Induced S-phase Cell Cycle Arrest Research Articles

Bioguided Fractionation of Phyllanthus spp.: Unveiling Anticancer Potential through Metabolomic Correlation and ADMETox Insights.

Cancer remains a significant global health concern, with mortality rates steadily rising and prompting an urgent search for effective treatments. This study focuses on the medicinal properties of plants from the Phyllanthus genus, specifically Phyllanthus amarus and Phyllanthus niruri, which have shown promise in traditional medicine. Through bioguided fractionation using preparative high-performance liquid chromatography (HPLC), bioactive compounds were isolated and identified using ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC-QTOF-MSE) and nuclear magnetic resonance (NMR) spectroscopy. Chemometric analyses such as principal component analysis (PCA) aided in understanding metabolite distribution. Biological assays demonstrated cytotoxic activities of specific fractions against cancer cell lines, notably the PhyN 4n fraction from P. niruri, which induced S-phase cell cycle arrest and apoptosis in HL60 cells. These findings underscore the anticancer potential of Phyllanthus species and lay the groundwork for future drug development efforts. The study's integration of advanced analytical techniques, chemometrics, and biological assays provides valuable insights for harnessing natural products in the fight against cancer.

Investigation of In Vitro Anti-cancer and Apoptotic Potential of Onion-Derived Nanovesicles Against Prostate and Cervical Cancer Cell Lines.

Plant-derived compounds have recently garnered significant interest in the field of medicine due to their rich repertoire of phytochemicals, which holds promise for exploring novel therapies to treat cancer. This study embarks on the first-time investigation of the anti-cancerous effect of onion-derived nanovesicles (ODNVs). ODNVs were isolated employing differential centrifugation followed by ultracentrifugation and subsequent characterization using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR). Furthermore, we delineated the anti-cancerous effect of ODNVs on two cancer cell line models HeLa (cervical cancer) and PC-3 (prostate cancer) using MTT assay, DAPI-based DNA damage using immunofluorescence microscopy, colony formation assay, migration assay, cell cycle analysis, and evaluation of apoptosis using flow cytometry and western blotting. The findings revealed dose- and time-dependent anti-proliferative effects of ODNVs on both HeLa and PC3 cell lines, accompanied by selective cytotoxicity against cancer cells. Additional results highlighted that ODNVs prevented colony growth and induced S-phase cell cycle arrest. Apoptosis induction was evaluated through alterations in nuclear morphology and the number of apoptotic cells, which increased significantly after ODNV treatment in both cancer cell lines. Furthermore, annexin V/PI staining evaluation of apoptotic cells by flow cytometry demonstrated that ODNV treatment significantly increased the number of apoptotic cells in both PC-3 and HeLa cells. Finally, Western blot analysis indicated changes in apoptosis-related proteins including bcl-2, bax, and caspase-3, emphasizing that the anti-cancerous effect of ODNVs is attributed to the induction of apoptosis and suggests the unexplored anti-cancerous potential of ODNVs.

Identification of potential target genes of cardiac glycosides from Vernonia amygdalina Delile in HER2+ breast cancer cells

Vernonia amygdalina Delile or bitter leaf, a traditional medicinal plant endemic to Africa, has shown anticancer properties by inhibiting the downstream signaling of human epidermal growth factor receptor 2 (HER2) in several cancer cells through the PI3K/AKT/mTOR pathways. This study explored the potential target of Vemonia cardiac glycosides for the treatment of HER2+ breast cancer (CTG) using bioinformatics and in vitro experiments. The similarity ensemble technique Swiss TargetPrediction was used to predict protein targets of cardiac glycosides. DisGeNET and UALCAN were used to collect the regulatory genes of HER2+ breast cancer cells. We obtained 75 CTG sequences from the predicted target and regulatory genes of HER2+ breast cancer. Subsequent analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment revealed that CTG was enriched for multiple pathways, such as PI3K-Akt signaling, breast cancer, EGFR tyrosine kinase inhibitor resistance, and ErbB signaling pathways. Further bioinformatic analysis identified five CTG: ERBB2, ESR1, EGFR, PIK3CA, and PTPN11. The ethanolic extract and its ethyl acetate fraction of V. amigdalina were referred to as REF and EA, respectively. Cytotoxicity tests showed that EA exerted strong cytotoxicity on MCF-7/HER2 cells by inducing S-phase cell cycle arrest and apoptosis, modulating the mRNA expression of CTG: ERBB2, ESR1, and proliferation and apoptosis markers, PCNA, CCND1, BAX, BCL2, and CASP7. Future studies should develop EA and cardiac glycosides as anticancer agents against HER2+breast cancer cells.

Abstract A151: Establishing assays to investigate combinations of fractioned radiotherapy with DNA damage response agents in vitro and in vivo to enable investigation of radiosensitization and improved anti-tumour responses

Abstract Introduction: Radiotherapy is a main treatment modality for multiple cancer types, with approximately half of all cancer patients receiving radiotherapy as part of their treatment regimen. In addition to direct cytotoxic effects on cancer cells, it is now appreciated that radiosensitization using specific drugs inhibiting DNA damage response (DDR) pathways can enhance the sensitivity of tissues or cells to radiation therapy. Establishing assays to screen for potential radiosensitizing compounds is therefore valuable to inform drug discovery research. Methods: The MDA-MB-436 human breast cancer cell line was selected for assay optimization. DDR inhibitors of DNA-dependent protein kinase (DNA-PK) (AZD7648) and Poly-(ADP-Ribose)-Polymerase (PARP) (niraparib) were used as tool radiosensitizing compounds, as these proteins play key roles in the repair of radiation-induced DNA double strand breaks. Effects on cell viability, cell cycle progression and DDR biomarkers were determined under a variety of irradiation (IR) and compound conditions. In parallel, in vivo validation experiments were performed. Results and Conclusions: Both AZD7648 and niraparib radiosensitize MDA-MB-436 cells to IR treatment. A dose of 2 Gray (Gy) reduced the observed anti-proliferative compound IC50 compared to IR treatment or compound treatment alone. Furthermore, combined treatment of 2 Gy IR with either DDR inhibitor induces S-phase cell cycle arrest and increases cell death. Analysis of DDR biomarkers confirms their induction by radiotherapy in combination with DDR inhibitors. Similar changes to DDR biomarker expression were also observed in the in vivo xenograft mouse model. In summary, in vitro and in vivo assays have been established to investigate radiosensitization through the combination of IR and DDR inhibitors. Furthermore, these assays can identify novel compounds acting via a synergistic mechanism. Citation Format: Charlotte Bell, Stewart Brown, Amy Cantrell, Paul Farrington, Miguel Garcia, Ben Hodgson, Yin Xin Ho, Allan Jordan, Theoni Katopodi, Jane Kendrew, Wen Hao Neo, Stuart Thomson, Graeme E Walker, Emily Wright. Establishing assays to investigate combinations of fractioned radiotherapy with DNA damage response agents in vitro and in vivo to enable investigation of radiosensitization and improved anti-tumour responses [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A151.

PARP inhibitor exerts an anti-tumor effect via LMO2 and synergizes with cisplatin in natural killer/T cell lymphoma

BackgroundPARP inhibitor (PARPi), as a kind of DNA damage repair inhibitor, has been shown to be effective in various solid tumors and hematologic malignancies. Natural killer/T cell lymphoma (NKTCL) is a highly aggressive malignancy, the treatment of which has long been a major challenge in the clinic. Here, we investigated the efficacy and mechanism of PARPi, and the therapeutic value of PARPi combined with cisplatin in NKTCL.MethodsThe cell proliferation, cell apoptosis, and cell cycle of NKTCL cells were detected respectively by CCK-8 and flow cytometry. The changes of mRNA expression and protein level were measured respectively by mRNA-sequencing, quantitative real-time PCR, western blotting, and immunofluorescence. LMO2 expression was detected by immunohistochemistry and western blotting. Targeted knockdown of LMO2 was conducted by short hairpin RNA. The tumor xenograft models were established to evaluate the efficacy of drugs in vivo.ResultsPARPi inhibited cell proliferation, promoted cell apoptosis, and induced S-phase cell cycle arrest in NKTCL cells. PARPi led to the accumulation of DNA damage by blocking DNA repair and DNA replication. Additionally, LMO2 deficiency reduced the sensitivity of NKTCL cells to PARPi. Finally, the combination of PARPi and cisplatin exhibited significant synergistic effects both in vitro and in vivo.ConclusionsIn summary, we found that PARPi exerted an anti-tumor effect via LMO2 and synergized with cisplatin in NKTCL, which provides the theoretical basis for the clinical application of PARPi.

Design, synthesis and antiproliferative evaluation of lipidated 1,3-diaryl propenones and their cyclized pyrimidine derivatives as tubulin polymerization inhibitors

Malignant transformations are dependent on an aberrant increase in tubulin and microtubule activities for cancer cell growth, migration, invasion and metastasis. The present work includes design and synthesis of a new series of lipidated 1,3-diaryl propenones and their cyclized pyrimidine derivatives as tubulin polymerization inhibitors. These derivatives harness lipophilicity, ease of synthesis and antiproliferative activity of lipidated 1,3-diaryl propenones and their cyclized derivatives. New compounds were synthesized from 4′-hydroxyacetophenone via O-alkylation, condensation with different aromatic aldehydes followed by cyclization with urea, thiourea or guanidine. Cyclization of 1,3-diaryl propenones into 4,6-diaryl pyrimidines increased their antiproliferative activity with the most potent derivative 19 achieving IC50 values at low micro molar concentration against two human cancer cell lines; MCF-7 (breast) and HepG-2 (liver). Compound 19 induced S-phase cell cycle arrest and apoptosis in MCF-7 with tubulin IC50 = 9.7 μM. It is well accommodated at the colchicine binding site of the tubulin protein as demonstrated by molecular docking.

Essential oil of lemon myrtle (Backhousia citriodora) induces S-phase cell cycle arrest and apoptosis in HepG2 cells

Ethnopharmacological relevanceLemon myrtle (Backhousia citriodora F.Muell.) leaves, whether fresh or dried, are used traditionally in folk medicine to treat wounds, cancers, skin infections, and other infectious conditions. However, the targets and mechanisms related to anti-cancer effect of lemon myrtle are unavailable. In our study, we found that the essential oil of lemon myrtle (LMEO) showed anti-cancer activity in vitro, and we initially explored its mechanism of action. Materials and methodsWe analyzed the chemical compositions of LMEO by GC-MS. We tested the cytotoxicity of LMEO on various cancer cell lines using the MTT assay. Network pharmacology was used also to analyze the targets of LMEO. Moreover, the mechanisms of LMEO were investigated through scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. ResultsLMEO showed cytotoxicity on various cancer cell lines with values of IC50 40.90 ± 2.23 (liver cancer HepG2 cell line), 58.60 ± 6.76 (human neuroblastoma SH-SY5Y cell line), 68.91 ± 4.62 (human colon cancer HT-29 cell line) and 57.57 ± 7.61 μg/mL (human non-small cell lung cancer A549 cell line), respectively. The major cytotoxic chemical constituent in LMEO was identified as citrals, which accounted for 74.9% of the content. Network pharmacological analysis suggested that apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1), androgen receptor (AR), cyclin-dependent kinases 1 (CDK1), nuclear factor erythroid 2-related factor 2 (Nrf-2), fatty acid synthase (FASN), epithelial growth factor receptor (EGFR), estrogen receptor 1 (ERα) and cyclin-dependent kinases 4 (CDK4) are potential cytotoxic targets of LMEO. These targets are closely related to cell migration, cycle and apoptosis. Notley, the p53 protein had the highest confidence to co-associate with the eight common targets, which was further confirmed by scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. LMEO significantly inhibited the migration of HepG2 cells in time-dependent and dose-dependent manner. Moreover, LMEO caused a S-phase blocking on HepG2 cells and promoted apoptosis in the meanwhile. Western blot results indicated that p53 protein, Cyclin A2 and Bax proteins were up-regulated, while Cyclin E1 and Bcl-2 proteins were down-regulated. ConclusionLMEO showed cytotoxicity in various cancer cell lines in vitro. Pharmacological networks showed LMEO to have multi-component and multi-targeting effects that are related to inhibit migration of HepG2 cells, and affect cell cycle S-phase arrest and apoptosis through modulation of p53 protein.

Clioquinol induces autophagy by down-regulation of calreticulin in human neurotypic SH-SY5Y cells

Clioquinol (CQ) is considered as a promising drug of neurodegenerative diseases. However, the underlying mechanism is unclear. Our previous study has proved that CQ induces S-phase cell cycle arrest through the elevation of intracellular calcium concentration ([Ca2+]i) with high levels of SERCA2. Furthermore, it could induce autophagy in an intracellular calcium independent manner in human neurotypic SH-SY5Y cells. In this study, the involvement of calreticulin (CRT) in autophagy induced by CQ was investigated. Our results illustrated the endoplasmic reticulum (ER) stress induced by CQ and DTT led to the cell death in different manners. DTT, an ER stress positive control, induced UPR accompanied with up-regulation of CRT and apoptosis, while CQ inhibited UPR accompanied with down-regulation of CRT，resulting in autophagy. Then, overexpression of CRT was shown to cause UPR and decrease [Ca2+]i, leading to cell apoptosis and inhibition of S-phase arrest induced by CQ. While the UPR was alleviated and autophagy was further enhanced in CRT deficient cells by using targeted siRNA. Meanwhile, down-regulation of CRT resulted in [Ca2+]i overload and induction of S-phase arrest. Finally, we found that the effect of CQ on the HT22 cells was similar to that on the SH-SY5Y cells. Our data showed for the first time that CQ decreased expression of CRT, leading to autophagy, an increase of [Ca2+]i, and cell S-phase arrest in the neurotypic cells. The present study describes the cellular signal pathways regulating autophagy by CQ and highlights the potential therapeutic application of CQ in neurodegenerative disorders.

Planispine A Sensitized Cancer Cells to Cisplatin by Inhibiting the Fanconi Anemia Pathway.

The use of cisplatin as a chemotherapeutic drug is impeded by the development of drug resistance. Combination therapies of a chemosensitizer for cisplatin have been studied, but with little success, and the search for an effective combination therapy is continuing. Our earlier reports have shown that Zanthoxylum armatum DC. extract enhances the apoptotic effect of cisplatin in cancer cell lines. In this study, we purified and identified the bioactive phytocompound through bio-assay-guided purification, using column chromatography and HPLC. Chemical characterization using NMR and mass spectrometry revealed the compound as planispine A, with molecular structure C25H30O6 and molecular weight, 426.16 g/mol. Planispine A was found to inhibit cancer cell proliferation in a dose-dependent manner and to sensitize the cancer cells to cisplatin-augmented apoptotic cell death, in a caspase-dependent manner. A combination of planispine A and cisplatin induced S-phase cell cycle arrest, and reduced the expression of survival proteins such as cyclin D1. Interestingly, planispine A inhibits the Fanconi anemia pathway, as shown by reduced FANCD2 foci formation and FANCD2 monoubiquitination, which revealed the molecular mechanism of chemo-sensitization of cancer cells to cisplatin. Evaluation of this combination therapy in cisplatin-resistant tumors may lead to more efficient cisplatin treatment.

Erdafitinib Inhibits Tumorigenesis of Human Lung Adenocarcinoma A549 by Inducing S-Phase Cell-Cycle Arrest as a CDK2 Inhibitor.

Lung adenocarcinoma (LADC) is the most prevalent lung cancer sub-type, and targeted therapy developed in recent years has made progress in its treatment. Erdafitinib, a potent and selective pan-FGFR tyrosine kinase inhibitor, has been confirmed to be effective for the treatment of LADC; however, the molecular mechanism responsible for this effect is unclear. The in vitro study showed that erdafitinib exhibited an outstanding anti-cancer activity in human LADC cell line A549 by inducing S-phase cell-cycle arrest and cell apoptosis. The mechanistic study based on the transcriptomic data revealed that erdafitinib exerted its anti-cancer effect by affecting the cell cycle-related pathway, and CDK2 was the regulatory target of this drug. In addition, CDK2 overexpression significantly attenuated the anti-cancer effect of erdafitinib by affecting the transcriptional activity and expression of E2F1, as well as the expression of CDK1. The in vivo study showed that erdafitinib presented an obvious anti-cancer effect in the A549 xenograft mice model, which was accompanied by the reduced expression of CDK2. Thus, this study demonstrates the anti-cancer effect of erdafitinib against LADC for the first time based on in vitro and in vivo models, whose activity is achieved by targeting CDK2 and regulating downstream E2F1-CDK1 signaling. This study may be helpful for expanding the clinical application of erdafitinib in treating LADC.

Taraxasterol Inhibits Tumor Growth by Inducing Apoptosis and Modulating the Tumor Microenvironment in Non-Small Cell Lung Cancer.

Simple SummaryTaraxasterol (TAX) demonstrates strong pharmacological activity in some diseases. In this study, we demonstrate that TAX induces S-phase cell cycle arrest, prevents cell migration by interfering EMT, and induces cancer cell apoptosis. In addition, TAX administration downregulated the proportion of Treg cells and upregulated CD107a + NK cells in TME. Our in vitro and in vivo findings indicate that TAX could serve as a potential natural drug for lung cancer therapy.Taraxasterol (TAX), one of the active components in Dandelion, demonstrated strong antitumor properties in several cancers. However, the effect and underlying mechanism of TAX in non-small cell lung cancer (NSCLC) is unclear. In this study, we showed that TAX inhibited the proliferation of cells by inducing S-phase cell cycle arrest and prevented cell migration by interfering epithelial-mesenchymal transition (EMT) in Lewis lung cancer (LLC) cells and lung carcinoma SPC-A1 cells. The pharmacological network analysis predicted that induction of apoptosis might be the potential mechanism of TAX-mediated cell deaths. Further in vitro experiments showed that TAX could significantly induce cancer cell apoptosis as verified by increased pro-apoptotic molecules including Bax, caspase-9, and PARP1 downregulated anti-apoptotic protein Bcl-2; and decreased mitochondrial potential. The LLC subcutaneous tumor model demonstrated that TAX inhibited tumor growth by induction of apoptosis and inhibition of proliferation in vivo, which is consistent with the in vitro data. Importantly, TAX administration downregulated the proportion of Treg cells and upregulated CD107a+ NK cells in the tumor microenvironment in the tumor model. Together, these data reveal that TAX performs its antitumor effect by inducing apoptosis and modulating the tumor microenvironment, providing evidence that TAX could serve as a potential natural drug for lung cancer therapy.

Ginger polysaccharide UGP1 suppressed human colon cancer growth via p53, Bax/Bcl-2, caspase-3 pathways and immunomodulation

In previous study, we got a purified ginger polysaccharide UGP1 and verified its significant antitumor activities on colon cancer HCT116 cells. In this article, we aimed to illustrate the underlying mechanism of UGP1 exerted antitumor activities on colon cancer by using in vitro cell models and in vivo animal models. The results demonstrated that UGP1 could induce S-phase cell cycle arrest, up-regulate the expression of Bax and p53, down-regulate the expression of Bcl-2, and activate the downstream protein caspase-9 and caspase-3, which was related to intrinsic apoptosis pathway on HCT116 cells. Moreover, UGP1 significantly stimulated RAW264.7 cell proliferation and secretion activity. Similarly, UGP1 inhibited tumor proliferation on tumor-bearing mice, increased the expression of p53 and the ratio of Bax/Bcl-2, enhanced the secretion of pro-inflammatory cytokines TNF-α, IL-2, IL-6 and decreased the secretion of pro-tumor cytokines TGF-β and bFGF in serum. In conclusion, it indicated that the UGP1 could suppress human colon cancer growth by inducing apoptosis via the regulation of p53, caspase-3, and Bax/Bcl-2 ratio-dependent pathway and regulating immune system activity. This investigation provided basic theoretical mechanism of ginger polysaccharide-exerted antitumor activities, and contributed to develop a possible functional food or adjuvant agent for prevention or treatment of colon cancer.

New alkaloids and their in vitro antitumor activity of Corydalis balansae

The chemical investigation on Corydalis balansae resulted in the isolation of three previous undescribed compounds (1, 10, and 11) and 17 known compounds. Compound 1 and 2 were obtained as two lignanamide dimers, and compound 11 had a spiro [benzofuranone-benzazepine] skeleton, which was found in Corydalis for the first time. The structures of new compound were determined by the detailed analysis of 1D/2D NMR, UV, and IR data. Absolute configurations of compounds 10 and 11 were defined by their crystal X-ray diffraction data and calculations of electronic circular dichroism (ECD). The CCK-8 method was used to assay the inhibition effect of all the compounds on the growth of Hela, MGC-803, A549, and HepG2 cancer cells. Compound 2, 13, and 14 showed moderate inhibitory activity against the tested cell lines. Compound 2 exhibited potential antitumor activity against MGC-803 cells with an IC50 value of 20.8 μM, while the positive control etoposide was 17.3 μM. Furthermore, results from the cellular-mechanism investigation indicated that compound 2 could induce S-phase cell-cycle arrest and MGC-803 cells apoptosis, which was triggered by the up-regulation of PARP1, caspase-3 and -9, Bax, and down-regulation of Bcl-2. The 2-induced strong apoptosis indicated that compound 2 had good potential as an antitumor lead compound.

The radiosensitizing effect of β-Thujaplicin, a tropolone derivative inducing S-phase cell cycle arrest, in head and neck squamous cell carcinoma-derived cell lines

BackgroundResistance to radiotherapy is a common cause of treatment failure in advanced head and neck squamous cell carcinoma (HNSCC). ß-Thujaplicin, a natural tropolone derivative, acts as an anti-cancer agent and has recently been shown to radiosensitize non-HNSCC cancer cells. However, no data is currently available on its radiosensitizing potential in HNSCC.MethodsTo investigate the effect of ß-Thujaplicin and irradiation in HNSCC cell lines CAL27 and FADU, we performed a cell viability assay, colony forming assay, flow cytometry for cell cycle analysis and a wound healing assay. Drug-irradiation interaction was analyzed using a zero-interaction potency model.ResultsTreatment with ß-Thujaplicin led to a dose-dependent decrease in cell viability and enhanced the effect of irradiation. Clonogenic survival was inhibited with synergistic drug-irradiation interaction. ß-Thujaplicin further led to S-phase arrest and increased the sub-G1 population. Moreover, combined ß-Thujaplicin and irradiation treatment had a higher anti-migratory effect compared to irradiation alone.Conclusionsß-Thujaplicin acts as a radiosensitizer in HNSCC cell lines. Further evaluation of its use in HNSCC therapy is warranted.

Root extract of Plumbago zeylanica L. induces cytotoxicity, inhibits cell migration and induces S-phase cell cycle arrest through down regulation of EGFR in HeLa cervical cancer cells

Plumbago zeylanica has been used in the traditional system of medicine from thousands of years owing to its potential therapeutic properties, however the anticancer and anti-metastatic effects are largely unknown against cervical cancer cells. In this study we demonstrated the cytotoxicity activity, inhibition of cell migration, induction of S-phase cell cycle arrest and the down regulation of expression level of epidermal growth factor receptor (EGFR) by ethanol extract of the root of P. zeylanica (ERPZ). The cytotoxicity effects were analyzed by MTT assay the IC50 was determined to be 10.49 ​μg/ml after 72 ​h of incubation. Besides, strong inhibition of wound healing activity was observed at 20 ​μg/ml concentration, where the wound size was reduced to 33%. The ethanol root extract of P. zeylanica also showed significant S-phase cell cycle arrest of 68.9% at 20 ​μg/ml concentration in HeLa cells which was accompanied by the down regulation of EGFR. Ethanol extracts of the root of P. zeylanica (ERPZ) treatment inhibited the growth of cervical cancer cells. The ERPZ arrested cells at the S-phase of the cell cycle. Besides the HRLC-MS analysis of ERPZ identified 15 compounds and among which the five major compounds such as 7,8-dihydroxy-4-methylcoumarin, neodiosmin, diosmetin, hispidulin, and formononetin were reported to possess antioxidant and anticancer activities, could plausibly induce cell death in HeLa cells.

Extracellular ATP Induced S-Phase Cell Cycle Arrest via P2Y Receptor-Activated ERK Signaling in Poorly Differentiated Oral Squamous Cell Carcinoma SAS Cells.

Extracellular ATP in the tumor microenvironment exhibits either pro- or antitumor effect via interaction with P2Y receptors, but the intracellular signaling and functional roles of P2Y receptors in oral squamous cell carcinoma (OSCC) are unclear. We aimed to study the effect of ATP on OSCC cell lines and the potential mechanisms involved. Through GEPIA dataset analysis, high expression levels of mRNA encoding P2Y receptors, the ATP-induced G protein-coupled receptors, were associated with better overall patient survival in head and neck squamous cell carcinoma. qPCR analysis showed that the poorly differentiated OSCC SAS cell line, had higher P2RY1 expression level compared to the well-differentiated H103 and H376 cell lines. Western blotting and flow cytometry analyses revealed that ATP phosphorylated ERK and elevated intracellular calcium signaling in all tested cell lines. A significant S-phase cell cycle arrest was observed in SAS, and preincubation with the MEK inhibitor PD0325901 reversed the ATP-induced S-phase arrest. We further demonstrated that ATP induced a slight reduction in cell count and colony formation yet significant apoptosis in SAS. Overall, we postulate that the ATP-induced S-phase arrest effect in SAS cells may be regulated through P2Y receptor-mediated ERK signaling, thus suggesting a potential antitumor effect of ATP via interaction with its distinct profile of P2Y receptors.

Granzyme B and perforin produced by SEC2 mutant-activated human CD4+ T cells and CD8+ T cells induce apoptosis of K562 leukemic cells by the mitochondrial apoptotic pathway

Staphylococcal enterotoxin C2 (SEC2), a classical representative of superantigens, activates T cells that produce massive cytokines. This characteristic makes SEC2 a promising candidate drug for cancer immunotherapy. Previous study showed that ST-4, a SEC2 mutant, enhanced recognition of mouse T-cell receptor Vβ regions, and activated the increased number of T cells that produced more cytokines. However, the underlying molecular mechanism for stimulation of human peripheral blood mononuclear cells (PBMCs) and antitumor effect on human tumor cells remains unknown. Herein, we showed that ST-4 significantly activated TCR Vβ 12, 13A, 14, 15, 17, and 20 CD4+ and CD8+ T cells, which produced substantial amounts of granzyme B and perforin. These cytokines exhibited antitumor effect on K562 cells by promoting apoptosis and inducing S-phase cell cycle arrest. Conversely, the granzyme B inhibitor or perforin inhibitor significantly weakened antitumor effect of ST-4, accompanied by a decrease of cleaved proapoptotic BAX and cytochrome c, and an increase of antiapoptotic BCL2. Taken together, these data suggest that granzyme B and perforin produced by ST-4-activated CD4+ T cells and CD8+ T cells play a pivotal role in inducing K562 cell apoptosis by the mitochondrial apoptotic pathway, and support ST-4 as a potential candidate for cancer immunotherapy.

Anticancer Activity of Ipomoea purpurea Leaves Extracts in Monolayer and Three-Dimensional Cell Culture.

Cancer is a leading cause of death and a vital health care challenge in the world. Hence, this work was conducted to determine the in vitro anticancer property and also the molecular mechanism of aqueous and organic extracts of Ipomoea purpurea leaves in three human cancer cell lines, including A-549 (human lung cancer), HepG-2 (human liver cancer), MDA-MB-231 (human breast cancer), and MCF-10A (breast normal cell line). In vitro cytotoxic potential of organic extracts, such as hexane, chloroform, ethyl-acetate, methanol, and aqueous extract was examined using a standard (3-(4,5-dimethylthiazole)-2,5-diphenyltetrazolium bromide) MTT method in both monolayer two-dimensional (2D) and spheroids multicellular three-dimensional (3D) cultures. The MTT assay data showed that methanol and chloroform extracts of I. purpurea leaves had the antiproliferative effect on lung and breast cancer cells with IC50 of 53.62 ± 0.07 and 124.5 ± 0.01 µg/mL, respectively. The results of further examinations, such as dual acridine orange/ethidium bromide, Annexin V-FITC/PI, and caspase-3 colorimetric assay, confirmed that methanol and chloroform extracts of I. purpurea as the most potent cytotoxic extracts might contain a variety of phytochemicals, promoting apoptosis in lung and breast cancer cells. The present research findings suggested that methanolic extract of I. purpurea leaves induced S-phase cell cycle arrest and intrinsic pathway of apoptosis in A-549 lung cancer cells. The study further showed that I. purpurea could be a helpful candidate for cancer treatment.

Rhein Suppresses Colorectal Cancer Cell Growth by Inhibiting the mTOR Pathway In Vitro and In Vivo.

Simple SummaryColorectal cancer (CRC) is the fourth most common cancer and the second most common cause of cancer-related deaths globally. Rhein is a natural anthraquinone extract from rhubarb, which exhibits potent anticancer activity in various cancers. In this study, we show that rhein significantly inhibited the growth, migration, and invasion of CRC cells by directly binding to mTOR and inhibiting the mTOR signaling pathway. Rhein promotes mTOR degradation through the ubiquitin–proteasome pathway. In addition, rhein significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity. Our results indicate that rhein is a promising anticancer agent that may be useful for the prevention and treatment of CRC.Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial–mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC.

Multifunctional hybrid nanoplatform based on Fe3O4@Ag NPs for nitric oxide delivery: development, characterization, therapeutic efficacy, and hemocompatibility

The combination of Fe3O4@Ag superparamagnetic hybrid nanoparticles and nitric oxide (NO) represents an innovative strategy for a localized NO delivery with a simultaneous antibacterial and antitumoral actions. Here, we report the design of Fe3O4@Ag hybrid nanoparticles, coated with a modified and nitrosated chitosan polymer, able to release NO in a biological medium. After their synthesis, physicochemical characterization confirmed the obtention of small NO-functionalized superparamagnetic Fe3O4@Ag NPs. Antibacterial assays demonstrated enhanced effects compared to control. Bacteriostatic effect against Gram-positive strains and bactericidal effect against E. coli were demonstrated. Moreover, NO-functionalized Fe3O4@Ag NPs demonstrated improved ability to reduce cancer cells viability and less cytotoxicity against non-tumoral cells compared to Fe3O4@Ag NPs. These effects were associated to the ability of these NPs act simultaneous as cytotoxic (necrosis inductors) and cytostatic compounds inducing S-phase cell cycle arrest. NPs also demonstrated low hemolysis ratio (<10%) at ideal work range, evidencing their potential for biomedical applications.Targeted and hemocompatible nitric oxide-releasing multi-functional hybrid nanoparticles for antitumor and antimicrobial applications.