Biomedical subjects

K Takenaga

Publications and source records attributed to K Takenaga.

At least 37 records · Page 2Linked to original sources

PubMed1998

Reduced tumorigenicity of human gastric carcinoma cells engineered to produce IL-2 in SCID mice reconstituted with peripheral blood cells from cancer patients.

We have examined the validity of a humanized immune system with an animal model to assess cytokine gene therapy for cancer patients. For that purpose, we prepared hematologically-reconstituted severe combined immunodeficiency mice by transferring patient's peripheral blood cells containing CD34+ cells. These animals were inoculated subcutaneously with human gastric cancer lines transduced with cytokine genes. Tumorigenicity of interleukin-2-producing cells was significantly reduced in reconstituted but not in non-reconstituted mice, whereas that of wild-type and interleukin-6 producer cells was not affected irrespective of the reconstitution status. An inability to induce protective immunity in the reconstituted mice, which had rejected interleukin-2-producers, suggested that the effector cells mediating the antitumor response were non-T cells of donor origin. The experimental system presented in this study seems to be a feasible model to investigate applicable cytokines for patients.

Adult↗

PubMed1998

Hypomethylation of the metastasis-associated S100A4 gene correlates with gene activation in human colon adenocarcinoma cell lines.

The DNA methylation status of the metastasis-associated S100A4 gene in S100A4-positive and -negative human colon adenocarcinoma cell lines was examined. Northern and Western blot analyses revealed that HT-29, SW480, SW620, WiDr and Colo201 cells expressed S100A4, whereas SW837, LoVo and DLD-1 cells expressed little S100A4. Using CpG methylation-sensitive and -insensitive restriction enzymes and PCR-based methylation assay, it was found that the S100A4 gene in HT-29, SW480, SW620, WiDr and Colo201 cells, but not in SW837, LoVo and DLD-1 cells, was hypomethylated and that the hypomethylation of the second intron was correlated well with the expression of S100A4. 5-Aza-2'-deoxycytidine, an inhibitor of the eukaryotic DNA methyltransferase, induced the expression of the S100A4 gene in SW837, LoVo and DLD-1 cells, while it showed no effect on the expression of the gene in WiDr cells. These results indicate that hypomethylation of the S100A4 gene results in the expression of the gene in colon adenocarcinoma cells.

Adenocarcinoma↗

PubMed1998

Cloning and characterization of a novel zinc finger protein that associates with nuclear matrix.

We have recently reported that the nuclei of B16 melanoma cells are intensely stained with anti-rat vitronectin (Vn) antibody, which reacts with both mouse and rat Vn. In the present study, we characterized the protein immunoreactive with the antibody using NIH3T3 cells, whose nuclei were also stained with the antibody. Western blot analysis showed that a protein with an approximate molecular weight of 75 kDa (p75), which was distinct from Vn, existed in the nuclear fraction, and, more specifically, in the nuclear matrix fraction, of NIH3T3 cells. Screening of an NIH3T3 cDNA library resulted in the isolation of a nearly full-length cDNA clone encoding p75. A database search revealed that the cDNA represents a novel gene. The deduced amino acid sequence showed that the protein is 580 amino acids long and contains two C2H2-type zinc finger motifs and glutamic acid-rich domains in the C-terminal region. When a fusion protein of green fluorescence protein and p75 was expressed in NIH3T3 cells, fluorescence was preferentially observed in the nuclei, demonstrating that the protein has a nuclear localization signal. The p75 protein, termed ZAN75, exhibited DNA-binding activity in a zinc-dependent manner. Southern blot analysis demonstrated that the ZAN75 gene exists in a single copy in the mouse genome and that a closely related gene is also present in chicken, rat, and human. Northern blot analysis showed that the ZAN75 gene is ubiquitously expressed in adult mouse tissues. In the cell cycle of NIH3T3 cells, expression was low in the G0/G1 phase, increased during the G1 phase, and persisted during the S and G2/M phases, suggesting that ZAN75 plays a role in regulating cell growth.

3T3 Cells↗

PubMed1998

cDNA cloning of S100 calcium-binding proteins from bovine periodontal ligament and their expression in oral tissues.

The periodontal ligament (PDL) is a unique tissue that is crucial for tooth function. However, little is known of the molecular mechanisms controlling PDL function. To characterize PDL cells at the molecular level, we constructed a cDNA library from bovine PDL tissue. We then focused on the isolation of S100 calcium-binding proteins (CaBPs), because they mediate Ca2+ signaling and control important cellular processes such as differentiation and metabolism. We screened the PDL cDNA library with a mouse S100A4 cDNA, and cloned the bovine cDNAs of two S100 CaBPs (S100A4 and S100A2). In northern blotting analysis, the highest expression of S100A4 was detected in PDL from erupted teeth (PDLE). PDL from teeth under eruption (PDLU) showed a lower expression of S100A4, and its expression in gingiva was faintly detectable. S100A4 expression was also high in the pulp tissue followed by the dental papilla of the tooth germ. S100A2 expression was high in PDLE and gingiva. Interestingly, only PDLE exhibited a high expression of both S100A4 and S100A2. PDLE also expressed the highest level of beta-actin, a target cytoskeletal protein for S100A4. It is conceivable that the high expression of S100A4 in PDLE is a result of the maturation of the PDL and/or a response to mechanical stress generated by mastication. Since there was a marked difference of S100A4 expression between PDL and gingiva, we propose that S100A4 could be a useful marker for distinguishing cells from these two tissues.

Amino Acid Sequence↗

PubMed1998

Induction of antitumor effect on human esophageal carcinoma cells by the retroviral expression of granulocyte macrophage-colony stimulating factor gene.

We have examined antitumor effect of human esophageal carcinoma cells (T.Tn) which were retrovirally transduced to express mouse granulocyte macrophage-colony stimulating factor (mGM-CSF) gene. Nude mice inoculated with T.Tn cells secreting mGM-CSF developed small tumors but the tumors regressed spontaneously, although the proliferation in vitro of transduced cells was not different from that of wild-type cells. In contrast, the tumor of T.Tn cells transduced with human GM-CSF grew as that of wild-type cells, since murine GM-CSF receptors do not bind to human GM-CSF. Histological examination of the regressing tumor of mGM-CSF-producing T.Tn cells revealed predominant infiltration of inflammatory cells including macrophages. In addition, local injection of mGM-CSF-producing T.Tn cells into the established wild-type tumors significantly induced the retardation of subsequent wild-type tumor growth, suggesting that T-cell independent local response plays a crucial role in destroying tumor cells.

Animals↗

PubMed1998

Impaired tumorigenicity of IL-4-producing murine neuroblastoma cells in immunodeficient nude mice.

We have examined antitumor effect of murine neuroblastoma cells (C1300) retrovirally transduced with interleukin-4 (IL-4) gene in syngeneic A/J and nude mice. Although in vitro proliferation of IL-4-secreting C1300 cells (C1300/IL-4) was not different from that of wild-type cells, the in vivo tumor growth of C1300/IL-4 cells subcutaneously inoculated into immunocompetent A/J mice was retarded compared with that of wild-type cells and consequently, the survival of the A/J mice which received C1300/IL-4 cells was prolonged. In immunodeficient nude mice we observed accelerated growth rate of wild-type tumors in comparison with the tumors developed in A/J mice. In contrast, the tumor growth of C1300/IL-4 cells in nude mice was significantly suppressed and the growth was much slower than that of C1300/IL-4 cells inoculated in A/J mice. Thus, the secretion of IL-4 from tumor cells produced antitumor effect more efficiently in mature T cell-defective hosts than in immunocompetent mice. Our results suggest a possible clinical application of IL-4 expression in tumor cells via genetic manipulations especially in immunocompromised cancer patients.

Animals↗

PubMed1998

Antitumor vaccine effect of irradiated murine neuroblastoma cells producing interleukin-2 or granulocyte macrophage-colony stimulating factor.

We have examined vaccination effects of cytokine-producing murine neuroblastoma cells (C1300). C1300 cells retrovirally transduced with interleukin-2 (IL-2) or granulocyte macrophage-colony stimulation factor (GM-CSF) gene were established. Their in vitro proliferation rates and the class I expression of major histocompatibility complex were not different from those of wild-type cells. Five-Gy irradiation of the respective cytokine producers slightly reduced the in vitro cell growth but treatment with 15 Gy significantly impaired the proliferation. In contrast, the secretion of both cytokines from the respective transduced cells was retained compared with the cell growth. We immunized syngeneic mice with irradiated wild-type cells as a control or cytokine-producing cells and challenged the mice with unirradiated wild-type cells. The control mice developed tumors of the challenged wild-type cells, on the contrary, the mice which had received irradiated IL-2 or GM-CSF producers did not. Thus, IL-2- or GM-CSF-expressing syngeneic tumor cells can be potentially used as a tumor vaccine by inducing protective immunity against low immunogenic neuroblastomas in the inoculated hosts.

Animals↗

PubMed1997

Transforming growth factor beta1 increases the expressions of high molecular weight tropomyosin isoforms and vinculin and suppresses the transformed phenotypes in human lung carcinoma cells.

Exposure of the human lung carcinoma cell line, A549 cells, to transforming growth factor beta1 (TGFbeta1) resulted in an alteration in the morphology from epithelial-like to fibroblastic flat cells. Immunofluorescent study revealed that microfilament organization was partially restored in the TGFbeta1-treated cells. We also investigated the effects of TGFbeta1 on the transformed phenotypes including the anchorage-independent growth and invasive ability of A549 cells and found that the phenotypes were strikingly suppressed in TGFbeta1-treated A549 cells. Accompanying these changes, the levels of the expression of high molecular weight tropomyosin (TM) isoforms, especially TM1 and TM2, were significantly increased in the TGFbeta1-treated cells. The expression level of vinculin was also increased in these cells. These results suggest that the increased tropomyosin and vinculin syntheses may be involved in the suppression of the transformed phenotypes of A549 cells.

Actins↗

PubMed1997

Expression of antisense RNA to S100A4 gene encoding an S100-related calcium-binding protein suppresses metastatic potential of high-metastatic Lewis lung carcinoma cells.

S100A4 (also known as pEL98/mts1/p9Ka/18A2/42A/calvasculin /FSP1/CAPL), a member of S100-related calcium-binding proteins, has been implicated to play a role in metastasis. In the present study, we examined the effect of antisense S100A4 RNA on metastatic potential of Lewis lung carcinoma (LLC) cells. High-metastatic All cells were transfected with the expression vector containing S100A4 cDNA in an inverted (antisense) orientation under the transcriptional control of the mouse metallothionein promoter. Treatment of a stably transfected clone (AS10 cells) with Zn2+ resulted in the suppression of the experimental metastatic ability, which was accompanied with the expression of antisense S100A4 RNA and the suppression of the S100A4 expression at both the mRNA and the protein levels. To further confirm the effect of antisense S100A4 RNA, we established several clones after retroviral transduction with an antisense S100A4 construct. Notably, reduced metastatic potential was also evident in these clones. In the antisense S100A4 RNA-expressing cells, cell motility and in vitro invasiveness were found to be suppressed.

Animals↗

PubMed1997

Increased expression of S100A4, a metastasis-associated gene, in human colorectal adenocarcinomas.

The S100A4 gene (also known as pEL98/mts1/p9Ka/18A2/42A/calvasculin /FSP1/CAPL) encoding an S100-related calcium-binding protein is implied to be involved in the invasion and metastasis of murine tumor cells. In the present study, the expression of S100A4 in human colorectal adenocarcinoma cell lines (SW837, LoVo, DLD-1, HT-29, SW480, SW620, WiDr, and Colo201) and surgically resected neoplastic tissues was examined to investigate whether S100A4 plays a role in the invasion and metastasis of human tumor cells. Northern blot analysis using total RNA isolated from the adenocarcinoma cell lines revealed that five of the eight cell lines expressed substantial amounts of S100A4 mRNA. Normal colon fibroblasts (CCD-18Co) expressed little of the RNA. Using surgically resected specimens, it seemed that the amount of S100A4 mRNA in adenomas was nearly equal to that in normal colonic mucosa, whereas adenocarcinomas expressed a significantly higher amount of the RNA than did the adjacent normal colonic mucosa. Immunohistochemical analysis using formalin-fixed paraffin-embedded surgical specimens and monoclonal anti-S100A4 antibody demonstrated that none of 12 adenoma specimens were immunopositive, whereas 8 of 18 (44%) focal carcinomas in carcinoma in adenoma specimens and 50 of 53 (94%) adenocarcinoma specimens were immunopositive. Interestingly, the incidence of immunopositive cells increased according to the depth of invasion, and nearly all of the carcinoma cells in 14 metastases in the liver were positive. These results suggest that S100A4 may be involved in the progression and the metastatic process of human colorectal neoplastic cells.

Adenocarcinoma↗

PubMed1996

Inhibition of peritoneal dissemination of colon carcinoma in syngeneic mice immunized with interleukin-2-producing cells.

We have examined the antitumor effect of murine colon carcinoma cells engineered to produce human interleukin-2 (IL-2) in syngeneic mice. Subcutaneous inoculation of retrovirally-transduced cells with IL-2 gene formed small tumors, but they became regressed spontaneously. Consequently, the inoculated mice showed prolonged survival. Histological examination of the tumors derived from IL-2-producers revealed predominant infiltration of macrophages around tumor necrotic masses. Thus, inoculation of IL-2-producing cells could protect the mice from subsequent subcutaneous or intraperitoneal challenges with wild-type cells, suggesting the induction of acquired immunity due to the effect of tumor vaccination.

Animals↗

PubMed1996

Augmentation of in vivo growth of Lewis lung carcinoma cells transduced with granulocyte macrophage-colony stimulating factor gene.

Cloned high-metastatic Lewis lung carcinoma. A11 cells were retrovirally transduced with either granulocyte macrophage-colony stimulating factor (GM-CSF) or beta-galactosidase gene and examined for their tumorigenicity. GM-CSF-engineered A11 cells produced a much higher amount of GM-CSF than the parental and control cells. Unexpectedly, GM-CSF-engineered A11 cells grew more rapidly than the control cells, while in vitro growth rates of these cells were almost the same. The enhanced tumor growth seemed to be unique to GM-CSF among various cytokines, because interleukin 2 (IL-2), interleukin 4 (IL-4) and interleukin 6 (IL-6) producer cells exhibited suppressed tumor growth.

Animals↗

PubMed1996

Role of a signal transduction pathway which controls disassembly of microfilament bundles and suppression of high-molecular-weight tropomyosin expression in oncogenic transformation of NRK cells.

Role of disassembly of microfilament bundles and suppression of high-molecular-weight tropomyosin (TM) expression in growth factor- and various oncogene-induced transformation was studied by using NRK cells and its transformation-deficient mutants. In NRK cells which show a transformed phenotype by treatment with EGF and TGF-beta, cellular stress fibers became dissociated by EGF or EGF and TGF-beta combination, whereas TGF-beta alone caused thicker appearance of stress fibers. Accompanying these changes, the expression of TM isoforms 1 and 2 was suppressed by treatment with EGF or EGF and TGF-beta, but elevated by TGF-beta with similar time courses. On the other hand, the transformation-deficient mutant cell lines, 39-1 and 39-3, did not show the transformed phenotypes by treatment with EGF and TGF-beta. Neither EGF nor EGF and TGF-beta combination affected cellular stress fibers and expression of TM isoforms 1 and 2 in both mutant lines. The relationship between the formation of stress fibers and the expression of TM isoforms was consistent in NRK cells, the mutant lines and their various oncogene-expressing sublines under various culture conditions. NRK cells overexpressing exogenous mouse TM isoform 2 showed markedly decreased susceptibility to EGF-induced dissociation of stress fibers and decreased anchorage-independent growth potential in the presence of EGF and TGF-beta. These results indicate that the transformation-deficient NRK mutant lines, 39-1 and 39-3 have defects in an EGF signal transduction pathway which induces suppression of high-molecular-weight TM expression and disassembly of microfilament bundles and suggested that the activation of the pathway is important for morphological transformation and oncogenic growth in growth factors- and various oncogene-induced transformation of NRK cells.

Actin Cytoskeleton↗

PubMed1996

Antitumor effect induced by the expression of granulocyte macrophage-colony stimulating factor gene in murine colon carcinoma cells.

Murine colon carcinoma cells which secrete several kinds of cytokine after retroviral transduction with corresponding genes, were examined for their antitumor effects in syngeneic mice. The mice inoculated with granulocyte macrophage-colony stimulating factor (GM-CSF) producer cells showed not only prolonged survival but also reduced tumorigenicity. The antitumor effect caused by the expression of interleukin-4 was less than that of GM-CSF, and interleukin-6 producer cells did not show any effects on the survival of the host animals. Histological examination of the GM-CSF-producing tumor revealed predominant infiltration of neutrophils and necrotic change of the tumor. The present study indicates the feasibility of cancer gene therapy with the expression of GM-CSF gene in tumor cells.

Animals↗

PubMed1996

Murine colon carcinoma cells engineered to produce human interleukin-2 induce tumor-specific anti-tumor response.

Murine colon carcinoma cells (colon 26) transduced by a retrovirus vector with the human interleukin-2 (IL-2) cDNA were studied for their tumorigenicity. Although cell growth in vitro was not affected by integration of the IL-2 gene, s.c. tumors of IL-2-producing colon 26 cells (H2) in syngeneic mice regressed spontaneously after producing small masses. Histological examination of the sites of tumor rejection revealed predominant infiltration of macrophages around the tumor necrotic mass. Subsequent challenge with parent colon 26 cells, but not with Meth A cells (fibrosarcoma of the same genetic background), did not result in tumor formation in mice which had been protected against H2 cells. Inoculation of H2 cells into syngeneic nude mice resulted in tumors with a retarded growth rate. Taken together, T cell-dependent, tumor-specific immunity is obtained by local IL-2 secretion around colon tumors, and this experimental animal model gives us a clue(s) for investigating host anti-tumor responses by cytokine production.

Animals↗

PubMed1996

Cloning of mouse DAN cDNA and its down-regulation in transformed cells.

Recently, we have demonstrated that DAN gene product exhibits a tumor-suppressive activity in vitro. We report here the cloning and sequencing of a mouse DAN cDNA that contains the entire coding region. Sequence analysis revealed that mouse DAM cDNA is 1691 nucleotides in length and contains an open reading frame of 178 amino acids. The deduced mouse DAN protein sequence shows 96% and 93% identity with the counterparts isolated from rat 3Y1 fibroblasts and normal human lung, respectively. Genomic Southern blot hybridization indicated that DAN gene exists as a single copy in the mouse genome. The expression of DAN gene was suppressed in a variety of transformed NIH3T3 cells when compared with that in the parental NIH3T3 cells.

3T3 Cells↗

PubMed1996

Suppression of metastatic potential of high-metastatic Lewis lung carcinoma cells by vanadate, an inhibitor of tyrosine phosphatase, through inhibiting cell-substrate adhesion.

Treatment of high-metastatic Lewis lung carcinoma A11 cells with sodium orthovanadate, a phosphotyrosine phosphatase inhibitor, resulted in a dose- and time-dependent suppression of cell spreading on various extracellular matrix components such as Matrigel, fibronectin, laminin and type IV collagen, while the treatment did not significantly inhibit attachment of the cells to these substrates. Orthovanadate slightly and reversibly inhibited the in vitro cell growth of A11 cells, but the suppression of cell spreading was not directly due to the inhibition of cell growth. Orthovanadate-treated A11 cells showed reduced invasive ability in a reconstituted basement membrane invasion assay and experimental metastatic ability. Protein tyrosine phosphorylation level in A11 cells was elevated after treatment with orthovanadate. The increase in tyrosine phosphorylation level was partially diminished by the tyrosine kinase inhibitor ST638, concomitantly with restoration of the suppressed cell spreading as well as invasive and metastatic abilities. These results suggest that protein tyrosine phosphorylation influences invasive and metastatic potential of tumor cells possibly through regulating cell-substrate adhesion.

3T3 Cells↗

PubMed1995

Suppression of syntheses of high molecular weight nonmuscle tropomyosins in macrophages.

In mouse fibroblasts, at least five TM isoforms are identified and they can be grouped into the high (TM1, TM2, and TM3) and low molecular weight TM isoforms (TM4 and TM5). Suppression of one of the high molecular weight tropomyosin (TM) isoforms in nonmuscle cells is implicated to be one of the causes for disorganization of actin microfilament bundles and subsequent changes in cell motility and cell shape. In this study, we studied the expression of tropomyosin isoforms in macrophages that exhibit high motility and ability to change cell shape. Two-dimensional gel electrophoresis followed by Western blot analysis using polyclonal anti-TM antiserum revealed that the high molecular weight TM isoforms were lacking in both resident and activated mouse peritoneal macrophages. Analyses of newly synthesized TM isoforms, Northern blot analyses using isoform-specific cDNA probes, and immunostaining with monoclonal anti-TM antibody that recognizes only the high molecular weight TM isoforms also demonstrated that the syntheses of the high molecular weight TM isoforms (TM1, TM2, and TM3) were completely suppressed, whereas the low molecular weight TM isoforms (TM4 and TM5) were expressed in macrophages. These results indicate that macrophages intrinsically lack the high molecular weight TM isoforms. In order to obtain information about cellular localization of the low molecular weight TM isoforms in macrophages, they were immunostained with polyclonal anti-TM antiserum that recognizes both the high and low molecular weight TM isoforms. The results showed that the low molecular weight TM isoforms were co-localized with F-actin in punctate and short fibrous structures. In addition, we performed in situ hybridization analysis to examine localizations of the TM mRNAs in fibroblasts and macrophages. The results showed that TM mRNAs were localized throughout the cytoplasm.

Actin Cytoskeleton↗