Hae-Nim Lee

Anticancer Effect of Fucoidan on DU-145 Prostate Cancer Cells through Inhibition of PI3K/Akt and MAPK Pathway Expression

In this study, we showed that PI3K/Akt signaling mediates fucoidan’s anticancer effects on prostate cancer cells, including suppression of proliferation. Fucoidan significantly decreased viability of DU-145 cancer cells in a concentration-dependent manner as shown by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The drug also significantly increased chromatin condensation, which indicates apoptosis, in a concentration-dependent manner as shown by DAPI (4′,6-diamidino-2-phenylindole) staining. Fucoidan increased expression of Bax, cleaved poly-ADP ribose polymerase and cleaved caspase-9, and decreased of the Bcl-2, p-Akt, p-PI3K, p-P38, and p-ERK in a concentration-dependent manner. In vivo, fucoidan (at 5 and 10 mg/kg) significantly decreased tumor volume, and increased apoptosis as assessed by the TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay, confirming the tumor inhibitory effect. The drug also increased expression of p-Akt and p-ERK as shown by immunohistochemistry staining. Therefore, fucoidan may be a promising cancer preventive medicine due to its growth inhibitory effects and induction of apoptosis in human prostate cancer cells.

Antitumor and apoptosis-inducing effects of α-mangostin extracted from the pericarp of the mangosteen fruit (Garcinia mangostana L.)in YD-15 tongue mucoepidermoid carcinoma cells

α-mangostin is a dietary xanthone which has been shown to have antioxidant, anti-allergic, antiviral, antibacterial, anti-inflammatory and anticancer effects in various types of human cancer cells. In the present study, we aimed to elucidate the molecular mechanisms responsible for the apoptosis-inducing effects of α-mangostin on YD-15 tongue mucoepidermoid carcinoma cells. The results from MTT assays revealed that cell proliferation significantly decreased in a dose-dependent manner in the cells treated with α-mangostin. DAPI staining illustrated that chromatin condensation in the cells treated with 15 µM α-mangostin was far greater than that in the untreated cells. Flow cytometric analysis indicated that α-mangostin suppressed YD-15 cell viability by inducing apoptosis and promoting cell cycle arrest in the sub-G1 phase. Western blot analysis of various signaling molecules revealed that α-mangostin targeted the extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) signaling pathways through the inhibition of ERK1/2 and p38 phosphorylation in a dose-dependent manner. α-mangostin also increased the levels of Bax (pro-apoptotic), cleaved caspase-3, cleaved caspase-9 and cleaved-poly(ADP-ribose) polymerase (PARP), whereas the levels of the anti-apoptotic factors, Bcl-2 and c-myc, decreased in a dose-dependent manner. The anticancer effects of α-mangostin were also investigated in a tumor xenograft mouse model. The α-mangostin-treated nude mice bearing YD-15 tumor xenografts exhibited a significantly reduced tumor volume and tumor weight due to the potent promoting effects of α-mangostin on cancer cell apoptosis, as determined by TUNEL assay. Immunohistochemical analysis revealed that the level of cleaved caspase-3 increased, whereas the Ki-67, p-ERK1/2 and p-p38 levels decreased in the α-mangostin-treated mice. Taken together, the findings of our study indicate that α-mangostin induces the apoptosis of YD-15 tongue carcinoma cells through the ERK1/2 and p38 MAPK signaling pathways.

Ixeris dentata (Thunb. Ex Thunb.) Nakai Extract Inhibits Proliferation and Induces Apoptosis in Breast Cancer Cells through Akt/NF-κB Pathways

Ixeris dentata (Thunb. Ex Thunb.) Nakai (ID) exhibits various physiological activities, and its related plant derived-products are expected to represent promising cancer therapeutic agents. However, the anticancer effects of ID extract on breast cancer cells classified as estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are still unknown. In this study, we investigated the anti-cancer effects and analyzed the molecular mechanism of ID extract in T47D, MCF-7 (ER-, PR-positive, HER2-negative), SK-BR-3(ER-, PR-negative, HER2-positive), and MDA-MB-231 (Triple-negative) through in vitro studies. Additionally, we examined its anti-tumor effects through in vivo studies. Our findings indicated that ID extract-induced apoptosis was mediated via various survival pathways on four breast cancer cells by identifying the factors including Bcl-2 family, phospho-Akt and phospho-nuclear factor-κB (NF-κB). Based on in vitro findings that induced apoptosis via Akt-NF-κB signaling, we investigated the effects of ID extract on mice bearing MDA-MB-231 cells. The results showed that ID extract significantly decreased MDA-MB-231 tumor volume and weight via inducing apoptosis by suppressing phospho-Akt. Overall, these results indicate that ID extract induces apoptosis through the Akt-NF-κB signaling pathway in MDA-MB-231 breast cancer cells and tumors, and it may serve as a therapeutic agent for triple-negative human breast cancer.

Anti‑inflammatory effect of quercetin and galangin in LPS‑stimulated RAW264.7 macrophages and DNCB‑induced atopic dermatitis animal models

Flavonols are compounds that have been shown to possess potent anti-inflammatory effects in cellular and animal models of inflammation. In the present study, the anti-inflammatory effects and mechanisms of two natural flavonols, quercetin and galangin, in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages were investigated. It was identified that quercetin and galangin markedly reduced the production of nitric oxide (NO), inducible NO synthase and interleukin-6, and the nuclear translocation of nuclear factor-κB (NF-κB). In addition, LPS-induced activation of extracellular signal-regulated kinase 1/2 (Erk1/2) and c-Jun N-terminal kinase (JNK) was suppressed by quercetin and galangin. Taken together, these data implied that NF-κB, Erk1/2 and JNK may be potential molecular targets of quercetin and galangin in an LPS-induced inflammatory response. Subsequently, the effects of oral administration of quercetin or galangin, either alone or in combination, in a 2,4-dinitrochlorobenzene-induced atopic dermatitis (AD) mouse model were investigated. As a result, measurements of ear thickness and the levels of serum immunoglobulin E, and histological analysis revealed that the two flavonols led to a decrease in inflammation, whereas, in combination, they were even more effective. These results suggested that quercetin and galangin may be promising therapeutic agents for AD. Additionally, their combination may be a novel therapeutic strategy for the prevention of AD.

Targeting ERK1/2-bim signaling cascades by BH3-mimetic ABT-737 as an alternative therapeutic strategy for oral cancer

To date, many different chemotherapeutic agents have been widely used as common treatments for oral cancers. However, their therapeutic effects have been disappointing, and these agents may have unwanted side effects. Among the many regulatory factors, overexpression of pro-survival Bcl-2 family members may promote resistance to chemotherapeutic drugs in many tumors. The BH3 domain-only proteins effectively antagonize their apoptotic activities. Therefore, there is substantial interest in developing chemotherapeutic drugs that directly target pro-survival Bcl-2 proteins by mimicking the BH3 domain and unleashing pro-apoptotic molecules in tumor cells. Among the numerous available small molecule BH3 mimetics, ABT-737, a potent small molecule that binds to Bcl-2/Bcl-xL with high affinity, has anti-tumor activity in a wide variety of cancer cells. However, the effects of ABT-737 on human oral cancers and the underlying molecular mechanisms have not previously been elucidated. In the present study, we observed that inactivation of the ERK1/2 signaling pathway using ABT-737 dramatically increased the expression of pro-apoptotic protein Bim via transcriptional and/or posttranslational regulation, in a cell type-dependent manner, inducing mitochondria-mediated apoptosis of human oral cancer cells. To the best of our knowledge, this is the first demonstration of the antitumor effects of ABT-737 on human oral cancers.

Nitidine chloride acts as an apoptosis inducer in human oral cancer cells and a nude mouse xenograft model via inhibition of STAT3

Nitidine chloride (NC) is a natural alkaloid compound derived from the plant Zanthoxylum nitidum and is known for its therapeutic anticancer potential. In this study, we investigated the effects of NC on growth and signaling pathways in human oral cancer cell lines and a tumor xenograft model. The apoptotic effects and related molecular targets of NC on human oral cancer were investigated using trypan blue exclusion assay, DAPI staining, Live/Dead assay, Western blotting, Immunohistochemistry/Immunofluorescence and a nude mouse tumor xenograft. NC decreased cell viability in both HSC3 and HSC4 cell lines; further analysis demonstrated that cell viability was reduced via apoptosis. STAT3 was hyper-phosphorylated in human oral squamous cell carcinoma (OSCC) compared with normal oral mucosa (NOM) and dephosphorylation of STAT3 by the potent STAT3 inhibitor, cryptotanshinone or NC decreased cell viability and induced apoptosis. NC also suppressed cell viability and induced apoptosis accompanied by dephosphorylating STAT3 in four other oral cancer cell lines. In a tumor xenograft model bearing HSC3 cell tumors, NC suppressed tumor growth and induced apoptosis by regulating STAT3 signaling without liver or kidney toxicity. Our findings suggest that NC is a promising chemotherapeutic candidate against human oral cancer.

Induction of Apoptosis in Human Cancer Cells with Extracts of Taraxacum coreanum, Youngia sonchifolia and Ixeris dentate

This research examined the effects of Compositae extract on the inhibition of proliferation and apoptosis in human breast and human gastric cancer cells. Compositae extracts which is used in the experiment are Taraxacum coreanum (TC), Youngia sonchifolia (YS) and Ixeris dentata (ID). The proliferation of SK-BR-3, MDA- MB-231 and AGS cells were investigated by MTT assay. ID and YS extracts inhibited proliferation of SK-BR-3, MDA-MB-231 and AGS cells in a dose-dependent manner, but TC have barely affected. In addition, the most effec- tive extract was ID. To assess the apoptosis of ID extract, the nuclei of human cancer cells were stained with DAPI solution respectively. Chromatin condensation, indicated apoptosis, was increased in a dose-dependent manner. We investigated change of ID extract-induced apoptosis proteins on human cancer cells by western blot analysis. The level of Bcl-2 decreased, whereas the level of Bax, cleaved-PARP increased in dose-dependent manner compared with non-treatment. Also Bax/Bcl-2 ratio, which is used in clinical indicator of apoptosis, was increased at ID extract treat- ment group compared with non-treatment. Moreover the Bax/Bcl-2 ratio of MDA-MB-231 cell was significantly increased as against SK-BR-3, AGS cells. These results indicated that ID extract have anti-proliferation effect better than YS or TC, and induced apoptosis in human breast cancer MDA-MB-231 cell better than human breast cancer SK- BR-3 cell, human gastric cancer. Even if further research is needed, ID can be developed as a chemopreventive or therapeutic agent of breast cancer.

Effect of Repeated MSG Administration on Cognitive Ability and Anxiety of Juvenile Rats

The objective of this study is to investigate the effect of MSG on cognitive function and anxiety by the T-maze and elevated-plus-maze test and repeated oral dose toxicity in SD rat of MSG. The rats were treated with MSG of control group, low group (3 g/kg) and high group (5 g/kg) intragastrically for 4 weeks, respectively. We examined the body weight, the clinical signs, T-maze, Elevated-plus-maze, hematological analysis and serum bio- chemical analysis, we also observed the histopathological changes of liver, kidney in rats. No significant differences in body weights, biochemical analysis and histopathological observations between control and MSG treatment group were found. In the elevated plus maze (EPM), MSG-treatment group has more open arm visited than controls. MSG- treatment group has been more activated in T-maze test. These data indicate the continuous high MSG intake could be increased the anxiety and could be decreased cognitive ability. In conclusion, MSG is physiologically safety, but high MSG intake could be increased the anxiety and could be decreased cognitive ability in juvenile rat.

Evaluation of Macrophage Activity and Repeated Oral Dose Toxicity in Sprague-Dawley Rats on Multivitamin

The objective of this study is to investigate the effect of multivitamin on macrophage activity in Raw 264.7 cell and repeated oral dose toxicity in Sprague-Dawely rat of multivitamin. Raw 264.7 cells were treated with 50 and 100 µg/mL multivitamin for 24 h. To measure the activity of macrophages, NO and TNF-α assays were performed in Raw 264.7 cells. Treatment with 50 and 100 µg/mL multivitamin for 24 h significantly increased pro- duction of NO and TNF-α compared with control groups, indicating activation of macrophages. The female rats were treated with multivitamin of control group, low group (0.24 g/kg), medium group (1 g/kg) and high group (2 g/kg) intragastrically for 4 weeks, respectively. We examined the body weight, the feed intake, the clinical signs and serum biochemical analysis. We also observed the histopathological changes of liver, ovary, brain, adrenal gland, spleen, kid- ney, heart and lung in rats. No significant differences in body weights, feed intake, biochemical analysis and histo- pathological observations between control and multivitamin treatment group were found. In conclusion, multivitamin is physiologically safe and improve macrophage activity.