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Articles 1 - 11 of 11

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Molecular Targets Of Apigenin In Colorectal Cancer Cells: Involvement Of P21, Nag-1 And P53., Yi Zhong, C Krisanapun, Seong-Ho Lee, T Nualsanit, C Sams, P Peungvicha, Seung Baek Nov 2010

Molecular Targets Of Apigenin In Colorectal Cancer Cells: Involvement Of P21, Nag-1 And P53., Yi Zhong, C Krisanapun, Seong-Ho Lee, T Nualsanit, C Sams, P Peungvicha, Seung Baek

Seung J Baek

Persuasive epidemiological and experimental evidence suggests that dietary flavonoids have anti-cancer activity. Since conventional therapeutic and surgical approaches have not been able to fully control the incidence and outcome of most cancer types, including colorectal neoplasia, there is an urgent need to develop alternative approaches for the management of cancer. We sought to develop the best flavonoids for the inhibition of cell growth, and apigenin (flavone) proved the most promising compound in colorectal cancer cell growth arrest. Subsequently, we found that pro-apoptotic proteins (NAG-1 and p53) and cell cycle inhibitor (p21) were induced in the presence of apigenin, and kinase ...


Epicatechin Gallate Suppresses Oxidative Stress-Induced Muc5ac Overexpression By Interaction With Epidermal Growth Factor Receptor, Hj Kim, Jh Ryu, Ch Kim, Jw Lim, Uy Moon, Gh Lee, Seung Baek, Jh Yoon Aug 2010

Epicatechin Gallate Suppresses Oxidative Stress-Induced Muc5ac Overexpression By Interaction With Epidermal Growth Factor Receptor, Hj Kim, Jh Ryu, Ch Kim, Jw Lim, Uy Moon, Gh Lee, Seung Baek, Jh Yoon

Seung J Baek

The goal of this study was to investigate the effect of epicatechin gallate (ECG), a component of green tea polyphenols, on the signal pathway for oxidative stress-induced intracellular reactive oxygen species (ROS) generation and MUC5AC overexpression in normal human nasal epithelial (NHNE) cells. Passage-2 NHNE cells were used, and ECG was administered before stimulation with exogenous hydrogen peroxide (H(2)O(2)). MUC5AC gene and protein levels were measured by real-time PCR and dot blot analysis. Western blot analysis and immunocytofluorescence study were performed for detecting the activity of epidermal growth factor receptor (EGFR). Exogenous H(2)O(2) increases ...


Activating Transcription Factor 2 (Atf2) Controls Tolfenamic Acid-Induced Atf3 Expression Via Map Kinase Pathways., Seong-Ho Lee, Jae Hoon Bahn, Nichelle Whitlock, Seung Baek Aug 2010

Activating Transcription Factor 2 (Atf2) Controls Tolfenamic Acid-Induced Atf3 Expression Via Map Kinase Pathways., Seong-Ho Lee, Jae Hoon Bahn, Nichelle Whitlock, Seung Baek

Seung J Baek

Tolfenamic acid (TA) is a non-steroidal anti-inflammatory drug associated with anti-tumorigenic and pro-apoptotic properties in animal and in vitro models of cancer. However, the underlying cellular mechanisms by which TA exerts its effects are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/CREB subfamily of the basic region-leucine zipper family and has been known as a tumor suppressor in human colorectal cancer cells. The present study was performed to observe whether ATF3 mediates TA-induced apoptosis and to elucidate the molecular mechanism of ATF3 transcription induced by TA. TA treatment and ectopic expression of ATF3 ...


Autonomous Bioluminescent Expression Of The Bacterial Luciferase Gene Cassette (Lux) In A Mammalian Cell Line, Dan Close, Patterson, Ripp, Seung Baek, Sanseverino, Gary Sayler Jul 2010

Autonomous Bioluminescent Expression Of The Bacterial Luciferase Gene Cassette (Lux) In A Mammalian Cell Line, Dan Close, Patterson, Ripp, Seung Baek, Sanseverino, Gary Sayler

Seung J Baek

No abstract provided.


(-)-Epigallocatechin-3-Gallate (Egcg) Post-Transcriptionally And Post-Translationally Suppresses The Cell Proliferative Protein Trop2 In Human Colorectal Cancer Cells., Seung Baek, Mugdha Sukhthankar, Saverio Alberti Jul 2010

(-)-Epigallocatechin-3-Gallate (Egcg) Post-Transcriptionally And Post-Translationally Suppresses The Cell Proliferative Protein Trop2 In Human Colorectal Cancer Cells., Seung Baek, Mugdha Sukhthankar, Saverio Alberti

Seung J Baek

BACKGROUND: TROP-2 is a tumor-promoting molecule that has been found to be overexpressed in many cancer cells, making it a plausible biomarker of carcinogenesis. The main aim of this study was to examine the effect of green tea catechins (namely, (-)-epigallocatechin-3-gallate; EGCG) on TROP-2 expression. MATERIALS AND METHODS: Western blot and RT-PCR were applied to assess TROP2 expression in colorectal cancer cells and tissues. RESULTS: Two different mechanisms were found to operate in diverse cell lines. In SW480 cells, EGCG affected the post-transcriptional processing of the TROP-2 mRNA, as this was quickly and specifically degraded in the presence of EGCG ...


Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek Jun 2010

Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek

Seung J Baek

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a central role in cell differentiation, metabolism and tumorigenesis. We have investigated the therapeutic properties of 5-[[6-[(2-fluorophenyl)-methoxy]-2-napthalenyl]-methyl]-2,4-thiazolidinedione (MCC-555) a PPARgamma agonist in human colorectal cancer cells. To elucidate the molecular mechanism(s), by which MCC-555 exerts its effects on the human colorectal cancer cells, we have analyzed the expression of two pro-apoptotic proteins, Kr├╝ppel-like factor 4 (KLF4) and nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1). MCC-555-induced expression of the transcription factor, KLF-4 was blocked by a PPARgamma specific antagonist GW9662 in PPARgamma-dependent manner in HCT-116 cells. We ...


Effects Of Atmospheric Non-Thermal Plasma On Invasion Of Colorectal Cancer Cells., Seung Baek, Chul-Ho Kim, S Kwon, K Lee, S Jun, Philip Rack May 2010

Effects Of Atmospheric Non-Thermal Plasma On Invasion Of Colorectal Cancer Cells., Seung Baek, Chul-Ho Kim, S Kwon, K Lee, S Jun, Philip Rack

Seung J Baek

No abstract provided.


Cell Adhesion Property Affected By Cyclooxygenase And Lipoxygenase: Opto-Electric Approach (With Chang Kyoung Choi, Mugdha Sukhthankar, Chul-Ho Kim, Seong-Ho Lee, Anthony English, Kenneth D. Kihm., Seung Baek Dec 2009

Cell Adhesion Property Affected By Cyclooxygenase And Lipoxygenase: Opto-Electric Approach (With Chang Kyoung Choi, Mugdha Sukhthankar, Chul-Ho Kim, Seong-Ho Lee, Anthony English, Kenneth D. Kihm., Seung Baek

Seung J Baek

Expression of cyclooxygenases (COX) and lipoxygenases (LOX) has been linked to many pathophysiological phenotypes, including cell adhesion. However, many current approaches to measure cellular changes are performed only in a fixed-time point. Since cells dynamically move in conjunction with the cell matrix, there is a pressing need for dynamic or time-dependent methods for the investigation of cell properties. In the presented study, we used stable human colorectal cancer cell lines ectopically expressing COX-1, COX-2, and 15LOX-1, to investigate whether expression of COX-1, COX-2, or 15LOX-1 would affect cell adhesion using our opto-electric methodology. In a fixed-time point experiment, only COX-1- ...


Nsaid-Activated Gene-1 As A Molecular Target For Capsaicin-Induced Apoptosis Through A Novel Molecular Mechanism Involving Gsk3beta, C/Ebpbeta And Atf3, Seung Baek, Seong-Ho Lee, Chutwadee Krisanapun Dec 2009

Nsaid-Activated Gene-1 As A Molecular Target For Capsaicin-Induced Apoptosis Through A Novel Molecular Mechanism Involving Gsk3beta, C/Ebpbeta And Atf3, Seung Baek, Seong-Ho Lee, Chutwadee Krisanapun

Seung J Baek

Capsaicin, a natural product of the Capsicum species of red peppers, is known to induce apoptosis and suppress growth. Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and antitumorigenic property in colorectal and lung cancer. Our data demonstrate that capsaicin leads to induction of apoptosis and up-regulates NAG-1 gene expression at the transcriptional level. Overexpression of CCAAT/enhancer binding protein beta (C/EBPbeta) caused a significant increase of basal and capsaicin-induced NAG-1 promoter activity. We subsequently identified C/EBPbeta binding sites in the NAG-1 promoter responsible for capsaicin-induced NAG-1 transactivation. Electrophoretic mobility shift assay and chromatin immunoprecipitation ...


A Potential Proliferative Gene, Nudt6, Is Down-Regulated By Green Tea Catechins At The Posttranscriptional Level, Seung Baek, Mugdha Sukthankar, Ck Choi, A English, Js Kim Dec 2009

A Potential Proliferative Gene, Nudt6, Is Down-Regulated By Green Tea Catechins At The Posttranscriptional Level, Seung Baek, Mugdha Sukthankar, Ck Choi, A English, Js Kim

Seung J Baek

The main aims of this study were to elucidate the effect of green tea catechins on Nudix-type motif 6 (NUDT6) suppression and to characterize NUDT6's biological activity. Our microarray data showed that the green tea component epicatechin-3-gallate suppressed NUDT6 expression, and this was confirmed by RT-PCR. Subsequently, the use of different catechins showed that the effect of epigallocatechin-3-gallate (EGCG) was stronger than that of other catechins. At the posttranscriptional level, EGCG decreased the RNA stability of NUDT6, indicating it as a potential mechanism of NUDT6 suppression. Further cloning of the 3' untranslated region of human NUDT6 mRNA resulted in ...


In Vitro Anti-Proliferative Activity Of Alcoholic Stem Extract Of Coscinium Fenestratum In Human Colorectal Cancer Cells, P Rojsanga, M Sukthankar, C Krisanapun, W Gritsanapan, D Lawson, Seung Baek Dec 2009

In Vitro Anti-Proliferative Activity Of Alcoholic Stem Extract Of Coscinium Fenestratum In Human Colorectal Cancer Cells, P Rojsanga, M Sukthankar, C Krisanapun, W Gritsanapan, D Lawson, Seung Baek

Seung J Baek

Coscinium fenestratum (Gaertn.) Colebr. is traditionally used for the treatment of cancer, arthritis and diabetes mellitus. The purpose of this study was to determine the molecular mechanisms by which this plant shows beneficial effects. An 80% ethanolic extract of C. fenestratum (80ET) was separated by its polarity into dichloromethane (DCM) and aqueous fractions (WF), and the anti-proliferative effects of 80ET, DCM and WF were investigated. Berberine, one of the major components of C. fenestratum, was used as a control. The 80ET, DCM, WF and berberine showed anti-proliferative activity as assessed by cell growth assay. Subsequently, the pro-apoptotic proteins NAG-1 and ...