Diallyl sulfide, diallyl disulfide and diallyl trisulfide affect drug resistant gene expression in colo 205 human colon cancer cells in vitro and in vivo

To elevate chemo-resistance of human cancer cells is a major obstacle in the treatment and management of malignant cancers. Diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS) are presented in the Alliaceae family particularly in garlic. Although DAS, DADS and DATS have been shown to exhibit anticancer activities, there is little information on effects of these compounds on drug resistant genes in human colon cancer cells in vitro and in vivo. Herein, we are the first to show that DAS, DADS and DATS at 25 μM for 24-h and 48-h incubations promoted expression of drug resistant genes in colo 205 human colon cancer cells. In vitro experiments indicated that DATS promoted gene expression of multidrug resistant 1 (Mdr1) (p<0.05), and DAS and DADS promoted MRP3 gene expression and DATS alone stimulated gene expression of multidrug resistance-associated protein-1 (MRP1) (p<0.05) in colo 205 cells. In vivo studies demonstrated that DADS and DATS induced Mdr1 and MRP1 gene expression (p<0.05). DADS promoted MRP3 gene expression (p<0.05) as well as DADS and DATS increased MRP4 and MRP6 gene expression (p<0.05) in the colo 205 xenograft mice. Based on our in vitro and in vivo results, diallyl polysulfides (DAS, DADS and DATS) affected the gene expression of the multidrug resistance in colo 205 human colon cancer cells in vitro and in vivo.

Capsaicin induces apoptosis in SCC-4 human tongue cancer cells through mitochondria-dependent and -independent pathways

Although there have been advances in the fields of surgery, radiotherapy, and chemotherapy of tongue cancer, the cure rates are still not substantially satisfactory. Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the major pungent ingredient of hot chili pepper and has been reported to have an antitumor effect on many human cancer cell types. The molecular mechanisms of the antitumor effect of capsaicin are not yet completely understood. Herein, we investigated whether capsaicin induces apoptosis in human tongue cancer cells. Capsaicin decreased the percentage of viable cells in a dose-dependent manner in human tongue cancer SCC-4 cells. In addition, capsaicin produced DNA fragmentation, decreased the DNA contents (sub-G1 phase), and induced G0/G1 phase arrest in SCC-4 cells. We demonstrated that capsaicin-induced apoptosis is associated with an increase in reactive oxygen species and Ca²⁺ generations and a disruption of the mitochondrial transmenbrane potential (ΔΨ(m)). Treatment with capsaicin induced a dramatic increase in caspase-3 and -9 activities, as assessed by flow cytometric methods. A possible mechanism of capsaicin-induced apoptosis is involved in the activation of caspase-3 (one of the apoptosis-executing enzyme). Confocal laser microscope examination also showed that capsaicin induced the releases of AIF, ATF-4, and GADD153 from mitochondria of SCC-4 cells.

Arsenic trioxide (As₂O₃) inhibits murine WEHI-3 leukemia in BALB/c mice in vivo

Arsenic trioxide (As₂O₃) is used clinically to treat acute promyelocytic leukemia (APL) and has activity in vitro for induction of apoptosis in several solid tumor cell lines. To investigate the potential therapeutic application of As₂O₃ for leukemia, we analyzed the effects of As₂O₃ on the WEHI-3 cells-induced orthotopic leukemia animal model in vivo in this study. We established the WEHI-3 cells leukemia mice through the injection of murine WEHI-3 cells into BALB/c mice, and they were then treated with As₂O₃ (0.9 and 4.5 mg kg⁻¹ ; p.o.) and/or combined with all-trans-retinoic acid (ATRA), (30 mg kg⁻¹ ; i.p.). The results indicated that (1) As₂O₃ alone or As₂O₃ combined with ATRA promoted the total survival rate of leukemia mice and these effects are dose-dependent; (2) As₂O₃ did not affect the body weight but decreased the spleen weight; however, it did not affect liver weight; (3) As₂O₃ alone or As₂O₃ combined with ATRA increased the levels of CD3 and CD19, indicating that the differentiation of T and B cells were promoted; and (4) As₂O₃ alone or As₂O₃ combined with ATRA did not change the levels of Mac-3 and CD11b markers, indicating that the differentiation of the precursor of macrophage were not inhibited. Based on these observations, As₂O₃ alone or As₂O₃ combined with ATRA have efficacious antileukemia activity in WEHI-3 cells leukemia in vivo.

Safrole induces G0/G1 phase arrest via inhibition of cyclin E and provokes apoptosis through endoplasmic reticulum stress and mitochondrion-dependent pathways in human leukemia HL-60 cells

Safrole, a component of Piper betle inflorescence, is a carcinogen which has been demonstrated to induce apoptosis on human oral cancer HSC-3 cells in vitro and to inhibit HSC-3 cells in xenograft tumor cells in vivo. In our previous study, safrole promoted phagocytosis by macrophages and natural killer cell cytotoxicity in normal BALB/c mice. The cytotoxic effects of safrole on HL-60 cells were investigated by using flow cytometric analysis, comet assay, 4',6-diamidino-2-phenylindole (DAPI) staining, western blotting and confocal laser microscopy. The obtained results indicate that safrole induced a cytotoxic response through reducing the percentage of viable cells and induction of apoptosis in HL-60 cells in a dose-dependent manner. DAPI staining and comet assay also showed that safrole induced apoptosis (chromatin condensation) and DNA damage in HL-60 cells. The flow cytometric assay showed that safrole increased the production of reactive oxygen species (ROS) and Ca(2+) and reduced the mitochondrial membrane potential in HL-60 cells. Safrole enhanced the levels of the pro-apoptotic protein BAX, inhibited those of the anti-apoptotic protein BCL-2 and promoted the levels of apoptosis-inducing factor (AIF) and endonuclease G (Endo G) in HL-60 cells. Furthermore, safrole promoted the expression of glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153) and of activating transcription factor 6α (ATF-6α). Based on these findings, we suggest that safrole-induced apoptosis in HL-60 cells is mediated through the ER stress and intrinsic signaling pathways.

Gallic acid inhibits migration and invasion in human osteosarcoma U-2 OS cells through suppressing the matrix metalloproteinase-2/-9, protein kinase B (PKB) and PKC signaling pathways

Advanced cancer is a multifactorial disease which complicates treatment if the cancer cells have metastasized calling for the targeting of multiple cellular pathways. Gallic acid (GA) is known to possess multiple pharmacological activity including antitumor effects. This study investigated the mechanisms for the anticancer properties of GA on migration and invasion of human osteosarcoma U-2 OS cells. The migration and invasion in U-2 OS cells were determined by a Boyden chamber transwell assay. The expression levels and activities of MMP-2 and MMP-9 were measured by Western blotting, real-time PCR and gelatin zymography assays. All examined proteins levels from Western blotting indicated that GA decreased the protein levels of GRB2, PI3K, AKT/PKB, PKC, p38, ERK1/2, JNK, NF-κB p65 in U-2 OS cells. GA also inhibited the activities of AKT, IKK and PKC by in vitro kinase assay. GA suppressed the migration and invasive ability of U-2 OS cells, and it decreased MMP-2 and MMP-9 protein and mRNA levels and secreted enzyme activities in vitro. These results suggest that potential signaling pathways of GA-inhibited migration and invasion in U-2 OS cells may be due to down-regulation of PKC, inhibition of mitogen-activated protein kinase (MAPK) and PI3K/AKT, resulting in inhibition of MMP-2 and MMP-9 expressions.

Bufalin induces G0/G1 phase arrest through inhibiting the levels of cyclin D, cyclin E, CDK2 and CDK4, and triggers apoptosis via mitochondrial signaling pathway in T24 human bladder cancer cells

Most of the chemotherapy treatments for bladder cancer aim to kill the cancer cells, but a high recurrence rate after medical treatments is still occurred. Bufalin from the skin and parotid venom glands of toad has been shown to induce apoptotic cell death in many types of cancer cell lines. However, there is no report addressing that bufalin induced cell death in human bladder cancer cells. The purpose of this study was investigated the mechanisms of bufalin-induced apoptosis in a human bladder cancer cell line (T24). We demonstrated the effects of bufalin on the cell growth and apoptosis in T24 cells by using DAPI/TUNEL double staining, a PI exclusion and flow cytometric analysis. The effects of bufalin on the production of reactive oxygen species (ROS), the level of mitochondrial membrane potential (ΔΨ(m)), and DNA content including sub-G1 (apoptosis) in T24 cells were also determined by flow cytometry. Western blot analysis was used to examine the expression of G(0)/G(1) phase-regulated and apoptosis-associated protein levels in bufalin-treated T24 cells. The results indicated that bufalin significantly decreased the percentage of viability, induced the G(0)/G(1) phase arrest and triggered apoptosis in T24 cells. The down-regulation of the protein levels for cyclin D, CDK4, cyclin E, CDK2, phospho-Rb, phospho-AKT and Bcl-2 with the simultaneous up-regulation of the cytochrome c, Apaf-1, AIF, caspase-3, -7 and -9 and Bax protein expressions and caspase activities were observed in T24 cells after bufalin treatment. Based on our results, bufalin induces apoptotic cell death in T24 cells through suppressing AKT activity and anti-apoptotic Bcl-2 protein as well as inducing pro-apoptotic Bax protein. The levels of caspase-3, -7 and -9 are also mediated apoptosis in bufalin-treated T24 cells. Therefore, bufalin might be used as a therapeutic agent for the treatment of human bladder cancer in the future.

Benzyl isothiocyanate (BITC) induces G2/M phase arrest and apoptosis in human melanoma A375.S2 cells through reactive oxygen species (ROS) and both mitochondria-dependent and death receptor-mediated multiple signaling pathways

Benzyl isothiocyanates (BITC), a member of the isothiocyanate (ITC) family, inhibits cell growth and induces apoptosis in many types of human cancer cell lines. The present study investigated mechanisms underlying BITC-induced apoptosis in A375.S2 human melanoma cancer cells. To observe cell morphological changes and viability, flow cytometric assays, cell counting, and a contrast-phase microscopic examination were carried out in A375.S2 cells after BITC treatment. Cell cycle distribution and apoptosis were assessed with the analysis of cell cycle by flow cytometric assays, DAPI staining, propidium iodide (PI), and annexin V staining. Apoptosis-associated factors such as reactive oxygen species (ROS) formation, loss of mitochondrial membrane potential (ΔΨ(m)), intracellular Ca(2+) release, and caspase-3 activity were evaluated by flow cytometric assays. Abundance of cell cycle and apoptosis associated proteins was determined by Western blotting. AIF and Endo G expression was examined by confocal laser microscope. Results indicated that (1) BITC significantly reduced cell number and induced cell morphological changes in a dose-dependent manner in A375.S2 cells; (2) BITC induced arrest in cell cycle progression at G(2)/M phase through cyclin A, CDK1, CDC25C/Wee1-mediated pathways; (3) BITC induced apoptosis and increased sub-G(1) population; and (4) BITC promoted the production of ROS and Ca(2+) and loss of ΔΨ(m) and caspase-3 activity. Furthermore, BITC induced the down-regulation of Bcl-2 expression and induced up-regulation of Bax in A375.S2 cells. Moreover, BITC-induced cell death was decreased after pretreatment with N-acetyl-l-cysteine (NAC, a ROS scavenger) in A375.S2 cells. In conclusion, the results showed that BITC promoted the induction of G(2)/M phase arrest and apoptosis in A375.S2 human melanoma cells through ER stress- and mitochondria-dependent and death receptor-mediated multiple signaling pathways. These data suggest that BITC has potential as an agent for the treatment of melanoma.

Induction of DNA damage by deguelin is mediated through reducing DNA repair genes in human non-small cell lung cancer NCI-H460 cells

It has been shown that deguelin, one of the compounds of rotenoids from flavonoid family, induced cytotoxic effects through induction of cell cycle arrest and apoptosis in many types of human cancer cell lines, but deguelin-affected DNA damage and repair gene expression (mRNA) are not clarified yet. We investigated the effects of deguelin on DNA damage and associated gene expression in human lung cancer NCI-H460 cells in vitro. DNA damage was assayed by using the comet assay and DNA gel electrophoresis and the results indicated that NCI-H460 cells treated with 0, 50, 250 and 500 nM deguelin led to a longer DNA migration smear based on the single cell electrophoresis and DNA fragmentation occurred based on the examination of DNA gel electrophoresis. DNA damage and repair gene expression (mRNA) were evaluated by using real-time PCR assay and the results indicated that 50 and 250 nM deguelin for a 24-h exposure in NCI-H460 cells, decreased the gene levels of breast cancer 1, early onset (BRCA1), DNA-dependent serine/threonine protein kinase (DNA-PK), O⁶-methylguanine-DNA methyltransferase (MGMT), p53, ataxia telangiectasia mutated (ATM) and ataxia-telangiectasia and Rad3-related (ATR) mRNA expressions. Collectively, the present study showed that deguelin caused DNA damage and inhibited DNA damage and repair gene expressions, which might be due to deguelin-inhibited cell growth in vitro.

Butylated hydroxyanisole affects immunomodulation and promotes macrophage phagocytosis in normal BALB/c mice

Butylated hydroxyanisole (BHA), a synthetic antioxidant, has been used in fat and fatty foods to prevent oxidative deterioration. However, the functions of BHA on immune responses in normal mice remain elusive. The aim of the present study was to investigate the effects of oral treatment of BHA on immune responses in normal mice in vivo. BALB/c mice received various treatments. Blood samples were collected and analyzed. Flow cytometry was used to determine the levels of the cell markers. Results showed that BHA did not significantly affect the weight of the animal body and spleen in normal mice. BHA promoted macrophage phagocytosis from peripheral blood mononuclear cells, but did not alter this process in the peritoneal cavity. Furthermore, BHA did not influence natural-killer cell cytotoxicity in normal mice. Notably, BHA promoted the levels of CD3 (T cells) and decreased the level of CD19 (B cells), but did not significantly affect the levels of CD11b (monocytes) and macrophages (Mac-3) in normal mice. Based on these observations it can be concluded that BHA promotes immune responses by increasing T cells and activating phagocytosis by macrophages in normal mice. However, the molecular mechanisms require further investigation.

Bee venom induces apoptosis through intracellular Ca2+ -modulated intrinsic death pathway in human bladder cancer cells

OBJECTIVES

To focus on bee venom-induced apoptosis in human bladder cancer TSGH-8301 cells and to investigate its signaling pathway to ascertain whether intracellular calcium iron (Ca(2+)) is involved in this effect.

METHODS

Bee venom-induced cytotoxic effects, productions of reactive oxygen species and Ca(2+) and the level of mitochondrial membrane potential (ΔΨm) were analyzed by flow cytometry. Apoptosis-associated proteins were examined by Western blot analysis and confocal laser microscopy.

RESULTS

Bee venom-induced cell morphological changes and decreased cell viability through the induction of apoptosis in TSGH-8301 cell were found. Bee venom promoted the protein levels of Bax, caspase-9, caspase-3 and endonuclease G. The enhancements of endoplasmic reticulum stress-related protein levels were shown in bee venom-provoked apoptosis of TSGH-8301 cells. Bee venom promoted the activities of caspase-3, caspase-8, and caspase-9, increased Ca(2+) release and decreased the level of ΔΨm. Co-localization of immunofluorescence analysis showed the releases of endonuclease G and apoptosis-inducing factor trafficking to nuclei for bee venom-mediated apoptosis. The images revealed evidence of nuclear condensation and formation of apoptotic bodies by 4',6-diamidino-2-phenylindole staining and DNA gel electrophoresis showed the DNA fragmentation in TSGH-8301 cells.

CONCLUSIONS

Bee venom treatment induces both caspase-dependent and caspase-independent apoptotic death through intracellular Ca(2+) -modulated intrinsic death pathway in TSGH-8301 cells.

A novel synthetic 2-(3-methoxyphenyl)-6,7-methylenedioxoquinolin-4-one arrests the G2/M phase arrest via Cdc25c and induces apoptosis through caspase- and mitochondria-dependent pathways in TSGH8301 human bladder cancer cells

2-(3-methoxyphenyl)-6,7-methylenedioxoquinolin-4-one (MMEQ) is a novel synthesized compound, and this study investigated the effects of MMEQ on molecular signal pathways of the induction of apoptosis in TSGH8301 human bladder cancer cells. The studies included examining the effects of morphological changes by contrast-phase microscope, the percentage of viable cells, cell cycle distribution mitochondria membrane potential (ΔΨm), ROS and caspase activities were examined by flow cytometry, apoptotic cells were examined by DAPI staining and the changes of associated apoptosis proteins levels were examined by Western blotting. Release of apoptotic factors from mitochondria was examined by confocal laser microscope. Our results showed that MMEQ caused morphological changes and inhibited the cell growth of TSGH8301 cells in a time- and dose-dependent manner. MMEQ induced G2/M arrest through the promotion of chk1, chk2 and cdc25c in TSGH8301 cells. MMEQ caused a marked increase in the percentage of DNA damage and apoptosis as characterized by DAPI and DNA fragmentation. The specific inhibitors of caspase-8, -9, and -3 blocked MMEQ-induced growth inhibition action. A remarkable loss of ΔΨm and increase in ROS production were observed after a 24-h treatment. MMEQ promoted the levels of caspase-3, caspase-8, caspase-9, Bax, Bcl-xs, decreased the levels of Bcl-2 and Bid and then led to dysfunction of ΔΨm, following the releases of cytochrome c, AIF and Endo G from mitochondria to cytosol and nuclei, and finally caused cell apoptosis. In conclusions, these molecular mechanisms provide insight into MMEQ-caused growth inhibition, G2/M arrest and apoptotic cell death in TSGH8301 cells.

Molecular evidence of anti-leukemia activity of gypenosides on human myeloid leukemia HL-60 cells in vitro and in vivo using a HL-60 cells murine xenograft model

We have shown that gypenosides (Gyp) induced cell cycle arrest and apoptosis in many human cancer cell lines. However, there are no reports showing that show Gyp acts on human leukemia HL-60 cells in vitro and in a murine xenograft model in vivo. In the present study effects of Gyp on cell morphological changes and viability, cell cycle arrest and induction of apoptosis in vitro and effects on Gyp in an in vivo murine xenograft model. Results indicated that Gyp induced morphological changes, decreased cell viability, induced G0/G1 arrest, DNA fragmentation and apoptosis (sub-G1 phase) in HL-60 cells. Gyp increased reactive oxygen species production and Ca(2+) levels but reduced mitochondrial membrane potential in a dose- and time-dependent manner. Gyp also changed one of the primary indicators of endoplasmic reticulum (ER) stress due to the promotion of ATF6-α and ATF4-α associated with Ca(2+) release. Gyp reduced the ratio of Bcl-2 to Bax due to an increase in the pro-apoptotic protein Bax and inhibited levels of the anti-apoptotic protein Bcl-2. Oral consumption of Gyp reduced tumor size of HL-60 cell xenograft mode mice in vivo. These results provide new information on understanding mechanisms by which Gyp induces cell cycle arrest and apoptosis in vitro and in vivo.

Novel quinazoline HMJ-30 induces U-2 OS human osteogenic sarcoma cell apoptosis through induction of oxidative stress and up-regulation of ATM/p53 signaling pathway

Human osteogenic sarcoma is the most common primary bone tumor. Despite of the success of frontline therapy, about 40% of patients have disease progression and further therapy is palliative and toxic. In this study, we developed a novel quinazoline HMJ-30 to investigate the cell growth inhibition and apoptotic responses in U-2 OS human osteogenic sarcoma cells. Our results demonstrated that HMJ-30 significantly reduced cell viabilities of U-2 OS, HOS, and 143B cells in a dose-dependent manner, but it exhibited low cytotoxicity in normal hFOB cells. HMJ-30 induced DNA damage and apoptosis in U-2 OS cells as revealed by morphologic changes, comet assay and DAPI staining. Immuno-staining, colorimetric assays, and Western blotting analyses indicated that activities of caspase-8, caspase-9, and caspase-3 and the levels of Bcl-2 family-related proteins (Bcl-2, Mcl-1, Bax, BAD, and t-Bid) were altered in HMJ-30-treated U-2 OS cells. Pretreatment of cells with caspase-8, -9, and -3 specific inhibitors significantly reduced the cell growth inhibition. HMJ-30-induced apoptosis was mediated through both death-receptor and mitochondria-dependent apoptotic pathways in U-2 OS cells. HMJ-30 induced early phosphorylation of p53(Ser18) was through the activation of ataxia telangiectasia mutated (ATM) in U-2 OS cells. The cell growth inhibition by HMJ-30 was substantially attenuated either by the pre-incubation of U-2 OS cells with N-acetylcysteine (NAC, an antioxidant) and caffeine (an ATM kinase inhibitor) or by p53 knockdown via RNAi. In conclusion, ROS dependent-ATM/p53 signaling pathway is involved in HMJ-30-induced apoptosis in U-2 OS cells.

Gallic acid induces G₀/G₁ phase arrest and apoptosis in human leukemia HL-60 cells through inhibiting cyclin D and E, and activating mitochondria-dependent pathway

Gallic acid (GA) induces apoptosis in different types of cancer cell lines. In this study, we investigate the apoptotic effects induced by GA in human promyelocytic leukemia HL-60 cells, and clarify the underlying mechanism. Our results showed that GA reduced the viability of HL-60 cells in a dose- and time-dependent manner. GA led to G(0)/G(1) phase arrest in HL-60 cells through promoting p21 and p27 and inhibiting the levels of cyclin D and cyclin E. GA caused DNA damage and fragmentation in HL-60 cells as assayed using DAPI staining and Comet assay. Flow cytometric analysis revealed that GA increased Ca(2+) levels and reduced the mitochondrial membrane potential (ΔΨ(m)) in HL-60 cells. Apoptotic protein expressions were determined by Western blotting. The results indicated that GA-mediated apoptosis of HL-60 cells mainly depended on mitochondrial pathway, by promoting the release of cytochrome c, apoptosis-inducing factor (AIF) and endonuclease G (Endo G) and by up-regulating the protein expression of Bcl-2-associated X protein (BAX), caspase-4, caspase-9 and caspase-3. In addition, GA also activated the death receptor-dependent pathway by enhancing the protein expressions of fatty acid synthase (FAS), FAS ligand (FASL), caspase-8 and BCL-2 interacting domain (BID). We determined the mRNA expression of the gene levels of these proteins by real-time PCR. The results showed that GA-mediated apoptosis of HL-60 cells mainly depended on up-regulation of the mRNA of caspase-8, caspase-9, caspase-3, AIF and Endo G. In conclusion, GA-induced apoptosis occurs through the death receptor and mitochondria-mediated pathways. The evaluation of GA as a potential therapeutic agent for treatment of leukemia seems warranted.

Butein inhibits the migration and invasion of SK-HEP-1 human hepatocarcinoma cells through suppressing the ERK, JNK, p38, and uPA signaling multiple pathways

Liver cancer is one of the most commonly diagnosed cancers and the leading cause of death in human populations. Butein, a tetrahydroxychalcone, has been shown to induce apoptosis in many human cancer cells, but the effects of butein on the migration and invasion of human liver cancer cells are not reported. Herein, we found that butein is effective in the suppression of migration and invasion in SK-HEP-1 human hepatocarcinoma cells by using the Matrigel cell migration assay and invasion system. The gelatin zymography assay indicated that butein inhibited the activity of matrix metalloproteinases 2 (MMP-2) and MMP-9. Western blotting analysis indicated that butein decreased the levels of MMP-2, -7, and -9, uPA, Ras, Rho A, ROCK1, ERK1/2, JNK1/2, p-p38, and p-c-Jun in SK-HEP-1 cells. Furthermore, butein inhibited the NF-κB binding activity in SK-HEP-1 cells by electrophoretic mobility shift assay. We also found that butein decreased the ERK, JNK, and p38 in SK-HEP-1 cells by in vitro kinase assay. In conclusion, this is the first study to demonstrate that butein might be a novel anticancer agent for the treatment of hepatocarcinoma through inhibiting migration and invasion.

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC)-mediated generation of reactive oxygen species causes cell cycle arrest and induces apoptosis via activation of caspase-3, mitochondria dysfunction and nitric oxide (NO) in human osteogenic sarcoma U-2 OS cells

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC), a member of the isothiocyanate family, have been shown to exhibit antineoplastic ability against many human cancer cells. In this study, we found that exposure of human osteogenic sarcoma U-2 OS cells to BITC and PEITC led to induce morphological changes and to decrease the percentage of viable cells in a time- and dose-dependent manner. BITC and PEITC induced cell cycle arrest at G2/M phase at 48 h treatment and inhibited the levels of cell cycle regulatory proteins such as cyclin A and B1 in U-2 OS cells but promoted the level of Chk1 and p53 that led to G2/M arrest. BITC and PEITC induced a marked increase in apoptosis (DNA fragmentation) and poly(ADP-ribose)polymerase (PARP) cleavage, which was associated with mitochondrial dysfunction and the activation of caspase-9 and -3. BITC and PEITC also promoted the ROS production in U-2 OS cells and the N-acetylcysteine (NAC, an antoxidant agent) was pretreated and then treated with both compounds which led to decrease the levels of ROS and increase the cell viability. Interestingly, BITC and PEITC promoted the levels of NO production and increased the iNOS enzyme. Confocal laser microscope also demonstrated that BITC and PEITC promoted the release of cytochrome c and AIF, suggesting that both compounds induced apoptosis through ROS, caspase-3 and mitochondrial, and NO signaling pathways. Taken together, these molecular alterations and signaling pathways offer an insight into BITC and PEITC-caused growth inhibition, G2/M arrest, and apoptotic death of U-2 OS cells.

Proteomic approaches to study epigallocatechin gallate-provoked apoptosis of TSGH-8301 human urinary bladder carcinoma cells: roles of AKT and heat shock protein 27-modulated intrinsic apoptotic pathways

Epigallocatechin-3-gallate (EGCG), a polyphenol constituent present in green tea, has been shown to inhibit the growth of cancer cells in vitro and in vivo. However, studies regarding human bladder carcinoma cells are limited and not well investigated. Hence, our study focused on the evaluation of EGCG-triggered apoptosis in TSGH-8301 human urinary bladder carcinoma cells in vivo and in vitro as well as its related molecular mechanisms. In an in vivo study, EGCG inhibited xenograft tumor size of TSGH-8301 cells in a nude mouse model. Based on an in vitro study, EGCG resulted in morphological changes and increased growth inhibition in a dose- and time-dependent manner in TSGH-8301 cells. Furthermore, sub-G1 populations were shown and caspase-9 and -3 activities were stimulated in EGCG-treated TSGH-8301 cells. Moreover, a caspase-9 inhibitor (Z-LEHD-FMK) and a caspase-3 inhibitor (Z-DEVD-FMK) were able to reduce EGCG-stimulated caspase-9 and -3 activities, respectively. Loss of mitochondrial membrane potential (∆Ψm) resulted in an increase of protein levels of cytochrome c, Apaf-1, caspase-9 and -3 in TSGH-8301 cells following exposure to EGCG. Proteomic analysis revealed that EGCG affected the expression levels of various proteins, including HSP27, porin, tropomyosin 3 isoform 2, prohibitin and keratin 5, 14, 17 in TSGH-8301 cells. EGCG also suppressed AKT kinase activity and protein levels and also altered the expression levels of Bcl-2 family-related proteins such as Bcl-2, Bax, BAD and p-BAD. Based on the above findings, this study suggests that EGCG-provoked apoptotic death in TSGH-8301 cells is mediated through targeting AKT and HSP27 and modulating p-BAD, leading to activation of the intrinsic apoptotic pathway.

Extract of Hedyotis diffusa Willd influences murine leukemia WEHI-3 cells in vivo as well as promoting T- and B-cell proliferation in leukemic mice

Medicinal plants and herbs are widely used in the treatment of various types of cancer in Taiwan, China and many other countries. Hedyotis diffusa Willd (HDW) has been known as a traditional Chinese medicine for a long time, and possesses various bioactivities and anticancer activity. There is no available information on the effects of HDW extracts in leukemic mice and on immune responses in vivo. In this study, we established murine WEHI-3 leukemia in BALB/c mice and hypothesized that an aqueous HDW extract might have antileukemia effects on leukemic animals in vivo. The major characteristic of leukemic mice was an enlarged spleen after intraperitoneal injection with WEHI-3 cells. HDW extract reduced the weights of spleen and liver, but had no significant effect on body weight in WEHI-3 leukemic mice. HDW extract increased the percentage of CD11b cell surface marker (monocytes), but it reduced the percentage of CD3 (T-cell) and CD19 (B-cell) markers. However, HDW extract did not affect the level of Mac-3 and there was no influence on phagocytosis by macrophages from peripheral blood mononuclear cells and the peritoneal cavity in leukemic mice. The isolated splenocytes from HDW extract-treated leukemic mice demonstrated an increase of T- and B-cell proliferation in vivo. Based on these results, HDW extract would appear to have antileukemia activity in WEHI-3 cell-induced leukemia in vivo.

Diallyl trisulfide (DATS) inhibits mouse colon tumor in mouse CT-26 cells allograft model in vivo

Our earlier studies showed that DATS induced apoptosis in human colon cancer HT29 and colo 205 cell lines in vitro. However, there is no report to show that DATS induced apoptosis in vitro and inhibited CT26 cancer cells in vivo on a murine allograft animal model. In vitro studies, the results indicated that DATS induced morphological changes and induction of apoptosis in CT26 cells. In vivo studies, CT26 cancer cells were implanted into BALB/c mice and groups of mice were treated with vehicle, DATS (10 and 50 mg/kg of body weight). DATS were injected once per four days intraperitoneally (i.p.), with treatment starting 4 weeks prior to cells inoculation. Treatment with vehicle or with 10 and 50 mg/kg of DATS resulted in a reduction in tumor volume and weight. Tumor volume and total hemoglobin in allograft mice treated with 50 mg/kg DATS were significantly smaller than that in the control group. These findings indicated that DATS inhibits tumor growth in an allograft animal model. Thus, DATS may represent a colon cancer preventive agent and can be used in the future.

Gypenosides suppress growth of human oral cancer SAS cells in vitro and in a murine xenograft model: the role of apoptosis mediated by caspase-dependent and caspase-independent pathways

PURPOSE

Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino. The authors investigated the effects of Gyp on cell morphology, viability, cell cycle distribution, and induction of apoptosis in human oral cancer SAS cells and the determination of murine SAS xenograft model in vivo.

EXPERIMENTAL DESIGN

Flow cytometry was used to quantify the percentage of viable cells; cell cycle distribution; sub-G1 phase (apoptosis); caspase-3, -8, and -9 activity; reactive oxygen species (ROS) production, intracellular Ca(2+) determination; and the level of mitochondrial membrane potential (ΔΨ(m)). Western blotting was used to examine levels of apoptosis-associated proteins, and confocal laser microscopy was used to examine the translocation of proteins in cells.

RESULTS

Gyp induced morphological changes, decreased the percentage of viable cells, caused G0/G1 phase arrest, and triggered apoptotic cell death in SAS cells. Cell cycle arrest induced by Gyp was associated with apoptosis. The production of ROS, increased intracellular Ca(2+) levels, and the depolarization of ΔΨ(m) were observed. Gyp increased levels of the proapoptotic protein Bax but inhibited the levels of the antiapoptotic proteins Bcl-2 and Bcl-xl. Gyp also stimulated the release of cytochrome c and Endo G. Translocation of GADD153 to the nucleus was stimulated by Gyp. Gyp in vivo attenuated the size and volume of solid tumors in a murine xenograft model of oral cancer.

CONCLUSIONS

Gyp-induced cell death occurs through caspase-dependent and caspase-independent apoptotic signaling pathways, and the compound reduced tumor size in a xenograft nu/nu mouse model of oral cancer.

The novel synthesized 6-fluoro-(3-fluorophenyl)-4-(3-methoxyanilino)quinazoline (LJJ-10) compound exhibits anti-metastatic effects in human osteosarcoma U-2 OS cells through targeting insulin-like growth factor-I receptor

Our previous study demonstrated that 6-fluoro-(3-fluorophenyl)-4-(3-methoxyanilino)quinazoline (LJJ-10) possesses potential anticancer activity and exhibits greater antitumor effect than the other quinazoline compounds in human osteogenic sarcoma U-2 OS cells via in vitro screening. In this study, we focused on investigating the anti-metastatic activity and the signaling pathways involved in LJJ-10 action in U-2 OS cells. The results from wound healing and Boyden chamber transwell assays indicated that LJJ-10 exhibited an inhibitory effect on the migration and invasion of U-2 OS cells. LJJ-10 also inhibited matrix metalloproteinase-2 (MMP-2) and MMP-9 enzyme activities and caused a concentration-dependent decrease in protein levels by gelatin zymography assay and Western blot analysis, respectively. Meanwhile, LJJ-10 suppressed MMP-2 and MMP-9 mRNA levels in a concentration-dependent fashion after 12-h exposure in U-2 OS cells. Computational modeling showed that LJJ-10 is bound into the IGF-1R via hydrophobic interactions with Leu975, Val983, Ala1001, Glu1050 and Met1052 with one hydrogen bond between 6-F and Met1052. LJJ-10 reduced the protein levels of p-JNK, p-p38, p-ERK, p-AKT and p-IGFR by Western blotting and these influences are concentration-dependent. Based on these observations, this study suggests that molecular targeting of the insulin-like growth factor-I receptor (IGF-1R) signaling leads to the suppression of downstream MAPK/AKT signaling and downregulation of MMP-2 and -9 RNA levels and protein levels in LJJ-10-treated U-2 OS cells. Therefore, the inhibition of metastasis in human osteosarcoma cells by treatment with this novel agent, LJJ-10 may be a useful chemotherapeutic approach.

Etomidate induces cytotoxic effects and gene expression in a murine leukemia macrophage cell line (RAW264.7)

Etomidate is an important tool in the arsenal of the emergency physician, and it has been used in a variety of scenarios for both intubation and procedural sedation. In the present study, we investigated the cytotoxicity of etomidate including induction of apoptosis, and levels of protein and gene expressions associated with apoptotic cell death in murine leukemia RAW264.7 cells in vitro. Cytotoxic and apoptotic responses to etomidate of RAW264.7 cells, including cell morphological changes and cell viability were examined and measured by phase-contrast microscopy and flow cytometric assay, respectively. Results indicated that etomidate increased apoptotic cell morphological changes and reduced cell viability in RAW264.7 cells. 4',6-Diamidino-2-phenylindole (DAPI) staining also showed that etomidate induced the formation of apoptotic bodies, a characteristic of apoptosis. Results from Western blotting indicated that etomidate enhanced the levels of cytochrome c, apoptosis-inducing factor (AIF), endonuclease G (Endo G), caspase-9, caspase-3 active form and Bax proteins, but it inhibited the expression of Bcl-xl, leading to apoptosis. DNA microarray assay indicated that etomidate increased the expression of 17 genes (LOC676175; Gm14636; 2810021G02Rik; Iltifb; Olfr1167; Ttc30b; Olfr766; Gas5; Rgs1; LOC280487; V1rd4; Hist1h2bc; V1rj3; Gm10366; Olfr192; Gm10002 and Cspp1) and reduced the expression of 15 genes: (Gm10152; Gm5334; Olfr216; Lcn9; Gm10683; Gm5100; Tdgf1; Cypt2; Gm5595; 1700018F24Rik; Gm10417; Maml2; Olfr591; Trdn and Apol7c). In conclusion, etomidate induced cytotoxic and apoptotic effects the in murine leukemia RAW264.7 cells in vitro.

Apoptotic death in curcumin-treated NPC-TW 076 human nasopharyngeal carcinoma cells is mediated through the ROS, mitochondrial depolarization and caspase-3-dependent signaling responses

Curcumin, a potent candidate anticancer agent, is a dietary pigment (phenolic compound) derived from the food flavoring spice turmeric (Curcuma longa), and it has been shown to have inhibitory effects on tumor cells through anti-proliferative and proapoptotic activities. However, there is no report showing curcumin-induced apoptotic cell death in human nasopharyngeal carcinoma cells in vitro. Thus, this study was performed to elucidate whether mitochondria and caspase cascades are involved in the modulation of apoptosis and cell cycle arrest in curcumin-treated NPC-TW 076 human nasopharyngeal carcinoma cells. The effects of curcumin on cell cycle arrest and apoptosis were measured by flow cytometry, and caspase-3 activity, apoptosis-associated protein levels and its regulated molecules were studied by flow cytometric assay and immunoblots. The results indicated that curcumin-induced G2/M phase arrest was associated with a marked decrease in the protein expression of cyclin A, cyclin B and cyclin-dependent kinase 1 (Cdk1). Curcumin-induced apoptosis was accompanied with upregulation of the protein expression of Bax and downregulation of the protein levels of Bcl-2, resulting in dysfunction of mitochondria and subsequently led to cytochrome c release and sequential activation of caspase-9 and caspase-3 in NPC-TW 076 cells in a time-dependent manner. These findings revealed that mitochondria, AIF caspase-3- dependent pathways play a vital role in curcumin-induced G2/M phase arrest and apoptosis of NPC-TW 076 cells in vitro.