Hibernation-associated gene regulation of plasma proteins with a collagen-like domain in mammalian hibernators.

In mammals, hibernation is expressed by only a limited number of species, and the molecular mechanisms underlying hibernation are not well understood. Recently, we have found plasma proteins which disappear from blood specifically during hibernation in a mammalian hibernator, the chipmunk. Here, we report the cDNA cloning of these chipmunk hibernation-related proteins, HP-20, -25, and -27, and analyses of their expression. All three proteins contain a collagen-like domain near the N terminus and are highly homologous to each other. Their mRNAs were detected only in liver in nonhibernating chipmunks, and in hibernating chipmunks, the amounts were reduced to less than 1/10 of those in nonhibernating chipmunks, indicating that HP-20, -25, and -27 mRNA expression is regulated similarly in association with hibernation. Southern blot analyses of the squirrel family with each of chipmunk HP-20, -25, and -27 cDNA revealed that a nonhibernating species (tree squirrel) as well as another hibernating species (ground squirrel) retained the corresponding genes. However, their transcripts were detected only with the hibernating species, and in hibernating ground squirrels, their levels were greatly reduced compared with those in nonhibernating animals, as were the cases with the chipmunk. These observations are the first line of evidence for occurrence of hibernation-associated gene regulation. The results would indicate the commitment of HP-20, -25, and -27 to hibernation and support the idea that genetic controls are involved in mammalian hibernation.

Stromal cell-derived factor-1 and CXCR4 receptor interaction in tumor growth and metastasis of breast cancer.

Stromal cell-derived factor-1 (SDF-1)/CXCR4 interaction is critical for the trafficking of lymphocytes, homing and retention of hematopoietic stem cells within the bone marrow and is essential in fetal hematopoiesis. Binding of SDF-1 to CXCR4 activates a variety of intracellular signal transduction pathways and effector molecules that regulate cell survival, proliferation, chemotaxis, migration and adhesion. Recently, intensive research has demonstrated that SDF-1/CXCR4 interaction also regulates several key events in wide variety of cancers. Serum-depleted media in the presence of SDF-1 protected the breast cancer cells from apoptosis. CXCR4-low-expressing MCF-7 formed small tumor at inoculated site in SCID mice 8-9 weeks after inoculation while completely failed to metastasis into various organs. In contrast, CXCR4-high-expressing MDA-231 cells were most efficient in the formation of a large tumor and organ-metastasis within 3 weeks in SCID mice. This review briefly focuses on the role of SDF-1/CXCR4 interaction in tumor growth and metastasis of breast cancer cell both in vitro and in vivo.

Purification and molecular properties of two cadmium-binding glycoproteins from the hepatopancreas of a whelk, Buccinum tenuissimum.

Two cytoplasmic cadmium-binding glycoproteins from the hepatopancreas of a whelk, Buccinum tenuissimum, were purified to homogeneity by Sephadex G-75 gel filtration and two DEAE-Sephadex A-25 chromatographies in the presence of 2-mercaptoethanol. These two cadmium-binding glycoproteins, termed FIIA and FIIB, each showed a single band after electrophoresis on 10% polyacrylamide gel at pH 8.9. The molecular weight of FIIA was estimated as 8000 and that of FIIB as 13000 by SDS-polyacrylamide gel electrophoresis. Based on molecular weights of 6500 and 11900 for the protein moiety of FIIA and FIIB, respectively, the total number of amino acid residues was 52 in the former and 94 in the latter. Three and two cysteine residues in FIIA and FIIB, respectively, were titratable with p-chloromercuribenzoate. FIIB also contained two more half-cystine residues. The sugar contents of FIIA and FIIB were about 20.5% and 8.7% by weight, respectively, consisting of galactose, mannose, fucose and amino sugar. The purified glycoproteins FIIA and FIIB contained about 0.6% and 1.0% cadmium by weight, respectively, and both showed strong metal-binding capacity, especially for cadmium, copper and mercury. The apparent cadmium dissociation constants for FIIA and FIIB after treatment with 2-mercaptoethanol were 7.3 X 10(-6) and 9.1 X 10(-7) M, respectively. Cadmium contents at saturation were nearly 6 and 8 gatom per mole for FIIA and FIIB, respectively.

Analysis of inhibition by H89 of UCP1 gene expression and thermogenesis indicates protein kinase A mediation of beta(3)-adrenergic signalling rather than beta(3)-adrenoceptor antagonism by H89.

Although it has generally been assumed that protein kinase A (PKA) is essential for brown adipose tissue function, this has not as yet been clearly demonstrated. H89, an inhibitor of PKA, was used here to inhibit PKA activity. In cell extracts, it was confirmed that norepinephrine stimulated PKA activity, which was abolished by H89 treatment. In isolated brown adipocytes, H89 inhibited adrenergically induced thermogenesis (with an IC(50) of approx. 40 microM), and in cultured cells, adrenergically stimulated expression of the uncoupling protein-1 (UCP1) gene was abolished by H89 (full inhibition with 50 microM). However, H89 has been reported to be an adrenergic antagonist on beta(1)/beta(2)-adrenoceptors (AR). Although adrenergic stimulation of thermogenesis and UCP1 gene expression are mediated via beta(3)-ARs, it was deemed necessary to investigate whether H89 also had antagonistic potency on beta(3)-ARs. It was found that EC(50) values for beta(3)-AR-selective stimulation of cAMP production (with BRL-37344) in brown adipose tissue membrane fractions and in intact cells were not affected by H89. Similarly, the EC(50) of adrenergically stimulated oxygen consumption was not affected by H89. As H89 also abolished forskolin-induced UCP1 gene expression, and potentiated selective beta(3)-AR-induced cAMP production, H89 must be active downstream of cAMP. Thus, no antagonism of H89 on beta(3)-ARs could be detected. We conclude that H89 can be used as a pharmacological tool for elucidation of the involvement of PKA in cellular signalling processes regulated via beta(3)-ARs, and that the results are concordant with adrenergic stimulation of thermogenesis and UCP1 gene expression in brown adipocytes being mediated via a PKA-dependent pathway.

Natural killer cells in breast cancer cell growth and metastasis in SCID mice.

Natural killer (NK) cell is an important component of the innate immune system and plays a central role in host defense against tumor and virus-infected cells. This review briefly summarizes the role of murine NK cells in tumor growth and metastasis of breast cancer cells in severe combined immunodeficiency (SCID) mice. Conventional SCID and NOD-SCID strains have been used to study for xenotransplantion of human tumors. SCID mice models of cancer mimic human diseases and have provided valuable information. However, these mice strains have some residual immunity such as NK cells that somewhat limit post-transplantation growth and metastasis of human xenografts. In contrast, NOD/SCID/gammac(null) (NOG) mice without common gamma-chain inoculated with breast cancer cells were most efficient in the formation of a large tumor and metastasis. NOG mouse strain without NK activity appears to be more promising as tool for xenotransplantion of human cancer. This new xenotransplant model is relevant and can be recommended for use in clarifying the mechanism of growth of cancer cells as well as for developing new therapeutic strategies against cancer.

Efficacy and safety of systemic chemotherapy and intra-arterial chemotherapy with/without radiotherapy for bladder preservation or as neo-adjuvant therapy in patients with muscle-invasive bladder cancer: a single-centre study of 163 patients.

INTRODUCTION: Patients with muscle-invasive bladder cancer (MIBC) often undergo various preoperative treatments to improve survival; however, their efficacy and safety remain unclear. MATERIALS AND METHODS: The anti-tumour effects and adverse events were evaluated in 163 MIBC patients who received systemic chemotherapy (SC, n = 34), intra-arterial chemotherapy (IAC, n = 50), or combined IAC and radiotherapy (IAC + R, n = 79). RESULTS: Pathological complete responses were observed in 17.6%, 22.0%, and 43.0% of patients in the SC, IAC, and IAC + R groups, respectively, with respective 5-year overall survival rates of 42.0%, 46.7%, and 50.3%. Multivariate analysis showed that successful IAC + R protocol administration was a significant predictor for survival (hazard ratio = 0.16, p = 0.028). The incidence of severe adverse events was higher in the IAC + R group (36.7%) than in the SC (9.8%) and IAC groups (16.0%). CONCLUSIONS: IAC + R was useful for patients with MIBC. Successful completion and optimal patient selection were important for this treatment strategy.

Application of the RLGS method to large-size genomes using a restriction trapper.

We developed a method for producing restriction landmark genomic scanning (RLGS) profiles of large-size genomes, such as those of higher plants or amphibians using a restriction trapper. Use of the conventional RLGS method is limited to genomes smaller than 3 x 10(9) bp, because the larger genomic DNAs, especially those of more than 1 x 10(10) bp, produce high background due to incorporation of radioactivity at non-specifically damaged sites. Our new method reduces the background levels by reducing genome complexity to 1/200-1/300 using a purification step to enrich DNA fragments carrying specific restriction landmarks at their ends using a restriction trapper. This step makes it possible to obtain RLGS patterns of larger genomes. Our paper describes the practical application for the RLGS method using a restriction trapper with the pine tree genome (3 x 10(10) bp/haploid genome; Pinus koraiensis Sieb. et Zucc.) as an example.

Expression of multiple alpha1-antitrypsin-like genes in hibernating species of the squirrel family.

In the chipmunk, a mammalian hibernator, a 140 kDa protein complex found in the blood, drastically decreases in concentration during hibernation. This complex contains four species of proteins, HP-20, -25, -27 and -55. In the present study, cDNA clones coding for the chipmunk HP-55 were isolated from a liver cDNA library. Sequence analysis revealed that HP-55 is produced as a precursor protein of 413 amino acids (aa), that it has a signal peptide of 24 aa, and that it contains four potential N-glycosylation sites. The deduced aa sequence shows 63% identity with that of rat alpha1-antitrypsin (alpha1-AT); however, the sequence corresponding to the reactive center P1-P1' residues was found to be Met-Leu, whereas it is Met-Ser in the rat alpha1-AT. During screening of the chipmunk liver cDNA library, four other related classes of cDNA clones were obtained, each also coding for an alpha1-AT-like protein. In spite of more than 86% overall aa sequence identity among the five chipmunk alpha1-AT-like proteins, they are highly divergent in the putative reactive center region; the putative P1-P1' sequences are Met-Leu (HP-55 or CM55-ML), Met-Met (CM55-MM), Met-Ser (CM55-MS), Ser-Ile (CM55-SI) and Ser-Thr (CM55-ST). Each of the alpha1-AT-like protein mRNAs was expressed in chipmunk liver, and the HP-55 mRNA level was greatly reduced during hibernation. Genomic Southern blot analysis and screening of a liver cDNA library from another hibernating squirrel species, the ground squirrel, also revealed expression of multiple members of the alpha1-AT gene family, whereas analysis of a cDNA library from a non-hibernating species, the tree squirrel, found only a single alpha1-AT gene.

Evolutionary relationship of hepatitis C, pesti-, flavi-, plantviruses, and newly discovered GB hepatitis agents.

Two flavivirus-like viruses, GB virus-A (GBV-A) and GB virus-B (GBV-B), were recently identified in the GB hepatitis agent, and are distinct from the hepatitis A to E viruses. The putative helicase domain of GBV-A and GBV-B was found to have amino acid sequence homology with hepatitis C virus (HCV), and distantly, is also related to pestiviruses, flaviviruses, and plant viruses. A phylogenetic tree construction showed that GBVs and HCV are closely related, and they are clustered with pestiviruses, flaviviruses and plant viruses in that order.

African origin of GB virus C/hepatitis G virus.

Ninety-four GB virus C/hepatitis G virus (GBV-C/ HGV) RNA-positive serum samples were obtained from all over the world. We found that all 15 GBV-C/HGV isolates from the Pygmies and the Bantu in the Central African region had a 12-amino acid indel (i.e. insertion or deletion) in the non-structural protein (NS) 5A region. Phylogenetic analyses of the NS5A region, using GBV-A as an outgroup, showed that these 15 isolates had diverged from the common ancestor much earlier than the remaining isolates, indicating an African origin of GBV-C/HGV.

Three different GB virus C/hepatitis G virus genotypes. Phylogenetic analysis and a genotyping assay based on restriction fragment length polymorphism.

The 5'-untranslated region (5'-UTR) sequences of 33 GB virus C/hepatitis G virus (GBV-C/HGV) obtained from different geographic areas were determined through reverse-transcription polymerase chain reaction and dideoxy chain termination sequencing, the alignment of sequences, the estimation of the number of nucleotide substitution per site, and construction of phylogenetic trees. The 5'-UTR of GBV-HGV was found to be heterogeneous, with 70.9-99.5% homology. Three distinct phylogenetic branches were observed consistently in all phylogenetic trees. GBV-C is the prototype for one, HGV for another, and there is a new branch which consisted of GBV-C/HGV isolates from Asia. Genotype-specific restriction sites for the restriction enzymes, ScrFI and BsmFI, were identified, and a simple restriction fragment polymorphism analysis was developed for genotyping. These data provide evidence that GBV-C/HGV consists of three different genotypes. Our simple genotyping assay will also provide a tool for epidemiological studies of GBV-C/HGV infection.

Interferon-alpha therapy exerts selective pressure on hepatitis C virus quasispecies equilibrium.

Two patients with chronic hepatitis C virus (HCV) genotype 2b infection were studied. They responded biochemically to interferon (IFN) but had early virological and later biochemical relapse. The HCV quasispecies equilibrium in these patients was studied by a combination of cloning, sequencing and construction of phylogenetic trees. Another patient with chronic HCV genotype 2b infection was followed every 6 months for 30 months (including one episode of biochemical exacerbation) to serve as the control. Quasispecies equilibrium drifted during IFN therapy but moved back in the direction of the original equilibrium during biochemical relapse. In the control patient, there was no significant drifting throughout the follow-up period. These data suggest that IFN therapy exerts selective pressure on HCV quasispecies equilibrium.

GB virus C (GBV-C)/hepatitis G virus (HGV) infection among intravenous drug users in Japan.

A sero-epidemiologic survey of 74 IVDUs and 86 age-matched controls was performed to investigate the prevalence, clinical significance, and genetic distribution of GB virus C (GBV-C)/hepatitis G virus (HGV) infection among intravenous drug users (IVDUs) in Japan. GBV-C/HGV RNA was detected by reverse transcriptase-hemi-nested polymerase chain reaction (RT-hemi-nested PCR) for the 5'-untranslated region (5'-UTR) in 43.2% (32/79) of the IVDUs compared with 1.2% (1/86) of the controls (P < 0.001). The duration of drug use did not correlate with the prevalence of GBV-C/HGV. Thirteen subjects positive for GBV-C/HGV RNA without HCV RNA had normal serum aminotransferase concentrations. Phylogenetic tree showed that the 32 GBV-C/HGV-positive isolates from IVDUs were classified within a new GBV-C/HGV group, which has been identified mainly in Asian subjects (type 3). The present study illustrated, (1) the high incidence of GBV-C/HGV infection among Japanese IVDUs, (2) GBV-C/HGV alone may not be an important pathogenic factor for hepatic injury, and (3) type 3 GBV-C/HGV was the most prevalent among IVDUs in Japan.

Relationships between serotypes and genotypes of hepatitis B virus: genetic classification of HBV by use of surface genes.

Hepatitis B virus (HBV) surface antigen (HBsAg), which is encoded by the HBV S gene, is conventionally classified into 4 serological subtypes, adw, adr, ayw and ayr. To determine the relationship between the HBsAg seroreactivity and the nucleotide sequence diversity of the HBV S gene, the nucleotide sequences of S genes for HBV isolates reported so far were aligned with each other. The numbers of nucleotide substitutions were then estimated by the 6-parameter method, and a phylogenetic tree was constructed by the unweighted paired grouping method with arithmetic mean (UPGMA) and the neighboring-joining (NJ) method. The phylogenetic trees constructed showed that all isolates were grouped into 4 genotypes (gyw, gdw-1, gdw-2, and gdr). More importantly, the genotypes did not necessarily correspond to the conventional serotypes. In particular, serotype 'adw' can be any of genotypes gdw-1, gdw-2, or gdr. Thus, genotyping by S genes gives more accurate information about genetic variation of HBV.

Classification of hepatitis C virus into major types and subtypes based on molecular evolutionary analysis.

Molecular evolutionary analysis was applied to determine the number of hepatitis C virus (HCV) types and subtypes based on all the HCV nucleotide sequences available from the DNA data banks (DDBJ, GenBank (NCBI), EMBL) and the literature. There was an excellent concordance among the types and subtypes assigned based on different HCV genomic regions. Only one HCV isolate was assigned to different HCV types based on the 5' non-coding (NC) and envelope 1 (E1) regions. The 5' NC region was well conserved and could be used to assign only types and not subtypes. From the sequence data available there were 13 subtypes based on the core region and 14 subtypes based on the E1 and non-structural protein 5 (NS5) regions.

Genotype of GB virus C/hepatitis G virus by molecular evolutionary analysis.

GB virus C/hepatitis G virus is a newly described virus. Classification of GB virus C/hepatitis G virus into genotypes has not been established. We analyzed nucleotide sequences within the 5' untranslated region of GB virus C/hepatitis G virus isolates and segregated these isolates into genotypes. Twenty serum samples with GB virus C/hepatitis G virus RNA from Australia, Cameroon, the Congo, Japan, Mongolia, and Bangladesh were studied. Reverse transcription and polymerase chain reaction were used to obtain GB virus C/hepatitis G virus RNA. After nucleotide sequences from the 5' untranslated region were determined, 68 nucleotide sequences, including 48 previously reported sequences, were analyzed by molecular evolutionary methods. The phylogenetic tree of the 5' untranslated region showed that all strains could be divided into three major genotypes, GB type (type 1), HG type (type 2), and Asian type (type 3). Bootstrap analysis indicated that the strains could be divided into three major genotypes but could not be further subdivided. Moreover, frequency histograms of pairwise distances between nucleotide sequences demonstrated only one peak. These result indicated that GB virus C/hepatitis G virus can be classified into three major genotypes, GB type (type 1), HG type (type 2), and Asian type (type 3), and should not be divided into minor subtypes.

GB virus C/hepatitis G virus infection among Japanese patients with chronic liver diseases and blood donors.

Recently, a novel hepatitis virus, GB virus C/hepatitis G virus (GBV-C/HGV), has been isolated. To elucidate the seroprevalence of chronic GBV-C/HGV infection in Japan and the phylogenetic relationship between Japanese strains and the strains previously reported, serum GBV-C/HGV RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) in 203 patients with chronic liver diseases and 200 samples of voluntary blood donors. RT-PCR was performed with primers derived from the 5'-untranslated region which were conserved between GBV-C and HGV and distant from other flaviviruses including hepatitis C virus (HCV). The nucleotide sequences were determined by the dideoxy chain termination method. The phylogenetic analysis was performed by the neighbor-joining method. In 10 (4.7%) of 203 patients with chronic liver diseases and in 1 (0.5%) of 200 blood donor samples, serum GBV-C/HGV RNA was detected. Of 10 patients, 9 patients were positive for anti-HCV and negative for HBsAg, and 1 patient was positive for HBsAg and negative for anti-HCV. The phylogenetic analysis indicated that there were three major groups which were group 1 (GBV-C), group 2 (HGV), and group 3 (a group of Japanese strains). These data indicated that (1) there was a low prevalence of GBV-C/HGV infection in Japanese patients with chronic liver diseases, (2) a high proportion of patients with GBV-C/HGV infection had chronic HCV infection however, and (3) there were at least three groups in strains of GBV-C/HGV.

High prevalence of GB virus C/hepatitis G virus infection among the Jewish population in Uzbekistan.

Although a new virus, GB virus C/hepatitis G virus (GBV-C/HGV), has been isolated from patients with hepatitis by two different research groups, its prevalence in the world and pathogenesis are still unknown. In this study, 92 samples from the Jewish population of Uzbekistan were investigated for the prevalence of GBV-C/HGV. GBV-C/HGV RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) using specific primers derived from the 5'-untranslated region (5'-UTR). Sequences were analyzed by a molecular evolutionary method. Of 92 samples, GBV-C/HGV RNA was detected in ten (10.9%), HCV RNA was present in two (2.2%), and HBsAg in eight (8.7%). HTLV-I and HIV infection was not detected. Single GBV-C/HGV infection was detected in eight (80%), and co-infection with HBV or HCV was detected in only two of the GBV-C/HGV infections. Alanine aminotransferase (ALT) levels were elevated in three (3.3%), but none with single GBV-C/HGV infection had an elevated ALT level. Nine people (90%) with GBV-C/HGV infection were distributed under the mean age of the population (P < 0.05). Molecular evolutionary analysis showed all GBV-C/HGV strains in this study were related to the HGV derived from the US. These results indicate that (1) GBV-C/HGV infection is highly prevalent among the Jewish population in Uzbekistan; (2) single GBV-C/HGV infections without persistent hepatitis are common; and (3) GBV-C/HGV infection is present among the younger generation.

Identification of two novel splicing variants of human type II iodothyronine deiodinase mRNA.

Human type II iodothyronine deiodinase (hDII) belongs to a family of selenoproteins. It catalyzes 5'-deiodination of thyroxine to generate an active thyroid hormone, 3,3',5-triiodothyronine. Two novel splice variants of hDII gene transcript; namely hDII-b and hDII-c, were identified. Three distinct DNA fragments (hDII-a-c) were amplified by a reverse transcription-polymerase chain reaction (RT-PCR) with hDII intron-spanning primers using total-RNA from human umbilical vein endothelial cell line, ECV304. The sequence of hDII-a was identical to that of previously reported hDII. hDII-b and hDII-c had an additional insertion of 108 and 242 bp, respectively. The insertion sequences were found in the intron of hDII gene, therefore, two novel exons exist between exons 1 and 2 of hDII gene. The splice sites of new exons (b and c) conserved the consensus sequences of splice acceptor and donor sites. hDII-b contains exon b with an in-frame TGA codon that may encode an extra selenocysteine. hDII-c contained exons b and c and the predicted open reading frame is interrupted by a stop codon (TAA) produced by a frame shift. RT-PCR analysis showed that hDII-a and hDII-b mRNAs are expressed in human tissues including brain, kidney, lung and trachea. The mRNA abundance of hDII-c was lower than that of hDII-a or hDII-b. Thus, the new variants of hDII transcripts suggest the presence of two short exons between exons 1 and 2 of hDII gene, and of functional variant of hDII.