Colon Carcinoma Research Papers - Academia.edu (original) (raw)

␣-Difluoromethylornithine (DFMO) is commonly used as a specific ornithine decarboxylase (ODC, EC4.1.1.17) irreversible inhibitor. ODC is the enzyme responsible for polyamine biosynthesis, which has been shown to be strictly necessary for cell proliferation. In HT-29 Glc Ϫ/ϩ cells, L-arginine is the major precursor of these molecules through the sequential actions of arginase, which leads to L-ornithine generation and ODC. L-ornithine, a substrate for ODC, retroinhibits arginase. Since DFMO is an ornithine analogue, we searched for a direct effect of this agent upon arginase. The flux of L-arginine through arginase in intact cells was inhibited by 51 Ϯ 11% by 10 mM of DFMO whereas 10 mM of L-valine, a known potent arginase inhibitor, inhibited this flux by 73 Ϯ 6%. DFMO equilibrated between extracellular and intercellular spaces and, when used at 10-mM concentration, was without effect on L-arginine net uptake. Measurement of arginase activity in HT-29 cell homogenates with increasing concentrations of DFMO and L-arginine led to an inhibition with a calculated K i (inhibitory constant) equal to 3.9 Ϯ 1.0 mM. L-ornithine was less effective than DFMO in inhibiting arginase activity. Bovine liver arginase, used as another source of the enzyme, was also severely inhibited by DFMO. The inhibitory effect of DFMO upon arginase, one step upstream of the ODC reaction in the metabolic conversion of L-arginine to polyamines, is of potential physiological importance, since it could alter the production of ornithine and thus its metabolism in pathways other than the ODC pathway.

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- Enzyme Inhibitors, Liver, Enzyme, Cattle

The cell-cell adhesion molecule 1 (C-CAM1) plays an important role as a tumor suppressor for prostate cancer. Decreased expression of C-CAM1 was detected in prostate, breast, and colon carcinoma. Reexpression of C-CAM1 in prostate and breast cancer cell lines was able to suppress tumorigenicity in vivo. These observations suggest that C-CAM1 may be used as a marker for cancer detection or diagnosis. To generate monoclonal antibodies specific to C-CAM1, we have overexpressed full-length human C-CAM1 in Sf9 cells using a baculovirus expression system. The protein was purified 104-fold using nickel affinity chromatography. About 0.4 mg purified C-CAM1 was obtained from 200 mg of infected cells. When the purified protein was digested with peptidyl-N-glycosidase, the apparent mobility of the protein on SDS-PAGE changed from 90 to 58 kDa, which is close to the molecular weight predicted from the cloned cDNA sequence. This observation suggests that C-CAM1 was glycosylated on asparagine residues when expressed in Sf9 cells. Western blotting and internal protein sequencing analysis confirmed that the purified protein is human C-CAM1. Biochemical and functional assays indicate that this protein expressed in Sf9 cells displays characteristics similar to those of native protein, including adhesion function and glycosylation modification. Using this protocol, sufficient quantity of this protein can be produced with purity suitable for monoclonal antibody generation and biochemical study.

We examined 36 cases of human sporadic colon carcinoma and corresponding normal tissue samples to evaluate loss of heterozygosity at the APC and DCC tumor suppressor genes loci using restriction fragment length polymorphism polymerase chain reaction and variable nucleotide tandem repeat analysis. Observed informativity was 83% for APC and 75% for DCC. DNA from 6 (20%) of 30 informative tumors exhibited loss of heterozygosity at the APC locus. Loss of heterozygosity at the DCC locus was observed in 7 (26%) of 27 informative tumor DNAs. Our results support the view that malignant progression is a consequence of more than one genetic change and suggest that inactivation of APC and DCC genes plays a role in a multistep process of colon tumor progression.

- by Radan Spaventi
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- Genetics, Molecular Medicine, Polymerase Chain Reaction, Tumor Suppressor Gene

The conventional approach for analyzing the protein complement of a genome involves the combination of two-dimensional gel electrophoresis (2-DE) and mass spectrometric based protein identification technologies. While 2-DE is a powerful separation technique, it is severely limited by the insolubility of certain classes of proteins (e.g. hydrophobic membrane proteins), as well as the amount of protein that can be processed. Here, we describe a simple procedure for resolving complex mixtures of proteins that involves a combination of free flow electrophoresis (FFE), a liquid-based isoelectric focussing (IEF) method, and sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Resolved proteins were identified by peptide fragment sequencing using capillary column reversed-phase high performance liquid chromatography (RP-HPLC)/mass spectrometry (MS). An initial demonstration of the method was performed using digitonin/ethylenediaminetetraacetic acid EDTA extracted cytosolic proteins from the human colon carcinoma cell line, LIM 1215. Cytosolic proteins were separated by liquid-based IEF (pH range 3-10) into 96 fractions, and each FFE fraction was further fractionated by SDS-PAGE. Selected protein bands were excised from the SDS-PAGE gel, digested in situ with trypsin, and subsequently identified by on-line RP-HPLC/electrospray-ionization ion trap MS. Our results indicate that FFE is: (i) an extremely powerful liquid-based IEF method for resolving proteins; (ii) not limited by the amount of sample that can be loaded onto the instrument; and (iii) capable of fractionating intact protein complexes (a potentially powerful tool for cell-mapping proteomics). An up-to-date list of cytosolic proteins from the human colorectal carcinoma cell line LIM 1215 can be found in the Joint Protein Structure Laboratory (JPSL) proteome database. This information will provide an invaluable resource for future proteomics-based biological studies of colon cancer. The JPSL proteome database can be accessed through the World Wide Web (WWW) network

- by Meredith Layton
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- Mass Spectrometry, Proteomics, Biological Sciences, Cell line

a b s t r a c t 5,6-Disubstituted pyrimidine derivatives (4)(17) were prepared by intramolecular cyclization reaction of a-(1-carbamyliminomethylene)-c-butyrolactone (2) with sodium ethoxide and subsequent chemical transformation of 2-hydroxy group in C-5 side chain as well as lithiation reaction for introduction of acyclic side chain at C-6. All compounds were characterized by 1 H NMR, 13 C NMR and mass spectra. Structures of compounds 4, 7 and 14 were unambiguously confirmed by X-ray crystal structural analysis. Supramolecular structures of these three compounds differ significantly. Two N-HÁ Á ÁO and one C-HÁ Á ÁO hydrogen bonds in 4 form three-dimensional network. One O-HÁ Á ÁN hydrogen bond and one pÁ Á Áp interaction self-assemble the molecules of 7 into sheets. In supramolecular aggregation of 14, only pÁ Á Áp stacking interactions participate, so forming chains. The compounds were evaluated for their cytostatic activities against human malignant cell lines. Of all tested compounds, 2,4-dimethoxy-5-methoxytritylethylpyrimidine (9) and 2,4-dichloro-5-chloroethylpyrimidine (14) exhibited the most prominent inhibitory effects. Furthermore, compound 14 showed marked activity against human colon carcinoma (IC 50 = 0.4 lM).

Human SW 1116 colon carcinoma cells were grown on matrix-covered coverslips and flat embedded in specially prepared gelatin capsules in the hydrophylic resin LR White. Dehydration and polymerization were carried out so as to maximize preservation of antigenicity. Sections were cut perpendicular to the substratum. To visualize mucin, semithin sections of SW 1116 cells were stained with periodic acid Schiff (PAS) reagent for light microscopy, and ultrathin sections were labelled with a monoclonal mucin antibody (Mab 19-9) and immunogold for electron microscopy. Immunofluorescence was carried out on whole cultured cells using Mab 19-9. The morphological preservation of SW 1116 cells embedded in LR White was comparable to that of Epon-embedded cells. Mucin was localized on the microvillar surface of the apical plasma membrane and occasionally in intercellular spaces between adjacent cells. Mucin was also present in vesicles in the apical and lateral part, and to a lesser extent in the basal part of the cells. We conclude that this new technology significantly improves the morphological preservation of cells and tissues in LR White, while also serving to sustain the antigenicity of cellular antigens.

- by Harvey Pollard
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- Materials Engineering, Electron Microscopy, Microscopy, Polymers

The present paper shows, for the Wrst time, the membrane expression of the dendritic cell maturation marker CD83 on tumor cells from lung cancer patients. CD83 was also detected on freshly cultured Wbroblast-like cells from these tissues and on several adherent human tumor cell lines (lung adenocarcinomas P9, A459 and A549, melanomas A375 and C81-61, breast adenocarcinomas SKBR-3 and MCF-7 and colon carcinoma AR42-J), but not in the non-adherent MOT leukemia cell line. CD83 may have immunosuppressive properties and its expression by cancer cells could have a role in facilitating tumor growth.

- by Fabio Haddad and +1
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- Immunology, Dendritic Cells, Cancer Immunology, Lung Cancer

Labrador tea (Ledum groenlandicum Retzius) is an ericaceae widely distributed in North America. The leaves and twigs were used in Native American traditional medicine to treat several inflammatory pathologies such as asthma, rheumatisms and burns. Reactive oxygen species as well as reactive nitrogen species such as nitric oxide (NO) contribute significantly to these pathologies. In this study, the antioxidant, anti-inflammatory

Here we describe the discovery and optimization of hexahydro-2H-pyrano[3,2-c]quinolines (HHPQs) as potent and selective inhibitors of the mitotic kinesin-5 originally found during a high-throughput screening (HTS) campaign sampling our in-house compound collection. The compounds optimized subsequently and characterized herein were potently inhibiting the ATPase activity of Kinesin-5 and also exhibited consistent cellular activity, in that cells arrested in mitosis and apoptosis induction could be observed. X-ray crystallographic data demonstrated that these inhibitors bind in an allosteric pocket of Kinesin-5 distant from the nucleotide and microtubule binding sites. The selected clinical candidate EMD 534085 caused strong growth inhibition in human tumor xenograft models using Colo 205 colon carcinoma cells at doses below 30 mg/kg administered twice weekly without showing severe toxicity as determined by loss of body weight.

The aim of this study was to investigate the adhesive phenotype of the human intestinal isolate Bifidobacterium bifidum MIMBb75 to human colon carcinoma cell lines. We have previously shown that the adhesion of this strain to Caco-2 cells is mediated by an abundant surface lipoprotein named BopA. In this study, we found that this strain adheres to Caco-2 and HT-29 cells, and that its adhesion strongly depends on the environmental conditions, including the presence of sugars and bile salts and the pH. Considerably more adhesion to a Caco-2 monolayer occurred in the presence of fucose and mannose and less when MIMBb75 grew in Oxgall bile salts compared to standard environmental conditions. In particular, growth in Oxgall bile salts reduced the adhesion ability of MIMBb75 and modified the SDS-PAGE profile of the cell wall associated proteins of the strain. The pH markedly affected both adhesion to Caco-2 and bacterial autoaggregation. Finally, experiments with sodium metaperiodate suggested that not only proteinaceous determinants are involved in the adhesion process of B. bifidum. In conclusion, it seems that the colonization strategy of this bacterium can be influenced by factors varying along the gastrointestinal tract, such as the presence of specific sugars and bile salts and the pH, possibly limiting the adhesion of B. bifidum to only restricted distal sites of the gut.

- by Simone Guglielmetti
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- Microbiology, Medical Microbiology, Colonization, Cell line
- by Zvi Malik
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- Kinetics, Photochemistry, Quantitative analysis, Mice

Background: Arrest of the cell cycle in G2 phase following DNA damage helps protect cell viability by allowing time for DNA repair before entry into mitosis (M phase). Abrogation of G 2 arrest sensitizes cells to the effects of DNA-damaging agents. UCN-01 (7-hydroxystaurosporine), a protein kinase C inhibitor that may block G 2 checkpoint regulation, has been reported to enhance the cytotoxicity of mitomycin C, a known DNA-damaging agent. Purpose: We studied the effect of UCN-01 on G 2 checkpoint control in human lymphoma CA46 cells, whose sensitivity to various DNA-damaging agents and G2 response to DNA damage have been characterized. We also assessed the ability of UCN-01 to enhance the cytotoxicity of y irradiation in CA46 cells and human colon carcinoma HT-29 cells, both of which are mutant for p53 function. The influence of p53 function on UCN-01mediated abrogation of the G 2 checkpoint and enhancement of DNA-damaging agent cytotoxicity was studied in transfected human breast carcinoma MCF-7 cells that either expressed or did not express the human papillomavirus type-16 E6 protein. MCF-7 cells have normal p53 function, and the E6 protein binds p53 protein and promotes its destruction. Methods: The effect of UCN-01 on cell cycle arrest induced by y irradiation was studied in CA46 cells and in transfected MCF-7 cells by use of flow cytometry. A histone HI phosphorylation assay was employed to measure cyclin Bl/Cdc2 kinase activity in extracts derived from irradiated and nonirradiated CA46 cells that had been either treated or not treated with UCN-01; the phosphorylation status of Cdc2 kinase protein in the same extracts was determined by use of western blotting. The effect of UCN-01 on the cytotoxicity of y irradiation in CA46 and HT-29 cells was determined by use of MTT (thiazolyl blue) and clonogenic (colony-forming) assays, respectively; a clonogenic assay was also used to measure the effect of UCN-01 on the cytotoxicity of cisplatin in transfected and nontransfected MCF-7 cells.

- by Edward Sausville and +1
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- Flow Cytometry, Cell Cycle, Gamma Rays, DNA damage

Le rétablissement de la continuité caecorectale par le procédé de Deloyers a l'inconvénient d'entraîner une torsion du pédicule vasculaire. La technique proposée consiste à faire une simple anastomose caecorectale mécanique antipéristaltique sans retournement du caecum. Cette technique a été utilisée avec succès chez 26 patients après colectomie subtotale pour cancers coliques multiples ou pour constipation grave. © 2000 Éditions scientifiques et médicales Elsevier SAS anastomose caecorectale antiperistaltique / colectomie ABSTRACT Antiperistaltic caecorectal anastomosis without torsion of the vascular pedicle. Caecorectal anastomosis by Deloyers' procedure has the disadvantage of creating torsion of the vascular pedicle. The technique reported here is a simple mechanical antiperistaltic anastomosis without inversion of the caecum. This technique was performed successfully in 26 patients after subtotal colectomy for multiple colonic carcinomas or severe constipation. © 2000 Éditions scientifiques et médicales Elsevier SAS antiperistaltic caecorectal anastomosis / colectomy Reçu le 25 avril 2000 ; accepté le 26 juillet 2000. * Correspondance et tirés à part. Adresse

- by Renato Costi
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- Clinical Sciences, Colon Carcinoma

The hPepT1-mediated transport properties of a series of 11 synthesized -and γ-peptides have been studied in Caco-2 cells. The results show that several of the compounds interact with the peptide transporter, but only two -dipeptides act as substrates and are transported across the cell monolayers. These two are lessefficient substrates than R-peptides. Larger derivatives than -dipeptides do not act as hPepT1 substrates, but instead, they appear to be substrates for P-glycoprotein efflux. ionization; HOBt, 1-hydroxy-1H-benzotriazole hydrate; TFA, trifluoroacetic acid. Three-letter amino-acid abbreviations are used for homologated amino acid derivatives: hXaa ( n , homoamino acid) 1 and γhhXaa (γ m,n , doubly homologated amino acid), where n indicates the position of the proteinogenic side chain.

- by Per Artursson
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- Pharmacology, Biochemistry, Bioinformatics, Endocrinology

Reçu le 22 novembre 2004 ; accepté le 8 mars 2005 Disponible sur internet le 10 mai 2005

- by toumi mohamed
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- Ultrasonography, Staphylococcus aureus, Medical Image, Colon Carcinoma

The most active vitamin D metabolite, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), is a pleiotropic hormone with wide regulatory actions. Classically, vitamin D deficiency was known to alter calcium and phosphate metabolism and bone biology. In addition, recent epidemiological and experimental studies support the association of vitamin D deficiency with a large variety of human diseases, and particularly with the high risk of colorectal cancer. By regulating the expression of many genes via several mechanisms, 1,25(OH)2D3 induces differentiation, controls the detoxification metabolism and cell phenotype, sensitises cells to apoptosis and inhibits the proliferation of cultured human colon carcinoma cells. Consistently, 1,25(OH)2D3 and several of its analogues decrease intestinal tumourigenesis in animal models. Molecular, genetic and clinical data in humans are scarce but they suggest that vitamin D is protective against colon cancer. Clearly, the available evidence warrants new, well-de...

- by Alberto MUNOZ
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- Vitamin D, Apoptosis, Energy Metabolism, Colorectal cancer
- by Ismael Hidalgo
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- Kinetics, Epidermal Growth Factor, Colon Carcinoma, Biochemistry and cell biology

Tumour cell adhesion within the microvasculature of host organs, its stabilisation and cell invasion into the host organs, appear to be important steps in the formation of distant metastases. Intravital fluorescence-video microscopy was used to investigate the early steps in metastasis formation of colon carcinoma cells within the liver, which is the main target organ of colorectal carcinomas. The involvement of av-integrins was analysed in vivo using HT-29 cells after treatment with different function-blocking antibodies [pan-av (n = 9 animals), specific avb3 (n = 8 animals) and avb5 (n = 8 animals)] or linear Arg-Gly-Asp (RGD)-containing peptides (RGDpeptides) (n = 6 animals). Treatment with anti-av and anti-avb5 antibodies resulted in significantly (P < 0.001) decreased tumour cell adhesion in vivo within the hepatic microvasculature. Cells treated with anti-avb3 antibodies or unspecific immunoglobulin-G (IgG) did not show significant changes in their adhesive properties. Furthermore, inhibition of cell adhesion was achieved by linear RGDpeptides in a dose-dependent manner. Relative numbers of migrated cells were not affected by any of the treatments. These results suggest that av-integrins, especially avb5, can influence the ability of circulating tumour cells to adhere within the hepatic microvessels. In contrast, migration of adherent cells into the liver parenchyma was not affected by av-integrin inhibition. Our findings support the hypothesis that specific interactions between circulating tumour cells and host organs are required for organ-specific tumour cell arrest.

- by Andreas Enns
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- Cell Adhesion, Integrins, Neoplasm Invasiveness, Colon Carcinoma

It was shown that CEACAM5 can mediate cell-cell adhesion through homotypic and heterotypic interactions; however, its role in the expression of the malignant phenotype remains obscure. To study whether the formation of both primary tumors and metastases is directly related to the presence or absence of CEACAM5, we applied the antisense RNA strategy. By transfecting human CX-1.1 colon carcinoma cells with CEACAM5 antisense-expressing vector or with the vector itself, cell variants with a highly decreased expression of CEACAM5 were obtained. Profound differences in proliferative abilities among parental and obtained subclones of CX-1.1 cells were revealed when cells were implanted subcutaneously into nude mice. In contrast to their highly tumorigenic parental CX-1.1 cells (with high expression of membrane-bound and secreted CEACAM5), two subclones (3E and AS6Q) with substantially decreased expression of membrane-bound and secreted CEA showed a considerably diminished growth rate. Even...

- by Joanna Wietrzyk
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- Cell Adhesion, Mice, P-glycoprotein, Plasmids

The carbohydrate-binding activity of the algal lectins from the closely related red marine algal species Bryothamnion triquetrum (BTL) and Bryothamnion seaforthii (BSL) was used to differentiate human colon carcinoma cell variants with respect to their cell membrane glyco-receptors. These lectins interacted with the cells tested in a dose-dependent manner. Moreover, the fluorescence spectra of both lectins clearly differentiated the cells used as shown by FACS profiles. Furthermore, as observed by confocal microscopy, BTL and BSL bound to cell surface glycoproteins underwent intense internalization, which makes them possible tools in targeting strategies.

- by Victor Carneiro
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- Bioinformatics, Life Sciences, Biomedical Research, Pharmacological Sciences

Carcinoembryonic antigen (CEA, CEACAM5) is expressed on several human carcinomas including colon cancer. CEA contains signal peptides that target the protein through the endoplasmic reticulum and to the cell membrane. We constructed a plasmid DNA vaccine encoding a truncated CEA (DCEA), devoid of its signal peptides, and demonstrated that it was retained inside the cell, while full-length CEA (wtCEA) was expressed on the membrane. We hypothesized that intracellular retention of DCEA would enhance MHC class I presentation of CEA peptides, thus favoring cellular immune responses. In addition, a promiscuous T-helper epitope (Q830-L844 of tetanus toxoid) was fused to the N-terminal of the truncated CEA gene (tetDCEA). C57BL/6 mice immunized with DNA encoding wtCEA or tetDCEA developed both humoral and cellular immune responses to CEA. SCID mice transplanted with spleen cells from tetDCEA but not wtCEA-immunized C57BL/6 mice showed strong suppression of tumor growth after inoculation of human CEA-expressing colon carcinoma cells. Immune spleen cell populations depleted for either B, T or both B and T cells were active, indicating that effector cells might also reside in other populations. The present approach to manipulating antigen presentation may open new possibilities for immunotherapy against colon and other CEA-secreting carcinomas.

- by Gosta Winberg and +1
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- Immune response, Cell Division, Spleen, Mice

We have previously established that insulin-like growth factor (IGF)-I, -II and insulin exert a strong protective effect against tumor necrosis factor-a (TNF)-induced apoptosis in interferon-g (IFN)-sensitized HT29-D4 human colon carcinoma cells. In this study, we report that this effect was still operative when cells were cultured in the absence of integrin-and E-cadherinmediated cell ± extracellular matrix and cell ± cell interactions. In this model, IGF-I did not activate the focal adhesion kinase, whereas it induced tyrosine phosphorylation of the insulin receptor substrate-1 and activation of the extracellular signalrelated kinase 1 and 2, p38, phosphatidylinositol 3'-kinase and protein kinase B/Akt. However, the use of specific inhibitors indicated that these pathways did not play a role in the adhesion-independent IGF-I anti-apoptotic signal. In contrast, inhibition of the NF-kB activation induced a complete reversal of the IGF-I anchorage-independent protective effect. Correspondingly, IGF-I markedly enhanced the TNF-and IFN/TNFinduced NF-kB-dependent interleukin-8 production. Our results provide evidence that IGF-I induces resistance against cytokine-induced cell death even in the absence of cell adhesion-mediated signaling. NF-kB appears to be a key mediator of this anti-apoptotic effect that should contribute to the resistance of colon cancer cells to immune-destruction during metastasis.

- by jose luis
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- Immunology, Cancer, Cell Adhesion, Apoptosis

Santolina insularis (Genn ex Fiori) Arrig. is a medicinal plant whose essential oil shows antiviral and antibacterial activities and potent and selective cytotoxic activity against the human colon carcinoma cell line. The occurrence of... more

- by Giorgio Gnavi
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- Phytochemistry, Medicinal Plants, Biological Sciences, Essential Oil

We have assessed two commercial software tools employing physiologically based models for prediction of intestinal absorption in human. IDEAீ 2.0 and GASTROPLUSீ 3.1.0 were compared both in their ability to predict fraction absorbed for a set of 28 drugs and in terms of the functionality offered. The emphasis was placed on the practical usefulness to pharmaceutical drug discovery. Predictions were assessed for three levels of input data (i) pure in silico input, (ii) thermodynamic solubility and in silico permeability, (iii) thermodynamic solubility and human colon carcinoma cell line (CACO-2) permeability. We found the pure in silico prediction ability of the tools to be comparable with 70% correct classification rate. With measured input data the IDEAீ prediction rate improved to 79% while GASTROPLUSீ stayed at 70%. In terms of functionality GASTROPLUSீ is a powerful system for the trained user. Open access to model parameters, diagnostic tools and the ability to integrate data make it particularly suitable for the later stages of discovery and development. IDEAீ is web based and presents a simple interface suitable for widespread use with minimal training. However the limited functionality and inconvenient handling of multiple compound batches currently restrict the usefulness of version 2.0 for drug discovery.  (N. Parrott).

- by Neil Parrott
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- Thermodynamics, Open Access, Power System, Drug Discovery

Protection from colon cancer by vitamin D can be traced to the role of 1,25-dihdroxyvitamin D 3 (1,25-(OH) 2 D 3 ) in controlling proliferation, differentiation and apoptosis of colonic epithelial cells. Human colonocytes express the CYP27B1-encoded 25-(OH)D-1-hydroxylase, and therefore are able to convert 25-(OH)D 3 to 1,25-(OH) 2 D 3 . In vitamin D insufficiency, availability of 25-(OH)D is low, so that CYP27B1 activity in colonocytes may be not high enough to achieve tissue concentrations of 1,25-(OH) 2 D 3 necessary to prevent tumor cell growth. Progression of colon tumors to well and moderately differentiated cancers is associated with a considerable increase in CYP27B1 mRNA expression. Thus, colon carcinoma cells may still produce enough 1,25-(OH) 2 D 3 to halt or retard further tumor growth. However, during progression to higher grades of malignancy, the efficiency of growth control by 1,25-(OH) 2 D 3 is diminished due to low CYP27B1 activity and by the predominance of the catabolic CYP24A1-encoded 25-(OH)D-24-hydroxylase. There is evidence that the differentiation-dependent change in CYP27B1 and CYP24A1 expression is the result of differential epigenetic regulation of gene activity.

- by Fábio Pereira
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- Vitamin D, Apoptosis, Energy Metabolism, Colorectal cancer
- by Gabriela Pavlinkova
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- Genetics, Immunology, Cancer Immunology, Mice

Copper-64-labeled monoclonal antibodies (mAbs) have previously demonstrated unexpectedly effective tumor control in rodent models of cancer at relatively low tumor-absorbed radiation doses. This property has been associated with delivery platforms resulting in cellular internalization. The purpose of the present studies was to evaluate the in vitro internalization and in vivo distribution of a two-antibody model of 64 Cu radioimmunotherapy (RIT) in the same cell and animal models of cancer. Biodistributions of an internalizing antibody, cBR96, and a noninternalizing antibody, cT84.66, labeled with 64 Cu, were obtained in nude mice bearing LS174T colon carcinoma xenografts from 15 min to 48 h. The 64 Cu-DOTA-cBR96 conjugate demonstrated rapid tumor uptake, reaching 20.2% ID/g at 3 h and peaking at 35.4% ID/g by 24 h. Tumor accumulation of 64 Cu-DOTA-cT84.66 was more gradual, 8.19% ID/g at 3 h and 43.8% ID/g by 24 h, but maximum uptake was not statistically different from 64 Cu-DOTA-cBR96. Mouse xenograft dosimetry was estimated to be 1128 rad/mCi (304.9 mGy/MBq) for 64 Cu-DOTA-cBR96 and 1409 rad/mCi (380.5 mGy/MBq) for 64 Cu-DOTA-cT84.66. In LS174T cells, internalized radioactivity increased by a factor of 3.8 over 4 h for 64 Cu-DOTA-cBR96, but remained unchanged 64 Cu-DOTA-cT84.66. When normalized to uptake at 1 h, cellular efflux of 64 Cu was essentially identical for both mAbs. The biodistributions and tumor dosimetry of these internalizing and noninternalizing radiolabeled mAbs were sufficiently similar for direct comparison of the therapeutic efficacies of low doses of 64 Cu RIT agents in the same animal model of cancer. D 2005 Elsevier Inc. All rights reserved.

- by Carolyn Henry and +1
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- Nuclear medicine, Low Dose, Copper, Mice

Multidrug resistance (MDR) is still a major threat to successful clinical application of cancer chemotherapy. Copper plays an important role in biological systems, and copper is also involved in carcinogenesis. In the present investigation, we addressed the question whether metal copper might be involved in drug resistance of murine and human tumors. By means of atomic absorption spectroscopy, we determined serum copper concentrations. We found that the blood serum of tumor-bearing mice contained higher amounts of copper than healthy mice with tumors. Secondly, mice bearing doxorubicin-resistant Ehrlich ascites carcinoma-or cyclophosphamide-resistant Lewis lung carcinoma contained more copper in their serum than mice bearing the corresponding drug-sensitive parental tumors. Furthermore, the analysis of patients with breast cancer, colon carcinoma or lung cancer showed that the serum copper contents were higher in patients not responding to chemotherapy when compared to patients whose tumors responded to treatment. The copper levels in serum of healthy volunteers were lower than in cancer patients irrespective of their response to chemotherapy. Our results imply that the level of serum copper may be considered as a biomarker for treatment response.

- by Soumitra Choudhuri and +1
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- Breast Cancer, Lung Cancer, Copper, Mice

Carcinoma tumor cells express highly glycosylated mucins acting as ligands for selectin adhesion receptors and thus facilitating the metastatic process. Recently, a sulfated galactocerebroside SM4 was detected as solely P-selectin ligand on MC-38 colon carcinoma cells. Here we characterize the functionality of SM4 as selectin ligand using model membrane approaches. SM4 was found concentrated in lipid rafts of MC-38 cells indicating a local clustering that may increase the avidity of P-selectin recognition. To confirm this, SM4 was incorporated at various concentrations into POPC model membranes and lateral clustering was analyzed by fluorescence microscopy and found to be comparable to glycolipids carrying the sLe x epitope. SM4 containing liposomes were used as cell models, binding to immobilized P-selectin. Quartz crystal microbalance data confirmed SM4/P-selectin liposome binding that was inhibited dose-dependently by heparin. Comparable binding characteristics of SM4 and sLe x liposomes underscore the similarity of these epitopes. Thus, clustering of SM4 on tumor cells is a principle for binding P-selectin.

- by Lubor Borsig
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- Fluorescence Microscopy, Biophysical Chemistry, Biological Sciences, Heparin

The present study assessed the influence of essential oil and aqueous infusion from wild-grown caper (Capparis spinosa L.) on cell growth, NF-jB activation, apoptosis and cell cycle in the human colon carcinoma cell line, HT-29. Methyl isothiocyanate (92.06%), a degradation product of glucosinolate glucocapparin, was detected as major component of essential oil from caper leaves and flower buds. Aqueous infusion of caper showed an interesting and variegate compositional pattern containing several phenolic compounds, among which a flavonol glycoside, rutin (quercetin 3-O-rutinoside, 50.7%) and 5-caffeoylquinic acid (chlorogenic acid, 17.5%) were detected as dominant. Caper essential oil and aqueous infusion showed time-and dose-dependent high inhibitory effect on HT-29 cell proliferation. In addition, they induced the inhibition on nuclear factor jB (NF-jB) activity in a dose-dependent manner, while they did not show any effect on apoptosis in HT-29 cells. Flow cytometric analysis indicated that treatment with caper essential oil and aqueous infusion resulted in G 2 /M cell cycle arrest in a dose-dependent manner. Presented results suggest that caper contains volatile and non-volatile compounds which potentially can play an important role in colon cancer prevention.

- by Laura Siracusa
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- Cell Cycle, Food Chemistry, Multidisciplinary, Essential Oil

CD200 was recently described as a new prognosis factor in multiple myeloma and acute myeloid leukemia. CD200 is a membrane glycoprotein that imparts an immunoregulatory signal through CD200R, leading to the suppression of T-cellmediated immune responses. We investigated the expression of CD200 in cancer using publicly available gene expression data. CD200 gene expression in normal or malignant human tissues or cell lines was obtained from the Oncomine Cancer Microarray database, Amazonia database and the ITTACA database. We found significant overexpression of CD200 in renal carcinoma, head and neck carcinoma, testicular cancer, malignant mesothelioma, colon carcinoma, MGUS/smoldering myeloma, and in chronic lymphocytic leukemia compared to their normal cells or their tissue counterparts. Moreover, we show that CD200 expression is associated with tumor progression in various cancers. Taken together, these data suggest that CD200 is a potential therapeutic target and prognostic factor for a large array of malignancies.

- by Jérôme Moreaux
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- Gene expression, Head and Neck, Cell line, Acute Myeloid Leukemia
- by Thijs Hendriks
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- Cell line, Experimental Study, Carcinoma, Rats

Hematogenous carcinoma metastasis is associated with tumor cell emboli formation, which is now known to be facilitated by selectins. P-selectin-mediated interactions of platelets with cancer cells are based mostly on mucin-and glycosaminoglycan-type selectin ligands. We previously showed that mouse colon carcinoma cells (MC-38) carry P-selectin ligands of nonmucin origin, which were not identified. Here we show that P-selectin ligands recognized on MC-38 cells are sulfated glycolipids, thereby facilitating experimental metastasis in a syngeneic mouse model. Metabolic inhibition of sulfation by incubation of cells with sodium chlorate almost completely abrogated Pselectin binding. Metabolic labeling of MC-38 cells with 35 S sulfate revealed only a single band as detected by high-performance thin layer chromatography analysis of a total lipid extract. Matrix-assisted laser desorption/ ionization tandem time-of-flight/time-of-flight analysis (MALDI-TOF-TOF) analysis of the purified sulfatecontaining lipid fraction identified the selectin ligand to be a sulfated galactosylceramide SM4 (HSO 3 -3Galb-1Cer). Modulation of glycolipid biosynthesis in MC-38 cells altered P-selectin binding, thereby confirming sulfoglycolipids to be major P-selectin ligands. In addition, P-selectin was also found to recognize lactosylceramide sulfate SM3 (HSO 3 -3Galb-4Glcb-1Cer) and gangliotriaosylceramide sulfate SM2 [GalNAcb-4(HSO 3 -3)Galb-4Glcb-1Cer] in human hepatoma cells. Finally, the enzymatic removal of sulfation from the cell surface of MC-38 cells resulted in decreased P-selectin binding and led to attenuation of metastasis. Thus, SM4 sulfatide serves as a native ligand for P-selectin contributing to cell -cell interactions and to facilitation of metastasis.

- by José García
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- Glycobiology, Biological Sciences, Mice, Time of Flight

This work relates to studies on modes of phototoxicity by protoporphyrin (PpIX) after incubation of 5-aminolevulinic acid (5-ALA) on cultured cells. Lipid peroxidation in the 5-ALA incubated primary adenocarcinoma cells from the rectosigmoid colon (WiDr cells) was determined by measurement of protein-associated thiobarbituric acid reactive substances (TBARS). TBARS were increased 2-fold in cells treated with 2 mM 5-ALA for 3.5 h in serum enriched medium. After illumination of 5-ALA incubated cells, TBARS were formed in a light dose dependent manner. TBARS analysis were compared with highperformance liquid chromatography (HPLC) analysis of malondialdehyde, and results indicate that 90% of the thiobarbituric reactive substances were due to malondialdehyde. Pretreating WiDr cells with a-tocopherol for 48 h inhibits the cytotoxic effect of 5-ALA and increases 5-fold the light dose needed to kill 50% of the cells. Pretreatment with a-tocopherol shows a considerable decrease (about 80%) on TBARS formation after illumination. The cellular content of a-tocopherol was determined by HPLC and found to be 15.3 pmol/10 6 cells. q

- by Tom Dubbelman
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- Photodynamic Therapy, Cell Culture, Light, Vitamin E

Background Carcinoma of the colon and rectum is rare in the pediatric age group, and usually presents with an advanced stage disease bearing a poor prognosis. Colorectal carcinoma should be considered in children with signs of intestinal obstruction, alteration in bowel habits, gastrointestinal bleeding and chronic abdominal pain. We performed a retrospective study to evaluate the clinical characteristics, and prognosis of these patients. Methods Between 1974 and 2007, 11 patients were identified and treated for colorectal carcinoma at the Oncology Unit. The medical records were studied to analyze the age, sex, clinical presentation, diagnostic procedures, extent of disease (Dukes staging), treatment, histological types, and outcome. Results There were seven boys and four girls ranging from 7 to 17 of age. Predisposing diseases and syndromes were encountered in three children, (1 with Turner’s syndrome and two with adenomatous familial polyposis). Abdominal pain, acute intestinal obstruction, rectal bleeding and weight loss were the commonest symptoms. Surgical procedures were done in 11 patients (incomplete resection with segmental resection in 4 patients, complete resection in the other 4, and biopsy alone in 3 patients).The predominant histological type was mucinous carcinoma. Seven patients received adjuvant chemotherapy, all of whom did not survive. Two patients died shortly after initial surgery, and two patients are alive, and well. Conclusions Colorectal carcinoma in children is very uncommon and could be easily misdiagnosed, resulting in advanced stage disease at diagnosis. Because radical surgery which is the mainstay of treatment is possible only in patients with early stage disease, a high level of awareness and early diagnosis are critical.

- by SILVIA VALVERDE
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- Costa Rica, Adolescent, Biopsy, Child

Background & Aims-Regulatory T cells (Tregs) express the forkhead box transcription factor (FoxP3) and suppress the anti-tumor immune response. We investigated whether the intratumoral densities of FoxP3+ and effector CD3+ lymphocytes are... more

- by Daniel Sargent
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- Gastroenterology, Fluorescence Microscopy, Treatment Outcome, Risk assessment

We describe the characteristics of SR 48692, a selective, nonpeptide antagonist of the neurotensin receptor. In vitro, this compound competitively inhibits 125I-labeled neurotensin binding to the high-affinity binding site present in brain tissue from various species with IC50 values of0.99 ± 0.14 nM (guinea pig), 4.0 ± 0.4 nM (rat mesencephalic cells), 7.6 ± 0.6 nM (COS-7 cells transfected with the cloned high-affinity rat brain receptor), 13.7 + 0.3 nM (newborn mouse brain), 17.8 ± 0.9 nM (newborn human brain), 8.7 + 0.7 nM (adult human brain), and 30.3 ± 1.5 nM (HT-29 cells). It also

- by Toshiaki Mase
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- Kinetics, Aging, Calcium, Dopamine

The specific application and transport of drugs into malignant tissue is a critical point during diagnosis and therapy. Nanoparticles are known as excellent drug carrier systems and offer the possibility of surface modification with targeting ligands, leading to a specific accumulation in the targeted tissue. First, the specificity of such a carrier system has to be proven. In this study, cetuximab-modified nanoparticles based on biodegradable human serum albumin (HSA) are investigated regarding their cellular binding and intracellular accumulation. Different EGFR-expressing colon carcinoma cells were used to test possible cytotoxic potential, specific binding and intracellular accumulation. A specific accumulation targeting the EGFR could be shown. These results emphasize that cetuximab-modified HSA-nanoparticles are a promising carrier system for later drug transport. To our knowledge, this is the first study investigating the specific accumulation of HSA nanoparticles into different EGFR-expressing colon carcinoma cells.

- by Matthias Wacker
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- Technology, Nanoparticles, Nanotechnology, Biological Sciences

Background: The majority of cancer patients experience dramatic weight loss, due to cachexia and consisting of skeletal muscle and fat tissue wasting. Cachexia is a negative prognostic factor, interferes with therapy and worsens the patients' quality of life by affecting muscle function. Mice bearing ectopically-implanted C26 colon carcinoma are widely used as an experimental model of cancer cachexia. As part of the search for novel clinical and basic research applications for this experimental model, we characterized novel cellular and molecular features of C26-bearing mice.

- by Emanuele Berardi
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- Electron Microscopy, Skeletal muscle biology, Cancer, Flow Cytometry

Sagopilone (ZK-EPO) is the first fully synthetic epothilone undergoing clinical trials for the treatment of human tumors. Here, we investigate the cellular pathways by which sagopilone blocks tumor cell proliferation and compare the intracellular pharmacokinetics and the in vivo pharmacodynamics of sagopilone with other microtubule-stabilizing (or tubulinpolymerizing) agents. Cellular uptake and fractionation/ localization studies revealed that sagopilone enters cells more efficiently, associates more tightly with the cytoskeleton, and polymerizes tubulin more potently than paclitaxel. Moreover, in contrast to paclitaxel and other epothilones [such as the natural product epothilone B (patupilone) or its partially synthetic analogue ixabepilone], sagopilone is not a substrate of the P-glycoprotein efflux pumps. Microtubule stabilization by sagopilone caused mitotic arrest, followed by transient multinucleation and activation of the mitochondrial apoptotic pathway. Profiling of the proapoptotic signal transduction pathway induced by sagopilone with a panel of small interfering RNAs revealed that sagopilone acts similarly to paclitaxel. In HCT 116 colon carcinoma cells, sagopilone-induced apoptosis was partly antagonized by the knockdown of proapoptotic members of the Bcl-2 family, including Bax, Bak, and Puma, whereas knockdown of Bcl-2, Bcl-X L , or Chk1 sensitized cells to sagopilone-induced cell death. Related to its improved subcellular pharmacokinetics, however, sagopilone is more cytotoxic than other epothilones in a large panel of human cancer cell lines in vitro and in vivo. In particular, sagopilone is highly effective in reducing the growth of paclitaxel-resistant cancer cells. These results underline the processes behind the therapeutic efficacy of sagopilone, which is now evaluated in a broad phase II program. [Cancer Res 2008;68(13):5301-8]

- by Theocharis Panaretakis
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- Clinical Trial, Cancer, Mitochondria, Apoptosis
- by Thijs Hendriks
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- Cell line, Rats, Colon Carcinoma, Antineoplastic Agents

EphA2 (Eck) is a tyrosine kinase receptor that is overexpressed in several human cancers such as breast, colon, lung, prostate, gastric carcinoma, and metastatic melanoma but not in nonmalignant counterparts. To validate EphA2 as a tumor antigen recognized by CD8+ T lymphocytes, we used reverse immunology approach to identify HLA-A*0201-restricted epitopes. Peptides bearing the HLA-A*0201-specific anchor motifs were analyzed for their capacity to bind and stabilize the HLA-A*0201 molecules. Two peptides, EphA2(58) and EphA2(550), with a high affinity for HLA-A*0201 were selected. Both peptides were immunogenic in the HLA-A*0201-transgenic HHD mice. Interestingly, peptide-specific murine CTLs cell lines responded to COS-7 cells coexpressing HLA-A*0201 and EphA2 and to EphA2-positive human tumor cells of various origin (renal cell, lung, and colon carcinoma and sarcoma). This demonstrates that EphA2(58) and EphA2(550) are naturally processed from endogenous EphA2. In addition, EphA2(5...

- by Stephanie Graff-dubois
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- Cancer, Prostate Cancer, Cercopithecus aethiops, Cell line

MATERIALS AND METHODS Reagents. PFM was kindly supplied bythe Natural Products Branch, Division of Cancer Treatment, National Cancer Institute (Bethesda, Received 2/8/89; revised 5/12/89; accepted 6/20/89. The costs of publication of this... more

- by Hector Gonzalez
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- Chemistry, Kinetics, Cancer, Medicine

a b s t r a c t 1-(2-Chloroethyl)-3-(4-cyclohexylphenyl)urea (cHCEU) has been shown to abrogate the presence of thioredoxin-1 into the nucleus through its selective covalent alkylation. In the present letter we have evaluated the structure-activity relationships of the substituents at positions 3 and 4 of the phenyl ring of cHCEU derivatives on cell cycle progression and thioredoxin-1 nuclear translocation. Active CEU derivatives exhibited GI 50 ranging from 1.9 to 49 lM on breast carcinoma MCF-7, skin melanoma M21, and colon carcinoma HT-29 cells. On one hand, compounds 1, 2, 9c, 10c, 13, and 14 arrested the cell cycle in G 2 /M phase while CEUs 3, 4, 5c, 6c, 11c, and 12c blocked the cell division in G 0 /G 1 phase. On the other hand, CEUs 2-4, 5c, 7c, 8c, 11c, and 12c abrogated the translocation of thioredoxin-1 while the other CEU derivatives were inactive in that respect. Our results suggest that CEU substituted on the phenyl ring at position 3 or 4 by lower cycloalkyl or cycloalkoxy groups arrest cell progression in G 0 /G 1 phase through mechanism of action different from their antimicrotubule counterparts, presumably via thioredoxin-1 alkylation and modulation of its activity. The mechanism of action of these new molecules is still undetermined. However, the significant accumulation of cells in G 0 /G 1 phase suggests that these molecules may act similarly to known chemopreventive agents against cancers. In addition, the inhibition of Trx-1 nuclear localization also suggests the abrogation of an important chemoresistance mechanism towards a variety of chemotherapeutic agents.

- by Alexandre Patenaude
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- Organic Chemistry, Cell Cycle, Cell Division, Signal Transduction

In cancer biology, cell lines are often used instead of primary tumors because of their widespread availability and close reflection of the in vivo state. Cancer is a genetic disease, commonly caused by small-and large-scale DNA rearrangements. Therefore, it is essential to know the genomic profiles of tumor cell lines to enable their correct and efficient use as experimental tools. Here, we present a comprehensive study of the genomic profiles of 20 colon cancer cell lines combining conventional karyotyping (G-banding), comparative genomic hybridization (CGH), and multicolor fluorescence in situ hybridization (M-FISH). Major differences between the microsatellite instability (MSI) and chromosome instability (CIN) cell lines are shown; the CIN cell lines exhibited complex karyotypes involving many chromosomes (mean: 8.5 copy number changes), whereas the MSI cell lines showed considerably fewer aberrations (mean: 2.6). The 3 techniques complement each other to provide a detailed picture of the numerical and structural chromosomal changes that characterize cancer cells. Therefore, 7 of the cell lines (Colo320, EB, Fri, IS2, IS3, SW480, and V9P) are here completely karyotyped for the first time and, among these, 5 have not previously been cytogenetically described. By hierarchical cluster analysis, we show that the cell lines are representative models for primary carcinomas at the genome level. We also present the genomic profiles of an experimental model for tumor progression, including 3 cell lines (IS1, IS2, and IS3) established from a primary carcinoma, its corresponding liver-and peritoneal metastasis from the same patient. To address the question of clonality, we compared the genome of 3 common cell lines grown in 2 laboratories. Finally, we compared all our results with previously published CGH data and karyotypes of colorectal cell lines. In conclusion, the large variation in genetic complexity of the cell lines highlights the importance of a comprehensive reference of genomic profiles for investigators engaged in functional studies using these research tools. Ć

- by Kristine Kleivi
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- Genetics, Cancer Genetics, Cell line, Fluorescence in situ hybridization

In order to get insight into the chemical heterogeneities of solid tumors, here we report the first surfaceenhanced Raman scattering (SERS) experiment from normal and altered epithelial layer in human colon carcinoma tissues. The Ag colloidal nanoparticles that can be incorporated into the interstitial space in solid tumors or those penetrating into cytoplasm or nucleus of many cells allowed high quality SERS signal. Different tissue structures of tumor and normal colon have characteristic features in SERS spectra. Prominent SERS features of malignant tissue spectra are related to the strong enhancement of the bands preponderantly attributable to DNA or RNA bases. The preliminary studies demonstrate that it is possible to probe Ag colloidal nanoparticles adsorption onto the tissue resulting in a strong molecular signaling with high specificity and rapid acquisition time using visible laser line excitation.

- by Simion Astilean
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- Condensed Matter Physics, Raman Spectroscopy, Colon Carcinoma

Homocamptothecin (hCPT) contains a seven-membered -hydroxylactone in place of the conventional six-membered R-hydroxylactone ring found in camptothecin and its tumor active analogues, including topotecan and irinotecan. The homologation of the lactone E-ring reinforces the stability of the lactone, thus reducing considerably its conversion into a carboxylate form which is inactive. We have recently shown that hCPT is much more active than the parent compound against a variety of tumor cells in vitro and in xenograft models, suggesting that a highly reactive lactone is not essential for topoisomerase I-mediated anticancer activity ) Cancer Res. 59, 2939-2943. In the present study, we provide further evidence that hCPT has superior topoisomerase I inhibition capacities to CPT. In particular, we show that replacement of the camptothecin lactone E-ring with a homologous sevenmembered lactone ring changes the sequence-specificity of the drug-induced DNA cleavage by topoisomerase I. Both CPT and hCPT stimulate the cleavage by topoisomerase I at T V G sites, but in addition, hCPT stabilizes cleavage at specific sites containing the sequence AAC V G. At low drug concentrations, the cleavage at the T V G sites and at the hCPT-specific C V G sites is more pronounced and more stable with hCPT than with CPT. The in vitro data were confirmed in cells. Higher levels of protein-DNA complexes were detected in P388 leukemia cells treated with hCPT than those treated with CPT. Immunoblotting experiments revealed that endogenous topoisomerase I was efficiently trapped onto DNA by hCPT in cells. Finally, the use of a leukemia cell line resistant to CPT provided evidence that topoisomerase I is involved in the cytotoxicity of hCPT. Altogether, the results show that the -hydroxylactone ring of hCPT plays an important and positive role in the poisoning of topoisomerase I. An explanation is proposed to account for such remarkable changes in the sequence specificity of topoisomerase I cleavage consequent to the modification of the lactone. The study sheds new light on the importance of the lactone ring of camptothecins for the stabilization of topoisomerase I-DNA complexes.

- by A. Lansiaux
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- Biochemistry, Cancer, Enzyme Inhibitors, Cell Division

Resection of liver metastases in patients with colon cancer increases survival but success depends on removal of all tumour tissue. For this purpose, understanding of spatial relationships between metastases and liver architecture is essential. Because metastatic cancer growth is essentially a three-dimensional (3D) event, we decided to apply 3D reconstruction techniques to study these spatial relationships between metastases and liver structures such as blood vessels, stroma and the liver capsule (Glisson's capsule). Colon carcinoma metastases were experimentally induced in rat liver by injection of colon cancer cells (CC531) into the portal vein. Three weeks later, livers from these animals and control livers were removed and immediately frozen in liquid nitrogen. Thirty-seven to 110 consecutive sections were used for each 3D reconstruction of 26 metastases in eight livers. Contours of different structures were stained by (immuno)histochemical means, traced in each section and stored in a database. From the contour model, a volume model was generated. Among the 26 metastases, seven were found to grow distantly from the liver capsule. They were small and consisted of well-differentiated cancer cells that were totally surrounded by a basement membrane and stroma which was always connected with adjacent blood vessels of a portal tract. The remaining 19 metastases showed a more advanced pattern of development. Infiltration of poorly differentiated colon cancer cells progressed through the stroma at various sites and areas of direct contact between cancer cells and hepatocytes were frequently found. This type of outgrowth of cancer cells was only found when metastases had made contact with the liver capsule. However, some areas in sections of these advanced stages still resembled small metastases. On the basis of these findings, we conclude that stroma affects the differentiation pattern of cancer cells and has at least a dual role in tumour growth. On the one hand it limits invasion of cancer cells in the surrounding host tissue. On the other hand, stroma formation at the capsule, which consists mainly of granulation tissue, facilitates outgrowth of the tumours. Furthermore, our 3D reconstructions demonstrate the spatial heterogeneity of larger metastases and the importance of a 3D approach to understand growth and development of metastases in general and colon cancer metastases in the liver in particular.

- by Fons Verbeek
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- Materials Engineering, Condensed Matter Physics, Microscopy, 3-D Reconstruction
- by Israel Vlodavsky
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- Clinical Trial, Cancer, Drug development, Pancreatic Cancer

IFN- knockout mice (GKO) rejected C26 colon carcinoma cells trans- duced to secrete interleukin (IL)-12 but do not reject similarly transduced TSA mammary adenocarcinoma (C26/12 and TSA/12 cells, respectively). To determine whether such difference could be because of a different tumor response to IFN-, we injected BALB/c mice with TSA, C26, and their IL-12-transduced counterparts rendered unresponsive to IFN- by

- by Mario Colombo
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- Immune response, Cancer, Growth Kinetics, Cell Division