bluuebunny/crossref_metadata_2025 huggingface dataset:
Inter‐laboratory variation as an explanation for varying prevalence estimates of human papillomavirus infection
Authors: Brandsma Janet , Burk Robert D. , Lancaster Wayne D. , Pfister Herbert , Schiffman Mark H.
Published: February 2007

Human papillomavirus (HPV) infection has been strongly implicated as a cause of genital neoplasia. Although Southern blot DNA hybridization techniques are regarded as the most accurate means of identifying HPV infection, studies using this technique to measure infection have provided varying estimates of the prevalence of HPV among healthy and diseased groups. This investigation provides a possible explanation for study‐to‐study differences, by demonstrating interlaboratory variability in the detection and typing of HPV by Southern blot. Four experienced laboratories tested 40 identical, masked samples of DNA extracted from presumed infected and non‐infected tissues. The pairwise percentage agreement between the laboratories in judging samples as HPV‐positive or negative ranged from 66 to 97%. Among samples judged to contain HPV, agreement as to type ranged from 77 to 96%. We conclude that inter‐laboratory differences are an important consideration in any discussion of HPV prevalence estimates.
Lectin‐resistant variants and revertants of mouse melanoma cells: Differential expression of a fucosylated cell‐surface antigen and altered metastasizing capacity
Authors: Finne Jukka , Castori Serenella , Feizi Ten , Burger Max M.
Published: February 2007

In order to evaluate the possible role of cell‐surface carbohydrates in metastasis of tumour cells, 2 wheat‐germ agglutinin‐resistant (WGAr) variants of B16 mouse melanoma and 8 back revertants selected with other lectins were analyzed with respect to the surface expression of fucosylated carbohydrate antigens and their metastasizing capacity. The variant cells, expressing a greatly increased fucosyltransferase activity, were found to express the fucose‐containing SSEA‐I antigen on their cell surface. The revertant cells selected for lower fucosylation with Lotus tetragonolobus lectin and ricin had lost this particular antigen. Seven of the 8 revertant lines also reverted back to a state of increased metastasizing capacity as compared to the WGAr variants they were derived from. A single one of the revertants displayed reduced metastasizing capacity, suggesting that additional changes can also be present in some of the cell lines. These results suggest a possible linkage between expression of the developmental SSEA‐I antigen and reduced metastasizing capacity in the mouse melanoma model.
Differential expression of n‐myc and c‐src proto‐oncogenes during neuronal and schwannian differentiation of human neuroblastoma cells
Authors: Horii Yoshihiro , Sugimoto Tohru , Sawada Tadashi , Imanishi Jiro , Tsuboi Kazuhiko , Hatanaka Masakazu
Published: February 2007

Neuroblastoma (NB) cells can be induced to differentiate bidirectionally into either neuronal or schwannian cells by different inducers. However, the underlying mechanisms are poorly understood. We examined the expression of N‐myc and c‐src genes in 3 human NB‐cell lines during either neuronal or schwannian differentiation in vitro, since proto‐oncogenes are considered to play a pivotal role in regulating cell proliferation and differentiation. Decreased N‐myc expression and increased c‐src expression were observed during neuronal differentiation by retinoic acid, polyprenoic acid (E5166) and dibutyryl cyclic AMP, whereas the expression of N‐myc and c‐src genes was considerably reduced during schwannian differentiation by bromodeoxyuridine, demonstrating that the expression of N‐myc and c‐src genes was regulated independently in the bipolar differentiation processes of NB cells. Our results suggest that enhanced N‐myc expression might be closely linked to the undifferentiated phenotypes of NB cells, that c‐src expression might be related to the neuronal differentiation of NB cells, and that N‐myc and c‐src genes might be regulated independently in the determination of the bipolar differentiation of NB cells.
Recruitment and activation of tumor‐specific immune t cells in situ: Functional studies using a sponge matrix model
Authors: Zangemeister Uwe , Thiede Kerstin , Schirrmacher Volker
Published: February 2007

The activation of tumor‐specific precursor cytotoxic T lymphocytes (CTLP) into cytotoxic T cells (CTL) was demonstrated in situ using the well‐defined, highly metastatic ESb tumor as murine model system. Ten days after optimal immunization of syngeneic mice with a sublethal dose of live ESb tumor cells in the pinna, tumor‐sensitized non‐cytotoxic CTLP were recovered from the spleen and lymph nodes. These cells mature into tumor‐specific CTL upon restimulation in vitro. Using a confined sponge matrix compartment, in combination with a specific tumor vaccine (autologous inactivated tumor cells), we induced a CD8+ (Lyt 2+) T‐cell‐mediated, highly cytotoxic anti‐tumor immune response in situ in immunized mice. It was not possible to activate a similar response directly in lymphoid organs such as the spleen. The cytotoxic CD8+ T cells, recovered by simple mechanical pressing of the sponge, were active against the specific tumor cells in a 51Cr‐release assay in vitro and also in a Winn neutralization assay in vivo. CTL activity was increased and remained in the non‐adherent fraction when the cell mixture, squeezed out of the sponges, was passed over nylon wool. In a cell recruitment assay, the delayed‐type hypersensitivity (DTH) potential of the activated sponge‐infiltrating T cells was demonstrated by their capacity to recruit circulating host lymphocytes to sites of tumor‐cell location in situ.
Characterization of htlv‐i isolates and t lymphoid cell lines derived from french west indian patients with tropical spastic paraparesis
Authors: Gessain A. , Saal F. , Morozov V. , Lasneret J. , Vilette D. , Gout O. , Emanoil‐Ravier R. , Sigaux F. , De Thé G. , Périès J.
Published: February 2007

Lymphoid cell lines derived from the peripheral blood of French West Indian patients with HTLV‐I sero‐positive Tropical Spastic Paraparesis and HTLV‐I isolates were characterized. While patients' peripheral blood lymphocytes did not express detectable HTLV‐I antigens when uncultured, they did so after short‐term culture. Established cell lines were of T‐cell lineage: CD2+, CD3+, CD4+, CD7+, WT31+ with activated T‐cell markers CD25+ DR+ and a clonal rearrangement of the ß and γ genes of the T‐cell receptor. HTLV‐I antigens were detected in cell lines by indirect immunofluorescence, Western blot and radio‐immunoprecipitation assays. After 4 months in culture, low levels of Mg2+ dependent reverse transcriptase activity were detected and electron microscopy revealed numerous type‐C retroviral particles similar to HTLV‐I virions. Western blot and radio‐immunoprecipitation analysis of purified viruses revealed gp46, p24, p19 and Pr53gag proteins similar to those detected in HUT 102 and MT2 cell lines. Deep analysis of env‐coded precursor of one TSP versus ATL isolates revealed minor differences in their molecular weights. Southern blot analysis using 32P HTLV‐I env gene as a probe showed the presence of HTLV‐I proviral fragments clonally integrated into the genome of the cell lines. Our data suggest that HTLV‐I isolated from Tropical Spastic Paraparesis does not differ significantly from the leukemogenic prototypes. Does HTLV‐I induce either acute lymphoproliferative diseases or chronic neuromyelopathies depending upon as yet unknown co‐factors? This question remains to be determined.
Immunohistochemical detection of P‐glycoprotein in human tumor cells with a low degree of drug resistance
Authors: Broxterman Henricus J. , Pinedo Herbert M. , Kuiper Catharina M. , Van Der Hoeven Jacobus J. M. , De Lange Pieter , Quak Jasper J. , Scheper Rik J. , Keizer Hiskias G. , Schuurhus Gerrit Jan , Lankelma Jan
Published: February 2007

We report the immunohistochemical detection of the 170–180 kDa multi‐drug‐resistance‐related P‐glycoprotein in human tumor cells with a low level of resistance. A series of human squamous lung cancer cell lines with increasing levels of resistance to doxorubicin (DOX) was developed and stained for P‐glycoprotein, using the JSB‐lMAb. Subline SW1573/50A with a 4‐ to 6‐fold cross‐resistance to daunorubicin (DNR) and vincristine (VCR) showed rather uniform positive staining for P‐glycoprotein apparently at cytoplasmic sites. Only in cells with higher degrees of resistance (> 10‐fold) could plasmamembrane‐associated P‐glycoprotein be made visible. DNR efflux was increased in SW1573I50A as compared to the parent line SWl573 (52 and 70% DNR were retained during 3 min efflux respectively). Verapamil partially reversed DNR and VCR resistance in SWl573/50A. Cells obtained from a metastasized renal cell carcinoma and cultured in vitro stained in a similar way to SWl573/50A and showed some sensitivity to verapamil modulation of VCR cytotoxicity. Our results suggest that weakly resistant cancer cells obtained from patients can be routinely detected with JSB‐l on cytospins, and Implicate that in such weakly resistant cells P‐glycoprotein may be present, while plasma membrane expression is not yet readily detectable.
Induction of tumor‐cell lysis by bi‐specific monoclonal antibodies recognizing renal‐cell carcinoma and cd3 antigen
Authors: Van Duk J. , Warnaar S. O. , Van Eendenburg J. D. H. , Thienpont M. , Braakman E. , Boot J. H. A. , Fleuren G. J. , Bolhuis R. L. H.
Published: February 2007

Bi‐specific monoclonal antibodies (MAbs) were developed by somatic hybridization of 2 mouse hybridomas, one producing MAb against the G250 renal‐cell carcinoma (RCC)‐associated antigen and the other against the T‐cell antigen CD3 (OKT3). The dual specificity of the hybrid MAb produced by these so‐called quadromas was analyzed by immunohisto chemistry on tissue sections and by cytotoxicity assays with relevant target and effector cells. The bi‐specific MAb could induce TCRαβ/CD3+ and TCRγδ/CD3+ cloned lymphocytes to kill RCC cells. A noteworthy finding was that the TCRαβ and γδ lymphocyte clones showed different triggering abilities. The specificity of target‐cell lysis by the cytotoxic T cells (CTL) was dictated by the specificity of the G250 MAb. Control bi‐specific MAb, recognizing a cell‐surface structure not involved in T‐cell activation, did not induce lysis. Several lgG subclass switch variants of the G250 hybridoma, i.e., lgG1, 2a, and lgE, were used for somatic hybridization with the OKT3 hybridoma (lgG2a. Except for lgE, all lgG subclass combinations could equally induce cytolysis. Induction of cytolysis was inhibited only by excess OKT3 MAb. Comparison of 2 bi‐specific MAb preparations of the same combination (lgG2a/1), produced by 2 quadromas derived from the same parental hybridomas after identical purification procedures, produced different amounts of bispecific MAb.
Restriction fragment length polymorphism of the l‐myc gene and susceptibility to metastasis in renal cancer patients
Authors: Kakehi Yoshiyuki , Yoshida Osamu
Published: February 2007

We examined Southern blot analyses of normal and tumor DNAs from 50 patients with sporadic renal cancer, using the human L‐myc oncogene fragment as a hybridization probe. Our purpose was to study the relationship between the restriction fragment length polymorphism (RFLP) of the L‐myc and the frequencies of metastases. There was no individual difference in patterns of L‐myc RFLP between normal and tumor‐tissue DNAs digested with EcoRI. The patients were classified into 3 genetic types according to the polymorphic patterns defined by the 2 alleles [10‐kilobase (kb) and 6.6‐kb fragments]. The relative ratios of the 3 genotypes in the renal cancer patients were similar to those seen in healthy Japanese. However, of 16 patients who exhibited distant organ metastases at the time of surgery, only one was a 10‐kb fragment homozygote. The incidence of distant metastases in 10‐kb homozygotes was significantly lower than that in 6.6‐kb homozygotes plus heterozygotes (p = 0.06). These results basically correspond to the previous findings in the lung cancer patients, and suggest that L‐myc RFLP is a widely applicable genetic marker to predict prognosis in cancer patients.
Computer‐assisted image analysis of silver staining in normal and leukemic bone marrow
Authors: Arden K. C. , Bucana C. D. , Johnston D. A. , Pathak S.
Published: February 2007

Computer‐assisted image analysis was used to quantitate the amount of silver staining in interphase nuclei of bone marrow cells from acute lymphocytic leukemia (ALL) patients. When we compared the data obtained for the interphase nuclei with that obtained for the metaphase spreads, we found a strong correlation between the fraction of bone‐marrow metaphases stained positively with silver, the average number of silver‐positive nucleolus organizer regions per metaphase, and the amount of silver staining in the interphase nuclei. Computer‐assisted image analysis of interphase nuclei can be used, therefore, to differentiate normal from ALL bone‐marrow samples.
Lack of correlation between peripheral blood lymphokine‐activated killer (lak) cell function and clinical response in patients with advanced malignant melanoma receiving recombinant interleukin 2
Authors: Ghosh A. K. , Dazzi H. , Thatcher N. , Moore M.
Published: February 2007

A phase‐1/II study of recombinant interleukin 2 (rIL‐2) was performed in 31 melanoma patients. The first dose of rIL‐2 was given intrasplenically followed 4 hr later by an i.v. dose and 3 further i.v. doses on alternate days. Three courses of treatment were planned at 3‐week intervals. The maximum tolerated single dose was 11 × 106 Cetus U/m2. Haematological and immunological data were available on 20 patients. Post‐treatment response to rIL‐2 therapy was evident from (i) a rapid depletion of peripheral blood lymphocytes (PBL) with a rebound at 4–7 days (2 times pre‐treatment values); (ii) an increase in the number of IL‐2 receptor‐positive lymphocytes (4–15 times pre‐treatment values); (iii) an increase in the number of “positive” patients with cytotoxic (anti‐K562) peripheral blood mononuclear cells (PBMC) from 30% to 80%; (iv) amplified killing of K562 by positive patients in relation to pre‐treatment values; and (v) the induction of PBMC cytotoxicity (in 45% of patients) against the NK‐resistant, LAK‐sensitive target, Mel 1. Partial clinical responses to rIL‐2 treatment were observed in 4 patients, but these were not reflected in the PBMC LAK activity or the other parameters examined.
Evidence of enhancement of the ras oncogene protein product (p21) in a spectrum of human tumors
Authors: De Biasi F. , Del Sal G. , Horan Hand P.
Published: February 2007

Using a direct binding liquid competition radioimmunoassay, the amount of the ras oncogene protein product, p21, was quantitated in a variety of human tumors and adjacent apparently normal tissues. In 48 of 50 matched tumor and normal tissue biopsy specimens from 50 patients, more ras p21 was detected in the tumor than in its normal counterpart. Twenty‐five of 28 breast tumors demonstrated more ras p21 than the average of the values obtained for fibroadenomas. Furthermore, in 17 of the 19 cases studied, over 20% more ras p21 was observed in breast carcinomas compared with their respective normal counterparts. More ras p21 was also demonstrated in the majority of tumors of the stomach, lung, colon and bladder compared with their respective adjacent normal tissues. Our data therefore indicate that ras p21 expression is quantitatively enhanced in many human tumors originating from several different tissue types.
Co‐regulation of metastatic and transforming activity of normal and mutant ras genes
Authors: Egan Sean E. , Broere James J. , Jarolim Lenka , Wright Jim A. , Greenberg Arnold H.
Published: February 2007

We have analyzed the metastatic properties of NIH‐3T3 cells transformed by H‐ras activated through over‐expression and/or mutation. Our results reveal that elevated expression of H‐ras proto‐oncogene can induce the complete metastatic phenotype. Cells transformed by the proto‐oncogene have a lower metastatic potential than those transformed by a mutated ras gene. ras oncogenes activated through alterations in codon 12 which encode p21 molecules with impaired GTPase activity, or in codon 59 which produce p21 molecules that release bound guanine nucleotides faster, or in codon 61 which produce p21 having impaired GTPase activity and altered nucleotide release properties, are all able to induce the metastatic phenotype. Leucine‐61‐activated oncogenes with an additional mutation in codons 116, 117 or 119, resulting in a reduced affinity for guanine nucleotides, are also capable of inducing metastatic behavior. These data indicate that ras genes which are capable of transforming are also capable of inducing the full metastatic phenotype in NIH‐3T3 cells. This suggests that both phenotypes are induced through an increase in p21‐GTP concentration in ras‐transformed cells. This established model for ras‐mediated transformation can also explain the qualitative and quantitative regulation of metastatic behavior by ras.
Use of the membrane invasion culture system (mics) as a screen for anti‐invasive agents
Authors: Welch Danny R. , Lobl Thomas J. , Seftor Elisabeth A. , Wack Peter J. , Aeed Paul A. , Yohem Karin H. , Seftor Richard E. B. , Hendrix Mary J. C.
Published: February 2007

The Membrane Invasion Culture System (MICS) assay was adapted for relatively rapid screening of compounds and used to identify anti‐invasive drugs that inhibit human and murine tumor cell migration through a reconstituted basement membrane in vitro. Cell lines demonstrating low and high invasive and metastatic potentials were tested with all compounds for tumoricidal effects prior to evaluation in MICS at non‐cytotoxic doses. The effect on invasive potential in the MICS assay was determined in 3 categories: (1) 48 hr drug pre‐treatment prior to seeding in the MICS (exceptions: 90 min pre‐treatment with pertussis toxin and, for some studies, continuous exposure for 2‐7 days); (2) peptide or prostaglandins 2 hr after seeding and attachment to the membranes in MICS followed by continuous exposure; and (3) cells receiving neither drug nor peptide treatment and serving as controls in each MICS chamber. Since invasion involves cellular motility and deformability, some cytoskeleton disrupting agents were selected. Of these, vincristine, colcemid and colchicine inhibited invasion but taxol did not. Pre‐treatment with cAMP agonists produced conflicting results: dibutyryl cAMP and 8‐(4‐chloro‐phenylthio) cAMP resulted in 50% and 38% reduction in invasion, respectively, whereas 8‐bromo cAMP stimulated invasive potential by 30%. Forskolin and cholera toxin both significantly reduced invasiveness. Pre‐treatment with 5‐azacytidine and araC, to consider the role of methylation and proliferations decreased invasive ability. Anti‐metastatic drugs such as γ‐interferon and razoxane inhibited invasive potential but to varying degrees. Treatment of cells with prostaglandins E2, F2α, A2, and D2 were ineffectual; however, indomethacin mildly inhibits invasion (< 30%). With respect to the cell surface and metastatic potential, pre‐treatment with tunicamycin did not alter invasiveness; whereas pre‐treatment with swainsonine blocked invasion by approximately 50% at 0.3 μg/ml. The inhibition caused by swainsonine was enhanced (to 92%) if cells were continuously exposed to drug and was reversible. Several RGD‐containing peptides which inhibit attachment to various substrates did not modify invasion in the MICS if added after cell attachment was completed. The peptide which inhibits laminin attachment, CDPGYIGSR, inhibited invasion by 48%. Two peptides from the fibrinogen gamma chain were mildly inhibitory and peptides from TGF‐α inhibited invasion >60%. Collectively, these results demonstrate the potential utility of the MICS for prescreening compounds for anti‐invasive potential, and ultimately anti‐metastatic therapy.
Actions of medroxyprogesterone acetate on the efficacy of cytotoxic drugs: Studies with human breast cancer cells in culture
Authors: Shaikh Naeem A. , Owen Alison M. , Ghilchik Margaret W. , Braunsberg Hannelore
Published: February 2007

Human breast cancer cells (MCF‐7) showed increased responses to methotrexate and vincristine after a 48‐hr pretreatment with medroxyprogesterone acetate. The effect of the hormone, which was detectable at concentrations of between 10 and 100nm, was independent of its growth‐inhibitory action. These findings confirm a previous clinical study and have important implications with regard to the management of advanced breast cancer.
Protection against chemically induced skin tumorigenesis in sencar mice by tannic acid
Authors: Das Mukul , Bickers David R. , Mukhtar Hasan
Published: February 2007

Tannic acid, a naturally occurring dietary polyphenol, was evaluated as a possible anticarcinogen in an initiation‐and‐promotion skin tumorigenesis protocol. In the 2‐stage tumor protocol in SENCAR mice, using DMBA, BP and MNU as the initiating agents followed by twice‐weekly applications of TPA as tumor promotor, tannic acid was found to be an effective inhibitor of tumor formation whether the tumor data are considered as cumulative number of tumors, percentage of mice with tumors or tumors/mouse. After 9 weeks of TPA application, the number of tumors/mouse in the groups receiving DMBA, BP and MNU were 32.10 ± 3.18, 3.70 ± 0.55 and 2.00 ± 0.53, respectively, whereas the corresponding numbers in the DMBA, BP and MNU groups receiving prior applications of tannic acid were 11.50 ± 2.38, 0.35 ± 0.15 and 0.35 ± 0.13, respectively. These results suggest that tannic acid may prove useful in reducing the risk of chemically‐induced skin tumorigenesis.
Over‐expression of MDR gene with no dna amplification in a multiple‐drug‐resistant human ovarian carcinoma cell line
Authors: Bénard Jean , Silva Jacqueline Da , Teyssier Jean‐Raymond , Riou Guy
Published: February 2007

Human ovarian adenocarcinoma cells IGROVI were induced to become resistant in vitro to Vincristine (VCR) by continuous and discontinuous stepwise exposure to the drug. Both sublines exhibited similar indexes of resistance (approx. 800). The acquisition of VCR resistance was associated with changes of morphology and with cross‐resistance to Adriamycin, VP16 and actinomycin D. Addition of verapamil enhanced sensitivity of resistant cells to VCR. This multi‐drug‐resistant (MDR) phenotype was associated with high levels of human MDR, gene transcripts (25‐ to 100‐fold). In contrast to other reports, no significant amplification of the locus could be observed. Reactivity with MRK16, a monoclonal antibody (MAb) directed against the MDR 170 kDa protein, was found to be related to the level of MDR1 transcription. In addition, both OVI/VCR sublines exhibited a marked loss of tumorigenicity. Besides the chromosomal markers of OVI/p, the two resistant sublines revealed a common cytogenetic rearrangement: a deletion of the short arm of one chromosome II: del(11)(p12). We suggest that the acquisition of this marker might be associated with the non‐tumorigenic phenotype of OVI/VCR‐resistant sublines.
Carcinogenicity of iron in conjunction with a chlorinated environmental chemical, hexachlorobenzene, in c57bl/10scsn mice
Authors: Smith Andrew G. , Cabral Jose R. P. , Carthew Philip , Francis Jean E. , Manson Margaret M.
Published: February 2007

Pre‐loading of C57BL/10ScSn mice with iron greatly sensitizes them to the induction of hepatic porphyria caused by hexachlorobenzene (HCB) (Smith and Francis, 1983). HCB will also cause liver tumours in experimental animals. Elevated liver iron stores are implicated in the development of some human liver cancers. To determine whether iron overload will potentiate the hepatocarcinogenicity of HCB, male C57BL/10ScSn mice received a single dose of iron‐dextran complex or the dextran carrier and were then fed HCB in the diet (0.01%) for up to 18 months. A very clear potentiation by iron of liver tumour incidence occurred. Of the mice which received HCB, but no iron, for 12 months a low incidence of liver hyperplastic nodules was observed, whereas preadministration of iron increased the incidence. After 18 months, all surviving mice initially given iron followed by HCB developed advanced hepatic nodules and 90% had hepatocellular carcinomas. No tumours were seen in animals that only received HCB. Nodules were not seen in iron‐dosed mice receiving control diet, but another novel observation was that these animals developed porphyria by 6 months. Although iron enhanced tumour formation in the presence of HCB, the foci, nodules and carcinomas formed all excluded iron. Preliminary studies with the DBA/2 strain suggested that these mice were considerably less susceptible to potentiation by iron.
In vivo localization of a bispecific antibody which targets human t lymphocytes to lyse human colon cancer cells
Authors: Barr Ian G. , Miescher Sylvia , Fliedner Vladimir Von , Buchegger Franz , Barras Catherine , Lanzavecchia Antonio , Mach Jean‐Pierre , Carrel Stefan
Published: February 2007

A bispecific MAb was derived from the fusion of a hybridoma producing MAb CD3 with a hybridoma producing MAb L‐Dl (which is directed against a 41‐kDa glycoprotein expressed in most gastro‐intestinal and pancreatic carcinomas). Bispecific antibody molecules were isolated from parental antibody molecules by the use of hydroxylapatite‐HPLC and shown to target human cytolytic T lymphocytes, irrespective of their original specificity, to specifically lyse human colon carcinoma cells. Localization studies in vivo using nude mice bearing human colon carcinoma xenografts showed significant accumulation of the HPLC‐purified 125l‐labelled bispecific antibodies into the tumor compared to 131l‐labelled control CD3 antibody.
Tumor prevention by a xanthate compound in experimental mouse‐skin tumorigenesis
Authors: Fürstenberger G. , Amtmann E. , Marks F. , Sauer G.
Published: February 2007

The antiviral and antitumoral compound tricyclodecan‐9‐yl‐xanthogenate (D609), which is an inhibitor of protein kinase C activation, has been used for tumor prevention in vivo. When applied chronically together with 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) in the classic initiationpromotion mouse‐skin model, D609 prevented tumor induction in a dose‐dependent manner. At the concentration that inhibited tumor formation by 97%, no toxic effects were detected and the TPA‐induced hyperplasia remained unaffected. As D609 failed to prevent the activity of a chronically applied carcinogen, it is concluded that the observed tumor prevention achieved with D609 is tumor‐promotion‐specific and is not due to killing of tumor cells.
Growth‐inhibitory activity of interferon‐beta against human colorectal carcinoma cell lines
Authors: Wong Vicky L. Y. , Rieman Dave J. , Aronson Lori , Dalton Barbara J. , Greig Russell , Anzano Mario A.
Published: February 2007

Recombinant human interferon beta (rIFN‐β) inhibited in a time‐ and dose‐dependent manner the proliferation of 18/18 human colon carcinoma cell lines in monolayer culture and 8/9 lines in a soft agar assay but had no effect on 4 human fibroblast cell lines. Maximal inhibition of cell proliferation by rIFN‐β required repetitive treatment (every 2 days) with lymphokine (50 units/ml). Furthermore, the inhibitory activity of rIFN‐β was neutralized by polyclonal antibodies against natural IFN‐β. In contrast to rIFN‐β, rIFN‐α was inactive against all colon cell lines tested, and rIFN‐γ, with the exception of HT‐29 cells, was similarly ineffective. These data demonstrate that rIFN‐β is a potent growth inhibitor of colon carcinoma cells in vitro, and suggest that studies on its mechanism of action may lead to a better understanding of the regulation of colon tumor cell proliferation.
Minimal dose and time protection by lindane (γ‐isomer of 1,2,3,4,5,6 hexachlorocyclohexane) against liver tumors induced by aflatoxin b1
Authors: Angsubhakorn Subhkij , Bhamarapravati Natth , Pradermwong Apichat , Im‐Emgamol Nipa , Sahaphong Somphong
Published: February 2007

This study was carried out in order to investigate the minimal exposure to lindane (LD, 99.72% gamma isomer of 1,2,3,4,5,6 hexachlorocyclohexane), a chlorinated hydrocarbon insecticide, required to protect against liver tumor induced by aflatoxin B1 (AFB1). Materials fed to Buffalo strain rats were as follows: LD 100 ppm; AFB1 I ppm, LD 100 ppm plus AFB1 1 ppm; and control basal diet. The experimental animals were clinically observed and then serially killed at 1, 3, 5, 10, 15 and 82 weeks. Concurrent administration of LD with AFB1 to rats for more than 3 weeks totally inhibited the incidence of AFB1‐induced hepatocellular carcinomas by week 82. Only 1 of 20 rats (5%) fed the same regimen for 1 week developed liver tumors. Animals given 1 ppm AFB1 singly for 15 weeks had a high liver tumor incidence (31.5%). No animals developed liver tumors in LD‐treated and control groups. LD may inhibit AFB1‐induced liver tumors by stimulating hepatic metabolism and excretion of AFB1 so that less carcinogen is available to liver tissue.
Altered restriction pattern of the putative DNA binding domain of estrogen receptor or related genes in primary human meningiomas
Authors: Vacca A. , Fazio V. M. , Gandini O. , Oppido P. , Delfini R. , Frati L. , Gulino A.
Published: February 2007

We analyzed by restriction mapping the genomic organization of the estrogen receptor gene in several primary human brain tumors in order to investigate the possible relationships between the development of these tumors and gonadal steroid hormones. In 5 out of 23 meningiomas the Eco RI restriction of genomic DNAs revealed 6 invariant normal fragments of 6.5, 4.8, 3.8, 3.1, 2.7 and 1.7 kb, plus 2 additional variant fragments of either 8.6 or 2.5 kb. More detailed analysis showed that these variant bands hybridized with a probe specific for the middle region of the estrogen receptor cDNA, coding for the DNA‐binding domain of the receptor. This abnormal restriction pattern was found only in these meningiomas and not in other brain tumors or DNAs obtained from peripheral blood lymphocytes.
Search for human papillomavirus, herpes simplex virus and c‐myc oncogene in human genital tumors
Authors: Di Luca D. , Costa S. , Monini P. , Rotola A. , Terzano P. , Savioli A. , Grigioni W. , Cassai E.
Published: February 2007

We tested grade III cervical intra‐epithelial neoplasms (CIN III), genital invasive carcinomas and healthy genital tissues for the presence of a number of viral and cellular parameters, considered to be risk factors in genital oncogenesis. The results show that: (1) about 30% of genital tumors had homology to HSV‐2 BgIII N and/or BamHI E DNA fragments; (2) positivity to HSV‐2‐specific protein ICP10, encoded by sequences within the HSV‐2 BamHI E DNA fragment, was detected in 29/55 neoplastic genital tissues but not in healthy genital tissues or tumors at other sites; (3) HPV‐16 DNA was found in about 50% of tumor samples, but none of the positive tissues reacted to HPV capsid protein or to the protein encoded by the HPV‐16 E6 ORF; (4) 6/8 tumor samples showing homology to HSV‐2 DNA fragments also hybridized to HPV‐16 DNA; (5) c‐myc amplification was not detected in any of the analyzed samples, but tissues from 4 patients were positive for c‐myc expression. None of the considered factors was present in all the analyzed samples; nevertheless, some tissues showed the simultaneous involvement of several parameters, suggesting that a number of risk factors may be involved in different steps of human genital oncogenesis.
A monoclonal antibody (D612) with selective reactivity for malignant and normal gastro‐intestinal epithelium
Authors: Muraro R. , Nuti M. , Natali P. G. , Bigotti A. , Simpson J. F. , Primus F. J. , Colcher D. , Greiner J. W. , Schlom J.
Published: February 2007

We describe the generation and characterization of a monoclonal antibody (MAb), designated D612, with selective reactivity for malignant and normal gastro‐intestinal epithelium. MAb D612, a murine lgG2a, was generated using a membrane‐enriched fraction of a human colon carcinoma biopsy as immunogen. Employing radioimmunoassays (RIAs) of biopsy extracts to a range of normal and neoplastic tissues, and both immunofluorescence and immunoperoxidase assays on frozen sections of a range of normal and neoplastic tissues, we have shown that MAb D612 binds to 82% of colorectal carcinomas tested (n = 67) and to normal gastro‐intestinal epithelium, but does not bind similarly to either neoplastic or normal tissues from a wide range of other sites. Western blotting has shown MAb D612 to react with a high‐molecular‐weight antigen. Live cell RIAs and FACS analyses demonstrate the reactive epitope to be present on the surface of colon carcinoma cells. Immunohistochemical studies have shown intense membrane staining of colon adenocarcinomas with MAb D612; the vast majority of both primary and metastatic colon adenocarcinomas from a variety of sites were positive with many lesions showing homogeneous staining of virtually all cells present. Using human effector cells, we also showed that MAb D612 mediates antibody‐dependent cell‐mediated cytotoxicity (ADCC) of human colon carcinoma cells; this activity was enhanced in the presence of interleukin (IL‐2). Radiolabelled D612‐purified IgG selectively binds a human colon carcinoma xenograft in situ. The pattern of membrane‐associated staining, the molecular weight of the reactive antigen, the lgG2a isotype, the ability to mediate ADCC in the presence of IL‐2, and the immunohistochemical and RIA studies demonstrating highly restricted reactivity to malignant and normal gastro‐intestinal tissue, all distinguish MAb D612 from other MAbs thus far described.
Sister chromatid exchange and nasopharyngeal carcinoma
Authors: Li Gui‐Yuan , Yao Kai‐Tai , Glaser Ronald
Published: February 2007

Sister chromatid exchange (SCE) is a genetic indicator of DNA damage in mammalian cells and may afford a sensitive monitor to follow genomic instability of some individuals with fragile chromosomal diseases or malignancies. In studies on the effect of dinitrosopiperazine (DNP), aflatoxin BI (AFBI), methyl‐nitro‐nitroso‐guanidine (MNNG) and Epstein‐Barr virus (EBV) infection on SCE in lymphocytes from nasopharyngeal carcinoma (NPC) patients, we found that: (I) the spontaneous SCEs in peripheral blood lymphocytes (PBLs) from 75 NPC patients were significantly higher than those of PBLs from 44 normal adults, 24 cord blood (CBL) specimens, and PBLs from 20 patients with chronic inflammation of the nasopharynx; (2) PBLs from NPC patients who were positive for EBV virus capsid antigen (VCA) lgA antibody had a higher SCE frequency as compared with PBLs from VCA lgA‐negative NPC patients; (3) the chemical carcinogens used induced significantly higher SCEs in lymphocytes from NPC patients than in PBLs from normal adults and CBLs; (4) the mean SCEs of EBV growth‐transformed CBLs increased from 5.17 to 14.12 after infection and was similar to the level of SCEs found in PBLs from the VCA lgA‐positive NPC patients. The data suggest that lymphocytes of NPC patients might be more fragile than the lymphocytes of the control groups studied.
Properties of recombinant interleukin 2‐cultured tumor‐infiltrating lymphocytes in human lung cancer
Authors: Yano Tokujiro , Yasumoto Kosei , Togami Masatoshi , Ishida Teruyoshi , Kimura Genki , Sugimachi Keizo , Nomoto Kikuo
Published: February 2007

It is thought that TIL can be activated in vitro by rIL‐2 and acquire specific anti‐tumor activity. In this study, we investigated this possibility, using lymphocytes isolated from primary lung cancer tissues. In a first series of experiments, TILs and autologous PBLs from 16 patients were cultured in rIL‐2 from 7 to 14 days under identical conditions, and were compared for proliferation (16 cases), cytolytic activity (11 cases), gamma interferon (IFN‐γ) production (8 cases), and phenotypes (10 cases). TILs grew in response to rIL‐2 as well as PBLs. However, the induced cytolytic activity of TIL was significantly lower than that of PBL against autologous tumor cells and 2 human tumor cell lines. IL‐2‐mediated IFN‐γ production by TILs was also significantly lower than that of PBLs. TILs were phenotypically characterized by their high CD4/CD8 ratio and lack of Leu 11‐positive cells. Further investigations with 7 other cases showed that exogenous addition of IFN‐γ to rIL‐2 cultures of TILs enhanced cytolytic activity in 4 cases. Our results indicate that IL‐2 alone is sufficient for TILs to proliferate but not to acquire new functions (cytotoxicity and production of IFN‐γ).
Immunophenotypic characterization of follicle‐center‐cell‐derived non‐hodgkin's lymphomas
Authors: Sakthivel Ramasamy , Christensson Birger , Ehlin‐Henriksson Barbro , Klein George
Published: February 2007

The distribution of the BLA, CALLA (CD 10), AC‐2 (CD 39), MHM‐6 (CD 23), LB‐I, and 35IC5 (CD 45R) antigens in 40 non‐Hodgkin's lymphomas was demonstrated by immunohistochemical staining of frozen tissue sections. Nine out of 10 centroblastic and centrocytic follicular and diffuse type of lymphomas (CB/CC F/D) and all 10 cases of CB/CC follicular lymphomas were BLA+ and CALLA+. A few cases also showed weak expression of activation antigens (AC‐2, MHM‐6 and LB‐1) and 35IC5. In contrast, 3 CC and 3 lymphoblastic (non‐Burkitt) lymphomas showed a heterogeneous pattern of distribution with dominating activation antigen expression. A single case of lymphoblastic lymphoma of Burkitt‐like type expressed BLA and CALLA but not activation antigens. In reactive follicular center and FCC lymphomas different cell populations appeared to express BLA and activation antigens, respectively. Assessment of staining intensity and proportion of the stained cells indicated that almost all BLA+ cells are CALLA+. CALLA+ BLA− cells were regularly present, in addition. The co‐expression of BLA and CALLA in the same cell was confirmed by double immuno‐enzymatic staining. By the same technique, BLA+ and CALLA+ cells were shown to be activation‐antigen negative.
Alcohol consumption and risk of benign proliferative epithelial disorders of the breast in women
Authors: Rohan Thomas E. , Cook Martin G.
Published: February 2007

Many studies have shown a positive association between alcohol consumption and risk of breast cancer. Benign proliferative epithelial disorders (BPED) of the breast are conditions which, although not proven precursors of breast cancer, are strongly associated with increased risk of this disease. The association between alcohol consumption and risk of BPED was examined in a case‐control study conducted in Adelaide, South Australia. The study involved 383 cases with biopsy‐confirmed BPED, 192 controls whose biopsy did not show epithelial proliferation, and 383 unbiopsied community controls individually matched (1:1) to cases on age and area of residence. When cases were compared with community controls, the unadjusted relative risk of BPED for drinkers versus non‐drinkers was 0.9 (95% CI 0.6–1.3), and the corresponding relative risk derived from comparing cases with biopsy controls was 1.0 (95% CI 0.6–1.4); these estimates were not altered after adjustment for potential confounding. Variation in risk of BPED across levels defined in terms of daily total alcohol intake, and in terms of daily alcohol intake from individual beverages, was mostly insubstantial and not dose‐dependent. Also, there was little variation in risk with age at first drink, or by current drinking status, and risk of BPED in association with alcohol consumption did not increase with severity of cytologic atypia. Despite the absence of an association in this study, further investigation is warranted, since it may provide opportunities for the prevention of BPED and of breast cancer.
Establishment and characterization of a human neuroblastoma cell line
Authors: Scarpa Susanna , Dominici Carlo , Grammatico Paola , Porto Giuseppe Del , Raschellà Giuseppe , Castello Manuel , Forni Guido , Modesti Andrea
Published: February 2007

A continuous human cell line RN‐GA was established from a stage‐III primary neuroblastoma prior to therapy. Light and electron microscopic analysis of the biopsy showed morphological features typical of neuroectodermal origin. Relative cellular DNA content and N‐myc oncogene copy number were also analyzed in the biopsy tissue: the tumor cells presented a near‐diploid genome with N‐myc amplification. The derived tumor cell line expressed distinctive ultrastructural, cytogenetic and immunological markers of neuroblastoma. Moreover, cells from the culture could be serially transplanted into splenectomized‐irradiated nude mice, where they formed a progressively growing solid tumor. Surprisingly, the cells in culture did not show any N‐myc amplification, while they retained a near‐diploid DNA content. We propose that several techniques (electron microscopy, oncogene analysis, flow cytometry, cytogenetics, tissue culture, cell antigen immunodetection) should be used to establish a firm diagnosis and a correct clinical grading of this tumor. The establishment of this continuous cell line should be valuable as an experimental in vitro system for further studies of neuroblastoma biology and morphology.
New anti‐GD2 monoclonal antibodies produced from gamma‐interferon‐treated neuroblastoma cells
Authors: Gross Nicole , Beck Daniel , Portoukalian Jacques , Favre Simone , Carrel Stefan
Published: February 2007

Three monoclonal antibodies (IgG2) have been produced from hybridomas obtained by fusion of murine myeloma cells and spleen cells of mice hyperimmunized with gamma‐interferon‐treated neuroblastoma cells. The 3 MAbs, 7A4, 2A6 and IG8, detected an antigen present on neuroblastoma tumors and cell lines, but also on some neuro‐ectoderm‐derived tissues and cells. All 3 clones were shown to react with an epitope of the di‐sialo‐ganglioside GD2 molecules highly expressed by some neuro‐ectoderm‐derived tumors, mainly neuroblastoma. Whereas MAb IG8 specificity was restricted to GD2 and its o‐acylated form, MAb 2A6 and 7A4 were also able to detect GD3 at high concentration of antibody as shown by TLC analysis and immunodetection. The 3 MAbs were able to lyse 100% neuroblastoma cells in the presence of rabbit or human complement. Direct binding assays with125‐labelled MAbs showed that MAb 7A4 might be a good candidate forin vivoimmunolocalization experiments. The high proportion of anti‐GD2 MAbs obtained by our fusion and the increased binding of anti‐GD2 MAbs on gamma‐IFN‐treated neuroblastoma cells suggests a modulation of the exposure and an increase in the immunogenicity of GD2 induced by gamma‐IFN.
The in vitro growth response of primary human colorectal and gastric cancer cells to gastrin
Authors: Watson S. A. , Durrant L. G. , Crosbie J. D. , Morris D. L.
Published: February 2007

A series of 31 colorectal and 13 gastric primary human tumours were screened for their growth response to human gastrin‐17 in vitro, as assessed by 75Se‐seleno‐methionine incorporation. Fifty‐five percent of colorectal and 69% of gastric tumours showed a significant trophic response to the hormone. The responses were achieved at physiological gastrin concentrations (post‐prandial circulating gastrin levels) in 35% of colorectal and 55% of gastric tumours. Lymphocytes from tumour‐associated lymph nodes showed no response to the hormone and “normal” mucosal cells (obtained from the resection margin of the surgical specimen) showed lower mean levels of 75Se‐seleno‐methionine uptake (colorectal: 110%; gastric: 119%, expressed as a percentage of the control) when compared to tumours (colorectal: 151%; gastric: 147%). The small number of well differentiated and/or Dukes' stage A colorectal tumours examined were gastrin‐responsive, but all the responsive gastric tumours were poorly differentiated. With respect to ploidy, 89% of diploid and 67% of aneuploid colorectal tumours responded trophically to gastrin. Patients with colorectal or gastric tumours may benefit from treatment with gastrin antagonists.
High toxic efficiency of ricin immunotoxins specific for the t‐cell antigen receptor of a human leukemia t‐cell line
Authors: Izquierdo Manuel , Balboa María A. , Lamana María L. , Löpez‐Botet Miguel
Published: February 2007

Immunotoxins (ITs) were prepared by covalently coupling ricin to monoclonal antibodies (MAbs) directed against: (a) 2 different epitopes of the T‐cell receptor (TcR) expressed by the Jurkat leukemia T‐cell line (JTi2 and JTi4 MAb), (b) 2 epitopes of the CD3 complex (SpV‐T3b and IID8 MAb), (c) the CD2 and the CD8 cell‐surface molecules. Conjugates were assayed for their cytotoxic activity by pre‐incubating the Jurkat cell line with different concentrations (10‐250 ng/ml) of each IT for 2 hr at 37°C in the presence of 0.1 M lactose. After washing, cells were cultured for 24 hr and their protein synthesis and proliferative capacities were assessed. Doseresponse experiments indicated that JTi2, JTi4 and anti‐CD3 (IID8) ITs inhibited by >90% the cell line proliferation at 50 ng/ml, a 5‐fold lower concentration than that required to achieve a similar effect when anti‐CD2 and anti‐CD3 (SpVT3b) were used. After 4 hr of culture subsequent to treatment with JTi2 or JTi4 ITs (250 ng/ml), protein synthesis was inhibited (>80%). By limiting dilution analysis (LDA) we estimated that the frequency of proliferating Jurkat cells (1/1.5) was reduced to 1/20, 1/460 and 1/300 after treatment with anti‐CD3 (SpVT3b), JTi4 and JTi2 ITs, respectively. Phenotypic analysis of 13 clones derived from JTi2 IT‐treated Jurkat cells showed that 50% were CD7+ CD3− JTi− variants. When bone‐marrow mononuclear cells, previously mixed with low concentrations of Jurkat cells, were treated with anti‐JTi ITs, the toxic efficiency estimated by LDA was maintained whereas the growth of CFU‐GM remained unaltered.
Epstein‐barr virus and a tumour‐promoting phorbol ester use similar mechanisms in the stimulation of human b‐cell proliferation
Authors: Guy Graeme R. , Gordon John
Published: February 2007

In marked contrast to ligands which activate B cells via their physiological receptors for antigen, transforming Epstein‐Barr virus (EBV) was found to be mitogenic for human B lymphocytes without increasing inositol phospholipid hydrolysis. B‐cell stimulation by EBV showed similar characteristics to those achieved by the tumour‐promoting phorbol ester TPA, in terms of the temporal appearance of surface activation antigens, the induction of RNA and DNA synthesis and the lower requirement for medium Ca++ in comparison to agonists that lead to an increase in inositol phospholipid hydrolysis. The calcium‐ and phospholipid‐dependent kinase, protein kinase C (PKC), is activated by TPA and a proteolytically cleaved fragment (PKM) results. EBV induced the appearance of a calcium‐ and phospholipid‐independent activity that was chromatographically inseparable from PKM and this activity was capable of phosphorylating vimentin, a cell component that is thought to participate in the signal transduction cascade. These findings are discussed with special reference to the biochemical signalling pathways on which EBV might impinge to usurp growth control in B lymphocytes.
Differential expression of cell adhesion molecules in variants of K1735 melanoma cells differing in metastatic capacity
Authors: Linnemann Dorte , Raz Avraham , Bock Elisabeth
Published: February 2007

We have investigated the expression of 2 neural‐cell adhesion molecules, NCAM and L1, in K1735‐C116 and ‐M1 melanoma cells which differ qualitatively in their metastatic potential, i.e., M1 cells are metastatic whereas C116 cells are not. We have found that NCAM in C116 cells are expressed as 2 quantitatively major glycosylated polypeptides with Mr of 145,000 and 120,000 and a minor 190,000 Mr polypeptide, whereas M1 cells expressed NCAM as 3 glycosylated polypeptides with Mr of 200,000, 140,000 and 120,000. The amount of NCAM in M1 cells constituted only 60% of the amount observed in C116 cells. In C116 cells, the 145,000 and 120,000 Mr NCAM polypeptides were sulphated whereas NCAM did not appear to be sulphated in M1 cells. No phosphorylation of NCAM in the 2 cell lines was observed. L1 was expressed as a phosphorylated glycoprotein with Mr of 210,000 in M1 cells whereas no L1 expression was observed in C116 cells. L1 was not sulphated in M1 cells.