Continuous distribution of cancer cells in the cell cycle unveiled by AI-segmented imaging of 37,000 HeLa FUCCI cells

Classification of live or fixed cells based on their unlabeled microscopic images would be a powerful tool for cell biology and pathology. For such software, the first step is the generation of a ground truth database that can be used for training and testing AI classification algorithms. The Application of cells expressing fluorescent reporter proteins allows the building of ground truth datasets in a straightforward way. In this study, we present an automated imaging pipeline utilizing the Cellpose algorithm for the precise cell segmentation and measurement of fluorescent cellular intensities across multiple channels. We analyzed the cell cycle of HeLa-FUCCI cells expressing fluorescent red and green reporter proteins at various levels depending on the cell cycle state. To build the dataset, 37,000 fixed cells were automatically scanned using a standard motorized microscope, capturing phase contrast and fluorescent red/green images. The fluorescent pixel intensity of each cell was integrated to calculate the total fluorescence of cells based on cell segmentation in the phase contrast channel. It resulted in a precise intensity value for each cell in both channels. Furthermore, we conducted a comparative analysis of Cellpose 1.0 and Cellpose 2.0 in cell segmentation performance. Cellpose 2.0 demonstrated notable improvements, achieving a significantly reduced false positive rate of 2.7 % and 1.4 % false negative. The cellular fluorescence was visualized in a 2D plot (map) based on the red and green intensities of the FUCCI construct revealing the continuous distribution of cells in the cell cycle. This 2D map enables the selection and potential isolation of single cells in a specific phase. In the corresponding heatmap, two clusters appeared representing cells in the red and green states. Our pipeline allows the high-throughput and accurate measurement of cellular fluorescence providing extensive statistical information on thousands of cells with potential applications in developmental and cancer biology. Furthermore, our method can be used to build ground truth datasets automatically for training and testing AI cell classification. Our automated pipeline can be used to analyze thousands of cells within 2 h after putting the sample onto the microscope.

Discovery of harmiprims, harmine-primaquine hybrids, as potent and selective anticancer and antimalarial compounds

Although cancer and malaria are not etiologically nor pathophysiologically connected, due to their similarities successful repurposing of antimalarial drugs for cancer and vice-versa is known and used in clinical settings and drug research and discovery. With the growing resistance of cancer cells and Plasmodium to the known drugs, there is an urgent need to discover new chemotypes and enrich anticancer and antimalarial drug portfolios. In this paper, we present the design and synthesis of harmiprims, hybrids composed of harmine, an alkaloid of the β-carboline type bearing anticancer and antiplasmodial activities, and primaquine, 8-aminoquinoline antimalarial drug with low antiproliferative activity, covalently bound via triazole or urea. Evaluation of their antiproliferative activities in vitro revealed that N-9 substituted triazole-type harmiprime was the most selective compound against MCF-7, whereas C1-substituted ureido-type hybrid was the most active compound against all cell lines tested. On the other hand, dimeric harmiprime was not toxic at all. Although spectrophotometric studies and thermal denaturation experiments indicated binding of harmiprims to the ds-DNA groove, cell localization showed that harmiprims do not enter cell nucleus nor mitochondria, thus no inhibition of DNA-related processes can be expected. Cell cycle analysis revealed that C1-substituted ureido-type hybrid induced a G1 arrest and reduced the number of cells in the S phase after 24 h, persisting at 48 h, albeit with a less significant increase in G1, possibly due to adaptive cellular responses. In contrast, N-9 substituted triazole-type harmiprime exhibited less pronounced effects on the cell cycle, particularly after 48 h, which is consistent with its moderate activity against the MCF-7 cell line. On the other hand, screening of their antiplasmodial activities against the erythrocytic, hepatic, and gametocytic stages of the Plasmodium life cycle showed that dimeric harmiprime exerts powerful triple-stage antiplasmodial activity, while computational analysis showed its binding within the ATP binding site of PfHsp90.

Design, synthesis, and anticancer evaluation of 1-benzo[1,3]dioxol-5-yl-3-N-fused heteroaryl indoles

A series of 1-benzo[1,3]dioxol-5-yl-indoles bearing 3-N-fused heteroaryl moieties have been designed based on literature reports of the activity of indoles against various cancer cell lines, synthesized via a Pd-catalyzed C-N cross-coupling, and evaluated for their anticancer activity against prostate (LNCaP), pancreatic (MIA PaCa-2), and acute lymphoblastic leukemia (CCRF-CEM) cancer cell lines. A detailed structure-activity relationship study culminated in the identification of 3-N-benzo[1,2,5]oxadiazole 17 and 3-N-2-methylquinoline 20, whose IC50 values ranged from 328 to 644 nM against CCRF-CEM and MIA PaCa-2. Further mechanistic studies revealed that 20 caused cell cycle arrest at the S phase and induced apoptosis in CCRF-CEM cancer cells. These 1-benzo[1,3]dioxol-5-yl-3-N-fused heteroaryl indoles may serve as a template for further optimization to afford more active analogs and develop a comprehensive understanding of the structure-activity relationships of indole anticancer molecules.

Production and bioprocessing of Taxol from Aspergillus niger, an endophyte of Encephalartos whitelockii, with a plausible biosynthetic stability: antiproliferative activity and cell cycle analysis

The biosynthetic potency of Taxol by fungi raises their prospective to be a platform for commercial production of Taxol, nevertheless, the attenuation of its productivity with the fungal storage, is the challenge. Thus, screening for a novel fungal isolate inhabiting ethnopharmacological plants, with a plausible metabolic stability for Taxol production could be one of the most affordable approaches. Aspergillus niger OR414905.1, an endophyte of Encephalartos whitelockii, had the highest Taxol productivity (173.9 μg/L). The chemical identity of the purified Taxol was confirmed by HPLC, FTIR, and LC-MS/MS analyses, exhibiting the same molecular mass (854.5 m/z) and molecular fragmentation pattern of the authentic Taxol. The purified Taxol exhibited a potent antiproliferative activity against HepG-2, MCF-7 and Caco-2, with IC50 values 0.011, 0.016, and 0.067 μM, respectively, in addition to a significant activity against A. flavus, as a model of human fungal pathogen. The purified Taxol displayed a significant effect against the cellular migration of HepG-2 and MCF-7 cells, by ~ 52-59% after 72 h, compared to the control, confirming its interference with the cellular matrix formation. Furthermore, the purified Taxol exhibited a significant ability to prompt apoptosis in MCF-7 cells, by about 11-fold compared to control cells, suppressing their division at G2/M phase. Taxol productivity by A. niger has been optimized by the response surface methodology with Plackett-Burman Design and Central Composite Design, resulting in a remarkable ~ 1.6-fold increase (279.8 μg/L), over the control. The biological half-life time of Taxol productivity by A. niger was ~ 6 months of preservation at 4 ℃, however, the Taxol yield by A. niger was partially restored in response to ethyl acetate extracts of E. whitelockii, ensuring the presence of plant-derived signals that triggers the cryptic Taxol encoding genes.

d-α-tocopheryl polyethylene glycol 1000 succinate surface scaffold polysarcosine based polymeric nanoparticles of enzalutamide for the treatment of colorectal cancer: In vitro, in vivo characterizations

In this study, Enzalutamide (ENZ) loaded Poly Lactic-co-Glycolic Acid (PLGA) nanoparticles coated with polysarcosine and d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) were prepared using a three-step modified nanoprecipitation method combined with self-assembly. A three-factor, three-level Box-Behnken design was implemented with Design-Expert® software to evaluate the impact of three independent variables on particle size, zeta potential, and percent entrapment efficiency through a numeric optimization approach. The results were corroborated with ANOVA analysis, regression equations, and response surface plots. Field emission scanning electron microscopy and transmission electron microscope images revealed nanosized, spherical polymeric nanoparticles (NPs) with a size distribution ranging from 178.9 ± 2.3 to 212.8 ± 0.7 nm, a zeta potential of 12.6 ± 0.8 mV, and entrapment efficiency of 71.2 ± 0.7 %. The latter increased with higher polymer concentration. Increased polymer concentration and homogenization speed also enhanced drug entrapment efficiency. In vitro drug release was 85 ± 22.5 %, following the Higuchi model (R2 = 0.98) and Fickian diffusion (n < 0.5). In vitro cytotoxicity assessments, including Mitochondrial Membrane Potential Estimation, Apoptosis analysis, cell cycle analysis, Reactive oxygen species estimation, Wound healing assay, DNA fragmentation assay, and IC50 evaluation with Sulforhodamine B assay, indicated low toxicity and high efficacy of polymeric nanoparticles compared to the drug alone. In vivo studies demonstrated biocompatibility and target specificity. The findings suggest that TPGS surface-scaffolded polysarcosine-based polymer nanoparticles of ENZ could be a promising and safe delivery system with sustained release for colorectal cancer treatment, yielding improved therapeutic outcomes.

New 2-alkoxycyanopyridine derivatives as inhibitors of EGFR, HER2, and DHFR: Synthesis, anticancer evaluation, and molecular modeling studies

New series of substituted 2-alkoxycyanopyridine derivatives were synthesized and evaluated for their in vitro and in vivo anticancer activities. Comparing the evaluated activities against cancer cell lines to the broad-spectrum anticancer doxorubicin, and the kinase inhibitor sorafenib, compounds 3a, 4b, 4c, 7a, and 8d demonstrated superior anticancer efficacy with elevated safety profiles and selectivity indices, particularly against MCF7 breast cancer. For exploration of their mechanism of action, assays for inhibition of EGFR, HER2 kinase, and DHFR were performed. The promising synthesized compounds exhibited potent dual kinase EGFR/HER2 inhibitory activity with IC50values of 0.248/0.156 μM for 4b and 0.138/0.092 μM for 4c. Additionally, with IC50 values of 0.138 and 0.193 M, respectively, 4b and 4c had the greatest DHFR inhibitory activity that was comparable to methotrexate. In the MCF7 breast cancer cell line, they caused arrest at the S phase of the cell cycle and exhibited apoptosis induction activity. With restored caspase-3 immunoexpression, the anti-breast cancer assay performed in vivo of 4b and 4c demonstrated a substantial decrease in tumor volume. Results from molecular modeling were in agreement with biological assays proving the importance of the 3-caynopyridine, two substituted phenyl rings attached to central pyridine ring, and propoxy side chain moieties for binding with the receptors. As 4c works by inhibiting both EGFR/HER2 kinase, DHFR enzymes, in addition to cellular apoptosis, it could be viewed as a model of compounds possessing a multi-targeting anticancer activity. Collectively, compounds 4b and 4c might represent prototypes for further development as anticancer molecules.

Molecular properties prediction, anticancer and anti-inflammatory activities of some pyrimido[1,2-b]pyridazin-2-one derivatives

Introduction

The anticancer and anti-inflammatory activities of a novel series of eleven pyrimido[1,2-b]pyridazin-2-one analogues substituted at position 7 were assessed in the current study.

Methods

The physicochemical characteristics were studied using MolSoft software. The antiproliferative activity was investigated by MTT cell viability assay, and cell cycle analysis elucidated the antiproliferative mechanism of action. Western blot analysis examined the expression levels of key pro-apoptotic (Bax, p53) and pro-survival (Bcl-2) proteins. The anti-inflammatory activity was assessed by measuring the production levels of nitric oxide in RAW264.7 cells, and the expression levels of COX-2 enzyme in LPS-activated THP-1 cells. In addition, the gene expression of various pro-inflammatory cytokines (IL-6, IL-8, IL-1β, TNF-α) and chemokines (CCL2, CXCL1, CXCL2, CXCL3) was assessed by RT-qPCR.

Results

Compound 1 bearing a chlorine substituent displayed the highest cytotoxic activity against HCT-116 and MCF-7 cancer cells where IC50 values of 49.35 ± 2.685 and 69.32 ± 3.186 µM, respectively, were achieved. Compound 1 increased the expression of pro-apoptotic proteins p53 and Bax while reducing the expression of pro-survival protein Bcl-2. Cell cycle analysis revealed that compound 1 arrested cell cycle at the G0/G1 phase. Anti-inflammatory assessments revealed that compound 1 displayed the strongest inhibitory activity on NO production with IC50 of 29.94 ± 2.24 µM, and down-regulated the expression of COX-2. Compound 1 also induced a statistically significant decrease in the gene expression of various cytokines and chemokines.

Conclusion

These findings showed that the pyrimidine derivative 1 displayed potent anti-inflammatory and anticancer properties in vitro, and can be selected as a lead compound for further investigation.

Design, synthesis and biological evaluation of a novel bioactive indane scaffold 2-(diphenylmethylene)c-2,3-dihydro-1H-inden-1-one with potential anticancer activity

Over the past decades, designing of privileged structures has emerged as a useful approach to the discovery and optimisation of novel biologically active molecules, and many have been successfully exploited across and within different target families. Examples include indole, quinolone, isoquinoline, benzofuran and chromone, etc. In the current study, we focus on synthesising a novel hybrid scaffold constituting naturally occurring benzophenone (14) and indanone (22) ring systems, leading to a general structure of 2-(diphenylmethylene)-2,3-dihydro-1H-inden-1-one (23). It was hypothesised this new hybrid system would provide enhanced anti-cancer activity owing to the presence of the common features associated with the tubulin binding small molecule indanocine (10) and the estrogen receptor (ER) antagonist tamoxifen (24). Key hybrid molecules were successfully synthesised and characterised, and the in vitro cytotoxicity assays were performed against cancer cell lines: MCF7 (breast) and SKBR3 (breast), DU145 (prostate) and A549 (lung). The methyl-, chloro- and methoxy-, para-substituted benzophenone hybrids displayed the greatest degree of cytotoxicity and the E-configuration derivatives 45, 47 and 49 being significantly most potent. We further verified that the second benzyl moiety of this novel hybrid scaffold is fundamental to enhance the cytotoxicity, especially in the SKBR3 (HER2+) by the E-methyl lead molecule 47, MCF7 (ER+) by 45 and 49, and A549 (NSCLC) cell lines by 49. These hybrid molecules also showed a significant accumulation of SKBR3 cells at S-phase of the cell cycle after 72 hrs, which demonstrates besides of being cytotoxic in vitro against SKBR3 cells, 47 disturbs the replication and development of this type of cancer causing a dose-dependent cell cycle arrest at S-phase. Our results suggest that DNA damage might be involved in the induction of SKBR3 cell death caused by the hybrid molecules, and therefore, this novel system may be an effective suppressor of HER2+/Neu-driven cancer growth and progression. The present study points to potential structural optimisation of the series and encourages further focussed investigation of analogues of this scaffold series toward their applications in cancer chemoprevention or chemotherapy.

New benzothienopyran and benzothienopyranopyrimidine derivatives as topoisomerase I inhibitors: Design, synthesis, anticancer screening, apoptosis induction and molecular modeling studies

New benzothienopyran and benzothienopyranopyrimidine derivatives were synthesized based on the structural requirements of topoisomerase I inhibitors. All target compounds exhibited strong cytotoxic activity with GI₅₀ range of 70.62 %-87.29 % in one dose NCI (USA) screening against 60 human tumor cell lines. Among the tested derivatives, eight compounds namely 4d, 4e, 4f, 5b, 5e, 6b, 6d, and 6f demonstrated broad spectrum and potent anticancer efficacy in five dose screening against all tested panels. DNA relaxation assay for the latter compounds showed that 4d, 5b, and 6f exhibited excellent inhibitory activity with IC₅₀ range of 2.553-4.495 µM as compared to indenoisoquinoline reference drug (IC₅₀ = 3.911 ± 0.21 µM). Moreover, the most active compounds were investigated for being topoisomerase poisons or catalytic inhibitors using DNA nicking assay. Compounds 4d and 6f were found to be potential Topo I poisons, whereas compound 5b has acted as Topo I suppressor. Analyzing cell cycle and induction of apoptosis for the most active compound 4d, revealed growth arrest at the S phase in MDA-MB-435 cells similarly to indenoisoquinoline reference drug. Additionally, in silico molecular modeling study for eight most active cytotoxic compounds in five dose screening demonstrated interaction with DNA as well as distinctive binding pattern similar to the reference indenoisoquinoline, indicating that the newly discovered targets are supposed to be promising candidates as Topo I inhibitors.

Discovery of PIM-1 kinase inhibitors based on the 2,5-disubstituted 1,3,4-oxadiazole scaffold against prostate cancer: Design, synthesis, in vitro and in vivo cytotoxicity investigation

PIM-1 kinases play an established role in prostate cancer development and progression. This research work tackles the design and synthesis of new PIM-1 kinase targeting 2,5-disubstituted-1,3,4-oxadiazoles 10a-g&11a-f, and investigation thereof as potential anti-cancer agents through in vitro cytotoxicity assay followed by in vivo studies along with exploration of this chemotype's plausible mechanism of action. In vitro cytotoxicity experiments have disclosed 10f as the most potent derivative against PC-3 cells (IC₅₀ = 16 nM) compared to the reference drug Staurosporine (IC₅₀ = 0.36 μM), also eliciting good cytotoxicity against HepG2 and MCF-7 cells (IC₅₀ = 0.13 and 5.37 μM, respectively). Investigating PIM-1 kinase inhibitory activity of compound 10f revealed an IC₅₀ of 17 nM paralleled to that of Staurosporine (IC₅₀ = 16.7 nM). Furthermore, compound 10f displayed an antioxidant activity eliciting a DPPH inhibition ratio of 94% as compared to Trolox (96%). Further investigation demonstrated that 10f induced apoptosis in treated PC-3 cells by 43.2-fold (19.44%) compared to 0.45% in control. 10f also disrupted the PC-3 cell cycle by increasing the cell population at the PreG1-phase by 19.29-fold while decreasing the G2/M-phase by 0.56-fold compared to control. Moreover, 10f affected a downregulation of JAK2, STAT3 and Bcl-2 and upregulation of caspases 3, 8 and 9 levels that activated the caspase-dependent apoptosis. Finally, in vivo 10f-treatment caused a significant increase in tumor inhibition by 64.2% compared to 44.5% in Staurosporine treatment of the PC-3 xenograft mouse model. Additionally, it improved the hematological, biochemical parameters, and histopathological examinations compared to control untreated animals. Finally, docking of 10f with the ATP-binding site of PIM-1 kinase demonstrated good recognition of and effective binding to the active site. In conclusion, compound 10f represents a promising lead compound that merits further future optimization for controlling prostate cancer.

Design, synthesis, modeling studies and biological evaluation of pyrazole derivatives linked to oxime and nitrate moieties as nitric oxide donor selective COX-2 and aromatase inhibitors with dual anti-inflammatory and anti-neoplastic activities

Two new series of pyrazole derivatives 10a-f and 11a-f with selective COX-2 inhibition pharmacophore and oxime/nitrate moieties as NO donor moiety were designed, synthesized and tested for anti-inflammatory, cytotoxic activities and NO release. Compounds 10c, 11a, 11e were more selective for COX-2 isozyme (S.I. = 25.95, 22.52 and 21.54 respectively) in comparison to celecoxib (S.I. = 21.41). Regarding anti-cancer activity, all synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compounds 10c, 11a, 11e were found to be the most potent inhibitors on breast, ovarian and melanoma cell lines (MCF-7, IGROV1 and SK-MEL-5), compound 11a causing 79 % inhibition in case of MCF-7, 78.80 % inhibition in case of SK-MEL-5 and unexpected cell growth -26.22 % inhibition in case of IGROV1 (IC₅₀ = 3.12, 4.28, 4.13 μM respectively). On the other hand, compounds 10c and 11e showed lower inhibition on the same cell lines with IC₅₀ = 3.58, 4.58, 4.28 μM respectively for 10c, IC₅₀ = 3.43, 4.73, 4.43 μM respectively for 11e. Furthermore, DNA-flow cytometric analysis showed that compound 11a induces cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Additionally, these derivatives examined against F180 fibroblasts to investigate their selectivity indexes. The pyrazole derivative with internal oxime 11a was the most potent compound against most used cell lines especially MCF-7, IGROV1 and SK-MEL-5 (IC₅₀ = 3.12, 4.28, 4.13 μM respectively) with 4.82-fold selectivity towards MCF-7 than F180 fibroblasts. Moreover, oxime derivative 11a showed potent aromatase inhibitory activity (IC₅₀ 16.50 μM) when compared with reference compound letrozole (IC₅₀ 15.60 μM). All compounds 10a-f and 11a-f released NO in a slow rate (0.73-3.88 %) and the six derivatives 10c, 10e, 11a, 11b, 11c and 11e were the highest NO releasers (3.88, 2.15, 3.27, 2.27, 2.55 and 3.74 % respectively). Herein structure based and ligand based studies were implemented to under stand and evaluate the compounds activity for further in vivo and preclinical studies. Docking mode of final designed compounds with celecoxib (ID: 3LN1) represented that their triazole ring adopted as the core aryl in Y shaped structure. Regarding aromatase enzyme inhibition, docking was carried out with ID: 1 M17. The internal oxime series was more active as anticancer because of their ability to form extra HBs with receptor cleft.

In vitro evaluation of growth reticence and anticancer potential of 5α,8α-epidioxy-24ᶓ-methylcholesta-6,22-dien-3β-ol and ergosta-5,7,22-trien-3β-ol bioactive isolated from an edible mushroom Lentinus tuberregium (fr.)

The focus point of this current work is to evaluate the anticancer and growth inhibitory efficacy of compounds 5α,8α-epidioxy-24ᶓ-methylcholesta-6,22-dien-3β-ol (LT1), and Ergosta-5,7,22-trien-3β-ol (LT2) of Lentinus tuberregium (Fr.) on three cell lines such as A673 (Rhabdomyosarcoma), MCF7 (breast cancer), and HCT116 (colorectal carcinoma) by MTT assay. LT1 and LT2 exerted maximal growth inhibition in the order as A673 > HCT116 > MCF7. Comparatively, LT1 was more potent in causing cell growth inhibition than LT2 in the A673 cancer cell line. Based on the MTT assay, A673 cells alone proceeded further as a model to evaluate the anticancer potential of LT1 and LT2 at three different semilogarithmic concentrations (3, 10, 30 μM). The cells exposed with compounds at 24 and 48 h were analyzed by flow cytometry. Exposure of LT1 at 3 and 10 μM concentrations for 24 h caused a G2-M arrest. At 10 μM concentration, cells also accumulated in the G0-G1 phase, indicating a G1 block. These effects were only transient as prolonged exposure (48 h) of LT1 treatment brought back the cell population to normalcy. Both the compounds only at 30 μM concentration have the potential to induce a hypodiploid peak (sub G0), indicating an induction of apoptosis which was explicit by nuclear condensation and fragmentation of nuclei in cells. The dose-dependent and compound-specific apoptotic induction was further confirmed by caspase activity higher in LT1 than LT2. The results highlight the significant growth inhibitory activity and anticancer potential of LT1 and LT2 which are recommended for further in-depth analysis.

FUCCI Reporter Gene-Based Cell Cycle Analysis

One of the most commonly assessed parameters in cellular analyses is the proliferative activity of a cell population. The fluorescence ubiquitin cell cycle indicator (FUCCI)-based system allows live and in vivo observation of cell cycle progression. Based on the mutually exclusive activity of two fluorescently labeled proteins cdt1 and geminin during the G0/1 and S/G2/M phases of the cell cycle, individual cells can be assigned to their respective cell cycle phase by fluorescence imaging of the nucleus. Here, we describe the generation of NIH/3T3 cells containing the FUCCI reporter system by lentiviral transduction and their use in 3D culture assays. The protocol can be adapted to other cell lines.

Elucidation of the interaction of apocarotenoids with calf thymus DNA by biophysical techniques and in vitro study in MCF-7 cells to explore their potential in cancer therapy

Objectives

DNA is one of the targets of cancer-therapeutic small molecules. Cisplatin, a DNA intercalator, is one of the first-line drugs in the cancer chemo regimen which comes with health-compromising side effects during chemotherapy. The synergistic effect of natural molecules with cisplatin can help to potentiate its anti-cancer efficacy and decrease its negative effect on health. Here, we report the interaction of cisplatin with calf thymus-DNA (ct-DNA) in combination with natural molecules like apocarotenoids which are reported for their therapeutic properties.

Materials and Methods

The combinatorial effect of apocarotenoids on ct-DNA was explored through various biophysical techniques such as UV-Visible spectroscopy, circular dichroism studies, DNA melt curve analysis, viscosity measurements, and an in vitro study in MCF-7 cells by cell cycle analysis.

Results

UV-Visible spectroscopy studies suggest apocarotenoids and their combination shows a non-intercalative mode of binding. Circular dichroism analysis showed no major changes in DNA form during the interaction of DNA with apocarotenoids and their respective combinations with cisplatin, which is suggestive of the groove-binding mode of apocarotenoids. DNA melt curve analysis showed a decrease in the intensity of the fluorescence for apocarotenoids with cisplatin which indicates the possibility of DNA interaction through groove binding. Viscosity studies suggested a groove binding mode of interaction of ct-DNA with apocarotenoids and their combination as there was minimal change in the viscosity measurements. The in vitro analysis exhibits that the apocarotenoids and their combination have a considerable effect on DNA synthesis.

Conclusion

This study provides a better perspective on the possible mode of interaction between ct-DNA and natural molecules along with cisplatin.

Anti-proliferative and apoptosis-inducing effects of juvenile hormone analogue, fenoxycarb in the Sf21cell line

The apprehension regarding the possible environmental effects of synthetic pesticides has led to the discovery and production of environmental friendly pesticides. Insect hormone mimics, mainly juvenile hormone analogues, like fenoxycarb have acquired attention due to their greater specificity than conventional broad-range insecticides as pest control agents. The study explored the effects of the insecticide juvenile hormone analogue (JHA), fenoxycarb, on the Sf21 cell line of Spodoptera frugiperda to illustrate the mode of action. Cytotoxicity assay was conducted at different concentrations of fenoxycarb ranging from 0.5 nM to 10 μM. The results showed the concentration-and time-dependent anti-proliferative effect of fenoxycarb. The median inhibitory concentration (IC₅₀) was calculated as 28 nM at 48 h of exposure, and IC₅₀ and IC₂₅ concentrations were used for further cytotoxicity screening assays. Furthermore, the significant morphological changes of the cells after 48 h revealed the development of apoptotic bodies, membrane blebbing, cell size reduction, and irregular cell aggregation; additionally, enlarged cell spaces and widely diffused apoptotic bodies were observed after 72 h of insecticide exposure. In the confocal microscopic analysis of fenoxycarb treated cells, the nucleus was observed to condense and collapse into many fragments by Hoechst-33,342. Assessment of the relative potential of the cell cycle at two concentrations (IC₅₀& IC₂₅) reported the concentration-and time-dependent reduction of cells in the G1 phase with an upsurge in apoptotic cells. The percentage of cells that underwent apoptotic changes, such as loss of mitochondrial membrane potential (MMP), was strictly dependent on the fenoxycarb concentration and duration of exposure. The findings confirm the presence of fenoxycarb-mediated cell proliferation inhibition and apoptosis in Sf21 cell lines.

Segmentation, tracking and cell cycle analysis of live-cell imaging data with Cell-ACDC

Background

High-throughput live-cell imaging is a powerful tool to study dynamic cellular processes in single cells but creates a bottleneck at the stage of data analysis, due to the large amount of data generated and limitations of analytical pipelines. Recent progress on deep learning dramatically improved cell segmentation and tracking. Nevertheless, manual data validation and correction is typically still required and tools spanning the complete range of image analysis are still needed.

Results

We present Cell-ACDC, an open-source user-friendly GUI-based framework written in Python, for segmentation, tracking and cell cycle annotations. We included state-of-the-art deep learning models for single-cell segmentation of mammalian and yeast cells alongside cell tracking methods and an intuitive, semi-automated workflow for cell cycle annotation of single cells. Using Cell-ACDC, we found that mTOR activity in hematopoietic stem cells is largely independent of cell volume. By contrast, smaller cells exhibit higher p38 activity, consistent with a role of p38 in regulation of cell size. Additionally, we show that, in S. cerevisiae, histone Htb1 concentrations decrease with replicative age.

Conclusions

Cell-ACDC provides a framework for the application of state-of-the-art deep learning models to the analysis of live cell imaging data without programming knowledge. Furthermore, it allows for visualization and correction of segmentation and tracking errors as well as annotation of cell cycle stages. We embedded several smart algorithms that make the correction and annotation process fast and intuitive. Finally, the open-source and modularized nature of Cell-ACDC will enable simple and fast integration of new deep learning-based and traditional methods for cell segmentation, tracking, and downstream image analysis.

Source code: https://github.com/SchmollerLab/Cell_ACDC

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01372-6.

New phthalimide-based derivatives as EGFR-TK inhibitors: Synthesis, biological evaluation, and molecular modeling study

A novel series of phthalimide derivatives was synthesized and evaluated for in vitro antitumor activity against six human cancer cell lines; HepG-2, HCT-116, MCF-7, Hep2, PC3 and Hela.The obtained results revealed that compound 32 was the most potent antitumor, while compounds 33, 22 and 24 showed strong activity against all tested cell lines. Further biological evaluation of the most active compounds was done and their in vitro EGFR-TK inhibition was tested, and the results came in accordance with the results of antitumor testing, where 32 displayed promising inhibitory activity (IC₅₀ = 0.065 µM) compared to the standard drug erlotinib (IC₅₀ = 0.067 µM). In addition, compounds 48, 22, 28 and 19 showed strong inhibitory activity (IC₅₀ = 0.089, 0.093, 0.147 and 0.152 µM respectively). Cell cycle analysis was conducted and the results revealed that 32 induced cell cycle arrest on Hela and MCF-7 at G0-G1 phase and Pre-G1 phase causing cell death mainly via apoptosis. Additionally, in vivo antitumor screening revealed that 32 reduced both body weight and tumor volume in solid tumor utilizing Ehrlich ascites carcinoma (EAC) animal model. Molecular modeling study showed that 32 and 48 have the highest affinity for binding with the active site of EGFR-TK with docking score comparable to erlotinib. Compounds 32 and 48 could be used as template models for further optimization.

Insights into the transformation of VO2+ motif to VO3+, V2O34+ and VO2+ motifs and their interconversion along with a detailed mechanistic study of their anti-cancer activity in SiHa cervical cancer cells

The basic criteria for the formation of complexes with VO³⁺, V₂O₃⁴⁺ and VO₂⁺ motifs from the VO²⁺ motif and their interconversion were explored utilizing two multidentate O,N-donor hydrazone ligands namely, E-2-Hydroxy-N'-(4-oxopentan-2-ylidine)benzohydrazide (H₃L¹) and E-2-Hydroxy-N'-(4-oxo-4-phenylbutan-2-ylidine)benzohydrazide (H₃L²), derived from the condensation of 2-hydroxybenzoylhydrazide with acetylacetone and benzoylacetone respectively. Under aerobic condition, the possibility of forming complexes with different motifs in different solvents with varying pH was examined theoretically by computational methods with results that were verified experimentally. This study reveals that under aerobic condition, complexes with VO³⁺ (1,2) and V₂O₃⁴⁺ (3, 4) motifs were formed in protic CH₃OH and neutral CHCl₃ solvent respectively while the formation of complexes (5-14) with VO₂⁺ motif required protic CH₃OH solvent and higher pH (≥ 7). Interconversion of VO³⁺, V₂O₃⁴⁺ and VO₂⁺ motifs are associated with specific acid-base equilibria, substantiated by ⁵¹V NMR titrations. Complexes containing these three motifs exhibited promising in vitro anticancer activity in SiHa cervical cancer cells without affecting healthy cells; among them complexes (5-14) with VO₂⁺ motif are more potent. A detailed systematic mechanistic study was carried out, utilizing the two most potent complexes 5 and 6 (IC₅₀ = 13, 6 μM respectively), which indicates that cytotoxicity and anti-proliferative activity of these complexes are manifested through oxidative stress induced apoptotic pathways (caspase mediated).

Chemical alternative for cell identification and cross-contamination detection

Misidentification of human cell lines has previously led to confusing results during cell culture experiments. Although several enzymatic as well as molecular analysis approaches have been developed for cell-line authentication, these methods remain costly. In the present paper, we describe a simple chemical alternative based on known compound cell cytotoxicity. In addition to cisplatin, a pool of eight tamoxifen derivative compounds was used to compare the cytotoxic effects on three different breast cancer cell lines: MCF-7, T47D and MDA-MB-231. Our results show that four out of the eight cytotoxic-related compounds allowed to distinguish the different cell lines based on their IC₅₀ (the half maximal inhibitory concentration) values which are cell type dependent. The remaining chemicals, particularly the most cytotoxic P15, showed close IC₅₀ values for all the cell lines. Interestingly, flow cytometry experiments have identified notable differences among the three cell lines treated with P15. T47D and MDA-MB231 cells were blocked in SubG1 phase and S phase, respectively, while no significant change in cell cycle profile was noticed for MCF-7 cells. Differences were also noted at the level of caspase-3 activity and cell proliferation in P15-treated cells.

Synthesis and characterization of zinc derivatized 3, 5-dihydroxy 4', 7-dimethoxyflavone and its anti leishmaniasis activity against Leishmania donovani

This study reports the synthesis and characterization of zinc derivatized 3,5-dihydroxy 4', 7- dimethoxyflavone (DHDM-Zn) compound for the development of new antileishmanial agents. The interaction studies of DHDM with zinc were carried out by UV spectra and fluorescence spectra analysis. Characterization of the complex was further accomplished by multi-spectroscopic techniques such as FTIR, Raman, HRMS, NMR, FESEM-EDX. The morphological and topographical studies of synthesized DHDM-Zn were carried out using FESEM with EDX. Further, it was demonstrated that DHDM-Zn exhibited an excellent in vitro antagonistic effect against the promastigote form of L. donovani. In addition, the possible mechanisms of promastigote L. donovani cell death, by involvement of derivatized compound in arrest of the cell cycle in the G1 phase and residual cell count reduction were investigated. Promastigote growth kinetics performed in the presence of the derivatized compound revealed a slow growth rate. The combination of growth kinetics and cell cycle analysis, made it possible to interpret and classify the cause of leishmanial cell death accurately. These results support that zinc derivatized complex (DHDM-Zn) might work as a lead compound for designing and developing a new antileishmanial drug.

Development of a G2/M arrest high-throughput screening method identifies potent radiosensitizers

Radiation is a powerful tool used to control tumor growth and induce an immune response; however, it is limited by damage to surrounding tissue and adverse effects such skin irritation. Breast cancer patients in particular may endure radiation dermatitis, and potentially lymphedema, after a course of radiotherapy. Radio-sensitizing small molecule drugs may enable lower effective doses of both radiation and chemotherapy to minimize toxicity to healthy tissue. In this study, we identified a novel high-throughput method for screening radiosensitizers by image analysis of nuclear size and cell cycle. In vitro assays were performed on cancer cells lines to assess combined therapeutic and radiation effects. In vivo, radiation in combination with proflavine hemisulfate led to enhanced efficacy demonstrated by improved tumor volume control in mice bearing syngeneic breast tumors. This study provides a proof of concept for utilizing G2/M stall as a predictor of radiosensitization and is the first report of a flavin acting as an X-ray radiation enhancer in a breast cancer mouse model.

Design, synthesis and biological evaluation of novel o-aminobenzamide derivatives as potential anti-gastric cancer agents in vitro and in vivo

Although gastric cancer has become a major public health problem, oral agents applied in clinics for gastric cancer therapy are scarce. Therefore, to explore new oral chemical entities with high efficiency and low toxicity, 41 o-aminobenzamide derivatives based on the scaffolds of MS-275 and SAHA were designed, synthesized, and evaluated for their anti-gastric cancer abilities in vitro and in vivo. Structure-activity relationships were discussed, leading to the identification of compounds F8 (IC₅₀ = 0.28 μM against HGC-27 cell) and T9 (IC₅₀ = 1.84 μM against HGC-27 cell) with improved cytotoxicity, anti-gastric cancer proliferation potency, induction of cell apoptosis and cell cycle arrest ability, inhibition of cell migration and invasion. What is worth mentioning is that compound F8 was more efficient and less toxic than the positive drug capecitabine in vivo on the HGC-27-xenograft model. Meanwhile, compound F8 exhibited suitable pharmacokinetic properties and less acute toxicity (LD₅₀ > 1000 mg/kg). Besides, western blotting analysis, IHC analysis, differentially expressed proteins analysis and ABPP experiment indicated that compound F8 could modulate molecular pathways involved in apoptosis and cell cycle progression. Consequently, compound F8 is a strong candidate for the development of human gastric cancer therapy.

Studying Stem Cell Biology in Intact and Whole-Body Regenerating Hydra by Flow Cytometry

The freshwater Hydra polyp is a versatile model to study whole-body regeneration from a developmental as well as a cellular point of view. The outstanding regenerative capacities of Hydra are based on its three populations of adult stem cells located in the central body column of the animal. There, these three populations, gastrodermal epithelial, epidermal epithelial, and interstitial, continuously cycle in homeostatic conditions, and their activity is locally regulated after mid-gastric bisection. Moreover, they present an unusual cycling behavior with a short G1 phase and a pausing in G2. This particular cell cycle has been studied for a long time with classical microscopic methods. We describe here two flow cytometry methods that provide accurate and reproducible quantitative data to monitor cell cycle regulation in homeostatic and regenerative contexts. We also present a cell sorting procedure based on flow cytometry, whereby stem cells expressing a fluorescent reporter protein in transgenic lines can be enriched for use in applications such as transcriptomic, proteomic, or cell cycle analysis.

Design, synthesis and evaluation of anticancer activity of new pyrazoline derivatives by down-regulation of VEGF: Molecular docking and apoptosis inducing activity

Two series of pyrazoline compounds were designed and synthesized as antiproliferative agents by VEGFR pathway inhibition. All synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines. Compound 3f exhibited the highest anticancer activity on the ovarian cell line (OVCAR-4) with IC₅₀ = 0.29 μM and on the breast cell line (MDA-MB-468) with IC₅₀ = 0.35 μM. It also exhibited the highest selectivity index (SI = 74). Compound 3f caused cell cycle arrest in OVCAR-4 cell line at the S phase which consequently inhibited cell proliferation and induced apoptosis. Moreover, 3f showed potent down-regulation of VEGF and p-VEGFR-2. Docking studies showed that compound 3f interacts in a similar pattern to axitinib on the VEGFR-2 receptor. The same compound was also able to fit into the gorge of STAT3 binding site, the transcription factor for VEGF, which explains the VEGF down-regulation.

Hybrids of 4-hydroxy derivatives of goniothalamin and piplartine bearing a diester or a 1,2,3-triazole linker as antiproliferative agents

A library of nine hybrids of 4-hydroxygoniothalamin (2), 4-hydroxypiplartine (4), monastrol (5) and oxo-monastrol (6) was prepared via a modular synthetic route with a diester or a 1,2,3-triazole as linkers. The compounds were assayed against a panel of human cancer cell lines, including MCF-7 (breast adenocarcinoma), HeLa (cervical adenocarcinoma), Caco-2 (colorectal adenocarcinoma) and PC3 (prostate adenocarcinoma), as well as against normal breast (MCF10A) and prostate (PNT2) cells. In general, hybrids with an ester linker containing 4-hydroxypiplartine (4) were more potent than the corresponding hybrids with 4-hydroxygoniothalamin (2). On the other hand, compounds presenting the 1,2,3-triazole linker displayed enhanced cytotoxicity and selectivity when compared to their corresponding hybrids with the diester linker. The 4-hydroxypiplartine-based hybrids 12 and 22 displayed high cytotoxicity (IC50 values below 10 μM) against all cancer cells studied, especially in MCF-7 cells with IC50 values of 1.7 ± 0.1 and 1.6 ± 0.9 μM, respectively. Furthermore, the 4-hydroxygoniothalamin-monastrol hybrid (compound 21) and the 4-hydroxypiplartine-oxo-monastrol hybrid (compound 25), both bearing a 1,2,3-triazole linker, displayed high selectivity and potency towards breast cancer cell line (MCF-7 vs. MCF10 cells, selectivity index = 15.8 and 7.1, respectively), while the 4-hydroxypiplartine -4-hydroxymethylgoniothalamin hybrid with a diester linker (compound 33) showed high selectivity towards melanoma cancer cells (selectivity index = 9.6). Antiproliferative and pro-apoptotic potential of compounds 12 and 22 against MCF-7 cancer cells were further investigated. Cell cycle studies revealed increased G2/M population in MCF-7 cultures as well as reduced G0/G1 population compared to the control groups indicating cell cycle arrest in G2/M phase. In addition, the frequency of positive cells for annexin V was higher in treated samples suggesting that compounds 12 and 22 induce apoptosis in estrogen-positive MCF-7 cells.

New thieno[3,2-d]pyrimidine-based derivatives: Design, synthesis and biological evaluation as antiproliferative agents, EGFR and ARO inhibitors inducing apoptosis in breast cancer cells

An array of newly synthesized thieno[3,2-d]pyrimidine-based derivatives and thienotriazolopyrimidines hybridized with some pharmacophoric anticancer fragments were designed, synthesized and assessed for their in vitro antiproliferative activity against MCF-7 and MDA-MB-231 breast cancer cell lines using erlotinib and pictilisib as reference standards in the MTT assay. In general, many compounds were endowed with considerable antiproliferative activity (IC₅₀ = 0.43-1.31 µM). Some of the tested compounds, namely 3c, 5b, 5c, 9d, 10, 11b and 13 displayed remarkable antiproliferative activity against both cell lines. Meanwhile, compounds 2c-e, 3b, 4a, 5a, 9c and 15b showed noticeable selectivity against MCF-7 cells while compounds 2b, 3a, 4b, 6a-c, 7, 8, 9b and 12 exhibited considerable selectivity against MDA-MB-231 cells. Further mechanistic evidences for their anticancer activities were provided by screening the most potent compounds against MCF-7 and/or MDA-MB-231 cells for EGFR and ARO inhibitory activities using erlotinib and letrozole as reference standards respectively. Results proved that, in general, tested compounds were better EGFRIs than ARIs. In addition, significant overexpression in caspase-9 level in treated MCF-7 breast cell line samples was observed for all tested compounds with the 4-fluorophenylhydrazone derivative 2d exhibiting the highest activation. In treated MDA-MB-231 breast cell line samples, 11b was found to highly induce caspase-9 level thereby inducing apoptosis. Cell cycle analysis and Annexin V-FITC/PI assay were also assessed for active compounds where results indicated that all tested compounds induced preG1 apoptosis and cell cycle arrest at G2/M phase. Compound 9d, as an inhibitor of ARO, was observed to downregulate the downstream signaling proteins HSP27 and p-ERK in MCF-7 cells. Furthermore, compound 11b downregulated EGFR expression as well as the downstream signaling protein p-AKT. Docking experiments on EGFR and ARO enzymes supported their in vitro results. Thus, the thienotriazolopyrimidines 11b and 12 showing good EGFR inhibition and the thieno[3,2-d]-pyrimidine derivatives 3b and 9d, eliciting the best ARO inhibition activity, can be considered as new candidates as anti-breast cancer agents that necessitate further development.

Design, synthesis and biological evaluation of novel 2,4-disubstituted quinazoline derivatives targeting H1975 cells via EGFR-PI3K signaling pathway

In order to find new and highly effective anti-tumor drugs with targeted therapeutic effects, a series of novel 4-aminoquinazoline derivatives containing N-phenylacetamide structure were designed, synthesized and evaluated for antitumor activity against four human cancer cell lines (H1975, PC-3, MDA-MB-231 and MGC-803) using MTT assay. The results showed that the compound 19e had the most potent antiproliferative activity against H1975, PC-3, MDA-MB-231 and MGC-803 cell lines. At the same time, compound 19e could significantly inhibit the colony formation and migration of H1975 cells. Compound 19e also arrested the H1975 cell cycle in the G1 phase and mediated cell apoptosis, promoted the accumulation of ROS in H1975 cells. Furthermore, compound 19e exerted antitumor effect in vitro by reducing the expression of anti-apoptotic protein Bcl-2 and increasing the pro-apoptotic protein Bax and p53. Mechanistically, compound 19e could significantly decreased the phosphorylation of EGFR and its downstream protein PI3K in H1975 cells. Which indicated that compound 19e targeted H1975 cell via interfering with EGFR-PI3K signaling pathway. Molecular docking showed that compound 19e could bind into the active pocket of EGFR. Those work suggested that compound 19e would have remarkable implications for further design of anti-tumor agents.

Design, synthesis and evaluation of new quinazolin-4-one derivatives as apoptotic enhancers and autophagy inhibitors with potent antitumor activity

This work presents the design and synthesis of a series of new quinazolin-4-one derivatives, based on the established effectiveness of quinazoline-based small molecules as anticancer agents. Synthesized compounds were more potent against MCF-7 than A-549 with low to submicromolar IC₅₀s. Compound 17 exhibited the best IC₅₀ being equipotent with the positive control doxorubicin (IC_50 = 0.06 μM) and better than 5-fluorouracil (IC_50 = 2.13 μM). Compound 17 was further tested against MDA-MB-231 and MCF-10A and was found to be > 2 folds more cytotoxic on MCF-7. Significant apoptotic activity was elicited by 17 on MCF-7 where it increased apoptotic cell death along with induction of pre-G1 and G1-phase cell cycle arrest. Similarly, 17 was able to induce apoptosis in MD-MB-231 treated cells associated with a disruption of the cell cycle causing arrest at the pre-G1 and S phases. Investigation of gene expression in MCF-7 demonstrated an increased expression of the proapoptotic genes P53, PUMA, Bax, caspases 3, 8 and 9 and a decrease of the anti-apoptotic gene Bcl2. Also, 17 reduced autophagy giving way for apoptosis to induce cancer cells death. This latter observation was associated with downregulation of EGFR and its downstream effectors PI3K, AKT and mTor. As its biomolecular target, 17 also inhibited EGFR similar to erlotinib (IC₅₀ = 0.072 and 0.087 μM, respectively). Additionally, in vivo testing in a mouse model of breast cancer affirmed the anti-tumor efficacy of 17. Finally, docking of 17 against EGFR ATP binding site demonstrated its ability to bind with EGFR resembling erlotinib.

Synthesis, biological evaluation, and molecular docking analysis of novel linker-less benzamide based potent and selective HDAC3 inhibitors

A series of novel linker-less benzamides with different aryl and heteroaryl cap groups have been designed, synthesized, and screened as potent histone deacetylase (HDAC) inhibitors with promising anticancer activity. Two lead compounds 5e and 5f were found as potent and highly selective HDAC3 inhibitors over other Class-I HDACs and HDAC6. Compound 5e bearing a 6-quinolinyl moiety as the cap group was found to be a highly potent HDAC3 inhibitor (IC₅₀ = 560 nM) and displayed 46-fold selectivity for HDAC3 over HDAC2, and 33-fold selectivity for HDAC3 over HDAC1. The synthesized compounds possess antiproliferative activities against different cancer cell lines and significantly less cytotoxic to normal cells. Molecular Docking studies of compounds 5e and 5f reveal a similar binding mode of interactions as CI994 at the HDAC3 active site. These observations agreed with the in vitro HDAC3 inhibitory activities. Significant enhancement of the endogenous acetylation level on H3K9 and H4K12 was found when B16F10 cells were treated with compounds 5e and 5f in a dose-dependent manner. The compounds induced apoptotic cell death in Annexin-V/FITC-PI assay and caused cell cycle arrest at G2/M phase of cell cycle in B16F10 cells. These compounds may serve as potential HDAC3 inhibitory anticancer therapeutics.

New bioactive 5-arylcarboximidamidopyrazolo[3,4-c]pyridines: Synthesis, cytotoxic activity, mechanistic investigation and structure-activity relationships

In this study, a series of novel substituted pyrazolo[3,4-c]pyridin-5-ylamidines was synthesized and their cytotoxicity against three cancer cell lines (MDA-MB-231, HT-1080, PC-3), as well as a human normal cell line (AG01523) was evaluated. A number of derivatives could strongly reduce cancer cells proliferation and exhibit apoptotic induction capability, while reasonable structure-activity relationships could be extracted. Certain analogues were endowed with low toxicity against normal cells. Cell cycle analysis revealed that most of the active compounds induced a G₀/G₁ arrest of HT-1080 cells. Moreover, the potential mechanisms of the cytotoxic activity of the promising compounds were investigated in HT-1080 cells, upon study of their effects on the phosphorylation of Akt, ERK and p38 MAPK. Most of the active derivatives inhibit phosphorylation of Akt and ERK and/or induce p38 MAPK phosphorylation, providing a potential indication on the mode of action of this class.

Optimized semisolid self-nanoemulsifying system based on glyceryl behenate: A potential nanoplatform for enhancing antitumor activity of raloxifene hydrochloride in MCF-7 human breast cancer cells

Raloxifene hydrochloride (RLX) is a selective estrogen receptor modulator used for treatment and protection against postmenopausal osteoporosis. The drug has been used for protection against breast cancer and more recently, for management of the disease by virtue of its estrogen antagonist action. However, the drug has reduced bioavailability related to low water solubility and first pass metabolism. To surmount these pitfalls, this study aimed at developing and optimizing RLX-loaded semisolid self-nanoemulsifying system (SSNES) with minimized globule size to improve the drug solubility, tumor penetration, and consequently antitumor activity. A simplex lattice mixture design was employed for the formulation and optimization of SSNESs. The mixture components, namely, Compritol® 888 ATO, Tween 20, and polyethylene glycol 200 exhibited significant effect on globule size at P < 0.05. The optimized formulation with globule size of 109.19 ± 2.11 nm showed acceptable thermodynamic stability under stress conditions. Anti-cancer efficacy of the obtained formulation was evaluated in MCF-7 breast cancer cell line. MTT viability assay revealed that RLX-loaded SSNES notably inhibited MCF-7 cell proliferation. Flow cytometry and dual staining with annexin V-FITC/PI were used to assay this anti-proliferative effect and induction of apoptosis, respectively. Cells treated with RLX-loaded SSNES showed significant arrest at G2/M phase associated with significant increase in early/late-stages of apoptotic and necrotic cells. The results exhibited that RLX-loaded SSNES induces apoptosis via the activation of caspase-3 and loss of mitochondrial membrane potential. Accordingly, the proposed SSNES could be regarded as a promising platform for enhancing RLX antitumor activity against breast cancer.

Antiproliferative activity, enzymatic inhibition and apoptosis-promoting effects of benzoxazole-based hybrids on human breast cancer cells

New benzoxazole derivatives containing 1,3,4-oxadiazole, 1,2,4-triazole or triazolothiadiazine rings were synthesized and screened for their in vitro antiproliferative activities against MCF-7 and MDA-MB-231 breast cancer cell lines using MTT assay. Doxorubicin, cisplatin and 2-(4-aminophenyl)benzothiazole (CJM 126) were used as references. The most active compounds 7a, 8d, 8e and 10c were screened for their antiproliferative activities against MCF-10A normal breast cells where compounds 8e and 7a were the most selective towards MCF-7 and MDA-MB-231 cell lines, respectively compared to CJM 126. In vitro enzymatic inhibition assays of epidermal growth factor receptor (EGFR) and aromatase (ARO) enzymes were performed. Compound 7a showed inhibition of EGFR comparable to that of erlotinib while compound 8e exhibited nearly half the inhibitory activity of erlotinib towards EGFR and was more potent inhibitor of ARO than letrozole. Caspase-9 activation assay, cell cycle analysis and Annexin-V/ Propidium iodide assay performed for compounds 7a, 8d, 8e and 10c demonstrated over expression of caspase-9 protein level, pre G₁ apoptosis and high annexin V binding affinity. Therefore, these compounds are considered as potent apoptosis-promoting agents. The predicted docking studies and in silico chemo-informatic properties of compounds 7a and 8e were appropriate. Compounds 7a and 8e are promising anti-breast cancer agents exhibiting potent apoptosis-promoting properties.

Enhanced anti-cancer activity by localized delivery of curcumin form PVA/CNCs hydrogel membranes: Preparation and in vitro bioevaluation

This study targets to develop curcumin-loaded polyvinyl alcohol/cellulose nanocrystals (PVA/CNCs) membrane as localized delivery system for breast/liver cancer. A novel strategy was developed for enhancing encapsulation capacity and maximizing therapeutic efficiency of curcumin-loaded PVA/CNCs membranes. Membranes were prepared by solution-casting method using citric acid as crosslinker. SEM revealed that PVA/CNCs ratio (80:20) was chosen as the optimum for loading curcumin. FT-IR indicated that, curcumin was incorporated into PVA/CNCs in amorphous-phase via intermolecular hydrogen bond between curcumin and membrane components. Curcumin showed biphasic-release through burst-release of 41% of curcumin during the first hour, followed by sustained-release of 70% and 94% during 24 h and 48 h, respectively. In vitro cytotoxicity of PVA/CNCs/Curcumin membrane exhibited a selective inhibition proliferation of breast and liver cancer cells in a concentration-dependent without any toxic effect on normal cells. At high concentration (8 mg/ml) of PVA/CNCs/Curcumin, reduced viability to 35% and 7% of MCF-7 and Huh-7 cells, respectively; meanwhile high HFB-4 normal cell viability ≥80% was investigated. Antimicrobial activity of PVA/CNCs/Curcumin was investigated by multi-drug-resistant strains, and MIC values. PVA/CNCs/Curcumin membranes with concentration (40 mg/ml) showed broad-spectrum antimicrobial activities, thus inhibited ~96-99% of microbial growth. PVA/CNCs/Curcumin membranes could be as promised anti-infective biomaterials for breast and liver cancer wound healing.

Design, synthesis and antiproliferative evaluation of new tricyclic fused thiazolopyrimidines targeting topoisomerase II: Molecular docking and apoptosis inducing activity

A novel series of thiazolopyrimidines and fused thiazolopyrimidines was designed and synthesized as topoisomerase II alpha inhibitors. All synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compound 3a was found to be the most potent inhibitor on renal cell line (A-498) causing 83.03% inhibition (IC₅₀ = 1.89 μM). DNA-flow cytometric analysis showed that compound 3a induce cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Moreover, fused thiazolopyrimidines 3a showed potent topoisomerase II inhibitory activity (IC₅₀ = 3.19 μM) when compared with reference compound doxorubicin (IC₅₀ = 2.67 μM). Docking study of all the synthesized compounds showed that compound 3a interacts in a similar pattern to etoposide and stabilizing the topoisomerase cleavage complex (Top2-cc) that accounts for its high potency.

Flow cytometric determination of cell cycle progression via direct labeling of replicated DNA

The reported method allows for a simple and rapid monitoring of DNA replication and cell cycle progression in eukaryotic cells in vitro. The DNA of replicating cells is labeled by incorporation of a metabolically-active fluorescent (Cy3) deoxyuridine triphosphate derivative, which is delivered into the cells by a synthetic transporter (SNTT1). The cells are then fixed, stained with DAPI and analyzed by flow cytometry. Thus, this protocol obviates post-labeling steps, which are indispensable in currently used incorporation assays (BrdU, EdU). The applicability of the protocol is demonstrated in analyses of cell cycles of adherent (U-2 OS, HeLa S3, RAW 264.7, J774 A.1, Chem-1, U-87 MG) and suspension (CCRF-CEM, MOLT-4, THP-1, HL-60, JURKAT) cell cultures, including those affected by a DNA polymerase inhibitor (aphidicolin). Owing to a short incorporation time (5-60 min) and reduced number of steps, the protocol can be completed within 1-2 h with a minimal cell loss and with excellent reproducibility.

New cyanopyridine-based scaffold as PIM-1 inhibitors and apoptotic inducers: Synthesis and SARs study

Two novel series of 6-(4-benzamido-/4-phthalimido)-3-cyanopyridine derivatives were designed and synthesized as inhibitors of PIM-1 kinase. Based on cytotoxicity results via MTT assay against prostate carcinoma PC3, human hepatocellular carcinoma HepG2 and breast adenocarcinoma MCF-7 cell lines, the most potent cytotoxic cyanopyridine hits, 6, 7, 8, 12 and 13 were 1.5-3.3 times more inhibitor of cell proliferation than the reference standard, 5-FU. Selectivity profile of the latter compounds on normal human cells (WI-38), was executed, indicating that they are highly selective (IC₅₀ > 145 μM) in their cytotoxic effect. The promising compounds were further evaluated as PIM-1 kinase inhibitors. These compounds elicited remarkable inhibition of PIM-1 kinase (76.43-53.33%). Extensive studies on apoptosis were conducted for these compounds; they enhanced caspase-3 and boosted the Bax/Bcl-2 ratio 27-folds in comparison to the control. Molecular docking study of the most potent compound, 13 in PIM-1 kinase active site was consistent with the in vitro activity. Finally, prediction of chemo-informatic properties released compound 13 as the most promising ligand.

Synthesis of (Z)-3-(arylamino)-1-(3-phenylimidazo[1,5-a]pyridin-1-yl)prop-2-en-1-ones as potential cytotoxic agents

The new derivatives based on (Z)-3-(arylamino)-1-(3-phenylimidazo[1,5-a]pyridin-1-yl)prop-2-en-1-one scaffold was synthesized and evaluated for their in vitro cytotoxic potential against a panel of cancer cell lines, viz., A549 (human lung cancer), HCT-116 (human colorectal cancer), B16F10 (murine melanoma cancer), BT-474 (human breast cancer), and MDA-MB-231 (human triple-negative breast cancer). Among them, many of the synthesized compounds exhibited promising cytotoxic potential against the panel of tested cancer cell lines with IC₅₀ <30 µM. Based on the preliminary screening results, the structure-activity relationship (SAR) of the compounds was established. Among the synthesized compounds, 15i displayed a potential anti-proliferative activity against HCT-116 cancer cell line with an IC₅₀ value of 1.21 ± 0.14 µM. Flow cytometric analysis revealed that compound 15i arrested the G0/G1 phase of the cell cycle. Moreover, increased reactive oxygen species (ROS) generation, clonogenic assay, acridine orange staining, DAPI nuclear staining, measurement of mitochondrial membrane potential (ΔΨm), and annexin V-FITC assays revealed that compound 15i promoted cell death through apoptosis.

Novel scaffold hopping of potent benzothiazole and isatin analogues linked to 1,2,3-triazole fragment that mimic quinazoline epidermal growth factor receptor inhibitors: Synthesis, antitumor and mechanistic analyses

A series of benzothiazole/isatin linked to 1,2,3-triazole moiety and terminal sulpha drugs 5a-e and 6a-e were synthesized and evaluated for cytotoxic activity against a panel of cancer cell lines. The novel compounds showed variable IC₅₀ range of activity and some of them were potent compared to reference drug. The promising compounds were subjected as postulated the mimicry proposal for quinazoline-based EGFR inhibitors for their inhibitory profile against EGFR TK enzyme. That data obtained revealed that most of these compounds were potent EGFR TK inhibitors at nanomolar concentrations. Among these, compounds 5a and 5b showed more potent activity on EGFR compared to erlotinib (IC₅₀ 103 and 104 versus 67.6 nM). Based upon the results, molecular docking analysis was performed on EGFR receptor and proved the strong contribution of fragments; benzothiazole, isatin, and triazole to the binding ATP pocket. When these selected compounds 5a and 5b were tested in an HepG2 model, they could effectively inhibited tumor growth, strongly induced cancer cell apoptosis, and suppressed cell cycle progression leading to DNA fragmentation. Well-DMET profile of the most active derivatives was presented and compared to the reference drugs. Taken together, we introduced novel triazole-sulpha drug hybrid for the first time as EGFR inhibitors and the results of our studies indicate that the newly discovered inhibitors have significant potential for anticancer treatment.

Ni(II) curcumin complexes for cellular imaging and photo-triggered in vitro anticancer activity

Nickel(II) complexes [Ni(cur)(L)₂](OAc) (1-3) where L is N,N-donor heterocyclic bases namely 1,10-phenanthroline (phen in 1), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 2), dipyrido[3,2-a:2',3'-c]phenazine (dppz in 3) and Hcur is curcumin were prepared, fully characterized and light-induced in vitro anticancer activity studied. Three nickel(II) complexes containing acetylacetonato (Hacac) ligand, viz.[Ni(acac)(L)₂](OAc) (4-6) where L is phen (in 4), dpq (in 5), dppz (in 6) were prepared and used as controls. Complex 4 was structurally characterized by single crystal X-ray diffraction technique, which revealed an octahedral NiN₄O₂ geometry around the metal centre. Complexes 1-3 showed an intense curcumin-based band at ∼440 nm in DMSO-Tris-HCl buffer (pH = 7.2) (1:4 v/v) which masks the nickel based d-d band. The curcumin comlexes (1-3) were redox inactive at the nickel centre, whereas the acetylacetonato complexes (4-6) displayed an irreversible voltammetric response at ∼1.00 V vs. Ag/AgCl reference electrode in DMF. The complexes bind to calf thymus DNA (ct-DNA) with considerable affinity and interacted with human serum albumin (HSA) with moderate affinity. The Ni(II) curcumin complexes display significant in vitro light-induced cytotoxicity in HeLa (human cervical carcinoma) and A549 (lung cancer cells) involving reactive oxygen species (ROS), with very low dark toxicity. The complexes were found to be much less toxic to immortalized lung epithelial normal cells (HPL1D). Confocal microscopic images using complex 2 and 3 showed that they primarily localize in the cytosol of A549 cells. The mechanism of cell death is mainly apoptosis in nature showing arrest of sub-G1 phase of cell cycle progression in A549 cells under visible light exposure and involves significant loss of mitochondrial membrane potential as observed from JC-1 assay.

6-Shogaol suppresses the growth of breast cancer cells by inducing apoptosis and suppressing autophagy via targeting notch signaling pathway

OBJECTIVES

Breast cancer is one of the most commonly diagnosed cancer among women globally. Shogaol, the active constituent of many spices belonging to the Zingiberaceae family, has received wide attention among other shogaols in terms of its anticancer activity against different neoplasms. To date, its efficacy at the detailed molecular level against breast cancer has not been established.

METHODS

In the current study, we investigated the cytotoxic potential and the underlying molecular details of 6-shogaol against breast adenocarcinomacells (MCF-7), and breast ductal carcinoma cells (T47D). Cytotoxicity assay, cell cycle analysis. Real-time PCR (qPCR), apoptosis and autophagy techniques were used for the determination and molecular investigation of its anticancer properties.

RESULTS

The current study shows that, Notch signaling downregulation (Hes1 and CyclinD1 genes), caused by 6-shogaol, lead to antiproliferative activity in breast cancer cells. The study further shows that treatment with 6-shogaol induced significant and time dependent cell cycle accumulation in G₂/M-phase. 6-Shogaol also induced significant apoptosis in breast cancer cells. Interestingly, 6-shogaol inhibited autophagy in breast cancer cell lines, which might force these cells to undergo apoptosis.

CONCLUSION

6-Shogaol is a promising candidate to be considered as a treatment of breast cancer.

Benzoxazole derivatives as new generation of anti-breast cancer agents

New 2-substituted benzoxazole derivatives were synthesized and screened for their in vitro anti-proliferative activities against MCF-7 and MDA-MB-231 cell lines. Compounds 4b, 4d and 11c eliciting the highest activity against MCF-7 cells were further assayed for their cytotoxic activities against A431 and HCC827 cancer cells in addition to their in vitro inhibition of wild and mutated epidermal growth factor receptor (EGFR) enzymes. Compound 11c was the most active against A431 cells and it displayed a potent inhibition of EGFR^WT while compounds 4b and 4d elicited higher potencies than erlotinib against mutated EGFR^L858R. Compounds 4a, 6c and 8a showed the most potent cytotoxic activity against MDA-MB-231 cancer cells where compounds 4a and 6c were slightly less potent aromatase (ARO) inhibitors than letrozole. MCF-7 cells treated with compounds 4b, 4d, 11c and MDA-MB-231 cells treated with compounds 4a, 6c and 8a showed remarkable over-expression of caspase-9 protein level and elicited pre G1 apoptosis and cell cycle arrest at G2/M phase in addition to high annexin V binding affinity indicating significant apoptosis. Chemo-informatic and docking properties were also predicted. Docking results revealed that docked compounds displayed binding modes with EGFR and ARO enzymes comparable to that of the reference ligands. The benzoxazole derivatives 11c and 6c possessing amide and dithiocarbamate moieties respectively were found to be potent apoptosis-inducing anti-breast cancer agents with acceptable physicochemical properties. They exert their activity via inhibition of EGFR and ARO enzymes respectively.

1,2,3-Triazole-Chalcone hybrids: Synthesis, in vitro cytotoxic activity and mechanistic investigation of apoptosis induction in multiple myeloma RPMI-8226

A new series of 1,2,3-triazole-chalcone hybrids has been synthesized and screened in vitro against a panel of 60 human cancer cell lines according to NCI (USA) protocol. Compound 4d having 3, 4-dimethoxyphenyl chalcone moiety, the most potent derivative, inhibited the growth of RPMI-8226 and SR leukemia cell lines by 99.73% and 94.95% at 10 μM, respectively. Also, it inhibited the growth of M14 melanoma, K-562 leukemia, and MCF7 breast cancer cell lines by more than 80% at the same test concentration. 4d showed IC₅₀ values less than 1 μM on six types of tumor cells and high selectivity index reached to 104 fold on MCF7. Compound 4d showed superior activity than methotrexate and gefitinib against the most sensitive leukemia cell lines in addition to higher or comparable activity against the rest sensitive cell lines. Flow cytometry analysis in RPMI-8226 cells revealed that compound 4d caused cell cycle arrest at G2/M phase and induced apoptosis in a dose dependant manner. Mechanistic evaluation referred this apoptosis induction to triggering mitochondrial apoptotic pathway through inducing ROS accumulation, increasing Bax/Bcl-2 ratio and activation of caspases 3, 7 and 9.

A proficient microwave synthesis with structure elucidation and the exploitation of the biological behavior of the newly halogenated 3-amino-1H-benzo[f]chromene molecules, targeting dual inhibition of topoisomerase II and microtubules

In our endeavors to develop novel and powerful agents with antiproliferative activities, a series of β-enamionitriles, linked to the 8-bromo-1H-benzo[f]chromene moieties (4a-m), was designed and synthesized under microwave irradiation conditions. The structures of the target compounds were established on the basis of their spectral data: IR, ¹H NMR, ¹³C NMR, ¹³C NMR-DEPT/APT, ¹⁹F NMR and MS. Furthermore, the antiproliferative properties were evaluated against the human cancer cell lines MCF-7, HCT-116, and HepG-2 in comparison to the positive controls Vinblastine and Doxorubicin, employing the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activities against the three cancer cell lines. The most potent cytotoxic compounds 4b, 4d, 4e, 4i, and 4k were elected for further examination, such as the cell cycle analysis, the apoptosis assay, the Caspase production, and the DNA fragmentation. This study also revealed that the desired compounds stimulate cell cycle arrest at the G2/M phases, increase the production of Caspases 3, 8, and 9, and finally cause intrinsic and extrinsic apoptotic cell death. Moreover, these compounds suppress the action of the topoisomerase II enzyme and also disrupt the microtubule functions. The SAR study of the synthesized compounds verified that the substitution on the phenyl ring of the 1H-benzo[f]chromene nucleus, accompanied with the presence of the bromine atom at the 8-position, increases the ability of these molecules against different cell lines.

Microwave synthesis of novel halogenated β-enaminonitriles linked 9-bromo-1H-benzo[f]chromene moieties: Induces cell cycle arrest and apoptosis in human cancer cells via dual inhibition of topoisomerase I and II

A novel series of halogenated β-enaminonitriles (4a-m), linked 9-bromo-1H-benzo[f]-hromene moieties, were synthesized via microwave irradiation and were predestined for their cytotoxic activity versus three cancer cell lines, namely: MCF-7, HCT-116, and HepG-2. Several of the tested compounds showed high growth inhibitory activities versus the tumor cell lines. Particularly, compounds 4c, 4d, 4f, 4h, 4j, 4l, and 4m demonstrated superior antitumor activities against the aforementioned cell lines. Moreover, the apoptosis process in all the tested cells was induced by compounds 4c, 4d, 4h, 4l, and 4m, as observed by the Annexin V/PI double staining flow cytometric assay. The DNA flow, cytometric analysis revealed that these compounds prompted cell cycle arrest at the G2/M phases. Furthermore, the topoisomerase catalytic activity assays indicated that these compounds inhibited both the topoisomerase I and II enzymes.

Protection to immune system of mice by N-acetyl tryptophan glucoside (NATG) against gamma radiation induced immune suppression

Immune system is a critical modulator of radiation-induced biological effects. In this study, we have assessed protective potential of N-acetyl tryptophan glucoside (NATG) pre-treatment in bone marrow of gamma radiation challenged mice. Isolated bone marrow cells were analysed for cell cycle progression by flow cytometry, while various pro-/anti-inflammatory cytokine profiles were performed by ELISA method. Overall radioprotective ability of NATG in ensuring protection against gamma radiation-induced damage was assessed by evaluating whole body survival analysis and haematological studies on 9 Gy irradiated mice with/without NATG pre-treatment. Results exhibited pre-treatment with 150 mg/kg b.wt oral administration of NATG as most effective against 9 Gy radiation exposure. Moreover, NATG showed non-interfering effect on cell cycle progression in pre-treated irradiated mice group when compared to radiation alone group. In addition, cytokine expression analysis indicated significant (p > 0.05) elevation in levels of IFN-γ, IL-2, IL-12, IL-13 and IL-17 in NATG pre-treated irradiated mice in comparison to radiation alone group. On the contrary, NATG pre-treatment was observed to alleviate levels of TNF-α and IL-10 significantly (p < 0.05) in radiated group as compared to only irradiated mice group. Furthermore, NATG pre-treatment to 9 Gy radiation exposed mice aided in restoring their haematological parameters in terms of haemoglobin counts, RBC counts, WBC counts, hematocrit levels, platelets and granulocyte levels in comparison to irradiated alone mice, thus enhancing their immune system and contributing towards a better survival against gamma radiation-induced deleterious effects. Conclusively, this study highlights the potential of NATG as a prospective radiation countermeasure agent against ionizing radiation-induced assaults to the immune system.

Synthesis and anticancer activity of bis-benzo[d][1,3]dioxol-5-yl thiourea derivatives with molecular docking study

New thiourea derivatives incorporating two benzo[d][1,3]dioxol-5-yl moieties have been synthesized through the reaction of two molecules of benzo[d][1,3]dioxol-5-yl isothiocyanate with one molecule of various diamino derivatives. The synthesized compounds were examined for their cytotoxic effects using SRB assay on three cancer cell lines HepG2, HCT116 and MCF-7. Most of compounds showed significant antitumor activity and some compounds showed strong results greater than the reference drug. As example, IC₅₀ values of 1,1'-(1,4-phenylene)bis(3-(benzo[d][1,3]dioxol-5-yl)thiourea) 5 were 2.38 µM for HepG2, 1.54 µM for HCT116 and 4.52 µM for MCF7, while the IC₅₀ values of standard drug doxorubicin were 7.46, 8.29 and 4.56 µM, respectively. Interestingly, these compounds were non cytotoxic toward the tested normal cell line (IC₅₀ value > 150 µM). The anticancer mechanisms were studied via EGFR inhibition assessment, annexin V-FITC apoptosis assessment, cell cycle analysis and study the effect on mitochondrial apoptosis pathway proteins Bax and Bcl-2 as well as molecular docking studies.

In vitro cytotoxic and apoptotic induction effect of earthworm coelomic fluid of Eudrilus eugeniae, Eisenia foetida, and Perionyx excavatus on human oral squamous cell carcinoma-9 cell line

The current protocol of cancer management includes surgery, radiotherapy and chemotherapy. However, these modalities have significant adverse effects and affect the quality of life. Further intensification of treatment is hindered as maximal toxicity levels are reached impeding improvement. Hence researchers are in the quest for adjunctive naturally available therapies that can alter tumor proliferation without causing significant adverse reactions. The present study aims to explore the cytotoxic potential of earthworm coelomic fluid (ECF) of Eudrilus eugeniae (EE), Eisenia foetida (EF), and Perionyx excavatus (PE) on oral cancer cell line SCC-9. The effect of ECF on cell cycle analysis and mechanism of cell death have also been investigated. All experiments reported in this paper were performed as 3 replicates per experiment. The results indicated that ECF of EE, EF and PE have potent variable cytotoxic effect on SCC-9 cells demonstrated through LDH, clonogenic and comet assay. An effective cell cycle arrest was observed at the G2M phase of cell cycle with apoptotic induction that was observed through an Annexin V - FITC/PI assay. ECF of EE was found to be superior in its cytotoxic action closely followed by ECF of PE. The present findings provide evidence for the first time that ECF of EE, EF and PE have potent cytotoxic effect on oral cancer cells in vitro. They significantly induce G2M cell cycle arrest and promote apoptosis in SCC-9 cell line. Gene expression studies have been planned to ascertain the pathways of cell death.

Antiproliferative effect, cell cycle arrest and apoptosis generation of novel synthesized anticancer heterocyclic derivatives based 4H-benzo[h]chromene

Novel β-enaminonitrile/ester compounds (4, 6) and an imidate of 4 (9) were utilized as key scaffolds for the synthesis of newly 2-substituted 4H-benzo[h]chromene (7, 8, 10, 11, 13, 14) and 7H-benzo[h]chromeno[2,3-d]pyrimidine derivatives (15-19). The spectral data confirmed the successful isolation of the desired compounds. The targeted compounds were assessed for their in vitro anticancer activity against mammary gland breast cancer cell line (MCF-7), human colon cancer (HCT-116), and liver cancer (HepG-2), while doxorubicin, vinblastine, and colchicine were utilized as standard references drugs. Some of the examined compounds displayed high growth inhibitory activity against the three different cell lines. For example, the aminoimino derivative (18) exhibited excellent antitumor activity versus all cancer cell lines with IC₅₀ values = 0.45 µg/mL, 0.7 µg/mL, and 1.7 µg/mL. Among the tested molecules, compounds 9, 15, and 18 were selected for further study regarding their effects on cell cycle analysis, apoptosis assay, caspase 3/7 activity, and DNA fragmentation. We found that these three potent cytotoxic compounds induce cell cycle arrest at the S and G2/M phases, which causes apoptosis. Furthermore, these compounds significantly inhibit the invasion and migration of the different tested cancer cells. Finally, the SAR survey highlighted the antitumor activity of the new molecules that was remarkably influenced by the hydrophilicity of substituent as well the fused rings at certain positions.

Synthesis of new derivatives of boehmeriasin A and their biological evaluation in liver cancer

Two series of boehmeriasin A analogs have been synthesized in short and high yielding processes providing derivatives differing either in the alkaloid's pentacyclic scaffold or its peripheral substitution pattern. These series have enabled, for the first time, comparative studies into key biological properties revealing a new lead compound with exceptionally high activity against liver cancer cell lines in the picomolar range for both well (Huh7, Hep3B and HepG2) and poorly (Mahlavu, FOCUS and SNU475) differentiated cells. The cell death was characterized as apoptosis by cytochrome-C release, PARP protein cleavage and SubG1 cell cycle arrest. Subsequent testing associated apoptosis via oxidative stress with in situ formation of reactive oxygen species (ROS) and altered phospho-protein levels. Compound 19 decreased Akt protein phosphorylation which is crucially involved in liver cancer tumorigenesis. Given its simple synthetic accessibility and intriguing biological properties this new lead compound could address unmet challenges within liver cancer therapy.

Analysis of hematopoietic stem cells using a composite approach

Stem cells or Cancer stem cells (CSCs) have now been identified in different type of tissues by using surface markers. Functional assays such as ALDEFLUOR and side population which are marker independent have been additional approaches. However, whether all these approaches identify the same population of cells remain uncertain. To address this issue we have used hematopoietic stem cells as a model. Peripheral blood stem cells enumerated by CD34 are used routinely in bone marrow transplantation which supports the recovery of bone marrow after ablative chemotherapy or radiation. Hematopoietic stem cells (HSCs) were obtained from normal donor bone marrow (n = 5) and G-CSF stimulated peripheral blood stem cells (PBSCs) (n = 5) from patients undergoing leukapheresis prior to bone marrow transplantation. The stem cells were identified by combining CD34 expression with functional assays (ALDEFLUOR and side population). The cell cycle profile was further determined by simultaneous labeling of these cells with Hoechst and Pyronin Y. The simultaneous analysis showed that both CD34+ and CD34- cells co-exist with ALDH1A1+ cells but side population did not segregate with CD34+ cells. Though stem cell populations identified by functional assays were different, the cell cycle analysis showed that both ALDH1A1+ and CD34+ cells were in the G1 phase of cell cycle rather than in the quiescent (G0) phase.