Methotrexate-induced apoptosis in human ovarian adenocarcinoma SKOV-3 cells via ROS-mediated bax/bcl-2-cyt-c release cascading

Role of PI3K/AKT signaling pathway involved in self-renewing and maintaining biological properties of chicken primordial germ cells

Avian primordial germ cells (PGCs) are important culture cells for the production of transgenic chickens and preservation of the genetic resources of endangered species; however, culturing these cells in vitro proves challenging. Although the proliferation of chicken PGCs is dependent on insulin, the underlying molecular mechanisms remain unclear. In the present study, we explored the expression of the PI3K/AKT signaling pathway in PGCs, investigated its effects on PGC self-renewal and biological properties, and identified the underlying mechanisms. Our findings indicated that although supplementation with the PI3K/AKT activator IGF-1 failed to promote proliferation under the assessed culture conditions, the PI3K/AKT inhibitor LY294002 resulted in retarded cell proliferation and reduced expression of germ cell-related markers. We further demonstrated that inhibition of PI3K/AKT regulates the cell cycle and promotes apoptosis in PGCs by activating the expression of BAX and inhibiting that of Bcl-2. These findings indicated that the PI3K/AKT pathway is required for cell renewal, apoptosis, and maintenance of the reproductive potential in chicken PGCs. This study aimed to provide a theoretical basis for the optimization and improvement of a culture system for chicken PGCs and provide insights into the self-renewal of vertebrate PGCs as well as potential evolutionary changes in this unique cell population.

T cell exhaustion and senescence for ovarian cancer immunotherapy

Ovarian cancer is a common gynecological malignancy, and its treatment remains challenging. Although ovarian cancer may respond to immunotherapy because of endogenous immunity at the molecular or T cell level, immunotherapy has so far not had the desired effect. The functional status of preexisting T cells is an indispensable determinant of powerful antitumor immunity and immunotherapy. T cell exhaustion and senescence are two crucial states of T cell dysfunction, which share some overlapping phenotypic and functional features, but each status possesses unique molecular and developmental signatures. It has been widely accepted that exhaustion and senescence of T cells are important strategies for cancer cells to evade immunosurveillance and maintain the immunosuppressive microenvironment. Herein, this review summarizes the phenotypic and functional features of exhaust and senescent T cells, and describes the key drivers of the two T cell dysfunctional states in the tumor microenvironment and their functional roles in ovarian cancer. Furthermore, we present a summary of the molecular machinery and signaling pathways governing T cell exhaustion and senescence. Possible strategies that can prevent and/or reverse T cell dysfunction are also explored. An in-depth understanding of exhausted and senescent T cells will provide novel strategies to enhance immunotherapy of ovarian cancer through redirecting tumor-specific T cells away from a dysfunctional developmental trajectory.

Multitargeted molecular docking and dynamics simulation studies of flavonoids and volatile components from the peel of Citrus sinensis L. (Osbeck) against specific tumor protein markers

Citrus sinensis (L.) Osbeck (Rutaceae), commonly known as the sweet orange, is a popular and widely consumed fruit with several medicinal properties. The present study aimed to perform the in silico screening of 18 flavonoids and eight volatile components from the peel of C. sinensis against apoptotic and inflammatory proteins, metalloprotease, and tumor suppressor markers. Flavonoids obtained higher probabilities than volatile components against selected anti-cancer drug targets. Hence, the data from the binding energies against the essential apoptotic and cell proliferation proteins substantiate that they may be promising compounds in developing effective candidates to block cell growth, proliferation, and induced cell death by activating the apoptotic pathway. Further, the binding stability of the selected targets and the corresponding molecules were analyzed by 100 ns molecular dynamics (MD) simulations. Chlorogenic acid has the most binding affinity against the important anti-cancer targets iNOS, MMP-9, and p53. The congruent binding mode to different drug targets focused on cancer shown by chlorogenic acid suggests that it may be a compound with significant therapeutic potential. Moreover, the binding energy predictions indicated that the compound had stable electrostatic and van der Waal energies. Thus, our data reinforce the medicinal importance of flavonoids from C. sinensis and expand the need for more studies, seeking to optimize results and amplify the impacts of further in vitro and in vivo studies. Communicated by Ramaswamy H. Sarma.

The Role of Oxidative Stress in Tumorigenesis and Progression

Oxidative stress refers to the imbalance between the production of reactive oxygen species (ROS) and the endogenous antioxidant defense system. Its involvement in cell senescence, apoptosis, and series diseases has been demonstrated. Advances in carcinogenic research have revealed oxidative stress as a pivotal pathophysiological pathway in tumorigenesis and to be involved in lung cancer, glioma, hepatocellular carcinoma, leukemia, and so on. This review combs the effects of oxidative stress on tumorigenesis on each phase and cell fate determination, and three features are discussed. Oxidative stress takes part in the processes ranging from tumorigenesis to tumor death via series pathways and processes like mitochondrial stress, endoplasmic reticulum stress, and ferroptosis. It can affect cell fate by engaging in the complex relationships between senescence, death, and cancer. The influence of oxidative stress on tumorigenesis and progression is a multi-stage interlaced process that includes two aspects of promotion and inhibition, with mitochondria as the core of regulation. A deeper and more comprehensive understanding of the effects of oxidative stress on tumorigenesis is conducive to exploring more tumor therapies.

Toxic effects of combined exposure to homoyessotoxin and nitrite on the survival, antioxidative responses, and apoptosis of the abalone Haliotis discus hannai

Homoyessotoxin (homo-YTX) and nitrite (NO2-N), released during harmful dinoflagellate cell lysis adversely affect abalones. However, their toxicity mechanisms in shellfish remain unclear. This study investigated the economic abalone species Haliotis discus hannai exposed to varying concentrations of homo-YTX (0, 2, 5, and 10 µg L-1) and NO2-N (0, 3, and 6 mg L-1) on the basis of their 12 h LC50 values (5.05 µg L-1 and 4.25 mg L-1, respectively) and the environmentally relevant dissolved concentrations during severe dinoflagellate blooms, including mixtures. The test abalones were exposed to homo-YTX and NO2-N for 12 h. The mortality rate (D), reactive oxygen species (ROS) levels, antioxidant defense capabilities, and expression levels of antioxidant-related, Hsp-related, and apoptosis-related genes in abalone gills were assessed. Results showed that the combined exposure to homo-YTX and NO2-N increased the D and ROS levels and upregulated B-cell lymphoma-2 (BCL2)-associated X (BAX) and caspase3 (CASP3) expression levels while reducing glutathione peroxidase (GPx) activity and GPx, CuZnSOD, and BCL2 expression levels. High concentrations of homo-YTX (10 µg L-1) and NO2-N (6 mg L-1) solutions and the combinations of these toxicants inhibited the activities of superoxide dismutase (SOD) and catalase (CAT) and downregulated the expression levels of MnSOD, CAT, Hsp70, and Hsp90. The ROS levels were negatively correlated with the activities of SOD, CAT, and GPx and the expression levels of MnSOD, CuZnSOD, CAT, GPx, Hsp70, Hsp90, and BCL2. These results suggest that homo-YTX, in conjunction with NO2-N, induces oxidative stress, disrupts antioxidant defense systems, and triggers caspase-dependent apoptosis in the gills of abalone. ROS-mediated antioxidative and heat-shock responses and apoptosis emerge as potential toxicity mechanisms affecting the survival of H. discus hannai due to homo-YTX and NO2-N exposure.

Vinpocetine mitigates methotrexate-induced duodenal intoxication by modulating NF-κB, JAK1/STAT-3, and RIPK1/RIPK3/MLKL signals

OBJECTIVES

Methotrexate (MTX) is an antimetabolite agent widely used to manage a variety of tumors and autoimmune diseases. Nonetheless, MTX-induced intestinal intoxication is a serious adverse effect limiting its clinical utility. Inflammation and oxidative stress are possible mechanisms for MTX-induced intestinal toxicity. Vinpocetine (VNP) is a derivative of the alkaloid vincamine with potent anti-inflammatory and antioxidant effects. The current study investigated the protective intestinal impact of VNP in attenuating MTX-induced intestinal intoxication in rats.

MATERIALS AND METHODS

VNP was administered orally in a dose of 20 mg/kg, while MTX was injected intraperitoneal in a dose of 20 mg/kg.

RESULTS

VNP administration attenuated drastic histological changes induced by MTX and preserved both normal villus and crypt histology. VNP significantly attenuated oxidative injury by upregulating intestinal Nrf2 and HO-1 expression. VNP attenuated inflammation by reducing MPO, NO2-, TNF-α, and IL-1β levels mediated by downregulating NF-κB, NDAPH-oxidase, IRF3, p-JAK-1, and p-STAT-3 expressions. Moreover, VNP potently counteracted intestinal necroptosis by effectively downregulating RIPK1, RIPK3, MLKL, and caspase-8 proteins.

CONCLUSION

Therefore, VNP may represent a promising approach that can attenuate intestinal toxicity in patients receiving MTX.

ROS-mediated physiological activities and apoptotic effect on the survival of abalone (Haliotis discus hannai) under homoyessotoxin and ammonia stresses

Serious dinoflagellate blooms produce homoyessotoxin (homo-YTX) and ammonia (NH3-N) in eutrophic seawaters, posing threats to the healthy development of the mariculture industry. This study aimed to explore the toxicity mechanism of homo-YTX and NH3-N on the survival of abalone, which is important for the ecotoxicological research and cultivation of shellfish. The economy abalone Haliotis discus hannai was placed in homo-YTX (0, 2, 5, and 10 μg L-1) and NH3-N (0, 1.08, and 3.16 mg L-1) and a mixture of the two compounds to determine the survival rate (S), antioxidative responses, physiological activities, and apoptosis of abalone. Results show that the combination of homo-YTX and NH3-N increased the reactive oxygen species level, the malondialdehyde content, and the expression level of BCL2-associated X but decreased S; the activities of superoxide dismutase, catalase, adenosine triphosphatase, glutamic-pyruvic transaminase, xanthine oxidase, lactate dehydrogenase, and lysozyme; and the expression level of B-cell lymphoma-2. The activities of alkaline phosphatase and acid phosphatase in 10 μg L-1 of homo-YTX and 3.16 mg L-1 of NH3-N solutions and in the mixture of the two toxicants decreased. The caspase3 expression level was downregulated in 10 μg L-1 of homo-YTX. These results suggest that homo-YTX and NH3-N enhanced the oxidative stress and lipid peroxidation reactions, inhibited the energy supply, disrupted the metabolic and immune physiological functions, and activated apoptosis in the gills of abalone. ROS-mediated physiological activities and apoptosis were among the potential toxicity mechanisms of the interactive effects of homo-YTX and NH3-N on abalone.

Modulatory effect of amifostine (WR-1065) against genotoxicity and oxidative stress induced by methotrexate in human umbilical vein endothelial cells (HUVECs)

Amifostine is used in chemotherapy and radiotherapy as a cytoprotective adjuvant alongside DNA-binding chemotherapeutic agents. It functions by reducing free radicals and detoxifying harmful metabolites. Methotrexate, as an antimetabolite drug has been considered for treating various cancers and autoimmune diseases. However, the cytotoxic effects of methotrexate extend beyond tumor cells to crucial organs, including the heart. This study applied the HUVEC cell line as a reference in vitro model for researching the characteristics of vascular endothelium and cardiotoxicity. The current study aimed to assess amifostine's potential cytoprotective properties against methotrexate-induced cellular damage. Cytotoxicity was measured using the MTT assay. Apoptotic rates were evaluated by Annexin V-FITC/PI staining via flow cytometry. The genoprotective effect of amifostine was determined using the comet assay. Cells were exposed to various amifostine doses (10-200 μg/mL) and methotrexate (2.5 μM) in pretreatment culture condition. Methotrexate at 2.5 μM revealed cytotoxicity, apoptosis, oxidative stress and genotoxicity while highlighting amifostine's cyto/geno protective properties on HUVECs. Amifostine significantly decreased the levels of ROS and LPO while preserving the status of GSH and SOD activity. Furthermore, it inhibited genotoxicity (tail length, %DNA in tail, and tail moment) in the comet assay. Amifostine markedly attenuated methotrexate-induced apoptotic cell death (early and late apoptotic rates). These findings convey that amifostine can operate as a cytoprotectant agent.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae)

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.

In vitro hepatotoxicity evaluation of methotrexate-loaded niosome formulation: fabrication, characterization and cell culture studies

BACKGROUND

Methotrexate (MTX) is a folic acid antagonist that is widely used to treat osteosarcoma, leukemia, breast cancer, and autoimmune and inflammatory diseases. The most important concerns with MTX are its poor solubility and high toxicity, particularly in liver cells. To enhance its solubility and to minimize its toxicity, we encapsulated MTX in niosomes and investigated its hepatotoxicity mechanisms using genetic biomarkers.

METHODS

Niosomes were successfully prepared using a modified thin film method, and the prepared monodisperse smallsized formulation was subsequently characterized. In vitro cytotoxicity studies were performed both in hepatocarcinoma (HEP3G) and healthy liver (AML12) cell lines. Specifically, immunofluorescence assay and evaluation of the expression levels of apoptotic, antioxidant, heat shock protein, and oxidative stress genes were performed.

RESULTS

The formulation had a particle size of 117.1 ± 33 nm, a surface charge of -38.41 ± 0.7 mV, and an encapsulation efficiency of 59.7% ± 2.3%. The results showed that the niosomal formulation exhibited significantly higher cytotoxic effects in HEP3G than in AML12. The immunofluorescence and genetic analyses showed that the increased cytotoxicity of niosomes resulted mainly from oxidative stress and slight apoptosis.

DISCUSSION

These results demonstrated that niosomal drug delivery systems could be a new potential formulation for minimizing MTX-related hepatotoxicity.

Synthesis and characterization of poly(3-hydroxybutyrate)/chitosan-graft poly (acrylic acid) conjugate hyaluronate for targeted delivery of methotrexate drug to colon cancer cells

Anti-cancer medications that are delivered specifically to the tumor site possess greater efficacy with less negative effects on the body. So, the current research relies on a novel method for intercalating the anticancer medication methotrexate in poly(3-hydroxybutyrate)/chitosan-graft poly (acrylic acid) conjugated with sodium hyaluronate. The graft copolymers were synthesized through persulfate-initiated grafting of acrylic acid onto a binary mixture of various amounts of chitosan and poly(3-hydroxybutyrate) (2/1, 1/1 and 1/2, w/w) using microwave irradiation. The graft copolymer was conjugated with sodium hyaluronate for targeted delivery of methotrexate drug specifically to colon cancer cell lines (Caco-2). The graft copolymers were characterized by many physical techniques. The maximum drug loading efficiency was observed in case of the graft copolymer/hyaluronate rich in chitosan content 69.7 ± 2.7 % (4.65 mg/g) with a sustained release about 98.6 ± 1.12 %, at pH 7.4. The findings of severe cytotoxicity having a value of the IC₅₀ of 11.7 μg/ml, a substantial proportion of apoptotic cells (67.88 %), and an elevated level of DNA breakage inside the treated Caco-2 cells verified the effective release of methotrexate from the loaded copolymer matrix. Besides, the high stability and biological activity of the released drug was exhibited through occurrence of greater increment of reactive oxygen species and effect on the extent of expression of genes connected to apoptosis and anti-oxidant enzymes within the treated cells. Ultimately, this system can be recommended as potent carrier for methotrexate administration to targeted cancerous cells in the colon.

Chlorpyrifos induces apoptosis and necroptosis via the activation of CYP450s pathway mediated by nuclear receptors in LMH cells

Chlorpyrifos (CPF), an organophosphorus pesticide, is detected commonly in environments, where it is thought to be highly toxic to non-target organisms. However, the mechanism of CYP450s pathway mediated by nuclear receptors on CPF-induced apoptosis and necroptosis at the cellular level and the effect of CPF on the cytotoxicity of the chicken hepatocarcinoma cell line (LMH) has also not been reported in detail. Therefore, this experiment aims to explore whether CPF can improve apoptosis and necroptosis in LMH cells by activating the nuclear receptors/CYP450s axis. LMH cells, the subject of this study, were exposed to 5 μg/mL, 10 μg/mL, and 15 μg/mL doses of CPF. With the increase of CPF concentration, the increase of nuclear receptor level led to the up-regulation of CYP450s activity. With the massive production of ROS, the expression of apoptotic pathway genes (Bax, Caspase9, and Caspase3) enhanced, while Bcl-2 expression dropped sharply. The expression of programmed necroptosis genes (RIPK1, RIPK3, and MLKL) heightened, and Caspase8 reduced considerably. In short, our data suggests that excessive activation of nuclear receptors and CYP450s induced by CPF promotes ROS production, which directs apoptosis and programmed necroptosis in LMH cells.

MicroRNA-122 overexpression promotes apoptosis and tumor suppressor gene expression induced by microcystin-leucine arginine in mouse liver

Microcystin-leucine arginine (MC-LR), an important hepatoxin, has the effect of promoting hepatocarcinogenesis. MicroRNA-122 (miR-122), an important tumor suppressor in liver, plays an important role in promoting cell apoptosis. Previous studies found that the expression of miR-122 was reduced after MC-LR exposure in liver. In this study, C57BL/6 mice were exposed to saline, negative control agomir, and MC-LR with or without miR-122 agomir transfection. The results indicated that MC-LR promoted the expressions of tumor suppressor genes and decreased the expressions of anti-apoptotic proteins B cell lymphoma-2 (Bcl-2) and Bcl-2-like 2 (Bcl-w), causing hepatocyte apoptosis. Under MC-LR exposure, miR-122 agomir transfection could further increase the expressions of tumor suppressor genes and the release of cytochrome-c (Cyt-c) and decrease the expressions of Bcl-2 and Bcl-w. In conclusion, miR-122 reduction can mitigate MC-LR-induced apoptosis to a certain extent, which in turn, it is likely to have contributed to MC-LR-induced hepatocarcinogenesis.

Targeting purine metabolism in ovarian cancer

Purine, an abundant substrate in organisms, is a critical raw material for cell proliferation and an important factor for immune regulation. The purine de novo pathway and salvage pathway are tightly regulated by multiple enzymes, and dysfunction in these enzymes leads to excessive cell proliferation and immune imbalance that result in tumor progression. Maintaining the homeostasis of purine pools is an effective way to control cell growth and tumor evolution, and exploiting purine metabolism to suppress tumors suggests interesting directions for future research. In this review, we describe the process of purine metabolism and summarize the role and potential therapeutic effects of the major purine-metabolizing enzymes in ovarian cancer, including CD39, CD73, adenosine deaminase, adenylate kinase, hypoxanthine guanine phosphoribosyltransferase, inosine monophosphate dehydrogenase, purine nucleoside phosphorylase, dihydrofolate reductase and 5,10-methylenetetrahydrofolate reductase. Purinergic signaling is also described. We then provide an overview of the application of purine antimetabolites, comprising 6-thioguanine, 6-mercaptopurine, methotrexate, fludarabine and clopidogrel. Finally, we discuss the current challenges and future opportunities for targeting purine metabolism in the treatment-relevant cellular mechanisms of ovarian cancer.

Photoactivation of Chemotherapeutic Agents with Cerenkov Radiation for Chemo-Photodynamic Therapy

Cerenkov radiation (CR) can be used as an internal light source in photodynamic therapy (PDT). Methotrexate (MTX) and paclitaxel (PTX), chemotherapeutic agents with wide clinical use, have characteristics of photosensitizers (PS). This work evaluates the possibility of photoexciting MTX and PTX with CR from ¹⁸F-FDG to produce reactive oxygen species (ROS) capable of inducing cytotoxicity. PTX did not produce ROS when excited by CR from ¹⁸F-FDG, so it is not useful for PDT. In contrast, MTX produces ¹O₂ (detected by ABMA) in amounts sufficient to significantly decrease the viability of the T47D cells. MTX solutions of 100 nM combined with ¹⁸F-FDG activities of 50 (1.85 MBq) and 100 μCi (3.7 MBq) produced a significant decrease in cell viability to (50.09 ± 4.95) and (47.96 ± 11.19)%, respectively, compared to MTX (66.29 ± 5.92)% and ¹⁸F-FDG (91.35 ± 7.00% for 50 μCi and 99.43 ± 11.03% for 100 μCi) alone. Using the CellRox Green reagent, the intracellular production of ROS was confirmed as the main mechanism of cytotoxicity. The results confirm the therapeutic potential of photoactivation with CR and the synergy of the combined treatment with chemotherapy + photodynamic therapy (CMT + PDT). The combination of chemotherapeutic agents with PS properties and β-emitting radiopharmaceuticals, previously approved for clinical use, will make it possible to shorten the evaluation stages of new CMT + PDT systems.

Mitochondria preserve an autarkic one-carbon cycle to confer growth-independent cancer cell migration and metastasis

Metastasis is the most common cause of death in cancer patients. Canonical drugs target mainly the proliferative capacity of cancer cells, which leaves slow-proliferating, persistent cancer cells unaffected. Metabolic determinants that contribute to growth-independent functions are still poorly understood. Here we show that antifolate treatment results in an uncoupled and autarkic mitochondrial one-carbon (1C) metabolism during cytosolic 1C metabolism impairment. Interestingly, antifolate dependent growth-arrest does not correlate with decreased migration capacity. Therefore, using methotrexate as a tool compound allows us to disentangle proliferation and migration to profile the metabolic phenotype of migrating cells. We observe that increased serine de novo synthesis (SSP) supports mitochondrial serine catabolism and inhibition of SSP using the competitive PHGDH-inhibitor BI-4916 reduces cancer cell migration. Furthermore, we show that sole inhibition of mitochondrial serine catabolism does not affect primary breast tumor growth but strongly inhibits pulmonary metastasis. We conclude that mitochondrial 1C metabolism, despite being dispensable for proliferative capacities, confers an advantage to cancer cells by supporting their motility potential.

Chemotherapeutic antifolates, such as methotrexate (MTX), impair cancer cell proliferation by inhibiting nucleotide synthesis. Here, the authors show that MTX sustains an autarkic mitochondrial one-carbon metabolism leading to serine synthesis to promote cancer cell migration and metastasis.

Anticancer evaluation of methotrexate and curcumin coencapsulated niosomes against colorectal cancer cell line

Aim: The aim of the present investigation was to develop niosomes containing both curcumin (CUR) and methotrexate (MTX). Also, the combinational effect of CUR and MTX in both free and niosomal forms on growth inhibition potential and induction of apoptosis in the HCT-116 cell line were exploited. Materials & methods: Niosomes were prepared by the thin-film hydration method and their physicochemical properties were determined by various techniques. Cellular uptake, cell apoptosis, wound healing and MTT assay were conducted to ascertain niosomes' feasibility for cancer therapy. Results: The combination of CUR and MTX in niosomal formulation showed more toxicity than their combination in free form. Conclusion: The nanocarrier-based approach was effective for the codelivery of CUR and MTX against cancer cells in vitro.

Activation of RSK2 upregulates SOX8 to promote methotrexate resistance in gestational trophoblastic neoplasia

Resistance to chemotherapy is frequently driven by aberrantly activated kinases in cancer. Herein, we characterized the global phosphoproteomic alterations associated with methotrexate (MTX) resistance in gestational trophoblastic neoplastic (GTN) cells. A total of 1111 phosphosites on 713 proteins were significantly changed, with highly elevated Ribosomal S6 Kinase 2 (RSK2) phosphorylation (pS227) observed in MTX-resistant GTN cells. Activation of RSK2 promoted cell proliferation and survival after MTX treatment in GTN cell models. Interestingly, RSK2 might play an important role in the regulation of reactive oxygen species (ROS) homeostasis, as manipulation of RSK2 activation affected ROS accumulation and SOX8 expression in GTN cells. In addition, overexpression of SOX8 partly rescued cell proliferation and survival in RSK2-depleted MTX-resistant GTN cells, suggesting that SOX8 might serve as a downstream effector of RSK2 to promote MTX resistance in GTN cells. Highly activated RSK2/SOX8 signaling was observed in MTX-resistant GTN specimens. Further, the RSK2 inhibitor BIX02565 effectively reduced SOX8 expression, induced ROS accumulation, and enhanced MTX-induced cytotoxicity in vitro and in vivo. Collectively, our findings suggested that RSK2 activation could promote MTX resistance via upregulating SOX8 and attenuating MTX-induced ROS in GTN cells, which may help to develop experimental therapeutics to treat MTX-resistant GTN.

Study on the effects of the different polar group of EPA-enriched phospholipids on the proliferation and apoptosis in 95D cells

EPA-enriched phosphatidylcholine (EPA-PC) and EPA-enriched phosphatidylethanolamine (EPA-PE) are newly identified marine phospholipids. The polar group of phospholipids is known to influence EPA-phospholipid activity. However, the differences in anti-tumor effects between EPA-PC and EPA-PE have not been reported. In this study, we evaluated the effects of two forms of EPA on the proliferation and apoptosis in the lung-cancer cell line 95D as well as possible molecular mechanisms. Our results showed that EPA-PC effectively inhibited proliferative activity and promoted apoptosis of 95D cells in a dose-dependent manner, while EPA-PE had no effect on cell proliferation, although it slightly promoted apoptosis. Western blot results showed that EPA-PC and EPA-PE upregulated the expression of PPARγ, RXRα, and PTEN, and downregulated the PI3K/AKT signaling pathway. Furthermore, EPA-PC and EPA-PE induced the expression of the pro-apoptotic gene, Bax, and reduced the expression of the anti-apoptotic gene, Bcl-xl. Additionally, EPA-PC and EPA-PE promoted the release of cytochrome c and activated the apoptotic enzyme-cleaved caspase-3. These data suggest that the anti-tumor effect of EPA-phospholipids may be exerted via a PPARγ-related mechanism. EPA-PC was more efficacious as compared to EPA-PE, which might be due to the different polar groups of phospholipids.

Insights into the Role of Oxidative Stress in Ovarian Cancer

Oxidative stress (OS) arises when the body is subjected to harmful endogenous or exogenous factors that overwhelm the antioxidant system. There is increasing evidence that OS is involved in a number of diseases, including ovarian cancer (OC). OC is the most lethal gynecological malignancy, and risk factors include genetic factors, age, infertility, nulliparity, microbial infections, obesity, smoking, etc. OS can promote the proliferation, metastasis, and therapy resistance of OC, while high levels of OS have cytotoxic effects and induce apoptosis in OC cells. This review focuses on the relationship between OS and the development of OC from four aspects: genetic alterations, signaling pathways, transcription factors, and the tumor microenvironment. Furthermore, strategies to target aberrant OS in OC are summarized and discussed, with a view to providing new ideas for clinical treatment.

Fenton-magnetic based therapy by dual-chemodrug-loaded magnetic hydroxyapatite against colon cancer

Fenton-based therapy is emerging as an effective and selective strategy against cancer. However, a low concentration of transition metal ions, insufficient endogenous H₂O_2, and a high level of antioxidant activity within the cancer cells have hindered the therapeutic efficacy of this strategy. To address these issues, in this study, the Fenton reagent (magnetic hydroxyapatite, mHAP) was accompanied with chemotherapy drugs (cisplatin (CDDP) and methotrexate (MTX)) and static magnetic field (SMF), in such a way to be a pH-, redox-, and magnetic-responsive nanoplatform. In vitro and in vivo experiments revealed higher toxicity of the final construct, MTX.CDDP@mHAP, toward colon cancer cells, as compared with that of free drugs. The most effective antitumor activity was observed as MTX.CDDP@mHAP-treated tumor cells were exposed to SMF (0.9 T) and no noticeable damage was observed in the normal cells and tissues. Active targeting by MTX and magnetic targeting by mHAP under magnetic field increased the tumor selectivity and enhanced the tumor site accumulation and cellular uptake of MTX.CDDP@mHAPs. The released iron ions within the cancer cells trigger the Fenton reaction while the release of chemotherapy drugs, reduction of intracellular glutathione, and application of SMF aggravated the Fenton reaction, subsequently leading to the generation of reactive oxygen species (ROS) and induction of apoptosis. Therefore, Fenton magnetic-based therapy-mediated by MTX.CDDP@mHAP could be considered as a promising strategy against colon cancer with high therapeutic efficiency and biosafety.

Daphnoretin induces reactive oxygen species-mediated apoptosis in melanoma cells

Research suggests that daphnoretin exhibits a diverse array of antitumor mechanisms and pharmacological activities. However, there is no definitive explanation for the antitumor mechanisms of daphnoretin in malignant melanoma. In the present study, MTT and colony formation assays demonstrated that daphnoretin significantly inhibited the proliferation of melanoma A375 and B16 cells. Following treatment with daphnoretin, apoptotic bodies were observed in A375 and B16 cells via Hoechst 33258 staining. Furthermore, western blot analysis revealed that the apoptosis-related proteins cleaved caspase-3, cleaved caspase-9, Bax, cytochrome c and apoptotic protease-activating factor 1 were significantly upregulated, while the expression levels of caspase-3, caspase-9 and Bcl-2 were downregulated in A375 and B16 cells. Flow cytometry and fluorescence microscopy revealed that daphnoretin induced higher levels of reactive oxygen species (ROS). Therefore, the results of the present study indicated that daphnoretin induced ROS-mediated mitochondria apoptosis in human (A375) and murine (B16) malignant melanoma cells.

Fabrication of methotrexate-loaded gold nanoconjugates and its enhanced anticancer activity in breast cancer

Methotrexate (MTX) is known antagonist of folic acid and widely used as an anti-cancer drug. The folate receptor (FR) and reduced folate carrier are mostly responsible for internalization of methotrexate in tumor cells. Mutation in reduced folate carrier (RFC) leads to resistance against MTX in various tumor cell lines including MDA-MB-231 breast cancer cells. To overcome the resistance of MTX, folate receptor targeted nanoparticles have been commonly used for targeting breast tumors. The aim of the study is to determine the ability of methotrexate gold nanoparticles (MTX-GNPs) in the induction of apoptosis and to explore the molecular changes at genomics and proteomics level. Different assays like cell viability assay, cell cycle analysis, apoptosis, real-time PCR and western blot were carried out to evaluate the anti-cancer effect of MTX-Gold NPs on MCF-7 and MDA-MB-231 cells. Our observations demonstrated the decrease in the percent viable cells after the treatment of MTX-GNPs, with an arrest in cell cycle at G0/G1 phase and a significant increase in apoptotic cell population and loss of mitochondrial membrane potential in MCF-7 and MDA-MB-231 cells. Folate receptor targeted MTX-GNPs showed significant cellular uptake in breast cancer cells along with significant down-regulation in expression of anti-apoptotic gene (Bcl-2) and up-regulation in expression of pro-apoptotic genes (Bax, Caspase-3, Caspase-9, APAF-1, p53). These results unveil the increased anti-cancer effect of MTX-GNPs in cancer cells.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02718-7.

The protective role of luteolin against the methotrexate-induced hepato-renal toxicity via its antioxidative, anti-inflammatory, and anti-apoptotic effects in rats

Methotrexate (MTX) is frequently used drug in treatment of cancer and autoimmune diseases. Unfortunately, MTX has many side effects including the hepato-renal toxicity. In this study, we hypothesized that Luteolin (Lut) exhibits protective effect against the MTX-induced hepato-renal toxicity. In order to investigate our hypothesis, the experiment was designed to examine the effect of exposure of male rats to MTX (20 mg/kg, i.p., at day 9) alone or together with Lut (50 mg/kg, oral for 14 days) compared to the control rats (received saline). The findings demonstrated that MTX treatment induced significant increases in the liver and kidney functions markers in serum samples including Aspartate transaminase (AST), Alanine transaminase (ALT), creatinine, urea and uric acid. MTX also mediated an oxidative stress expressed by elevated malondialdehyde (MDA) level and decreased level of reduced glutathione (GSH), antioxidant enzyme activities, and downregulation of the Nrf2 gene expression as an antioxidant trigger. Moreover, the inflammatory markers (NF-κB, TNF-α, and IL-1β) were significantly elevated upon MTX treatment. In addition, MTX showed an apoptotic response mediated by elevating the pro-apoptotic (Bax) and lowering the anti-apoptotic (Bcl-2) proteins. All of these changes were confirmed by the observed alterations in the histopathological examination of the hepatic and renal tissues. Lut exposure significantly reversed all the MTX-induced changes in the measured parameters suggesting its potential protective role against the MTX-induced toxicity. Finally, our findings concluded the antioxidative, anti-inflammatory and anti-apoptotic effects of Lut as a mechanism of its protective role against the MTX-induced hepato-renal toxicity in rats.

Effect of methotrexate on embryonal implantation: an experimental rat model

The aim of this study is to investigate the methotrexate (MTX) in rat embryonal implantation and its association with Glycodelin A (GdA) and Mucin-1 (MUC-1) expression. For this purpose, 32 pregnant rats were divided into four equal groups: non-pregnant rats in group I (n = 8, control) and pregnant rats in group III (n = 8) were injected intraperitoneal with single dose of normal saline, non-pregnant rats in group II (n = 8) and pregnant rats in group IV (n = 8) were given 0.2 mg i.m. injection of MTX before three months of pregnancy. The dams were killed on 5th day of gestation and uterine horn samples were removed. Following dissection and routine histological preparation, immunohistochemical analysis was carried out. During immunohistochemical examination of the tissue samples prepared from the control and experimental groups, a statistically significant difference was observed between the groups in the luminal-glandular-decidualized epithelium of the uterus with GdA and MUC-1. Finally, in light of our findings, MTX adversely affected the expression of two molecules in Wistar Albino rats embryonal implantation model.

DEHP induces neutrophil extracellular traps formation and apoptosis in carp isolated from carp blood via promotion of ROS burst and autophagy

Di (2-ethylhexyl) phthalate (DEHP), a widely spreading environmental endocrine disruptor, has been confirmed to adversely affect the development of animals and humans. The formation of neutrophil extracellular traps (NETs) termed NETosis, is a recently identified antimicrobial mechanism for neutrophils. Though previous researches have investigated inescapable role of the immunotoxicity in DEHP-exposed model, relatively little is known about the effect of DEHP on NETs. In this study, carp peripheral blood neutrophils were treated with 40 and 200 μmol/L DEHP to investigate the underlying mechanisms of DEHP-induced NETs formation. Through the morphological observation of NETs and quantitative analysis of extracellular DNA, we found that DEHP exposure induced NETs formation. Moreover, our results proved that DEHP could increase reactive oxygen species (ROS) levels, decrease the expression of the anti-autophagy factor (mTOR) and the anti-apoptosis gene Bcl-2, and increase the expression of pro-autophagy genes (Dynein, Beclin-1 and LC3B) and the pro-apoptosis factors (BAX, Fas, FasL, Caspase3, Caspase8, and Caspase9), thus promoting autophagy and apoptosis. These results indicate that DEHP-induced ROS burst stimulates NETs formation mediated by autophagy and increases apoptosis in carp neutrophils.

Bcl2 inhibitor ABT737 reverses the Warburg effect via the Sirt3-HIF1α axis to promote oxidative stress-induced apoptosis in ovarian cancer cells

AIMS

Compared to normal cells, tumor cells maintain higher concentrations of reactive oxygen species (ROS) to support proliferation, invasion, and metastasis. Chemotherapeutic drugs often induce tumor cell apoptosis by increasing intracellular ROS concentrations to highly toxic levels. ABT737, which inhibits the apoptosis regulator B cell lymphoma 2 (Bcl2), increases the sensitivity of ovarian cancer cells to chemotherapeutic drugs by regulating the glucose metabolism, but the underlying mechanisms remain unclear. Therefore, we aimed to determine whether ABT737 promoted H₂O₂-induced tumor cell apoptosis by reversing glycolysis in ovarian cancer cells.

MAIN METHODS

SKOV3 ovarian cancer cells were treated with H₂O₂, ABT737, or both. Cell viability was compared using methyl thiazolyl tetrazolium (MTT), and flow cytometry was used to detect differences in apoptosis, ROS, and mitochondrial membrane potential. The relative expression levels of proteins associated with apoptosis and the glucose metabolism were measured using immunoblotting. Finally, glucose uptake and lactate secretion were measured using kits and compared.

KEY FINDINGS

ABT737 downregulated proteins associated with glucose uptake (GLUT1) and glycolysis (LHDA, PKM2 and HK2) via the Sirt3-HIF1α axis, reducing glucose uptake and lactate secretion in SKOV3 cells. This reversed glycolysis in the tumor cells, and promoted H₂O₂-induced apoptosis.

SIGNIFICANCE

The Bcl2 inhibitor ABT737 enhanced the anti-tumor effect of oxidative stress by reversing the Warburg effect in ovarian cancer cells, providing powerful theoretical support for further clinical applications of Bcl2 inhibitors.

Raman-tag labelled Au@ZIF-8 for cell metabolism monitoring in vitro

 Cell metabolism decides the state of cells in division, differentiation and growth, maintaining intracellular balance. Monitoring the metabolic behavior of cells is of great significance to study the development of diseases in cell levels. Surface-enhanced Raman spectroscopy (SERS) is a powerful technique to detect and quantify analytes in extremely low concentration. Combined with SRES technology, we can monitor the concentration of metabolites in live cells and thus study the biological behavior of cells. In this work, Raman-tag labelled Au@ZIF-8 nanoparticles were used to monitor the distribution of reactive oxygen species (ROS) in SKOV3 cells. With the help of the ultrasensitive Raman enhancement material, the distribution of ROS in SKOV3 cells was mapped, the results were further confirmed in the fluorescent images. The SERS platform provides an ultrasensitive monitoring method of ROS distribution, which may offer an opportunity for real-time monitoring the cell metabolism in the cell biology applications.

Active Monomer RTR-1 Derived from the Root of Rhodomyrtus t omentosa Induces Apoptosis in Gastric Carcinoma Cells by Inducing ER Stress and Inhibiting the STAT3 Signaling Pathway

Purpose

Rhodomyrtus tomentosa, a flowering plant from the Myrtaceae family, is considered  an antitumour substance with versatile biological and pharmacological activities. RTR-1 is an active monomer purified from the root of Rhodomyrtus tomentosa. However, the detail of mechanism involving in RTR-1 anti-cancer activity remains to be elucidated, and the effect on gastric cancer cells is unknown.

Methods

Cell proliferation was determined by MTT and clone formation assay. The effect of RTR-1 on cell cycle distribution and apoptosis was analysed utilizing flow cytometry, respectively. Moreover, Western blotting was used to detect the expression of cell cycle- and apoptosis-related protein.

Results

Based on MTT and clone formation assay, we noticed that RTR-1 inhibited the proliferation of gastric carcinoma (BGC823 and SGC7901) cells in a dose- and time-dependent manner. Furthermore, the results of flow cytometry and Western blotting showed that RTR-1 induced cell cycle arrest in the G2/M phase through the ATM-Chk2-p53-p21 signaling pathway and induced cell apoptosis by inhibiting the signal transducers and activators of transcription 3 (STAT3) pathway and activating the endoplasmic reticulum stress (ER stress) pathway.

Conclusion

Taken together, these results demonstrate that RTR-1 induces cell cycle arrest and promotes apoptosis in gastric carcinoma, indicating its potential application for gastric cancer therapy.

Histopathological and biochemical alterations of the parotid gland induced by experimental hypothyroidism in adult male rats and the possible therapeutic effect of Nigella sativa oil

Thyroid hormones are essential for metabolic rate regulation and play a role on the integrity of the salivary glands. Nigella sativa is a widely used plant in medicine. This study aimed to evaluate the effect of Nigella sativa oil (NSO) on the hypothyroidism-induced parotid gland pathological alterations. Rats were divided into four groups: control group, hypothyroid group: received daily oral carbimazole for 3 weeks, hypothyroid-NSO group: NSO was orally given for 4 weeks after hypothyroidism induction and NSO group: administrated NSO only for 4 weeks. After 7 weeks, all rats were sacrificed, serum thyroid hormones were estimated, and parotid glands were assessed by histopathological, immunohistochemical, ultrastructural and morphometric analyses. Hypothyroid group showed a significant decrease in thyroid hormones with increase in thyroid-stimulating hormone (TSH) levels and decrease in body and parotid weights compared to the control rats that were improved with NSO treatment. Sections of the hypothyroid group showed fibrosis, acinar cytoplasmic vacuolations, vascular congestion, ductal dilatation, wide intercellular canaliculi, nuclear pyknosis and decreased number of secretory granules. Also, there were decreased B-cell lymphoma 2 (Bcl-2) and increased p53, Bcl-2 Associated X (Bax) and alpha-smooth muscle actin (α-SMA) immune-expressions; with decreased Bax/ Bcl-2 ratio that all were attenuated by NSO. NSO ameliorates hypothyroidism-induced parotid changes by altering p53, Bax and Bcl-2 pathway.