Tumor Growth Inhibitory Activity Research Articles

Albendazole nanosuspension coated granules for the rapid localized release and treatment of colorectal cancer

Albendazole (ABZ), an anthelmintic drug, has been repurposed to treat various types of cancers. However, poor solubility of ABZ, resulting in low bioavailability, limits its application. Nanosuspension is a versatile method for enhancing the dissolution of hydrophobic molecules, but a successful drying has been the biggest challenge in the field. The objective of this research is to formulate and optimize ABZ nanosuspension (NS) coated granules for rapid delivery of ABZ for the treatment of colorectal cancer. ABZ NS was prepared by dual centrifugation method using Kollidon® VA64 and sodium lauryl sulphate (SLS) as stabilizers. The processing method was optimized to obtain a stable nanosuspension with particle size < 300 nm. The optimized ABZ NS was coated on microcrystalline cellulose (MCC) to form the nano-coated granules (NCG) and filled in EUDRACAP® for colon targeted delivery. The ABZ NS and NCG achieved ∼ 60 % and ∼55 % drug release, respectively, in presence of bile salt at colonic pH. Half-maximal inhibitory concentration (IC50) of ABZ NS was found to be 1.18 ± 0.081 µM and 3.59 ± 0.080 µM in two colorectal cancer cell lines: HCT 116 and HT-29, respectively. In addition, In vitro 3D tumor assay revealed that ABZ NS has superior tumor growth inhibition activity compared to the control and pure ABZ. The preparation of ABZ NCG in EUDRACAP® could be a promising approach to achieve colon targeted delivery and to repurpose ABZ for the treatment of colorectal cancer.

Enhancer reprogramming underlies therapeutic utility of a SMARCA2 degrader in SMARCA4 mutant cancer.

Genomic studies have identified frequent mutations in subunits of the SWI/SNF (switch/sucrose non-fermenting) chromatin remodeling complex including SMARCA4 and ARID1A in non-small cell lung cancer (NSCLC). Genetic evidence indicates that the paralog SMARCA2 is synthetic lethal to SMARCA4 suggesting SMARCA2 is a valuable therapeutic target. However, the discovery of selective inhibitors of SMARCA2 has been challenging. Here, we utilized structure-activity relationship (SAR) studies to develop YD23, a potent and selective proteolysis targeting chimera (PROTAC) targeting SMARCA2. Mechanistically, we show that SMARCA2 degradation induces reprogramming of the enhancer landscape in SMARCA4-mutant cells with loss of chromatin accessibility at enhancers of genes involved in cell proliferation. Furthermore, we identified YAP/TEADas key partners to SMARCA2 in driving growth of SMARCA4-mutant cells. Finally, we show that YD23 has potent tumor growth inhibitory activity in SMARCA4-mutant xenografts. These findings provide the mechanistic basis for development of SMARCA2 degraders as synthetic lethal therapeutics against SMARCA4-mutant lung cancers.

Discovery of 5-(Piperidin-4-yl)-1,2,4-oxadiazole Derivatives as a New Class of Human Caseinolytic Protease P Agonists for the Treatment of Hepatocellular Carcinoma.

Chemical agonism of human caseinolytic protease P (HsClpP) is increasingly being recognized as a potential anticancer strategy due to its critical role in maintaining mitochondrial homeostasis. We unveil the discovery of 5-(piperidin-4-yl)-1,2,4-oxadiazole derivatives as a novel class of HsClpP agonists and demonstrate for the first time the application of HsClpP agonists in the treatment of hepatocellular carcinoma (HCC) (Pace, A.; Pierro, P. The new era of 1,2,4-oxadiazoles. Org. Biomol. Chem. 2009, 7 (21), 4337-4348). Compound SL44 exhibited potent HsClpP agonistic activity in the α-casein hydrolysis assay (EC50 = 1.30 μM) and inhibited the proliferation of HCCLM3 cells (IC50 = 3.1 μM, 21.4-fold higher than hit ADX-47273). Mechanistically, SL44 induces degradation of respiratory chain complex subunits and leads to apoptosis in HCC cells. In vivo results demonstrated that SL44 has potent tumor growth inhibitory activity and has a superior safety profile compared to the kinase inhibitor sorafenib. Overall, we developed a novel class of HsClpP agonists that can potentially be used for the treatment of HCC.

An open-label, multicenter, phase I study of ATG-022 in patients with advanced/metastatic solid tumors (CLINCH).

3032 Background: Claudin 18.2 (CLDN 18.2) is a tumor associated antigen broadly expressed in gastric, pancreatic, and other solid tumors. ATG-022 is an antibody drug conjugate (ADC), consisting of a humanized monoclonal antibody that binds to CLDN 18.2 with high affinity of sub-nM grade and a conjugated linker-payload vc-MMAE. ATG-022 has displayed promising tumor growth inhibition activity both in vitro and in vivo. Methods: CLINCH is a phase I, multi-center, open-label, dose-finding study (NCT05718895) of ATG-022 in patients with advanced solid tumours. The study design includes a dose escalation phase, enrolling subjects with advanced/metastatic solid tumors, regardless of CLDN 18.2 expression, and a dose expansion phase which will enroll select advanced/metastatic solid tumors with CLDN 18.2-positive expression at the defined maximum tolerated dose and/or recommended Phase 2 dose to further evaluate the safety, tolerability, and efficacy of ATG-022. Other endpoints include pharmacokinetics (PK) and exploratory biomarkers of drug activity. In the dose escalation phase, ATG-022 is administered intravenously every 3 weeks (Q3W) at the starting dose of 0.3 mg/kg, followed by 0.9, 1.8, 2.4, 3.0, and 3.6 mg/kg Q3W using a modified 3+3 dose-escalation design. Efficacy assessments are evaluated per RECIST1.1 criteria. Results: As of 9 Oct 2023, 10 patients (pts) with advanced solid tumors have been enrolled to receive ATG-022 at a dose from 0.3 to 2.4 mg/kg. Median age was 59 years. Baseline ECOG scores were 0 (0 pts) and 1 (10 pts); 8 pts had stage IV disease. Three pts had received more than 3 prior lines of systemic therapy. Eight pts (80%) had ≥ 1 TRAEs; 1 pt (10%) had ≥ 1 Serious TRAEs; 3 (30%) pts had grade ≥ 3 TRAEs. The most common grade ≥ 3 TRAEs included nausea (30%), vomiting (30%) and decreased appetite (30%). No DLT was reported among the current dose levels. Among 7 pts with gastric cancer, 3 pts are confirmed to be CLDN 18.2 positive. One of these pts has maintained stable disease with tumor shrinkage for more than 6 months (treatment ongoing) at a dose of 0.9 mg/kg, demonstrating tolerability of ATG-022. One PR was observed in a gastric cancer pt (CLDN 18.2 expression to be determined) at the dosage of 1.8 mg/kg. It was noteworthy that a CR was seen in a gastric cancer pt dosed at 2.4 mg/kg, with negative CLDN 18.2 expression. PK analysis of ATG-022 from 0.3 to 2.4 mg/kg revealed that the exposure of total antibody, MMAE and ADC drug is increased as dose increased. No accumulation of ATG-022 was observed. Conclusions: ATG-022 demonstrated preliminary anti-tumor activity, tolerability, safety, as well as comparable PK properties at current dose levels. The high affinity of sub-nM grade of ATG-022 in pts with low CLDN 18.2 expression needs further investigation. The dose escalation is ongoing and updated data will be presented. Clinical trial information: NCT05718895 .

A combination of a TLR7/8 agonist and an epigenetic inhibitor suppresses triple-negative breast cancer through triggering anti-tumor immune

BackgroundCombination therapy involving immune checkpoint blockade (ICB) and other drugs is a potential strategy for converting immune-cold tumors into immune-hot tumors to benefit from immunotherapy. To achieve drug synergy, we developed a homologous cancer cell membrane vesicle (CM)-coated metal-organic framework (MOF) nanodelivery platform for the codelivery of a TLR7/8 agonist with an epigenetic inhibitor.MethodsA novel biomimetic codelivery system (MCM@UN) was constructed by MOF nanoparticles UiO-66 loading with a bromodomain-containing protein 4 (BRD4) inhibitor and then coated with the membrane vesicles of homologous cancer cells that embedding the 18 C lipid tail of 3M-052 (M). The antitumor immune ability and tumor suppressive effect of MCM@UN were evaluated in a mouse model of triple-negative breast cancer (TNBC) and in vitro. The tumor immune microenvironment was analyzed by multicolor immunofluorescence staining.ResultsIn vitro and in vivo data showed that MCM@UN specifically targeted to TNBC cells and was superior to the free drug in terms of tumor growth inhibition and antitumor immune activity. In terms of mechanism, MCM@UN blocked BRD4 and PD-L1 to prompt dying tumor cells to disintegrate and expose tumor antigens. The disintegrated tumor cells released damage-associated molecular patterns (DAMPs), recruited dendritic cells (DCs) to efficiently activate CD8+ T cells to mediate effective and long-lasting antitumor immunity. In addition, TLR7/8 agonist on MCM@UN enhanced lymphocytes infiltration and immunogenic cell death and decreased regulatory T-cells (Tregs). On clinical specimens, we found that mature DCs infiltrating tumor tissues of TNBC patients were negatively correlated with the expression of BRD4, which was consistent with the result in animal model.ConclusionMCM@UN specifically targeted to TNBC cells and remodeled tumor immune microenvironment to inhibit malignant behaviors of TNBC.

DB-1310, an ADC comprised of a novel anti-HER3 antibody conjugated to a DNA topoisomerase I inhibitor, is highly effective for the treatment of HER3-positive solid tumors

BackgroundHER3 (ErbB3), a member of the human epidermal growth factor receptor family, is frequently overexpressed in various cancers. Multiple HER3-targeting antibodies and antibody–drug conjugates (ADCs) were developed for the solid tumor treatment, however none of HER3-targeting agent has been approved for tumor therapy yet. We developed DB-1310, a HER3 ADC composed of a novel humanized anti-HER3 monoclonal antibody covalently linked to a proprietary DNA topoisomerase I inhibitor payload (P1021), and evaluate the efficacy and safety of DB-1310 in preclinical models.MethodsThe binding of DB-1310 to Her3 and other HER families were measured by ELISA and SPR. The competition of binding epitope for DB-1310 and patritumab was tested by FACS. The sensitivity of breast, lung, prostate and colon cancer cell lines to DB-1310 was evaluated by in vitro cell killing assay. In vivo growth inhibition study evaluated the sensitivity of DB-1310 to Her3 + breast, lung, colon and prostate cancer xenograft models. The safety profile was also measured in cynomolgus monkey.ResultsDB-1310 binds HER3 via a novel epitope with high affinity and internalization capacity. In vitro, DB-1310 exhibited cytotoxicity in numerous HER3 + breast, lung, prostate and colon cancer cell lines. In vivo studies in HER3 + HCC1569 breast cancer, NCI-H441 lung cancer and Colo205 colon cancer xenograft models showed DB-1310 to have dose-dependent tumoricidal activity. Tumor suppression was also observed in HER3 + non-small cell lung cancer (NSCLC) and prostate cancer patient-derived xenograft (PDX) models. Moreover, DB-1310 showed stronger tumor growth-inhibitory activity than patritumab deruxtecan (HER3-DXd), which is another HER3 ADC in clinical development at the same dose. The tumor-suppressive activity of DB-1310 synergized with that of EGFR tyrosine kinase inhibitor, osimertinib, and exerted efficacy also in osimertinib-resistant PDX model. The preclinical assessment of safety in cynomolgus monkeys further revealed DB-1310 to have a good safety profile with a highest non severely toxic dose (HNSTD) of 45 mg/kg.ConclusionsThese finding demonstrated that DB-1310 exerted potent antitumor activities against HER3 + tumors in in vitro and in vivo models, and showed acceptable safety profiles in nonclinical species. Therefore, DB-1310 may be effective for the clinical treatment of HER3 + solid tumors.

Abstract CT066: Phase 1 study of MDM2 antagonist ASTX295 in patients with solid tumors with wild-type TP53

Abstract Background: ASTX295 is a novel small molecule antagonist of human Murine Double Minute 2 (MDM2), which tightly regulates the level and activity of the p53 tumor suppressor. To minimize potential thrombocytopenia previously seen with antagonism of this target, ASTX295 was designed to have a short half-life (t1/2) with decreased bone marrow (BM) exposure. ASTX295 has proapoptotic and tumor growth inhibitory activity in preclinical cancer (CA) models. We report here the safety and preliminary efficacy of the phase 1 and dose expansion portions of Study ASTX295-01. Methods: ASTX295-01 is a first-in-human, open-label, multicenter, phase 1/2 study to assess safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary clinical activity of ASTX295 (NCT03975387). Eligible patients (advanced solid tumors with Wild-Type [WT] TP53, ECOG PS 0-2, adequate organ and bone marrow function, etc.) had oral administration of ASTX295 starting at a daily dose of 15 mg. Dose escalation was by standard 3 + 3 with cohorts testing multiple regimens. Safety was assessed by CTCAE and disease was assessed by RECIST 1.1. Safety and efficacy and dosing recommendations were overseen by the Data Safety Review Committee. Results:83 subjects were enrolled in over 14 cohorts, evaluating daily (QD) and intermittent dosing regimens and the effect of food. The mean age of subjects on study was 60.1 year, 56.9 were male, with 2.94 (0-15) prior chemotherapy regimens. For PK exposure, the total weekly AUC for 400 mg QD and 660 twice a week (BIW) are similar. The median tmax is 3 hours and mean t1/2 is 4-6 hours. PD demonstrates p53 pathway modulation. Nausea, vomiting, diarrhea, and fatigue were dose limiting. RP2D regimens were 660 mg BIW and 400 mg QD and these regimens were expanded with a total of 25 additional subjects. The most common treatment related AEs for both regimens were nausea, diarrhea, and vomiting at 76.2%,76.2%, and 33.3% respectively, for daily and 71.4%, 47.6%, and 33.3%, for intermittent. Grade 3 GI AEs were reported in 14.3% of subjects in the daily cohort vs 9.5% in the intermittent; none had Grade ≥ 4. One subject had grade 2 thrombocytopenia. Based on decreased incidence and duration of GI AEs, 660 mg BIW was selected as the RP2D.Multiple objective responses were seen, including 1 subject with non-small cell lung CA and 3 subjects with liposarcoma (LPS), a tumor with frequent MDM2 amplification. For LPS the ORR is 7.9% (de-differentiated 7.7%, well differentiated 8.0%), with a PFS of 7.95 and 9.66 months respectively, along with a 16-week disease control rate of 69.2% and 72.0%. Five subjects with GBM were enrolled, 4 with MDM2 amplification, 3 of whom showed evidence of tumor regression, with one subject remaining on study for &amp;gt; 34 cycles. Conclusion:ASTX295 was well tolerated at doses producing p53 pathway modulation with manageable toxicities, notably avoiding significant thrombocytopenia. Preliminary single agent efficacy was observed in heavily pretreated subjects across multiple solid tumor types with WT TP53. Citation Format: Ecaterina E. Dumbrava, Fabio M. Iwamoto, Mark Agulnik, Mohammed Milhem, Anthony W. Tolcher, Rashmi Chugh, Michael J. Demeure, Alain Mita, Kurt Demel, Mark Diamond, Beloo Mirakhur, Laksmi Wilson, Aram Oganesian, Danna Chan, Harold N. Keer, Jason Taylor, Martin J. Sims, Andrea Biondo, Simone Jueliger, Alexander Spira. Phase 1 study of MDM2 antagonist ASTX295 in patients with solid tumors with wild-type TP53 [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 CT066.

Abstract LB126: Generation of a novel ROR1 x CD3 bispecific T-cell engager for better tumor killing and minimal cytokine release

Abstract Receptor tyrosine kinase-like orphan receptor 1 (ROR1) expression is a highly specific tumor associated antigen expressed in multiple hematological malignancies and solid tumors. EMB-07 is a novel monovalent asymmetrical tandem Fab (MAT-Fab) antibody composed of two different Fab fragments targeting ROR1 and CD3ε respectively, and a “knob-in-hole” Fc fragment maintaining FcRn binding and Ig-like pharmacokinetics in vivo. To avoid light chain miss-pairing, the anti-ROR1 light chain was directly connected to the N-terminus of the anti-CD3 heavy chain. The ROR1 binding arm has a high affinity of 0.52 nM and recognizes a membrane distal epitope, which is different from a reference BiTE molecule currently in clinical trial. In comparison with this BiTE molecule, EMB-07 showed similar tumor killing efficacy to ROR1 expressing tumor cell lines while it induced much lower levels of cytokines both in vitro and in vivo. Moreover, comparing with a clinical stage ROR1-vc-MMAE ADC, EMB-07 demonstrated ~500-fold increased tumor lysis potency in vitro. In PD-1 resistant tumor xenograft mice models, EMB-07 showed potent tumor growth inhibition and synergistic activity in combination with PD-1 blockade. In a preclinical GLP toxicological study, EMB-07 was well tolerated in cynomolgus monkeys with no evidence of lethality, life-threatening toxicity, or obvious EMB-07-related macroscopic and histopathological adverse findings up to 50 mg/kg. By using a highly specific IHC clone, we validated membrane-associated ROR1 expression in multiple tumor types, including triple negative breast cancer, ovarian cancer, endometrial cancer, lung adenocarcinoma, and pancreatic cancer, while the observation of its expression in normal tissues is very limited. This study supports the clinical development of EMB-07 for treating multiple solid tumors with ROR1 expression. A FIH study of EMB-07 in locally advanced/metastatic solid tumors or relapse/refractory lymphoma is currently ongoing (NCT05607498). Citation Format: Danqing Wu, Shiyong Gong, Xuan Wu, Gaowa Naren, Liqin Dong, Stephan Lensky, Chengbin Wu. Generation of a novel ROR1 x CD3 bispecific T-cell engager for better tumor killing and minimal cytokine release [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 LB126.

Abstract 4073: Decoy-resistant IL-18 enhances checkpoint inhibitor combinations beyond anti-PD-1 in vitro and in vivo

Abstract Background: Interleukin-18 (IL18) is a proinflammatory cytokine that modulates both innate and adaptive immune responses. Historically, wild-type recombinant IL-18 has shown limited anti-tumor efficacy in preclinical models and clinical trials, likely due to upregulation of IL-18 binding protein (IL-18BP), a negative regulator of the IL-18 signaling axis. Accordingly, an engineered IL-18 cytokine capable of interacting with the IL-18 receptor, but resistant to IL-18BP interactions (i.e., “Decoy-Resistant IL-18”, DR-18), has demonstrated enhanced therapeutic potential in mouse tumor models, both as a single agent and in combination with anti-PD-1 [1, 2]. Here we evaluated murine DR-18 in combination with additional checkpoint inhibitors beyond anti-PD-1 in a set of mouse tumor models, and tested human DR-18 activity in vitro/ex vivo for activation of human immune cells and anti-tumor activity. Results: Treatment with mDR-18 elicited strong efficacy as a single agent and combination activity with immune checkpoint inhibitors (ICIs) across diverse syngeneic mouse models of solid tumors. As a single agent, mDR-18 demonstrated robust single agent activity in tumor growth inhibition for MC38 (&amp;gt;80%), CT26 (&amp;gt;60%) and B16-F10 (&amp;gt;55%). Combination treatment of mDR-18 with anti-PD-1, anti-CTLA-4, or anti-LAG-3 increased the efficacy for the MC38 (&amp;gt;85-95%), CT26 models (&amp;gt;80-85%), while the B16-F10 (&amp;gt;60%) showed smaller efficacy enhancement with the combinations. In vitro assays revealed human DR-18 (ST-067) activated immune cells and enhanced A549 tumor cell killing over 72hrs. Furthermore, ex vivo studies of 3D patient-derived tumor spheroids demonstrated that ST-067 impaired growth and increased immune cell infiltration, highlighting the potential of hDR-18 to enhance immune activity within the human tumor microenvironment. Conclusion: These studies expand the breadth of IL-18/checkpoint synergism beyond anti-PD-1 and confirm enhanced human immune response in vitro with the clinical candidate ST-067. Taken together, these findings strengthen the rationale for clinical combination of ST-067 with ICI agents in patients with solid tumors. 1.Zhou T, Damsky W, Weizman OE, et al. IL-18BP is a secreted immune checkpoint and barrier to IL-18 immunotherapy. Nature. 2020;583(7817):609-614. doi:10.1038/s41586-020-2422-62.Minnie SA, Waltner OG, Ensbey KS, et al. Depletion of exhausted alloreactive T cells enables targeting of stem-like memory T cells to generate tumor-specific immunity. Sci Immunol. 2022;7(76):eabo3420. doi:10.1126/sciimmunol.abo3420 Citation Format: Jeffrey N. Lindquist, Kai Qin, Aaron M. Ring, Hirdesh Uppal. Decoy-resistant IL-18 enhances checkpoint inhibitor combinations beyond anti-PD-1 in vitro and in vivo [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 4073.

Abstract 7202: Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells

Abstract Pancreatic cancer (PC) is one of the most malignant cancers with limitation of treatment options such as resection surgery, radiation therapy and gemcitabine-based chemotherapy. To treating PC patients, gemcitabine-based chemotherapy is common and effective for PC, acquired gemcitabine resistance is one of the major reasons for treatment failure. Therefore, there is a need to suggest effective strategies and novel therapeutic approach for gemcitabine-resistant PC. Protein Kinase C β1 (PKC β1) is known as involved in multiple signal transduction related to oncogenic functions in cancer. We suggested that PKC β as one of the novel biomarker of drug resistance and further investigated the molecular mechanism. Among the natural products as small molecule inhibitor, we found that evodiamine has potent antitumor activity and various biological activities. Based on various biological activities of evodiamine, the scaffold was synthesized and investigated for antiproliferative and antitumor activities against gemcitabine resistant PANC-1 (PANC-GR) cells. Also, target validation experiment was employed to elucidate the molecular mechanism and verifying the target to overcoming gemcitabine resistance. Mechanistically, evodiamine derivatives have shown that inhibition of PKC β1 can modulate the proliferation of PANC-GR cells and exhibited tumor growth inhibitory activity in xenograft mouse model. Keywords: Pancreatic cancer cell, Gemcitabine resistance, Protein Kinase C β1 (PKC β1), Molecular mechanism Acknowledgements: This research was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (RS-2023-00273240). Citation Format: EunSeo Bae, Yijae Lim, Junhwa Hong, Woong Sub Byun, Simin Chun, Suckchang Hong, Sang Kook Lee. Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells [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 7202.

Targeting the Melanocortin 1 Receptor in Melanoma: Biological Activity of α-MSH-Peptide Conjugates.

Malignant melanoma is one of the most aggressive and resistant tumor types, with high metastatic properties. Because of the lack of suitable chemotherapeutic agents for treatment, the 5-year survival rate of melanoma patients with regional and distant metastases is lower than 10%. Targeted tumor therapy that provides several promising results might be a good option for the treatment of malignant melanomas. Our goal was to develop novel melanoma-specific peptide-drug conjugates for targeted tumor therapy. Melanocortin-1-receptor (MC1R) is a cell surface receptor responsible for melanogenesis and it is overexpressed on the surface of melanoma cells, providing a good target. Its native ligand, α-MSH (α-melanocyte-stimulating hormone) peptide, or its derivatives, might be potential homing devices for this purpose. Therefore, we prepared three α-MSH derivative-daunomycin (Dau) conjugates and their in vitro and in vivo antitumor activities were compared. Dau has an autofluorescence property; therefore, it is suitable for preparing conjugates for in vitro (e.g., cellular uptake) and in vivo experiments. Dau was attached to the peptides via a non-cleavable oxime linkage that was applied efficiently in our previous experiments, resulting in conjugates with high tumor growth inhibition activity. The results indicated that the most promising conjugate was the compound in which Dau was connected to the side chain of Lys (Ac-SYSNleEHFRWGK(Dau=Aoa)PV-NH2). The highest cellular uptake by melanoma cells was demonstrated using the compound, with the highest tumor growth inhibition detected both on mouse (38.6% on B16) and human uveal melanoma (55% on OMC-1) cells. The effect of the compound was more pronounced than that of the free drug.

Targeting aromatase to restrain oestrogen production and developing efficacious interventions against ER-positive cancer

Being the most frequently diagnosed disease, breast cancer is mainly classified as ER+ cancers due to the detection of estrogen receptor (ER) expression. Irrespetive of the successes achieved in the treatment of ER+ cancers by the use of selective estrogen receptor modulator (SERM) drugs like tamoxifen, resistance to the drug is a major clinical obstacle. Working on alternative treatment approaches, here, on the basis of mode of action of aromatase for the conversion of androstenedione to oestrogen, a series of compounds was developed. Results of all the experiments performed with these compounds led to the identification of three highly potent compounds 5d, 5e and 7d with their IC50 61.0, 83.0 and 54.0 nM for aromatase. Indicating their effectiveness in the treatment of ER+ cancers, appreciable tumor growth inhibitory activities of these compounds were observed against breast cancer cell lines. Further, the physico-chemical experiments including plasma protein binding, HSA binding, kinetic studies, solubility, ADME properties and molecular modelling studies supported the drug like features of the compounds.

Discovery of Potent, Selective, and Orally Bioavailable DYRK2 Inhibitors for the Treatment of Prostate Cancer.

Prostate cancer (PCa) seriously threatens male health, and targeting dual-specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) has been verified to reduce PCa burden, while the research progress on the DYRK2 inhibitors was relatively slow. In this work, we discovered DYRK2 inhibitor 12 (IC50 = 9681 nM) through virtual screening. Subsequently, we performed systematic structural optimization to obtain 54 (IC50 = 14 nM). Compound 54 exhibited high selectivity among 215 kinases and significantly suppressed the proliferation and metastasis of PCa cells in vitro. Moreover, compound 54 displayed high safety, favorable bioavailability, and potent tumor growth inhibitory activity in vivo, which could be used as a potential candidate in the discovery of novel anti-PCa drugs.

Synthesis and anti-tumor activity evaluation of 1H-pyrrolo[2,3-b]pyridine-2-carboxamide derivatives with phenyl sulfonamide groups as potent RSK2 inhibitors.

Ribosome S6 Protein Kinase 2 (RSK2) is involved in many signal pathways such as cell growth, proliferation, survival and migration in tumors. Also, RSK2 can phosphorylate YB-1, which induces the expression of tumor initiating cells, leading to poor prognosis of triple negative breast cancer. Herein, phenyl sulfonamide was introduced to a series of 1H-pyrrolo[2,3-b]pyridine-2-carboxamide derivatives to obtain novel RSK2 inhibitors which were evaluated RSK2 inhibitory activity and proliferation inhibitory activity against MDA-MB-468. The newly introduced sulfonamide group was observed to form a hydrogen bond with target residue LEU-74 which played crucial role in activity. The results showed that most of compounds exhibited RSK2 enzyme inhibitory with IC50 up to 1.7 nM. Compound B1 exhibited the strongest MDA-MB-468 cell anti-proliferation activity (IC50 = 0.13 μM). The invivo tumor growth inhibitory activities were evaluated with compounds B1-B3 in MDA-MB-468 xenograft model which gave up to 54.6% of TGI.

Asymmetric anti-CLL-1×CD3 bispecific antibody, ABL602 2+1, with attenuated CD3 affinity endows potent antitumor activity but limited cytokine release

BackgroundAcute myeloid leukemia (AML) is a type of leukemia in adults with a high mortality rate and poor prognosis. Although targeted therapeutics, chemotherapy, and hematopoietic stem cell transplantation can improve...

Piper nigrum Extract Inhibits the Growth of Human Colorectal Cancer HT-29 Cells by Inducing p53-Mediated Apoptosis.

Colorectal cancer (CRC) is a prevalent malignancy of the digestive tract with the second highest mortality rate globally. Piper nigrum is a widely used traditional medicinal plant, exhibiting antitumor activity against various tumor cells. At present, research on the effect of Piper nigrum on CRC is limited to in vitro cytotoxicity, lacking comprehensive mechanism investigations. This study aimed to explore the inhibitory effect and mechanism of Piper nigrum extract (PNE) on HT-29 cells. Firstly, we identified the chemical components of PNE. Then, MTT assay, colony formation assay, JC-1 staining, and flow cytometry were used to analyze the effect of PNE on HT-29 cells in vitro. A xenograft model, histopathological examination, immunohistochemistry, and western blot were used to evaluate the tumor growth inhibitory activity and mechanism of PNE in vivo. The results indicated that PNE could inhibit cell proliferation and colony formation, reduce mitochondrial membrane potential, induce cell apoptosis in vitro, and inhibit tumor growth in vivo. Furthermore, PNE could regulate p53 and its downstream proteins, and subsequently activate the caspase-3 pathway. In summary, PNE probably induced apoptosis of HT-29 cells through the mitochondrial pathway mediated by p53. All these results suggested that PNE might be a potential natural-origin anti-CRC drug candidate.

In vitro and in vivo anticancer activity of novel Rh(III) and Pd(II) complexes with pyrazolopyrimidine derivatives

Six pyrazolopyrimidine rhodium(III) or palladium(II) complexes, [Rh(L1)(H2O)Cl3] (1), [Rh(L2)(CH3OH)Cl3] (2), [Rh(L3)(H2O)Cl3] (3), [Rh2(L4)Cl6]·CH3OH (4), [Rh(L5)(CH3CN)Cl3]·0.5CH3CN (5), and [Pd(L5)Cl2] (6), were synthesized and characterized. These complexes showed high cytotoxicity against six tested cancer cell lines. Most of the complexes showed higher cytotoxicity to T-24 cells in vitro than cisplatin. Mechanism studies indicated that complexes 5 and 6 induced G2/M phase cell cycle arrest through DNA damage, and induced apoptosis via endoplasmic reticulum stress response. In addition, complex 5 also induced cell apoptosis via mitochondrial dysfunction. Complexes 5 and 6 showed low in vivo toxicity and high tumor growth inhibitory activity in mouse tumor models. The inhibitory effect of rhodium complex 5 on tumor growth in vivo was more pronounced than that of palladium complex 6.

In vitro and in vivo studies of plant-produced Atezolizumab as a potential immunotherapeutic antibody

Immune checkpoint inhibitors are a well-known class of immunotherapeutic drugs that have been used for effective treatment of several cancers. Atezolizumab (Tecentriq) was the first antibody to target immune checkpoint PD-L1 and is now among the most commonly used anticancer therapies. However, this anti-PD-L1 antibody is produced in mammalian cells with high manufacturing costs, limiting cancer patients’ access to the antibody treatment. Plant expression system is another platform that can be utilized, as they can synthesize complex glycoproteins, are rapidly scalable, and relatively cost-efficient. Herein, Atezolizumab was transiently produced in Nicotiana benthamiana and demonstrated high expression level within 4–6 days post-infiltration. After purification by affinity chromatography, the purified plant-produced Atezolizumab was compared to Tecentriq and showed the absence of glycosylation. Furthermore, the plant-produced Atezolizumab could bind to PD-L1 with comparable affinity to Tecentriq in ELISA. The tumor growth inhibitory activity of plant-produced Atezolizumab in mice was also found to be similar to that of Tecentriq. These findings confirm the plant’s capability to serve as an efficient production platform for immunotherapeutic antibodies and suggest that it could be used to alleviate the cost of existing anticancer products.

Unusual 5/5 fused bicyclosesquiterpenoids from Eupatorium adenophorum

The chemical analysis on the aerial sections of Eupatorium adenophorum Spreng. resulted in the identification of four unprecedented 5/5 fused bicyclosesquiterpenoids, eupatorid A (1), and its analogues named eupatorester A-C (2–4) using various chromatographic techniques. Their structures were unambiguously confirmed by detailed spectroscopic investigations (including 1D, 2D-NMR and HRMS), and single crystal X-ray diffraction. The anti-inflammatory activities, in vitro tumor growth inhibitory activities and antibacterial activities of these compounds were evaluated.

Abstract B062: ERGi-USU selectively inhibit ERG positive prostate cancer through ATF3 mediated ferroptosis

Abstract Introduction: Prostate cancer (PCa) is the second leading cause of cancer deaths among men in the United States. Approximately 50% of patients with PCa harbor an oncogenic TMPRRS2- ERG gene fusion in their primary and 35% of patients with metastatic castration resistant prostate cancer that often coincides with defective PTEN. We have identified a small molecule, ERGi-USU, with previously described metal chelator activity that binds to the atypical kinase RIOK2 and selectively inhibits the growth of ERG positive cancer cells in vitro and in vivo. ERGi- USU is also effective in inhibiting the growth of tumorigenic mouse prostate organoids harboring TMPRSS2-ERG in Pten null background. We developed a salt formulated derivative of ERGi-USU with improved tumor growth inhibition activity. The objective of our study is to gain insights into the mechanism of action of parental and new ERGi-USU compounds. Methods: The anti-tumorigenic activities of ERGi-USU, was assessed in the hormone-refractory metastatic tissue derived ERG positive prostate cancer cell line (VCaP) and mouse prostate derived TMPRSS2-ERG/Pten null organoids. We monitored cell cycle proteins and ferroptosis pathways and RIOK2 in response to treatment with ERGi-USU compounds. The normal primary endothelium derived HUVEC cells were used as normal control due to the normal endogenous expression of ERG in endothelial cells. Results: Cell growth of tumorigenic ERG positive mouse prostate organoids were inhibited in response to ERGi-USU treatments. Consistent with the response of VCaP cells the ERG and RIOK2 protein levels were down regulated by ERGi-USU treatment in ERG positive tumorigenic mouse prostate organoids. Altered levels of ferroptosis associated proteins were found indicating the involvement of ferroptosis in the activity of ERGi-USU compounds. Conclusions: Our results showed that ferroptosis, the iron-dependent form of programmed cell- death may be involved in the cancer selective activity of ERGi-USU compounds. Disclaimer: The contents of this publication are the sole responsibility of the author(s) and do not necessarily reflect the views, opinions or policies of Uniformed Services University of the Health Sciences (USUHS), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., the Department of Defense (DoD), the Departments of the Army, Navy, or Air Force. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Government. Citation Format: Binil Eldhose, Katherine Beck, Cyrus Eghtedari, Gartrell C. Bowling, Mallesh Pandrala, Sanjay V. Malhotra, Xiaofeng A. Su, Albert Dobi. ERGi-USU selectively inhibit ERG positive prostate cancer through ATF3 mediated ferroptosis [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr B062.