Biomedical subjects

Mee Suk Hong

Publications and source records attributed to Mee Suk Hong.

4 recordsLinked to original sources

PubMed2006

Epigallocatechin gallate reduces hypoxia-induced apoptosis in human hepatoma cells.

Cell detachment from extracellular matrix is closely related to induction of apoptosis. Epigallocatechin gallate (EGCG) has been shown to have antioxidant effect and to protect hypoxia-induced damage. We investigated whether EGCG reduced hypoxia-induced apoptosis and cell detachment in HepG2 cells. EGCG prevented cell death by hypoxia (0.5% O2) in a dose-dependent manner (hypoxic cell viability, 54.67%). RT-PCR and caspase3 activity assay showed that the hypoxia-induced cell death was caused by apoptosis increasing mRNA level of BAX, CASP3, and caspase3 activity. EGCG reduced increase of these mRNA and caspase3 activity. Western blot analysis and immunocytochemistry showed that EGCG increased cell adhesion proteins including E-cadherin (CDH1), tumor-associated calcium signal transducer 1 (TACSTD1), and protein tyrosine kinase 2 (PTK2) decreased by hypoxia. Hypoxia-induced apoptosis in HepG2 cells, and EGCG contributed to the HepG2 cell survival by attenuating the apoptosis.

Antigens, Neoplasm↗

PubMed2006

Microarray analysis of transcription factor gene expression in melatonin-treated human peripheral blood mononuclear cells.

The existence of specific melatonin-binding sites in lymphoid cells led to the discovery of signal transduction pathway for melatonin in human lymphocytes and immunomodulatory role of melatonin in immune cells. In recent years, transcriptional regulation of melatonin on various transcription factors has been demonstrated. Therefore, this study was designed to assess by cDNA microarray analysis the regulatory effects of melatonin on transcription factors in human peripheral blood mononuclear cells (PBMCs). Forty-six genes were upregulated and 23 were downregulated more than twofold in melatonin-treated PBMCs. Of the more than twofold upregulated transcription factor genes, homeo box A4 (HOXA4), forkhead box O1A (FOXO1A), transcription elongation factor B (SIII), polypeptide 3 (TCEB3), and peroxisome proliferative activated receptor delta (PPARD) were identified. Of the more than twofold downregulated genes, PHD finger protein 15 (PHF15) and zinc finger protein 33a (ZNF33A) were identified. In summary, identification of these genes by cDNA microarray analysis in response to melatonin administration may provide a foundation for further studies on the function of melatonin in human PBMCs.

Base Sequence↗

PubMed2005

Citrus Reticulata blanco induces apoptosis in human gastric cancer cells SNU-668.

Citrus fruits have been known to reduce the proliferation of many cancer cells. The antiproliferative effects of Citrus reticulata Blanco (CR) extract, the immature tangerine peel, on human gastric cancer cell line SNU-668 were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4,6-diamidineo-2-phenylindole staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, reverse transcription-polymerase chain reaction expressions of BCL-2, BAX and CASP-3 genes, caspase-3 activity, and immunocytochemistry of caspase-3. From the results of the morphological and biochemical assays, CR (50 microg/ml) increased the apoptosis of human gastric cancer cells with typical apoptotic characteristics, including morphological changes of chromatin condensation and apoptotic body formation. CR (50 microg/ml) reduced the expression of BCL-2, whereas the expression of BAX and CASP-3 was increased compared with the control group. Furthermore, caspase-3 activity and caspase-3 protein expression in the CR-treated group was significantly increased compared with that in control group. These results suggest that CR may induce the apoptosis through the caspase-3 pathway in human gastric cancer cells.

Antineoplastic Agents↗

PubMed2004

Coptidis rhizoma induces apoptosis in human colorectal cancer cells SNU-C4.

Coptidis rhizoma has been used as traditional herb medicine in gastrointestinal disorders in the Eastern Asia. We investigated whether the anticancer effects of the C. rhizoma induced apoptosis on human colorectal cancer cells SNU-C4. The cytotoxic effect of C. rhizoma was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. To determine apoptotic cell death, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, reverse transcription-polymerase chain reaction (RT-PCR) and caspase-3 enzyme assay were performed. In this study, C. rhizoma treatment (100 microg/ml) revealed typical morphological apoptotic features. Additionally, C. rhizoma treatment (100 microg/ml) increased levels of BAX and CASPASE-3, and decreased levels of BCL-2. Caspase-3 enzyme activity by treatment of C. rhizoma (100 microg/ml) also significantly increased compared to the control (p < 0.05). These data indicate that C. rhizoma caused cell death by apoptosis through caspase pathways on human colorectal cancer cells SNU-C4.

Anticarcinogenic Agents↗