Effects of <Emphasis Type="Italic">A.marina</Emphasis>-Derived Isoquercitrin on TNF-Related Apoptosis-Inducing Ligand Receptor (TRAIL-R) Expression and Apoptosis Induction in Cervical Cancer Cells

TNF-related apoptosis-inducing ligand (TRAIL) is an anticancer agent, which has greater apoptosis inducing capacity, but most of the cancer cells become resistant to TRAIL-induced apoptosis. The combined treatment of TRAIL with natural products could restore the cancer cell sensitivity to recombinant human TRAIL (rhTRAIL) protein and might enhance the TNF-related apoptosis-inducing ligand receptor (TRAIL-R) expression. This investigation was aimed to isolate flavonoids from leaves of Avicennia marina and evaluate their potential for sensitization of rhTRAIL in human cervical cancer cells (SiHa). The methanolic extract of A.marina leaves were purified and structure was elucidated as isoquercitrin by NMR and LC-MS analysis. Isolated isoquercitrin showed cytotoxicity against SiHa cell line at IC₅₀ of 980 μM. Messenger RNA (mRNA) expression of TRAIL-Rs was quantified by qRT-PCR, combination of isoquercitrin, and/or rhTRAIL increased TRAIL-R1 and TRAIL-R2 gene expression by 7 folds and 4 folds, respectively. Also, FACS assay revealed that combined treatment has increased the early apoptosis up to 7.24%. In the present study, we found that isoquercitrin enhances the mRNA expression of TRAIL-Rs, but the percentage of apoptosis was meager, possibly due to the influence of other anti-apoptotic proteins.     

Human hepatocellular carcinoma cells resist to TRAIL-induced apoptosis,and the resistance is abolished by cisplatin

TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF family, selectively induce apoptosis in various transformed cell lines but not in almost-normal tissues. It is regulated by 2 death receptors, TRAIL receptor 1 (TRAIL-R1) and TRAIL-R2 and 2 decoy receptors, TRAIL-R3 and TRAIL-R4. However, the determining factors of the sensitivity to TRAIL-induced apoptosis are not clearly understood. Herein, we investigated the expression of TRAIL-R, c-FLIP, FADD-like interleukin-1beta-converting enzyme inhibitory protein, and TRAIL-induced apoptosis in human hepatocellular carcinoma (HCC) cell lines. Seven of ten HCC cell lines showed resistance to TRAIL-induced apoptosis and five of seven TRAIL-resistant cell lines became sensitive to TRAIL by co-treatment with cycloheximide. In HCC cell lines, their TRAIL resistance did not correlate with the basal expression level of TRAIL receptors or c-FLIP, however, in human tissues, TRAIL-R1 and TRAIL-R2 expressions were notably decreased compared to normal counterpart. Cisplatin showed synergistic effect on TRAIL-induced apoptosis in most HCC cell lines regardless of their p53 status and TRAIL-R1 was induced by cisplatin treatment in certain cell lines. Inhibition of nuclear factor K B (NF-kappaB) by SN50, a peptide inhibitor of NF-KB activity, had no effect on TRAIL-induced apoptosis in HCC cells. These results suggest that (a) the majority of human HCC cell lines are resistant to TRAIL-induced apoptosis and cycloheximide-sensitive short-lived antiapoptotic molecule(s) is responsible for this resistance, (b) the expression of TRAIL-R1 and TRAIL-R2 is reduced in HCC tissues, and the increased expression of TRAIL-R1 may be a mechanism of cisplatininduced sensitization to TRAIL-induced apoptosis in some HCC cells, and (c) the activation of NF-kappaB may not be involved in the TRAIL resistance of HCC cells     

Triptolide sensitizes lung cancer cells to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis by inhibition of NF-kappaB activation

TNF-related apoptosis-inducing ligand (TRAIL/Apo- 2L), a newly identified member of the TNF family promotes apoptosis by binding to the transmembrane receptors (TRAIL-R1/DR4 and TRAIL-R2/DR5). TRAIL known to activate NF-kappaB in number of tumor cells including A549 (wt p53) and NCI-H1299 (null p53) lung cancer cells exerts relatively selective cytotoxic affects to the human tumor cell lines without much effect on the normal cells. We set out to identify an agent that would sensitize lung cancer cells to TRAIL-induced apoptosis through inhibition of NF-kappaB activation. We found that triptolide, an oxygenated diterpene extracted and purified from the Chinese herb Tripterygium wilfordii sensitized A549 and NCI-H1299 cells to TRAIL-induced apoptosis through inhibition of NF-kappaB activation. Pretreatment with MG132 which is a well-known NF-kappaB inhibitor by blocking degradation of IkappaBalpha also greatly sensitized lung cancer cells to TRAIL-induced apoptosis. Triptolide did not block DNA binding of NF-kappaB activated by TRAIL as in the case of TNF-alpha. It has been already proven that triptolide blocks transactivation of p65 which plays a key role in NF-kappaB activation. These observations suggest that triptolide may be a potentially useful drug to enhance TRAIL-induced tumor killing in lung cancer.     

Bisphosphonate enhances TRAIL sensitivity to human osteosarcoma cells via death receptor 5 upregulation

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily of cytokines, is one of the most promising candidates for cancer therapeutics. However, many osteosarcomas are resistant to TRAIL. Bisphosphonates are very effective in the treatment of bone problems associated with malignancies; the antitumor effects are due to the inhibition of protein prenylation that is essential for cell function and survival. The purpose of this study was to determine the effects of bisphosphonates on TRAIL-resistant MG 63 human osteosarcoma cells. The cells showed no response to TRAIL alone; however, pre-treatment with bisphosphonates significantly increased TRAIL-mediated apoptosis and cellular activation of caspase-3. Bisphosphonates significantly induced mRNA and protein expression of the TRAIL receptor, DR5. Bisphosphonates induced protein unprenylation in MG 63 cells; in addition, co-treatment with TRAIL also significantly increased protein unprenylation. Blocking of protein unprenylation using geranylgeraniol attenuated the cellular responses, including cell apoptosis and protein unprenylation induced by bisphosphonates and TRAIL. This is the first study to demonstrate that bisphosphonates markedly enhanced TRAIL-induced apoptosis in human osteosarcoma cells. These findings suggest that bisphosphonates may be a new and effective anticancer treatment with TRAIL proteins for TRAIL-resistant cancer cells.     

Effects of Curcumin Analogues DMC and EF24 in Combination with the Cytokine TRAIL against Kidney Cancer

The natural compound curcumin has been shown to have therapeutic potential against a wide range of diseases such as cancer. Curcumin reduces cell viability of renal cell carcinoma (RCC) cells when combined with TNF-related apoptosis-inducing ligand (TRAIL), a cytokine that specifically targets cancer cells, by helping overcome TRAIL resistance. However, the therapeutic effects of curcumin are limited by its low bioavailability. Similar compounds to curcumin with higher bioavailability, such as demethoxycurcumin (DMC) and 3,5-bis(2-fluorobenzylidene)-4-piperidone (EF24), can potentially have similar anticancer effects and show a similar synergy with TRAIL, thus reducing RCC viability. This study aims to show the effects of DMC and EF24 in combination with TRAIL at reducing ACHN cell viability and ACHN cell migration. It also shows the changes in death receptor 4 (DR4) expression after treatment with these compounds individually and in combination with TRAIL, which can play a role in their mechanism of action.     

Paxilline enhances TRAIL-mediated apoptosis of glioma cells via modulation of c-FLIP, survivin and DR5

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) induces apoptosis selectively in cancer cells while sparing normal cells. However, many cancer cells are resistant to TRAIL-induced cell death. Here, we report that paxilline, an indole alkaloid from Penicillium paxilli, can sensitize various glioma cells to TRAIL-mediated apoptosis. While treatment with TRAIL alone caused partial processing of caspase-3 to its p20 intermediate in TRAIL-resistant glioma cell lines, co-treatment with TRAIL and subtoxic doses of paxilline caused complete processing of caspase-3 into its active subunits. Paxilline treatment markedly upregulated DR5, a receptor of TRAIL, through a CHOP/GADD153-mediated process. In addition, paxilline treatment markedly downregulated the protein levels of the short form of the cellular FLICE-inhibitory protein (c-FLIPs) and the caspase inhibitor, survivin, through proteasome-mediated degradation. Taken together, these results show that paxilline effectively sensitizes glioma cells to TRAIL-mediated apoptosis by modulating multiple components of the death receptor-mediated apoptotic pathway. Interestingly, paxilline/TRAIL co-treatment did not induce apoptosis in normal astrocytes, nor did it affect the protein levels of CHOP, DR5 or survivin in these cells. Thus, combined treatment regimens involving paxilline and TRAIL may offer an attractive strategy for safely treating resistant gliomas.     

人血清白蛋白与Cu(II)配合物的生物活性研究

Cu(II)配合物很有可能成为下一代的抗肿瘤药物。本文以2-氨基-5-氯苯酚和2-喹啉甲醛合成的席夫碱作为配体,与Cu(II)络合形成配合物1。分别对配合物1和其与人血清白蛋白(HSA)的复合物HSA-1进行体外抗肿瘤测试,发现HSA能提高配合物1的抗肿瘤活性,并降低了对正常细胞的毒性。通过线粒体膜电位等实验,可以推断出配合物1是通过线粒体通路诱导癌细胞凋亡。     

Iron(II)−Polypyridyl Complexes Inhibit the Growth of Glioblastoma Tumor and Enhance TRAIL‐Induced Cell Apoptosis

A promising cancer‐targeting agent for the induction of apoptosis in tumor necrosis factor (TNF) proteins, the TNF‐related apoptosis‐inducing ligand (TRAIL) ligand, has found limited applications in the treatment of cancer cells, owing to its resistance by cancer cell lines. Therefore, the rational design of anticancer agents that could sensitize cancer cells towards TRAIL is of great significance. Herein, we report that synthetic iron(II)−polypyridyl complexes are capable of inhibiting the proliferation of glioblastoma cancer cells and efficiently enhancing TRAIL‐induced cell apoptosis. Mechanistic studies demonstrated that the synthesized complexes induced cancer‐cell apoptosis through triggering the activation of p38 and p53 and inhibiting the activation of ERK. Moreover, uPA and MMP‐2/MMP‐9, among the most important metastatic regulatory proteins, were also found to be significantly alerted after the treatment. Furthermore, we also found that tumor growth in nude mice was significantly inhibited by iron complex Fe2 through the induction of apoptosis without clear systematic toxicity, as indicated by histological analysis. Taken together, this study provides evidence for the further development of metal‐based anticancer agents and chemosensitizers of TRAIL for the treatment of human glioblastoma cancer cells.     

Fluorescent Coumarin–Artemisinin Conjugates as Mitochondria‐Targeting Theranostic Probes for Enhanced Anticancer Activities

Mitochondria‐targeting theranostic probes that enable the simultaneously reporting of and triggering of mitochondrial dysfunctions in cancer cells are highly attractive for cancer diagnosis and therapy. Three fluorescent mitochondria‐targeting theranostic probes have been developed by linking a mitochondrial dye, coumarin‐3‐carboximide, with a widely used traditional Chinese medicine, artemisinin, to kill cancer cells. Fluorescence images showed that the designed coumarin–artemisinin conjugates localized mainly in mitochondria, leading to enhanced anticancer activities over artemisinin. High cytotoxicity against cancer cells correlated with the strong ability to accumulate in mitochondria, which could efficiently increase the intracellular reactive oxygen species level and induce cell apoptosis. This study highlights the potential of using mitochondria‐targeting fluorophores to selectively trigger and directly visualize subcellular drug delivery in living cells.     

Intracellular Uptake of PEG-Funtionalized Baicalein Loaded Iron Oxide Nanoparticles Regulates Apoptotic Genes in Triple Negative Breast Cancer Cells: Mitochondrial Pathway Targeted Therapy for Breast Cancer

The recent focus and development of nanotechnology in medicine is countless, which involves diagnostic, therapeutic and preventive systems for various diseases. Nanoparticles have received much attention due to their uses in cancer therapy. The current study focused on the synthesis of baicalein loaded iron oxide nanoparticles and their efficacy against triple negative breast cancer (TNBC) MDA-MB-231. The electron microscopic analysis reveals that the particles were internalized with the various sub cellular regions of selected cancer cells. Further flow cytometric analysis of mitochondrial membrane potential using JC-1 staining showed that significant aggregates were found in the cells treated with baicalein loaded iron oxide nanoparticles, which, in turn, implies momentous mitochondrial membrane potential loss that occurs. Similarly apoptotic and anti-apoptotic gene expression pattern showed that baicalein loaded iron oxide nanoparticles were upregulates the apoptotic genes like Bad, Bax, GADD45 and PARP cleavage in a dose dependant manner. Detailed kit based flowcytometric analysis also reveals that the above findings were significant in the focused field, it is apparent that nano conjugates have the ability to induce apoptosis, DNA damage and cell cycle arrest and decrease the rate of cell proliferation in TNBC cells.     

Piperine loaded zinc oxide nanocomposite inhibits the PI3K/AKT/mTOR signaling pathway via attenuating the development of gastric carcinoma: In vitro and in vivo studies

Gastric cancer (GC) is the fifth most cancer type and the third most cause of cancer-associated deaths worldwide along with the 5-year survival rate is less the 30%. This investigation was aimed to synthesis the piperine-loaded zinc oxide nanocomposite (ZnO-Pip-NC) and investigating its anticancer activity against the GC by in vitro and in vivo models by the inhibiting the apoptotic and PI3K/Akt/mTOR signaling pathways. The synthesized ZnO-Pip-NC was characterized by different techniques. The cytotoxicity of zinc oxide, piperine and the formulated ZnO-Pip-NC was tested against the AGS cells by MTT assay. The intracellular ROS level, mitochondrial membrane potential, and apoptotic cell necrosis in the AGS cells was examined by fluorescent staining techniques. The expression of apoptotic and PI3K/Akt/mTOR signaling markers were inspected by western blotting and the expression of pro0inflammatory markers analyzed by RT-PCR technique. The antioxidant levels were examined by standard methods and histopathology of gastric mucosa was analyzed. The ZnO-Pip-NC treatment appreciably inhibited the AGS cell viability. ZnO-Pip-NC treated cells also exhibited excessive intracellular ROS, diminished MMP, nuclear damages, and apoptosis induction in AGS cells. The enhanced expression of pro-apoptotic proteins and inhibition of PI3K/Akt/mTOR signaling pathway was noted in ZnO-Pip-NC treated cells. In vivo studies proved that the ZnO-Pip-NC noticeably restored the antioxidants in the GC animals and also prevented the gastric mucosa and inhibited the GC tumor formation. In conclusion, the findings of this investigation confirmed the anticancer potential of ZnO-Pip-NC against the GC via inhibiting the PI3K/Akt/mTOR signaling pathway.     

Tunicamycin enhances TRAIL-induced apoptosis by inhibition of cyclin D1 and the subsequent downregulation of survivin

TNF-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising cancer therapy that preferentially induces apoptosis in cancer cells, but not most normal tissues. However, many cancers are resistant to TRAIL by mechanisms that are poorly understood. In this study, we showed that tunicamycin, a naturally occurring antibiotic, was a potent enhancer of TRAIL-induced apoptosis through downregulation of survivin. The tunicamycin-mediated sensitization to TRAIL was efficiently reduced by forced expression of survivin, suggesting that the sensitization was mediated at least in part through inhibition of survivin expression. Tunicamycin also repressed expression of cyclin D1, a cell cycle regulator commonly overexpressed in thyroid carcinoma. Furthermore, silencing cyclin D1 by RNA interference reduced survivin expression and sensitized thyroid cancer cells to TRAIL; in contrast, forced expression of cyclin D1 attenuated tunicamycin-potentiated TRAIL-induced apoptosis via over-riding downregulation of survivin. Collectively, our results demonstrated that tunicamycin promoted TRAIL-induced apoptosis, at least in part, by inhibiting the expression of cyclin D1 and subsequent survivin. Of note, tunicamycin did not sensitize the differentiated thyroid epithelial cells to TRAIL-induced apoptosis. Thus, combined treatment with tunicamycin and TRAIL may offer an attractive strategy for safely treating resistant thyroid cancers.     

Micelle-in-Liposomes for Sustained Delivery of Anticancer Agents That Promote Potent TRAIL-Induced Cancer Cell Apoptosis

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces cancer cell-specific apoptosis and has garnered intense interest as a promising agent for cancer treatment. However, the development of TRAIL has been hampered in part because most human cancer cells are resistant to TRAIL. A few small molecules including natural compounds such as piperlongumine (PL) have been reported to sensitize cancer cells to TRAIL. We prepared a novel type of nanomaterial, micelle-in-liposomes (MILs) for solubilization and delivery of PL. PL-loaded MILs were used to sensitize cancer cells to TRAIL. As visualized by cryo-TEM, micelles were successfully loaded inside the aqueous core of liposomes. The MILs increased the water solubility of PL by ~20 fold. A sustained PL release from MILs in physiologically relevant buffer over 7 days was achieved, indicating that the liposomes prevented premature drug release from the micelles in the MILs. Also demonstrated is a potent synergistic apoptotic effect in cancer cells by PL MILs in conjunction with liposomal TRAIL. MILs provide a new formulation and delivery vehicle for hydrophobic anticancer agents, which can be used alone or in combination with TRAIL to promote cancer cell death.     

Synthesis,characterization and biological evaluation of a cobalt(II) complex with 5‐chloro‐8‐hydroxyquinoline as anticancer agent

A new cobalt(II) complex ( 1 ) of 5‐chloro‐8‐hydroxyquinoline was prepared and structurally characterized using infrared spectroscopy, electrospray ionization mass spectrometry, elemental analysis, single‐crystal X‐ray diffraction as well as powder X‐ray diffraction. Its biological activities including DNA binding and anticancer activity were investigated. The DNA binding study of complex 1 suggested that it interacted with calf thymus DNA mainly via an intercalative binding mode. The in vitro anticancer activity of complex 1 was screened against a series of tumor cell lines as well as the normal liver cell line HL‐7702 using MTT assay. complex 1 showed much higher cytotoxicity than corresponding metal salt and ligand towards the five tested tumor cell lines, in which T‐24 was the most sensitive tumor cell line towards 1, with IC₅₀ value of 7.04 ± 0.06 μM. complex 1 was found to greatly induce cell cycle arrest in T‐24 cells at S phase, and consequently to induce cell apoptosis in a dose‐dependent mode suggested by cell apoptosis analysis via Hoechst 33258 and acridine orange/ethidium bromide staining assays. The cell apoptosis mechanism of 1 was studied targeting the mitochondrion‐mediated pathway, since the apoptotic mechanism in the T‐24 cells treated by 1 was investigated by reactive oxygen species (ROS) detection, intracellular calcium concentration measurement and caspase‐9/3 activity assay. The results suggested that the cell apoptosis induced by 1 was closely related to the loss of mitochondrial membrane potential, ROS production and enhancement of intracellular [Ca²⁺], which would trigger the caspase‐9/3 activation via a mitochondrial dysfunction pathway. Copyright © 2016 John Wiley & Sons, Ltd.     

Wnt/GSK3β/β-catenin signaling pathway regulates calycosin-mediated anticancer effects in glioblastoma multiforme cells

Calycosin, an O-methylated isoflavone, has been widely reported to induce anticancer activity in different cancer cells in vitro. Nonetheless, the associated mechanism of calycosin in glioblastoma multiforme cells (U87) still remains unknown. To explore the anticancer effects, the apoptotic mechanism of calycosin via Wnt/GSK3β/β-catenin signaling was explored in U87 cells. Different assays including: cytotoxicity, free radical determination, SOD and CAT activity, GSH content, qPCR, mitochondrial membrane potential, caspase activity, and western blotting assays were performed. It was shown that calycosin mitigated cell viability in U87 cells, whereas it showed no apparent effect on BV2 microglial cells. Calycosin triggered apoptosis via upregulating the mitochondria-associated caspase pathway in U87 cells. Calycosin induced the reduction of the mitochondrial membrane potential, overexpression of Bax, downexpression of Bcl-2, and activation of caspase-9 and caspase-3. Calycosin-stimulated apoptosis was associated with the upregulation of free radical scavenging through the modulation of antioxidant enzymes, such as SOD and CAT as well as the level of GSH. The apoptotic activity of calycosin was mediated by suppression of pGSK-3βser9, β-catenin, and c-Myc at protein level. The present study suggested that calycosin triggers U87 cell death through an antioxidant effect mediated by Wnt/GSK3β/β-catenin signaling pathway.     

An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells

Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentage^TM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.     

Zinc oxide nanoparticle synthesized from Euphorbia fischeriana root inhibits the cancer cell growth through modulation of apoptotic signaling pathways in lung cancer cells

Lung cancer is the widespread carcinogenesis in men and the third most familiar cancer in women. It is one of the mostly aggressive human cancers, which is responsible for around 1.4 million deaths per annum and has utmost mortality and incidence with 1.8 million new incidences and 1.6 million new deaths yearly. In this present study, we have evaluated the anticancer potential of zinc oxide nanopartices (ZnONPs) synthesized from a root extract of Euphorbia fischeriana (EF), through the apoptosis signaling markers in A549 lung cancer cells. The synthesized EF-ZnONPs were evaluated through the transmission electron microscope (TEM), Fourier transform infra red (FTIR), UV–visible spectroscopy and dynamic light scattering (DLS) techniques. The EF-ZnONPs were assessed for their cytotoxicity activity towards A549 cells by MTT test. The induction of apoptosis was analysed by the mitochondria membrane potential (MMP), reactive oxygen species (ROS), cell migration and dual staining. Furthermore, pro and anti-apoptotic signaling protein expression was evaluated by western blotting method. We found the bioformulated EF-ZnONPs has a spherical morphology and revealed the existence of diverse bioactive compounds. Also we found the cytotoxic effect of EF-ZnONPs. Apoptosis was activated by the EF-ZnONPs with improved ROS, decreased MMP, inhibited cell migration and altered dual staining was observed. Furthermore, the diminished expression of anti-apoptotic protein Bcl-2 was noted. In this study, we observed the formulation, characterization and anticancer potency of ZnONPs of EF plant extract (EF-ZnONPs) was useful for treatments of lung cancer.     

Chamaejasmine induces apoptosis in human lung adenocarcinoma A549 cells through a Ros-mediated mitochondrial pathway

In the present study, the anticancer activity of chamaejasmine towards A549 human lung adenocarcinoma cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of chamaejasmine, cell cycle distribution, ROS generation, mitochondrial membrane potential (Δψ(m)) disruption, and expression of cytochrome c, Bax, Bcl-2, caspase-3, caspase-9 and PARP were measured in A549 cells. Chamaejasmine inhibited the growth of A549 cells in a time and dose-dependent manner. The IC?? value was 7.72 μM after 72 h treatment. Chamaejasmine arrested the cell cycle in the G2/M phase and induced apoptosis via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that chamaejasmine inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade, and active-caspase-3 was involved in PARP cleavage. All of these signal transduction pathways are involved in initiating apoptosis. To the best of our knowledge, this is the first report demonstrating the cytotoxic activity of chamaejasmine towards A549 in vitro.     

Rutin induces endoplasmic reticulum stress-associated apoptosis in human triple-negative breast carcinoma MDA-MB-231 cells – In vitro and in silico docking studies

Rutin is a bioactive compound that possesses anti-tumor activities through triggering apoptosis. Triple-negative breast cancer (TNBC) is insensitive to targeted anti-tumoral drugs, and drug resistance in TNBC poses a challenge for a successful cure. The accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER) results in cellular stress that initiates a specialized response designated as the unfolded protein response. This study aimed to find potential ER stress targets in triple-negative breast cancer. The viability of cells was evaluated using an MTT assay. Cell migration and proliferation were done by wound scratch and colony formation assay. Cell cycle detection, measurement of ER stress, mitochondrial membrane potential disruption, and cell death identification was performed using flow cytometry. The interaction of rutin with ER stress proteins is predicted using in silico docking. The pattern of gene expression was determined by qRT-PCR. The elevated rate of cell viability, cell cycle arrest, ER stress, MMP, and apoptotic induction was observed in combination treatment. Rutin exhibited the highest glide score with ASK1 and JNK. The results of qRT-PCR showed that rutin induced apoptosis through upregulation of ASK1 and JNK. The present study provides strong evidence supporting an important role of the ER stress response in mediating rutin-induced apoptosis in triple-negative breast cancer.