Selenocystine induces S-phase arrest and apoptosis in human breast adenocarcinoma MCF-7 cells by modulating ERK and Akt phosphorylation

Recent Insights into the Roles of PEST-Containing Nuclear Protein

PEST-containing nuclear protein (PCNP), a short-lived small nuclear protein with 178 amino acids, is a nuclear protein containing two PEST sequences. PCNP is highly expressed in several malignant tumors such as cervical cancer, rectal cancer, and lung cancer. It is also associated with cell cycle regulation and the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and Wnt signaling pathways during tumor growth. The present article discuss how PCNP regulates the PI3K/AKT/mTOR and Wnt signaling pathways and related proteins, and the ubiquitination of PCNP regulates tumor cell cycle as well as the progress of the application of PCNP in the pathophysiology and treatment of colon cancer, human ovarian cancer, thyroid cancer, lung adenocarcinoma and oral squamous cell carcinoma. The main relevant articles were retrieved from PubMed, with keywords such as PEST-containing nuclear protein (PCNP), cancer (tumor), and signaling pathways as inclusion/exclusion criteria. Relevant references has been included and cited in the manuscript.

Exposure to Selenomethionine and Selenocystine Induces Redox-Mediated ER Stress in Normal Breast Epithelial MCF-10A Cells

Selenium is an essential trace element co-translationally incorporated into selenoproteins with important biological functions. Health benefits have long been associated with selenium supplementation. However, cytotoxicity is observed upon excessive selenium intake. The aim of this study is to investigate the metabolic pathways underlying the response to the selenium-containing amino acids selenomethionine and selenocysteine in a normal human breast epithelial cell model. We show that both selenomethionine and selenocystine inhibit the proliferation of non-cancerous MCF-10A cells in the same concentration range as cancerous MCF-7 and Hela cells, which results in apoptotic cell death. Selenocystine exposure in MCF-10A cells caused a severe depletion of free low molecular weight thiols, which might explain the observed upregulation of the expression of the oxidative stress pathway transcription factor NRF2. Both selenomethionine and selenocystine induced the expression of target genes of the unfolded protein response (GRP78, ATF4, CHOP). Using a redox-sensitive fluorescent probe targeted to the endoplasmic reticulum (ER), we show that both selenoamino acids shifted the ER redox balance towards an even more oxidizing environment. These results suggest that alteration of the redox state of the ER may disrupt protein folding and cause ER stress-induced apoptosis in MCF-10A cells exposed to selenoamino acids.

Enhancing cisplatin efficacy in hepatocellular carcinoma with selenocystine: The suppression of DNA repair and inhibition of proliferation in hepatoma cells

Cisplatin (cDDP) is a crucial chemotherapy drug for treating various cancers, including hepatocellular carcinoma (HCC). However, its effectiveness is often hindered by side effects and drug resistance. Selenocystine (SeC) demonstrates potential as an anticancer agent, particularly by inhibiting DNA repair mechanisms. This study explored the synergistic potential of SeC combined with cDDP for treating HCC. Our results show that SeC pretreatment followed by cDDP significantly suppresses HCC cell proliferation more effectively than either treatment alone, with minimal toxicity to normal liver cells. The combination induces significant DNA damage by inhibiting homologous recombination (HR) and non-homologous end joining (NHEJ) pathways. Xenograft experiments confirmed that the combined therapy strongly inhibits tumor growth. SeC boost the effectiveness of cDDP by amplifying DNA damage and inhibiting DNA repair, presenting a promising approach to enhancing liver cancer treatment.

Inhibition of the thioredoxin system for radiosensitization therapy of cancer

Radiotherapy (RT) stands as a cornerstone in the clinical armamentarium against various cancers due to its proven efficacy. However, the intrinsic radiation resistance exhibited by cancer cells, coupled with the adverse effects of RT on normal tissues, often compromises its therapeutic potential and leads to unwanted side effects. This comprehensive review aims to consolidate our understanding of how radiosensitizers inhibit the thioredoxin (Trx) system in cellular contexts. Notable radiosensitizers, including gold nanoparticles (GNPs), gold triethylphosphine cyanide ([Au(SCN) (PEt3)]), auranofin, ceria nanoparticles (CONPs), curcumin and its derivatives, piperlongamide, indolequinone derivatives, micheliolide, motexafin gadolinium, and ethane selenide selenidazole derivatives (SeDs), are meticulously elucidated in terms of their applications in radiotherapy. In this review, the sensitization mechanisms and the current research progress of these radiosensitizers are discussed in detail, with the overall aim of providing valuable insights for the judicious application of Trx system inhibitors in the field of cancer radiosensitization therapy.

5-Nitrobenzo[c][1, 2, 5]selenadiazole as therapeutic agents in the regulation of oxidative stress and inflammation induced by influenza A(H1N1)pdm09 in vitro and in vivo

Currently, various problems are being faced in the treatment of influenza, so the development of new safe and effective drugs is crucial. Selenadiazole, an important component of selenium heterocyclic compounds, has received wide attention for its biological activity. This study aimed to verify the antiviral activity of 5-nitrobenzo[c][1,2,5]selenadiazole (SeD-3) in vivo and in vitro. The cell counting kit-8 assay and observation of cytopathic effect verified that SeD-3 could improve the survival of influenza A(H1N1)pdm09-infected Madin-Darby canine kidney cells. Polymerase chain reaction quantification and neuraminidase assay showed that SeD-3 could inhibit the proliferation of H1N1 virus. The time of addition assay demonstrated that SeD-3 may have a direct effect on virus particles and block some stages of H1N1 life cycle after virus adsorption. Cell cycle, JC-1, Annexin V, and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling-4',6-diamidino-2-phenylindole (TUNEL-DAPI) assays showed that SeD-3 inhibited H1N1 infection-induced apoptosis. Cytokine detection demonstrated SeD-3 inhibited the production of proinflammatory factors after infection, including tumor necrosis factor-α (TNF-α), TNF-β, interferon-γ, interleukin 12 (IL-12), and IL-17F. In vivo experiments suggested that the pathological damage in the lungs was significantly alleviated after treatment with SeD-3 by hematoxylin and eosin staining. The TUNEL assay of lung tissues indicated that SeD-3 inhibited DNA damage during H1N1 infection. Immunohistochemical assays were performed to further explore the mechanism that SeD-3 inhibited H1N1-induced apoptosis via reactive oxygen species-mediated MAPK, AKT, and P53 signaling pathways. In conclusion, SeD-3 may become a new potential anti-H1N1 influenza virus drug due to its antiviral and anti-inflammatory activity.

Selenocystine-Derived Label-Free Fluorescent Schiff Base Nanocomplex for siRNA Delivery Synergistically Kills Cancer Cells

Chemo and siRNA synergic treatments for tumors is a promising new therapeutic trend. Selenocystine, a selenium analog of cysteine, has been considered a potential antitumor agent due to its redox perturbing role. In this study, we developed a nanocarrier for siRNA based on a selenocystine analog engineered polyetherimide and achieved traceable siRNA delivery and the synergic killing of tumor cells. Notably, we applied the label-free Schiff base fluorescence mechanism, which enabled us to trace the siRNA delivery and to monitor the selenocystine analogs' local performance. A novel selenocystine-derived fluorescent Schiff base linker was used to crosslink the polyetherimide, thereby generating a traceable siRNA delivery vehicle with green fluorescence. Moreover, we found that this compound induced tumor cells to undergo senescence. Together with the delivery of a siRNA targeting the anti-apoptotic BCL-xl/w genes in senescent cells, it achieved a synergistic inhibition function by inducing both senescence and apoptosis of tumor cells. Therefore, this study provides insights into the development of label-free probes, prodrugs, and materials towards the synergic strategies for cancer therapy.

Silver(I) complexes containing diclofenac and niflumic acid induce apoptosis in human-derived cancer cell lines

We investigated the anti-cancer activity of [Ag(μ-dicl)]_n 1 and [AgH(nif)₂] 2 complexes against human cancer cell lines (MCF-7, HT-29, and HepG2) and mouse fibroblast (3T3-L1) cell line. Anti-proliferative activity was monitored by XTT cell viability and LDH leakage assays. Cell death mode was evaluated by multi-caspase activity, annexin V cytofluorimetric, MMP, cell cycle arrest, and ROS generation assays. Antioxidant capacity was evaluated on SOD, GPx, GR, and CAT enzymes. The XTT and LDH assay results showed that both complexes exhibited strong cytotoxicity against the tested cancer cell lines. The apoptotic mechanisms of the complexes were demonstrated by loss of MMP and increase in phosphatidylserine translocation, sub-G1 phase, and multi-caspase activity. Besides, both complexes induced the oxidative stress in MCF-7 cells by decreasing the activity of GPx, GR, and CAT enzymes. In conclusion, both Ag(I) complexes, especially 1, warrant for further in vivo evaluation as a new alternative in cancer treatment.HighlightsAg(I) complexes inhibited cell proliferation and induced LDH leakage in human cancer cell lines.Ag(I) complexes induced apoptosis through MMP disruption and ROS generation.Ag(I) complexes mimicked the multi-caspase activity.Ag(I) complexes increased the accumulation of sub-G1 phase.Ag(I) complexes inhibited the activity of antioxidant system enzymes.

An overview on breast cancer genetics and recent innovations: Literature survey

Breast cancer is one of the leading cancers nowadays. The genetical mechanism behind breast cancer development is an intricate one. In this review, the genetical background of breast cancer, particularly BRCA 1 and BRCA 2 had been included. Moreover, to summarize the genetics of breast cancer, the recent and ongoing preclinical and clinical studies on the treatment of BRCA-associated breast cancer had also been included. A prime knowledge is that the BRCA gene is the basis of breast cancer risk. How it mediates cell proliferation and associated mechanisms are reviewed here. BRCA 1 gene can influence all phases of the cell cycle and regulate cell cycle progression. BRCA 1 gene can also respond to DNA damages and induce responsive mechanisms. The action of the BRCA gene on associated protein has a wide consideration in breast cancer development. Heterogeneity in breast cancer makes them a fascinating and challenging stream to diagnose and treat. Several clinical therapies are available for breast cancer treatments. Chemotherapy, endocrine therapy, radiation therapy and immunotherapy are the milestones in the cancer treatments. Ral binding protein 1 is a promising target for breast cancer treatment and the platinum-based chemotherapies are the other remarkable fields. In immunotherapy, the usage of anti-programmed death (PD)-1 antibody is a new class of cancer immunotherapy that hinders immune effecter inhibition and potentially expanding preexisting anticancer immune responses. Breast cancer genetics and treatment strategies are crucial in escalating survival rates.

Norcantharidin induces G2/M arrest and apoptosis via activation of ERK and JNK, but not p38 signaling in human renal cell carcinoma ACHN cells

Renal cell carcinoma (RCC) is generally acknowledged as the most resistant primary malignancy unresponsive to conventional radiotherapy and chemotherapy treatments. Norcantharidin (NCTD), a therapeutic compound derived from medicinal plants, has been shown to trigger apoptosis, as well as antimetastatic and antioxidant activities in several tumor cells. However, NCTD's mechanism of antitumor activity in the RCC cell line remains unclear. In this study, we report that NCTD led to a time- and dose-dependent inhibition of cell proliferation. It had also markedly induced apoptosis and G2/M phase cell cycle arrest in a dose-dependent manner by decreasing the expressions of pro-caspase-3, pro-caspase-9, cyclin B1, and pCDC25C while increasing active caspase-3, cleaved-PARP, P21, and pCDC2 levels. Interestingly, NCTD treatment provoked the phosphorylation of extracellular-regulated protein kinase (ERK) and c-Jun-N-terminal kinase (JNK), but not of p38 MAPK. Moreover, SCH772984 and SP600125, ERK and JNK inhibitors, respectively, could partially abolish NCTD-induced apoptosis and G2/M phase cell cycle arrest. Collectively, these findings suggest that NCTD might activate JNK and ERK signaling pathways, consequently inducing apoptosis and G2/M arrest through the modulation of related proteins. This study provided evidence that NCTD is a promising therapeutic drug for the treatment of RCC.

Cytotoxicity of black phosphorus quantum dots on lung-derived cells and the underlying mechanisms

Black phosphorus quantum dots (BP-QDs) are a new type of zero-dimensional (0D) nanomaterial that has been widely used due of their superior properties in many biomedical fields, but limited studies have focused on the biocompatibility of BP-QDs, particularly in the respiratory system. In this study, we investigated the potential lung cell toxicity of BP-QDs in vitro. Two human lung-derived cells, A549 and Beas-2B, were treated with 5∼20 μg/mL BP-QDs for 24 h. The results showed that BP-QDs triggered significant lung cell toxicity, including a dose-dependent decrease in cell viability, lactate dehydrogenase (LDH) leakage, cell shape changes, cellular oxidative stress and cell cycle arrest. In addition, pretreatment with the classical phagocytosis inhibitor cytochalasin D (Cyto D) alleviated the decrease in cell viability and LDH leakage induced by BP-QDs. In contrast, BP-QDs induced the production of cellular reactive oxygen species (ROS) and decreases in the glutathione level, whereas the ROS scavenger N-acetyl-L-cysteine (NAC) could protect A549 and Beas-2B cells from BP-QD-induced cellular oxidative stress. Taken together, the results from this study indicate that the potential toxic effects and mechanisms of BP-QDs in two different human lung cells should be considered to evaluate the lung cell safety of BP-QDs.

Attenuation of Lipopolysaccharide-Induced Acute Lung Injury by Hispolon in Mice, Through Regulating the TLR4/PI3K/Akt/mTOR and Keap1/Nrf2/HO-1 Pathways, and Suppressing Oxidative Stress-Mediated ER Stress-Induced Apoptosis and Autophagy

The anti-inflammatory effect of hispolon has identified it as one of the most important compounds from Sanghuangporus sanghuang. The research objectives were to study this compound using an animal model by lipopolysaccharide (LPS)-induced acute lung injury. Hispolon treatment reduced the production of the pro-inflammatory mediator NO, TNF-α, IL-1β, and IL-6 induced by LPS challenge in the lung tissues, as well as decreasing their histological alterations and protein content. Total cell number was also reduced in the bronchoalveolar lavage fluid (BALF). Moreover, hispolon inhibited iNOS, COX-2 and IκB-α and phosphorylated IKK and MAPK, while increasing catalase, SOD, GPx, TLR4, AKT, HO-1, Nrf-2, Keap1 and PPARγ expression, after LPS challenge. It also regulated apoptosis, ER stress and the autophagy signal transduction pathway. The results of this study show that hispolon regulates LPS-induced ER stress (increasing CHOP, PERK, IRE1, ATF6 and GRP78 protein expression), apoptosis (decreasing caspase-3 and Bax and increasing Bcl-2 expression) and autophagy (reducing LC3 I/II and Beclin-1 expression). This in vivo experimental study suggests that hispolon suppresses the LPS-induced activation of inflammatory pathways, oxidative injury, ER stress, apoptosis and autophagy and has the potential to be used therapeutically in major anterior segment lung diseases.

Micronutrients Selenomethionine and Selenocysteine Modulate the Redox Status of MCF-7 Breast Cancer Cells

Selenium is a micronutrient which is found in many foods, with redox status modulation activity. Our aim was to evaluate the effects of two chemical forms of selenoamino acids, Seleno-L-methionine and Seleno-L-cystine (a diselenide derived from selenocysteine), at different concentrations on cell viability, hydrogen peroxide production, antioxidant enzymes, UCP2 protein expression, as well as lipid and protein oxidative damage in MCF-7 breast cancer cells. Results showed that Seleno-L-methionine did not cause an increase in hydrogen peroxide production at relatively low concentrations, accompanied by a rise in the antioxidant enzymes catalase and MnSOD, and UCP2 protein expression levels. Furthermore, a decrease in protein and lipid oxidative damage was observed at 10 µM concentration. Otherwise, Seleno-L-cystine increased hydrogen peroxide production from relatively low concentrations (100 nM) to a large increase at high concentrations. Moreover, at 10 µM, Seleno-L-cystine decreased UCP2 and MnSOD protein expression. In conclusion, the chemical form of selenoamino acid and their incorporation to selenoproteins could affect the regulation of the breast cancer cell redox status. Taken together, the results obtained in this study imply that it is important to control the type of selenium-enriched nutrient consumption, taking into consideration their composition and concentration.

Sulforaphane regulates apoptosis- and proliferation‑related signaling pathways and synergizes with cisplatin to suppress human ovarian cancer

Ovarian cancer is currently the most life‑threatening type of gynecological malignancy with limited treatment options. Therefore, improved targeted therapies are required to combat ovarian cancer across the world. Sulforaphane is found in raw cruciferous vegetables. The chemotherapeutic and anti‑carcinogenic properties of sulforaphane have been demonstrated, however, the underlying mechanisms remain to be fully elucidated, particularly in ovarian cancer. In the present study, the possibility of repurposing sulforaphane as an anti‑ovarian cancer agent was examined. Cell viability and colony formation assay were used to test the anticancer efficiency of sulforaphane. Then wound healing assay, migration assay, cell cycle and apoptosis assays were used to detect how the drug worked on the cells. The mechanism of sulforaphane was investigated by western blot analysis. It was found that sulforaphane effectively suppressed the progression of human ovarian cancer cell proliferation, migration and cell cycle, and promoted apoptosis. Sulforaphane inhibited multiple cancer‑associated signaling pathways, including B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein, cytochrome c, Caspase‑3, phosphorylated AKT, phosphorylated nuclear factor‑κB, P53, P27, Cyclin‑D1 and cMyc, and reduced the expression levels of human epidermal growth factor receptor 2 in human ovarian cancer cells. Sulforaphane synergized with cisplatin to suppress the cancer cell proliferation and enhance ovarian cancer cell apoptosis. Xenograft experiments in vivo confirmed that sulforaphane effectively suppressed tumor growth by inhibiting ovarian cancer cell proliferation through targeting tumor‑related signals. The results indicated that sulforaphane may be repurposed as an effective anti‑ovarian cancer agent, with further preclinical or clinical investigations required.

The first examples of multiply bonded dirhenium(iii,ii) paramagnetic complexes containing nitrobenzoate ligands: spectroscopic, structural, cytotoxicity and computational studies

4-Nitrobenzoic acid, 3-nitrobenzoic acid and 4'-nitro[1,1'-biphenyl]-4-carboxylic acid react with the multiply bonded paramagnetic dirhenium(iii,ii) complex Re₂(μ-O₂CCH₃)Cl₄(μ-Ph₂PCH₂PPh₂)₂ (1) in refluxing ethanol to afford the paramagnetic substitution products of the type Re₂(μ-L)Cl₄(μ-Ph₂PCH₂PPh₂)₂, where L represents the nitrobenzoate ligands [L = 4-nitrobenzoate, 2; 3-nitrobenzoate, 3; 4'-nitro[1,1'-biphenyl]-4-carboxylate, 4]. These are the first examples of paramagnetic dirhenium complexes containing nitrobenzoate ligands. The spectral (UV-vis, IR, and EPR) and electrochemical properties of the complexes are described. The identity of 4 has been established by single-crystal X-ray structure determination (Re-Re distance of 2.2967(4) Å). The electronic structures of the complexes were scrutinized by density functional theory (DFT) calculations. X-band EPR spectral measurements along with the DFT analysis show that the unpaired electron resides in the metal-metal δ* antibonding orbital. The complexes were also screened in vitro for their antiproliferative properties against the human breast cancer cell line MCF-7 by the MTT assay. Flow cytometry analysis showed that the complexes arrested the sub-G0/G1 phase.

Selenides and Diselenides: A Review of Their Anticancer and Chemopreventive Activity

Selenium and selenocompounds have attracted the attention and the efforts of scientists worldwide due to their promising potential applications in cancer prevention and/or treatment. Different organic selenocompounds, with diverse functional groups that contain selenium, have been reported to exhibit anticancer and/or chemopreventive activity. Among them, selenocyanates, selenoureas, selenoesters, selenium-containing heterocycles, selenium nanoparticles, selenides and diselenides have been considered in the search for efficiency in prevention and treatment of cancer and other related diseases. In this review, we focus our attention on the potential applications of selenides and diselenides in cancer prevention and treatment that have been reported so far. The around 80 selenides and diselenides selected herein as representative compounds include promising antioxidant, prooxidant, redox-modulating, chemopreventive, anticancer, cytotoxic and radioprotective compounds, among other activities. The aim of this work is to highlight the possibilities that these novel organic selenocompounds can offer in an effort to contribute to inspire medicinal chemists in their search of new promising derivatives.

Norcantharidin induce apoptosis in human nasopharyngeal carcinoma through caspase and mitochondrial pathway

While Nasopharyngeal carcinoma (NPC) is uncommon in western countries, it is endemic in Southeast Asia and Southern China. Previous study of norcantharidin (NCTD), isolated from blister beetles, has proved its anticancer effect on various tumors. However, the effect of NCTD in NPC has never been studied. The purpose of this study is to inspect the suppression activity of NCTD on NPC, along with the underlying mechanism. NPC cell line NPC-BM was treated with NCTD. NCTD remarkably inhibited proliferation and induce apoptosis in NPC-BM cell. Activation of caspase-3, -8, -9 was observed through western blotting. The expression of antiapoptotic protein Bcl-XL was significantly reduced, but expression of proapoptotic protein Bak was increased after treatment of NCTD. The cytotoxic effect of NCTD on NPC-BM cell is mainly due to apoptosis, mediated by caspase and mitochondrial pathway. These results suggested that NCTD could be a potential anticancer agent for NPC.

EGR1 mediates miR-203a suppress the hepatocellular carcinoma cells progression by targeting HOXD3 through EGFR signaling pathway

EGR1 plays a critical role in cancer progression. However, its precise role in hepatocellular carcinoma has not been elucidated. In this study, we found that the overexpression of EGR1 suppresses hepatocellular carcinoma cell proliferation and increases cell apoptosis by binding to the miR-203a promoter sequence. In addition, we investigated the function of miR-203a on progression of HCC cells. We verified that the effect of overexpression of miR-203a is consistent with that of EGR1 in regulation of cell progression. Through bioinformatic analysis and luciferase assays, we confirmed that miR-203a targets HOXD3. Silencing HOXD3 could block transition of the G2/M phase, increase cell apoptosis, decrease the expression of cell cycle and apoptosis-related proteins, EGFR, p-AKT, p-ERK, CCNB1, CDK1 and Bcl2 by targeting EGFR through EGFR/AKT and ERK cell signaling pathways. Likewise, restoration of HOXD3 counteracted the effects of miR-203a expression.In conclusion, our findings are the first to demonstrate that EGR1 is a key player in the transcriptional control of miR-203a, and that miR-203a acts as an anti-oncogene to suppress HCC tumorigenesis by targeting HOXD3 through EGFR-related cell signaling pathways.

Recent advances in the mechanism of selenoamino acids toxicity in eukaryotic cells

Selenium is an essential trace element due to its incorporation into selenoproteins with important biological functions. However, at high doses it is toxic. Selenium toxicity is generally attributed to the induction of oxidative stress. However, it has become apparent that the mode of action of seleno-compounds varies, depending on its chemical form and speciation. Recent studies in various eukaryotic systems, in particular the model organism Saccharomyces cerevisiae, provide new insights on the cytotoxic mechanisms of selenomethionine and selenocysteine. This review first summarizes current knowledge on reactive oxygen species (ROS)-induced genotoxicity of inorganic selenium species. Then, we discuss recent advances on our understanding of the molecular mechanisms of selenocysteine and selenomethionine cytotoxicity. We present evidences indicating that both oxidative stress and ROS-independent mechanisms contribute to selenoamino acids cytotoxicity. These latter mechanisms include disruption of protein homeostasis by selenocysteine misincorporation in proteins and/or reaction of selenols with protein thiols.

Chiral ruthenium(ii) complex as potent radiosensitizer of 125I through DNA-damage-mediated apoptosis

A chiral ruthenium(ii) complex, Λ-[Ru(bpy)₂(o-tFMPIP)] (ClO₄)₂ (o-tFMPIP = 2′-trifluoromethylphenyl) imidazo [4,5-f][1,10]phenanthroline, was prepared and evaluated for its enhancement of the radiosensitivity of ¹²⁵I seeds. The synthetic Ru(ii) complex, LR042, effectively enhanced growth inhibition against HepG2 human hepatocellular liver carcinoma cells induced by ¹²⁵I seeds and consequently effectively promoted the apoptosis of tumor cells with increasing level of cleave-caspase-3. Furthermore, the results of immunofluorescence indicated that LR042 enhanced the phosphorylation of H2AX by ¹²⁵I seeds vigorously in response to damaged DNA. LR042 improved DNA damage induced by ¹²⁵I seeds, which resulted in apoptosis through the activation of the p53/AKT signal. In conclusion, synthetic LR042 can be further developed as a potential radiosensitizer of ¹²⁵I seed radiotherapy for cancer therapy.

Synthetic LR042 can be further developed as a radiosensitizer of ¹²⁵I by inducing DNA-damage-mediated apoptosis for cancer therapy.

Overcoming blood–brain barrier by HER2-targeted nanosystem to suppress glioblastoma cell migration, invasion and tumor growth

Herein we synthesize an HER2 antibody-conjugated selenium nanoparticle platform can efficiently deliver both therapeutic agents and diagnostic agents (superparamagnetic iron oxide nanoparticles) across the BBB into the tumor tissues and enhances their effects on brain tumor treatment and MR imaging.

Nimbolide induces apoptosis in human nasopharyngeal cancer cells

Nasopharyngeal carcinoma (NPC), a tumor arising from epithelial cells that cover the surface and line the nasopharynx, is a rare malignancy worldwide but is prevalent in certain geographical areas, such as Southern Asia (Taiwan, Hong Kong, Singapore, Malaysia, and Southern China) and North Africa. Despite advances in diagnostic techniques and improvements in treatment modalities, the prognosis of NPC remains poor. Therefore, an effective chemotherapy regimen that enhances tumor sensitivity to chemotherapeutics is urgently required. Nimbolide, derived from Azadirachta indica, has a wide range of beneficial effects, including anti-inflammatory and anticancer properties. The present study evaluated the antitumor activity of nimbolide in NPC cells and its underlying mechanisms. Our results revealed that the treatment of HONE-1 cells with nimbolide potently inhibited cell viability. Moreover, nimbolide led to cell cycle arrest, which subsequently activated caspase-3, -8, and -9 and poly (ADP-ribose) polymerase to induce cell apoptosis. Moreover, nimbolide induced Bik, Bax, and t-Bid expression in HONE-1 cells. The results indicated that nimbolide induces apoptosis through the modulation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathways. Nimbolide induces apoptosis in human NPC cells and is a potential chemopreventive agent against NPC proliferation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2085-2092, 2017.

Selenocysteine induces apoptosis in human glioma cells: evidence for TrxR1-targeted inhibition and signaling crosstalk

Thioredoxin reductase (TrxR) as a selenium (Se)-containing antioxidase plays key role in regulating intracellular redox status. Selenocystine (SeC) a natural available Se-containing amino acid showed novel anticancer potential through triggering oxidative damage-mediated apoptosis. However, whether TrxR-mediated oxidative damage was involved in SeC-induced apoptosis in human glioma cells has not been elucidated yet. Herein, SeC-induced human glioma cell apoptosis was detected in vitro, accompanied by PARP cleavage, caspases activation and DNA fragmentation. Mechanically, SeC caused mitochondrial dysfunction and imbalance of Bcl-2 family expression. SeC treatment also triggered ROS-mediated DNA damage and disturbed the MAPKs and AKT pathways. However, inhibition of ROS overproduction effectively attenuated SeC-induced oxidative damage and apoptosis, and normalized the expression of MAPKs and AKT pathways, indicating the significance of ROS in SeC-induced apoptosis. Importantly, U251 human glioma xenograft growth in nude mice was significantly inhibited in vivo. Further investigation revealed that SeC-induced oxidative damage was achieved by TrxR1-targeted inhibition in vitro and in vivo. Our findings validated the potential of SeC to inhibit human glioma growth by oxidative damage-mediated apoptosis through triggering TrxR1-targeted inhibition.

Celastrol-induced apoptosis in human nasopharyngeal carcinoma is associated with the activation of the death receptor and the mitochondrial pathway

Nasopharyngeal carcinoma (NPC) is a cancer that arises from the epithelium of the nasopharynx. Celastrol is a triterpene from traditional Chinese medicine, which demonstrates anti-proliferative activity in several cancer cell lines. However, the effect of celastrol on human NPC and the underlying mechanisms are not yet elucidated. The present study investigated whether celastrol induced apoptosis in human NPC cells, and the underlying molecular mechanisms were explored. Celastrol decreased the viability of HONE-1 and NPC-039 cells in a dose-dependent manner, and induced G1 and G2/M phase cell cycle arrest. The level of cleaved caspases-3, -8, and -9 and poly (ADP-ribose) polymerase 1 increased in cells treated with celastrol. There was an increase in active Bcl-2-like 11 isoform S, Bcl-2-associated X, Bcl-2 antagonist/killer and truncated BH3-interacting death antagonist, and the levels of the anti-apoptotic Bcl-2 and Bcl-2-like 1 decreased. Celastrol induced an increase in Fas, Fas-associated via death domain, TNF receptor superfamily members (TNRSF) 1A and 10B, and TNFRSF1A associated via death domain, and induced a dose-dependent reduction in mitochondrial membrane potential. Celastrol inhibited activation of mitogen-activated protein kinase (MAPK) 1/3 and 14, and induced MAPK 8/9 activation. The results indicated that celastrol induced apoptosis through the death receptor and the mitochondrial pathway in human NPC cells, and is a promising candidate in the development of drugs against NPC.

Eugenol alleviated breast precancerous lesions through HER2/PI3K-AKT pathway-induced cell apoptosis and S-phase arrest

Eugenol can be separated from the oil extract of clove bud, and has many pharmacological functions such as anticancer and transdermal absorption. HER2/PI3K-AKT is a key signaling pathway in the development of breast cancer. In this study, 80 μM eugenol could significantly inhibit the proliferation of HER-2 positive MCF-10AT cells and the inhibition rate was up to 32.8%, but had no obvious inhibitory effect on MCF-7 and MCF-10A cells with HER2 weak expression. Eugenol also significantly induced human breast precancerous lesion MCF-10AT cell apoptosis and cell cycle S-phase arrest, but the biological effects nearly disappeared after HER2 over-expression through transfecting pcDNA3.1-HER2. In MCF-10AT cells treated by 180 μM eugenol, the protein expressions of HER2, AKT, PDK1, p85, Bcl2, NF-κB, Bad and Cyclin D1 were decreased and the decreased rates were respectively 63.0%, 60.0%, 52.9%, 62.9%, 37.1%, 47.2%, 61.7%, 59.1%, while the p21, p27 and Bax expression were increased by 4.48-, 4.76- and 2.57-fold respectively. In the rat models of breast precancerous lesion, 1 mg eugenol for external use significantly inhibited the progress of breast precancerous lesion and the occurrence rate of breast precancerous lesions and invasive carcinomas was decreased by about 30.5%. Furthermore eugenol for external (1 mg) markedly decreased the protein expressions of HER2 (62.9%), AKT (58.6%), PDK1 (56.4%), p85 (54.3%), Bcl2 (59.3%), NF-κB (65.7%), Bad (64.0%), Cyclin D1 (43.0%), while p21, p27 and Bax protein expressions were respectively increased 1.83-, 2.52- and 2.51-fold. The results showed eugenol could significantly inhibit the development of breast precancerous lesions by blocking HER2/PI3K-AKT signaling network. So eugenol may be a promising external drug for breast precancerous lesions.

Selenadiazole derivatives antagonize glucocorticoid-induced osteoblasts cells apoptosis by blocking ROS-mediated signaling, a new anti-osteoporosis strategy

Herein we demonstrate that synthetic selenadiazole derivatives could protect osteoblasts cells against Dex-induced cell apoptosisviaattenuating oxidative stress and downstream signalling pathways.

Selenium–phycocyanin from selenium-enriched cultures of Nostoc sp. isolated from rice field prevents human kidney cells from paraquat-induced damage

Herein we demonstrate that Se-containing phycocyanin (Se–PC) purified from Se-enriched cultures of Nostoc sp. could reverse paraquat (PQ)-induced DNA cell apoptosis through inhibition of superoxide overproduction in human kidney cells.

Polyphyllin G induces apoptosis and autophagy cell death in human oral cancer cells

BACKGROUND

Polyphyllin G (also called polyphyllin VII), extract from rhizomes of Paris yunnanensis Franch, has been shown to have strong anticancer activities in a wide variety of human cancer cell lines. However, the underlying influences of autophagy in human oral squamous cell carcinoma (OSCC) remain unclear.

METHODS

In this study, the roles of apoptosis and autophagy in polyphyllin G-induced death in human oral cancer cells were investigated. Moreover, the molecular mechanism of the anticancer effects of polyphyllin G in human oral cancer cells was investigated.

RESULTS

The results revealed that polyphyllin G significantly inhibited cell proliferation in human oral cancer cells; it dose-dependently induced apoptosis in SAS and OECM-1 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, changes were observed in Bcl-2 and proapoptosis-related protein expression in different human oral cancer cell lines. The expression of both LC3-II and beclin-1 was markedly increased, suggesting the induction of autophagy in polyphyllin G-treated oral cells. To further clarify whether polyphyllin G-induced apoptosis and autophagy depended on Akt/extracellular signal-regulated kinases (ERK)/c-Jun N-terminal kinases (JNK)/p38 mitogen-activated protein kinases (MAPK) signaling pathways, the cells were cotreated with inhibitors. The results demonstrated polyphyllin G-induced apoptosis in oral cells through the activation of ERK, Akt, p38 MAPK, and JNK, whereas ERK and JNK accounted for polyphyllin G-induced autophagy.

CONCLUSION

This study is the first to demonstrate apoptosis and autophagy during polyphyllin G-induced cell death in human oral cancer cell lines. These results suggest that polyphyllin G is a promising candidate for developing antitumor drugs targeting human oral squamous cell carcinoma.

Enhancing Therapeutic Efficacy of Cisplatin by Blocking DNA Damage Repair

Self-repair of nuclear DNA damage is the most known reason that leads to drug resistance of cancer tissue and limited therapeutic efficacy of anticancer drugs. Inhibition of protein phosphatase 2A (PP2A) would block DNA damage-induced defense of cancer cells to suppress DNA repair for enhanced cancer treatment. Here, we combined a PP2A inhibitor LB (4-(3-carboxy-7-oxa-bicyclo[2.2.1]heptane-2-carbonyl) piperazine-1-carboxylic acid tert-butyl ester) and the DNA damage chemotherapeutic drug cisplatin through a simple physical superposition. The two drugs administrated at a ratio of 1:1 exhibited an optional synergistic antitumor efficacy in vitro and in vivo. LB was demonstrated to specifically activate the protein kinase B (Akt) and mitogen-activated protein kinases (MAPK) signaling pathways by PP2A inhibition to overcome cell cycle arrest caused by cisplatin-induced DNA damage.

Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells

Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death.

Microwave-Assisted Synthesis of Arene Ru(II) Complexes Induce Tumor Cell Apoptosis Through Selectively Binding and Stabilizing bcl-2 G-Quadruplex DNA

A series of arene Ru(II) complexes coordinated with phenanthroimidazole derivatives, [(η⁶-C₆H₆)Ru(l)Cl]Cl(1b L = p-ClPIP = 2-(4-Chlorophenyl)imidazole[4,5f] 1,10-phenanthroline; 2b L = m-ClPIP = 2-(3-Chlorophenyl)imidazole[4,5f] 1,10-phenanthroline; 3b L = p-NPIP = 2-(4-Nitrophenyl)imidazole[4,5f] 1,10-phenanthroline; 4b L = m-NPIP = 2-(3-Nitrophenyl) imidazole [4,5f] 1,10-phenanthroline) were synthesized in yields of 89.9%-92.7% under conditions of microwave irradiation heating for 30 min to liberate four arene Ru(II) complexes (1b, 2b, 3b, 4b). The anti-tumor activity of 1b against various tumor cells was evaluated by MTT assay. The results indicated that this complex blocked the growth of human lung adenocarcinoma A549 cells with an IC₅₀ of 16.59 μM. Flow cytometric analysis showed that apoptosis of A549 cells was observed following treatment with 1b. Furthermore, the in vitro DNA-binding behaviors that were confirmed by spectroscopy indicated that 1b could selectively bind and stabilize bcl-2 G-quadruplex DNA to induce apoptosis of A549 cells. Therefore, the synthesized 1b has impressive bcl-2 G-quadruplex DNA-binding and stabilizing activities with potential applications in cancer chemotherapy.

Glabridin induces apoptosis and autophagy through JNK1/2 pathway in human hepatoma cells

BACKGROUND

Extensive research results support the use of herbal medicine or natural food to augment therapy for various cancers. Studies have associated glabridin with numerous biological activities, such as regulating energy metabolism and estrogenic, neuroprotective, antiosteoporotic, and skin-whitening activities.

HYPOTHESIS/PURPOSE

However, how glabridin affects tumor cell autophagy has not been clearly determined.

METHODS

Autophagy is a lysosomal degradation pathway essential for cell survival and tissue homeostasis. In this study, the roles of autophagy and related signaling pathways during glabridin-induced autophagy in human liver cancer cells were investigated. Additionally, the molecular mechanism of the anticancer effects of glabridin in human hepatoma cells was investigated.

RESULTS

The results revealed that glabridin significantly inhibited cell proliferation in human hepatoma cells. Glabridin induced apoptosis dose-dependently in Huh7 cells through caspase-3, -8, and -9 activation and PARP cleavage. Furthermore, autophagy was detected as early as 12h after exposure to a low dose of glabridin, as indicated by the up-regulated expression of LC3-II and beclin-1 proteins. The inhibition of JNK1/2 and p38 MAPK by specific inhibitors significantly reduced glabridin-induced activation of caspases-3, -8, and -9. Blocking autophagy sensitize the Huh7 cells to apoptosis.

CONCLUSION

This study demonstrated for the first time that autophagy occurs earlier than apoptosis does during glabridin-induced apoptosis in human liver cancer cell lines. Glabridin induces Huh7 cell death through apoptosis through the p38 MAPK and JNK1/2 pathways and is a potential chemopreventive agent against human hepatoma.

Tailoring Particle Size of Mesoporous Silica Nanosystem To Antagonize Glioblastoma and Overcome Blood-Brain Barrier

The blood-brain barrier (BBB) is the main bottleneck to prevent some macromolecular substance entering the cerebral circulation, resulting the failure of chemotherapy in the treatment of glioma. Cancer nanotechnology displays potent applications in glioma therapy owing to their penetration across BBB and accumulation into the tumor core. In this study, we have tailored the particle size of mesoporous silica nanoparticles (MSNs) through controlling the hydrolysis rate and polycondensation degree of reactants, and optimized the nanosystem that could effectively penetrate BBB and target the tumor tissue to achieve enhanced antiglioma efficacy. The nanoparticle was conjugated with cRGD peptide to enhance its cancer targeting effect, and then used to load antineoplastic doxorubicin. Therefore, the functionalized nanosystem (DOX@MSNs) selectively recognizes and binds to the U87 cells with higher expression level of ανβ3 integrin, sequentially enhancing the cellular uptake and inhibition to glioma cells, especially the particle size at 40 nm. This particle could rapidly enter cancer cells and was difficult to excrete outside the cells, thus leading to high drug accumulation. Furthermore, DOX@MSNs exhibited much higher selectivity and anticancer activity than free DOX and induced the glioma cells apoptosis through triggering ROS overproduction. Interestingly, DOX@MSNs at about 40 nm exhibited stronger permeability across the BBB, and could disrupt the VM-capability of glioma cells by regulating the expression of E-cadherin, FAK, and MMP-2, thus achieving satisfactory antiglioblastoma efficacy and avoiding the unwanted toxic side effects to normal brain tissue. Taken together, these results suggest that tailoring the particle size of MSNs nanosystem could be an effective strategy to antagonize glioblastoma and overcome BBB.

Sophoraflavanone G Induces Apoptosis in Human Leukemia Cells and Blocks MAPK Activation

Sophoraflavanone G (SG) was isolated from Sophora flavescens. Previously, we have found that SG is able to suppress the inflammatory response in lipopolysaccharide-stimulated RAW 264.7 macrophages. This study aimed to evaluate the effects of SG on apoptosis, and explore its molecular mechanism in human leukemia HL-60 cells. HL-60 cells were treated with various concentrations of SG (3–30 [Formula: see text]M). The viability of the HL-60 cells was assessed using the MTT method, and the nuclear condensation indicative of apoptosis was observed by DAPI fluorescence staining. In addition, apoptotic signal proteins were examined using Western blotting. The results showed that apoptosis, including DNA fragmentation and nuclear condensation, increased significantly in SG-treated HL-60 cells. SG activated caspase-3 and caspase-9, and downregulated Bcl-2 and Bcl-xL. SG also upregulated Bax and released cytochrome c from the mitochondria into the cytoplasm, enabling apoptosis via the mitochondrially-mediated “intrinsic” pathway. Additionally, SG was able to cleave poly (ADP-ribose) polymerase 1 and activate mitogen-activated protein kinase (MAPK) pathways. These results suggest that SG might increase the effect of apoptosis on HL-60 cells through caspase-3 activation, mitochondrial-mediated pathways, and the MAPK pathway.

Induction of S-Phase Arrest in Human Glioma Cells by Selenocysteine, a Natural Selenium-Containing Agent Via Triggering Reactive Oxygen Species-Mediated DNA Damage and Modulating MAPKs and AKT Pathways

Selenocysteine (SeC) a natural available selenoamino acid exhibits novel anticancer activities against human cancer cell lines. However, the growth inhibitory effect and mechanism of SeC in human glioma cells remain unclear. The present study reveals that SeC time- and dose-dependently inhibited U251 and U87 human glioma cells growth by induction of S-phase cell cycle arrest, followed by the marked decrease of cyclin A. SeC-induced S-phase arrest was achieved by inducing DNA damage through triggering generation of reactive oxygen species (ROS) and superoxide anion, with concomitant increase of TUNEL-positive cells and induction of p21waf1/Cip1 and p53. SeC treatment also caused the activation of p38MAPK, JNK and ERK, and inactivation of AKT. Four inhibitors of MAPKs and AKT pathways further confirmed their roles in SeC-induced S-phase arrest in human glioma cells. Our findings advance the understanding on the molecular mechanisms of SeC in human glioma management.

Highly stable selenadiazole derivatives induce bladder cancer cell apoptosis and inhibit cell migration and invasion through the activation of ROS-mediated signaling pathways

Herein highly stable selenadiazole derivatives were synthesized and found to be able to induce bladder cancer cell apoptosis and inhibit cell migration and invasion through the activation of ROS-mediated pathways.

Red Light Combined with Blue Light Irradiation Regulates Proliferation and Apoptosis in Skin Keratinocytes in Combination with Low Concentrations of Curcumin

Curcumin is a widely known natural phytochemical from plant Curcuma longa. In recent years, curcumin has received increasing attention because of its capability to induce apoptosis and inhibit cell proliferation as well as its anti-inflammatory properties in different cancer cells. However, the therapeutic benefits of curcumin are severely hampered due to its particularly low absorption via trans-dermal or oral bioavailability. Phototherapy with visible light is gaining more and more support in dermatological therapy. Red light is part of the visible light spectrum, which is able to deeply penetrate the skin to about 6 mm, and directly affect the fibroblast of the skin dermis. Blue light is UV-free irradiation which is fit for treating chronic inflammation diseases. In this study, we show that curcumin at low concentrations (1.25–3.12 μM) has a strong anti-proliferative effect on TNF-α-induced psoriasis-like inflammation when applied in combination with light-emitting-diode devices. The treatment was especially effective when LED blue light at 405 nm was combined with red light at 630 or 660 nm, which markedly amplified the anti-proliferative and apoptosis-inducing effects of curcumin. The experimental results demonstrated that this treatment reduced the viability of human skin keratinocytes, decreased cell proliferation, induced apoptosis, inhibited NF-κB activity and activated caspase-8 and caspase-9 while preserving the cell membrane integrity. Moreover, the combined treatment also down-regulated the phosphorylation level of Akt and ERK. Taken together, our results indicated that the combination of curcumin with LED blue light united red light irradiation can attain a higher efficiency of regulating proliferation and apoptosis in skin keratinocytes.

Selenocysteine derivative overcomes TRAIL resistance in melanoma cells: evidence for ROS-dependent synergism and signaling crosstalk

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), as one of the most promising targeted drug for new cancer therapeutics, is limited in clinical application by the evolution of resistance in many cancer cell lines, especially in malignant melanoma. Thus, it is urgently needed to identify chemosensitizers to enhance the apoptotic inducing efficacy of TRAIL and overcome resistance of malignant melanoma cells. Herein, we reported that 3,3'-diselenodipropionic acid (DSeA), a Selenocysteine derivative, could synergistically enhance the growth inhibitory effect of TRAIL on A375 melanoma cells though induction of ROS-dependent apoptosis with involvement of PTEN-mediated Akt inactivation and DNA damage-mediated p53 phosphorylation, which subsequently activated mitochondrial and death receptor apoptotic pathways. Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis. Suppression of PI3K significantly increased the apoptotic cell death. In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways. Taken together, the combination of DSeA and TRAIL could be a novel strategy to overcome TRAIL resistance in malignant melanoma, and DSeA may be candidates for further evaluation as a chemosensitizer in clinical trails.