Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

Tumor protein p53-induced nuclear protein 1 (TP53INP1) is a well known stress-induced protein that plays a role in both cell cycle arrest and p53-mediated apoptosis. Loss of TP53INP1 expression has been reported in human melanoma, breast carcinoma, and gastric cancer. However, TP53INP1 expression and its regulatory mechanism in esophageal squamous cell carcinoma (ESCC) remain unclear. Our findings are in agreement with previous reports in that the expression of TP53INP1 was downregulated in 28% (10/36 cases) of ESCC lesions, and this was accompanied by significant promoter methylation. Overexpression of TP53INP1 induced G1 cell cycle arrest and increased apoptosis in ESCC cell lines (EC-1, EC-109, EC-9706). Furthermore, our study showed that the oncoprotein c-Myc bound to the core promoter of TP53INP1 and recruited DNA methyltransferase 3A to methylate the local promoter region, leading to the inhibition of TP53INP1 expression. Our findings revealed that TP53INP1 is a tumor suppressor in ESCC and that c-Myc-mediated DNA methylation-associated silencing of TP53INP1 contributed to the pathogenesis of human ESCC.     

大蒜素诱导人食管癌EC-109细胞凋亡

为寻找毒副作用小并且治疗效果好的抗癌药物,研究大蒜素对人食管癌EC-109细胞凋亡的影响,同时探讨了大蒜素引发细胞凋亡的可能机制。通过激光共聚焦显微镜观察细胞形态变化,琼脂糖凝胶电泳检测DNA片段化情况,流式细胞术检测细胞凋亡率和线粒体膜电位变化,qRT-PCR和Western blotting检测细胞凋亡相关基因Bax、Bcl-2的mRNA和蛋白表达水平。结果显示,大蒜素作用人食管癌EC-109细胞48 h后,线粒体膜电位显著降低,并且早期凋亡细胞和晚期凋亡细胞所占百分比均显著增加。同时,与对照组相比,Bax mRNA和蛋白水平均显著升高(p<0.05),Bcl-2 mRNA和蛋白水平均显著降低(p<0.05)。据此,本研究得出大蒜素可诱导人食管癌EC-109细胞凋亡,并呈剂量依赖性,有潜在的药用价值。     

RNA of Enterococcus faecalis Strain EC-12 Is a Major Component Inducing Interleukin-12 Production from Human Monocytic Cells

Interleukin-12 (IL-12) is an important cytokine for the immunomodulatory effects of lactic acid bacteria (LAB). Using murine immune cells, we previously reported that the RNA of Enterococcus faecalis EC-12, a LAB strain exerting probiotic-like beneficial effects, is the major IL-12-inducing immunogenic component. However, it was recently revealed that bacterial RNA can be a ligand for Toll-like receptor (TLR) 13, which is only expressed in mice. Because TLR13 is not expressed in humans, the immuno-stimulatory and -modulatory effects of LAB RNA in human cells should be augmented excluding TLR13 contribution. In experiment 1 of this study, the role of LAB RNA in IL-12 induction in human immune cells was studied using three LAB strains, E.faecalis EC-12, Lactobacillus gasseri JCM5344, and Bifidobacterium breve JCM1192. RNase A treatment of heat-killed LAB significantly decreased the IL-12 production of human peripheral blood mononuclear cells on stimulation, while RNase III treatment revealed virtually no effects. Further, IL-12 production against heat-killed E. faecalis EC-12 was abolished by depleting monocytes. These results demonstrated that single stranded RNA (ssRNA) of LAB is a strong inducer of IL-12 production from human monocytes. In experiment 2, major receptor for ssRNA of E. faecalis EC-12 was identified using THP-1 cells, a human monocytic cell line. The type of RNA molecules of E. faecalis EC-12 responsible for IL-12 induction was also identified. IL-12 production induced by the total RNA of E. faecalis EC-12 was significantly reduced by the treatment of siRNA for TLR8 but not for TLR7. Furthermore, both 23S and 16S rRNA, but not mRNA, of E. faecalis EC-12 markedly induced IL-12 production from THP-1 cells. These results suggested that the recognition of ssRNA of E. faecalis EC-12 was mediated by TLR8 and that rRNA was the RNA molecule that exhibited IL-12-inducing ability in human cells.     

A novel peptide from alpha5 helix of Asterina pectinifera cyclin B conjugated to HIV-Tat(49-57) with cytotoxic and apoptotic effects against human cancer cells

A series of novel peptides from various motifs of Asterina pectinifera cyclin B and their derivatives conjugated to HIV-Tat(49-57) were designed and synthesized. Their bioactivities on two human cancer cell lines were determined. Among them, Tat-a5 (KAQIRAMECNILGRKKRRQRRR) exhibited significant cytotoxic effects on cancer cell lines EC-9706 and HCT-116. Tat-a5 could arrest cancer cells at G(2)/M phase and make them apoptotic. Our results suggested that Tat-a5 could be a novel leading peptide with anticancer activity.     

A facile and efficient synthesis of some (6E)-hydroximino-4-en-3-one steroids, steroidal oximes from Cinachyrella spp. sponges

Using beta-sitosterol as a starting material, (6E)-hydroximino-24-ethylcholest-4-en-3-one (1), a natural steroidal oxime from Cinachyrella alloclada and C. apion, was synthesized in four steps with a high overall yield. First, beta-sitosterol (5a) is transformed into the corresponding 24-ethylcholest-4-en-3,6-dione (6a) via oxidation with pyridinium chlorochromate (PCC). Selective reduction of 6a by NaBH(4) in the presence of CoCl(2) gives 24-ethylcholest- 4-en-3beta-ol-6-one (7a). The reaction of 7a with hydroxylamine hydrochloride offers the oxime 8a and the oxidation of 8a by Jones reagent gives the target steroid 1. (6E)-Hydroximinocholest-4-en-3-one (2) and (6E)-hydroximino-24-ethylcholest-4,22-dien-3-one (4) were synthesized by a similar method. The cytotoxicity of the synthesized compounds against sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells were investigated. The presence of a cholesterol-type side chain appears to be necessary for the biological activity.     

Discovery of novel 1,5-benzodiazepine-2,4-dione derivatives as potential anticancer agents

A series of novel 1,5-benzodiazepine-2,4-dione derivatives with C-6 amide substituents were designed and synthesized using three-component reactions. The preliminary assays showed that most of them displayed moderate to good antitumor activities against human lung carcinoma (A549), human breast epithelial carcinoma (MCF-7), human colon carcinoma (HCT116), human cervical carcinoma (Hela) and Lewis lung carcinoma (2LL). Exhilaratingly, the activity level of 6m rivaled that of 5-Fluorouracil (5-Fu) against MCF-7 cell lines, which might be used as novel lead scaffold for potential anticancer development.     

Synthesis and antiproliferative activity of some steroidal lactone compounds

Using cholesterol as starting material, some steroidal lactone compounds with the structures of 3-substituted-6-oxo-7-oxa-B-homo-cholestane or 3-substituted-7-oxo-6-oxa-B-homo-cholestane were synthesized by oxidation, reduction, Baeyer-Villiger reaction and condensation reaction. The cytotoxicity of these compounds against MGC 7901 (human gastric carcinoma), HeLa (human cervical carcinoma) and SMMC 7404 (human liver carcinoma) cells was investigated. Our results showed that the synthesized compounds displayed a distinct cytotoxicity against these cancer cells. In particular, compounds 8 and 9 have similar cytotoxic capability as cisplatin does. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs.     

Enhanced internalization of ErbB2 in SK-BR-3 cells with multivalent forms of an artificial ligand

Targeting and down-regulation of ErbB2, a member of EGF receptor family, is regarded as one of the key aspect for cancer treatment because it is often overexpressed in breast and ovarian cancer cells. Although natural ligands for ErbB2 have not been found, unlike other ErbB receptors, EC-1, a 20-amino acid circular peptide, has been shown to bind to ErbB2 as an artificial ligand. Previously we showed EC-1 peptide did not induce the internalization of ErbB2 in SK-BR-3 cells. In this report, we designed divalent and multivalent forms of EC-1 peptide with the Fc portion of the human IgG and bionanocapsule modified with ZZ-tag on its surface to improve the interaction with ErbB2. These forms showed higher affinity to ErbB2 than that of EC-1 monomer. Furthermore, prominent endosomal accumulation of ErbB2 occurred in SK-BR-3 cells when stimulated with EC-Fc ligand multivalently displayed on the surface of the bionanocapsule, whereas SK-BR-3 cells as themselves displayed stringent mechanism against ErbB2 internalization without stimulation. The multivalent form of EC-1 peptide appeared to internalize ErbB2 more efficiently than divalent form did. This internalization was unaffected by the inhibition of clathrin association, but inhibited when the cholesterol was depleted which explained either caveolar or GPI-AP-early endocytic compartment (GEEC) pathway. Because of the lack of caveolin-1 expression, caveolar machinery may be lost in SK-BR-3 cell line. Therefore, it is suggested that the multivalent form of EC-1 induces the internalization of ErbB2 through the GEEC pathway.     

Synthesis and biological evaluation of novel steroidal[17,16-d][1,2,4]triazolo[1,5-a]pyrimidines

The preparation of steroidal[17,16-d][1,2,4]triazolo[1,5-a]pyrimidines and their biological evaluation as potential anticancer agents are herein reported. These novel heterosteroids (2, 4) were prepared through the condensation reaction of 3-amino-1,2,4-triazole with 16-arylidene-17-ketosteroids (1, 3). All the synthesized compounds were evaluated for their anticancer activity in vitro against PC-3 (human prostatic carcinoma), MCF-7 (human breast carcinoma) and EC9706 (human esophageal carcinoma) cell lines. Among the screened compounds, 2i, 2n and 4f showed significant inhibitory activity against all the three human cell lines.     

Reactive oxygen species and mitochondrial membrane potential are modulated during CDDP-induced apoptosis in EC-109 cells.

cis-Diamminedichloroplatinum (CDDP), commonly know as cisplatin, is a well known DNA-damaging agent, which is highly active in suppressing the proliferation of tumor cells. However, it is not clear that CDDP can induce growth inhibition of esophagus cancer cells. Using the cell line EC-109 from the esophagus, we found that CDDP would induce apoptotic responses. The addition of CDDP to cells led to the inhibition of growth in a time- and dose-dependent manner. CDDP generated reactive oxygen species (ROSs) in cells, which brought about a reduction in the intracellular mitochondrial transmembrane potential (Deltapsim), leading to apoptosis. Our findings demonstrate that ROSs, and the resulting oxidative stress, play a pivotal role in apoptosis. Preincubation of EC-109 cells with the hydrogen-peroxide-scavenging enzyme catalase partially inhibited the following: (i) the production of ROS; (ii) the disruption of the Deltapsim; and (iii) apoptosis. These results indicate that the enhancement of the generation of ROS and the disruption of Deltapsim are events involved in the apoptotic pathway of EC-109 induced by CDDP.     

Productive, persistent infection of human colorectal cell lines with human immunodeficiency virus.

Thirteen adherent human non-lymphocyte cell lines were tested for their susceptibility to infection by human immunodeficiency virus. Productive infection could be demonstrated in three of five colorectal carcinoma cell lines examined; the other eight human non-lymphocyte cell lines were uninfectible. A susceptible colon carcinoma cell line (HT29), as well as normal colonic mucosa, was shown to contain a 3.0-kilobase species of poly(A)+ CD4 RNA, whereas uninfectible colon carcinoma and rhabdomyosarcoma cell lines synthesized no detectable T4 RNA. A persistently infected colon carcinoma cell line was established that continued to produce progeny human immunodeficiency virus for more than 10 weeks postinfection.     

Synthesis of some acrylophenones with N-methylpiperazine and evaluation of their cytotoxicities

In this study, the compounds having acrylophenone structure, 1-aryl-2-(N-methylpiperazinomethyl)-2-propen-1-one dihydrochlorides, were synthesized and their chemical structures were identified with ¹H NMR, ¹³C NMR and HRMS spectra. The cytotoxicities of the compounds were tested towards Ca9-22 (human gingival carcinoma), HSC-2 (human oral squamous carcinoma), HSC-3 (human oral squamous carcinoma) and HSC-4 (human oral squamous carcinoma) cell lines as tumor cell lines and HGF (gingival fibroblasts), HPLF (periodontal ligament fibroblasts) and HPC (pulp cells) cell lines as non-tumor cell lines. PSE of the compound TA2, which has a methyl substituent on phenyl ring, pointed out the compound TA2 as a leader compound to be considered.     

Synthesis and cytotoxicity of A-homo-lactam derivatives of cholic acid and 7-deoxycholic acid

Using cholic acid and deoxycholic acid as starting materials, a series of 3-aza-A-homo-4-one bile acid and 7-deoxycholic acid derivatives were synthesized by the esterification, oxidation, reduction, oximation and Beckman rearrangement etc. The cytotoxicity of the synthesized compounds against MGC 7901 (human ventriculi carcinoma cell line), hela (human cervical carcinoma cell line), SMMC 7404 (human liver carcinoma cell line) were investigated. The results showed that bile acid and 7-deoxycholic-acid derivatives with 3-aza-A-homo-4-one configuration bearing a 6-hydroximino or 12-hydroximino group displayed a distinct cytotoxicity to Hela tumor cell line. In particular, the IC₅₀ values of the compounds 6 and 13 were 14.3 and 24.3  μmol/L against Hela human tumor cell line respectively. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs.     

The preparation of ethylenediamine‐modified fluorescent carbon dots and their use in imaging of cells

In this work, fluorescent carbon dots (CDs) were synthesized using a hydrothermal method with glucose as the carbon source and were surface‐modified with ethylenediamine. The properties of as‐prepared CDs were analyzed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), ultraviolet–visible light (UV/vis) absorption and fluorescent spectra. Furthermore, CDs conjugated with mouse anti‐(human carcinoembryonic antigen) (CEA) monoclonal antibody were successful employed in the biolabeling and fluorescent imaging of human gastric carcinoma cells. In addition, the cytotoxicity of CDs was also tested using human gastric carcinoma cells. There was no apparent cytotoxicity on human gastric carcinoma cells. These results suggest the potential application of the as‐prepared CDs in bioimaging and related fields. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis, cytotoxic activities and structure-activity relationships of topoisomerase I inhibitors: indolizinoquinoline-5,12-dione derivatives

A series of indolizinoquinoline-5,12-dione derivatives (IQDs) are synthesized and evaluated for their cytotoxic activities toward human lung adenocarcinoma (GLC-82), large-cell lung carcinoma (NCI-H460), promyelocytic leukemia (HL-60) and breast carcinoma (MCF-7) cells by MTT method. Most of the IQDs show significant cytotoxic potency. In addition, the evaluation of structure-activity relationships indicated that the incorporation of electron-withdrawing substituents at the C or D ring will enhance the activities of the target compounds distinctly. The topoisomerase I inhibitory activity is also measured.     

Oral administration of a heat-killed cell preparation of Enterococcus faecalis strain EC-12 stimulates the gene expression of Na(+)-K(+)-2Cl- co-transporter 1 in rat ileal epithelial cells

The effect of a heat-killed cell preparation of Enterococcus faecalis strain EC-12 (EC-12) on the gene expression of Na(+)-K(+)-2Cl(-) co-transporter 1 (NKCC1) in intestinal epithelial cells was evaluated by using rats. The NKCC1 gene in ileal epithelial cells was significantly up-regulated by the oral administration of EC-12. The results of this study suggest in vivo that EC-12 had the potential to stimulate intestinal NKCC1 expression.     

Synthesis, characterization and biological activity of lanthanum(III) complexes containing 2-methylene-1,10-phenanthroline units bridged by aliphatic diamines

Two novel lanthanum(III) complexes containing 2-methylene-1,10-phenanthroline units bridged by aliphatic diamines were synthesized and characterized by elemental analysis, IR, NMR, thermal analysis and conductance measurements. They have been assayed for anticancer activity in vitro against HL-60 (human leukocytoma) cells, PC-3MIE8 (human prostate carcinoma) cells, BGC-823 (human stomach carcinoma) cells, MDA-MB-435 (human galactophore carcinoma) cells, Bel-7402 (human liver carcinoma) cells, and Hela (human cervix carcinoma) cells. The results show that the two complexes exhibit good cytotoxic activities against different cell lines in general, especially more effective than cisplatin against Bel-7402, BGC-823 and MDA-MB-435 cell lines. DNA-binding studies indicate that, besides the intercalation, the complexes bind to DNA by the other interaction(s), which might be responsible for the production of more compact DNA, coinciding with more A-like feature of DNA as suggested by CD spectra.