Broad Anticancer Activity Research Articles

Colon-Targeted Sustained-Release Combinatorial 5-Fluorouracil and Quercetin poly(lactic-co-glycolic) Acid (PLGA) Nanoparticles Show Enhanced Apoptosis and Minimal Tumor Drug Resistance for Their Potential Use in Colon Cancer.

Colorectal cancer (CRC) is the third most common cancer worldwide, acting as a significant public health problem. 5-Fluorouracil (5-FU) is a key chemotherapy for various types of cancer, due to its broad anticancer activity. However, the emergence of drug resistance is a considerable limitation in the clinical application of 5-FU. Quercetin (QC) is proposed as an adjuvant therapy to minimize drug resistance to chemotherapeutics and enhance their pharmacological efficacy. The oral delivery of 5-FU and QC is challenged by poor aqueous solubility of QC and poor cellular permeability of 5-FU. To solve this issue, novel polylactide-co-glycolide (PLGA) combinatorial nanoparticles loading 5-FU and QC were prepared to deliver them directly to the colon. These sustained-release combinatorial nanoparticles recorded a significant decrease in cancer cell proliferation, C-reactive protein (CRP) level, and Interleukin-8 (IL-8) expression by 30.08%, 40.7%, and 46.6%, respectively. The results revealed that this combination therapy may offer a new strategy for the targeted delivery of chemotherapeutics to the colon.

Discovery of the Natural Bibenzyl Compound Erianin in Dendrobium Inhibiting the Growth and EMT of Gastric Cancer through Downregulating the LKB1-SIK2/3-PARD3 Pathway.

Erianin, a bibenzyl compound found in dendrobium extract, has demonstrated broad anticancer activity. However, its mechanism of action in gastric cancer (GC) remains poorly understood. LKB1 is a tumor-suppressor gene, and its mutation is an important driver of various cancers. Yet some studies have reported contradictory findings. In this study, we combined bioinformatics and in vitro and in vivo experiments to investigate the effect and potential mechanism of Erianin in the treatment of GC. The results show that LKB1 was highly expressed in patients' tumor tissues and GC cells, and it was associated with poor patient prognosis. Erianin could promote GC cell apoptosis and inhibit the scratch repair, migration, invasion, and epithelial-mesenchymal transition (EMT) characteristics. Erianin dose-dependently inhibited the expression of LKB1, SIK2, SIK3, and PARD3 but had no significant effect on SIK1. Erianin also inhibited tumor growth in CDX mice model. Unexpectedly, 5-FU also exhibited a certain inhibitory effect on LKB1. The combination of Erianin and 5-FU significantly improved the anti-tumor efficacy of 5-FU in the growth of GC cells and xenograft mouse models. In summary, Erianin is a potential anti-GC compound that can inhibit GC growth and EMT properties by targeting the LKB1-SIK2/3-PARD3-signaling axis. The synergistic effect of Erianin and 5-FU suggests a promising therapeutic strategy for GC treatment.

Prodrug-inspired adenosine triphosphate-activatable celastrol-Fe(III) chelate for cancer therapy.

Celastrol (CEL), an active compound isolated from the root of Tripterygium wilfordii, exhibits broad anticancer activities. However, its poor stability, narrow therapeutic window and numerous adverse effects limit its applications in vivo. In this study, an adenosine triphosphate (ATP) activatable CEL-Fe(III) chelate was designed, synthesized, and then encapsulated with a reactive oxygen species (ROS)-responsive polymer to obtain CEL-Fe nanoparticles (CEL-Fe NPs). In normal tissues, CEL-Fe NPs maintain structural stability and exhibit reduced systemic toxicity, while at the tumor site, an ATP-ROS-rich tumor microenvironment, drug release is triggered by ROS, and antitumor potency is restored by competitive binding of ATP. This intelligent CEL delivery system improves the biosafety and bioavailability of CEL for cancer therapy. Such a CEL-metal chelate strategy not only mitigates the challenges associated with CEL but also opens avenues for the generation of CEL derivatives, thereby expanding the therapeutic potential of CEL in clinical settings.

An RNA Helicase DHX33 Inhibitor Shows Broad Anticancer Activity via Inducing Ferroptosis in Cancer Cells.

RNA helicase DHX33 has been identified as a critical factor promoting cancer development. In the present study, a previously developed small molecule inhibitor for DHX33, KY386, was found to robustly kill cancer cells via a new path, the ferroptosis pathway. Mechanistically, DHX33 promotes the expression of critical players in lipid metabolism including FADS1, FADS2, and SCD1 genes, thereby sensitizing cancer cells to ferroptosis mediated cell death. Our study reveals a novel mechanism of DHX33 in promoting tumorigenesis and highlights that pharmacological targeting DHX33 can be a feasible option in human cancers. Normally differentiated cells are insensitive to DHX33 inhibition, and DHX33 inhibitors have little cellular toxicity in vitro and in vivo. Our studies demonstrated that DHX33 inhibitors can be promising anticancer agents with great potential for cancer treatment.

Regioselective Palladium-Catalyzed Chain-Growth Allylic Amination Polymerization of Vinyl Aziridines.

Organometallic-mediated chain growth polymerization of readily accessible chemical building blocks is responsible for important commercial and technological advances in polymer science, but the incorporation of heteroatoms into the polymer backbone through these mechanisms remains a challenge. Transition metal π-allyl complexes are well-developed organometallic intermediates for carbon-heteroatom bond formation in small-molecule catalysis yet remain underexplored in polymer science. Here, we developed a regioselective palladium-phosphoramidite-catalyzed chain-growth allylic amination polymerization of vinyl aziridines for the synthesis of novel nitrogen-rich polymers via ambiphilic π-allyl complexes. The polymerization accessed a linear microstructure with four carbons between each nitrogen, which is challenging to achieve through other chain-growth polymerization approaches. The highly regioselective allylic amination polymerization demonstrated the characteristics of a controlled polymerization and was able to achieve molar masses exceeding 20 kg mol-1 with low dispersities (D̵ < 1.3). The identification of the polymer structure and well-defined chain ends were supported by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and chain extension experiments demonstrate opportunities for building more complex materials from this method. A Hammett study was performed to understand the role of the catalyst and monomer structure on regioselectivity, and the data supported a mechanism wherein regioselectivity was primarily controlled by the ligand-metal complex. Postpolymerization desulfonylation provided access to a novel polyamine that demonstrated broad anticancer activity in vitro, which highlights the benefits of unlocking novel polyamine microstructures through regioselective chain-growth allylic amination polymerization.

Ophiobolin A Covalently Targets Mitochondrial Complex IV Leading to Metabolic Collapse in Cancer Cells.

Ophiobolin A (OPA) is a sesterterpenoid fungal natural product with broad anticancer activity. While OPA possesses multiple electrophilic moieties that can covalently react with nucleophilic amino acids on proteins, the proteome-wide targets and mechanism of OPA remain poorly understood in many contexts. In this study, we used covalent chemoproteomic platforms to map the proteome-wide reactivity of the OPA in a highly sensitive lung cancer cell line. Among several proteins that OPA engaged, we focused on two targets: lysine-72 of cytochrome c oxidase subunit 5A (COX5A) and cysteine-53 of mitochondrial hypoxia induced gene 1 domain family member 2A (HIGD2A). These two subunit proteins are part of complex IV (cytochrome C oxidase) within the electron transport chain and contributed significantly to the antiproliferative activity of OPA. OPA activated mitochondrial respiration in a COX5A- and HIGD2A-dependent manner, leading to an initial spike in mitochondrial ATP and heightened mitochondrial oxidative stress. OPA compromised mitochondrial membrane potential, ultimately leading to ATP depletion. We have used chemoproteomic strategies to discover a unique anticancer mechanism of OPA through activation of complex IV leading to compromised mitochondrial energetics and rapid cell death.

Bioinformatics and In Vitro Study Reveal ERα as The Potential Target Gene of Honokiol to Enhance Trastuzumab Sensitivity in HER2+ Trastuzumab-Resistant Breast Cancer Cells

Trastuzumab resistance presents a significant challenge in the treatment of HER2+ breast cancer, necessitating the investigation of combination therapies to overcome this resistance. Honokiol, a compound with broad anticancer activity, has shown promise in this regard. This study aims to discover the effect of honokiol in increasing trastuzumab sensitivity in HER2+ trastuzumab-resistant breast cancer cells HCC1954 and the underline mechanisms behind. A bioinformatics study performed to explore the most potential target hub gene for honokiol in HER2+ breast cancer. Honokiol, trastuzumab and combined treatment cytotoxicity activity was then evaluated in both parental HCC1954 and trastuzumab resistance (TR-HCC1954) cells using MTT assay. The expression levels of these hub genes were then analyzed using qRT-PCR and those that could not be analyzed were subjected to molecular docking to determine their potential. Honokiol showed a potent cytotoxicity activity with an IC50 of 41.05 μM and 69.61 μM in parental HCC1954 and TR-HCC1954 cell line respectively. Furthermore, the combination of honokiol and trastuzumab resulted in significant differences in cytotoxicity in TR-HCC1954 cells at specific concentrations. Molecular docking and the qRT-PCR showed that the potential ERα identified from the bioinformatics analysis was affected by the treatment. Our results show that honokiol has the potential to increase the sensitivity of trastuzumab in HER2+ trastuzumab resistant breast cancer cell line HCC1954 by affecting regulating estrogen receptor signaling. Further research is necessary to validate these findings.

Combination of Phenethyl Isothiocyanate and Dasatinib Inhibits Hepatocellular Carcinoma Metastatic Potential through FAK/STAT3/Cadherin Signalling and Reduction of VEGF Secretion.

Cancerous cells are characterised by their ability to invade, metastasise, and induce angiogenesis. Tumour cells use various molecules that can be targeted to reverse these processes. Dasatinib, a potent Src inhibitor, has shown promising results in treating hepatocellular carcinoma (HCC) in vitro and in vivo. However, its effectiveness is limited by focal adhesion kinase (FAK) activation. Isothiocyanates, on the other hand, are phytochemicals with broad anticancer activity and FAK inhibition capabilities. This study evaluated the synergistic effect of dasatinib and phenethyl isothiocyanate (PEITC) on HCC. The combination was tested using various assays, including MTT, adhesion, scratch, Boyden chamber, chorioallantoic membrane (CAM), and yolk sac membrane (YSM) assays to evaluate the effect of the drug combination on HCC metastatic potential and angiogenesis in vitro and in vivo. The results showed that the combination inhibited the adhesion, migration, and invasion of HepG2 cells and reduced xenograft volume in the CAM assay. Additionally, the combination reduced angiogenesis in vitro, diminishing the growth of vessels in the tube formation assay. The inhibition of FAK/STAT3 signalling led to increased E-cadherin expression and reduced VEGF secretion, reducing HCC metastatic potential. Therefore, a combination of PEITC and dasatinib could be a potential therapeutic strategy for the treatment of HCC.

Designing of Anticancer Therapeutical Strategies: Implications of Molecular Docking Studies of Phytochemicals of Cichorium Intybus to Metabolic Regulatory Enzymes

Background: Altered metabolism is a significant characteristic of cancer, with malignant cells exhibiting elevated levels of enzymes involved in bioenergetic and biosynthetic processes. Targeting metabolic enzymes has become a key approach in anticancer therapy, leading to the discovery of metabolic inhibitors such as 3-bromopyruvate (3-BP) with broad anticancer activity. Novel therapeutics are needed to treat and prevent this fatal disease, and natural substances are gaining attention as potentially safer alternatives to conventional therapies like chemotherapy. Methods: This study aimed to identify novel drug-like molecules for anticancer treatment using an in-silico approach. Twenty-eight phytocompounds from Cichorium intybus were selected for molecular docking against target enzymes involved in the TCA and glycolysis cycles and compared with 3-BP, a standard broad-spectrum anticancer drug, using Maestro (Schrodinger software). Results: Comparison of docking scores revealed that the phytoconstituents of Cichorium intybus exhibited stronger binding to metabolic enzymes compared to 3-BP. Additionally, drug-likeness analysis using the admetSAR and Lipinski filter indicated that most of the selected phytoconstituents and 3-BP demonstrated desirable criteria as anticancer drugs. Conclusion: Conclusion This research offers insightful information about molecular interactions between phytoconstituents of Cichorium intybus, 3-BP, and metabolic enzymes. These findings may contribute to the development and optimization of therapeutic approaches against cancer, utilizing these phytoconstituents as ligands.

The synthesis of decyl-o-phenanthrolinium organic salt and a study of the impact of anion type on in vitro antibacterial activities

According to evidence in the literature, organic salts have an affinity for biological membranes that makes them easily absorbed into cells and capable of having a wide range of biological effects, such as broad antibacterial potential and anticancer activity. The present work describes the preparation of three organic salts with a common decyl-1,10-phenanthrolinium cation ([C22H25N2]+) differing in the anions (Br−, PF6− and (CF3SO2)2N−). The synthesis was confirmed using spectrometry methods (NMR (1H 13C, 19F, 31P), ESI MS, Uv-Vis), CHNSBr elemental and thermal analysis as well as conductivity measurements. In vitro biological activities were tested on two Gram-positive (Staphylococcus aureus (S. aureus), Streptococci pyogenes (S. pyogenes)) and two Gram-negative (Escherichia coli (E. Coli) and Klebsiellae pneumoniae (K. Pneumoniae)) bacteria and compared with a commercial antibiotic (Gentamicin). The salt with the halide anion demonstrated better inhibition activities than the commercially available gentamicin. Their ion-conductivity in ethanol was found to decrease in the order [C22H25N2][PF6], [C22H25N2][(CF3SO2)2N] and [C22H25N2]Br while, their thermal stability was found to increase in the order [C22H29N2]Br, [C22H29N2][PF6], and [C22H29N2][(CF3SO2)2N]. The minimum inhibitory concentration (MIC) values show that the salts could inhibit bacterial growth at concentrations as low as 50 μg/L. Passing the cytotoxicity investigations, these salts can be considered as alternative antibiotics in combating the emerging drug resisting bacteria.

Abstract 6241: LP-184, an acylfulvene class small molecule therapeutic, is synthetically lethal in DNA damage repair deficient cancers

Abstract As many as one third of solid tumors (ovarian, breast, pancreatic, prostate cancers) harbor deficiency in some DNA Damage Repair (DDR) pathways. Such cancers become dependent on alternative DDR pathways to maintain genome integrity, making them selectively vulnerable to DDR inhibitors. The concept of synthetic lethality has been successfully applied to develop strategies to treat subsets of such tumors. Clinically, PARP inhibitors (PARPi) have been successful particularly in Homologous Recombination Deficiency (HRD) cancers. Other agents have also been designed to target these DDR deficiencies in cancer cells and have potential to be clinically beneficial. LP-184 is a next generation acylfulvene prodrug metabolized to an active compound by prostaglandin reductase 1 (PTGR1) that is often elevated in multiple tumors. LP-184-induced DNA lesions are likely repaired by the Nucleotide Excision Repair (NER) and Homologous Repair (HR) pathways. Reduced activities of multiple DDR-related pathways in solid tumor models correlated with increased sensitivities to LP-184 as indicated by Gene Set Enrichment Analysis. Chinese Hamster Ovary cells with NER mutations (ERCC1/2/6) were at least 4 fold more sensitive to LP-184 relative to otherwise isogenic parental cells. ERCC2 or BRCA2 depletion enhanced LP-184 sensitivity 5-8X in a metastatic prostate cancer cell line. LP-184 showed ~120 fold higher potency (IC50 77 nM) compared to Olaparib in HRD prostate cancer organoid model LuCaP 96 (BRCA2/CHEK2 inactivating mutations). Across 14 patient-derived pancreatic, lung and prostate tumor models harboring HR mutations (BRCA1/2, CHEK1/2, ATM/ATR, PALB2, PARP1/2, RAD51, FANCA/B), LP-184 showed ex vivo IC50s in the range of 30-300 nM, whereas Olaparib IC50s ranged from 1700-6900 nM. LP-184 treatment resulted in complete tumor regression (107-141% TGI) in 10/10 HR deficient triple negative breast cancer PDX models of which 7/10 were resistant Olaparib/Niraparib and to Doxorubicin/Cyclophosphamide. LP-184 treatment resulted in complete and durable tumor regression in HRD (BRCA1/ATR mutant) pancreatic cancer PDX models (112-140% TGI). In the ovarian cancer cell line OVCAR3 having HRD/NERD phenotype, LP-184 IC50 was 13 nM, Olaparib IC50 was 145 nM and their combination Bliss Synergy Score was 16 indicating synergy. LP-184 is synthetic lethal resulting from its abilities to cause unresolvable DNA damage if tumor cells express high PTGR1 and are deficient in NER/HR genes. Unlike PARPi, LP-184 has striking activity in both NERD as well as HRD cancers. These strong data have prompted the development of a soon to be launched clinical trial to translate the broad preclinical anticancer activity of LP-184 in solid tumors with HR/NER pathway defects, such as pancreatic, prostate, ovarian and breast cancers. Citation Format: Aditya Kulkarni, Jianli Zhou, Neha Biyani, Kishor Bhatia, Panna Sharma. LP-184, an acylfulvene class small molecule therapeutic, is synthetically lethal in DNA damage repair deficient cancers. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6241.

Multi-omics analyses reveal ClpP activators disrupt essential mitochondrial pathways in triple-negative breast cancer.

ClpP activators ONC201 and related small molecules (TR compounds, Madera Therapeutics), have demonstrated significant anti-cancer potential in vitro and in vivo studies, including clinical trials for refractory solid tumors. Though progress has been made in identifying specific phenotypic outcomes following ClpP activation, the exact mechanism by which ClpP activation leads to broad anti-cancer activity has yet to be fully elucidated. In this study, we utilized a multi-omics approach to identify the ClpP-dependent proteomic, transcriptomic, and metabolomic changes resulting from ONC201 or the TR compound TR-57 in triple-negative breast cancer cells. Applying mass spectrometry-based methods of proteomics and metabolomics, we identified ∼8,000 proteins and 588 metabolites, respectively. From proteomics data, 113 (ONC201) and 191 (TR-57) proteins significantly increased and 572 (ONC201) and 686 (TR-57) proteins significantly decreased in this study. Gene ontological (GO) analysis revealed strong similarities between proteins up- or downregulated by ONC201 or TR-57 treatment. Notably, this included the downregulation of many mitochondrial processes and proteins, including mitochondrial translation and mitochondrial matrix proteins. We performed a large-scale transcriptomic analysis of WT SUM159 cells, identifying ∼7,700 transcripts (746 and 1,100 significantly increasing, 795 and 1,013 significantly decreasing in ONC201 and TR-57 treated cells, respectively). Less than 21% of these genes were affected by these compounds in ClpP null cells. GO analysis of these data demonstrated additional similarity of response to ONC201 and TR-57, including a decrease in transcripts related to the mitochondrial inner membrane and matrix, cell cycle, and nucleus, and increases in other nuclear transcripts and transcripts related to metal-ion binding. Comparison of response between both compounds demonstrated a highly similar response in all -omics datasets. Analysis of metabolites also revealed significant similarities between ONC201 and TR-57 with increases in α-ketoglutarate and 2-hydroxyglutaric acid and decreased ureidosuccinic acid, L-ascorbic acid, L-serine, and cytidine observed following ClpP activation in TNBC cells. Further analysis identified multiple pathways that were specifically impacted by ClpP activation, including ATF4 activation, heme biosynthesis, and the citrulline/urea cycle. In summary the results of our studies demonstrate that ONC201 and TR-57 induce highly similar and broad effects against multiple mitochondrial processes required for cell proliferation.

Anticancer Activities of Novel Nicotinamide Phosphoribosyltransferase Inhibitors in Hematological Malignancies.

Targeting cancer cells that are highly dependent on the nicotinamide adenine dinucleotide (NAD+) metabolite is a promising therapeutic strategy. Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme catalyzing NAD+ production. Despite the high efficacy of several developed NAMPT inhibitors (i.e., FK866 (APO866)) in preclinical studies, their clinical activity was proven to be limited. Here, we report the synthesis of new NAMPT Inhibitors, JJ08, FEI191 and FEI199, which exhibit a broad anticancer activity in vitro. Results show that these compounds are potent NAMPT inhibitors that deplete NAD+ and NADP(H) after 24 h of drug treatment, followed by an increase in reactive oxygen species (ROS) accumulation. The latter event leads to ATP loss and mitochondrial depolarization with induction of apoptosis and necrosis. Supplementation with exogenous NAD+ precursors or catalase (ROS scavenger) abrogates the cell death induced by the new compounds. Finally, in vivo administration of the new NAMPT inhibitors in a mouse xenograft model of human Burkitt lymphoma delays tumor growth and significantly prolongs mouse survival. The most promising results are collected with JJ08, which completely eradicates tumor growth. Collectively, our findings demonstrate the efficient anticancer activity of the new NAMPT inhibitor JJ08 and highlight a strong interest for further evaluation of this compound in hematological malignancies.

Artemisitene suppresses rheumatoid arthritis progression via modulating METTL3-mediated N6-methyladenosine modification of ICAM2mRNA in fibroblast-like synoviocytes.

Rheumatoid arthritis (RA) is a chronic autoimmune disease. We previously revealed that the natural compound artemisitene (ATT) exhibits excellent broad anticancer activities without toxicity on normal tissues. Nevertheless, the effect of ATT on RA is undiscovered. Herein, we aim to study the effect and potential mechanism of ATT on RA management. A collagen-induced arthritis (CIA) mouse model was employed to confirm the anti-RA potential of ATT. Cell Counting Kit-8(CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays, cell cycle and apoptosis analysis, immunofluorescence, migration and invasion assays, quantitative real-time PCR (RT-qPCR), Western blot, RNA-sequencing (RNA-seq) analysis, plasmid construction and lentivirus infection, and methylated RNA immunoprecipitation and chromatin immunoprecipitation assays, were carried out to confirm the effect and potential mechanism of ATT on RA management. ATT relieved CIA in mice. ATT inhibited proliferation and induced apoptosis of RA-fibroblast-like synoviocytes (FLSs). ATT restrained RA-FLSs migration and invasion via suppressing epithelial-mesenchymal transition. RNA-sequencing analysis and bioinformatics analysis identified intercellular adhesion molecule 2 (ICAM2) as a promoter of RA progression in RA-FLSs. ATT inhibits RA progression by suppressing ICAM2/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/p300 pathway in RA-FLSs. Moreover, ATT inhibited methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine methylation of ICAM2 mRNA in RA-FLSs. Interestingly, p300 directly facilitated METTL3 transcription, which could be restrained by ATT in RA-FLSs. Importantly, METTL3, ICAM2 and p300 expressions in synovium tissues of RA patients were related to clinical characteristics and therapy response. We provided strong evidence that ATT has therapeutic potential for RA management by suppressing proliferation, migration and invasion, in addition to inducing apoptosis of RA-FLSs through modulating METTL3/ICAM2/PI3K/AKT/p300 feedback loop, supplying the fundamental basis for the clinical application of ATT in RA therapy. Moreover, METTL3, ICAM2 and p300 might serve as biomarkers for the therapy response of RA patients.

The magic bullet: Niclosamide.

The term 'magic bullet' is a scientific concept proposed by the German Nobel laureate Paul Ehrlich in 1907, describing a medicine that could specifically and efficiently target a disease without harming the body. Oncologists have been looking for a magic bullet for cancer therapy ever since. However, the current therapies for cancers-including chemotherapy, radiation therapy, hormone therapy, and targeted therapy-pose either pan-cytotoxicity or only single-target efficacy, precluding their ability to function as a magic bullet. Intriguingly, niclosamide, an FDA-approved drug for treating tapeworm infections with an excellent safety profile, displays broad anti-cancer activity in a variety of contexts. In particular, niclosamide inhibits multiple oncogenic pathways such as Wnt/β-catenin, Ras, Stat3, Notch, E2F-Myc, NF-κB, and mTOR and activates tumor suppressor signaling pathways such as p53, PP2A, and AMPK. Moreover, niclosamide potentially improves immunotherapy by modulating pathways such as PD-1/PDL-1. We recently discovered that niclosamide ethanolamine (NEN) reprograms cellular metabolism through its uncoupler function, consequently remodeling the cellular epigenetic landscape to promote differentiation. Inspired by the promising results from the pre-clinical studies, several clinical trials are ongoing to assess the therapeutic effect of niclosamide in cancer patients. This current review summarizes the functions, mechanism of action, and potential applications of niclosamide in cancer therapy as a magic bullet.

Opaganib Protects against Radiation Toxicity: Implications for Homeland Security and Antitumor Radiotherapy.

Exposure to ionizing radiation (IR) is a lingering threat from accidental or terroristic nuclear events, but is also widely used in cancer therapy. In both cases, host inflammatory responses to IR damage normal tissue causing morbidity and possibly mortality to the victim/patient. Opaganib, a first-in-class inhibitor of sphingolipid metabolism, has broad anti-inflammatory and anticancer activity. Opaganib elevates ceramide and reduces sphingosine 1-phosphate (S1P) in cells, conditions that increase the antitumor efficacy of radiation while concomitantly suppressing inflammatory damage to normal tissue. Therefore, opaganib may suppress toxicity from unintended IR exposure and improve patient response to chemoradiation. To test these hypotheses, we first examined the effects of opaganib on the toxicity and antitumor activity of radiation in mice exposed to total body irradiation (TBI) or IR with partial bone marrow shielding. Oral treatment with opaganib 2 h before TBI shifted the LD75 from 9.5 Gy to 11.5 Gy, and provided substantial protection against gastrointestinal damage associated with suppression of radiation-induced elevations of S1P and TNFα in the small intestines. In the partially shielded model, opaganib provided dose-dependent survival advantages when administered 4 h before or 24 h after radiation exposure, and was particularly effective when given both prior to and following radiation. Relevant to cancer radiotherapy, opaganib decreased the sensitivity of IEC6 (non-transformed mouse intestinal epithelial) cells to radiation, while sensitizing PAN02 cells to in vitro radiation. Next, the in vivo effects of opaganib in combination with radiation were examined in a syngeneic tumor model consisting of C57BL/6 mice bearing xenografts of PAN02 pancreatic cancer cells and a cross-species xenograft model consisting of nude mice bearing xenografts of human FaDu cells. Mice were treated with opaganib and/or IR (plus cisplatin in the case of FaDu tumors). In both tumor models, the optimal suppression of tumor growth was attained by the combination of opaganib with IR (± cisplatin). Overall, opaganib substantially protects normal tissue from radiation damage that may occur through unintended exposure or cancer radiotherapy.

P11.03.B BXQ-350: Modulating ceramide and Sphingosine-1-Phosphate for anti-tumor activity and potential mitigation of chemotherapy induced peripheral neuropathy

Abstract Background Sphingolipids are a class of bioactive signaling molecules implicated in multiple cellular processes and molecular pathways. Many publications have indicated that among these sphingolipids, sphingosine-1-phosphate (S1P) is a key sphingolipid that promotes cancer cell survival and proliferation, activates multiple oncogenic pathways, and stimulates immuno-suppressor cell populations promoting a pro-tumoral microenvironment. Many of these publications have also implicated S1P with chemotherapy induced peripheral neuropathy, a debilitating and serious side effect that may impact therapeutic treatments and patient’s quality of life. Material and Methods BXQ-350 is a nanovesicle of Saposin C, an allosteric activator of sphingolipid metabolism, that has broad anticancer activity, potentially in part by lowering systemic S1P levels. BXQ-350 was investigated in a Phase 1 dose-escalation safety study in an all-comer cancer patients with advanced solid malignancies, including CNS tumors (NCT02859857) to determine its safety profile and its potential clinical activity as a single agent in cancer patients. Samples were collected to determine pharmacokinetics and explore potential biomarkers. Results 11 patients (~15% of evaluable patients) with advanced disease had a clinical benefit and amongst these, 8 patients (~11% of evaluable patients) had PFS&amp;gt; 6 months with 2 patients still on study five years after enrollment. Analysis of patient’s samples revealed that BXQ-350 decreases systemic S1P levels in the majority of the patients experiencing a clinical benefit. In addition, several patients with established CIPN spontaneously reported improvements of their symptoms shortly after BXQ-350 administration. Analysis of these patients’ samples also revealed that S1P systemic levels had decreased, as well as pro-inflammatory cytokines associated with CIPN. Conclusion While these results are exploratory and preliminary in nature, they suggest that BXQ-350’s mechanism of action may represent a novel anti-cancer approach that may also mitigate CIPN.

Ligand- and structure-based identification of novel CDK9 inhibitors for the potential treatment of leukemia

Cyclin-dependent kinase 9 (CDK9) plays a vital role in controlling cell transcription and has been an attractive target for cancer treatment. Herein, ten predictive models derived from 1330 unique molecules against CDK9 were constructed based on molecular fingerprints and graphs using two conventional machine learning and four deep learning methods. The evaluation results showed that FP-GNN deep learning architecture performed best for CDK9 inhibitors prediction with the highest BA and F1 values of 0.681 and 0.912 for testing set. We then performed virtual screening to identify new CDK9 inhibitors by incorporating the optimal established predictive model and molecular docking. Five compounds were identified to show broad anticancer activity against various cancer cell lines through bioassays. For example, C9 exhibited antiproliferative activities against HeLa, MOLM-13 and MDA-MB-231 with IC50 values of 2.53, 3.92 and 11.65 μM. Kinase inhibition assay results demonstrated that these compounds displayed submicromolar (214 ∼ 504 nM) inhibitory activities against CDK9. Further cellular mechanism evaluation revealed that C9 suppressed the activity of CDK9 and interfered with the expression of Mcl-1 and cleaved PARP in MOLM-13 cells, resulting in the induction of cellular apoptosis. In addition, C9 displayed a good stability in rat liver microsomes, artificial gastrointestinal fluid and plasm. An online platform (called DEEPCDK9Pred) was developed based on the FP-GNN models to predict or design new CDK9 inhibitors. Collectively, our findings demonstrated that FP-GNN algorithm can achieve accurate prediction of CDK9 inhibitors and the subsequent discovery of C9 as a new potential CDK9 inhibitor deserves further structural modification for the treatment of leukemia.

Abstract 5455: Nuclear export inhibitor selinexor synergizes with proteasome inhibitor marizomib in preclinical models of glioblastoma

Abstract Background: Glioblastoma (GBM) is an aggressive brain cancer with poor prognosis and limited treatment options. Selinexor is a first-in-class oral inhibitor of Exportin 1 (XPO1/CRM1) with broad anti-cancer activities and is clinically approved to treat multiple myeloma and diffuse large B cell lymphoma. In a phase 2 study of recurrent GBM, monotherapy of selinexor demonstrated clinically relevant disease control (Lassman 2021 Clin Cancer Res). Our previous preclinical studies identified synergy between selinexor and proteasome inhibitors in GBM in vitro. Among the proteasome inhibitors tested, we chose to focus on marizomib due to its ability to cross the blood-brain-barrier, supporting its use in GBM. We tested GBM cell lines and mouse xenograft models to evaluate the anti-GBM effects of selinexor and marizomib in combination. Methods: Cytotoxic effects of selinexor and marizomib were evaluated with two GBM cell lines LN18 and U87MG. The anti-GBM effects of selinexor and marizomib were further investigated in vivo with U87MG mouse xenograft models of GBM. Female nude mice carrying U87MG subcutaneous implants were treated with vehicle, selinexor, marizomib or the combination of the two agents (six mice per treatment group). Tumor volume and body weight were monitored throughout the study. Tumor samples were collected at the end of the study for transcriptomic analysis and immunohistochemistry tests. Results: Synergistic anti-GBM effects of selinexor and marizomib were observed in both LN18 and U87MG cells in vitro. In mouse xenograft models of U87MG, tumor growth was significantly inhibited by selinexor and marizomib single agents relative to controls, at Day 15 of the study, tumor growth inhibition (TGI) was 60.0% (p=0.0009) for selinexor (10 mg/kg, once per week), 49.2% (p=0.0069) for marizomib once weekly at 75 µg/kg, and 33.1% (p=0.0991) for marizomib once every 2 weeks at 75 µg/kg. Synergistic anti-GBM effect was observed in the combination groups, with a TGI of 99.6% (p&amp;lt;0.0001) for selinexor with once weekly marizomib, and a TGI of 90.0% (p&amp;lt;0.0001) for selinexor with once every other week marizomib. Conclusions: Synergistic anti-GBM effects of selinexor and marizomib in preclinical models warrants further investigation. The synergism is likely due to enhanced inhibition of the NFκB signaling pathways as previously demonstrated for selinexor and proteasome inhibitor combination. Citation Format: Hua Chang, Leah Henegar, Christopher J. Walker, Trinayan Kashyap, Marie Maloof, Feng Wang, Kathleen Martyn, Shira Orr, Sharon Tamir, Michael G. Kauffman, Sharon Shacham, Yosef Landesman. Nuclear export inhibitor selinexor synergizes with proteasome inhibitor marizomib in preclinical models of glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5455.

Abstract 1132: A systems biology approach combining ProLiFiler and Cancer Data Miner for an enhanced preclinical characterization of the WEE-1 inhibitor Adavosertib

Abstract Adavosertib (AZD1775, MK-1775), a clinical stage inhibitor of the tyrosine kinase WEE1, was investigated in a cell proliferation and survival assay with 140 human cancer cell lines (CLs) representing all major tumor types (ProLiFiler platform of Reaction Biology) followed by mechanism of action (MoA) and biomarker analyses using 4HF Biotec’s Cancer Data Miner in silico platform. Adavosertib exhibited a broad anti-cancer activity across all hematological and solid tumor types with IC50 values ranging from 0.06 to 10 µM (median: 0.38 µM), matching the consistently high expression of the WEE1 gene. Among 900 reference compounds, the activity profile of adavosertib correlated best with the profiles of compounds targeting the replication stress response including other WEE1 inhibitors but also inhibitors of checkpoint kinase 1 and 2 (CHK1/2) or ataxia telangiectasia-mutated (ATM). Significant correlations were also seen with compounds blocking mitosis, DNA replication and DNA repair. Interestingly, we observed a subset of cell lines that were resistant to both DNA synthesis and PARP inhibitors but were sensitive to WEE1 inhibition. Moreover, by using multiple datasets of WEE1 inhibitors connected to the molecular annotations of CLs for a data driven biomarker screening, we identified MYC mutations as a predictive marker of sensitivity and PIK3CA or ERBB2 gene amplifications as predictors of resistance. Transcriptome analysis identified up to 900 genes for which higher expression in CLs was associated with CL sensitivity to the compound. Preliminary pathway analysis indicated that these genes are well represented among nuclear factor and Myc-regulated genes. In conclusion, our studies demonstrate broad anticancer activity of adavosertib and confirm its proposed MoA. The biomarkers we identified will facilitate the selection of pre-clinical in vivo tumor models and, if confirmed, even patient selection for clinical trials. The combined use of the ProLiFiler and Cancer Data Miner Platforms has the potential to accelerate and de-risk the development of anti-cancer agents. Citation Format: Vincent Vuaroqueaux, Daniel Feger, Anne-Lise Peille, Oliver Siedentopf, Sadhana Panzade, Sarah Ulrich, Sebastian Dempe, Heinz-Herbert Fiebig, Jan Erik Ehlert. A systems biology approach combining ProLiFiler and Cancer Data Miner for an enhanced preclinical characterization of the WEE-1 inhibitor Adavosertib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1132.