Antiproliferative and apoptotic activities of sequence-specific histone acetyltransferase inhibitors

The p53 protein, recognized as the guardian of the genome, plays a pivotal role in suppressing tumor formation. The TP53 gene, which encodes the p53 protein, is commonly subject to mutations and deletions in many cancer types resulting in loss of tumor suppressor activity. A significant proportion of patients diagnosed with lung, pancreatic, ovarian, and head and neck cancers exhibit the expression of mutant p53 in their tumors, correlating with unfavorable prognosis and survival outcomes.This study endeavors to assess the efficacy of therapeutic tumor suppressive mRNA which induces expression of wild-type p53 protein across diverse cancer types. Optimization of the 5’ and 3’ untranslated regions (UTRs) and the 5’ cap has been undertaken to enhance the efficient expression of p53 mRNA. The growth inhibitory potential of p53 mRNA therapy has been evaluated across p53 mutant cancer cell lines representing various cancer origins, along with normal or p53 wild-type cancer cell lines. We have substantiated that the p53 mRNA therapeutics can selectively inhibit the proliferation of p53 mutant cancer cells. Furthermore, we have confirmed that p53 mRNA treatment upregulated modulator of apoptosis (PUMA) and B-cell translocation gene 2 (BTG2) and cell cycle arrest via p21 upregulation. In vivo efficacy assessments of the lipid nanoparticle (LNP)-encapsulated p53 mRNA have been conducted in lung, pancreatic, and ovarian cancer xenograft models. Both regional intratumoral (i.t) and systemic intravenous (i.v) administrations of the p53 mRNA therapeutics have shown substantial suppression of tumor growth, leading to prolonged mouse survival. These results underscore the potential of the p53 mRNA therapeutics as a promising avenue for targeted cancer treatment, offering insights into the selective inhibition of p53 mutant cancer cells. Citation Format: Yong Ho Heo, Seung-Hyun Shin, Youngjin Han, Chang Gyu Lim, Innah Kim, Ji Hee Lee, Gunwoo Lee, Seongju Jeong, Yunjae Kim, Jooyun Byun, Daejin Kim, In Young Choi. Unleashing the power of p53 mRNA therapeutics to suppress proliferation of p53 mutant tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB048.

Purpose : This study aimed to evaluate the possible cytotoxic activity of the essential oil of the Eugenia uniflora leaves on normal and tumoral human cells by colorimetric cell viability assay, based on the use of tetrazolium salt (XTT). Methods : To achieve the cytotoxicity it was used normal human lung fibroblast cell line GMO7492A and the evaluation of antiproliferative activity was performed on three tumor cell lines, as follows: human glioblastoma (MO59J), human cervical adenocarcinoma (HeLa) and human breast adenocarcinoma (MCF-7). For the determination of cytotoxic concentration to the normal line, 12 concentrations were evaluated being from 2.44 to 5000 µg/mL. In the evaluation of antiproliferative activity were tested 8 different concentrations of the extract (3.91 to 500 µg/mL). Results : The results in the normal line GM07492A showed that concentrations higher or equal to 39.1 µg/mL are significantly different of the negative control. In the evaluation of antiproliferative activity on tumor cell lines MO59J, HeLa and MCF-7 was observed that the concentration of 125 µg/mL showed a cytotoxic effect on these lines being significantly different from the negative control. The results from the evaluation of the antiproliferative activity in different tumor cell lines of E. uniflora oil was not selective for the tested cell types. Conclusion : E. uniflora oil did not show cytotoxic activity in concentrations lower than 39.1 µg/mL, however, the values found to IC 50 for tumor cells were superior, concluding that the oil has no selectivity for tumor cells tested.

BackgroundWithout doubt, natural products have been, and still are, the cornerstone of the health care armamentarium. Of all natural sources, the marine environment is clearly the last great frontier for pharmaceutical and medical research.MethodsThis work progresses in the direction of identifying component(s) from the Mediterranean sponge, Spongia officinalis with pharmacological activities. In the present study we investigated the efficacy of methanol extract and its semi-purified fractions (F2, F3) from Spongia officinalis for their in vivo anti-inflammatory activity using the carrageenan-induced paw edema in rats and their in vitro antiproliferative effects by their potential cytotoxic activity using the MTT colorimetric method and clonogenic inhibition against three human cancer cell lines (A549, lung cell carcinoma, HCT15, colon cell carcinoma and MCF7, breast adenocarcinoma).ResultsThe fractions F2 and F3 showed interesting anti-inflammatory and antiproliferative activities in a dose dependent manner.ConclusionsThe present study indicates that the methanolic extrac and its fractions from Spongia officinalis are a significant source of compounds with the antiproliferative and anti-inflammatory activities, and this may be useful for developing potential chemopreventive substances.

In this work, we evaluated the antiproliferative and anti-inflammatory activities of two diosgenin prodrugs. The prodrugs were obtained by esterification of diosgenin at position 3 with 4-oxo-4-(prop-2-yn-1-yloxy)butanoic acid followed by click reaction on terminal alkyne with 3-azidopropan-1-ol N-alkylated dendrons, resulting in a prodrug with methyl ester end-groups and a derivative with tert-butyl ester end-groups, hydrolysis of tert-butyl ester derivative afforded a prodrug with carboxylic acid terminals. All compounds were fully characterized by 1H and 13C NMR, ATR-FTIR and HR-ESI TOF. Studies of the anti-inflammatory effects on mouse ear edema of prodrugs methyl ester and carboxylic acid, ended, using diosgenin and dexamethasone as positive controls, showed the superiority of methyl ester ended prodrug with an ED50 four times lower than that of dexamethasone. Further, carboxylic acid ended prodrug was found to be more active than diosgenin as an antiproliferative agent, according to crystal violet assay. Diosgenin was transformed to ester and acid prodrugs through succinic ester and a 1,2,3-triazole linkers. The prodrug with methyl ester terminals was four times more active than dexamethasone as anti-inflammatory compound, while prodrug with carboxylic acid terminals improved antiproliferative activity over MCF-7 cells.

Background High-throughput drug screening and computational methods to associate genomic features of cell lines to drug sensitivity are valuable tools for predicting biomarkers of sensitivity. In addition, integrating genomic features to expression-based patterns could improve biomarker prediction and patient stratification. Particularly weighted gene co-expression networks represent an effective approach to identify key modules and possible biological mechanisms of sensitivity. Using a combination of cell panel screening and gene co-expression networks, we predicted markers of sensitivity to ASTX295 (MDM2i) in cancer cell lines and confirmed expression-based signatures in publicly available clinical datasets. Method ASTX295 was screened in a panel of 210 p53 wild-type cancer cell lines derived from a range of tumor tissues. ANOVA was used to identify significant associations of genomics features of cell lines to drug response. Transcriptomics profiling of apoptotic and non-apoptotic patient-derived cell lines was performed and significant differentially expressed genes were identified. Further, pathway enrichment and expression-based signatures identified in cell lines were further confirmed in TCGA patient data using weighted gene co-expression network analysis (WGCNA). Expression modules identified by WGCNA were correlated to genomic features and clinical parameters to identify potentially clinically relevant biomarkers. Results Analysis of the cell panel data identified CDKN2A loss as a statistically significant biomarker predictive of sensitivity to ASTX295. As mesothelioma is one of the indications with high prevalence of loss of CDKN2A, the anti-proliferative activity of ASTX295 was further confirmed in an independent panel of p53 wild-type, patient-derived mesothelioma cell lines. Further, pathway and transcriptional regulator analysis identified the Interferon signalling as significantly enriched in apoptotic cell lines and was confirmed in a TCGA mesothelioma patient data set and the module was found to be significantly correlated with a subgroup of P53 wild-type patients with CDKN2A loss. In conclusion, combining cell panel drug screening with co-expression networks helped to identify biomarkers associated with ASTX295 sensitivity, and provided new insights into the underlying mechanism of ASTX295 response. Citation Format: Harpreet Kaur Saini, Maria Ahn, George Ward, Justyna Kucia-Tran, Christina Gewinner, Nicola Ferrari, Jessica Brothwood, Luke Bevan, Matthew Davis, Lynsey Fazal, Martin Sims, Marc O'Reilly, Gianni Chessari, Roberta Ferraldeschi, John Lyons, Nicola Wallis, Neil Thompson. Identification of biomarkers of response to MDM2 inhibition in solid tumours using computational, multi-omics approaches [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 667.

A series of pyrazolone compounds with different substitution patterns have been synthesized using microwave-assisted methods and evaluated their in vitro antiproliferative activity against human lung adenocarcinoma cell lines (A549 and NCI-H522). Among the tested compounds, the pyrazolone P7 exhibited high antiproliferative activity against both A549 and NCIH522 cancer cell lines while being 10 times less cytotoxic to non-cancerous cells. Moreover, our compounds P7 and P11 exhibited higher antiproliferative activity and selectivity against A549 and NCIH522 cells compared with the clinically approved drugs Afatinib and Gefitinib. The cell cycle analysis showed that the compound P7 and P11 arrests the cell cycle at G0/G1 phase, whereas the compounds P13 and P14 involved in G2/M phase arrest. The results from antiproliferative activity screening, cell cycle analysis, and kinase profiling indicate that the suitably substituted 1,3-diarylpyrazolones exhibit high antiproliferative activity against non-small cell lung cancer cells.

e15119 Background: Rearrangements of the mixed-lineage leukemia (MLL) gene result in the production of MLL fusion proteins, which occurs in 5-10% of acute leukemia in adults and > 70% of infant leukemia, respectively. Menin protein, encoded by the MEN1 gene, interacts with MLL fusion proteins to induce leukemia. D0060-319, a Menin-MLL inhibitor, shows a significant antitumor effect in vivo and in vitro. Methods: The fluorescence polarization (FP) binding assay to assess inhibition of D0060-319 to Menin-MLL interaction. The cross reactivity of 44 molecular targets was tested to assess their off-target binding potential. The anti-proliferative ability of D0060-319 was evaluated by CCK-8 in different cell lines. The in vivo anti-tumor effect of D0060-319 was evaluated in a human MV4-11 and MOLM-13 cell mouse xenograft tumor model. Briefly, five million MV4-11 cells or 500 thousand MOLM-13 cells were subcutaneously implanted the right flank of CB-17 SCID mice to establish cell mouse xenograft tumor model. When tumor volume reached 100-120mm3, the animals were grouped and administrated with D0060-319 at the dose of 25, 50, 75, 100 mg/kg or vehicle at twice daily for 21days. Tumor measurements and body weights were performed twice weekly to assess the antitumor efficacy and tolerability of D0060-319. Results: D0060-319 competitively binds Menin to inhibit the interaction with MLL fusion protein with IC50 of 7.46nM, has high antiproliferative activity in MV4-11 and MOLM-13 cell lines containing MLL fusion proteins with IC50 values of 4.0nM and 1.7nM, respectively. However, in Kasumi-1, K562, HL-60 and KG-1 cell lines lacking MLL rearrangement, D0060-319 antiproliferative activity with IC50 > 10 μM, indicating selectivity for leukemia cell lines containing MLL fusion proteins active. In the MV4-11 cell mouse xenograft tumor model, D0060-319 significantly inhibited tumor growth at the dose of 25mg/kg, with a tumor growth inhibition (TGI) rate of 82.97%, and other doses (50, 75 and 100mg/kg) tumor completely regressed. In the MOLM-13 cell mouse xenograft tumor model, a dose-dependent anti-tumor effect was observed after 14 days of administration, with TGIs of 81.08%, 88.47% and 90.26% at the dose of 50, 75 or 100 mg/kg, respectively. In both CDX models, no bodyweight loss was observed, suggesting that D0060-319 was well tolerated. Furthermore, off-target screening assays showed that D0060-319 did not cross-react with any of the 44 molecular targets at 10 μM, indicating that D0060-319 is highly selective, high-affinity for the MLL-binding pocket on Menin. Conclusions: In MLL-rearranged leukemia, D0060-319 showed high antitumor activity and good tolerability both in vitro and in vivo.

In the search of multifunctional compounds we designed benzimidazole derivatives endowed with phenolic hydroxy groups and a hydrazone moiety as potential radical-scavenger and the antioxidant agents. The target molecules have been prepared by a simple synthetic procedure and tested for their antioxidant activity by DPPH, FRAP, and ORAC test, for photoprotective activity against UV rays and for antiproliferative activity against Colo-38 melanoma cells. Furthermore, two different dermocosmetic formulations were prepared with the compounds endowed with the best antioxidant and photoprotective profile and their release from formulation evaluated using Franz Cells system. High antioxidant activity is related to the presence of at least two hydroxy groups on arylidene moiety of benzimidazoles. Structure activity analysis revealed that the position of hydroxy groups is crucial for antioxidant activity as well as the presence of a 2-hydroxy-4-(diethylamino)arylidene group. The same correlation pattern was found to be related to photoprotective activity resulting in an UVA Protection Factor better than the commercial solar filter PBSA and antiproliferative activity against melanoma cells without producing cytotoxicity on normal keratinocytes. The release analysis indicated that high antioxidant activities are achieved with limited release at concentration compatible with the use as UV sunscreen filter.

The current study was performed to screen the extracts of Artemisia nilagirica (C.B. Clarke) Pamp. for antiproliferative and antiinflammatory properties. Antiproliferative activity was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Antiinflammatory activity was evaluated in terms of lipoxygenase and xanthine oxidase inhibitory activities. Results indicated that out of the 3 extracts tested, methanol extract was found to inhibit Y79 (human retinoblastoma) and MCF-7 (human breast adenocarcinoma) cell lines. The same extract was also found to inhibit lipoxygenase and xanthine oxidase enzymes in a concentration-dependent manner with an IC50 of 128.20±3.39 and 144.23±2.04 μg/ml for lipoxygenase and xanthine oxidase, respectively. The present study highlighted the antiproliferative potential of the plant against cancer cell lines. The extracts inhibited lipoxygenase and xanthine oxidase enzymes. Therefore, this plant could be a valuable source for anticancer and antiinflammatory molecules.

An important role has been considered forthe vascular endothelial growth factor receptor 2 (VEGFR-2) in the angiogenesis process, so that its inhibition is an important scientific way for cancer treatment. In this work, new thienopyrimidine derivatives were synthesized and evaluated. Compared with sorafenib, the majority of the target compounds had antiproliferative activity against the PC3, HepG2, MCF7, SW480, and HUVEC cell lines, especially 9h with IC50 values of 4.5-15.1 μM, confirming the noticeable cytotoxic effects on the listed cell lines (PC3, HepG2, SW480, and HUVEC). Analyses by flow cytometry on SW480 and HUVEC cells revealed that 9n, 9k, 9h, and 9q led to apoptotic cell death. The result of the chick chorioallantoic membrane assay showed that 9h effectively reduced the number of corresponding blood vessels. Finally, the inhibitory effect on VEGFR-2 phosphorylation was considered as the outcome of Western blot analysis of compound 9h.

In view of the various and promising biological activities of gallic acid, we designed and prepared a series of poly-phenolic compounds carrying multi-gallic acids residues. These dimer and tetramer of gallic acids were facilely synthesized by convergent approach. Subsequently, antioxidant activity evaluation was carried out using DPPH assay, and the resulting polyphenol exerted enhanced activity to gallic acid monomer. Antiproliferative activity evaluation was performed using MTT assay with three human cancer cell lines (Hela, A549 and MCF-7) and two human normal cell lines (HEK293 and HUVEC). The cytotoxicity of the dimer and tetramer of gallic acid were higher than that of the monomer against both cancer and normal cell lines, however the cytotoxicity of the dimer and tetramer against cancer cells was much fiercer than normal cells, which resulted in better selectivity. Consequently, vanlency effects embodied in both antioxidant and antiproliferative activities of the obtained multi-gallic acid derivatives. Keywords: Gallic acid, Polyphenol, Antioxidant activity, Antiproliferative activity, Vanlency effects, Convergent synthesis.

USP7 is a promising target for cancer therapy as its inhibition is expected to decrease function of oncogenes, increase tumor suppressor function, and enhance immune function. Using a structure-based drug design strategy, a new class of reversible USP7 inhibitors has been identified that is highly potent in biochemical and cellular assays and extremely selective for USP7 over other deubiquitinases. The succinimide was identified as a key potency-driving motif, forming two strong hydrogen bonds to the allosteric pocket of USP7. Redesign of an initial benzofuran-amide scaffold yielded a simplified ether series of inhibitors, utilizing acyclic conformational control to achieve proper amine placement. Further improvements were realized upon replacing the ether-linked amines with carbon-linked morpholines, a modification motivated by free energy perturbation (FEP+) calculations. This led to the discovery of compound 41, a highly potent, selective, and orally bioavailable USP7 inhibitor. In xenograft studies, compound 41 demonstrated tumor growth inhibition in both p53 wildtype and p53 mutant cancer cell lines, demonstrating that USP7 inhibitors can suppress tumor growth through multiple different pathways.

BackgroundThe tumor suppressor p53 is a major regulator of the DNA damage response and has been suggested to selectively bind and activate cell-type specific gene expression programs. However recent studies and meta-analyses of genomic data propose largely uniform, and condition independent p53 binding and thus question the selective and cell-type dependent function of p53.ResultsTo systematically assess the cell-type specificity of p53, we measured its association with DNA in 12 p53 wild-type cancer cell lines, from a range of epithelial linages, in response to ionizing radiation. We found that the majority of bound sites were occupied across all cell lines, however we also identified a subset of binding sites that were specific to one or a few cell lines. Unlike the shared p53-bound genome, which was not dependent on chromatin accessibility, the association of p53 with these atypical binding sites was well explained by chromatin accessibility and could be modulated by forcing cell state changes such as the epithelial-to-mesenchymal transition.ConclusionsOur study reconciles previous conflicting views in the p53 field, by demonstrating that although the majority of p53 DNA binding is conserved across cell types, there is a small set of cell line specific binding sites that depend on cell state.

The p53 family of transcription factors comprises several proteins produced by three genes, TP63, TP63 and TP73, through alternative promoters and splicing, that exhibit critical functions for cell homeostasis and act as prominent tumor suppressors. The p53 pathway is often activated in stress conditions during which the global cap-dependent translation is inhibited. Although p53 protein is highly regulated at post-translational level, cells maintain continuous p53 protein synthesis also taking advantage of the presence of two Internal Ribosome Entry Sites (IRESs) elements residing within the p53 mRNA. The first IRES is located in the 5′UTR of the full-length isoform, the second is located into the protein-coding region and mediates the translation of a ΔN-p53 isoform. IRES elements are complex RNA structural elements in 5′UTRs that can mediate cap-independent initiation of translation under stress conditions. Even though an IRES activity has been already established for p53, no studies are available for p63 and p73 transcripts. This work is mainly focused on the regulation of translation initiation efficiency for the p53 family members p63 and p73. For this purpose, we have cloned the 5′UTR from human full-length p53 (as positive control), TA-p63, TA*-p63, TA-p73 and ΔN-p63 and ΔN-p73 transcript isoforms in a bicistronic reporter construct (named pRuF, where R stands for Renilla reniformis luciferase cDNA, u for 5′UTR tested and F for Firefly luciferase cDNA). The c-Myc and p16 or β-globin and β-actin 5′UTRs were included as positive or negative controls. We performed gene reporter assays in MCF7 and HCT116 p53 wild-type cancer cell lines and in their derivative clones with reduced (shp53) or null (p53-/-) p53 expression. It has been previously demonstrated that p53, through transcriptional repression of fibrillarin (FBL) is able to negatively impact on rRNA methylation pattern and IRES-dependent translation, hence p53 status can be an important factor to unmask cap-independent translation initiation. Results showed that TA*-p63, TA-p73 and ΔN-p73 can potentially contain an IRES-like sequence in their 5′UTR. Translation stimulation was increased in MCF7 cells with p53 was knocked-down. Treatment with the mTOR inhibitors Rapamycin and Torin1, that inhibit cap-dependent translation, led to an enhanced relative activity of the putative IRES contained in TA-p73. Interestingly, differences in responses of the various 5′UTRs between the two cell lines were observed. Based on these initial observations, the identification of different and tissue specific RNA binding proteins targeting the distinct p63 and p73 5′UTRs will be pursued with the aim to dissect a mechanism regulating mRNA translation initiation that could play an important role in development as well as in cancer progression. Note: This abstract was not presented at the meeting. Citation Format: Alessandra Bisio, Alberto Inga. Cis-mediated regulation of mRNA translation initiation of p53 family members. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2125. doi:10.1158/1538-7445.AM2015-2125

p53 Activity is controlled in large part by MDM2, an E3 ubiquitin ligase that binds p53 and promotes its degradation. The MDM2 antagonist Nutlin-3a stabilizes p53 by blocking its interaction with MDM2. Several studies have supported the potential use of Nutlin-3a in cancer therapy. Two different p53 wild-type cancer cell lines (U2OS and HCT116) treated with Nutlin-3a for 24 hours accumulated 2N and 4N DNA content, suggestive of G(1) and G(2) phase cell cycle arrest. This coincided with increased p53 and p21 expression, hypophosphorylation of pRb, and depletion of Cyclin B1, Cyclin A, and CDC2. Upon removal of Nutlin-3a, 4N cells entered S phase and re-replicated their DNA without an intervening mitotic division, a process known as endoreduplication. p53-p21 pathway activation was required for the depletion of Cyclin B1, Cyclin A, and CDC2 in Nutlin-3a-treated cells and for endoreduplication after Nutlin-3a removal. Stable tetraploid clones could be isolated from Nutlin-3a treated cells, and these tetraploid clones were more resistant to ionizing radiation and cisplatin-induced apoptosis than diploid counterparts. These data indicate that transient Nutlin-3a treatment of p53 wild-type cancer cells can promote endoreduplication and the generation of therapy-resistant tetraploid cells. These findings have important implications regarding the use of Nutlin-3a in cancer therapy