Experimental Oncology Differential expression of TIS21 and TIS1 genes in the various organs of Balb/c mice,thymic carcinoma tissues and human cancer cell lines

As a part of a series of investigations on the functions of TIS21 and TIS1 genes, we measuredin vivo 12-O-tetradecanoylphorbol-13-acetate (TPA) inducibility of primary response genes (TIS21, TIS8 and TIS1) in the Balb/c mice and the changes of TIS gene expression in thymic carcinoma tissues and A549 and NCIH69 human lung cancer cell lines.In vivo induction of the TIS genes (TIS21, –8 and –1) by intraperitoneal injection of TPA was dramatic only at the needle contact site,i.e. in the abdominal muscle, not in the thigh muscle. Expression of TIS21 and TIS1 in the Balb/c mice thymus, lung, stomach and spleen was very strong (Lim IK et al. 1994a), regardless of TPA injection. Thymic carcinoma tissues developed in SV40-T-antigen-containing transgenic mice did not express TIS21 and TIS1, and expressed TIS8 weakly. Interestingly, induction of TIS21 expression was obliterated in the human lung cancer cells; A549 cells completely lost the ability to express TIS21 after a combined treatment of TPA and cycloheximide. We also measured the induction of TIS genes by TPA and/or cycloheximide in Raw264.7 mouse macrophage cells and U937 human histiocytic lymphoma cells. However, the induction profile was quite different; repressed and deregulated expression in the U937 cells as compared to rapid and transient induction of TIS genes in the Raw264.7 cells. These data may suggest a repressed expression of TIS21 and TIS1 in the cancer tissue and cells derived from the organs that constitutively express TIS21 in mice and in human cancer cells.Abbreviations TPA 12-O-tetradecanoylphorbol-13-acetate - PBS phosphate-buffered saline - FBS fetal bovine serum     

mda7-/IL2-4和IL2-4delE5诱导急性髓系白血病细胞向单核细胞分化

目的:研究人黑素瘤分化相关基因-7(melanoma differentiation associated gene-7,mda-7;又称IL-24)及其剪接体IL-24 delE5与急性髓系白血病(acute myeloid leukemia,AML)细胞分化的关系。方法:十四烷酰佛波醇-乙酯(12-O-tetrade-canoylphorbol-13-acetate,TPA)处理人急性髓系白血病细胞系U937、HL-60,real-time PCR及Western blotting检测细胞中mda-7/IL-24和IL-24 delE5的表达,FACS检测细胞表面CD11b、CD14和CD115的表达。siRNA干扰U937、HL-60细胞中mda-7/IL-24和IL-24 delE5的表达后,再以TPA诱导细胞分化,FACS检测CD11b、CD14和CD115的表达。用前期构建的mda-7/IL-24和IL-24 delE5载体转染U937、HL-60及AML-M5患者的原代白血病细胞,观察异位过表达mda-7/IL-24和IL-24 delE5能否诱导白血病细胞向单核细胞分化。结果:TPA在诱导U9...     

Precancerous lesions upon sporadic activation of beta-catenin in mice

BACKGROUND & AIMS: Inappropriate activation of beta-catenin in adult tissues is associated with a wide variety of cancers, especially in the digestive tract. Classic transgenic and knockout murine models in which beta-catenin is activated in large fields of cells have provided experimental support in favor of a role for this molecule in tumorigenesis. However, these models do not reproduce the sporadic nature of the majority of human cancers, beginning with the activation of an oncogene at random in a single cell. METHODS: We used the "hit and run" strategy to generate a mouse model in which the expression of an activated form of beta-catenin occurs sporadically in vivo. RESULTS: Sporadic, multifocal lesions were observed in the stomach of 3% of mice aged 8 months and older. These lesions were associated with loss of Sonic hedgehog (Shh), and a causal relationship between beta-catenin activation and Shh inhibition was established in gastric cells in vitro. No lesion was detected in the intestine or in the liver. In addition, one third of female mutant mice developed benign perimammary papillomas. Mutant mice were also hypersensitive to chemically induced premalignant skin lesions. CONCLUSIONS: These results challenge the view that activation of beta-catenin induces malignant cancerogenesis, because they show in mice that sporadically activated beta-catenin is sufficient for tumor initiation, yet without further malignant progression, and that it sensitizes cells to environmental hits. This model represents a powerful tool to investigate the interplay between genetic and environmental factors in tumor progression.     

Protective effect of Ocimum sanctum on 3-methylcholanthrene, 7,12-dimethylbenz(a)anthracene and aflatoxin B1 induced skin tumorigenesis in mice

A study on the protective effect of alcoholic extract of the leaves of Ocimum sanctum on 3-methylcholanthrene (MCA), 7,12-dimethylbenzanthracene (DMBA) and aflatoxin B1 (AFB1) induced skin tumorigenesis in a mouse model has been investigated. The study involved pretreatment of mice with the leaf extract prior to either MCA application or tetradecanoyl phorbol acetate (TPA) treatment in a two-stage tumor protocol viz a viz, DMBA/TPA and AFB1/TPA. The results of the present study indicate that the pretreatment with alcoholic extract of the leaves of O. sanctum decreased the number of tumors in MCA, DMBA/TPA and AFB1/TPA treated mice. The skin tumor induced animals pretreated with alcoholic extract led to a decrease in the expression of cutaneous gamma-glutamyl transpeptidase (GGT) and glutathione-S-transferase-P (GST-P) protein. The histopathological examination of skin tumors treated with leaf extract showed increased infiltration of polymorphonuclear, mononuclear and lymphocytic cells, decreased ornithine decarboxylase activity with concomitant enhancement of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the serum, implying the in vivo antiproliferative and immunomodulatory activity of leaf extract. The decrease in cutaneous phase I enzymes and elevation of phase II enzymes in response to topical application of leaf extract prior to MCA, AFB1, DMBA/TPA and AFB1/TPA treatment indicate the possibility of impairment in reactive metabolite(s) formation and thereby reducing skin carcinogenicity. Furthermore, pretreatment of leaf extract in the carcinogen induced animals resulted in elevation of glutathione levels and decrease in lipid peroxidation along with heat shock protein expression, indicating a scavenging or antioxidant potential of the extract during chemical carcinogenesis. Thus it can be concluded that leaf extract of O. sanctum provides protection against chemical carcinogenesis in one or more of the following mechanisms: (i) by acting as an antioxidant; (ii) by modulating phase I and II enzymes; (iii) by exhibiting antiproliferative activity.     

Safety assessment of diacylglycerol oil as an edible oil: A review of the published literature

Diacylglycerol oil is an edible oil with taste and usability characteristics comparable to naturally occurring oils. The objective of this review is to examine literature on diacylglycerol oil to assess its safety-in-use. Feeding rats with unheated or heated diacylglycerol oil at levels up to 5.5% in diet for 90 days did not cause any toxic effects. In chronic studies, dietary administration of diacylglycerol oil (up to 5.3%) to rats for 2 years or at 9.5% to Beagle dogs for 1 year had no adverse effects. Genotoxicity studies of unheated and heated diacylglycerol oil did not reveal any genotoxic effects. Carcinogenicity studies in rodents demonstrate that diacylglycerol oil is non-carcinogenic. In a two-generation reproductive and developmental toxicity study, gavage administration of diacylglycerol oil at dose levels of 5.0 ml/kg body weight/day did not reveal any adverse effects. In several human clinical investigations, administration of diacylglycerol oil at levels up to 0.5 g/kg body weight/day for up to 1 year did not cause adverse effects. Collectively, there is sufficient qualitative and quantitative scientific evidence available from animal and human studies suggesting that intake of diacylglycerol oil is safe for human consumption when used in a manner similar to other edible oils.     

Protective effects of leaf extract of Zanthoxylum ailanthoides on oxidation of low-density lipoprotein and accumulation of lipid in differentiated THP-1 cells

It has been reported that extracts of stem and leaf of Zanthoxylum ailanthoides (ZLE) possess antioxidative properties. However, the biological importance of the ZLE is not well known. In our preliminary study, it showed that ZLE prepared from 75% alcohol highly contains flavonoids (5.8%). By HPLC analysis, it shows that the ZLE consists of flavonoid glycosides including rutin and hyperoside. We investigate the effects of ZLE on the oxidation of low-density lipoprotein (LDL; d = 1.019–1.063 g/mL) and the uptake of lipid in macrophage. Firstly, we explored the effect of ZLE on the oxidation of LDL by employing copper (II) sulfate (CuSO₄) as an oxidative inducer. Oxidation was monitored by the formation of conjugated diene and thiobarbituric acid relative substances (TBARS), relative electrophoretic mobility (REM), and fragmentation of apolipoprotein B-100 (Apo B). Our data showed that ZLE reduced the oxidation properties of LDL induced by CuSO₄. In addition, ZLE inhibited lipid accumulation in differentiated THP-1 cells treated with ox-LDL involving decreasing the expression of scavenger receptors such as scavenger receptor class AI (SR-AI) and CD36, which belongs to the class B scavenger receptor (SR-B). These results demonstrate the protective effect of ZLE on LDL oxidation and lipid accumulation in macrophage.     

Antioxidant and antimicrobial properties of Moltkia petraea (Tratt.) Griseb. flower,leaf and stem infusions

Antioxidant and antimicrobial activities as well as the quantity of phenolic substances (total phenol, flavonoid and phenolic acid contents) were determined in aqueous extracts of leaves, stems and flowers of Moltkia petraea (Tratt.) Griseb. from two mountainous localities (Sveti Jure and Snije?nica) in Croatia. In addition, the profile of phenolic acids was analyzed by UPLC–MS/MS. Antioxidant activities of all extracts in different test systems, namely the DPPH radical scavenging, reducing power assay and chelating activity, increased with extract concentration. Activity of the extracts from Snije?nica in β-carotene-linoleic acid assay did not differ from the activity of standard, BHA. The leaf extracts from Snije?nica demonstrated superior antioxidant activity in most of the assays, while the stem extract from the same locality was the most effective Fe²⁺ ion chelator. In general, the extracts from Snije?nica were more effective antioxidants than the corresponding extracts from Sveti Jure. The aqueous extracts of M. petraea did not show antimicrobial activity against bacteria and fungi tested in the diffusion and dilution assays.     

Molecular targets of dietary agents for prevention and therapy of cancer

While fruits and vegetables are recommended for prevention of cancer and other diseases, their active ingredients (at the molecular level) and their mechanisms of action less well understood. Extensive research during the last half century has identified various molecular targets that can potentially be used not only for the prevention of cancer but also for treatment. However, lack of success with targeted monotherapy resulting from bypass mechanisms has forced researchers to employ either combination therapy or agents that interfere with multiple cell-signaling pathways. In this review, we present evidence that numerous agents identified from fruits and vegetables can interfere with several cell-signaling pathways. The agents include curcumin (turmeric), resveratrol (red grapes, peanuts and berries), genistein (soybean), diallyl sulfide (allium), S-allyl cysteine (allium), allicin (garlic), lycopene (tomato), capsaicin (red chilli), diosgenin (fenugreek), 6-gingerol (ginger), ellagic acid (pomegranate), ursolic acid (apple, pears, prunes), silymarin (milk thistle), anethol (anise, camphor, and fennel), catechins (green tea), eugenol (cloves), indole-3-carbinol (cruciferous vegetables), limonene (citrus fruits), beta carotene (carrots), and dietary fiber. For instance, the cell-signaling pathways inhibited by curcumin alone include NF-kappaB, AP-1, STAT3, Akt, Bcl-2, Bcl-X(L), caspases, PARP, IKK, EGFR, HER2, JNK, MAPK, COX2, and 5-LOX. The active principle identified in fruit and vegetables and the molecular targets modulated may be the basis for how these dietary agents not only prevent but also treat cancer and other diseases. This work reaffirms what Hippocrates said 25 centuries ago, let food be thy medicine and medicine be thy food.