Strong Antiproliferative Effect Research Articles

Design, synthesis and antitumour activity of pyrimidine derivatives as novel selective EGFR kinase inhibitors.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, often linked to overexpression or abnormal activation of the epidermal growth factor receptor (EGFR). The issue of developing resistance to third-generation EGFR kinase inhibitors, such as osimertinib, underscores the urgent need for new therapies to overcome this resistance. Our findings revealed that compound A8 exhibits 88.01% kinase inhibition efficacy against the EGFRL858R/T790M mutation at a concentration of 0.1 μM, with an IC50 value of 5.0 nM. Moreover, its selectivity for this double mutation is 29.5, surpassing that of osimertinib. Most notably, A8 demonstrates an inhibitory activity of 2.9 nM against the EGFRL858R/T790M/C797S triple mutation, outperforming the benchmark drug osimertinib. Furthermore, compound A8 has demonstrated strong antiproliferative effects against H1975 cells, and its activity was better than osimertinib. The mechanism by which compound A8 operates as a selective EGFRL858R/T790M inhibitor was confirmed through a series of cell migration, apoptosis, and cell cycle assays. This lays the foundation for the development of a new structural type of EGFR kinase inhibitors.

Distribution, Phytochemical Insights, and Cytotoxic Potential of the Sesbania Genus: A Comprehensive Review of Sesbania grandiflora, Sesbania sesban, and Sesbania cannabina.

This review evaluates the cytotoxic potential of the Sesbania genus, with a focus on Sesbania sesban, Sesbania grandiflora, and Sesbania cannabina. These species, known for their diverse phytochemical compositions, exhibit notable cytotoxic effects that suggest their utility in natural cancer treatments. Compounds such as quercetin, kaempferol, and sesbagrandiforian A and B have been highlighted for their strong antioxidant and antiproliferative effects, further emphasizing their therapeutic potential. The genus Sesbania exhibits a wide range of in vitro and in vivo bioactivities. Extensive research on S. grandiflora has uncovered mechanisms such as the activation of caspase cascades and the induction of apoptosis, attributed to its rich content of flavonoids and alkaloids. Notably, sesbanimides derived from S. grandiflora seeds have demonstrated potent cytotoxic effects by disrupting mitochondrial function. While S. sesban and S. cannabina have been less extensively studied, early findings highlight their potential through the inhibition of key cancer pathways and the identification of bioactive compounds such as galactomannan derivatives and 2-arylbenzofurans. Notably, the galactomannan derivatives from S. sesban exhibit significant immune-modulating properties. Additionally, nanoparticles synthesized from Sesbania species, including Cadmium oxide and PEGylated silver nanoparticles, have demonstrated promising cytotoxic activity by disrupting mitosis and enhancing immune responses. While further research is warranted, the Sesbania genus offers a promising basis for the development of innovative anticancer therapies.

Synthesis, characterization, and investigation of photochemical and in vitro properties of novel Zn(II) phthalocyanine.

A new nonperipheral zinc(II) phthalocyanine bearing octa carboxylic acid ethyl ester derivative substituted triazole attached propylmercaptothiobenzylmercapto derivative was synthesized via the tetramerization reaction of phthalonitrile. The photochemical in vitro photodynamic activity of zinc(II) phthalocyanine (ZnPc-I), such as human nonsmall cell lung carcinoma cell lines, was investigated in this study. The singlet oxygen generation property of novel zinc(II) phthalocyanine (ZnPc-I) was also examined due to the significantly high singlet oxygen quantum yield of ZnPc-I (FD = 0.66). The antiproliferative effects of ZnPc-I were also investigated on the A549 and H1299 cell lines, and the results demonstrated that ZnPc-I had a strong antiproliferative effect on both cell lines.

Phytochemical screening and evaluation of anti-oxidant, anti-inflammatory and anticancer activities of leaves of Vernonia amygdalina, Otostegia integrifolia, and Salvia rosmarinus

ABSTRACT This study assessed leaves extract from Vernonia amygdalina, Otostegia integrifolia, and Salvia rosmarinus plants for their phytochemical content and in-vitro antioxidant, anti-inflammatory, and anti-cancer activities. The DPPH bioassay for antioxidants, MTT bioassay for anticancer, measurement of the inhibition of albumin-denaturation, and anti-proteinase for anti-inflammatory activities methods were used. The result of phytochemical-screening tests confirmed the presence of alkaloids, steroids, terpenoids, flavonoids, tannins, and saponins in plants. The three plants exhibited IC50 (μg mL−1) for radical – scavenging activities at a concentration 10–30 μg mL−1 which was higher than that of the positive control ascorbic acid. Chloroform/methanol (1:1) S. rosmarinus leaves extract showed the highest anti-inflammatory activity against albumin-denaturation with an IC50 value of 0.58 μg mL−1, followed-by chloroform/methanol (1:1) V. amygdalina leaves extract with an IC50 value of 0.81μg mL−1 [positive control aspirin (IC50 value of 4.59 μg mL−1)]. Both plants’ chloroform/methanol (1:1) extracts demonstrated higher inhibitory activity against proteinase than aspirin. The three plants were tested for anti-cervical-cancer activity at 1250 μg mL−1 concentration. All the plants showed the strong anti-proliferative effects on continuous cell culture of HeLa cells line. The plants that were studied scientifically have provided support for the traditional-therapists’ claim of anticancer activity.

Cytotoxic and apoptotic potentials of four native apricot varieties from Malatya, Turkey: A comprehensive evaluation.

In recent years, the role of functional foods in addressing various health issues, including cancer, has gained significant attention. Among these, the cytotoxic and apoptotic properties of Malatya apricots hold particular interest for their potential therapeutic benefits. This study focused on exploring the effects of methanol and acetone extracts from four popular Malatya apricot varieties-Hacıhaliloğlu, Hasanbey, Kabaaşı, and Soğancı-on cancer cell lines. The extracts were derived from apricots in their raw, ripe, and dried form, which can be consumed in three ways, and were tested for their cytotoxic and apoptotic activities against MCF-7 and Caco-2 cell lines using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, wound scratch, and acridine orange/ethidium bromide (AO/EB) staining tests. Additionally, we assessed the total phenolic and flavonoid contents of the extracts. Our findings revealed that the acetone extracts of dried and raw Kabaaşı apricots exhibited the lowest IC50 values against the MCF-7 cell line over 24 and 48h, with values of 3.9 and 0.5mg/mL, respectively. Similarly, in the Caco-2 cell line, the dried Kabaaşı apricot extracts showed the lowest IC50values of 3.59 and 1.95mg/mL for the same time frames. In the wound scratch assay, utilizing apricot extracts at their lowest IC50 values revealed significant differences in cell migration inhibition between treated and control groups. For Caco-2 cells, the control group's wound closure was around 70%, whereas apricot extract treatment resulted in 10%-30% opening after 24h, indicating a strong antiproliferative effect. Similarly, in MCF-7 cells, the control group showed approximately 80% wound closure, in contrast to the 0%-12% opening observed in cells treated with apricot extract, further emphasizing the extracts' potent inhibitory impact on cell proliferation. Additionally, morphological evidence of cell death and apoptosis was observed in the images obtained through the AO/EB staining method, conducted to showcase the cytotoxic and apoptotic effects of the apricot extract. Apricot extracts consistently demonstrated strong cytotoxic and apoptotic effects on both Caco-2 and MCF-7 cell lines, underscoring Malatya apricots' potential as a functional food component with promising therapeutic properties against cancer.

In vitro and In Silico Molecular Modeling Studies of Newly Synthesized Pyrrole Derivatives for their Antimicrobial and Anticancer Properties

Background: Pyrroles are biologically active scaffolds that can have a number of different effects. They also have unique pharmacophores inside their ring system that make it easier to make molecules that are more active. Significantly, in the past ten years, research has been conducted on the anti-bacterial properties, with a particular emphasis on drug-resistant Gram-positive and Gram-negative pathogens such as mycobacteria. Additionally, scaffolds based on pyrroles were utilized in the production of anti-tumor medicines that function by modulating or suppressing genes. Objective: This research aimed to create new pyrrole derivatives by chemical means and evaluate their antimicrobial and anticancer properties. Methods: By reacting diverse 1H-pyrrole-2-carbohydrazide derivatives with benzaldehyde under normal conditions, a number of pyrrole variations were created. IR, mass spectroscopy, NMR, and elemental analysis were used to characterize the synthesized compounds. The serial dilution method was used to assess antimicrobial activity, along with a molecular docking study against the enzyme α-topoisomerase II (α-Topo II), which effectively controls the topology of DNA. This enzyme is strongly expressed in rapidly dividing cells and is crucial for transcription, replication, and chromosome structure. Pyrrole and its synthetic derivatives are known to exhibit strong anticancer activity by specifically targeting α-Topo II, which has led multiple researchers to investigate α-Topo II inhibitors as potential anticancer medicines. Consequently, designing pyrroline derivatives is interesting since the succinimide portion of the joined heteroaromatic molecule can selectively engage with the ATP binding pocket via the hydrogen bond network. Newer synthesized compounds were also docked via Schrodinger 2022-4 into the active pocket of the three-dimensional crystallographic structure of the ATP site of human topoisomerase IIα (htopo IIα) (PDB ID: 1zxm). Results: Among the newly synthesized pyrrole derivatives, compounds demonstrated significant anti- microbial activity. In addition, the AutoDock Vina application was used to perform in-silico docking computations. Compounds 1a and 1h were found to have a stronger antiproliferative effect than compounds against MCF-07 breast cancer cell linen our study, ligands 1a and 1b exhibited better binding energies of -5.049 and -5.035 kcal/mol, respectively. Most of the synthesized pyrrole derivatives showed promising antiproliferative effects; however, further in vivo investigations are needed to confirm or refute these results. Conclusion: The results of this investigation show that pyrrole derivatives have the potential to be effective antimicrobial and anticancer agents. While resolving safety issues, the structural alterations carried out in this study enhanced the compounds' medicinal capabilities. To clarify the underlying mechanisms of action and enhance the pharmacological characteristics of these new pyrrole derivatives, further research is necessary.

Evaluation of Annona muricata Linn Leaves Extracts from Maceration and Ultrasonic-Assisted Methods for Anticancer Activity on HLFa Cells

Non-small cell lung cancer (NSCLC) is a deadly kind of cancer that contributes significantly to the global cancer mortality rate. It is distinguished by a significant level of malignancy and unfavourable prognosis. The molecular pathways responsible for tumour invasion and migration in NSCLC are not fully understood, despite their widespread occurrence and significant consequences. Moreover, the ability of cancer cells to withstand the effects of chemical treatments presents a substantial obstacle in the creation of successful treatment approaches for NSCLC. Annona muricata Linn (A. muricata) is known to possess powerful anticancer bioactive components. A. muricata extracts have demonstrated significant therapeutic potential among a wide range of botanical compounds. However, the specific molecular interactions of the plant have not yet been revealed. This study aims to evaluate the anticancer potential of A. muricata leaves extracts on the NSCLC cell line and compare the efficacy of two different extraction methods, namely maceration extraction (ME) and ultrasonic-assisted extraction (UAE). Results showed that ME demonstrated significantly higher antioxidant activity compared to UAE, with respective percentages of 81.4% and 29.4%. However, the UAE extract demonstrated more pronounced cytotoxic effects on the NSCLC cell line (HLFa) with an IC50 value of 139.6 µg/ml, indicating a stronger antiproliferative effect on cancer cell. Both ME and UAE extracts reduced nitrite release in HLFa cell supernatants, with the ME extract showing superior activity. Treatment with ME and UAE also resulted in the activation of Caspase3/7, indicating the induction of apoptosis in HLFa cells compared to the untreated control. The extracts and Cisplatin differ approximately 0.3-fold in caspase 3/7 activation though it was not statistically significant. This activation suggests that both extraction methods effectively initiate the apoptotic cascade which is crucial for the elimination of cancer cells. Furthermore, the UAE extract significantly reduced BCL-2 mRNA levels (p<0.05). The significant reduction in BCL-2, a protein that prevents apoptosis reflect the extract’ ability to modulate key apoptotic regulators with the most significant activity when UAE extracts were used. In summary, A.muricata leaves extracts obtained through both ME and UAE methods exhibited promising anticancer effects against NSCLC, with UAE extracts exhibiting superior activity. These findings pave the way for further investigations into the use of A.muricata in cancer treatment and the development of new therapeutic agents based on its properties.

Benzoxaborinine, New Chemotype for Carbonic Anhydrase Inhibition: Ex Novo Synthesis, Crystallography, In Silico Studies, and Anti-Melanoma Cell Line Activity.

The benzoxaborinine scaffold, a homologue of benzoxaborole with an additional carbon atom in the boracycle, shows significant potential in developing new therapeutic agents. This study reports the synthesis, inhibition assays against four human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms, and anti-melanoma evaluation of 7-aryl(thio)ureido-substituted benzoxaborinines. Some derivatives, particularly compound 11, exhibited potent inhibitory activity (below 65 nM) against hCA IX and XII and stronger antiproliferative effects than SLC-0111 on human melanoma cells under hypoxia. Crystallographic studies of benzoxaborinine 3 adducts with hCA I and II demonstrated the binding mode of this chemotype, revealing that although both benzoxaborinine 3 and benzoxaborole 10 share a similar zinc-binding mode, the expanded ring in benzoxaborinine led to a different orientation within the active site. These findings suggest that benzoxaborinines hold promise for designing novel carbonic anhydrase inhibitors.

A bioengineered tumor matrix-based scaffold for the evaluation of melatonin efficacy on head and neck squamous cancer stem cells

Head and neck squamous cell carcinoma (HNSCC) presents a significant challenge worldwide due to its aggressiveness and high recurrence rates post-treatment, often linked to cancer stem cells (CSCs). Melatonin shows promise as a potent tumor suppressor; however, the effects of melatonin on CSCs remain unclear, and the development of models that closely resemble tumor heterogeneity could help to better understand the effects of this molecule. This study developed a tumor scaffold based on patient fibroblast-derived decellularized extracellular matrix that mimics the HNSCC microenvironment. Our study investigates the antitumoral effects of melatonin within this context. We validated its strong antiproliferative effect on HNSCC CSCs and the reduction of tumor invasion and migration markers, even in a strongly chemoprotective environment, as it is required to increase the minimum doses necessary to impact tumor viability compared to the non-scaffolded tumorspheres culture. Moreover, melatonin exhibited no cytotoxic effects on healthy cells co-cultured in the tumor hydrogel. This scaffold-based platform allows an in vitro study closer to HNSCC tumor reality, including CSCs, stromal component, and a biomimetic matrix, providing a new valuable research tool in precision oncology.

Neratinib plus dasatinib is highly synergistic in HER2-positive breast cancer in vitro and in vivo

BackgroundHER2-targeted therapies have revolutionised the treatment of HER2-positive breast cancer. However, de novo resistance or the emergence of acquired resistance is a persistent clinical problem. Here we report that neratinib, an irreversible pan-HER inhibitor, in combination with the multi-kinase inhibitor dasatinib, currently used to treat certain leukemias, has strong anti-proliferative effects against models of HER2-positive breast cancer that are innately resistant to trastuzumab or have acquired resistance to neratinib. MethodsNeratinib plus dasatinib was examined in a panel of 20 breast cancer cell lines, including HER2-positive, estrogen-receptor-positive, triple negative, and acquired HER2-targeted therapy resistant models. Drug effects on migration and apoptosis induction was evaluated and signaling alterations were determined by reverse phase protein array (RPPA). In vivo efficacy was examined using orthotopically-implanted HCC1954 cells. ResultsSynergy was observed in cell lines innately resistant to trastuzumab, models with acquired resistance to neratinib, and in triple negative breast cancer cell lines. Further investigation showed that neratinib plus dasatinib induced apoptosis and inhibited cell migration to a greater degree than either drug alone. RPPA revealed that the combination caused suppression of key survival signaling through EGFR, Akt, and MAPK inhibition. In vivo, neratinib plus dasatinib was well tolerated and had a prolonged anti-tumor effect against HCC1954 xenografts. ConclusionsThis study provides a strong pre-clinical rationale for the clinical investigation neratinib and dasatinib in HER2+ breast cancer.

Design, synthesis, and biological evaluation of novel halogenated chlorido[N,N′-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes as anticancer agents

Iron(III) complexes based on N,N´-bis(salicylidene)ethylenediamine (salene) scaffolds have demonstrated promising anticancer features like induction of ferroptosis, an iron dependent cell death. Since poor cellular uptake limits their therapeutical potential, this study aimed to enhance the lipophilic character of chlorido[N,N′-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes by introducing lipophilicity improving ligands such as fluorine (X1), chlorine (X2) and bromine (X3) in 5-position in the salicylidene moieties. After detailed characterization the binding to nucleophiles, logP values and cellular uptake were determined. The complexes were further evaluated regarding their biological activity on MDA-MB 231 mammary carcinoma, the non-tumorous SV-80 fibroblast, HS-5 stroma and MCF-10A mammary gland cell lines. Stability of the complexes in aqueous and biological environments was proven by the lack of interactions with amino acids and glutathione. Cellular uptake was positively correlated with the logP values, indicating that higher lipophilicity enhanced cellular uptake. The complexes induced strong antiproliferative and antimetabolic effects on MDA-MB 231 cells, but were inactive on all non-malignant cells tested. Generation of mitochondrial reactive oxygen species, increase of lipid peroxidation and induction of both ferroptosis and necroptosis were identified as mechanisms of action. In conclusion, halogenation of chlorido[N,N′-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes raises their lipophilic character resulting in improved cellular uptake.Graphical abstract

Design, synthesis, and in vivo and in vitro biological screening of pseudolaric acid B derivatives as potential anti-tumor agents

Pseudolaric Acid B (PAB), a natural product with remarkable anti-tumor activity, is a starting point for new anticancer therapeutics. We designed and synthesized 27 PAB derivatives and evaluated their anti-proliferative activities against four cancer cell lines: MCF-7, HCT-116, HepG2, and A549. Compared with unmodified PAB, the PAB derivatives showed stronger anti-proliferative activity. The ability of compound D3 (IC50 = 0.21 μM) to inhibit HCT-116 cells was approximately 5.3 times that of PAB (IC50 = 1.11 μM) and the antiproliferative action was unrelated to cytotoxicity (SI=20.38), indicating its superior safety profile (PAB; SI=0.95). Compound D3 effectively suppressed the EdU-positive rate and reduced colony formation, arrested HCT-116 cells in the S and G2/M phases and induced apoptosis. In vivo experiments further demonstrated low toxicity of compound D3 while suppressing tumor growth in mice. In summary, given its strong anti-proliferative effect and relative safety, further development of compound D3 is warranted.

Aspirin Stimulates the Osteogenic Differentiation of Human Adipose Tissue-Derived Stem Cells In Vitro.

This study investigates the impact of acetylsalicylic acid (ASA), also known as aspirin, on adipose tissue-derived stem cells (ASCs), aiming to elucidate its dose-dependent effects on morphology, viability, proliferation, and osteogenic differentiation. Isolated and characterized human ASCs were exposed to 0 µM, 100 µM, 200 µM, 400 µM, 800 µM, 1000 µM, 10,000 µM, and 16,000 µM of ASA in vitro. Cell morphology, viability, and proliferation were evaluated with fluorescent live/dead staining, alamarBlue viability reagent, and CyQUANT® cell proliferation assay, respectively. Osteogenic differentiation under stimulation with 400 µM or 1000 µM of ASA was assessed with alizarin red staining and qPCR of selected osteogenic differentiation markers (RUNX2, SPP1, ALPL, BGLAP) over a 3- and 21-day-period. ASA doses ≤ 1000 µM showed no significant impact on cell viability and proliferation. Live/dead staining revealed a visible reduction in viable cell confluency for ASA concentrations ≥ 1000 µM. Doses of 10,000 µM and 16,000 µM of ASA exhibited a strong cytotoxic and anti-proliferative effect in ASCs. Alizarin red staining revealed enhanced calcium accretion under the influence of ASA, which was macro- and microscopically visible and significant for 1000 µM of ASA (p = 0.0092) in quantification if compared to osteogenic differentiation without ASA addition over a 21-day-period. This enhancement correlated with a more pronounced upregulation of osteogenic markers under ASA exposure (ns). Our results indicate a stimulatory effect of 1000 µM of ASA on the osteogenic differentiation of ASCs. Further research is needed to elucidate the precise molecular mechanisms underlying this effect; however, this discovery suggests promising opportunities for enhancing bone tissue engineering with ASCs as cell source.

Total Synthesis and Biological Profiling of Putative (±)-Marinoaziridine B and (±)-N-Methyl Marinoaziridine A.

The total synthesis of two new marine natural products, (±)-marinoaziridine B 7 and (±)-N-methyl marinoaziridine A 8, was accomplished. The (±)-marinoaziridine 7 was prepared in a six-step linear sequence with a 2% overall yield. The key steps in our strategy were the preparation of the chiral epoxide (±)-5 using the Johnson Corey Chaykovsky reaction, followed by the ring-opening reaction and the Staudinger reaction. The N,N-dimethylation of compound (±)-7 gives (±)-N-methyl marinoaziridine A 8. The NMR spectra of synthetized (±)-marinoaziridine B 7 and isolated natural product did not match. The compounds are biologically characterized using relevant in silico, in vitro and in vivo methods. In silico ADMET and bioactivity profiling predicted toxic and neuromodulatory effects. In vitro screening by MTT assay on three cell lines (MCF-7, H-460, HEK293T) showed that both compounds exhibited moderate to strong antiproliferative and cytotoxic effects. Antimicrobial tests on bacterial cultures of Escherichia coli and Staphylococcus aureus demonstrated the dose-dependent inhibition of the growth of both bacteria. In vivo toxicological tests were performed on zebrafish Danio rerio and showed a significant reduction of zebrafish mortality due to N-methylation in (±)-8.

Advanced Design, Synthesis, and Evaluation of Highly Selective Wee1 Inhibitors: Enhancing Pharmacokinetics and Antitumor Efficacy.

Wee1 is a kinase that regulates cell cycle arrest in response to DNA damage. Wee1 inhibition is a potential strategy to suppress the growth of tumors with defective p53 or DNA repair pathways. However, the development of Wee1 inhibitors faces some challenges. AZD1775, the first-in-class Wee1 inhibitor, has poor kinase selectivity and dose-limiting toxicity. Here, we report the discovery of 12h, a highly selective and potent Wee1 inhibitor with a favorable pharmacokinetic profile. 12h showed strong antiproliferative effects against Lovo cells, a colorectal cancer cell line, both in vitro and in vivo. Moreover, 12h showed a clean kinase profile and effectively induced cell apoptosis. Our results suggest that 12h is a promising drug candidate for further development as a novel anticancer agent.

Abstract PR012: KAT6A/B and Menin-MLL complexes coordinately regulate estrogen receptor-driven gene expression programs in breast cancer

Abstract The estrogen receptor (ER) is expressed in ∼70% of breast cancers where it functions as a critical transcription factor that regulates cell growth and tumor progression. ER inhibition is a mainstay treatment for ER-positive (ER+) breast cancer, but despite the clinical benefit of targeting ER signaling, breast cancer remains the second leading cause of cancer-related death in women, with ∼50% of deaths resulting from ER+ tumors. While recurrent and metastatic ER+ tumors are typically resistant to endocrine therapies they continue to rely on ER signaling suggesting that disruption of other chromatin associated complexes that mediate ER-driven gene expression may present an alternative therapeutic strategy. One chromatin modifier important in regulating ER function is the histone acetyltransferase KAT6A. KAT6A is amplified and/or overexpressed in ∼15% of ER+ tumors and a novel KAT6A/B inhibitor has entered clinical trials for advanced breast cancer. However, as with most single agent therapies, compensatory mechanisms may attenuate the effects of KAT6A/B inhibition on ER-driven gene expression. We hypothesized that the dual targeting of distinct chromatin complexes would enhance the effects of KAT6A/B inhibition, by altering chromatin state and transcriptional output. To that end we performed an epigenetic focused CRISPR-Cas9-based functional genetic screen to identify chromatin-associated proteins that enhance KAT6A/B inhibition. CRISPR guides targeting MEN1 (encoding Menin) were among our top hits as sensitizers to treatment with the KAT6A/B inhibitor PF-9363. We confirmed that co-treatment of PF-9363, and the Menin inhibitor, SNDX-5613, had strong synergistic anti-proliferative effects in a panel of ER+ breast cancer cell lines. Mechanistically, our data revealed that KAT6A/B and Menin cooperatively regulate ER-driven gene expression and chromatin accessibility, both through direct effects on ESR1 expression as well as through effects at ER target genes. Specifically, we found that KAT6A and Menin-KMT2A complexes co-localized at promoters of ER target genes and treatment with KAT6A/B or Menin inhibitors displaced KAT6A and Menin/KMT2A from ER target genes, respectively. Yet only the combination effectively displaced both complexes from chromatin, which produced more dramatic changes in ER-directed gene expression than either small molecule alone. Combined displacement of KAT6A and Menin/KMT2A at ER-regulated genes induced loss of an active chromatin landscape characterized by reduction of activating histone modifications and loss of RNA Polymerase II binding to ER target loci. Importantly, the combination of KAT6A/B and Menin inhibition was effective in a panel of ER+ patient-derived organoid models as well as in various models of endocrine resistance, including models with ESR1 mutations, NF1 loss, and FOXA1 mutations. Both KAT6A/B and Menin inhibitors are in Phase I/II clinical trials and have shown manageable toxicity profiles to date. This combination represents a novel potential therapeutic combination for ER+ breast cancer. Citation Format: Sarah Naomi Olsen, Bryn Anderson, Charles Hatton, Rinath Jeselsohn, Myles Brown, Eneda Toska, Scott Armstrong. KAT6A/B and Menin-MLL complexes coordinately regulate estrogen receptor-driven gene expression programs in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr PR012.

The antiproliferative effects of Marrubium vulgare, and toxicity screening in zebrafish embryos

Consider the medicinal usefulness and ethnomedicinal uses referring to Marrubium vulgare; the CH3OH extract of whole plant was investigated for the antiproliferative, effect and toxicological screening. Its antiproliferative effect was evaluated against A549 (lung), HepG2 (Liver), MDA-MB-231 (breast) and MCF-7 cancer cell-lines. Doxorubicin was used as a positive control. Toxicological evaluation of the Marrubium vulgare methanol extract (MVM) was carried out in zebrafish embryos. The MVM showed more effective inhibition against MCF-7and MDA-MB-231 breast-cancer cells. The IC50 value ranged from 43.5 to 223.5 μg/mL. In term of IC50 MVM showed a strong antiproliferative effect averse to MDA-MB-231 and MCF-7 in terms of IC50 values (43.5 and 46.5 μg/mL respectively). Lethal concentration of MVM in zebrafish embryos remained 5 µg/ml. The results obtained from zebrafish embryos tests indicates that the extract is toxic at some level and should be used carefully or avoid it during the pregnancy.

Biological activity and computational analysis of novel acrylonitrile derived benzazoles as potent antiproliferative agents for pancreatic adenocarcinoma with antioxidative properties

Continuing our research into the anticancer properties of acrylonitriles, we present a study involving the design, synthesis, computational analysis, and biological assessment of novel acrylonitriles derived from methoxy, hydroxy, and N-substituted benzazole. Our aim was to examine how varying the number of methoxy and hydroxy groups, as well as the N-substituents on the benzimidazole core, influences their biological activity. The newly synthesized acrylonitriles exhibited strong and selective antiproliferative effects against the Capan-1 pancreatic adenocarcinoma cell line, with IC50 values ranging from 1.2 to 5.3 μM. Consequently, these compounds were further evaluated in three other pancreatic adenocarcinoma cell lines, while their impact on normal PBMC cells was also investigated to determine selectivity. Among these compounds, the monohydroxy-substituted benzimidazole derivative 27 emerged with the most profound and broad-spectrum anticancer antiproliferative activity being emerged as a promising lead candidate. Moreover, a majority of the acrylonitriles in this series exhibited significant antioxidative activity, surpassing that of the reference molecule BHT, as demonstrated by the FRAP assay (ranging from 3200 to 5235 mmolFe2+/mmolC). Computational analysis highlighted the prevalence of electron ionization in conferring antioxidant properties, with computed ionization energies correlating well with observed activities.

Discovery of CBPD-409 as a Highly Potent, Selective, and Orally Efficacious CBP/p300 PROTAC Degrader for the Treatment of Advanced Prostate Cancer.

CBP/p300 are critical transcriptional coactivators of the androgen receptor (AR) and are promising cancer therapeutic targets. Herein, we report the discovery of highly potent, selective, and orally bioavailable CBP/p300 degraders using the PROTAC technology with CBPD-409 being the most promising compound. CBPD-409 induces robust CBP/p300 degradation with DC50 0.2-0.4 nM and displays strong antiproliferative effects with IC50 1.2-2.0 nM in the VCaP, LNCaP, and 22Rv1 AR+ prostate cancer cell lines. It has a favorable pharmacokinetic profile and achieves 50% of oral bioavailability in mice. A single oral administration of CBPD-409 at 1 mg/kg achieves >95% depletion of CBP/p300 proteins in the VCaP tumor tissue. CBPD-409 exhibits strong tumor growth inhibition and is much more potent and efficacious than two CBP/p300 inhibitors CCS1477 and GNE-049 and the AR antagonist Enzalutamide. CBPD-409 is a promising CBP/p300 degrader for further extensive evaluations for the treatment of advanced prostate cancer and other types of human cancers.

Abstract 6564: SOS1 inhibitor treatment improves response to Venetoclax in acute myeloid leukemia

Abstract Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. First-line treatment of AML patients consists primarily of chemotherapy, sometimes combined with a targeted therapy. However, elderly patients unfit for chemotherapy receive venetoclax, a BCL2 inhibitor, combined with azacitadine or decitabine. While responses in these patients are high (50-70%, with median OS of 10-17 months), around 30-50% of them do not respond and most relapse within 1-10 years. Increased MAPK pathway activity or low frequency RAS pathway mutations have been identified as key mediators of resistance to standard-of-care targeted therapies for AML, including venetoclax. Here, we found that in DepMap whole-genome CRISPR screens, leukemia cell lines, including AML, show a particular dependency on SOS1. A subsequent PRISM screen with a selective inhibitor of SOS1 confirmed these results. To validate these results in vitro, we treated 7 AML cell lines showing strongest dependency on SOS1 based on DepMap and PRISM screens, with SOS1i or a SHP2 inhibitor. We found that in 4 of 7 cell lines treatment with SOS1i or SHP2i strongly impaired proliferation. In 3 of 4 responding cell lines, the anti-proliferative effect with either SOS1i or SHP2i was stronger than azacytidine single agent treatment. We next treated 29 primary ex vivo cultures of AML with SOS1i and found that the treatment induced strong or intermediate anti-proliferative effect in 21 of 29 models (72%). In two AML PDX models, treatment with SOS1i as a single agent resulted in approximately 25% reduction of human CD45+ AML blast cells in both models. Venetoclax treatment led to approximately 75% decrease in AML blasts, while the combined venetoclax and SOS1i treatment resulted in near complete eradication of the disease. Annexin V staining of AML monoblasts demonstrated that this decrease was due to an increase in apoptosis in the combination groups. In summary, we demonstrate that SOS1 inhibitor treatment may be used to improve responses to venetoclax in AML patients. Citation Format: Kaja Kostyrko, Melanie Hinkel, Matthew G. Rees, Melissa M. Ronan, Jennifer A. Roth, Daniel Gerlach, Irene Waizenegger. SOS1 inhibitor treatment improves response to Venetoclax in acute myeloid leukemia [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 6564.