Shu Chun Hsu

Bio: Shu Chun Hsu is an academic researcher from China Medical University (Taiwan). The author has contributed to research in topics: Apoptosis & Cancer cell. The author has an hindex of 28, co-authored 57 publications receiving 1994 citations. Previous affiliations of Shu Chun Hsu include China Medical University (PRC) & Hsiuping University of Science and Technology.

Quercetin inhibits migration and invasion of SAS human oral cancer cells through inhibition of NF-κB and matrix metalloproteinase-2/-9 signaling pathways

Abstract: Quercetin, a principal flavanoid compound in onions, has been shown to possess a wide spectrum of pharmacological properties, including anticancer activities. Our earlier study showed that quercetin induced cytotoxic effects on SAS human oral cancer cells. In this study, we found that quercetin significantly reduced wound closure of SAS cells in culture plates after 12- and 24-h treatments. Results indicated that quercetin inhibited the expression and activity of matrix metalloproteinase (MMP)-2 and MMP-9, as measured by western blotting and gelatin zymography. The results from western blotting also showed that quercetin reduced the protein levels of MMP-2, -7, -9 and -10, vascular endothelial growth factor (VEGF), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65, inductible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), urokinase-type plasminogen activator (uPA), phosphatidylinositide-3 kinases (PI3K), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IKBα), IKB-α/β, phosphorylated nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor kinase, alpha/beta (p-IKKα/β), focal adhesion kinase (FAK), son of sevenless homolog-1 (SOS1), growth factor receptor-bound protein-2 (GRB2), mitogen-activated protein kinase kinase kinase-3 (MEKK3), MEKK7, extracellular-signal-regulated kinase 1/2 (ERK1/2), p-ERK1/2, c-Jun N-terminal kinase 1/2 (JNK1/2), p38, p-p38, Jun proto-oncogene (c-JUN) and p-c-JUN but it did not affect Ras homolog gene family, member A (RhoA), Protein kinase C (PKC) and rat sarcoma viral oncogene homolog (RAS) in SAS cells. Confocal laser microscopy also showed that quercetin promoted the expressions of RhoA and Rho-associated, coiled-coil containing protein kinase-1 (ROCK1), but inhibited the expression of NF-κB p65 in SAS cells. It is concluded from these data that inhibition of migration and invasion of SAS cells by quercetin is associated with the down-regulation of PKC and RhoA by blocking MAPK and PI3K/AKT signaling pathways and NF-κB and uPA, resulting in inhibition of MMP-2 and MMP-9 signaling.

Antitumor Activity of Capsaicin on Human Colon Cancer Cells in Vitro and Colo 205 Tumor Xenografts in Vivo

Abstract: Capsaicin was reported to inhibit cancer cell growth. The aim of this study was to evaluate the antitumor potential of capsaicin by studying antitumor activity in vitro as well as in vivo. The in vitro studies are to examine the effects of capsaicin on human colon cancer colo 205 cells after exposure to capsaicin. The results showed that capsaicin induced cytotoxic effects in a time- and dose-dependent manner and increased reactive oxygen species (ROS) and Ca2+ but decreased the level of mitochondrial membrane potential (ΔΨm) in colo 205 cells. Data from Western blotting analysis indicated that the levels of Fas, cytochrome c, and caspases were increased, leading to cell apoptosis. Capsaicin decreased the levels of anti-apoptotic proteins such as Bcl-2 and increased the levels of pro-apoptotic proteins such as Bax. Capsaicin-induced apoptosis in colo 205 cells was also done through the activations of caspase-8, -9 and -3. In vivo studies in immunodeficient nu/nu mice bearing colo 205 tumor xenografts show...

The role of Ca2+ in baicalein-induced apoptosis in human breast MDA-MB-231 cancer cells through mitochondria- and caspase-3-dependent pathway.

Abstract: Baicalein was investigated for tumor cell-specific cytotoxicity, apoptosis-inducing activity and signal pathway against the MDA-MB-231 human breast cancer cell line. After the MDA-MB-231 cells had been treated with baicalein, trypan blue exclusion, propidium iodide (PI) assay and 4',6-diamidino-2-phenylindole (DAPI) were used to stain the dead cells and detect apoptosis, respectively. The effects of baicalein on the levels of reactive oxygen species (ROS), Ca2+ and mitochondrial membrane potential (deltapsim) on MDA-MB-231 cells were examined by flow cytometric assays. The ROS caused endoplasmic reticulum (ER) stress, confirmed by the increase of GADD153 and GRP78 in the examined cells. GADD153 and GRP78 increases were also confirmed by confocal laser microscopy examination and indicated that both proteins translocated to the nucleus. The effects of baicalein on the expression of apoptotic-regulated genes, such as Bcl-2 family and caspase, were detected by Western blotting. To further investigate the apoptotic pathway and the role of Ca2+ induced by baicalein, a caspase-3 inhibitor and Ca2+ chelator were used to block caspase-3 activity and Ca2+ in MDA-MB-231 cells. Baicalein induced apoptosis in a time-dependent effect through the inhibition of Bcl-2 expression, increased the levels of Bax, reduced the level of deltapsim, and promoted the cytochrome c release and caspase-3 activation. MDA-MB-231 cells were pretreated with BAPTA which reduced the levels of Ca2+, deltapsim and apoptosis. In conclusion, baicalein induced apoptosis via Ca2+ production, mitochondria-dependent and caspase-3 activation in MDA-MB-231 cells.

Mammalian caspases: structure ,a ctivation ,s ubstrates, and functions during apoptosis

Abstract: ■ Abstract Apoptosis is a genetically programmed, morphologically distinct form of cell death that can be triggered by a variety of physiological and pathological stimuli. Studies performed over the past 10 years have demonstrated that proteases play critical roles in initiation and execution of this process. The caspases, a family of cysteine-dependent aspartate-directed proteases, are prominent among the death proteases. Caspases are synthesized as relatively inactive zymogens that become activated by scaffold-mediated transactivation or by cleavage via upstream proteases in an intracellular cascade. Regulation of caspase activation and activity occurs at several different levels: ( a) Zymogen gene transcription is regulated; ( b) antiapoptotic members of the Bcl-2 family and other cellular polypeptides block proximity-induced activation of certain procaspases; and ( c) certain cellular inhibitor of apoptosis proteins (cIAPs) can bind to and inhibit active caspases. Once activated, caspases cleave a variety of intracellular polypeptides, including major structural elements of the cytoplasm and nucleus, components of the DNA repair machinery, and a number of protein kinases. Collectively, these scissions disrupt survival pathways and disassemble important architectural components of the cell, contributing to the stereotypic morphological and biochemical changes that characterize apoptotic cell death.

Curcumin: A review of anti-cancer properties and therapeutic activity in head and neck squamous cell carcinoma

Abstract: Curcumin (diferuloylmethane) is a polyphenol derived from the Curcuma longa plant, commonly known as turmeric. Curcumin has been used extensively in Ayurvedic medicine for centuries, as it is nontoxic and has a variety of therapeutic properties including anti-oxidant, analgesic, anti-inflammatory and antiseptic activity. More recently curcumin has been found to possess anti-cancer activities via its effect on a variety of biological pathways involved in mutagenesis, oncogene expression, cell cycle regulation, apoptosis, tumorigenesis and metastasis. Curcumin has shown anti-proliferative effect in multiple cancers, and is an inhibitor of the transcription factor NF-κB and downstream gene products (including c-myc, Bcl-2, COX-2, NOS, Cyclin D1, TNF-α, interleukins and MMP-9). In addition, curcumin affects a variety of growth factor receptors and cell adhesion molecules involved in tumor growth, angiogenesis and metastasis. Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and treatment protocols include disfiguring surgery, platinum-based chemotherapy and radiation, all of which may result in tremendous patient morbidity. As a result, there is significant interest in developing adjuvant chemotherapies to augment currently available treatment protocols, which may allow decreased side effects and toxicity without compromising therapeutic efficacy. Curcumin is one such potential candidate, and this review presents an overview of the current in vitro and in vivo data supporting its therapeutic activity in head and neck cancer as well as some of the challenges concerning its development as an adjuvant chemotherapeutic agent.

Curcumin and cancer cells: how many ways can curry kill tumor cells selectively?

Abstract: Cancer is a hyperproliferative disorder that is usually treated by chemotherapeutic agents that are toxic not only to tumor cells but also to normal cells, so these agents produce major side effects. In addition, these agents are highly expensive and thus not affordable for most. Moreover, such agents cannot be used for cancer prevention. Traditional medicines are generally free of the deleterious side effects and usually inexpensive. Curcumin, a component of turmeric (Curcuma longa), is one such agent that is safe, affordable, and efficacious. How curcumin kills tumor cells is the focus of this review. We show that curcumin modulates growth of tumor cells through regulation of multiple cell signaling pathways including cell proliferation pathway (cyclin D1, c-myc), cell survival pathway (Bcl-2, Bcl-xL, cFLIP, XIAP, c-IAP1), caspase activation pathway (caspase-8, 3, 9), tumor suppressor pathway (p53, p21) death receptor pathway (DR4, DR5), mitochondrial pathways, and protein kinase pathway (JNK, Akt, and AMPK). How curcumin selectively kills tumor cells, and not normal cells, is also described in detail.

Regulation of survival, proliferation, invasion, angiogenesis, and metastasis of tumor cells through modulation of inflammatory pathways by nutraceuticals

Abstract: Almost 25 centuries ago, Hippocrates, the father of medicine, proclaimed “Let food be thy medicine and medicine be thy food.” Exploring the association between diet and health continues today. For example, we now know that as many as 35% of all cancers can be prevented by dietary changes. Carcinogenesis is a multistep process involving the transformation, survival, proliferation, invasion, angiogenesis, and metastasis of the tumor and may take up to 30 years. The pathways associated with this process have been linked to chronic inflammation, a major mediator of tumor progression. The human body consists of about 13 trillion cells, almost all of which are turned over within 100 days, indicating that 70,000 cells undergo apoptosis every minute. Thus, apoptosis/cell death is a normal physiological process, and it is rare that a lack of apoptosis kills the patient. Almost 90% of all deaths due to cancer are linked to metastasis of the tumor. How our diet can prevent cancer is the focus of this review. Specifically, we will discuss how nutraceuticals, such as allicin, apigenin, berberine, butein, caffeic acid, capsaicin, catechin gallate, celastrol, curcumin, epigallocatechin gallate, fisetin, flavopiridol, gambogic acid, genistein, plumbagin, quercetin, resveratrol, sanguinarine, silibinin, sulforaphane, taxol, γ-tocotrienol, and zerumbone, derived from spices, legumes, fruits, nuts, and vegetables, can modulate inflammatory pathways and thus affect the survival, proliferation, invasion, angiogenesis, and metastasis of the tumor. Various cell signaling pathways that are modulated by these agents will also be discussed.