Study on like-stem characteristics of tumor sphere cells in human gastric cancer line HGC-27.

Stem-like cancer cells are called cancer stem cells (CSCs) or tumor stem cells (TSCs). Methods for sorting CSCs are mainly based on the marker (CD133+/CD44+) or side population cells. However, CD133+/CD44+ cells or side population cells are very rare or even undetectable.

TAK1 promotes cell survival by TNFAIP3 and IL-8 dependent and NF-κB independent pathway in HeLa cells exposed to heat stress.

Purpose: Transforming growth factor-β-activated kinase 1 (TAK1) plays a role in inhibiting apoptosis in response to multiple stresses. In the present study, we investigated the role of TAK1 in cell death induced by heat stress (HS).

Materials And Methods: TAK1 knockdown HeLa cells and their parental cells were exposed to HS at 44 °C for 15, 30, 45 min followed by colony formation assay.

TGF-β-activated kinase 1 promotes cell cycle arrest and cell survival of X-ray irradiated HeLa cells dependent on p21 induction but independent of NF-κB, p38 MAPK and ERK phosphorylations.

Transforming growth factor-β-activated kinase 1 (TAK1) appears to play a role in inhibiting apoptotic death in response to multiple stresses. To assess the role of TAK1 in X-ray induced apoptosis and cell death, we irradiated parental and siRNA-TAK1-knockdown HeLa cells. Changes in gene expression levels with and without TAK1-knockdown were also examined after irradiation to elucidate the molecular mechanisms involved.

Mitochondria-targeted superoxide dismutase (SOD2) regulates radiation resistance and radiation stress response in HeLa cells.

Reactive oxygen species (ROS) act as a mediator of ionizing radiation-induced cellular damage. Previous studies have indicated that MnSOD (SOD2) plays a critical role in protection against ionizing radiation in mammalian cells. In this study, we constructed two types of stable HeLa cell lines overexpressing SOD2, HeLa S3/SOD2 and T-REx HeLa/SOD2, to elucidate the mechanisms underlying the protection against radiation by SOD2.

Parafibromin expression is an independent prognostic factor for colorectal carcinomas.

Parafibromin is a protein encoded by hyperparathyroidism 2, and its down-regulated expression is involved in the pathogenesis of parathyroid, breast, and gastric carcinomas. This study aimed to clarify the roles of parafibromin expression in tumorigenesis, progression, and prognosis of colorectal carcinomas. Parafibromin-expressing plasmid was transfected into DLD-1 cells with the phenotypes, and related molecules were examined.

Aptamer-Based Sensitive Detection of Target Molecules via RT-PCR Signal Amplification.

In the efforts to explore an aptamer-based approach for target sensing and detection with higher sensitivity and specificity, instead of directly labeling aptamer with fluorophores, we proposed a new strategy by attaching a polymerase chain reaction (PCR) template to an oligonucleotide aptamer selected by systematic evolution of ligands by exponential enrichment (SELEX), so that after aptamer target binding, the template moiety serves as the PCR template in real-time quantitative PCR (RT-PCR), and therefore, the binding event can be reported by the following RT-PCR signals. Using the subtractive SELEX method, the oligonucleotide aptamers specific for the Fc fragment of mouse IgG were selected and subjected to coupling with the PCR dsDNA template by using overlap and the asymmetric extension PCR method. The target binding affinity of the PCR template tethered aptamer has been proven by electrophoretic mobility shift assay (EMSA), and further template tethered aptamer mediated real-time quantitative PCR (A-PCR) was conducted to validate the application for such a template tethered aptamer to be a sensitive probe for IgG detection.

Role of fatty acid chain length on the induction of apoptosis by newly synthesized catechin derivatives.

The catechins, a family of polyphenols found in tea, can evoke various responses, including apoptosis. In this study we investigated whether the chemical modification of (-)-epigallocatechin gallate (EGCG) could enhance its apoptosis activity. We found that one of the catechin conjugated with capric acid [(2R,3S)-3',4',5,7-tetrahydroxyflavan-3-yl decanoate; catechin-C10] was most potent to induce apoptosis in U937 cells.

Nuclear or cytoplasmic localization of Bag-1 distinctly correlates with pathologic behavior and outcome of gastric carcinomas.

Bag-1 is an antiapoptotic protein with its altered expression and localization in malignancies. To clarify the role of Bag-1 in gastric carcinogenesis, its expression was examined by immunohistochemistry and in situ hybridization on a tissue microarray containing gastric carcinomas, adjacent nonneoplastic mucosa (NNM), adenomas, intestinal metaplasia (IM), or gastritis. Gastric carcinoma tissue and cell lines were studied for Bag-1 expression by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR).

Mild hyperthermia prior to electroporation increases transfection efficiency in HCT 116, HeLa S3 and SGC 7901 cells.

The change in transfection efficiency of electroporation by the combined treatment with mild preheating (40 degrees C for 30 min) was investigated. HCT 116, HeLa S3 and SGC 7901 cells were treated with electroporation in medium containing pBKCMV-Luc plasmid with or without preheating. After 24 h, luciferase activity was increased by 36, 28 and 77%; luciferase mRNA transcription was increased by 45, 50 and 68%; and fluorescein isothiocyanate-dextran accumulation was increased by 9, 35 and 15% in preheated groups, respectively.

Enhancement of hyperthermia-induced apoptosis by sanazole in human lymphoma U937 cells.

Sanazole has been tested clinically as a hypoxic cell radiosensitizer. The aim of the present study was to investigate whether sanazole enhances apoptosis induced by hyperthermia at 44 degrees C for 20 min in human lymphoma U937 cells. Sanazole alone induced continuous increase in the intracellular superoxide generation in a time-dependent manner and transient increase in the peroxide formation, which further were enhanced at 1 hour after HT treatment.

Design, synthesis, and biological evaluation of artificial macrosphelides in the search for new apoptosis-inducing agents.

Various artificial macrosphelides were designed and synthesized, including ring-enlarged analogues and epothilone-hybrid compounds. Syntheses were accomplished in an efficient manner by using a ring-closing metathesis (RCM) strategy in a key macrocyclization step. Biological evaluation of these new macrosphelide-based derivatives revealed that several epothilone hybrids, in which a thiazole-containing side chain was incorporated, exhibited potent apoptosis-inducing activity toward human lymphoma cells.

Enhancement of radiation-induced apoptosis of human lymphoma U937 cells by sanazole.

Sanazole has been tested clinically as a hypoxic cell radiosensitizer. In this study, we determined whether sanazole enhances the radiation-induced apoptosis of human lymphoma U937 cells. Our results revealed that, compared with 10 mM sanazole or radiation alone, the combination of both resulted in a significant enhancement of apoptosis after 6 h, which was evaluated on the basis of DNA fragmentation, morphological changes, and phosphatidylserine externalization.

Novel 3,4-diazabenzotropone compounds (2,3-benzodiazepin-5-ones): synthesis, unique reactivity, and biological evaluation.

Efficient synthesis of 3,4-diazabenzo[b]tropone was first achieved utilizing 4pi-8pi sequential electrocyclic reactions of functionalized benzocyclobutenone derivatives. These compounds are highly electron deficient and readily form amine adducts at ambient temperature. Furthermore, gentle heating resulted in quantitative nitrogen extrusion to produce indenone derivatives.

Enhancement of sodium butyrate-induced cell death and apoptosis by X-irradiation in the human colorectal cancer cell line HCT 116.

In this study, we aimed at evaluating the possible enhancing effect exerted by the combined use of sodium butyrate (SB) and X-rays on eradicating the human colorectal cancer cell line HCT 116 containing wild-type p53. We assessed the effect of this combination on the molecular pathways leading to cell death. HCT 116 cells were subjected to SB (1 mM) treatment followed by X-irradiation (5 Gy), and the effects on cell death, cell proliferation and cell cycle were examined.

Enhancement of sodium butyrate-induced cell death by hyperthermia in HCT 116 human colorectal cancer cells.

Aim: The possible enhancing effect of the combined use of sodium butyrate (SB) and hyperthermia to kill HCT 116 cells was evaluated.

Materials And Methods: HCT 116 cells were subjected to SB (1 mM) treatment followed by hyperthermia (44 degrees C 60 min) and the effects on cell death, cell proliferation and the cell cycle were examined. Apoptosis-indicating protein expressions and intracellular superoxide formation were also analysed.

Enhancement of hyperthermia-induced apoptosis by a new synthesized class of benzocycloalkene compounds.

The aim of this study was to examine whether, a new synthesized class of benzocycloalkene derivatives (BCs), enhances apoptosis induced by hyperthermia. The combined effects of hyperthermia (44 degrees C, 20 min) and BCs on apoptosis in human lymphoma U937 cells were investigated. Among the tested compounds (BC1 approximately 9), the combined treatment of 10 muM BC2 or BC4 and hyperthermia showed the largest potency to induce DNA fragmentation at 6 h after hyperthermia.

Enhancement of hyperthermia-induced apoptosis by a new synthesized class of furan-fused tetracyclic compounds.

The combined effects of hyperthermia (44 degrees C, 20 min) or X-rays (10 Gy) and a new class of furan-fused tetracyclic synthesized compounds (DFs), on apoptosis in human lymphoma U937 cells were investigated. Among the tested compounds (DF1 approximately 6), the combined treatment of 10 microM DF with TIPS (triisopropylsilyloxy) (Designated #3 DF3) and hyperthermia showed the largest potency to induce DNA fragmentation at 6 h after hyperthermia but no enhancement was observed if it was combined with X-rays. Enhancement of hyperthermia-induced apoptosis by DF3 in a dose-dependent manner was observed.

Expression of Fas ligand and caspase-3 contributes to formation of immune escape in gastric cancer.

Aim: To study the role of Fas ligand (FasL) and Caspase-3 expression in carcinogenesis and progression of gastric cancer and molecular mechanisms of relevant immune escape.

Methods: FasL and Caspase-3 expression was studied in adjacent epithelial cells, cancer cells and lymphocytes of primary foci, and cancer cells of metastatic foci from 113 cases of gastric cancer by streptavidin-biotin-peroxidase (S-P) immunohistochemistry. Expression of both proteins in cancer cells of primary foci was compared with clinicopathological features of gastric cancer.