bluuebunny/crossref_metadata_2025 huggingface dataset:
Population‐based study of cancer among carriers of a constitutional structural chromosomal rearrangement
Authors: Bache Iben , Hasle Henrik , Tommerup Niels , Olsen Jørgen H.
Published: November 2005

We measured the occurrence of cancer in an unselected cohort of carriers of constitutional structural rearrangements in virtually complete nationwide registries for cancer and constitutional cytogenetic abnormalities. We identified 4,816 carriers of a constitutional structural rearrangement in the Danish Cytogenetic Registry and searched for cancer diagnoses by linkage to the Danish Cancer Registry. There was no overall increased risk for cancer among carriers (standardized incidence ratio [SIR], 0.96; 95% confidence interval [CI], 0.84–1.10), and no significant difference from that expected was found in balanced and unbalanced rearrangements or in any subtypes of rearrangements. We found significantly lower risks for carriers with rearrangements involving chromosome 21 (SIR, 0.50; 95% CI, 0.22–0.99) and for paternally inherited rearrangements (SIR, 0.30; 95% CI, 0.06–0.88). Risk estimates for the observed type‐specific cancers showed an increased risk for non‐Hodgkin lymphoma (SIR, 2.11; 95% CI, 1.09–3.69). However, subgroup analyses were not guided by study hypotheses, and our statistical evaluation of the data should be looked upon as exploratory. In addition, we found 12 constitutional structural rearrangements with a breakpoint potentially associated with a cancer‐related gene. Potential new loci associated with type‐specific cancers were suggested by the findings of families with more than one affected carrier and by the involvement of the same cytogenetic bands in unrelated carriers. Molecular mapping of these breakpoints might provide new insight into cancer predisposition. © 2005 Wiley‐Liss, Inc.
Amplified, lost, and fused genes in 11q23–25 amplicon in acute myeloid leukemia, an array‐CGH study
Authors: Tyybäkinoja Anne , Saarinen‐Pihkala Ulla , Elonen Erkki , Knuutila Sakari
Published: November 2005

Gene amplifications occur rarely in hematologic neoplasms. We characterized two cases of acute myeloid leukemia (AML) with marker chromosomes and 11q23–25 amplicons. Case 1 was a 14‐year‐old male with an additional ring of chromosome 11 material as the sole karyotypic abnormality, as determined by G‐banding and multicolor fluorescence in situ hybridization. Standard comparative genomic hybridization (CGH) showed amplification in 11q23–qter. However, the MLL gene, in 11q23, was not amplified by FISH. Case 2 was a 38‐year‐old male with the G‐banding karyotype 51,XY,+8,+19,+3mar and with 11q22–qter amplification by standard CGH. This patient also had the MLL–LARG fusion gene. We used microarray‐based CGH (array‐CGH) to characterize the amplicons. In case 1, the amplified region in 11q24.3–25 (5.5 Mb) was continuous, and MLL was not amplified, as expected. In case 2, the amplicon was divided into two distinct parts, in 11q23.3 (1.2 Mb) and in 11q23.3–25 (13.3 Mb). It contained a loss (∼1 Mb) in 11q23.3, and the amplicon breakpoint was in the middle of MLL. Although the amplicon size varied, the patients had a common amplified region in 11q24–25 that comprised 14 genes. Expression microarray of case 1 revealed that three of these genes, FLI1, NFRKB, and SNX19, were also overexpressed. The results indicate that the 11q24–q25 region may harbor new candidate oncogenes. In addition, the complex amplicon of case 2 suggests some intriguing chromosomal mechanisms. © 2005 Wiley‐Liss, Inc.
Spectrum of single‐ and multiexon NF1 copy number changes in a cohort of 1,100 unselected NF1 patients
Authors: Wimmer K. , Yao S. , Claes K. , Kehrer‐Sawatzki H. , Tinschert S. , De Raedt T. , Legius E. , Callens T. , Beiglböck H. , Maertens O. , Messiaen L.
Published: November 2005

Neurofibromatosis type 1 (NF1), the most common tumor‐predisposing disorder in humans, is caused by defects in the NF1 tumor‐suppressor gene. Comprehensive mutation analysis applying RNA‐based techniques complemented with FISH analysis achieves mutation detection rates of ∼95% in NF1 patients. The majority of mutations are minor lesions, and ∼5% are total gene deletions. We found 13 single‐ and/or multiexon deletions/duplications out of 1,050 detected mutations using our RNA‐based approach in a cohort of 1,100 NF1 patients and confirmed these changes using multiplex ligation‐dependent probe amplification (MLPA). With MLPA, we found another 12 novel multiexon deletion/duplications in 55 NF1 patients for whom analysis with multiple assays had not revealed a NF1 mutation, including 50 previously analyzed comprehensively. The extent of the 22 deletions and 3 duplications varied greatly, and there was no clustering of breakpoints. We also evaluated the sensitivity of MLPA in identifying deletions in a mosaic state. Furthermore, we tested whether the MLPA P122 NF1 area assay could distinguish between type I deletions, with breakpoints in low‐copy repeats (NF1‐LCRs), and type II deletions, caused by aberrant recombination between the JJAZ gene and its pseudogene. Our study showed that intragenic deletions and/or duplications represent only ∼2% of all NF1 mutations. Although MLPA did not substantially increase the mutation detection rate in NF1 patients, it was a useful first step in a comprehensive mutation analysis scheme to quickly pinpoint patients with single‐ or multiexon deletions/duplications as well as patients with a total gene deletion who will not need full sequencing of the complete coding region. © 2005 Wiley‐Liss, Inc.
Specific dynamic and noninvasive labeling of pancreatic β cells in reporter mice
Authors: Ben‐Yehudah Ahmi , Reinhart Bonnie , Navara Chris , Kotzuk Joyce , Witchel Selma , Schatten Gerald , Chaillet J. Richard
Published: November 2005

Noninvasive detection of differentiated cells is increasingly demanded for accurate and reliable assessments of both in vitro and in vivo experimental systems. Here we present an efficient, innovative approach for imaging the β cells of the pancreatic islets of Langerhans. The main physiologic function of β cells is glucose‐stimulated insulin secretion. This function is facilitated through the synthesis and storage of insulin in secretory vesicles of β cells, which then release their contents when β cells are exposed to hyperglycemic conditions. To visualize β cells in vivo in the mouse, we used targeted mutagenesis techniques to construct a modified insulin II (InsII) gene allele, InsIIEGFP, that expresses a proinsulin‐EGFP (enhanced green fluorescent protein) fusion peptide. The EGFP portion of this fusion is entirely within the C‐peptide portion of the proinsulin peptide. This fusion protein is processed in β cells to insulin and EGFP‐tagged C peptide, which are stored together in cytoplasmic secretory vesicles. The large amount of vesicular EGFP‐tagged C peptide is evident as a characteristic robust and specific fluorescence pattern in the β cells of InsIIEGFP mice. This innovative method of visualizing β cells will be a useful tool in the study of both β cell physiology and the development of the endocrine cells of the pancreas.genesis 43:166–174, 2005. © 2005 Wiley‐Liss, Inc.
Vowel sound extraction in anterior superior temporal cortex
Authors: Obleser Jonas , Boecker Henning , Drzezga Alexander , Haslinger Bernhard , Hennenlotter Andreas , Roettinger Michael , Eulitz Carsten , Rauschecker Josef P.
Published: November 2005

We investigated the functional neuroanatomy of vowel processing. We compared attentive auditory perception of natural German vowels to perception of nonspeech band‐passed noise stimuli using functional magnetic resonance imaging (fMRI). More specifically, the mapping in auditory cortex of first and second formants was considered, which spectrally characterize vowels and are linked closely to phonological features. Multiple exemplars of natural German vowels were presented in sequences alternating either mainly along the first formant (e.g., [u]‐[o], [i]‐[e]) or along the second formant (e.g., [u]‐[i], [o]‐[e]). In fixed‐effects and random‐effects analyses, vowel sequences elicited more activation than did nonspeech noise in the anterior superior temporal cortex (aST) bilaterally. Partial segregation of different vowel categories was observed within the activated regions, suggestive of a speech sound mapping across the cortical surface. Our results add to the growing evidence that speech sounds, as one of the behaviorally most relevant classes of auditory objects, are analyzed and categorized in aST. These findings also support the notion of an auditory “what” stream, with highly object‐specialized areas anterior to primary auditory cortex. Hum. Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Amygdala–prefrontal dissociation of subliminal and supraliminal fear
Authors: Williams Leanne M. , Liddell Belinda J. , Kemp Andrew H. , Bryant Richard A. , Meares Russell A. , Peduto Anthony S. , Gordon Evian
Published: November 2005

Facial expressions of fear are universally recognized signals of potential threat. Humans may have evolved specialized neural systems for responding to fear in the absence of conscious stimulus detection. We used functional neuroimaging to establish whether the amygdala and the medial prefrontal regions to which it projects are engaged by subliminal fearful faces and whether responses to subliminal fear are distinguished from those to supraliminal fear. We also examined the time course of amygdala‐medial prefrontal responses to supraliminal and subliminal fear. Stimuli were fearful and neutral baseline faces, presented under subliminal (16.7 ms and masked) or supraliminal (500 ms) conditions. Skin conductance responses (SCRs) were recorded simultaneously as an objective index of fear perception. SPM2 was used to undertake search region‐of‐interest (ROI) analyses for the amygdala and medial prefrontal (including anterior cingulate) cortex, and complementary whole‐brain analyses. Time series data were extracted from ROIs to examine activity across early versus late phases of the experiment. SCRs and amygdala activity were enhanced in response to both subliminal and supraliminal fear perception. Time series analysis showed a trend toward greater right amygdala responses to subliminal fear, but left‐sided responses to supraliminal fear. Cortically, subliminal fear was distinguished by right ventral anterior cingulate activity and supraliminal fear by dorsal anterior cingulate and medial prefrontal activity. Although subcortical amygdala activity was relatively persistent for subliminal fear, supraliminal fear showed more sustained cortical activity. The findings suggest that preverbal processing of fear may occur via a direct rostral–ventral amygdala pathway without the need for conscious surveillance, whereas elaboration of consciously attended signals of fear may rely on higher‐order processing within a dorsal cortico–amygdala pathway. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Medial septal modulation of the ascending brainstem hippocampal synchronizing pathways in the anesthetized rat
Authors: Jackson Jesse , Bland Brian H.
Published: November 2005

Independent and combined electrical stimulation pairings of the medial septum (MS), posterior hypothalamus (PH), and reticular pontine oralis (RPO) of the brainstem were performed in the acute urethane anesthetized rat, while recording field activity from electrodes in either the stratum oriens or stratum moleculare of the hippocampal formation. Theta frequency and power were measured during independent stimulation of each nuclei and during combined stimulation using three pairings: (1) MS–PH (2) MS–RPO and (3) PH–RPO. Each pairing consisted of parameters known to elicit theta of a high frequency for one nucleus, and parameters known to elicit a low frequency for the second nucleus. This methodology allowed us to observe whether one nucleus preferentially modulated theta activity in the hippocampus in terms of frequency and power. The MS was observed to reset theta frequency in both the upward and downward direction when stimulated in combination with either the PH (Experiment 1) or the RPO (Experiment 2). In Experiment 3 (PH–RPO), the structure receiving the higher intensity stimulation had the predominate effect on theta frequency. With MS stimulation combinations, the power of the elicited theta activity was found to increase over the independent stimulation in some cases during Experiment 1. Likewise, in Experiment 2, the combined stimulation produced a power that in most cases was significantly greater than that measured during the independent stimulations. This effect was not observed with PH and RPO stimulation combinations. The combined stimulation of the PH and RPO yielded a power similar to the independent PH stimulations. The findings support the following conclusions: (1) the major theta generating activity of the ascending brainstem synchronizing pathways involves projections from the RPO to the PH, relayed through the MS, to the hippocampal formation; and (2) that the MS directly controls theta amplitude and secondarily translates the level of ascending brainstem activity into the appropriate frequency of hippocampal theta. © 2005 Wiley‐Liss, Inc.
The V617F JAK2 mutation and the myeloproliferative disorders
Authors: Percy Melanie J , McMullin Mary Frances
Published: November 2005

The discovery this year of a single mutation in the Janus Kinase (JAK)‐2 gene in a high percentage of cases of polycythaemia vera (PV), essential thrombocythaemia (ET) and myelofibrosis suggests that it maybe the underlying molecular mechanism for these disorders. Different approaches from the inhibition of the tyrosine kinase JAK2, widespread search for mutations in tyrosine kinases, and investigation of the short arm of chromosome 9 where JAK2 is located all led to the discovery of the V617F JAK2 mutation. Substitution of a valine for a phenylalanine destabilizes the JH2 domain of JAK2 causes loss of the auto‐inhibitory activity of this domain and explains some of the biological phenomena observed in patients with myeloproliferative disorders (MPD). The V617F JAK2 mutation can be detected by PCR‐direct sequencing using DNA from the granulocyte lineage or with increased sensitivity by the amplification refractory mutation system using DNA from unfractionated blood. Pyrosequencing assays can be used to quantitate allele ratios to accurately define homozygote and heterozygote status. This single mutation is widespread having been detected in related MPD and other haematological malignancies. This leads to a number of further questions about the role of this single mutation in the clinical pattern of disease. Copyright © 2005 John Wiley & Sons, Ltd.
Continuity wave in the elongated bubble region of horizontal slug flow
Authors: Liu Lei , Gong Sheng‐Jie , Sun He‐Dong , Zhou Fang‐De
Published: November 2005

Visualized observation on the wave feature in a horizontal slug flow was made with a high‐speed digital camera. It was found that the liquid film flow in the elongated bubble region of slug flow behaves as a continuity wave. Theoretical analysis was carried out and it reveals that the liquid film flow is a continuity wave with celerity the same as the translational velocity of the elongated bubble. The control equation for the liquid film height in the elongated bubble region was derived. The results predicted by the equation fit well with the observed data. A new conclusion was obtained that slug flow has continuity wave in it, explaining the stable slug flow wave characterization. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(8): 547–554, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20092
Theoretical calculation and experimental investigation on acoustic characteristics of a regenerator in thermoacoustic apparatus
Authors: Xie X.J. , Li Q. , Yu Z.B.
Published: November 2005

An acoustic‐driven thermoacoustic device, which is used to investigate acoustic characteristics of a regenerator, was designed and manufactured. A model of the acoustic characteristics of the regenerator is discussed. The acoustic characteristics of the regenerator, such as acoustic impedance Ẑn, reflection coefficient $\hat{\alpha}_{n}$, transmission loss TL, and phase angle $\hat{\theta}$ between incident and reflected wave at x=0, were obtained by processing the experimental results with the correlation‐spectra analysis (the auto‐ and cross‐spectra) methods theoretically. Comparisons of acoustic characteristics between two cases, A (regenerator) and B (regenerator and two additional heat exchangers), are discussed. Different heating power influence on acoustic characteristics is also investigated. The results obtained will be helpful in further investigations on the regenerator model. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(8): 539–546, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20093
Differences in expression patterns of the tight junction proteins,claudin 1, 3, 4 and 5, in human ovarian surface epithelium as compared to epithelia in inclusion cysts and epithelial ovarian tumours
Authors: Zhu Yihong , Brännström Mats , Janson P.‐O. , Sundfeldt Karin
Published: November 2005

Human ovarian surface epithelium (OSE), regarded as the precursor cell of epithelial ovarian adenocarcinoma, is not a fully developed epithelium when situated on the ovarian surface. It lacks epithelial characteristics such as the cell–cell adhesion factor epithelial (E)‐cadherin, but as we have shown earlier, this OSE can form functional tight junctions (TJs) in culture. Recent gene‐expression data on ovarian adenocarcinoma has pointed out a family of TJ proteins, the claudins, to be highly expressed in malignant compared to benign ovarian tumours. The purpose of this study was to investigate the distribution of claudin 1–5 proteins in cultured OSE (n = 4), normal ovarian (n = 11), benign (n = 8), borderline (n = 7) and ovarian cancer (n = 22) tissues. We found that a weak or absence of expression of claudin 3 and claudin 4 in surface OSE changed to typical cell‐border localisation in OSE of inclusion cysts in the normal ovarian stroma. Semiquantitative estimations of immunoblots showed that claudin 3 was significantly increased in ovarian adenocarcinomas compared to benign and borderline‐type tumours. Claudin 4 was significantly increased in both borderline‐type and ovarian adenocarcinomas compared to benign tumours, whereas no changes were found for claudin 1 or 5. Concerning relation to Federation for International Gynaecology and Obstetrics (FIGO) grade, claudin 3, but not claudin 4, was significantly increased in moderately, poorly and undifferentiated adenocarcinomas compared to well‐differentiated and borderline‐type tumours. No significant changes were noticed for any claudin with regard to FIGO stages. We conclude that both claudin 3 and 4, even though they differ in expression during ovarian malignant transformation, might be used as novel markers for ovarian tumours. The observations of lack of claudin 4 and low expression of claudin 3 in OSE strengthen our current knowledge about the biological nature of these cells as an undeveloped epithelium. © 2005 Wiley‐Liss, Inc.
Seventy‐five years is an appropriate upper age limit for population‐based mammography screening
Authors: Fracheboud Jacques , Groenewoud Johanna Helëne , Boer Rob , Draisma Gerrit , de Bruijn Arry E. , Verbeek André L.M. , de Koning Harry J.
Published: November 2005

In this study, we assessed the results of the Dutch breast cancer screening programme for women aged 70–75, and discussed the current upper age limit of the women invited. We compared the main outcome parameters of the screening programme 1998–2000 for women aged 70–75, with those in women aged 50–69. Breast cancer detection rates were also compared with prediction from 2 variants of a simulation model of breast cancer screening, assuming the mean sojourn time, i.e., the duration of the preclinical detectable phase, to increase or not with age above the age of 65. The underlying idea is that an increase of the sojourn time with age will lead to a less favourable balance between screening benefits and harms from a certain age on. Of the 315,103 women (aged 70–75) invited, 65.6% participated. The attendance increased from 1998 to 2000. For women aged 74 and 75 years, this increase was almost 10%. As a result of the 187,207 screening examinations performed within this age group, 18.3 per 1,000 women were referred and 10.3 per 1,000 breast cancer were diagnosed. Detection rates in both initial and subsequent screens increased steadily with age and got close to those model‐simulated rates, which assume a continuously increasing sojourn time with age. A major finding of this study is that the screening participation among elderly women is high. The outcomes of our study suggest a steadily increasing sojourn time of breast tumours beyond the age of 69, leading to a strong increase in detection of cancers, and therefore, disfavouring the balance with the benefits of screening. At present, 75 years of age can be regarded as an appropriate upper age limit for the Dutch programme. © 2005 Wiley‐Liss, Inc.
Quantitative analysis of aromatase mRNA expression derived from various promoters (I.4, I.3, PII and I.7) and its association with expression of TNF‐α, IL‐6 and COX‐2 mRNAs in human breast cancer
Authors: Irahara Natsumi , Miyoshi Yasuo , Taguchi Tetsuya , Tamaki Yasuhiro , Noguchi Shinzaburo
Published: November 2005

The purpose of the present study was to study the aromatase mRNA expression as well as promoter usage (I.4, I.3, PII and I.7) in axillary adipose tissue (AA), mammary adipose tissue (MA), breast tumor tissue (BT) and adjacent normal breast tissue (NB), and to study the relationship between aromatase mRNA expression and tumor necrosis factor (TNF)‐α, interleukin (IL)‐6 and cyclooxygenase (COX)‐2 mRNA expression. BT (n = 108), NB (n = 54), AA (n = 41) and MA (n = 34) from patients with breast cancer were subjected to real‐time PCR assays for the mRNA levels of aromatase, TNF‐α, IL‐6 and COX‐2. We also studied the usage of promoters I.4, I.3, PII and the recently reported endothelial promoter I.7. Total aromatase mRNA levels were significantly up‐regulated in BT as compared with NB, AA and MA. Proportion of promoter l.4‐specific transcripts against the total transcripts was significantly decreased and that of promoter l.3‐ and l.7‐specific transcripts was significantly increased in BT than NB, AA and MA. However, the amount of transcripts from all the 4 promoters was significantly up‐regulated in BT than NB, AA and MA. Estrogen receptor‐α (ER‐α) positive tumors showed a higher percentage of promoter I.7 usage than ER‐α negative tumors with a marginal significance (p = 0.05), and tumor with high microvessel counts tended (p = 0.06) to show a higher percentage of promoter I.7 usage than those with low microvessel counts. There was a significant association between aromatase mRNA levels and TNF‐α, IL‐6 or COX‐2 mRNA levels in BT, AA and MA but not in NB. These results suggest that enhanced transcription of promoters l.4, I.3, PII and I.7 explains the up‐regulation of aromatase mRNA levels in BT. It has also been suggested that angiogenesis might stimulate the growth of ER‐α positive tumors through the enhanced transcription of aromatase from promoter I.7 in endothelial cells in BT, and that TNF‐α, IL‐6 and COX‐2 might be implicated in the up‐regulation of aromatase mRNA in BT, AA and MA but not in NB. © 2005 Wiley‐Liss, Inc.
Expression profiling of Wilms tumors reveals new candidate genes for different clinical parameters
Authors: Zirn B. , Hartmann O. , Samans B. , Krause M. , Wittmann S. , Mertens F. , Graf N. , Eilers M. , Gessler M.
Published: November 2005

Wilms tumor is the most frequent renal neoplasm in children, but our understanding of its genetic basis is still limited. We performed cDNA microarray experiments using 63 primary Wilms tumors with the aim of detecting new candidate genes associated with malignancy grade and tumor progression. All tumors had received preoperative chemotherapy as mandated by the SIOP protocol, which sets this study apart from related approaches in the Unites States that are based on untreated samples. The stratification of expression data according to clinical criteria allowed a rather clear distinction between different subsets of Wilms tumors. Clear‐cut differences in expression patterns were discovered between relapse‐free as opposed to relapsed tumors and tumors with intermediate risk as opposed to high risk histology. Several differentially expressed genes, e.g.TRIM22, CENPF, MYCN, CTGF, RARRES3 and EZH2, were associated with Wilms tumor progression. For a subset of differentially expressed genes, microarray data were confirmed by real‐time RT‐PCR on the original set of tumors. Interestingly, we found the retinoic acid pathway to be deregulated at different levels in advanced tumors suggesting that treatment of these tumors with retinoic acid may represent a promising novel therapeutic approach. © 2005 Wiley‐Liss, Inc.
Expression of hiwi gene in human gastric cancer was associated with proliferation of cancer cells
Authors: Liu Xiaoying , Sun Yu , Guo Jianping , Ma Hong , Li Jiyou , Dong Bin , Jin Genglin , Zhang Jianzhi , Wu Jian , Meng Lin , Shou Chengchao
Published: November 2005

Stem cell genetics research may be critical to our understanding of carcinogenesis, as both stem cells and cancer cells possess the ability to self‐renew. Recent discoveries have indicated that the piwi family of genes plays an essential role in stem cell self‐renewal in diverse organisms. The hiwi gene, the human homolog of the piwi family, participates in germ cell proliferation and its overexpression may cause the development of germ cell malignancy, but its expression and function in epithelial solid cancers have not been explored. In the present study, we investigated whether there was an association between hiwi expression and human gastric cancer and its potential mechanism. RT‐PCR findings demonstrated that hiwi was expressed in different gastric cancer cell lines. To identify the HIWI protein in gastric cancer, we developed a specific monoclonal antibody against HIWI and immunohistochemistry was performed on various gastric tissues. We found that the expression ratio of hiwi in normal gastric tissues, atrophic gastritis, intestinal metaplasia and gastric cancers was 10% (5/50), 36% (18/50), 36% (18/50) and 76% (38/50), respectively, which was consistent with precancerous development. Notably, the expression pattern of hiwi in gastric cancer tissues was similar to that of Ki67, which was used as a marker of proliferation. Moreover, the suppression of hiwi by antisense or RNAi inhibited the growth of gastric cancer cells and induced cell cycle arrest in G2/M phase. These results suggest that hiwi may be involved in the development of gastric cancer and is a potential target for cancer therapy. © 2005 Wiley‐Liss, Inc.
Proteasome inhibitor MG132 sensitizes HPV‐positive human cervical cancer cells to rhTRAIL‐induced apoptosis
Authors: Hougardy Brigitte M.T. , Maduro John H. , van der Zee Ate G.J. , de Groot Derk Jan A. , van den Heuvel Fiona A.J. , de Vries Elisabeth G.E. , de Jong Steven
Published: November 2005

In cervical carcinogenesis, the p53 tumor suppressor pathway is disrupted by HPV (human papilloma virus) E6 oncogene expression. E6 targets p53 for rapid proteasome‐mediated degradation. We therefore investigated whether proteasome inhibition by MG132 could restore wild‐type p53 levels and sensitize HPV‐positive cervical cancer cell lines to apoptotic stimuli such as rhTRAIL (recombinant human TNF‐related apoptosis inducing ligand). In a panel of cervical cancer cell lines, CaSki was highly, HeLa intermediate and SiHa not sensitive to rhTRAIL‐induced apoptosis. MG132 strongly sensitized HeLa and SiHa to rhTRAIL‐induced apoptosis in a caspase‐dependent and time‐dependent manner. MG132 massively induced TRAIL receptor DR4 and DR5 membrane expression in HeLa, whereas in SiHa only DR5 membrane expression was upregulated from almost undetectable to high levels. Antagonistic DR4 antibody partially inhibited apoptosis induction by rhTRAIL and MG132 in HeLa but had no effect on apoptosis in SiHa. Inhibition of E6‐mediated p53 proteasomal degradation by MG132 resulted in elevated levels of active p53 as demonstrated by p53 small interfering RNA (siRNA) sensitive p21 upregulation. Although p53 siRNA partially inhibited MG132‐induced DR5 upregulation in HeLa and SiHa, no effect on rhTRAIL‐induced apoptosis was observed. MG132 plus rhTRAIL enhanced caspase 8 and caspase 3 activation and concomitant cleavage of X‐linked inhibitor of apoptosis (XIAP), particularly in HeLa. In addition, caspase 9 activation was only observed in HeLa. Downregulation of XIAP using siRNA in combination with rhTRAIL induced high levels of apoptosis in HeLa, whereas MG132 had to be added to the combination of XIAP siRNA plus rhTRAIL to induce apoptosis in SiHa. In conclusion, proteasome inhibition sensitized HPV‐positive cervical cancer cell lines to rhTRAIL independent of p53. Our results indicate that not only DR4 and DR5 upregulation but also XIAP inactivation contribute to rhTRAIL sensitization by MG132 in cervical cancer cell lines. Combining proteasome inhibitors with rhTRAIL may be therapeutically useful in cervical cancer treatment. © 2005 Wiley‐Liss, Inc.
Alcohol dehydrogenase 1C*1 allele is a genetic marker for alcohol‐associated cancer in heavy drinkers
Authors: Homann Nils , Stickel Felix , König Inke R. , Jacobs Arne , Junghanns Klaus , Benesova Monika , Schuppan Detlef , Himsel Susanne , Zuber‐Jerger Ina , Hellerbrand Claus , Ludwig Dieter , Caselmann Wolfgang H. , Seitz Helmut K.
Published: November 2005

Chronic alcohol consumption is associated with an increased risk for upper aerodigestive tract cancer and hepatocellular carcinoma. Increased acetaldehyde production via alcohol dehydrogenase (ADH) has been implicated in the pathogenesis. The allele ADH1C*1 of ADH1C encodes for an enzyme with a high capacity to generate acetaldehyde. So far, the association between the ADH1C*1 allele and alcohol‐related cancers among heavy drinkers is controversial. ADH1C genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism in a total of 818 patients with alcohol‐associated esophageal (n = 123), head and neck (n = 84) and hepatocellular cancer (n = 86) as well as in patients with alcoholic pancreatitis (n = 117), alcoholic liver cirrhosis (n = 217), combined liver cirrhosis and pancreatitis (n = 17) and in alcoholics without gastrointestinal organ damage (n = 174). The ADH1C*1 allele and genotype ADH1C*1/1 were significantly more frequent in patients with alcohol‐related cancers than that in individuals with nonmalignant alcohol‐related organ damage. Using multivariate analysis, ADH1C*1 allele frequency and rate of homozygosity were significantly associated with an increased risk for alcohol‐related cancers (p<0.001 in all instances). The odds ratio for genotype ADH1C*1/1 regarding the development of esophageal, hepatocellular and head and neck cancer were 2.93 (CI, 1.84–4.67), 3.56 (CI, 1.33–9.53) and 2.2 (CI, 1.11–4.36), respectively. The data identify genotype ADH1C*1/1 as an independent risk factor for the development of alcohol‐associated tumors among heavy drinkers, indicating a genetic predisposition of individuals carrying this genotype. © 2005 Wiley‐Liss, Inc.
Adenovirus‐mediated intra‐tumoral delivery of the human endostatin gene inhibits tumor growth in nasopharyngeal carcinoma
Authors: Li Li , Liu Ran‐Yi , Huang Jia‐Ling , Liu Qi‐Cai , Li Yan , Wu Pei‐Hong , Zeng Yi‐Xin , Huang Wenlin
Published: November 2005

The growth and metastasis of nasopharyngeal carcinoma (NPC), one of the most common cancers in southern China, is closely related to neovascularization. Here, we examined whether intra‐tumoral delivery of endostatin gene could lead to long‐term local expression of bioactive endostatin at therapeutic levels. We constructed a recombinant adenoviral vector carrying the human endostatin gene (Ad/hEndo), which expressed high‐level endostatin protein in NPC CNE‐2 cells, and significantly inhibited the proliferation and migration of vascular endothelial cells in vitro. Tumor growth and angiogenesis in NPC CNE‐2 xenografted tumors were significantly inhibited after 5 courses of intra‐tumoral treatment with Ad/hEndo in vivo. Endostatin mRNA in tumor tissues peaked at 1–2 days after intra‐tumoral administration and disappeared within 1 week, whereas the plasma endostatin protein levels peaked at 3 days after administration and lasted 2–3 weeks. The therapeutically relevant endostatin transgene expression was achieved during the course of multiple intra‐tumoral administrations with Ad/hEndo. Multiple injections with adenoviral vectors did not lead to continuous increases of adenovirus neutralizing antibodies in serum. Thus, adenovirus‐mediated intra‐tumoral introduction of the human endostatin gene may form a viable new treatment for NPC, although readministration every 2–3 weeks may be necessary for the best effect. © 2005 Wiley‐Liss, Inc.
Estradiol and its metabolites 4‐hydroxyestradiol and 2‐hydroxyestradiol induce mutations in human breast epithelial cells
Authors: Fernandez Sandra V. , Russo Irma H. , Russo Jose
Published: November 2005

An elevated incidence of breast cancer in women has been associated with prolonged exposure to high levels of estrogens. Our laboratory demonstrated that treatment of the immortalized human breast epithelial cells MCF‐10F with 17β‐estradiol (E2), 4‐hydroxyestradiol (4‐OHE2) or 2‐hydroxyestradiol (2‐OHE2) induces phenotypical changes indicative of neoplastic transformation. MCF‐10F cells treated with E2, 4‐OHE2 or 2‐OHE2 formed colonies in agar methocel and lost their ductulogenic capacity in collagen, expressing phenotypes similar to those induced by the carcinogen benzo[a]pyrene. To investigate whether the transformation phenotypes were associated with genomic changes, cells treated with E2, 4‐OHE2 or 2‐OHE2 at different doses were analyzed using microsatellite markers. Since microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 13 and 17 have been reported in human breast carcinomas, we tested these parameters in MCF‐10F cells treated with E2, 2‐OHE2, or 4‐OHE2 alone or in combination with the antiestrogen ICI182780. MCF‐10F cells treated with E2 or 4‐OHE2, either alone or in combination with ICI182780, exhibited LOH in the region 13q12.3 with the marker D13S893 located at ∼0.8 cM telomeric to BRCA2. Cells treated with E2 or 4‐OHE2 at doses of 0.007 and 70 nM and 2‐OHE2 only at a higher dose (3.6 μM) showed a complete loss of 1 allele with D13S893. For chromosome 17, differences were found using the marker TP53‐Dint located in exon 4 of p53. Cells treated with E2 or 4‐OHE2 at doses of 0.007 nM and 70 nM and 2‐OHE2 only at a higher dose (3.6 μM) exhibited a 5 bp deletion in p53 exon 4. Our results show that E2 and its catechol estrogen metabolites are mutagenic in human breast epithelial cells. ICI182780 did not prevent these mutations, indicating that the carcinogenic effect of E2 is mainly through its reactive metabolites 4‐OHE2 and 2‐OHE2, with 4‐OHE2 and E2 being mutagenic at lower doses than 2‐OHE2. © 2005 Wiley‐Liss, Inc.
A point mutation in the NFYC gene generates an antigenic peptide recognized by autologous cytolytic T lymphocytes on a human squamous cell lung carcinoma
Authors: Takenoyama Mitsuhiro , Baurain Jean‐Françis , Yasuda Manabu , So Tomoko , Sugaya Masakazu , Hanagiri Takeshi , Sugio Kenji , Yasumoto Kosei , Boon Thierry , Coulie Pierre G.
Published: November 2005

We have identified an antigen recognized by cytolytic T lymphocytes (CTL) on the autologous tumor cells of a nonsmall cell lung cancer patient. The antigenic peptide, presented by HLA‐B*5201 molecules, was encoded by a mutated sequence in the gene coding for the C subunit of transcription factor NF‐Y. The mutation was present in the tumor sample from which the cell line was derived, and appeared to be unique to the tumor of this patient. In a lymph node draining the tumor, precursors of CTL recognizing the autologous tumor cells were detected at a frequency of about 1/30,000 of the CD8 cells, and 85% of them recognized the mutated NF‐YC peptide, suggesting that the patient mounted a T cell response against this antigen. These results strengthened the notion that unique tumor‐specific antigens are highly represented not only in melanoma but also in other types of tumors, like nonsmall cell lung cancer. © 2005 Wiley‐Liss, Inc.
Is there an association between SV40 contaminated polio vaccine and lymphoproliferative disorders? An age–period–cohort analysis on Norwegian data from 1953 to 1997
Authors: Thu Guri Olsen , Hem Ling Yuan , Hansen Svein , Møller Bjørn , Norstein Jarle , Nøkleby Hanne , Grotmol Tom
Published: November 2005

Between 1955 and 1963, an estimated number of 150 million people in various parts of the world, including Norway, received poliomyelitis vaccine possibly contaminated with infectious simian virus 40 (SV40). Human studies have investigated the hypothesised association between SV40 and various cancers, but the results have so far been contradicting. The aim of the present study was to examine Norwegian cancer incidence data to assess a possible association between birth cohorts assumed to have been subjected to the vaccine and the incidence rate of lymphoproliferative disorders (excluding Hodgkin's lymphoma), further subdivided into non‐Hodgkin's lymphoma (NHL), lymphocytic leukemia and plasma cell neoplasms. Between 1953 and 1997, the incidence rate of lymphoproliferative diseases combined increased about 3‐fold in both males and females. Subgroup analysis showed that this increase was largely attributable to NHL. Age–period–cohort modelling of the subgroups, as well as of all groups combined, showed that the cohort effect was more prominent than the period effect. However, the variations in incidence patterns across the birth cohorts did not fit with the trends that would be expected if a SV40 contaminated vaccine did play a causative role. Thus, our data do not support the hypothesis of an association between the vaccine and any subgroup of lymphoproliferative diseases. © 2005 Wiley‐Liss, Inc.
Attachment, growth, and activity of rat osteoblasts on polylactide membranes treated with various low‐temperature radiofrequency plasmas
Authors: Gugala Zbigniew , Gogolewski Sylwester
Published: November 2005

Nonporous and porous membranes from poly(L/DL‐lactide) 80/20% were treated with low‐temperature oxygen, ammonia, or sulphur dioxide–hydrogen plasmas and the late effects of plasma treatment on physicochemical characteristics of the membranes' surface were analyzed. The plasma treatment resulted in the permanent attachment of sulphur and nitrogen functionalities to the membrane's surface, and increased the surface concentration of oxygen, thereby increasing the surface wettability. To assess whether the plasma treatment affects the cellular response, primary rat osteoblasts were cultured on nontreated and plasma‐treated nonporous and microporous membranes, and attachment, growth, and activity of cells were investigated. It was found that attachment and growth of osteoblasts on all the plasma‐treated membranes were greater compared with nontreated controls. The treatment with ammonia plasma was most efficacious. The beneficial effects of plasma treatment on cells were most pronounced for microporous polylactide membranes irrespective of the plasma used. The results of the study suggest that the treatment of porous polylactide structures with plasma can be an effective means of enhancing their suitability for tissue engineering. Plasma exposure may also have an advantageous effect on bone healing when polylactide membranes are used to treat bone defects. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Fabrication and evaluation of porous 2,3‐dialdehydecellulose membrane as a potential biodegradable tissue‐engineering scaffold
Authors: RoyChowdhury P. , Kumar V.
Published: November 2005

A simple, novel method to produce porous 2,3‐dialdehydecellulose (DAC) membranes as a potential tissue‐engineering scaffold has been developed from methylolcellulose by the simultaneous water‐induced phase separation and sodium chloride salt leaching techniques, followed by oxidation with sodium periodate in water. Membrane pores increased in size with increasing weight or particle size of the sodium chloride salt. The porosity of the membrane was not affected by the salt particle size, but it increased with an increase in the salt weight to 60%. At higher salt weight percentages, no significant change in the membrane porosity was observed. The oxidation step had no effect on the membrane porosity or pore size. All membranes with a porosity value ranging between 87 and 93% showed interconnected porous structures. The use of these membranes as a potential tissue‐engineering scaffold was evaluated with the use of human neonatal skin fibroblast cells. Confocal microscopy showed cell attachment and spreading on these membranes. Immunohistochemical tests revealed the presence of collagen type III and fibronectin, indicating that the cells were viable and formed the extracellular matrix. In conclusion, the DAC membrane supports cell adhesion and proliferation and hence shows potential to be used as a tissue‐engineering scaffold. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Thin calcium phosphate coatings on titanium by electrochemical deposition in modified simulated body fluid
Authors: Peng Ping , Kumar Sunil , Voelcker Nicolas H. , Szili Endre , Smart Roger St. C. , Griesser Hans J.
Published: November 2005

Adherent and optically semitransparent thin calcium phosphate (CaP) films were electrochemically deposited on titanium substrates in a modified simulated body fluid at 37°C. Coatings deposited by using periodic pulsed potentials showed better adhesion and better mechanical properties than coatings deposited with use of a constant potential. Scanning electron microscopy was used to study the morphology of the coatings. The coatings displayed a polydispersed porous structure with pores in the range of a few nanometers to 1 μm. Furthermore, X‐ray diffractometry and the O(1s) satellite peaks in X‐ray photoelectron spectroscopy indicated that the coatings possessed a similar surface chemistry to that of natural bone minerals. These results were confirmed by inductively coupled plasma optical emission spectrometry, which yielded a Ca:P ratio of 1.65, close to that of hydroxyapatite. Contact mode atomic force microscopy (AFM) showed the average thickness of the coatings was in the order of 200 nm. Root‐mean‐square (RMS) roughness values, also derived by AFM, were shown to be much higher on the titanium‐CaP surfaces in comparison with untreated titanium substrates, with RMS values of about 300 and 110 nm, respectively. Cell culture experiments showed that the CaP surfaces are nontoxic to MG63 osteoblastic cells in vitro and were able to support cell growth for up to 4 days, outperforming the untreated titanium surface in a direct comparison. These easily prepared coatings show promise for hard‐tissue biomaterials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Extensive H+release by bone substitutes affects biocompatibilityin vitrotesting
Authors: Jäger M. , Fischer J. , Schultheis A. , Lensing‐Höhn S. , Krauspe R.
Published: November 2005

Bone substitutes are widespread in orthopedic and trauma surgery to restore critical bony defects and/or promote local bone healing. Cell culture systems have been used for many years to screen biomaterials for their toxicity and biocompatibility. This study applies a human bone marrow cell culture system to evaluate the toxicin vitroeffects of soluble components of different bone substitutes, which are already in clinical use. Different specimens of tricalcium phosphates (TCP) (Vitoss™, Cerasorb™), nondecalcified bovine bone (Lubboc™), demineralized human bone matrices (DBM) (Grafton™ Flex/Putty), and collagen I/III matrix (ACI‐Maix™) were tested in Dulbecco's modified Eagle's medium (DMEM) and Mesencult™ culture solution and compared with a biomaterial‐free cell culture. Biocompatibility parameters were cell viability evaluated by phase‐contrast microscopy and laser flow cytometry, morphology, and the local H+release by bone substitutes. There were significant differences (p< 0.05) between the tested biomaterials and culture solutions. Collagen I/III, nondemineralized bovine bone, and TCP materials showed advantages for cell survival over other tested biomaterials (average values of vital cells/mL MesenCult™/DMEM: Collagen I/III: 1090/1083; Vitoss™: 893/483; Cerasorb™: 471/523; Lubboc™: 815/410; Grafton™ Putty: 61/44; Grafton™ Flex: 149/57). Especially the DBM materials lead to a significant decrease of pH, which is considered to be a major factor for cell death. DMEM culture solution supports cell survival for those bone substitutes that induce an alkaline reaction, whereas MesenCult™ media promotes cell vitality in biomaterials, which leads to an acidification of culture solution. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Effect of filament diameter and extracellular matrix molecule precoating on neurite outgrowth and Schwann cell behavior on multifilament entubulation bridging device in vitro
Authors: Wen Xuejun , Tresco Patrick A.
Published: November 2005

At present there is no clinically effective treatment for injuries or pathological processes that disrupt the continuity of axons in the mature central nervous system. However, a number of studies suggest that a tremendous potential exists for developing biomaterial based therapies. In particular, biomaterials in the form of bridging substrates have been shown to support at least some level of axonal regeneration across the lesion site, but display a limited capacity for directing axons toward their targets. To improve the directionality and outgrowth rate of the axonal regeneration process, filaments and tubes appear promising, but the technology is far from optimized. As a step toward optimization, the influence of filament diameter and various extracellualr matrix coatings on nerve regeneration was evaluated in this article using a dorsal root ganglion (DRG) explant model. An increasing pattern of alignment and outgrowth of neurites in the direction parallel the long axis of the packed filament bundles with decreasing filament diameters ranging from supracellular and beyond (500 to 100 μm), cellular (30 μm), down to subcellular size (5 μm) was observed. Such effects became most prominent on filament bundles with individual filament diameters in the range of cellular size and below (5 and 30 μm) where highly directional and robust neuronal outgrowth was achieved. In addition, laminin‐coated filaments that approached the size of spinal axons support significantly longer regenerative outgrowth than similarly treated filaments of larger diameter, and exceed outgrowth distance on similarly sized filaments treated with fibronectin. These data suggested the feasibility of using a multifilament entubulation bridging device for supporting directional axonal regeneration. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006