bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong uptake of 111in‐pentetreotide by an MIBG‐negative, xenografted neuroblastoma
Authors: Manil L. , Perdereau B. , Barbaroux C. , Buixy F. 
Published: February 2007

AbstractWe investigated the distribution of 111In‐pentetreotide (Octreoscan, Mallinckrodt) in nude mice xenografted with a human neuroblastoma cell line (SKLAN, derived from the LAN I line). These cells develop into solid tumours in nude mice and can be grafted repeatedly in grafts of 108 cells. Animals were sequentially explored by scintigraphy 2, 4, 24 and 48 hr after i.v. injection of 2.5‐4 MBq of the tracer and killed at various times up to 46 hr. 111In‐pentetreotide was rapidly and strongly taken up by all tumours, with a tumour/muscle (T/M) ratio on resected samples of 20.0 ± 5.7 at 2 hr, 23.7 ± 3.0 at 4 hr, 75.6 ± 12.6 at 24 hr and 78.7 ± 12.4 at 48 hr, for tumours ranging from 0.5 to 8 g. Scintigraphy results were quantitatively in agreement Pre‐injection of a 15‐20 times larger quantity of unlabelled octreotide s.c. reduced the tumour uptake by a factor of 2. For comparison, nude mice xenografted with the same cell line were also studied with 123I‐MIBG (4 MBq). At 24 hr, the T/M ratio was 0.62 ± 0.18. Two other cell lines (glioblastoma ROM and small‐cell lung carcinoma SC41) which were similarly tested with 111In‐pentetreotide (2.5‐4 MBq) gave T/M ratios at 24 hr of 4.8 ± 2.8 and 38.4 ± 21.8, respectively. Pentetreotide seems to have a high affinity for this MIBG‐negative neuroblastoma cell line, which exhibited a clearly higher tumour uptake than the 2 other lines. This work provides new experimental arguments in favour of the particular interest of somatostatin analogues in neuroblastoma and confirms our first clinical results. © 1994 Wiley‐Liss, Inc.
Cd4+ T cells recovered from a mixed immune lymphocyte‐tumor cell culture induce thymidine incorporation by naive rat lymphocytes in response to tumor cells
Authors: Reisser Danièle , Martin François 
Published: February 2007

AbstractSpleen cells from tumor‐immune rats incorporate thymidine when co‐cultured for 4 days with syngeneic cancer cells. Non‐adherent cells, recovered from a 7‐day mixed culture with cancer cells, had lost their capacity for incorporating thymidine when exposed again to the same tumor cells; however, in these conditions, the non‐adherent cells induce thymidine incorporation by fresh naive spleen cells. This response is restricted to tumor lines which originate from the same tumor as the cells used for immunization and is due to memory and/or activated CD45RC‐CD4+ T cells. Our results indicate that tumor‐specific T cells maintain their capacity to respond to tumor antigens, even after an extended culture time with tumor cells. In another study, in the same conditions, spleen cells from normal or tumor‐bearing rats did not evoke significant responses. © 1994 Wiley‐Liss, Inc.
Multiple mechanisms of resistance in a series of human testicular teratoma cell lines selected for increasing resistance to etoposide
Authors: Hosking Louise K. , Whelan Richard D. H. , Shellard Sharon A. , Davies Sally L. , Hickson Ian D. , Danks Mary K. , Hill Bridget T. 
Published: February 2007

AbstractMechanisms of resistance to VP‐16 were monitored in a series of sublines of the human testicular teratoma cell line (SuSa) derived following exposure either to fractionated X‐irradiation (DXR‐10) or to VP‐16 using pulsed 24‐hr exposures (VP 10) or continuous exposure conditions (VPC2, VPC3 and VPC4). Orders of resistance expressed (ranging from 3‐ to 33‐fold based on ICS0 values derived from colony forming assays) were comparable with those likely to be encountered clinically, All of these resistant sublines showed some cross ‐resistance to VCR, and the 3 drug‐selected sublines tested also proved cross‐resistant to ADR. Resistance was not associated with modified 3H‐VP‐16 accumulation. However, decreased VP‐16‐induced SSBs were detectable in all the resistant sublines and a strong positive correlation was noted between the extent of SSB formation and VP‐16 resistance by linear regression analysis. Topo IIα protein content, as judged by Western blotting, was significantly decreased only in the sublines derived by continuous exposure to VP‐16, but this was not progressive with increasing levels of resistance expressed. RNase protection assays also showed no significant differences in Topo IIα expression in the low‐level resistant DXR‐10 and VP 10 sublines, contrasting with the 2‐fold decreases identified in the VPC2, VPC3 and VPC4 sublines. Significantly, however, mRNA levels of two alternately spliced Topo IIβ mRNAs were markedly decreased (2‐ to 9‐fold) in all the drug‐selected resistant sublincs. No mutations in consensus ATP‐binding sequences or in the DNA‐binding region of Topo Ma were detected by single strand conformations I polymorphism analysis. Significant Pgp over express ion was only identified in the most highly resistant sublines VPC3 and VPC4, which both showed 4‐fold cross‐resistance to VCR. Decreased 3H‐VCR accumulation and partial reversal of resistance by VPM (6.6 μM) addition was also identified, consistent with a functional Pgp being overexpressed in these sublines. Modifications of Topo II expression therefore appear to precede Pgp overexpression in this series of sequentially derived VP‐16 resistant sublines and to represent the predominate mechanism underlying low level (< 10‐fold) resistance. © 1994 Wiley‐Liss, Inc.
Cytoreductive effects of anti‐transferrin receptor immunotoxins in a multicellular tumor spheroid model
Authors: Chignola Roberto , Foroni Roberto , Candiani Carola , Franceschi Antonia , Pasti Murcella , Stevanoni Gabriella , Anselmi Cristina , Tridente Giuseppe , Colombatti Marco 
Published: February 2007

AbstractWe have evaluated the sensitivity to immunotoxins (IT) of monolayer and of 200‐250 μM multicellular tumor spheroid (MTS) cultures obtained with human breast (MCF7) and glioblastoma (U 118) tumor cells and with rat glioblastoma (9L) cells. Monolayer MCF7 and U118 cells were highly sensitive to anti‐transferrin receptor (anti‐TfnR) ricin A chain (RTA)‐IT (Tfn‐RTA and Mab OKT9‐RTA) treatment in the presence of the intracellular RTA‐IT enhancing agent human serum albumin monensin (HSA‐Mo) conjugate. A 790‐ to 2000‐fold higher concentration of anti‐TfnR IT was instead required to reduce by 50% the volume of individually treated MCF7 spheroids, as evaluated by applying the Gompertz growth model. Monolayer 9L cells showed 230‐ to 5700‐fold lower sensitivity to Tfn‐RTA IT than MCF7 and UI 18 monolayers, yet 9L spheroid cells were almost as sensitive to anti‐TfnR IT as monolayer 9L cultures. Binding studies performed with [125I]‐Tfn and FITC‐labelled anti‐TfnR MAb revealed that 9L monolayers and MTS expressed 4.1‐fold and 8.8‐fold lower amounts of TfnR than MCF7 monolayers and MTS, respectively. However, Tfn bound to TfnR sites of 9L and of MCF7 cells with comparable affinity. Experiments carried out with the diphtheria toxin mutant CRMI07 linked to Tfn con‐firmed the pattern observed with RTA‐IT. Monolayers and spheroids showed no considerable differences in sensitivity to ricin toxin. Collectively, these results indicated that the efficacy of IT against 3‐D tumors is heavily influenced by the number of target Ag expressed by the tumor cells, as well as by the affinity of IT/toxin‐cell interaction. © 1994 Wiley‐Liss, Inc.
Expression of proliferating cell nuclear antigen (PC10), p53 protein and c‐erbB‐2 in renal adenocarcinoma
Authors: Lipponen Pertti , Eskelinen M. , Hietala K. , Syrjänen K. 
Published: February 2007

AbstractExpressions of proliferating cell nuclear antigen (PC 10), p53 protein (CMI) and c‐erbB‐2 (NCL‐I) were immunohistochemically analysed in 123 renal adenocarcinomas with known follow‐up data. e‐erbB‐2 protein was weakly and focally expressed in 10% of the tumours, and the expression was not related to clinical or histological variables or survival. p53 protein was expressed in 33% of the tumours. Expression of p53 protein was independent of stage, grade and prognosis, while expressions of c‐erbB‐2 and p53 were weakly interrelated. Proliferating cell nuclear antigen was expressed in all tumours, and the fraction of PC 10‐positive nuclei was significantly related to grade, stage and prognosis. Multivariate analysis of clinical, histological and immunohistochemical prognostic factors indicated that the extent of the tumour, its histological differentiation and proliferation rate of the cancer cells are the most important prognostic factors. Recurrence‐free survival was related to the fraction of PCIO‐positive nuclei, histological differentiation, sex and expression of p53 protein. Over‐expression of p53 protein was related to a long recurrence‐free survival. Our results show that PC10 immunolabelling can be used to determine the prognostic category in renal adenocarcinoma, whereas the expressions of p53 protein or c‐erbB‐2 are only weak prognostic indicators. © 1994 Wiley‐Liss, Inc.
Effect of protein kinase C inhibitors on invasiveness of human melanoma clones expressing different levels of protein kinase C isoenzymes
Authors: Mapelli Elena , Banfi Patrizia , Sala Elena , Sensi Marialuisa , Supino Rosanna , Zunino Franco , Gambetta Romolo A. 
Published: February 2007

AbstractThe involvement of protein kinase C (PKC) in the mechanism of chemotaxis and invasiveness of human melanoma has been studied in 6 clones of 665/2 cell line characterized by a different integrin profile, differentiation grade and in vitro invasive ability. The levels of total protein kinase C activity revealed a direct correlation with the chemotactic and invasive ability of these clones. Protein kinase C inhibitors, sphingosine and staurosporine, reduced chemotaxis and invasiveness of the highly invasive clone 2/60, while 1‐(5‐isoquinolinylsulfonyl)‐2‐methylpiperazine (H7) was ineffective. Immunofluorescence analysis revealed high levels of protein kinase C α in clone 2/60, while the less invasive clone 2/21 expressed low levels of protein kinase C α and β but surprisingly appreciable levels of protein kinase C γ Downregulation with phorbol 12‐myristate 13‐acetate(TPA) did not affect invasiveness of clone 2/60 unless the compound was present during the assay. H7 strongly increased invasiveness of clone 2/21 and was able to reverse the inhibitory effect of TPA on clone 2/60. Preliminary experiments showed higher levels of diacylglycerol in clones with lower protein kinase C, suggesting a constitutive down regulation of the enzyme in low invasive clones. Our results support a role for protein kinase C in the invasion process, but point out the complexity of the mechanism which might involve the proteolytic fragment of the enzyme, protein kinase M. © 1994 Wiley‐Liss, Inc.
Immunolocalization of granulocyte‐colony‐stimulating factor in human glial and primitive neuroectodermal tumors
Authors: Stan A.‐C. , Walter G. F. , Welte K. , Pietsch T. 
Published: February 2007

AbstractGranulocyte‐colony‐stimulating factor (G‐CSF) is a hematopoietic cytokine that regulates the differentiation of myeloid progenitors and the function of mature neutrophils. It is produced in vitro by monocytes/macrophages, mesothelial cells, fibroblasts and endothelial cells after appropriate induction by inflammatory mediators like IL‐I and TNF. Normal as well as tumorous glial cells can also be induced to produce CSFs in vitro. However, little is yet known about the in vivo expression of G‐CSF as a mediator in inflammation and malignancy withiin the human central nervous system. The aim of the present study was to investigate by immunostaining the expression of the G‐CSF protein within non‐tumorous and tumorous glial tissues, and primitive neuroectodermal tumors. Using the murine monoclonal anti‐G‐CSF TM 82/60 antibody, we found high G‐CSF expression in astrocytoma WHO grades I and II and reactive brain tissue, low expression in astrocytoma WHO grade III, and none in glioblastoma, oligodendroglioma WHO grades II and III, none medulloblastoma. In consecutive sections of the tissue samples, G‐CSF protein was localized in GFAP‐positive glial cells, but not in macrophages/microglial cells, which expressed HLA‐DR, detected by the antibody CR3/43. Computer‐assisted microdensitometric evaluation of the intensity of immunostaining for G‐CSF and statistic analysis of the data revealed significant differences between the diagnostic entities studied (p < 0.0001). We conclude that in vivo expression of G‐CSF is a characteristic of reactive as well as tumorous astrocytes, with the latter losing this feature at higher degrees of dedifferentiation. © 1994 Wiley‐Liss, Inc.
Cyclin D1 protein expression and function in human breast cancer
Authors: Bartkova Jirina , Lukas Jiri , Müller Heiko , Lützhøt Dorrit , Strauss Michael , Bartek Jiri 
Published: February 2007

AbstractCyclin D1 is a cell‐cycle regulator essential for G1, phase progression and a candidate proto‐oncogene implicated in pathogenesis of several human tumour types, including breast carcinomas. In spite of the accumulating genetic evidence, however, there are no data regarding abundance and properties of the cyclin D1 protein in breast cancer. We now report aberrant nuclear overexpression/accumulation of the cyclin D1 protein in about half of the 170 primary breast carcinoma specimens analyzed by monoclonal antibody immunohistochemistry, indicating that the frequency of cyclin D1 abnormalities may be considerably higher than previously deduced from DNA amplification studies. A comparison of the expression patterns in matched lesions at different stages of tumour progression revealed that the cyclin D1 protein aberration appears to reflect a relatively early event and that, when acquired by a tumour, it is maintained throughout breast cancer progression including metastatic spread. In both tumour tissues and breast cancer cell lines, the abundance of this protein shows characteristic variations consistent with a cell‐cycle oscillation and the peak levels expressed in G1. In all 7 cell lines whose retinoblastoma (Rb) protein is mutant or complexed to SV40 T antigen, exceptionally low levels of cyclin D1 protein and mRNA were found. Antibody‐mediated and anti‐sense oligonucleotide knockout experiments demonstrate the requirement for the cell‐cycle regulatory function of cyclin D1 in breast cancer lines with single or multiple copies of the gene and reveal the absence of such a requirement in the cell lines with Rb defects. Our data are consistent with the notion that the emerging “Rb‐cyclin D1 pathway” represents a frequent target of oncogenic abnormalities in breast cancer. © 1994 Wiley‐Liss, Inc.
Study of the resistance of tumor‐cell spheroids to penetration and lysis by activated effector cells
Authors: Ochalek Tomasz , von Kleist Sabine 
Published: February 2007

AbstractTumor spheroids and growing cell monolayers were used as 2‐ and 3‐dimensional targets in the in vitro study of the interactions of colorectal tumor cells with various in vitro II‐2‐activated lymphocyte effectors. The study examined tumor‐cell susceptibility to the cytotoxic activity of effector cells in correlation with the ability of the effectors to infiltrate spheroids. No restriction of lymphocyte activity was found when the susceptibility of tumor cells to the panel of autologous and allogeneic II‐2‐stimulated PBL (LAK cells) and TIL was compared. Their activity against a given tumor specimen was similar, but differed against the various other tumor specimens. Thus, the tumor susceptibility and not the cytotoxic potential of the lymphocytes determined the interaction result. An inhibition of lymphocyte penetration was observed in some tumor spheroids, which considerably influenced the resistance to lymphocyte lysis. Apparently it is this inhibition of the migratory capacity of the effector cells by tumor cells that is responsible for tumor resistance to lymphocyte attack. © 1994 Wiley‐Liss, Inc.
Internalization and degradation of monoclonal antibody chCE7 by human neuroblastoma cells
Authors: Novak‐Hofer Ilse , Amstutz Hans Peter , Morgenthaler Jean‐Jacques , Schubiger P. August 
Published: February 2007

AbstractInternalization and cellular degradation of a chimeric monoclonal anti‐neuroblastoma antibody (MAb chCE7) is described. Immunofluorescence localization showed temperature‐dependent redistribution of MAb chCE7 from the cell surface at O°C to vesicular structures after heating to 37°C. SKN‐AS cells which were pulse‐labelled at O°C with radioiodinated chCE7 released 50% of the initial cell‐bound radioactivity into the medium after 20 hr at 37°C. Low‐molecular‐weight radioactivity in the medium was identified as iodotyrosine and the major intracellular degradation product was found to be an antibody fragment of 43 kDa. Degradation was blocked by chloroquine, an inhibitor of lysosomal function. MAb chCE7 binds to a carbohydrate epitope, as treatment with tunicamycin abolishes cell binding. In adherent cells in culture, inhibition of protein synthesis by cycloheximide affected cell‐surface binding sites for chCE7 in a biphasic manner, with an initial increase followed by long‐term decrease. Expression of binding sites was also found to be inhibited by sodium azide, by the lysosomotropic drug chloroquine and by Brefeldin A, a drug which prevents export of newly synthetized proteins to the cell surface. When cells were treated with high doses of chCE7 up to 24 hr and cell‐surface binding sites were then measured after an acidic buffer wash, no loss of surface binding sites was found, indicating that pretreatment with MAb chCE7 does not induce down‐regulation of its binding sites. © 1994 Wiley‐Liss, Inc.
DCC gene alteration in human endometrial carcinomas
Authors: Gima Tomonao , Kato Hidenori , Honda Tsuyoshi , Imamura Toshiro , Sasazuki Takehiko , Wake Norio 
Published: February 2007

AbstractThe present study was undertaken to define the gene(s) of importance on the long arm of chromosome 18 (chromosome 18q) in endometrial carcinomas. We analyzed loss of heterozygosity (LOH) at 3 loci on chromosome 18q and DCC gene expression by the reverse‐transcriptase/polymerase chain reaction (RT‐PCR) method. Among 61 tumors that were informative, 16 (26%), estimated to be a minimum number, showed allelic losses at one or more chromosome 18q loci. Deletions in these tumors possibly involved the region within or near the chromosome 18q 21.3 band where the DCC gene was localized. Moreover, the incidence of altered DCC mRNA expression was high in these tumors. Appropriate transcription was lost in 5 of 7 (71%) carcinoma cell lines in addition to 14 of 28 (50%) surgically resected tumors. Histopathological differentiation and clinical stage of disease were not related to LOH frequency or to DCC mRNA expression. These results suggest that the target for allelic loss on chromosome 18q seen in endometrial carcinomas is the DCC gene, and that inactivation of this gene may be critical for the development of most endometrial carcinomas. © 1994 Wiley‐Liss, Inc.
Association among p53 gene mutation, nuclear accumulation of the p53 protein and aggressive phenotypes in breast cancer
Authors: Tsuda Hitoshi , Hirohashi Setsuo 
Published: February 2007

AbstractIn order to reveal whether differences in the type and site of p53 gene mutations influence the function of the gene and tumor phenotype, we examined nuclear accumulation of the p53 protein immunohistochemically, loss of the other p53 allele by restriction‐fragment‐length polymorphism analysis, and histological grade of atypia in 52 breast‐cancer tissue specimens in which the position and pattern of the mutation were identified. When mis‐sense point mutations ordeletionsof3nbases(n = 1, 2,…), which did not cause a frame shift downstream, occurred within codons 110‐180 or 234‐285, containing highly conserved regions, the p53 protein was almost always (92%) accumulated in nuclei in a majority of the cancer cells. When these mutations occurred outside these regions, only 46% of the cases showed nuclear accumulation of the protein in a majority of cancer cells. In tumors with non‐sense point mutations or deletion of 3n+1 or 3n + 2 bases (n = 0, 1, 2,…), which caused a downstream frameshift, nuclear accumulation of the p53 protein was absent in 93% of cases. Irrespective of the mutation site or pattern, a majority of cases showing p53 mutation revealed loss of hetero‐zygosity on 17p13 (83%), which suggested they do not carry wild‐type p53 allele, and the highest histological grade of atypia (90%). Regardless of differences in their protein‐expression pattern, a majority of the p53 gene mutations were suggested to function in a recessive mode and to be involved in the development of histologically aggressive breast cancer. © 1994 Wiley‐Liss, Inc.
Oxygen consumption rate and mitochondrial density in human melanoma monolayer cultures and multicellular spheroids
Authors: Hystad Marit E. , Rofstad Einar K. 
Published: February 2007

AbstractRate of oxygen consumption per cell has been shown in previous studies to decrease with increasing depth in the viable rim of multicellular spheroids initiated from rodent cells, human colon‐carcinoma cells, and human glioma cells, due to progressive accumulation of quiescent cells during spheroid growth. The purpose of our work was to determine oxygen‐consumption profiles in human melanoma spheroids. Monolayer cultures of 4 lines (BEX‐c, COX‐c, SAX‐c, and WIX‐c) and spheroid cultures of 2 lines (BEX‐c and WIX‐c) were subjected to investigation. Spheroids were initiated from monolayer cell cultures and grown in spinner flasks. Rate of oxygen consumption was measured with a Clarke‐type electrode. Mitochondrial density was determined by stereological analysis of transmission electron micrographs. Thickness of viable rim and cell packing density were assessed by light microscopy of central spheroid sections. Cell‐cycle distribution was determined by analysis of DNA histograms measured by flow cytometry. Cell volume was measured by an electronic particle counter. Rate of oxygen consumption per cell differed by a factor of approximately 1.8 between the 4 cell lines and was positively correlated to total volume of mitochondria per cell. Rate of oxygen consumption per cell and total volume of mitochondria per cell were equal for monolayer cell cultures, 600‐μm spheroids and 1,200‐μm spheroids of the same line. Mitochondrial density and location in the cell did not differ between cells at the spheroid surface, in the middle of the viable rim and adjacent to the central necrosis. Cell‐cycle distribution, cell volume, and cell‐packing density in the outer and inner halves of the viable rim were not significantly different. Consequently, the rate of oxygen consumption per cell in inner regions of the viable rim was probably equal to that at the spheroid surface, suggesting that oxygen diffusion distances may be shorter in some melanomas than in many other tumor types. © 1994 Wiley‐Liss, Inc.