bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular analysis of PinX1 in medulloblastomas
Authors: Chang Qing , Pang Jesse Chung‐sean , Li Jing , Hu Landian , Kong Xiangyin , Ng Ho‐keung 
Published: January 2004

AbstractOur group has previously demonstrated a high frequency of allelic loss on the short arm of chromosome 8 and identified a region of homozygous deletion of 1.41 Mb, flanked by D8S520 and D8S1130, on 8p23.1 in medulloblastomas, suggesting the presence of a tumor suppressor gene in this critical deletion region. The aim of our study was to investigate whether PinX1, a newly identified gene whose product is a potent inhibitor of telomerase, is the target gene in the homozygous deletion region identified in medulloblastomas. We assessed for alterations in gene sequence and transcript expression of PinX1, as well as the correlation between PinX1 expression and telomerase activity in a series of 52 medulloblastomas, 3 medulloblastoma cell lines (D283, D341 and Daoy) and 4 primitive neuroectodermal tumors (PNETs). Direct sequence analysis of all 7 exons and splice junctions of the PinX1 gene revealed no somatic mutations but 11 genetic polymorphisms. Transcript expression of PinX1, as evaluated by reverse transcription‐polymerase chain reaction, in microdissected tumors and normal cerebellum showed 2 transcript variants, corresponding to the full‐length form and an alternative spliced variant lacking exon 6, in all samples. This result indicated that PinX1 expression was not suppressed in medulloblastomas. Using the telomeric repeat amplification protocol (TRAP) assay, 13 of 19 (68%) medulloblastomas, 1 of 2 PNETs and all 3 cell lines showed telomerase activity. There is no significant correlation between PinX1 transcript expression and telomerase activity, but our results showed that telomerase activation is involved in medulloblastomas. Taken together, our results suggest that PinX1 does not play a major role in the oncogenesis of medulloblastomas. © 2003 Wiley‐Liss, Inc.
Apc10.1: An ApcMin/+ intestinal cell line with retention of heterozygosity
Authors: De Giovanni Carla , Landuzzi Lorena , Nicoletti Giordano , Astolfi Annalisa , Croci Stefania , Micaroni Massimo , Nanni Patrizia , Lollini Pier‐Luigi 
Published: January 2004

AbstractAPC10.1 is a new intestinal cell line derived from ApcMin/+ mice that retains both the heterozygous Apc genotype and a nonactivated Wnt signaling pathway and displays an early neoplastic phenotype. Although tumorigenic both in immunodepressed and in immunocompetent syngeneic mice, it requires a high cell dose and a long latency. Its epithelial/intestinal origin is shown, in a gene expression profile, by the expression of epithelial transcripts (such as cytokeratin and laminin isoforms) and of developmental regulatory genes (such as Tcf‐4, Hnf3β, p21, Ihh, Hes1) necessary for, or involved in, the maintenance of intestinal stem cells. The lack of activation of the Wnt cascade in APC10.1 cells is shown both by the expression profile of Wnt target genes and by the standard TCF reporter assay. APC10.1 cell line is a novel in vitro model that can contribute to a better understanding of the clinical evolution of familial adenomatous polyposis and to finding of new prophylactic and therapeutic approaches. Supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020‐7136/suppmat/index.html.© 2003 Wiley‐Liss, Inc.
Mechanisms of genomic instability in human cancer: Insights from studies with human papillomavirus oncoproteins
Authors: Duensing Stefan , Münger Karl 
Published: January 2004

AbstractGenomic instability is a hallmark of most human cancers including high‐risk human papillomavirus (HPV)‐associated anogenital neoplasia. The two HPV‐encoded oncoproteins, E6 and E7, can independently induce chromosomal abnormalities. We summarize the current state of knowledge concerning HPV‐induced genomic instability and discuss its significance in the context of human carcinogenesis. © 2003 Wiley‐Liss, Inc.
Identification of biomarkers for the initiation of apoptosis in human preneoplastic colonocytes by proteome analysis
Authors: Herzog Angelika , Kuntz Sabine , Daniel Hannelore , Wenzel Uwe 
Published: January 2004

AbstractDevelopment of resistance of cells toward proapoptotic signals is regarded as one of the key processes that allow tumor development. To identify proteins that are crucial for the initiation of apoptosis in NCOL‐1 human preneoplastic colonocytes, we analyzed the proteome of cells exposed to the flavonoids flavone and quercetin that differ in their ability to induce apoptosis although they possess similar structures. Both flavonoids inhibited proliferation and induced differentiation of NCOL‐1 cells but only quercetin committed the cells to apoptosis. The accessible proteome of NCOL‐1 cells was separated by 2D‐polyacrylamide‐gelelectrophoresis and proteins with changed expression level were identified by peptide mass fingerprints of tryptic digests of the protein spots. A pre‐fractionation of soluble and lipophilic proteins was used to enhance the resolution of analysis. After exposure to the test compounds for 24 hr, 73 proteins displayed changed steady state levels in case of quercetin and 32 in case of flavone. Several heat‐shock proteins, annexins and cytoskeletal caspase substrates were regulated by quercetin but not by flavone and these protein classes are known to play a role in apoptosis induction and execution. Whereas proteins like lamin A, C and desmoplakin, are indicators that apoptosis has already proceeded, others, such as annexin IV or protein kinase C‐beta play a pivotal role in the early phases of apoptosis. In conclusion, proteome analysis allowed the identification of marker proteins that are involved in the initiation of apoptotic cell death in preneoplastic colonocytes and those may help to develop new strategies for cancer prevention. © 2003 Wiley‐Liss, Inc.
Proliferation assay on a silicon chip applicable for tumors extirpated from mammalians
Authors: Torisawa Yu‐suke , Shiku Hitoshi , Kasai Shigenobu , Nishizawa Matsuhiko , Matsue Tomokazu 
Published: January 2004

AbstractWe describe a novel anticancer drug sensitivity assay on a silicon chip applicable for tumors extirpated from in vivo mammalians. Human promyelocytic leukemia (HL‐60) cells were subcutaneously (s.c.) inoculated in SCID mice, then removed 31 days after the inoculation. The cells were embedded in a small volume (18 nL) of a collagen‐gel matrix on a pyramid‐shaped silicon microstructure for further cultivation. The respiration activity of the cells on the chip was measured by scanning electrochemical microscopy (SECM). The proliferation behavior was continuously monitored for 6 days. It seemed that the proliferation rate of the cells removed from the mice was lower than that cultured in a flask and conformed to that in mice. The effects of cisplatin (CDDP) and etoposide (VP‐16) on the HL‐60 cultured in vivo were in good agreement with those obtained by a conventional colorimetric assay. Our results suggest that the SECM‐based assay is appropriate for biopsy specimens in a relatively short‐time evaluation. © 2003 Wiley‐Liss, Inc.
Acetylation of histones associated with the p21WAF1/CIP1 gene by butyrate is not sufficient for p21WAF1/CIP1 gene transcription in human colorectal adenocarcinoma cells
Authors: Kobayashi Hanako , Tan Er Mei , Fleming Sharon E. 
Published: January 2004

AbstractButyric acid is well recognized as a histone deacetylase (HDAC) inhibitor, and changes in histone acetylation are thought to alter gene expression. The mechanism by which sodium butyrate (NaB) induces p21WAF1/CIP1, a critical gene involved in the antiproliferative effect of NaB, was studied at the chromatin level. Using chromatin immunoprecipitation (ChIP) assay, acetylation of histone H3 was observed at the proximal region of the promoter within 30 min of NaB exposure and this extended to the distal region within 2 hr. By contrast, histone H4 was acetylated both at the proximal and the distal regions of the promoter within 30 min. NaB did not influence other histone modifications. NaB stimulated recruitment of the transcription factors ZBP89 and Sp1 as well as GCN5, but did not influence recruitment of Sp3, HDAC1, p300, or CBP. As recruitment of HDAC1 to the promoter appeared not to account for NaB‐induced changes in histone acetylation, we aimed to influence HDAC activity by altering its phosphorylation status. The kinase inhibitor, H7, suppressed p21WAF1/CIP1 mRNA in both the absence and the presence of NaB without influencing the butyrate‐induced hyperacetylation of H3 and H4 associated with the p21WAF1/CIP1 promoter. These results suggest that acetylation of histones at the p21WAF1/CIP1 promoter is not sufficient for NaB to exert antiproliferative effects via transcription of the p21WAF1/CIP1 gene. Induction of p21WAF1/CIP1 transcription by the phosphatase inhibitor, okadaic acid, in the absence of changes in association of acetylated histones with the p21WAF1/CIP1 promoter provides further evidence of the importance of phosphorylation to p21WAF1/CIP1 transcription. © 2003 Wiley‐Liss, Inc.
Promoter hypermethylation of E‐cadherin and its abnormal expression in Epstein‐Barr virus‐associated gastric carcinoma
Authors: Sudo Makoto , Chong Ja‐Mun , Sakuma Kazuya , Ushiku Tetsuo , Uozaki Hiroshi , Nagai Hideo , Funata Nobuaki , Matsumoto Yoshiro , Fukayama Masashi 
Published: January 2004

AbstractPromoter hypermethylation of various tumor‐related genes is extremely frequent in Epstein‐Barr virus (EBV)‐associated gastric carcinoma (EBVaGC). To investigate the significance of the promoter methylation in EBVaGC, we focused on one of the important proteins in the carcinogenesis of the stomach, E‐cadherin. Methylation‐specific PCR analysis (MSP) was applied to surgically resected gastric carcinomas, together with immunohistochemistry, PCR‐based analysis of mutations and allelic loss, and site‐specific MSP of E‐cadherin gene. By MSP, nearly all of the carcinomas showed aberrant methylation of E‐cadherin promoter in EBVaGC (21/22), and the frequency of this aberration was significantly higher than that in EBV‐negative gastric carcinoma (GC; 45/81; p = 0.0003). According to immunohistochemistry of E‐cadherin, the frequency of abnormal staining pattern in EBVaGC (87%) was comparable to that in the diffuse type (80%), but higher than that in the intestinal type of EBV‐negative GC (47%). Promoter methylation was well correlated with abnormal staining pattern in EBVaGC, but not in EBV‐negative GC. Neither mutation nor allelic loss of E‐cadherin was observed in EBVaGC. Methylation status of E‐cadherin within each carcinoma was heterogeneous as far as examined. Thus, in addition to the known association involving p16, we determined that promoter methylation‐mediated silencing of E‐cadherin gene was also closely associated with the development of EBVaGC, although it becomes heterogeneous within a given tumor along its progression. © 2003 Wiley‐Liss, Inc.
Target cell‐restricted and ‐enhanced apoptosis induction by a scFv:sTRAIL fusion protein with specificity for the pancarcinoma‐associated antigen EGP2
Authors: Bremer Edwin , Kuijlen Jos , Samplonius Douwe , Walczak Henning , de Leij Lou , Helfrich Wijnand 
Published: January 2004

AbstractThe apparent tumor selective apoptosis‐inducing activity of recombinant soluble TNF‐related apoptosis‐inducing ligand (TRAIL) has aroused much interest for use in clinical application. However, to exploit fully its therapeutic potential, the characteristics of both the TRAIL receptor system and soluble TRAIL (sTRAIL) should be taken into account: first, the widespread expression of the various TRAIL receptors throughout the human body; second, the differential binding affinities and crosslinking requirements of the agonistic receptors TRAIL‐R1 and TRAIL‐R2; and third, the solution behavior of particular sTRAIL preparations. Therefore, we constructed a novel TRAIL fusion protein, designated scFvC54:sTRAIL, comprising the human scFv antibody fragment C54 genetically linked to the N‐terminus of human sTRAIL. The scFvC54:sTRAIL fusion protein was designed to induce apoptosis by crosslinking of agonistic TRAIL receptors only after specific binding of scFvC54:sTRAIL to the abundantly expressed carcinoma‐associated cell surface antigen EGP2 (alias EpCAM). Target antigen‐restricted apoptosis induction was demonstrated for various EGP2‐positive tumor cells and could be inhibited by an EGP2 competing antibody. Target antigen binding converted soluble scFvC54:sTRAIL into a membrane‐bound form of TRAIL that was capable of signaling apoptosis not only through TRAIL‐R1 but also through TRAIL‐R2. Size‐exclusion fast protein liquid chromatography (FPLC) indicated that scFvC54:sTRAIL was produced as stable and homogeneous trimers in the absence of detectable TRAIL aggregates. The favorable characteristics of the scFvC54:sTRAIL fusion protein potentially reduce the amount of sTRAIL required for antitumor activity and may be of value for the treatment of various human carcinomas. © 2003 Wiley‐Liss, Inc.
CDH1 and CDH13 methylation in serum is an independent prognostic marker in cervical cancer patients
Authors: Widschwendter Andreas , Ivarsson Lennart , Blassnig Anya , Müller Hannes M. , Fiegl Heidi , Wiedemair Annemarie , Müller‐Holzner Elisabeth , Goebel Georg , Marth Christian , Widschwendter Martin 
Published: January 2004

AbstractCervical cancer is the principal cause of death due to cancer in women. Five‐year survival rate ranges from 15–80%, depending on the extent of the disease. New predictive markers for relapse may increase survival rates by improving treatment of patients at high risk for relapse. The gene products of CDH1 and CDH13, namely E‐cadherin and H‐cadherin, play a key role in cell–cell adhesion. Inactivation of the cadherin‐mediated cell adhesion system, caused by aberrant methylation, is a common finding in human cancers. To test the hypothesis that CDH1/CDH13 methylation is a prognostic marker in cervical cancer we determined the methylation status of CDH1/CDH13 in serum samples from 93 cervical cancer patients. Methylation analysis was carried out using MethyLight. Aberrant methylation of the 5′‐region of CDH1 or CDH13 was observed in 43% (40 of 93) of the patients. Cervical cancer patients with unmethylated CDH1/CDH13 in serum samples showed significantly better disease‐free survival in univariate and multivariate analysis. Median disease‐free survival for CDH1/CDH13 methylation negative and positive patients was 4.3 years and 1.2 years, respectively. Our results suggest that detection of aberrant methylation of CDH1/CDH13 may be of potential use as a marker for selecting cervical cancer patients at high risk for relapse who could benefit from additional systemic therapy. © 2003 Wiley‐Liss, Inc.
Resveratrol modulates the phosphoinositide 3‐kinase pathway through an estrogen receptor α‐dependent mechanism: Relevance in cell proliferation
Authors: Pozo‐Guisado Eulalia , Lorenzo‐Benayas M. Jesús , Fernández‐Salguero Pedro M. 
Published: January 2004

AbstractResveratrol (RES), a natural phytoalexin, has antiproliferative activity in human‐derived cancer cells and in rodent models of tumor development. We have previously shown that RES induced apoptotic death in estrogen‐responsive MCF‐7 human breast cancer cells. Recent data have indicated that the estrogen receptor‐α (ERα), through interaction with p85, regulates phosphoinositide 3‐kinase (PI3K) activity, revealing a physiologic, nonnuclear function of the ERα potentially relevant in cell proliferation and apoptosis. In our study, using MCF‐7, we have analyzed the ability of RES to modulate the ERα‐dependent PI3K pathway. Immunoprecipitation and kinase activity assays showed that RES increased the ERα‐associated PI3K activity with a maximum stimulatory effect at concentrations close to 10 μM; concentrations >50 μM decreased PI3K activity. Stimulation of PI3K activity by RES was ERα‐dependent since it could be blocked by the antiestrogen ICI 182,780. RES did not affect p85 protein expression but induced the proteasome‐dependent degradation of the ERα. Nevertheless, the amount of PI3K immunoprecipitated by the ERα remained unchanged in presence of RES, indicating that ERα availability was not limiting PI3K activity. Phosphoprotein kinase B (pPKB/AKT) followed the pattern of PI3K activity, whereas RES did not affect total PKB/AKT expression. PKB/AKT downstream target glycogen synthase kinase 3 (GSK3) also showed a phosphorylation pattern that followed PI3K activity. We propose a mechanism through which RES could inhibit survival and proliferation of estrogen‐responsive cells by interfering with an ERα‐associated PI3K pathway, following a process that could be independent of the nuclear functions of the ERα. © 2003 Wiley‐Liss, Inc.
Endothelial cells co‐cultured with wild‐type and dominant/negative p53‐transfected glioblastoma cells exhibit differential sensitivity to radiation‐induced apoptosis
Authors: Khodarev Nikolai N. , Labay Edwardine , Darga Thomas , Yu Jianqing , Mauceri Helena , Gupta Nalin , Kataoka Yasushi , Weichselbaum Ralph R. 
Published: January 2004

AbstractWe performed expressional profiling of isogenic glioblastoma cell lines U87‐Lux8 and U87‐175.4. These cell lines differ in that U87‐Lux8 expresses wild‐type p53 and U87‐175.4 expresses a dominant‐negative p53 (175His mutation). DNA array analysis and real‐time PCR measurements demonstrated that basal expression and response to irradiation were different in these isogenic glioblastoma cell lines. These differences included genes involved in growth regulation and genes associated with cell‐to‐cell and cell/ECM communications. Co‐cultivation of U87‐175.4 and U87‐Lux8 with HUVE cells demonstrated that U87‐175.4 cells suppress the angiogenic phenotype of HUVEC and increase their sensitivity to radiation‐induced apoptosis compared to co‐culture of U87‐Lux8/HUVEC. These data suggest that blockade of p53 function may alter the communication between tumor cells and endothelial cells such that endothelial cells exhibit an increase in radiosensitivity. These findings may have important implications for the treatment of glioblastoma tumors and other human cancers. © 2003 Wiley‐Liss, Inc.
Genetic alterations in the peritumoral stromal cells of malignant and borderline epithelial ovarian tumors as indicated by allelic imbalance on chromosome 3p
Authors: Tuhkanen Hanna , Anttila Maarit , Kosma Veli‐Matti , Ylä‐Herttuala Seppo , Heinonen Seppo , Kuronen Arja , Juhola Matti , Tammi Raija , Tammi Markku , Mannermaa Arto 
Published: January 2004

AbstractStromal accumulation of hyaluronan in epithelial ovarian cancers is an independent predictor of tumor spreading and unfavorable outcome of the disease. We started to screen for chromosomal causes of this accumulation by studying deletions in 3p21.3, a region harboring 3 hyaluronidase genes (HYAL1‐3) among other potentially important tumor suppressors. Using 6 microsatellite markers from this region, allelic imbalance was found in 60–87% of the informative tumor cells microdissected from histologic sections of 58 patients with epithelial ovarian cancer. However, adjacent stromal cells originally intended as controls showed allelic imbalance at a frequency almost as high as the tumor cells (52–80%). A further laser capture microdissection on 10 borderline tumors also showed a high rate of allelic imbalance, both in the epithelial and stromal cells, but with a pattern slightly different from cancers. Allelic imbalance in the tumor epithelium or stroma was not correlated with the accumulation of hyaluronan or clinicopathologic parameters, including tumor stage and grade. The results suggest that factors other than inactivation of the HYAL1‐3 genes are responsible for hyaluronan accumulation in epithelial ovarian tumors. Moreover, the results indicate that the stromal cells of the epithelial ovarian cancers not only respond to the signals from malignant epithelium but also have themselves undergone genetic alterations in markers partly identical to those in the cancer epithelial cells and may actively contribute to the development of the tumor from its early stages to the late determinants of patient mortality. © 2003 Wiley‐Liss, Inc.
Analysis of the role of the leucine zipper motif in regulating the ability of AFAP‐110 to alter actin filament integrity
Authors: Qian Yong , Gatesman Amanda S. , Baisden Joseph M. , Zot Henry G. , Cherezova Lidia , Qazi Ihtishaam , Mazloum Nayef , Lee Marietta Y. , Guappone‐Koay Anne , Flynn Daniel C. 
Published: January 2004

AbstractAFAP‐110 has an intrinsic ability to alter actin filament integrity as an actin filament crosslinking protein. This capability is regulated by a carboxy terminal leucine zipper (Lzip) motif. The Lzip motif facilitates self‐association stabilizing the AFAP‐110 multimers. Deletion of the Lzip motif (AFAP‐110Δlzip) reduces the stability of the AFAP‐110 multimer and concomitantly increases its ability to crosslink actin filaments, in vitro, and to activate cSrc and alter actin filament integrity, in vivo. We sought to determine how the Lzip motif regulates AFAP‐110 function. Substitution of the c‐Fos Lzip motif in place of the AFAP‐110 Lzip motif (AFAP‐110fos) was predicted to preserve the α‐helical structure while changing the sequence. To alter the structure of the α‐helix, a leucine to proline mutation was generated in the AFAP‐110 α‐helical Lzip motif (AFAP‐110581P), which largely preserved the sequence. The helix mutants, AFAP‐110Δlzip, AFAP‐110fos, and AFAP‐110581P, demonstrated reduced multimer stability with an increased capacity to crosslink actin filaments, in vitro, relative to AFAP‐110. An analysis of opposing binding sites indicated that the carboxy terminus/Lzip motif can contact sequences within the amino terminal pleckstrin homology (PH1) domain indicating an auto‐inhibitory mechanism for regulating multimer stability and actin filament crosslinking. In vivo, only AFAP‐110Δlzip and AFAP‐110581P were to activate cSrc and to alter cellular actin filament integrity. These data indicate that the intrinsic ability of AFAP‐110 to crosslink actin filaments is dependent upon both the sequence and structure of the Lzip motif, while the ability of the Lzip motif to regulate AFAP‐110‐directed activation of cSrc and changes in actin filament integrity in vivo is dependent upon the structure or presence of the Lzip motif. We hypothesize that the intrinsic ability of AFAP‐110 to crosslink actin filaments or activate cSrc are distinct functions. © 2003 Wiley‐Liss, Inc.