bluuebunny/crossref_metadata_2025 huggingface dataset:
Diet, body mass and colorectal cancer: A case‐referent study in Stockholm
Authors: De Verdier Maria Gerhardsson , Hagman Ulla , Steineck Gunnar , Rieger ÅKe , Norell Staffan E.
Published: February 2007

A population‐based case‐referent study on diet (total energy, protein, fat, dietary fiber), body mass and colorectal cancer was performed in Stockholm in 1986–1988. The study included 1,081 subjects. The relative risks (RR, with a 95% confidence interval, highest versus lowest quintile) for colon cancer were as follows: total energy (1.7, 1. 0–3.0), protein (2.4, 1.5–4.0), total fat (2.2, 1.3–3.6), dietary fiber for men (0.5, 0.2–1.1), dietary fiber for women (1.2, 0.7–2.3) and body mass (2.0, 1.3–3.1). The relative risks for rectal cancer were: total energy (2.4, 1.2–4.7), protein (3.6, 2.0–6.4), total fat (2.5, 1.4 4.6), dietary fiber (0.5, 0.3–0.9), body mass for men (1.7, 0.7–4.0), and body mass for women (1.0, 0.5–1.9). Adjustment for physical activity, body mass (in the diet analysis), the abovementioned dietary factors (in the body mass analysis), and browned meat surface had little or no influence on the results.
Detection of colonic growth factors using a human colonic carcinoma cell line (LIM 1215)
Authors: Whitehead R. H. , Nice E. C. , Lloyd C. J. , James R. , Burgess A. W.
Published: February 2007

Although the colonic mucosa is one of the most rapidly proliferating epithelial tissues in the body, little is known about the factors that direct this proliferation. In this report we have studied the parameters of both a mitogenic and a clonogenic assay for detecting potential colonic growth factors (CGF). Using a colon carcinoma cell line (LIM 1215), which has retained a number of the properties of normal colonic mucosa, we have assayed a range of mitogenic factors for CGF activity. 3H‐thymidine incorporation by the LIM 1215 cell line was stimulated by low concentrations of epidermal growth factor and basic fibroblast growth factor and, to a lesser extent, by higher concentrations of interleukin‐I and insulin‐like growth factor I. The cells did not respond to a range of other mitogens and lymphokines. Optimal clonogenic response in a soft‐agar assay was obtained using a primary pituitary extract.
Epidermal growth factor receptors and EGF‐responsiveness of the human breast‐carcinoma cell line PMC42
Authors: Monaghan Paul , Ormerod Michael G. , O'hare Michael J.
Published: February 2007

PMC42 is an early‐passage, well‐differentiated, pleiomorphic human breast‐cancer cell line. It expresses an average of 2.4 × 105 EGF receptor (EGFR) sites per cell when cultures are assayed using a radioreceptor assay. This is a relatively high figure for breast‐carcinoma cell lines. Its responses to epidermal growth factor (EGF) were analyzed morphologically and by flow cytometry and immunocytochemistry. PMC42 responded in vitro to EGF with morphological changes, inhibition of “doming” and an increase in DNA synthesis in serum‐containing medium in confluent or near confluent cultures. When EGF receptor sites were localized immunocytochemically in PMC42, they were found to be variably expressed on the membrane of cells grown in the absence of EGF, with discrete areas of strong and weak cells of different morphological appearances; flow cytometry indicated a 10‐fold range in EGFR levels between individual cells. Cultures maintained in the presence of EGF were less heterogeneous in their morphology and had a predominantly cytoplasmic, relatively uniform localization of EGFR with downregulation of membrane EGFR levels. EGF‐stimulated cultures were stained simultaneously for the presence of EGFR and the proliferation‐related antigen Ki‐67 and analyzed by both flow cytometry and immunocytochemistry. No correlation was observed between Ki‐67 positivity and level of EGFR expression by individual cells. Electron microscopic localization of receptor sites demonstrated that the receptors were concentrated predominantly on the lateral and basal membranes. These results show that the PMC42 line reflects a number of the properties of heterogeneous breast tumours in situ. It may also continue to express growth‐factor receptors in a manner that reflects their topographical distribution on normal luminal breast epithelial cells.
Biliary‐tract cancer in Chile
Authors: Serra Ivan , Calvo Alfonso , Maturana Mauricio , Sharp Allan
Published: February 2007

This epidemiological study in Chile shows a marked increase in biliary‐tract cancer based on mortality data, from an age‐adjusted rate (1970 world population) of 5.1 per 100,000 in 1970 to 12.0 per 100,000 in 1988. There is an increased risk of this cancer in all age groups but especially in young adults (15‐44 years). The female ratio of 3:1 persists. The increase in biliary‐tract cancer in 1970‐1985 was particularly important for young women but occurred in all female age groups whereas in men it was mostly in the elderly (65 years and more) and less in the middle‐aged (45‐64 years); no changes were observed in young men. Regional differences have begun to be appreciated. One of the factors which may account for this impressive and unexpected increase is the remarkable decrease in cholecystectomy rates. Less than 20% of the 154% increase in biliary‐tract cancer mortality in the period 1970‐1985 could be attributed to population aging. Improvements in diagnostic methods did not appear to be an important contributing factor. Other factors that could affect this increase in the incidence to epidemic levels include: an increase in the prevalence of cholelithiasis, an increase in the number of typhoid carriers and possible environmental carcinogens.
Reproductive factors and breast cancer risk in Iceland. A second cohort study
Authors: Tulinius Hrafn , Sigvaldason Helgi , Hrafnkelsson Jón , Ólafsdóttir Guðriður , Tryggvadóttir Laufey , Sigurðsson Kristján
Published: February 2007

In a previous prospective study we showed elevated risks for breast cancer in nulliparous women compared to parous women, in those having their first pregnancy at a higher age, and those with few children. This was based on 216 women diagnosed with breast cancer during 1965 to 1975 among 34,525 women having attended the cervix cancer detection clinic in Iceland by the end of 1974, and born between 1906 and 1945. The present investigation on 848 cases, diagnosed among 6 1,040 women attending the cervix cancer detection clinic during 1964 to 1984 and born between 1901 and 1960, shows the same risk factors to be significant. The relative risks are, however, smaller. The reasons for the difference in relative risks are discussed, We find that the effect of age at first birth is significant for women up to the age of 65 and not for older women. In both cohorts, women older than 55 are underrepresented and more so in the earlier report. In addition, the small number of cases in the reference group with age at first birth below 20 appears to have made the figures of our earlier report unreliable.
Monoclonal antibody against a tumor‐associated sialoglycoprotein of superficial papillary bladder tumors and cervical condylomas
Authors: Fradet Yves , Larue Hélène , Parent‐Vaugeois Carmen , Bergeron Alain , Dufour Colette , Boucher Lucie , Bernier Léonard
Published: February 2007

A mouse IgG1 monoclonal antibody (MAb), 19A211, defining a tumor‐associated cell‐surface antigen of superficial papillary bladder tumors, was generated by immunizing with fresh bladder tumor cells mice neonatally injected with normal human urothelial cells. The reactivity of the antibody with cell lines was examined by indirect immunofluorescence staining and was restricted to 3/14 bladder cancer lines and 3/31 cancer cell lines of non‐bladder origin, including HeLa cervical cancer. No normal fibroblast, kidney cells, EBV‐lymphocytes, erythrocytes or leukocytes expressed the antigen. Reactivity of MAb 19A211 was well preserved on tissue paraffin sections. Immunoperoxidase staining of normal adult or fetal tissues showed no reactivity except for a patchy or uniform staining of umbrella cells in 6/23 adult and 1/4 fetal urothelium samples. Positive and often heterogeneous staining was observed on 24/38 papillary superficial tumors (Ta) and 4/5 carcinoma in situ bladder lesions but on only 4/20 infiltrating tumors. It was also observed on 5/6 cervical condylomas and one bladder condyloma, but none of 6 penile or vulvar condylomas. All other tumors tested were negative. The antigenic determinant is present on a heterogeneous group of proteins with molecular weights ranging from 90 to 200 kDa. It is sensitive to periodate treatment and to neuraminidase but only partially sensitive to proteases. MAb 19A211 is different from other reported MAbs with similar reactivity to superficial bladder tumors and umbrella cells of normal urothelium. When tested in competition assays, several of these MAbs, but not 19A211, were found to react with Lewis X blood group determinant. Our results suggest that 19A211 may be useful for detection and stratification of bladder tumors.
Expression of intercellular adhesion molecule‐1 (ICAM‐1) on renal‐cell cancer: Possible significance in host immune responses
Authors: Tomita Yoshihiko , Nishiyama Tsutomu , Watanabe Hisami , Fujiwara Michio , Sato Shotaro
Published: February 2007

In this study we examined the expression of intercellular adhesion molecule‐1 (ICAM‐I) in 28 cases of renal‐cell cancer (RCC). We also examined ICAM‐I expression on RCC cell lines in response to cytokines. Immunohistochemistry revealed frequent expression (23 positive cases among the 28 RCCs) of ICAM‐I in RCC. The molecule was not detected on renal tubular cells as far as could be determined. Furthermore, the number of ICAM‐I‐positive cells in RCC was significantly correlated with the degree of mononuclear cell infiltration, involving mainly T lymphocytes and a smaller number of macrophages bearing the LFA‐I molecule. Expression of ICAM‐I on RCC cell lines was augmented by in vitro treatment with interferon (IFN)‐γ, tumor necrosis factor (TNF)‐α and interleukin‐I (IL‐I)β. These results suggest that the expression of ICAM‐I on RCC might be modified by cytokines produced by tumor‐infiltrating mononuclear cells, and that ICAM‐I expression on RCC might augment the host immune reaction.
Loss of MHC class‐I expression in cervical carcinomas
Authors: Connor Mary E. , Stern Peter L.
Published: February 2007

The expression of MHC class‐I antigens was analysed in 67 cervical carcinoma biopsies; 16% of the biopsies showed complete or heterogeneous loss of HLA expression as judged by reactivity with antibodies recognizing monomorphic determi nants of the class‐I heavy chain bound to β2 microglobulin (β2m). In addition, other biopsies showed a loss in expression of particular allelic products: 23% for HLA‐A2; 17% for HLA‐A3; 23% for HLA‐Bw4 and 19% for HLA‐Bw6. Three biopsies showed changes at 2 alleles, 2 of which were at both HLA‐A and ‐B loci. Down‐regulation of class‐I expression may be virally mediated and HPV DNA is frequently found in cervical carcinomas. However, there appeared to be no direct correlation between the detection of HPV 16 or 18 DNA in these tumours and changes in HLA expression. There was also no correlation with the expression of the oncofoetal antigen 5T4. Our results show that a significant proportion (at least 30%) of the cervical carcinomas showed some alteration in MHC class‐I expression. Such changes may allow tumours to evade immune surveillance with more rapid progression. There was, however, no correlation with tumour type, degree of differentiation or stage of disease at presentation.
Participation of CD11a‐c/CD18, CD2 and ROD‐binding receptors in endogenous and interleukin‐2‐stimulated NK activity of CDS‐negative large granular lymphocytes
Authors: Timonen Tuomo , Gahmberg Carl G. , Patarroyo Manuel
Published: February 2007

The effect of RGD‐sequence‐containing pentapeptides and monoclonal antibodies (MAbs) against the adhesion molecules CD) la‐c/CDIB, ICAM‐1 (CD54) and CD2 on the binding and cytotoxicity of endogenous (freshly purified) and IL‐2‐stimulated CD3‐negative NK cells has been studied. Antibody to CD 18 exerted the most significant inhibition of adhesion and cytotoxicity of endogenous NK cells to MOLT‐4 lymphoma cells, followed by antibodies to CD2 and CD54. Antibodies to either CD 11 a, CD 11 b or CD 11c did not inhibit adhesion when used separately, whereas as a mixture their inhibitory capacity was as strong as that of anti‐CD 18. Antibodies against CD 18, CD54 and CD2 exerted an additive effect on the inhibition of adhesion. Their combination eradicated the binding of endogenous NK cells. The RGD‐containing peptide did not inhibit the binding or cytotoxicity of freshly purified NK cells to MOLT‐4, whereas some inhibition was detected against the adenocarcinoma cell line COLO‐205. According to FACS analysis, IL‐2 increases the expression of CD2 and CD54 on NK cells. However, the relative contribution of the adhesion molecules to the NK cell binding did not change as a result of the stimulation with IL‐2. The RGD‐peptide substantially in hibited the binding of IL‐2‐stimulated killer cells to COLO, and the combination of this peptide with MAbs to CD 18, CD54 and CD2 practically blocked the adhesion. Our results indicate that both CD 11a‐c/CD18‐ (involving the 3 heterodimers) and CD2‐dependent adhesion pathways are used by LGL in endogenous and IL‐2 stimulated natural killing. In addition, RGD‐binding receptors are involved in adhesion to some target cells.
Potentiation of tnf‐mediated cell killing by VP‐16: Relationship to DNA single‐strand break formation
Authors: Branellec Didier , Markovits Judith , Chouaib Salem
Published: February 2007

Interaction between tumor necrosis factor (TNF) and the DNA topoisomerase II inhibitor, etoposide VP‐16, in cell killing has been studied. To accurately investigate the nature of DNA damage during the cell killing process, experiments were assessed using the highly TNF‐sensitive WEH1164.13 murine fibrosarcoma clone and DNA filter elution methodology. Concomitant treatment of cells with combination of TNF/VP‐16 resulted in marked enhancement of cell lysis. Using the alkaline elution technique, we show that TNF fails to induce DNA single‐strand breaks as compared to those generated by VP‐16. In addition, the potentiating effect of VP‐16 on TNF‐mediated WEH1164.13 cell killing was not associated with an increase in its intrinsic activity with respect to DNA single‐strand break formation. While the 2 phospholipase A2 inhibitors, quinacrine and dexamethasone, were efficient in inhibiting TNF‐mediated cell lysis, only quinacrine was efficient in selectively abrogating the TNF/VP‐16 cell killing pathway. The inhibitory effect of quinacrine on VP‐16/TNF‐mediated cell lysis was accompanied by a marked decrease in VP‐16‐mediated DNA single‐strand break generation. Taken together, our findings suggest that TNF and TNF/VP‐16 treatments may involve different events during cell killing and support the hypothesis that 2 signals are required for optimal induction of cell lysis by the combination of VP‐16/TNF: one signal provided by VP‐16 resulting in topoisomerase II inhibition and subsequent DNA single‐strand break generation, and a second signal involving TNF.
Effect of retinoic acid on tumor‐mediated immunologic alterations in mice bearing a variant of the ß16 melanoma
Authors: Jiang Cheng Gan , Taylor Douglas D. , Black Paul H.
Published: February 2007

This investigation examined the effect of retinoic acid on tumor progression and immunological status of mice bearing the B16‐F10 melanoma (previously selected for high lungcolonizing capacity). Tumor cells were implanted s. c. in syngeneic C57BL/6 mice, half of which were treated with β‐all trans retinoic acid (RA). Although RA failed to exhibit direct toxicity on this variant at the concentration used, the immunologic aberrations induced by the tumors were diminished by i. p. RA administration (at45μ twice/week for 3 weeks). In mice bearing B16‐F10 tumors, tumor burdens were decreased from 2.9% of body weight to 1.6%. The mitogenic responses of splenic lymphocytes to concanavalin A (ConA) were increased in tumor‐bearing mice following this RA treatment. The presence of these tumor cells decreased the absolute number of CD4‐ and CD8‐positive splenic lymphocytes. Following RA treatment, the CD8‐positive population was increased in tumor‐bearing mice, while the CD+ population was not significantly altered. Since previous studies indicated that plasma membrane fragments (or vesicles) could alter lymphocyte distributions and proliferative capacities, the in vitro shedding of membrane fragments from B16‐F10 tumor cells was assayed and observed to be decreased after continuous treatment of cultures with 10−6M RA for 21 days. Membrane shedding from B16‐F10 cells was inhibited by 48.5% following RA treatment. Based on these in vivo and in vitro results, we suggest that RA treatment may diminish tumor growth by decreasing tumor‐induced immunosuppressive events.
Eradication of a disseminated mouse lymphoma by 1,3‐BIS(2‐chloroethyl)‐1‐nitrosourea is immunologically mediated and accompanied by de novo generation of anti‐tumor cytotoxicity
Authors: Sensi Marialuisa , Bergomi Marzia , Formelli Franca , Parmiani Giorgio
Published: February 2007

The anti‐tumor effect of 1, 3‐bis(2‐chloroethyl)‐I‐nitrosourea (BCNU) was examined in BALB/c mice bearing increasing burdens of a syngeneic lymphoma (YCB). A single i. p. injection of the drug resulted in over 75% of cures when given at day 3, 5, 7 or 10 after an i. v. inoculum of 104 YCB cells. The efficacy of BCNU on mice bearing large tumor burdens (from day 5 on) was not only due to its tumoricidal activity, but was immunologically mediated. Residual tumorigenic cells could be recovered in the livers of 5‐day tumor bearers (TB) up to 2 weeks after BCNU treatment and only a low percentage of cures could be achieved when BCNU was administered to nude mice. In addition, BCNU‐cured mice specifically rejected a lethal YC8 challenge and their splenocytes developed anti‐tumor cytotoxicity in response to in vitro stimulation with YC8 cells. During kinetic experiments a 2‐week period elapsed after BCNU injection before an anti‐tumor cytotoxic T‐lymphocyte (CTL) response could be generated by spleen cells of BCNU‐treated 5‐day TB. This period was characterized by immunosuppression as evaluated from impairment in the generation of lymphokine‐activated killer (LAK) cells or of allospecific primary CTL responses by spleen cells from BCNU‐treated 5‐day TB and BCNU‐treated normal mice. LAK cells first recovered and could be generated 7 days later, whereas primary allospecific CTL responses could only be detected by day 14. concomitantly with the generation of antitumor cytotoxicity by 5‐day TB. The development of secondary in vitro CTL responses, however, was permanently abrogated. Spleen cells from BALB/c mice immunized either with YC8 or with DBA/2 minor histocompatibility antigens and treated with BCNU I week after the last immunization failed to mount an in vitro CTL response to their immunizing antigen, even when the cultures were supplemented with recombinant interleukin‐2.
Degradation of alpha‐melanocyte stimulating hormone (alpha‐MSH) by CALLA/endopeptidase 24. 11 expressed by human melanoma cells in culture
Authors: Deschodt‐Lanckman Monique , Vanneste Yves , Loir Béatrice , Michel Alain , Libert Anita , Ghanem Ghanem , Lejeune Ferdinand
Published: February 2007

The common acute lymphoblastic leukemia antigen (CALLA) is identical to human endopeptidase 24.11 (E‐24.11) and is expressed on certain human melanoma lines. This work was conducted in order to investigate whether alphamelanocyte‐stimulating hormone (alpha‐MSH) could be a substrate for E‐24.11, its degradation leading to the negative alpha‐MSH radiobinding assay results observed with some CALLA‐positive cell lines. We used 3 human melanoma cell lines (GLL‐19, Mel Juso and G361) which lack receptors to alpha‐MSH and express CALLA, and, as a control, one CALLA‐negative melanoma cell line (HBL) with specific receptors for alpha‐MSH. Radioimmunoassays give evidence that alpha‐MSH was degraded in the presence of the 4 melanoma cell lines and that disappearance of the peptide was significantly reduced by phosphoramldon in 2 lines (GLL‐19 and G361). Upon incubation of alpha‐MSH with GLL‐19 and G361 cell membranes, 3 degradation products were completely abolished in the presence of phosphoramidon. Amino acid content analysis of alpha‐MSH fragments produced by purified E‐24.11 permitted identification of 6 peptide bonds in the sequence of alpha‐MSH susceptible to cleavage by the enzyme. It is concluded that alpha‐MSH is a substrate in vitro for purified E‐24.11 and for the enzyme present on the human melanoma cell lines GLL‐19 and G361, expressing a high level of endopeptidase activity. However, hydrolysis of alpha‐MSH by this enzyme does not seem to represent the main factor responsible for the apparent absence of receptors for the hormone on some cell lines.
Nutrition and cancer of the oral cavity and pharynx in north‐east italy
Authors: Franceschi Silvia , Bidoli Ettore , Barón Anna E. , Barra Salvatore , Talamini Renato , Serraino Diego , La Vecchia Carlo
Published: February 2007

The relation between dietary indicators and the risk of cancer of the oral cavity and pharynx was investigated in a case‐control study conducted in Pordenone province, north‐east Italy, on 302 cases (266 males and 36 females) and 699 controls admitted to hospital for acute, non‐neoplastic and non‐digestive disorders. Positive associations were observed, after allowing for occupation, smoking and drinking habits, with more frequent consumption of pasta or rice, polenta, cheese, eggs and pulses (odds ratios ‐ Ors = 1.6, 2.1, 1.9, 1.9 and 2.0 for highest vs. lowest tertile), whereas reduced ORs emerged in subjects reporting more frequent consumption of carrots, fresh tomatoes and green peppers (ORs = 0.6, 0.5 and 0.5, respectively). Higher frequency of daily meals was also associated with a significantly elevated OR (1.7 for ≥ 4 vs. ≤ 2 meals). The role of various indicator foods must be assessed in the context of the very high levels of alcohol consumption in the study area (≥ 8 alcoholic drinks/day in 2/3 cancer cases).
Prognostic importance of cellular dna content in head‐and‐neck squamous‐cell cancers. A comparison of retrospective and prospective series
Authors: Kearsley John H. , Bryson Greg , Battistutta Diana , Collins Russell J.
Published: February 2007

Flow cytometric DNA‐ploidy measurements were performed on formalin‐fixed tumour specimens from 172 patients with squamous‐cell cancers (SCCs) of the head and neck region. One hundred and two samples were chosen retrospectively and a further 70 consecutive patients were analysed prospectively in order to assess the prognostic significance of DNA ploidy and DNA index (D1). There were no statistically significant differences between retrospective and prospective groups in regard to age, sex, TNM stage, ploidy or D1. Sixty‐seven percent of patients were aneuploid (65% retrospective; 71% prospective). The proportion of aneuploid tumours was significantly higher among poorly differentiated tumours. Survival analysis using Cox multivariate regression modelling revealed that DNA aneuploidy and increasing D1 were significant independent prognostic factors for both relapse‐free and overall survival. The relapse and death rates among aneuploid subjects were approximately 3 times as high as those for diploid subjects. Patients with a D1 >2.11 (hyper‐tetraploidy) experienced a 6.6‐fold higher death rate than diploid subjects. These results provide strong support for the incorporation of DNA ploidy profiles into the clinical management of patients with head and neck cancer.
Kaposi's sarcoma and non‐hodgkin's lymphoma in european aids cases. no excess risk of kaposi's sarcoma in mediterranean countries
Authors: Casabona Jordi , Melbye Mads , Biggar Robert J.
Published: February 2007

Prior to the AIDS epidemic, Kaposi's sarcoma (non‐AIDS‐KS) in Europe was mainly a disease of elderly Mediterranean men. In 1989 AIDS data from 15 European countries were collected to study proportional trends in AIDS‐related Kaposi's sarcoma (AIDS‐KS) in order to determine whether specific factors in Southern Europe might be important in the development of KS among AIDS patients. Another AIDS‐related cancer, non‐Hodgkin's lymphoma (NHL) was included as a malignancy control. Of 22,367 AIDS cases reported, 3,779 (16.9%) were KS and 741 (3.3%) were NHL. A significant, continuous fall in the percentage of AIDS‐KS was seen for both homosexual men and other members of exposure groups during the period 1981‐89 (p‐trend <0.000l). The proportion with AIDS‐KS decreased from 40.5% in 1983 to 26.5% in 1988 in homosexual men and from 12.2 to 3.6% in other exposure groups, respectively. No significant change was observed in the proportion of NHL cases among any of the risk groups over time, although a tendency towards a slight increase was noted for homosexual men. Comparing proportional trends of KS and NHL geographically, no significant difference was found overall, by time or by exposure group. In conclusion, a specific decline is observed over time for AIDS‐KS. However, if geographically‐restricted factors are important in the development of non‐AIDS‐KS in Europe, the same factors do not appear to affect the risk of AIDS‐KS.
Enhancement by sulpiride of the inhibitory effects of cysteamine on gastric carcinogenesis induced by n‐methyl‐n'‐nitro‐n‐nitrosoguanidine in wistar rats
Authors: Tatsuta Masaharu , Iishi Hiroyasu , Baba Miyako , Nakaizumi Akihiko , Uehara Hiroyuki , Taniguchi Haruo
Published: February 2007

The effects of sulpiride on cysteamine inhibition of gastric carcinogenesis induced by N‐methyl‐N′‐nitro‐N‐nitroso‐guanidine (MNNG) and on the BUdR labelling index of gastric mucosa were investigated in inbred Wistar rats. After 25 weeks of oral treatment with MNNG, rats received one of the following alternate‐day injections: cysteamine (2 doses), cysteamine (2 doses) plus sulpiride or sulpiride. At week 52, prolonged administration of cysteamine significantly reduced the incidence of adenocarcinomas of the glandular stomach. Cysteamine at low dose had no effect on the incidence of gastric cancers, but a combination of low‐dose cysteamine and sulpiride caused a significantly greater reduction in the incidence of gastric cancers. Administration of sulpiride alone had no influence on gastric carcinogenesis. The labelling index of the antral mucosa was significantly lower in rats treated with high but not low doses of cysteamine. However, a combination of low‐dose cysteamine and sulpiride significantly decreased the labelling index of the antral mucosa. Our findings indicate that cysteamine suppressed gastric carcinogenesis and that sulpiride enhanced this inhibition. Because sulpiride is a dopamine antagonist, these findings also indicate that dopamine may play an important role in cysteamine inhibition of gastric carcinogenesis.
Role of activated c‐H‐ras Oncogene in the induction and progression of immortal liver epithelial cell lines derived from normal C3H mice
Authors: Lee Gang‐Hong , Sakai Ryuichi , Nagao Minako , Kitagawa Tomoyuki
Published: February 2007

The nature of 15 immortal mouse liver epithelial cell (MLEC) lines established from normal C3H mice was investigated specifically in terms of ras oncogene activation. Neither transforming activity nor point mutation within codon 61 of c‐H‐ras could be demonstrated in any of the cell lines by DNA transfection in a NIH/3T3 cell system or by the direct sequencing method after polymerase chain reaction, respectively. Acrylamide gel migration analysis of ras p2l products did not show any shift from the normal. Transplantation experiments demonstrated only 2 out of the 15 lines to be tu‐morigenic in nude mice. When 4 of the non‐tumorigenic MLEC lines were transfected with cloned activated c‐H‐ras containing a point mutation within codon 61, they all became tumorigenic, the resultant neoplasms being hepatocellular carcinomas often associated with albumin mRNA expression. Our results thus indicate that ras activation is not necessary for immortalization or even for transformation of mouse liver cells in culture, and that ras activation may be an event during the progression process in mouse hepatocarcinogene‐sis in vivo.
Heterotransplantation of human breast carcinomas in nude mice. Correlation between successful heterotransplants, poor prognosis and amplification of the her‐2/neu oncogene
Authors: Giovanella Beppino C. , Vardeman Dana M. , Williams Leo J. , Taylor D. Jane , De Ipolyi Peter D. , Greeff Pierre J. , Stehlin John S. , Ullrich Axel , Cailleau Relda , Slamon Dennis J. , Gary Howard E.
Published: February 2007

Four hundred and thirty‐three human breast carcinomas and 23 cell lines derived from human breast carcinomas were heterotransplanted in nude mice. Twenty‐eight tumors and 13 cell lines took and could be serially transplanted. Their human origin was established by isozyme analysis performed on successive passages. Sixteen primary infiltrating duct‐cell carcinomas (PIDC) took, from a total of 262 transplanted (6.1%). This is in striking contrast to the >50% rate of takes of most major cancers of epithelial origin. All 16 PIDC growing in nude mice were highly cellular and lacked desmoplastic hyperplasia. The clinical prognosis of the PIDC patients whose tumors were successfully transplanted was poor. Ten of 16 (63%) died of their disease within 3 years, compared to only 49 (20%) of the 246 PIDC patients whose tumors did not take in nude mice. This could not be attributed to later stage disease of the tumors that took, because only 15% of these patients had 4 or more positive axillary lymph nodes as opposed to 28% of the patients whose tumors did not take. Sixty‐four percent of the breast carcinomas growing in nude mice exhibited amplification of the HER‐2/neu oncogene which is also correlated with poor prognosis in human breast cancer. It is possible that the nude mouse is more susceptible to a population of highly invasive and lethal breast carcinomas.
Human ovarian cancer xenografts in nude mice: Characterization and analysis of antigen expression
Authors: Molthoff Carla F. M. , Calame Johannes J. , Pinedo Herbert M. , Boven Epie
Published: February 2007

We have characterized 13 different human ovarian cancer xenografts grown subcutaneously in nude mice. The tumor lines represented 5 histological subtypes: serous (4), mucinous (4), clear‐cell carcinoma (1), carcinosarcoma (1) and undifferentiated (3). The specific histology and the degree of differentiation resembled those of the original patients' tumors and were maintained upon serial transfer. Volume doubling times of the xenografts ranged from 3.5 to 15 days. The xenografts were also analyzed for their antigen expression using 20 monoclonal antibodies (MAbs) reactive with 15 tumor‐associated antigens. Immunohistochemical examination of tissue sections showed a positive reaction pattern with MAbs 115D8, 140C1, 139H2, 175C5, HMFG1 and HMFG2, each recognizing episialin, as well as with MAbs AUA1, 358.4.32 and 199‐157 in xenografts of the serous, mucinous and clear‐cell carcinoma subtype. MAb OC125 was reactive with xenografts of the serous subtypes. Other antibodies, such as 494 and OV‐TL3 infrequently demonstrated positive reactions. Reactivity of all MAbs was low in the carcinosarcoma and undifferentiated tumor lines. With the exception of AUA1, 495 and I26E5, all MAbs revealed a heterogeneous staining pattern. MAbs against episialin and OC125 predominantly stained the apical site of the tumor cells. Strongest reactivity with almost all histological subtypes was observed with MAbs 115D8, 140C1, 139H2 and AUA1. In cases where we were able to compare the patients' tumor tissue with the respective xenografts, retention of antigen expression was demonstrated in each instance. Release of tumor‐associated antigens was shown for CA125 in 2 serous‐tumor lines, for CA15.3 in I serous‐tumor line, and for CEA in 3 lines of the mucinous subtype. This panel of human tumor xenografts could be a valuable tool to determine the potential usefulness of MAb‐guided therapy in ovarian cancer.
Counteraction of estradiol‐induced activation of tissue‐type plasminogen activator in a human breast cancer cell line by an anti‐estrogen, LY117018
Authors: Uchiumi T. , Mizoguchi H. , Hagino Y. , Kohno K. , Kuwano M.
Published: February 2007

LY117018 is a non‐steroid anti‐estrogen which exhibits about 100 times higher affinity for estrogen receptor than tamoxifen, another anti‐estrogen. The cell line ES‐1, which was isolated from human breast cancer MCF‐7 cells, was highly sensitive to the cytocidal action of estradiol. Growth of ES‐I cells was inhibited by 10−8M 17 β‐estradiol, a concentration that stimulated the growth of parental MCF‐7 cells. The estradiol‐induced growth inhibition of ES‐1 cells was almost completely reversed by treatment with LY 117018, but not by treatment with tamoxifen. The relative binding affinity of LYI17018 for estradiol receptor was equal to that of estradiol in both MCF‐7 and ES‐1 cells. Treatment of ES‐1 cells with estradiol specifically induced tissue‐type plasminogen activator (t‐PA), whereas such estradiol‐induced activation was not observed in parental MCF‐7 cells. Quantitative immunoreac‐tive assays and Northern blot analysis showed that estradiol‐induced expression of t‐PA was blocked by LYI 17018 in ES‐1 cells. The inhibitory effect of tamoxifen was about 100 times lower than that of LYI 17018. The inhibition of t‐PA gene expression by LYI 17018 might be due to competitive inhibition with estradiol in estradiol receptor binding.
Regressing nude mouse grafts of burkitt's lymphoma×lymphoblastoid cell hybrids show deregulation of the c‐myc gene and expression of the EBV latent membrane protein
Authors: Wolf Jürgen , Klevenz Britta , Pawlita Michael , Komitowski Dimitrij , Moldenhauer Gerd , Hausen Harald Zur
Published: February 2007

Somatic cell hybrids between the malignant Burkitt lymphoma cell line BL 60 and the non‐malignant Epstein‐Barr virus (EBV) immortalized lymphoblastoid cell line (LCL) IARC 277 demonstrate the deregulated c‐myc transcription pattern of the parental BL cell line during exponential growth in tissue culture. Subcutaneous nude mouse grafts of these hybrids, however, completely regress after an initial growth phase. To investigate whether regression of these grafts is mediated by a down‐regulation of the BL‐60‐derived deregulated c‐myc gene in vivo, c‐myc transcription was analyzed in growing versus regressing hybrid grafts. In the initial growth phase as well as during regression, these grafts showed the deregulated c‐myc expression pattern of the parental BL cell line with highly abundant c‐myc transcripts originating from the BL specific translocation chromosome 8q+. Our results question the significance of c‐myc deregulation for an unlimited in vivo growth potential of B‐lymphoblastoid cells. To further characterize the hybrids, surface expression of B‐cell‐specific antigens was analyzed on the hybrids and shown to correspond to that of the parental LCL. In addition, transcription of the gene encoding for the EBV latent membrane protein (LMP) as well as histological features were analyzed in growing versus regressing hybrid grafts. The LMP gene, which is down‐regulated in the tumors produced by the parental BL cells, was expressed in the hybrid grafts as well as in the parental LCL grafts. This finding might be compatible with a host response of the nude mouse against LMP. The histological analysis, however, which revealed massive necrosis in the center of the regressing grafts without pronounced inflammatory infiltrates, rather points to a hypoxemic process leading to graft regression.
Receptor‐mediated endocytosis and recycling of alpha‐fetoprotein in human B‐lymphoma and T‐leukemia cells
Authors: Torres Juan M. , Geuskens Maurice , Uriel Jose
Published: February 2007

The kinetics of iodinated human alpha‐fetoprotein (AFP) binding and uptake by 2 human neoplastic lymphoid cell lines (CEM and RAJI) have been studied. Three saturation plateaus were obtained by incubating CEM and RAJI cells at 4°C with 125I‐AFP at different concentrations. Scatchard analysis suggested the presence of 3 types of receptor site with different affinities and capacities on cells of both lines. AFP binding was inhibited by unlabelled human and bovine AFP, and to a lesser extent by human serum albumin (SAH); no significant competition was observed with human transferrin (Tf) or ovalbumin (Ova). Pulse‐chase experiments showed that 125I‐AFP was released practically undegraded from the cells. Covalent conjugates of AFP and Tf with horseradish peroxidase (HRP) were used to follow the endocytosis and intracellular pathway of these serum proteins by electron microscopy. Both proteins were observed in coated vesicles, endosomes and a tubular vesicular network localized in the Golgi‐centrosphere region. SAH‐HRP was internalized to a much lesser extent. Ova‐HRP was poorly internalized and was observed in lysosome‐like organelles.
Dominance of metastatically competent cells in primary murine breast neoplasms is necessary for distant metastatic spread
Authors: Theodorescu D. , Cornil I. , Sheehan C. , Man S. , Kerbel R. S.
Published: February 2007

We have previously shown, using tumor cell populations genetically tagged by random integrations of plasmid DNA, that metastatically‐competent clonal cell variants have a strong growth advantage within primary tumors over their non‐metastatic counterparts. As a result, primary tumors can become overgrown by the progeny of such cells, a process referred to as “clonal dominance” of primary tumors by metastatically‐competent cells. Because of the well‐known “metastatic inefficiency” of the multi‐step cascade process of spread and growth, clonal dominance within primary tumors may be necessary for distant metastatic spread or increase the probability of its occurrence. To examine this hypothesis mice were inoculated s.c. with mixtures of non‐metastatic and genetically tagged, metastatically‐competent mouse mammary carcinoma cells in defined ratios, but always containing an excess of the unmarked non‐metastatic population. Progressive overgrowth of the metastatic subpopulation was monitored as a function of time by Southern analysis of DNA obtained from mixed primary tumors. This allowed us to evaluate the effects that surgical removal of the primary tumor had before, during and after effective clonal dominance, and what influence this had on the subsequent formation of distant metastases. Surgical removal of primary tumors before metastatic clonal dominance resulted in a low (0‐25%) frequency of lung metastases, whereas removal just 1 or 2 weeks later during or after clonal dominance was achieved resulted in a high (75‐100%) frequency of such metastases. Our results support the hypothesis that dominance of primary tumors by metastatically competent cells may be necessary for distant metastatic spread, and also suggest that clonal interactions play a significant role in modulating the metastatic ability of tumor cells in vivo.
Protein kinase C activation by anthracyclines in swiss 3T3 cells
Authors: Lanzi Cinzia , Gambetta Romolo Achille , Perego Paola , Banfi Patrizia , Franzi Aimarita , Guazzoni Lorena , Zunino Franco
Published: February 2007

The effects of the anti‐cancer anthracyclines doxorubicin and daunorubicin on the activity of protein kinase C (PKC) were examined in intact Swiss 3T3 cells. The 2 drugs stimulated the phosphorylation of an 80K phosphoprotein found to be identical to that generated in response to the PKC activator 12‐O‐tetradecanoylphorbol‐13‐acetate as indicated by gel electrophoresis and peptide mapping. The effect of doxorubicin was dose‐dependent in the range 10−5 to 10−3 M and was not associated with a detectable translocation of PKC activity from cytosol to the cell membrane. Doxorubicin and daunorubicin were found to increase the incorporation of phosphate into phosphatide acid, phosphatidylinositol 4‐monophosphate and phosphatidyl inositol 4,5‐bisphosphate. In addition, the anthracyclines induced a rise in inositol phosphates, thus indicating a stimulation of the breakdown of phosphoinositides. These data are consistent with an indirect mechanism of PKC activation by anthracyclines. We propose that diacylglycerol, which is derived from the hydrolysis of phospholipids, (including the phosphoinositides), by activation of phospholipases, could mediate PKC activation. The described effects, involving cell‐signal‐transducing pathways, emphasize a new aspect of the cellular actions of these anti‐tumor agents.
Anti‐tumor effects of recombinant human macrophage colony‐stimulating factor, alone or in combination with local irradiation, in mice inoculated with lewis lung carcinoma cells
Authors: Lu Li , Shen Rong‐Nian , Lin Zhong‐Hua , Aukerman Sharon L. , Ralph Peter , Broxmeyer Hal E.
Published: February 2007

Recombinant human (rhu) macrophage colony‐stimulating factor (M‐CSF) was evaluated for efficacy, either alone or in combination with local X‐irradiation (LR), in mice inoculated subcutaneously (s.c.) with Lewis lung carcinoma (LLC) cells. The size of the primary tumor and numbers of lung metastases, 21 days after tumor inoculation and 15 days after the start of treatment, were reduced by 87% in tumor‐bearing mice treated with 20 μg/dose M‐CSF s.c. twice a day for 5 days. LR (800 cGy) to the tumor once a week for 2 weeks had a moderate anti‐tumor effect and enhanced the anti‐tumor effect of M‐CSF. Hematological parameters, including nucleated cellularity in peripheral blood, femoral marrow, spleen and peritoneal exudate, as well as marrow and splenic granulocyte‐macrophage progenitor cells, and numbers of splenic Thy1.2+ cell and peritoneal mast cells, were perturbed in LLC‐bearing mice, and were influenced by treatment with M‐CSF and LR. Treatment with M‐CSF plus LR, but not with either agent alone, was associated with a significant, although slight, enhancement in survival time for LLC‐bearing mice. Inability to obtain a better survival‐enhancing effect appeared to be related to the limited treatment, since the anti‐tumor effects of M‐CSF were more notable early on in disease progression and were related to the dose of M‐CSF used. The effects of M‐CSF were most probably indirect ones on the host immune system. M‐CSF, in combination with LR, may be of benefit in the treatment of human tumors that have metastatic potential.
Normal tissue reactivity of four anti‐tumor monoclonal antibodies of clinical interest
Authors: Stein Rhona , Goldenberg David M. , Mattes M. Jules
Published: February 2007

Normal tissue reactivity on frozen sections was examined with 4 monoclonal antibodies (MAbs) that were reported previously to be negative or weakly reactive with normal tissues, and strongly reactive with some types of carcinoma. All 4 antibodies reacted strongly with certain normal epithelial cells. The antibodies tested include 2 antibodies to ovarian cancer, MOv18 and MOv19, one antibody to breast cancer, H23, and one antibody reactive with a range of carcinomas, B72.3. MOv18, MOv19 and H23 reacted with many normal glandular and ductal epithelial cells, while B72.3 reacted most strongly with secretions of the small intestine epithelium and the suprabasal squamous epithelial cells of the esophagus. Since the tissue distribution of MOv19 was very similar to that of another antibody described previously, MW207, these two antibodies were compared by competitive binding inhibition, and found to recognize the same epitope. Our data emphasize the importance of repeated, independent tests of antibody specificity.
Blood group and blood‐group‐related antigens in normal pancreas and pancreas cancer: Enhanced expression of precursor type 1, Tn and Sialyl‐Tn in pancreas cancer
Authors: Schuessler Martina H. , Pintado Susan , Welt Sidney , Real Francisco X. , Xu Mai , Melamed Myron R. , Lloyd Kenneth O. , Oettgen Herbert F.
Published: February 2007

Expression of blood‐group antigens A, B, Lea, sialyl‐Lea(sLea), Leb, Lex, Ley, precursor type 1, Tn and sialyl‐Tn (sTn) was examined in non‐neoplastic pancreas (n = 37) and pancreas cancer (n = 21) using mouse monoclonal antibodies (MAbs). Immunohistochemical assays were performed on sections of paraffin‐embedded tissues using the avidin‐biotin complex method. In normal pancreas, antibodies detecting Lea, sLeaand Tn reacted with ductal epithelium, and antibodies detecting A and B reacted with acini and ducts, independently of secretor status. Lexwas weakly expressed in ducts and acini, and sTn could not be detected in normal pancreas. Expression of Leb, Leyand precursor type 1 was regulated by secretor status: Leband Leywere expressed in ducts of secretor and Lea‐b−individuals, but not in ducts of non‐secretors; precursor type I was weakly expressed in acini and ducts of non‐secretors and Lea‐b−individuals, and was absent in acini and ducts of secretors. The following alterations in the expression of blood‐group antigens were observed in pancreas cancer: (1) enhanced expression of Lex, Tn and sTn; (2) enhanced expression of precursor type I independently of secretor status; (3) loss of regulation of Lebby the secretor gene; (4) decreased expression of Ley. The weak expression of precursor type 1, Tn and sTn in non‐neoplastic pancreas, and their stronger expression in pancreas cancer, suggests that up‐regulation of their expression is associated with malignant transformation of pancreatic duct cells.
Expression of epstein‐barr virus‐encoded growth‐transformation‐associated proteins in lymphoproliferations of bone‐marrow transplant recipients
Authors: Gratama Jan W. , Zutter Mary M. , Minarovits Janos , Oosterveer Maria A. P. , Donnall Thomas E. , Klein George , Ernberg Ingemar
Published: February 2007

The expression of Epstein‐Barr virus (EBV)‐encoded, growth‐transformation‐associated proteins was studied in lymphoproliferations of 9 allogeneic bone‐marrow transplant (BMT) recipients. Immunoblots of cell lysates were probed with polyspecific and monospecific antisera directed against EBNA I, 2, 3 and 6, and the membrane protein LMP. All tumors expressed EBNA I and LMP. EBNA 2 was detected in the tumors of 8 patients, and EBNA 3 and 6 in the tumors of 5 patients. The LMP regulatory sequences, 5′ of the LMP gene, were totally unmethylated in all 7 cases, while the coding sequences of LMP and EBNA 2 were more methylated in CpG dinucleotides. EBV‐transformed lymphoblastoid cell lines (LCL) express EBNA I to 6 and LMP; in contrast, Burkitt lymphomas express only EBNA I.In vitroexperiments have shown that EBNA 2, 3 and LMP can generate targets for cytotoxic T cells (CTL). These combined observations are consistent with the hypothesis that the EBV‐associated lym‐phoprod'ferative disease of the BMT recipients escapes CTL‐mediated rejection due to the failure of host immunosurveillance rather than to the down‐regulation of immunogenic EBV‐encoded antigens.