bluuebunny/crossref_metadata_2025 huggingface dataset:
K‐ras mutations in human adenocarcinoma of the lung: Association with smoking and occupational exposure to asbestos
Authors: Husgafvel‐Pursiainen K. , Hackman P. , Ridanpää M. , Anttila S. , Karjalainen A. , Partanen T. , Taikina‐Aho O. , Heikkilä L. , Vainio H.
Published: February 2007

We investigated point mutational activation of the ras genes (K‐ras codons 12, 13 and 61; N‐ras codons 12, 13 and 61; H‐ras codons 12 and 61) in primary, resected lung cancer by dot blotting and oligonucleotide hybridization. K‐ras mutations were found in 14 (29%) of the 48 lung tumour specimens examined, but no N‐ras or H‐ras mutations were found. The highest frequency of K‐ras mutation was observed in adenocarcinoma: 12 of the 21 samples studied (57%) had a mutation, which is one of the highest frequencies reported for lung adenocarcinoma. The commonest type of mutation in these lung tumour samples consisted of transversions: we observed 11, of which 8 (57% of all mutations) were G to T transversions. Most of the 48 patients studied had a history of heavy smoking, either with or without evidence of occupational exposure to asbestos. Statistical analysis revealed‐in addition to the highly significant association between the adenocarcinoma type of lung cancer and K‐ras mutation‐a clear association of K‐ras mutations with heavy life‐time smoking (≥50 pack‐years of cigarette smoking; odds ratio (OR) 4.9, 90% CI 1.2 ‐ 19.5, multivariate analysis). In addition, occupational asbestos exposure showed an elevated, but non‐significant, OR of 2.2 (90% CI 0.6 ‐ 8.7) with the presence of K‐ras mutation. We conclude that the occurrence of K‐ras mutations in adenocarcinoma of the lung is frequent, and that such mutations are associated with heavy life‐time exposure to tobacco smoke, possibly in combination with occupational exposure to asbestos fibres.
Decreased expression of DCC mRNA in human colorectal cancers
Authors: Itoh Fumio , Hinoda Yuji , Ohe Mutsumi , Ohe Yasuo , Ban Toshihiro , Endo Takao , And Kohzoh Imai , Yachi Akira
Published: February 2007

The mRNA expression levels of DCC gene, which is cloned from the deleted region of chromosome 18q in colorectal cancers and thought to be a tumor‐suppressor gene, was evaluated in tissue specimens surgically resected from patients with colorectal cancer by RT‐PCR. This method was chosen as the expression level of DCC mRNA is below the detectable level for Northern‐blot analysis. Semi‐quantitative measurements of DCC mRNA were performed based on a standard curve defined by serial dilution of DCC cDNA. As a result, the expression level of DCC mRNA was found to be lower in 17 out of 30 colorectal cancers than in adjacent non‐cancerous tissues. Inclusion of smooth muscle in tissue specimens was observed to have little disturbing effect on comparisons between cancerous and non‐cancerous regions. In addition, all 4 specimens of colorectal cancer with liver metastasis showed the decreased expression level of DCC mRNA, suggesting that functional loss of DCC in cancerous tissues may play an important role in metastatic events.
Thymosin β‐10 expression in melanoma cell lines and melanocytic lesions: A new progression marker for human cutaneous melanoma
Authors: Weterman Marian A. J. , Van Muijen Goos N. P. , Ruiter Dirk J. , Bloemers Henri P. J.
Published: February 2007

When screening a subtraction library for sequences that were specifically expressed in highly metastatic human melanoma cell lines, a cDNA clone was isolated encoding thymosin β‐10. We found that expression of thymosin β‐10 mRNA was associated with metastatic behavior of various human melanoma cell lines in nude mice. Furthermore, Northern blot analysis showed that also in freshly harvested human melanocytic lesions thymosin β‐10 was differentially expressed. Although expression of thymosin β‐10 was also examined in other non‐melanoma model systems and materials, no clear relation could be established with metastatic potential or malignancy. Therefore, we conclude that thymosin β‐10 can be considered as a new progression marker for human cutaneous melanoma.
A monoclonal anti‐idiotypic antibody with an internal image of a “phosphatidylinositol‐like” structure derived from anti‐“phosphatidylinositol‐like” igg from the sera of patients with proliferative malignancies
Authors: Faiderbe S. , Chagnaud J. L. , Geffard M.
Published: February 2007

Using an enzyme‐linked immunosorbent assay (ELISA) with phosphatidylinositol (Ptdlns) coated on well‐plates, high levels of anti‐“Ptdlns‐like” autoantibodies (autoAbs) have been previously described in sera of cancer patients. These anti‐“Ptdlns‐like” autoAbs were purified and injected into BALB/c mice. A monoclonal anti‐idiotypic antibody (Ab2), internal image of human endogenous “Ptdlns‐like” structure called AIPI, was selected. Then the immunological binding in sera of cancer patients was evaluated on AIPI coated on well‐plates. Using this indirect ELISA method, we found a statistically highly significant immunological binding in sera of patients with epithelial tumors, which correlated with that previously found with the Ptdlns molecule coated on well‐plates. Moreover, AIPI mimics an endogenous structure closely associated with Ptdlns specifically encountered in epithelial proliferative disease.
Inhibition of growth‐factor‐activated proliferation by anti‐estrogens and effects on early gene expression of mcf‐7 cells
Authors: Wosikowski Katja , Küng Willy , Hasmann Max , Löser Roland , Eppenberger Urs
Published: February 2007

Recently, it was reported that the anti‐estrogen tamoxifen not only inhibits estradiol‐stimulated growth of MCF‐7 cells but also significantly reduces the proliferation rate of cells stimulated by growth factors. We have confirmed this finding and also shown that the new anti‐estrogen droloxifene inhibits the proliferation of epidermal growth factor (EGF) and insulin‐like growth factor‐I (IGF‐I)‐stimulated MCF‐7 cells. The growth‐factor‐induced proliferation was inhibited in a dose‐dependent manner by the anti‐estrogens in the complete absence of estrogen and FCS. Of the anti‐estrogens, droloxifene was considerably more potent than tamoxifen. Because the exprersion of the proto‐oncogenes c‐fos and c‐myc has been considered a key event in development of the mitogenic response, we examined the effects of anti‐estrogens on c‐myc and c‐fos gene expression. We included in these investigations the steroidal anti‐estrogen ICI 164,384 because this compound has no or very little estrogenic activity. The studies revealed that all 3 antiestrogens transiently induced c‐myc mRNA expression. However, the anti‐estrogens inhibited estradiol‐induced c‐myc mRNA expression, although with different potencies. Pre‐incubation of MCF‐7 cells with droloxifene and tamoxifen resulted in elevated levels of growth‐factor‐induced c‐myc mRNA expression. In contrast, the anti‐estrogens did not induce c‐fos mRNA or affect the expression of c‐fos mRNA induced by growth factors. In conclusion, non‐steroidal anti‐estrogens inhibit growth‐factor‐stimulated proliferation of MCF‐7 cells without inhibitinggrowth‐factor‐induced c‐myc or c‐fos mRNA expression.
Increased radioresistance of ejras‐transformed human osteosarcoma cells and its modulation by lovastatin, an inhibitor of p21ras isoprenylation
Authors: Miller Alexandra C. , Kariko Katalin , Myers Charles E. , Clark Edward P. , Samid Dvorit
Published: February 2007

Alterations in ras oncogene expression have been associated with increased cellular resistance to ionizing radiation. As an extension of studies with murine cell models, we have now explored the radioresponses of human osteosarcoma (HOS) sub‐clones that differ in their EJras expression. Quantitative analysis revealed a tight correlation between the amounts of ras‐encoded mRNA and p21 produced, and the degree of cell radioresistance. Interestingly, treatment of the ras‐transformed cells with lovastatin, an inhibitor of p21ras post‐translational processing via the mevalonate pathway, markedly decreased their radioresistance. Under the experimental conditions used, lovastatin prevented the membrane association, but not the biosynthesis, of p21. The decline in radiation resistance following lovastatin treatment could not be attributed to perturbation of cholesterol metabolism or to non‐specific cell‐cycle effects. In agreement, lovastatin did not alter the radiation responses of control HOS cells that do not express EJras, or those with an activated met oncogene. The results indicate that elevation in ras gene expression can lead to increased radioresistance of human tumor cells. It appears, however, that p21ras membrane localization is critical for maintenance of the radioresistant phenotype, thus providing a target for pharmacological intervention.
Establishment of l1210 leukemia cells resistant to the distamycin‐a derivative (FCE 24517): Characterization and cross‐resistance studies
Authors: Geroni Cristina , Pesenti Enrico , Tagliabue Giovanna , Ballinari Dario , Mongelli Nicola , Broggini Massimo , Erba Eugenio , D'Incalci Maurizio , Spreafico Federico , Grandi Maria
Published: February 2007

N‐deformyl‐N‐[4‐N,N‐bis(2‐chloroethylamino)benzoyl] distamycin‐A (FCE 24517) is a new cytotoxic anti‐tumor agent in phase‐I clinical trials. We have isolated stable FCE‐24517‐resistant cell sublines from murine leukemia L1210 cells by in vitro exposure to the drug. FCE 24517 selects a mixed population of resistant cells: the L1210/245171 cell line in vitro was in fact resistant to the selecting agent (RI 48.3), as well as to L‐PAM (RI 5.4) and DX (RI 8.6) and over‐expressed the mdr‐I gene. When L1210/245171 cells were implanted in vivo and evaluated for sensitivity to the same agents, resistance was observed only to FCE 24517 and partially to L‐PAM. whereas DX had the same anti‐tumor efficacy as on the sensitive line. The clone derived from the above subline (L1210/245172) was resistant to FCE 24517, distamycin‐A and other cytotoxic compounds bearing the distamycin‐A skeleton, and fully sensitive to DX and other anti‐tumor compounds involved in the multi‐drug resistance mechanisms, with a complete disappearance of the mdr phenotype. L1210/245172 cell line is partially cross‐resistant to L‐PAM, this resistance being accounted for by higher GSH intracellular levels, which however do not influence the resistance to FCE 24517. In fact, BSO treatment was capable of significantly modifying only the cytotoxicity of L‐PAM. Our data suggest that L1210/245172 cells present a mechanism of resistance specific for FCE 24517 and related molecules.
Multidrug‐resistant human kb carcinoma cells are highly resistant to the protein phosphatase inhibitors okadaic acid and calyculin A. Analysis of potential mechanisms involved in toxin resistance
Authors: Chambers Timothy C. , Raynor Robert L. , Kuo J. F.
Published: February 2007

In this study we show that multidrug‐resistant (MDR) human KB‐VI cells are highly resistant to the cytotoxicity of okadaic acid and calyculin A, 2 toxins from marine sponges that are potent inhibitors of type‐I and type‐2A protein phosphatases (PP1 and PP2A). Cytotoxicity and colony‐forming assays indicated that, relative to parental drug‐sensitive KB‐3 cells, KB‐VI cells are 35‐fold more resistant to okadaic acid and 70‐fold more resistant to calyculin A. Cytotoxicity of the toxins was associated with mitotic arrest characterized by chromosome scattering and over‐condensation, with KB‐3 cells being more sensitive than KB‐VI cells and calyculin A being more potent than okadaic acid. The resistance of KB‐VI cells to both okadaic acid and calyculin A was completely reversed by verapamil, suggesting that the toxins may be transported by P‐glycoprotein (P‐gp). To further assess the possibility of an interaction with P‐gp, the toxins were employed as potential modulators of the photoaffinity labeling of P‐gp by [3H]azidopine. Relative to vinblastine, which effectively competed with [3H]azidopine for P‐gp photolabeling, calyculin A was 100‐fold less potent and okadaic acid did not inhibit photolabeling at concentrations up to 50 μM. To determine whether the resistance mechanism involved differences in toxin‐sensitive phosphatase activity, the activity was assayed in extracts from both cell lines and found to be slightly higher (1.6‐fold) in KB‐VI than in KB‐3 cells. Our results demonstrate a novel, marked resistance of MDR KB‐VI cells to these phosphatase inhibitors and suggest that a major mechanism of resistance may involve toxin transport by P‐gp at sites apparently different from those which bind azidopine.
De Novo expression of intercellular adhesion molecule 1(ICAM‐1, CD54) in pancreas cancer
Authors: Schwaeble Wilhelm , Kerlin Mariola , Meyerzum Büschenfelde Karl‐Hermann , Dippold Wolfgang
Published: February 2007

We examined the expression of intercellular—adhesion molecule‐I (ICAM‐I, CD54) in 6 surgically removed pancreatic tumors and 8 pancreatic tumor cell lines. Immunohistochemistry revealed a varying percentage of ICAM‐I‐positive pancreas tumor cells, while normal pancreatic tissue (except for slight reactivity of endothelial cells) was not stained. The presence of the ICAM‐I molecule on the cell surface and the expression of ICAM‐I mRNA were investigated for 8 different pancreatic tumor cell lines. Three of these (Capan‐I, Capan‐2, QGP‐I) expressed ICAM‐I constitutively. In 4 of the ICAM‐I‐negative pancreas cancer cell lines, it was possible to induce a remarkable expression of ICAM‐I by incubating the cells in the presence of inflammatory cytokines, whereas one cell line, 818‐4, remained ICAM‐I‐negative. The responsiveness to either IFN‐γ, TNF‐α, or IL‐Iβ treatment was shown to vary from cell line to cell line, indicating complex mechanisms that regulate the expression of ICAM‐I at both, the transcriptional and the post‐transcriptional level. Interestingly, ICAM‐I is shed by pancreatic tumor cells, since soluble SICAM‐I was detected in the cell‐culture supernatants. In comparison with normal sera, the mean level of sICAM‐I in sera of patients with pancreas carcinoma is elevated 2‐fold.
Molecular and serological studies of human papillomavirus among patients with anal epidermoid carcinoma
Authors: Heino P. , Goldman S. , Lagerstedt U. , Dillner J.
Published: February 2007

Certain types of human papillomavirus (HPV) are associated with anogenital carcinomas, including carcinomas of the anal canal. Whereas several serological studies have found an association between papillomavirus antibody responses and cervical carcinoma, the antibody response against papillomavirus antigens among patients with anal carcinoma has not been investigated. The present study has examined the antibody responses to a panel of papillomavirus‐derived antigens and compared the serological profile with the histology and HPV carrier state of the tumor, as well as with the stage and prognosis of the disease. Sera from 64 patients with anal cancer and from 79 healthy blood donors were studied in ELISA for the presence of IgA and IgG antibodies to 5 previously described HPV16‐derived synthetic peptide antigens. Serum IgA antibodies to a peptide antigen derived from the E2 region of HPV16 were found in 89% of patients with anal cancer as compared to 24% of controls (p = 0.0001). The IgA reactivity to the 4 other antigens showed only low and non‐significant increases in mean titer. Serum IgG responses were similar among patients and controls. Among patients who had progressive disease, 21/21 were seropositive for IgA anti‐E2 at diagnosis, as compared to 36/43 patients who were in remission after a mean follow‐up of 41 months (p = 0.05). Forty‐seven cases of anal carcinoma were also studied for the presence of HPV by in situ hybridization using a probe mix of 7 anogenital HPV types. Sixteen patients (35%) carried HPV in their anal cancer and one patient had an HPV‐positive benign lesion adjacent to the tumor. Patients with HPV‐carrying anal cancer were significantly younger than those with HPV‐negative anal cancers (mean age: 57 and 68 years, respectively, p = 0.03). No differences in seroreactivity or HPV carrier state were seen depending on the stage or histological type of the tumor.
Concordant p53 and DCC alterations and allelic losses on chromosomes 13q and 14q associated with liver metastases of colorectal carcinoma
Authors: Ookawa Keizou , Sakamoto Michiie , Hirohashi Setsuo , Yoshida Yutaka , Sugimura Takashi , Terada Masaaki , Yokota Jun
Published: February 2007

To identify genetic alterations associated with acquisition of metastatic ability in colorectal carcinoma, 31 liver metastases and 40 primary tumors of colorectal carcinoma from 55 patients were analyzed for loss of chromosomal heterozygosity using 46 polymorphic DNA markers covering 15 chromosomes. Loss of heterozygosity (LOH) and/or rearrangement at the TP53 and DCC loci were detected in all liver metastases (10 of 10 at TP53 and 19 of 19 at DCC), and were observed in 59% (10 of 17) at TP53 and 75% (18 of 24) at DCC respectively in the primary tumors. Furthermore, the incidence of LOH on chromosomes 13q and 14q was higher than that on other chromosomes in liver metastasis, and it was higher in liver metastases than in primary tumors (20/30 vs. 18/39, p = 0.072 on chromosome 13q and 21/31 vs. 16/40, p = 0.018 on chromosome 14q). In 4 cases, LOH or rearrangement at loci on chromosomes I3q. 14q and 18q not detected in primary tumors was observed in liver metastases from the same patients. These results suggest that concordant p53 and DCC alterations and inactivation of several other tumor‐suppressor genes, especially those on chromosomes 13q and 14q, play important roles in the acquisition of metastatic potential of colorectal carcinoma.
Isolation and characterization of an oestrogen‐responsive breast‐cancer cell line, eff‐3
Authors: Healicon R. M. , Westley B. R. , May F. E. B.
Published: February 2007

A novel oestrogen‐responsive breast‐tumour cell line, EFF‐3, has been established from a pleural exudate of a patient with metastatic breast cancer. The cells show morphological and immunohistochemical features consistent with their origin from a metastatic breast carcinoma. The cells aggregate and form sheets in culture, and electron microscopy confirms the presence of cell‐surface microvilli and intercellular tight junctions. The epithelial origin of EFF‐3 cells was confirmed by their expression of low‐molecular‐weight cytokeratins and carcinoembryonic antigen. The karyotype of the cells is markedly abnormal and there are large numbers of structurally abnormal chromosomes. EFF‐3 cells express oestrogen receptor, oestrogen‐receptor mRNA, their growth is oestrogen‐responsive, and specific genes are regulated by oestrogens. The pNR‐2/p52 and pNR‐25 oestrogen‐regulated mRNAs are induced 15‐ and 13‐ fold respectively by oestrogen, whereas the oestrogen‐receptor and cathepsin D mRNAs are not regulated. This pattern of regulation differs from that reported previously for other cell lines. The EFF‐3 cell line should be useful for studying the mechanisms involved in oestrogen‐stimulated proliferation and the factors determining the regulation of specific genes by oestrogens.
Structure‐activity relationships of four anti‐cancer alkylphosphocholine derivatives In Vitro and In Vivo
Authors: Sobottka Stephan B. , Berger Martin R. , Eibl Hansjörg
Published: February 2007

This study was carried out to investigate whether structureactivity relationships of alkylphosphocholines, a new group of anti‐neoplastic agents, which had been detected in methylnitrosourea(MNU)‐induced rat mammary carcinoma, can be transferred to in vitro systems. Therefore, the anti‐neoplastic activity of 4 alkylphosphocholines (APCs) was compared in 6 tumor cell lines in vitro and in MNU‐induced rat mammary carcinoma in vivo. The in vitro system consisted of 2 rat mammary‐carcinoma‐derived cell lines (I/C2 and I/C32), as well as 2 human mammary‐gland (MDA‐MB‐231 and MCF‐7)‐and gastrointestinal tract (HT‐29 and KB)‐derived tumor cell lines. As assessed by both cell counting and MTT‐assay, the ranking of concentrations effecting 50% growth inhibition (IC50) was parallel in all cell lines for octadecylphosphocholine (18:0‐PC), octadecenyl‐(trans‐9.IO)‐phosphocholine (t‐ 18:1‐PC) and octadecenyl‐(cis‐9.10)‐phosphocholine (c‐ 18:1‐PC). Only hexa‐decylphosphocholine (16:0‐PC) differed in its activity, being least active in I/C2, I/C32 and MDA‐MB‐231 cells, moderately active in KB and MCF‐7 cells, and most active in HT‐29 cells. The IC50 concentrations of APCs in the 2 rat mammary carcinoma cell lines significantly correlated with dosages effecting a 50% tumor growth delay in vivo. Remarkably, the 2 gastrointestinal cell lines were more sensitive to APC exposure than the mammary‐carcinoma cell lines. In all cell lines except KB cells, growth‐stimulation effects were seen in the concentration range preceding the anti‐proliferative activity; in vivo, however, no accelerated cancer growth was observed. The in vitro system failed to describe the superior therapeutic ratio of c‐18:1‐PC, as assessed in vivo, because it does not take the relative sensitivity of tumor vs. normal cells into account. Complementary in vivo trials are therefore indispensable for a final evaluation. Comparison of the 2 in vitro assays shows good agreement of the interrelationship of IC50 values, those obtained by MTT assay being on average 25% higher than those obtained from cell counting.
Combination effect of vaccination with IL2 and IL4 cdna transfected cells on the induction of a therapeutic immune response against lewis lung carcinoma cells
Authors: Ohe Yuichiro , Podack Eckhard R. , Olsen Kristin J. , Miyahara Yuki , Ohira Tatsuo , Miura Kaoru , Nishio Kazuto , Saijo Nagahiro
Published: February 2007

In order to develop a more effective method of immunotherapy we have transfected mouse interleukin‐2 (IL2) or mouse interleukin‐4 (IL4) cDNA into a spontaneous non‐immunogenic murine lung cancer, Lewis lung carcinoma (LLC). IL2 cDNA transfection more strongly decreases tumorigenicity of LLC than IL4 cDNA transfection. Recombinant‐human‐IL2 treatment of mice that were transplanted with untransfected LLC could not prolong their survival. In contrast, vaccination with IL2‐cDNA‐transfected LLC (LLC‐IL2) and LLC‐ILZ mixed with IL4‐cDNA‐transfected LLC (LLC‐114) could significantly suppress tumor growth of LLC in a tumor‐specific manner. The vaccination with LLC‐IL2 mixed with the same number of LLC‐IL4 cells was more suppressive to the growth of LLC than that with LLC‐ILZ cells alone, while LLC‐IL4 vaccination alone was ineffective. Nude, severe‐combined‐immune‐deficient (SCID) and beige mice were unable to reject LLC‐IL2 cells. However, immunodeficient mice responded to LLC‐IL2, but not to LLC, since their survival times after transplantation with LLC‐IL2 cells were significantly longer than the survival time of normal or immunodeficient mice transplanted with untransfected LLC cells. We conclude that vaccination with IL2‐producing tumors and, with more pronounced effect, in combination with IL4‐producing tumors, is able to induce an immune response to this normally non‐immunogenic tumor. Tumor rejection appears to be achieved by the combined activity of CTL and NK cells. This strategy has potential for new immunotherapeutic interventions in cancer patients.
Down‐regulation of riα subunit of camp‐dependent protein kinase induces growth inhibition of human mammary epithelial cells transformed by c‐ha‐ras and c‐erbb‐2 proto‐oncogenes
Authors: Ciardiello Fortunato , Pepe Stefano , Bianco Caterina , Baldassarre Gustavo , Ruggiero Angela , Bianco Cataldo , Selvam Mouna P. , Raffaele Bianco A. , Tortora Giampaolo
Published: February 2007

MCF‐ 10A is a spontaneously immortalized, non‐transformed human mammary epithelial cell line. We have recently obtained MCF‐ 10A clones (MCF‐ 1OA HE cells) that are transformed following over‐expression of both a human point‐mutated c‐Ha‐ras and the c‐erbB‐2 proto‐oncogenes. Two isoforms of the cAMP‐dependent protein kinase (cAK) have been described in mammalian cells. Enhanced levels of type‐I cAK (cAKI) are generally found in tumor cells. To determine whether inhibition of cAKl expression may interfere with ras and erbB‐2 oncogene‐induced transformation of human mammary epithelial cells, we have tested the effects of 2 agents that specifically down‐regulate cAKI, such as 8‐chloro‐cAMP and an anti‐sense oligodeoxynucleotide targeted against the R1α regulatory subunit of cAKl on MCF‐10A HE cells. Treatment of MCF‐10A HE cells with 8‐chloro‐cAMP induces a dose‐dependent growth inhibition under both monolayer and soft‐agar growth conditions, that is correlated with an accumulation of MCF‐10A HE cells in G0/G, phases of the cell cycle and a reduction of the number of cells in S phase. In contrast, 8‐chloro‐cAMP has no effect on MCF‐10A cell growth. Furthermore, 8‐chloro‐cAMP treatment of MCF‐10A HE cells induces a 4‐ to 6‐fold reduction in p185erbB‐2 expression and brings p21 ras expression to levels comparable to those found in MCF‐10A cells. Treatment of MCF‐10A HE cells with an Rlα anti‐sense oligodeoxynucleotide determines a comparable inhibition of both anchorage‐dependent and anchorage‐independent cell growth. Our results suggest that cAKl may act as a mediator of ras and erbB‐2 oncogene action in human breast cells and that interference with cAKl action provides a potential tool for inhibiting the growth‐promoting effects of these oncogenes.
The role of the urokinase receptor in extracellular matrix degradation by ht29 human colon carcinoma cells
Authors: Reiter Lars S. , Kruithof Egbert K. O. , Cajot Jean‐Francois , Sordat Bernard
Published: February 2007

Urokinase (u‐PA) and the urokinase receptor (u‐PAR), are thought to play a critical role in the invasive and metastatic properties of cancer cells. The HT29 human colon‐carcinoma cell line was selected to evaluate these aspects. HT29 cells express u‐PA receptors (100,000 site/cell, KD = 1.5 nM), but no PA activity and therefore are unable to generate plasmin in the presence of plasminogen. These cells have been transfected with a human u‐PA cDNA to investigate whether secreted U‐PA would enhance in vitro extracellular matrix degradation, and whether the binding of u‐PA to the cell surface is determinant. Five clones were selected for stable expression of high PA activity. These clones were capable of marked plasminogen‐dependent degradation of R22 smooth‐muscle‐cell‐derived extracellular matrix, whereas the parental cell line contributed to an insignificant breakdown only. Aprotinin, polyclonal anti‐u‐PA IgG, recombinant PAI‐2, and co‐culture with human PAI‐I ‐ producing mouse L cells significantly inhibited this degradation. Furthermore, a peptide displacing u‐PA from its receptor as well as 2 different polyclonal anti‐u‐PA receptor lgGs decreased the breakdown after 24 hr by as much as 70% and 81%, respectively. These results show that the binding of U‐PA to its receptor plays an important role in in vitro matrix breakdown by HT29 u‐PA transfectants.
Distinct P‐glycoprotein expression in two subclones simultaneously selected from a human colon carcinoma cell line by cis‐diamminedichloroplatinum (II)
Authors: Yang Li‐Ying , Trujillo Jose M. , Siciliano Michael J. , Kido Yuichiro , Siddik Zahid H. , Su Yong‐Zhuang
Published: February 2007

Two drug‐resistant sublines, CP2.0 and RT, were simultaneously selected by cis‐diamminedichloroplatinum (CDDP) from the human colon carcinoma cell line LoVo by the conventional method of continuous drug exposure. The 2 sublines differed in morphology, growth kinetics and pattern of gene expression. Genetic signature analysis indicated that the lines were independent subclones but that both arose from LoVo. These sublines were maintained in a growth medium containing 2.0 μg/ml CDDP. However, CP2.0 cells were 3 times more resistant to CDDP than were RT cells. Although both were cross‐resistant to mustargen and 5‐fluorouracil, only CP2.0 was resistant to Adriamycin and vincristine. Western‐blot analysis, immunocytochemical staining and in vitro phosphorylation experiments indicated that the level of P‐glycoprotein was significantly elevated in CP2.0 but not in RT. Despite the differences between these sublines, they possess similar CDDP‐resistance mechanisms, including decreased intracellular CDDP accumulation, elevated levels of glutathione and metallothionein‐like proteins, increased glutathione transferase‐μ mRNA, and enhanced susceptibility to CDDP cytotoxicity after treatment with DL‐buthionine‐[S,R]‐sulfoximine. Nevertheless, our results suggest that, in certain tumor types, P‐glycoproteinmediated multi‐drug resistance and CDDP‐resistance phenotypes can coexist in cells with primary resistance to CDDP.
Cytokeratins expressed in experimental rat bronchial carcinomas
Authors: Kal H. B. , Van Berkel A. H. , Broers J. L. V. , Klein J. C. , Mijnheere E. P. , Roholl P. J. M. , Zurcher C. , Ramaekers F. C. S.
Published: February 2007

Cytokeratin expression in rat lung tumors was studied using polypeptide‐specific monoclonal antibodies (MAbs) to human cytokeratins 4, 5, 7, 8, 10, 13, 14, 18 and 19. Experiments were performed on tumor fragments derived from 5 experimental rat squamous‐cell lung tumors and one adenocarcinoma, as well as on cell lines obtained from the same tumors. The aims of this study were to investigate the differentiation profile of the rat tumor tissue and established tumor cell lines based on light and electron microscopical features and on cytokeratin phenotype, to characterize the tumor type and degree of differentiation of the lung tumors maintained during passaging in experimental animals, and to compare the cytokeratin expression pattern in transplanted tumors with that of the cultures derived from these tumors. Our results indicate that, in general, the antibodies used cross‐react with rat cytokeratins and that these MAbs can be used to phenotype rat lung carcinomas. Both the tumor fragments and the cultured cells revealed a similar pattern of cytokeratin expression. In addition, the degree of differentiation was maintained upon prolonged culturing in vitro. MAbs to cytokeratin sub‐types can therefore be used to distinguish the main sub‐types of rat lung tumors and can give an indication about the degree of differentiation.
Expression of functional PDGF β receptors in a human large‐cell lung‐carcinoma cell line
Authors: Forsberg K. , Berch J. , Westermark B.
Published: February 2007

In this study we have investigated a panel of lung‐cancer cell lines, both of small‐cell carcinoma and non‐small‐cell type, for the expression of receptors for platelet‐derived growth factor. Although we found mRNA expression for the β‐type receptor on one small‐cell and one non‐small‐cell line and α‐type receptor mRNA expression on one small‐cell‐cancer cell line, only the β receptors of the non‐small‐cell line (H‐157) proved to be functional. Thus, the cell line H‐157 displayed specific binding of 125I‐PDGF‐BB in addition to mRNA expression of the 6‐kb transcript for the PDGF β type receptor. Further evidence for the presence of functional PDGF β receptors in H‐157 cells was obtained from an in vitro kinase assay, which demonstrated a ligand‐induced receptor autophosphorylation as well as the phosphorylation of a number of potential substrates associated with the activated receptor.
Dietary carcinogens and the risk for glioma and meningioma in Germany
Authors: Boeing Heiner , Schlehofer Brigitte , Blettner Maria , Wahrendorf Jürgen
Published: February 2007

A population‐based case‐control study was performed in South‐West Germany in 1987/88 with 115 histological confirmed glioma and 81 meningioma cases and 418 randomly selected controls. On the basis of information from a foodfrequency questionnaire and questions on food preparation and food supply, the role of dietary carcinogens, in particular N‐nitroso compounds or their precursors, on risk for glioma and meningioma were analyzed by multiple logistic regression. Eleven food groups were investigated. The intake of processed meat was significantly associated with an increased risk of glioma. The intake of any food group was not significantly related to meningioma risk. Among single meat products, a significantly higher risk of glioma was found for cooked ham, processed pork meat and fried bacon. For the consumption of 3 N‐nitrosamines, assessed from the intake of processed meat and cheese, significant positive relations to glioma risk were found. These N‐nitrosamines were also related to meningioma risk, although to a less pronounced extent. The risk for occurrence of glioma was significantly increased for those using vegetable fat frequently for deep frying, as compared with non‐users. For the dietary intake of nitrate, nitrite, vitamin C, specific alcoholic beverages, total alcohol, and water from a non‐central supply, no elevated risk was found in this study.
Ganglioside expression on human malignant melanoma assessed by quantitative immune thin‐layer chromatography
Authors: Hamilton Wm. Bradley , Helling Friedhelm , Lloyd Kenneth O. , Livingston Philip O.
Published: February 2007

The ganglioside composition of 20 human malignant melanomas and 5 normal tissues (muscle, spleen, kidney, liver and brain) was analyzed by high‐performance thin‐layer chromatography (HPTLC) and immune HPTLC using a panel of antiganglioside monoclonal antibodies, and quantified by photoden‐sitometry. The most prominent gangliosides were GM3 and GD3, present in all 20 melanomas; however these were expressed in the 5 normal tissues as well. GD2, GM2, GT3 and 9‐O‐Ac‐GD3 were each expressed in at least 17 of 20 melanomas, but distribution on the normal tissues examined was largely restricted to brain. The detection of several additional glycolipids was studied. GMI was highly expressed in normal brain tissue, but was not detected in any melanoma biopsies, and SGPG was detected in neither. Fuc‐GM I was identified in melanoma specimens and a base‐sensitive ganglioside, not previously identified in melanoma, was detected in 4 of 20 melanomas with the anti‐GD2 MAb 3F8. This compound is most likely O‐acetylated GD2. GD3 lactones were identified in 16 of 20 melanoma biopsies, however the proportion that are naturally occurring rather than artifacts of extraction is unclear. The total expression of the more restricted gangliosides (GM2, GD2, GT3 and 9‐O‐Ac‐GD3) in these 20 melanomas ranged between 2.4 and 102.5 μg/g representing 8 × 106 to 3 × 108 ganglioside molecules per cell. This number of tumor‐surface antigens provides the rationale for a polyvalent anti‐melanoma vaccine containing GM2, GD2, GT3 and 9‐O‐Ac‐GD3.
Reduced occurrence of mdr‐1 amplification in stage‐IV breast‐cancer patients treated with tamoxifen compared with other endocrine treatments
Authors: Lönn Ulf , Lönn Sigrid , Stenkvist Björn
Published: February 2007

Amplification of mdr‐1 occurs in breast cancer patients receiving endocrine treatment. We have compared a group of patients receiving tamoxifen and a group receiving second‐line endocrine treatment after failure of tamoxifen treatment. Chronological tumor samples were obtained by fine‐needle biopsies from the same tumor lesion of each patient and PCR was used to detect the appearance of gene amplification. Three of 20 patients receiving tamoxifen developed amplified mdr‐1 whereas 7 of 17 patients receiving second‐line endocrine treatment developed mdr‐1 amplification.
Cigarette smoking, alcohol, tea and coffee consumption and pancreas cancer risk: A case‐control study from opole, Poland
Authors: Zatonski W. A. , Boyle P. , Przewozniak K. , Maisonneuve P. , Drosik K. , Walker A. M.
Published: February 2007

A population‐based, case‐control study of pancreas cancer was undertaken in Opole, Poland, within the framework of the SEARCH Programme of the International Agency for Research on Cancer: this is the first aetiological study of pancreas cancer reported from Poland where the reported mortality rate has doubled since 1963. This study of pancreas cancer has provided some further supporting evidence of an association between increased pancreas risk with increasing levels of cigarette smoking. The risk rose with increasing lifetime cigarette consumption with a trend which was weakly significant (p=0.061). Findings regarding lifetime tea and coffee consumption were not consistent with intake of either beverage increasing the risk of this disease. There was a strongly significant trend of decreasing risk with increasing lifetime consumption of tea (p<0.001), which was also apparent when the analysis was restricted to subjects who were interviewed directly. For coffee consumption, which is low in Poland, there was also a negative association apparent in the data which was not statistically significant among the sub‐set of subjects who were directly interviewed. The findings regarding alcoholic beverages were overall null, although the weakly positive trend in risk with spirits consumption (p=0.71) may deserve further investigation in view of the special nature of the source of spirits (vodka) in Poland.
Establishment and characterization of 7 ovarian carcinoma cell lines and one granulosa tumor cell line: Growth features and cytogenetics
Authors: van den Berg‐Bakker Cornelia A. M. , Hagemeijer Anne , Franken‐Postma Elsa M. , Smit Vincent T. H. B. M. , Kuppen Peter J. K. , Claasen Hedda H. Van Ravenswaay , Cornelisse Cees J. , Schrier Peter I.
Published: February 2007

The characteristics of 7 newly established ovarian carcinoma cell lines and one granulosa tumor cell line obtained from tumor samples of 7 patients with varying histology of the primary tumor are reported. The cell lines were isolated from 5 serous carcinomas, a mucinous carcinoma, an endometrioid carcinoma and a granulosa cell tumor. All cell lines were passaged at least 25 times and showed stable growth rates. Colony‐forming efficiency varied on plastic from 2 to 57% and in agar from 0.01 to 9.30%. The DNA index of the granulosa tumor cell line was diploid, while the ovarian carcinoma cell lines were all aneuploid. In 2 cell lines polyploidisation occurred during culturing. A thorough cytogenetic analysis of 7 cell lines revealed that the granulosa tumor cell line has only minor cytogenetic abnormalities (+5, 22q+). In contrast, the epithelial ovarian‐cancer cell lines gave very complex karyotypes with numerous markers and structurally rearranged chromosomes. The chromosomes most often in excess were 15 and 20. Structural rearrangements of chromosomes 1, 3, 7 and 11 were prominent in all ovarian cell lines. In addition, we found changes in chromosomes X, 5, 8 and 13 that have rarely been described before.
Inhibition of N‐linked oligosaccharide processing in tumor cells is associated with enhanced tissue inhibitor of metalloproteinases (TIMP) gene expression
Authors: Korczak Bozena , Dennis James W.
Published: February 2007

Previous studies on tumor‐cell glycosylation mutants and drugs which inhibit oligosaccharide processing suggest that expression of sialylated and highly branched complex‐type N‐linked oligosaccharides is required for efficient tumor‐cell metastasis. These observations prompted the present investigation, in order to determine whether loss of sialylated and highly branched complex‐type oligosaccharide in cellular glycoproteins might affect the expression of genes, particularly of genes which can influence the malignant phenotypes. Swainsonine, an inhibitor of Golgi α‐mannosidase II, has previously been shown to inhibit invasion in vitro and reduces solid tumor in vivo. Metastatic sub‐lines of the SPI murine mammary carcinoma cells cultured in the presence of swainsonine for 48 hr showed approximately 3‐fold enhancement of TIMP mRNA levels, while urokinase (uPA) transcripts remained unchanged. To determine whether swainsonine's effect on TIMP mRNA levels was related to inhibition of oligosaccharide processing, we examined somatic glycosylation mutants with processing defects which attenuate metastatic potential. The Golgi UDP‐Gal transport defect in murine MDAY‐D2 lymphoma cells, Chinese hamster ovary cells (CHO) and human MeWo melanoma cells (i.e., D35W25, Lec8, 355 cell lines, respectively) was associated with increased TIMP mRNA levels. A revertant of Lec8 showed a return to the wild‐type levels of TIMP mRNA, consistent with a causal relationship between the glycosylation mutation and TIMP gene expression. Similarly, CHO and MDAY‐D2 mutants defective in GlcNAc‐TV (i.e., Lec4 and KBL‐I respectively), which also reduces metastatic potential, showed increases in TIMP transcript levels. Nuclear run‐on assays showed that transcription of the TIMP gene was increased in cells where N‐linked oligosaccharide processing was inhibited either by swainsonine or by a glycosylation mutation. The results suggest that cell‐specific patterns of glycoprotein glycosylation in human, murine and hamster cell lines affects the transcription of select genes, including TIMP, which may influence the invasive phenotype.
Gp51 of bovine leukemia virus gene expression in hamster cells
Authors: Slávikova Katarína , Zajac Vladimir , Klobuǐká Margita , Aida Yoko , Tevurková Viola
Published: February 2007

Recombinant pMMEx‐bovine leukemia virus env gene DNA fragments were produced and expressed in eukaryotic cells. Clone C4, containing an Smal‐Smal fragment of the gene coding for gp51, was co‐transfected with pSVZneo DNA into Chinese hamster cells. About 800 geneticin‐resistant cell clones were isolated and then morphologically and biologically characterized. The presence of gp51 encoding env gene fragments was detected in 17 of them by Southern blotting. The expression of gp51 gene in hamster cells was confirmed by Western blotting of their lysates with monoclonal antibodies (MAbs) directed against different epitopes of gp51 of bovine leukemia virus. The immunoreactivity of the expressed peptides with MAbs directed against neutralizing epitopes of gp51 of bovine leukemia virus was confirmed.
Anti‐tumor activity of ceramides and glycosphingolipids in a murine tumor system
Authors: Maru Morimasa , Haraguchi Muneo , Higashi Hideyoshi , Kato Shiro , Kurimura Takashi , Naiki Masaharu , Wakamiya Nobutaka
Published: February 2007

The anti‐tumor activity of 7 sphingolipids, 2 ceramides and 5 glycosphingolipids against the syngeneic murine ascitic tumors MH 134 and MM 102 in C3H mice was examined. Five of these compounds showed anti‐tumor activity against the tumors, ceramide type‐IV (Cer‐lv) having the highest activity without cytotoxic or cytostatic activity. These results indicate that the fatty acid in ceramide and sugar chains binding to it affect the anti‐tumor activity in vivo. The anti‐tumor activity of Cer‐IV depended on the time of treatment. Mice treated with Cer‐IV one day after tumor implantation showed the highest rate of survival. The cured mice were resistant to rechallenge with the same tumor (MH 134 → MH134, MM102 → MM102) but not with a heterologous tumor (MH 134 → X5563, MM102 → X5563), indicating that the effect of Cer‐IV may be due to in vivo induction of specific immunity. Studies with various antibodies demonstrated that the anti‐tumor effect of Cer‐IV was inhibited by all the antibodies tested (L3T4, Lyt‐2, and Thy‐1.2 T cells, macrophages, and TNFα) in the induction phase (before Cer‐IV administration) and by the antibodies of L3T4 and TNFα in the effector phase (after Cer‐IV administration). Therefore, the anti‐tumor effect of Cer‐IV in this system depended on the host immune response rather than on its direct cytotoxic and/or cytostatic action.
In vivo and in vitro reactivity of rat spleen cells against regressor and progressor colon‐cancer cell variants
Authors: Reisser Danièle , Olsson Nils‐Olivier , Martin François
Published: February 2007

Previous reports demonstrated that progressor and regressor tumor‐cell variants isolated from the same colon carcinoma chemically induced in a BD‐IX rat differed in their capacity to induce an immune response. The present study was aimed at analyzing the characteristics of the responses to the regressor REGb and progressor PROb clones. Spleen cells from rats bearing early REGb tumors neutralized PROb cell tumorigenicity in a Winn‐type local transfer assay, but responded occasionally to REGb and PROb cells in vitro. However, spleen cells from rats immunized by several injections of REGb and PROb cells strongly proliferated when cultured with PROb or REGb cells. This response was selective for the cell lines generated from the individual tumor at the origin of PROb and REGb lines, was dependent on CD4+ spleen cells, and was partially inhibited by an antibody against major histocompatibility complex class‐II molecules. Although PROb cells shared tumor‐rejection antigen(s) with REGb cells, splenocytes from PROb tumor‐bearing rats did not neutralize PROb‐cell tumorigenicity in vivo, nor did they proliferate when cultured with PROb or REGb cells in vitro. The unresponsiveness of spleen cells from PROb tumor‐bearing rats was not due to the presence of immune suppressive cells, and a defect of antigen‐presenting cells was shown to be unlikely. This unresponsiveness was limited to a lymphocyte subpopulation, since spleen cells from tumor‐bearing rats responded normally to stimulation by PHA or allogeneic lymphocytes. These results strongly suggest that unresponsiveness of spleen cells from tumor‐bearing rats is due to a tumor‐specific anergy of the lymphocyte clones able to respond to tumorassociated antigens.
Binding activities of cis‐platin‐damage‐recognition proteins in human tumour cell lines
Authors: McLaughlin Karen , Coren Grant , Masters John , Brown Robert
Published: February 2007

Proteins can be detected by South‐western analyses of human tumour‐cell extracts binding to double‐stranded oligonucleotide DNA treated in vitro with the chemotherapeutic drug cis‐diamminedichloroplatinum (11) (CDDP), but not to untreated DNA. The relative molecular masses of proteins binding to the CDDP‐treated double‐stranded oligonucleotide are 25, 48 and 97 kDa. The binding activity of 2 of the CDDP‐damage‐recognition proteins, of relative molecular mass 48 and 97 kDa, is greater in a CDDP‐resistant human ovarian tumour cell line than in the parental sensitive line. South‐western analysis of panel of human bladder cell lines and CDDP‐sensitive testicular cell lines show consistent patterns of CDDP‐damage‐recognition proteins within each cell type, however with differences between the 2 cell types. Binding of the proteins to CDDP‐damaged DNA and the altered binding activity detected in tumour cell lines suggests that alteration in damage‐recognition proteins could play a role in tumour response to CDDP.