Fluoxetine Simultaneously Induces Both Apoptosis and Autophagy in Human Gastric Adenocarcinoma Cells

( Wah Wah Po ),( Wynn Thein ),( Phyu Phyu Khin ),( Tin Myo Khing ),( Khin Wah Wah Han ),( Chan Hee Park ),( Uy Dong Sohn ) 한국응용약물학회 2020 Biomolecules & Therapeutics(구 응용약물학회지) Vol.28 No.2

Fluoxetine is used widely as an antidepressant for the treatment of cancer-related depression, but has been reported to also have anti-cancer activity. In this study, we investigated the cytotoxicity of fluoxetine to human gastric adenocarcinoma cells; as shown by the MTT assay, fluoxetine induced cell death. Subsequently, cells were treated with 10 or 20 μM fluoxetine for 24 h and analyzed. Apoptosis was confirmed by the increased number of early apoptotic cells, shown by Annexin V- propidium iodide staining. Nuclear condensation was visualized by DAPI staining. A significant increase in the expression of cleaved PARP was observed by western blotting. The pan-caspase inhibitor Z-VAD-FMK was used to detect the extent of caspase-dependent cell death. The induction of autophagy was determined by the formation of acidic vesicular organelles (AVOs), which was visualized by acridine orange staining, and the increased expression of autophagy markers, such as LC3B, Beclin 1, and p62/SQSTM 1, observed by western blotting. The expression of upstream proteins, such as p-Akt and p-mTOR, were decreased. Autophagic degradation was evaluated by using bafilomycin, an inhibitor of late-stage autophagy. Bafilomycin did not significantly enhance LC3B expression induced by fluoxetine, which suggested autophagic degradation was impaired. In addition, the co-administration of the autophagy inhibitor 3-methyladenine and fluoxetine significantly increased fluoxetine-induced apoptosis, with decreased p-Akt and markedly increased death receptor 4 and 5 expression. Our results suggested that fluoxetine simultaneously induced both protective autophagy and apoptosis and that the inhibition of autophagy enhanced fluoxetine-induced apoptosis through increased death receptor expression.

Benzyl Isothiocyanate-Induced Cytotoxicity via the Inhibition of Autophagy and Lysosomal Function in AGS Cells

( Wah Wah Po ),( Won Seok Choi ),( Tin Myo Khing ),( Ji-yun Lee ),( Jong Hyuk Lee ),( Joon Seok Bang ),( Young Sil Min ),( Ji Hoon Jeong ),( Uy Dong Sohn ) 한국응용약물학회 2022 Biomolecules & Therapeutics(구 응용약물학회지) Vol.30 No.4

Gastric adenocarcinoma is among the top causes of cancer-related death and is one of the most commonly diagnosed carcinomas worldwide. Benzyl isothiocyanate (BITC) has been reported to inhibit the gastric cancer metastasis. In our previous study, BITC induced apoptosis in AGS cells. The purpose of the present study was to investigate the effect of BITC on autophagy mechanism in AGS cells. First, the AGS cells were treated with 5, 10, or 15 μM BITC for 24 h, followed by an analysis of the autophagy mechanism. The expression level of autophagy proteins involved in different steps of autophagy, such as LC3B, p62/SQSTM1, Atg5-Atg12, Beclin1, p-mTOR/mTOR ratio, and class III PI3K was measured in the BITC-treated cells. Lysosomal function was investigated using cathepsin activity and Bafilomycin A1, an autophagy degradation stage inhibitor. Methods including qPCR, western blotting, and immunocytochemistry were employed to detect the protein expression levels. Acridine orange staining and omnicathepsin assay were conducted to analyze the lysosomal function. siRNA transfection was performed to knock down the LC3B gene. BITC reduced the level of autophagy protein such as Beclin 1, class III PI3K, and Atg5-Atg12. BITC also induced lysosomal dysfunction which was shown as reducing cathepsin activity, protein level of cathepsin, and enlargement of acidic vesicle. Overall, the results showed that the BITC-induced AGS cell death mechanism also comprises the inhibition of the cytoprotective autophagy at both initiation and degradation steps.

The Process of Building a Collaborative Relationship in a School Improvement Project

Chan Po Wah,Lai Ha Yuen,Kwong Wai Man,Wai Yee Lee 한국유아교육학회 2005 INTERNATIONAL JOURNAL OF EARLY CHILDHOOD EDUCATION Vol.11 No.1

Autophagy and Digestive Disorders: Advances in Understanding and Therapeutic Approaches

( Wynn Thein ),( Wah Wah Po ),( Won Seok Choi ),( Uy Dong Sohn ) 한국응용약물학회 2021 Biomolecules & Therapeutics(구 응용약물학회지) Vol.29 No.4

The gastrointestinal (GI) tract is a series of hollow organs that is responsible for the digestion and absorption of ingested foods and the excretion of waste. Any changes in the GI tract can lead to GI disorders. GI disorders are highly prevalent in the population and account for substantial morbidity, mortality, and healthcare utilization. GI disorders can be functional, or organic with structural changes. Functional GI disorders include functional dyspepsia and irritable bowel syndrome. Organic GI disorders include inflammation of the GI tract due to chronic infection, drugs, trauma, and other causes. Recent studies have highlighted a new explanatory mechanism for GI disorders. It has been suggested that autophagy, an intracellular homeostatic mechanism, also plays an important role in the pathogenesis of GI disorders. Autophagy has three primary forms: macroautophagy, microautophagy, and chaperone-mediated autophagy. It may affect intestinal homeostasis, host defense against intestinal pathogens, regulation of the gut microbiota, and innate and adaptive immunity. Drugs targeting autophagy could, therefore, have therapeutic potential for treating GI disorders. In this review, we provide an overview of current understanding regarding the evidence for autophagy in GI diseases and updates on potential treatments, including drugs and complementary and alternative medicines.

The Altered Signaling on EFS-Induced Colon Contractility in Diabetic Rats

( Wynn Thein ),( Wah Wah Po ),( Dong Min Kim ),( Uy Dong Sohn ) 한국응용약물학회 2020 Biomolecules & Therapeutics(구 응용약물학회지) Vol.28 No.4

Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α1 adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca²⁺ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE₅ inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE₅ were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE₅.

The Education of Young Children in Hong Kong: Implications for Early Childhood Teacher Education

Wai Yee Margaret Kwong Lee,Po Wah Tse Chan 한국유아교육학회 2000 INTERNATIONAL JOURNAL OF EARLY CHILDHOOD EDUCATION Vol.5 No.-

Teacher educators need to be more responsive to the views of stakeholders in the provision of teacher education programs. In the planning phase of two new preschool teacher education courses, a large scale, systematic study ("the contextual analysis") was conducted to collect stake-holders‘ views on the following: What is it like for young children to grow up in Hong Kong and what are the contextual factors impinging on it? What is the role of early childhood education? Who are the competent early childhood teachers and what makes them competent? Qualitative and quantitative data was collected through focus group interviews, a questionnaire survey and an archival study. This paper reports the process and outcome, and examines the utility of the study.

Long-Term Treatment with Shengmai San-Derived Herbal Supplement (Wei Kang Su) Enhances Antioxidant Response in Various Tissues of Rats with Protection Against Carbon Tetrachloride Hepatotoxicity

Pou Kuan Leong,Na Chen,Po Yee Chiu,Hoi Yan Leung,Chung Wah Ma,Qing Tao Tang,Kam Ming Ko 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.2

Wei Kang Su (WKS) is a commercial herbal product based on a Chinese herbal formula, Shengmai San. Here, we investigated the effects of long-term treatment with WKS on mitochondrial antioxidant status and functional ability, as well as heat shock protein (Hsp) 25/70 production, in various tissues of rats. WKS treatment enhanced mitochondrial antioxidant status and ATP generation capacity, as well as Hsp 25/70 production in various rat tissues. WKS treatment suppressed plasma reactive oxygen metabolite levels and protected against carbon tetrachloride hepatotoxicity in rats. Long-term WKS treatment may prevent diseases by enhancing the resistance of mitochondria to oxidative stress.

The Education of Young Children in Hong Kong : Implications for Early Childhood Teacher Education

Kwong-Lee, Wai Yee Margaret,Chan, Po-Wah Tse 한국유아교육학회 2000 INTERNATIONAL JOURNAL OF EARLY CHILDHOOD EDUCATION Vol.5 No.-

Teacher educators need to be more responsive to the views of stakeholders in the provision of teacher education programs. In the planning phase of two new preschool teacher education courses, a large scale, systematic study ("the contextual analysis") was conducted to collect stake-holders' views on the following: What is it like for young children to grow up in Hong Kong and what are the contextual factors impinging on it? What is the role of early childhood education? Who are the competent early childhood teachers and what makes them competent? Qualitative and quantitative data was collected through focus group interviews, a questionnaire survey and an archival study. This paper reports the process and outcome, and examines the utility of the study.

Study on Treatment Planning for the Prostate in Proton Therapy with Oxygen Enhancement Ratio Effect

Yoo Seung Hoon,Geng Hui,Lam Wai Wang,Kong Chi Wah,Yang Bin,Chiu Tin Lok,Wu Po Man,Cheung Kin Yin,Yu Siu Ki,Shin Dongho,Min Byung Jun 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.7

The purpose of this study was to investigate the oxygen enhancement ratio (OER) effects on treatment planning for a hypoxic prostate tumor with proton scanning beams. Two different OER-based dose calculation models (the average model and the voxel model) were investigated by using hypoxic tumor models in this simulation study. For the hypoxic tumor model, an oxygen distribution with a range of 2.4-9.4 mmHg was used according to the clinical data. The results given by the average model and the voxel model were compared for 50% and 90% tumor control probabilities with variations in the hypoxic tumor volume and fractionation. Comparison between the treatment plans with OER-based higher predicted dose and with the conventional prescription dose was conducted to investigate the organ-at-risk (OAR) doses for the prostate case. The average model showed a higher calculated dose than the voxel model. The voxel model with a 50% control probability showed good agreement with the current prescription dose. The OER values of the average model ranged from 1.05 to 1.25, which were applied to the whole tumor volume in treatment planning. The voxel-model-based OERs were higher (1.50-1.75) than those of average model, and these OERs should be applied only for the hypoxic boost region. Regarding treatment plans, the doses of the rectum and the bladder were reduced to the tolerable range V80Gy (volume receiving equal to or greater than 80Gy) < 15% and V75Gy (volume receiving equal to or greater than 75Gy) < 15% respectively after an optimization, but the maximum dose to femoral heads was higher than 50 Gy. In conclusion, we investigated the possible ranges of the OER (1.3-1.8) for proton-beam treatment of prostate cases. A dose escalation of up to about 1.8 times can be applied for the small hypoxic region. This result, which was obtained using a model study, should be verified through clinical experiment.