Synergistic Tumoricidal Effects of Alpha-Lipoic Acid and Radiotherapy on Human Breast Cancer Cells via HMGB1.

PURPOSE: Radiotherapy (RT) is one of main strategies of cancer treatment. However, some cancer cells are resistant to radiation-induced cell death, including apoptosis. Therefore, alternative approaches targeting different anti-tumor mechanisms such as cell senescence are required. This study aimed to investigate the synergistic effect of alpha-lipoic acid (ALA) on radiation-induced cell death and senescence in MDA-MB-231 human breast cancer cells. MATERIALS AND METHODS: The cells were divided into four groups depending on the cell treatment (control, ALA, RT, and ALA+RT). Cells were analyzed for morphology, apoptotic cell death, mitochondrial reactive oxygen species, membrane potential, cellular senescence, and cell cycle. RESULTS: Our data showed that ALA significantly promoted apoptotic cell death when combined with RT, as reflected by Annexin V staining, expression of apoptosis-related factors, mitochondrial damages as well as cell morphological changes and reduction of cell numbers. In addition, ALA significantly enhanced radiation-induced cellular senescence, which was shown by increased HMGB1 expression in the cytosol fraction compared to the control, increased p53 expression compared to the control, activation of p38 as well as nuclear factor кB, and G2/M cell cycle arrest. CONCLUSION: The current study is the first report showing a new mode of action (senescence induction) of ALA beyond apoptotic cell death in MDA-MB-231 cancer cells known to be resistant to RT.

Anthocyanins Derived from Vitis coignetiae Pulliat Contributes Anti-Cancer Effects by Suppressing NF-κB Pathways in Hep3B Human Hepatocellular Carcinoma Cells and In Vivo.

We previously demonstrated that anthocyanins from the fruits of Vitis coignetiae Pulliat (AIMs) induced the apoptosis of hepatocellular carcinoma cells. However, many researchers argued that the concentrations of AIMs were too high for in vivo experiments. Therefore, we performed in vitro at lower concentrations and in vivo experiments for the anti-cancer effects of AIMs. AIMs inhibited the cell proliferation of Hep3B cells in a dose-dependent manner with a maximum concentration of 100 µg/mL. AIMs also inhibited the invasion and migration at 100 µg/mL concentration with or without the presence of TNF-α. To establish the relevance between the in vitro and in vivo results, we validated their effects in a Xenograft model of Hep3B human hepatocellular carcinoma cells. In the in vivo test, AIMs inhibited the tumorigenicity of Hep3B cells in the xenograft mouse model without showing any clinical signs of toxicity or any changes in the body weight of mice. AIMs inhibited the activation NF-κB and suppressed the NF-κB-regulated proteins, intra-tumoral microvessel density (IMVD) and the Ki67 activity of Hep3B xenograft tumors in athymic nude mice. In conclusion, this study indicates that AIMs have anti-cancer effects (inhibition of proliferation, invasion, and angiogenesis) on human hepatocellular carcinoma xenograft through the inhibition of NF-κB and its target protein.

Pretreatment of Anthocyanin from the Fruit of Vitis coignetiae Pulliat Acts as a Potent Inhibitor of TNF-α Effect by Inhibiting NF-κB-Regulated Genes in Human Breast Cancer Cells.

Vitis coignetiae Pulliat (Meoru in Korea) has been used in Korean folk medicine for the treatment of inflammatory diseases and cancers. Evidence suggests that NF-κB activation is mainly involved in cancer cell proliferation, invasion, angiogenesis, and metastasis. TNF-α also enhances the inflammatory process in tumor development. Recently, flavonoids from plants have been reported to have inhibitory effects on NF-κB activities. We investigated the effects of anthocyanins extracted from the fruits of Vitis coignetiae Pulliat (AIM, anthocyanins isolated from Meoru (AIM)) on TNF-α-induced NF-κB activities in MCF-7 human breast cancer cells and the molecules involved in AIM-induced anti-cancer effects, especially on cancer metastasis. We performed cell viability assay, gelatin zymography, invasion assay, and western blot analysis to unravel the anti-NF-κB activity of AIMs on MCF-7 cells. AIM suppressed the TNF-α effects on the NF-κB-regulated proteins involved in cancer cell proliferation (COX-2, C-myc), invasion, and angiogenesis (MMP-2, MMP9, ICAM-1, and VEGF). AIM also increased the expression of E-cadherin, which is one of the hallmarks of the epithelial-mesenchymal transition (EMT) process. In conclusion, this study demonstrates that the anthocyanins isolated from the fruits of Vitis coignetiae Pulliat acts as an inhibitor of TNF-α induced NF-κB activation, and subsequent downstream molecules involved in cancer proliferation, invasion, adhesion, angiogenesis, and thus have anti-metastatic activities in MCF-7 breast cancer cells.

Alpha-Lipoic Acid Ameliorates Radiation-Induced Salivary Gland Injury by Preserving Parasympathetic Innervation in Rats.

Radiation therapy is a standard treatment for patients with head and neck cancer. However, radiation exposure to the head and neck induces salivary gland (SG) dysfunction. Alpha lipoic acid (ALA) has been reported to reduce radiation-induced toxicity in normal tissues. In this study, we investigated the effect of ALA on radiation-induced SG dysfunction. Male Sprague-Dawley rats were assigned to the following treatment groups: control, ALA only (100 mg/kg, intraperitoneally), irradiation only, and ALA administration 24 h or 30 min prior to irradiation. The neck area, including SGs, was irradiated evenly at 2 Gy/min (total dose, 18 Gy) using a photon 6 MV linear accelerator. The rats were sacrificed at 2, 6, 8, and 12 weeks after irradiation. Radiation decreased SG weight, saliva secretion, AQP5 expression, parasympathetic innervation (GFRα2 and AchE expression), regeneration potentials (Shh and Ptch expression), salivary trophic factor levels (brain-derived neurotrophic factor and neurturin), and stem cell expression (Sca-1). These features were restored by treatment with ALA. This study demonstrated that ALA can rescue radiation-induced hyposalivation by preserving parasympathetic innervation and regenerative potentials.

Effects of pepsin and pepstatin on reflux tonsil hypertrophy in vitro.

There is evidence that pepsin can aggravate tonsil hypertrophy. Pepstatin is a potent inhibitor of pepsin activity and could protect patients against reflux tonsil hypertrophy by inhibiting pepsin. We examined the effects of pepstatin on the development of tonsil hypertrophy to investigate pepsin's role in the pathogenesis of tonsil lesions. We investigated whether pepstatin suppresses pepsin-mediated lymphocyte proliferation in tonsil hypertrophy. Forty-nine children with tonsil hypertrophy and twenty-two adults with tonsillitis were recruited to the study prior to surgery. Tonsil tissue from each patient was harvested and assessed for changes in the number of lymphocytes and macrophages in the presence of pepsin and pepstatin. We found that the proportions of CD4- and CD14-positive cells were significantly lower (p < 0.05), but that the proportions of CD19- and CD68-positive cells were significantly higher (p < 0.05), in children than in adults. There were significantly more CD4-positive cells after pepsin treatment, but these numbers were reduced by pepstatin. The levels of both interleukin-2 (IL-2) and interferon gamma (IFN-γ) increased significantly in response to pepsin, but were reduced when pepsin was inhibited by pepstatin. The level of IL-10 is reduced in pepsin-treated CD4 cells and the level is restored by pepstatin. IL-2 blocking reduced the increased CD4 cell number by pepsin. But, an additive or a synergic effect is not founded in combined with IL-2 blocking and pepstatin. Pepsin-positive cells did not co-localize with CD20 and CD45 cells, but they were found surrounding CD20- and CD45-positive hypertrophic tonsil cells. Pepsin-positive cells co-localized with CD68-positive cells. It is probable that pepsin from extraesophageal reflux aggravates tonsil hypertrophy and pepstatin exerts a protective effect by inhibiting pepsin activity.

Ursodeoxycholic Acid Induces Death Receptor-mediated Apoptosis in Prostate Cancer Cells.

BACKGROUND: Bile acids have anti-cancer properties in a certain types of cancers. We determined anticancer activity and its underlying molecular mechanism of ursodeoxycholic acid (UDCA) in human DU145 prostate cancer cells. METHODS: Cell viability was measured with an MTT assay. UDCA-induced apoptosis was determined with flow cytometric analysis. The expression levels of apoptosis-related signaling proteins were examined with Western blotting. RESULTS: UDCA treatment significantly inhibited cell growth of DU145 in a dose-dependent manner. It induced cellular shrinkage and cytoplasmic blebs and accumulated the cells with sub-G1 DNA contents. Moreover, UDCA activated caspase 8, suggesting that UDCA-induced apoptosis is associated with extrinsic pathway. Consistent to this finding, UDCA increased the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, death receptor 4 (DR4) and death receptor 5 (DR5), and TRAIL augmented the UDCA-induced cell death in DU145 cells. In addition, UDCA also increased the expressions of Bax and cytochrome c and decreased the expression of Bcl-xL in DU145 cells. This finding suggests that UDCA-induced apoptosis may be involved in intrinsic pathway. CONCLUSIONS: UDCA induces apoptosis via extrinsic pathway as well as intrinsic pathway in DU145 prostate cancer cells. UDCA may be a promising anti-cancer agent against prostate cancer.

Tetraarsenic hexoxide induces G2/M arrest, apoptosis, and autophagy via PI3K/Akt suppression and p38 MAPK activation in SW620 human colon cancer cells.

Tetraarsenic hexoxide (As4O6) has been used in Korean folk medicines for the treatment of cancer, however its anti-cancer mechanisms remain obscured. Here, this study investigated the anti-cancer effect of As4O6 on SW620 human colon cancer cells. As4O6 has showed a dose-dependent inhibition of SW620 cells proliferation. As4O6 significantly increased the sub-G1 and G2/M phase population, and Annexin V-positive cells in a dose-dependent manner. G2/M arrest was concomitant with augment of p21 and reduction in cyclin B1, cell division cycle 2 (cdc 2) expressions. Nuclear condensation, cleaved nuclei and poly (adenosine diphosphate­ribose) polymerase (PARP) activation were also observed in As4O6-treated SW620 cells. As4O6 induced depolarization of mitochondrial membrane potential (MMP, ΔΨm) but not reactive oxygen species (ROS) generation. Further, As4O6 increased death receptor 5 (DR5), not DR4 and suppressed the B­cell lymphoma­2 (Bcl-2) and X-linked inhibitor of apoptosis protein (XIAP) family proteins. As4O6 increased the formation of AVOs (lysosomes and autophagolysosomes) and promoted the conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3)-I to LC3-II in a dose- and time- dependent manner. Interestingly, a specific phosphoinositide 3-kinase (PI3K)/Akt inhibitor (LY294002) augmented the As4O6 induced cell death; whereas p38 mitogen-activated protein kinases (p38 MAPK) inhibitor (SB203580) abrogated the cell death. Thus, the present study provides the first evidence that As4O6 induced G2/M arrest, apoptosis and autophagic cell death through PI3K/Akt and p38 MAPK pathways alteration in SW620 cells.

In vitro and long-term (2-year follow-up) in vivo osteogenic activities of human periosteum-derived osteoblasts seeded into growth factor-releasing polycaprolactone/pluronic F127 beads scaffolds.

Polycaprolactone (PCL) is a biodegradable polyester that is bioresorbable and biocompatible, and is widely used in medical fields. This study examines in vitro and in vivo osteogenic activities of cultured human periosteum-derived osteoblasts (POs) seeded into growth factor (bone morphogenic protein 2 [BMP-2] or vascular endothelial growth factor [VEGF])-releasing scaffolds of PCL beads coated with Pluronic F127. Each growth factor immobilized in the PCL/F127 is cumulatively released from the beads for more than 40 days (up to 3.04 ± 0.08 ng mg-1 BMP-2 and 3.41 ± 0.18 ng mg-1 VEGF in 42 days). Long-term (∼2 years) experimental results obtained in a miniature pig model suggest that POs seeded into BMP-2 + VEGF-releasing PCL/P-F127 beads are the most effective for bone repair. In in vitro assays, osteogenic activities were higher in POs seeded into BMP-2-releasing PCL/Pluronic F127 beads at earlier time points and in POs seeded into BMP-2 + VEGF-releasing PCL/Pluronic F127 beads at later time points. These results suggest that the combination of BMP-2 and VEGF more sufficiently stimulates (in particular at late time points) osteoblast differentiation of POs seeded in the PCL/F127 in vitro and in vivo, and thus allows effective bone regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 363-376, 2017.

Cultured Human Periosteum-Derived Cells Can Differentiate into Osteoblasts in a Perioxisome Proliferator-Activated Receptor Gamma-Mediated Fashion via Bone Morphogenetic Protein signaling.

The differentiation of mesenchymal stem cells towards an osteoblastic fate depends on numerous signaling pathways, including activation of bone morphogenetic protein (BMP) signaling components. Commitment to osteogenesis is associated with activation of osteoblast-related signal transduction, whereas inactivation of this signal transduction favors adipogenesis. BMP signaling also has a critical role in the processes by which mesenchymal stem cells undergo commitment to the adipocyte lineage. In our previous study, we demonstrated that an agonist of the perioxisome proliferator-activated receptor γ (PPARγ), a master regulator of adipocyte differentiation, stimulates osteoblastic differentiation of cultured human periosteum-derived cells. In this study, we used dorsomorphin, a selective small molecule inhibitor of BMP signaling, to investigate whether BMP signaling is involved in the positive effects of PPARγ agonists on osteogenic phenotypes of cultured human periosteum-derived cells. Both histochemical detection and bioactivity of ALP were clearly increased in the periosteum-derived cells treated with the PPARγ agonist at day 10 of culture. Treatment with the PPARγ agonist also caused an increase in alizarin red S staining and calcium content in the periosteum-derived osteoblasts at 2 and 3 weeks of culture. In contrast, dorsomorphin markedly decreased ALP activity, alizarin red S staining and calcium content in both the cells treated with PPARγ agonist and the cells cultured in osteogenic induction media without PPARγ agonist during the culture period. In addition, the PPARγ agonist clearly increased osteogenic differentiation medium-induced BMP-2 upregulation in the periosteum-derived osteoblastic cells at 2 weeks of culture as determined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), immunoblotting, and immunocytochemical analyses. Although further study will be needed to clarify the mechanisms of PPARγ-regulated osteogenesis, our results suggest that the positive effects of a PPARγ agonist on the osteogenic phenotypes of cultured human periosteum-derived cells seem to be dependent on BMP signaling.

Autophagy Has a Beneficial Role in Relieving Cigarette Smoke-Induced Apoptotic Death in Human Gingival Fibroblasts.

The deleterious role of cigarette smoke has long been documented in various human diseases including periodontal complications. In this report, we examined this adverse effect of cigarette smoke on human gingival fibroblasts (HGFs) which are critical not only in maintaining gingival tissue architecture but also in mediating immune responses. As well documented in other cell types, we also observed that cigarette smoke promoted cellular reactive oxygen species in HGFs. And we found that this cigarette smoke-induced oxidative stress reduced HGF viability through inducing apoptosis. Our results indicated that an increased Bax/Bcl-xL ratio and resulting caspase activation underlie the apoptotic death in HGFs exposed to cigarette smoke. Furthermore, we detected that cigarette smoke also triggered autophagy, an integrated cellular stress response. Interesting, a pharmacological suppression of the cigarette smoke-induced autophagy led to a further reduction in HGF viability while a pharmacological promotion of autophagy increased the viability of HGFs with cigarette smoke exposures. These findings suggest a protective role for autophagy in HGFs stressed with cigarette smoke, highlighting that modulation of autophagy can be a novel therapeutic target in periodontal complications with cigarette smoke.

Development of Porous Beads to Provide Regulated BMP-2 Stimulation for Varying Durations: In Vitro and In Vivo Studies for Bone Regeneration.

It is commonly accepted that the sustained release of bone morphogenetic protein-2 (BMP-2) can enhance bone regeneration and minimize its safety issues. However, little is known regarding the appropriate duration of BMP-2 stimulation for sufficient osteogenic differentiation and new bone formation because of the short half-life of BMP-2 in the physiological environment and the lack of a well-defined delivery matrix that can regulate the release period of BMP-2. In this study, we prepared porous poly(lactic-co-glycolic acid) (PLGA) beads with different surface pore sizes that can regulate the release period of BMP-2 (i.e., 7, 17, and 30 days) while providing the BMP-2 concentration required for bone regeneration. Our findings in both in vitro cell culture and in vivo animal studies using these BMP-2-loaded beads demonstrate that release of BMP-2 within 7 days affects only the initial differentiation of human periosteum-derived cells (hPDCs) and does not significantly enhance their subsequent differentiation into mature functional cells. However, extending the duration of BMP-2 stimulation over 17 days can provide a suitable environment for osteogenic differentiation of hPDCs and new bone formation.

FOXO1 Is Involved in the Effects of Cigarette Smoke Extract on Osteoblastic Differentiation of Cultured Human Periosteum-derived Cells.

Cigarette smoke is associated with delayed fracture healing, alterations in mineral content, and osteoporosis, however, its effects on osteoblastic differentiation of osteoprogenitor cells are not fully understood. In the present study, we examined the effects of cigarette smoke extract (CSE) on osteoblastic differentiation of cultured human periosteum-derived cells. We found that CSE inhibited alkaline phosphatase (ALP) activity, mineralization and Runx2 transactivation of the periosteum-derived cells. Nucleofection of RUNX2 into the periosteum-derived cells increased expression of endogenous osteocalcin (OC) and ALP genes in osteogenic induction medium and increased OC expression in non-osteogenic medium. Treatment of the periosteum-derived cells with CSE resulted in decreased phosphorylation of AKT and forkhead box protein O1 (FOXO1). The AKT phosphorylation-resistant mutant, FOXO1-A3, inhibited transcriptional activity of RUNX2 in the periosteum-derived cells. The current study suggests one mechanism by which CSE exposure leads to inhibition of osteoblastic differentiation of cultured human periosteum-derived cells.

Tetraarsenic hexoxide demonstrates anticancer activity at least in part through suppression of NF-κB activity in SW620 human colon cancer cells.

Tetraarsenic hexoxide (As4O6) has been used in Korean traditional medicine for the treatment of cancer since the late 1980's, and arsenic trioxide (As2O3) is currently used as a chemotherapeutic agent. Previous studies suggest that the As4O6-induced cell death pathway is different from that of As2O3 and its mechanism of anticancer activity remains unclear. Nuclear factor (NF)-κB is a well-known transcription factor involved in cell proliferation, invasion and metastasis. Hence, in the present study, we investigated the effects of As4O6 on NF-κB activity and NF-κB-regulated gene expression in vitro and in vivo. The cytotoxicity assay revealed that As4O6 inhibited the growth of SW620 cells in a dose-dependent manner, and the half maximal inhibitory concentration (IC50) was ~1 µM after a 48 h treatment. As4O6 suppressed NF-κB activation and suppressed inhibitory κBα (IκBα) phosphorylation stimulated by tumor necrosis factor (TNF). As4O6 also suppressed downstream NF-κB-regulated proteins involved in cancer anti-apoptosis, proliferation, invasion and metastasis. In addition, As4O6 marginally suppressed tumor growth and the anti-NF-κB activity was confirmed using an in vivo xenograft mouse model in which animals were injected with SW620 cells. The present study provides evidence that As4O6 has anticancer properties through suppression of NF-κB activity and NF-κB-mediated cellular responses.

Flavonoids from Orostachys japonicus A. Berger induces caspase-dependent apoptosis at least partly through activation of p38 MAPK pathway in U937 human leukemic cells.

BACKGROUND: Orostachys japonicus A. Berger (A. Berger) is commonly used as a folk remedy for cancer therapy. However, the mechanisms of its anti-cancer activity are poorly investigated in human cancer cells. In this study, we investigated whether flavonoids extracted from Orostachys japonicus A. Berger (FEOJ) might have anticancer effects in human leukemia cells, focusing on cell death mechanisms. MATERIALS AND METHODS: U937 human leukemic cancer cells were used. RESULTS: FEOJ induced apoptosis in a dose-dependent manner in human U937 cancer cells. Flow cytometry revealed significant accumulation of cells with sub-G1 DNA content at the concentrations of 200 µg/mL and 400 µg/mL. FEOJ-induced apoptosis was caspase-dependent through loss of mitochondrial membrane potential (MMP, ΔΨm) in human U937 cancer cells, which might be associated with suppression of Bcl-2 and XIAP proteins. FEOJ induced the p38 MAPK signaling pathway, playing at least in part an important role in FEOJ-induced apoptosis. CONCLUSIONS: This study suggested that FEOJ may induce caspase-dependent apoptosis in human leukemic cells by regulating MMP (ΔΨm) through suppressing Bcl-2 and X-IAP. In addition, the results indicated that upstream p38 MAPK signaling regulates the apoptotic effect of FEOJ. This study provides evidence that FEOJ might have anti-cancer potential for human leukemic cells.

Synthesized tetrahydroisoquinoline alkaloid exerts anticancer effects at least in part by suppressing NF-κB-regulated proteins in A549 human lung cancer cells.

CKD-712, a newly synthesized tetrahydroisoquinoline (THI) and an enantiomer (S form) of YS 49 (a derivative of higenamine) has been reported to suppress nuclear factor-κB (NF-κB) activity in normal cells. In the present study, we investigated the anticancer effects of THI at a low concentration where CKD-712 did not induce cell death in normal cells. At the range of concentrations used, CKD-712 induced cell growth arrest, and inhibited the invasion and motility of A549 cells as determined by cell cycle analysis, a Matrigel-coated chamber assay, and a wound-healing assay, respectively. CKD-712 suppressed MMP-9, but not MMP-2 and other NF-κB-regulated proteins involved in cancer metastasis such as VEGF. Moreover, CKD-712 induced cell cycle arrest at G2M phase by suppressing cyclin A, cyclin B and CDK-1 expression. Taken together, these data suggested that CKD-712 may exert anticancer effects by suppressing NF-κB pathways and inducing cell cycle arrest at G2M phase.

Polyphenols Isolated from Allium cepa L. Induces Apoptosis by Induction of p53 and Suppression of Bcl-2 through Inhibiting PI3K/Akt Signaling Pathway in AGS Human Cancer Cells.

BACKGROUND: The extract of Allium cepa Linn is commonly used as adjuvant food for cancer therapy. We assumed that it includes a potential source of anti-cancer properties. METHODS: We investigated anti-cancer effects of polyphenols extracted from lyophilized A. cepa Linn (PEAL) in AGS human cancer cells. RESULTS: PEAL inhibited cell growth in a dose-dependent manner. It was related to caspase-dependent apoptosis. We confirmed this finding with annexin V staining. PEAL up-regulated p53 expression, and subsequent Bax induction, down regulated Bcl-2 protein, anti-apoptotic protein. In addition, PEAL suppressed Akt activity and PEAL-induced apoptosis were significantly accentuated with Akt inhibitor (LY294002). CONCLUSIONS: Our data suggested that PEAL induce caspase-dependent apoptosis through mitochondrial pathway by up-regulating p53 protein, and subsequent Bax protein as well as by modulating Bcl-2 protein, and that PEAL induces caspase-dependent apoptosis at least in part through the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This study provides evidence that PEAL might be useful for the treatment of cancer.

The inhibitory effect of anthocyanins on Akt on invasion and epithelial-mesenchymal transition is not associated with the anti-EGFR effect of the anthocyanins.

Evidence suggests that anthocyanins inhibit EGFR and Akt activity. However, it is still unknown whether the inhibitory effect of anthocyanins on Akt is associated with the anti-EGFR effect. The effect of anthocyanins on epithelial-mesenchymal transition (EMT) has not been extensively studied. Therefore, we investigated the effects of anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) on EGF-induced EMT and the underlying molecular mechanisms. AIMs suppressed the invasion of A549 cells in a dose-dependent manner. AIMs inhibited the phosphorylation of Akt and EGFR, but the inhibitory effect on Akt was not derived from EGFR. EGF re-induced Akt phosphorylation at Thr308 in the AIM-treated cells, but not Akt phosphorylation at Ser473. AIMs also inhibited EMT of cancer cells. AIMs inhibited glycogen synthase kinase-3ß phosphorylation and ß-catenin expression that are invovled in EMT. We confirmed these findings with transforming growth factor (TGF)-ß. In conclusion, these data suggest that the inhibitory effect of AIMs on Akt activity is independent of EGFR, and that AIMs suppressed invasion and migration at least in part by suppressing EMT by inhibiting Akt activity as well as EGFR. This study provides evidence that AIMs may have anticancer effects on human cancer cells.

Arsenic hexoxide enhances TNF-α-induced anticancer effects by inhibiting NF-κB activity at a safe dose in MCF-7 human breast cancer cells.

Arsenic hexoxide (As4O6) has been used in Korean folk remedy for the treatment of cancer since the late 1980s. Evidence suggests that the anticancer effects of As4O6 are different from those of As2O3. Tumor necrosis factor-α (TNF-α) is generally increased in advanced cancer and is closely related to cancer progression, although it has cancer-killing effects. The reason is that TNF-α activates nuclear factor-κB (NF-κB) that is involved in cell proliferation, invasion, drug resistance and metastasis. In the present study, we investigated the effects of As4O6 on NF-κB activity, NF-κB-mediated cellular responses, and NF-κB-regulated gene expressions involved in metastasis at the concentrations of As4O6 where no cytotoxicity was observed. As4O6 suppressed NF-κB activation in both TNF-α-treated and control cells, and also suppressed IκB phosphorylation in a time-dependent manner, suggesting the suppression of NF-κB results, in part, from the inhibition of IκB degradation. We also confirmed the anti-NF-κB activity of As4O6 with synergism with TNF-α by augmenting caspase-8 activation. As4O6 also suppressed NF-κB activation induced by TNF-α, and some of the downstream NF-κB-regulated proteins involved in cancer proliferation, anti-apoptosis and metastasis. In conclusion, the present study demonstrated that As4O6 has anticancer properties by inhibiting NF-κB activation and NF-κB-regulated proteins at least in part through the inhibition of IκB phosphorylation, especially in the conditions of advanced cancer where TNF-α is highly secreted.

Flavonoids from Citrus unshiu Marc. inhibit cancer cell adhesion to endothelial cells by selective inhibition of VCAM-1.

Citrus fruits have been used as edible fruit and a component of traditional medicine for various diseases including cancer since ancient times. Herein, we investigated the anticancer activity of flavonoids of Citrus unshiu Marc. (FCM) focusing on anti-metastatic effects. We prepared FCM and performed experiments using MDA-MB-231 human breast cancer cells. FCM inhibited TNF-induced cancer cell adhesion to human umbilical vein endothelial cells (HUVECs) without showing any toxicity. FCM inhibited the expression of VCAM-1, but not of ICAM-1, on MDA-MB-231 cells as well as HUVECs. FCM inhibited protein kinase C (PKC) phosphorylation, but not Akt phosphorylation. FCM also inhibited cancer cell invasion in a dose-dependent manner, but not MMP-9 expression. In conclusion, this study suggested that FCM inhibits TNF-induced cancer cell adhesion to HUVECs by inhibiting VCAM-1 through inhibition of PKC, providing evidence that FCM have anti-metastatic activity by inhibiting adhesion molecules and invasion on human breast cancer cells.

Anthocyanins from Vitis coignetiae Pulliat Inhibit Cancer Invasion and Epithelial-Mesenchymal Transition, but These Effects Can Be Attenuated by Tumor Necrosis Factor in Human Uterine Cervical Cancer HeLa Cells.

Recently we have demonstrated that anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) have anticancer effects. Here, we investigate the effects of AIMs on cell proliferation and invasion as well as epithelial-mesenchymal transition (EMT) which have been linked to cancer metastasis in human uterine cervical cancer HeLa cells. AIMs inhibited the invasion of HeLa cells in a dose-dependent manner. AIMs inhibited MMP-9 expression in a dose-dependent manner. AIMs inhibited the motility of HeLa cells in a wound healing test. AIMs still suppressed NF- κ B activation induced by TNF. AIMs also inhibited EMT in HeLa cells. AIMs suppressed vimentin, N-cadherin, and ß-catenin expression and induced E-cadherin. AIMs also suppressed expression of ß-catenin and Snail, which was regulated by GSK-3. These effects of AIMs were also limited in the HeLa cells treated with TNF. In conclusion, this study indicates that AIMs have anticancer effects by suppressing NF- κ B-regulated genes and EMT, which relates to suppression of I κ B α phosphorylation and GSK-3 activity, respectively. However, the effects of AIMs were attenuated in the TNF-high condition.