bluuebunny/crossref_metadata_2025 huggingface dataset:
p53 mutations in esophageal tumors from high‐incidence areas of China
Authors: Liang Yuan‐Yuan , Estève Asuncion , Martel‐Planche Ghyslaine , Takahashi Satoru , Lu Shih‐Hsin , Montesano Ruggero , Hollstein Monica
Published: February 2007

Carcinomas of the upper digestive tract (squamous‐cell carcinoma of the esophagus, adenocarcinoma of the cardia) from 24 patients residing in Linxian (China) and near‐by high‐incidence areas were analyzed for mutations in exons 5–8 of the p53 tumor‐suppressor gene. Mutations were identified by polymerase chain reaction amplification and direct sequencing in 50% of the specimens. Eleven tumors harbored a single base‐pair substitution leading to either an amino‐acid substitution (8 tumors) or a chain‐termination signal (3 tumors), and one tumor revealed a 15‐bp deletion in exon 7 with a silent base substitution adjacent to the deletion site. Mutations occurred in all 4 exons examined, with a preponderance in exon 5. Of the 6 mutations identified among the 14 adenocarcinomas examined, 3 were G to T transversions, a mutation that has thus far been absent from reported mutations in Barrett's esophageal adenocarcinomas and dysplasias from patients residing in Europe and North America. © 1995 Wiley‐Liss, Inc.
Synergistic effects of co‐expression of the Th1 cytokines il‐2 and IFNγ on generation of murine tumor‐reactive cytotoxic cells
Authors: McAdam Alexander J. , Pulaski Beth A. , Harkins Stephanie S. , Hutter Elizabeth K. , Lord Edith M. , Frelinger John G.
Published: February 2007

While the effect of cytokines on the generation of tumor‐reactive cytotoxic cells has been a topic of active investigation, the effect of physiological cytokine combinations has not been determined. We have investigated the effect of co‐expression of IL‐2 and IFN‐γ on the generation of cytotoxic cells against the murine line 1 tumor in vivo. These cytokines were selected because they are normally produced in concert by a subset of T‐helper cells called T‐helper 1 (Th1). We transfected the line 1 murine carcinoma with cDNA for IL‐2 and IFN‐γ, alone or combined. IFN‐γ alone does not elicit rejection of the transfectant, but IL‐2 increases the tumorigenic dose by 10,000‐fold above the parental cells. Co‐expression of IFN‐γ and IL‐2 increases this rejection to at least 100,000‐fold above parental line 1. Unlike IL‐2 transfectants, tumor cells expressing both IFN‐γ and IL‐2 can also elicit rejection of admixed parental tumor cells. Finally, the IFN‐γ/IL‐2 transfectants are more effective at generating memory cells that are cytolytic for the parental tumor. Our results show that synergistic interactions of Th1 cytokines can remarkably enhance the cytotoxic response to tumors. © 1995 Wiley‐Liss, Inc.
Human skin fibroblasts induce anchorage‐independent growth of HPV‐16‐DNA‐immortalized cervical epithelial cells
Authors: Zheng Jie , Vaheri Antti
Published: February 2007

Immortalized non‐malignant cells do not grow in soft agarose. We found, however, that HPV‐16‐DNA‐immortalized human uterine exocervical epithelial cells (HCE 16/3 cell line) formed colonies when co‐cultured with human embryonic skin fibroblasts. This appeared to be mediated by diffusible growth factors, and direct cell‐cell contacts were not required. HCE 16/3 cells from colonies remained unable to grow alone in soft agarose like the parental HCE 16/3 cells, indicating that only transient phenotypic changes without genetic alterations had occurred in the co‐cultures. In a modified soft‐agarose assay, HCE 16/3 cells grown as an underlying monolayer did not produce enough (transforming) growth factors which could confer an anchorage‐independent phenotype to non‐transformed fibroblasts. Lethally irradiated fibroblasts were able to stimulate DNA synthesis and proliferation of HCE 16/3 cells. Northern‐blot analysis showed that HPV‐16‐DNA expression of the immortalized cells was not altered in the presence of fibroblasts. The expression of the IL‐I gene in the immortalized cells, however, was augmented by the co‐cultured fibroblasts compared with immortalized cells alone. In organotypic collagen raft co‐cultures, in which epithelial cells were grown on top of a collagen gel containing fibroblasts, HCE 16/3 cells appeared to be chemotactic to fibroblasts and fibroblasts stimulated the growth of the immortalized epithelial cells. Our results suggest that fibroblasts may contribute to human epithelial carcinogenesis in vivo. © 1995 Wiley‐Liss, Inc.
Mediation of glucocorticoid receptor function by the activation of latent transforming growth factor beta 1 in MG‐63 human osteosarcoma cells
Authors: Boulanger Jocelyn , Reyes‐Moreno Carlos , Koutsilieris Michael
Published: February 2007

We analyzed glucocortcoid receptor function using ligand binding assays, DNA band‐shift analysis and trans‐activation of the murine mammary tumor virus‐thymidine kinase‐chloramphenicol acetyltransferase reporter gene in transiently transfected MG‐63 human osteosarcoma cells. Dexamethasone increased the distribution of MG‐63 cells in the G1/G0 phase of the cell cycle, thus decreasing the rate of DNA synthesis and cell growth. Its effect on MG‐63 cell growth was neutralized by RU486 and anti‐transforming growth factor beta 1 (TGFβ1) antibody. In addition, (i) dexamethasone increased the levels of active TGFβ1 in MG‐63‐conditioned media without significantly altering the expression of TGFβ1 mRNA in MG‐63 cells and (ii) TGFβ1 inhibited proliferation of MG‐63 cells. Therefore, we conclude that glucocorticoid receptor function is mediated by the activation of latent‐TGFβ1 in MG‐63 osteosarcoma cells. © 1995 Wiley‐Liss, Inc.
Melanoma and use of sunscreens: An EORTC case‐control study in germany, belgium and france
Authors: Autier Philippe , Doré Jean‐François , Schifflers Eugène , Cesarini Jean‐Pierre , Bollaerts Anne , Koelmel Klaus F. , Gefeller Olaf , Liabeuf André , Lejeune Ferdy , Lienard Danièle , Joarlette Marie , Chemaly Philippe , Kleeberg Ulrich R.
Published: February 2007

Use of sunscreens is widely advocated as a preventive measure against sun‐induced skin cancers. However, to date, no epidemiologic study has reported a decreased melanoma risk associated with sunscreen use. We have conducted a case‐control study aimed at evaluating the influence of sunscreen use on the occurrence of cutaneous malignant melanoma. In 1991 and 1992, 418 melanoma cases and 438 healthy controls were interviewed in Germany, France and Belgium. The questionnaire used differentiated between regular sunscreens, psoralen sunscreen (prepared with 5‐methoxypsoralen, a tanning activator and photocarcinogen), and self‐tanning cosmetics (which produce a tan without ultraviolet radiation). After adjusting for age, sex, hair colour and holiday weeks spent each year in sunny resorts, the melanoma risk was of 1.50 (95% CI:1.09–2.06) for regular sunscreens, and of 2.28 (95% CI: 1.28–4.04) for psoralen sunscreens. No melanoma risk was associated with use of self‐tanning cosmetics. Among subjects with a poor ability to tan, psoralen sunscreen users displayed a melanoma risk of 4.45 (95% CI: 1.25–15.8) when compared with regular sunscreen users. There was a significant negative interaction between regular sunscreen use and sunburns experienced in adulthood. Use of sunscreens, especially psoralen sunscreen, was associated with higher density of pigmented lesions of the skin. Although we cannot exclude the presence of an unknown confounding factor, our results support the hypothesis that sunscreens do not protect against melanoma, probably because of their ability to delay or avoid sunburn episodes, which may allow prolonged exposure to unfiltered ultraviolet radiation. Serious doubts are raised regarding the safety of sunscreens containing psoralens. © 1995 Wiley‐Liss, Inc.
Trends in incidence of testicular cancer in boys and adolescent men
Authors: Møller Henrik , Jørgensen Niels , Forman David
Published: February 2007

Several epidemiological studies have described increasing trends over time in the incidence of testicular cancer in adult men. Less attention has been given to the trends in young boys, adolescents and old men. This paper describes the incidence of testicular cancer in young boys (0–4 years) and adolescents (15–19 years) in Denmark, Norway and Sweden, and compares these trends with the corresponding data on adults. Although only small numbers were available, the data suggest that the incidence of testicular cancer in young boys has been constant, at a level around 0.5 per 100,000. This observation lends support to the idea that testicular cancer in young boys is aetiologically distinct from testicular cancer in adults. In all three populations we found a particularly high average annual increase in the incidence of testicular cancer in adolescents (around 6% per year). It is proposed that this increase is mainly caused by a secular trend towards earlier age at puberty. © 1995 Wiley‐Liss, Inc.
Cytogenetic findings in malignant peripheral nerve sheath tumors
Authors: Mertens Fredrik , Rydholm Anders , Bauer Henrik F. C. , Limon Janusz , Nedoszytko Boguslaw , Szadowska Anna , Willén Helena , Heim Sverre , Mitelman Felix , Mandahl Nils
Published: February 2007

Clonal chromosome aberrations were detected in 8 short‐term cultured malignant peripheral nerve sheath tumors (MPNST). Seven had a near‐triploid chromosome number and I was in the hyperhaploid‐hypodiploid range. No recurrent structural rearrangements were found; the bands most frequently involved (3 tumors) were 7p11, 12p13 and 14q11. The most common numerical changes were loss of a sex chromosome (all tumors) and loss of at least 1 copy of chromosomes 8, 16 and 22 (4 tumors). Pooling our data with those on the 20 previously published MPNST with abnormal karyotypes, we found that the chromosome number has often been in the triploid range (12 tumors), with stem line variation between 34 and 270. All chromosome arms, except 22p and the Y chromosome, were involved in recombinations. The most frequently rearranged bands were 7p22 (6 tumors) and 1p21, 7p11 and 14q11 (5 tumors each). Most numerical and unbalanced structural aberrations have led to loss of genetic material, in particular from Xq26‐qter (13 tumors); 11q22‐qter and 13p (12 tumors); 9p22‐pter, 11p13‐pter, 17p and 17q11‐21 (11 tumors); 1p22‐32 and 1p34‐pter (10 tumors) and 6q25‐qter and chromosome 16 (9 tumors). © 1995 Wiley‐Liss, Inc.
Integrin expression on colorectal tumor cells growing as monolayers, as multicellular tumor spheroids, or in nude mice
Authors: Hauptmann Steffen , Denkert Carsten , Löhrke Heinz , Tietze Lothar , Ott Stephan , Klosterhalfen Bernd , Mittermayer Christian
Published: February 2007

In this study we compared the expression of integrin alpha chains 2, 3, 4, 5, 6, v and the beta chains 1, 3, 4 in 2 colorectal carcinoma cell lines (HRT‐18 and CX‐2), growing in confluent and subconfluent monolayer cultures, as multicellular tumor spheroids and in nude mice, using the immunofluorescence technique (confocal microscopy) and flow cytometry. The fast‐growing cell line HRT‐18 expressed, in confluent and subconfluent monolayer cultures, alpha 2, 3 and beta 1 with a continuous membranous staining pattern, whereas alpha v, alpha 6, and beta 4 were expressed continuously membranous in the intermediate and apical part of the cell layer, and clustered at focal contacts at the base of the cells. In spheroids and tumors of nude mice the focal pattern of alpha v, 6 and beta 4 was changed into a diffuse one. Using flow cytometry, the expression of alpha 3 was found to be reduced in spheroids of HRT‐18. The slowly‐growing cell line CX‐2 expressed, under the same conditions in monolayer culture, alpha 6, beta 1 and beta 4, and very weakly alpha 2, 3, 5 and v. Alpha 3 was expressed in spheroids of CX‐2 only at the outer rim where the cells proliferate. In contrast, alpha 2 and 5 were expressed mainly in the quiescent, non‐proliferating area. Alpha 6 was reduced in spheroids of CX‐2. In the nude mouse tumor of CX‐2, alpha 5 was expressed only focally and very weakly, alpha 2 was no longer detectable, but alpha v appeared to be enhanced in a focal pattern. These data indicate that integrin expression of tumor cells depends upon the culture system and that integrin expression in multicellular tumor spheroids is more similar to the in vivo situation in nude mouse tumors. © 1995 Wiley‐Liss, Inc.
Suramin sodium: Pronounced effects on methotrexate transport and anti‐folate activity in cultured tumor cells
Authors: Rideout Darryl C. , Bustamante Andres , Patel Rena , Henderson Gary B.
Published: February 2007

Suramin is an experimental anti‐neoplastic agent which has shown promising activity against prostatic carcinoma and lymphoma in clinical trials. To elucidate its mechanism of action, suramin was examined for an effect on the transport of folate compounds by tumor cells. Influx of the anti‐folate methotrex‐ate via the reduced‐folate carrier system of CCRF‐CEM cells was found to be highly sensitive to inhibition by suramin but not to various other arylsulfonic acids. Inhibition by suramin was competitive, and the inhibition constant Ki was 1.3 μM, a value 3‐fold lower than the Kt for half‐maximal influx of methotrexate. Folate binding to the membrane‐associated folate‐binding protein of KB cells was not affected by suramin. Growth studies revealed that the response of human CCRF‐CEM, KB, PC‐3 and MCF‐7 cells to methotrexate was antagonized from 6‐ to 17‐fold by pharmacological levels (10–200 μM) of suramin. Conversely, growth inhibition was additive or synergistic when suramin was combined with metoprine, a lipophilic anti‐folate which enters cells by diffusion. Synergism was observed between metoprine and suramin in CCRF‐CEM cells, which take up folate exclusively through the reduced‐folate carrier (inhibitable by suramin), whereas additivity was observed for KB cells, which rely largely on the folate‐binding protein (unaffected by suramin) for folate import. Our results indicate that inhibition of cellular transport of folate compounds may explain part of the anti‐neoplastic effects of suramin on tumor cells. © 1995 Wiley‐Liss, Inc.
Circumvention of confluence‐dependent resistance in a human multi‐drug‐resistant colon‐cancer cell line
Authors: Garrido Carmen , Chauffert Bruno , Pinard Dominique , Tibaut Florence , Genne Philippe , Assem Mahfoud , Dimanche‐Boitrel Marie‐Thérèse
Published: February 2007

Colorectal adenocarcinomas are inherently resistant to anthracyclines and other topoisomerase‐II inhibitors. Resistance to doxorubicin of colon cancer cells (Caco2) depends on 2 main mechanisms. The first is typical multi‐drug resistance, characterized by the mdr1 gene and its product the P170 membrane glycoprotein. P170 effluxes anthracyclines out of cancer cells and is antagonized in vitro by verapamil. The second mechanism, which develops when cell‐culture density increases, we have designated confluence‐dependent resistance. Confluence‐dependent resistance depends on the reduced topoisomerase II content of the G0/G1,‐phase cells which accumulate in the confluent population. We show here that short treatments of confluent Caco2 cells with slightly toxic concentrations of DNA‐damaging agents (cisplatin, melphalan or mitomycin C) produced a transient accumulation of cells in S‐ and G2/M‐phases of the cell cycle. Concomitantly with the increase in the S‐phase population, the topoisomerase II cellular level and the sensitivity of cells to doxorubicin were greatly enhanced. Over‐coming confluence‐dependent resistance through S‐phase accumulation and inhibition of multi‐drug resistance by verapamil were fully additive, and a nearly complete reversal of confluent Caco2 cells' resistance to doxorubicin was obtained when both strategies were combined. © 1995 Wiley‐Liss, Inc.
Mouse embryo fibroblasts transformed by activated ras or dominant‐negative p53 express cross‐reactive tumor rejection antigens
Authors: Appleman Leonard J. , Uyeki James , Frey Alan B.
Published: February 2007

To study the immune response against oncogene‐trans‐formed tumors, C3H/HeN mouse embryo fibroblasts (MEF) were transfected with an activated allele of the H‐ras proto‐oncogene Val12 and a dominant‐negative allele of the murine p53 tumor suppressor gene Val135. Transformed cell lines were derived and found to be tumorigenic in syngeneic mice. Immunization with irradiated p53 + ras‐transformed MEF, but not primary MEF or unrelated syngeneic cells, protected mice from subsequent challenge with live tumor cells. The role of different immune cell subsets in the effector phase of anti‐tumor immunity induced by immunization with p53 + ras‐transformed MEF was investigated by in vivo antibody depletion experiments. Immunized mice depleted of CD8+ T, NK or B cells were resistant, but depletion of CD4+ T cells rendered mice susceptible to tumorigenic challenge. In contrast to the tumor‐specific immune responses mounted against most chemically or UV‐induced tumors, a series of independently derived p53 + ras‐transformed MEF were cross‐reactive in tumor rejection assays. In addition, immunization with C3H‐derived L‐929 cell lines expressing single gene products H‐ras or p53 did not protect mice against tumorigenic challenge with p53 + ras‐transformed tumors. However, MEF transformed by expression of either H‐ras or p53 were cross‐protective in vivo. Our data suggest that the p53 + ras‐transformed MEF share tumor rejection antigens which are also induced by single gene transformation of the parental primary cell but are not the products of oncogenic ras or p53 protein. © 1995 Wiley‐Liss, Inc.
Analgesics and cancers of the renal pelvis and ureter
Authors: Linet Martha S. , Chow Wong‐Ho , McLaughlin Joseph K. , Wacholder Sholom , Yu Mimi C. , Schoenberg Janet B. , Lynch Charles , Fraumeni Joseph F.
Published: February 2007

To evaluate renal pelvis and ureter (RPU) cancer risk in relation to lifetime use of analgesics, a population‐based case‐control study was carried out in 3 areas of the United States. Among 502 cases and 496 controls diagnosed and interviewed during 1983–1986, no significant increases in risk were found for any of the non‐prescription and prescription analgesics evaluated or among regular users of phenacetin, acetaminophen or aspirin. Neither cumulative lifetime ingestion nor duration of regular use of these 3 drugs, whether alone or in combination, was associated with significantly increased risk of RPU cancer, although a slight excess was observed among long‐term users of acetaminophen. Risk was not increased among persons reporting highest cumulative dose and/or longest duration of phenacetin use. Although our study of RPU cancer is the largest to date, it was nonetheless limited by the small number of regular analgesic users and the relatively low response rates. Because of the relatively recent onset of widespread use of acetaminophen, its pharmacologic similarity to phenacetin, a known urothelial carcinogen, and the elevation in risk seen in long‐term users, further surveillance of this analgesic is warranted. © 1995 Wiley‐Liss Inc.
Mechanisms of allele‐selective down‐regulation of HLA class I in Burkitt's lymphoma
Authors: Imreh Marta P. , Zhang Qian‐Jin , De Campos‐Lima Pedro O. , Imreh Stephan , Krausa Peter , Browning Michael , Klein George , Masucci Maria G.
Published: February 2007

Burkitt lymphomas (BL) that arise in HLA‐A11‐positive individuals are characterized by selective loss/down‐regulation of the HLA AII polypeptide. We have investigated the molecular basis of such down‐regulation by comparing 5 pairs of BL lines and Epstein‐Barr virus (EBV)‐transformed lymphoblastoid cell lines (LCL) derived from the normal B cells of the same individuals. The presence of apparently intact HLA A11 genes was confirmed in all 5 BL/LCL pairs by polymerase chain reaction (PCR) typing and by Southern‐blot hybridization with HLA A locus‐specific probes. Northern‐blot analysis with locus‐and allele‐specific probes revealed a significantly lower expression or absence of A11‐specific mRNA in all 5 BL lines compared to the corresponding LCLs. Up‐regulation of Al1 ‐specific mRNA was achieved by IFNα treatment of 2 BL lines with low HLA A11 expression (BL‐28 and BL‐72) while the treatment had no effect in 3 BL fines (WWI ‐BL, WW2‐BL and BL41) that did not express the endogenous gene. HLA A11 expression was restored by transfection of the gene in WWI‐BL whereas transfectants of BL‐41 remained Al1‐negative. An HLA‐A11‐promoter‐driven chloramphenicol acetyl transferase reporter gene (pAl1 CAT) was active in WWI‐BL but not in BL‐41. HLA‐A11 was expressed in hybrids of BL‐41 with an A11‐positive LCL, while expression of the endogenous HLA A11 gene could not be restored by fusion of BL‐41 with an A11 ‐negative LCL, although an adequate set of transcription factors was present in the hybrid. Our results suggest that genetic defects and lack of transcription factors may contribute to the selective downregulation of HLA A11 in BL cells. © 1995 Wiley‐Liss Inc.
Hereditary aspects of endometrial adenocarcinoma
Authors: Suomi Raila , Hakala‐Ala‐Pietilä Tiina , Leminen Arto , Mecklin Jukka‐Pekka , Lehtovirta Pentti
Published: February 2007

The importance of heredity in the etiology of endometrial cancer (EC) was examined in a series of 326 patients with EC diagnosed at age 60 years or less. If one or both of the proband's parents had died of cancer, a thorough family history of malignancies was studied. Altogether 291 cases with complete parental data were found. Nine kindred (3.1%) showed features compatible with the dominantly inherited cancer trait known as hereditary non‐polyposis colorectal cancer (HNPCC). In another 9 cases, clustering of malignancies in 2 or more successive generations was indicative of familial cancer. A specific cancer aggregates were found in 112 probands' families, and family history was negative in 161 cases. No families had gynecological cancer as the only malignancy. HNPCC, the genetic etiology of which was recently revealed, seems to be an important risk factor for EC, indicating the significance of family‐history investigations of all patients with EC. Colorectal carcinoma (CRC) was here associated with EC also in families with clusterings of malignancies, but in these families no typical features of any known hereditary cancer syndrome could be found. On the basis of the results of the present study, proper surveillance for colorectal cancer should be recommended for patients with endometrial carcinoma if they belong to a family with features indicative of HNPCC. Furthermore, healthy gene carriers in an HNPCC family also need careful surveillance for CRC, EC and perhaps for other extra‐cofonic malignancies typical for HNPCC. Prophylactic surgery should even be considered in these cases. © 1995 Wiley‐Liss, Inc.
Age as a prognostic factor in breast cancer: Relationship to pathologic and biologic features
Authors: Bonnier Pascal , Romain Sylvie , Charpin Colette , Lejeune Christiane , Tubiana Nicole , Martin Pierre‐Marie , Piana Lucien
Published: February 2007

The relationship of age with prognostic factors and outcome of breast cancer has long been controversial due to numerous confounding factors. In order to clarify the prognostic value of age, we analyzed a homogeneous population of 1,266 patients treated for breast cancer at the same institution (mean follow‐up: 62 months). Three groups were compared: patients under 35 years of age, non‐menopausal patients over 35 years of age, and post‐menopausal patients under the age of 70 years. A higher frequency of undifferentiated tumors, histoprognostic grade‐3 cancer, microscopic lymph‐node involvement and negative hormonal receptor status was observed in patients under 35 years. In addition, clinical but not anatomical tumor size was greater in young patients, suggesting higher stromal activity. Metastasis‐free survival and overall survival were significantly poorer before 35 years. Differences were observed when patients were matched with regard to stage, anatomic size, histoprognostic grade, microscopic lymph‐node involvement and receptor status. Multivariate analysis of both overall and metastasis‐free survival demonstrated that age younger than 35 years was an independent risk factor. Younger women had a higher risk of local recurrence but, unlike older women, they did not experience any worsening of the already unfavorable outcome due to recurrence. © 7995 Wiley‐Liss, Inc.
EGFR gene amplification ‐ rearrangement in human glioblastomas
Authors: Schwechheimer Karl , Huang Su , Cavenee Webster K.
Published: February 2007

Immunostaining using an affinity‐purified rabbit polyclonal antibody against the extracellular domain of the epidermal‐growth‐factor receptor (EGFR) showed over‐expression occurring in a fraction of tumor cells in 17 out of 18 human glioblastomas and in a majority of cells in 7 of the 18. Southern‐blotting technique using a full‐length EGFR cDNA probe showed a variable degree of amplification in 10 of the 17 glioblastomas, which was associated with EGFR over‐expression in each case. In 2 of the glioblastomas with EGFR gene amplification, a rearrangement of the gene affecting the extracellular domain of the receptor was identified and DNA sequence analyses revealed an identical deletion‐rearrangement of 801 base pairs between exons 2 to 7, resulting in an in‐frame fusion of exons I and 8. © 1995 Wiley‐Liss, Inc.
Comparison of cell‐cycle phase perturbations induced by the DNA‐minor‐groove alkylator tallimustine and by melphalan in the SW626 cell line
Authors: Erba E. , Mascellani E. , Pifferi A. , D'Incalci M.
Published: February 2007

Tallimustine or N‐deformyl‐N‐[4‐N‐N,N‐bis(2‐chloroethylamino)benzoyl], a distamycin‐A derivative (FCE 24517), is a novel anti‐cancer agent which alkylates N3 adenine in the minor groove of DNA. The cell‐cycle phase perturbations induced by the drug were investigated and compared with those caused by melphalan (L‐PAM) in SW626 human ovarian‐cancer cells. By coupling bromodeoxyuridine (BUdR) immunoreaction with biparametric flow‐cytometric (FCM) analysis, we investigated the cell‐cycle phase perturbation induced by tallimustine or L‐PAM, considering separately the cells which, during the 1‐hr treatment, were in the S phase or in G1‐G2/M phases of the cell cycle. L‐PAM delayed the S‐phase progression of cells exposed to the drug when they were in S phase, with a consequent accumulation of cells as soon as they reached the G2 phase. In contrast, the S‐phase cells treated with tallimustine were not perturbed during the DNA‐synthesis phase progression, and were blocked in G2 only after they had passed through the G1/S transition of a new cell cycle. In cells which were in G1 or G2/M phases during drug treatment, tallimustine and L‐PAM caused similar accumulation in G2. The differences in the cell‐cycle perturbation caused by tallimustine and L‐PAM may well be related to the different DNA damage the 2 drugs produced. These findings emphasize the different properties of DNA‐minor‐groove alkylating agents and conventional ones. © 1995 Wiley‐Liss, Inc.
Rodent model of systemic mammary tumor disease by surgical removal of the spontaneously metastasizing SMT2A mammary carcinoma: Inhibitory effect of the stable prostacyclin Analogue cicaprost on occult metastasis
Authors: Schirner Michael , Schneider Martin R.
Published: February 2007

Cicaprost, a stable prostacyclin Analogue, has been shown to be anti‐metastatically active in a series of metastasizing rodent tumors. Start of treatment with cicaprost immediately before tumor implantation was a characteristic feature of our previous investigations. We have reported that in rats bearing mammary‐fat‐pad‐implanted SMT2A mammary carcinoma, cicaprost treatment starting before tumor implantation led to a strong decrease in the number of lung metastases. In order to determine the effect on occult tumor metastasis, the present study examined the effect of starting treatment when tumor metastasis is already present. Cicaprost in daily oral doses of 0.1 mg/kg given from day 10 to day 32 reduced the number of lung metastases by about 75% compared with the control, whereas surgical removal of palpable primary tumors on day 5 or day 10 failed to influence lung metastasis. Using different treatment schedules, a pronounced reduction of the number of lung metastases was achieved by administration of cicaprost until the end of the experiment (from day 5 to day 35), whereas short‐term treatments (from day 5 to day 15 or to day 25) were without significant effect. In rats whose SMT2A tumors were surgically removed 10 days after tumor implantation, there was a strong decrease of lung metastases by cicaprost given from day 20 to day 36. In addition to its inhibitory potential in animals with advanced tumor disease, cicaprost showed anti‐metastatic action when used in peri‐operative treatment of animals whose primary tumors had been removed. In conclusion, the present results demonstrate that cicaprost exhibits strong anti‐metastatic activity in the SMT2A rat mammary‐carcinoma model with treatment started when occult tumor metastases are already present. Results also indicate that direct effects on tumor cells may contribute to the anti‐metastatic action of cicaprost in spontaneously metastasizing tumors. © 1995 Wiley‐Liss, Inc.
Dna methylation status of the MUC1 gene coding for a breast‐cancer‐associated protein
Authors: Zrihan‐Licht Sheila , Weiss Mordechai , Keydar Iafa , Wreschner Daniel H.
Published: February 2007

The MUC1 gene codes for protein products that are highly expressed in human breast‐cancer tissue and that serve as tumor markers for disease progression. The factors contributing to the disease‐specific over‐expression of the MUC1 gene are under intensive investigation and are yet to be determined. A large transcribed region of the human MUCl gene is a CpG island that consists of 60‐bp tandemly repeating units, each of which contains one Smal restriction site. The methylation status of regulatory regions, upstream to the transcriptional start site, is essential for the regulation of gene expression. We therefore evaluated whether the methylation status of the various regions of the MUC1 gene may affect its expression. Using Smal, and its isoschizomer Xmal endonucleases, we demonstrated that in peripheral‐blood leukocytes (PBL‐DNA) that do not express the MUC1 gene, the repeat array is completely methylated, whereas the same sequences are entirely non‐methylated in breast‐tumor‐tissue DNA (BT‐DNA). In contrast, sequences upstream and downstream to the repeat array showed no difference in the methylation pattern in PBL‐DNA and BT‐DNA. Hypomethylation within the repeat array was also observed in other epithelial tissues that express the MUC1 gene at much lower levels to those seen in breast‐cancer tissue. These studies demonstrate that hypomethylation of the tandem repeat array is an absolute requirement for MUC1 gene expression in epithelial tissues, although in breast‐cancer tissue additional regulatory mechanisms must pertain for its over‐expression. © 1995 Wiley‐Liss Inc.
Retinoic acid and methotrexate specifically increase PHA‐E‐lectin binding to a 67‐kDa glycoprotein in LA‐N‐1 human neuroblastoma cells
Authors: Ross Sharon A. , Jones Carol S. , De Luca Luigi M.
Published: February 2007

Retinoic acid (RA) decreased growth and increased morphologic differentiation of human neuroblastoma LA‐N‐1 cells. These phenomena correlated with a specific enhancement of PHA‐E lectin binging to a glycoprotein of MW 67 kDa (gp67). Gp67 was found susceptible to N‐glycanase and displayed BSA binding by affinity chromatography analysis. The chemotherapeutic agent methotrexate (MTX) also reduced growth and induce differentiation of LA‐N‐1 cells. In addition, the cells responded to MTX as well as to doxorubicin by a marked increase in PHA‐E binding to gp67. We conclude that reduced growth and induction of morphological differentiation of LA‐N‐1 cells correlated with increased binding of PHA‐E to gp67. © 1995 Wiley‐Liss Inc.
Therapy of human B‐cell lymphoma bearing scid mice is more effective with anti‐CD19‐and anti‐CD38‐saporin immunotoxins used in combination than with either immunotoxin used alone
Authors: Flavell David J. , Boehm Deborah A. , Emery Loretta , Moss Armorel , Ramsay Alan , Flavell Sopsamorn U.
Published: February 2007

The CD 19+ CD38+ human Burkitt's lymphoma cell line Ramos grows aggressively when injected intravenously (i.v.) into severe combined immunodeficient (SCID) mice, killing 100% of animals within a 33–42 day period with widely disseminated disease. Treatment commencing 7 days after i.v. injection of Ramos cells, with 3 doses of an anti‐CD 19 immunotoxin (IT; BU12‐SAPORIN) or an anti‐CD38 IT (OKTIO‐SAPORIN) led to a significant prolongation of survival compared with shamtreated controls; the anti‐CD38 IT gave the greatest prolongation of survival, but all treated animals eventually succumbed to disease. When both ITs were used in combination at equivalent dose levels, the therapeutic outcome was significantly improved over that obtained for single IT therapy, with 20% of animals surviving disease‐free to 300 days. When anti‐CD38 IT was given in combination with anti‐CD 19 antibody there was no therapeutic improvement over anti‐CD38 IT used alone. However, when anti‐CD 19 IT was given in combination with CD38 antibody, a significant prolongation of survival ensued over that obtained with anti‐CD 19 IT alone, though this was not as significantly pronounced as that obtained when both ITs were used in combination and was only as good as the survival obtained with OKT10 antibody used alone. CD 19 and CD38 are expressed on the surface of the vast majority of B‐cell lymphoma and common acute lymphoblastic leukaemia cells, and our findings provide a sound rationale for a combination immunotoxin trial in these diseases directed against both these target molecules. © 1995 Wiley‐Liss Inc.
Administration of disulfide‐stabilized Fv‐immunotoxins B1(dsFv)‐PE38 and B3(dsFv)‐PE38 by continuous infusion increases their efficacy in curing large tumor xenografts in nude mice
Authors: Benhar Itai , Reiter Yoram , Pai Lee H. , Pastan Ira
Published: February 2007

B1 (dsFv)‐PE38 and B3(dsFv)‐PE38 are recombinant immunotoxins in which the Fv fragments of MAbs B1 and B3, respectively, are stabilized by an engineered interchain disulfide bond and are fused at their C‐termini to a modified Pseudomonas exotoxin from which the cell‐binding domain has been deleted (PE38). Both immunotoxins have been shown to be specifically cytotoxic toward human cancer cell lines which express LeY‐related carbohydrates on their surface, and when given i.v., eradicated 30‐to 50‐mm3 s.c. A431 tumors growing in nude mice. A major advantage of dsFv‐immunotoxins is their stability at 37°C compared with the relatively unstable single‐chain Fvs. This allows them to be given continuously by osmotic pumps placed in the peritoneal cavity. In an attempt to increase the therapeutic index of the immunotoxins, we have now delivered them continuously for 6 days through mini‐osmotic pumps placed in the peritoneal cavity of tumor‐bearing nude mice. Using this mode of administration, we were able to maintain a constant level of immunotoxin in the serum which was non‐toxic to the mice, but caused complete regressions of large 150‐to 200‐mm3 tumors which lasted for over a month at 1/11 of the LD50 with B1(dsFv)‐PE38 and 1/6 of the LD50 with B3(dsFv)‐PE38. Complete regression of tumors of similar size could also be achieved by i.v. bolus injections of these immunotoxins at 1/7 of the LD, o with B1 (dsFv)‐PE38) and 1/3 of the LD50 with B3(dsFv)‐PE38. These results suggest that in patients it may be advantageous to administer dsFv‐immunotoxins by continuous infusion, since a larger therapeutic index is achieved. © 1995 Wiley‐Liss Inc.
Enhanced expression of transforming growth factor‐β and its type‐I and type‐II receptors in human glioblastoma
Authors: Yamada Naoshi , Kato Mitsuyasu , Yamashita Hidetoshi , Nistér Monica , Miyazono Kohei , Heldin Carl‐Henrik , Funa Keiko
Published: February 2007

Immunohistochemical studies of transforming growth factor‐p (TGF‐P) and its receptors have been carried out on 16 glioma tissues and compared with 5 cases of gliosis. Significantly higher expressions of TGF‐βI, as well as type‐I and type‐II TGF‐β receptors (TβR‐I and TβR‐II, respectively), were observed in advanced‐malignant‐glioma tissues when compared with non‐tumorous gliosis. Immunoreactivities of TGF‐β and TβR‐I were localized in the cytoplasm of spindle‐shaped tumor cells surrounding proliferating vessels or around areas of necrosis. The advancing edge of the tumor clusters frequently stained positive. Similar expression patterns were found for TGF‐β2 and TGF‐β3, whereas only weak or no expression was found for endoglin. In low‐grade astrocytomas and in gliosis cases, the expression was moderate for TβR‐I and weak for TGF‐β and TβR‐II. In 3 examined human malignant glioma cell lines, clear immunostainings were detected for TGF‐β and its receptors. Ligand‐induced heteromeric complexes of the receptors were formed in these cell lines, but the amount of the receptors was less than that of mink lung epithelial cells, which are sensitive target cells for TGF‐β. TGF‐β I showed no growth‐inhibitory activity on any of these glioma cell lines. These results suggest that malignant gliomas produce TGF‐β and receptors, but are refractory to TGF‐β, implying dysregulation in the signalling pathway in the tumor cells. It is possible that the released TGF‐β acts on neighboring cells and affects stromal growth, angiogenesis, metastasis or immune surveillance in human glioma. © 1995 Wiley‐Liss, Inc.
Comparison of protein kinase C activity and isoform expression in cisplatin‐sensitive and ‐resistant ovarian carcinoma cells
Authors: Basu Alakananda , Weixel Kelly M.
Published: February 2007

Cellular sensitivity to cis‐diamminedichloroplatinum(II) (cDDP) can be regulated by protein kinase C (PKC) signal transduction pathway. Activators of PKC were shown to en‐ hance the sensitivity of human ovarian carcinoma 2008 cells to cDDP. We have examined whether or not the PKC signal transduction pathway is affected during‐development of resistance by tumor cells to cDDP. A 2‐fold decrease in PKC activity was observed in cDDP‐resistant ovarian carcinoma 2008 J. C13*5.25 cells compared with the drug‐sensitive 2008 cells. Subceflular distribution studies revealed a reduction in both cytosolic and paniculate PKC activities in 2008/C13*5.25 cells. The pattern of PKC isoform expression was compared in cDDP‐sensitive and ‐resistant cell lines by Western blot analysis with isoform‐specific antibodies to PKC. The parental cells expressed PKCα, ‐ε, and ‐ζ isoforms. The abundance of PKCα decreased significantly in 2008/C 13*5.25 cells, whereas the amount of PKCe increased moderately in the resistant variant, with no alteration in PKCε content. Therefore, a reduction in PKCa and/or an increase in PKCε expression may be associated with the drug‐resistant phenotype. © 1995 Wiley‐Liss, Inc.
Determinants of plasma pepsinogen levels in a population at high risk for stomach cancer in venezuela
Authors: Kato Ikuko , Miki Kazumasa , Muñoz Nubia , Vivas Jorge H. , Lopez Gladys , Peraza Simon , Carillo Elsa , Castro Denis , Andrade Olga , Sanchez Victor , Cano Elsa , Ramirez Hernan , Muggli Reto , Benz Maja , Oliver Walter
Published: February 2007

Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre‐cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG‐I and PG‐II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre‐cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (<2.0) was inversely associated with tobacco consumption. This may be due to a pharmacological effect of nicotine. The severe reduction of I/II ratio was also inversely associated with fresh fruit consumption. In addition, a decreased I/II ratio was positively associated with rice/pasta and arepas (tortilla made from corn) consumption and inversely associated with plantain consumption. Possible effects of vitamins and starchy food on the development of atrophic gastritis need to be studied further. © 1995 Wiley‐Liss, Inc.
Induction of platelet‐derived growth factor A and B chains and over‐expression of their receptors in human pancreatic cancer
Authors: Ebert Matthias , Yokoyama Munehiro , Friess Helmut , Kobrin Michael S. , Büchler Markus W. , Korc Murray
Published: February 2007

Expression of platelet‐derived growth factor (PDGF) and PDGF receptors was examined in cultured human pancreatic cancer cells, in the normal human pancreas and in pancreatic adenocarcinomas. mRNA transcripts encoding PDGF A and B chains, and PDGF receptor 0 (PDGFR3) were present in PANC‐I and HPAF human pancreatic cancer cells. Transforming growth factor β I (TGF‐βl), but not PDGF‐AA or ‐BB, enhanced PDGF A and B chain mRNA levels in both cell lines. In the normal human pancreas PDGF A chain mRNA levels were relatively abundant, whereas PDGF B chain mRNA levels were not detected and PDGF receptor a (PDGFRa) and p mRNA transcripts were present at low levels. PDGF immunoreactivity was present in islet cells, and PDGFRa was present in acinar cells, whereas PDGFRβ was present in acinar cells and in the connective tissue. In the pancreatic cancers, PDGF A chain mRNA transcripts were also abundant, and 6 of 13 samples exhibited the PDGF B chain mRNA transcript. In addition, there was a 7‐fold increase in the levels of PDGFRa and PDGFRp in the cancer samples by comparison with the normal pancreas. By immunohistochemistry, PDGF and both PDGF receptors were present in the cancer cells, and PDGFR3 was abundant in fibroblasts and endothelial cells within the connective tissue. © 1995 Wiley‐Liss, Inc.
Tumor‐infiltrating T lymphocytes from renal‐cell carcinoma express B7‐1 (CD80): T‐Cell expansion by T‐T cell co‐stimulation
Authors: Thurnher Martin , Radmayr Christian , Hobisch Alfred , Böck Günther , Romani Nikolaus , Bartcch Georg , Klocker Helmut
Published: February 2007

B7‐I (CD80) provides co‐stimulation for T‐cell activation by interacting with CD28 or CTLA4. Here we demonstrate the expression of B7‐I in freshly isolated and cultured lymphocytes from renal‐cell carcinoma. In fresh preparations of lymphocytes infiltrating renal‐cell‐carcinoma tissue, B7‐1 mRNA could readily be detected by reverse transcription PCR, and 2‐color flow‐ cytometry analysis revealed substantial B7‐1 expression on T cells from these isolates. As expected, tumor‐derived T cells also expressed CD28, the B7 receptor. While B7‐1 expression of tumor‐derived T cells was maintained during culture in interleukin‐2‐supplemented medium, CD28 expression was further enhanced. We also show that B7‐I is functionally involved in T‐cell expansion: anti‐B7‐1 MAb inhibited the PHA‐induced proliferation of tumor‐derived B7‐1+ T cells (35%) in the absence of exogenous antigen‐presenting cells, indicating that B7‐1 mediates T‐T cell co‐stimulation (self‐co‐stimulation). Our data demonstrate that T cells infiltrating renal‐cell carcinoma express B7‐I, and that mutual co‐stimulation via the B7‐I/ CD28 pathway contributes to the interleukin‐2‐driven expansion of tumor‐derived T cells in vitro. The frequency of B7‐1+ T cells in tumor lesions and the level of B7‐I on these cells may determine the time course of T‐cell expansion in vivo. Self‐co‐stimulation, however, might also represent one mechanism leading to the state of suppression or anergy characteristic of tumor‐infiltrating lymphocytes. © 1995 Wiley‐Liss, Inc.
Progression toward metastatic phenotype with loss of growth‐inhibiting tumor‐cell/cell interactions in vivo
Authors: Takeda Yasutaka , Sayama Kazutoshi , Saegusa Yoshiyuki , Matsuzawa Akio
Published: February 2007

Five autonomous sub lines, T4‐O1320, T4‐O1320CY, T4‐O1165, T4‐O1145 and T4‐O196, were established from the transplantable hormone‐dependent mouse mammary tumor, TPDMT‐4, by pass aging under different conditions. These autonomous tumors were characterized by rapid growth in DDD virgin mice and the parental TPDMT‐4 by no growth in these mice. Thus, 105 T4‐O1320, 2 × 104 T4‐O1320CY, 2 × 103 T4‐O1165, 2 × 103 T4‐O1145 and 103 T4‐O196 cells were co‐injected with 5 × 102 TPDMT‐4 cells into virgin mice to determine whether or not hormone‐dependent tumor cells influence the growth of autonomous tumor cells. TPDMT‐4 cells retarded the growth of T4‐O1320 and T4‐O1320CY tumors but accelerated that of T4‐O1165, T4‐O1145 and T4‐O196. Irradiated TPDMT‐4 cells stimulated the growth of all the sub lines except T4‐O1320. In 3‐dimensional collagen‐gel culture, T4‐O1320 and T4‐O1320CY cells formed branched or stellate structures similar to normal mammary glands, as did TPDMT‐4, but T4‐O1165, T4‐O1145 and T4‐O196 cells grew as rounded masses with knobs and showed a completely different morphology. T4‐O1165, T4‐ O1145 and T4‐O196 cells, but not the others, had lung‐colonizing ability. Chromosomal aberration was found in T4‐O1320CY and T4‐O196 but not in the others. Thus, the susceptibility of autonomous sub line tumor cells to growth‐inhibitory regulation from the parental hormone‐dependent tumor cells correlated well with growth morphology within collagen gels and meta‐static ability, but not with chromosomal aberration. The results suggest that meta‐statically‐competent tumor‐cell variants, once they appear, may have a growth advantage in hormone‐ dependent mammary tumors. © 1995 Wiley‐Liss, Inc.
Effect of hyperthermia on the cytotoxicity of 2′,2′‐difluorodeoxycytidine (gemcitabine) in cultured SW1573 cells
Authors: Haveman J. , Rietbroek R. C. , Geerdink A. , van Rijn J. , Barker P. J. M.
Published: February 2007

Difluorodeoxycitidine (dFdCyd, gemcitabine) was tested for cytotoxicity in cultured human lung‐cancer cells SW1573 in combination with 1 hr hyperthermia at 43°C. The results show that the timing is extremely important. Simultaneous application led to decreased cytotoxicity, whereas an interval of 20 or 24 hr between exposure to dFdCyd and hyperthermia led to enhanced cell killing. The decrease in cytotoxicity after simultaneous hyperthermia and dFdCyd probably results from inhibition of activation of dFdCyd to the triphosphate metabolite. The enhanced cytotoxicity in sequential application of dFdCyd and hyperthermia is not caused by accumulation of cells in a sensitive cell‐cycle phase. Our results show that the G1 phase becomes relatively abundant 20 hr after exposure to 0.1 μM dFdCyd, approximately 48% versus 31% in control cultures. Presumably,. inhibition by hyperthermia of repair of DNA damage plays a role. Our results confirm earlier data with regard to reutilization of activated dFdCyd at high cell density. dFdCyd was clearly more toxic to SW1573 cells at 4 × 105 cells per dish than at 400 cells per dish. This reutilization of activated drug is evidently not a restricted property of a particular cell fine and may add to the value of the drug in cancer treatment. © 1995 Wiley‐Liss, Inc.