Allyl isothiocyanate inhibits cell migration and invasion in human gastric cancer AGS cells via affecting PI3K/AKT and MAPK signaling pathway in vitro.

Metastasis is commonly occurred in gastric cancer, and it is caused and responsible for one of the major cancer-related mortality in gastric cancer patients. Allyl isothiocyanate (AITC), a natural product, exhibits anticancer activities in human many cancer cells, including gastric cancer. However, no available report shows AITC inhibits gastric cancer cell metastasis. Herein, we evaluated the impact of AITC on cell migration and invasion of human gastric cancer AGS cells in vitro. AITC at 5-20 µM did not induce significant cell morphological damages observed by contrast-phase microscopy but decreased cell viability assayed by flow cytometry. After AGS cells were further examined by atomic force microscopy (AFM), which indicated AITC affected cell membrane and morphology in AGS cells. AITC significantly suppressed cell motility examined by scratch wound healing assay. The results of the gelatin zymography assay revealed that AITC significantly suppressed the MMP-2 and MMP-9 activities. In addition, AITC suppressed cell migration and invasion were performed by transwell chamber assays at 24 h in AGS cells. Furthermore, AITC inhibited cell migration and invasion by affecting PI3K/AKT and MAPK signaling pathways in AGS cells. The decreased expressions of p-AKTThr308 , GRB2, and Vimentin in AGS cells also were confirmed by confocal laser microscopy. Our findings suggest that AITC may be an anti-metastasis candidate for human gastric cancer treatment.

Mangiferin induces immune responses and evaluates the survival rate in WEHI-3 cell generated mouse leukemia in vivo.

Mangiferin is a naturally occurring polyphenol, widely distributed in Thymeraceae families, and presents pharmacological activity, including anti-cancer activities in many human cancer cell lines. Mangiferin has also been reported to affect immune responses; however, no available information concerning the effects of mangiferin on immune reactions in leukemia mice in vivo. In the present study, we investigated the effects of mangiferin on leukemia WEHI-3 cell generated leukemia BLAB/c mice. Overall, the experiments were divided into two parts, one part was immune responses experiment and the other was the survival rate experiment. The immune responses and survival rate study, 40 mice for each part, were randomly separated into five groups (N = 8): Group I was normal animals and groups II-V WEHI-3 cell generated leukemia mice. Group II mice were fed normal diet as a positive control; group III, IV, and V mice received mangiferin at 40, 80, and 120 mg/kg, respectively, by intraperitoneal injection every 2 days for 20 days. Leukocytes cell population, macrophage phagocytosis, and NK cell activities were analyzed by flow cytometry. Isolated splenocytes stimulated with lipopolysaccharide (LPS) and concanavalin A (Con A) were used to determine the proliferation of B and T cells, respectively, and subsequently were analyzed by flow cytometry. Results indicated that mangiferin significantly increased body weight, decreased the liver and spleen weights of leukemia mice. Mangiferin also increased CD3 T-cell and CD19 B cell population but decreased Mac-3 macrophage and CD11b monocyte. Furthermore, mangiferin decreased phagocytosis of macrophages from PBMC and peritoneal cavity at 40, 80, and 120 mg/kg treatment. However, it also increased NK cell activity at 40 and 120 mg/kg treatment. There were no effects on T and B cell proliferation at three examined doses. In survival rate studies, mangiferin significantly elevated survival rate at 40 and 120 mg/kg treatment of leukemia mice in vivo.

Genistein enhances the effects of L-asparaginase on inducing cell apoptosis in human leukemia cancer HL-60 cells.

Genistein (GEN) has been shown to induce apoptotic cell death in various human cancer cells. L-asparaginase (Asp), a clinical drug for leukemia, has been shown to induce cell apoptosis in leukemia cells. No available information concerning GEN combined with Asp increased the cell apoptosis compared to GEN or Asp treatment alone. The objective of this study is to evaluate the anti-leukemia activity of GEN combined with Asp on human leukemia HL-60 cells in vitro. The cell viability, the distribution of cell cycle, apoptotic cell death, and the level of ΔΨm were examined by flow cytometric assay. The expressions of apoptosis-associated proteins were measured by western blotting. GEN combined with Asp revealed a more significant decrease in total viable cells and induced a higher percentage of G2/M phase arrest, DNA damage, and cell apoptosis than that of GEN or Asp treatment only in HL-60 cells. Furthermore, the combined treatments (GEN and Asp) showed a higher decrease in the level of ΔΨm than that of GEN or Asp treatment only. These results indicated that GEN combined with Asp induced mitochondria dysfunction by disrupting the mitochondrial membrane potential. The results from western blotting demonstrated that the treatment of GEN combined with Asp showed a higher increase in the levels of Bax and Bak (pro-apoptotic proteins) and an active form of caspase-3 and a higher decrease in Bcl-2 (anti-apoptotic protein) than that of GEN or Asp treatment alone. GEN significantly enhances the efficiency of Asp on cytotoxic effects (the induction of apoptosis) in HL-60 cells.

Casticin Induces DNA Damage and Affects DNA Repair Associated Protein Expression in Human Lung Cancer A549 Cells (Running Title: Casticin Induces DNA Damage in Lung Cancer Cells).

Casticin was obtained from natural plants, and it has been shown to exert biological functions; however, no report concerns the induction of DNA damage and repair in human lung cancer cells. The objective of this study was to investigate the effects and molecular mechanism of casticin on DNA damage and repair in human lung cancer A549 cells. Cell viability was determined by flow cytometric assay. The DNA damage was evaluated by 4',6-diamidino-2-phenylindole (DAPI) staining and electrophoresis which included comet assay and DNA gel electrophoresis. The protein levels associated with DNA damage and repair were analyzed by western blotting. The expression and translocation of p-H2A.X were observed by confocal laser microscopy. Casticin reduced total viable cell number and induced DNA condensation, fragmentation, and damage in A549 cells. Furthermore, casticin increased p-ATM at 6 h and increased p-ATR and BRCA1 at 6-24 h treatment but decreased p-ATM at 24-48 h, as well as decreased p-ATR and BRCA1 at 48 h. Furthermore, casticin decreased p-p53 at 6-24 h but increased at 48 h. Casticin increased p-H2A.X and MDC1 at 6-48 h treatment. In addition, casticin increased PARP (cleavage) at 6, 24, and 48 h treatment, DNA-PKcs and MGMT at 48 h in A549 cells. Casticin induced the expressions and nuclear translocation of p-H2AX in A549 cells by confocal laser microscopy. Casticin reduced cell number through DNA damage and condensation in human lung cancer A549 cells.

Gefitinib and curcumin-loaded nanoparticles enhance cell apoptosis in human oral cancer SAS cells in vitro and inhibit SAS cell xenografted tumor in vivo.

Curcumin (Cur), a natural product, has been shown to have anti-tumor activities in many human cancer cells. Gefitinib (Gef) is a clinical drug for cancer patients. However, there is no available information to show whether Gef/Cur nanoparticles (NPs) increased cell apoptosis and anti-tumor effects on xenograft mice model in vivo. In this study, γ-polyglutamic acid-coated nanoparticles loaded with Gef and Cur (γ-PGA-Gef/Cur NPs) were developed and its physicochemical properties and antitumor effects were investigated in vitro and in vivo. The γ-PGA-Gef/Cur NPs showed 548.5 ±â€¯93.7 nm in diameter and -40.3 ±â€¯3.87 mV on surface charge. The loading efficiencies of Gef and Cur were 89.5 and 100%, respectively. γ-PGA-Gef/Cur NPs could be internalized into SAS cells and significantly decreased total cell viability of SAS cells. Western blotting results indicated that both free Gef/Cur and γ-PGA-Gef/Cur NPs induced apoptotic cell death via caspase- and mitochondria-dependent pathways. In vivo studies indicated that treatments of PLGA NPs, free Gef/Cur, and γ-PGA-Gef/Cur NPs did not significantly affect appearances and bodyweights of mice. But the γ-PGA-Gef/Cur NPs significantly suppressed tumor size when comparing to free Gef/Cur-treated group. The nanoparticles developed in this study may be used as a potential therapy for oral cancer.

Genistein induces apoptosis in vitro and has antitumor activity against human leukemia HL-60 cancer cell xenograft growth in vivo.

Genistein, a major isoflavone compound in soybeans, has been shown to have biological activities including anti-cancer activates. In the present, we investigated the anti-leukemia activity of genistein on HL-60 cells in vitro. The percentage of viable cell, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS), and Ca2+ production and the level of ΔΨm were measured by flow cytometric assay. Cell apoptosis and endoplasmic reticulum (ER) stress associated protein expressions were examined by Western blotting assay. Calpain 1, GRP78, and GADD153 expression were measured by confocal laser microscopy. Results indicated that genistein-induced cell morphological changes, decreased the total viable cells, induced G2 /M phase arrest and DNA damage and fragmentation (cell apoptosis) in HL-60 cells. Genistein promoted ROS and Ca2+ productions and decreased the level of ΔΨm in HL-60 cells. Western blotting assay demonstrated that genistein increased ER stress-associated protein expression such as IRE-1α, Calpain 1, GRP78, GADD153, caspase-7, caspase-4, and ATF-6α at 20-50 µM treatment and increased apoptosis associated protein expression such as pro-apoptotic protein Bax, PARP-cleavage, caspase-9, and -3, but decreased anti-apoptotic protein such as Bcl-2 and Bid in HL-60 cells. Calpain 1, GRP78, and GADD153 were increased in HL-60 cells after exposure to 40 µM of genistein. In animal xenografted model, mice were intraperitoneally injected with genistein (0, 0.2, and 0.4 mg/kg) for 28 days and the body weight and tumor volume were recorded. Results showed that genistein did not affect the body weights but significantly reduced the tumor weight in 0.4 mg/kg genistein-treated group. Genistein also increased the expressions of ATF-6α, GRP78, Bax, Bad, and Bak in tumor. In conclusion, genistein decreased cell number through G2 /M phase arrest and the induction of cell apoptosis through ER stress- and mitochondria-dependent pathways in HL-60 cells and suppressed tumor properties in vivo.

Triptolide induced cell death through apoptosis and autophagy in murine leukemia WEHI-3 cells in vitro and promoting immune responses in WEHI-3 generated leukemia mice in vivo.

Triptolide, a traditional Chinese medicine, obtained from Tripterygium wilfordii Hook F, has anti-inflammatory, antiproliferative, and proapoptotic properties. We investigated the potential efficacy of triptolide on murine leukemia by measuring the triptolide-induced cytotoxicity in murine leukemia WEHI-3 cells in vitro. Results indicated that triptolide induced cell morphological changes and induced cytotoxic effects through G0/G1 phase arrest, induction of apoptosis. Flow cytometric assays showed that triptolide increased the production of reactive oxygen species, Ca2+ release and mitochondrial membrane potential (ΔΨm ), and activations of caspase-8, -9, and -3. Triptolide increased protein levels of Fas, Fas-L, Bax, cytochrome c, caspase-9, Endo G, Apaf-1, PARP, caspase-3 but reduced levels of AIF, ATF6α, ATF6ß, and GRP78 in WEHI-3 cells. Triptolide stimulated autophagy based on an increase in acidic vacuoles, monodansylcadaverine staining for LC-3 expression and increased protein levels of ATG 5, ATG 7, and ATG 12. The in vitro data suggest that the cytotoxic effects of triptolide may involve cross-talk between cross-interaction of apoptosis and autophagy. Normal BALB/c mice were i.p. injected with WEHI-3 cells to generate leukemia and were oral treatment with triptolide at 0, 0.02, and 0.2 mg/kg for 3 weeks then animals were weighted and blood, liver, spleen samples were collected. Results indicated that triptolide did not significantly affect the weights of animal body, spleen and liver of leukemia mice, however, triptolide significant increased the cell populations of T cells (CD3), B cells (CD19), monocytes (CD11b), and macrophage (Mac-3). Furthermore, triptolide increased the phagocytosis of macrophage from peripheral blood mononuclear cells (PBMC) but not effects from peritoneum. Triptolide promoted T and B cell proliferation at 0.02 and 0.2 mg/kg treatment when cells were pretreated with Con A and LPS stimulation, respectively; however, triptolide did not significant affect NK cell activities in vivo. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 550-568, 2017.

Fisetin-induced apoptosis of human oral cancer SCC-4 cells through reactive oxygen species production, endoplasmic reticulum stress, caspase-, and mitochondria-dependent signaling pathways.

Oral cancer is one of the cancer-related diseases in human populations and its incidence rates are rising worldwide. Fisetin, a flavonoid from natural products, has been shown to exhibit anticancer activities in many human cancer cell lines but the molecular mechanism of fisetin-induced apoptosis in human oral cancer cells is still unclear; thus, in this study, we investigated fisetin-induced cell death and associated signal pathways on human oral cancer SCC-4 cells in vitro. We examined cell morphological changes, total viable cells, and cell cycle distribution by phase contrast microscopy and flow cytometry assays. Reactive oxygen species (ROS), Ca2+ , mitochondria membrane potential (ΔΨm ), and caspase-8, -9, and -3 activities were also measured by flow cytometer. Results indicate that fisetin induced cell death through the cell morphological changes, caused G2/M phase arrest, induction of apoptosis, promoted ROS and Ca2+ production, and decreased the level of ΔΨm and increased caspase-3, -8, and -9 activities in SCC-4 cells. DAPI staining and DNA gel electrophoresis were also used to confirm fisetin-induced cell apoptosis in SCC-4 cells. Western blotting also found out that Fisetin increased the proapoptotic proteins such as Bax and Bid and decreased the antiapoptotic proteins such as Bcl-2. Furthermore, results also showed that Fisetin increased the cytochrome c, AIF, and Endo G release from mitochondria in SCC-4 cells. We also used ATF-6α, ATF-6ß, GADD153, and GRP78 which indicated that fisetin induced cell death through ER stress. Based on those observations, we suggest that fisetin induced cell apoptosis through ER stress, mitochondria-, and caspase-dependent pathways.

Suppression of the migration and invasion is mediated by triptolide in B16F10 mouse melanoma cells through the NF-kappaB-dependent pathway.

Melanoma cancer is one of the major causes of death in humans worldwide. Triptolide is one of the active components of Tripterygium wilfordii Hook F, and has biological activities including induced cell cycle arrest and induction of apoptosis but its antimetastatic effects on murine melanoma cells have not yet been elucidated. Herein, we investigated the effect of triptolide on the inhibition of migration and invasion and possible associated signal pathways in B16F10 murine melanoma cancer cells. Wound healing assay and Matrigel Cell Migration Assay and Invasion System demonstrated that triptolide marked inhibiting the migration and invasion of B16F10 cells. Gelatin zymography assay demonstrated that triptolide significantly inhibited the activities of matrix metalloproteinases-2 (MMP-2). Western blotting showed that triptolide markedly reduced CXCR4, SOS1, GRB2, p-ERK, FAK, p-AKT, Rho A, p-JNK, NF-κB, MMP-9, and MMP-2 but increased PI3K and p-p38 and COX2 after compared to the untreated (control) cells. Real time PCR indicated that triptolide inhibited the gene expression of MMP-2, FAK, ROCK-1, and NF-κB but did not significantly affect TIMP-1 and -2 gene expression in B16F10 cells in vitro. EMSA assay also showed that triptolide inhibited NF-κB DNA binding in a dose-dependent manner. Confocal laser microscopy examination also confirmed that triptolide inhibited the expression of NF-κB in B16F10 cells. Taken together, we suggest that triptolide inhibited B16F10 cell migration and invasion via the inhibition of NF-κB expression then led to suppress MMP-2 and -9 expressions. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1974-1984, 2016.

Tetrandrine Induces Apoptosis of Human Nasopharyngeal Carcinoma NPC-TW 076 Cells through Reactive Oxygen Species Accompanied by an Endoplasmic Reticulum Stress Signaling Pathway.

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy of the head and neck and the incidence is higher in Southeast Asia. Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid, a natural product, and exhibits biological activities including action against many human cancer cell lines. However, the molecular mechanism of TET-induced cell apoptosis in human NPC cells is still unclear. In the present study, we investigated TET-induced apoptotic cell death and associated possible signal pathways on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Phase contrast microscopy was used to examine cell morphology and DAPI staining was used to examine chromatin condensation. Flow cytometry assay was used to measure total viable cells, cell cycle and sub-G1 phase distribution, reactive oxygen species (ROS), Ca2+, and mitochondria membrane potential (ΔΨm) in NPC-TW 076 cells. Results indicate that TET induced cell death through the cell morphological changes, caused G0/G1 phase arrest, increased ROS and Ca2+ production, and finally caused apoptotic cell death in NPC-TW 076 cells. There was no influence on the level of ΔΨm after TET treatment. Western blotting indicated that TET increased endoplasmic reticulum (ER) stress associated protein expression such as GADD153, GRP78, ATF-6α and ATF-6 ßwhich indicated that TET induced cell death through ER stress. ER stress is a potential target in cancer treatment, so the ability of TET to induce ER stress response and to activate programming cell death in NPC-TW 076 cells make this molecule become a promising anticancer agent.

The roles of endoplasmic reticulum stress and mitochondrial apoptotic signaling pathway in quercetin-mediated cell death of human prostate cancer PC-3 cells.

Prostate cancer has its highest incidence and is becoming a major concern. Many studies have shown that traditional Chinese medicine exhibited antitumor responses. Quercetin, a natural polyphenolic compound, has been shown to induce apoptosis in many human cancer cell lines. Although numerous evidences show multiple possible signaling pathways of quercetin in apoptosis, there is no report to address the role of endoplasmic reticulum (ER) stress in quercetin-induced apoptosis in PC-3 cells. The purpose of this study was to investigate the effects of quercetin on the induction of the apoptotic pathway in human prostate cancer PC-3 cells. Cells were treated with quercetin for 24 and 48 h and at various doses (50-200 µM), and cell morphology and viability decreased significantly in dose-dependent manners. Flow cytometric assay indicated that quercetin at 150 µM caused G0/G1 phase arrest (31.4-49.7%) and sub-G1 phase cells (19.77%) for 36 h treatment and this effect is a time-dependent manner. Western blotting analysis indicated that quercetin induces the G0/G1 phase arrest via decreasing the levels of CDK2, cyclins E, and D proteins. Quercetin also stimulated the protein expression of ATF, GRP78, and GADD153 which is a hall marker of ER stress. Furthermore, PC-3 cells after incubation with quercetin for 48 h showed an apoptotic cell death and DNA damage which are confirmed by DAPI and Comet assays, leading to decrease the antiapoptotic Bcl-2 protein and level of ΔΨm , and increase the proapoptotic Bax protein and the activations of caspase-3, -8, and -9. Moreover, quercetin promoted the trafficking of AIF protein released from mitochondria to nuclei. These data suggest that quercetin may induce apoptosis by direct activation of caspase cascade through mitochondrial pathway and ER stress in PC-3 cells.

Lenvatinib Suppresses Protein Kinase B Signaling and Induces Apoptosis in Osteosarcoma Cells.

BACKGROUND/AIM: Lenvatinib, an oral multikinase inhibitor, has demonstrated promising activity in patients with osteosarcoma (OS). Therefore, it is worth exploring the inhibitory efficacy and mechanism of action of lenvatinib in osteosarcoma. The primary goal of this study was to examine the inhibitory effectiveness and mechanism of lenvatinib on the growth and invasion of OS cells. MATERIALS AND METHODS: The effects of lenvatinib on cell viability, apoptosis, protein kinase B (AKT) activation, its downstream effector proteins involved in tumor progression, and invasion capability were assessed using MTT assay, flow cytometry, western blotting, and invasion/migration assay on U-2 OS and MG63 cells. RESULTS: Lenvatinib effectively induced cytotoxicity, apoptosis, as well as extrinsic and intrinsic apoptotic signaling in OS cells. Lenvatinib also significantly decreased the invasion/migration capability, AKT activation, and downstream effector proteins. CONCLUSION: The anti-OS effect of lenvatinib may be associated with the induction of apoptosis and the inactivation of AKT.

cDNA microarray analysis of the gene expression of murine leukemia RAW 264.7 cells after exposure to propofol.

Propofol (2,6-diisopropylphenol) is the most extensively used general anesthetic-sedative agent and it is employed in clinical patients. It has been shown that propofol exhibits anticancer activities. However, there is no available information to address propofol-induced cytotoxic effects and affected gene expressions on murine leukemia cells. Therefore, we investigated the effects of propofol on the levels of protein and gene expression, which are associated with apoptotic death in mouse leukemia RAW 264.7 cells in vitro. Results indicated that propofol induced cell morphological changes, cytotoxicity, and induction of apoptosis in RAW 264.7 cells in vitro. Western blot analysis demonstrated that propofol promoted Fas, cytochrome c, caspase-9 and -3 active form and Bax levels, but inhibited Bcl-xl protein level which led to cell apoptosis. Furthermore, cDNA microarray assay indicated that propofol significantly enhanced 5 gene expressions (Gm4884; Gm10883; Lce1c; Lrg1; and LOC100045878) and significantly suppressed 26 gene expressions (Gm10679; Zfp617; LOC621831; LOC621831; Gm5929; Snord116; Gm3994; LOC380994; Gm5592; LOC380994; Gm4638; LOC280487; Gm4638; Tex24; A530064D06Rik; BC094916; EG668725; Gm189; Hist2h3c2; Gm8020; Snord115; Gm3079; Olfr198; Tdh; Snord115; and Olfr1249). Based on these observations, propofol-altered apoptosis-related proteins might result from induction of apoptotic gene expression and inhibition of cell growth gene expression, which finally led to apoptosis in a mouse leukemia cell line (RAW 264.7) in vitro.

Gallic acid provokes DNA damage and suppresses DNA repair gene expression in human prostate cancer PC-3 cells.

Our earlier studies have demonstrated that gallic acid (GA) induced cytotoxic effects including induction of apoptosis and DNA damage and inhibited the cell migration and invasion in human cancer cells. However, GA-affected DNA damage and repair gene expressions in human prostate cancer cells are still unclear. In this study, we investigated whether or not GA induces DNA damage and inhibits DNA repair gene expression in a human prostate cancer cell line (PC-3). The results from flow cytometric assay indicated that GA decreased the percentage of viable PC-3 cells in a dose- and time-dependent manner. PC-3 cells after exposure to different doses (50, 100, and 200 µM) of GA and various periods of time (12, 24, and 48 h) led to a longer DNA migration smear (comet tail) occurred based on the single cell gel electrophoresis (comet assay). These observations indicated that GA-induced DNA damage in PC-3 cells, which also confirmed by 4,6-diamidino-2-phenylindole dihydrochloride staining and DNA agarose gel electrophoresis. Alternatively, results from real-time polymerase chain reaction assay also indicated that GA inhibited ataxia telangiectasia mutated, ataxia-telangiectasia and Rad3-related, O6-methylguanine-DNA methyltransferase, DNA-dependent serine/threonine protein kinase, and p53 mRNA expressions in PC-3 cells. Taken together, the present study showed that GA caused DNA damage and inhibited DNA repair genes as well as both effects may be the critical factors for GA-inhibited growth of PC-3 cells in vitro.

Inactivation of AKT/ERK Signaling and Induction of Apoptosis Are Associated With Amentoflavone Sensitization of Hepatocellular Carcinoma to Lenvatinib.

BACKGROUND/AIM: AKT/ERK signaling transduction and anti-apoptosis effects have both been recognized as important mediators of hepatocellular carcinoma (HCC) progression. Targeting AKT/ERK signaling and mediating apoptosis may be beneficial for alleviating HCC growth. Lenvatinib, a tyrosine kinase inhibitor, has been approved by the FDA to treat HCC since 2018 as a monotherapy with limited efficacy. Amentoflavone, a biflavonoid in natural plants, has been shown to have the potential to suppress HCC progression in previous studies. Whether the combination of lenvatinib and amentoflavone may show superior HCC suppression is unclear. MATERIALS AND METHODS: We used MTT, flow cytometry and western blotting assays to identify the role of lenvatinib and amentoflavone in both Hep3B and Huh7 cells. RESULTS: We found that amentoflavone enhances the suppressive effect of AKT/ERK signaling induced by lenvatinib and, thus, sensitizes HCC to lenvatinib. The intrinsic/extrinsic apoptosis pathways induced by lenvatinib were also boosted by amentoflavone. CONCLUSION: Amentoflavone sensitization of HCC to lenvatinib is associated with AKT/ERK inactivation and apoptosis induction.

Ouabain Induces DNA Damage in Human Osteosarcoma U-2 OS Cells and Alters the Expression of DNA Damage and DNA Repair-associated Proteins.

BACKGROUND/AIM: Ouabain, isolated from natural plants, exhibits anticancer activities; however, no report has presented its mechanism of DNA damage induction in human osteosarcoma cancer cells in vitro. The aim of this study was to investigate whether ouabain induces DNA damage and repair, accompanied with molecular pathways in human osteosarcoma cancer U-2 OS cells in vitro. MATERIALS AND METHODS: The percentage of viable cell number was measured by flow cytometric assay; DNA damage was assayed by DAPI staining, comet assay, and agarose gel electrophoresis. DNA damage and repair associated protein expressions were assayed by western blotting assays. RESULTS: Ouabain reduced total cell viability, induced chromatin condensation, DNA fragmentation, and DNA damage in U-2 OS cells. Ouabain increased p-ATMSer1981, p-ATRSer428, and p53 at 2.5-10 µM, increased p-p53Ser15 at 10 µM; however, it decreased p-MDM2Ser166 at 2.5-10 µM. Ouabain increased p-H2A.XSer139, MDC-1, and PARP at 2.5-10 µM and BRCA1 at 5-10 µM; however, it decreased DNA-PK and MGMT at 2.5-10 µM in U-2 OS cells at 48 h treatment. Ouabain promoted expression and nuclear translocation of p-H2A.XSer139 in U-2 OS cells and this was confirmed by confocal laser microscopy. CONCLUSION: Ouabain reduced total viable cell number through triggering DNA damage and altering the protein expression of DNA damage and repair system in U-2 OS cells in vitro.

Tetrandrine Enhances H2O2-Induced Apoptotic Cell Death Through Caspase-dependent Pathway in Human Keratinocytes.

BACKGROUND: Tetrandrine, a bis-benzylisoquinoline alkaloid, induces apoptosis of many types of human cancer cell. Hydrogen peroxide (H2O2) is a reactive oxygen species inducer; however, there are no reports to show whether pre-treatment of tetrandrine with H2O2 induces more cell apoptosis than H2O2 alone. Thus, the present study investigated the effects of tetrandrine on H2O2-induced cell apoptosis of human keratinocytes, HaCaT, in vitro. MATERIALS AND METHODS: HaCaT cells were pre-treated with and without tetrandrine for 1 h, and then treated with H2O2 for examining cell morphological changes and cell viability using contrast-phase microscopy and propidium iodide (PI) exclusion assay, respectively. Cells were measured apoptotic cell death by using annexin V/PI double staining and further analyzed by flow cytometer. Cells were further assessed for DNA condensation using 2-(4-amidinophenyl)-6-indolecarbamidine staining. Western blotting was used to measure expression of apoptosis-associated proteins and confocal laser microscopy was used to measure the protein expression and nuclear translocation from the cytoplasm to nuclei. RESULTS: Pre-treatment of tetrandrine for 1 h and treatment with H2O2 enhanced H2O2-induced cell morphological changes and reduced cell viability, whilst increasing apoptotic cell death and DNA condensation. Furthermore, tetrandrine significantly increased expression of reactive oxygen species-associated proteins such as superoxide dismutase (Cu/Zn) and superoxide dismutase (Mn) but significantly reduced the level of catalase, which was also confirmed by confocal laser microscopy. It also increased expression of DNA repair-associated proteins ataxia telangiectasia mutated, ataxia-telangectasia and Rad3-related, phospho-P53, P53 and phosphorylated histone H2AX, and of pro-apoptotic proteins BCL2 apoptosis regulator-associated X-protein, caspase-3, caspase-8, caspase-9 and poly ADP ribose polymerase in HaCaT cells. CONCLUSION: These are the first and novel findings showing tetrandrine enhances H2O2-induced apoptotic cell death of HaCaT cells and may provide a potent approach for the treatment of proliferated malignant keratinocytes.

Demethoxycurcumin Promotes Macrophage Cell Population and Phagocytosis in WEHI-3 Cell-generated Leukemia BALB/c Mice In Vivo.

BACKGROUND/AIM: Demethoxycurcumin (DMC), one of the components of curcuminoids, has antitumor activities in many human cancer cells and is known to induce apoptosis in human leukemia cells. However, there are no reports showing the effects of DMC on the immune response in leukemia mice in vivo. Herein, we evaluated the impact of DMC on immune responses in WEHI-3-generated leukemia mice in vivo. MATERIALS AND METHODS: Fifty male BALB/c mice were separated randomly into five groups. Group I is normal mice, and groups II-V mice of generated leukemia by WEHI-3 cells. Group II-V mice were intraperitoneally injected with dimethyl sulfoxide (DMSO, as the positive control), 15, 30, and 60 mg/kg of DMC, respectively, every two days for 14 days. The body weight, blood, peritoneal fluid, liver, and spleen were individually analyzed. RESULTS: DMC did not significantly affect animal appearance and body weight. It decreased liver and spleen weight at a high dose. DMC did not affect the cluster of differentiation 3 (CD3) and CD19 cell populations but induced decrease of CD11b at 30 mg/kg treatment. However, DMC at low dose significantly increased the cluster of macrophage (Mac-3) cell populations, but at high dose it decreased them. DMC increased macrophage phagocytosis from peripheral blood mononuclear cells at 15 mg/kg treatment and peritoneal cavity at 15, 30 and 60 mg/kg of DMC treatments. DMC did not significantly affect the cytotoxic activity of natural killer (NK) cells. Furthermore, DMC decreased B and T cell proliferation at high doses. CONCLUSION: DMC elevated macrophage phagocytosis in leukemia mice in vivo.

Maslinic Acid Induces DNA Damage and Impairs DNA Repair in Human Cervical Cancer HeLa Cells.

BACKGROUND/AIM: Maslinic acid, a natural plant-derived triterpenoid compound, exhibits pharmacological activities, including anti-cancer. In the present study, we investigated the cytotoxic effects of maslinic acid on human cervical cancer HeLa cells in vitro and further investigated the molecular mechanism of maslinic acid-induced DNA damage and repair. MATERIALS AND METHODS: Cell viability was measured by flow cytometry. DNA condensation (apoptotic cell death), DNA damage, and DNA fragmentation (DNA ladder) were assayed by DAPI staining, comet assay, and agarose gel electrophoresis, respectively. The expression of DNA damage and repair proteins was assayed by western blotting. RESULTS: Maslinic acid decreased total cell viability and induced DNA condensation, damage, and fragmentation in HeLa cells. Furthermore, maslinic acid elevated the levels of p-ATMSer1981, p-ATRSer428, p53, p-p53Ser151, p-H2A.XSer139, BRCA1 and PARP at 30-40 µM. However, it decreased the levels of DNA-PK and MGMT. CONCLUSION: Maslinic acid reduced the number of viable HeLa cells by inducing DNA damage and altering the expression of proteins involved in DNA damage and repair.

The roles of endoplasmic reticulum stress and Ca2+ on rhein-induced apoptosis in A-549 human lung cancer cells.

Although rhein has been shown to induce apoptosis in several cancer cell lines, the mechanism of action of rhein-induced cell cycle arrest and apoptosis at the molecular level is not well known. In this study, the mechanism of rhein action on A-549 human lung cancer cells was investigated. Rhein induced G0/G1 arrest through inhibition of cyclin D3, Cdk4 and Cdk6. The efficacious induction of apoptosis was observed at 50 microM for 12 h and up to 72 h as examined by a flow cytometric method. Flow cytometric analysis demonstrated that rhein increased the levels of GADD153 and GRP78, both hallmarks of endoplasmic reticulum stress, promoted ROS and Ca2+ production, induced the loss of mitochondrial membrane potential (delta psi(m)), promoted cytochrome c release from mitochondria, promoted capase-3 activation and led to apoptosis. Rhein also increased the levels of p53, p21 and Bax but reduced the level of Bcl-2. The Ca2+ chelator BAPTA was added to the cells before rhein treatment, thus blocking the Ca2+ production and inhibiting rhein-induced apoptosis in A-549 cells. Our data demonstrate that rhein induces apoptosis in A-549 cells via a Ca2+ -dependent mitochondrial pathway.