bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of treatments given to the grain, on the growth of wheat roots under drought conditions
Authors: Carceller M. S. , Soriano A.
Published: March 2008

The effect of pretreatments given to wheat grains which are supposed to increase drought resistance was studied in young plants under controlled conditions of water stress. In one of the two cultivars used, root growth was found to be significantly greater in plants from pretreated seeds, during and after a period of water stress.Under conditions of ample water availability, root growth was not influenced by the pretreatments.
Patterns of change in the soluble nitrogen pool in seeds of Acer ginnala during stratification
Authors: Dumbroff E. B. , Silva N. De
Published: March 2008

Respiration and water uptake were previously shown to follow a three-phase pattern during the stratification period of Acer ginnala. The present study indicates that metabolism of several nitrogenous components also follows a multiphasic pattern during this period. However, total soluble nitrogen showed a rapid decline from day 9 to day 18 when respiration and water uptake were in what was essentially a plateau phase. This trend suggests that synthetic activities may be competing for substrates common to the respiratory pathway.The neutral fraction accounted for the major portion of the amino nitrogen pool and generally followed the pattern of total soluble nitrogen. The changes in the acidic and basic fractions were also phasic, but the patterns differed somewhat from that of the much larger neutral component. These results indicate that stratification is a highly active process composed of several well-defined phases.
AMPK inactivation in mononuclear cells: a potential intracellular mechanism for exercise-induced immunosuppression
Authors: Moir Hannah , Butcher Lee , Jones Ken P. , Hughes Michael G. , Neale Huw , Jia Huidong , Al-Ismaily Zuleikha , Webb Richard
Published: March 2008

There is much evidence that prolonged intense exercise suppresses the immune system. However, the intracellular biochemical mechanisms linking exercise and immunosuppression remain obscure. The purpose of this study was to investigate the hypothesis that exercise-induced inactivation of 5′AMP-activated protein kinase (AMPK) disrupts individual immune cell function, and thus may be linked to exercise-induced immunosuppression. To confirm AMPK’s role in immune cells, AMPK activity was assessed in cultured monocytic Mono Mac 6 (MM6) cells. The effects of single bouts of intense exercise (45 min cycling; 70% VO2 max) on several immune parameters including mononuclear cell AMPK phosphorylation were investigated in 10 male volunteers. In vitro, the mitochondrial ATP synthase inhibitor oligomycin brought about transient decreases in cellular [ATP] (0.41 ± 0.04 pmol/cell to 0.31 ± 0.02 pmol/cell), and activation of AMPKα1 (170.7% ± 31.2% basal) and the glycolytic enzyme inducible phosphofructokinase 2 (iPFK-2) (225.0% ± 46.1% basal), with the latter effects coinciding with recovery from ATP depletion. In contrast, exercise-induced transient (~1 h) decreases in AMPKα1 phosphorylation (64.4% ± 17.6% basal). This AMPK inactivation coincided with comparable transient decreases in other immune parameters (salivary IgA levels, serum cytokine levels, monocyte CD36 expression). Although the brief exercise bout employed here is not sufficient to cause full-fledged immunosuppression, exercise-induced transient decreases in mononuclear cell AMPK activation (as seen in this study) may cause energy depletion within individual immune cells, and therefore have an impact upon their ability to carry out their functions. Thus, we suggest that prolonged, repeated, high-intensity exercise that leads to clinically relevant immunosuppression may do so via AMPK inactivation within immune cells.
Effect of dietary protein content during recovery from high-intensity cycling on subsequent performance and markers of stress, inflammation, and muscle damage in well-trained men
Authors: Rowlands David S. , Rössler Karin , Thorp Rhys M. , Graham David F. , Timmons Brian W. , Stannard Stephen R. , Tarnopolsky Mark A.
Published: March 2008

Nutrition is an important aspect of recuperation for athletes during multi-day competition or hard training. Post-exercise carbohydrate is likely to improve recovery, but the effect of protein is equivocal. The objective of this study was to determine the effect of post-exercise dietary protein content imposed over a high-carbohydrate background on subsequent performance. Using a crossover design, 12 cyclists completed 3 high-intensity rides over 4 days. Day 1 comprised 2.5 h intervals, followed by repeat-sprint performance tests on days 2 (15 h post) and 4 (60 h post), interspersed with a rest day. During 4 h recovery on days 1 and 2, cyclists ingested either 1.4 g·kg–1·h–1 carbohydrate, 0.7 g·kg–1·h–1 protein and 0.26 g·kg–1·h–1 fat (protein-enriched) or 2.1 g·kg–1·h–1 carbohydrate, 0.1 g·kg–1·h–1 protein, and equal fat (control). At other times, cyclists ingested a standardized high-carbohydrate diet. Anabolism was gauged indirectly by nitrogen balance, stress and inflammation via cortisol and cytokines, skeletal-muscle membrane disruption by creatine kinase, and oxidative stress by malonyl dealdehyde. Sprint mean power was not clearly different on day 2 (0.0%; 95%CL: ±3.9%), but on day 4 it was 4.1% higher (±4.1%) in the protein-enriched condition relative to control. Reduced creatine kinase was possible (26%; ±30%) but effects on oxidative stress, inflammatory markers, and cortisol were inconclusive or trivial. Overnight nitrogen balance was positive in the protein-enriched condition on day 1 (249 ± 70 mg N·kg FFM–1; mean ± SD), but negative (–48 ± 26 mg N·kg FFM–1) in the control condition. A nutritive effect of post-exercise protein content was not discernible short term (15 h), but a delayed performance benefit (60 h) was observed following protein-enriched high-carbohydrate ingestion.
Resistance training, sarcopenia, and the mitochondrial theory of aging
Authors: Johnston Adam P.W. , De Lisio Michael , Parise Gianni
Published: March 2008

Skeletal muscle aging is associated with a significant loss of muscle mass, strength, function, and quality of life. In addition, the healthcare cost of aging and age-related disease is growing, and will continue to grow as a larger proportion of our population reaches retirement age and beyond. The mitochondrial theory of aging has been identified as a leading explanation of the aging process and describes a path leading to cellular senescence that includes electron transport chain deficiency, reactive oxygen species production, and the accumulation of mitochondrial DNA deletions and mutations. It is also quite clear that regular resistance exercise is a potent and effective countermeasure for skeletal muscle aging. In this review, we discuss age-related sarcopenia, the mitochondrial theory of aging, and how resistance exercise may directly affect key components of the mitochondrial theory. It is clear from the data discussed that regular resistance training can effectively disturb processes that contribute to the progression of aging as it pertains to the mitochondrial theory.
The impact of nutritional and exercise strategies for aging bone and muscle
Authors: Candow Darren G.
Published: March 2008

This symposium addressed recent evidence suggesting that nutritional intervention and resistance-training strategies may be important for aging bone and muscle. The physiological consequences of aging and the potential mechanistic actions of nutritional aids during resistance training were emphasized.
The role of protein-mediated transport in regulating mitochondrial long-chain fatty acid oxidation
Authors: Holloway Graham Paul
Published: March 2008

This thesis is an investigation of the role of fatty acid translocase (FAT/CD36), plasma membrane associated fatty acid binding protein (FABPpm), and carnitine palmitoyltransferase I (CPTI) in transporting long-chain fatty acids (LCFAs) across mitochondrial membranes. Maximal CPTI activity, as well as the sensitivity of CPTI for its substrate palmitoyl-CoA (P-CoA) and its inhibitor malonyl-CoA (M-CoA), were measured in mitochondria isolated from human vastus lateralis muscles at rest and following muscle contraction. Exercise did not alter maximal CPTI activity or the sensitivity of CPTI for P-CoA. In contrast, exercise progressively attenuated the ability of M-CoA to inhibit CPTI activity. Mitochondrial FAT/CD36 protein content was also measured at rest, during, and following 2 h of cycling at ~60% maximal oxygen uptake. Exercise progressively increased the content of mitochondrial FAT/CD36 (+59%), which was significantly (p < 0.05) correlated with palmitate oxidation during exercise (r = 0.52), while palmitate oxidation was inhibited ~80% by the administration of a specific FAT/CD36 inhibitor. These data suggest that alterations in CPTI M-CoA sensitivity and increases in mitochondrial FAT/CD36 coordinate exercise-induced increases in fatty acid oxidation. FABPpm, another plasma membrane transport protein, has identical amino acid sequence to mitochondrial aspartate aminotransferase (mAspAT). Since FABPpm contributes to plasma membrane fatty acid transport, the role of FABPpm with respect to mitochondrial LCFA transport was investigated. However, unlike FAT/CD36, muscle contraction did not induce an increase in mitochondrial FABPpm protein in rat or human skeletal muscle. In addition, electrotransfecting FABPpm cDNA into rat skeletal muscle upregulated this protein in mitochondria by 80% without altering mitochondrial palmitate oxidation. In contrast, electrotransfection increased mAspAT activity  by 90%, and this was correlated (r = 0.75; p < 0.01) with FABPpm protein. These data suggest that FABPpm does not contribute to the regulation of mitochondrial LCFA transport. Previously, it has been suggested that mitochondria from obese individuals contain an inherent dysfunction to oxidize LCFAs. In age-matched lean (BMI = 23.3 ± 0.7 kg·m–2) and obese (BMI = 37.6 ± 2.2 kg·m–2) individuals, isolated mitochondrial palmitate oxidation was not altered. In addition, mitochondrial FAT/CD36 content was not different in lean and obese individuals. In contrast, citrate synthase and β-hydroxyacyl-CoA dehydrogenase, common markers of total mitochondrial content, were decreased with obesity. Therefore, the decrease in mitochondrial content appeared to account for the observed reductions in whole-muscle LCFA oxidation.
Determinants ofVO2 maxdecline with aging: an integrated perspective
Authors: Betik Andrew C. , Hepple Russell T.
Published: March 2008

Aging is associated with a progressive decline in the capacity for physical activity. Central to this decline is a reduction in the maximal rate of oxygen utilization, or VO2 max. This critical perspective examines the roles played by the factors that determine the rate of muscle oxygen delivery versus those that determine the utilization of oxygen by muscle as a means of probing the reasons for VO2 maxdecline with aging. Reductions in muscle oxygen delivery, principally due to reduced cardiac output and perhaps also a maldistribution of cardiac output, appear to play the dominant role up until late middle age. On the other hand, there is a decline in skeletal muscle oxidative capacity with aging, due in part to mitochondrial dysfunction, which appears to play a particularly important role in extreme old age (senescence) where skeletal muscle VO2 maxis observed to decline by approximately 50% even under conditions of similar oxygen delivery as young adult muscle. It is noteworthy that at least the structural aspects of the capillary bed do not appear to be reduced in a manner that would compromise the capacity for muscle oxygen diffusion even in senescence.
Transient gene expression in differentiating pine wood using microprojectile bombardment
Authors: Loopstra Carol A. , Weissinger Arthur K. , Sederoff Ronald R.
Published: March 2008

We have used microprojectile bombardment to obtain transient expression of the reporter gene β-glucuronidase in differentiating wood (secondary xylem) of loblolly pine (Pinustaeda L.), thereby providing a method for studying expression of introduced DNA in this important tissue. β-Glucuronidase activity can be observed in different cell types, including tracheids, ray parenchyma, and axial parenchyma associated with resin canals. Microprojectile bombardment can be used to identify active promoters and to compare the relative activities of different promoters in specific cell types. We have studied the expression of three promoter gene fusions by bombardment of loblolly pine stem sections. Wood samples bombarded with an abscisic acid inducible (Em) promoter–β-glucuronidase fusion contained nearly 10 times the number of stained cells as those bombarded with two more commonly used promoter fusions (nopaline synthase or cauliflower mosaic virus 35S). Microprojectile bombardment of differentiating wood should be useful for studying promoters and gene constructs in future attempts to modify wood properties by genetic engineering.
Conifer wood quality and marker-aided selection: a case study
Authors: Williams Claire G. , Neale David B.
Published: March 2008

Using marker-aided selection for improving wood specific gravity in loblolly pine (Pinustaeda L.) could shorten the generation interval and improve selection response. A genetic map with restriction fragment length polymorphisms and other markers is in progress using a pedigree suited to mapping genes for specific gravity. Mapping quantitative trait loci for specific gravity provides a prototype for demonstrating benefits of marker-aided selection and for testing hypotheses on the mode of gene action in forest tree species. Ultimately, the utility of marker-aided selection must be compared with phenotype-based selection in small specialty populations.
Marker-aided selection and propagation systems in trees: advantages of cloning for studying quantitative inheritance
Authors: Bradshaw Jr. H. D. , Foster G. S.
Published: March 2008

Genetic maps with a high density of markers have been used to locate discrete Mendelian components of quantitatively inherited traits in a few crop plants. In principle, a similar approach can be used to map economically important quantitative trait loci in trees; however, tree pedigrees and propagation systems are quite different from those used in crops. Recent theoretical work suggests that clonal propagation of advanced generation offspring from pedigrees segregating for molecular marker genotype, and with substantial segregating variation in the phenotype(s) of interest, is an effective strategy for linkage analysis of polygenic traits. The successful application of marker-aided selection to tree improvement depends upon precise estimation of phenotypic variation attributable to marker genotype even when heritability is low, and clonal testing is the best experimental design to achieve this goal. For many practical reasons (including replication of plantations in time and space, destructive sampling, or sharing known genotypes with other researchers), clonal propagation maximizes the benefits from genome mapping efforts.
I-CONVERGENCE OF SEQUENCES OF FUZZY NUMBERS
Authors: NURAY FATIH
Published: March 2008

In this study, the concepts of I-convergent, I-Cauchy, I-bounded, I-limit points and I-cluster points for fuzzy number sequences have been introduced and discussed.
HEURISTIC OPTIMIZATION OF NATURAL PRODUCTION INVENTORY MODELS WITH THE PREFERENCE OF A DECISION MAKER
Authors: HSIEH CHIH HSUN
Published: March 2008

In this paper, two natural production inventory models based on fuzzy total production inventory cost with the preference of a decision maker are introduced, and combined by natural number parameters in which values are linguistic values in natural language, crisp real number variables, and fuzzy number variables. These are the one natural production inventory model for crisp production quantity, and the other natural production inventory model for fuzzy production quantity. The natural arithmetical operations of both natural numbers and fuzzy numbers by Function Principle are used to compute fuzzy total production inventory cost of each natural production inventory model. Graded k-preference integration representation method is discussed for defuzzifying fuzzy total production inventory cost by preference of decision maker. Furthermore, Extension of the Lagrangean method is used to solve inequality constrain problem in our natural production inventory model. We find out that our optimal solutions can be specified to the classical production inventory model when preference 0.5 of decision maker and natural numbers and fuzzy numbers in our models are crisp real numbers.
CHARACTERIZATIONS OF ORDERED SEMIGROUPS BY THE PROPERTIES OF THEIR FUZZY GENERALIZED BI-IDEALS
Authors: SHABIR M. , KHAN A.
Published: March 2008

In this paper, we define fuzzy generalized bi-ideals in ordered semigroups and we characterize regular and left weakly regular ordered semigroups by the properties of their fuzzy generalized bi-ideals.
Radiation Enhances Adenoviral Gene Therapy in Pancreatic Cancer via Activation of Cytomegalovirus Promoter and Increased Adenovirus Uptake
Authors: Egami Takuya , Ohuchida Kenoki , Mizumoto Kazuhiro , Onimaru Manabu , Toma Hiroki , Nishio Shoko , Nagai Eishi , Matsumoto Kunio , Nakamura Toshikazu , Tanaka Masao
Published: March 2008

Purpose: Adenovirus-mediated gene therapy combined with radiation is expected to be a new approach to treat pancreatic cancer. However, there are no reports of definitive effects of radiation on adenovirus-mediated gene therapies. In the present study, we investigated the effect of radiation on the transduction efficiency of an adenovirus-based gene therapy.

Experimental Design: We used adenovirus expressing NK4 (Ad-NK4), an antagonist for hepatocyte growth factor, as a representative gene therapy. Pancreatic cancer cells preinfected with Ad-NK4 were irradiated, and NK4 levels in culture media of these cells were measured. We investigated cytomegalovirus (CMV) promoter activity and uptake of adenovirus in these cells. To examine the effect of radiation in vivo, Ad-NK4 was given to irradiated subcutaneous tumors in nude mice, and NK4 levels in tumors were measured.

Results: NK4 levels in culture media of irradiated cells were 4.5-fold (P < 0.01) higher than those of nonirradiated cells. Radiation enhanced activation of the CMV promoter and adenovirus uptake (P < 0.01), leading to increased levels of NK4. We found that activation of p38 mitogen-activated protein kinase and up-regulation of dynamin 2 may be involved in the radiation-induced activation of the CMV promoter and adenovirus uptake, respectively. NK4 levels in irradiated tumors were 5.8-fold (P = 0.017) higher than those in nonirradiated tumors.

Conclusions: The present findings suggest that radiation significantly improves the efficiency of adenovirus-mediated gene transfer in pancreatic cancer and probably contributes to decreasing the dose of adenovirus required for gene transfer and controlling side effects of adenovirus infection in nonirradiated normal tissue.
Antimyeloma Effects of a Sesquiterpene Lactone Parthenolide
Authors: Suvannasankha Attaya , Crean Colin D. , Shanmugam Rajasubramaniam , Farag Sherif S. , Abonour Rafat , Boswell H. Scott , Nakshatri Harikrishna
Published: March 2008

Purpose: Nuclear factor-κB (NF-κB), activated in multiple myeloma (MM) cells by microenvironmental cues, confers resistance to apoptosis. The sesquiterpene lactone parthenolide targets NF-κB. However, its therapeutic potential in MM is not known.

Experimental Designs: We explored the effects of parthenolide on MM cells in the context of the bone marrow microenvironment.

Results: Parthenolide inhibited growth of MM cells lines, including drug-resistant cell lines, and primary cells in a dose-dependent manner. Parthenolide overcame the proliferative effects of cytokines interleukin-6 and insulin-like growth factor I, whereas the adhesion of MM cells to bone marrow stromal cells partially protected MM cells against parthenolide effect. In addition, parthenolide blocked interleukin-6 secretion from bone marrow stromal cells triggered by the adhesion of MM cells. Parthenolide cytotoxicity is both caspase-dependent and caspase-independent. Parthenolide rapidly induced caspase activation and cleavage of PARP, MCL-1, X-linked inhibitor of apoptosis protein, and BID. Parthenolide rapidly down-regulated cellular FADD-like IL-1β–converting enzyme inhibitory protein, and direct targeting of cellular FADD-like IL-1β–converting enzyme inhibitory protein using small interfering RNA oligonucleotides inhibited MM cell growth and lowered the parthenolide concentration required for growth inhibition. An additive effect and synergy were observed when parthenolide was combined with dexamethasone and TNF-related apoptosis-inducing ligand, respectively.

Conclusion: Collectively, parthenolide has multifaceted antitumor effects toward both MM cells and the bone marrow microenvironment. Our data support the clinical development of parthenolide in MM therapy.
Synergistic Antipancreatic Tumor Effect by Simultaneously Targeting Hypoxic Cancer Cells With HSP90 Inhibitor and Glycolysis Inhibitor
Authors: Cao Xianhua , Bloomston Mark , Zhang Tao , Frankel Wendy L. , Jia Guang , Wang Bing , Hall Nathan C. , Koch Regina M. , Cheng Hao , Knopp Michael V. , Sun Duxin
Published: March 2008

Purpose: We sought to examine the synergistic antipancreatic cancer effect by simultaneously targeting hypoxic cancer cells with heat-shock protein 90 (HSP90) inhibitor and blockade of energy production.

Experimental Design: The anticancer effects of an HSP90 inhibitor (geldanamycin) in pancreatic cells were investigated in hypoxia and normoxia. A hexokinase II inhibitor, 3-broma-pyruvate (3BrPA), was evaluated for selective glycolysis inhibition in hypoxia as a sensitizer of HSP90 inhibitor against pancreatic cancer. The HSP90 client protein degradation was monitored by Western blot. The synergistic antitumor effect of geldanamycin and 3BrPA was evaluated in a xenograft pancreatic cancer model and monitored by a noninvasive dynamic contrast-enhanced magnetic resonance imaging.

Results: Hypoxia enhanced HIF-1α expression by 11-fold in pancreatic cancer cells, and HSP90 inhibitor exhibited a seven- to eightfold higher anticancer effect in hypoxia compared with normoxia via HSP90 client protein degradation. 3BrPA selectively inhibited glycolysis and sensitized geldanamycin against pancreatic cancer cells by 17- to 400-fold through HSP90 client protein degradation. The synergistic anticancer effect of reduced doses of geldanamycin and 3-BrPA was confirmed in xenograft models in vivo by more than 75% tumor growth inhibition.

Conclusions: The combination of HSP90 inhibitors and glycolysis inhibitors provides preferential inhibition of cancer cells in hypoxia through HSP90 client protein degradation and selective glycolysis inhibition. This may provide a new therapeutic regimen to battle chemotherapy-resistant pancreatic cancers, by enhancing the synergistic therapeutic efficacy and reducing dose-limiting toxicity.
Molecular Alterations in Spontaneous Sputum of Cancer-Free Heavy Smokers: Results from a Large Screening Program
Authors: Baryshnikova Ekaterina , Destro Annarita , Infante Maurizio Valentino , Cavuto Silvio , Cariboni Umberto , Alloisio Marco , Ceresoli Giovanni Luca , Lutman Romano , Brambilla Giorgio , Chiesa Giuseppe , Ravasi Gianni , Roncalli Massimo
Published: March 2008

Purpose: The high mortality rate for lung cancer is likely to be reduced by the development of a panel of sensitive biological markers able to identify early-stage lung cancers or subjects at high risk. The aim of this study was to establish the frequency of K-ras and p53 mutations and p16INK4A, RASSF1A, and NORE1A hypermethylation in sputum of a large cohort of cancer-free heavy smokers and to assess whether these markers are suitable for a routine use in the clinical practice for the early diagnosis of pulmonary cancer.

Experimental Design: Sputum samples were collected from 820 heavy smokers. Inclusion criteria consisted of radiologic and cytologic absence of pulmonary lesions, age at least 60 years, male gender, and a smoking history of at least 20 pack-years.

Results: The analysis identified 56 individuals (6.9%) with one molecular alteration. p53 mutation and p16INK4A, RASSF1A, and NORE1A methylation frequencies were 1.9%, 5.1%, 0.8%, and 1.0%, respectively; no K-ras mutations were found. One patient with p53 mutations was diagnosed with an early-stage lung cancer after 3-years of follow-up. The molecular analysis of bronchoscopy samples confirmed in half of the cases alterations present in sputum without revealing additional molecular changes.

Conclusions: Genetic and epigenetic abnormalities can be detected in cancer-free heavy smokers. Although the predictive value of the cancer risk is still to be established as it requires not less than 5 years of follow-up, p53 and p16INK4A are more promising candidates than K-ras, RASSF1A, and NORE1A for the pulmonary molecular screening of heavy smokers healthy individuals.
Vitamin E Succinate Induces Ceramide-Mediated Apoptosis in Head and Neck Squamous Cell Carcinoma In vitro and In vivo
Authors: Gu Xinbin , Song Xiaodong , Dong Yongheng , Cai Hui , Walters Eric , Zhang Renshu , Pang Xiaowu , Xie Tianpei , Guo Yinhan , Sridhar Rajagopalan , Califano Joseph A.
Published: March 2008

Purpose: Vitamin E succinate (α-TOS) inhibits the growth of cancer cells without unacceptable side effects. Therefore, the mechanisms associated with the anticancer action of α-TOS, including ceramide-mediated apoptosis, were investigated using head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo.

Experimental Design: Five different human HNSCC cell lines (JHU-011, JHU-013, JHU-019, JHU-022, and JHU-029) were treated with α-TOS, and its effects on cell proliferation, cell cycle progression, ceramide-mediated apoptosis, and ceramide metabolism were evaluated. The anticancer effect of α-TOS was also examined on JHU-022 solid tumor xenograft growth in immunodeficient mice.

Results: α-TOS inhibited the growth of all the HNSCC cell lines in vitro in a dose- and time-dependent manner. Thus, JHU-013 and JHU-022 cell lines were more sensitive to α-TOS than the other cell lines. Cellular levels of ceramide, sphingomyelinase activity, caspase-3, and p53 were elevated with increasing time of exposure to α-TOS. The degradation of poly(ADP-ribose) polymerase protein in JHU-022 cells treated with α-TOS provided evidence for apoptosis. The amounts of nuclear factor κB, Bcl-2, and Bcl-XL proteins were reduced in the cells treated with α-TOS for 6 hours. The levels of caspase-9, murine double minute-2, and IκB-α proteins were unchanged after α-TOS treatment. I.p. administration of α-TOS slowed tumor growth in immunodeficient mice.

Conclusions: α-TOS showed promising anticancer effects to inhibit HNSCC growth and viability in vivo and in vitro. The induction of enzymes involved in ceramide metabolism by α-TOS suggests that ceramide-mediated apoptosis may expand therapeutic strategies in the treatment of carcinoma.
A Gene Expression Signature that Can Predict the Recurrence of Tamoxifen-Treated Primary Breast Cancer
Authors: Chanrion Maïa , Negre Vincent , Fontaine Hélène , Salvetat Nicolas , Bibeau Frédéric , Grogan Gaëtan Mac , Mauriac Louis , Katsaros Dionyssios , Molina Franck , Theillet Charles , Darbon Jean-Marie
Published: March 2008

Purpose: The identification of a molecular signature predicting the relapse of tamoxifen-treated primary breast cancers should help the therapeutic management of estrogen receptor–positive cancers.

Experimental Design: A series of 132 primary tumors from patients who received adjuvant tamoxifen were analyzed for expression profiles at the whole-genome level by 70-mer oligonucleotide microarrays. A supervised analysis was done to identify an expression signature.

Results: We defined a 36-gene signature that correctly classified 78% of patients with relapse and 80% of relapse-free patients (79% accuracy). Using 23 independent tumors, we confirmed the accuracy of the signature (78%) whose relevance was further shown by using published microarray data from 60 tamoxifen-treated patients (63% accuracy). Univariate analysis using the validation set of 83 tumors showed that the 36-gene classifier is more efficient in predicting disease-free survival than the traditional histopathologic prognostic factors and is as effective as the Nottingham Prognostic Index or the “Adjuvant!” software. Multivariate analysis showed that the molecular signature is the only independent prognostic factor. A comparison with several already published signatures demonstrated that the 36-gene signature is among the best to classify tumors from both training and validation sets. Kaplan-Meier analyses emphasized its prognostic power both on the whole cohort of patients and on a subgroup with an intermediate risk of recurrence as defined by the St. Gallen criteria.

Conclusion: This study identifies a molecular signature specifying a subgroup of patients who do not gain benefits from tamoxifen treatment. These patients may therefore be eligible for alternative endocrine therapies and/or chemotherapy.
Capitalizing on the Immunogenicity of Dying Tumor Cells
Authors: Fonseca Catia , Dranoff Glenn
Published: March 2008

Cancer cell death occurs continually during tumor development and progression, whereas the selective killing of surviving cancer cells remains the primary objective of antineoplastic treatments. Recent insights into the immunologic consequences of cancer cell death have begun to elucidate the ways in which host antitumor immunity is shaped during cancer pathogenesis and then modulated by therapeutic intervention. Dying tumor cells evoke a range of host responses, dependent in part upon the mode of cell death, which may either impede or foster additional immune-mediated cancer destruction. Within the tumor microenvironment, the capture of apoptotic tumor cells by macrophages and dendritic cells may trigger tolerance networks that contribute to immune suppression, whereas the uptake of necrotic cancer cells may engender inflammatory pathways that fuel antitumor cytotoxicity. Milk fat globule epidermal growth factor 8, a phosphatidylserine-binding protein, and MHC class I chain–related protein A, an NKG2D ligand, play key roles in these competing outcomes. A deeper understanding of the mechanisms underlying the immunogenicity of dying cells informs the crafting of strategies that exploit endogenous or treatment-induced cancer cell death as the basis for stimulating sustained host antitumor cytotoxic reactions.
Cyclin D1 Expression in Breast Cancer Patients Receiving Adjuvant Tamoxifen-Based Therapy
Authors: Rudas Margaretha , Lehnert Martina , Huynh Anh , Jakesz Raimund , Singer Christian , Lax Sigurd , Schippinger Walter , Dietze Otto , Greil Richard , Stiglbauer Wolfgang , Kwasny Werner , Grill Renate , Stierer Michael , Gnant Michael F.X. , Filipits Martin ,   for the Austrian Breast and Colorectal Cancer Study Group
Published: March 2008

Purpose: The objective of our study was to determine the clinical relevance of cyclin D1 expression in hormone receptor–positive breast cancer patients who were treated with tamoxifen-based therapy.

Experimental Design: We assessed expression of cyclin D1 in surgical specimens of breast carcinoma by means of immunohistochemistry. Patients had been enrolled in either Austrian Breast and Colorectal Cancer Study Group (ABCSG) Trial 05 or ABCSG Trial 06 and received tamoxifen as part of their adjuvant treatment. Overall survival and relapse-free survival were analyzed with Cox models adjusted for clinical and pathologic factors.

Results: Cyclin D1 was expressed in 140 of 253 (55%) tumors of ABCSG Trial 05 and in 569 of 948 (60%) tumors of ABCSG Trial 06. Expression of cyclin D1 was associated with poor outcome in both cohorts. Overall survival was significantly shorter in patients with cyclin D1–positive tumors compared with patients with cyclin D1–negative tumors [adjusted hazard ratio (HR) for death (ABCSG Trial 05), 2.47; 95% confidence interval (95% CI), 1.08-5.63; P = 0.03; adjusted HR for death (ABCSG Trial 06), 1.78; 95% CI, 1.36-2.34; P < 0.0001]. Relapse-free survival was also shorter in patients with cyclin D1–positive tumors than in patients with cyclin D1–negative tumors [adjusted HR for relapse (ABCSG Trial 05), 2.73; 95% CI, 1.50-4.96; P = 0.001; adjusted HR for relapse (ABCSG Trial 06), 1.52; 95% CI, 1.14-2.04; P = 0.005].

Conclusion: Cyclin D1 expression is an independent poor prognostic factor in women with early-stage, hormone receptor–positive breast cancer who received adjuvant tamoxifen-based therapy.
Sensitivity of Squamous Cell Carcinoma Lymph Node Metastases to Herpes Oncolytic Therapy
Authors: Yu Zhenkun , Li Sen , Huang Yu-Yao , Lin Shu-Fu , Fong Yuman , Wong Richard J.
Published: March 2008

Purpose: Cancer metastases may have phenotypic and genetic differences from their primary cancers of origin. Engineered, replication-competent, attenuated viruses based on herpes simplex virus-1 (HSV-1) have shown potent oncolytic effects in treating primary tumors in animal tumor models, but their efficacy in treating lymph node metastases is poorly understood. We compared the efficacy of an attenuated oncolytic HSV-1 (NV1023) in treating a series of murine squamous carcinoma cell lines derived from serial implantation and harvest from metastatic lymph nodes.

Experimental Design and Results: The auricles of C3H/HeJ mice were implanted with SCCVII. Cervical nodal metastases were isolated, expanded in vitro, and reimplanted into new mice. A series of cell lines (LN1-LN7) were generated through seven serial passages. Cells from higher LN passages showed consistent trends toward increased migratory and invasive ability, increased cell surface nectin-1 (an HSV-1 receptor) expression, and increased glycoprotein D binding. Exposure to NV1023 showed increased viral entry, replication, and cytotoxicity with higher LN passages. Intratumoral injection of NV1023 in a murine flank tumor model caused significantly greater tumor regression and increased viral infection of LN7 compared with SCCVII.

Conclusions: These results show that lymph node metastases may undergo selection for characteristics, including increased nectin-1 expression, that make them more sensitive targets for herpes oncolytic therapy. These findings support the clinical application of these agents for the treatment of lymph node metastases.
Doxorubicin activates FOXO3a to induce the expression of multidrug resistance gene ABCB1 (MDR1) in K562 leukemic cells
Authors: Hui Rosaline C-Y. , Francis Richard E. , Guest Stephanie K. , Costa Joana R. , Gomes Ana R. , Myatt Stephen S. , Brosens Jan J. , Lam Eric W-F.
Published: March 2008

Using the doxorubicin-sensitive K562 cell line and the resistant derivative lines KD30 and KD225 as models, we found that acquisition of multidrug resistance (MDR) is associated with enhanced FOXO3a activity and expression of ABCB1 (MDR1), a plasma membrane P-glycoprotein that functions as an efflux pump for various anticancer agents. Furthermore, induction of ABCB1 mRNA expression on doxorubicin treatment of naive K562 cells was also accompanied by increased FOXO3a activity. Analysis of transfected K562, KD30, and KD225 cells in which FOXO3a activity can be induced by 4-hydroxytamoxifen showed that FOXO3a up-regulates ABCB1 expression at protein, mRNA, and gene promoter levels. Conversely, silencing of endogenous FOXO3a expression in KD225 cells inhibited the expression of this transport protein. Promoter analysis and chromatin immunoprecipitation assays showed that FOXO3a regulation of ABCB1 expression involves binding of this transcription factor to the proximal promoter region. Moreover, activation of FOXO3a increased ABCB1 drug efflux potential in KD30 cells, whereas silencing of FOXO3a by siRNA significantly reduced ABCB1 drug efflux ability. Together, these findings suggest a novel mechanism that can contribute towards MDR, involving FOXO3a as sensor for the cytotoxic stress induced by anticancer drugs. Although FOXO3a may initially trigger a program of cell cycle arrest and cell death in response to doxorubicin, sustained FOXO3a activation promotes drug resistance and survival of cells by activating ABCB1 expression. [Mol Cancer Ther 2008;7(3):670–8]
Differential effects of prostate cancer therapeutics on neuroendocrine transdifferentiation
Authors: Frigo Daniel E. , McDonnell Donald P.
Published: March 2008

Androgen ablation therapy is widely used for the treatment of advanced prostate cancer. However, the effectiveness of this intervention strategy is generally short-lived as the disease ultimately progresses to a hormone-refractory state. In recent years, it has become clear that even in antiandrogen-resistant cancers the androgen receptor (AR) signaling axis is intact and is required for prostate cancer growth. Thus, there is a heightened interest in developing small molecules that function in part by down-regulating AR expression in tumors. Paradoxically, AR expression has been shown to be important in preventing the transdifferentiation of epithelial prostate cancer cells toward a neuroendocrine phenotype associated with tumor progression. Consequently, we have evaluated the relative effect of prostate cancer therapeutics that function in part by depleting AR levels on neuroendocrine differentiation in established cellular models of prostate cancer. These studies reveal that although histone deacetylase inhibitors can down-regulate AR expression they increase the expression of neuroendocrine markers and alter cellular morphology. Inhibition of AR signaling using classic AR antagonists or small interfering RNA–mediated AR ablation induces incomplete neuroendocrine differentiation. Importantly, the Hsp90 inhibitor geldanamycin effectively down-regulates AR expression while having no effect on neuroendocrine differentiation. Taken together, these data show that the phenotypic responses to pharmacologic agents used in the clinic to prevent the progression of prostate cancer are not equivalent, a finding of significant therapeutic importance. [Mol Cancer Ther 2008;7(3):659–69]
Blockade of viral interleukin-6 expression of Kaposi's sarcoma–associated herpesvirus
Authors: Zhang Yan-Jin , Bonaparte Rheba S. , Patel Deendayal , Stein David A. , Iversen Patrick L.
Published: March 2008

Kaposi's sarcoma–associated herpesvirus (KSHV), also known as human herpesvirus 8, is associated with several malignant disorders, including Kaposi's sarcoma, primary effusion lymphoma (PEL), and multicentric Castleman's disease. An early lytic gene of KSHV encodes viral interleukin-6 (vIL-6), a viral homologue of the proinflammatory cytokine and an autocrine/paracrine growth factor human IL-6. In this study, we examined the effects of suppressing vIL-6 expression in PEL cells with antisense peptide-conjugated phosphorodiamidate morpholino oligomers (PPMO). PPMO are ssDNA-analogues that have a modified backbone and enter cells readily. Treatment of PEL cells with a PPMO designed against vIL-6 mRNA led to a marked reduction in the proportion of vIL-6-positive cells detected by immunofluorescence assay. Analysis by Western blot confirmed a specific reduction in the vIL-6 protein level and showed that the reduction was dependent on the dose of vIL-6 PPMO. PEL cells treated with the vIL-6 PPMO exhibited reduced levels of cellular growth, IL-6 expression and KSHV DNA, and an elevated level of p21 protein. Treatment of PEL cells with a combination of two vIL-6 PPMO compounds targeting different sequences in the vIL-6 mRNA led to an inhibitory effect that was greater than that achieved with either PPMO alone. These results show that PPMO targeting vIL-6 mRNA can potently reduce vIL-6 protein translation and indicate that further exploration of these compounds in an animal model for potential clinical application is warranted. [Mol Cancer Ther 2008;7(3):712–20]
Agelastatin A: a novel inhibitor of osteopontin-mediated adhesion, invasion, and colony formation
Authors: Mason Charlene K. , McFarlane Suzanne , Johnston Patrick G. , Crowe Paul , Erwin Pauline J. , Domostoj Mathias M. , Campbell F. Charles , Manaviazar Soraya , Hale Karl J. , El-Tanani Mohamed
Published: March 2008

Effective inhibitors of osteopontin (OPN)–mediated neoplastic transformation and metastasis are still lacking. (-)-Agelastatin A is a naturally occurring oroidin alkaloid with powerful antitumor effects that, in many cases, are superior to cisplatin in vitro. In this regard, past comparative assaying of the two agents against a range of human tumor cell lines has revealed that typically (-)-agelastatin A is 1.5 to 16 times more potent than cisplatin at inhibiting cell growth, its effects being most pronounced against human bladder, skin, colon, and breast carcinomas. In this study, we have investigated the effects of (-)-agelastatin A on OPN-mediated malignant transformation using mammary epithelial cell lines. Treatment with (-)-agelastatin A inhibited OPN protein expression and enhanced expression of the cellular OPN inhibitor, Tcf-4. (-)-Agelastatin A treatment also reduced β-catenin protein expression and reduced anchorage-independent growth, adhesion, and invasion in R37 OPN pBK-CMV and C9 cell lines. Similar effects were observed in MDA-MB-231 and MDA-MB-435s human breast cancer cell lines exposed to (-)-agelastatin A. Suppression of Tcf-4 by RNA interference (short interfering RNA) induced malignant/invasive transformation in parental benign Rama 37 cells; significantly, these events were reversed by treatment with (-)-agelastatin A. Our study reveals, for the very first time, that (-)-agelastatin A down-regulates β-catenin expression while simultaneously up-regulating Tcf-4 and that these combined effects cause repression of OPN and inhibition of OPN-mediated malignant cell invasion, adhesion, and colony formation in vitro. We have also shown that (-)-agelastatin A inhibits cancer cell proliferation by causing cells to accumulate in the G2 phase of cell cycle. [Mol Cancer Ther 2008;7(3):548–58]
Turning the gene tap off; implications of regulating gene expression for cancer therapeutics
Authors: Curtin James F. , Candolfi Marianela , Xiong Weidong , Lowenstein Pedro R. , Castro Maria G.
Published: March 2008

Cancer poses a tremendous therapeutic challenge worldwide, highlighting the critical need for developing novel therapeutics. A promising cancer treatment modality is gene therapy, which is a form of molecular medicine designed to introduce into target cells genetic material with therapeutic intent. Anticancer gene therapy strategies currently used in preclinical models, and in some cases in the clinic, include proapoptotic genes, oncolytic/replicative vectors, conditional cytotoxic approaches, inhibition of angiogenesis, inhibition of growth factor signaling, inactivation of oncogenes, inhibition of tumor invasion and stimulation of the immune system. The translation of these novel therapeutic modalities from the preclinical setting to the clinic has been driven by encouraging preclinical efficacy data and advances in gene delivery technologies. One area of intense research involves the ability to accurately regulate the levels of therapeutic gene expression to achieve enhanced efficacy and provide the capability to switch gene expression off completely if adverse side effects should arise. This feature could also be implemented to switch gene expression off when a successful therapeutic outcome ensues. Here, we will review recent developments related to the engineering of transcriptional switches within gene delivery systems, which could be implemented in clinical gene therapy applications directed at the treatment of cancer. [Mol Cancer Ther 2008;7(3):439–48]
Transient exposure of carcinoma cells to RAS/MEK inhibitors and UCN-01 causes cell deathin vitroandin vivo
Authors: Hamed Hossein , Hawkins William , Mitchell Clint , Gilfor Donna , Zhang Guo , Pei Xin-Yan , Dai Yun , Hagan Michael P. , Roberts John D. , Yacoub Adly , Grant Steven , Dent Paul
Published: March 2008

The present studies were initiated to determine in greater molecular detail how MEK1/2 inhibitors [PD184352 and AZD6244 (ARRY-142886)] interact with UCN-01 (7-hydroxystaurosporine) to kill mammary carcinoma cells in vitro and radiosensitize mammary tumors in vitro and in vivo and whether farnesyl transferase inhibitors interact with UCN-01 to kill mammary carcinoma cells in vitro and in vivo. Expression of constitutively activated MEK1 EE or molecular suppression of JNK and p38 pathway signaling blocked MEK1/2 inhibitor and UCN-01 lethality, effects dependent on the expression of BAX, BAK, and, to a lesser extent, BIM and BID. In vitro colony formation studies showed that UCN-01 interacted synergistically with the MEK1/2 inhibitors PD184352 or AZD6244 and the farnesyl transferase inhibitors FTI277 and R115,777 to kill human mammary carcinoma cells. Athymic mice carrying ∼100 mm3 MDA-MB-231 cell tumors were subjected to a 2-day exposure of either vehicle, R115,777 (100 mg/kg), the MEK1/2 inhibitor PD184352 (25 mg/kg), UCN-01 (0.2 mg/kg), or either of the drugs in combination with UCN-01. Transient exposure of tumors to R115,777, PD184352, or UCN-01 did not significantly alter tumor growth rate or the mean tumor volume in vivo ∼15 to 30 days after drug administration. In contrast, combined treatment with R115,777 and UCN-01 or with PD184352 and UCN-01 significantly reduced tumor growth. Tumor cells isolated after combined drug exposure exhibited a significantly greater reduction in plating efficiency using ex vivo colony formation assays than tumor cells that were exposed to either drug individually. Irradiation of mammary tumors after drug treatment, but not before or during treatment, significantly enhanced the lethal effects of UCN-01 and MEK1/2 inhibitor treatment. These findings argue that UCN-01 and multiple inhibitors of the RAS-MEK pathway have the potential to suppress mammary tumor growth, and to interact with radiation, in vitro and in vivo. [Mol Cancer Ther 2008;7(3):616–29]
Association between Deposition of Beta-Amyloid and Pathological Prion Protein in Sporadic Creutzfeldt-Jakob Disease
Authors: Debatin Laura , Streffer Johannes , Geissen Markus , Matschke Jakob , Aguzzi Adriano , Glatzel Markus
Published: March 2008

Background: Alzheimer’s disease (AD) and prion diseases such as sporadic Creutzfeldt-Jakob disease (sCJD) share common features concerning their molecular pathogenesis and neuropathological presentation and the coexistence of AD and CJD in patients suggest an association between the deposition of the proteolytically processed form of the amyloid precursor protein, β-amyloid (Aβ), which deposits in AD, and the abnormal form of the prion protein, PrPSc, which deposits in sCJD. Methods: We have characterized sCJD patients (n = 14), AD patients (n = 5) and nondemented controls (n = 5) with respect to the deposition of PrPSc and Aβ morphologically, biochemically and genetically and correlated these findings to clinical data. Results: sCJD-diseased individuals with abundant deposits of Aβ present with a specific clinicopathological profile, defined by higher age at disease onset, long disease duration, a genetic profile and only minimal amounts of PrPSc in the cerebellum. Conclusion: The co-occurrence of pathological changes typical for sCJD and AD in combination with the inverse association between accumulation of Aβ and PrPSc in a subgroup of sCJD patients is indicative of common pathways involved in the generation or clearance of Aβ and PrPSc in a subgroup of sCJD patients.