bluuebunny/crossref_metadata_2025 huggingface dataset:
Over‐expression of the epidermal growth factor receptor in human breast cancer cells fails to induce an Estrogen‐independent phenotype
Authors: Valverius Eva M. , Velu Thierry , Shankar Vidya , Ciardiello Fortunato , Kim Nancy , Salomon David S.
Published: February 2007

An association exists in primary human breast tumors between high epidermal growth factor receptor (EGFR) expression and a reduced number or even absence of estrogen receptors (ER). To determine whether an increase in EGFR expression might alter the estrogen responsiveness of an ERpositive human breast cancer cell line, ZR 75‐1 cells were cotransfected with a plasmid containing the full‐length cDNA for the human EGFR under the transcriptional control of the Harvey murine sarcoma virus (HaMSV) long terminal repeat (LTR) and with a pSV2neo plasmid. Two of the isolated G4 18‐resistant clones were found to constitutively express EGFR levels 15‐ to 60‐fold higher than those found on nontransfected ZR 75‐ I cells. The EGFR in these clones were functionally normal since EGF could increase their autophosphorylation and since EGF could enhance the transphosphorylation of p185erbe‐2. No change was seen in either the number or affinity of ER in these clones. In addition, the ability of estrogen to stimulate the anchorage‐dependent and anchorageindependent growth of these clones was not significantly modified. These results suggest that an increase in EGFR expression alone is not sufficient to induce a hormoneindependent phenotype in vitro in human breast cancer cells.
Aluminum phthalocyanines with asymmetrical lower sulfonation and with symmetrical higher sulfonation: A comparison of localizing and photosensitizing mechanism in human tumor LOX xenografts
Authors: Peng Q. , Moan J. , Nesland J. M. , Rimington C.
Published: February 2007

A comparison of time‐dependent localization patterns between lower, asymmetrical (AIPCS2a) and higher, symmetrical (AIPCS4) sulfonates of aluminum phthalocyanines in human malignant melanoma LOX transplanted to athymic nude mice from 1 to 120 hr after i. v. administration was made by means of laser scanning fluorescence microscopy. The lipophilic AIPCS2a was distributed mainly in tumor cells, while the hydrophilic AIPCS4, localized only in the vascular stroma of the tumor tissue. Concomitantly, comparative observations on the killing mechanism of photodynamic effects after treatment with a much lower i. v. dose of AIPCS2a and AIPCS4 plus laser light on the human tumor LOX were also made by morphological studies. Light and electron microscopy showed that there was a direct, extensive, photo‐damaging action on all organelles and nuclear structure in the tumor cells after PDT with AIPCS2a; whereas the photo‐induced injury to the tumor tissue after treatment with AIPCS4 and light was largely the consequence of initial functional vasogenic response and ultimate damage to vascular structure. These findings correlate well with the different localization patterns of the 2 dyes observed in human tumor tissues.
Epidermal cell‐shape regulation and subpopulation kinetics during butyrate‐induced terminal maturation of normal and SV40‐transformed human keratinocytes: Epithelial models of differentiation therapy
Authors: Staiano‐Coico Lisa , Steinberg Mark , Higgins Paul J.
Published: February 2007

Recent data indicate that malignant human epidermal cells may be appropriate targets for sodium butyrate (NaB)‐mediated differentiation therapy. The response of pre‐ and post‐crisis populations of SV40‐transformed human keratinocytes (SVKs) to this differentiation‐inducing agent was assessed, therefore, within the framework of NaB‐directed normal human keratinocyte (NHK) maturation. NaB augmented cornified envelope (CE) production in NHK and pre‐crisis SVK cultures; the time‐course and efficiency of induced maturation were similar in the 2 cell systems. In NHKs, the percentage of amplifying (“B” substate) cells decreased with time in NaB correlating with increases in both “C” stage keratinocytes and CEs. The latter formed over one or 2 layers of nucleated basal‐like cells. Inductions were accompanied by immediate cell cycle blocks (in both the G1 and G2/M phases), reorganization within the actin cytoskeleton, and transient early increases in cellular actin content. Increased NHK and pre‐crisis SVK cytoskeletal‐associated actin reached a maximum approximately 48 hr after NaB addition and preceded development of CEs. The CE precursors, thus, probably reside in the “B” substate. Post‐crisis SVKs, in contrast, were refractive to NaB‐induced terminal maturation or cell‐cyccle perturbation, failed to initiate actin filament rearrangements, and retained a basal cell‐like phenotype. Stable transformation of human SVKs in post‐crisis phase, therefore, appears to be associated with loss of maturation “competence” within the “B” keratinocyte subpopulation.
The presence of plasmin receptors on three mammary carcinoma MCF‐7 sublines
Authors: Correc Philippe , Fondanèche Marie‐Claude , Bracke Marc , Burtin Pierre
Published: February 2007

We studied plasmin receptors on 3 MCF‐7 sublines: MCF7, MCF7R which was derived by transfection with v‐Ha‐ras oncogene, and MCF7MF which has been studied for the secretion of procathepsin D in the presence of estrogen. All 3 sublines bound plasmin (Pli) with a much higher affinity than plasminogen (Pg). The number of binding sites was increased about 4‐fold by weak proteolytic pretreatment of tumor cells. Transfection by v‐Ha‐ras oncogene did not apparently change the affinity of Pli binding sites (KD 27‐26 nM) and increased their number very slightly (3,800 against 3,200 fmoles/mg protein). However, this number was 5 times higher for MCF7MF (15,000 fmoles/mg protein) and the affinity was 4 times lower (106 nM). MCF7 and MCF7R sublines have previously been reported to be non‐invasive in the in vitro invasion assay system (embryo chick heart muscle) but tumorigenic and metastatic in nude mice. In contrast, the MCF7MF subline has been shown to be invasive in both in vivo and in vitro invasion systems. Thus, the number of Pli binding sites at the MCF7 tumor‐cell surface may be associated directly or indirectly with tumor‐cell invasiveness.
Occurrence of non‐gastric cancer in the digestive tract after remote partial gastrectomy: Analysis of an Amsterdam cohort
Authors: Tersmette Anne C. , Offerhaus Johan G. A. , Giardiello Francis M. , Tersmette W. F. Kasper , Vandenbroucke Jan P. , Tytgat N. J. Guido
Published: February 2007

If peptic ulcer surgery favors the formation of carcinogenic N‐nitroso compounds in the gastric remnant, an increased risk of cancer at sites in the gastrointestinal tract distant from the stomach might be predicted. To estimate the risk of carcinomas in the digestive tract, other than the stomach, occurring after partial gastrectomy, we analyzed an Amsterdam cohort of 2,633 post‐gastrectomy patients operated on for benign disease between 1931 and 1960. Mortality in the study population was compared with the general Dutch population through person‐year analysis. An excess mortality of biliary tract cancer (O/E:2.64; CL:1.32‐4.72; p < 0.01) and pancreatic cancer (O/E:1.65; CL:1.06‐2.44; p < 0.05) was found in males more than 5 years after surgery; females showed only an increased risk of pancreatic cancer in the first 5 years postoperatively (O/E: 15.33; CL: 1.85‐55.43; p < 0.01), probably due to misdiagnosis. All other non‐gastric sites of the digestive tract carried no increased risk for cancer. In males, mortality due to colorectal cancer more than 5 years post‐operatively was significantly decreased (O/E:0.58; CL 0.34‐0.92; p < 0.01). The excess mortality of biliary‐tract and pancreatic cancer in males, which increases with the duration of post‐operative interval, is consistent with a dose‐response phenomenon. This study therefore supports the hypothesis that carcinogens are not only locally activated in the gastric remnant, but are hepatically excreted and initiate cancer in the biliary tree and pancreatic duct. Further exploration of this mechanism of carcinogenesis is warranted, since it may also explain the pathogenesis of pancreatic and biliary cancers in patients without gastrectomy.
Evaluation of CA 125 as a serum marker of hepatocellular carcinoma
Authors: Elias John , Kew Michael C.
Published: February 2007

Serum CA 125 concentrations were raised in 90.4% of 115 southern African black patients with hepatocellular carcinoma. Seventy‐four percent of 62 patients with amebic hepatic abscess, 60% of 40 patients with chronic hepatic parenchymal disease (chronic hepatitis or cirrhosis), and 60.9% of 41 patients with acute viral hepatitis also had raised values. The median serum CA 125 concentration for patients with hepatocellular carcinoma differed significantly from the benign hepatic disease groups analysed (p < 0.0002). Serum alphafetoprotein levels were raised in 90.4% of the 115 hepatocellular carcinoma patients. CA 125 is thus a highly sensitive marker for hepatocellular carcinoma, but lacks specificity.
Patterns of expression of the p53 tumour suppressor in human breast tissues and tumours in situ and in vitro
Authors: Bártek Jiří , Bártková Jiřina , Vojtěšek Bořivoj , Stašková Zdenka , Rejthar Aleš , Kovařík Jan , Lane David P.
Published: February 2007

An extensive series of histological sections reflecting the various states of normal breast tissue, and a range of benign and malignant lesions, were examined for the expression of the p53 protein using a panel of anti‐p53 antibodies. In 2 separate series the results of using frozen or methacarn‐fixed, paraffin‐embedded sections were compared. Strong positive staining for p53 was detected in over 50% of the malignant lesions when frozen sections were used. This number fell to just over 20% when methacarn‐fixed sections were examined. In neither series was any p53 staining seen in normal breast or in the benign lesions. Studies by Western blotting on breast cell lines confirmed that this histological signal is due to a pronounced over‐expression of the p53 protein. Earlier studies show that this over‐expression is associated with mutation of the p53 gene. Mutation of the p53 gene with over‐expression of the mutant protein is therefore one of the most frequent specific genetic changes in malignant breast cancer.
Abelson murine leukemia virus transforms preneoplastic Eμ‐myc transgene‐carrying cells of the B‐lymphocyte lineage into plasmablastic tumors
Authors: Sugiyama Hiroyuki , Silva Santiago , Wang Yisong , Weber Gunther , Babonits Magdalena , Rosén Anders , Wiener Francis , Klein George
Published: February 2007

Eμ‐myc transgenic mice were back‐crossed to BALB/c mice up to back‐cross generation 3. The offspring that included transgene‐carrying and ‐negative mice in approximately equal proportions were randondy divided into 2 groups. Thirty‐four mice (group I) were treated with pristane, fol‐lowed by A‐MuLV, and 40 (groulp II) were injected with AMuLV alone. Altogether, 16 lymphoid tumors developed in group I and 17 in group II. Nine oJ the tumors in group I and 4 in group II appeared as ascitic tumors. The ascites contained lymphoblasts and 10 to 45% plasrriacytoid cells. These tumors were designated as plasmablastic lymphomas (PLs). All tumors except one were transgene‐positive and did not carry translocations. An exceptional tunnor in group I carried a variant 6; 15 translocation but not the transgene. It obviously corresponds to the regular Abelson + pristane‐induced plasmacytoma. Among II tested PLs, 10 had a single retroviral insertion site, while one tumor showed 3. Among 18 untreated transgenic descendants (group III), chosen randomly during serial back‐crosses, 15 (83%) developed lymphomas, with no sign of plasmacytoid differentiation. The incidence was comparable in all 3 groups, assuming 50% of the mice in groups I and II to be transgenic. The time distribution of tumor development was also similar. Spleen cells from transgene‐carrying mice with no clinical sign of lymphoma were infected in vitro with A‐MuLV and transplanted i. p. into BALB/c recipients. PLs developed in 26 of 31 pristane‐treated recipients, but in only one of 18 untreated recipients. One of 6 PLs tested was monoclonal, whereas the remainiing 5 were oligoclonal. They all expressed v‐abl. These results show that some of the preneoplastic B‐cells that expressed constitutively active rnyc transgene turned into plasmablasts after infection with AMuLV. Full development of their neoplastic potential was facilitated by the presence of pristane‐granuloma.
Enhancement of an anti‐tumor effect of interferon by dipyridamole in established human malignant melanoma cell lines
Authors: Kojima Takayuki , Suzuki Nobuo , Sugano Isamu , Hayata Isamu
Published: February 2007

Enhancement of the anti‐proliferative effect of human interferon (HuIFN) preparations (α, β and γ) by dipyridamole was detected in a human malignant melanoma cell line, MMICB, which we originally established. Cell growth was inhibited by HulFN alone, but a marked increase in inhibition was noted in vitro and in vivo when dipyrydamole was added. Cellular DNA synthesis, as dletermined by 3H‐deoxythymidine incorporation into the acid‐insoluble cellular fraction, was more inhibited by combined treatment than by any of the agents used alone. Two other melanoma cell lines that we established, MM‐2CB and MM‐3CB, also exhibited sensitivity to combined treatment both in vitro and in vivo. Furthermore, the HMV‐I and SEKI melanoma cell lines were susceptible to the combination. Even non‐cytotoxic concentrations of dipyridamole could enhance the effect of HulFN on MM‐ICB, MM‐2CB, and SEKI cells.
Immunochemical comparison of transformation‐associated protein and secreted phosphoprotein
Authors: Chan James C. , Scanlon Mike , Denhardt David T. , Singh Krishna , Mukherjee Barid B. , Farach‐Carson Mary C. , Butler William T.
Published: February 2007

Transformation‐associated protein (TAP) has been detected in MSV‐M‐transformed rat cell lines as glycosylated, weakly phosphorylated protein of molecular weight (Mr) 66,000 and 68,000. In the ts‐MSV‐M‐transformed rat kidney cell line (6m2), the synthesis of TAP and the v‐mos gene product is temperature‐sensitive and accompanies the expression of transformation phenotypes. Therefore, TAP potentially plays a role in cellular transformation. On the other hand, SPP represents a family of glycosylated phosphoprotein with apparent Mr ranging from 42,000 to 69,000. SPP has been detected in osteoblasts and in avian and murine retrovirustransformed rat and mouse epithelial cells. Therefore, the potential relatedness of TAP and SPP was studied. Using the 6m2 cells, we found that SPP was strongly phosphorylated and was synthesized at both the permissive (33°C) and nonpermissive (39°C) temperatures. By contrast, TAP was weakly phosphorylated, and was synthesized, as we found previously, only at the permissive temperature of 33°C. Furthermore, in 35S‐methionine incorporation studies, TAP became heavily labelled whereas SPP was not (consistent with its amino acid composition having few methionine residues). Using 125I‐TAP in both immunoprecipitation and radioimmunoassays, it was found that an antiserum raised against SPP did not cross‐react with 125I‐TAP. Additionally, SPP has now been found in many human and rodent cells, while TAP thus far has only been detected in MSV‐transformed rat cells. These data suggest that structurally, TAP and SPP are not closely related phosphoproteins.
Evidence for the role of 34‐kDa galactoside‐binding lectin in transformation and metastasis
Authors: Raz Avraham , Zhu Daguang , Hogan Victor , Shah Nipa , Raz Tirza , Karkash Rivka , Pazerini Galit , Carmi Pnina
Published: February 2007

The endogenous M, 34,000 galaictoside‐binding lectin (L‐34) is found at elevated levels in a wilde variety of neoplastic cells and correlative evidence suggests that it is involved in tumor metastasis in vivo and in transformation in vitro. We demonstrate here that introduction of recombinant L‐34 into tumorigenic, weakly metastatic UV‐2237‐cl‐ I 5 fibrosarcoma cells results in an increased incidence of experimental lung metastases in syngeneic and nude mice. Transfection of normal BALB/c‐A3 I cloned fibroblasts with functional L‐34 results in acquisition of anchorage‐independent growth and in morphological transformation in vitro but not in tumorigenicity in vivo. These results provide direct evidence that the cellular expression of L‐34 is associated with some aspects of transformation and with metastasis, but not with tumorigenicity per se.
Clonal analysis of tumor‐infiltrating lymphocytes from human primary and metastatic liver tumors
Authors: Shimizu Yukihiro , Iwatsuki Shunzaburo , Herberman Ronald B. , Whiteside Theresa L.
Published: February 2007

Phenotypic and functional characteristics of tumor‐infiltrating lymphocytes (TIL) obtained from human primary and metastatic liver tumors were studied. Lymphocytes isolated from 18 tumors and autologous (A) peripheral blood (6 cases) were phenotyped by 2‐color flow cytometry and cloned in a limiting dilution system, which allows virtually all normal T lymphocytes to proliferate; 70‐80% of fresh TIL were T cells (i. e., CD3+), and the ratio of CD4+/CD8+ cells was 1.2 in both primary and metastatic liver tumors. TIL contained significantly more CD56+ (NKHI+) cells, half of which were CD3+ CD56+, CD3+ CD25+ cells and CD3+ HLA‐DR+ cells, than A‐PBL. The frequencies of proliferating T‐cell precursors (PTL‐p) and cytolytic T‐lymphocyte precursors (CTL‐p) reactive with K562, allogeneic tumor cells and autologous tumor cells, were determined. Mean PTL‐p frequencies for TIL from hepatocellular carcinomas, cholangiocarcinomas and metastatic liver tumors were 0.52 (0.22‐0.83), 0.10 (0.05‐0.16) and 0.16 (0.01‐0.30), respectively. The frequency of CTL‐p with natural‐killer‐like activity was lower in TIL than in A‐PBL. The frequency of CTL‐p for autologous tumor cells in fresh TIL isolated from primary liver tumors was 0.02‐0.13 and 12/81 clones were reactive against autologous tumor. In contrast, only 1/66 TIL clones obtained from colon carcinomas metastatic to liver showed autotumor reactivity. No clones reactive with autologous tumor were obtained from peripheral blood of patients with liver cancer. These data indicate that substantial differences in anti‐tumor functions of TIL between primary and metastatic liver tumors exist, which can be detected at a clonal level.
Suppressive effects of intracellular glutathione on hydroxyl radical production induced by tumor necrosis factor
Authors: Yamauchi Naofumi , Watanabe Naoki , Kuriyama Hiroshi , Neda Hiroshi , Maeda Masahiro , Himeno Takeshi , Tsuji Yasushi , Nutsu Yoshiro
Published: February 2007

Protective effects of intracellular glutathione (GSH) against the cytotoxicity of human recombinant tumor necrosis factor (TNF) were investigated. Three tumor cell lines (L‐M, B‐16, HeLa) were used as target cells. Exposure of these cells to buthionine sulfoximine (BSO) or diethyl maleate (DEM) resulted in the depletion of intracellular GSH content to 5.2‐43.0% of control values and enhancement of their susceptibility to TNF cytotoxicity. The hydroxyl radical production in L‐M cells stimulated by TNF was increased by treatment with BSO or DEM. These results are consistent with the suggestion that intracellular GSH exerts its protective function against the cytocidal effect of TNF by inhibiting the hydroxyl radical production stimulated by TNF.
Tumor necrosis factor‐α and interleukin‐1α production in cachectic, tumor‐bearing mice
Authors: Lönnroth Christina , Moldawer Lyle L. , Gelin Johan , Kindblom Lars , Sherry Barbara , Lundholm Kent
Published: February 2007

Weight‐stable mice bearing a syngeneic, methylcholanthrene‐induced, rapidly growing tumor lost approximately 22% of their lean tissue, became significantly hypoalbuminemic and had a marked increase in serum amyloid P concentrations during progressive tumor growth. Tumors from cachectic mice were producing both TNF‐α and IL‐1α in vivo as documented by the presence of TNF‐α and IL‐1α mRNA and immune‐reactive protein for IL‐1α. Only spleens from tumor‐bearing mice had statistically significantly elevated quantities of IL‐1 mRNA. In general, alterations in tissue concentrations of IL‐1 mRNA in tumor‐bearing animals agreed qualitatively with those found in endotoxin‐stimulated, nontumor‐bearing control mice. However, endotoxin‐stimulated mice had significantly elevated tissue concentrations of TNF mRNA in spleen and livers, while TNF mRNA levels were not significantly increased in any host tissues. Cytokine mRNA levels in tumor tissue were not higher than those found constitutively in various tissues from non‐tumor‐bearing control animals. Plasma from tumor‐bearing mice and endotoxinstimulated controls contained high levels of IL‐6 but low (endotoxin‐stim.) or no measurable levels (tumor‐bearing) of either IL‐1 or TNF. When tumor cells from cachectic mice were placed into long‐term cell culture, immune reactive TNF‐α and IL‐1α were produced, but IL‐6 bioactivity was not produced in measurable amounts.
Progestin induction of 17β‐hydroxysteroid dehydrogenase enzyme protein in the t‐47D human breast‐cancer cell line
Authors: Poutanen M. , Isomaa V. , Kainulainen K. , Vihko R.
Published: February 2007

Steroid regulation of 17β‐hydroxysteroid dehydrogenase (17‐HSD) was studied in the T‐47D human breast‐cancer cell line, using a radioimmunoassay. In addition, 3 mRNA species (2.4, 1.4, and 0.9 kb) specific for the enzyme were shown to be present in these cells. All the synthetic progestins tested (ORG 2058, R5020, medroxyprogesterone acetate) significantly increased the immunoreactive enzyme protein concentration, while other types of steroids, such as testosterone, oestradiol and dexamethasone, were ineffective. The progestin‐specific induction of 17‐HSD was dose‐related and was maximum in about 5 days. An antiprogestin, RU 486, when used in combination with synthetic progestins, blocked the progestin‐induced increase of 17‐HSD concentration very effectively. A good correlation was observed in the different experiments between the enzyme activity and the immunoreactive 17‐HSD concentration. We conclude that progestins induce 17‐HSD in T‐47D cells and that the induction occurs via an increased accumulation of enzyme protein.
Interleukin‐1 and interleukin‐2 control granulocyte‐ and granulocyte‐macrophage colony‐stimulating factor gene expression and cell proliferation in cultured acute myeloblastic leukemia
Authors: Cozzolino Federico , Torcia Maria , Bettoni Stefania , Aldinucci Donatella , Burgio Vito L. , Petti Maria C. , Rubartelli Anna , Barbui Tiziano , Rambaldi Alessandro
Published: February 2007

In vitro proliferation of leukemic cells purified from 10 cases of acute myeloblastic leukemia (AML) was analyzed in basal conditions or in the presence of exogenous recombinant (r) Interleukin (IL) I. In parallel, blasts from 5 of these patients were studied for granulocyte‐macrophage colonystimulating factor (GM‐CSF) or granulocyte‐CSF (G‐CSF) mRNA. IL‐I augmented the spontaneous AML cell proliferation in all cases and induced de novo expression or increased amounts of GM‐CSF and/or G‐CSF transcripts in 4 of the 5 cases evaluated. IL‐I‐induced AML cell proliferation was modulated by neutralizing anti‐GM‐CSF or anti‐G‐CSF antibodies in those cases in which CSF mRNAs were induced or increased by exogenous cytokine. In the same cases, biosynthetic labelling and immunoprecipitation studies using monospecific anti‐GM‐CSF antibodies showed that IL‐I also increased the levels of GM‐CSF protein synthesis. Addition of neutralizing anti‐IL‐I antibodies to AML cell cultures completely abolished ongoing GM‐CSF synthesis, suggesting that endogenous IL‐I is needed to maintain autocrine production of CSFs. The effects of rlL‐2 were investigated in a larger series of 21 patients. The cytokine reduced spontaneous AML cell proliferation in 8 cases. It caused complete disappearance of GM‐CSF mRNA in I case, and marked reduction of G‐CSF mRNA in 2 cases. Increased AML cell proliferation was observed in 2 of 21 cases. These findings suggest that expression of CSF genes and cell proliferation in AML are under the control of different cytokines acting in autocrine or paracrine fashion.
Oncogene expression of fanft‐ or BBN‐induced rat urothelial cells
Authors: Debiec‐Rychter Maria , Jones Richard F. , Zukowski Kim , Wang Ching Yung
Published: February 2007

Proto‐oncogene expression by cultured urothelial cells prepared from the bladders of male F344 rats that had been treated with N‐[4‐(5‐nitro‐2‐furyl)‐2‐thiazolyl]‐formamide (FANFT) or N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN) were examined. Although all of the cultured cells showed varying degrees of anchorage‐independent growth, only 9 of them were transplantable into nude mice. A Northern blot technique was employed for the detection of proto‐oncogene transcripts. The c‐Ha‐ras transcripts were detected in all the cultured urothelial cells prepared from the carcinogentreated rats and in normal urothelial cells. However, the transcript levels were several‐fold higlher in the former than in normal cells. Increased expression of p21, as determined by immunohistochemical techniques, was also observed in all the original bladder tissues from which the cultures were derived. c‐myc transcripts were detected in the cells from carcinogentreated rats but not in the normal cells. The presence of myc product in hyperplastic urothelial lesions and carcinomas of original bladder tissues was confirrned by immunohistochemical methods. Transcripts of mos, erb B, Ki‐ras, abl and src were not detected. Since increased expression of c‐myc and c‐Ha‐ras were present in both transplantable and non‐transplantable cell lines, and the expression of p21 occurs in preneoplastic cells, this suggests that elevated expression of these 2 genes may be an early genetic event during bladder carcinogenesis in the rat and further alteration of these 2 genes or mutation of additional genes may be required for the completion of malignant transformation.
Retardation of metastatic tumor growth after immunization with metastasis‐specific monoclonal antibodies
Authors: Reber S. , Matzku S. , Günthert U. , Ponta H. , Herrlich P. , Zöller M.
Published: February 2007

The influence of 4 murine monoclonal antibodies (MAbs) directed against surface determinants of a metastasizing rat adenocarcinoma (BSp73ASML) on metastatic spread was evaluated and compared to their in vivo binding as well as to the induction of a humoral anti‐MAb response, especially with respect to the development of anti‐idiotypic (ID) antibodies of the internal image type. In a protocol of explicit immunization, all 4 MAbs transiently inhibited metastatic growth. Survival was prolonged only with one MAb (4.4ASML). With another MAb (1.1ASML), directed against a new variant form of CD44, metastatic growth was accelerated after transient retardation. Retardation of metastatic growth correlated with the humoral anti‐MAb response. This accounted for the isotype‐ as well as for the idiotype‐specific response. An exception was noted after immunization with MAb 1.1ASML. Rats with high levels of anti‐1.1ASML antibodies, which inhibited binding to the tumor cells (internal image‐type antibodies) showed accelerated metastatic spread. Data are interpreted to mean that MAb‐induced inhibition of metastatic spread may be based on 2 independent mechanisms: blockade of metastasis‐associated epitopes (i. e., with MAb 1.1ASML) and induction of an anti‐mouse lg response. In the latter case it was irrelevant whether the response was isotype‐ or idiotype‐specific.
Increased sensitivity to two‐stage skin carcinogenesis of mice heterozygous for the repeated epilation mutation (Er)
Authors: Reddy A. Lakshma , Fialkow Philip J.
Published: February 2007

Mice heterozygous for repeated epilation mutation (Er) have cutaneous abnormalities that result in repeated loss of hair. Skin papillomas and carcinomas occur spontaneously in suchErl+ mice. BALB/c mice are generally resistant to induced skin cancers. We investigated whetherErl+ heterozygous mice of BALB/c genetic background exhibit increased susceptibility to spontaneous and induced skin tumors. Although none of theErl+ CXB(N5) mice spontaneously developed skin tumors, they exhibited increased sensitivity to the development of skin papillomas induced by an initiationpromotion regimen.Erl+ mice developed papillomas after 20 μg DMBA initiation in the absence of TPA promotion, but the same dose of DMBA was subtumorigenic in +/+ (sibling) mice. Although 15 weeks of TPA promotion resulted in similar tumor susceptibilities, tumor latencies and tumor frequencies in the 2 groups of initiated mice, the papillomas were qualitatively different.Erl+ mice, the developed more papillomas of the delayed promoter‐independent type, which occur after termination of promotion. In contrast, +/+ mice developed more promoter‐dependent papillomas, which regress after termination of promotion. ThereforeErl+ mice had a significantly higher number of papillomas than +/+ mice at the termination of the experiment. These results suggest that Er‐mutation‐induced skin defects not only lead to the repeated loss of hair, but also influence the mode of development of skin papillomas from carcinogen‐initiated cells.
The in vivo antimelanoma effect of 4‐S‐cysteaminylphenol and its N‐acetyl derivative
Authors: Miura Takako , Jimbow Kowichi , Ito Shosuke
Published: February 2007

Phenolic melanin precursors can be utilized for the development of anti‐melanoma agents. The sulphur homologue of tyrosine, 4‐S‐cysteinylphenol (CP) and its decarboxylation product, 4‐S‐cysteaminylphenol (CAP) were shown to be substrates of melanoma tyrosinase, forming melanin‐like pigment. Both, but in particular the 4‐S‐CAP, exhibited a significant in vivo depigmenting effect. Here, we report on the in vivo anti‐melanoma effect of 4‐S‐CP, and 4‐S‐CAP and its N‐acetyl derivative. In a previous in vitro study, it was shown that 4‐S‐CP and 4‐S‐CAP required a catalytic amount of dopa for optimal mammalian tyrosinase activity. To enhance the potential anti‐melanoma effect of these two compounds, L‐dopa and a decarboxylase inhibitor (carbidopa) were given concomitantly. We found that 4‐S‐CAP showed a significant growth inhibition of B16 melanoma inoculated S. C. into C57BL/6J mice. The anti‐melanoma effect was increased significantly by combination of L‐dopa and carbidopa. In addition, we tested the in vivo anti‐melanoma effect of an N‐acetyl derivative of 4‐S‐CAP (N‐Ac‐4‐S‐CAP). We found that N‐Ac‐4‐S‐CAP was the tyrosinase substrate and potent inhibitor of melanoma growth. N‐acetyl 4‐S‐CAP showed a marked increase in water solubility. We suggest that N‐Ac‐4‐S‐CAP may prove to be a valuable model for the development of anti‐melanoma agent using a metabolic pathway of melanin synthesis.
Expression of the epstein‐barr virus genome in a nasopharyngeal carcinoma epithelial tumor cell line
Authors: Zhang Hai‐Ying , Yao Kaitai , Zhu He‐Cheng , Glaser Ronald
Published: February 2007

An epithelial tumor cell line was recently established from a biopsy specimen of a nasopharyngeal carcinoma (NPC), and designated HONE‐1. Uncloned (parental) HONE‐1 and HONE‐1 clone (C)‐40 cells were found to contain latent Epstein‐Barr virus (EBV). Expression of the latent EBV genome in HONE‐1 C‐40 cells has been examined. It was possible to detect a small percentage of cells spontaneously synthesizing EBV early antigen (EA) and virus capsid antigen (VCA) by immunofluorescence (IF). In addition, the EBV nuclear antigens (EBNA‐I and EBNA‐2), as well as the EBV latent membrane protein (LMP) were detected in the HONE‐1 cells. Attempts were made to induce the latent EBV genome in these cells with iododeoxyuridine (IUdR). We observed a significant increase in the number of EA/VCA‐positive cells, an increase in EBV DNA, the synthesis of virus particles, and the rescue of infectious virus after treatment of HONE‐1 C‐40 cells with IUdR. The HONE‐1 C‐40 cells should facilitate studies of the expression and regulation of the EBV genome in NPC epithelial tumor cells, which have not previously been available.
Role of catalase and oxidative stress in hepatic peroxisome proliferator‐induced morphological transformation of syrian hamster embryo cells
Authors: Mikalsen Svein‐Ole , Kaalhus Olav , Reith Albrecht , Sanner Tore
Published: February 2007

Several hepatic peroxisome proliferators (HHPs), such as di(2‐ethylhexyl)phthalate (DEHP), mono(2‐ethylhexyl)‐phthalate, clofibrate and tiadenol, induce morphological transformation of Syrian hamster embryo (SHE) cells in vitro. According to one hypothesis, the hepatocarcinogenic effect of HPPs is caused by an oxidative stress due to increased H2O2‐production from the strongly induced peroxisomal β‐oxidation of fatty acids. Thus, increased transformation frequencies by HPPs should be obtained when catalase was inhibited by 3‐amino‐1, 2, 4‐triazole (amitrole). However, coexposure to HPPs and amitrole did not enhance the transformation frequencies for any of the HPPs. The sensitivity of SHE cells for oxidative agents was studied by using menadione and H2O2. Menadione only induced transformation at a toxic concentration, while H2O2 induced transformation at non‐toxic concentrations. To study the generation of oxidative radicals in SHE cells, electron spin resonance was employed. No oxidative radical formation was detected in tiadenol‐ or DEHP‐exposed SHE cells. When menadione or H2O2 were added during the measurements, oxidative radicals were found. A transmission electron microscopic study showed a small number of peroxisomes, and did not reveal any increase in the number of peroxisomes in clofibrate treated SHE cells.
Expression of epstein‐barr virus‐encoded proteins and B‐cell markers in fatal infectious mononucleosis
Authors: Falk Kerstin , Ernberg Ingemar , Sakthivel Ramasamy , Davis Jack , Christensson Birger , Luka Janos , Okano Motohiko , Grierson Helen L. , Klein George , Purtilo David T.
Published: February 2007

We assessed 33 lymphoid tissues from 15 patients, including 7 with X‐linked lymphoproliferative disease (XLP) and 8 pa tients with sporadic fatal infectious mononucleosis (IM), to determine whether the cellular infiltrate had the immu nophenotype and expressed Epstein‐Barr virus (EBV)‐encoded proteins characteristic of either EBV‐immortalized lymphoblastoid cell lines (LCL) or EBV‐carrying Burkitt lymphoma (BL) cells. The results of these studies revealed that in 13 cases the proliferating B cells were polyclonal, LCL‐like, and in 2 cases they were monoclonal, malignant lymphomalike.
Number of children and death from hormone‐dependent cancers
Authors: Lund Eiliv
Published: February 2007

The association between number of children of current marriage reported by 431,604 women aged 45‐74 years at the Norwegian Census in 1970 and mortality, at follow‐up through 1985, from hormone‐dependent cancers, i. e., cancers of breast, corpus uteri and ovary combined, has been investigated. The reduction in age‐adjusted mortality was 9.6% (95% confidence interval; 8.3–10.9%) for each child with no deviation from linearity. Women with 8‐11 children had a relative risk of 0.34 (0.25–0.47) compared to nullipara. Adjustment for age at first birth slightly changed the effect of number of children on mortality to 9.3% per child. The reduction in mortality per child was for cancer of the breast 7.2%, corpus uteri 12.2% and ovary 12.7%. Our findings indicate that having few children is a major risk factor for death from the 3 hormone‐dependent cancers combined.
Cell‐surface antigens of human lung tumors detected by mouse monoclonal antibodies: Definition of blood‐group‐ and non‐blood‐group‐related antigenic systems
Authors: Feickert Hans‐Joachim , Anger Bernd R. , Cordon‐Cardo Carlos , Lloyd Kenneth O.
Published: February 2007

The pattern of antigen expression in human non‐small‐cell cancers of various histiological subtypes has been studied. Mouse monoclonal antibodies (MAbs) were generated following immunizations with cell lines of squamous, adeno‐ and anaplastic large‐cell carcinomas of the lung. Seven nonblood‐group‐related antigens were defined in addition to 5 antigens related to blood‐group determinants. Detailed specificity was established with a large panel of cultured cell lines and normal and neoplastic tissues. MAb F‐18 reacted in direct tests with the immunizing squamous lung carcinoma cell line, with 5 out of 5 choriocarcinoma cell lines, but with no other cell lines. No expression of F‐18 antigen was observed in any normal or malignant tissue examined. The other 6 nonblood‐group‐reactive MAbs (F‐7, F‐8, F‐11, F‐15, F‐16 and F‐17) could be distinguished by their reactivity on a panel of cultured cells and tissues. One MAb in this group (F‐17) reacted strongly with 19/35 lung tumor cell lines, 32/76 other tumor‐derived cell lines, cultured normal kidney cells and fetal lung fibroblasts. This antibody did not react with any normal adult tissues examined, but did react with several cancer tissues including 1/17 lung tumors, 2/4 ovarian cancers and 1/5 colon tumors. Immunoprecipitation tests revealed that 5 of the antigens were glycoproteins: F‐18 (Mr > 200,000), F‐15 (Mr 44,000), F‐16 (Mr 90,000), F‐17 (Mr 95,000) and F‐8 (Mr 95,000). Four MAbs detected Y blood‐group antigen (Ley), only 2 of which were able to agglutinate O erythrocytes. Another antibody detected X blood‐group antigen (Lex).
Mitogenic peptides in breast cyst fluid: Relationship with intracystic electrolyte ratios
Authors: Lai L. C. , Ghatei M. A. , Takahashi K. , Patel K. V. , Schrey M. P. , Ghilchik M. W. , Bloom S. R. , James V. H. T.
Published: February 2007

Women with palpable breast cysts which are lined with apocrine epithelium may be at higher risk of developing breast cancer than women with breast cysts which are lined with flattened epithelium, the former group being characterized by intracystic sodium to potassium ratios below 3, while the latter group has intracystic sodium to potassium ratios above 3. In this study the distribution of intracystic concentrations of the mitogenic peptides, epidermal growth factor, endothelin and gastrin‐releasing peptide in the 2 groups of breast cysts were compared to see whether differences in concentrations between the 2 cyst groups might provide an explanation for the higher risk of breast cancer observed in women with “apocrine” breast cysts. The concentrations of epidermal growth factor and gastrin‐releasing peptide were significantly higher in the low electrolyte ratio group (p < 0.001). There was no difference in endothelin concentrations between the 2 groups. Negative correlations were found between epidermal growth factor concentrations and Na+/K+ and between gastrin‐releasing peptide concentrations and Na+/K+ (p < 0.001). A positive correlation was found between gastrin‐releasing peptide and epidermal growth factor concentrations in breast cyst fluid (p < 0.001). The significantly higher intracystic concentrations of both epidermal growth factor and gastrin‐releasing peptide in the low‐electrolyte‐ratio group may provide an explanation for the higher risk of breast cancer which has been observed in women with “apocrine” breast cysts.
Lymphokine‐activated killer cell cytotoxicity against human colon carcinomas enhanced by monoclonal antibody D612
Authors: Pendurthi Tribhuvan K. , Parker Ricardo , Schlom Jeffrey , Primus F. James
Published: February 2007

The antibody‐dependent cellular cytotoxicity (ADCC) properties of a murine monoclonal antibody (MAb), designated D612 (IgG2a), which reacts with human colon carcinomas, was studied using normal human peripheral blood lymphocytes (PBMNC). Although the level of ADCC of PBMNC with D612 varied among different donors, it was 20 to 30 times higher than the lytic activity of control cultures containing isotype‐matched control MAb. Incubation of PBMNC with recombinant interleukin‐2 (IL‐2) resulted in a 2‐ to 5‐fold augmentation in the cytotoxicity of effector cells exposed to MAb. This augmentation was apparent after subtracting nonspecific cellular cytotoxicity from the total cytotoxicity mediated by activated effector cells in the presence of D612. Optimal stimulation of specific ADCC with IL‐2 appeared after 24 hr of culture in 500 U/ml of IL‐2, resulting in a 3.8 ± 1.7 fold increase in lytic units. However, stimulation of ADCC was also evident at 10 U/ml of IL‐2. Furthermore, antibody dose titrations with untreated and IL‐2 activated effectors showed that the threshold dose of MAb needed for efficient ADCC was reduced by 200‐fold with IL‐2. Depletion of FcRγIII‐positive lymphoid cells markedly reduced D612 ADCC, demonstrating the participation of NK/LAK cells in D612‐mediated ADCC. Low levels of ADCC activity were found associated with adherent cells, either untreated or following their activation with γ‐interferon, while D612 was most active with non‐adherent effectors. The specificity and ADCC properties of the D612 MAb suggest that it should be considered as a candidate for immunotherapy of colon cancer, particularly when used in combination with IL‐2 plus LAK cell treatment.
Expression of messenger RNAs for platelet‐derived growth factor and its receptors in human sarcoma cell lines
Authors: Leveen P. , Claesson‐Welsh L. , Heldin C. H. , Westermark B. , Betsholtz C.
Published: February 2007

Growth factors of the platelet‐derived growth factor (PDGF) family have been thought to possess autocrine functions in certain neoplasms of mesenchymal and glial origin. This notion has been based on observations that these tumors express PDGF genes and produce PDGF‐like growth factors. Corresponding data on PDGF receptor expression in sarcoma cell lines is essentially lacking. The cloning of cDNA for 2 distinct PDGF receptors with different abilities to recognize the members of the PDGF family and availability of recombinant PDGF for binding studies have recently made it possible to study the expression of both receptor types in tumor cell lines. We present here a study on 8 human sarcoma cell lines, and show a large variability and independency in the expression of the 2 PDGF receptor types as well as of the genes encoding the corresponding ligands.
Transfection of a non‐metastatic diploid rat mammary epithelial cell line with the oncogenes for EJ‐RAS‐1 and polyoma large T antigen
Authors: Jamieson Susan , Barraclough Roger , Rudland Philip S.
Published: February 2007

Transfection of rat mammary (Rama) 37 epithelial cells which yield non‐metastasizing adenomas in syngeneic Wistar‐Furth rats with a drug resistance plasmid containing both the neo gene and EJ‐ras‐I (pSV2neo‐ras) or with pSV2neo and a plasmid encoding the large T Antigen (pLT214) of polyoma virus yields drug‐resistant transformants with a frequency of 10−5. Representative transformants have been propagated in neo‐selecting medium to yield various cell lines. The 7 lines transfected with pSV2neo‐ras (EJI set) and the 10 lines cotransfected with pSV2neo and pLT214 (LTI set) all produce tumours at subcutaneous (s. c.) sites with a shorter median latent period than tumours produced by the parental Rama 37 cells. In addition, the LTI set: of transformants yields a higher incidence of tumours than the Rama 37 cells. No metastases are produced when any of the oncogene transformants are inoculated s. c. into rats. However, when an EJi representative is inoculated intravenously (i. v.), tumour deposits are found in the lungs of the host animals. In contrast, other Rama 37 variants that metastasize from s. c. sites fail to produce any metastases when inoculated i. v. The oncogene transfectants contain integrated DNA that hybridizes to neo and to the requisite oncogenic DNAs; the pattern of hybridizing bands to the transfected genes and their expression as mRNA is complex, and is presented in detail.
A fluorouridine‐anti‐CEA immunoconjugate is therapeutically effective in a human colonic cancer xenograft model
Authors: Shih Lisa B. , Xuan Hong , Sharkey Robert M. , Goldenberg David M.
Published: February 2007

5‐fluorouridine (FUR), an antineoplastic agent, was sitespecifically conjugated to the carbohydrate moiety of a anticarcinoembryonic antigen (CEA) monoclonal antibody (MAb) by using amino‐dextran as the intermediate carrier. The final immunoconjugate contains approximately 30‐35 molecules of FUR per molecule of immunoglobulin, has immunoreactivity retained as examined by flow cytometry, and is cytotoxic to the target cells as examined by 75selenomethionine incorporation studies. In the GW‐39/nude mouse model, the conjugate remained efficient in targeting the human colonic tumor and possessed greater inhibitory growth effects on the subcutaneous tumor than free FUR or an irrelevant antibody conjugate. In addition, the reduced host toxicity of the conjugate may permit the use of this agent in a high‐dose therapy of this tumor system.
Establishment and characterization of a new human B‐cell line (ONHL‐1) from non‐Hodgkin's lymphoma: Constant expression of bcl‐2 gene during mitogen‐induced growth inhibition
Authors: Matsumura Itaru , Tamaki Toshiharu , Katagiri Shuichi , Taniwaki Masafumi , Tominaga Nobuhiko , Oritani Kenji , Iida Masato , Yagura Hirosuke , Yonezawa Takeshi , Tarui Seiichiro
Published: February 2007

A new B‐cell line (ONHL‐I) was established from non‐Hodgkin's lymphoma. ONHL‐I was free from Epstein‐Barr virus nuclear antigen and expressed CD20, CD24, and slg (μ, δ, γ and κ), thus being equivalent to the mature B‐cell stage. Chromosome analysis revealed a markedly abnormal pattern including 14q+ and 6q‐ In accordance with the positive expression of surface K light chains, one of the K genes was found to be rearranged. However, rearrangement of the À locus was also detected, contrary to the supposed hierarchy for the rearrangement of the light‐chain genes. The cell line showed rearrangement of the bcl‐2 gene. Further, the rearranged fragments of the JH, CA, and bci‐2 genes were of the same size in the EcoRI and HindIII digests on the same filter. This may suggest that the bcl‐2 gene is juxtaposed with the JH and CA locus. The proliferation of ONHL‐I was inhibited by adding Staphylococcus aureus Cowan I or 12‐O‐tetradecanoyl‐phorbol‐13‐acetate. During this growth inhibition, the expression of c‐myc decreased, while that of bcl‐2 mRNA remained steady. This result suggests that not the bcl‐2 gene but other oncogenes, such as c‐myc, play a key role in the proliferation of ONHL‐I. This agrees with the hypothesis that the bcl‐2 gene is not concerned with aggressive proliferation but with cell survival. This new cell line will therefore be of value in studying the differentiation and tumorigenesis of B cells.
Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity
Authors: Chignola Roberto , Colombatti Marco , Dell'arciprete Lorena , Candiani Carola , Tridente Giuseppe
Published: February 2007

We have investigated the internalization to low PH intracellular compartments of transferrin (Tfn), diphtheria toxin (DT) and of anti‐cell surface antibodies (MAb) by a cytofluorometric assay based on low PH quenching of fluorescein (FITC) emission. FITC‐labelled Tfn, anti‐CD3, anti‐CD5 and anti‐Thy 1.2 MAb internalization resulted in a progressively lower FITC quenching effect, Following internalization, a distinction could be made between molecules that enter low PH compartments without undergoing intracellular degradation (e. g., Tfn, anti‐CD3 MAb) and molecules that are internalized through low PH organelles and are then degraded within the cell (e. g., DT). A strict correlation was observed between quenching of internalized FITC‐protein fluorescent emission and the cytotoxic activity of DT‐based immunotoxins (IT).