Cell Cycle Analysis Research Articles

An arresten-derived anti-angiogenic peptide triggers apoptotic cell death in endothelial cells.

In recent years, anti-angiogenic peptides have received considerable attention as candidates for cancer treatment. Arresten is an angiogenesis inhibitor that cleaves from the α1 chain of type IV collagen and stimulates apoptosis in endothelial cells. We have recently indicated that a peptide corresponding to the amino acid 78 to 86 of arresten, so-called Ars, prevented the migration and tube formation of HUVECs and the colon carcinoma growth in mice significantly. The current study aimed to determine whether induction of apoptotic cell death in endothelial cells is one of the biochemical mechanisms of this anti-angiogenic peptide. This hypothesis was assessed using the MTT assay, cell cycle analysis, Annexin V-FITC/PI staining, BCL2, CASP8, CASP9, p53, and CDKN2A gene expression studies as well as evaluating apoptosis in tumor tissues by TUNEL assay. Results demonstrated that 40µM of Ars significantly stimulated 46.2% of early and late apoptosis in HUVECs compared to 13.6% in the untreated cells and did not significantly alter the cell cycle distribution. Moreover, BCL2 and CASP8 were down-regulated, while CASP9 and p53 were up-regulated in endothelial cells. CDKN2A gene expression, the regulator of G1 cell cycle arrest, was not significantly altered. It might be suggested that Ars induced apoptosis in endothelial cells through the mitochondrial pathway and had no effect on the cell cycle. Besides, Ars induced apoptosis significantly in vivo. However, further studies are required to confirm the detailed molecular mechanism of Ars, this peptide has the potential to be optimized for clinical translations.

Dual pH/redox-responsive hyperbranched polymeric nanocarriers with TME-trigger size shrinkage and charge reversible ability for amplified chemotherapy of breast cancer

A novel pH/redox-responsive hyperbranched MeO-PEG-b-(NIPAAm-co-PBAE) nanoparticles (NPs) were designed with size shrinkage and charge-reversible potential for targeted delivery of docetaxel (DTX) to MDA-MB-231 cell lines. In the tumor microenvironment (TME), amine protonation induces charge reversal and disulfide bond cleavage under high TME GSH concentration causing size shrinkage, improved deep tumor penetration, and active targeting of the therapeutic agents. These nano drug delivery systems (NDDSs) significantly promoted cancer cell uptake (~ 100% at 0.5 h), facilitating site-specific delivery and deep tumor penetration. The MTT assay revealed significantly higher cytotoxicity (P value < 0.0001) for DTX-loaded NPs compared to free DTX. Cell cycle analysis revealed G2/M (58.3 ± 2.1%) and S (21.5 ± 1.3%) arrest for DTX-loaded NPs, while free DTX caused G2/M (67.9 ± 1.1%) and sub-G1 (10.3 ± 0.8%) arrest. DTX-loaded NPs induced higher apoptosis (P value < 0.001) in MDA-MB-231 cells (71.5 ± 2.8%) compared to free DTX (42.3 ± 3.1%). Western blotting and RT-PCR assays confirmed significant up-regulation of protein levels and apoptotic genes by DTX-loaded NPs compared to free DTX. In conclusion, TME-responsive charge reversal and size-shrinkable smart NDDSs designed based on low pH, and high glutathione (GSH), offer more effective site-specific delivery of therapeutic agents to tumors.

Arsenic and Benzo[a]pyrene Co-exposure Effects on MDA-MB-231 Cell Viability and Migration.

Although humans are frequently exposed to multiple pollutants simultaneously, research on their harmful effects on health has typically focused on studying each pollutant individually. Inorganic arsenic (As) and benzo[a]pyrene (BaP) are well-known pollutants with carcinogenic potential, but their co-exposure effects on breast cancer cell progression remain incompletely understood. This study aimed to assess the combined impact of BaP and As on the viability and migration of MDA-MB-231 cells. The results indicated that even at low levels, both inorganic As (0.01μM, 0.1μM, and 1μM) and BaP (1μM, 2.5μM), individually or in combination, enhanced the viability and migration of the cells. However, the cell cycle analysis revealed no significant differences between the control group and the cells exposed to BaP and As. Specifically, exposure to BaP alone or in combination with As (As 0.01μM + BaP 1μM) for 24h led to a significant increase in vimentin gene expression. Interestingly, short-term exposure to As not only did not induce EMT but also modulated the effects of BaP on vimentin gene expression. However, there were no observable changes in the expression of E-cadherin mRNA. Consequently, additional research is required to evaluate the prolonged effects of co-exposure to As and BaP on the initiation of EMT and the progression of breast cancer.

Chemical derivatization leads to the discovery of novel analogs of azotochelin, a natural siderophore, as promising anticancer agents.

Siderophores are structurally unique medicinal natural products and exhibit considerable therapeutic potential. Herein, we report the design and synthesis of azotochelin, a natural siderophore, and an extensive library of azotochelin analogs as a potential anticancer agent. We modified the carboxylic acid and the aromatic ring motifs of azotochelin using various chemical motifs. We tested the compounds against six different cancer cell lines (KB-3-1, SNB-19, MCF-7, K-562, SW-620, and NCI-H460) and a non-cancerous cell line (HEK-293) to assess the cytotoxicity. Among the twenty compounds tested, the IC50values of eight compounds (14, 32, 35-40, and 54) were between 0.7 to 2.0 μM against a lung cancer cell line (NCI-H460). Moreover, several compounds had a good cytotoxicity profile (IC50< 10 μM) against many tested cancer cell lines. The flow cytometry analysis showed that compounds36and38induce apoptosis in NCI-H460 in a dose-dependent manner. The cell cycle analysis indicated that compounds36and38significantly arrest the cell cycle at the S phase to block cancer cell proliferation in the NCI-H460 cell line. The study has produced various novel azotochelin analogs that are potentially effective anticancer agents and leads for further synthetic and medicinal chemistry exploration.

Novel 2-[thio]acetamide linked quinazoline/1,2,4-triazole/chalcone hybrids: Design, synthesis, and anticancer activity as EGFR inhibitors and apoptotic inducers.

Novel triazoloquinazolines carrying the 2-[thio]acetamide entity (4 and 5a-d) and triazoloquinazoline/chalcone hybrids incorporating the 2-[thio]acetamide linker (8a-b and 9a-f) were developed as anticancer candidates. NCI screening of the synthesized compounds at 10 μM concentration displayed growth inhibition not only up to 99.74% as observed for 9a but also a lethal effect could be achieved as stated for compounds 9c (RPMI-8226 and HCT-116) and 8b, 9a, and 9e on the HCT-116 cell line. The antiproliferative activity was determined for the chalcone series on three cell lines: RPMI-8226, HCT-116, and MCF-7. Compounds 8b, 9a, 9b, and 9f were the most active ones. To understand the mechanistic study, the inhibitory effect on the epidermal growth factor receptor (EGFR) kinase was evaluated. The results stated that the activity of compound 8b (IC50 = 0.07 μM) was near that of the reference drug erlotinib (IC50 = 0.052 μM) whereas compound 9b (IC50 = 0.045 μM) was found to be more potent than erlotinib. Both compounds 8b and 9b were selected for cell cycle analysis and apoptotic assays. Moreover, molecular docking results of the selected chalcone hybrids showed high binding scores and good binding affinities especially for 8b and 9b, which were consistent with the biological activity (EGFR).

Hydroxychloroquine an Antimalarial Drug, Exhibits Potent Antifungal Efficacy Against Candida albicans Through Multitargeting.

Candida albicans is the primary etiological agent associated with candidiasis in humans. Unrestricted growth of C. albicans can progress to systemic infections in the worst situation. This study investigates the antifungal activity of Hydroxychloroquine (HCQ) and mode of action against C. albicans. HCQ inhibited the planktonic growth and yeast to hyphal form morphogenesis of C. albicans significantly at 0.5mg/ml concentration. The minimum inhibitory concentrations (MIC50) of HCQ for C. albicans adhesion and biofilm formation on the polystyrene surface was at 2mg/ml and 4mg/ml respectively. Various methods, such as scanning electron microscopy, exploration of the ergosterol biosynthesis pathway, cell cycle analysis, and assessment of S oxygen species (ROS) generation, were employed to investigate HCQ exerting its antifungal effects. HCQ was observed to reduce ergosterol levels in the cell membranes of C. albicans in a dose-dependent manner. Furthermore, HCQ treatment caused a substantial arrest of the C. albicans cell cycle at the G0/G1 phase, which impeded normal cell growth. Gene expression analysis revealed upregulation of SOD2, SOD1, and CAT1 genes after HCQ treatment, while genes like HWP1, RAS1, TEC1, and CDC 35 were downregulated. The study also assessed the in vivo efficacy of HCQ in a mice model, revealing a reduction in the pathogenicity of C. albicans after HCQ treatment. These results indicate that HCQ holds for the development of novel antifungal therapies.

Synthesis, anticancer evaluation, molecular docking and ADME study of novel pyrido[4ʹ,3ʹ:3,4]pyrazolo[1,5-a]pyrimidines as potential tropomyosin receptor kinase A (TrKA) inhibitors

The starting compound 3-amino-1,7-dihydro-4H-pyrazolo[4,3-c]pyridine-4,6(5H)-dione (1) is reacted with each of diketone and β-ketoester, forming pyridopyrazolo[1,5-a]pyrimidines 4a,b and 14a,b, respectively. The compounds 4 and 14 reacted with each of aromatic aldehyde and arenediazonium salt to give the respective arylidenes and arylhydrazo derivatives, respectively. The structure of the new products was established using spectroscopic techniques. The cytotoxic activity of selected targets was tested in vitro against three cancer cell lines MCF7, HepG2 and HCT116. The data obtained from enzymatic assays of TrKA indicated that compounds 7b and 16c have the strongest inhibitory effects on TrKA with IC50 = 0.064 ± 0.0037 μg/ml and IC50 = 0.047 ± 0.0027 μg/ml, respectively, compared to the standard drug Larotrectinib with IC50 = 0.034 ± 0.0021 μg/ml for the HepG2 cancer cell line. In cell cycle analysis, compounds 7b, 15b, 16a and 16c caused the greatest arrest in cell cycle at the G2/M phase. In addition, compound 15b has a higher apoptosis-inducing effect (36.72%) than compounds 7b (34.70%), 16a (21.14) and 16c (26.54%). Compounds 7b, 16a and 16c were shown fit tightly into the active site of the TrKA kinase crystal structure (PDB: 5H3Q). Also, ADME study was performed on some selected potent anticancer compounds described in this study.

Decreasing the ability of HCT116 cells to escape from therapy induced senescence by increasing the duration of doxorubicin treatment

Contacts: Maria Anatolievna Zamkova zamkovam@gmail.com Introduction. Due to the toxicity of high doses of chemotherapy, low concentrations used in cancer treatment leads to the development of senescence phenotype in tumor cells, characterized by a block in the cell cycle progression and the absence of division; changes in the transcriptional and metabolic profile of cells. A negative consequence of this stage is acquisition of individual cells the ability to escape from senescence and return to re-proliferation.Aim. To estimate the effect of the duration of drug treatment of HCT116 tumor cells on their ability to escape from therapy induced senescence.Materials and methods. The senescence phenotype was confirmed by the analysis of β-galactosidase activity; cell cycle analysis; estimation of protein levels by western blotting. Colonies were stained with crystal violet dye.Results. In our study, we showed that the duration of HCT116 cells incubation with low-dose doxorubicin affects their ability to return to re-proliferation – increasing the treatment time using same drug dose reduces the process of colony formation. The duration of doxorubicin treatment does not affect the formation of the senescence phenotype, which was confirmed by analyzing different markers of this stage (changes in β-galactosidase activity, cell cycle analysis, assessment of p21 and γH2AX protein levels). However, there is a delay in the development of cellular response to DNA damage caused by doxorubicin in cells exposed to prolong treatment protocol (increase in β-galactosidase activity, formation of polyploid cells).Conclusion. The duration of doxorubicin treatment of HCT116 cancer cells affects long-term consequences, reducing the ability of senescent cells to escape this stage when the incubation time with the drug is extended.

Abstract LB273: Pharmacological synthetic lethality by co-inhibition of PARP and HDAC enzymes

Abstract Introduction: Inhibition of poly(ADP-ribose) polymerase (PARP) induces synthetic lethality in cells exhibiting defects in homologous repair (HR) pathways, such as BRCA1 and BRCA2-mutated breast or ovarian cancers, and 4 different PARP inhibitors (PARPi) are currently approved by the FDA. While HR-deficient cancers usually respond well to single agent PARPi, HR-proficient cancers are generally less sensitive to the treatment. Acquired resistance to PARPi due to activating mutations in BRCA genes are also not uncommon. In this work, we have examined strategies for enhancing PARPi activity in a HR-proficient context and identified histone deacetylases (HDACs) as targets for pharmacological synthetic lethality in the context of PARPi. Materials and methods: PARP1 and PARP2 activity were measured using Trevigen Universal Colorimetric PARP Assay Kit, BPS Bioscience PARP2 Colorimetric PARP2 Assay Kit, and PARylation assay. HDAC activity was measured using HeLa cell nuclear extracts and a fluorogenic peptide-based biochemical assay. Cell survival EC50 were determined using CellTiter Glo viability assay. Cell cycle analysis was performed by flow cytometry with propidium iodide staining. DNA damage was investigated by immunoblotting and immunofluorescence using gamma-H2AX antibodies, and comet assays for confirmation of double-strand breaks. Spheroid assays were performed using the Incucyte® S3 spheroid analysis module. In vivo metastasis formations were examined using the pulmonary metastasis assay (PuMA). Results and discussion: Combinations of PARP and HDAC inhibitors in HR-proficient tumor cells demonstrated that HDACi could enhance the efficacy of PARPi in vitro. This was associated with increased acute and sustained DNA-damage distinct cell cycle profiles showing activity in both S- and G2/M-phases. Importantly, dual single-molecule PARP-HDAC inhibitors showed potent inhibition of PARP1 and PARP2 activity and PAR synthesis, comparable to olaparib, as well as inhibition of HDAC with IC50 values in the low µM range. Dual PARP-HDAC inhibition decreased survival of HR-proficient cells in both 2D cultures and 3D spheroid assays with lower EC50 values than olaparib or vorinostat alone. Importantly, lung metastasis formation was significantly impaired by dual PARP-HDAC inhibition. Conclusion: Combination of PARP inhibition and HDAC inhibition showed increased efficacy compared to single agent PARP inhibition in HR-proficient cells. Development of bifunctional inhibitors may provide a novel therapeutic opportunity for tumors with limited response rates to single agent PARPi. Citation Format: Sarah Truong, Louise Ramos, Beibei Zhai, Fariba Ghaidi, Mona Marzban, Hans Adomat, Xiaoqi Chen, John Langlands, Dennis Brown, Jeffrey Bacha, Colin Collins, Poul H. Sorensen, Wang Shen, Mads Daugaard. Pharmacological synthetic lethality by co-inhibition of PARP and HDAC enzymes [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 LB273.

Abstract LB421: Entinostat alters cell cycle in ovarian cancer cells

Abstract Introduction: We have reported that Class I/II HDACi sensitize PARPi resistant tumors, creating a possibility to expand the use of PARPi beyond homologous recombination deficient tumors. However, the underlying mechanism is still unknown. Here, we report leads obtained from differential gene expression in ovarian cancer cells treated with entinostat and olaparib. Methods: OVCAR3 cells were treated with 0.5 µM entinostat and 10 µM olaparib (alone and combined) for 6h, followed by RNA Seq. Cell cycle was analyzed by flow cytometry in SKOV-3 cells treated with olaparib and entinostat (alone and combined) for 24h, 48h and 72h. Results: RNA-Seq analysis showed reduced expression of genes that regulate G2/M checkpoint progression with both entinostat and olaparib. This correlated with flow cytometry results in SKOV-3 cells, where we observed accumulation of G2/M phase cells when treated with entinostat and olaparib. At 24h post treatment, olaparib and entinostat treated cells had higher population of cells in G2/M phase compared to control (18.5% and 16.7% respectively compared to 14.7% in control). Olaparib combined with entinostat further increased G2/M population to 21.7%. At 48h olaparib treated cells had 17.4% cells in G2/M compared to 14% in control. Entinostat treated cells had 18% G2/M cells. Combination treated cells had 19.7% G2/M cells. At 72h, olaparib and control had similar number of G2/M cells (9.2% and 9.7% respectively). Entinostat treated cells had 12% G2/M cells and combination treated cells had 13.6% cells at G2/M cells. This indicates that entinostat and olaparib disrupt progression of cells from G2/M phase, potentially leading to cell death before they can enter mitosis/cell division. Cell cycle analysis in OVCAR3 cells is in progress. Conclusion: Entinostat and olaparib cause G2/M cell cycle arrest in ovarian cancer cells. Entinostat maintains G2/M cell cycle arrest longer than olaparib, potentially extending the window of efficacy of the combination therapy. Validation of G2/M markers and other gene targets/pathways is in progress. Citation Format: Vijayalaxmi G. Gupta, Heng Liu, Rugang Zhang, Michael Onken, Andrew Wilson, Fiona Yull, Marta Crispens, Mary Mullen, Dineo Khabele. Entinostat alters cell cycle in ovarian cancer cells [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 LB421.

Citalopram, an antipsychotic agent, induces G1/G0 phase cell cycle arrest and promotes apoptosis in human laryngeal carcinoma HEP-2 cells

Human laryngeal squamous carcinoma (LSCC) is a common malignant tumor in the head and neck. Despite the recently developed therapies for the treatment of LSCC, patients’ overall survival rate still did not enhance remarkably; this highlights the need to formulate alternative strategies to develop novel treatments. The antitumor effects of antidepressant drugs such as citalopram have been reported on several cancer cells; however, they have yet to be investigated against LSCC. The current study was directed to explore the possible antitumor effects of citalopram on human laryngeal carcinoma cell lines (HEP-2). HEP-2 cells were cultured and treated with different doses of citalopram (50–400 µM) for 24, 48, and 72 h. The effects of citalopram on the viability of cancer cells were determined by the MTT assay. In addition, apoptosis and cell cycle analysis were performed by flow cytometry. Moreover, evaluation of the expression of proapoptotic and apoptotic proteins, such as cytochrome c, cleaved caspases 3 and 9, Bcl-2, and BAX, was performed by western blotting analysis. Our results revealed that citalopram significantly suppressed the proliferation of HEP-2 cells through the upregulation of p21 expression, resulting in the subsequent arrest of the cell cycle at the G0/G1 phase. Furthermore, citalopram treatment-induced HEP-2 cell apoptosis; this was indicated by the significant increase of cytochrome c, cleaved caspases 3 and 9, and BAX protein expression. On the contrary, Bcl-2 protein expression was significantly downregulated following treatment with citalopram. The ultrastructure studies were in accordance with the protein expression findings and showed clear signs of apoptosis with ring chromatin condensation upon treatment with citalopram. These findings suggest that citalopram’s anti-tumor activities on HEP-2 cells entailed stimulation of the intrinsic apoptotic pathway, which was mediated via Bcl-2 suppression.

L-kynurenine and quinolinic acid inhibited markers of cell survival in B16 F10 melanoma cells in vitro.

Melanoma is an aggressive malignancy and remains a major cause of skin cancer mortality, highlighting the need for new treatment strategies. Recent findings revealed that L-kynurenine and quinolinic acid induce cytotoxicity and morphological changes in B16 F10 melanoma cells in vitro. This paper highlights the effects of L-kynurenine and quinolinic acid at previously determined half-maximal inhibitory concentrations on cell cycle progression, cell death and extracellular signal-regulated protein kinase inhibition. Melanoma, B16 F10 and murine macrophages, RAW 264.7 cells were used in this study, as both cell lines express all the enzymes associated with the kynurenine pathway. Post exposure to the compounds at half-maximal inhibitory concentrations, transmission electron microscopy was used to assess intracellular morphological changes. Flow cytometry was used to analyse cell cycle progression and quantify apoptosis via the dual staining of Annexin V and propidium iodide and cell survival via extracellular signal-regulated protein kinase. L-kynurenine and quinolinic acid at half-maximal inhibitory concentrations induced intracellular morphological changes representative of cell death. Flow cytometry revealed alterations in cell cycle distribution, increased apoptosisand significantlyinhibition of cell survival. L-kynurenine and quinolinic acid are exogenous kynurenine compounds which inhibited cell survival through extracellular signal-regulated protein kinase inhibition, induced cell cycle alterations and induced apoptosis in B16 F10 melanoma cells.

Comparing the toxicity effects of copper oxide nanoparticles conjugated with Lapatinib on breast (MDA-MB-231) and lung (A549) cancer cell lines.

In recent years, the increase in cancer morbidity and mortality has presented scientists with a major challenge in developing new therapeutic agents against cancer cells. This study aims to characterize the anticancer effects of copper oxide nanoparticles (NPs) conjugated with Lapatinib (CuO@Lapatinib) on breast and lung cancer cell lines. The physicochemical properties of the NPs were characterized by fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and zeta potential analyses. The antiproliferative potential of the NPs in the breast (MDA-MB-231) and lung (A549) cancer cell lines and a normal cell line (MRC5) was investigated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. Flow cytometry and Hoechst staining were used to evaluate cell apoptosis and cell cycle analysis. The reactive oxygen species (ROS) levels in the treated and control cells were also determined. The NPs were spherical, with a size range of 20-59nm, a DLS size of 338nm, and a zeta potential of -42.9 mV. The half maximal inhibitory concentration (IC50) of CuO@Lapatinib NPs for the normal, breast cancer, and lung cancer cell lines was 105, 98, and 87 µg/ml, respectively. Treatment with CuO@Lapatinib NPs caused considerable apoptosis induction in breast cancer (from 0.65% to 68.96%) and lung cancer cell lines (from 1.11% to 44.11%). Also, an increased level of cell cycle arrest at the S phase was observed in both cancer cell lines. The ROS level in the breast and lung cancer cell lines after treatment with CuO@Lapatinib NPs increased by 3.45 and 21.04 folds, respectively. Nuclear morphological alterations, including chromatin condensation and fragmentation, were observed in both cancer cell lines. This study indicates CuO@Lapatinib is a potent antiproliferative compound with more efficient inhibitory effects on lung cancer than breast cancer cells, which can be related to the higher ROS generation in the A549 cell line.

Single cell RNA-sequencing reveals the cellular senescence of placental mesenchymal stem/stromal cell in preeclampsia

IntroductionPreeclampsia (PE) is a severe obstetric complication closely associated with placental dysfunction. Placental mesenchymal stem/stromal cells (PMSCs) modulate placental development while PE PMSCs are excessively senescent to disturb placental function. Nevertheless, the senescence mechanism of PE PMSCs remains unclear. MethodsPE-related single-cell RNA sequencing datasets (GSE173193), data of chip detection (GSE99007) and bulk transcriptome RNA sequencing datasets (GSE75010) were extracted from the GEO database. Firstly, the functional enrichment analyses of the differentially expressed genes (DEGs) in PMSCs were conducted. Then, the clusters of PE PMSCs were distinguished according to the expressions of senescence-related genes (SRGs) by consensus clustering analysis. Cell cycle analysis, senescence β-galactosidase, Transwell, and tube formation were conducted. Next, the expressions of the senescence-associated secretory phenotype (SASPs) were displayed. The characteristic genes of PE were screened by the least absolute shrinkage and selection operator analysis. CTSZ was suppressed in PMSCs and the cellular senescence levels were evaluated. ResultsIn this study, The DEGs in PMSCs were closely associated with cellular senescence. The score of SRGs was significantly higher and most of the SASPs were abnormally expressed in the senescent group. Seven characteristic genes of PE were identified, thereinto, CTSZ reduction may accelerate the senescence in PMSCs in vitro. DiscussionCombined with bioinformatic analysis and lab experiments, our study emphatically revealed the abnormal cellular senescence in PE PMSCs, in which CTSZ, one of the PE characteristic genes, regulated the cellular senescence levels in PMSCs. These findings might help to deepen the understanding of the senescence mechanism of PMSCs in PE.

Design and Synthesis of Aspirin-chalcone Mimic Conjugates as Potential Anticancer Agents.

Extensive research has been conducted on aspirin, a widely recognized NSAID medication, regarding its potential as an anticancer agent. Studies have revealed its ability to trigger cell death in different types of cancer cells. A set of aspirin-chalcone mimic conjugates 5a-k and 6a-d utilizing the freshly prepared acid chloride of aspirin moiety has been designed and synthesized. To evaluate the newly developed compounds, the NCI 60- cell line panel was employed to assess their anti-proliferative properties. Subsequently, cell cycle analysis was conducted along with an examination of the compounds' impact on the levels of p53, Bax, Bcl-2, active caspase- 3, and their inhibition mechanism of tubulin polymerization. Derivative 6c displayed the best anticancer activity among the tested series while 6d was the best against breast cancer MDA-MB-468, therefore both of them were selected for the 5-dose stage, however, targeting MDA-MB-468, PI-flow cytometry of compound 6d proved the triggered cell growth arrest at the G1/S phase avoiding the mitotic cycle in MDA-MB-468 cells. Similarly, the upregulation of oncogenic parameters such as caspase-3, p53, and Bax/Bcl-2, along with the inhibition of PARP-1 enzyme level, was observed with compound 6d. This compound also exhibited a significant ability to induce apoptosis and disrupt the intracellular microtubule network through a promising activity as a tubulin polymerization inhibitor with IC50 = 1.065 ± 0.024 ng/ml. Furthermore, to examine the manner in which compound 6d binds to the active pocket of the tubulin polymerization enzyme, a molecular docking study was conducted. The study indicated that compound 6d could be a powerful microtubule-destabilizing agent. Therefore, further research on 6d could be worthwhile.

7-O-tyrosyl Silybin Derivatives as a Novel Set of Anti-Prostate Cancer Compounds

Silybin is a natural compound extensively studied for its hepatoprotective, neuroprotective and anticancer properties. Envisioning the enhancement of silybin potential by suitable modifications in its chemical structure, here, a series of new 7-O-alkyl silybins derivatives were synthesized by the Mitsunobu reaction starting from the silybins and tyrosol-based phenols, such as tyrosol (TYR, 3), 3-methoxytyrosol (MTYR, 4), and 3-hydroxytyrosol (HTYR, 5). This research sought to explore the antioxidant and anticancer properties of eighteen new derivatives and their mechanisms. In particular, the antioxidant properties of new derivatives outlined by the DPPH assay showed a very pronounced activity depending on the tyrosyl moiety (HTYR &gt; MTYR &gt;&gt; TYR). A significant contribution of the HTYR moiety was observed for silybins and 2,3-dehydro-silybin-based derivatives. According to the very potent antioxidant activity, 2,3-dehydro-silybin derivatives 15ab, 15a, and 15b exerted the most potent anticancer activity in human prostate cancer PC-3 cells. Furthermore, flow cytometric analysis for cell cycle and apoptosis revealed that 15ab, 15a, and 15b induce strong G1 phase arrest and increase late apoptotic population in PC-3 cells. Additionally, Western blotting for apoptotic marker cleaved caspase-3 confirmed apoptosis induction by these silybin derivatives in PC-3 cells. These findings hold significant importance in the investigation of anticancer properties of silybin derivatives and strongly encourage swift investigation in pre-clinical models and clinical trials.

Exploring the Therapeutic Effects of Atractylodes macrocephala Koidz against Human Gastric Cancer.

Atractylodes macrocephala Koidz (AMK) is a traditional herbal medicine used for thousands of years in East Asia to improve a variety of illnesses and conditions, including cancers. This study explored the effect of AMK extract on apoptosis and tumor-grafted mice using AGS human gastric adenocarcinoma cells. We investigated the compounds, target genes, and associated diseases of AMK using the Traditional Chinese Medical Systems Pharmacy (TCMSP) database platform. Cell viability assay, cell cycle and mitochondrial depolarization analysis, caspase activity assay, reactive oxygen species (ROS) assay, and wound healing and spheroid formation assay were used to investigate the anti-cancer effects of AMK extract on AGS cells. Also, in vivo studies were conducted using subcutaneous xenografts. AMK extract reduced the viability of AGS cells and increased the sub-G1 cell fraction and the mitochondrial membrane potential. Also, AMK extract increased the production of ROS. AMK extract induced the increased caspase activities and modulated the mitogen-activated protein kinases (MAPK). In addition, AMK extract effectively inhibited AGS cell migration and led to a notable reduction in the growth of AGS spheroids. Moreover, AMK extract hindered the growth of AGS xenograft tumors in NSG mice. Our results suggest that AMK has anti-cancer effects by promoting cell cycle arrest and inhibiting the proliferation of AGS cancer cells and a xenograft model through apoptosis. This study could provide a novel approach to treat gastric cancer.

Novel hybrid compounds of sclareol and doxorubicin as potential anticancer nanotherapy for glioblastoma

Two novel hybrid compounds, CON1 and CON2, have been developed by combining sclareol (SC) and doxorubicin (DOX) into a single molecular entity. These hybrid compounds have a 1:1 molar ratio of covalently linked SC and DOX. They have demonstrated promising anticancer properties, especially in glioblastoma cells, and have also shown potential in treating multidrug-resistant (MDR) cancer cells that express the P-glycoprotein (P-gp) membrane transporter. CON1 and CON2 form nanoparticles, as confirmed by Zetasizer, transmission electron microscopy (TEM), and chemical modeling. TEM also showed that CON1 and CON2 can be found in glioblastoma cells, specifically in the cytoplasm, different organelles, nucleus, and nucleolus. To examine the anticancer properties, the U87 glioblastoma cell line, and its corresponding multidrug-resistant U87-TxR cell line, as well as patient-derived astrocytoma grade 3 cells (ASC), were used, while normal human lung fibroblasts were used to determine the selectivity. CON1 and CON2 exhibited better resistance and selectivity profiles than DOX, showing less cytotoxicity, as evidenced by real-time cell analysis, DNA damage determination, cell death induction, mitochondrial respiration, and mitochondrial membrane depolarization studies. Cell cycle analysis and the β-galactosidase activity assay suggested that glioblastoma cells die by senescence following CON1 treatment. Overall, CON1 and CON2 showed great potential as they have better anticancer features than DOX. They are promising candidates for additional preclinical and clinical studies on glioblastoma.

Enhancing RECK Expression Through miR-21 Inhibition: A Promising Strategy for Bladder Carcinoma Control.

Bladder carcinoma (BC) is the tenth most frequent malignancy worldwide, with high morbidity and mortality rates. Despite recent treatment advances, high-grade BC and muscle-invasive BC present with significant progression and recurrence rates, urging the need for alternative treatments. The microRNA-21 (miR-21) has superexpression in many malignancies and is associated with cellular invasion and progression. One of its mechanisms of action is the regulation of RECK, a tumor suppressor gene responsible for inhibiting metalloproteinases, including MMP9. In a high-grade urothelial cancer cell line, we aimed to assess if miR-21 downregulation would promote RECK expression and decrease MMP9 expression. We also evaluated cellular migration and proliferation potential by inhibition of this pathway. In a T24 cell line, we inhibited miR-21 expression by transfection of a specific microRNA inhibitor (anti-miR-21). There were also control and scramble groups, the last with a negative microRNA transfected. After the procedure, we performed a genetic expression analysis of miR-21, RECK, and MMP9 through qPCR. Migration, proliferation, and protein expression were evaluated via wound healing assay, colony formation assay, flow cytometry, and immunofluorescence.After anti-miR-21 transfection, miR-21 expression decreased with RECK upregulation and MMP9 downregulation. The immunofluorescence assay showed a significant increase in RECK protein expression (p < 0.0001) and a decrease in MMP9 protein expression (p = 0.0101). The anti-miR-21 transfection significantly reduced cellular migration in the wound healing assay (p < 0.0001). Furthermore, in the colony formation assay, the anti-miR-21 group demonstrated reduced cellular proliferation (p = 0.0008), also revealed in the cell cycle analysis by flow cytometry (p = 0.0038). Our results corroborate the hypothesis that miR-21 is associated with BC cellular migration and proliferation, revealing its potential as a new effective treatment for this pathology.

Abstract 4677: Characterizing resistant and metastatic phenotypes to pharmacological ascorbate in pancreatic cancer

Abstract Background and purpose: Pharmacological ascorbate (P-AscH) is a prooxidant that oxidizes to produce high levels of hydrogen peroxide. It is currently being investigated as an anti-cancer neoadjuvant for pancreatic cancer (PC). In phase I clinical trials, P-AscH has generated encouraging results in terms of efficiency and safety. However, 50% of patients do not respond to P-AscH suggesting that resistance occurs in a subset of patients. We have generated PC cell lines resistant to P-AscH to characterize mechanisms of resistance. Methodology: PANC-1 and MIA PaCa-2 PC cell lines were treated with a stepwise progression of increasing concentrations of P-AscH until 10-fold IC50 concentration was fully tolerated (AscR, ascorbate resistant) as determined by clonogenic survival. Once resistance was achieved, various redox enzyme protein expression and activity were measured to determine their role in resistance to P-AscH. Proliferation and cell cycle analysis were conducted on resistant and sensitive cells. An RNA sequencing screen was conducted as an unbiased approach to identify potential candidates crucial for resistance. Finally, phenotypes associated to increased metastatic potential, including collagen invasion and in vivo tumor colonization were explored for characterization. Results: PANC-1 and MIA PaCa-2 AscR cells developed unique mechanisms to tolerate high levels of P-AscH. PANC-1 AscR cells almost exclusively rely on catalase to detoxify H2O2 generated during P-AscH treatments, while MIA PaCa-2 AscR cells do not. It is interesting to note that not every redox enzyme was upregulated in response to P-AscH treatments, including GPx1/4. The AscR cell lines also differed in growth rates. PANC-1 AscR cells developed a faster proliferation rate, whereas MIA PaCa-2 AscR cells significantly decreased their growth. This is consistent with a shortened G1/G0 cell cycle phase and an accumulation in G2/M, respectively. The RNA sequencing screen revealed a metastatic signature in association with resistance to P-AscH, including upregulation of the PI3K/AKT axis. We observed a significant increase in collagen matrix invasion, as well as metastatic colonization in vivo. Additionally, we have observed increased expression of active AKT in both AscR cell lines, indicating a potential mechanism for the increased metastatic phenotype. Conclusion: Our findings demonstrate distinct mechanisms for AcsR cells to tolerate high doses of P-AscH. Although catalase has demonstrated to be a key factor in controlling redox flux, it may not be necessary for all cell types. Not only can P-AscH resistance alter redox enzyme expression, but we have also observed substantial increase in metastatic potential to drive invasion and tumor colonization. In summary, our data indicate a potential route for PC to tolerate high levels of P-AscH and may explain how some patients do not respond to this treatment regimen. Citation Format: Amanda N. Pope, Brianne R. O'Leary, Juan Du, Garry R. Buettner, Michael D. Henry, Joseph J. Cullen. Characterizing resistant and metastatic phenotypes to pharmacological ascorbate in pancreatic cancer [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 4677.