bluuebunny/crossref_metadata_2025 huggingface dataset:
P‐glycoprotein and alterations in the glutathione/glutathione‐peroxidase cycle underlie doxorubicin resistance in HL‐60‐R, a subclone of the HL‐60 human leukemia cell line
Authors: Raghu Ganapathirama , Pierre‐Jerome Mario , Dordal Margaret S. , Simonian Philip , Bauer Kenneth D. , Winter Jane N.
Published: February 2007

HL‐60‐R, a multi‐drug‐resistant (MDR) subclone of the human leukemia cell line HL‐60, was selected in continuous culture in doxorubicin (DOX) in the absence of mutagenic agents. When compared to the parent line HL‐60, HL‐60‐R showed greater relative resistance to vinblastine than to etoposide, or to the selecting agent DOX. Co‐exposure to verapamil, a known modulator of MDR, partially increased its sensitivity to DOX and vinblastine. The HL‐60‐R cell line stained positively with the P‐glycoprotein‐specific monoclonal antibody (MAb), C219, whereas the HL‐60 parent was negative. Southern analysis showed 32‐fold amplification of the mdr I gene in HL‐60‐R, whereas slot‐blot analysis demonstrated 70‐fold over‐expression of the specific mdrI message in HL‐60‐R compared to HL‐60. Northern blot analysis revealed the presence of 2 species of messenger RNA of sizes 5.1 kb and 4.5 kb. No transcripts were detectable in the parent. Flow cytometric analysis showed significantly reduced cellular retention of DOX as well as rapid efflux from the drug‐resistant cell line. HL‐60‐R proved to be nearly 4 times more resistant to hydrogen peroxide than its parent, and 1,000 times more resistant to inhibition of cellular glutathione synthesis by D,L‐buthionine sulfoxirnine (BSO). Verapamil modulated DOX resistance in HL‐60‐R incompletely but, in the presence of glutathione depletion, nearly completely reversed DOX resistance. Elevated levels of glutathione and glutathione‐peroxidase activity were demonstrated, thereby implicating enhanced activity of the glutathionel/glutathione‐peroxidase cycle as an additional basis for its resistance to DOX. These findings suggest that an enhanced capacity for detoxifying oxyradicals may contribute to anthracycline resistance in acute leukemia.
Calcium intake and 28‐year gastro‐intestinal cancer mortality in dutch civil servants
Authors: Slob Ingrid C. M. , Lambregts Johannes L. M. C. , Schuit Albertine J. , Kok Frans J.
Published: February 2007

The association between calcium intake and gastrointestinal cancer mortality was investigated in a 28‐year follow‐up study. Data were obtained from a general health examination in 1953–1954 among Dutch civil servants and their spouses, aged 40 to 65 years. Information from 2,591 participants was used for this study. Risk analyses were performed using logistic regression models with the highest quintile of calcium intake as reference. No statistically significant relation between calcium intake and gastrointestinal cancer mortality is observed, although the risk estimate for women with the lowest calcium intake is substantial. Odds ratios (OR) were adjusted for age, energy intake and dietary fiber. After inclusion of other potential confounders to the models (body‐mass index and smoking habits), the results hardly differed. Both men and women who died of colorectal cancer had a lower mean calcium intake compared to the rest of the population. For women this was statistically significant. Our results suggest that a low calcium intake may be related to gastrointestinal cancer mortality among women of this study population.
Expression of P‐cadherin in gastric carcinomas and its reduction in tumor progression
Authors: Yasui Wataru , Sano Toshiaki , Nishimura Kenji , Kitadai Yasuhiko , Ji Zhong‐Qiang , Yokozaki Hiroshi , Ito Hisao , Tahara Eiichi
Published: February 2007

The expression of P‐cadherin, one of the Ca2+‐dependent cell‐cell adhesion molecules, in human gastric carcinomas was examined by Northern blotting, Western blotting and immuno‐histochemistry. P‐cadherin mRNA was expressed in all the gastric carcinoma tissues examined, whereas no message was detected in non‐neoplastic mucosa. By Western‐blot analysis, P‐cadherin protein was expressed in 83% and 29% of the well‐differentiated and poorly differentiated gastric adenocarcinomas, respectively, the incidence being significantly different. Immunohistochemically, P‐cadherin immunoreactivity was localized on the cell surface or the cell‐to‐cell borders of well‐differentiated adenocarcinomas. P‐cadherin was not detected in Borrmann's type‐4 or scirrhous carcinomas where the tumor cells proliferate diffusely with productive fibrosis. The level of P‐cadherin expression in stage‐2 carcinomas was significantly higher than in stage‐1 carcinomas. In the case of patients in stages 2 to 4, however, the level of P‐cadherin expression decreased as the stage progressed, the difference between stages 2 and 3 and between stages 3 and 4 being significant. Our findings suggest that P‐cadherin might play an important role in the development of well‐differentiated gastric adenocarcinomas and the decreased expression of P‐cadherin might be responsible for the infiltrative growth and progression of gastric carcinomas.
Breast cancer risk in mothers of multiple births
Authors: Hsieh Chung‐Chcng , Goldman Marlene , Pavia Maria , Trichopoulos Dimitrios , Ekbom Anders , Adami Hans‐Olov , Petridou Eleni
Published: February 2007

Data from an international case‐control study of breast cancer that was conducted in the 1960s were used to examine whether multiple births affect the risk of breast cancer in the mother. Among 2821 parous breast‐cancer patients, 88 had had one or more multiple births, whereas among 8882 controls 247 had had one or more multiple births; the logistic‐regression‐adjusted odds ratio (OR) was 1.21, the 95% confidence interval (Cl), 0.94 to 1.55. The OR was significantly elevated during the 15‐year period following the latest multiple birth (1.76; Cl, 1.12 to 2.75), but declined toward the null afterwards. A late first pregnancy imparted a substantially higher breast‐cancer risk when it was multiple rather than singleton; the OR was 2.34 for a multiple and 1.48 for a singleton first pregnancy when the cutoff point was 30 years, and 4.58 and 1.57, respectively, when the cutoff point was 35 years. Since multiple pregnancies are characterized by higher levels of pregnancy estrogens, the results of this study would be compatible with the hypothesis that these hormones may be responsible for the transient increase in breast–cancer risk following a term pregnancy and, in particular, a multiple term pregnancy. The long‐term reduction of breast‐cancer risk is probably due to a different mechanism, most likely the terminal differentiation of susceptible mammary‐gland cells.
Studies on the role of platelet eicosanoid metabolism and integrin αIIbβ3 in tumor‐cell‐induced platelet aggregation
Authors: Steinert Bruce W. , Tang Dean G. , Grossi Irma M. , Umbarger Lillian A. , Honn Kenneth V.
Published: February 2007

Platelet eicosanoid metabolism resulting from tumor‐cell‐induced platelet aggregation (TCIPA) was examined in a homologous in vitro system. Rat Walker 256 carcinosarcoma cells induced the aggregation of rat platelets via a thrombin‐dependent mechanism with concomitant production of eicosanoid metabolites (e.g., 12‐HETE, TXA2. TCIPA was dependent on the concentration of tumor cells inducing aggregation, as well as cyclooxygenase and lipoxygenase products. Cyclooxygen‐ase inhibitors, but not lipoxygenase inhibitors, blocked platelet aggregation induced in vitro by a low concentration of agonist. At a high agonist concentration, neither cyclooxygenase nor lipoxygenase inhibitors alone affected platelet aggregation; however, the combined inhibition of both the cyclooxygenase and lipoxygenase pathways resulted in subsequent inhibition of platelet aggregation regardless of agonist concentration. The extent of platelet TXA2 and 12‐HETE biosynthesis was likewise dependent on and correlated with agonist concentration. The inhibitors used in this study did not significantly inhibit protein kinase C activity at the doses tested. Platelet surface glycoproteins αIIbβ3 play an important role in platelet aggregation. The effect of platelet cyclooxygenase and lipoxygenase inhibition in regulating αIIbβ3 surface expression was examined by flow cytometric analysis. Thrombin stimulation of washed rat platelets resulted in significantly increased surface expression of platelet αIIbβ3 integrin complex. The enhanced surface expression was not inhibited by a cyclooxygenase inhibitor (aspirin), a thromboxane synthase inhibitor (CGS‐14854) or a throm‐boxane receptor antagonist (SQ 29,548), nor was it stimulated by a thromboxane A2 mimic (pinane‐thromboxane A2). However, αIIbβ3 expression was blocked by lipoxygenase inhibition and stereospecifically increased by the platelet lipoxygenase metabolite 12(S)‐HETE. These results suggest that both the platelet lipoxygenase and cyclooxygenase pathways are important for TCIPA but that different mechanisms of action are involved.
12(S)‐hete promotes tumor‐cell adhesion by increasing surface expression of αVβ3 integrins on endothelial cells
Authors: Tang D. G. , Grossi I. M. , Chen Y. Q. , Diglio C. A. , Honn K. V.
Published: February 2007

The present work was undertaken to investigate the regulatory role of 12(S)‐HETE, a lipoxygenase metabolite of arachidonic acid, in the surface expression of αvβ3 integrin receptors in endothelial cells (rat aortic endothelial cells, or RAEC). Several monoclonal and polyclonal antibodies localized αvβ3 in focal adhesions in both subconfluent and post‐confluent RAEC. RAEC αvβ3 integrins were further characterized by immunoblotting and immunoprecipitation. 12(S)‐HETE, but not 12(R)‐HETE or other lipoxygenase‐derived hydroxy fatty acids, induced a dose‐dependent increase in αvβ3 surface expression in RAEC, which was antagonized by prostacyclin or its analog iloprost as well as by 13‐HODE, a 15‐lipoxygenase product of linoleic acid. 12(S)‐HETE promoted RAEC adhesion to vitronectin, an effect inhibited by antibodies against αvβ3 12(S)‐HETE also promoted tumor‐cell (W256 carcinosarcoma) adhesion to vitronectin, which was inhibited by various antibodies against αIIbβ3 but not by an antibody against αv. W256 adhesion to 12(S)‐HETE‐treated RAEC demonstrated a significant increase, which was inhibited by anti‐αv, ‐β3, or ‐αvβ3antibodies and by 13‐HODE. Western blotting, immunoprecipitation and reverse transcription‐polymerase chain reaction indicated that W256 carcinosarcoma cells expressed αIIbβ3 integrins but not αvβ3. The results suggest that the lipoxygenase metabolites [i.e., 12(S)‐HETE and 13‐HODE] play a significant role in modulating tumor‐cell interactions with en'dothelium by enhancing endothelial cell integrin (e.g., αvβ3)expression.
Role of aminopeptidase N (CD13) in tumor‐cell invasion and extracellular matrix degradation
Authors: Saiki Ikuo , Yoneda Junya , Azuma Ichiro , Fujii Hideji , Abe Fuminori , Nakajima Motowo , Tsuruo Takashi
Published: February 2007

We have investigated the effect of monoclonal antibodies (MAbs) specific for aminopeptidase N/CD13 on the invasion of human metastatic tumor cells into reconstituted basement membrane (Matrigel). The invasion of human metastatic tumor cells (SN12M renal‐cell carcinoma, HT1080 fibrosarcoma and A375M melanoma) into Matrigel‐coated filters was inhibited by an anti‐CD 13 MAb, WM15, in a concentration‐dependent manner. However, this MAb did not have any effect on tumor‐cell adhesion and migration to the extracellular matrices, which may be involved in tumor‐cell invasion. MAb WM15 inhibited the degradation of type‐IV collagen by tumor cells in a concentration‐dependent manner. We also found that WM15 inhibited hydrolysing activities towards substrates of aminopeptidases in 3 different tumor cells. Since our previous study indicated that bestatin, an aminopeptidase inhibitor, was able to inhibit tumor‐cell invasion, as well as aminopeptidase activities of murine and human metastatic tumor cells, cell‐surface aminopeptidase N/CD13 may be partly involved in the activation mechanism for type‐IV collagenolysis to achieve tumor‐cell invasion, and anti‐CD13 MAb WM15 may inhibit tumor‐cell invasion through a mechanism involving its inhibitory action on the aminopeptidase N in tumor cells.
Spontaneous and induced differentiation of human melanoma cells
Authors: Valyi‐Nagy Istvan , Shih Ie‐Ming , Györfi Tibor , Greenstein David , Juhasz Istvan , Herlyn Meenhard , Elder David E.
Published: February 2007

Malignant melanoma cells can differentiate spontaneously in vivo and in vitro into cells with a finite lifespan. Analysis of differentiating cells from primary melanomas in culture revealed a flat, fibroblast‐like morphology and expression of the fibroblast‐associated marker leucine aminopeptidase (LAP). Differentiation was also observed in a minor sub‐population of permanent cell lines derived from metastatic lesions. An experimental model of melanoma cell differentiation was then developed, using the pyrimidine analog bromodeoxyuridine (BUdR). BUdR‐treated cells had a flat morphology, were contact‐inhibited, had up to 20‐fold increased surface area, expressed LAP, no longer proliferated anchorage‐independently in soft agar, and 3 out of 4 cell lines were non‐tumorigenic in athymic nude mice. Our results show that models of differentiation of melanoma cells can be established that help to define pathways of differentiation.
In situ evaluation of the relationship between epidermal‐growth‐factor‐receptor status and tumor‐cell proliferation in colon carcinomas
Authors: Porschen Rainer , Classen Susanne , Kahle Yvonne , Borchard Franz
Published: February 2007

The association between the expression of the epidermal‐growth‐factor receptor (EGFR) and tumor proliferation was studied in 69 resected human adenocarcinomas of the colon. EGFR was detected immunohistochemically using the monoclonal antibody (MAb) EGFRI. Tumor‐cell proliferation was assessed with the MAb Ki‐67 directed against a proliferation‐associated nuclear antigen expressed only in proliferating cells. The percentage of Ki‐67‐positive tumor cells (Ki‐67 index) was evaluated by the point‐counting method. Forty‐seven carcinomas contained detectable EGFR immunoreactivity. Statistical analysis failed to reveal correlations between the EGFR status and T, N and M stages or tumor differentiation. The mean Ki‐67 index did not differ between EGFR‐positive and ‐negative carcinomas. Seven tumors contained clearly distinguishable areas with different EGFR staining intensity. In these tumors with a locally heterogeneous EGFR expression, tumor proliferation also did not correlate with EGFR immunoreactivity. These in situ observations suggest that EGFR expression may not play an important role in the growth regulation of human colonic carcinomas.
Histologic grading in soft‐tissue sarcomas. An analysis of 194 cases including agnor count and mast‐cell count
Authors: Tomita Y. , Aozasa K. , Myoui A. , Kuratsu S. , Matsumoto K. , Uchida A. , Ono K.
Published: February 2007

In order to establish a new histologic grading system for STS, we evaluated histologic prognostic factors. For this purpose, we selected 194 patients with STS: 31 in the upper extremities, 63 in the trunk, and 100 in lower extremities. All the patients were treated by surgery, followed by chemotherapy in 74 cases, radiotherapy in 11, chemotherapy and radiotherapy in 30, or no adjuvant treatment in 79. Histologic factors evaluated were mitotic count, extent of necrosis, cellularity, cellular pleomorphism, extent of myxoid change, sclerosis, non‐specific histologic diagnosis, counting of reaction product in silver stain for nucleolar organizer regions (AgNOR) and mast‐cell counts. Univariate analysis revealed mitotic count, necrosis, cellularity, cellular pleomorphism, non‐specific histologic classification, AgNOR count and mast‐cell count to be significantly related to prognosis. Multivariate analysis revealed that AgNOR count, cellularity and necrosis were independent prognostic factors. A new grading system was introduced: low‐grade, intermediate‐grade and high‐grade. The survival between each group were significantly different; the 5‐year‐survival rate in patients of the low‐, intermediate‐ and high‐grade groups was 87%, 74% and 35% respectively. Our findings suggest that this histologic grading system may be useful for making therapeutic decisions.
Establishment and characterization of a human gastric scirrhous carcinoma cell line in serum‐free chemically defined medium
Authors: Yanagihara Kazuyoshi , Kamada Nanao , Tsumuraya Masaru , Amano Fumio
Published: February 2007

We have established a human gastric scirrhous carcinoma cell line (designated as HSC‐43) in a serum‐free chemically defined medium (CDM) without any polypeptide growth factor, from a primary tumor of a 56‐year‐old male patient. HSC‐43 cells grew in vitro in adherence with a population doubling time of 55 hr, and had the cytological properties of mucinous epithelial tumor cells. Cytogenetic analysis of the cells revealed pseudo‐tetraploidy, with structural abnormalities of deletion at chromosome Iq25 and with 3 marker chromosomes. Some cells had retained features of signet‐ring cells and caused fibroblastic proliferation when transplanted into athymic nude mice. The possible involvement of transforming growth factor‐α(TGF‐α), and its receptor, the epidermal‐growth‐factor receptor (EGFR), on the growth of HSC‐43 cells was studied. Synthesis and secretion of TGF‐α by HSC‐43 cells were confirmed by biological assay and enzyme‐linked immunosorbent assay. Radioreceptor analysis showed the presence of receptors for EGF in HSC‐43 cells. Proliferation of HSC‐43 cells was inhibited by antibodies against TGF‐α and/or the EGFR. However, neither TGF‐α nor epidermal growth factor (EGF) was effective in stimulating the cell growth of HSC‐43 cells, irrespective of the cell density when supplemented exogenously. Our data suggest that TGF‐α and EGFR play a role in the autocrine growth of HSC‐43 cells. This may be another example of growth regulation of gastric carcinoma.
Very frequent loss of heterozygosity throughout chromosome 17 in sporadic ovarian carcinoma
Authors: Foulkes William D. , Black Donald M. , Solomon Ellen , Trowsdale John , Stamp Gordon W. H.
Published: February 2007

Frequent loss of heterozygosity (LOH) on both arms of chromosome 17 has been described in ovarian carcinoma (OC) by a number of groups, and the recent fine mapping of an inherited breast‐ovarian cancer gene (brcAl) to a small region at 17q 12–21 has focused interest on this area. We studied 28 sporadic OCs with 21 markers at 18 loci on chromosome 17 (5 on 17p and 13 on 17q). LOH on 17p was 78%, and always involved p53. In 86% of cases showing LOH, all informative markers on chromosome 17 showed reduction to homozygosity. Using 6 markers flanking the brcAI locus on 17q, LOH was 75%, but only one tumour showed LOH with telomeric retention. The data therefore suggest that small deletions on chromosome 17 are very uncommon in sporadic OC. No genomic rearrangements by Southern blotting were seen in the brcAl candidate gene estradiol 17β dehydrogenase 2 (17hsd2), or in erbB2, prohibitin (phb) and nmel (previously nm23‐HI). LOH on chromosome 17 was more common in high‐grade, late‐stage carcinomas, and no LOH was seen in any benign or borderline tumour. This study has clearly demonstrated that LOH at any one site on chromosome 17 is most commonly explained by LOH over the whole of the chromosome. We consider possible reasons for the absence of small deletions on chromosome 17 in OC.
Prognostic significance of human papillomavirus genomes (type‐16, ‐18) and aberrant expression of p53 protein in human esophageal cancer
Authors: Furihata Mutsuo , Ohtsuki Yuji , Ogoshi Shohei , Takahashi Akira , Tamiya Tatsuo , Ogata Takuro
Published: February 2007

The presence and distribution of human papillomavirus (HPV) DNA or of increased expression of the p53 protein were determined in 71 patients with esophageal squamous‐cell carcinoma (SCC) by in situ hybridization with biotinylated DNA probes for HPV‐16, ‐18,‐31 and ‐33, and immunohistochemical techniques using antibody to p53 protein. Of 71 patients from Kochi prefecture, 24 (Group I) were positive for HPV DNA, including 10 for HPV type‐16 and 14 for HPV type‐18; in contrast, none were positive for HPV‐31 or ‐33. Of the remaining 47 patients, 24 (Group II) showed positive nuclear staining in cancer cells with p53 antibody. The group of 23 patients with neither HPV nor p53 expression (Group III) had a significantly better survival rate than Group I or II. These results suggest that HPV‐16 and ‐18 may play a role in the pathogenesis of esophageal SCC, particularly with regard to its striking geographical distribution; that esophageal cancers do occur in the absence of HPV infection when over‐expression of p53 is present; and that the presence of HPV infection and over‐expression of p53 may each be a factor indicating a relatively poor prognosis.
Appearance of amplified thymidylate synthase or dihydrofolate reductase genes in stage‐IV breast‐cancer patients receiving endocrine treatment
Authors: Lönn Ulf , Lönn Sigrid , Stenkvist Björn
Published: February 2007

We have examined the appearance of amplification of 2 genes involved in resistance to chemotherapy (thymidylate synthase, dihydrofolate reductase) in patients receiving endocrine treatment. Chronological tumor samples were obtained from breast‐cancer patients with clinical stage‐IV disease, using fine‐needle biopsies. The presence of amplification of thymidylate synthase and dihydrofolate reductase was determined using PCR in 185 fine‐needle biopsies from 37 patients. None of the initial samples of each patient showed amplification. However, in 7 of the 37 patients (19%) we detected development of gene amplification: in 2 cases of thymidylate synthase and in 5 cases of dihydrofolate reductase. Five of the 7 patients with amplification were receiving second‐line endocrine treatment after failing to respond to tamoxifen.
Prevalence of G‐TO‐T transversions among K‐ras oncogene mutations in human colorectal tumors in Yugoslavia
Authors: Urošević Nadežda , Dujić Aleksandar , Krtolica Koviljka , Škaro‐Milić Andjelija , Knežević‐Ušaj Slavica
Published: February 2007

Human colorectal carcinoma tissue sampled from 37 patients, routinely graded into Dukes' stages A, B and C and histologically examined for the level of differentiation, were analyzed for the presence of point mutations in the K‐ras oncogene. Seventeen cases out of the 37 analyzed were found to have a mutation in either the 12th or the 13th codon of the K‐ras gene, giving an overall frequency of mutation of 46%. The incidence of mutations in Dukes' stages A, B and C was 33, 46 and 58% respectively. Although the frequency of mutation appears to be similar to that reported for the USA population, the spectrum of point mutations in codons 12 and 13 of the K‐ras gene in the Yugoslav population appears to differ significantly. G‐to‐T trans‐versions make up 77% of all mutations present, with the distribution as follows: 18% at the first base and 59% at the second base of codons 12 and 13. G‐to‐A transitions at the second base is the only other mutation identified, occurring mainly in codon 13 in colorectal tumors of all 3 stages.
Expression of MaTu‐MN protein in human tumor cultures and in clinical specimens
Authors: Závada J. , Závadová Z. , Pastoreková S. , Čiampor F. , Pastorek J. , Zelník V.
Published: February 2007

MaTu is a novel agent which may be of relevance in human oncogenesis, and has 2 components. One of them, the exogenous MX (coding for protein p58X), is transmissible to human fibroblasts, to HeLa and to HeLa × fibroblast (H/F) hybrids. The other component, MN, is a cellular gene. Its product, the protein p54/58N, is inducible by infecting HeLa cells with MX or by growing them in dense cultures. This p54/58N appears to be a tumor‐associated antigen: it is expressed in HeLa and in tumorigenic cells (H/F‐T), but not in fibroblasts or in non‐tumorigenic hybrid cells (H/F‐N). Proteins related to p54/58N were also found on immunoblots prepared from human carcinomas of ovary, endometrium and uterine cervix, but not from normal tissues from corresponding organs or from placenta. Using genetically engineered MN protein, we developed a radioimmunoassay for MN‐specific antibodies, and for quantitative determination of MN proteins in cell extracts. In HeLa cells infected with MX we observed conspicuous ultrastructural alterations: formation of abundant filaments on the cell surface and amplification of mitochondria. Using immunogold‐staining, we visualized the p54/58N on the surface microvilli and in the nucleus, particularly in nucleoli.
Effect of bombesin, gastrin‐releasing peptide (GRP)(14–27) and bombesin/GRP receptor antagonist RC‐3095 on growth of nitrosamine‐induced pancreatic cancers in hamsters
Authors: Szepeshazi Karoly , Halmos Gabor , Schally Andrew V. , Groot Kate
Published: February 2007

Female Syrian golden hamsters with N‐nitroso‐bis (2‐oxopropyl) amine (BOP)‐induced pancreatic cancers were treated for 2 months with bombesin/gastrin‐releasing peptide (GRP) antagonist D‐Tpi6, Leu13Ψ(CH2NH)Leu14 bombesin(6‐14) (RC‐3095). Bombesin and GRP(14–27) were also administered alone and in combination with the antagonist RC‐3095. RC‐3095 exerted a dose‐dependent inhibitory effect on growth of pancreatic cancers. The number of animals with pancreatic cancers was significantly lower in the group treated with 60 μg/day of RC‐3095 and the weight of tumorous pancreata was reduced. Administration of bombesin or GRP alone did not stimulate the growth of pancreatic tumors and, in fact, had a slightly suppressive effect on cancers which was significant only in Experiment I. Bombesin and GRP (14–27) given together with RC‐3095 did not nullify the inhibitory effect of the antagonist on pancreatic cancer growth. Actually, a greater inhibition of pancreatic tumors was observed after administration of RC‐3095 together with bombesin or GRP, than with RC‐3095 alone. The mechanism of action of bombesin, GRP, and bombesin antagonists on pancreatic cancers appears to be complex. The inhibitory effect of bombesin antagonists on pancreatic cancer growth was accompanied by a decrease in the binding capacity of EGF receptors in tumor membranes. Administration of bombesin also caused a down‐regulation of EGF receptors and the greatest decrease in binding capacity of EGF receptors was observed after treatment with RC‐3095 in combination with GRP. Inhibition of pancreatic cancer can thus be tentatively explained by some common pathways in the action of bombesin, GRP and their antagonists, that could be mediated by interference with EGF‐receptor mechanisms.
Uptake of the neuron‐blocking agent meta‐iodobenzylguanidine and serotonin by human platelets and neuro‐adrenergic tumour cells
Authors: Rutgers M. , Tytgat G. A. M. , Verwijs‐Janssen M. , Buitfnhuis C. , Smets L. A. , Voûte P. A.
Published: February 2007

The adrenomedulla‐imaging agent meta‐iodobenzylguanidine (MIBG) is concentrated by various tumours of neuro‐ectodermal origin. Radio‐iodinated [131I]MIBG is therefore increasingly used for diagnosis and therapy of these disorders. To study the cause of thrombocytopenia associated with [131l]MIBG therapy, we investigated the uptake of MIBG in human platelets in comparison with that of serotonin. Specific imipramine‐sensitive uptake of [131I]MIBG was much slower than of [3H]serotonin, but after prolonged incubation high and serotonin‐equivalent uptake levels were observed. Accumulation of MIBG saturated at 10‐ to 100‐fold higher concentration than serotonin, and the affinity for uptake and intracellular storage in platelets was much higher for serotonin than for MIBG. Conversely, serotonin was not detectably concentrated by neuro‐adrenergic Uptake‐I in SK‐N‐SH neuroblastoma and PC 12 pheochromocytoma cells. Fluvoxamine inhibited the uptake of norepinephrine and MIBG in PC 12 cells, similarly to that of serotonin in platelets. However, the drug was 100‐fold more effective in inhibiting platelet transport of MIBG than of serotonin. The results indicate that MIBG uptake in platelets is not mediated by a neuro‐adrenergic Uptake‐I, but probably proceeds via the serotonin transport system. MIBG concentration by platelets was at least as efficient as in neuro‐adrenergic tumour cells and has therefore (radio)biological potential for injuring these cells or precursor megakaryocytes. Platelet uptake of MIBG could be selectively blocked by fluvoxamine in concentrations which minimally affected its accumulation in neuro‐adrenergic target cells.
Abnormalities in the p53 gene in tumors and cell lines of human squamous‐cell carcinomas of the head and neck
Authors: Yin Xiao‐Ying , Smith Martin L. , Whiteside Theresa L. , Locker Joseph , Johnson Jonas T. , Herberman Ronald B.
Published: February 2007

Abnormalities in the p53 gene were studied in a series of cell lines of human squamous‐cell carcinoma of the head and neck (SCCHN) and in tumor tissues. Restriction‐fragment‐length polymorphism (RFLP), quantitative hybridization and immunochemical analysis of mutant p53 proteins were combined to detect and characterize 3 different phases in the p53 gene alteration: mutation (in 9/9 cases), 17p 13 deletion (9/10 cases) and amplification of the non‐deleted allele (9/31 cases). In SCCHN, deletion of the p53 gene was nearly always accompanied by mutation, only one cell line studied having mutation without deletion. Alterations in the p53 gene are common in SCCHN, and involve a series of genetic events which occur in sequence during tumor progression.
Suppression of tumorigenicity in temperature‐sensitive mutants of embryonal carcinoma cells by induction of cell differentiation at non‐permissive temperature
Authors: Sumi Tetsuro , Sakuda Masayoshi , Nishina Yukio , Kosaka Mitsuko , Nishimune Yoshitakc
Published: February 2007

The temperature‐sensitive (ts) mutants of cell differentiation derived from the mouse teratocarcinoma cell line F9, when exposed to non‐permissive temperature, undergo stem‐cell differentiation concomitant with a transient retardation of cell‐cycle progression. By incubating these mutant strains at non‐permissive temperature, we were able to study the relationship between cell differentiation and tumorigenicity. Upon exposure to non‐permissive temperature, the mutant cells undergo extensive differentiation and lose their ability to initiate tumors in vivo, but retain their in vitro proliferative potential. Our data suggest that the loss of tumorigenicity is not caused by altered proliferative potential, but rather by cell differentiation. We therefore suggest that the loss of proliferative potential and the onset of cell differentiation in teratocarcinoma F9 cells are 2 independent events which can be genetically dissected, and that there is (a) crucial step(s) in the differentiation pathway at which these ts mutant cells lose their tumorigenicity.
Phenotypic properties of cultured tumor cells: Integrin αIIbβ3 expression, tumor‐cell‐induced platelet aggregation, and tumor‐cell adhesion to endothelium as important parameters of experimental metastasis
Authors: Tang Dean G. , Onoda James M. , Steinert Bruce W. , Grossi Irma M. , Nelson Kevin K. , Umuarger Lillian , Diglio Clement A. , Taylor John D. , Honn Kenneth V.
Published: February 2007

The present study was undertaken to investigate the factors involved in determining the metastatic potential of cultured cells derived from solid tumors. We first investigated the effects of cell source and culture conditions on lung colony formation by i.v. injected B16a (B16 amelanotic melanoma) cells and inhibition of tumor colony formation by the thromboxane A2 syn‐thase inhibitor, CGS14854. Prolonged culture resulted in a 10‐fold decrease in the incidence of B16a lung colonies, whereas passage in vivo for 150 days did not affect lung colony formation by tumor cells isolated from enzymatic dispersates by centrifugal elutriation. Cultured BI6a cells maintained at low density (LD) and harvested at low passage (LP) formed significantly more lung colonies than B16a cells harvested at high densities (HD) or high passage (HP). Over‐confluent tumor cells produced even lower number of lung colonies. Lung colony formation by elutriated BI6a cells (i.e., cells freshly isolated from tumor tissue) was consistently inhibited by CGS14854, whereas inhibition of lung colony formation by cultured B16a cells was dependent upon culture conditions. CGS 14854 was ineffective or less effective against HD/HP B16a cells. The differences in lung colony formation between LD, HD and elutriated B16a cells were not due to differential cell‐cycle distribution. Mechanistic studies indicated that LD/LP tumor cells induced aggregation of homologous platelets, whereas HD/HP BI6a cells failed to induce significant platelet aggregation. Aggregation of homologous platelets correlated positively with lung‐colonizing ability. Additionally, LD/LP cells demonstrated higher adhesion to endothelium than HD/HP BI6a cells. Finally, LD/LP BI6a cells expressed higher levels of αIIbβ3 integrins than HD/HP tumor cells, as determined by flow cytometry and immunofluorescence.
FK506 and cyclosporin a regulate proliferation and proto‐oncogene expression in HTLV‐1 ‐associated myelopathy/tropical‐spastic‐paraparesis‐derived T cells
Authors: Natazuka Toshiki , Umemiya‐Okada Tomoyo , Matsui Toshimitsu , Nakao Yoshinobu , Saida Takahiko
Published: February 2007

Human T‐cell‐leukemia‐virus‐type‐1 (HTLV‐I) infection is associated with adult T‐cell leukemia/lymphoma (ATL) and HTLV‐1 ‐associated myelopathy (HAM)/tropical spastic paraparesis (TSP). The T‐cell‐targeting immunosuppressants, FK506 and cyclosporin A (CsA), suppressed proliferation of the HAM/TSP‐derived T‐cell lines, H89–59, H89–79 and H109. FK506 and CsA also reduced expression of the proto‐oncogenes, c‐myc and c‐fos, but not c‐jun and interleukin‐2‐receptor‐α (IL‐2Rα) gene in H109 cells. The growth‐inhibitory effects of FKS06 and CsA were not abrogated by interleukin 2 (IL‐2). These results suggest that the inhibitory effects of FK506 and CsA are independent of IL‐2, and are associated with the reduction of c‐myc and c‐fos gene expression.
Usage of T‐cell receptor Vβ chain genes in fresh and cultured tumor‐infiltrating lymphocytes from human melanoma
Authors: Weidmann Eckhart , Trucco Massimo , Lotze Michael T. , Whiteside Theresa L. , Elder Elaine M.
Published: February 2007

Tumor‐infiltrating lymphocytes (TIL) freshly obtained from human malignant melanomas as well as the same TIL grown in the presence of interleukin 2 (IL2) were studied for gene expression of the T‐cell receptor (TCR) variable β regions (Vβ). To perform the TCR‐Vβ analysis, total RNA was isolated from TIL and reverse‐transcribed into cDNA, which was then amplified by PCR using 22 different 5′ primers specifically recognizing the sequences of 20 Vβ gene families and a 3′ primer annealing to the constant region of the β chain. The TCR‐α constant region (Cα) gene was co‐amplified as a standard for the calculation of the percentage of each TCR‐Vβ gene expressed. The frequency of individual Vβ regions expressed on TIL was computed from the ratio of cpm Vβ to cpm Ca for each Vβ region in relation to the total of all 22 ratios. With fresh TIL obtained from 8 different melanomas, oligoclonal distribution of Vβ genes expressed on TIL was observed, in comparison with a broader and unrestricted distribution seen with peripheral‐blood T cells of 8 normal individuals. The oligoclonal patterns of Vβ‐gene expression in fresh melanoma TIL were distinct in every tumor. Several of the Vβ‐genes usually expressed in normal PBL were not expressed in fresh TIL. In melanoma TIL cultured in the presence of IL2 and IL4 and in the absence of autologous tumor (AuTu) or antigen‐presenting cells for 23 to 65 days, selection of T‐cell lines expressing a restricted number of Vβ genes occurred. Although in 4/5 TIL cultures this selection involved the Vβ7 gene, no relationship could be established between Vβ gene expression in fresh TIL and that in T‐cell lines outgrowing in long‐term cultures. Selection in culture of CD3+ CD8+ T‐cell lines with Vβ‐gene expression restricted to I or 2 Vβ families did not correlate with the presence or level of AuTu cytotoxicity mediated by these T cells. The results indicate that in TIL cultures random selection of T‐cell lines with reactivity not relevant to AuTu may account for poor expression or loss of AuTu cytotoxicity by most TIL cultured long‐term in the presence of cytokines and in the absence of specific antigenic stimulation.
Monoclonal antibody 4D3 detects small intestinal mucin antigen (SIMA)—Glycoprotein in the serum of patients with colorectal cancer
Authors: Pinczower Gideon D. , Gianello Robert D. , Williams Roderick P. W. , Preston Barry N. , Preston Henry , Linnane Anthony W.
Published: February 2007

We have developed a sensitive ELISA using MAb 4D3 for the detection of a novel epitope on Small Intestinal Mucin Antigen (SIMA) and report here that SIMA is present in the serum of patients with colorectal cancer. SIMA has been shown to occur in tissue from a high proportion of patients with colorectal cancer. SIMA derived from serum was similar to tissue‐derived SIMA: both eluted in the void volume of a Superose 6 column indicating a molecular weight above 5,000 kDa and they exhibited similar buoyant densities on CsCI gradients. The ELISA was most reliable after pre‐treatment of serum with 0.4 M perchloric acid to remove interfering substances. The upper limit for SIMA in normal serum was set as the mean plus 2 standard deviations determined from a group of 97 healthy control subjects. In a samßle of 113 patients with colorectal cancer, SIMA serum levels were elevated in 15% of patients with Dukes' Stage A, 38% with Stage B, 32% with Stage C and 75% with Stage D colorectal cancer. SIMA serum levels were compared with those of the widely used tumor marker, carcino‐embryonic antigen (CEA). The SIMA assay detected a significant number of sera that were not detected by the test for CEA. We propose that SIMA will prove to be a valuable serological tumor marker, in combination with CEA and other tumor markers, for the detection of colorectal cancer.
Increasing incidence of both major histological types of esophageal carcinomas among men in Sweden
Authors: Hansson Lars‐Erik , Sparén Pär , Nyrén Olof
Published: February 2007

Although a rare tumor form, there is evidence that the incidence of esophageal adenocarcinomas is increasing in Western Europe and the US. The aim of this nationwide population‐based study was to describe the secular trends in the incidence rates of adenocarcinoma and squamous‐cell carcinoma of the esophagus over a 28‐year period from I960 to 1987. The Swedish Cancer Registry, complete to more than 95%, was used to identify the cases. The percentage verified by histology rose from 89% to 98%. The age‐standardized incidence rate of adenocarcinoma increased in males from 0.5 per I05 in 1960–63 to 1.1 per 105 in 1984–87, corresponding to an average annual increase of 1.5%. In females the incidence remained stable around 0.2 per I05. The age‐standardized incidence rate of squamous‐cell carcinoma in males increased from 2.9 to 4.0 per 105, corresponding to an average annual increase of 1.0%. In females the rate decreased from 1.4 to 1.2 per I05, corresponding to an annual average decrease of 0.5%. The male/female ratio was 4.6 for adenocarcinoma and 2.7 for squamous‐cell carcinoma of the esophagus. Since the incidence rates of squamous‐cell carcinoma of the esophagus and of adenocarcinoma seem to be rising, there is a great need for well‐planned analytical epidemiological studies of these tumor locations, taking the histological type into consideration.
Quantitative and qualitative assessment of CA‐125 production by human endometrial epithelial cells: Comparison of eutopic and heterotopic epithelial cells
Authors: Kobayashi Hiroshi , Ida Wakaba , Terao Toshihiko , Kawashima Yoshiro
Published: February 2007

We have established an in vitro system for the culture of epithelial cells (ECs) from human uterine endometrium to examine the production of CA 125 and to characterize the CA‐125 antigen purified from the conditioned media. CA‐125 secretion was higher in heterotopic ECs than in eutopic ECs and it was more significant after heterotopic ECs reached confluence than during the logarithmic growth phase. CA‐125 expression was observed mainly in the G0/G,‐phase. CA‐125 expression on cell membranes did not correlate with the volume of CA 125 released per cell, and there was no amplification of CA‐125 expression in heterotopic EC membranes. Treatment of the purified CA‐125 antigen with 6 M urea yielded a much lower molecular‐mass peak (200 kDa). The results of Western blot indicated the presence of a single polydisperse band of 200 kDa in the conditioned media from eutopic ECs, whereas 2 major CA‐125 isoforms of 200 kDa and 110 kDa, as well as 2 minor forms of 100 kDa and 70 kDa, were observed in the conditioned media of the heterotopic ECs. We conclude that, in heterotopic ECs, the 1 10‐kDa CA‐125 is more prominent than the 200‐kDa antigen, and that the elevation of CA‐125 levels in the conditioned media could be attributed to significantly increased release of I 10‐kDa CA‐125 from heterotopic ECs.
Quercetin induces type‐II estrogen‐binding sites in estrogen‐receptor‐negative (MDA‐MB231) and estrogen‐receptor‐positive (MCF‐7) human breast‐cancer cell lines
Authors: Scambia G. , Mancuso S. , Panici P. Benedetti , De Vincenzo R. , Ferrandina G. , Bonanno G. , Ranelletti F. O. , Piantelli M. , Capelli A.
Published: February 2007

We show that flavonoids positively regulate type‐II estrogen‐binding site (type‐ll EBS) levels both in MCF‐7 (ER‐positive) and in MDA‐MB231 (ER‐negative) breast‐cancer cells. Type‐ll EBS were measured by a whole‐cell assay at 4°C for 2.5 hr using [3H]‐estradiol as tracer. In both cell lines the effect of quercetin (Q) was dose‐related and already evident after 12 hr of Q treatment. The increase of type‐ll EBS levels after Q exposure requires both RNA and protein synthesis, since actinomycin D and cycloheximide completely abolished the stimulatory effect. The ability of flavonoids in inducing type‐ll EBS is well correlated with their relative binding affinity for type‐ll EBS. The flavonoid‐induced enhancement of type‐ll EBS levels is accompanied by increased sensitivity of cancer cells to the inhibitory effect of low Q concentrations. Our data suggest that type‐ll EBS are ligand‐regulated receptors.
Superantigen‐induced cytokines suppress growth of human colon‐carcinoma cells
Authors: Dohlsten Mikael , Sundstedt Anette , Björklund Mariana , Hedlund Gunnar , Kalland Terje
Published: February 2007

We have recently demonstrated that the superantigen staph‐ylococcal enterotoxin A (SEA) conjugated to colon‐carcinoma‐reactive monoclonal antibodies (MAbs) directs T cells to lyse human colon‐carcinoma cells, representing a potential novel tumor therapy. To further analyze the mechanism of anti‐tumor effects of superantigen‐activated T cells, we compared the activity of free and MAb‐conjugated SEA in a long term in vitro co‐culture assay of human peripheral‐blood mononuclear cells (pBMC) and colon‐carcinoma cell lines. Activation of resting T lymphocytes with SEA conjugated to the colon‐carcinoma‐reactive MAb C215 or free SEA resulted in strong inhibition of the growth of all studied colon‐carcinoma cell lines. The growth of WiDr colon‐carcinoma cells was unaffected by the presence of unactivated mononuclear cells, whereas addition of pM concentrations of SEA or C215‐SEA conjugate completely suppressed tumor‐cell growth. The suppressive effect was mediated by both CD4+ and CD8+ T cells and required the presence of MHC‐Class‐ll+ monocytes. The inhibition of tumor‐cell growth was to a large extent mediated by soluble factors present in supernatants from SEA‐ or C215‐SEA‐activated mononuclear cells. Quantitation of cytokine mRNA in SEA‐activated mononuclear cells by the reverse transcriptase‐polymerase chain reaction (RT‐pCR) revealed strong induction of mRNA encoding the cytokines IL‐1α, IL‐1 β, IL‐2, IL‐6, TNF‐α, TNF‐β and IFN‐γ. The use of cytokine‐specific MAb demonstrated that IFN‐γ was of major importance for the tumor‐growth‐inhibitory activity in supernatants of SEA‐activated lymphocytes. Addition of recombinant cytokines to WiDr colon‐carcinoma cells showed that TNF‐α was able to act synergisti‐cally with IFN‐γ to suppress tumor‐cell growth. The local production of tumor‐suppressive cytokines induced by MAb‐targeted superantigens is likely to be of particular relevance for inhibition of the growth of tumor cells not expressing the targeted tumor‐associated antigen.
Carcinogenic potential of some pesticides in a medium‐term multi‐organ bioassay in rats
Authors: Cabral Ricardo , Hasegawa Ryohci , Hoshiya Toru , Hakoi Kazuo , Ogiso Tadashi , Boonyaphiphat Plcumjit , Shirai Tomoyuki , Ito Nobuyuki
Published: February 2007

The carcinogenic potential of 5 pesticides was analyzed using a medium‐term multi‐organ bioassay for carcinogenicity. Male F344 rats were initially treated with 3 known carcinogens (diethylnitrosamine, N‐methyl‐N‐nitrosourea and N‐bis(2‐hydroxypropyl)nitrosamine) during a period of 4 weeks to induce neoplastic changes in a variety of organs, and then given one of 5 pesticides in the diet for a further 16 weeks. Neoplastic and pre‐neoplastic lesions were found in the thyroid, kidney and urinary bladder with propineb, in the forestomach, kidney and thyroid with captan and folpet. The number of glutathione S‐transferase placental‐form‐positive liver‐cell foci was significantly increased in the captan‐ and phosmet‐treated groups. Based on these findings, captan and propineb can be considered as carcinogens and carcinogenicity is suspected for folpet and phosmet. These results are in concordance with reported long‐term carcinogenicity for captan, folpet and propineb. Daminozide was considered not to be carcinogenic. Thus, the present assay of 20 weeks' duration is useful for the prediction of potential carcinogens.
Interaction of human malignant melanoma tumor spheroids with endothelium and reconstituted basement membrane: Modulation by RGDS
Authors: Offner Felix Albert , Feichtinger Hans , Bigalke Iris , Schiefer Johannes , Wirtz Hans Christian , Klosterhalfen Bernd , Kirkpatrick Charles James
Published: February 2007

Tumor‐cell extravasation involves sequential adhesive interactions with vascular endothelium and the subendothelial basement membrane. We have established a 3‐dimensional model in vitro to simulate these events and to elucidate targets of the anti‐cell‐adhesive synthetic peptide RGDS. Tumor spheroids of the melanoma cell line ST‐ML‐12 served as models of tumor‐cell emboli and were transferred onto human umbilical vein endothelial cells. To imitate the vascular anatomy, the latter were grown on reconstituted basement membranes produced by dextran‐stimulated bovine corneal endothelial cells. RGDS did not affect the homotypic aggregation of the tumor cells and only minimally inhibited the attachment of the spheroids to the reconstituted vessel. A short‐term (20 min) inhibition of adhesion to denuded basement membranes was observed. The attachment was closely associated with damage to the endothelial cells by oxygen‐derived free radicals. RGDS retarded endothelial injury for up to 3 hr. The most prominent effect was observed after penetration of the endothelium. RGDS suppressed the emigration of tumor cells from the attached tumor‐cell cluster in a dose‐ and time‐dependent fashion. After 12 hr, the inhibitory effect progressively declined. This was not due to loss of activity of the peptide, indicating a resistance mechanism in the melanoma cells. On purified components of the basement membrane, RGDS effectively inhibited the initial spheroid attachment to fibronectin and collagen IV but had no effect on attachment to laminin. By contrast, subsequent migration was significantly suppressed on all substrata. Our model permits the study of dynamic cell‐cell and cell‐extracellular‐matrix interactions and indicates that RGDS might predominantly act on early tumor‐cell locomotion after penetration of the endothelium.