bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of parity and exogenous female hormones on the risk of colorectal cancer
Authors: Davis F. G. , Furner S. E. , Persky V. , Koch M. 
Published: February 2007

AbstractEvidence that female sex hormones may play a role in the subsequent development of colorectal cancer has accumulated from time trends in colorectal cancer rates and from epidemiologic studies. Using data available from the Cross Cancer Institute Northern Alberta Cancer Program, the relationship of parity, exogenous hormones and colorectal cancer was evaluated. Five hundred and twenty‐eight colon cancer and 192 rectal cancer cases were identified and 349 non‐endocrine cancers were selected as controls. All subjects were diagnosed and interviewed between 1969 and 1973. Protective associations between previous pregnancies and colorectal cancer were found in women over age 50 at diagnosis (OR = 0.5, 95% CI = 0.3–0.9) and in women who never used exogenous hormones (OR = 0.3, 95% CI = 0.2–0.7). Results from this study provide additional support for earlier suggestions that parity may have a protective effect against the development of colorectal cancer, similar to the effects reported in the case of breast, endometrial and ovarian tumors.
Multifactorial analysis of parameters influencing chemosensitivity of human cancer xenografts in nude mice
Authors: Fujita Fumiko , Fujita Masahide , Taguchi Tetsuo , Shimozuma Kojiro , Sakamoto Yasuo , Kimoto Yasuhiko , Hirai Toshihiro 
Published: February 2007

AbstractThe results of single‐agent chemotherapy, with 11 anti‐cancer agents, of 15 human gastro‐intestinal and breast cancer lines xenografted into nude mice indicate inherent individuality of chemosensitivity spectrum of each tumor. The following 9 parameters have been measured as factors possibly relevant to chemosensitivity of tumor tissue or tumor‐bearing mice: grade of histological differentiation, vascularity, percentage of necrosis, VDT, 3H‐thymidine LI, human LDH activity in the cancer tissue, tissue/serum LDH ratio, TdR Pase activity, and serum CEA. These parameters exhibited presumably constant values for each tumor line. Chemosensitivity, i.e., inhibition of tumor growth by a given drug, was used as the dependent variable, and values of the 9 parameters in each cancer as the explanatory variables. Multiple regression analyses with stepwise deletion were performed for each of the 11 drugs. The equations for 8 drugs exhibited coefficients of determination of over 70%, and in particular those for M‐83 (a derivative of mitomycin C), nimustine hydrochloride and doxorubicin exceeded 80% by equations with 3–4 parameters. Consequently, the estimated value for each line of effectiveness derived from the equations for these 8 drugs showed remarkable coincidences with the actual values for the inhibition rates of the corresponding drugs.
Acquisition of tumorigenic potential in the human myoepithelial HBL100 cell line is associated with decreased expression of HLA class I, class II and integrin β3 and increased expression of c‐myc
Authors: Krief P. , Saint‐Ruf C. , Bracke M. , Boucheix C. , Billard C. , Billard M. , Cassingena R. , Jasmin C. , Mareel M. , Azzarone B. 
Published: February 2007

AbstractThe human breast cell line HBL100 acquires the capacity to invade normal tissues and to replace them by proliferation in vitro only at high passage levels (HPL). These cells therefore are a useful model for studying tumor progression in vitro. We have analyzed the expression of cell‐surface markers supposed to be involved in the control of the neoplastic process. Quantitative flow cytometry has revealed that: (I) spontaneous expression of HLA class‐1 antigens strongly decreases in HPL HBL100 cells vs. LPL cells, which parallels amplification and over‐expression of c‐myc oncogene; (2) HLA DR antigens can be induced by IFN‐gamma in LPL but not in HPL HBL100 cells; (3) HBL100 cells secrete a soluble protein factor which specifically inhibits HLA DR induction by IFN‐gamma even in heterologous cell systems; (4) 50% of LPL HBL100 cells express integrin β3, whereas HPL HBL100 cells lose this antigen; (5) this cell line is myoepithelial in origin, since 100% of HBL100 cells exhibit the CD 10 antigen. Our data stress a role of HLA antigens, of some integrins and of c‐myc in the acquisition of malignant potential by myoepithelial mammary cells of the HBL100 line.
Properties of a non‐tumorigenic human cervical keratinocyte cell line
Authors: Stanley Margaret A. , Browne Helena M. , Appleby Mark , Minson Anthony C. 
Published: February 2007

AbstractA human cervical keratinocyte cell line, W12, has been initiated from a low‐grade cervical lesion histologically diagnosed as CIN I. This cell line has, to date, undergone over 300 generations in vitro with an average doubling time of 30 hr: an aneuploid karyotype has developed with progressive in vitro growth. W12 contains HPV16 DNA present at approximately 100 copies and the state of the viral DNA over a number of passages has been examined. The HPV13 DNA is stably maintained at high copy number over several passages and restriction enzyme analysis together with electrophoresis of uncleaved viral DNA indicate that it is present predominantly as the episomal molecule. W12 cells exhibit a typical keratinocyte morphology and, when transplanted into the flank of the nude mouse, form an epithelial lesion with the histological features of CIN I/II.
Androgen receptors, androgen‐dependent proliferation, and 5α‐reductase activity of small‐cell lung cancer cell lines
Authors: Maasberg M. , Rotsch M. , Jaques G. , Enderle‐Schmidt U. , Weehle R. , Havemann K. 
Published: February 2007

AbstractWe investigated the influence of testosterone on binding to established small‐cell lung cancer (SCLC) cell lines and were able to show specific high‐affinity and low‐capacity binding sites in some cell lines with a typical receptor size, using sucrose density gradient centrifugation. In addition, we demonstrated marked growth stimulation with testosterone and dehydrotestosterone using different androgen‐receptor‐positive small‐cell lung cancer cell lines. This growth stimulation could be counteracted by the addition of anti‐androgens like cyproterone acetate or flutamide. The presence of 5α‐reductase activity, 17ß‐hydroxysteroid‐dehydrogenase and 3α‐hydroxy‐steroid‐dehydrogenase activities could be demonstrated, suggesting testosterone metabolism of small‐cell lung cancer cell lines.
Adriamycin action on human breast cancer cells: Enhancement by medroxyprogesterone acetate
Authors: Shaikh Naeem A. , Owen Alison M. , Ghilchik Margaret W. , Braunsberg Hannelore 
Published: February 2007

AbstractExposure of cultured human breast cancer cells (MCF‐7) to medroxyprogesterone acetate (MPA) prior to treatment with adriamycin (ADR) enhanced the effect of the cytotoxic drug on cell yield after further growth of viable cells. Pre‐treatment with oestradiol (E2) produced similar synergism, but no such effect was observed using dexamethasone. Exposure to ADR before MPA led to an additive effect, but not to synergism. When cells resistant to the growth‐inhibitory action of MPA were examined, progestogen/drug synergism could still be demonstrated. We conclude that the effects of ADR, like those of methotrexate and vincristine, can be enhanced by pre‐treatment with MPA and that further clinical trials of such a regimen are needed.
Possible involvement of chromosome 1 in in vitro immortalization: Evidence from progression of a human adenoma‐derived cell line in vitro
Authors: Paraskeva Christos , Harvey Amanda , Finerty Susan , Powell Susan 
Published: February 2007

AbstractWe have previously reported that continuous in vitro passage in the presence of 3T3 feeders of a non‐tumorigenic adenoma‐derived epithelial cell line, designated PC/AA, resulted in its becoming immortal. At early passage PC/AA was normal diploid, whereas every cell of PC/AA late passage had an isochromosome I(q) which led us to suggest that abnormalities of chromosome I may be involved in tumour progression. We now report the isolation of a 3T3‐feeder‐independent variant of early‐passage PC/AA, designated PC/AA/FI, which was immortal in vitro and remained non‐tumorigenic. Each cell of PC/AA/FI again has an isochromosome I(q), like the late‐passage PC/AA. However, with PC/AA/FI it is the other chromosome I of the homologous pair which is involved in the formation of the isochromosome I(q). This is possible to determine because of the polymorphic cen‐tromeric heterochromatin on chromosome I of the early‐passage PC/AA. With the late‐passage PC/AA (grown with 3T3 feeders) the homologue with the large C‐band has given rise to an isochromosome I(q) whereas with PC/AA/FI it is the other homologue with the smaller C‐band which has given rise to this isochromosome. Both the immortal PC/ AA/FI and the immortal PC/AA late passage, therefore, have independent abnormalities involving chromosome I. These results indicate that chromosome I may be involved in in vitro immortalization.
Expression of 7F7‐antigen, a human adhesion molecule identical to intercellular adhesion molecule‐1 (ICAM‐1) in human carcinomas and their stromal fibroblasts
Authors: Vogetseder Werner , Feichtinger Hans , Schulz Thomas F. , Schwaeble Wilhelm , Tabaczewski Piotr , Mitterer Manfred , Böuck Günther , Marth Christian , Dapunt Otto , Mikuz Gregor , Dierich Manfred P. 
Published: February 2007

AbstractThe 7F7‐antigen is a widespread 85‐kDa membrane adherence molecule involved in heterotypic adhesion between PHA‐blasts and fibroblasts. Immunofluorescence analysis of COS cells transfected with clone p1CAM‐1 indicated that 7F7‐antigen is identical with ICAM‐1, the ligand for the contact molecule LFA‐1. We have investigated the expression of ICAM‐1 on several human carcinomas. Tumor cells in most carcinomas, with the exception of squamous‐cell carcinomas, expressed very little ICAM‐1 or none at all. In contrast, marked expression of this molecule was observed on fibrous tissue in the vicinity of carcinoma cells, its intensity correlating with lymphatic infiltration in these tumors. We also examined the expression of ICAM‐1 on carcinoma cell lines and its induction by treatment with interferon‐gamma (IFN‐γ). The inducibility of ICAM‐1 expression on cultured fibroblasts by several lymphokines suggests that the expression of ICAM‐1 in the vicinity of carcinoma cells is effected by lymphokines produced by activated lymphocytes/macrophages within the tumor.
The role of alcohol in oesophageal cancer in non‐smokers, and of tobacco in non‐drinkers
Authors: La Vecchia Carlo , Negri Eva 
Published: February 2007

AbstractData from a hospital‐based case‐control study of oesophageal cancer conducted in Northern Italy were used to analyse the risk associated with alcohol in non‐smokers and with tobacco in non‐drinkers. Out of a total of 250 cases (198 males, 52 females) and 1,089 controls (800 males, 289 females), there were 38 cases and 404 controls who described themselves as lifelong non‐smokers. Among these persons, the relative risk was not different for teetotallers and moderate drinkers (<4 drinks per day), but increased markedly for higher levels of alcohol consumption. The point estimates were 2.1 for 4 to 8 and 3.6 for over 8 drinks per day, and the trend in risk was statistically significant. Likewise, among 30 cases and 189 controls who were non‐drinkers, the point estimates were 2.0, 3.9 and 6.2 for smokers of <15, 15–24 and ≥25 cigarettes per day, with, again, a statistically significant trend. This study supplies further evidence that both alcohol and tobacco are strongly related to the risk of oesophageal cancer, even in the absence of exposure to the other risk factor. This confirms previous indications from a study in Calvados, France and also provides statistically significant epidemiological evidence of an independent role of exposure to tobacco alone in the aetiology of oesophageal cancer. The relative risks associated with exposure to either of the 2 factors among subjects not exposed to the other were readily comparable to the estimates adjusted for the other factor in the overall data‐set, thus further confirming the independent effect of alcohol and tobacco on oesophageal carcinogenesis.
Identification of a human epithelial cell surface protein sharing an epitope with the C3d/epstein‐barr virus receptor molecule of B lymphocytes
Authors: Young L. S. , Dawson C. W. , Brown K. W. , Rickinson A. B. 
Published: February 2007

AbstractThis work examines the basis for our earlier observation that certain monoclonal antibodies (MAbs) specific for the B‐cell‐associated C3d/Epstein‐Barr virus (EBV) receptor molecule CD21 also react with the surface of some epithelial cells. Of 9 proven anti‐CD21 MAbs now examined on frozen sections of human nasopharynx, tonsil and ecto‐cervix, only 3 (HB5, anti‐B2, AB1) showed staining of stratified epithelium; 2 of these (HB5, anti‐B2) also reacted with the surface of epithelial cells freshly dispersed from these sites. The proportion of HB5‐ and anti‐B2‐reactive cells in primary epithelial cultures fell to a low but stable level within days of explantation, while almost all permanently established epithelial cell lines, whether SV40 virus‐transformed or of malignant origin, were not reactive with either MAb. This contrasts with the pattern of expression of another surface marker also found selectively on cells of the lymphoid and epithelioid lineages, the CDw40 antigen. Staining with CDw40 MAbs on epithelial sections was usually restricted to the basal (proliferating) layer, but the proportion of CDw40‐positive cells increased to a relatively high level in normal epithelial cultures; furthermore, most epithelial cell lines expressed this antigen. Immunoprecipitation from the surface of metabolically labelled epithelial cells with the anti‐CD21 MAb HB5 yielded a protein of approximate MW 200 kDa, clearly different in size from the 145 kDa CD21 molecule on B cells. This 200 kDa protein was identified on fresh ecto‐cervical epithelium, on primary cultures of a laryngeal carcinoma and on one unusual SV40‐transformed epithelial cell line. We conclude that stratified human epithelial cells express a 200 kDa surface molecule which is antigenically related to, but not identical with, the CD21 antigen on B cells. It remains to be seen whether this epithelial cell protein can function as an EBV receptor.
Multiple infections in cases of cervical cancer from a high‐incidence area in tropical Africa
Authors: Schmauz R. , Okong P. , De Villiers E.‐M. , Dennin R. , Brade L. , Lwanga S. K. , Owor R. 
Published: February 2007

AbstractThe presence of several infections was determined in tissue and serum samples from 34 cases and 23 controls seen in 1984–85 at Mulago Hospital in Kampala, Uganda. When assessing single infections, association with cervical cancer could be shown for 5 agents, namely by Southern blot assay for human papillomavirus types 16 and 18 (HPV), and by serological tests at varying levels of antibody titres, for herpes simplex virus type 1 and/or 2 (HSV), cytomegalovirus (CMV), Epstein‐Barr virus, viral capsid antigen (EBV‐VCA), and Chlamydia trachomatis (CLT). Due to interaction, HSV and CMV were associated with cervical cancer only when infection by both of these agents was demonstrable. In the assessment of the simultaneous presence of these 5 infections, moderately high antibody titres were taken as the cut‐off point for infection by HSV, CMV, EBV‐VCA, and CLT. This showed that 3 and 4 infections at a time were seen in the majority of the cases in contrast to the controls with essentially no more than 2 such infections. A linear trend in the rise of risk for cervical cancer was noted with increasing number of infections.
Mammary adenocarcinomas induced by medroxyprogesterone acetate: Hormone dependence and egf receptors of BALB/c In vivo sublines
Authors: Lanari Claudia , Kordon Edith , Molinolo Alfredo , Pasqualini Christiane Dosne , Charreau Eduardo H. 
Published: February 2007

AbstractMammary adenocarcinomas were induced by medroxyprogesterone acetate (MPA) in female BALB/c mice. From 5 primary tumors, 9 different sublines were established by s.c. transplantation into syngeneic female mice; these developed after a long latent period (4‐12 months). Each subline was transplanted both into 4 mice treated with 40mg of MPA depot (s.c. contralaterally to the tumor inoculum) and into 4 non‐treated mice. Of the 9 sublines, 6 proved to be hormonedependent (MPA‐D) and 3 hormone‐independent or autonomous (MPA‐I). However, even the autonomous lines, when treated with MPA, showed a slight increase in growth. All MPA‐D lines had a high content of ER (20‐254 fmoles/mg of protein), PR (63‐710), PRL‐R (44‐74) and low or nondetectable EGF‐R. Of the 3 MPA‐I sublines that were studied, 2 showed a high content of ER (16‐125), PR (27‐708), PRL‐R (19‐70) and EGF‐R (29‐65) while the other one had a low content of ER (0‐36), PR (0‐13), no EGF‐R and moderate PRL‐R (15‐52). Spontaneous mammary tumors of BALB/c and C3H origin, which also showed an MPA‐l pattern of tumor growth, had high levels of EGF‐R. We postulate that MPA has a direct effect on mammary tumor cells in MPA‐D lines and that the expression of EGF‐R is correlated with an autonomous pattern of growth.
Monoclonal anti‐idiotypic antibody mimicking a tumor‐associated sialoglycoprotein antigen induces humoral immune response against human small‐cell lung carcinoma
Authors: Barth Andreas , Waibel Robert , Stahel Rolf A. 
Published: February 2007

AbstractWe have previously described the tumor‐associated sialoglycoprotein antigen sGP90‐135 defined by the murine LAM8 MAb. The antigen is characterized by strong membrane expression in a proportion of small‐cell carcinomas of the lung, but little or no expression on normal tissues of epithelial or neural origin or on blood cells. With the aim of obtaining anti‐idiotypic antibodies which might be useful as surrogates for sGP90‐135 in vaccination studies, LOU rats were immunized with LAM8 MAb and their spleen cells fused with Y3 rat myeloma cells. The LY8‐229 hybrid was selected by an antiidiotype competition radioimmunoassay on antigen‐positive target cells. LY8‐229 was shown to be a rat IgG1 with high specificity for LAM8 combining site. Solubilized small‐cell carcinoma extract, as well as antibody SEN16, which recognizes the same tumor‐associated antigen sGP90‐135, selectively inhibited 125I‐LY8‐229 binding to LAM8. Serum from BALB/c mice and DA rats immunized with anti‐idiotypic antibody LY8‐229 showed reactivity with antigen‐positive target cell lines, but not with antigen‐negative control cell lines. The induction of a specific immune response in 2 different species by the anti‐idiotypic antibody LY8‐229 suggests that LY8‐229 bears the internal image of the antigen sGP90‐135 and that it might be a candidate for immunotherapy trials in cancer patients.
Anti‐tumor effect of recombinant murine TNF‐alpha (rmutnfa) given by continuous I.V. infusion as compared to repeated I.V. injections in a rat liver metastasis model
Authors: Scheringa M. , Keizer A. , Jeekel J. , Marquet R. L. 
Published: February 2007

AbstractAnti‐tumor effects of TNF in animal models are well documented. Therapeutic use of TNF, however, is hampered by its toxicity. In rats a single intravenous (i.v.) injection of 40 μg/kg is lethal. When given by continuous i.v. infusion, much higher doses are well tolerated. To compare the therapeutic efficacy of rMuTNF given either as repeated i.v. injections or as a continuous infusion, we have used a liver metastasis model (tumor CC531). The number of liver metastases at day 28 after tumor inoculation served as a parameter. The route of administration, administration schedule and dose, did, in general, not influence the effect produced by rMuTNFa. Only early continuous infusion had an effect on the number of liver metastases. A sublethal dose, given as a late continuous infusion, had no significant effect. It thus appears that rTNFa, even when administered at high doses, is not a very efficient anti‐tumor agent. Attention should rather be focused on the use of rTNFa in combination with other substances, for example, interferons.
Characterization of immunoglobulin mrna expression in burkitt lymphoma cell lines
Authors: Anker Roberto , Caldwell James , Brokaw Jane , Pollok Brian A. 
Published: February 2007

AbstractImmunoglobulin heavy‐ and light‐chain mRNA of II Burkitt lymphoma (BL) cell lines (9 African and 2 American) were analyzed for various structural characteristics. In agreement with previous results at the protein level, all the BL cell lines express heavy‐chain mRNA transcripts of the μ class. Surprisingly, a high μ/μm mRNA ratio was found in 2 lgM‐producing BL cell lines (Raji and CCL85), that do not secrete immunoglobulin. Variable region gene use was also assessed in the cell lines: while 4 out of 7 endemic BL cell lines use VH genes that belong to the VH3 gene family, no clear bias in the expression of particular VH or VL gene families among this sampling of BL lines was found. Northern blot analysis of immunoglobulin transcripts in endemic BL cell lines did show that 2 such lines (AG876 and HTB62) expressed truncated heavy‐chain transcripts; RNA sequence analysis of the VH region demonstrated different abnormal 5‐localized RNA splicing events for the 2 shortened μ transcripts. The light‐chain mRNA in these 2 cell lines also showed structural abnormalities and, in the case of HTB62, 3 different K light‐chain transcripts are produced (of elongated, native and truncated sizes). In vitro translation of mRNA from HTB62 showed μ and K chain proteins corresponding with the relative size for each message.
Variations in serum alkaline dnase activity in rats during growth and treatment of tumors sensitive or resistant to therapy
Authors: Economidou‐Karaoglou Anna , Brasseur Francis , Lans Marc , Taper Henryk S. , Roberfroid Marcel B. 
Published: February 2007

AbstractSerum alkaline DNase activity (SADA) was investigated in rats receiving s.c. transplants of tumor cells sensitive or resistant to chemotherapy. Serum samples from each animal were collected before transplantation, during the development of tumors and after therapy. Within a few days after transplantation of both tumor lines (sensitive or resistant), SADA levels decreased progressively to 52% of the normal pre‐transplantation level (p < 0.01). This decrease in SADA preceded by 4 to 5 days the appearance of any palpable tumor mass. In all untreated animals as well as in treated rats bearing resistant tumors, SADA remained at a low level until death. In rats bearing tumors sensitive to therapy a progressive increase in SADA was observed after treatment, paralleling tumor regression. When tumor regression was complete, SADA resumed the levels of activity measured prior to transplantation.