Fangchinoline Inhibits Human Esophageal Cancer by Transactivating ATF4 to Trigger Both Noxa-Dependent Intrinsic and DR5-Dependent Extrinsic Apoptosis.

Esophageal squamous cell carcinoma (ESCC) is a recalcitrant cancer. The Chinese herbal monomer fangchinoline (FCL) has been reported to have anti-tumor activity in several human cancer cell types. However, the therapeutic efficacy and underlying mechanism on ESCC remain to be elucidated. In the present study, for the first time, we demonstrated that FCL significantly suppressed the growth of ESCC both in vitro and in vivo. Mechanistic studies revealed that FCL-induced G1 phase cell-cycle arrest in ESCC which is dependent on p21 and p27. Moreover, we found that FCL coordinatively triggered Noxa-dependent intrinsic apoptosis and DR5-dependent extrinsic apoptosis by transactivating ATF4, which is a novel mechanism. Our findings elucidated the tumor-suppressive efficacy and mechanisms of FCL and demonstrated FCL is a potential anti-ESCC agent.

Purified Tea (Camellia sinensis (L.) Kuntze) Flower Saponins Induce the p53-Dependent Intrinsic Apoptosis of Cisplatin-Resistant Ovarian Cancer Cells.

Ovarian cancer is currently ranked at fifth in cancer deaths among women. Patients who have undergone cisplatin-based chemotherapy can experience adverse effects or become resistant to treatment, which is a major impediment for ovarian cancer treatment. Natural products from plants have drawn great attention in the fight against cancer recently. In this trial, purified tea (Camellia sinensis (L.) Kuntze) flower saponins (PTFSs), whose main components are Chakasaponin I and Chakasaponin IV, inhibited the growth and proliferation of ovarian cancer cell lines A2780/CP70 and OVCAR-3. Flow cytometry, caspase activity and Western blotting analysis suggested that such inhibitory effects of PTFSs on ovarian cancer cells were attributed to the induction of cell apoptosis through the intrinsic pathway rather than extrinsic pathway. The p53 protein was then confirmed to play an important role in PTFS-induced intrinsic apoptosis, and the levels of its downstream proteins such as caspase families, Bcl-2 families, Apaf-1 and PARP were regulated by PTFS treatment. In addition, the upregulation of p53 expression by PTFSs were at least partly induced by DNA damage through the ATM/Chk2 pathway. The results help us to understand the mechanisms underlying the effects of PTFSs on preventing and treating platinum-resistant ovarian cancer.

Gedunin isolated from the mangrove plant Xylocarpus granatum exerts its anti-proliferative activity in ovarian cancer cells through G2/M-phase arrest and oxidative stress-mediated intrinsic apoptosis.

Gedunin is a natural tetranorterpenoid secondary metabolite found in plants of the Meliaceae family, which has been reported for its antiparasitic, antifungal and anticancer activities. Here, we describe the molecular mechanisms underlying the in vitro anti proliferative activity of gedunin (isolated from the mangrove plant Xylocarpus granatum) in human ovarian cancer cells. We observed that gedunin triggered severe ROS generation leading to DNA damage and cell cycle arrest in G2/M phase thus inhibiting cell proliferation. ROS upregulation also led to mitochondrial stress and membrane depolarization, which eventually resulted in mitochondria-mediated apoptosis following cytochrome C release, caspase 9, 3 activation, and PARP cleavage. Transmission electron microscopy of gedunin treated cells revealed sub-cellular features typical of apoptosis. Moreover, an upregulation in stress kinases like phospho-ERK 1/2, phospho-p38 and phospho-JNK was also observed in gedunin treated cells. Free radical scavenger N-Acetyl-L-Cysteine (NAC) reversed all these effects resulting in increased cell survival, abrogation of cell cycle arrest, rescue of mitochondrial membrane potential and suppression of apoptotic markers. Interestingly, gedunin is also an inhibitor of the evolutionarily conserved molecular chaperone Heat Shock Protein 90 (hsp90) responsible for maintaining cellular homeostasis. Targeting this chaperone could be an attractive strategy for developing cancer therapeutics since many oncogenic proteins are also client proteins of hsp90. Collectively, our findings provide insights into the molecular mechanism of action of gedunin, which may aid drug development efforts against ovarian cancer.

Glycyrrhizic Acid Modulates Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits Protein Kinase B- and Extracellular Signal-Regulated Kinase-Mediated Metastatic Potential in Hepatocellular Carcinoma In Vitro and In Vivo.

A previous study presented that glycyrrhizic acid as the hepatoprotective agent inhibits total parenteral nutrition-associated acute liver injury in rats. However, the anticancer effect and mechanism of glycyrrhizic acid in human hepatocellular carcinoma (HCC) is ambiguous. The purpose of the present study was to investigate the effect of glycyrrhizic acid on apoptosis dysregulation and metastatic potential in HCC in vitro and in vivo. Both SK-Hep1 and Hep3B cells were treated with different concentrations of glycyrrhizic acid for 24 or 48h. SK-Hep1/luc2 tumor-bearing mice were treated with vehicle or glycyrrhizic acid (50mg/kg/day by intraperitoneal injection) for 7 days. Tumor cells growth, apoptotic, and metastatic signaling transduction were evaluated by using MTT assay, digital caliper, bioluminescence imaging (BLI), flow cytometry, western blotting assay, and immunohistochemistry (IHC) staining. The results demonstrated glycyrrhizic acid significantly inhibits tumor cell growth, cell invasion, and expression of AKT (Ser473), extracellular-signal-regulated kinase (ERK), epidermal growth factor receptor (EGFR) phosphorylation, anti-apoptotic and metastatic proteins in HCC in vitro and in vivo. Glycyrrhizic acid also significantly triggered apoptosis and extrinsic/intrinsic apoptotic signaling transduction. In addition, PD98059 (ERK inhibitor) and LY294002 (AKT inhibitor) obviously reduced cell invasion and expression of metastasis-associated proteins. Taken together, these results indicated that glycyrrhizic acid induces apoptosis through extrinsic/intrinsic apoptotic signaling pathways and diminishes EGFR/AKT/ERK-modulated metastatic potential in HCC in vitro and in vivo.

Regulation of p21 expression for anti-apoptotic activity of DDX3 against sanguinarine-induced cell death on intrinsic pathway.

BACKGROUND: DDX3 plays a role in multicellular pathways, especially exerting an anti-apoptotic effect on extrinsic apoptosis. However, studies on the role of DDX3 in intrinsic apoptosis are lacking. PURPOSE: In this study, we aimed to study the bio-function of DDX3 anti-apoptotic activity in the intrinsic pathway using HeLa cells treated with sanguinarine. STUDY DESIGN: Screening of apoptosis-inducing agents found that sanguinarine was the most effective. After treatment with sanguinarine, cell viability, caspase-3 activity, and intrinsic gene expression were analyzed. FACS assays were used to analyze the effect of overexpression and knockdown of DDX3 to determine its role on intrinsic apoptosis. The relationship between DDX3 and the inhibition of p21 and apoptosis was investigated. RESULTS: Sanguinarine was determined to be the most effective intrinsic apoptosis-inducing agent in HeLa cervical cancer cells. DDX3 upregulated anti-apoptotic gene expression (Bcl-xL, cyclin D1, cyclin E, and cyclin B1) and downregulated pro-apoptotic gene expression (caspase-3, Bax) after sanguinarine treatment. The apoptotic cell death rate increased from 8.74% (sanguinarine-treated control) to 17.6% after the knockdown of DDX3 but decreased to 5.29% after DDX3 overexpression. The results implied that p21 might be involved in the toxicity of sanguinarine to HeLa cells. Overexpression and knockdown of DDX3 under sanguinarine-treated conditions showed that DDX3 inhibited p21 expression in sanguinarine-treated HeLa cells. Notably, when we tested p21 expression among eight mutants located in the functional residues of DDX3 (S90A, S90E, T204A, T204E, GET, NEAD, LAT, and HRISR) under sanguinarine-treated conditions, only the S90E mutation in DDX3 had an effect on the inhibition of p21 expression and levels of pro-apoptotic genes (Bax and caspase-3) and anti-apoptotic genes (Bcl-xL, cyclin D1, cyclin E, and cyclin B1), as well as DDX3. CONCLUSION: Taken together, the results suggest that the S90E residue is important for the regulation of p21 expression responsible for the anti-apoptotic activity of DDX3 in HeLa cells treated with sanguinarine. A model of the antiapoptotic function of DDX3 on sanguinarine-treated HeLa cells was proposed to understand the molecular mechanism of the intrinsic apoptosis inhibition in cervical cancer cells.

Hepatoprotective effect of boldine against diethylnitrosamine-induced hepatocarcinogenesis in wistar rats.

Discovering the utmost effective and targeted chemotherapy for hepatocellular carcinoma is still a significant challenge. In the present study, diethylnitrosamine was used as a liver carcinogen and boldine a compound of boldo. We anticipated the hypothesis that boldine endow antiproliferative and promote apoptosis on hepatocarcinoma rats. We analyzed that boldine alters the tumor biomarkers and liver markers enzyme levels. Also, we determined boldine modulate the enzymatic and nonenzymatic antioxidant activities, as well as messenger RNA and protein expressions of Bcl2, Bax, and cleaved caspase 3 by reverse transcription polymerase chain reaction and Western blot analysis, respectively. It was also manifested by histopathology studies in liver tissues of HCC rats. Our finding suggested that boldine has antioxidant activity, and moreover, also contributes apoptotic nature by upregulating the protein expression of Bax, and cleaved caspase 3. Our data accomplishes that boldine a candidate drug has dynamic therapeutic activity and suitable for the treatment of HCC.

Induction of intrinsic apoptotic signaling pathway in A549 lung cancer cells using silver nanoparticles from Gossypium hirsutum and evaluation of in vivo toxicity.

In the past decade, the research communities raised wide concerns on using medicinal plants for synthesis of nanomaterials due to its effective biological activity, lower side effects and also eco-friendly manner. Our previous report concentrated on the biomedical efficacy of fine characterized silver nanoparticles (AgNPs) from Gossypium hirsutum (cotton) leaf extract. Further, the current examination is planned to reveal the molecular mechanisms involving for activation of mitochondria-mediated signaling pathway by AgNPs in human lung cancer cells (A549) using various biological endpoints such as apoptotic induction by HOECHST 33342, AO/EtBr and Rhodamine 123 staining, cell cycle analysis using flow cytometry, gene and protein expressions by RT-PCR and immunoblotting respectively. This study was further extended to identify the toxicity of AgNPs using an animal model. Interestingly, we observed that A549 cells treated with AgNPs resulted in G2/M arrest and ultimately leads to induction of apoptosis cell death. Moreover, gene analysis demonstrated that diminished expression of anti-apoptotic (Bcl-2) and enhanced expression of pro-apoptotic (Bax) mitochondrial genes. The alterations in the gene pattern may interrupt of mitochondrial membrane potential which facilitates the releasing of cytochrome c (cyt c) into cytosol. The cyt c act as a key molecule for activation of caspases (9 and 3) to initiate intrinsic apoptotic signaling cell death process. The histological analysis proven the application of AgNPs in nanomedicine is quietly harmless and would not cause any discernible stress like swelling and inflammation to the organs of mice. Taken together, this investigation may provide solid evidence for cotton crop mediated AgNPs induced apoptosis cell death pathway and offer a novel approach for cancer therapy.

Emodin Induced SREBP1-Dependent and SREBP1-Independent Apoptosis in Hepatocellular Carcinoma Cells.

Reynoutria multiflora (Thunb.) Moldenke (He Shou Wu) has been used for about 20 centuries as a Chinese medicinal herb for its activities of anticancer, anti-hyperlipidemia, and anti-aging. Previously, we found that He Shou Wu ethanol extract could induce apoptosis in hepatocellular carcinoma cells, and we also screened its active components. In this study, we investigated whether lowering lipid metabolism of emodin, a main active component in He Shou Wu, was associated with inhibitory effects in hepatocellular carcinoma cells. The correlation of apoptosis induction and lipid metabolism was investigated. The intrinsic apoptotic cell death, lipid production, and their signaling pathways were investigated in emodin-treated human hepatocellular carcinoma cells Bel-7402. The data showed that emodin triggered apoptosis in Bel-7402 cells. The mitochondrial membrane potential (ΔΨm) was reduced in emodin-treated Bel-7402 cells. We also found that emodin activated the expression of intrinsic apoptosis signaling pathway-related proteins, cleaved-caspase 9 and 3, Apaf 1, cytochrome c (CYTC), apoptosis-inducing factor, endonuclease G, Bax, and Bcl-2. Furthermore, the level of triglycerides and desaturation of fatty acids was reduced in Bel-7402 cells when exposed to emodin. Furthermore, the expression level of messenger RNA (mRNA) and protein of sterol regulatory element binding protein 1 (SREBP1) as well as its downstream signaling pathway and the synthesis and the desaturation of fatty acid metabolism-associated proteins (adenosine triphosphate citrate lyase, acetyl-CoA carboxylase alpha, fatty acid synthase (FASN), and stearoyl-CoA desaturase D) were also decreased. Notably, knock-out of SREBP1 in Bel-7402 cells was also found to induce less intrinsic apoptosis than did emodin. In conclusion, these results indicated that emodin could induce apoptosis in an SREBP1-dependent and SREBP1-independent manner in hepatocellular carcinoma cells.

The role of insulin-like growth factor 1 in ALS cell and mouse models: A mitochondrial protector.

Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disorder, but little is known about the exact causes and pathophysiology of this disease. In transgenic mouse models of ALS, mitochondrial abnormalities develop during the disease and might contribute to the progression of ALS. Gene therapy was recently shown to induce beneficial effects. For example, the delivery of human insulin-like growth factor-1 (hIGF-1) by self-complementary adeno-associated virus (AAV) vectors has been shown to prolong the lifespan of ALS transgenic mice. However, the function of IGF-1 in mitochondria has not been systematically studied in ALS models. In this study, scAAV9-hIGF-1 was intramuscularly injected into transgenic SOD1G93A mice and administered to cell lines expressing the ∼25-kDa C-terminal fragment of transactive response DNA-binding protein (TDP-25). The mitochondrial electrical transmembrane potential was hyperpolarized, and electron microscopy findings revealed that the abnormal mitochondria were transformed. Moreover, the intrinsic mitochondrial apoptotic process was modified through the upregulation of anti-apoptotic proteins (B-cell lymphoma-extra large (Bcl-xl) and B-cell lymphoma-2 (Bcl-2)), the downregulation of pro-apoptotic proteins (Bcl-2-associated x protein (Bax) and Bcl-2 homologous antagonist killer (Bak)) and a reduction in mitochondrial cytochrome c release. Mitophagy was also increased after scAAV9-hIGF-1 treatment, as evidenced by a decrease in the p62 level and an increase in the LC3-II level. Furthermore, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system was used to delete the IGF-1 gene in SOD1G93A model mice via an intrathecal injection of scAAV9-sgRNA-IGF1-Cas9 to confirm these findings. The protective effect of IGF-1 on the mitochondria decreased after genetic deletion. These novel findings demonstrate that IGF-1 strongly protects mitochondria from apoptosis and upregulates mitophagy in mouse and cell models of ALS. Therefore, therapies that specifically protect mitochondrial function might be promising strategies for treating ALS.

Zhiheshouwu ethanol extract induces intrinsic apoptosis and reduces unsaturated fatty acids via SREBP1 pathway in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is the major incidence and one of the most life-threatening cancer. How to conquer HCC is a worldwide issue for patients. Zhiheshouwu (Polygoni multiflori Radix Praeparata) is a Chinese medicinal herb exhibiting both lowering lipid and inhibiting cancer cells. However, it remains a matter if its inhibiting cancer cells is related to its lowering lipid. In this study, we investigate the effects of Zhiheshouwu ethanolic extract (HSWE) on apoptosis and the underlying mechanisms in Bel-7402 cells. The results showed that HSWE inhibited the proliferation with an increased level of ALT and AST in Bel-7402 cells. The decreased mitochondrial membrane potential (ΔΨm) was observed in HSWE-treated Bel-7402 cells. The flow cytometry results showed that HSWE triggered apoptosis. Since mitochondrial injury is characterized as intrinsic apoptotic cell death, these data indicated that HSWE may induce intrinsic apoptosis in Bel-7402 cells. In addition, HSWE decreased the production of unsaturated fatty acids, and inhibited the mRNA and protein of SCD1 and its up-stream factor, sterol-regulatory element binding proteins 1 (SREBP1), a master transcriptional regulator of lipogenic gene. Taken together, these data suggest that HSWE induces an intrinsic apoptosis, and reduced unsaturated fatty acids by blocking SREBP1 in hepatocellular carcinoma cells.

Cytotoxicity of the compounds isolated from Pulsatilla chinensis saponins and apoptosis induced by 23-hydroxybetulinic acid.

CONTEXT: The rizoma of Pulsatilla chinensis (Bunge) Regel has been used as a traditional Chinese medicinal herb for thousands of years. Total saponins from P. chinensis can induce the apoptosis of solid cancer cells; however, their activity on chronic myeloid leukemia and the mechanisms remains unknown. OBJECTIVE: To study the activity of total saponins and the main active fractions from P. chinensis saponins on chronic myeloid leukemia, and to illustrate the mechanisms underlying the anticancer activities. MATERIALS AND METHODS: The cytotoxic activity were assayed by MTT; cell cycle arrest and apoptosis were tested by flow cytometry system; changes in the mitochondrial membrane potential were determined using JC-1; and the apoptosis signaling pathway was determined by western blotting. RESULTS: We demonstrated that total P. chinensis saponin displayed cytotoxic activity against K562 cell line. In addition, we identified 23-hydroxybetulinic acid (HBA), pulchinenoside A (PA), and anemoside B4 (AB4) from the total saponins, with the most cytotoxic compound HBA. Glycosylation at C3 and C28 of HBA significantly reduces its cytotoxicity. HBA could promote cell cycle arrest at S phase and induce apoptosis via intrinsic pathway. HBA disrupts mitochondrial membrane potential significantly (p < 0.01) and selectively downregulates the levels of Bcl-2, survivin and upregulates Bax, cytochrome C, cleaved caspase-9 and -3. DISCUSSION AND CONCLUSION: Total saponins from P. chinensis may be effective natural products against human chronic myelogenous leukemia; HBA is one of the bioactive components responsible for its anticancer activity, and could be further investigated as an alternative therapeutic drug for leukemia.

Intrinsic apoptotic pathway and G2/M cell cycle arrest involved in tubeimoside I-induced EC109 cell death.

OBJECTIVE: Squamous esophageal carcinoma is highly prevalent in developing countries, especially in China. Tu Bei Mu (TBM), a traditional folk medicine, has been used to treat esophageal squamous cell carcinoma (ESCC) for a long term. tubeimoside I (TBMS1) is the main component of TBM, exhibiting great anticancer potential. In this study, we investigated the mechanism of TBMS1 cytotoxic effect on EC109 cells. METHODS: Comparative nuclear proteomic approach was applied in the current study and we identified several altered protein spots. Further biochemical studies were carried out to detect the mitochondrial membrane potential, cell cycle and corresponding proteins' expression and location. RESULTS: Subcellular proteomic study in the nucleus from EC109 cells revealed that altered proteins were associated with mitochondrial function and cell proliferation. Further biochemical studies showed that TBMS1-induced molecular events were related to mitochondria-induced intrinsic apoptosis and P21-cyclin B1/cdc2 complex-related G2/M cell cycle arrest. CONCLUSIONS: Considering the conventional application of TBM in esophageal cancer, TBMS1 therefore may have a great potential as a chemotherapeutic drug candidate for ESCC.

Astaxanthin inhibits NF-κB and Wnt/ß-catenin signaling pathways via inactivation of Erk/MAPK and PI3K/Akt to induce intrinsic apoptosis in a hamster model of oral cancer.

BACKGROUND: The oncogenic transcription factors NF-κB and ß-catenin, constitutively activated by upstream serine/threonine kinases control several cellular processes implicated in malignant transformation including apoptosis evasion. The aim of this study was to investigate the chemopreventive effects of astaxanthin, an antioxidant carotenoid, in the hamster buccal pouch (HBP) carcinogenesis model based on its ability to modulate NF-κB and Wnt signaling pathways and induce apoptosis. METHODS: We determined the effect of dietary supplementation of astaxanthin on the oncogenic signaling pathways - NF-κB and Wnt/ß-catenin, their upstream activator kinases - Erk/MAPK and PI-3K/Akt, and the downstream event - apoptosis evasion by real-time quantitative RT-PCR, western blot, and immunohistochemical analyses. RESULTS: We found that astaxanthin inhibits NF-κB and Wnt signaling by downregulating the key regulatory enzymes IKKß and GSK-3ß. Analysis of gene expression and docking interactions revealed that inhibition of these pathways may be mediated via inactivation of the upstream signaling kinases Erk/Akt by astaxanthin. Astaxanthin also induced caspase-mediated mitochondrial apoptosis by downregulating the expression of antiapoptotic Bcl-2, p-Bad, and survivin and upregulating proapoptotic Bax and Bad, accompanied by efflux of Smac/Diablo and cytochrome-c into the cytosol, and induced cleavage of poly (ADP-ribose) polymerase (PARP). CONCLUSIONS: The results provide compelling evidence that astaxanthin exerts chemopreventive effects by concurrently inhibiting phosphorylation of transcription factors and signaling kinases and inducing intrinsic apoptosis. GENERAL SIGNIFICANCE: Astaxanthin targets key molecules in oncogenic signaling pathways and induces apoptosis and is a promising candidate agent for cancer prevention and therapy.