt1 variant, both of endometrioid type and carrying mutant TP53. In the latter cells, persistent G1 accumulation upon combined treatment associated with p27(kip1) protein levels was observed. The synergy was not dependent on apoptosis induction, and appeared to occur in cells with higher USP8 levels. In vivo antitumor activity studies supported the advantage of the combination of CAPE and cisplatin in the subcutaneous model of cisplatin-resistant IGROV-1/Pt1 ovarian carcinoma as well as CAPE activity on intraperitoneal disease. This study reveals the therapeutic potential of CAPE in cisplatin-resistant ovarian tumors as well as in tumors expressing USP8.
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| 2. |
- Corno, Cristina, et al.
(författare)
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The deubiquitinase USP8 regulates ovarian cancer cell response to cisplatin by suppressing apoptosis
- 2022
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Ingår i: Frontiers in Cell and Developmental Biology. - : FRONTIERS MEDIA SA. - 2296-634X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The identification of therapeutic approaches to improve response to platinum-based therapies is an urgent need for ovarian carcinoma. Deubiquitinases are a large family of ubiquitin proteases implicated in a variety of cellular functions and may contribute to tumor aggressive features through regulation of processes such as proliferation and cell death. Among the subfamily of ubiquitin-specific peptidases, USP8 appears to be involved in modulation of cancer cell survival by still poorly understood mechanisms. Thus, we used ovarian carcinoma cells of different histotypes, including cisplatin-resistant variants with increased survival features to evaluate the efficacy of molecular targeting of USP8 as a strategy to overcome drug resistance/modulate cisplatin response. We performed biochemical analysis of USP8 activity in pairs of cisplatin-sensitive and -resistant cells and found increased USP8 activity in resistant cells. Silencing of USP8 resulted in decreased activation of receptor tyrosine kinases and increased sensitivity to cisplatin in IGROV-1/Pt1 resistant cells as shown by colony forming assay. Increased cisplatin sensitivity was associated with enhanced cisplatin-induced caspase 3/7 activation and apoptosis, a phenotype also observed in cisplatin sensitive cells. Increased apoptosis was linked to FLIPL decrease and cisplatin induction of caspase 3 in IGROV-1/Pt1 cells, cisplatin-induced claspin and survivin down-regulation in IGROV-1 cells, thereby showing a decrease of anti-apoptotic proteins. Immunohistochemical staining on 65 clinical specimens from advanced stage ovarian carcinoma indicated that 40% of tumors were USP8 positive suggesting that USP8 is an independent prognostic factor for adverse outcome when considering progression free survival as a clinical end-point. Taken together, our results support that USP8 may be of diagnostic value and may provide a therapeutic target to improve the efficacy of platinum-based therapy in ovarian carcinoma.
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| 3. |
- Girgis, Adel S., et al.
(författare)
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Synthesis and bio-properties of 4-piperidone containing compounds as curcumin mimics
- 2022
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 12:48, s. 31102-31123
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Forskningsöversikt (refereegranskat)abstract
- The broad spectrum of curcumins beneficial properties has encouraged medicinal researchers to investigate its therapeutic efficacy against diverse diseases. The clinical potential of curcumin is, however limited due to its poor pharmacodynamic/pharmacokinetic properties (such as low solubility, pH instability, poor absorption in circulation, rapid elimination from the body and photochemical degradation). 3,5-Bis(ylidene)-4-piperidone scaffolds are considered a curcumin mimic that exhibit diverse bio-properties. The current review provides a brief overview of these mimics and highlights biological activities relevant to drug development.
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| 4. |
- Gubat, Johannes, 1986-, et al.
(författare)
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Comprehensive Target Screening and Cellular Profiling of the Cancer-Active Compound b-AP15 Indicate Abrogation of Protein Homeostasis and Organelle Dysfunction as the Primary Mechanism of Action
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Dienone compounds have been demonstrated to display tumor-selective anti-cancer activity independently of the mutational status of TP53. Previous studies have shown that cell death elicited by this class of compounds is associated with inhibition of the ubiquitin-proteasome system (UPS). Here we extend previous findings by showing that the dienone compound b-AP15 inhibits proteasomal degradation of long-lived proteins. We show that exposure to b-AP15 results in increased association of the chaperones VCP/p97/Cdc48 and BAG6 with proteasomes. Comparisons between the gene expression profile generated by b-AP15 to those elicited by siRNA showed that knock-down of the proteasome-associated deubiquitinase (DUB) USP14 is the closest related to drug response. USP14 is a validated target for b-AP15 and we show that b-AP15 binds covalently to two cysteines, Cys203 and Cys257, in the ubiquitin-binding pocket of the enzyme. Consistent with this, deletion of USP14 resulted in decreased sensitivity to b-AP15. Targeting of USP14 was, however, found to not fully account for the observed proteasome inhibition. In search for additional targets, we utilized genome-wide CRISPR/Cas9 library screening and Proteome Integral Solubility Alteration (PISA) to identify mechanistically essential genes and b-AP15 interacting proteins respectively. Deletion of genes encoding mitochondrial proteins decreased the sensitivity to b-AP15, suggesting that mitochondrial dysfunction is coupled to cell death induced by b-AP15. Enzymes known to be involved in Phase II detoxification such as aldo-ketoreductases and glutathione-S-transferases were identified as b-AP15-targets using PISA. The finding that different exploratory approaches yielded different results may be explained in terms of a “target” not necessarily connected to the “mechanism of action” thus highlighting the importance of a holistic approach in the identification of drug targets. We conclude that b-AP15, and likely also other dienone compounds of the same class, affect protein degradation and proteasome function at more than one level.
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