[A modified administrated schedule for combination therapy with irinotecan and cisplatin as a neoadjuvant chemotherapy in locally advanced cervical cancer--a report of 2 cases as a pilot study]

To shorten the treatment term of neoadjuvant chemotherapy (NAC) for locally advanced cervical cancer, a combination of irinotecan (CPT-11) and cisplatin was administered on a modified administrated schedule for 2 eligible patients as a pilot study. CPT-11 70 mg/m2 was administered (div) on days 1 and 8, followed by cisplatin 70 mg/m2 given (div) on day 1. Treatment was repeated every 3 weeks for a total of two cycles. Both patients showed a complete clinical response. No severer toxicities were observed than with the usual regimen, and both cases could undergo radical hysterectomy after NAC. The results suggest that this modified regimen of combination of CPT-11 and cisplatin can be effective as an NAC in cases of locally advanced cervical cancer, especially in terms of shortening treatment term. This regimen is worthy of further study.

The Cbl protooncogene product: from an enigmatic oncogene to center stage of signal transduction

The c-cbl protooncogene was first identified as the cellular homologue of a viral oncogene v-cbl that induces pre-B lymphomas and myeloid leukemias in mice. Until recently, the biochemical basis for Cbl's transforming potential and its physiological role remained unclear. However, a convergence of biochemical studies in mammalian cells and genetic studies in C. elegans and Drosophila has now identified Cbl as a negative regulator of tyrosine kinase signaling. The N-terminal transforming region of Cbl (Cbl-N) and an adjacent RING finger domain are the elements most conserved during evolution. The Cbl-N region has now been shown to contain a novel phosphotyrosine-binding (PTB) domain that directly interacts with autophosphorylated tyrosine kinases via a D(N/D)XpY motif. A critical role of the PTB domain in Cbl function is demonstrated by the localization of a loss-of-function mutation in C. elegans Cbl homologue SLI-1 within this region. The corresponding mutation in human Cbl inactivates the PTB domain function and abrogates Cbl-mediated regulation of tyrosine kinase function. Recent studies have also identified a novel signaling pathway initiated by the interaction of mammalian Cbl proteins with the SH2 domains of Crk adaptor molecules, which results in Cbl's linkage with C3G, a guanine nucleotide exchange protein for Rap1 family of small G-proteins. Presently, Rap1 is thought to antagonize Ras function, although Rap1-specific targets have emerged recently. Thus, recent advances have firmly placed the little known protooncoprotein Cbl on the center stage of tyrosine kinase-mediated signal transduction.

Genomic structure of human alpha-pix, and variable deletions in a poly (T) tract in gastric cancer tissue

PAK-interacting exchange factor (PIX) has been reported to mediate the recruitment of PAK into focal adhesions and activate Rac, thus creating a feedback loop that stimulate PAK and other targets. This pathway is thought to be related to cellular changes, such as transformation and migration, that are often encountered in cancer cells. Here, we report the genomic structure of alpha-PIX, one of the PAK- interacting exchange factors, including the identification of the promoter region, which consisted 772 amino acids in 22 exons, spanning about 100 kb on genome of X chromosome. All splice sites conformed to the GT-AT rule. To investigate the role of alpha-PIX in carcinogenesis, we screened 60 cases of gastric cancer for mutations and polymorphisms using an intron-primer that covered all the exons, but no mutations or polymorphisms were found in the coding region. However an 18 bp repeat of thymidine tract was present in 50 bp downstream from exon 12 and the deletion of variable numbers of mononucleotide repeats was observed in seven out of the 60 gastric cancer tissue specimens that were examined. These seven cases all exhibited a mutator phenotype, suggesting that the deletions are passenger mutations. Thus our results revealed that alpha-PIX probably does not play any primary role in human gastric carcinogenesis.

Remission of metastatic cervical adenocarcinoma with weekly paclitaxel

We report the use of paclitaxel in the successful treatment of a patient with recurrent adenocarcinoma of the cervix. Paclitaxel, 70 mg/m2 by 1-h infusion weekly, was administered to a 59-year-old patient with cervical adenocarcinoma showing lung metastasis. She showed partial clinical response after seven cycles, and at the completion of 20 cycles she showed complete response, which was confirmed by chest X-ray and computed tomography scan. Toxicities including neurotoxicity were mild. She showed an objective response to treatment for over 8 months, and she enjoyed a favorable quality of life during and after treatment. Weekly paclitaxel was very well tolerated, yet was effective for recurrent cervical adenocarcinoma.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

Chemotherapy-induced unconjugated hyperbilirubinemia caused by a mutation of the bilirubin uridine-5'-diphosphate-glucuronosyltransferase gene

Chemotherapy for malignant neoplasms sometimes causes unconjugated hyperbilirubinemia in the absence of liver dysfunction. We analyzed the association of chemotherapy-induced hyperbilirubinemia with mutations of the bilirubin uridine-5'-diphosphate (UDP)-glucuronosyltransferase gene (UGT1A1) from two leukemic patients in whom chemotherapy resulted in a hyperbilirubinemic response. We isolated genomic DNA from peripheral blood samples and amplified UGT1A1 by polymerase chain reaction. The amplified DNA fragments were analyzed by direct sequencing. The genes of the two patients revealed an identical heterozygous missense mutation in exon 1 (211G-->A: G71R). This UGT1A1 mutation may be the basis of chemotherapy-induced unconjugated hyperbilirubinemia.

Allele frequencies and haplotypic associations defined by allelic DNA typing at HLA class I and class II loci in the Japanese population

HLA class I and class II allelic genotypes were determined in 371 unrelated individuals and 309 members of 81 families inhabiting the central Japan area. A total of 20 HLA-A alleles, 16 HLA-Cw alleles, 38 HLA-B alleles, 27 HLA-DRB1 alleles, 15 HLA-DQB1 alleles and 12 HLA-DPB1 alleles were detected. By the two-, three-, four-, five- and six-locus allelic association analyses extracted from the HLA-A to -DPB1 locus, 26 HLA-Cw-B haplotypes, 25 HLA-DRB1-DQB1 haplotypes, 42 HLA-Cw-B-DRB1 haplotypes, 37 HLA-Cw-B-DRB1-DQB1 haplotypes, 29 HLA-A-Cw-B-DRB1-DQB1 haplotypes and 21 HLA-A-Cw-B-DRB1-DQB1-DPB1 haplotypes with the frequencies of higher than 0.005 were recognized. Among 19 HLA-B alleles with the high allele frequencies (above 0.007), 9 HLA-B alleles, B*0702, B*1301, B*3701, B*3901, B*4006, B*4403, B*5201, B*5901 and B*6701 were found to be tightly associated with single HLA-Cw alleles. Most of HLA-DRB1 alleles showed strong associations with single HLA-DQB1 alleles, but DRB1*0802 and DRB1*1401 were associated with two different DQB1 alleles. Extended haplotypes carrying infrequent class I alleles with the allele frequencies of lower than 0.007 were defined by family studies. Gene frequencies and haplotypic associations within the entire HLA classical loci elucidated at the high resolution (four-digital) allelic level will provide useful information on anthropology, marrow donor registry, legal medicine and disease-association studies.

Successful treatment of two patients with recurrent endometrial cancer by weekly paclitaxel

OBJECTIVE

The aim of this study was to evaluate the toxicity and efficacy of weekly paclitaxel in patients with recurrent endometrial cancer.

METHODS

Paclitaxel (70 mg/m(2) by 1-h infusion weekly) was administered to two patients with recurrent endometrial cancer of the lung.

RESULTS

After 5 cycles, both patients with platinum-resistant disease achieved clinical partial responses confirmed by computed tomography (CT) scan. The serum CA125 levels of case 1 decreased to cut-off level. The response duration of both patients was 4 months. The toxicity was acceptable and probably less pronounced than that characterize of the standard tri-weekly schedules.

CONCLUSION

Although conclusions regarding survival are premature, weekly paclitaxel might offer better quality of life during treatment.

Fatal cerebral hemorrhage associated with cyclosporin-A/FK506-related encephalopathy after allogeneic bone marrow transplantation

We report a case of cerebral hemorrhage associated with cyclosporin A (CsA)/FK506-related encephalopathy that developed in a 16-year-old woman after allogeneic bone marrow transplantation. Hematopoietic engraftment occurred on day 15, and the patient developed systemic convulsions after CsA was replaced by FK506 for the treatment of acute graft-versus-host disease (GVHD). Based on magnetic resonance imaging, laboratory findings and cerebrospinal fluid studies, she was diagnosed as having CsA/FK506-related encephalopathy with cerebral hemorrhagic infarction. Although she recovered completely after discontinuation of FK506, she developed convulsions again 15 days after re-administration of FK506. A computed tomography scan showed cerebral hemorrhage. She died of respiratory failure. Vascular damage induced by immunosuppressive drugs and enhanced by acute GVHD seemed to be the cause of the cerebral hemorrhage. Since hypertension, which was present during both of the central nervous system events, seemed to have contributed to the development of the cerebral hemorrhage, it is proposed that CsA and FK506 should be reduced or discontinued when patients who have risk factors of hypertension become hypertensive even if they have no symptoms of neurotoxicity.

Genomic organization, chromosomal localization and regulation of expression of the neuronal nuclear matrix protein NRP/B in human brain tumors

The nuclear matrix and its role in cell physiology are largely unknown, and the discovery of any matrix constituent whose expression is tissue- and/or cell-specific offers a new avenue of exploration. Studies of the novel neuronal nuclear matrix protein, NRP/B, reveal that it is an early and highly specific marker of neuronal induction and development in vertebrates, since its expression is restricted mainly to the developing and mature nervous system. These studies also show that NRP/B is involved in neuronal differentiation. To further examine the structure-function of NRP/B, we have cloned and characterized the murine Nrp/b gene. The murine gene consists of four exons interrupted by three introns that span 7.6kb of DNA. The complete open reading frame is localized in exon 3, suggesting that NRP/B is highly conserved during evolution. Chromosomal analysis shows that NRP/B is localized to chromosome 13 in mouse and chromosome 5q12-13 in human. Since our previous studies demonstrated that NRP/B is expressed in primary hippocampal neurons but not in primary astrocytes, we have characterized NRP/B mRNA and protein expression in various brain cell lines and in human brain tumors. Abundant expression of NRP/B mRNA and protein was observed in human neuroblastoma cell lines (IMR32, SKN-MC, SKN-SH), in glioblastoma cell lines (A172, T98G, U87-MG, U118-MG, U138-MG, and U373-MG), in neuroglioma (H4) and astrocytoma cell lines (CCF-STTG1 and SW1088). Confocal analysis of NRP/B in U87-MG glioblastoma cells indicated nuclear localization of NRP/B. NRP/B expression was also observed in human primary brain tumors including glioblastoma multiformae and astrocytomas (total of five cases). These results suggest that NRP/B expression is upregulated in human brain tumors including glioblastomas and astrocytomas, while under normal conditions NRP/B expression is restricted to neurons. This study implicates a role for NRP/B in brain tumor development.

NJML: a hybrid algorithm for the neighbor-joining and maximum-likelihood methods

In the reconstruction of a large phylogenetic tree, the most difficult part is usually the problem of how to explore the topology space to find the optimal topology. We have developed a "divide-and-conquer" heuristic algorithm in which an initial neighbor-joining (NJ) tree is divided into subtrees at internal branches having bootstrap values higher than a threshold. The topology search is then conducted by using the maximum-likelihood method to reevaluate all branches with a bootstrap value lower than the threshold while keeping the other branches intact. Extensive simulation showed that our simple method, the neighbor-joining maximum-likelihood (NJML) method, is highly efficient in improving NJ trees. Furthermore, the performance of the NJML method is nearly equal to or better than existing time-consuming heuristic maximum-likelihood methods. Our method is suitable for reconstructing relatively large molecular phylogenetic trees (number of taxa >/= 16).

Prostaglandins up-regulate vascular endothelial growth factor production through distinct pathways in differentiated U937 cells

We previously reported that cyclooxygenase (COX)-2 was predominantly expressed in macrophages of human colonic adenomas (Int. J. Cancer 83, 470-475.). The role of prostaglandins (PGs) produced by COX-2-expressing macrophages in colon carcinogenesis is still unclear. Here we show that PGs up-regulate vascular endothelial growth factor (VEGF) production by activated macrophages through their specific receptors. mRNAs of both PGE-specific receptors and peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear receptor superfamily of ligand-dependent transcription factors, were expressed in phorbol 12-myristate 13-acetate-differentiated U937, a human macrophage model (H-Mac). Prostaglandin E(1) (PGE(1)) and 15-deoxy-Delta(12,14)-PGJ(2) (a potent PPARgamma ligand, 15d-PGJ(2)) dramatically increased VEGF production. The combination of PGE(1) and 15d-PGJ(2) additively increased VEGF production. In addition, PGE(1) significantly increased cAMP formation, whereas 15d-PGJ(2) did not affect cAMP formation. The effect of the combination of PGE(1) and 15d-PGJ(2) on cAMP formation was similar to that of PGE(1) alone. Unexpectedly, 15d-PGJ(2) also drastically increased IL-1beta production, an indicator of macrophage activation, although PGE(1) only mildly increased it. Additional enhancement of IL-1beta production was observed in the combination of PGE(1) and 15d-PGJ(2). These results suggest that PGs dramatically increased VEGF production by activated macrophages through specific PGE receptor and PPARgamma-mediated processes and that PGs may thereby promote tumor growth through VEGF production.

The role of protein kinase C isoforms in cell proliferation and apoptosis

Protein kinase C (PKC) was first described as a calcium-activated, phospholipid-dependent serine/threonine protein kinase 22 years ago, and it has since been studied extensively as a second messenger transducing diverse signals regarding cell proliferation, activation of cellular function, differentiation, and even apoptosis. Because PKC consists of at least 11 isoforms, with possibly different biological properties, it is necessary to reevaluate its known functions as functions of each isoform. Recent studies have revealed that several other lipid metabolites generated by signal-induced hydrolysis of membrane phospholipids, such as ceramide and phosphatidylinositol-3,4,5-triphosphate, may also have the potential to mediate external signals. Here we describe the roles of PKC isoforms in cell proliferation and apoptosis, particularly in relation to other lipid metabolites.

Effect of prostaglandin E1 on vascular endothelial growth factor production by human macrophages and colon cancer cells

We previously demonstrated that cyclooxygenase-2 (COX-2) was predominantly expressed in macrophages of sporadic human colonic adenomas; however, the role of COX-2-expressing cells during colon carcinogenesis has not yet been elucidated. In the present study, we showed the effect of PGE, on vascular endothelial growth factor (VEGF) production by PMA-differentiated U937 cells, a human macrophage model (H-Mac), and by human colon cancer cells T84. PGE1 dramatically induced VEGF production by H-Mac, but not that by T84. PGE1 significantly increased intracellular cAMP formation by H-Mac, but only modestly increased that by T84. 8-bromo-cAMP and cholera toxin also increased VEGF production by H-Mac. In contrast, neither of these agents modulated VEGF production by T84. EP2 and EP4 (PGE specific receptors) mRNA was expressed in both cells. PG dramatically increased VEGF production by activated macrophages, but not by cancer cells, through a specific PGE receptor-mediated process. These findings suggest that PGs produced by COX-2-expressing macrophages induce VEGF production by macrophages, but not by cancer cells, in an autocrine fashion.

Alterations in binding activity of T cell transcription factor CD28 responsive element binding complex (CD28RC) following allogeneic bone marrow transplantation

The CD28 responsive element binding complex (CD28RC) has an important role in transducing CD28/B7 costimulatory signals. Using electrophoretic mobility-shift assay (EMSA), we have analyzed the binding activity of CD28RC in the mixed lymphocyte culture (MLC) using peripheral blood mononuclear cells (PBMC) obtained from the patients before and after allogeneic bone marrow transplantation (allo-BMT). The binding activity of CD28RC was low in MLCs using PBMC from patients without acute GVHD and it was also low in MLCs using PBMC from patients without chronic GVHD (cGVHD). In contrast, this activity in patients with cGVHD was estimated to be high. The relative values of CD28RC in comparison with third party MLCs were significantly higher in MLCs using PBMC from patients with cGVHD than those in MLCs using PBMC from patients without GVHD (0.55+/-0.31 versus 0.23+/-0.12, respectively, n = 10, p = 0.05). IL-2 concentrations in the MLC medium from patients without GVHD were undetectable; however, a detectable level of IL-2 was present in MLC medium from a patient with extensive cGVHD. These data were interpreted to suggest that the CD28 costimulatory pathway was specifically activated against recipient antigen in allo-BMT patients with GVHD. In other words, it was suggested that the CD28 costimulatory pathway was specifically suppressed in allo-BMT patients without GVHD, and this suppression might contribute immunological tolerance after allo-BMT.

Colorectal cancer and non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) can prevent or reduce the occurrence of colorectal cancers. Anti-carcinogenic properties of NSAIDs have been demonstrated in epidemiological studies of humans and experimental animals. In addition, clinical studies of familial adenomatous polyposis and sporadic adenomas have demonstrated that NSAIDs induce regression of colorectal adenomas and prevent formation of these tumors. NSAIDs thus induce early disruption of the adenoma-carcinoma sequence and may mainly suppress subsequent cancer formation at adenoma stage. The mechanism of the anti-carcinogenic effect of these drugs is not known, but results of most studies support that cyclooxygenase-2 (an inducible isoform of prostaglandin synthetase, COX-2) is a major target of NSAIDs in this effect. Recent immunohistochemical studies have revealed that COX-2 is expressed not in tumor cells but in interstitial cells of colonic adenomas. Accordingly, NSAIDs may exhibit anti-carcinogenic property through the inhibition of prostaglandin production by COX-2 expressing interstitial cells. Future research should be focused on the role of prostaglandins in the interaction of tumor cells and interstitial cells in colon carcinogenesis.

The linker phosphorylation site Tyr292 mediates the negative regulatory effect of Cbl on ZAP-70 in T cells

The protooncogene product Cbl has emerged as a negative regulator of tyrosine kinases. We have shown previously that Cbl binds to ZAP-70 through its N-terminal tyrosine kinase binding (TKB) domain. In this study, we demonstrate that overexpression of Cbl in Jurkat T cells decreases the TCR-induced phosphorylation of ZAP-70 and other cellular phosphoproteins. Coexpression of Cbl with ZAP-70 in COS cells reproduced the Cbl-induced reduction in the level of phosphorylated ZAP-70. The effect of Cbl was eliminated by the TKB-inactivating G306E mutation in Cbl as well as by a phenylalanine mutation of Tyr292 within the TKB domain binding site on ZAP-70. Notably, the oncogenic Cbl-70Z/3 mutant associated with ZAP-70, but did not reduce the levels of phosphorylated ZAP-70. Overexpression of Cbl, but not Cbl-G306E, in Jurkat T cells led to a decrease in the TCR-induced NF-AT luciferase reporter activity. Overexpression of the TKB domain itself, but not its G306E mutant, functioned in a dominant-negative manner and led to an increase in NF-AT reporter activity. Cbl-70Z/3-overexpressing cells exhibited an increase in both basal and TCR-induced NF-AT luciferase reporter activity, and this trend was reversed by the G306E mutation. Finally, by reconstituting a ZAP-70-deficient Jurkat T cell line, p116, we demonstrate that wild-type ZAP-70 is susceptible to the negative regulatory effect of Cbl, whereas the ZAP-70-Y292F mutant is resistant. Together, our results establish that the linker phosphorylation site Tyr292 mediates the negative regulatory effect of Cbl on ZAP-70 in T cells.

The Cbl proto-oncogene product negatively regulates the Src-family tyrosine kinase Fyn by enhancing its degradation

Fyn is a prototype Src-family tyrosine kinase that plays specific roles in neural development, keratinocyte differentiation, and lymphocyte activation, as well as roles redundant with other Src-family kinases. Similar to other Src-family kinases, efficient regulation of Fyn is achieved through intramolecular binding of its SH3 and SH2 domains to conserved regulatory regions. We have investigated the possibility that the tyrosine kinase regulatory protein Cbl provides a complementary mechanism of Fyn regulation. We show that Cbl overexpression in 293T embryonic kidney and Jurkat T-lymphocyte cells led to a dramatic reduction in the active pool of Fyn; this was seen as a reduction in Fyn autophosphorylation, reduced phosphorylation of in vivo substrates, and inhibition of transcription from a Src-family kinase response element linked to a luciferase reporter. Importantly, a Fyn mutant (FynY528F) relieved of intramolecular repression was still negatively regulated by Cbl. The Cbl-dependent negative regulation of Fyn did not appear to be mediated by inhibition of Fyn kinase activity but was correlated with enhanced protein turnover. Consistent with such a mechanism, elevated levels of Fyn protein were observed in cell lines derived from Cbl(-/-) mice compared to those in wild-type controls. The effects of Cbl on Fyn were not observed when the 70ZCbl mutant protein was analyzed. Taken together, these observations implicate Cbl as a component in the negative regulation of Fyn and potentially other Src-family kinases, especially following kinase activation. These results also suggest that protein degradation may be a general mechanism for Cbl-mediated negative regulation of activated tyrosine kinases.

The evolutionarily conserved N-terminal region of Cbl is sufficient to enhance down-regulation of the epidermal growth factor receptor

The mammalian proto-oncoprotein Cbl and its homologues in Caenorhabditis elegans and Drosophila are evolutionarily conserved negative regulators of the epidermal growth factor receptor (EGF-R). Overexpression of wild-type Cbl enhances down-regulation of activated EGF-R from the cell surface. We report that the Cbl tyrosine kinase-binding (TKB) domain is essential for this activity. Whereas wild-type Cbl enhanced ligand-dependent EGF-R ubiquitination, down-regulation from the cell surface, accumulation in intracellular vesicles, and degradation, a Cbl TKB domain-inactivated mutant (G306E) did not. Furthermore, the transforming truncation mutant Cbl-N (residues 1-357), comprising only the Cbl TKB domain, functioned as a dominant negative protein. It colocalized with EGF-R in intracellular vesicular structures, yet it suppressed down-regulation of EGF-R from the surface of cells expressing endogenous wild-type Cbl. Therefore, Cbl-mediated down-regulation of EGF-R requires the integrity of both the N-terminal TKB domain and additional C-terminal sequences. A Cbl truncation mutant comprising amino acids 1-440 functioned like wild-type Cbl in down-regulation assays. This mutant includes the evolutionarily conserved TKB and RING finger domains but lacks the less conserved C-terminal sequences. We conclude that the evolutionarily conserved N terminus of Cbl is sufficient to effect enhancement of EGF-R ubiquitination and down-regulation from the cell surface.

The RING finger domain of Cbl is essential for negative regulation of the Syk tyrosine kinase

The proto-oncogene product Cbl has emerged as a negative regulator of a number of protein-tyrosine kinases, including the ZAP-70/Syk tyrosine kinases that are critical for signaling in hematopoietic cells. The evolutionarily conserved N-terminal tyrosine kinase-binding domain is required for Cbl to associate with ZAP-70/Syk and for their subsequent negative regulation. However, the role of the remaining C-terminal regions of Cbl remains unclear. Here, we used a COS-7 cell reconstitution system to address this question. Analysis of a series of C-terminally truncated Cbl mutants revealed that the N-terminal half of the protein, including the TKB and RING finger domains, was sufficient to mediate negative regulation of Syk. Further truncations, which delete the RING finger domain, abrogated the negative regulatory effects of Cbl on Syk. Point mutations of conserved cysteine residues or a histidine in the RING finger domain, which are required for zinc binding, abrogated the ability of Cbl to negatively regulate Syk in COS-7 cells and Ramos B lymphocytic cells. In addition, Syk-dependent transactivation of a serum response element-luciferase reporter in transfected 293T cells was reduced by wild type Cbl; mutations of the RING finger domain or its deletion abrogated this effect. These results establish the RING finger domain as an essential element in Cbl-mediated negative regulation of a tyrosine kinase and reveal that the evolutionarily conserved N-terminal half of the protein is sufficient for this function.

High expression of cyclooxygenase-2 in macrophages of human colonic adenoma

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

High expression of cyclooxygenase-2 in macrophages of human colonic adenoma

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

Massive gastrointestinal hemorrhage in systemic lupus erythematosus: successful treatment with corticosteroid pulse therapy

Although mesenteric vasculitis due to systemic lupus erythematosus (SLE) is relatively uncommon, it is the most dangerous manifestation associated with high mortality. We describe the case of a SLE patient with life-threatening gastrointestinal hemorrhage due to mesenteric vasculitis in whom methylprednisolone pulse therapy was quite effective in controlling the hemorrhage and resulted in a satisfactory long term outcome. A 47-yr-old woman presenting with high fever, rash, and melena was diagnosed with SLE from positive antinuclear antibodies, anti-dsDNA, and low complement titers. Although fever and rash subsided with administration of prednisolone, massive hematemesis appeared with melena. Endoscopy demonstrated bleeding ulceration of the antrum, which was intractable despite intensive antiulcer therapy and transfusion. Surgical exploration revealed ileal penetration, and multiple bleeding ulcerations were observed over the resected ileum as well as the antral ulceration. However, bleeding persisted after surgery and surgical findings prompted us to select methylprednisolone pulse. Hemorrhage responded promptly to the therapy, and the patient has remained well since then for >10 yr. Our report indicates that corticosteroid pulse may serve as one of the therapeutic options for SLE with massive hemorrhage due to widespread mesenteric vasculitis.

[Screening of prostate cancer with PSA and transperineal six sextant biopsy]

OBJECT

The objectives of this study are to examine how many cancer patients we can detect among the outpatients whose PSA values are above 4.0 ng/ml, and to compare the usefulness of transperineal six sextant biopsy (ss-biopsy) with that of transrectal one.

METHODS

All the male outpatients (above 50 years old) were inspected Tandem-R PSA levels and digital rectal examination (DRE). Among them, 129 patients showed more than 4.0 ng/ml of PSA values and/or positive finding of DRE, and underwent subsequent transperineal ss-biopsy.

RESULTS

Cancers were detected in 52 patients (40.3%) without major complications. Among 64 gray zone (PSA 4.1-10.0 ng/ml) patients, 17 (26.6%) were found to be cancer by ss-biopsy, meanwhile only 2 cancer patients (8.9%) were detected from 23 gray zone ones by traditional directed biopsy. Application of PSA density could not be found practicable to eliminate unnecessary biopsies in the gray zone group.

CONCLUSION

Prostate cancer could be found nearly a fourth in the gray zone group of the outpatients. To enhance the detection rate, obtaining at least 6 core samples are recommended from either perineal or rectal root.

A new quantitative method for rabies virus by detection of nucleoprotein in virion using ELISA

We have developed a new quantitative method for rabies virus (RV) detection using enzyme-linked immunosorbent assay (ELISA). The method named N-ELISA was based on the quantitation of nucleoprotein (N) in RV virions captured by RV-specific polyclonal antibodies on an ELISA plate. Both infective and defective interfering (DI) particles of RV could be detected by this method. When viruses were propagated in a medium of pH 7.4 adjusted with 7% NaHCO3, N-ELISA could detect them with titers of more than 10(6) pfu/ml, though the result did not correlate highly with that of the infectivity assay. The reason for this was considered to be that RVs included spikeless and damaged particles which were produced under conditions of low or high pH. However, in the time course of virus yield, titers of N-ELISA correlated well with those of the infectivity assay.

Endoscopic variceal ligation is a sufficient procedure for the treatment of oesophageal varices in patients with hepatitis C liver cirrhosis: comparison with injection sclerotherapy

AIMS

Endoscopic variceal ligation (EVL) is a recently developed alternative to endoscopic injection sclerotherapy (EIS) for the treatment of oesophageal varices. Endoscopic variceal ligation and EIS were compared in an attempt to clarify the efficacy and safety of EVL for patients with cirrhosis due to hepatitis C.

METHODS

Endoscopic variceal ligation was performed in 60 patients and EIS in 30. Varices were eradicated in all patients by EVL and 87% (26 out of 30) by EIS.

RESULTS

There was no significant difference between EVL and EIS in relation to the incidence of bleeding and the 5 year survival rate after treatment. There were no severe complications except mild substernal pain after EVL, while pulmonary embolism occurred in one patient receiving EIS.

CONCLUSIONS

Endoscopic variceal ligation is a safe and effective technique for eradicating oesophageal varices in patients with hepatitis C cirrhosis.

Nonsteroidal anti-inflammatory drugs may prevent colon cancer through suppression of hepatocyte growth factor expression

Nonsteroidal anti-inflammatory drugs which inhibit cyclooxygenase have been reported to suppress colon carcinogenesis. However the mechanism has not yet been elucidated. Growth factors such as hepatocyte growth factor, which are produced by fibroblasts, have been shown to be important in carcinogenesis and the progression of various human cancers. In the present study, we tested the hypothesis that nonsteroidal anti-inflammatory drugs inhibit hepatocyte growth factor expression through an endogenous prostaglandin-mediated pathway in cultured human colonic fibroblasts. Human colonic fibroblasts were obtained from a resected colon and cultured. Hepatocyte growth factor and prostaglandin E2 were measured by enzyme-linked immunosorbent assay. Induction of cyclooxygenase-1 and cyclooxygenase-2 protein was estimated by immunoblotting. Prostaglandins increased hepatocyte growth factor production significantly in a dose- and time-dependent manner. Cholera toxin and 8-bromo cAMP also stimulated hepatocyte growth factor production. Further, prostaglandin E1 significantly increased cellular cAMP. The prostaglandin EP2 and EP4 receptors were detected by reverse transcription-polymerase chain reaction. Interleukin-1beta dramatically increased prostaglandin E2 production and significantly stimulated hepatocyte growth factor synthesis. Interleukin-1beta induced cyclooxygenase-2 but not cyclooxygenase-1 protein. Indomethacin significantly reduced interleukin-1beta-induced prostaglandin E2 release and hepatocyte growth factor production. These results suggest that prostaglandin is a factor for the production of hepatocyte growth factor by human colonic fibroblasts. Nonsteroidal anti-inflammatory drugs may suppress colon carcinogenesis, in part, through the suppression of hepatocyte growth factor expression by inhibiting endogenous prostaglandin production.

Cloning and characterization of a novel Rab-family gene, Rab36, within the region at 22q11.2 that is homozygously deleted in malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) are rare, pediatric soft-tissue tumors. Homozygous deletions at chromosome 22q11.2 are a recurrent cytogenetic characteristic of MRTs, an indication that this locus may harbor one or more genes conferring tumor-suppressor activity. We constructed a deletion map of the relevant part of 22q11.2 from a panel of seven MRT cell lines, and isolated a novel gene from the center of the region. As it showed a high degree of sequence homology to genes of the Rab family, we designated it Rab36. The protein encoded by Rab36 was localized at the Golgi body. Sequencing of Rab36 cDNAs from three cell lines that retained at least one allele of this gene revealed no nonsense or frameshift mutations. Experiments to induce over-expression of Rab36 by transfection to an MRT cell line similarly failed to justify designation of this gene as a tumor suppressor that would contribute to tumorigenesis by a loss-of-function mechanism.

Enzymatic analysis of acetylpolyamine

An enzymatic method was proposed for measuring acetylpolyamine (AcPA) alone, even when non-acetylated polyamine co-exists. The method consisted of four enzymatic reactions. First, AcPA was hydrolysed by acylpolyamine amidohydrolase to yield acetate; followed by the other three reactions coupled with three enzymes, respectively, acetate kinase, pyruvate kinase, and lactate dehydrogenase; the acetate formation caused a decrease in NADH. The quantity of AcPA was then evaluated as the change in absorbance at 340 nm. The reagent composition of the reaction mixture was determined, and characteristics of the method were investigated. The validation tests produced satisfactory results. The co-existence of non-acetylated polyamine gave no effect on the measurement. The present method was found to be used easily, rapidly and reliably for the selective determination of AcPA itself.

Endoscopic ligation for non-esophageal variceal upper gastrointestinal hemorrhage

BACKGROUND

Endoscopic ligation can be used for bleeding lesions in non-fibrotic tissue; however, only small numbers of patients with non-esophageal variceal upper gastrointestinal hemorrhage have been treated in this way. To evaluate the utility of the technique, we performed the procedure to treat hemorrhage not from esophageal varices during emergency endoscopy.

PATIENTS AND METHODS

Bleeding was identified from gastric Dieulafoy's ulcers (n=4), duodenal ulcers (n=3), gastric angiodysplasia (n=2) and Mallory-Weiss tears (n=3). The bleeding points were aspirated and controlled by endoscopic ligation and complete hemostasis was achieved in all cases.

RESULTS

Although these lesions were located in difficult areas where endoscopic injection therapy and clipping sometimes fail, endoscopic ligation was performed easily and effectively without complications. Six of the patients had severe underlying disease, including acute and chronic myelogenous leukemia, liver cirrhosis and chronic renal failure; none suffered deterioration in their general condition after endoscopic ligation.

CONCLUSIONS

Our findings suggest that endoscopic ligation is an easy and effective method of treatment for patients with gastrointestinal hemorrhage not from esophageal varices, and is safe even in patients with poor general health.

A mesenteric liposarcoma with production of granulocyte colony-stimulating factor

A 77-year-old female was admitted to our hospital because of pyrexia and a right retroperitoneal mass. Leukocytosis and other inflammatory findings were noted. Bone-marrow aspiration revealed hypercellularity with no malignant cells. An additional mass was detected sonographically in the pelvis. The serum concentration of granulocyte colony-stimulating factor (G-CSF) was highly elevated (299 pg/ml). The tumors were removed at laparotomy, and the pelvic mass was found to arise from the ileocecal mesentery. Postoperatively, white blood cell count and serum G-CSF concentrations decreased to normal levels. The mesenteric tumor showed weakly positive immunostaining for human G-CSF, and Northern and polymerase chain reaction (PCR) analyses detected CSF and its mRNA in the mesenteric tumor.

Follow-up of improvement in regional cerebral blood flow and mental status in Alzheimer's disease: a case report

Cerebral SPECT imaging has the potential to make important contributions in the follow-up care of patients with Alzheimer's disease. An unusual case of a patient who showed a follow-up cerebral blood flow pattern different from that routinely seen in Alzheimer's disease patients is reported here. Qualitative and voxel-based objective evaluation of follow-up scans revealed improvement in parietotemporal deficits that had been observed on a baseline study. This change was observed without significant further deterioration in ratings by dementia batteries. This case shows that a baseline regional cerebral blood flow study might be necessary for reference and comparison in the proper follow-up care of Alzheimer's disease patients.

[Bone marrow relapse in high-risk pediatric patients with acute lymphoblastic leukemia: a comparison of relapse times and initial clinical features of patients on different protocols. Children's Cancer and Leukemia Study group (CCLSG)]

To clarify the efficacy of modern intensive chemotherapy for ALL patients with unfavorable features, we compared the time to failure and initial clinical features of children who relapsed in the bone marrow or combined sites, as documented by early CCLSG studies (H811 and H851; 1981-1987) and later studies (H874 and H/HH911; 1987-1993) concerning high-risk ALL patients. In the later studies patients outcomes with new intensive regimens employing early intensification and reinduction therapy were apparently better than those of patients in the early studies with conventional regimens. When we compared the number of relapsed patients based on duration of first remission, we found that the improved outcomes for patients in the later studies were due to a decrease in the number who relapsed 7-36 months after the start of treatment (intermediate relapse), and that the percentage of those who relapsed within the first 6 months of therapy (early relapse) was higher. Patients with high initial WBC counts tended to relapse much earlier than those with low initial WBC counts. However, in the later studies, patients with high WBC counts often relapsed after the termination of therapy (late relapse). These results suggest that the intensive chemotherapy regimens used in the later studies can prevent the development of drug resistant leukemic clones, except in extremely high-risk patients likely to relapse within the first 6 months of therapy.

Phosphorylation of CrkII adaptor protein at tyrosine 221 by epidermal growth factor receptor

CrkII adaptor protein becomes tyrosine-phosphorylated upon various types of stimulation. We examined whether tyrosine 221, which has been shown to be phosphorylated by c-Abl, was phosphorylated also by other tyrosine kinases, such as epidermal growth factor (EGF) receptor. For this purpose, we developed an antibody that specifically recognizes Tyr221-phosphorylated CrkII, and we demonstrated that CrkII was phosphorylated on Tyr221 upon EGF stimulation. When NRK cells were stimulated with EGF, the tyrosine-phosphorylated CrkII was detected at the periphery of the cells, where ruffling is prominent, suggesting that signaling to CrkII may be involved in EGF-dependent cytoskeletal reorganization. The EGF-dependent phosphorylation of CrkII was also detected in a c-Abl-deficient cell line. Moreover, recombinant CrkII protein was phosphorylated in vitro by EGF receptor. These results strongly suggest that EGF receptor directly phosphorylates CrkII. Mutational analysis revealed that the src homology 2 domain was essential for the phosphorylation of CrkII by EGF receptor but not by c-Abl, arguing that these kinases phosphorylate CrkII by different phosphorylation mechanisms. Finally, we found that the CrkII protein phosphorylated upon EGF stimulation did not bind to the phosphotyrosine-containing peptide and that CrkII initiated dissociation from EGF receptor within 3 min even with the sustained tyrosine phosphorylation of EGF receptor. This result implicated phosphorylation of Tyr221 in the negative regulation of the src homology 2-mediated binding of CrkII to EGF receptor.

Neonatal urinary ascites caused by urinary tract obstruction: two case reports

Two cases of neonatal urinary ascites are reported, one (case 1) caused by posterior urethral valves associated with right vesicoureteral reflux, and the other (case 2) secondary to bilateral obstructed megaureter--a very rare cause. Abdominal distension, electrolyte imbalance, and an elevated BUN/serum creatinine ratio were noted at the time of hospitalization in both cases. These laboratory values promptly returned to normal after the establishment of appropriate urinary drainage, accomplished through bladder catheterization in case 1 and bilateral percutaneous nephrostomy in case 2. In case 1, transurethral resection of the posterior urethral valves was followed by resumption of normal urination. In case 2, bilateral ureteroneocystostomy with ureteral tapering was performed successfully. These are only the fifth and sixth cases of neonatal urinary ascites reported in the Japanese literature.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

NRP/B, a novel nuclear matrix protein, associates with p110(RB) and is involved in neuronal differentiation

The nuclear matrix is defined as the insoluble framework of the nucleus and has been implicated in the regulation of gene expression, the cell cycle, and nuclear structural integrity via linkage to intermediate filaments of the cytoskeleton. We have discovered a novel nuclear matrix protein, NRP/B (nuclear restricted protein/brain), which contains two major structural elements: a BTB domain-like structure in the predicted NH2 terminus, and a "kelch motif" in the predicted COOH-terminal domain. NRP/B mRNA (5.5 kb) is predominantly expressed in human fetal and adult brain with minor expression in kidney and pancreas. During mouse embryogenesis, NRP/B mRNA expression is upregulated in the nervous system. The NRP/B protein is expressed in rat primary hippocampal neurons, but not in primary astrocytes. NRP/B expression was upregulated during the differentiation of murine Neuro 2A and human SH-SY5Y neuroblastoma cells. Overexpression of NRP/B in these cells augmented neuronal process formation. Treatment with antisense NRP/B oligodeoxynucleotides inhibited the neurite development of rat primary hippocampal neurons as well as the neuronal process formation during neuronal differentiation of PC-12 cells. Since the hypophosphorylated form of retinoblastoma protein (p110(RB)) is found to be associated with the nuclear matrix and overexpression of p110(RB) induces neuronal differentiation, we investigated whether NRP/B is associated with p110(RB). Both in vivo and in vitro experiments demonstrate that NRP/B can be phosphorylated and can bind to the functionally active hypophosphorylated form of the p110(RB) during neuronal differentiation of SH-SY5Y neuroblastoma cells induced by retinoic acid. Our studies indicate that NRP/B is a novel nuclear matrix protein, specifically expressed in primary neurons, that interacts with p110(RB) and participates in the regulation of neuronal process formation.

Nonsteroidal anti-inflammatory drugs may delay the repair of gastric mucosa by suppressing prostaglandin-mediated increase of hepatocyte growth factor production

Prostaglandins (PGs), hepatocyte growth factor (HGF), and induction of cyclooxygenase (PG synthetase, COX) play important roles in the repair process of gastric mucosa. We hypothesized that nonsteroidal anti-inflammatory drugs (NSAIDs), including indomethacin (IND), retard the healing of ulcers by suppressing these factors. In this study, we investigated the effects of cytokines, growth factors, and IND on production of PG and HGF, and induction of COX using cultured human gastric fibroblasts. Exogenous PGs significantly increased HGF production in a dose-dependent manner. Among various potential stimulants tested, interleukin-1 beta (IL-1 beta) dramatically increased PGE2 production and significantly stimulated HGF production. IL-1 beta induced COX-2 but not COX-1 protein. IND significantly reduced both basal and IL-1 beta-induced PGE2 release and HGF production. These results suggest that the IL-1 beta-PG-HGF pathway plays a role in the repair process of gastric mucosa. Further, NSAIDs may delay the healing of gastric mucosal ulcer, in part through suppression of HGF expression via inhibition of endogenous PG production.

Regulation of cyclin D-dependent kinase activity in rat liver regeneration

The regulation of cyclin D-dependent kinase activity in tissue regeneration in vivo has not been fully described. In young adult rat liver after 70% partial hepatectomy, the association of cyclin D1 with cdk4 was significantly promoted during G1 phase and was maximal at 18 hr, corresponding mainly to late G1. Cyclin D1-dependent kinase activity also strongly increased during G1 phase. The timing of the induction of cyclin D1 / cdk4 complex assembly correlated well with that of cyclin D1-dependent kinase activity. At 18 hr after partial hepatectomy, the amounts of CDK inhibitors p21(CIP1) and p27(KIP1) were also maximal, while only one-tenth of p21(CIP1) and of p27(KIP1) was associated with cyclin D1. These findings suggest that cyclin D1, cdk4 and their association act as promoting factors, and that both p21(CIP1) and p27(KIP1) may have physiological functions as adaptor proteins in additions to their roles as CDK inhibitors in rat liver regeneration.

Hepatocyte growth factor accelerates restitution of intestinal epithelial cells

Many cytokines are involved in the repair of damaged tissue, and one of these, hepatocyte growth factor (HGF), is involved not only with liver regeneration but also in the repair of other tissues. To investigate the importance of HGF in the repair of the small intestine, we evaluated its effect and that of other growth factors in IEC-6 cells, an intestinal epithelial cell line derived from normal rat small intestine. Round "wounds" were made in confluent monolayers of IEC-6 by silicon rubber-tipped steel rods and various cytokines; transforming growth factor alpha (TGF-alpha), transforming growth factor beta1 (TGF-beta1), keratinocyte growth factor (KGF), and HGF, were added. We photographed the repaired monolayers every 24 h and calculated the ratios of areas not covered by cells to initial areas. Cell proliferation with TGF-alpha, TGF-beta, KGF, or HGF was examined in terms of [3H]-thymidine uptake. Finally, we determined c-met (the HGF receptor) mRNA in the IEC-6 cells by Northern blot hybridization. HGF was the most potent of the cytokines in accelerating repair of the damaged monolayer of IEC-6. HGF was also 1.34 times more effective than control the medium for inducing cell proliferation of IEC-6. By Northern blot hybridization, three bands of mRNA bound to c-met cDNA. These results suggest that HGF is important in the repair of the small intestine.

Constitutive association of EGF receptor with the CrkII-23 mutant that inhibits transformation of NRK cells by EGF and TGF-beta

Crk belongs to the adapter proteins that participate in many signalling pathways from cell surface receptors. We have characterised the CrkII-23 mutant that inhibits the transformation of NRK cells induced by epidermal growth factor (EGF) and transforming growth factor (TGF)-beta. To study the biochemical difference, cDNAs of the wild-type CrkII and the CrkII-23 mutant were introduced stably into NIH 3T3 cells expressing EGF receptor (EGFR). Both CrkII and CrkII-23 were phosphorylated on tyrosine upon EGF simulation with similar time course and dose dependency. Whereas the wild-type CrkII bound to EGFR only after EGF stimulation, CrkII-23 bound to EGFR from before stimulation. Mutation in the Src homology (SH) 2 or amino-terminal SH3 domain did not abolish the binding of CrkII-23 to EGFR in the quiescent cells, suggesting that the binding is mediated by a novel mechanism. These CrkII-23-derived mutants, however, did not suppress transformation of NRK cells by EGF and TGF-beta. Hence, both the SH2 and amino-terminal SH3 domains are required to inhibit transformation of NRK cells. These results suggest that persistent signalling from CrkII-23 bound to EGFR suppresses transformation by EGF and TGF-beta in NRK23 cells.

[The intrarenal distribution of prostaglandin E2 and thromboxane A2 in the rat with unilateral ureteral obstruction or unilateral nephrectomy]

BACKGROUND

We evaluated the intrarenal distribution of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) on the rats that underwent unilateral ureteral obstruction (UUO), unilateral nephrectomy (UNX) or sham operation.

METHODS

Male Sprague-Dawley rats were divided into three groups; left ureteral obstruction (UUO), left nephrectomy (UNX) and sham-operation (Control). They were sacrificed at 1, 3, 6, 12, 24 hours and Day 2, Day 3, Day 5, Day 7 and Day 9 after surgery. Intrarenal distribution of eicosanoids were immunohistochemically detected on both kidneys of UUO rats, and on right kidneys of UNX and Control rats.

RESULTS

PGE2: In the obstructed kidneys, immunostained PGE2 increased in medullary interstitium at one hour to 6 hours, and in glomeruli and cortical interstitium at 6 hours. An increase of immunostained PGE2 was observed again in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, expression of immunostained PGE2 increased in glomeruli at Day 5 to 7, and in medullary interstitium at Day 3 to 5. In UNX, immunostained PGE2 increased in the medullary interstitium of the remnant kidneys at 3 hours and Day 3 to 7. On the other hand, an increase of immunostained PGE2 observed in glomeruli and cortical interstitium of these kidneys at Day 5 to 7. TxB2: In the obstructed kidneys, immunostained TxB2 increased in glomeruli and cortical interstitium at 6 hours, and in medullary interstitium at 3 to 12 hours. Predominant expression of TxB2 was observed in medullary interstitium at 3 hours compared to PGE2. We also observed an increase of immunostained TxB2 in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, immunostained TxB2 increased in medullary interstitium at 3 hours and Day 3. In the remnant kidneys of UNX, an increase of immunostained TxB2 was demonstrated in glomeruli at 6 hours and Day 7, and in medullary interstitium at 3 to 6 hours and Day 3 to 7.

CONCLUSION

In the obstructed kidneys, imbalance between PGE2 and TxA2 may contribute to the progression of renal injuries. The fact that expression patterns of these eicosanoids in the opposite kidneys of UUO different from that of the remnant kidneys of UNK, even though both were similarly associated with functional loss of contralateral kidneys, suggested that the opposite kidneys of UUO were affected by any additional factors different from that responsible for the remnant kidneys of UNK.

A carrier for clinical use of recombinant human BMP-2: dehydrothermally cross-linked composite of fibrillar and denatured atelocollagen sponge

The clinical applicability of a dehydrothermally cross-linked composite of fibrillar and denatured atelocollagen sponge (DCFD-AS), as a carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) was evaluated in the rat subcutaneous pouch. After four weeks, DCFD-AS with rhBMP-2 formed compact bone, without undergoing significant changes in shape and size, by means of intramembranous ossification. The ultimate size, shape and location of induced new bone was accurately controlled by the carrier. Low antigenicity of soluble atelocollagen, cross-linking without chemicals, the combination of gelatin with fibrillar collagen, and the spongy structure probably all contributed to new bone formation through intramembranous ossification without inducing an inflammatory response. Atelocollagen sponge is easily sterilized, can be stored at room temperature, and can act as a rhBMP-2 carrier without the need for complex procedures.