bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic mapping of allelic loss on chromosome 6q within heterogeneous prostate carcinoma
Authors: Konishi Noboru , Nakamura Mitsutoshi , Kishi Munehiro , Ishida Eiwa , Shimada Keiji , Matsuyoshi Syuichi , Nagai Hisaki , Emi Mitsuru
Published: August 2005

A number of genetic events have been reported in prostate carcinogenesis, including frequent loss of heterozygosity (LOH) on chromosomes 8q, 10q, 16q and 18q, In samples of heterogeneous, multifocal prostate carcinomas, we focused on chromosome 6q using PCR‐based techniques with 15 microsatellite markers to identify the specific 6q deletion within tumors. LOH of one or more polymorphic markers was detected in 10 of 21 tumors (48%). Two of these 10 tumors demonstrated LOH in all cancerous foci at specific loci and 4 tumors showed deletion in one focus. Different deletion patterns were found in 3 tumors when different polymorphic markers were used. In 90% of tumors showing LOH in one or more foci, however, two common regions of LOH were identified; one at 1.81 cM on 6q15–16.3 between markers D6S1631 and D6S1056, and the other at 5.11 cM on 6q16–21 between markers D6S424 and D6S283. By RT‐PCR analysis, the TAK1 gene located at these loci did not correlate with LOH status, indicating that TAK1 is not a target gene in prostate carcinoma. The 6q deletion occurs heterogeneously and LOH was more frequent in tumors of higher pathological stages, implying that this alteration is a late event in prostate carcinogenesis. Because prostate carcinomas are genetically multicentric and of multifocal origin, it remains unclear whether the foci containing 6q deletions specifically expand within tumors or to what extent they contribute to the histological heterogeneity characteristic of the disease.
Immunological evaluation of peptide vaccination for patients with gastric cancer based on pre‐existing cellular response to peptide
Authors: Sato Yuji , Shomura Hiroki , Maeda Yoshiaki , Mine Takashi , Une Yoshie , Akasaka Yoshinobu , Kondo Masao , Takahashi Shusaku , Shinohara Toshiki , Katagiri Kazuko , Sato Mika , Okada Shiori , Matsui Kanae , Yamada Akira , Yamana Hideaki , Itoh Kyogo , Todo Satoru
Published: August 2005

There is no standard treatment modality for advanced gastric cancer (GC) at the present time. To develop a new treatment modality, we investigated the immunological responses of advanced GC patients (n=13, 9 non‐scirrhous and 4 scirrhous types) vaccinated with peptides to a regimen under which pre‐vaccination peripheral blood mononuclear cells (PBMCs) were screened for their reactivity in vitro to each of 14 peptides on HLA‐A24 or 16 peptides on ‐A2 allele, then only the reactive peptides (maximum: 4) were administered in vivo. This regimen was generally well tolerated, although grade I levels of fever and local skin reactions were observed in several patients. Delayed‐type hypersensitivity (DTH) to the vaccinated peptides was observed in 4 patients. Increased cellular and humoral immune responses to the vaccinated peptides were observed in post‐vaccination PBMCs from 4 of 8 patients and in post‐vaccination sera of 8 of 10 patients tested, respectively. Prolonged survival was observed in patients showing cellular and humoral immune responses to the vaccinated peptides in the post‐vaccination samples, including all 4 patients with the scirrhous type. These results encourage further development of peptide‐based immunotherapy for GC patients.
Novel biomarker of HTLV‐1‐associated disease: Specific appearance of antibody recognizing the receptor‐binding site on HTLV‐1 envelope protein
Authors: Sagara Yasuko , Inoue Yukiko , Tsujimura Mitsushi , Kojima Eijiro , Shiraki Hiroshi , Kashiwagi Seizaburo
Published: August 2005

We previously showed that 71‐kDa heat shock cognate protein (HSC70) functions as a cellular receptor for gp46 protein via the gp46–197 region, corresponding to Asp197 to Leu216 of human T‐cell lymphotropic virus type 1 (HTLV‐1), leading to cell‐to‐cell transmission of HTLV‐1. We found that HSC70 protein was contained in goat serum and casein used as blocking agents in the usual ELISA method. Here, it was demonstrated that HSC70 contamination in the blocking agents causes a false‐negative result in the detection of anti‐gp46–197 antibody in serum samples from HTLV‐1‐infected individuals. By using ELISA without the blocking agents, we detected antibodies recognizing the HSC70‐binding site of gp46, and the anti‐gp46–197 antibody specifically appeared in sera from patients with HTLV‐1‐associated diseases. The frequency of serum anti‐gp46–197 antibody‐positive individuals was 98% and 100% among ATLL and HAM/TSP patients, respectively, but only 6% among asymptomatic HTLV‐1‐infected carriers (ACs). The antibody titer in ATLL and HAM/TSP patients was higher than that in ACs (P>0.002 for ATLL; P>0.0001 for HAM/ TSP). These findings suggest that appearance of the anti‐gp46–197 antibody is a predictive marker for the onset of HTLV‐1‐associated disease.
Sensitization of human glioblastomas to tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) by NF‐κB inhibitors
Authors: Kasuga Chinatsu , Ebata Tomohiko , Kayagaki Nobuhiko , Yagita Hideo , Hishii Makoto , Aral Hajime , Sato Kiyoshi , Okumura Ko
Published: August 2005

Glioblastoma is the most malignant form of primary brain tumor in adults, with no effective therapy and a low survival rate. TRAIL is a member of the TNF family, which selectively induces apoptosis in certain neoplastic cells, but not normal cells. In this study, we investigated the sensitivity of 7 human glioblastoma cell lines to TRAIL and the expression in them of TRAIL receptors. TRAIL exhibited significant cytotoxicity in 5 of 7 glioma cell lines. These glioblastoma cell lines expressed TRAIL‐R2, but not TRAIL‐R1, R3, or R4. However, no correlation was observed between the TRAIL sensitivity and the TRAIL‐R2 expression level, suggesting that there is an additional determinant of TRAIL sensitivity. Treatments with NF‐κB inhibitors, such as LLnL, MG132, and SN50, significantly increased the sensitivity of glioma cells to TRAIL. These results suggested that activation of NF‐κB is a protective mechanism against TRAIL‐induced cell death in some glioma cells, and thus NF‐κB inhibitors may be useful to improve the clinical treatment of glioblastoma with TRAIL.
Rapid induction of skin and mammary tumors in human c‐Ha‐ras proto‐oncogene transgenic rats by treatment with 7,12‐dimethylbenz[a]anthracene followed by 12‐O‐tetradecanoylphorbol 13‐acetate
Authors: Park Cheol Beom , Fukamachi Katsumi , Takasuka Nobuo , Han Beom Seok , Kim Chuel Kyu , Hamaguchi Tetsuya , Fujita Ken‐ichi , Ueda Shinobu , Tsuda Hiroyuki
Published: August 2005

We have established a transgenic rat line carrying 3 copies of the human c‐Ha‐ras proto‐oncogene with its own promoter region (Jcl/SD‐TgN(HrasGen)128Ncc) (Hras128 rat), expression being detectable in almost all organs. We have already demonstrated that the rat is highly sensitive to mammary, esophagus and bladder carcinogenesis. In the present study, male and female transgenic and wild‐type littermates were topically treated with 2.5 mg of 7,12‐dimethylbenz[a]anthracene (DMBA) dissolved in 1.0 ml of acetone on the back skin at 50 days after birth. Starting 1 week thereafter, they were again topically treated with 100 nmol of 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) dissolved in 0.5 ml of acetone 3 times weekly for the following 31 weeks. In males treated with DMBA and/or TPA, skin tumors, including both squamous cell papillomas (SCP) and carcinomas (SCC), were preferentially induced at the DMBA‐TPA painting sites: DMBA‐TPA, 15/15 (100%); DMBA, 6/8 (75%); TPA, 1/6 (16.7%). They were also, unexpectedly, induced on remote scrotal skin: DMBA‐TPA, 13/15 (86.7%); DMBA, 5/8 (62.5%); TPA, 0/6 (0%). Lesions were thus more frequent in the DMBA‐TPA group than with DMBA or TPA alone. In females, adenomas and adenocarcinomas of the mammary glands were preferentially induced: DMBA‐TPA, 12/14 (85.7%); DMBA, 6/8 (75%); TPA, 3/6 (50%), with only a few small skin papillomas at painting sites. Incidences and numbers of the mammary and skin tumors were much greater in Hras128 rats than in their wild‐type counterparts. PCR‐RFLP analysis of the transgene indicated that the percentage of the cell populations harboring a mutation in codons 12 and/or 61 ranged from 2% to 60% in individual tumors; skin tumors showed more mutations in codon 61 in the DMBA‐treated groups. In contrast, no mutations were detected in the endogenous rat c‐Ha‐ras gene. These results indicate that the Hras128 rat is highly susceptible to DMBA‐TPA skin and mammary carcinogenesis, thus providing a unique painting model for skin as well as mammary gland carcinogenesis, that would be suitable for investigating the role of transgene mutations.
Expression profiling to predict postoperative prognosis for estrogen receptor‐negative breast cancers by analysis of 25,344 genes on a cDNA microarray
Authors: Nagahata Takemitsu , Onda Masamitsu , Emi Mitsuru , Nagai Hisaki , Tsumagari Koji , Fujimoto Takashi , Hirano Akira , Sato Takamichi , Nishikawa Kiyohiro , Akiyama Futoshi , Sakamoto Goi , Kasumi Fujio , Miki Yoshio , Tanaka Toshihiro , Tsunoda Tatsuhiko
Published: August 2005

Estrogen receptor (ER) status is an essential determinant of clinical and biological behavior of human breast cancers. While ER‐positive breast cancers respond well to adjuvant hormone therapy, ER‐negative tumors are generally resistant. To date, no attempts have succeeded in finding molecular markers for classifying ER‐negative breast cancers with respect to postoperative prognosis. To identify a set of prognostic markers for this type of cancer, we used a cDNA microarray consisting of 25,344 human genes to investigate expression profiles of ten primary breast cancers from patients who had died of breast cancer within 5 years after surgery (5y‐D) and 10 from patients who had survived disease‐free for more than 5 years (5y‐S). Sets of genes characterizing each group were identified by Mann‐Whitney and random‐permutation tests. We documented 71 genes with higher expression in the 5y‐D group than in the 5y‐S group, and 15 with higher expression in the 5y‐S group than in the 5y‐D group. Semi‐quantitative RT‐PCR experiments were carried out to confirm the results of the microarray analysis. We established a scoring system for predicting postoperative prognosis of ER‐negative breast cancers on the basis of aberrant gene expression. The list of genes reported here provides valuable information with regard to progression of breast cancer and is a source of possible target molecules for development of novel drugs to treat patients with ER‐negative breast cancers.
A prospective study on the possible association between having children and colon cancer risk: Findings from the JACC Study
Authors: Tamakoshi Koji , Wakai Kenji , Kojima Masayo , Watanabe Yoshiyuki , Hayakawa Norihiko , Toyoshima Hideaki , Yatsuya Hiroshi , Kondo Takaaki , Tokudome Shinkan , Hashimoto Shuji , Suzuki Koji , Ito Yoshinori , Tamakoshi Akiko
Published: August 2005

If having children is regarded as an exposure in life, its effect on a host could be considered as being due to female sex hormones associated with pregnancy in women and some lifestyle factors associated with large families in both men and women. To explore the roles of having children in the etiology of colon cancer, we examined 36,629 women and 24,877 men aged 40–79 years who completed a questionnaire on the number of children and other lifestyle factors from 1988 to 1990 in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. During 291,080 and 200,648 person‐years of follow‐up, we documented 198 female and 202 male incident colon cancers, respectively. After adjusting for some factors known or suspected to modify the risk of colon cancer, compared with the women with no children, the multivariate‐adjusted relative risks of colon cancer were 0.74 (95% confidence interval [CI]: 0.30–1.84) for one child, 1.00 (95% CI: 0.46–2.20) for two, 0.70 (95% CI: 0.31–1.55) for three, and 0.59 (95% CI: 0.26–1.33) for four or more. The risk of colon cancer showed a significantly monotonic decrease with increasing number of children (P value for trend=0.047). There was no association between the number of children and colon cancer risk among men. From these prospective data, having children may reduce risk of colon cancer among women, but not among men, suggesting that modifications of hormone profiles secondary to pregnancies may influence female colon cancer risk.
Comparative genomic hybridization (CGH)‐arrays pave the way for identification of novel cancer‐related genes
Authors: Inazawa Johji , Inoue Jun , Imoto Issei
Published: August 2005

Comparative genomic hybridization (CGH) has already made a significant impact on cancer Cytogenetics. However, CGH to metaphase chromosomes can provide only limited resolution at the 5–10 Mb level. To circumvent this limitation, array‐based CGH has been devised. Since spotted DMAs in a CGH‐array contain sequence information directly connected with the genome database, we can easily note particular biological aspects of genes that lie within regions involved in copy‐number aberrations. High‐density, sub‐megabase arrays can reveal nonrandom chromosome copy‐number aberrations responsible for neoplastic transformation that have been masked under complex karyotypes in epithelial solid tumors. High‐density CGH‐array therefore paves the way for identification of disease‐related genetic aberrations that have not yet been detected by existing technologies, and array‐based CGH technology should soon be practical for diagnosis of cancer or genetic diseases in the clinical setting.
Intratumoral injection of IL‐2‐activated NK cells enhances the antitumor effect of intradermally injected paraformaldehyde‐fixed tumor vaccine in a rat intracranial brain tumor model
Authors: Ishikawa Eiichi , Tsuboi Koji , Takano Shingo , Uchimura Eiji , Nose Tadao , Ohno Tadao
Published: August 2005

Combined therapy with a fixed‐tumor cell vaccine and intratumoral injection of NK cells induced strong tumor regression of rat glioma. Rat 9L glioma cells were inoculated into syngeneic male rats at the flank (subcutaneous tumor model) or at the basal ganglia of the right hemisphere (intracranial tumor model). Rats were intradermally injected three times with vaccine comprising fixed 9L cells, IL‐2‐ and GMCSF‐microparticles, and tuberculin prior to (protective studies) or after (therapeutic studies) challenge with live 9L cells. In the protective studies, the vaccine alone achieved significant tumor growth inhibition and elongation of mean life span in both the subcutaneous and intracranial tumor models. No therapeutic effect was observed in the intracranial tumor model with the vaccine alone. However, intratumoral injection of rat NK cells strongly assisted the therapeutic effect of the vaccine in the brain tumor model and resulted in a statistically significant elongation of life span. We propose that intratumoral injection of NK cells may not only kill brain tumor cells directly, but also trigger a strong immune response in the focal lesion of the brain after vaccination. (Cancer Sci 2004; 95: 98–103)
Diagnostic potential in bladder cancer of a panel of tumor markers (calreticulin, γ‐synuclein, and catechol‐o‐methyltransferase) identified by proteomic analysis
Authors: Iwaki Hideaki , Kageyama Susumu , Isono Takahiro , Wakabayashi Yoshihiko , Okada Yusaku , Yoshimura Koji , Terai Akito , Aral Yoichi , Iwamura Hiroshi , Kawakita Mutsushi , Yoshiki Tatsuhiro
Published: August 2005

Using proteomic analysis, we previously identified calreticulin (CRT) as a potentially useful urinary marker for bladder cancer. Now, we have also identified γ‐synuclein (SNCG) and a soluble isoform of catechol‐o‐methyltransferase (s‐COMT) as novel candidates for tumor markers in bladder cancer, by means of proteomic analysis. In the process of establishing a superior tumor marker system, we investigated the diagnostic value of a combination assay of these three proteins. Voided urine samples were obtained from 112 bladder cancer and 230 control patients. Urinary CRT, SNCG, and s‐COMT were measured as a combined marker by quantitative western blot analysis. Relative concentration of each protein was calculated and the diagnostic value of a concomitant examination of these markers was evaluated by receiver operator characteristic analysis. With the best diagnostic cutoff, the overall sensitivity of the combined markers was 76.8% (95% confidence interval, 69–81%) with a specificity of 77.4% (72–80%), while those of a single use of CRT were 71.4% and 77.8%, respectively. When evaluated in relation to tumor characteristics, such as grade, stage, size, and outcome of urinary cytology, the diagnostic capacity of the combined markers was equal to or better than that of CRT in all categories. Concomitant use of CRT, SNCG, and s‐COMT had higher sensitivity for detection of bladder cancer than did single use of CRT. Our study suggests that use of this panel of markers will improve the diagnosis of bladder cancer and may allow the development of a protein microarray assay or multi‐channel enzyme‐linked immunosorbent assay.
Skp2 overexpression is a p27Kip1‐independent predictor of poor prognosis in patients with biliary tract cancers
Authors: Sanada Takahiro , Yokoi Sana , Arii Shigeki , Yasui Kohichiroh , Imoto Issei , Inazawa Johji
Published: August 2005

To better understand the pathogenesis of biliary tract carcinoma (ETC) and to increase the accuracy of predicting outcomes for patients with this disease, we performed molecular cytogenetic analyses of BTC cell lines and tumors to identify non‐random amplification(s) and target gene(s) within the amplicons. Among several non random chromosomal aberrations detected in BTC cell lines by comparative genomic hybridization, gain/amplification of DNA at 5p was the most frequently observed alteration. We assessed the copy number and expression status of the possible target gene SKP2 for 5p amplification in cell lines and 33 primary stage II or III tumors of BTC. SKP2 was amplified, and subsequently overexpressed in both cell lines and primary tumors of BTC. However, levels of Skp2 and p27Kip1 proteins were not correlated inversely. Heightened expression of Skp2 and reduced expression of p27Kip1 were both associated with a shorter disease‐free and/or overall survival in univariate analyses. In multivariate regression analyses, Skp2 and p27Kip1 were independent predictive factors. Those results suggest that (a) overexpression of Skp2 through an amplification mechanism may contribute to the progression of BTC, (b) not only each molecule, but also the combination of Skp2 and p27Kip1, might be a useful predictor of the prognosis of BTC, and (c) molecular targets of Skp2 other than p27Kip1 may also be important factors in the pathogenesis of this disease.
Integration of human T‐cell leukemia virus type 1 in genes of leukemia cells of patients with adult T‐cell leukemia
Authors: Hanai Shuji , Nitta Takayuki , Shoda Momoko , Tanaka Masakazu , Iso Naomi , Mizoguchi Izuru , Yashiki Shinji , Sonoda Shunro , Hasegawa Yuichi , Nagasawa Toshiro , Miwa Masanao
Published: August 2005

Adult T‐cell leukemia (ATL) occurs after a long latent period of persistent infection by human T‐cell leukemia virus type 1 (HTLV‐1). However, the mechanism of oncogenesis by HTLV‐1 remains to be clarified. It was reported that the incidence curve of ATL versus age was consistent with a multistage carcinogenesis model. Although HTLV‐1 is an oncogenic retrovirus, a mechanism of carcinogenesis in ATL by insertional mutagenesis as one step during multistage carcinogenesis has not been considered thus far, because the exact integration sites on the chromosome have not been analyzed. Here we determined the precise HTLV‐1 integration sites on the human chromosome, by taking advantage of the recently available human genome database. We isolated 25 integration sites of HTLV‐1 from 23 cases of ATL. Interestingly, 13 (52%) of the integration sites were within genes, a rate significantly higher than that expected in the case of random integration (P=0.043, ?2 test). These results suggest that preferential integration into genes at the first infection is a characteristic of HTLV‐1. However considering that some of the genes are related to the regulation of cell growth, the integration of HTLV‐1 into or near growth‐related genes might contribute to the clonal selection of HTLV‐1‐infected cells during multistage carcinogenesis of ATL.
Angiogenesis and the efficacy of postoperative administration of UFT in pathologic stage I non‐small cell lung cancer
Authors: Tanaka Fumihiro , Yanagihara Kazuhiro , Otake Yosuke , Miyahara Ryo , Wada Hiromi
Published: August 2005

UFT is an oral 5‐fluorouracil derivative drug that may improve postoperative survival in non‐small cell lung cancer (NSCLC), and experimental studies have shown that UFT inhibits tumor angiogenesis. In the present study, therefore, the correlation between tumor angiogenesis (intratumoral microvessel density, IMVD) and the efficacy of UFT in 162 patients with pathologic stage I NSCLC was examined. For higher IMVD tumors (IMVD≥20, n=80), the 5‐year survival rate of UFT‐treated patients (82.5%) was significantly higher than that of surgery‐alone patients (61.8%, P=0.032). For lower IMVD tumors (n=82), however, there was no difference in the survival between these groups (5‐year survival rates, 84.9% and 82.6%, respectively; P=0.657). Multivariate analyses confirmed that postoperative UFT administration was effective for higher IMVD tumors (P=0.046; relative risk [RR] and the 95% confidence interval [CI], 0.288 [0.084–0.979]), but not for lower IMVD tumors (P=0.616; 0.726 [0.208–2.539]). Moreover, vascular endothelial growth factor (VEGF) status was also a predictive factor. For tumor showing strong VEGF expression (n=63), UFT administration improved the survival (5‐year survival rates of UFT‐treated patients and surgery‐alone patients, 84.6% and 60.0%, respectively; P=0.048); for weakly VEGF‐expressing tumors (n=99), UFT administration did not influence the survival (5‐year survival rates, 83.4% and 79.1%, respectively; P=0.455). Multivariate analyses demonstrated that UFT administration seemed to be effective for strong VEGF tumors (P=0.063; RR and the 95% CI, 0.234 [0.051‐10.81]), but not for weak VEGF tumors (P=0.456; 0.673 [0.293‐1.900]). In conclusion, the efficacy of postoperative UFT administration in NSCLC was correlated with tumor angiogenesis.
Possible enhancing effects of atrazine and nonylphenol on 7,12‐dimethylbenz[a]anthracene‐induced mammary tumor development in human c‐Ha‐ras proto‐oncogene transgenic rats
Authors: Fukamachi Katsumi , Han Beom Seok , Kim Chuel Kyu , Takasuka Nobuo , Matsuoka Yoichiro , Matsuda Eiji , Yamasaki Tomomi , Tsuda Hiroyuki
Published: August 2005

Our transgenic (Tg) strain carrying copies of the human c‐Ha‐ras proto‐oncogene is highly susceptible to 7,12‐dimethylbenz[a]an‐thracene (DMBA)‐induced mammary carcinogenesis, possibly due to activation of the transgene, and can be used in medium‐term bioassay models to test for modifying effects of estrogenic environmental compounds on tumor development. The present study was conducted to assess the influence of dietary feeding of the endocrine disruptors atrazine and nonylphenol on DMBA‐induced carcinogenesis in c‐Ha‐ras Tg rats. Animals of both sexes were given a single oral dose of DMBA (25 mg/kg body weight) at 50 days of age and thereafter received soybean‐free diet containing 5, 50 or 500 ppm atrazine, or 10, 25, 100 or 250 ppm nonylphenol. In female Tg rats, atrazine at a dose of 5 ppm increased the incidences of mammary adenomas and adenocarcinomas (P<0.01 and P<0.05), while 50 ppm increased the adenocarcinoma incidence (P<0.05). In males, skin tumor development, in contrast, was significantly decreased at the highest dose. Nonylphenol at 10 ppm increased adenocarcinoma and total mammary tumor multiplicity in female Tg rats (P<0.05), but there was no dose dependence, a significant quadratic dose‐response trend rather being observed (P<0.05). In vitro, atrazine did not cause proliferation of MCF‐7 cells at any of a range of doses tested. These results suggest that endocrine disruptors may enhance mammary carcinogenesis, but only in a certain limited dose range under the present experimental conditions. The doses applied, moreover, were all extremely high compared to the possible environmental human exposure levels.
Expression of the c‐myc gene as a predictor of chemotherapy response and a prognostic factor in patients with ovarian cancer
Authors: Iba Takahiro , Kigawa Junzo , Kanamori Yasunobu , Itamochi Hiroaki , Oishi Tetsuro , Simada Muneaki , Uegaki Kazunori , Naniwa Jun , Terakawa Naoki
Published: August 2005

The present study was conducted to determine whether and how expression of the c‐myc gene is related to the response to chemotherapy in patients with epithelial ovarian cancer. This study includes 101 consecutive patients with stage Ic to IV epithelial ovarian cancer who underwent primary surgery followed by platinum‐based chemotherapy. Immunohistochemical studies were performed to detect Ki‐67 and ARF proteins. Apoptotic cells were identified by the terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate biotin nick‐end labeling method. Mutation of the p53 gene was screened by polymerase chain reaction (PCR)‐single strand conformation polymorphism analysis and confirmed by direct sequencing. mRNA expression of c‐myc was determined by means of reverse transcription‐PCR. Apoptotic index (AI) and ARF labeling index (LI) were significantly increased and Ki‐67 LI was decreased after chemotherapy in patients from whom specimens could be obtained before and after chemotherapy. AI, ARF LI, and Ki‐67 LI were not related to p53 gene status. A significant correlation between expression of c‐myc and ARF LI was observed. Of 38 patients with measurable lesion, 23 (60.5%) responded to chemotherapy and 15 (39.5%) did not. Tumors with the wild‐type p53 gene responded significantly better to chemotherapy than did tumors with the mutation. Responders showed a higher expression of c‐myc than nonresponders (468.76 vs. 187.68). The receiver operating characteristic (ROC) curve according to chemoresponse demonstrated that the cut‐off value of c‐myc expression was 200. Patients with c‐myc expression of more than 200 had a better 5‐year survival rate (69.8% vs. 43.5%; 101 patients). Multivariate analysis revealed that c‐myc expression was an independent prognostic factor. Our results suggest that the expression of c‐myc gene is related to chemoresponse and might be a useful prognostic factor in patients with epithelial ovarian cancer.
Conditional gene silencing utilizing the lac repressor reveals a role of SHP‐2 in cagA‐positive Helicobacter pylori pathogenicity
Authors: Higuchi Megumi , Tsutsumi Ryouhei , Higashi Hideaki , Hatakeyama Masanori
Published: August 2005

RNA interference (RNAi) is a newly described biological phenomenon mediated by small interfering RNA (siRNA) that targets mRNA for degradation by cellular enzymes and has become a powerful method for studying gene functions in mammalian systems. The development of systems for inducing siRNA expression should enable examination of acute loss‐of‐function phenotypes in a cell of interest without the need to consider lethality or epigenetic adaptation of cells. We describe in this report an inducible siRNA expression system made by combined utilization of the RNA polymerase III‐dependent promoter H1 and the bacterial lac repressor. Using this system, we established AGS gastric epithelial cells in which expression of SHP‐2, a cellular tyrosine phosphatase known to specifically bind the Helicobacter pylori virulence factor CagA, is conditionally and reversibly silenced by the lactose analog isopropyl‐1‐thio‐β‐D‐galactopyranoside (IPTG). Upon expression in AGS cells, CagA provoked a morphological transformation, termed the hummingbird phenotype, which is associated with CagA virulence. This morphogenetic activity of CagA was totally abolished when SHP‐2 expression was silenced by inducible siRNA expression in AGS cells. Our results indicate that SHP‐2 is a critical downstream effector of H. pylori CagA. The conditional gene silencing system described here should become a powerful tool for investigating the roles of cancer‐related genes through a reversed genetic approach.
The expressions of p21 and pRB may be good indicators for the sensitivity of esophageal squamous cell cancers to CPT‐11: Cell proliferation activity correlates with the effect of CPT‐11
Authors: Nakajima Yasuaki , Miyake Satoshi , Tanaka Koji , Ogiya Kazuo , Toukairin Yutaka , Kawada Kenrou , Nishikage Tetsurou , Nagai Kagami , Kawano Tatsuyuki
Published: August 2005

Previously, we demonstrated that CPT‐11 is an effective agent against esophageal squamous cell cancers (ESCC), and that the protein level of DNA topoisomerase I can be a predictor for sensitivity to CPT‐11 (Jpn J Cancer Res 2001; 92: 1335–41). Here, we describe our search for additional predictors of sensitivity to CPT‐11, mainly among cell cycle‐regulating proteins, because the cytotoxicity of CPT‐11 is significantly correlated with the percentage of ESCC cells in S‐phase. To this end, we selected and examined the expressions of 5 proteins involved in G1‐S transition, i.e., p53, cyclin D1, p21, p27, and pRB, in 14 ESCC cell lines by western blot analysis. Among these proteins, the expression levels of p21 and pRB showed significant differences that were associated with the IC50 values for CPT‐11 (P=0.0339 and P=0.0109, respectively). Namely, the expression of p21 or pRB independently could be a good indicator of CPT‐11 efficacy in ESCC. In addition, the cell proliferation activities examined by enzyme‐linked immunosorbent assay (ELISA) using 5‐bromo‐2′‐deoxyuridine (BrdU) showed a significant correlation with the percentage of total S‐phase cells (correlation coefficient=0.568, P=0.0324), and an inverse correlation with the IC50 values for CPT‐11 (correlation coefficient=−0.601, P=0.0213). Because, as in the case of DNA topoisomerase I, the cell proliferation activity determined using BrdU shows a close relationship with the MIB‐1 labeling index, immunohistochemical studies of p21, pRB, and MIB‐1 in resected ESCC specimens and/or biopsy samples could make it possible to predict more precisely the sensitivity of ESCC patients to CPT‐11 prior to treatment.
Thymus‐leukemia antigen (TL) as a major histocompatibility complex (MHC) class Ib molecule and tumor‐specific antigen
Authors: Tsujimura Kunio , Obata Yuichi , Takahashi Toshitada
Published: August 2005

Mouse thymus‐leukemia antigens (TL) belong to the family of major histocompatibility complex (MHC) class Ib antigens and have a unique mode of expression, i.e., in contrast to other MHC class Ib or la antigens, they are found restricted to the intestines in all mouse strains, but also in the thymus of certain strains (TL+ strains). Nevertheless, a proportion of T lymphomas/leukemias in strains that do not express TL in the thymus (TL− strains) feature TL as a tumor antigen. TL was originally defined serologically, but subsequently we have succeeded in generating T cell receptor (TCR) αβ and γδ cytotoxic T lymphocytes (CTL) recognizing TL. By use of TL tetramers free from peptides and transfectants expressing various TL/H‐2 chimeric molecules, we have been able to show that TL‐specific CTL recognize the α1 /α2 domain of TL without any additional antigen molecules. We previously reported that one of TL's functions in the thymus is positive selection of TCRγδ CTL. Recent studies with TL tetramers revealed that they can bind to normal intestinal intraepithelial lymphocytes (ilEL) and thymocytes in a CD8‐dependent, but TCR/CD3‐independent manner, while their binding to TL‐specific CTL is TCR/CD3‐and CDS‐dependent. The possible significance of these findings in relation to the roles of TL in the intestines is discussed. We have long been interested in TL as a model tumor antigen which shares characteristics with human differentiation tumor antigens, and we have demonstrated that growth of TL+ lymphoma cells in vivo is suppressed by immunization with TL+ skin or dendritic cells (DC) from TL transgenic mice. In addition, anti‐tumor effects against TL+ T lymphomas were obtained by adoptive transfer of TL tetramer strongly‐positive TL‐specific CTLs.
Genetic and epigenetic factors involved in B‐cell lymphomagenesis
Authors: Seto Masao
Published: August 2005

Malignant lymphomas have been classified by the WHO into disease categories based not only on histological features, but also on cell surface markers, cytogenetic and clinical features. It is known that chromosome translocation plays an important role in lymphoma development, but it is not entirely clear yet why a given type of chromosome translocation is associated with a specific type of lymphoma. This review deals with molecular mechanisms of B‐cell lymphoma development in association with chromosome translocations. The outcome of chromosome translo‐cations can be categorized into three factors: enhancement of proliferation, inhibition of differentiation and anti‐apoptotic activity. It is well known that chromosome translocation by itself cannot cause cells to become malignant because it is only one of the growth advantages leading to malignancy, while additional genetic and epigenetic alterations are required for cells to become fully malignant. Mucosa‐associated lymphoid tissue (MALT) lymphomas of the stomach are unique in that a majority can be cured by Helicobacter pylori eradication, although 20 to 30% remain resistant. Others as well as we have demonstrated that the presence of the API2‐MALT1 chimeric gene correlates well with resistance to H. pylori eradication treatment. These characteristics have led to the speculation that the classification of MALT lymphoma falls somewhere between tumor and inflammation. Although MALT lymphoma seems to have unique features in comparison with other types of B‐cell lymphomas, it shares common molecular mechanisms with B‐cell lymphoma development.
Leflunomide in the treatment of rheumatoid arthritis. An analysis of predictors for treatment continuation
Authors: Van Roon E. N. , Hoekstra M. , Tobi H. , Jansen T. L. TH. A. , Bernelot Moens H. J. , Brouwers J. R. B. J. , Van De Laar M. A. F. J.
Published: August 2005

Aims

To determine factors predictive for leflunomide drug survival in an outpatient population with rheumatoid arthritis in a setting of care‐as‐usual.

Methods

A standard dataset was collected from medical records of consecutive outpatients on leflunomide treatment for rheumatoid arthritis between January 2000 and June 2003. The dataset consisted of patient, disease and treatment characteristics at the start of leflunomide treatment, and data on leflunomide use.

Results

Leflunomide was started in 279 patients and 173 patients (62.0%) withdrew from treatment during follow‐up. From univariate analysis, concomitant systemic corticosteroid use [hazard ratio (HR) (95% confidence interval) 1.35 (1.00, 1.83)] and an erythrocyte sedimentation rate <35 mm h−1[HR 1.38 (1.01, 1.88)] at start of leflunomide were found to be predictive for better leflunomide survival. Furthermore, the attending rheumatologist was correlated with leflunomide drug survival. Hazard ratios varied, depending on the individual rheumatologist, from 0.60 to 2.66. Multivariate analysis suggested attending rheumatologist (HR varying from 0.54 to 2.30 depending on the individual rheumatologist), concomitant systemic corticosteroid use [HR 1.58 (1.14 2.21)] and erythrocyte sedimentation rate <35 mm h−1[HR 1.42 (1.03, 1.96)] at start of leflunomide to be associated with leflunomide survival.

Conclusions

Concomitant systemic corticosteroid use, erythrocyte sedimentation rate at the start of treatment and attending rheumatologist were found to be predictive for leflunomide survival. Information on these predictors at the start of leflunomide therapy may offer information on which patients are at an increased risk of withdrawal from leflunomide. Whether this information leads to optimization of leflunomide treatment outcomes remains to be studied.
Effects of grapefruit juice on the absorption of levothyroxine
Authors: Lilja Jari J. , Laitinen Kalevi , Neuvonen Pertti J.
Published: August 2005

Aims

Our aim was to study the effect of grapefruit juice on the pharmacokinetics of levothyroxine.

Methods

In a randomized cross‐over study with two phases, 10 healthy subjects ingested 200 ml grapefruit juice or water (control) three times daily for 2 days. On day 3, a single 600 µg dose of levothyroxine was administered with 200 ml grapefruit juice or water, which was also ingested 1 h before and 1 h after levothyroxine. Serum concentrations of total thyroxine (T4) and thyroid‐stimulating hormone (TSH) were measured up to 24 h.

Results

Grapefruit juice decreased slightly (11%; P < 0.01) the maximal increase of T4 concentration after ingestion of levothyroxine from 66.4 nmol l−1 to 59.4 nmol l−1 (95% CI on the difference −11.3, −2.7). The incremental areas under the serum T4 concentration‐time curve (dAUC) during the first 4 and 6 h were also decreased slightly: dAUC(0,4 h) by 13% (P < 0.05), from 195 nmol l−1 h to 169 nmol l−1 h (95% CI −51, −1) and dAUC(0,6 h) by 9% (P = 0.085), from 298 nmol l−1 h to 271 nmol l−1 h (95% CI −58, 4). The decrease in the serum concentration of TSH (1.25 mU l−1) measured 24 h after ingestion of levothyroxine, was not altered by grapefruit juice.

Conclusions

Grapefruit juice may slightly delay the absorption of levothyroxine, but it seems to have only a minor effect on its bioavailability. Accordingly, the clinical relevance of the grapefruit juice‐levothyroxine interaction is likely to be small.
Comparative ecology of seed mass in Psychotria (Rubiaceae): within‐ and between‐species effects of seed mass on early performance
Authors: PAZ H. , MAZER S. J. , MARTINEZ‐RAMOS M.
Published: August 2005

Experimental field data and interspecific comparative analyses were used to detect effects of seed mass on seedling performance within and among seven species of Psychotria sown in gaps and shaded rainforest sites. In addition we compared the effects of seed mass within and among species to detect concordance between the two ecological scales. We used two comparative methods: phylogenetically independent contrasts and cross‐species correlations.

Among species, we detected weak evidence of a positive correlation between seed mass and the probability of emergence in the shaded forest, and no effects of seed mass in gaps.

Among species, no significant correlations between seed mass and either seedling survival or seedling recruitment were found in any habitat. Other variables specific to each subgenus appear to be more important than seed mass in determining survival in the shaded forest.

There was a negative correlation between seed mass and relative growth rate (RGR) in both habitats. In gaps, small‐seeded taxa exhibited particularly high RGR, compensating for the initial advantages of higher seed mass.

All species studied exhibited recruitment in gaps equal to or higher than that in the shaded forest. However, recruitment success in shaded forest relative to gaps increased with seed mass, indicating a higher affinity for shaded forest among larger‐seeded taxa, but this relationship was only detected using PICS analysis.

6. Correlations between seed mass and seedling mass are similar within and among species, indicating a simple principle of mass transference. In contrast, correlations between seed mass and seedling emergence, seedling survival, seedling recruitment and RGR depend on the scale at which they are observed.
Egg carotenoids in passerine birds introduced to New Zealand: relations to ecological factors, integument coloration and phylogeny
Authors: CASSEY P. , EWEN J. G. , BOULTON R. L. , BLACKBURN T. M. , MØLLER A. P. , BIARD C. , OLSON V. , KARADAS F.
Published: August 2005

Carotenoids are a diverse group of organic compounds that function as important antioxidants and immunostimulants and are of particular importance to developing embryos and young birds. In addition, they constitute the majority of yellow to red hues in the integumentary pigments of birds.

We investigated the maternally derived carotenoid concentrations and balances in the yolks of eight European passerine species successfully introduced and abundant in New Zealand. Specifically, we addressed whether variation in maternally derived yolk carotenoids were related to phylogeny, integument coloration, native vs introduced distribution, breeding habitat and laying sequence.

Across species, the concentration and balance of carotenoids deposited in yolks varied significantly. Egg carotenoid concentration was positively associated with the occurrence of male carotenoid pigmented body regions. Carotenoid concentrations differed between agricultural habitat types within New Zealand but not between samples from New Zealand and Europe. Controlling for the differences among species, and among clutches within species, increased egg carotenoid concentrations were significantly associated with decreasing fresh egg mass and eggs laid earlier in the laying sequence.

We conclude that variability in the concentration and balance of carotenoids deposited in the egg yolk imply different relative roles for ecological and phylogenetic factors that warrant further investigation, both within and across species.
Functional linkages between leaf traits and net photosynthetic rate: reconciling empirical and mechanistic models
Authors: SHIPLEY B. , VILE D. , GARNIER E. , WRIGHT I. J. , POORTER H.
Published: August 2005

We had two objectives: (i) to determine the generality of, and extend the applicability of, a previously reported empirical relationship between leaf‐level net photosynthetic rate (AM, nmol g−1 s−1), specific leaf area (SLA, m2 kg−1) and leaf nitrogen mass fraction (NM, mmol g−1); and (ii) to compare these empirical results with a mechanistic model of photosynthesis in order to provide a mechanistic justification for the empirical pattern.

Our results were based on both literature and original data. There were a total of 160 and 87 data points for the leaf‐level and whole‐plant data, respectively.

Our multiple regression for single leaves was ln(AM) = 0·66 + 0·71 ln(SLA) + 0·79 ln(NM), r2 = −0·80; only the intercept (0·11) differed for the whole‐plant data. These results are not significantly different from previously published relationships.

We then converted the mechanistic model of Evans and Poorter, and a modified version which includes leaf lamina thickness (T) and leaf dry matter (tissue) concentration (CM), into directed acyclic graphs. We then derived reduced graphs that involved only T, CM, SLA, NM and AM. These were tested using structural equation modelling, with measured lamina thickness (T′) and leaf dry matter ratio (LDMR, g dry mass g−1 fresh mass) as indicators of T and CM. The original Evans–Poorter model was rejected, but the modified version fitted the structural relationships well. The same qualitative models also applied to the whole‐plant data, although the path coefficients sometimes differed.

Using simulations, we show that the original Evans–Poorter model predicts a positive correlation between SLA and NM that maximizes AM. The data closely follow this predicted relationship. The correlation between the actual values of AM (standardized units) and the predicted values obtained from the modified Evans–Poorter model was 0·74 and increased to 0·82 once three outlier points were removed.

These results provide a mechanistic explanation for the empirical trends relating leaf form and carbon fixation, and predict that SLA and leaf N must be quantitatively co‐ordinated to maximize C fixation.
Variation in pollination performance gradients in a Dudleya species complex: can generalization promote floral divergence?
Authors: AIGNER P. A.
Published: August 2005

Adaptive floral divergence may evolve in plants that are generalized for pollination when geographic variation in pollinator assemblages produces a mosaic of phenotypic optima. Within a Dudleya species complex, I estimated the relationship between pollination success and floral phenotype at four sites, and asked whether this relationship depended on the composition of the pollinator assemblage.

Flowers were visited by hummingbirds and insects (primarily bees), and the frequency of visitors varied among sites and between years. In 2000, pollination success did not depend on floral phenotype, but in 2001 visitation by hummingbirds increased, and flowers that were longer, produced more nectar, and had more inserted stigmas received more pollen.

An independent experiment with hummingbirds confirmed a positive relationship between pollination success and these floral traits, which was due in part to a hummingbird visitation preference for longer, more rewarding flowers.

The absence of a trade‐off in obtaining service from insects vs birds suggests that variation in pollination environment will not promote floral divergence in Dudleya. However, if longer, more rewarding flowers incur metabolic costs, then the difference between insects and birds as agents of selection on floral function may be sufficient to generate trade‐offs in total fitness.
Seed dispersal by small herbivores and tidal water: are they important filters in the assembly of salt‐marsh communities?
Authors: CHANG E. R. , ZOZAYA E. L. , KUIJPER D. P. J. , BAKKER J. P.
Published: August 2005

Characteristics of internal seed dispersal (endozoochory) by European Brown Hares were compared with similar dispersal by Brent Geese. Hares deposited more seeds of mid‐successional, perennial, high‐marsh species than did geese, which deposited more seeds of early successional, annual, low‐marsh species.

Seed survival and germination of salt‐marsh species were higher after ingestion and passage through the digestive system of hares compared with geese. Both hares and geese had a negative effect on the percentage of seeds that germinated in comparison with uningested seeds.

Small herbivores (hares and geese) dispersed two orders of magnitude fewer seeds than those dispersed by tidal water.

Thus these herbivores are not likely to be important filters (constraints) in community assembly at this salt‐marsh site on a coastal island in the Netherlands.
Sensitivity analysis of the tree distribution model Phenofitto climatic input characteristics: implications for climate impact assessment
Authors: Morin Xavier , Chuine Isabelle
Published: August 2005

Species distributions are already affected by climate change. Forecasting their long‐term evolution requires models with thoroughly assessed validation. Our aim here is to demonstrate that the sensitivity of such models to climate input characteristics may complicate their validation and introduce uncertainties in their predictions. In this study, we conducted a sensitivity analysis of a process‐based tree distribution model Phenofitto climate input characteristics. This analysis was conducted for two North American trees which differ greatly in their distribution and eight different types of climate input for the historic period which differ in their spatial (local or gridded data) and temporal (daily vs. monthly) resolution as well as their type (locally recorded, extrapolated or simulated by General Circulation Models). We show that the climate data resolution (spatial and temporal) and their type, highly affect the model predictions. The sensitivity analysis also revealed, the importance, for global climate change impact assessment, of (i) the daily variability of temperatures in modeling the biological processes shaping species distribution, (ii) climate data at high latitudes and elevations and (iii) climate data with high spatial resolution.