bluuebunny/crossref_metadata_2025 huggingface dataset:
Apoptotic Cytotoxic Effects of a Histone Deacetylase Inhibitor, FK228, on Malignant Lymphoid Cells
Authors: Murata Makoto , Towatari Masayuki , Kosugi Hiroshi , Tanimoto Mitsune , Ueda Ryuzo , Saito Hidehiko , Naoe Tomoki
Published: August 2005

Histone deacetylases are promising targets for cancer treatment. Here we studied the in vitro effects of a potent histone deacetylase inhibitor, FK228 (formerly FR901228), on human leukemia/lymphoma cells and cell lines compared with normal hematopoietic cells. In a lymphoma cell line, Raji, a nanomolar concentration of FK228 induced G1 arrest and/or apoptotic cell death, depending on the concentration and exposure time. Growth of lymphoid cell lines including Raji (N=13) was inhibited by 50% (IC50) after 2‐day treatment at concentrations of 0.83 to 1.87 ng/ml. Viability of clinical samples from patients with acute lymphoblastic leukemia was decreased by 50% at 0.78±0.46 ng/ml, whereas the IC50 values for normal mononuclear cells from peripheral blood and bone marrow were 2.3±0.96 and 7.8±1.0 ng/ml, respectively. The IC50 values for normal progenitor cells were 3.1, 4.4 and 7.8 ng/ml for BFU‐E, CFU‐GM and CFU‐Mix, respectively. Expression levels of HDAC‐1 and HDAC‐3 proteins, which varied among cell lines, but were stable during the treatment with FK228, did not correlate with the sensitivity to FK288. This novel agent might be useful in the treatment of lymphoid malignancies, because the above concentrations are clinically achievable in vivo according to a recent clinical study.
Retinoic Acid Receptor and Retinoid × Receptor in Ductal Carcinoma in situ and Intraductal Proliferative Lesions of the Human Breast
Authors: Ariga Naohiro , Moriya Takuya , Suzuki Takashi , Kimura Michio , Ohuchi Noriaki , Sasano Hironobu
Published: August 2005

Retinoic acid (RAR) and retinoid × receptors (RXR) are essential in the transcriptional actions of retinoids. To date, RAR and RXR have not been examined in precancerous lesions and/or ductal carcinoma in situ (DCIS) in human breast. Therefore, we examined RAR and RXR subtypes in DCIS (58 cases), atypical ductal hyperplasia (ADH) (32 cases), and proliferative disease without atypia (PDWA) (32 cases) to study the status of these RARs and RXRs. Immunoreactivities for RAR α, RXR α, RXR β, and RXR γ were all detected in the nuclei of normal ductal epithelia. Immunoreactivity for RAR β was detected exclusively in the nuclei of myoepithelial cells, but not in normal ductal epithelia. Immunoreactivity for RAR γ was not detected in any of the breast tissues examined except for a few cases of PDWA and ADH, and 11 cases of DCIS. The RXR α labeling index (LI) was significantly higher in both DCIS (mean 77.9) and ADH (mean 77.7) than in PDWA (mean 62.8) (P<0.001). RXR β LI was significantly lower in DCIS (mean 81.5) than in both ADH (mean 91.1) and PDWA (mean 91.9) (P=0.0001). Immunoreactivity for RAR α, RXR α, RXR β and RXR γ was widely distributed compared to that of RAR β and RAR γ in DCIS, ADH and PDWA. RAR α LI was significantly correlated with Ki67 LI in DCIS (P=0.0040), especially in estrogen receptor (ER)‐positive DCIS. Our results suggest that RXRs are much more widely distributed than RARs in intraductal proliferative lesions of the human breast, but ER‐positive DCIS cases with high cell proliferative activity are associated with RAR α, suggesting the possible involvement of retinoids through RAR α in tumor cell proliferation in DCIS.
Survivin as a Radioresistance Factor in Pancreatic Cancer
Authors: Asanuma Koichi , Moriai Ryosuke , Yajima Tomomi , Yagihashi Atsuhito , Yamada Mikako , Kobayashi Daisuke , Watanabe Naoki
Published: August 2005

We examined whether survivin acts as a constitutive and inducible radioresistance factor in pancreatic cancer cells. Using a quantitative TaqMan reverse transcription‐polymerase chain reaction for survivin mRNA in five pancreatic cancer cell lines, we found an inverse relationship between survivin mRNA expression and radiosensitivity. PANC‐1 cells, which had the highest survivin mRNA levels, were most resistant to X‐irradiation; MIAPaCa‐2 cells, which showed the least survivin mRNA expression, were the most sensitive to X‐irradiation. Our results suggested that survivin could act as a constitutive radioresistance factor in pancreatic cancer cells. To determine whether radioresistance is enhanced by induction of survivin expression by irradiation, PANC‐1 and MIAPaCa‐2 cells were subjected to sublethal doses of X‐irradiation followed by a lethal dose. Survivin mRNA expression was increased significantly in both PANC‐1 and MIAPaCa‐2 cell lines by pretreatment with a sublethal dose of X‐irradiation, as was cell survival after exposure to the lethal dose. In this system, enzymatic caspase‐3 activity was significantly suppressed in cells with acquired resistance. These results suggest that survivin also acts as an inducible radioresistance factor in pancreatic cancer cells. Survivin, then, appears to enhance radioresistance in pancreatic cancer cells; inhibition of survivin mRNA expression may improve the effectiveness of radiotherapy.
Isolation of Two Novel Genes, Down‐regulated in Gastric Cancer
Authors: Yoshikawa Yoshie , Mukai Hiroyuki , Hino Fumitsugu , Asada Kiyozo , Kato Ikunoshin
Published: August 2005

Using a differential display technique, we identified two genes that are down‐regulated in human gastric cancer tissue as compared to normal gastric mucosa. The down‐regulated expression of these genes in gastric cancer tissue was confirmed by northern blotting analysis and RT‐PCR. One, CA11, was a novel gene expressed predominantly in the stomach and was depleted in all of the gastric cancer cell lines examined. The other gene, GC36, was homologous to the digestive tract‐specific calpain gene, nCL‐4. The expression of both GC36 and nCL‐4 was suppressed or depleted in gastric cancer cell lines of differentiated and poorly differentiated types. This is the first report of genes, the expression of which is down‐regulated with considerable frequency in gastric cancer.
Long‐term Effect of Helicobacter pylori Infection on Serum Pepsinogens
Authors: Kikuchi Shogo , Kurosawa Michiko , Sakiyama Tsuguo , Tenjin Hiroshi , Miki Kazumasa , Wada Osamu , Inaba Yutaka
Published: August 2005

Serum pepsinogen values are markers of gastric mucosal status and of gastric cancer risk. The effect of Helicobacter pylori infection and sibship size on change of serum pepsinogen values over a seven‐year span was investigated. Data from 2584 subjects with phlebotomy were analyzed both in 1989 and in 1996. The subjects were classified by H. pylori serology and sibship size (1–3 vs. 4 and more). Pepsinogen I (PG I) to II (PG II) ratio in‘96 minus that in‘89 was defined as ΔPG I/II and compared among the groups. ΔPG I/II was lower and decrease of PG I/II was more frequent among H. pylori‐positive subjects than among negative subjects. The difference was owing to a decrease of PG I in all subjects and owing to an increase of PG II in those not younger than 30 years in‘89. In H. pylori‐positive subjects, those with a larger sibship size showed lower ΔPG I/II and higher frequency of PG I/II decline. H. pylori infection exerts a reducing effect on PG I/II during the seven‐year span. The effect of H. pylori is stronger among those with a larger sibship size, who are expected to have been infected with H. pylori in childhood. Inducing atrophy of gastric mucosa, which is reflected by a decline of PG I/II, may be one of the mechanisms through which H. pylori elevates the risk of gastric cancer.
Allelic Imbalances on Chromosome 20 in Human Transitional Cell Carcinoma
Authors: Higashi Shin , Habuchi Tomonori , Takahashi Takeshi , Kamoto Toshiyuki , Kakehi Yoshiyuki , Ogawa Osamu , Hiai Hiroshi
Published: August 2005

One determinant of the survival time of cancer‐bearing patients may be genetic factors. In chemically induced bladder cancers of mice, differences in survival time have been observed among several inbred strains. Genetic analyses of such differences in crosses between C57BL/6 and NON mice revealed that the survival period is determined by two quantitative trait loci on mouse chromosomes 6 and 2, respectively. We explored the possibility that genetic alterations may be observed in the syntenic conserved chromosomal regions of human transitional cell carcinoma corresponding to mouse chromosomes 6 and 2. Human chromosome 7, containing a region syntenic to mouse chromosome 6, is reported to harbor frequent genetic alterations in bladder cancers. In this study, we investigated 70 human urothelial cancers for possible genetic alterations on human chromosome 20p and 20q containing regions syntenic to mouse chromosome 2. Allelic imbalances were observed in 22 cases (31.4%) on 20p and 18 cases (25.7%) on 20q. Those allelic imbalances, however, did not show a direct correlation with the prognosis of the patients. Higher grade tumors tended to show more frequent imbalances on chromosome 20; however, this tendency was not significant.
Infrequent Mutation of the hBUB1 and hBUBR1 Genes in Human Lung Cancer
Authors: Sato Mitsuo , Sekido Yoshitaka , Horio Yoshitsugu , Takahashi Masahide , Saito Hidehiko , Minna John D. , Shimokata Kaoru , Hasegawa Yoshinori
Published: August 2005

Mitotic checkpoint defects of the cell cycle have been implicated in the development of human cancers. Since hBUB1 and hBUBR1, whose products function in the spindle checkpoint pathway, have been shown to be mutated in a subset of colon cancers with chromosomal instability, we investigated the contribution of these genes to lung cancer development. One hundred and two lung cancer (50 small cell lung cancers and 52 non‐small cell lung cancers) and 4 mesothelioma cell line DNAs were analyzed by Southern blot analysis, but no rearrangements or deletions of hBUB1 and hBUBR1 were detected. Using single strand conformation polymorphism analysis, we studied all the 25 exons except exon 1 of the hBUB1 gene in 88 lung cancer DNAs. One lung cancer cell line, NCI‐H345, showed a single nucleotide substitution, which resulted in an Arg‐to‐Gln change at codon 209 (CGA to CAA). Eleven cell line DNAs exhibited a single nucleotide polymorphism in intron 9 of hBUB1, all of which were heterozygous. Similar mutation analysis of hBUBR1 in 47 lung cancer cell line cDNAs revealed a frequent polymorphism at codon 349 (CAA to CGA) leading to a substitution of Gln to Arg but no mutations. Northern blot analyses showed that both hBUB1 and hBUBR1 genes were expressed in all of 31 lung cancer cell lines tested with no significant difference in the expression level. Our results suggest that alterations in hBUB1 and hBUBR1 rarely contributed to the genetic change of lung cancers.
Ras and Signal Transducer and Activator of Transcription (STAT) Are Essential and Sufficient Downstream Components of Janus Kinases in Cell Proliferation
Authors: Mizuguchi Rumiko , Noto Satoshi , Yamada Masafumi , Ashizawa Satoshi , Higashi Hideaki , Hatakeyama Masanori
Published: August 2005

Cytokines exert their activities in cell growth and differentiation by binding specific cell membrane receptors. Janus kinases (JAKs) are cytoplasmic protein tyrosine kinases that physically interact with intracellular domains of the cytokine receptors and they play crucial roles in transducing signals triggered by the cytokine‐receptor interaction. We have previously shown that conditional activation of JAK through membrane‐proximal dimerization confers cytokine‐independence on interleukin‐3 (IL‐3)‐dependent Ba/F3 lymphoid cells and that the cytokine‐independent proliferation is completely inhibited by dominant negative Ras. In this work, we demonstrate that ectopic expression of a dominant negative form of Stat5, a major signal transducer and activator of transcription (STAT) expressed in Ba/F3 cells, also inhibits JAK‐triggered mitogenesis. In contrast, overexpression of constitutively active Ras or conditional activation of Stat5 by chemical dimerization fails to confer cytokine‐independence. However, concomitant activation of ectopic Ras and Stat5 molecules in Ba/F3 cells suffices for cell proliferation in the absence of IL‐3. Our results indicate that Ras and STAT are essential and sufficient components of JAK‐triggered mitogenesis. Our findings further indicate that the cytokine signal bifurcates into Ras and STAT pathways following JAK activation.
Effects of Photodynamic Therapy Using Mono‐l‐aspartyl Chlorin e6 on Vessels and Its Contribution to the Antitumor Effect
Authors: Saito Koichi , Mikuniya Naoko , Aizawa Katsuo
Published: August 2005

The effect of photodynamic therapy (PDT) on the vascular system has a significant role in tumor tissue destruction. We investigated the contribution of vascular damage to the antitumor effects of PDT and analyzed the quantitative vascular changes after PDT. Fibrosarcoma‐bearing BALB/c male mice were injected with mono‐L‐aspartyl chlorin e6 (NPe6) at a dose of 0.25, 5 or 15 mg/kg, and photoradiation was performed with a diode laser 10 min, 2 h or 24 h after injection, respectively. Ten minutes after injection of 0.25 mg/kg, NPe6 was found to be present only in plasma, while at 2 h after injection of 5 mg/kg it was present in both plasma and tumor, and 24 h after injection of 15 mg/kg it was present only in the tumor. The antitumor effects observed in the 5 mg/ kg‐2 h and 0.25 mg/kg‐10 min groups were virtually the same, whereas the effect in the 15 mg/kg‐ 24 h group was weaker. The damage to the tumor vasculature and tumor cells in the 15 mg/kg‐24 h group occurred later than under the other conditions, and vascular damage in the tumor‐surrounding tissue was also less marked even 24 h after PDT. These results suggested that the plasma NPe6 concentration during laser irradiation contributed more than the tumor NPe6 concentration to the antitumor effect, and that the minimal damage to blood vessels around the tumor at the low plasma NPe6 concentration may be one reason for the failure to obtain a marked antitumor effect.
Usefulness of Tirapazamine as a Combined Agent in Chemoradiation and Thermo‐chemoradiation Therapy at Mild Temperatures: Reference to the Effect on Intratumor Quiescent Cells
Authors: Masunaga Shin‐ichiro , Ono Koji , Suzuki Minoru , Kinashi Yuko , Takagaki Masao , Hori Hitoshi , Kasai Soko , Nagasawa Hideko , Uto Yoshihiro
Published: August 2005

C3H/He mice bearing SCC VII tumors received 5‐bromo‐2′‐deoxyuridine (BrdU) continuously for 5 days via implanted mini‐osmotic pumps to label all proliferating (P) cells. The mice then received one of six different DNA‐damaging agents with or without mild temperature hyperthermia (40°C, 30 min, MTH). These agents were adriamycin (ADM), mitomycin C (MMC), cyclophosphamide (CPA), bleomycin (BLM), cisplatin (CDDP), and tirapazamine (TPZ). After the drug treatment, the tumor‐bearing mice were irradiated with a series of doses of γ‐rays. Immediately after irradiation, the tumors were excised, minced and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin‐B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (=quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P+Q) tumor cells was determined from the tumors that had not been pretreated with BrdU. MTH significantly increased the MN frequency of total cells in tumors irradiated with γ‐rays combined with CPA, BLM, CDDP or TPZ, and that of Q cells in tumors irradiated with γ‐rays combined with BLM or TPZ. The sensitivity difference in the MN frequency between total and Q tumor cells was significantly decreased by the combination with TPZ. TPZ combined with radiotherapy and TPZ combined with thermo‐radiotherapy at mild temperatures appear to be promising modalities for sensitizing tumor cells in vivo, including Q tumor cells.
Isolation and Characterization of Human NBL4, a Gene Involved in the β‐Catenin/Tcf Signaling Pathway
Authors: Ishiguro Hideyuki , Furukawa Yoichi , Daigo Yataro , Miyoshi Yasuo , Nagasawa Yutaka , Nishiwaki Tadashi , Kawasoe Teru , Fujita Manabu , Satoh Seiji , Miwa Nobutomo , Fujii Yoshitaka , Nakamura Yusuke
Published: August 2005

β‐Catenin, a key regulator of cellular proliferation, is often mutated in various types of human cancer. To investigate cellular responses related to the β‐catenin signaling pathway, we applied a differential display method using mouse cells transfected with an activated form of mutant β‐catenin. This analysis and subsequent northern‐blot hybridization confirmed that expression of a murine gene encoding NBL4 (novel band 4.1‐like protein 4) was up‐regulated by activation of β‐catenin. To examine a possible role of NBL4 in cancer, we isolated the human homologue of the murine NBL4 gene by matching mNBL4 against the human EST (expressed sequence tag) database followed by 5’ rapid amplification of cDNA ends (5′RACE). The cDNA of hNBL4 encoded a protein of 598 amino acids that shared 87% identity in amino acid sequence with murine NBL4 and 71% with zebrafish NBL4. A 2.2‐kb hNBL4 transcript was expressed in all human tissues examined with high levels of expression in brain, liver, thymus and peripheral blood leukocytes and low levels of expression in heart, kidney, testis and colon. We determined its chromosomal localization at 5q22 by fluorescence in situ hybridization. Expression of hNBL4 was significantly reduced when β‐catenin was depleted in SW480 cells, a human cancer cell line that constitutionally accumulates β‐catenin. The results support the view that NBL4 is an important component of the β‐catenin/Tcf pathway and is probably related to determination of cell polarity or proliferation.
Multidrug Resistance Reversal Activity of Taxoids from Taxus cuspidate in KB‐C2 and 2780AD Cells
Authors: Kobayashi Jun'ichi , Shigemori Hideyuki , Hosoyama Hirokazu , Chen Zhe‐Sheng , Akiyama Shin‐ichi , Naito Mikihiko , Tsuruo Takashi
Published: August 2005

Some non‐taxol‐type taxoids having neither an oxetane ring at C‐4 and C‐5 nor an N‐acylphenylisoserine group at C‐13, such as taxuspine C, 2′‐desacetoxyaustrospicatine, and 2‐desacetoxytaxinine J, which were isolated from the Japanese yew Taxus cuspidata, increased cellular accumulation of vincristine (VCR) in multidrug‐resistant 2780AD cells as potently as verapamil, and efficiently inhibited [3H]azidopine photolabeling of P‐glycoprotein (P‐gp). Taxuspine C, 2′‐desacetoxyaustrospicatine, and 2‐desacetoxytaxinine J at 10μM completely reversed the resistance to colchicine, VCR, and taxol in KB‐C2 cells, which overexpress P‐gp, while taxinine and taxinine M showed no effect. Taxuspine C, 2′‐desacetoxyaustrospicatine, and 2‐desacetoxytaxinine J may be candidate pharmaceuticals for reversing multidrug resistance (MDR) and also may be good modifiers of MDR in cancer chemotherapy.
Chemopreventive Effects of Coumaperine from Pepper on the Initiation Stage of Chemical Hepatocarcinogenesis in the Rat
Authors: Kitano Mitsuaki , Wanibuchi Hideki , Kikuzaki Hiroe , Nakatani Nobuji , Imaoka Susumu , Funae Yoshihiko , Hayashi Shuji , Fukushima Shoji
Published: August 2005

This study was designed to investigate the chemopreventive action of three natural products, coumaperine, aurapten and an extract from rosemary, against the initiation stage of rat hepatocarcinogenesis. Coumaperine has been isolated from white pepper as a naturally occurring antioxidative agent, but its potential modifying effects on carcinogenesis remain unclear. In experiment 1, a modification of the model developed by Tsuda et al. was applied, with assessment of numbers and areas of induced glutathione S‐transferase placental form (GST‐P)‐positive hepatocellular foci in male F344 rats. Coumaperine, aurapten and the extract from rosemary were administered i.g. at 100 mg/kg/day once daily for 5 days with initiation by diethylnitrosamine (DEN) on day 4 (20 mg/kg, i.p.). Numbers and areas of GST‐P‐positive foci in each group given test chemicals tended to be decreased as compared to the vehicle control group values, significance being achieved for number with coumaperine. Experiment 2 was planned to investigate the mechanism of the inhibitory effects of coumaperine. Livers at 8 h after initiation by DEN were examined with coumaperine administered at 100 mg/kg/day once daily for 3 days. Proliferating cell nuclear antigen (PCNA)‐ positive cells tended to be decreased as compared to the vehicle control, but no effects on apoptosis or cytochrome P‐450 (CYP) 2E1 expression were apparent. Our results suggest that coumaperine provides protection against initiation of hepatocarcinogenesis, and that this is related to inhibition of cell proliferation.
Suppression by Flavonoids of Cyclooxygenase‐2 Promoter‐dependent Transcriptional Activity in Colon Cancer Cells: Structure‐Activity Relationship
Authors: Mutoh Michihiro , Takahashi Mami , Fukuda Kazunori , Komatsu Hajime , Enya Takeji , Matsushima‐Hibiya Yuko , Mutoh Hiroshi , Sugimura Takashi , Wakabayashi Keiji
Published: August 2005

Cyclooxygenase‐2 (COX‐2) plays an important role in carcinogenesis. Investigation of the suppressive action of twelve flavonoids of different chemical classes on the transcriptional activity of the COX‐2 gene in human colon cancer DLD‐1 cells using a reporter gene assay have revealed quercetin to be the most potent suppressor of COX‐2 transcription (IC50=10.5 μM), while catechin and epicatechin showed weak activity (IC50=415.3 μM). Flavonoids have three heterocyclic rings as a common structure. A structure‐activity study indicated that the number of hydroxyl groups on the B ring and an oxo group at the 4‐position of the C ring are important in the suppression of COX‐2 transcriptional activity. A low electron density of the oxygen atom in the hydroxyl group of the A ring was also important. Further examination of the role of the hydroxyl group in the A ring showed that bromination of resacetophenone to give 3,5‐dibromo‐2,4‐dihydroxyacetophenone resulted in a 6.8‐fold increase in potency for suppressing COX‐2 promoter activity. These results provide a basis for the design of improved suppressors of COX‐2 transcriptional activity.
Bcl‐2 Inhibits Calcineurin‐mediated Fas Ligand Expression in Antitumor Drug‐treated Baby Hamster Kidney Cells
Authors: Simizu Siro , Shibasaki Futoshi , Osada Hiroyuki
Published: August 2005

It is well known that human leukemia cells, such as HL‐60 and U937 are sensitive to antitumor drugs, but human normal lung fibroblasts, such as WI‐38 cells are resistant to the drugs. However, the mechanisms of the different responses to apoptosis in these cell lines remain unclear. We report here that an increase of Fas and Fas ligand (FasL) expression was required for antitumor druginduced apoptosis in WI‐38 and baby hamster kidney (BHK) cells, but not in HL‐60 cells. Then, we used BHK cells transfected with the bcl‐2 gene to investigate the involvement of complex formation of Bcl‐2 and calcineurin. Calcineurin was imported to the nucleus in response to the drug treatment. Overexpression of Bcl‐2 and cyclosporin A treatment inhibited the nuclear import and FasL expression, and as a result, both inhibited apoptosis. Although a caspase inhibitor, z‐Asp‐CH2‐DCB, suppressed the drug‐induced apoptosis, it failed to inhibit the drug‐induced expression of Fas and FasL. These findings suggest that initially the Fas/FasL system is activated by calcineurindependent transcription followed by activation of the downstream caspase cascade resulting in antitumor drug‐induced apoptosis in BHK cells, but not in HL‐60 cells. Furthermore, Bcl‐2 inhibits the nuclear import of calcineurin and suppresses calcineurin‐mediated FasL expression during antitumor drug‐induced apoptosis.
A Novel Experimental Mouse Model of Peritoneal Dissemination of Human Gastric Cancer Cells: Different Mechanisms in Peritoneal Dissemination and Hematogenous Metastasis
Authors: Nishimori Hidefumi , Yasoshima Takahiro , Denno Ryuichi , Shishido Takayuki , Hata Fumitake , Okada Yohjiro , Ura Hideki , Yamaguchi Koji , Isomura Hiroshi , Sato Noriyuki , Hirata Koichi
Published: August 2005

We established a new cell line, AZ‐P7a, with high peritoneal‐metastatic potential in nude mice. AZ‐P7a cells were derived from the human gastric carcinoma line AZ‐521, which has low capacity for peritoneal dissemination. AZ‐P7a cells developed peritoneal metastasis in 11/14 (78.6%) mice, whereas the parental AZ‐521 cells developed metastasis in 2/6 (33.3%) mice. The metastatic foci in the peritoneum showed essentially the same histological appearance as those induced by parental cells. The tumorigenicity and the motile activity of AZ‐P7a cells were stronger than those of the parental AZ‐521 cells; in contrast, adhesion to the extracellular matrix and the production of vascular endothelial growth factor by AZ‐P7a cells were decreased. In fluorescence‐activated cell sorter (FACS) analysis, AZ‐P7a cells expressed significantly greater levels of integrins α2, α3, α5, α6 and αvβ5, as compared with AZ‐521 cells. However, α1, α4, αvβ3, hCD44H, hCD44v3, hCD44v6 and hCD44v10 were not expressed in either cell line. AZ‐P7a cells developed no liver metastasis when administered by the intrasplenic injection method, though the highly liver metastatic cell line AZ‐H5c showed the same rate of peritoneal dissemination as that exhibited by AZ‐P7a cells after intraabdominal injection. These findings suggested that the mechanism of peritoneal dissemination differed from that of hematogenous metastasis. Moreover, the latter appears to be controlled by more complex mechanisms than the former. Thus, this cell line might be useful for investigating the mechanism of peritoneal dissemination of human gastric cancer.
Photodynamic Therapy for Experimental Tumors Using ATX‐S10(Na), a Hydrophilic Chlorin Photosensitizer, and Diode Laser
Authors: Mori Masahiko , Sakata Isao , Hirano Toru , Obana Akira , Nakajima Susumu , Hikida Muneo , Kumagai Toshio
Published: August 2005

ATX‐S10(Na), a hydrophilic chlorin photosensitizer having an absorption maximum at 670 nm, is a candidate second‐generation photosensitizer for use in photodynamic therapy (PDT) for cancer treatment. The effectiveness of PDT using ATX‐S10(Na) and a diode laser for experimental tumors was evaluated in vitro and in vivo. In‐vitro PDT using ATX‐S10(Na) and the diode laser showed drug concentration‐, laser dose‐ and drug exposure time‐dependent cytotoxicity to various human and mouse tumor cell lines. In Meth‐A sarcoma‐implanted mice, optimal PDT conditions were found where tumors were completely eliminated without any toxicity. Against human tumor xenografts in nude mice, the combined use of 5 mg/kg ATX‐S10(Na) and 200 J/cm2 laser irradiation 3 h after ATX‐S10(Na) administration showed excellent anti‐tumor activity, and its efficacy was almost the same as that of PDT using 20 mg/kg porfimer sodium and a 100 J/cm2 excimer dye laser 48 h after porfimer sodium injection. Microscopic observation of tumor tissues revealed that PDT using ATX‐S10(Na) and the diode laser induced congestion, thrombus and degeneration of endothelial cells in tumor vessels, indicating that a vascular shutdown effect plays an important role in the anti‐tumor activity of PDT using ATX‐S10(Na) and the diode laser.
Suppressive Effects of Dietary Genistin and Daidzin on Rat Prostate Carcinogenesis
Authors: Kato Koji , Takahashi Satoru , Cui Lin , Toda Toshiya , Suzuki Shugo , Futakuchi Mitsuru , Sugiura Satoshi , Shirai Tomoyuki
Published: August 2005

High intake of phytoestrogens through soybeans and their products is thought to be associated with low incidences of prostate and/or breast cancer in Asian countries. Possible chemopreventive effects of genistin or daidzin on rat prostate carcinogenesis were therefore investigated. Male F344 rats were given 10 biweekly subcutaneous injections of 3,2′‐dimethyl‐4‐aminobiphenyl (DMAB) and then either genistin or daidzin in the diet at a concentration of 0.1% for 40 weeks. Other groups of rats given DMAB were treated with genistin or daidzin together with a high dose of testosterone propionate (TP). Both genistin and daidzin reduced the numbers of ventral prostate carcinomas (P<0.05), with a tendency for decrease in incidence. Invasive carcinomas which developed in the anterior prostate and seminal vesicles with TP were, however, not influenced by the two isoflavones. Thus, the present data suggest that genistin and daidzin possess anti‐cancer effects at relatively early stages of prostate cancer development, providing experimental support for epide‐miological findings.
Inhibitory Effect of ATF3 Antisense Oligonucleotide on Ectopic Growth of HT29 Human Colon Cancer Cells
Authors: Ishiguro Tatsuaki , Nagawa Hirokazu , Naito Mikihiko , Tsuruo Takashi
Published: August 2005

ATF3 is a transcription factor belonging to the Jun/Fos family whose mouse homologue (TI‐241) was isolated, using the differential screening method, from B16 mouse melanoma cells as a bloodborne metastasis‐associated gene. Here we show the tumorigenicity‐inhibiting effect of an antisense oligonucleotide designed to reduce the expression of ATF3 in HT29 colon cancer cells. HT29 cells were reported to metastasize to the skin after intravenous inoculation. The antisense oligonucleotide inhibited cell attachment to the collagen‐coated floor of the plates and invasion of HT29 cells in vitro, which are thought to be two important factors in the process of cancer metastasis and ectopic tumor growth. While the antisense oligonucleotide had no effect on cell growth of HT29 cells in vitro, mice that were inoculated subcutaneously with HT29 cells and treated with the antisense oligonucleotide survived longer than the control mice due to the inhibition of tumor growth in vivo.. These show that ATF3 plays an important role in the ectopic growth/metastasis of HT29 colon cancer cells.
The Combined Effect of Electroporation and Borocaptate in Boron Neutron Capture Therapy for Murine Solid Tumors
Authors: Ono Koji , Kinashi Yuko , Suzuki Minoru , Takagaki Masao , Masunaga Shin‐ichiro
Published: August 2005

10B‐Enriched borocaptate (BSH) was administered intraperitoneally to SCCVII tumor‐bearing C3H/He mice. Electroporation (EP) was conducted by using a tweezers‐type electrode. The 10B contents in tumors were measured by prompt γ‐ray spectrometry. The colony formation assay was applied to investigate the antitumor effects of boron neutron capture therapy (BNCT) and thereby to estimate the intratumor localization of BSH. The 10B concentrations in tumors decreased with time following BSH administration, falling to 5.4(±0.1) ppm at 3 h, whereas EP treatment (3 repetitions) 15 min after BSH injection delayed the clearance of BSH from tumors, and the 10B level remained at 19.4(±0.9) ppm at 3 h. The effect of BNCT increased with the 10B concentration in tumors, and the combination with EP showed a remarkably large cell killing effect even at 3 h after BSH injection. The effect of BNCT, i.e., slope coefficient of the cell survival curve of tumors, without EP was proportional to tumor 10B level (r=0.982), and that of BSH‐BNCT combined with EP lay close to the same correlation line. However, tumors subjected to EP after BSH injection did not show high radiosensitivity when irradiated after conversion to a single cell suspension by enzymatic digestion. This indicates that the increase of the BNCT effect by EP was a consequence of enclosure of BSH in the interstitial space of tumor tissue and not within tumor cells. This is different from a previous in vitro study. The combination of EP and BNCT may be clinically useful, if a procedure to limit EP to the tumor region becomes available or if an alternative similar method is employed.
Computed Tomography during Arteriography and Arterial Portography in Small Hepatocellular Carcinoma and Dysplastic Nodule: A Prospective Study
Authors: Mikami Shinichi , Kubo Shoji , Hirohashi Kazuhiro , Shuto Taichi , Kinoshita Hiroaki , Nakamura Kenji , Yamada Ryusaku
Published: August 2005

We studied the relationship between the findings of computed tomography during arteriography (CTA) and computed tomography during arterial portography (CTAP), and pathologic findings of 81 small nodular lesions (3 cm or less in diameter) in resected liver specimens. The 81 lesions consisted of 8 dysplastic nodule (DN) lesions, 23 well‐differentiated hepatocellular carcinomas (early HCCs) and 50 moderately or poorly differentiated HCCs (advanced HCCs). We also performed standard computed tomography (CT), digital subtraction angiography (DSA), magnetic resonance imaging (MRI), and ultrasonography, and compared sensitivities with CTA, CTAP, or combination of CTA and CTAP with other imaging methods. Forty‐four of the 50 advanced HCCs, 12 of the 23 early HCCs, and none of 8 DNs hyperattenuated with CTA and hypoattenuated with CTAP. The sensitivity for the early HCCs was significantly higher for CTA and CTAP in combination as compared with DSA or standard CT. The sensitivity for the advanced HCCs was significantly higher for CTA and CTAP in combination than with DSA. The sequential changes of the blood supply from the portal vein to the hepatic artery during the development of the HCCs were observed. Although CTA and CTAP in combination were useful for the distinction of advanced HCC from early HCC or DN, CTA and CTAP used in combination were not superior to CTA alone in the detection of such lesions.
Inhibition of DNA Adduct Formation and Mutagenic Action of 3‐Amino‐l‐methyl‐5H‐pyrido[4,3‐b]indole by Chlorophyllin‐chitosan in rpsL Transgenic Mice
Authors: Anzai Nobuhiro , Taniyama Takehiro , Nakandakari Namiko , Sugiyama Chitose , Negishi Tomoe , Hayatsu Hikoya , Negishi Kazuo
Published: August 2005

We have studied the inhibitory effect of chlorophyllin‐chitosan (Chl‐Chi) complex, an insoluble form of chlorophyllin, on the DNA adduct formation and mutagenesis by a heterocyclic food mutagen‐carcinogen, 3‐amino‐l‐methyl‐5H‐pyrido[4,3‐b]indole (Trp‐P‐2), in mice carrying the E. coli rpsL gene as a mutagenesis reporter. Upon administration of a diet containing 0.002% or 0.01% Trp‐P‐2, DNA adducts were formed in various tissues in a dose‐dependent manner, with the maximum level observed in the liver. Addition of 3% Chl‐Chi to the diet reduced the Trp‐P‐2 adduct by up to 90%. The rpsL mutant frequencies increased significantly in both the liver and spleen upon administration of a 0.01% Trp‐P‐2 diet. Addition of Chl‐Chi to the diet decreased these induced mutant frequencies to the background level. No harmful effect of Chl‐Chi was detected during these experiments. The results show that Chl‐Chi may be a candidate chemopreventive agent against the genotoxic action of Trp‐P‐2, and possibly also other aromatic carcinogens in the diet.
Expression of Periostin, Homologous with an Insect Cell Adhesion Molecule, as a Prognostic Marker in Non‐small Cell Lung Cancers
Authors: Sasaki Hidefumi , Lo Kin‐Ming , Chen Lan Bo , Auclair Daniel , Nakashima Yoshiaki , Moriyama Satoru , Fukai Ichiro , Tarn Carmen , Loda Massimo , Fujii Yoshitaka
Published: August 2005

We used our palindromic polymerase chain reaction (PCR)‐driven cDNA differential display technique to identify and isolate a gene, designated periostin, from cancer tissues and found it to be overexpressed in several human tumors. We attempted to determine the influence of periostin expression on clinical outcome in patients with non‐small cell lung cancer (NSCLC) by reverse transcriptase (RT)‐PCR analysis. Periostin gene was highly expressed at the tumor periphery of lung cancer tissue but not within the tumor by in situ RNA hybridization, suggesting that expression of periostin may be involved in the process of tumor invasion. Periostin transcripts were detected in 50 (49.0%) of the tumor samples, although some paired normal lung samples showed weak expression. There was no relationship between periostin gene expression and gender, N‐ or T‐status. The NSCLC patients with periostin expression had significantly poorer survival than the patients without periostin expression (P=0.0338).
Radiation hybrid mapping of all 10 characterized bovine Toll‐like receptors
Authors: McGuire K. , Jones M. , Werling D. , Williams J. L. , Glass E. J. , Jann O.
Published: August 2005

Toll‐like receptors (TLRs) are cell‐surface signalling molecules that recognize a range of highly conserved pathogen molecules and instigate the appropriate immune response. Here, we report the mapping of all 10 characterized bovine TLR genes using a radiation hybrid panel. The genomic organization of the bovine TLRs is similar to that of humans and mice. TLR1, TLR6 and TLR10 map closely together on Bos taurus chromosome 6 (BTA6), while TLR7 and TLR8 map to the X chromosome. TLR2, TLR3, TLR4, TLR5 and TLR9 map to BTA17, BTA27, BTA8, BTA16 and BTA22 respectively. Our increased knowledge of the genomic organization of the bovine TLR genes may promote our understanding of their evolution and help in the identification of bovine genes underlying disease‐resistance traits.
Membrane‐penetrating trehalase from silkworm Bombyx mori. Molecular cloning and localization in larval midgut
Authors: Mitsumasu K. , Azuma M. , Niimi T. , Yamashita O. , Yaginuma T.
Published: August 2005

The main blood sugar in insects, trehalose, differs from glucose in mammals. To incorporate trehalose into cells and utilize it, tissue cells possess the enzyme trehalase (EC3.2.1.28), which catalyses trehalose into glucose, in the organellar membrane or in the cytoplasm. Soluble and membrane‐bound trehalase proteins have been isolated from insects. To date, however, only genes encoding the soluble trehalase have been reported in insects. Soluble trehalase is therefore believed to become localized on the cell surface via modification. In contrast, cDNAs encoding trehalase localized on the apical cell surface via the glycosylphosphatidylinositol‐anchor have been isolated from mammalian small intestines. The amino acid sequence contains a specific hydrophobic region and an upstream omega site, which is cleaved for glycosylphosphatidylinositol‐attachment, at the C‐terminus. Here, we describe a cDNA from the silkworm Bombyx mori that encodes a novel trehalase (type‐2) with one transmembrane domain and lacking the omega site. Immunoblotting and immunohistochemical analyses demonstrated that in the midgut tissue of Bombyx larvae, soluble trehalase‐1 is present mainly in goblet cell cavities, but membrane‐bound trehalase‐2 is predominantly seen on the visceral muscle surrounding the midgut. To our knowledge, this is the first report of a cDNA encoding trehalase that penetrates the cell membrane in insects and its cellular localization.
The annexin gene family in the malaria mosquito Anopheles gambiae
Authors: Kotsyfakis M. , Vontas J. , Siden‐Kiamos I. , Louis C.
Published: August 2005

Annexins belong to a class of proteins that are known to bind to, and hold together structures such as membranes. Interestingly, Anopheles gambiae (and Drosophila melanogaster) annexins bind Plasmodium ookinetes in vitro. In the malaria mosquito three genes in two cytogenetic loci on chromosome arm 2R encode annexin homologues; their expression, monitored by quantitative real‐time PCR during mosquito development, as well as in various tissues, revealed little fluctuation in patterns of expression during all life stages. A different mode of transcription was observed for the three genes in the midgut in relation to the uptake of a blood meal. Immunohistochemical staining of midguts and ovaries with polyclonal anti‐annexin sera reveals that the Anopheles polypeptides are present in the epithelial cells of both tissues and associated with the plasma membrane.
Prediction of general mental ability based on neural oscillation measures of sleep
Authors: BÓDIZS RÓBERT , KIS TAMÁS , LÁZÁR ALPÁR SÁNDOR , HAVRÁN LINDA , RIGÓ PÉTER , CLEMENS ZSÓFIA , HALÁSZ PÉTER
Published: August 2005

The usual assessment of general mental ability (or intelligence) is based on performance attained in reasoning and problem‐solving tasks. Differences in general mental ability have been associated with event‐related neural activity patterns of the wakeful working brain or physical, chemical and electrical brain features measured during wakeful resting conditions. Recent evidences suggest that specific sleep electroencephalogram oscillations are related to wakeful cognitive performances. Our aim is to reveal the relationship between non‐rapid eye movement sleep‐specific oscillations (the slow oscillation, delta activity, slow and fast sleep spindle density, the grouping of slow and fast sleep spindles) and general mental ability assessed by the Raven Progressive Matrices Test (RPMT). The grouping of fast sleep spindles by the cortical slow oscillation in the left frontopolar derivation (Fp1) as well as the density of fast sleep spindles over the right frontal area (Fp2, F4), correlated positively with general mental ability. Data from those selected electrodes that showed the high correlations with general mental ability explained almost 70% of interindividual variance in RPMT scores. Results suggest that individual differences in general mental ability are reflected in fast sleep spindle‐related oscillatory activity measured over the frontal cortex.
Trypanosoma cruzi proline racemases are involved in parasite differentiation and infectivity
Authors: Chamond Nathalie , Goytia Maira , Coatnoan Nicolas , Barale Jean‐Christophe , Cosson Alain , Degrave Wim M. , Minoprio Paola
Published: August 2005

Polyclonal lymphocyte activation is one of the major immunological disturbances observed after microbial infections and among the primary strategies used by the parasite Trypanosoma cruzi to avoid specific immune responses and ensure survival. T. cruzi is the insect‐transmitted protozoan responsible for Chagas’ disease, the third public health problem in Latin America. During infection of its mammalian host, the parasite secretes a proline racemase that contributes to parasite immune evasion by acting as a B‐cell mitogen. This enzyme is the first described eukaryotic amino acid racemase and is encoded by two paralogous genes per parasite haploid genome, TcPRACA and TcPRACB that give rise, respectively, to secreted and intracellular protein isoforms. While TcPRACB encodes an intracellular enzyme, analysis of TcPRACA paralogue revealed putative signals allowing the generation of an additional, non‐secreted isoform of proline racemase by an alternative trans‐splicing mechanism. Here, we demonstrate that overexpression of TcPRAC leads to an increase in parasite differentiation into infective forms and in its subsequent penetration into host cells. Furthermore, a critical impairment of parasite viability was observed in functional knock‐down parasites. These results strongly emphasize that TcPRAC is a potential target for drug design as well as for immunomodulation of parasite‐induced B‐cell polyclonal activation.
It works: combinatorial biosynthesis for generating novel glycosylated compounds
Authors: Luzhetskyy Andriy , Bechthold Andreas
Published: August 2005

Combinatorial biosynthesis is a valuable method to generate novel glycosylated natural products. By coexpression of deoxysugar gene cassettes and genes from the staurosporine biosynthetic gene cluster it has now been applied to the generation of novel staurosporine derivatives. The work of Salas and co‐workers is highlighted in this article.
Cold‐ and salinity stress‐induced bipolar pea DNA helicase 47 is involved in protein synthesis and stimulated by phosphorylation with protein kinase C
Authors: Vashisht Ajay Amar , Pradhan Arun , Tuteja Renu , Tuteja Narendra
Published: August 2005

Helicases are involved in the metabolism of nucleic acid; this is very sensitive to the abiotic stresses that reduce plant growth and productivity. However, the molecular targets responsible for this sensitivity have not been well studied. Here we report on the isolation and characterization of cold‐ and salinity stress‐induced pea DNA helicase 47 (PDH47). The transcript of PDH47 was induced in both shoots and roots under cold (4°C) and salinity (300 mm NaCl) stress, but there was no change in response to drought stress. Tissue‐specific differential regulation was observed under heat (37°C) stress. ABA treatment did not alter expression of PDH47 in shoots but induced its mRNA in roots, indicating a role for PDH47 in both the ABA‐independent and ABA‐dependent pathways in abiotic stress. The purified recombinant protein (47 kDa) contains ATP‐dependent DNA and RNA helicase and DNA‐dependent ATPase activities. With the help of photoaffinity labeling, PDH47 was labeled by [α‐32P]‐ATP. PDH47 is a unique bipolar helicase that contains both 3′ to 5′ and 5′ to 3′ directional helicase activities. Anti‐PDH47 antibodies immunodeplete the activities of PDH47 and inhibit in vitro translation of protein. Furthermore, the PDH47 protein showed upregulation of protein synthesis. The activities of PDH47 are stimulated after phosphorylation by protein kinase C at Ser and Thr residues. Western blot analysis and in vivo immunostaining, followed by confocal microscopy, showed PDH47 to be localized in both the nucleus and cytosol. The discovery of cold‐ and salinity stress‐induced DNA helicase should make an important contribution to a better understanding of DNA metabolism and stress signaling in plants. Its bipolar helicase activities may also be involved in distinct cellular processes in stressed conditions.
Combining probability from independent tests: the weighted Z‐method is superior to Fisher's approach
Authors: WHITLOCK M. C.
Published: August 2005

The most commonly used method in evolutionary biology for combining information across multiple tests of the same null hypothesis is Fisher's combined probability test. This note shows that an alternative method called the weighted Z‐test has more power and more precision than does Fisher's test. Furthermore, in contrast to some statements in the literature, the weighted Z‐method is superior to the unweighted Z‐transform approach. The results in this note show that, when combining P‐values from multiple tests of the same hypothesis, the weighted Z‐method should be preferred.
Paternal inheritance of the primary sex ratio in a copepod
Authors: VOORDOUW M. J. , ROBINSON H. E. , ANHOLT B. R.
Published: August 2005

Uniparentally inherited genetic elements are under strong selection to manipulate sex determination in their host and shift the host sex ratio towards the transmitting sex. For any sex‐ratio trait, lineage analysis and quantitative genetics are important tools for characterizing the mode of inheritance (biparental vs. maternal vs. paternal) thereby narrowing the field of possible sex‐determining mechanisms (e.g. polygenic, sex chromosomes with meiotic drive, cytoplasmic microorganisms). The primary sex ratio of the harpacticoid copepod,Tigriopus californicusis often male‐biased and is highly variable among full sib families. We found that this extra‐binomial variation for the primary sex ratio is paternally but not maternally transmitted inT. californicus. Paternal transmission of the primary sex ratio has been well documented in the haplo–diploid hymenoptera but is relatively rare in diplo–diploid organisms. If the sex‐ratio trait is paternally transmitted in other closely related harpacticoid copepods it would explain why male biased primary sex ratios are so common in this group.