bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of genes differentially expressed in a newly isolated human metastasizing esophageal cancer cell line, T.Tn‐AT1, by cDNA microarray
Authors: Kawamata Hitoshi , Furihata Tadashi , Omotehara Fumie , Sakai Taro , Horiuchi Hideki , Shinagawa Yasuhiro , Imura Johji , Ohkura Yasuo , Tachibana Masatsugu , Kubota Keiichi , Terano Akira , Fujimori Takahiro
Published: August 2005

We isolated a metastasizing human esophageal squamous cell carcinoma (SCC) cell line, T.Tn‐AT1, from a parental non‐metastasizing cell line, T.Tn, by in vitro selection and by use of a nude mouse orthotopic inoculation model. Then, we compared the expression profiles of 9206 genes in T.Tn‐AT1 and T.Tn by cDNA microarray analysis. The gene expression profiles of T.Tn and T.Tn‐AT1 were very similar, and only 34 genes showed more than 3‐fold differential expression. Among the 34 genes, 29 genes were down‐regulated and only 5 genes were up‐regulated in T.Tn‐AT1 cells. Subsequently, we confirmed the expression levels of 14 of the 34 genes in T.Tn and T.Tn‐AT1 cells by means of reverse transcription‐polymerase chain reaction. The expression of 8 genes (KAL1, HPGD, NDN, REG1A, CXCR4, SPOCK, DIAPH2 and AIF1) was down‐regulated and that of one gene (VNN2) was up‐regulated in T.Tn‐AT1 cells. These 9 genes encoded proteins associated with metastatic processes, such as adhesion, migration, inflammation, proliferation, and differentiation. Thus, these genes might regulate the metastasis of esophageal SCC, and could be predictive markers for lymph node metastasis of esophageal SCC.
A nonsense mutation in exon 8 of the APC gene (Arg283Ter) causes clinically variable FAP in a Malaysian Chinese family
Authors: Mohamed Zulqarnain , Ahmad Rahimah , Yoke Ng Sau , Zakaria Zubaidah , Ahmad Harun , Yew Tong Hung
Published: August 2005

The present study was carried out to characterize the causative genetic mutation in a medium‐sized Malaysian Chinese pedigree of three generations affected with familial adenomatous polyposis (FAP). Clinical data and genetic studies revealed considerable phenotypic variability in affected individuals in this family. Blood was obtained from members of the FAP‐01 family and genomic DNA was extracted. Mutation screening of the adenomatous polyposis coli (APC) gene was carried out using the single strand conformation polymorphism (SSCP) technique. The possibility of exon skipping was predicted by splicing motif recognition software (ESEfinder release2.0). SSCP results showed mobility shifts in exon 8 of the APC gene which segregated with affected members of the family. Sequence analysis revealed that the affected individuals are heterozygous for a C847T transition, whilst all the unaffected family members and control individuals are homozygous C at the same position. This nucleotide substitution generates a stop codon at amino acid position 283, in place of the usual arginine (Arg283Ter). We conclude that an Arg283Ter mutation in the APC gene is causative of the FAP phenotype in this family, although there is considerable variation in the presentation of this disease among affected individuals. Computational analysis predicts that this mutation occurs within sequences that may function as splicing signals, so that the sequence change may affect normal splicing.
Antitumor activity of TZT‐1027 (Soblidotin) against vascular endothelial growth factor‐secreting human lung cancer in vivo
Authors: Natsume Tsugitaka , Watanabe Jun‐ichi , Koh Yasuhiro , Fujio Nami , Ohe Yuichiro , Horiuchi Toshi , Saijo Nagahiro , Nishio Kazuto , Kobayashi Motohiro
Published: August 2005

TZT‐1027 (Soblidotin), an antimicrotubule agent, has been demonstrated to show potent antitumor effects, though the relationships among antitumor effect, cytotoxicity and anti‐vascular effect of TZT‐1027 have not been studied. We established in vivo human lung vascular‐rich tumor models using a vascular endothelial growth factor‐secreting tumor (SBC‐3/VEGF). SBC‐3/VEGF tumors exhibited a high degree of angiogenesis in comparison with the mock transfectant (SBC‐3/Neo) tumors in a dorsal skinfold chamber model and grew much faster and larger than SBC‐3/Neo tumors in the tumor growth study. The antitumor activity of antimicrotubule agents, including TZT‐1027, was evaluated in both early‐ and advanced‐stage SBC‐3/Neo and SBC‐3/VEGF tumor models to elucidate the relationship between the antitumor activity and anti‐vascular effect of these agents. TZT‐1027 exhibited potent antitumor activity against both early‐ and advanced‐stage SBC‐3/Neo and SBC‐3/VEGF tumors, whereas combretastatin A4 phosphate did not. Vincristine and docetaxel exhibited potent antitumor activity against early‐stage SBC‐3/Neo and SBC‐3/VEGF tumors, and advanced‐stage SBC‐3/Neo tumors, but did not exhibit activity against advanced‐stage SBC‐3/VEGF tumors. The difference in antitumor activity between these agents could be ascribed to differences in direct cytotoxicity and anti‐vascular effect. Furthermore, a prominent accumulation of erythrocytes in the tumor vasculature, followed by leakage and scattering of these erythrocytes from the tumor vasculature, was observed after TZT‐1027 administration to mice bearing advanced‐stage SBC‐3/VEGF tumors. These findings strongly suggest that TZT‐1027 has a potent anti‐vascular effect, in addition to direct cytotoxicity.
The role of thymidine phosphorylase, an angiogenic enzyme, in tumor progression
Authors: Akiyama Shin‐ichi , Furukawa Tatsuhiko , Sumizawa Tomoyuki , Takebayashi Yuji , Nakajima Yuichi , Shimaoka Shunji , Haraguchi Misako
Published: August 2005

Thymidine phosphorylase (TP), an enzyme involved in pyrimidine metabolism, is identical with an angiogenic factor, platelet‐derived endothelial cell growth factor (PD‐ECGF). TP is overex‐pressed in various tumors and plays an important role in angiogenesis, tumor growth, invasion and metastasis. The enzymatic activity of TP is required for the angiogenic effect of TP. A novel, specific TP inhibitor, TPI, inhibits angiogenesis induced by overexpression of TP in KB/TP cells (human KB epidermoid carcinoma cells transfected with TP cDNA), as well as the growth and metastasis of KB/TP cells in vivo. 2‐Deoxy‐D‐ribose, the degradation product of thymidine generated by TP activity, has both angiogenic and chemotactic activity. Both 2‐deoxy‐D‐ribose and TP inhibit a hypoxia‐induced apoptotic pathway. These findings suggest that 2‐deoxy‐D‐ribose is a downstream mediator of TP function. 2‐Deoxy‐L‐ribose, a stereoisomer of 2‐deoxy‐D‐ribose, inhibits the promotion of angiogenesis, tumor growth and metastasis by TP. Although the mechanism of the action of 2‐deoxy‐D‐ribose is still unknown, 2‐deoxy‐L‐ribose may inhibit the physiological activities of 2‐deoxy‐D‐ribose, and consequently those of TP. Inhibition of TP activity and function appears to be a promising approach for the chemotherapy of various tumors.
Tumor‐derived heat shock protein 70‐pulsed dendritic cells elicit tumor‐specific cytotoxic T lymphocytes (CTLs) and tumor immunity
Authors: Ueda Gosei , Tamura Yasuaki , Hirai Itaru , Kamiguchi Kenjirou , Ichimiya Shingo , Torigoe Toshihiko , Hiratsuka Hiroyoshi , Sunakawa Hajime , Sato Noriyuki
Published: August 2005

Vaccination with autologous tumor‐derived heat shock proteins (Hsp), such as Hsp70, Hsp90 and gp96, has been demonstrated to elicit specific immune responses against the tumor from which the Hsps were isolated. The effect of Hsp immunization is wholly dependent on the presence of functional antigen‐presenting cells (APCs) in the immunized host, and Hsp receptors on APCs have recently been identified. Here we show that bone marrow‐derived dendritic cells (DCs) are able to internalize HSP‐peptide complex and that peptides are re‐presented by DCs via the major histocompatibility complex (MHC) class I presentation pathway. In addition, immunization with tumor‐derived HSP‐pulsed DCs induces strong cytotoxic T cell (CTL) responses against multiple antigenic peptides in a transporter‐associated antigen processing (TAP)‐dependent manner. The results of the present study provide strong evidence of an efficient cross‐priming activity of Hsp70, which could be exploited in the development of new and more effective immunotherapeutic strategies for cancer patients. (Cancer Sci 2004; 95: 248–253)
Heparanase as a molecular target of cancer chemotherapy
Authors: Simizu Siro , Ishida Keisuke , Osada Hiroyuki
Published: August 2005

Cancer cells require the ability to degrade the extracellular matrix (ECM) in order to turn into invasive and metastatic cancer cells. Many proteases and glycosidases are essential in the process of dissolving the components of the ECM. An endo‐β‐D‐glucuronidase, heparanase, is capable of specifically degrading one of the ECM components, heparan sulfate, and this activity is associated with the metastatic potential of tumor cells. Since heparanase mRNA is overexpressed in many human tumors (e.g., hepatomas, head and neck tumors, and esophageal carcinomas), the mechanisms regulating the activity of heparanase should be clarified; considering the possible role of heparanase in cancer, the development of heparanase inhibitors would appear to be advantageous. This review will focus on recent findings that have contributed to the characterization of heparanase and to the elucidation of the transcriptional regulation of heparanase mRNA expression, as well as the development of heparanase inhibitors.
Frequent and preferential infection of Treponema denticola, Streptococcus mitis, and Streptococcus anginosus in esophageal cancers
Authors: Narikiyo Michihiro , Tanabe Chikako , Yamada Yukishige , Igaki Hiroyasu , Tachimori Yuji , Kato Hoichi , Muto Manabu , Montesano Ruggero , Sakamoto Hiromi , Nakajima Yoshiyuki , Sasaki Hiroki
Published: August 2005

Multiple cancers frequently occur in the upper digestive tract. One possible explanation is that specific bacterial infection stimulates the normal epithelium to initiate inflammation and/or promotes carcinogenesis. This study was undertaken to determine which bacterial species is predominantly associated with esophageal cancer. We examined the bacterial diversity in this type of cancer and in the saliva from healthy people by using a culture‐independent molecular method. Here we report the preferential and frequent infection of the oral periodontopathic spirochete Treponema denticola (T. denticola), Streptococcus mitis (S. mitis), and Streptococus anginosus (S. anginosus) in esophageal cancer from different regions of the world, and we also describe the induction of inflammatory cytokines by infection of S. anginosus and S. mitis. Our present data suggest that these three bacteria could have significant roles in the carcinogenic process of many cases of esophageal cancer by causing inflammation and by promoting the carcinogenic process, and that eradication of these three bacteria may decrease the risk of recurrence.
Hepatitis C virus infection as a likely etiology of intrahepatic cholangiocarcinoma
Authors: Yamamoto Satoshi , Kubo Shoji , Hai Seikan , Uenishi Takahiro , Yamamoto Takatsugu , Shuto Taichi , Takemura Shigekazu , Tanaka Hiromu , Yamazaki Osamu , Hirohashi Kazuhiro , Tanaka Takashi
Published: August 2005

Although hepatitis C virus (HCV)‐related cirrhosis has been suggested as a risk factor for intrahepatic cholangiocarcinoma (ICC), few sizeable studies have tested this hypothesis. We investigated ICC risk factors, with special reference to HCV infection. We conducted a hospital‐based case‐control study including 50 ICC patients and 205 other surgical patients without primary liver cancer. HCV seropositivity was detected in 36% of ICC patients and 3% of controls. By univariate analysis, the odds ratio (OR) for association of anti‐HCV antibodies with development was 16.87 (95% confidence interval (CI), 5.69 to 50.00). History of blood transfusion or diabetes mellitus, elevated serum total bilirubin, elevated aspartate aminotransferase and alanine aminotrans‐ferase, decreased serum albumin and decreased platelet count were identified as other possible ICC risk factors. By multivariate analysis, anti‐HCV antibodies (adjusted OR, 6.02; 95% Cl, 1.51 to 24.1), elevated alanine aminotransferase, decreased serum albumin, and decreased platelet count were found to be independent risk factors for ICC development. As liver status worsened, the adjusted OR for ICC tended to increase. HCV infection is a likely etiology of ICC in Japan.
Metabolic activation of polycyclic aromatic hydrocarbons to carcinogens by cytochromes P450 1A1 and1B1
Authors: Shimada Tsutomu , Fujii‐Kuriyama Yoshiaki
Published: August 2005

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitously distributed environmental chemicals. PAHs acquire carcinogenicity only after they have been activated by xenobiotic‐metabolizing enzymes to highly reactive metabolites capable of attacking cellular DNA. Cytochrome P450 (CYP) enzymes are central to the metabolic activation of these PAHs to epoxide intermediates, which are converted with the aid of epoxide hydrolase to the ultimate carcinogens, diol‐epoxides. Historically, CYP1A1 was believed to be the only enzyme that catalyzes activation of these procarcinogenic PAHs. However, recent studies have established that CYP1B1, a newly identified member of the CYP1 family, plays a very important role in the metabolic activation of PAHs. InCYP1B1gene‐knockout mice treated with 7,12‐dimethyl‐benz[a]anthracene and dibenzo[a, l]pyrene, decreased rates of tumor formation were observed, when compared to wild‐type mice. Significantly, gene expression of CYP1A1 and 1B1 is induced by PAHs and polyhalogenated hydrocarbons such as 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin through the arylhydrocarbon receptor. Differences in the susceptibility of individuals to the adverse action of PAHs may, in part, be due to differences in the levels of expression of CYP1A1 and 1B1 and to genetic variations in theCYP1A1and1B1genes.
Inhibition of lymphangiogenesis‐related properties of murine lymphatic endothelial cells and lymph node metastasis of lung cancer by the matrix metalloproteinase inhibitor MMI270
Authors: Nakamura Eliane Shizuka , Koizumi Keiichi , Kobayashi Mitsuo , Saiki Ikuo
Published: August 2005

Based on a previous report on the effect of a matrix metalloproteinase (MMP) inhibitory compound, MMI270, in regulating tumor‐induced angiogenesis, as well as recent findings concerning functional correlations among tumor metastasis, angiogenesis and lymphangiogenesis, we investigated the anti‐metastatic efficacy of MMI270 in a murine model of lymph node metastasis of lung cancer, and analyzed whether this inhibitor could also regulate lymphangiogenesis‐related properties of murine lymphatic endothelial cells (LECs) and invasive properties of Lewis lung cancer (LLC) cells. The observation that MMI270 led to a significant decrease in the weight of tumor‐metastasized lymph nodes of mice led us to test its anti‐lymphangiogenic and anti‐invasive effects in vitro. Murine LECs were characterized by an in vitro tube formation assay, by semi‐quantitative RT‐PCR assay to examine the expression of mRNAs for flt‐4, Flk‐1, Tie‐1, Tie‐2, CD54/ICAM1, vWF, MMPs and uPA, and by western blotting to confirm the protein expression of flt‐4 and CD31/PECAM. This is the first report on the expression of MMP‐2, MMP‐9 and MT1‐MMP in murine LECs, as well as on the inhibition of their enzymatic activity, and of the invasive ability and tube‐forming property of LECs by an MMP inhibitor. Furthermore, MMI270 was shown to strongly inhibit the activity of MMP‐2 and ‐9 produced by LLC cells and the invasion of these cells through Matrigel. In summary, the present results indicate that MMI270, apart from its anti‐tumor angio‐genic application, might be useful as an anti‐metastatic drug, on the basis of its downregulatation of both the lymphangiogenesis‐related properties of LECs and the invasive properties of LLC cells in vitro. (Cancer Sci 2004; 95: 25–31)
Inhibition of cell proliferation by nobiletin, a dietary phytochemical, associated with apoptosis and characteristic gene expression, but lack of effect on early rat hepatocarcinogenesis in vivo
Authors: Ohnishi Hiroyuki , Asamoto Makoto , Tujimura Kazunari , Hokaiwado Naomi , Takahashi Satoru , Ogawa Kumiko , Kuribayashi Masanori , Ogiso Tadashi , Okuyama Harumi , Shirai Tomoyuki
Published: August 2005

Dietary phytochemicals can inhibit the development of certain types of tumors. We here investigated the effects of nobiletin (Nob), garcinol (Gar), auraptene (Aur), β‐cryptoxanthin‐ and hes‐peridine‐rich pulp (CHRP) and 1,1′‐acetoxychavicol acetate (ACA) on hepatocarcinogenesis in a rat medium‐term liver bioassay, and also examined their influence on cell proliferation, cell cycle kinetics, apoptosis and cell invasion of rat and human hepatocellular carcinoma (HCC) cells, MH1C1 and HepG2, respectively. While there were no obvious suppressive effects on the development of putative preneoplastic liver lesions, inhibition of hepatocarcinoma cell proliferation was evident in the Nob group. Nob also caused G2/M cell cycle arrest and apoptosis. Microarray analysis identified a set of genes specifically regulated by Nob, and these are likely to be involved in the observed growth suppression of HCC cells. These results suggest that phytochemicals might have chemopreventive potential in late stages of hepatocarcinogenesis.
DNA repair and cancer: Lessons from mutant mouse models
Authors: Ishikawa Takatoshi , Zhang Samuel S.‐M. , Qin Xiusheng , Takahashi Yoshihisa , Oda Hideaki , Nakatsuru Yoko , Ide Fumio
Published: August 2005

DNA damage, if the repair process, especially nucleotide excision repair (NER), is compromised or the lesion is repaired by some other error‐prone mechanism, causes mutation and ultimately contributes to neoplastic transformation. Impairment of components of the DNA damage response pathway (e.g., p53) is also implicated in carcinogenesis. We currently have considerable knowledge of the role of DNA repair genes as tumor suppressors, both clinically and experimentally. The deleterious clinical consequences of inherited defects in DNA repair system are apparent from several human cancer predisposition syndromes (e.g., NER‐compromised xeroderma pigmentosum [XP] and p53‐deficient Li‐Fraumeni syndrome). However, experimental studies to support the clinical evidence are hampered by the lack of powerful animal models. Here, we review in vivo experimental data suggesting the protective function of DNA repair machinery in chemical carcinogenesis. We specifically focus on the three DNA repair genes, O6‐methylguanine‐DNA methyltransferase gene (MGMT), XP group A gene (XPA) and p53. First, mice overexpressing MGMT display substantial resistance to nitrosamine‐induced hepatocarcinogenesis. In addition, a reduction of spontaneous liver tumors and longer survival times were evident. However, there are no known mutations in the human MGMT and therefore no associated cancer syndrome. Secondly, XPA mutant mice are indeed prone to spontaneous and carcinogen‐induced tumorigenesis in internal organs (which are not exposed to sunlight). The concomitant loss of p53 resulted in accelerated onset of carcinogenesis. Finally, p53 null mice are predisposed to brain tumors upon transplacental exposure to a carcinogen. Accumulated evidence in these three mutant mouse models firmly supports the notion that the DNA repair system is vital for protection against cancer.
Ultrasound‐induced killing of monocytic U937 cells enhanced by 2,2′‐azobis(2‐amidinopropane) dihydrochloride
Authors: Feril Loreto B. , Tsuda Yuko , Kondo Takashi , Zhao Qing‐Li , Ogawa Ryohei , Cui Zheng‐Guo , Tsukada Kazuhiro , Riesz Peter
Published: August 2005

To determine the effect of 2,2′‐azobis(2‐amidinopropane) dihydrochloride (AAPH) on ultrasound (US)‐induced cell killing, human monocytic leukemia cells (U937) were incubated at various temperatures (25.0, 37.0 and 40.0°C) for 1 min in air‐saturated phosphate‐buffered solution (PBS) containing 50 mM AAPH before exposure to nonthermal 1 MHz US for 1 min at an intensity of 2.0 W/cm2. Cell viability was determined by means of the Trypan blue dye exclusion test immediately after sonication. Apoptosis was measured after 6‐h incubation post‐sonication by flow cytometry. Free radicals generated by AAPH, a temperature‐dependent free radical generator, or US or both were also investigated using electron paramagnetic resonance (EPR) spin trapping. The results showed that US‐induced cell lysis and apoptosis were enhanced in the presence of AAPH regardless of the temperature at the time of sonication. At 40.0°C, US alone induced increased cell killing, while AAPH alone is capable of inducing significant but minimal apoptosis at this temperature. Although free radicals were increased in the combined treatment, this increase did not correlate well with cell killing. The mechanism of enhancement points to the increased uptake of the agent during sonication rather than potentiation by AAPH. These findings suggest the clinical potential of temperature‐dependent free radical generators in cancer therapy with therapeutic US.
Identification of NOL8, a nucleolar protein containing an RNA recognition motif (RRM), which was overexpressed in diffuse‐type gastric cancer
Authors: Jinawath Natini , Furukawa Yoichi , Nakamura Yusuke
Published: August 2005

In an attempt to identify novel therapeutic targets for diffusetype gastric cancer, we had previously compared expression profiles of 20 diffuse‐type gastric‐cancer tissues with corresponding non‐cancerous mucosae by means of a cDNA microarray consisting of 23,040 genes. Among 153 genes whose expression levels were elevated in cancers compared to non‐cancerous mucosae, we focused on a gene termed NOL8 that encodes a putative 150‐kDa protein with an RNA‐recognition motif (RRM) domain in its amino‐acid terminal region. Comparison of expression profiles between diffuse‐type and intestinal‐type gastric cancers showed that NOL8 was specifically up‐regulated in diffuse‐type cancers. Northern blot analysis revealed that NOL8 was expressed in skeletal muscle, but not expressed or hardly detectable in 22 other tissues examined. Immunocytochemical staining of NOL8 showed specific localization in the nucleolus. Subsequent protein phosphatase analysis coupled with western analysis revealed the presence of the phosphorylated form. Furthermore, transfection of short‐interfering RNA (siRNA) specific to NOL8 into three diffuse‐type gastric cancer cells, St‐4, MKN45 and TMK‐1, effectively reduced expression of this gene and induced apoptosis in these cells. These findings provide a new insight into diffuse‐type gastric carcinogenesis and may contribute to the development of new therapeutic strategies for diffuse‐type gastric cancer.
DNA intrastrand cross‐link at the 5′‐GA‐3′ sequence formed by busulfan and its role in the cytotoxic effect
Authors: Iwamoto Takuya , Hiraku Yusuke , Oikawa Shinji , Mizutani Hideki , Kojima Michio , Kawanishi Shosuke
Published: August 2005

Busulfan (1,4‐butanediol dimethanesulfonate) has been used widely for the treatment of patients with chronic myelogenous leukemia. Busulfan is bifunctional and thus may effectively induce DNA damage, which may play an important role in the cytotoxicity. In this study, we compared the cytotoxicity of bifunctional busulfan with that of monofunctional ethyl methanesulfonate (EMS) in human promyelocytic leukemia HL‐60 cells. Busulfan showed a significant inhibitory effect on cell growth, whereas the cells grew in the presence of EMS. To clarify the mechanism of cytotoxicity of busulfan, we investigated DNA damage induced by busulfan using32P‐5′‐end‐labeled DNA fragments obtained from the humanp16tumor suppressor gene. Busulfan induced DNA damage dose‐dependently, whereas EMS caused little DNA damage. DNA‐sequencing experiments using piperidine and 3‐methyladenine DNA glycosylase indicated that busulfan caused double‐base lesions mainly at 5′‐GA‐3′and, to a lesser extent, at 5′‐GG‐3’sequences. Time of flight mass spectrometry confirmed that busulfan forms an intrastrand cross‐link at the 5′‐GA‐3’sequence, in addition to mono‐alkylation. The mechanism and the role of cross‐linking at the 5′‐GA‐3’sequence are discussed in relation to the cytotoxicity induced by busulfan.
Expression of the prolactin‐indudble protein (PIP/GCDFP15) gene in benign epithelium and adenocarcinoma of the prostate
Authors: Tian Wei , Osawa Motoki , Horiuchi Hidekazu , Tomita Yoshihiko
Published: August 2005

Prolactin‐inducible protein (PIP), also known as gross cystic disease fluid protein 15, is a predominant secretory protein in various body fluids, including saliva, milk and seminal plasma. Immunohistochemistry of this protein has been exploited as a clinical marker for breast cancer and Paget's disease. This study comparatively examined PIP expression in normal prostate tissues and in adenocarcinomas of the prostate. Quantitative real‐time RT‐PCR revealed low‐level presence (6%) of PIP mRNA in normal prostate tissue in comparison with the seminal vesicle. Indirect immunostaining with monoclonal antibody 3E7 displayed a positive sign for benign epithelium in 8 cases (29.6%) among 27 normal specimens; however, the incidence significantly increased to 56.1% (37/66) in instances involving primary prostate carcinoma tissues of different types. Quantitative RT‐PCR also demonstrated that PIP transcript levels in carcinoma regions were significantly higher than corresponding levels in benign regions. These findings conclusively showed that benign prostate epithelium expresses PIP at low levels; in contrast, PIP is over‐expressed in carcinomas of the prostate.
A novel mouse model of rectal cancer established by orthotopic implantation of colon cancer cells
Authors: Takahashi Takuya , Morotomi Masami , Nomoto Koji
Published: August 2005

A novel intraluminal colon tumor model was established in mice by intrarectal instillation of colon cancer cells followed by short term induction of colitis by an irritant agent. Male BALB/c mice were fed a diet containing 3% (w/w) dextran sulfate sodium (DSS) for 7 days to induce colitis, and colon 26 cells (1–2±106 cells/mouse) were infused intrarectally after the mice had been deprived of food for the last 18 h of DSS treatment. The tumor incidence (%) and size (mean volume±SD, mm3) at the rectal mucosa were 35% (2±3), 95% (96±79), 95% (141 ±137) and 94% (325±270) at 1, 2, 3 and 4 weeks after instillation of tumor cells, respectively. Histopathological analyses revealed that a solid tumor was formed initially at the rectal mucosa at 1 week after instillation, then became invasive into the submucosal and muscular tissues at 3 weeks after implantation. Intrarectal instillation of human colon cancer cells, LS174T (1x107 cells/mouse), mixed with “Matrigel” (0±5 mg/mouse), an extracellular matrix solution, in SCID mice led to formation of rectal tumors at 4 weeks after instillation, and immunohistochemical analysis revealed that the tumor cells expressed human carcinoembryonic antigen, suggesting that the tumor nodule was derived from the instilled LS174T cells. Oral or intravenous administration of a camptothecin (CPT) derivative, CPT‐11, resulted in a significant reduction in tumor incidence and tumor volume in the colon 26‐in‐traluminal implantation system. In conclusion, it was suggested that the present intraluminal colon tumor model is useful for examination of chemotherapeutic agents and also intraluminal factors (dietary compounds, intestinal microflora, etc.) that might function to suppress or enhance the growth of colorectal cancer in situ.
Isolation of an anti‐angiogenic substance from Agaricus blazei Murill: Its antitumor and antimetastatic actions
Authors: Kimura Yoshiyuki , Kido Tadashi , Takaku Takeshi , Sumiyoshi Maho , Baba Kimiye
Published: August 2005

We previously found that ergosterol isolated from Agaricus blazei inhibited tumor growth through the inhibition of tumor‐induced neovascularization. In the present study, we isolated further anti‐angiogenic substances (A‐1 and A‐2) from this fungus using an assay system of angiogenesis induced by Matrigel supplemented with vascular endothelial growth factor, and A‐1 was identified as sodium pyroglutamate. Next, we examined the antitumor and antimetastatic actions of A‐1 using Lewis lung carcinoma (LLC)‐bearing mice. A‐1 (30, 100 and 300 mg/kg) inhibited tumor growth and metastasis to the lung. The reduction of the numbers of splenic lymphocytes, CD4+ and CD8+ T cells in LLC‐bearing mice was inhibited by the oral administration of A‐1 (30, 100 and 300 mg/kg). Further, A‐1 increased the number of apoptotic cells of tumors and the numbers of CD8+ T and natural killer cells invading the tumors, and inhibited the increase of von Willebrand factor expression (a measure of angiogenesis) in the tumors. These results suggest that the antitumor and antimetastatic actions of A‐1 (sodium pyroglutamate) may be associated with inhibition of the reduction of immune response caused by the tumor growth and tumor‐induced neovascularization. This is the first report showing that sodium pyroglutamate isolated from A. blazei as an anti‐angiogenic substance has potent antitumor and antimetastatic actions, as well as immune‐modulatory activity, in tumor‐bearing mice.
Deep root function in soil water dynamics in cerrado savannas of central Brazil
Authors: OLIVEIRA R. S. , BEZERRA L. , DAVIDSON E. A. , PINTO F. , KLINK C. A. , NEPSTAD D. C. , MOREIRA A.
Published: August 2005

Water is a key resource in tropical savannas. Changes in vegetation structure due to land‐use change and increased fire frequency may affect the availability of water and the flux of water through these ecosystems.

We compared the seasonal soil moisture dynamics of two adjacent savanna ecosystems with contrasting tree densities in central Brazil. Our goal was to investigate the influence of tree density on deep water uptake, soil water dynamics and evapotranspiration.

Soil water was measured using a depth of 7·5 m beneath the tree‐dominated cerrado denso ecosystem and to 4 m beneath the grass‐dominated campo sujo ecosystem. Plant‐available water (PAW) throughout the cerrado denso soil profile ranged from 293 mm at the end of the dry season to 689 mm during the wet season. In the grass‐dominated site, PAW in the profile ranged from 155 to 362 mm.

During the dry season, ≈82% of the water used in cerrado denso and 67% in campo sujo was extracted from the profile below 1 m. The tree‐dominated cerrado denso used 137 mm more water than the grass‐dominated campo sujo. Significant deep soil water uptake was also observed during the wet season of 1998, when rainfall was below average.

Evapotranspiration (ET) rates (estimated as change in soil moisture over time) were higher in cerrado denso than in campo sujo during both seasons. Estimated ET ranged from 1·4 mm day−1 during the dry season to 5·8 mm day−1 for the wet season in cerrado denso, and from 0·9 mm day−1 in the dry season to 4·5 mm day−1 in early wet season in campo sujo. The differences in PAW and ET rates between the two ecosystems are associated not only with differences in root distribution, but also with differences in tree densities and the phenology of full‐leaf canopies.

Our results suggest that deep‐rooted plants may contribute significantly to the water balance of cerrado ecosystems, and that the hydrological cycle of this biome could change as woody vegetation is replaced by exotic grasses and agricultural crops.
Nutrient availability induces contrasting allocation and starch formation in resprouting and obligate seeding shrubs
Authors: KNOX K. J. E. , CLARKE P. J.
Published: August 2005

Woody plant responses to crown removal in fire‐prone vegetation are of two types: resprouting (resprouters) or killed (obligate seeders). Obligate seeders maximize their fitness by ensuring they are reproductively mature before the next fire; resprouters invest in structures that increase their chance of surviving the next fire.

We tested whether seven congeneric pairs of resprouter and obligate seeder shrubs differ in plant size, leaf traits, water relations, biomass allocation and root starch formation in response to resource availability. This was tested by examining the interactive effects of water and nutrient availability in a factorial experiment.

Plant size (dry mass and shoot length), leaf area and stomatal conductance did not differ consistently among resprouters and obligate seeders, but were affected by water and nutrient availability. Leaf‐area ratio and specific leaf area were not affected consistently by nutrient or water availability, and did not differ among obligate seeders and resprouters.

Biomass allocation responded to resource availability and differed between resprouter and obligate seeder pairs. Nutrient addition reduced allocation to root mass, and resprouters consistently allocated more than obligate seeders to root mass. Leaf mass ratios were higher in obligate seeders, and were maintained at the expense of stem mass when nutrients limited growth.

Starch concentrations in the roots of resprouters were higher than in obligate seeders. Resprouters increased the concentration of starch in their roots when growth was limited by nutrients, but obligate seeders did not. Resprouters appear to develop a starch‐storage capacity through both reserve formation and accumulation mediated by nutrient availability.

Allocation, rather than growth differences, provide some insight into why resprouters are often more common than obligate seeders, especially on fertile sites. Seedlings of resprouters may be advantaged at fertile sites because allocation to roots and starch reserve formation enable them to be better competitors after fire. We predict that the interplay of biomass allocation, reproduction, starch storage and disturbance frequency provide a framework for patterns of coexistence in shrubs in fire‐prone ecosystems.
Potential impacts of future land use and climate change on the Red List status of the Proteaceae in the Cape Floristic Region, South Africa
Authors: Bomhard Bastian , Richardson David M. , Donaldson John S. , Hughes Greg O. , Midgley Guy F. , Raimondo Domitilla C. , Rebelo Anthony G. , Rouget Mathieu , Thuiller Wilfried
Published: August 2005

Using spatial predictions of future threats to biodiversity, we assessed for the first time the relative potential impacts of future land use and climate change on the threat status of plant species. We thus estimated how many taxa could be affected by future threats that are usually not included in current IUCN Red List assessments. Here, we computed the Red List status including future threats of 227 Proteaceae taxa endemic to the Cape Floristic Region, South Africa, and compared this with their Red List status excluding future threats. We developed eight different land use and climate change scenarios for the year 2020, providing a range of best‐ to worst‐case scenarios. Four scenarios include only the effects of future land use change, while the other four also include the impacts of projected anthropogenic climate change (HadCM2 IS92a GGa), using niche‐based models. Up to a third of the 227 Proteaceae taxa are uplisted (become more threatened) by up to three threat categories if future threats as predicted for 2020 are included, and the proportion of threatened Proteaceae taxa rises on average by 9% (range 2–16%), depending on the scenario. With increasing severity of the scenarios, the proportion of Critically Endangered taxa increases from about 1% to 7% and almost 2% of the 227 Proteaceae taxa become Extinct because of climate change. Overall, climate change has the most severe effects on the Proteaceae, but land use change also severely affects some taxa. Most of the threatened taxa occur in low‐lying coastal areas, but the proportion of threatened taxa changes considerably in inland mountain areas if future threats are included. Our approach gives important insights into how, where and when future threats could affect species persistence and can in a sense be seen as a test of the value of planned interventions for conservation.
Validation of species–climate impact models under climate change
Authors: Araújo Miguel B. , Pearson Richard G. , Thuiller Wilfried , Erhard Markus
Published: August 2005

Increasing concern over the implications of climate change for biodiversity has led to the use of species–climate envelope models to project species extinction risk under climate‐change scenarios. However, recent studies have demonstrated significant variability in model predictions and there remains a pressing need to validate models and to reduce uncertainties. Model validation is problematic as predictions are made for events that have not yet occurred. Resubstituition and data partitioning of present‐day data sets are, therefore, commonly used to test the predictive performance of models. However, these approaches suffer from the problems of spatial and temporal autocorrelation in the calibration and validation sets. Using observed distribution shifts among 116 British breeding‐bird species over the past ∼20 years, we are able to provide a first independent validation of four envelope modelling techniques under climate change. Results showed good to fair predictive performance on independent validation, although rules used to assess model performance are difficult to interpret in a decision‐planning context. We also showed that measures of performance on nonindependent data provided optimistic estimates of models' predictive ability on independent data. Artificial neural networks and generalized additive models provided generally more accurate predictions of species range shifts than generalized linear models or classification tree analysis. Data for independent model validation and replication of this study are rare and we argue that perfect validation may not in fact be conceptually possible. We also note that usefulness of models is contingent on both the questions being asked and the techniques used. Implementations of species–climate envelope models for testing hypotheses and predicting future events may prove wrong, while being potentially useful if put into appropriate context.
The Branchiopoda (Crustacea: Anomopoda, Ctenopoda and Cyclestherida) of the rain forests of Cameroon, West Africa: low abundances, few endemics and a boreal–tropical disjunction
Authors: Chiambeng George Y. , Dumont Henri J.
Published: August 2005

Aim  We provide the first in‐depth study of the Branchiopoda of the rain forests of Cameroon and also of the African continent.

Location  Surface water environments, Cameroon.

Methods  Qualitative plankton samples were collected in all types of surface water environments present, ranging from big lakes to water collected in rock crevices or fallen fruit cavities. A tow or hand‐held plankton net of mesh size 100 μm was used, and water volumes filtered were at least several m3 in large water bodies, or half to whole water volume in small water bodies.

Results  We recorded 61 species (53 first records for the country), based on 700+ samples collected between September 1998 and March 2002. Anomopoda (92%) was the dominant order, followed by Ctenopoda (6.5%) and Cyclestherida (1.5%). Chydoridae (67%) was the most speciose family followed by Macrothricidae (6.5%) and Daphniidae (5%). Alona (11%) was the dominant genus followed by Chydorus (10%) and Pleuroxus (8%). Several species of Chydorinae, especially of the genus Pleuroxus, are shared with continental Eurasia–North America, but are absent from the Mediterranean and desert–steppe–savanna zones of Africa (boreal–tropical disjunction). Daphnia was absent, as in most tropical lowlands. No single species was really abundant, and a majority were rare to very rare, and of restricted occurrence within the rain forest patches. Comparing Africa, South America and Southeast Asia, we found a current total of 196 species for the combined rain forest areas, out of a world total of 500+ species. Systematic trends in richness at three taxonomic levels were the same for all continents: Anomopoda–Ctenopoda–Cyclestherida at ordinal level, Chydoridae–Daphniidae–Macrothricidae–Sididae at family level and Alona–Chydorus–Macrothrix–Diaphanosoma at genus level. Southeast Asia was richest (111 species, 14 endemics) with South America a close second (110 species, 27 endemics). Africa was the most species‐poor (95 species, of which only 5 are endemics).

Main conclusions  We hypothesize that the post‐Miocene cooling and aridization of the world climate hit the freshwater biota of Africa particularly hard, with more extinction here than elsewhere, and little recolonization. Most extinction occurred in the savanna‐desert belt, and eight disjunct boreal species (four Pleuroxus, Picripleuroxus laevis, Kurzia latissima, Alonella exigua, and Monospilus dispar) survive morphologically unchanged since pre‐Pleistocene times in the Cameroon rain forest. Slow evolution thus appears typical of these cyclic parthenogenetic branchiopods in which sexual recombination occurs only at intervals. Illustrative of the same slow evolution is the fact that the two endemic cladocerans of Cameroon (Nicsmirnovius camerounensis and Bryospilus africanus) belong to tropicopolitan genera of Gondwanan age.
Tree growth response to drought and temperature in a mountain landscape in northern Arizona, USA
Authors: Adams Henry D. , Kolb Thomas E.
Published: August 2005

Aim To understand how tree growth response to regional drought and temperature varies between tree species, elevations and forest types in a mountain landscape.

Location Twenty‐one sites on an elevation gradient of 1500 m on the San Francisco Peaks, northern Arizona, USA.

Methods Tree‐ring data for the years 1950–2000 for eight tree species (Abies lasiocarpavar.arizonica(Merriam) Lemm.,Picea engelmanniiParry ex Engelm.,Pinus aristataEngelm.,Pinus edulisEngelm.,Pinus flexilisJames,Pinus ponderosaDougl. ex Laws.,Pseudotsuga menziesiivar.glauca(Beissn.) Franco andQuercus gambeliiNutt.) were used to compare sensitivity of radial growth to regional drought and temperature among co‐occurring species at the same site, and between sites that differed in elevation and species composition.

Results ForPicea engelmannii,Pinus flexilis,Pinus ponderosaandPseudotsuga menziesii, trees in drier, low‐elevation stands generally had greater sensitivity of radial growth to regional drought than trees of the same species in wetter, high‐elevation stands. Species low in their elevational range had greater drought sensitivity than co‐occurring species high in their elevational range at the pinyon‐juniper/ponderosa pine forest ecotone, ponderosa pine/mixed conifer forest ecotone and high‐elevation invaded meadows, but not at the mixed conifer/subalpine forest ecotone. Sensitivity of radial growth to regional drought was greater at drier, low‐elevation compared with wetter, high‐elevation forests. Yearly growth was positively correlated with measures of regional water availability at all sites, except high‐elevation invaded meadows where growth was weakly correlated with all climatic factors. Yearly growth in high‐elevation forests up to 3300 m a.s.l. was more strongly correlated with water availability than temperature.

Main conclusions Severe regional drought reduced growth of all dominant tree species over a gradient of precipitation and temperature represented by a 1500‐m change in elevation, but response to drought varied between species and stands. Growth was reduced the most in drier, low‐elevation forests and in species growing low in their elevational range in ecotones, and the least for trees that had recently invaded high‐elevation meadows. Constraints on tree growth from drought and high temperature are important for high‐elevation subalpine forests located near the southern‐most range of the dominant species.
The provenance of the Greek land snail species Isabellaria pharsalica: molecular evidence of recent passive long‐distance dispersal
Authors: Uit de Weerd Dennis R. , Schneider Dennis , Gittenberger Edmund
Published: August 2005

Aim  The slowly dispersing Greek land snail species Isabellaria (Carinigera) pharsalica (Nordsieck, 1974) can be readily distinguished from related species of the subgenus Carinigera on biogeographical grounds, i.e. by a separation of nearly 200 km. Nevertheless, I. pharsalica shows overlap in shell morphology with Isabellaria (Carinigera) buresi (A. J. Wagner, 1927). The aim of this paper is to study the interrelationships and phylogeography of I. pharsalica and selected I. buresi subspecies, in order to reconcile these apparently contradictory observations.

Location  Northern Greece, Macedonia, Serbia and southern Bulgaria.

Methods  Mitochondrial COI genealogical interrelationships were studied for specimens of I. pharsalica, selected I. buresi subspecies and other related Isabellaria species.

Results  COI sequences of I. pharsalica constitute a clade nested among sequences of I. buresi from north‐eastern Greece and adjacent Bulgaria. The genetic divergence among the I. pharsalica sequences is remarkably low compared to the divergence among the I. buresi sequences.

Main conclusions  I. pharsalica descended from specimens of I. buresi that dispersed into Thessaly, and it should therefore be classified as a subspecies within I. buresi. This find is in line with the conchological similarities between I. buresi pharsalica and other I. buresi subspecies. Given the low vagility of the snails in question and the c. 200‐km separation by land and sea between the ranges of I. buresi pharsalica and the combined range of the other I. buresi subspecies, passive dispersal of the I. pharsalica ancestors is most likely. Since the inferred area of origin of these hypothetical ancestors of I. buresi pharsalica nearly coincides with an ancient marble quarry, human‐aided dispersal during marble transport offers a possible explanation for I. buresi pharsalica's erratic distribution.
Modulation in aquaglyceroporin AQP1 gene transcript levels in drug‐resistant Leishmania
Authors: Marquis Nathalie , Gourbal Benjamin , Rosen Barry P. , Mukhopadhyay Rita , Ouellette Marc
Published: August 2005

Antimonial‐containing drugs are the first line of treatment against the parasite Leishmania. Resistance to antimonials has been correlated to its reduced accumulation. We used a dominant negative functional cloning strategy where a Leishmania mexicana expression cosmid bank was transfected in cells resistant to trivalent antimony (SbIII). Cells were selected for increased sensitivity to SbIII. One cosmid was isolated that could bestow SbIII sensitivity to resistant cells. The gene part of this cosmid that is responsible for increased SbIII sensitivity corresponds to AQP1, an aquaglyceroporin. AQP1 was recently shown to be a route by which SbIII can accumulate in Leishmania cells. Transport studies have shown that the L. mexicana AQP1 can restore SbIII transport in resistant cells. Southern blot analysis indicated that the copy number of neither the AQP1 gene nor the other AQP homologues was changed in antimony‐resistant mutants of several Leishmania species. The AQP1 gene sequence was also unchanged in mutants. However, the AQP1 RNA levels were downregulated in several Leishmania promastigote species resistant to antimonials. In general, but not always, the level of AQP1 transcript levels correlated well with the accumulation of SbIII and resistance levels in Leishmania cells. AQP1 thus appears to be a key determinant of antimonials accumulation and susceptibility in Leishmania.