bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of some dietary chemopreventive agents on the expression of functional differentiation of the mouse mammary gland in vitro
Authors: Chakraborty Sarbani , Menon Ravi , Banerjee Mihir R.
Published: February 2007

The purpose of the present studies was to determine the influence of the chemopreventive agents selenium, 4‐(hydroxyphenyl)‐retinamide (4‐HPR) and β‐carotene, on functional differentiation (lactogenesis) of the mouse mammary gland cells. The hormone‐induced expression of the milk‐protein genes, β‐casein, ϵ‐casein and the whey acidic protein (WAP) was used as molecular marker of differentiation of the mammary cells in organ culture medium containing insulin, prolactin, aldosterone and hydrocortisone. Quantitative determination of the cellular concentration of the respective mRNA was ascertained by molecular hybridization of RNA to the specific cloned cDNA probes using both the solution and the filter hybridization methods. Selenium at 100 nm concentration caused a pronounced inhibition of accumulation of the respective mRNAs. The retinoid, 4‐HPR, also caused a dose‐dependent inhibition of expression of these mRNA sequences. In contrast, concentrations of the 3 mRNAs in β‐carotene‐treated glands remained similar to those observed in glands cultured in medium containing the hormones and hexane (the latter being the solvent for β‐carotene). The significant antagonistic action of selenium and 4‐HPR, however, was reversible after removal of the chemicals from the culture medium. Thus, among the 3 chemicals tested, selenium and retinoid can cause an adverse effect on functional differentiation (lactogenesis) of the mammary cells. This inhibitory effect, however, was reversible. β‐Carotene, on the other hand, caused no apparent antagonistic effect on expression of the milk‐protein genes in the isolated whole mammary organ in culture.
Tumor‐cell‐induced platelet aggregation is a glycoprotein‐dependent and lipoxygenase‐associated process
Authors: Bastida Eva , Almirall Lourdes , Ordinas Antonio
Published: February 2007

To characterize the platelet receptor sites and the platelet metabolic pathways involved in tumor‐cell‐induced platelet aggregation, we have used a homologous system consisting of human platelets and 2 tumor cell lines of human origin, which activate platelets through different mechanisms. Preincubation of platelets with an MAb against platelet glycoprotein Ib partially blocked tumor‐cell‐induced platelet aggregation, and preincubation of platelets with an MAb against the glycoprotein complex GPIIbIIIa, totally blocked the aggregation induced by the 2 tumor‐cell lines. No inhibitory effect was found when platelets were treated with PAF‐receptor antagonists or with specific peptides which block the platelet sites involved in bacterially induced platelet aggregation. Compounds which raised intra‐platelet cAMP levels inhibited tumor‐cell‐induced platelet aggregation in a dose‐related manner. Inhibition of cyclo‐oxygenase by aspirin which blocked TxB2 formation by platelets did not inhibit platelet aggregation induced by tumor cells whereas the BW755 compound which inhibits cyclo‐ and lipoxygenase blocked platelet aggregation. These results demonstrate that tumor‐cell‐induced platelet aggregation is a glycoprotein‐dependent and a lipoxygenase‐associated phenomenon.
Inhibition of mannose incorporation into glycoproteins and dolichol‐linked intermediates of sarcoma 180 cells by 6‐methylmercaptopurine ribonucleoside
Authors: Sokoloski John A. , Sartorelli Alan C.
Published: February 2007

6‐Methylmercaptopurine ribonucleoside (6‐MMPR), an inhibitor of purine nucleotide biosynthesis de novo, was used as a model compound to evaluate the relationship between the levels of intracellular guanosine triphosphate (GTP) and the formation of cellular glycoproteins and their dolichol‐oligosaccharide precursors in Sarcoma 180 cells. Previous studies using the purine antimetabolite, 6‐thioguanine (6‐TG), demonstrated a relationship between the drug‐induced decrease in GTP levels and the incorporation of radiolabelled mannose and fucose into cellular glycoproteins; estimation of the importance of these cell‐surface alterations to the cytotoxicity produced by this agent was complicated by the incorporation of 6‐TG nucleotides into cellular DNA and RNA. In this report, evidence is presented to show that the toxicity of 6‐MMPR to Sarcoma 180 cells is associated with the effects of this agent on the intracellular pools of purine nucleotides. GTP functions in part in the activation of the sugar mannose, a step necessary for the biosynthesis of glycoproteins from nucleotide sugar precursors. Thus, 6‐MMPR, which blocks the de novo pathway of purine nucleotide biosynthesis, caused a pronounced decrease in the intracellular pools of GTP in Sarcoma 180 cells; this phenomenon was accompanied by a marked reduction in the incorporation of radiolabelled mannose into cellular glycoproteins and their dolichol‐linked oligosaccharide precursors. In contrast, the incorporation of glucosamine, a sugar not metabolically activated by GTP, into glycoproteins, and of leucine into protein, were depressed only after prolonged incubation with either 6‐MMPR or 6‐TG. Adenine restored purine nucleotide pools depleted by 6‐MMPR and partially prevented both the reduction in mannose incorporation into glycoprotein and the cytotoxic effects of this antimetabolite. Guanosine partially reversed the effects of 6‐MMPR on intracellular GTP pools and mannose incorporation but not the depression of ATP pools produced by this antimetabolite. However, guanosine did not reverse the cytotoxicity of 6‐MMPR but instead enhanced its toxicity. The findings are consistent with the possibility of membrane changes being involved in the cytotoxicity of 6‐MMPR, but clearly other factors are involved as well.
Several murine metastasizing tumors possess a cysteine proteinase with cancer procoagulant characteristics
Authors: Falanga Anna , Dalessandro Anna Paola Bolognese , Casali Bruno , Roncaglioni Maria Carla , Donati Maria Benedetta
Published: February 2007

Cancer Procoagulant (CP), a cysteine proteinase which triggers blood coagulation by directly activating Factor X (FX) in the absence of Factor VII (F VII), has recently been isolated from rabbit V2 carcinoma and biochemically characterized. We have studied the procoagulant activity of tissue extracts from 4 murine experimental tumors in order to define whether or not a F VII‐independent activity with cysteine proteinase characteristics was present. The tumors studied were: Lewis lung carcinoma (3LL), B16 melanoma (B16), JW sarcoma (JWS) and the M4 variant of the mFS6 fibrosarcoma (M4). Extracts from 3LL, B16 and JWS tumor initiated coagulation in both the presence and absence of F VII, their procoagulant activity was sensitive to iodoacetamide (1 mm) and mercury chloride (0.1 mm). The procoagulant of M4 extract was dependent on the presence of F VII and was not significantly affected by the cysteine proteinase inhibitors. An Ouchterlony double immunodiffusion study showed immunological cross‐reactivity of all but M4 extracts to a polyclonal antibody to purified CP. The present study suggests that the procoagulant(s) present in the murine tumors 3LL, B16 and JWS are enzymatically and immunologically indistinguishable from cancer procoagulant of the rabbit V2 carcinoma.
c‐yes and bc1‐2 genes located on 18q21.3 in a follicular lymphoma cell line carrying a t(14;18) chromosomal translocation
Authors: Ohno Hitoshi , Fukuhara Shirou , Takahashi Rei , Mihara Koh‐Ichirou , Sugiyama Taketoshi , Doi Shoichi , Uchino Haruto , Toyoshima Kumao
Published: February 2007

The c‐yes‐1 and bc1‐2 genes have been independently mapped at the same position of the chromosome band, 18q21.3, which is a breakpoint in the t(14; 18) chromosomal translocation. High‐molecular‐weight genomic DNAs and mRNA isolated from a follicular lymphoma cell line FL‐18 and an Epstein‐Barr virus harboring FL‐18EB cell line, which carried the t(14;18), were analyzed. Although there was no detectable c‐yes rearrangement, the chromosome 18‐specific probe b (bc1‐2) revealed one rearranged fragment after EcoRI, BamHI, PstI and SstI digestion. Therefore, breakage of chromosome 18 in the t(14;18) occurred at the SstI fragment containing the probe b sequence on the bc1‐2 gene. The transcript of c‐yes was undetectable, whereas active transcription of bc1‐2 was observed in the FL‐18 and FL‐18EB cell lines at a higher level than in other types of lymphoma cell line. These data suggest that the c‐yes‐1 is not involved in the t(14;18), and the 2 genes located at 18q21.3 are independent sequences.
Anti‐tumor effects of interferon in mice injected with interferonsensitive and interferon‐resistant friend leukemia cells. VI. Adjuvant therapy after surgery in the inhibition of liver and spleen metastases
Authors: Gresser Ion , Maury Chantal , Belardelli Filippo
Published: February 2007

Adult DBA/2 mice were injected s.c. with the highly malignant, interferon‐resistant 3C18 line of Friend erythroleukemia cells (FLC). Eight or 9 days after established s.c. tumors had developed, the primary tumor was excised and mice were treated i.p. with either mouse interferon α/β or a control preparation. At the time of surgery, mice already had tumor cells in the liver. All control‐treated mice died in the ensuing 2 weeks with extensive tumor metastases in the liver and spleen. Interferon treatment resulted in an inhibition of the development of liver and spleen metastases and a markedly increased survival time. We conclude that interferon α/β is effective as adjuvant therapy after surgery for metastatic disease in mice.
Immunohistological analysis of lymphocyte subpopulations infiltrating breast carcinomas and benign lesions
Authors: Von Kleist S. , Berling J. , Bohle W. , Wittekind C H.
Published: February 2007

We characterized different subpopulations of infiltrating mononuclear cells using 8 monoclonal antibodies (MAbs) on serial cryosections of breast tissue from 85 cancer patients and 32 samples of benign lesions, and the ABC technique. In general, lymphocytes were found more frequently and more abundantly in cancerous lesions. The infiltrates consisted mainly of T‐cells in close contact with malignant cell‐nests. T‐helper/inducer cells clearly predominated over T‐suppressor/ cytotoxic cells in neoplastic tissues, whereas in benign tissues the T‐helper/suppressor ratios seemed to be well balanced. While a few MAb Leu‐7 (HNK‐l)‐reactive NK cells were found in the stroma of the breast tumors, none could be identified in the noncancerous lesions. The correlation of these data with histology and tumor stage of patients has been evaluated by a quantitative approach using planimetry in an interactive registration system.
Defective expression of MHC class I antigens is frequent in B‐cell lymphomas of high‐grade malignancy
Authors: Möller P. , Herrmann B. , Moldenhauer G. , Momburg F.
Published: February 2007

An unselected series of 66 immunohistologically proven B‐cell lymphomas was examined for the expression of MHC class I antigens with monoclonal antibodies directed against non‐polymorphic determinants of HLA‐A,B,C heavy chain and β2‐microglobulin. The tumors were classified according to the Kiel classification. No significant differences were observed in the reaction for HLA‐A,B,C and β2m which may be indicative of a coordinate expression in our lymphoma series. In 37 cases (56%), all tumor cells exhibited strong staining for class I antigens as observed in normal B cells. The remaining 29 cases (44%) showed abnormally low or undetectable class I expression in varying tumor cell subsets; 13 cases were completely devoid of HLA‐A,B,C. Twenty‐two out of 30 lymphomas of high‐grade malignancy but only 7/36 lymphomas of low‐grade malignancy presented defective class I expression. This difference in proportion is highly significant (p < 0.00002). Eleven of the 13 class l‐negative lymphomas belonged to the group of high‐grade malignancy. Centrocytic lymphoma, which has the poorest prognosis among the B‐cell lymphomas of low‐grade malignancy, was defective in 40% of the cases examined. The lymphoblastic type represented an exception within the lymphomas of high‐grade malignancy as no defective expression was observed. In addition to the correlation between the high‐grade malignancy and defective class I expression, defects occurred more frequently in lymphomas with an extra‐nodal primary manifestation (p < 0.05). The grade of malignancy, however, was not correlated with the primary site of the lymphoma.
Anti‐proliferative effects of interferons on Daudiburkitt Lymphoma cells: Induction of cell differentiation and loss of response to autocrine growth factors
Authors: Exley Ruth , Gordon John , Nathan Paul , Walker Leonie , Clemens Michael J.
Published: February 2007

Treatment of Oaudi B‐lymphoblastoid cells with low concentrations of either natural or recombinant human α‐inter‐ferons inhibits cell proliferation and modulates the expression of a number of cell‐surface antigens. Using a panel of monoclonal antibodies (MAbs) identifying determinants expressed at the surface of normal plasma cells, and polyclonal antibodies against surface and cytoplasmic immunoglobulin, we have found that growth inhibition is accompanied by plasmacytoid differentiation. Assays of growth stimulation of heterologous cells indicate that the culture medium from interferon‐treated Daudi cells contains substantially more B‐cell growth factor activity than that from control cells. However, the interferon‐treated cells exhibit an impaired ability to respond to both these autocrine factors and exogenous factors produced by another Burkitt lymphoma line. These findings show that, in the case of Daudi cells, growth inhibition by interferons is closely associated with both terminal differentiation and a refractoriness to growth factors. In this system IFN‐α may therefore be considered to be a B‐cell differentiation factor, suggesting a possible basis for the anti‐proliferative effects observed with certain human B‐cell malignancies.
Influences of diethylnitrosamine on longevity of surrounding hepatocytes and progression of transplanted persistent nodules during phenobarbital promotion of hepatocarcinogenesis
Authors: Hayes M. Anthony , Lee George , Tatematsu Masae , Farber Emmanuel
Published: February 2007

The possibility that phenobarbital (PB) selectively promotes liver nodule development by decreasing survival of surrounding hepatocytes previously exposed to diethylnitrosamine (DENA) was evaluated. Livers of F‐344 rats were labelled with [3H‐methyl]‐thymidine (3H‐TdR) during developmental or regenerative growth. Neonatal rats given 3H‐TdR between days 3 and 12 were subjected at 12 weeks of age to partial hepatectomy (PH) followed 24 hr later by DENA (10 mg/kg) or saline. Subsequent administration of PB (0.1 % in drinking water) for 28 weeks reduced total liver label to 46 ± 10% (saline group) or 40 ± 4% (DENA group). Adult male rats initiated with DENA (200 mg/kg) and later labelled with 3H‐TdR after PH also lost total liver label during 28 weeks' promotion with PB (0.05% in water) at rates similar to those exhibited by non‐ initiated rats given PB, and by DENA‐treated or control rats not given PB. Large persistent (12 weeks) liver nodules generated by DENA in the Solt‐Farber model were transplanted as small fragments into the spleens of syngeneic rats previously given 0, 100 or 200 mg/kg of DENA. Subsequent exposure to PB (0.05% in drinking water for 40 weeks) or Aroclor 1254 (6 ± 300 mg/kg per month) promoted nodule and cancer development only in livers of DENA‐initiated recipients. Surviving transplanted nodules remained as small microscopic clusters even after 40 weeks of promotion. However, PB increased transplant survival (50% vs. 21% in controls) whereas Aroclor reduced it to 8%. These findings indicate that promotion of liver nodules by PB occurs without enhanced mortality of surrounding hepatocytes previously damaged by DENA. They further suggest that promoters such as PB and PCBs do not directly influence the progression of established persistent nodules.
Interrelationships among X‐ray‐induced anchorage independence, mutagenesis and chromosomal rearrangements in human diploid fibroblasts
Authors: Kano Yoshio , Grosovsky Andrew J. , Little John B.
Published: February 2007

The changes in the frequencies of X‐ray‐induced mutations to 6‐thioguanine resistance, chromosomal abnormalities and transformation to anchorage‐independent growth were examined during confluent holding recovery in density‐inhibited cultures of human diploid fibroblasts. Chromosomal abnormalities studied included non‐stable aberrations, deletions, and reciprocal translocations measured up to 20 mean population doublings post‐irradiation. Complex recovery kinetics were observed. A comparison of these kinetics suggests that reciprocal translocations are associated with the induction of both transformation and mutations. Mutagenesis correlated with deletions and translocations, whereas transformation correlated with translocations only.
The biological activity of hydrogen peroxide. III. Induction of Epstein‐Barr virus via indirect action, as compared with TPA and teleocidin
Authors: Oya Yukiko , Tonomura Akira , Yamamoto Kohtaro
Published: February 2007

Hydrogen peroxide (H2O2 ) was found to be a potent inducer of the production of the early antigen complex (EA) and/or virus capsid antigen (VCA), determined by Epstein‐Barr virus (EBV). Maximum synthesis of EBV antigens was induced by 0.2 mm H2O2, 5 days after a single 10‐min treatment, in both B95‐8 cells (30.2%) and P3HR‐1 cells (17.4%). These induction frequencies by H2O2 of proteins encoded by the EBV genome were almost the same as those obtained by 10 min treatment with the potent inducers, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and teleocidin. In combination with n‐butyrate (4mm), H2O2 showed an additive induction of EBV antigens (1.9‐ and 1.7‐fold in B95‐8 and P3HR‐1 cells, respectively) and was as efficient as TPA and teleocidin. H2O2 induced EBV antigens at a very low level (less than 1 %) in Raji cells by itself, but it induced EBV antigens synergistically in combination with n‐butyrate (about 25‐fold). In combined treatments using H2O2, TPA and teleocidin, the combination of H2O2 and TPA or H2O2 and teleocidin showed additive effects on the induction of synthesis of EBV antigens, but the combination of TPA and teleocidin showed almost the same induction level as that produced by H2O2, TPA or teleocidin alone. The inducing activities of H2O2, TPA and teleocidin were suppressed completely, in the case of H2O2, and slightly, in the cases of TPA and teleocidin, by treatment with catalase. Moreover, the effects of H2O2 were largely suppressed by scavengers of hydroxyl radical (‐OH) and singlet oxygen (1O2), but not by superoxide dismutase (SOD), whereas the induction of EBV proteins by TPA and teleocidin was largely suppressed by SOD, but only slightly by scavengers of ‐OH and 1O2. Thus, the biological actions of H2O2 on the activation of the EBV genome seem to be essentially different from those of TPA and teleocidin, though the biological actions of TPA and teleocidin may be partially ascribed to those of H2O2.
Studies on the polyoma tumor‐specific transplantation antigen (TSTA): Selection and characterization of TSTA‐negative segregants from somatic hybrids
Authors: Ramqvist Torbjörn , Reinholdsson Git , Szigeti Robert , Klein George , Dalianis Tina
Published: February 2007

Two polyoma‐TSTA‐negative variants were selected independently from a polyoma fibrosarcoma/Moloney lymphoma somatic hybrid, by repeated passages in polyoma‐virus‐preimmunized mice. One of the variants had lost all its polyoma DNA, while the other only retained a deleted piece of its integrated polyoma DNA. In contrast to the parental hybrid clone, none of the variants produced detectable amounts of T‐antigens. This finding indicates that a detectable expression of the products of the polyoma virus early genome, the T‐antigens, is important either directly or indirectly for the expression of TSTA.
An immunohistological study of cells infiltrating progressive and regressive tumors induced by two variant subpopulations of a rat colon cancer cell line
Authors: Martin M. S. , Caignard A. , Hammann A. , Pelletier H. , Martin F.
Published: February 2007

In order to understand the mechanisms leading up to progression or regression, tumors resulting from the s.c. inoculation of progressive or regressive variants of a cell culture established from a chemically‐induced rat colonic carcinoma were subjected to sequential histological study. As immune‐ logical factors have been previously described in this system of progressive or regressive tumors, special interest was given to inflammatory cells, T and B lymphocytes and macro‐phages, located inside and outside the tumor. Immunohisto‐ logical methods using monoclonal or polyclonal antibodies and enzyme histology were performed to identify different populations of infiltrative cells. In both variants of tumors an accumulation of these cells were seen at the periphery of the tumor, surrounding the nodules. In contrast, very few inflammatory cells, macrophages or T lymphocytes were seen inside the clumps of tumor cells where cytolytic cells could have a contact‐dependent tumoricidal effect. Only small differences were found between progressive and regressive tumors in the density of the various populations of T helper, T cytotoxic/suppressor, B lymphocytes or macrophages inside or around the tumor nodules. On the other hand, progressive and regressive tumors clearly differ in the relationship between tumor cells and the fibroblastic reaction they induce. Regressive tumors were rapidly encircled by a fibroblastic reaction isolating them from the peripheral tissues. The fibroblastic reaction was less dense around the progressive tumor cells which were able to migrate and invade the periphery. This suggests that immunological factors leading to tumor progression or regression could act indirectly through a control of the fibroblastic reaction, rather than through a direct cytotoxic effect on the tumor cells.
Appearance of serum antibodies to rat yolk‐sac carcinomas during the latent period prior to primary tumor development
Authors: Lindvall Magnus L. , Alumets Jan , Sjögren Hans Olov
Published: February 2007

Rat yolk‐sac tumors were induced by intraperitoneal (i.p.) displacement of the visceral yolk sac in fetectomized W/Fu rats. Serum was obtained from each female rat prior to the pregnancy preceding the tumor‐inducing procedure and then once a month during the induction period. The sera were analyzed for the presence of antibodies binding to cultured cells of one of the yolk‐sac tumors. Sera were also assayed for complement‐dependent cytotoxic antibodies on tumor cells. In rats that developed tumors, antibodies reacting specifically with the target tumor cells could be detected in all of 10 rats. Antibodies appeared before tumor detection in all animals but one, and in 6 rats as early as 11 to 25 weeks prior to tumor detection. Nine rats developed antibodies demonstrable in the binding assay and in 6 of those the antibodies appeared 8 to 25 weeks before the tumor became palpable. Analysis of the isotypes of the Ig that bound to tumor cells showed that IgG1 and lgG2b were most frequently present. In one rat lgG2a antibodies appeared one month before tumor detection followed by IgG1 and lgG2b antibodies detectable 4 weeks later. IgG2c and IgM antibodies were not detected in any of the rats. At dilution 1/10, sera of all 10 rats showed specific cytotoxicity to the tumor cells in the presence of added rabbit complement. In 9 of these animals antibodies were demonstrated 1 to 4 months prior to tumor detection.
Interactions of interferons and transforming growth factors during clonal growth of mouse or human cells in soft agar and in mice
Authors: Popik Waldemar , Inglot Anna D.
Published: February 2007

The mouse fibroblast‐like transformed cell line C‐243 adapted to growth in suspension was used as a source of virus‐induced interferons (MulFN‐α, β), and spontaneously produced active growth factors. These factors were purified from C‐243 cells grown as tumors in BALB/c mice, and had properties identical to those of TGF‐α or TGF‐β isolated by others from different tissues. Exogenous TGF‐α, β stimulated colony formation by C‐243 cells in soft agar, whereas MulFN‐α, β inhibited it. Clonal growth of human lung adenocarcinoma AS49 cells in soft agar was inhibited as well by human interferons (types α, β, or γ) as by TGF‐β. Inhibition was dose‐related. Pure EGF, which is an analogue of TGF‐α, diminished the anti‐proliferative activity of interferons α, β, and γ in A549 cells. On the other hand, the anti‐mitogenic action of IFN‐β and TGF‐β was clearly synergistic. In mice bearing C‐243 cell tumors, TGF‐α, β stimulated growth, whereas MulFN‐α, β inhibited it. Stimulation of tumor growth was also observed after administration of anti‐IFN serum that could neutralize endogenous IFN‐α, β. The simultaneous administration of MulFN‐α, β and TGF‐α, β diminished anti‐tumor effects of IFN in mice. Our results suggest that both TGFs and IFNs are autocrine, positive or negative growth factors modulating the rate of proliferation and the neoplastic behavior of the cells. The final effects depend on the target‐cell sensitivity and on the relative concentration of the various hormone‐like factors. Cancer cells overstimulated by TGF‐α, β or by EGF may not respond to IFNs.
A mammalian cell line designed to test the mutagenic activity of anti‐herpes nucleosides
Authors: Pizer Lewis I. , Mitchell Dawn H. , Bentele Beatrice , Betz Joan L.
Published: February 2007

The herpes simplex virus (HSV) thymidine kinase (tk) gene was transfected into Chinese hamster ovary (CHO) 51–11 gly−cells to test its effect on the cytotoxic and mutagenic activity of anti‐herpetic nucleoside analogues. Insertion of the viral tk was verified by Southern blot analysis, by sensitivity to acyclovir, and by elevated in vitro thymidine kinase (TK) activity. TK activity was increased by superinfection with a tk− virus and inhibited by antibody to viral TK. Acyclovir (ACV) was somewhat more cytotoxic in the 51‐D3 cell line that expresses the viral TK than in the 51–11 parent line. Growth in ACV did not increase over background mutations at the hprt locus. FIAC (2′‐fluoro‐5‐iodio‐aracytosine) was slightly cytotoxic to the parent 51–11 line and the tk‐containing clone 51‐D3. FMAU (2′‐fluoro‐5‐methyl‐arauracil) had pronounced cytotoxicity in both cell lines: the 50% survival points were 1.0 μM for 51–11 cells and 0.2 μM for 51‐D3. The clone 51‐D3 was more sensitive than 51–11 to low concentrations of FIAU (2′‐fluoro‐5‐iodo‐arauracil), and when treated with FIAU 51‐D3 had a mutation frequency to glycine independence 5 times greater than that of 51–11 cells. With both cell lines the mutation frequency at the hprt locus did not increase after growth in the presence of FIAC or FIAU. A 7‐fold increase in mutation frequency at the hprt locus was detected after 51‐D3 cells were grown with iododeoxyuridine. Trifluorothymidine was more toxic to 51‐D3 than to 51–11 cells and increased the mutation frequency 2‐ fold. Cytosine‐β‐D‐arabinofuranoside showed no differential cytotoxicity on the two cell lines and did not increase the mutation frequency at the hprt locus.
Regulation of tumor development: The biphasic effects of silica and of lipopolysaccharide on natural resistance
Authors: Sandstrom Paul A. , Chow Donna A.
Published: February 2007

The impact on tumor development of the BRM silica and LPS was assessed through anal/sis of changes in NR parameters in vivo and in vitro. Although injection of the fumed silica Cab‐o‐sil 3 days before a threshold s.c. inoculum of LSI78Y‐F9 cells increased the tumor frequency in syngeneic DBA/2 mice, tumors recovered from silica‐treated animals exhibited an augmented resistance to NAb and to in vivo NR. Cab‐o‐sil increased in vivo NR and induced a biphasic modulation of anti‐tumor NAb and NK activities. The appearance of more autonomous tumors in Cab‐o‐sil‐treated mice corresponding with a stimulation of NR parameters, suggests that the adjuvant activity of silica also contributes to its co‐carcinogenic effect by accelerating tumor development. While injection of LPS 2–3 days before a threshold tumor inoculum lowered the tumor incidence, the survival of tumor cells injected within I day of LPS was increased. A corresponding early decrease in NAb activity occurred, in contrast with increases in NK cell and NAb levels previously observed after 5 days. This biphasic effect of LPS on NR effectors assayed in vitro was also seen on in vivo NR. Although their frequency was higher, tumors initiated during the period of LPS‐induced NR abrogation exhibited greater reductions in NAb binding and sensitivity to NR than tumors from control mice. These data extend the support for NAb acting against tumor cells in vivo and reveal the dual nature of NR in tumor development, (1) defending against small tumor foci and (2) driving the progression of the surviving neoplasm.
Screening for lung cancer‐results from a case‐control study
Authors: Ebeling K. , Nischan P.
Published: February 2007

By means of a case‐control study, a screening programmer originally introduced to control tuberculosis and utilizing biennial chest X‐rays (70 × 70 pa.) was evaluated for its effect on lung cancer mortality. The case group consisted of 130 population‐based deaths from lung cancer (males below 70). One general population‐based and one hospital‐based control group were used, both consisting of 260 males matched for age and alive at the same time as the relevant case. The proportion of exposed persons, i.e. those having had at least one screening test within the 2 years preceding diagnosis, was similar in the case group and in. the 2 control groups: 76, 78 and 75%, respectively. The relative risk of lung cancer death was 0.9 and 1.1 (95% confidence intervals 0.5 to 1.5 and 0.7 to 1.8). There was no trend in relative risks with regard to the number of tests performed and the interval since the last test.
Defective cell‐mediated response to EBV‐transformed B cells in a healthy individual with regular EBV antibody titers
Authors: Bejarano Maria Teresa , Thorsteinsdottir Sigurbjörg , Andersson Jan P. , Andersson Ulf G. , Masucci Maria Grazia , Szigeti Robert , Klein Eva , Klein George
Published: February 2007

We have analyzed the EBV‐related immune parameters of a healthy EBV‐seropositive individual (ST) who has regular antibody titers but defective inhibitory capacity toward the growth of autologous EBV‐infected B cells. This in vitro function reflects the EBV‐specific memory because it does not occur in experiments performed with cells of seronegative individuals. An analysis of events following in vitro EBV infection showed that lymphocytes of ST behaved in some tests in the same way as those collected from seronegative individuals. These parameters were: (I) lack of‐γ‐IFN production 24 hr after EBV infection; (2) low production of soluble factors that inhibit EBV‐induced B‐cell proliferation; (3) lack of generation of LCL selective cytotoxicity after repeated stimulation with autologous LCL; and (4) high proportion of EBNA‐positive cells in 7‐day‐old EBV‐infected cultures. On the other hand, cellular memory to the virus detected by the production of IL–2 24 hr after infection, and by the production of LIF upon exposure to EBV‐encoded antigens, conformed with the results obtained with seropositive individuals. T‐cell‐mediated inhibition of EBV‐induced B‐cell growth in vitro has been regarded as a corollary of in vivo control of EBV‐infected B cells. However, it is absent or has a low efficiency in certain disease categories which are not accompanied by risk of B‐EBV growth. Our results with a healthy individual also indicate that several mechanisms contribute to a harmless lifelong virus carrier state.
Specific chromosome aberration in human renal cell carcinoma
Authors: Kovacs Gyula , Szücs Sandor , De Riese Werner , Baumgärtel Hermann
Published: February 2007

Using G‐banding technique, the chromosomes were studied in short‐term cultures of 25 primary renal‐cell carcinomas (RCC). Phytohaemagglutinin‐stimulated peripheral blood lymphocytes or normal kidney cells of the same patients growing in primary cultures were analysed to define the constitutional karyotype. The modal chromosome number of 23 RCC's was found to be pseudo‐diploid or near‐diploid with only few structural rearrangements, 22 of the RCC's showed an aberration of chromosome 3, deletion of 3p, or translocation of different chromosome segments to the deleted chromosome 3, leading to the loss of variable segments of chromosome 3. The breakpoints in rearrangements of chromosome 3 clustered in the region 3p11.2–p13. Shortest‐region overlap analysis localized a consistent change to a small area of 3p13‐pter. In 8 of the 25 RCCs, the rearrangement of chromosome 3 was the only karyotype change determined, and 4 other tumours had only one chromosomal rearrangement in addition to the aberration of chromosome 3. These results suggest that the aberration of chromosome 3 is the first cytogenetic event in the clonal evolution of RCCs. Translocation 3;5 was preferentially involved in the rearrangements between chromosome 3p and other chromosomes. The breakpoint on chromosome 3 was constant at p13, but the breaks on chromosome 5 varied between bands q11.2 and q22. Monosomy 14 was observed in 10 cases and loss of Y chromosome was detected in 6 of 14 tumours obtained from male patients. Since the normal somatic cells were free of chromosomal aberrations, one may conclude that the loss of 3p13‐pter segment is an acquired, consistent chromosomal aberration which marks human RCCs.
Colorectal polyps and diet: A case‐control study in Marseilles
Authors: Macquart‐Moulin Geneviève , Riboli Elio , Cornée Jacqueline , Kaaks Rudolf , Berthezène Patrice
Published: February 2007

This study investigates the differences in usual past diet between 252 subjects with newly diagnosed adenomatous or villous polyps of the colon and rectum and a group of 238 hospital controls. Cases and controls were interviewed in hospital by 3 nutritionists using a dietary history questionnaire focused on the diet during the preceding year. Nutrient intake was estimated by means of ad hoc food tables adapted from French and British tables. Out of 16 food groups considered in the analyses, the cases reported lower consumption of oil and potatoes and higher consumption of sugar added to food and drink. Among nutrients, we found that cases had a lower consumption of carbohydrates (not taking into account added sugar), potassium, magnesium and vitamin B6. We found a slightly lower intake of fibre and a slightly higher intake of saturated fat among cases, though neither was statistically significant. Intake values for fibre and for carbohydrates were highly Interco related and, due to measurement errors, the effect of one may be masked by the other and vice versa. The hypothesis that some components of carbohydrates (starches, fibre and natural sugars but not added sugar) play a protective role in relation to the biology of tumours of the intestinal tract is considered in further multivariate analyses and in the “Discussion”.
Amplification of the epidermal growth factor receptor gene in the BT20 breast carcinoma cell line
Authors: Lebeau Jérome , Goubin Gérard
Published: February 2007

Southern blot‐hybridization analysis of 10 breast carcinoma cell lines demonstrated an amplification of the epidermal growth factor (EGF) receptor gene in the BT20 cell line. The gene was amplified 10‐to 14‐fold when compared to the level seen in human placental DNA. Northern blot analysis indicated an increased level of transcription in this cell line which probably accounts for the high level of the EGF receptor reported in the BT20 cell line.
The level of expression of class‐I MHC antigens in adenovirus‐transformed human cell lines
Authors: Grand Roger J. A. , Rowe Martin , Byrd Philip J. , Gallimore Phillip H.
Published: February 2007

The level of expression of the class‐l major histocompatibility (MHC) antigen was determined in a series of human embryo cell lines transformed with either adenovirus 12 (Ad 12) early region I (El) or adenovirus 5 (Ad 5) E1 DNA or with combinations of Ad 12 early region IA (El A) or Ad 2 EIA with activated N‐ras DNA. MHC class‐l antigen expression was greatly reduced in all Ad 12 transformants, compared to primary cells. Expression was also reduced in the Ad 5 cell lines transformed with EIA and EIB DNA, but levels were near normal in those lines with only EIA DNA present. Amounts of MHC class‐l antigen on the cell surface, as determined by RIA and FACS analysis, generally reflected total cellular levels as determined by Western blotting. Expression of β2 microglobulin was also much reduced in those cell lines with low levels of MHC class‐l antigen. The treatment of primary cells and all the transformants with human γ‐interferon resulted in increased expression of HLA on the cell surface. Infection of primary human cells with Ad 12 or with a series of Ad 12 mutants did not have any effect on the MHC class‐l antigens present.
Receptors for epidermal growth factor and estradiol in canine mammary tumors
Authors: Nerurkar V. R. , Seshadri Rajeshwari , Mulherkar Rita , Ishwad C. S. , Lalitha V. S. , Naik S. N.
Published: February 2007

Both growth factors and steroid hormones are known to be associated with breast cancer. We have studied the epidermal growth factor receptor (EGFR) in canine mammary tumors and have shown the presence of a single class of 125I‐EGF binding receptor sites in 9 out of 13 (70%) tumors, using Scat‐chard plot. The dissociation contant (KD) was 10−9M. An inverse correlation between EGFR and estrogen receptor (ER) was observed in 54% of the tumors. Our data suggest that EGFR might be used as a biochemical marker in canine mammary tumors.
Serological survey and virus isolation of simian T‐cell leukemia/T‐lymphotropic virus type I (STLV‐I) in non‐human primates in their native countries
Authors: Ishikawa Koh‐Ichi , Fukasawa Masashi , Tsujimoto Hajime , Else James G. , Isahakia Mohamed , Ubhi Narinder K. , Ishida Takafumi , Takenaka Osamu , Kawamoto Yoshi , Shotake Takayoshi , Ohsawa Hideyuki , Ivanoff Bernard , Cooper Robert W. , Frost Eric , Grant Francis C. , Spriatna Yatna , Sutarman  , Abe Kenji , Yamamoto Kohtaro , Hayami Masanori
Published: February 2007

Infection with a simian retrovirus (STLV‐I) closely related to human T‐lymphotropic virus type I (HTLV‐I) was investigated in non‐human primates living in their native countries in Africa and Asia. Serum antibodies cross‐reacting with HTLV‐I antigens were detected in 85 of 567 non‐human primates of 30 species. Seropositive animals were found among African green monkeys, olive baboons, Sykes' monkeys, mandrills and patas monkeys in several countries in Africa, and cynomolgus monkeys, Celebes macaques and siamangs in Indonesia. The frequency of seropositivity was much higher in adult than in young African green monkeys, cynomolgus monkeys and Celebes macaques. STLV‐Is were isolated by establishing II lines of virus‐producing lymphoid cells in the presence of interleukin‐2 from 5 species of seropositive non‐human primates, i.e. the African green monkey, Sykes' monkey, Celebes macaque, cynomolgus monkey and siamang. All these cell lines had T‐cell markers and Tac antigen, and the cell lines from the African green monkey and Sykes' monkeys were Leu2a+ while those from other species were Leu3a+. These cell lines expressed viral antigens reacting with human sera from adult T‐cell leukemia (ATL) patients and monoclonal antibodies (MAbs) against p19 and p24 of HTLV‐I core proteins, and produced virus particles having RNA‐dependent DNA polymerase activity. Cellular DNAs from these cell lines contained provirus sequences homologous to HTLV‐I, shown by Southern blot hybridization. The restriction patterns of these provirus genomes were different from those of HTLV‐I and were also dissimilar in the different species.
Loss of basement membrane deposits and development of invasive potential by virally‐transformed rat mammary cells are independent of collagenase production
Authors: Warburton Michael J. , Ferns Sharon A. , Kimbell Rosemary , Rudland Philip S. , Monaghan Paul , Gusterson Barry A.
Published: February 2007

The myoepithelial‐type cell line, Rama 712, derived from a normal rat mammary gland, deposits an extracellular matrix containing type‐IV collagen and other basement membrane proteins round its cellular periphery. After transformation with a temperature‐sensitive mutant of Rous sarcoma virus (tsRSV) the cells fail to deposit an extracellular matrix at the permissive temperature (35°C), but retain the capacity to do so at the non‐permissive temperature (41°C). The synthesis of type‐IV collagen is not affected by the temperature shift. Rama 712 cells fail to form tumours in syngeneic rats. However, Rama 712‐tsRSV cells form tumours that are locally invasive but fail to metastasize. In histological sections, the tumour cells stain with an antibody to type‐IV collagen, but do not deposit any extracellular type‐IV collagen. Cells isolated from the tumours (Rama 712T) remain temperature‐sensitive for the extracellular deposition of type‐IV collagen when grown in vitro. Rama 712, Rama 712‐tsRSV and Rama 712T fail to produce any detectable type‐1 or type‐IV collage‐nase at either 35°C or 41 °C. These results show that in this system extracellular deposits of basement membrane proteins are lost from invasive tumours produced by myoepithelial‐type cells by mechanisms other than those due to the production of collagenolytic enzymes.
Prognostic implications of expression of the cellular genes myc, fos, Ha‐ras and Ki‐ras in colon carcinoma
Authors: Monnat M. , Tardy S. , Saraga P. , Diggelmann H. , Costa J.
Published: February 2007

Messenger RNA levels of the c‐fos, c‐myc, c‐Ha‐ras and c‐Ki‐ras genes were studied in 39 tissue samples obtained from 17 patients undergoing surgery for colon carcinoma and other colon diseases. DMA extracted from the same samples was studied by Southern analysis. The tissues were tumors and grossly normal mucosa from each case and in some instances benign polyps and metastases. Our results indicate: (1) that 50% of cases studied show an increase in expression of at least one of the oncogenes studied; (2) that over‐expression is not random, some cases over‐expressing several of the genes studied; (3) that the expression pattern of the oncogenes studied varies between primary tumor and metastases; (4) that amplification is a rare event, being limited to one instance in which c‐myc was amplified in a metastasis; (5) that cases which exhibit high levels of mRNA in one or more genes studied correlate with biologically aggressive tumors; and (6) that “non‐expressors” are at higher risk for local recurrence based on correlations with mucin histochemistry.
Subcellular concentrations of estrone, estradiol, androstenedione and 17β‐hydroxysteroid dehydrogenase (17‐β‐OH‐SDH) activity in malignant and non‐malignant human breast tissues
Authors: Mehta R. R. , Valcourt L. , Graves J. , Green R. , Gupta T. K. Das
Published: February 2007

Total and subcellular (cytosol and nuclear) concentrations of estrone (E1), estradiol (E2), and androstenedione were determined in non‐malignant (n = 61) and malignant (n = 65) human breast tissues obtained from post‐menopausal women. The 17β‐hydroxysteroid dehydrogenase (17 β‐OH‐SDH) activity was determined in 800g supernantant fraction. Total estrogens, E, and E2 levels and 17β‐OH‐SDH activity were significantly (p < 0.005, 0.0005, 0.001, respectively) higher in malignant than In non‐malignant breast tissues. We failed to observe significant changes in subcellular steroid concentrations or enzyme activity associated with patients' obesity or tumor estrogen receptor status. When the steroid levels were analyzed in relation to clinical staging of the disease, nuclear contents of estradiol were significantly higher (p < 0.005) In Stage‐IV patients than in those with less advanced disease (Stages I to III). 17β‐OH‐SDH activity was significantly (p < 0.001) lower in patients with advanced disease than in those with relatively less advanced (Stages I to III) disease and was positively correlated with tissue concentration of androstenedione. Our present data indicate that differential intracellular metabolism of steroid hormones may have some influence on availability of estradiol at nuclear sites. In postmenopausal women, local intercon version of estrogens may provide sufficient estrogenic stimulus to enhance the growth and progression of breast tumors.
Coffee consumption and risk of pancreatic cancer
Authors: La Vecchia Carlo , Liati Paola , Decaru Adriano , Negri Eva , Franceschi Slivia
Published: February 2007

The relationship between pancreatic cancer and coffee, decaffeinated coffee and tea drinking habits was evaluated using data from a hospital‐based case‐control study conducted in Northern Italy on ISO histologically confirmed cases and 605 controls with acute, non‐neoplastic, other than digestive tract diseases unrelated to coffee consumption or to any of the known or potential risk factors for cancer of the pancreas. Compared with subjects who did not drink coffee, the multivariate relative risks were 1.7 for those who drank less than 2 cups per day, but only 1.4, and 1.1 respectively for drinkers of 3 or 4 and 5 or more cups. Likewise, there was no association with duration of consumption of coffee, decaffeinated coffee or tea. These findings were reviewed together with published evidence from other case‐control studies (or cohort studies analyzed as case‐control) of coffee and pancreatic cancer. When appropriate statistical methods were used to pool information, and the data from the first study which was the basis of the hypothesis were omitted, the relative risk of pancreatic cancer based on 1,464 cases was 1.2 for moderate coffee drinkers and 1.4 for heavy drinkers, and we suspect that at least part of this moderate residual association is confounded by cigarette smoking. Thus, although the present investigation and a general overview of published epidemiological evidence are compatible with a small effect of coffee on pancreatic carcinogenesis, interpretation of these findings is not obvious on account of the possibility of residual confounding and other sources of bias.
Immunological analysis of mucin molecules expressed by normal and malignant mammary epithelial cells
Authors: Griffiths Andrew B. , Burchell Joy , Gendler Sandra , Lewis Angela , Blight Ken , Tilly Rita , Taylor‐Papadimitriou Joyce
Published: February 2007

Many existing MAbs raised against the human milk fat globule or against carcinoma cells recognise epitopes on high‐molecular‐weight glycoproteins. In a comparative ELISA assay a number of these antibodies have been shown to react with an extract of the human milk fat globule. In comparative immunoblots of cultured normal milk cells and breast cell lines, all were found to bind to large molecules which show some variation in molecular weight depending on the cell source. The HMFG‐2 antibody, which is widely used in cancer diagnosis, also recognises epitopes on lower‐molecular‐weight components. In T47D cells these may be as small as 80,000 Mr, and with electron microscopy this cell line can be shown to accumulate HMFG‐2‐reactive components in the Golgi apparatus. Using an HMFG‐2 affinity column we have immunopurified HMFG‐2‐reactive material from the 2 breast cancer cell lines MCF‐7 and T47D and shown that all of the above antibodies react in a solid‐phase ELISA with the purified material. In addition to high‐molecular‐weight components, the immunopurified material was found to contain lower‐molecular‐weight components including a glycoprotein of 68,000 Mrthat was not, however, recognised by the HMFG‐2 antibody on a Western blot. We have used this immunopurified material to generate new MAbs. All of these recognise the high‐molecular‐weight bands seen with the other antibodies, but 2 of them also recognise a band at 68,000 Mr in blots of MCF‐7 and T47D. The Second‐generation antibodies show a spectrum of reactivity on tissues similar to HMFG‐2 and one reacts at least as strongly as HMFG‐2 with methanol‐acetone‐fixed sections of breast cancers.