bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclooxygenase-2 Promotes Human Cholangiocarcinoma Growth
Authors: Han Chang , Leng Jing , Demetris A. Jake , Wu Tong 
Published: September 2005

Abstract
The expression of cyclooxygenase-2 (COX-2) is increased in human cholangiocarcinoma. However, the biologic function and molecular mechanisms of COX-2 in the control of cholangiocarcinoma cell growth have not been well established. This study was designed to examine the direct effect of COX-2 and its inhibitor celecoxib on the growth of human intrahepatic cholangiocarcinoma cells. Overexpression of COX-2 or treatment with prostaglandin E2 (PGE2) enhanced human cholangiocarcinoma cell growth, whereas antisense depletion of COX-2 in these cells decreased PGE2 production and inhibited growth. These findings demonstrate a direct role of COX-2-mediated PGE2 in the growth regulation of human cholangiocarcinoma cells. Furthermore, the COX-2 inhibitor celecoxib induced a dose-dependent inhibition of cell growth, cell cycle arrest at the G1-S checkpoint, and induction of cyclin-dependent kinase inhibitors p21waf1/cip1 and p27kip1. However, the high concentration of celecoxib (50 μm) required for inhibition of growth, the incomplete protection of celecoxib-induced inhibition of cell growth by PGE2 or COX-2 overexpression, and the fact that overexpression or antisense depletion of COX-2 failed to alter the level of p21waf1/cip1 and p27kip1 indicate the existence of a COX-2-independent mechanism in celecoxib-induced inhibition of cholangiocarcinoma cell growth.
Antisense Targeting Protein Kinase C α and β1 Inhibits Gastric Carcinogenesis
Authors: Jiang Xiao-Hua , Tu Shui-Ping , Cui Jian-Tao , Lin Marie C. M. , Xia Harry H. X. , Wong Wai Man , Chan Annie On-On , Yuen Man Fung , Jiang Shi-Hu , Lam Shiu-Kum , Kung Hsiang-Fu , Soh Jae Won , Weinstein I. Bernard , Wong Benjamin Chun-Yu 
Published: September 2005

Abstract
Protein kinase C (PKC) family, which functions through serine/threonine kinase activity, is involved in signal transduction pathways necessary for cell proliferation, differentiation, and apoptosis. Its critical role in neoplastic transformation and tumor invasion renders PKC a potential target for anticancer therapy. In this study, we investigated the effect of targeting individual PKCs on gastric carcinogenesis. We established gastric cancer cell lines stably expressing antisense PKCα, PKCβ1, and PKCβ2 cDNA. These stable transfectants were characterized by cell morphology, cell growth, apoptosis, and tumorigenicity in vitro and in vivo. PKCα-AS and PKCβ1-AS transfectants showed a different morphology with flattened, long processes and decreased nuclear:cytoplasmic ratio compared with the control cells. Cell growth was markedly inhibited in PKCα-AS and PKCβ1-AS transfectants. PKCα-AS and PKCβ1-AS cells were more responsive to mitomycin C- or 5-fluorouracil-induced apoptosis. However, antisense targeting of PKCβ2 did not have any significant effect on cell morphology, cell growth, or apoptosis. Furthermore, antisense inhibition of PKCα and PKCβ1 markedly suppressed colony-forming efficiency in soft agar and in nude mice xenografts. Inhibition of PKCα or PKCβ1 significantly suppressed transcriptional and DNA binding activity of activator protein in gastric cancer cells, suggesting that PKCα or PKCβ1 exerts their effects on cell growth through regulation of activator protein activity. These data provide evidence that targeting PKCα and PKCβ1 by antisense method is a promising therapy for gastric cancer.
Expression of Chicken Ovalbumin Upstream Promoter-Transcription Factor II Enhances Invasiveness of Human Lung Carcinoma Cells
Authors: Navab Roya , Gonzalez-Santos Juana Maria , Johnston Michael R. , Liu Jiang , Brodt Pnina , Tsao Ming-Sound , Hu Jim 
Published: September 2005

Abstract
Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) plays an essential role in angiogenesis and development. It is differentially expressed in tumor cell lines, but its role in carcinogenesis is largely unknown. We demonstrate here that noninvasive human lung cancer cells become invasive when COUP-TFII was expressed. The expression of extracellular matrix degrading proteinases, such as matrix metalloproteinase 2 and urokinase-type plasminogen activator, was up-regulated in these cells. This finding was confirmed by transduction of different human lung cancer cell lines with COUP-TFII protein and also by using antisense expression. We observed disorganization of actin filaments and focal adhesion kinase phosphorylation in COUP-TFII-transfected human lung cancer cells in addition to the increase in extracellular metalloproteinase activity. These results suggest that COUP-TFII may be considered as a new target for anticancer therapies.
Small Interfering Double-Stranded RNAs as Therapeutic Molecules to Restore Chemosensitivity to Thymidylate Synthase Inhibitor Compounds
Authors: Schmitz John C. , Chen Tian-min , Chu Edward 
Published: September 2005

Abstract
RNA interference is a post-transcriptional mechanism by which double-stranded RNA specifically silence expression of a corresponding gene. Small interfering double-stranded RNA (siRNA) of 21–23 nucleotides can induce the process of RNA interference. Studies from our laboratory have shown that translation of thymidylate synthase (TS) mRNA is controlled by its own protein end-product TS in a negative autoregulatory manner. Disruption of this process gives rise to increased synthesis of TS and leads to the development of cellular drug resistance to TS-targeted compounds. As a strategy to inhibit TS expression at the mRNA level, siRNAs were designed to target nucleotides 1058–1077 on human TS mRNA. Transfection of TS1058 siRNA into human colon cancer RKO cells resulted in a dose-dependent inhibition of TS expression with an IC50 value of 10 pm but had no effect on the expression of α-tubulin or topoisomerase I. Inhibition of TS expression by TS1058 was maximal at 48 h and remained suppressed for up to 5 days. Pretreatment of RKO cells with TS1058 siRNA suppressed TS protein induction following exposure to raltitrexed. In addition, TS1058 restored chemosensitivity of the resistant RKO-HTStet cell line to various TS inhibitor compounds. On treatment with TS1058, IC50 values for raltitrexed, 1843U89, and 5-fluoro-2′-deoxyuridine decreased by ∼15–16-fold. These studies suggest that TS-targeted siRNAs are effective inhibitors of TS expression and may have therapeutic potential by themselves or as chemosensitizers in combination with TS inhibitor compounds.
Cyclooxygenase-2 Induces EP1- and HER-2/Neu-Dependent Vascular Endothelial Growth Factor-C Up-Regulation
Authors: Su Jen-Liang , Shih Jin-Yuan , Yen Men-Luh , Jeng Yung-Ming , Chang Cheng-Chi , Hsieh Chang-Yao , Wei Lin-Hung , Yang Pan-Chyr , Kuo Min-Liang 
Published: September 2005

Abstract
Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin H synthase, has been implicated in the progression of human lung adenocarcinoma. However, the mechanism underlying COX-2’s effect on tumor progression remains largely unknown. Lymphangiogenesis, the formation of new lymphatic vessels, has recently received considerable attention and become a new frontier of tumor metastasis research. Here, we study the interaction between COX-2 and the lymphangiogenic factor, vascular endothelial growth factor (VEGF)-C, in human lung cancer cells and their implication in patient outcomes. We developed an isopropyl-β-d-thiogalactopyranoside-inducible COX-2 gene expression system in human lung adenocarcinoma CL1.0 cells. We found that VEGF-C gene expression but not VEGF-D was significantly elevated in cells overexpressing COX-2. COX-2-mediated VEGF-C up-regulation was commonly observed in a broad array of non-small cell lung cancer cell lines. The use of pharmacological inhibitors or activators and genetic inhibition by EP receptor-antisense oligonucleotides revealed that prostaglandin EP1 receptor but not other prostaglandin receptors is involved in COX-2-mediated VEGF-C up-regulation. At the mechanistic level, we found that COX-2 expression or prostaglandin E2 (PGE2) treatment could activate the HER-2/Neu tyrosine kinase receptor through the EP1 receptor-dependent pathway and that this activation was essential for VEGF-C induction. The transactivation of HER-2/Neu by PGE2 was inhibited by way of blocking the Src kinase signaling using the specific Src family inhibitor, PP1, or transfection with the mutant dominant negative src plasmid. Src kinase was involved in not only the HER-2/Neu transactivation but also the following VEGF-C up-regulation by PGE2 treatment. In addition, immunohistochemical staining of 59 lung adenocarcinoma specimens showed that COX-2 level was highly correlated with VEGF-C, lymphatic vessels density, and other clinicopathological parameters. Taken together, our results provided evidence that COX-2 up-regulated VEGF-C and promotes lymphangiogenesis in human lung adenocarcinoma via the EP1/Src/HER-2/Neu signaling pathway.
CD30 Is Involved in Inhibition of T-Cell Proliferation by Hodgkin’s Reed-Sternberg Cells
Authors: Su Che-Chun , Chiu Hsiu-Hui , Chang Chia-Che , Chen Jui-Chieh , Hsu Su-Ming 
Published: September 2005

AbstractCD30 is expressed on Hodgkin’s Reed-Sternberg (H-RS) cells, the tumor cells in Hodgkin’s disease. Increased levels of serum CD30 are observed in Hodgkin’s disease patients and are a good marker for predicting a poor prognosis and a poor response to therapy. In this study, we addressed the effect of CD30 on T cells. We showed that CD30, either as a membranous protein on H-RS cells and Chinese hamster ovary cells or as a plate-bound chimeric protein, inhibited T-cell proliferation. Anti-CD3-stimulated T cells in the presence of CD30 failed to increase tritium uptake and failed to express CD25 and CD26 and to produce interleukin 2. The inhibition of T-cell proliferation was, however, reversed with addition of exogenous interleukin 2 or pretreatment of H-RS cells with anti-CD30. Inability of T cells to express CD25 and CD26 in cocultures with H-RS cells or a plate-bound CD30 chimeric protein is in accordance with the results of immunohistochemistry on disease-involved tissues. We conclude that H-RS cells are able to inhibit the proliferation and activation of T cells through CD30-related interaction. The outcome of CD30-related interaction is an ineffective antitumor immunity, which is clearly in favor of the growth and survival of the tumor cells.
Increase of Nuclear Ceramide through Caspase-3-Dependent Regulation of the “Sphingomyelin Cycle” in Fas-Induced Apoptosis
Authors: Watanabe Mitsumasa , Kitano Toshiyuki , Kondo Tadakazu , Yabu Takeshi , Taguchi Yoshimitsu , Tashima Masaro , Umehara Hisanori , Domae Naochika , Uchiyama Takashi , Okazaki Toshiro 
Published: September 2005

Abstract
Regardless of the existence of ceramide-related molecules, such as sphingomyelin (SM), neutral sphingomyelinase (nSMase), and SM synthase, in the nucleus, the regulation of ceramide in the nucleus is poorly understood in stress-induced apoptosis. In Fas-induced Jurkat T-cell apoptosis, we found a time- and dose-dependent increase of ceramide content in the nuclear and microsomal fractions. Fas-induced increase of ceramide content in the nucleus also was detected by confocal microscopy using anticeramide antibody. Activation of nSMase and inhibition of SM synthase were evident in the nuclear fraction after Fas cross-linking, whereas nSMase was activated, but SM synthase was not affected, in the microsomal fraction. Pretreatment with d-609, a putative SM synthase inhibitor, enhanced Fas-induced increase of ceramide in the nucleus and induction of apoptosis along with increase of Fas-induced inhibition of nuclear SM synthase. Fas-induced activation of caspase-3 was detected in the nuclear fraction and in whole cell lysate. A caspase-3 inhibitor, acetyl-Asp-Glu-Val-Asp-chloromethyl ketone, blocked not only Fas-induced increases of apoptosis and ceramide content but also Fas-induced activation of nSMase and inhibition of SM synthase in the nuclear fraction. Taken together, it is suggested that the nucleus is a site for ceramide increase and caspase-3 activation in Fas-induced Jurkat T-cell apoptosis and that caspase-3-dependent regulation of the “SM cycle” consisting of nSMase and SM synthase plays a role in Fas-induced ceramide increase in the nucleus.
Graft-versus-Tax Response in Adult T-Cell Leukemia Patients after Hematopoietic Stem Cell Transplantation
Authors: Harashima Nanae , Kurihara Kiyoshi , Utsunomiya Atae , Tanosaki Ryuji , Hanabuchi Shino , Masuda Masato , Ohashi Takashi , Fukui Fumiyo , Hasegawa Atsuhiko , Masuda Takao , Takaue Yoichi , Okamura Jun , Kannagi Mari 
Published: September 2005

AbstractAdult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) is characterized by poor prognosis after chemotherapy. Recent clinical trials have indicated, however, that allogeneic but not autologous hematopoietic stem cell transplantation (HSCT) for ATL can yield better clinical outcomes. In the present study, we investigated cellular immune responses of ATL patients who obtained complete remission after nonmyeloablative allogeneic peripheral blood HSCT from HLA-identical sibling donors. In the culture of peripheral blood mononuclear cells (PBMCs) from a post-HSCT but not pre-HSCT ATL patient, CD8+ CTLs proliferated vigorously in response to stimulation with autologous HTLV-I-infected T cells that had been established before HSCT in vitro. These CTLs contained a large number of monospecific CTL population directed to a HLA-A2-restricted HTLV-I Tax 11-19 epitope. The frequency of Tax 11-19-specific CD8+ CTLs in this patient markedly increased also in vivo after HSCT, as determined by staining with HLA-A2/Tax 11-19 tetramers. Similar clonal expansion of HTLV-I Tax-specific CTLs exclusively directed to a HLA-A24-restricted Tax 301-309 epitope was observed in the PBMCs from another ATL patient after HSCT from a HTLV-I-negative donor. Among four post-HSCT ATL patients tested, HTLV-I-specific CTLs were induced in the PBMC culture from three patients but not from the remaining one who had later recurrence of ATL. These observations suggested that reconstituted immunity against antigen presentation in ATL patients after HSCT resulted in strong and selective graft-versus-HTLV-I response, which might contribute to graft-versus-leukemia effects.
Genome-Wide Profiling of Papillary Thyroid Cancer Identifies MUC1 as an Independent Prognostic Marker
Authors: Wreesmann Volkert B. , Sieczka Elizabeth M. , Socci Nicholas D. , Hezel Michael , Belbin Thomas J. , Childs Geoffrey , Patel Snehal G. , Patel Kepal N. , Tallini Giovanni , Prystowsky Michael , Shaha Ashok R. , Kraus Dennis , Shah Jatin P. , Rao Pulivarthi H. , Ghossein Ronald , Singh Bhuvanesh 
Published: September 2005

Abstract
Clinicopathological variables used at present for prognostication and treatment selection for papillary thyroid carcinomas (PTCs) do not uniformly predict tumor behavior, necessitating identification of novel prognostic markers. Complicating the assessment is the long natural history of PTC and our rudimentary knowledge of its genetic composition. In this study we took advantage of differences in clinical behavior of two distinct variants of PTC, the aggressive tall-cell variant (TCV) and indolent conventional PTC (cPTC), to identify molecular prognosticators of outcome using complementary genome wide analyses. Comparative genome hybridization (CGH) and cDNA microarray (17,840 genes) analyses were used to detect changes in DNA copy number and gene expression in pathological cPTC and TCV. The findings from CGH and cDNA microarray analyses were correlated and validated by real-time PCR and immunohistochemical analyses on a series of 100 cases of cPTC and TCV. Genes identified by this approach were evaluated as prognostic markers in cPTC by immunohistochemistry on tissue arrays. CGH identified significant differences in the presence (76 versus 27%; P = 0.001) and type of DNA copy number aberrations in TCV compared with cPTC. Recurrent gains of 1p34–36, 1q21, 6p21–22, 9q34, 11q13, 17q25, 19, and 22 and losses of 2q21–31, 4, 5p14-q21, 6q11–22, 8q11–22, 9q11–32, and 13q21–31 were unique to TCV. Hierarchical clustering of gene expression profiles revealed significant overlap between TCV and cPTC, but further analysis identified 82 dysregulated genes differentially expressed among the PTC variants. Of these, MUC1 was of particular interest because amplification of 1q by CGH correlated with MUC1 amplification by real-time PCR analysis and protein overexpression by immunohistochemistry in TCV (P = 0.005). Multivariate analysis revealed a significant association between MUC1 overexpression and treatment outcome, independent of histopathological categorization (P = 0.03). Analysis of a validation series containing a matched group of aggressive and indolent cPTCs confirmed the association between MUC1 overexpression and survival (relative risk, 2.3; 95% confidence interval, 1.1–5.5; P = 0.03). Our data suggest that MUC1 dysregulation is associated with aggressive behavior of PTC and may serve as a prognostic marker and potential therapeutic target in this disease.
Enhancement of DNA Vaccine Potency by Coadministration of a Tumor Antigen Gene and DNA Encoding Serine Protease Inhibitor-6
Authors: Kim Tae Woo , Hung Chien-Fu , Boyd David A. K. , He Liangmei , Lin Cheng-Tao , Kaiserman Dion , Bird Phillip I. , Wu T-C. 
Published: September 2005

AbstractSerine protease inhibitor 6 (SPI-6), also called Serpinb9, inhibits granzyme B and thus may provide a method for delaying apoptotic cell death in dendritic cells. We have previously enhanced DNA vaccine potency by targeting antigen to MHC antigen presentation pathways, using proteins such as Mycobacterium tuberculosis heat shock protein 70, calreticulin, domain II of Pseudomonas aeruginosa exotoxin A, or the sorting signal of the lysosome-associated membrane protein type 1. In this study, we explored intradermal coadministration of DNA encoding SPI-6 with DNA constructs encoding human papillomavirus type 16 E7 linked to these intracellular targeting molecules for its ability to generate E7-specific CD8+ T-cell immune responses and E7-specific antitumor effects. This combination of strategies resulted in significantly increased E7-specific CD8+ T-cell and CD4+ Th1-cell responses, enhanced tumor treatment ability, and stronger tumor protection when compared with vaccination without SPI-6. Among these targeting strategies tested, mice vaccinated with Sig/E7/lysosome-associated membrane protein type 1 mixed with SPI-6 showed the greatest fold increase in E7-specific CD8+ T cells (∼5-fold). Vaccination with a nonfunctional mutant of SPI-6 did not result in immune enhancement, indicating that enhancement was dependent on the antiapoptotic function of SPI-6. Our results suggest that DNA vaccines combining strategies that enhance MHC class I and II antigen processing with SPI-6 have potential clinical implications for control of viral infection and neoplasia.
Ceramide Reduction and Transcriptional Up-Regulation of Glucosylceramide Synthase through Doxorubicin-Activated Sp1 in Drug-Resistant HL-60/ADR Cells
Authors: Uchida Yoshikazu , Itoh Mitsuru , Taguchi Yoshimitsu , Yamaoka Syohei , Umehara Hisanori , Ichikawa Shin-ichi , Hirabayashi Yoshio , Holleran Walter M. , Okazaki Toshiro 
Published: September 2005

Abstract
Treatment with doxorubicin (DOX) induced apoptosis with an increase of ceramide content in drug-sensitive HL-60 cells, but not in drug-resistant HL-60/ADR cells. In HL-60/ADR cells (but not in HL-60 cells), the levels of mRNA, protein, and activity in glucosylceramide synthase (GCS), which converts ceramide to glucosylceramide, were up-regulated in response to DOX. Thus, abrogation of apoptosis in HL-60/ADR cells might be involved in ceramide reduction through DOX-induced up-regulation of GCS function. Because we reported that a GC-rich/Sp1 promoter binding region was of importance in the regulation of GCS expression, the role of Sp1 in DOX-induced up-regulation of GCS and apoptosis was investigated. DOX induced Sp1 activation in HL-60/ADR cells, as assessed by Sp1 gel shift and promoter-luciferase reporter assays, whereas transfection of double-stranded oligodeoxynucleotides (ODNs) containing a GC-rich/Sp1 region (Sp1 decoy ODNs) inhibited DOX-induced Sp1 activation. In addition, DOX-increased mRNA and enzyme activity in GCS were inhibited by Sp1 decoy, in conjunction with corresponding elevations of ceramide content. Moreover, DOX-induced apoptotic cell death was significantly increased in Sp1 decoy ODN-transfected HL-60/ADR cells over mock-transfected HL-60/ADR cells. Together, the results suggest that transcriptional up-regulation of GCS through DOX-induced activation of Sp1 is one potential mechanism to regulate ceramide increase and apoptosis in HL-60/ADR cells.
Platelet-Derived Growth Factor Production by B16 Melanoma Cells Leads to Increased Pericyte Abundance in Tumors and an Associated Increase in Tumor Growth Rate
Authors: Furuhashi Masao , Sjöblom Tobias , Abramsson Alexandra , Ellingsen Jens , Micke Patrick , Li Hong , Bergsten-Folestad Erika , Eriksson Ulf , Heuchel Rainer , Betsholtz Christer , Heldin Carl-Henrik , Östman Arne 
Published: September 2005

Abstract
Platelet-derived growth factor (PDGF) receptor signaling participates in different processes in solid tumors, including autocrine stimulation of tumor cell growth, recruitment of tumor stroma fibroblasts, and stimulation of tumor angiogenesis. In the present study, the B16 mouse melanoma tumor model was used to investigate the functional consequences of paracrine PDGF stimulation of host-derived cells. Production of PDGF-BB or PDGF-DD by tumor cells was associated with an increased tumor growth rate. Characterization of tumors revealed an increase in pericyte abundance in tumors derived from B16 cells producing PDGF-BB or PDGF-DD. The increased tumor growth rate associated with PDGF-DD production was not seen in mice expressing an attenuated PDGF β-receptor and was thus dependent on host PDGF β-receptor signaling. The increased pericyte abundance was not associated with an increased tumor vessel density. However, tumor cell apoptosis, but not proliferation, was reduced in tumors displaying PDGF-induced increased pericyte coverage. Our findings thus demonstrate that paracrine PDGF production stimulates pericyte recruitment to tumor vessels and suggest that pericyte abundance influences tumor cell apoptosis and tumor growth.
Adjuvant-Mediated Tumor Regression and Tumor-Specific Cytotoxic Response Are Impaired in MyD88-Deficient Mice
Authors: Akazawa Takashi , Masuda Hisayo , Saeki Yoshiko , Matsumoto Misako , Takeda Kiyoshi , Tsujimura Kunio , Kuzushima Kiyotaka , Takahashi Toshitada , Azuma Ichiro , Akira Shizuo , Toyoshima Kumao , Seya Tsukasa 
Published: September 2005

Abstract
The Mycobacterium bovis bacillus Calmette-Guérin cell-wall skeleton (BCG-CWS) activates Toll-like receptor (TLR) 2 and TLR4, but unlike the typical TLR4 agonist bacterial lipopolysaccharide barely induces type 1 IFN. BCG-CWS has been used for adjuvant immunotherapy for patients with cancer. We investigated the adjuvant potential of BCG-CWS for induction of CTLs subsequent to TLR-mediated dendritic cell (DC) maturation, using a syngeneic mouse tumor model (B16 melanoma in C57BL/6). We evaluated the retardation of tumor growth and cytotoxic response in wild-type and MyD88−/− mice immunized with tumor debris and/or BCG-CWS. Delays in tumor growth and cytotoxic response were induced by immunization with a mixture of BCG-CWS emulsion and the tumor. BCG-CWS was capable of activating DCs ex vivo by the criteria of CD80/CD86 up-regulation and cytokine (interleukin-12, tumor necrosis factor-α) induction. Efficient tumor suppression and ex vivo cytokine induction did not occur in MyD88-deficient mice and cells, suggesting that the MyD88 adapter is crucial for induction of tumor cytotoxicity. Because TLR4 is involved in both MyD88-dependent and -independent pathways and the latter affects DC maturation, our findings indicate that both pathways cooperate to induce CTL-based tumor immunity.