bluuebunny/crossref_metadata_2025 huggingface dataset:
Wage Compression and the Unemployment Crisis: Labor Market Institutions, Skills, and Inequality‐Unemployment Tradeoffs
Authors: Howell David R. , Huebler Friedrich
Published: August 2005

At the core of the orthodox view is the belief that policy makers face an ineluctable choice between employment and equality. With data from the OECD for the major affluent OECD countries, empirical support for a variety of tradeoffs is explored: between unemployment rates and earnings inequality; between the change in unemployment rates and the growth in earnings inequality; between unemployment inequality (high vs. low skill) and earnings inequality; and between employment rate inequality (high vs. low skill) and earnings inequality. The authors find little evidence for these predicted tradeoffs. The chapter also looks at skill distributions and finds that differences in institutions, not skill distributions, are the main source of cross-country differences in earnings inequality. They conclude that the labor market institutions that clearly compress wages do not appear to have similarly clear and substantial adverse effects on employment performance.
Seeing Through Language
Authors: Davidson Donald
Published: August 2005

This essay argues that while there is an important sense in which we see the world through language, common ways of understanding this metaphor are false. It criticises mentalese, the thesis that there is an inborn ‘language of thought’, and discusses the conditions necessary for creatures to acquire concepts, thoughts and language. The birth of meaning occurs through interpersonal communication about a shared, public world, and depends on the fact that human creatures have shared needs and interests.
Asset Pricing in Discrete Time
Authors: Poon Ser-Huang , Stapleton Richard
Published: August 2005

Relying on the existence, in a complete market, of a pricing kernel, this book covers the pricing of assets, derivatives, and bonds in a discrete time, complete markets framework. It is primarily aimed at advanced Masters and PhD students in finance. Topics covered include CAPM, non-marketable background risks, European-style contingent claims as in Black–Scholes and in cases where risk-neutral valuation relationship does not exist, multi-period asset pricing under rational expectations, forward and futures contracts on assets and derivatives, and bond pricing under stochastic interest rates. All the proofs, including a discrete time proof of the Libor market model, are shown explicitly.
Microeconomic Theory
Authors: Bergin James
Published: August 2005

Covers a standard range of topics in microeconomics theory. These include decision theory, strategic and extensive form games, the economics of information, bargaining, principal agent problems, cooperative games, and evolutionary game theory. Coverage is at the level of a graduate course in microeconomic theory.
THE MEASUREMENT OF POLICE FORCE EFFICIENCY: AN ASSESSMENT OF U.K. HOME OFFICE POLICY
Authors: DRAKE LEIGH M. , SIMPER RICHARD
Published: August 2005

Over the past 20 years, governments around the world have implemented strategies and targets to ensure that public services are efficient in the management of resources. In the United Kingdom this common agenda has led to the recent Police Reform Act 2002 in which consideration was given to how police forces can show value for money based on government strategic policy targets. This article presents a critique of the performance radar technique proposed by the Home Office in the United Kingdom as a new public policy objective to assess police force performance. Using an alternative and innovative nonparametric modeling strategy, the article shows that the use of the former approach can produce biased performance rankings and also demonstrate that environmental factors can have a substantial impact on the apparent efficiency of individual police forces. Finally, the results suggest that survey data (as used by the Home Office) should not be used as a basis to assess police performance. (JEL C14, L3, M2)
A network of transcriptionally coordinated functional modules in Saccharomyces cerevisiae
Authors: Petti Allegra A. , Church George M.
Published: August 2005

Recent computational and experimental work suggests that functional modules underlie much of cellular physiology and are a useful unit of cellular organization from the perspective of systems biology. Because interactions among modules can give rise to higher-level properties that are essential to cellular function, a complete knowledge of these interactions is necessary for future work in systems biology, including in silico modeling and metabolic engineering. Here we present a computational method for the systematic identification and analysis of functional modules whose activity is coordinated at the level of transcription. We applied this method, Search for Pairwise Interactions (SPIN), to obtain a global view of functional module connectivity in Saccharomyces cerevisiae and to provide insight into the biological mechanisms underlying this coordination. We also examined this global network at higher resolution to obtain detailed information about the interactions of particular module pairs. For instance, our results reveal possible transcriptional coordination of glycolysis and lipid metabolism by the transcription factor Gcr1p, and further suggest that glycolysis and phosphoinositide signaling may regulate each other reciprocally.
ATG deserts define a novel core promoter subclass
Authors: Lee Maxwell P. , Howcroft Kevin , Kotekar Aparna , Yang Howard H. , Buetow Kenneth H. , Singer Dinah S.
Published: August 2005

The MHC class I gene, PD1, has neither functional TATAA nor Initiator (Inr) elements in its core promoter and initiates transcription at multiple, dispersed sites over an extended region in vitro. Here, we define a novel core promoter feature that supports regulated transcription through selective transcription start site (TSS) usage. We demonstrate that TSS selection is actively regulated and context dependent. Basal and activated transcriptions initiate from largely nonoverlapping TSS regions. Transcripts derived from multiple TSS encode a single protein, due to the absence of any ATG triplets within ∼430 bp upstream of the major transcription start site. Thus, the PD1 core promoter is embedded within an “ATG desert.” Remarkably, extending this analysis genome-wide, we find that ATG deserts define a novel promoter subclass. They occur nonrandomly, are significantly associated with non-TATAA promoters that use multiple TSS, independent of the presence of CpG islands (CGI). We speculate that ATG deserts may provide a core promoter platform upon which complex upstream regulatory signals can be integrated, targeting multiple TSS whose products encode a single protein.
Up‐regulation and nuclear localization of β‐catenin in endometrial carcinoma in response to progesterone therapy
Authors: Saegusa Makoto , Hamano Mieko , Kuwata Takeshi , Yoshida Tsutomu , Hashimura Miki , Akino Fumiyuki , Watanabe Jun , Kuramoto Hiroyuki , Okayasu Isao
Published: August 2005

Ovarian hormones are considered to be capable of regulating expression of β‐catenins. A possible role of β‐catenin in alteration of cell morphology has been proposed, but little is known about β‐catenin expression during changes in the tumor morphology of endometrial carcinomas induced by progesterone therapy. To clarify changes in expression of β‐catenin and their relation to morphological alteration, expression of hormone receptors and several cell kinetic markers, sequential biopsy and hysterectomy specimens of 23 endometrial carcinoma and 6 complex hyperpla‐sia with atypia (atypical hyperplasia) cases receiving progesterone therapy were investigated. In vitro assay was also conducted using two endometrial carcinoma cell lines (HEC265 and Ishikawa) expressing progesterone receptors (PRs). An increase of nuclear β‐catenin accumulation was evident during progesterone therapy in endometrial carcinomas and atypical hyperplasias. The nuclear labeling indices were significantly associated with gene mutations and alteration in morphological features in response to progesterone, independently of the status of Ki‐67, p21WAF1 and p27Kip1, and hormone receptors. In HEC265 having a β‐catenin gene mutation (A32V), cytoplasmic p‐catenin levels were elevated by progesterone treatment, linked to down‐regulation of PR expression, but such changes were relatively minor in Ishikawa without the gene alterations. These findings demonstrate a possible role of progesterone in regulation of β‐catenin expression in endometrial tumors. Moreover, nuclear β‐catenin accumulation, like gene abnormalities, is associated with the alteration of tumor morphology due to progesterone, indicating that β‐catenin may be a clinically useful marker of hormone therapeutic effects. (Cancer Sci 2003; 94: 103‐111)
Establishment and characterization of unique cell lines derived from pyothorax‐associated lymphoma which develops in long‐standing pyothorax and is strongly associated with Epstein‐Barr virus infection
Authors: Takakuwa Tetsuya , Luo Wen‐Juan , Ham Maria Francisca , Mizuki Masao , Iuchi Keiji , Aozasa Katsuyuki
Published: August 2005

Malignant lymphoma frequently develops in the pleural cavity of patients with over 20 years' history of pyothorax. The term pyothorax‐associated lymphoma (PAL) has been proposed for this type of tumor. We established four novel lymphoma cell lines (OPL‐3, ‐4, ‐5, and ‐7) from four patients with PAL. Characteristics of the four cell lines are as follows: B‐cell nature with defective expression of B‐cell and T‐cell surface antigens, monoclonal pattern of Epstein‐Barr virus (EBV) infection in lymphoma cells (thus indicating an etiological role of EBV for lymphomagenesis), complicated chromosomal abnormalities with numerous structural and numerical abnormalities, and occasional but distinct genome instability. These abnormalities in cell character might be caused by the specific circumstances of PAL lymphomagenesis, i.e., chronic inflammation. Thus, PAL cell lines could be useful in analysis of molecular mechanisms leading to malignancy in chronic inflammation.
Cellular senescence, an unpopular yet trustworthy tumor suppressor mechanism
Authors: Ishikawa Fuyuki
Published: August 2005

The term “cellular senescence” refers to the state in which normal cells irreversibly stop dividing. Historically, this condition was first inferred from the finding that normal human fibroblasts cease dividing after a limited number of cell divisions. Since then, cellular senescence has been discussed as a potential cause of aging of organisms. However, recent studies have significantly expanded our view of cellular senescence in terms of both mechanistics and biological significance. Accordingly, cellular senescence is now considered to play an important adaptive role, namely, a tumor suppressor function. This review will focus on recent findings that have contributed to the elucidation of the adaptive role of cellular senescence.
High susceptibility of the ACI and spontaneously hypertensive rat (SHR) strains to 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) prostate carcinogenesis
Authors: Inaguma Shingo , Takahashi Satoru , Ohnishi Hiroyuki , Suzuki Shugo , Cho Young‐Man , Shirai Tomoyuki
Published: August 2005

Carcinogenic responses in the prostate to 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) were compared among seven rat strains (F344, ACI, Spontaneously Hypertensive Rat (SHR), Sprague‐Dawley (SD), Wistar, Lewis and Brown Norway (BN)). Ten‐week‐old animals of each strain were given PhIP at 400 ppm in the diet for 20 weeks then maintained until week 54. The final survival rates were 92, 92, 83, 75, 67, 42 and 42%, respectively, and the SHR strain showed the highest sensitivity with regard to development of prostatic intraepithelial neoplasias (PINs) in the ventral prostate. With regard to the induction of adenocarcinomas of the ventral prostate, the ACI strain was most sensitive, whereas Lewis and F344 rats were relatively resistant. No adenocarcinomas were found in the dorsolateral or anterior prostate or seminal vesicles in any of the strains. The levels of serum testosterone and estrogen, PhIP‐DNA adducts and cell kinetics did not correlate with the development of ventral prostatic lesions and thus other factors are presumably responsible for the variations in susceptibility. The present data indicate that ACI and SHR rats are appropriate strains for experimental investigation of PhIP‐induced prostate carcinogenesis.
Significance of overexpression of metallothionein in mouse urinary bladder focal lesions induced by treatment with N‐butyl‐N‐(4‐hydroxybutyl)‐nitrosamine
Authors: Mitsuhashi Makoto , Wanibuchi Hideki , Morimura Keiichirou , Doi Ken'ichiro , Wei Min , Wada Seiji , Nakatani Tatsuya , Fukushima Shoji
Published: August 2005

Metallothionein (MT) is expressed in various types of human tumors, including transitional cell carcinomas of the urinary bladder, but its biological significance remains unclear. In the present study, the role of MT in urinary bladder carcinogenesis induced by N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN) treatment was investigated using C57BL/6 mice. One hundred 5‐week‐old male C57BL/6 mice were divided into two groups, which were given drinking water with or without 0.05% BBN throughout the experimental period. Subgroups of ten animals from each group were sacrificed at weeks 5, 10, 15, 20 and 25, and urinary bladder samples were examined immunohistochemically for MT, proliferating cell nuclear antigen (PCNA) and apoptosis. MT was found to be abundant in normal‐looking mucosa, but decreased with progression from precancerous lesions to invasive carcinoma in the urinary bladder obtained from BBN‐treated mice. Lesions could be divided into MT‐positive and negative. There was a tendency for greater MT expression in PCNA‐positive lesions, while apoptosis was rather associated with MT‐negativity. These data suggest that the overexpression of MT may play a role in mouse urinary bladder carcinogenesis.
Identification of candidate predictive markers of anticancer drug sensitivity using a panel of human cancer cell lines
Authors: Dan Shingo , Shirakawa Mieko , Mukai Yumiko , Yoshida Yoko , Yamazaki Kanami , Kawaguchi Tokuichi , Matsuura Masaaki , Nakamura Yusuke , Yamori Takao
Published: August 2005

We previously investigated the correlations between the expression of 9216 genes and various chemosensitivities in a panel of 39 human cancer cell lines1) and found that the expression levels of AKR1B1 and CTSH were correlated with sensitivity and resistance to multiple drugs, respectively. To validate these correlations, we investigated the expression of these two genes and the chemosensitivities in 12 additional gastric cancer cell lines. The expression of AKR1B1 in the additional cell lines exhibited significant correlations with sensitivities to 8 of the 23 drugs examined, while that of CTSH displayed a significant negative correlation with only one (MS‐247) of the 27 drugs examined. Their expressions were weakly correlated with sensitivity and resistance, respectively, to the remainder of the drugs. Moreover, when the 12 cell lines were divided into high‐expressing and low‐expressing groups, a comparison of these groups using Mann‐Whitney's U test revealed that high expression levels of AKR1B1 and CTSH were related to sensitivity to 21 of the drugs and resistance to 8 of the drugs, respectively. The present results suggest that AKR1B1 and CTSH may be good markers for prediction of sensitivity to certain drugs and that our panel of 39 cell lines has the potential to identify candidate predictive marker genes.
Serum alanine aminotransferase levels and survival after hepatectomy in patients with hepatocellular carcinoma and hepatitis C virus‐associated liver cirrhosis
Authors: Tarao Kazuo , Rino Yasushi , Takemiya Shoji , Ohkawa Shinichi , Sugimasa Yukio , Miyakawa Kaoru , Tamai Setsuo , Masaki Takahiro , Hirokawa Satoru , Kameda Yoichi , Nagaoka Tadashi , Okamoto Naoyuki , Kokubu Shigehiro , Yoshida Muneki , Kakita Akira
Published: August 2005

We examined whether sustained alleviation of inflammation as monitored by serum alanine aminotransferase (ALT) levels was associated with longer survival in hepatectomized hepatocellular carcinoma (HCC) patients with hepatitis C virus‐associated liver cirrhosis (HCV‐LC). Thirty‐four hepatectomized patients with HCV‐LC and HCC as a single nodule, and for whom more than 5 years had elapsed after the hepatectomy, were studied. They had no histologic evidence of portal or hepatic vein invasion. They were subdivided into two groups according to their serum ALT levels in the 2 years after hepatectomy: the low ALT group comprised 13 patients whose serum ALT levels showed a sustained low level below 80 IU, and the high ALT group comprised 21 patients whose serum ALT levels showed several peaks or plateaus above 80 IU. The patients had been followed‐up prospectively with frequent ultrasonography and magnetic resonance imaging or computed tomography for recurrence for >5 years. The survival period, non‐recurrence interval and number of recurrences were observed. Recurrences were treated with transcatheter chemoembolization in all cases. The cumulative survival rate in the low ALT group was significantly better than that in the high ALT group (P<0.05). The 5‐year survival in the low ALT group was as high as 92.3% (12 of 13) compared with 33.3% (7 of 21) in the high ALT group (P<0.05). The cumulative non‐recurrence rate in the low ALT group was also significantly better than that in the high ALT group (P<0.01). The survival period correlated well with the interval until the first recurrence (r=0.545, P=0.006). There was a tendency for the number of recurrences in the low ALT group (1.5±0.4, mean±SE) to be fewer than that in the high ALT group (2.2±0.4), although this was not significant. Sustained alleviation of inflammation, as indicated by low ALT levels, provides a survival advantage mainly due to the longer non‐recurrence interval, and possibly because of fewer recurrences, in hepatectomized HCC patients with HCV‐LC.
Leptomycin B enhances CDDP‐sensitivity via nuclear accumulation of p53 protein in HPV‐positive cells
Authors: Naniwa Jun , Kigawa Junzo , Akeshima Ryoji , Kanamori Yasunobu , Itamochi Hiroaki , Oishi Tetsuro , Iba Takahiro , Terakawa Naoki
Published: August 2005

Cervical cancer, which commonly contains a wild‐type p53 gene, is highly correlated with human papilloma virus (HPV) infection. Because the oncoprotein E6, derived from HPV, inhibits the function of p53 protein, the inhibition of apoptosis via the p53 pathway by HPV may be related to cisplatin (CDDP)‐sensitivity in cervical cancer. We conducted the present study to determine whether and how HPV is related to CDDP‐sensitivity in HPV‐positive cervical cancer cells. We used cervical carcinoma cell lines HeLa with integrated HPV 18 and SiHa with integrated HPV 16. An HPV‐negative cell line, Yumoto, with wild‐type p53 gene was used as a control. Leptomycin B (LMB) enhanced sensitivity to CDDP and CDDP‐induced apoptosis in HeLa and SiHa cells, but not in Yumoto cells. After exposure to LMB or CDDP alone, we observed weak p53 staining in HeLa, SiHa and Yumoto cells. Nuclear p53 staining was significantly increased by combined treatment with CDDP and LMB in HeLa and SiHa cells, but not in Yumoto cells. The expression of p53 and Bax protein increased with exposure to CDDP and was enhanced by LMB in HeLa and SiHa cells. The present study demonstrated that LMB enhanced CDDP‐sensitivity via nuclear accumulation of p53 protein in HPV‐positive cells.
Cyclooxygenase‐2 inhibitor NS‐398 suppresses cell growth and constitutive production of granulocyte‐colony stimulating factor and granulocyte macrophage‐colony stimulating factor in lung cancer cells
Authors: Nakata Hideshi , Uemura Yoshiki , Kobayashi Makoto , Harada Ryoji , Taguchi Hirokuni
Published: August 2005

We previously established two lung cancer cell lines, OKa‐C‐1 and MI‐4, which constitutively produce abundant granulocyte‐colony stimulating factor (G‐CSF) and granulocyte macrophage‐colony stimulating factor (GM‐CSF). Inflammatory cytokines, tumor necrosis factor‐alpha (TNF‐α) and interleukin (IL)‐1β stimulated the expression of G‐CSF, GM‐CSF, and cyclooxygenase (COX)‐2 in the two cell lines. It is known that increased COX‐2 activity promotes tumor growth and induces G‐CSF and GM‐CSF expression in non‐malignant cells, and that selective COX‐2 inhibitors inhibit the growth of some types of malignant cells. Therefore, we hypothesized that inhibition of COX‐2 activity might suppress constitutive production of G‐CSF or GM‐CSF in addition to reducing the growth of malignant cells. We confirmed that the selective COX‐2 inhibitor, NS‐398 suppressed the constitutive production of G‐CSF and GM‐CSF, and the cell growth in both OKa‐C‐1 and MI‐4 cell lines. Prostaglandin E2 (PGE2) reversed the inhibitions of G‐CSF and GM‐CSF expression, as well as cell growth, by NS‐398. This result confirms that the effects of NS‐398 are based on the inhibition of COX activity. Some studies have indicated that nuclear factor kappa B (NF‐κB) or MARK (mitogen‐activated protein kinase) activation is related to upregulation of G‐CSF, GM‐CSF or COX‐2 expression in some types of cells. Therefore, we examined if the actions of NS‐398 might be mediated by the MAP kinase pathway or NF‐κB activity in OKa‐C‐1 and MI‐4 cells. We found that NS‐398 inhibits G‐CSF and GM‐CSF production and cell growth through an extracellular signal‐regulated kinase kinase (MEK) signaling pathway in these cell lines. The prognosis of non‐small cell lung cancer showing G‐CSF gene expression is significantly worse. G‐CSF overproduction by tumor cells is observed at an advanced clinical stage. Our findings imply that a COX‐2 inhibitor might improve the prognosis of patients with lung cancer through the reduction of G‐CSF or GM‐CSF. (Cancer Sci 2003; 94: 173–180)
Agaricus blazei (Himematsutake) does not alter the development of rat diethylnitrosamine‐initiated hepatic preneoplastic foci
Authors: Barbisan Luís Fernando , Spinardi‐Barbisan Ana Lúcia Tozzi , Moreira, Eduardo Luís Trindade , Salvadori, Daisy Maria Favero , Ribeiro Lúcia Regina , Eira Augusto Ferreira da , de Camargo João Lauro Viana
Published: August 2005

The modifying potential of crude extracts of the mushroom Agaricus blazei Murrill (Himematsutake) on the development and growth of glutathione S‐transferase placental form (GST‐P)‐positive liver foci (liver preneoplastic lesion) was investigated in adult male Wistar rats. Six groups of animals were used. Groups 2 to 5 were given a single i.p. injection of 200 mg/kg b.w. of diethylnitrosamine (DEN) and groups 1 and 6 were treated with saline at the beginning of the experiment. After 2 weeks, animals of groups 3 to 6 were orally treated with three dose levels of aqueous extracts of the mushroom A. blazei (1.2, 5.6, 11.5, and 11.5 mg/ml of dry weight of solids) for 6 weeks. All animals were subjected to two‐thirds partial hepatectomy at week 3 and sacrificed at week 8. Two hours before sacrifice, ten animals of each group were administered a single i.p injection of 100 mg/kg of bro‐modeoxyuridine (BrdU). Apoptotic bodies and BrdU‐positive hepatocyte nuclei were quantified in liver sections stained for hematoxylin and eosin (H&E) (eosinophilic foci) and simultaneously stained for GST‐P expression (GST‐P‐positive foci), respectively. The 6‐week treatment with A. blazei did not alter the development (number and size) of GST‐P‐positive foci and did not affect the growth kinetics of liver normal parenchyma or foci in DEN‐initiated animals. Our results indicate that the treatment with aqueous extracts of the mushroom A. blazei during the post‐initiation stage of rat liver carcinogenesis does not exert any protective effect against the development of GST‐P‐positive foci induced by DEN. (Cancer Sci 2003; 94: 188–192)
Blue light inhibits the growth of skin tumors in the v‐Ha‐ras transgenic mouse
Authors: Ohara Masayuki , Kawashima Yuzo , Kitajima Shunichi , Mitsuoka Chihomi , Watanabe Hiromitsu
Published: August 2005

12‐O‐Tetradecanoylphorbol‐13‐acetate (TPA) was applied to the back skin of v‐Ha‐ras (TG‐AC) female transgenic mice at a dose of 2.5 μg/200 μl twice a week for 9 weeks. The back skin was then exposed to blue light (wavelength, 470 nm; irradiance, 5.7 mW/ cm2) for 1 h daily for 9 weeks. The mice to which TPA was applied developed skin tumors at 6 weeks after the start of application. The tumor incidence rates at 6, 7, 8 and 9 weeks after the start of application were 70%, 80%, 100% and 100%, respectively, and the numbers of tumors 1 mm or more in diameter were 1, 5, 10 and 19, respectively. In the mice that were exposed to blue light after TPA application, the tumor incidence rates were 10%, 40%, 60% and 80%, respectively, and the numbers of tumors 1 mm or more in diameter were 0, 2, 5 and 9, respectively. Histopathologi‐cal examination of the skin revealed that TPA application induced diffuse hyperplasia, exaggerated keratinization, and papillomas in all 10 mice. A localized form of epidermal hyperplasia was also observed in 4 mice. The incidence rate of papillomas in the mice that were exposed to blue light after TPA application was lower and the degree of exaggerated keratinization was greater. Exaggerated keratinization was considered to represent a regressive change following exposure. These findings suggest that exposure to blue light may be a promising new approach in the treatment of skin tumors. (Cancer Sci 2003; 94: 205–209)
Large diversity in transport‐mediated methotrexate resistance in human leukemia cell line CCRF‐CEM established in a high concentration of leucovorin
Authors: Asai Satomi , Miyachi Hayato , Kobayashi Hiroyuki , Takemura Yuzuru , Ando Yasuhiko
Published: August 2005

To elucidate the mechanism(s) of methotrexate (MTX) resistance as a possible reason underlying treatment failure in high‐dose MTX regimens combined with leucovorin (LV) rescue, we established MTX‐resistant human T‐cell leukemia cell line CCRF‐CEM cells in the presence of excess LV, and characterized their properties. Continuous exposure of the cells to escalating concentrations of MTX up to 20 μM in the presence of 1000 nM LV resulted in establishment of three MTX‐resistant sublines with a wide disparity of resistance degree over a 4 logarithmic range (approximately 40‐, 900‐ and 44 000‐fold, respectively). Transmembrane transport of MTX in these sublines was diminished to 52%, 35% and 12%, respectively. Intracellular retention of MTX in these sublines was not different from that of the parent cells. A cell growth study in various concentrations of LV showed that cells with higher resistance to MTX required more LV for optimal growth. In parallel with the resistance levels, there was an increase in mRNA expression of dihydrofolate reductase gene and a decrease in that of thymidylate synthase gene, but no change in that of reduced folate carrier (RFC1) gene, as assessed by northern blot analysis. Sequencing of the RFC1 gene in all 3 sublines revealed a point mutation in codon 47 (TCC→TTC) resulting in substitution of Phe for Ser residue, and additional deletion of CTG of codon 112 in the subline with the highest resistance. In summary, MTX exposure to CCRF‐CEM cells in the presence of 1000 nM LV resulted in the establishment of heterogeneous cell populations with a wide range of transport‐mediated MTX resistance, which was associated with differential alterations of RFC gene. These cell lines may serve as models for investigation of the molecular mechanism(s) underlying refractory tumors in high‐dose MTX regimens with LV rescue. (Cancer Sci 2003; 94: 210–214)
Multifunctional interleukin‐1β promotes metastasis of human lung cancer cells in SCID mice via enhanced expression of adhesion‐, invasion‐ and angiogenesis‐related molecules
Authors: Yano Seiji , Nokihara Hiroshi , Yamamoto Akihiko , Goto Hisatsugu , Ogawa Hirohisa , Kanematsu Takanori , Miki Toyokazu , Uehara Hisanori , Saijo Yasuo , Nukiwa Toshihiro , Sone Saburo
Published: August 2005

We examined whether interleukin‐1 (IL‐1), a multifunctional proinflammatory cytokine, progresses or regresses metastasis of lung cancer. Exogenous IL‐lβ enhanced expression of various cytokines (IL‐6, IL‐8, and vascular endothelial growth factor (VEGF)) and intracellular adhesion molecule‐1 (ICAM‐1) by A549, PC14, RERF‐LC‐AI, and SBC‐3 cells expressing IL‐1 receptors. A549 cells transduced with human IL‐1β‐gene with the growth‐hormone signaling‐peptide sequence (A549/IL‐1β) secreted a large amount of IL‐1β protein. Overexpression of IL‐1β resulted in augmentation of expression of the cytokines, ICAM‐1, and matrix metallo‐proteinase‐2 (MMP‐2). A549/IL‐1β cells intravenously inoculated into severe combined immunodeficiency (SCID) mice distributed to the lung more efficiently and developed lung metastasis much more rapidly than did control A549 cells. Treatment of SCID mice with anti‐IL‐1β antibody inhibited formation of lung metastasis by A549/IL‐1β cells. Moreover, A549/IL‐1β cells inoculated in the subcutis grew more rapidly, without necrosis, than did control A549 cells, which produced smaller tumors with central necrosis, suggesting involvement of angiogenesis in addition to enhanced binding in the high metastatic potential of A549/IL‐1β cells. Histological analyses showed that more host‐cell infiltration, fewer apoptotic cells, more vascularization, and higher MMP activity were observed in tumors derived from A549/IL‐1β cells, compared with tumors derived from control A549 cells. These findings suggest that IL‐1β facilitates metastasis of lung cancer via promoting multiple events, including adhesion, invasion and angiogenesis. (Cancer Sci 2003; 94: 244–252)
Involvement of H2O2 and O2‐ in the cytotoxicity of N‐β‐alanyl‐5‐S‐glutathionyl‐3,4‐dihydroxyphenylalanine (5‐S‐GAD), a novel insect‐derived anti‐tumor compound
Authors: Akiyama Nobuko , Natori Shunji
Published: August 2005

We investigated the mechanism underlying the cytotoxicity of N‐β‐alanyl‐5‐S‐glutathionyl‐3, 4‐dihydroxyphenylalanine (5‐S‐GAD) toward MDA‐MB‐435S, a human breast cancer cell line sensitive to 5‐S‐GAD. We found that the addition of either catalase or superoxide dismutase (SOD) to a culture medium of MDA‐MB‐435S cells almost completely abolished the cytotoxic effect of 5‐S‐GAD, indicating that both hydrogen peroxide (H2O2) and the superoxide anion (O2‐) are involved in the cytotoxic action of 5‐S‐GAD. We compared the catalase and SOD levels in MDA‐MB‐435S and T47D, a cell line resistant to 5‐S‐GAD, and found that the levels in resistant cells are higher than those in sensitive cells. We concluded that the levels of these enzymes are crucial determinants of the sensitivity or insensitivity of cells to 5‐S‐GAD. (Cancer Sci 2003; 94: 400–404)
Homeobox gene expression and mutation in cervical carcinoma cells
Authors: Hung Yao‐Ching , Ueda Masatsugu , Terai Yoshito , Kumagai Koji , Ueki Ken , Kanda Koji , Yamaguchi Hiroyuki , Akise Daisuke , Ueki Minoru
Published: August 2005

An association between deregulation of homeobox (HOX) gene expression and oncogenic transformation has been recently reported in human tumors. In this study, we investigated HOX gene expression and mutation in cervical carcinoma cells. Using reverse transcription‐PCR, 11 human cervical carcinoma cell lines and 14 normal cervical tissue samples were examined for mRNA expression of the 39 class I HOX genes. DNA samples from 11 cell lines were tested for mutations in exons 1 and 2 of the HOXA10 and A13 genes using overlapping primer pairs which also cover intron 1 of these genes. HOXA1, B2, B4, C5, C10 and D13 genes were expressed in 8, 7, 9, 9, 9 and 11 of 11 cervical carcinoma cell lines, respectively, but not in any of the normal cervical tissues. HOXA9, A11, A13, B5, C4, D3 and D9 genes were expressed in all cell lines and normal tissues. In contrast, 13 of 39 HOX genes were silent in all materials examined. Single‐strand conforma‐tional polymorphism and sequence analysis revealed a C insertion after base 1042 and/or a G to C substitution at base 1113 in intron 1 of the HOXA13 gene in 4 of 11 cell lines, however, neither deletions nor mutations were detected in exons 1 and 2 of the HOXA10 and A13 genes. Our data suggest that the expression of HOXA1, B2, B4, C5, C10 and D13 genes might be involved in the process leading to the transformation of normal cervical cells. (Cancer Sci 2003; 94: 437–441)
Tumor cells in lymph vessels and lymph nodes closely associated with nodal metastasis by invasive ductal carcinoma of the breast
Authors: Hasebe Takahiro , Sasaki Satoshi , Imoto Shigeru , Ochiai Atsushi
Published: August 2005

No studies have ever precisely investigated the mechanism of nodal metastasis based on the histological characteristics of tumor cells in lymph vessels and lymph nodes. The purpose of this study was to investigate whether the histological characteristics of tumor cells in lymph vessels and lymph nodes of 393 patients with invasive ductal carcinoma (IDC) were significantly associated with increased nodal metastasis compared with well known histological characteristics of their primary‐invasive tumor cells. Multivariate analyses showed that having a single nodal metastasis was closely dependent on primary‐invasive tumor size or distance of lymph vessel tumor emboli from the margin of the primary‐invasive tumor (P<0.05) and that having 2 or more nodal metastases was significantly associated with the histological characteristics of the nodal metastatic tumors independently of the size of the primary‐invasive tumor, and the number of nodes with extra‐nodal invasion (ENI) significantly increased the relative risk (RR) of 4 or more nodal metastases in IDCs ≤20 mm and >20 to ≤50 mm in size (P<0.05). In IDCs >50 mm in size, number of lymph vessels invaded, severe fibrosis of the stroma of extra nodal invasive tumors, and distance of ENI from the node significantly increased the RR of 10 or more nodal metastases in the multivariate analysis (P<0.05). The results of this study strongly suggest that the histological characteristics of tumor cells in lymph nodes and lymph vessels play an important role in nodal metastasis in IDCs of the breast.
Immunological evaluation of CTL precursor‐oriented vaccines for advanced lung cancer patients
Authors: Mine Takashi , Gouhara Rumi , Hida Naoya , Imai Nobue , Azuma Kouichi , Rikimaru Touru , Katagiri Kazuko , Nishikori Misa , Sukehiro Aki , Nakagawa Masami , Yamada Akira , Aizawa Hisamichi , Shirouzu Kazuo , Itoh Kyogo , Yamana Hideaki
Published: August 2005

Recent clinical trials of peptide vaccine for cancer patients have rarely resulted in tumor regression. One of the reasons for this failure could be an insufficient induction of anti‐tumor responses in these regimens, in which peptide‐specific memory cytotoxic T lymphocytes (CTLs) were not measured prior to vaccination. We investigated in this study whether pre‐vaccination measurement of peptide‐specific CTLs can provide any advantages in lung cancer patients receiving peptide vaccination with regard to safety and immunological responses. Ten patients with advanced lung cancer received vaccination with peptides under a regimen of CTL precursor‐oriented vaccination, in which pre‐vaccination peripheral blood mononuclear cells (PBMCs) were at first screened for reactivity in vitro to each of 14 peptides, followed by in vivo administration of only the reactive peptides. Profiles of the vaccinated peptides varied markedly among the 10 patients. This regimen was generally well‐tolerated, although local skin reactions, diarrhea, and colitis were observed in 8, 2, and 1 patient, respectively. Increased CTL responses against the immunized peptides and tumor cells were observed in the post‐vaccination PBMCs from 4 of 8 and 3 of 10 patients tested, respectively. Peptide‐specific IgG became detectable in post‐vaccination sera in 4 of 10 patients tested, and these 4 patients had a long progression‐free survival. Furthermore, the median survival time of 9 patients with non‐small cell lung cancer was 668.0±164.2 days. These results encourage further development of CTL precursor‐oriented peptide vaccination for lung cancer patients.
Reversal of the resistance to STI571 in human chronic myelogenous leukemia K562 cells
Authors: Mukai Motoi , Che Xiao‐Fang , Furukawa Tatsuhiko , Sumizawa Tomoyuki , Aoki Shunji , Ren Xiao‐Qin , Haraguchi Misako , Sugimoto Yoshikazu , Kobayashi Motomasa , Takamatsu Hideo , Akiyama Shin‐ichi
Published: August 2005

STI571, an Abl‐specific tyrosine kinase inhibitor, selectively kills Bcr‐Abl‐containing cells in vitro and in vivo. However, some chronic myelogenous leukemia (CML) cell lines are resistant to STI571. We evaluated whether STI571 interacts with P‐glycopro‐tein (P‐gp) and multidrug resistance protein 1 (MRP1), and examined the effect of agents that reverse multidrug resistance (MDR) on the resistance to SI571 in MDR cells. STI571 inhibited the [125l]azidoagosterol A‐photolabeling of P‐gp, but not that of MRP1. K562/MDR cells that overexpress P‐gp were 3.67 times more resistant to STI571 than the parental Philadelphia‐chromosome‐positive (Ph+) CML K562 cells, and this resistance was most effectively reversed by cepharanthine among the tested reversing agents. The concentration of STI571 required to completely inhibit tyrosine phosphorylation in K562/MDR cells was about 3 times higher than that in K562 cells, and cepharanthine abolished the difference. In KB‐G2 cells that overexpress P‐gp, but not Bcr‐Abl, 2.5 μM STI571 partly reversed the resistance to vincristine (VCR), paclitaxel, etoposide (VP‐16) and actinomycin D (ACD) but not to Adriamycin (ADM) or colchicine. STI571 increased the accumulation of VCR, but not that of ADM in KB‐G2 cells. STI571 did not reverse resistance to any agent in KB/MRP cells that overexpress MRP1. These findings suggest that STI571 is a substrate for P‐gp, but is less efficiently transported by P‐gp than VCR, and STI571 is not a substrate for MRP1. Among the tested reversing agents that interact with P‐gp, cepharanthine was the most effective agent for the reversal of the resistance to STI571 in K562/ MDR cells. Furthermore, STI571 itself was a potent reversing agent for MDR in P‐gp‐expressing KB‐G2 cells.
Downregulation of Wnt4 and upregulation of Wnt5a expression by epithelialmesenchymal transition in human squamous carcinoma cells
Authors: Taki Masayuki , Kamata Nobuyuki , Yokoyama Kazuhiro , Fujimoto Ryoichi , Tsutsumi Satoshi , Nagayama Masaru
Published: August 2005

Gene expression of Wnt‐1, 2, 3, 4, 5a, 6 and 7a was analyzed by RT‐PCR in eleven squamous cell carcinoma (SCC) cell lines and compared with that in two normal oral keratinocyte strains. There appeared to be an inverse relationship between Wnt‐4 and Wnt‐5a expressions, i.e., Wnt‐4 was not expressed in HOC719‐NE, HOC313 or TSU cells, while Wnt‐5a was strongly expressed only in these cells. These cell lines showed decreased expression of E‐cadherin and elevated expression of vimentin accompanied with strong expressions of Snail and δEF1, which have been reported to be transrepressors of E‐cadherin and to trigger epithelial‐mesenchymal transition (EMT), suggesting associations of Wnt‐4 with epithelial phenotype and Wnt‐5a with mesenchymal phenotype of SCC cells. To study whether the expressions of these Wnt genes are regulated by EMT, we transfected a Snailexpression vector into A431 and OM1 cells, which express Wnt‐4 but not Wnt‐5a. The stably Snail‐overexpressing clones showed spindle morphology, increased expression of vimentin and decreased expression of E‐cadherin accompanied with augmented expression of δEF1. In these clones, down‐regulation of Wnt‐4 and up‐regulation of Wnt‐5a were clearly observed. These results indicated that Wnt‐4 and Wnt‐5a are oppositely affected by EMT, and down‐regulation of Wnt‐4 and up‐regulation of Wnt‐5a are possible markers of the malignant phenotype of human SCC.
Identification of a prostate‐specific membrane antigen‐derived peptide capable of eliciting both cellular and humoral immune responses in HLA‐A24+ prostate cancer patients
Authors: Kobayashi Kazuhiko , Noguchi Masanori , Itoh Kyogo , Harada Mamoru
Published: August 2005

We tried to identify prostate‐specific membrane antigen (PSMA)‐derived peptides capable of eliciting both cellular and humoral immune responses in peripheral blood mononuclear cells (PBMCs) and plasma of HLA‐A24+ prostate cancer patients, respectively. For cellular response, peptide‐specific and prostate cancer‐reactive responses of in vitro‐stimulated PBMCs were examined with regard to interferon (IFN)‐γ production and cytotoxicity against both a parental HLA‐A24− prostate cancer cell line (PC‐93) and an HLA‐A24‐expressing transfectant cell line (PC93‐A24). For humoral response, patients’ plasma was tested for reactivity to the peptides by means of an enzyme‐linked immunosorbent assay (ELISA). Among 13 PSMA peptides, PSMA 624–632 peptide induced peptide‐specific and tumor‐reactive cytotoxic T lymphocytes (CTLs) most effectively. The PSMA 624–632 peptide‐stimulated PBMCs from either healthy donors or prostate cancer patients produced a significant level of IFN‐γ in response to prostate cancer cells in an HLA‐A24‐restricted manner, and also showed a higher level of cytotoxicity against PC93‐A24 than against PC93. Antibodies to the PSMA 624–632 peptide, but not to any others, were detected in prostate cancer patients. These results demonstrate that the PSMA 624–632 peptide could be an appropriate molecule for use in specific immunotherapy of HLA‐A24+ patients with prostate cancer.
Differential gene expression profiles in colon epithelium of two rat strains with distinct susceptibility to colon carcinogenesis after exposure to PhIP in combination with dietary high fat
Authors: Fujiwara Kyoko , Ochiai Masako , Ubagai Tsuneyuki , Ohki Misao , Ohta Tsutomu , Nagao Minako , Sugimura Takashi , Nakagama Hitoshi
Published: August 2005

Colon cancers develop through accumulation of multiple genetic and epigenetic alterations in colon epithelial cells, and the environment of the genetically altered epithelial cells may also have a substantial impact on their further development to cancer. In the present study, groups of 6‐week‐old F344 and ACI male rats, the former strain being susceptible to colon carcinogenesis induced by 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) and the latter being relatively resistant, were subjected to a long‐term carcinogenesis experiment using our intermittent feeding protocol of PhIP in combination with a high‐fat diet, which serves as a relevant risk factor that promotes the development of colon cancers. Animals were sacrificed at 60 weeks, and global gene expression analyses of normal parts of colon epithelial tissues were conducted using a high‐density oligonucleotide microarray to elucidate the differential gene expression profile (environment) in normal colonic regions between F344 and ACI strains. Of 8799 entries on the RatU34A array, 74 genes exhibited 3‐fold or greater variation. A subset of genes encoding ribosomal RNAs and proteins were highly preferentially expressed in the F344 strain. In addition, genes encoding fatty acid binding proteins and the peroxisome membrane protein 70 appeared up‐regulated in the susceptible F344 strain. In the ACI strain, a mismatch repair gene, Msh2, was preferentially expressed, at approximately 20‐fold the F344 level, along with a gene encoding a detoxification enzyme, catechol‐O‐methyltransferase. The combined effects of the repertoire of these differentially expressed genes in normal colon epithelial tissues may account for the distinct susceptibilities of F344 and ACI strains to colon carcinogenesis.
The implication of background anthracosis in the development and progression of pulmonary adenocarcinoma
Authors: Wang Daye , Minami Yuko , Shu Yujian , Konno Sato , Iijima Tatsuo , Morishita Yukio , Noguchi Masayuki
Published: August 2005

In order to characterize the relationship between background anthracosis and pulmonary adenocarcinogenesis, surgically resected tissues of 66 cases of stage I pulmonary adenocarcinoma, 4 cm or less at their greatest dimension, were examined. These cases were diagnosed based on the classification of small‐sized adenocarcinoma of the lung (Noguchi et al., Cancer 75, 1995). Thirteen cases were diagnosed as types A (localized bronchioloalveolar adenocarcinoma, LBAC) and B (LBAC with alveolar collapse), 40 cases as type C (LBAC with a focus of fibroblastic proliferation), 8 as type D (poorly differentiated adenocarcinoma) and 5 as types E (bronchial gland type adenocarcinoma) and F (true papillary adenocarcinoma). The 5‐year survival rate of types A and B cases was 100%, while those of type C, type D and types E and F were 52%, 48% and 39%, respectively. Nuclear accumulation of abnormal p53 protein in non‐replacement type adenocarcinomas (types D, E and F) was detected more frequently than that in replacement type adenocarcinomas (types A, B and C) (P<0.05). In each case, black dusty material was extracted from tumorous lesions and non‐tumorous regions and blotted onto a nitrocellulose membrane. The anthracotic index (AI) was calculated with a densitometer. AIs of non‐tumorous regions in early and replacement type adenocarcinomas (types A and B) were significantly less than in relatively advanced (type C) and poorly differentiated (type D) adenocarcinomas (P<0.05). These results indicated that adenocarcinoma developing in heavily anthracotic lungs readily progresses to an advanced stage, or that adenocarcinoma with a less favorable prognosis tends to develop in severely anthracotic lungs.
Adenovirus‐mediated gene transduction of truncated IκBα enhances radiosensitivity in human colon cancer cells
Authors: Mukogawa Tomohide , Koyama Fumikazu , Tachibana Masaaki , Takayanagi Atsushi , Shimizu Nobuyoshi , Fujii Hisao , Ueno Masato , Matsumoto Hiroshi , Takeuchi Taku , Nakajima Yoshiyuki
Published: August 2005

Nuclear factor kappa B (NF‐κB) is a transcription factor that is known to regulate apoptosis when cells are exposed to DNA‐damaging agents such as ionizing radiation and cytotoxic drugs. We sought to determine if inhibition of NF‐κB could enhance radiosensitivity in human colon cancer cells in vitro and in vivo. To inhibit NF‐κB activation specifically, we constructed a recombinant adenovirus vector expressing a truncated form of the inhibitor protein lκβα (lκBαΔN) that lacks the phosphorylation sites essential for activation of NF‐κB, and transfected two human colon cancer cell lines (HT29 and HCT15) with this vector. In vitro colony‐forming assays revealed that the overexpression of the stable IκBα by AxIκBαΔN infection significantly suppressed cell growth after irradiation in both cell lines as compared to infection with a control vector, AxLacZ. Treatment with AxIκBαΔN and irradiation successfully inhibited the growth of HT29 xenografted subcutaneous tumors in nude mice with an 83.8% volume reduction on day 38 as compared to the untreated tumors. Furthermore, it was demonstrated that apoptosis was increased by adenovirus‐mediated gene transduction of IκBaLΔN in vitro and in vivo. These results indicated that inhibition of NF‐κB could enhance radiosensitivity through an increase in radiation‐induced apoptosis. We believe that radio‐gene therapy using adenovirusmediated gene transduction of IκBαΔN could be an attractive candidate as a treatment strategy for colorectal cancer.