Apoptosis-inducing Activity Research Articles

Gene augmented nuclear-targeting sonodynamic therapy via Nrf2 pathway-based redox balance adjustment boosts peptide-based anti-PD-L1 therapy on colorectal cancer

BackgroundColorectal cancer is known to be resistant to immune checkpoint blockade (ICB) therapy. Sonodynamic therapy (SDT) has been reported to improve the efficacy of immunotherapy by inducing immunogenic cell death (ICD) of cancer. However, the SDT efficacy is extremely limited by Nrf2-based natural redox balance regulation pathway in cancer cells in response to the increased contents of reactive oxygen species (ROS). Nuclear-targeting strategy has shown unique advantages in tumor therapy by directly destroying the DNA. Thus it can be seen that Nrf2-siRNA augmented nuclear-targeting SDT could boost ICB therapy against colorectal cancer.ResultsThe nuclear-targeting delivery system TIR@siRNA (TIR was the abbreviation of assembled TAT-IR780) with great gene carrier capacity and smaller diameter (< 60 nm) was designed to achieve the gene augmented nuclear-targeting SDT facilitating the anti-PD-L1 (programmed cell death-ligand-1) therapy against colorectal cancer. In CT26 cells, TIR@siRNA successfully delivered IR780 (the fluorescent dye used as sonosensitizer) into cell nucleus and Nrf2-siRNA into cytoplasm. Under US (utrasound) irradiation, TIR@siRNA notably increased the cytotoxicity and apoptosis-inducing activity of SDT through down-regulating the Nrf2, directly damaging the DNA, activating mitochondrial apoptotic pathway while remarkably inducing ICD of CT26 cells. In CT26 tumor-bearing mice, TIR@siRNA mediated gene enhanced nuclear-targeting SDT greatly inhibited tumor growth, noticeably increased the T cell infiltration and boosted DPPA-1 peptide-based anti-PD-L1 therapy to ablate the primary CT26 tumors and suppress the intestinal metastases.ConclusionsAll results demonstrate that TIR@siRNA under US irradiation can efficiently inhibit the tumor progression toward colorectal CT26 cancer in vitro and in vivo by its mediated gene augmented nuclear-targeting sonodynamic therapy. Through fully relieving the immunosuppressive microenvironment of colorectal cancer by this treatment, this nanoplatform provides a new synergistic strategy for enhancing the anti-PD-L1 therapy to ablate colorectal cancer and inhibit its metastasis.Graphical

Fatty acid synthase (FASN) regulates the mitochondrial priming of cancer cells

Inhibitors of the lipogenic enzyme fatty acid synthase (FASN) have attracted much attention in the last decade as potential targeted cancer therapies. However, little is known about the molecular determinants of cancer cell sensitivity to FASN inhibitors (FASNis), which is a major roadblock to their therapeutic application. Here, we find that pharmacological starvation of endogenously produced FAs is a previously unrecognized metabolic stress that heightens mitochondrial apoptotic priming and favors cell death induction by BH3 mimetic inhibitors. Evaluation of the death decision circuits controlled by the BCL-2 family of proteins revealed that FASN inhibition is accompanied by the upregulation of the pro-death BH3-only proteins BIM, PUMA, and NOXA. Cell death triggered by FASN inhibition, which causally involves a palmitate/NADPH-related redox imbalance, is markedly diminished by concurrent loss of BIM or PUMA, suggesting that FASN activity controls cancer cell survival by fine-tuning the BH3 only proteins-dependent mitochondrial threshold for apoptosis. FASN inhibition results in a heightened mitochondrial apoptosis priming, shifting cells toward a primed-for-death state “addicted” to the anti-apoptotic protein BCL-2. Accordingly, co-administration of a FASNi synergistically augments the apoptosis-inducing activity of the dual BCL-XL/BCL-2 inhibitor ABT-263 (navitoclax) and the BCL-2 specific BH3-mimetic ABT-199 (venetoclax). FASN inhibition, however, fails to sensitize breast cancer cells to MCL-1- and BCL-XL-selective inhibitors such as S63845 and A1331852. A human breast cancer xenograft model evidenced that oral administration of the only clinically available FASNi drastically sensitizes FASN-addicted breast tumors to ineffective single-agents navitoclax and venetoclax in vivo. In summary, a novel FASN-driven facet of the mitochondrial priming mechanistically links the redox-buffering mechanism of FASN activity to the intrinsic apoptotic threshold in breast cancer cells. Combining next-generation FASNis with BCL-2-specific BH3 mimetics that directly activate the apoptotic machinery might generate more potent and longer-lasting antitumor responses in a clinical setting.

Cytotoxic and apoptotic effects of Hypericum androsaemum on prostate adenocarcinoma (PC-3) and hepatocellular carcinoma (Hep G2) cell lines with identification of secondary metabolites by LC-HRMS.

The study aims to determine the secondary metabolites of Hypericum androsaemum L. extracts by liquid chromatography-high resolution mass spectrometry (LC-HRMS), and investigate the antioxidant and cytotoxic activities of the plant. Cytotoxic activity was evaluated by MTT assay, and apoptosis induction abilities on human prostate adenocarcinoma (PC-3), and hepatocellular carcinoma (Hep G2) cell lines. Accordingly, major secondary metabolites were found as hederagenin (762 ± 70.10 μg/g) in the leaves dichloromethane (LD), herniarin (167 ± 1.50 μg/g) in fruit dichloromethane (FD), (-)-epicatechin (6538 ± 235.36 μg/g) in the leaves methanol (LM), (-)-epigallocatechin gallate (758 ± 20.46 μg/g) in the fruit methanol (FM), and caffeic acid (370 ± 8.88 μg/g) in the fruit water (FW), and (3313 ± 79.51 μg/g) in the leaves water (LW) extracts. LM exerted strong antioxidant activity in DPPH free (IC50 10.94 ± 0.08 μg/mL), and ABTS cation radicals scavenging (IC50 9.09 ± 0.05 μg/mL) activities. FM exhibited cytotoxic activity with IC50 values of 73.23 ± 3.06 µg/mL and 31.64 ± 2.75 µg/mL on PC-3 and Hep G2 cell lines, respectively. Being the richest extract in terms of quillaic acid (630 ± 18.9 μg/g), which is a well-known cytotoxic triterpenoid with proven apoptosis induction ability on different cells, FM extract showed apoptosis induction activity with 64.75% on PC-3 cells at 50 μg/mL concentration. The study provides promising results about the potential of Hypericum androsaemum on cancer prevention.

In vitro and in vivo anti-periodontitis effects of combination treatment of photodynamic and antibiotic therapies

Objective: To investigate the effects of combination treatment of photodynamic therapy (PDT) based on photosensitizer chlorin e6 (Ce6) and antibiotic agent tinidazole (TNZ) against periodontitis both in vitro and in vivo. Methods: The Sprague-Dewley (SD) rat periodontitis model was constructed using the method of orthodontic wire ligation. After successful modeling, SD rats were randomly divided into the following 6 groups (3 rats in each group): positive control (Ctrl+), Ce6, TNZ, a mixture of Ce6 and TNZ (Ce6/TNZ), Ce6 with laser irradiation (Ce6+L), a mixture of Ce6 and TNZ with laser irradiation (Ce6/TNZ+L). Methyl thiazolyl tetrazolium (MTT) assay was used to assess the cytotoxic activities of Ce6 (concentration range: 0-20 mg/L), TNZ (concentration range: 0-16.6 mg/L) and their mixture (Ce6/TNZ) in mouse fibroblast L929 cells. Fluorescence probe method was applied to measure the production of reactive oxygen species in the dental plaque biofilms after various treatments with and without 5-minute laser irradiation at 635 nm at a power density of 0.5 W/cm2 (Ce6+L and Ce6/TNZ+L groups), thus to evaluate the PDT performances. Cell counting kit-8 (CCK-8) and live/dead staining were used to assess the antibacterial activity in each of the groups and the combination index (CI) of PDT combined with TNZ was calculated subsequently. Flow cytometry was utilized to detect the apoptosis-inducing effects of these treatments in macrophage RAW264.7 cells after processing with the apoptosis detection kit. The inhibitory effects of various treatments on the absorption of alveolar bone of SD rats were further evaluated in the periodontitis rats by using the micro-CT. Results: The survival rates of L929 cells in the preset concentration range were all above 90% in Ce6, TNZ and Ce6/TNZ groups. Upon laser irradiation, the plaque biofilms in Ce6 and Ce6/TNZ groups showed significant green fluorescence, indicating that large amounts of reactive oxygen species were triggered and generated significantly in the dental plaque biofilms. However, the survival rates of dental plaque microorganisms in 5 Ce6/TNZ concentrations were (85.4±5.5)%, (76.0±8.9)%, (61.7±0.6)%, (56.3±2.6)% and (43.5±0.6)% respectively, which were significantly lower than that in Ce6 only and TNZ only groups (P<0.01). The CI levle of each drug concentration group was less than 1.0, which showed a significant synergistic antibacterial efficiency. Stronger apoptotic activities were observed in Ce6+L and Ce6/TNZ+L groups compared with those in Ce6 only and Ce6/TNZ only groups (P<0.01). In periodontitis rats, Ce6/TNZ combined laser irradiation could effectively inhibit the absorption of alveolar bone. The alveolar bone volume and the ratio of bone volume and tissue volume were (1.49±0.07) mm3 and (47.08±0.71)%, respectively. The distances between cementoenamel junction to alveolar bone crest on buccal and palatal sites decreased to (2.13±0.07) mm and (1.94±0.10) mm respectively, showing a high inhibition efficiency. Conclusions: Ce6-mediated PDT combined with TNZ possessed notable synergistic effects against periodontitis, reflecting in the efficient antibacterial effect, the apoptosis-inducing action on macrophages, and the inhibitory efficacy on the alveolar bone absorption in vivo.

ANTITUMOR PROPERTIES OF VEGETABLE OIL EXTRACT FROM GREEN MICROALGA COELASTRELLA SP.

Microalgae are of great importance for the production of original natural substances of interest for food, health or biotechnological applications. Mass cultures of green microalgae are used for production of carotenoids such β-carotene, astaxanthin, canthaxanthin, lutein etc. The aim of this study was to obtain an oil extract from a Bulgarian green microalga strain Coelastrella sp. BGV and to assess its anticancer and apoptogenic activity in vitro against human tumor cells HeLa by means of MTT and fluorescence microscopy analyses. The results showed that the oil extract obtained by a direct extraction using a common vegetable oil reduces proliferation and induces apoptosis in HeLa cells. In contrast to widely used organic solvents for the production of carotenoids, the applied bio-solvent (sunflower oil) can be a valuable alternative approach for the needs of the food industry. The resulting oil extract showed promising antitumor and apoptosis-inducing activity against HeLa cells in vitro and potential for future use in practice.

Anti-Proliferative and Pro-Apoptotic Activities of Synthesized 3,4,5 Tri-Methoxy Ciprofloxacin Chalcone Hybrid, through p53 Up-Regulation in HepG2 and MCF7 Cell Lines.

Background:Cancer is a significant health problem around the world and one of the leading causes of human death. The need for novel, selective and non-toxic anti-cancer agents is still urging. Aim of the work: to investigate the anti-proliferative and pro-apoptotic effects of the synthesized ciprofloxacin 3,4,5 tri-methoxy chalcone hybrid (CCH) on the HepG2 hepatocellular carcinoma and MCF7 breast carcinoma cell lines. Materials and Methods:HepG2 and MCF7cell lines were treated with CCH. Cell viability and cell cycle analysis were performed. Protein and mRNA expression levels of P53, COX-2 and TNF-α were analyzed by western blotting and RT-PCR respectively. Results:CCH caused concentration and time-dependent reduction in the viability of human HepG2 and MCF7 cells, pre-G1 apoptosis and cell cycle arrest at G2/M stage, significantly higher P53 and TNF-α mRNA and protein expression levels but significantly lower COX2 mRNA and protein expression levels. Conclusion:CCH showed obvious anti-proliferative and apoptosis-inducing activities in both cell lines.

Investigation of 3-sulfamoyl coumarins against cancer-related IX and XII isoforms of human carbonic anhydrase as well as cancer cells leads to the discovery of 2-oxo-2H-benzo[h]chromene-3-sulfonamide - A new caspase-activating proapoptotic agent.

Herein we report the synthesis of a set of seventeen 3-sulfonamide substituted coumarin derivatives. Prepared compounds were tested invitro for inhibition of four physiologically relevant isoforms of the metalloenzyme human carbonic anhydrase (hCA, EC 4.2.1.1). Several coumarin sulfonamides displayed low nanomolar KI values against therapeutically relevant hCA II, IX, and XII, whereas they did not potently inhibit hCA I. Some of these compounds exerted a concentration-dependent antiproliferative action toward RT4 human bladder cancer and especially A431 human epidermoid carcinoma cell lines. In the meantime, the viability of non-tumorigenic hTERT immortalized human foreskin fibroblast cell line Bj-5ta was not significantly affected by the obtained derivatives. Interestingly, compound 10q (2-oxo-2H-benzo [h]chromene-3-sulfonamide) showed a profound and selective dose-dependent inhibition of A431cell growth with low nanomolar IC50 values. We demonstrated that 10q possessed a concentration-dependent apoptosis induction activity associated with caspase 3/7 activation in cancer cells. As carbonic anhydrase isoforms in question were not potently inhibited by this compound, its antiproliferative effects likely involve other mechanisms, such as DNA intercalation. Compound 10q clearly represents a viable lead for further development of new-generation anticancer agents.

Exploring the cytotoxicity and anticancer effects of doxycycline and azithromycin on human glioblastoma multiforme cells

ABSTRACT Background Previous studies had reported on the cytotoxic activities of generic antibiotics such as doxycycline (DOXY) and azithromycin (AZI) in multiple types of human cancers. Given that resistance to standard anti-glioblastoma multiforme (GBM) drug [temozolomide (TMZ)] is common and inevitable, alternative candidates are greatly needed. Purpose and method The present study was undertaken to explore the cytotoxicity and anticancer effects of DOXY and AZI on human GBM U87 cells via 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), Hoechst, Annexin V-FITC/PI, and clonogenic assays. CompuSyn software was used to determine the combination index (CI) for DOXY+AZI. Result Individual treatment with DOXY and AZI decreased U87 cell viability in dose- and time-dependent, and quantitatively comparable to TMZ. Nevertheless, combinations of both antibiotics evidenced antagonistic behaviour in U87 cells. Increased apoptotic event was also observed with the individual treatment of DOXY and AZI. Furthermore, the proliferative and clonogenic capability of 21-day survived U87 cells was completely terminated by DOXY and AZI, but not TMZ. Conclusion The antiproliferative and apoptosis-inducing activity exhibited by both antibiotics against U87 cells demonstrates their potential as a likely alternative to combat GBM. It would be interesting to find out more about their molecular players and cytotoxic effects in different types of GBM cells, including glioma stem cells (GSCs).

SARS-CoV-2 Accessory Protein ORF7b Mediates Tumor Necrosis Factor-α-Induced Apoptosis in Cells.

The accessory proteins of coronaviruses are essential for virus–host interactions and the modulation of host immune responses. It has been reported that accessory protein ORF3a encoded by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can induce apoptosis, and accessory protein ORF6 and ORF8 could be inhibitors of the type-I interferon (IFN) signaling pathway. However, the function of accessory protein ORF7b is largely unknown. We investigated the apoptosis-inducing activity of ORF7b in cells. Cytokine levels and host innate immune responses, including expression of interferon regulatory transcription factor (IRF)-3, signal transducer and activator of transcription (STAT)-1, interferon (IFN)-β, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, were also investigated. We found that ORF7b promoted expression of IFN-β, TNF-α, and IL-6, activated type-I IFN signaling through IRF3 phosphorylation, and activated TNFα-induced apoptosis in HEK293T cells and Vero E6 cells. These results could provide deeper understanding about the pathogenicity of SARS-CoV-2 as well as the interaction between the accessory protein ORF7b with host immune responses.

Regulation of Bax-dependent apoptosis by mitochondrial deubiquitinase USP30

Deubiquitinates (DUBs) have been suggested as novel promising targets for cancer therapies. Accumulating experimental evidence suggests that some metal compounds have the potential to induce cancer cell death via inhibition of DUBs. We previously reported that auranofin, a gold(I)-containing agent used for the treatment of rheumatoid arthritis in clinics, can induce cell death by inhibiting proteasomal DUBs in a series of cancer cell lines. Unfortunately, currently available gold compounds are not potent in inhibiting DUBs. Here, we report that: (i) aumdubin, a synthetic derivative of auranofin, exhibited stronger DUB-inhibiting and apoptosis-inducing activities than auranofin in lung cancer cells; (ii) aumdubin shows high affinity for mitochondrial DUB USP30; (iii) aumdubin induces apoptosis by increasing the ubiquitination and mitochondrial location of Bax protein; and (iv) USP30 inhibition may contribute to Bax-dependent apoptosis induced by aumdubin in lung cancer cells. These results suggest that gold(I)-containing agent aumdubin induces Bax-dependent apoptosis partly through inhibiting the mitochondrial DUB USP30, which could open new avenues for lung cancer therapy.

Dual Response to IL-21 and IFN-Alpha Reveals Human B-Cell Precursors With Multiple Differentiation Potentials

Immunological memory is essential for effective immune protection upon antigen rechallenge. Memory B cells encompass multiple subsets, heterogeneous in terms of phenotypes, origins and precursors, anatomical localization, and functional responses. B-cell responses are conditioned by micro-environmental signals, including cytokines. Here, we analyzed in vitro the effects of two cytokines implicated in B-cell differentiation, interferon-alpha (IFN-α) and interleukin (IL)-21, on the early functional response of four different mature B-cell subsets (IgD+ CD27- naive, IgD+ CD27+ unswitched, IgD- CD27+ switched and double-negative B cells). The dual response of naive and memory B cells to IL-21 allowed us to uncover a unique IgD+ CD27- CD10- B-cell population characterized by the expression of marginal zone B-cell markers CD45RB and CD1c (referred to as NARB+). Similar to memory B cells, NARB+ cells displayed a pre-activated state, allowing them to rapidly differentiate into plasmablasts upon innate signals. However, this population also maintained its susceptibility to IL-21 activation-induced apoptosis similarly to the naive compartment. Both in-depth phenotypic analysis of circulating B cells, and identification of these cells in spleen, tonsil, and gut-associated lymphoid tissues, suggested that NARB+ could be uncommitted precursors of different developmental pathways including human marginal zone-like B cells (MZB). In this regard, we showed that patients with primary Sjogren’s syndrome exhibited a severe reduction of IgD+CD27+ MZB-like cells associated with a diminution of the NARB+ subset suggesting a developmental relationship.

The requirement of mitochondrial RNA polymerase for non-small cell lung cancer cell growth

POLRMT (RNA polymerase mitochondrial) is responsible for the transcription of mitochondrial genome encoding key components of oxidative phosphorylation. This process is important for cancer cell growth. The current study tested expression and potential functions of POLRMT in non-small cell lung cancer (NSCLC). TCGA cohorts and the results from the local lung cancer tissues showed that POLRMT is overexpressed in human lung cancer tissues. In both primary human NSCLC cells and A549 cells, POLRMT silencing (by targeted lentiviral shRNAs) or knockout (through CRSIPR/Cas9 gene editing method) potently inhibited cell viability, proliferation, migration, and invasion, and induced apoptosis activation. On the contrast, ectopic overexpression of POLRMT using a lentiviral construct accelerated cell proliferation and migration in NSCLC cells. The mtDNA contents, mRNA levels of mitochondrial transcripts, and subunits of respiratory chain complexes, as well as S6 phosphorylation, were decreased in POLRMT-silenced or -knockout NSCLC cells, but increased after ectopic POLRMT overexpression. In vivo, intratumoral injection of POLRMT shRNA adeno-associated virus (AAV) potently inhibited NSCLC xenograft growth in severe combined immune deficiency mice. The mtDNA contents, mRNA levels of mitochondria respiratory chain complex subunits, and S6 phosphorylation were decreased in POLRMT shRNA AAV-injected NSCLC xenograft tissues. These results show that POLRMT is a novel and important oncogene required for NSCLC cell growth in vitro and in vivo.

Design, synthesis and apoptosis inducing activity of nonsteroidal flavone-methanesulfonate derivatives on MCF-7 cell line as potential sulfatase inhibitor

In recent years, focusing on new potent anticancer agents with selective activity is one of the greatest challenges in cancer therapy. Breast cancer is the most common cancer and the main cause of cancer deaths in women. The sulfatase enzyme plays an important role in converting the sulfated steroids into non-sulfate steroid hormones, which increases the growth and development of many hormone-dependent cancers, such as breast cancer. In this regard, structure-based optimization was conducted to design novel flavone-sulfonates pharmacophore as a new steroid sulfatase inhibitor. In the present work, the conventional methods for the synthesis of 4-oxo-2-phenyl-4H-chromen-7-yl methanesulfonate derivatives were reported. Their cytotoxicity was evaluated with MTT assay against a breast cancer cell line (MCF-7). The apoptosis inducing activity of the most cytotoxic compound 3c with an IC50 value of 0.615 µM was evaluated in comparison to docetaxel in the presence of estradiol which is a crucial growth factor to survive the cancerous cells. The results of double staining Annexin V-FITC/PI analysis suggested that the cytotoxic activity of this compound 3c in MCF-7 cells occurs via apoptosis. Molecular docking studies were conducted to clarify the inhibition mode of the most promising compound (3c) over the sulfatase (1P49) binding site. The analysis revealed the role of hydrogen bond interaction with Gly181 and hydrophobic interactions through the 1P49 active site in the ligand-receptor complex as significant descriptors to rationalize the potential inhibition activity.

Functional characterization of a putative tumor necrosis factor superfamily member 10 in blood clam (Tegillarca granosa)

Tumor necrosis factor superfamily member 10 (TNFSF10), also known as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or Apo-2L, is one of the important members of the TNF superfamily. It is well demonstrated that TNFSF10 preferentially induces a variety of tumor cell apoptosis, and therefore exerts an important role in tumor immune surveillance. However, the function of TNFSF10 in pathogen defense is poorly understood, especially in invertebrates. The blood clam (Tegillarca granosa), an important commercial marine bivalve, plays an important ecological role in the marine ecosystem. The identification of immune genes will provide new perspective for disease control in the blood clam (T. granosa) farming. To better understand the biological function of TNFSF10 protein, the full-length cDNA of TNFSF10 homologous gene of T. granosa (TgTNFSF10) was cloned and identified for the first time, which was found to contain 1239 base pairs and encode 254 amino acids with a molecular weight of 29.5 kDa and a conserved TNF domain in the C-terminal. Quantitative RT-PCR analysis showed that TgTNFSF10 gene was constitutively expressed in all tested tissues, with the highest expression in hemocytes. LPS, Vibrio alginolyticus and Vibrio parahaemolyticus stimulations dramatically increased the expression of TgTNFSF10 in T. granosa (11.47-fold, 3.71-fold and 8.29-fold compared with the control respectively). In vitro experiments showed that recombinant TgTNFSF10 protein strongly inhibited the proliferation of HepG2 cells. Further confocal microscopy and flow cytometry analysis showed that obvious apoptosis occurred in TgTNFSF10-treated hemocytes and HepG2 cells. To sum up, our study demonstrated that TgTNFSF10 had strong apoptosis-inducing activity, which may participate in the innate immune response of T. granosa to pathogen invasion.

Abstract 1256: JNJ-74856665, a novel DHODH inhibitor, mediates potent anti-leukemic activity and differentiation in vitro and in vivo

Abstract Acute myeloid leukemia (AML) is a heterogeneous disease characterized by uncontrolled clonal expansion of hematopoietic progenitor cells (myeloid blasts). Disease remission can be achieved with standard induction chemotherapy, but refractory and relapsed disease remains a challenge with a 5-year overall survival rate of approximately 25%. Induction of differentiation is an alternative approach to AML therapy. Dihydroorotate dehydrogenase (DHODH) catalyzes the ubiquinone-mediated oxidation of dihydroorotate (DHO) to orotate in the de novo pyrimidine synthesis pathway. Pre-clinical findings demonstrated that DHODH is a metabolic vulnerability in AML and a new target for differentiation therapy. Given the genetic complexity of myeloid malignancies, future use of DHODH inhibitors in combination with selected antineoplastic agents (e.g., azacitidine) with nonoverlapping mechanisms of action may address specific aspects of the complex pathogenesis of AML and MDS (myelodysplastic syndrome), ultimately improving patients' outcomes.JNJ74856665 is an orally available, potent and selective DHODH inhibitor. JNJ-74856665 inhibited the biochemical activity of human DHODH with a 50% inhibitory concentration (IC50) in the subnanomolar range and in vitro inhibited proliferation of MOLM-13, OCI-AML3, HL60 and THP-1 AML cell lines with low nanomolar IC50 values. Mechanism of action studies using these four cell lines demonstrated induction of CD11b and CD14 differentiation marker mRNA levels. Differentiation was accompanied by cell cycle arrest and apoptosis induction. Importantly, addition of excess uridine to the tissue culture conditions abrogated the anti-proliferative, differentiation and apoptosis inducing activity of JNJ-74856665, indicating on target activity. In vivo, JNJ-74856665 mediated significant activity in decreasing leukemic burden and increasing life span across subcutaneous (MOLM-13 and OCI-AML3) and disseminated (MOLM-13) xenografts, respectively. Pharmacodynamic investigations demonstrated target engagement as evidenced by upregulation of the DHODH substrate dihydroorotate in plasma and induction of differentiation markers in tumor. Combination of JNJ-74856665 with azacitidine in vivo demonstrated lack of antagonism in the anti-leukemic activity.The results described herein demonstrate that JNJ-74856665 exerts potent anti-leukemic activity in vitro and in vivo and warrant further investigation. To that end, a phase 1 clinical trial assessing the safety and efficacy of JNJ-74856665 in patients with AML and MDS is planned to initiate shortly. Citation Format: Christine Pietsch, Scott Kuduk, Xiaochun Zhang, Tammy Bush, Faraz Kazmi, Edgar Jacoby, Zhuming Zhang, Lindsey DeRatt, Weixue Wang, Aaron Patrick, Andrew Steele, Friedericke Pastore, Tony Greway, Nikki Daskalakis, Kathryn Bradford, Kathryn Packman, Gilles Bignan, James Edwards, Ricardo Attar, Yusri Elsayed, Jacqueline Bussolari, Ulrike Philippar. JNJ-74856665, a novel DHODH inhibitor, mediates potent anti-leukemic activity and differentiation in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1256.

Pancracine, a Montanine-Type Amaryllidaceae Alkaloid, Inhibits Proliferation of A549 Lung Adenocarcinoma Cells and Induces Apoptotic Cell Death in MOLT-4 Leukemic Cells.

Pancracine, a montanine-type Amaryllidaceae alkaloid (AA), is one of the most potent compounds among natural isoquinolines. In previous studies, pancracine exhibited cytotoxic activity against diverse human cancer cell lines in vitro. However, further insight into the molecular mechanisms that underlie the cytotoxic effect of pancracine have not been reported and remain unknown. To fill this void, the cell proliferation and viability of cancer cells was explored using the Trypan Blue assay or by using the xCELLigence system. The impact on the cell cycle was determined by flow cytometry. Apoptosis was evaluated by Annexin V/PI and by quantifying the activity of caspases (-3/7, -8, and -9). Proteins triggering growth arrest or apoptosis were detected by Western blotting. Pancracine has strong antiproliferative activity on A549 cells, lasting up to 96 h, and antiproliferative and cytotoxic effects on MOLT-4 cells. The apoptosis-inducing activity of pancracine in MOLT-4 cells was evidenced by the significantly higher activity of caspases. This was transmitted through the upregulation of p53 phosphorylated on Ser392, p38 MAPK phosphorylated on Thr180/Tyr182, and upregulation of p27. The pancracine treatment negatively altered the proliferation of A549 cells as a consequence of an increase in G1-phase accumulation, associated with the downregulation of Rb phosphorylated on Ser807/811 and with the concomitant upregulation of p27 and downregulation of Akt phosphorylated on Thr308. This was the first study to glean a deeper mechanistic understanding of pancracine activity in vitro. Perturbation of the cell cycle and induction of apoptotic cell death were considered key mechanisms of pancracine action.

Imatinib Induces Apoptosis of NK/T Cell Neoplasms by Inhibiting Hematopoietic Cell Kinase and NQO2

▪[Background] Natural killer and T (NK/T)-cell malignancies are uncommon in Western countries but relatively frequent in Asia. Although regimens that include L-asparaginase have improved outcomes, these disorders, particularly aggressive NK-cell leukemias/lymphomas, have poor prognoses. No molecular-targeting drugs have been developed so far. Current reports have provided evidence that a subset of NK cell malignancies is of myeloid origin. Some tyrosine kinase inhibitors (TKIs) that target multiple kinases, including LcK involved in the growth of myeloid malignancies, may therefore show inhibitory effects against NK/T cell neoplasms where LcK members are highly expressed. We investigated the potential anti-tumor activities of multitarget TKIs against malignant NK/T cell neoplasms. [Methods and Results] Three TKIs (imatinib, nilotinib, and dasatinib) were tested for their apoptosis-inducing activities against various NK cell lines including KHYG1, NK92, and NKL after 24-h incubation. Therapeutic doses of imatinib (7.5-27 µM) induced variable annexinV(+) cells in 5 out of 7 NK lines, ranging from 27.1%±6.9% to 87.8%±3.3% (Figure 1), while the apoptosis-inducing effects of therapeutic doses of nilobinib and dasatinib were marginal. Membrane array screenings, which can quantitate 43 phosphorylated proteins, showed that hematopoietic cell kinase (HcK) was constitutively active in KHYG1 cells, and treatment with imatinib inhibited pHcK by 80%. Other known imatinib-targets, including PDGFR, LcK, c-kit, and BCR/ABL, were undetectable in the NK cell lines tested. Further immunoblot analyses using anti-pHcK antibodies confirmed pHcK inhibition in imatinib-treated KHYG1 and NKL (Figure 2). Immunohistochemistry studies with anti-pHcK antibodies revealed two of eight extranodal NK/T-cell lymphomas, nasal type, to be strongly positive for pHcK (Figure 3). In addition, immunohistochemistry studies revealed that NAD(P)H dehydrogenase, quinone 2 (NQO2), a lesser-known imatinib target, was highly expressed in tumor tissues of all seven NK/T-cell lymphoma patients examined, including two pHcK(+) patients, and in vitro studies showed 50% NQO2 protein downregulation and 80% inhibition of its enzymatic activity in imatinib-treated cells. Notably, imatinib enhanced the pro-apoptotic and anti-proliferative activities of L-asparaginase against malignant NK and T cells (CI 0.77 and 0.86 respectively). [Conclusions] Imatinib induces the apoptosis of a subset of NK/T cell malignancies by inhibiting pHcK and NQO2. Imatinib and HcK inhibitors may have therapeutic potential against NK/T cell malignancies either alone or in combination with L-asparaginase. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Apoptosis-inducing activity of synthetic hydrocarbon-stapled peptides in H358 cancer cells expressing KRASG12C

Lung cancers are the leading cause of cancer deaths worldwide and pose a grave threat to human life and health. Non-small cell lung cancer (NSCLC) is the most frequent malignancy occupying 80% of all lung cancer subtypes. Except for other mutations (e.g., KRASG12V/D) that are also vital for the occurrence, KRASG12C gene mutation is a significant driving force of NSCLC, with a prevalence of approximately 14% of all NSCLC patients. However, there are only a few therapeutic drugs targeting KRASG12C mutations currently. Here, we synthesized hydrocarbon-stapled peptide 3 that was much shorter and more stable with modest KRASG12C binding affinity and the same anti-tumor effect based on the α-helical peptide mimic SAH-SOS1A. The stapled peptide 3 effectively induced G2/M arrest and apoptosis, inhibiting cell growth in KRAS-mutated lung cancer cells via disrupting the KRAS-mediated RAF/MEK/ERK signaling, which was verified from the perspective of genomics and proteomics. Peptide 3 also exhibited strong anti-trypsin and anti-chymotrypsin abilities, as well as good plasma stability and human liver microsomal metabolic stability. Overall, peptide 3 retains the equivalent anti-tumor activity of SAH-SOS1A but with improved stability and affinity, superior to SAH-SOS1A. Our work offers a structural optimization approach of KRASG12C peptide inhibitors for cancer therapy.

Alnus sibirica Compounds Exhibiting Anti-Proliferative, Apoptosis-Inducing, and GSTP1 Demethylating Effects on Prostate Cancer Cells.

Alnus sibirica (AS) is distributed in Korea, Japan, China, and Russia and has reported anti-oxidant, anti-inflammatory, and reducing activities on atopic dermatitis-like skin lesions, along with other beneficial health properties. In the present study, we tried to prove the cancer-preventive activity against prostate cancer. The extracted and isolated compounds, oregonin (1), hirsutenone (2), and hirsutanonol (3), which were isolated from AS, were tested for anti-proliferative activity. To do this, we used the MTT assay; NF-κB inhibitory activity, using Western blotting; apoptosis-inducing activity using flow cytometry; DNA methylation activity, using methylation-specific polymerase chain reaction in androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cell lines. The compounds (1–3) showed potent anti-proliferative activity against both prostate cancer cell lines. Hirsutenone (2) exhibited the strongest NF-κB inhibitory and apoptosis-inducing activities compared with oregonin (1) and hirsutanonol (3). DNA methylation activity, which was assessed for hirsutenone (2), revealed a concentration-dependent enhancement of the unmethylated DNA content and a reduction in the methylated DNA content in both PC-3 and LNCaP cells. Overall, these findings suggest that hirsutenone (2), when isolated from AS, may be a potential agent for preventing the development or progression of prostate cancer.

In vitro study of the antioxidant, antiproliferative, and anthelmintic properties of some medicinal plants of Kokrajhar district, India.

Alstonia scholaris, Cardiospermum halicacabum, Hydrocotyle sibthorpioides, and Hypericum japonicum are important folk medicinal plants used by tribal communities of Bodoland region of Assam to treat helminth infections. Because of their ethnomedicinal values, the present study was designed to investigate the antioxidant, antiproliferative, and anthelmintic activities of the plants. The antioxidant activity was measured by total antioxidant capacity, total phenolics (TPC), total flavonoid (TFC), FRAP, DPPH, ABTS, and TBARS assay. Antiproliferative and apoptosis-inducing activities of plants were conducted in Dalton's lymphoma (DL) cells. Cells were treated for 24h with different doses (25-200mg/mL) of plant extracts. Anthelmintic study was conducted by treating the Paramphistomum sp. at different doses of plant extracts. Phytochemical and antioxidant studies showed rich TPC, TFC, and free radical scavenging activity in H. japonicum and H. sibthorpioides. Both the antiproliferative and anthelmintic bioassays showed a dose-dependent efficacy in all plants. H. japonicum showed the strongest anthelmintic activity (LC50 0.21mg/mL) followed by H. sibthorpioides (5.36mg/mL), C. halicacabum (13.40mg/mL), and A. scholaris (18.40mg/mL). Evidently, H. sibthorpioides showed the strongest antiproliferative and apoptosis-inducing activities among all the plants. The study observed a positive correlation between the antioxidant properties and antiproliferative and anthelmintic activities of the plants. We, therefore, conclude that the phytocompounds present in the crude extracts along with antioxidant molecules may have combined effects contributing to the antiproliferative and anthelmintic activities of the plants.