bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential effects of static and cyclic stretching during elastase digestion on the mechanical properties of extracellular matrices
Authors: Jesudason Rajiv , Black Lauren , Majumdar Arnab , Stone Phillip , Suki Bela
Published: June 2007

Enzyme activity plays an essential role in many physiological processes and diseases such as pulmonary emphysema. While the lung is constantly exposed to cyclic stretching, the effects of stretch on the mechanical properties of the extracellular matrix (ECM) during digestion have not been determined. We measured the mechanical and failure properties of elastin-rich ECM sheets loaded with static or cyclic uniaxial stretch (40% peak strain) during elastase digestion. Quasistatic stress-strain measurements were taken during 30 min of digestion. The incremental stiffness of the sheets decreased exponentially with time during digestion. However, digestion in the presence of static stretch resulted in an accelerated stiffness decrease, with a time constant that was nearly 3× smaller (7.1 min) than during digestion alone (18.4 min). These results were supported by simulations that used a nonlinear spring network model. The reduction in stiffness was larger during static than cyclic stretch, and the latter also depended on the frequency. Stretching at 20 cycles/min decreased stiffness less than stretching at 5 cycles/min, suggesting a rate-dependent coupling between mechanical forces and enzyme activity. Furthermore, pure digestion reduced the failure stress of the sheets from 88 ± 21 kPa in control to 29 ± 15 kPa ( P < 0.05), while static and cyclic stretch resulted in a failure stress of 7 ± 5 kPa ( P < 0.05). We conclude that not only the presence but the dynamic nature of mechanical forces have a significant impact on enzyme activity, hence the deterioration of the functional properties of the ECM during exposure to enzymes.
Medical applications of X-ray fluorescence for trace element research
Authors: Börjesson Jimmy , Mattsson Sören
Published: June 2007

Techniques for estimation of element levels directly in humans (noninvasivein vivo) or in samples (in vitro) from humans are reviewed. Toxic, nonessential, trace elements may cause temporary or permanent damage to various organs and tissues in humans. There is thus a need to control the concentrations. Knowledge of the relations between toxic effects and element concentration may be extracted from measurements in humans as well as in samples from humans and her environment. Applications traditionally include occupationally exposed subjects, but an increasing research area is studies of members of the general population and of patients undergoing therapy for malignant and other diseases. Mostin vivoXRF studies deal with lead in bone and cadmium in kidneys. For retired lead workers, a clear association has been demonstrated between bone lead and blood lead, due to endogenous lead excretion from the skeleton. A study of mercuryin vivoshowed that the technique is capable of detecting mercury in heavily exposed worker’s kidneys.In vivoXRF in cancer and rheumatology patients has helped to understand how platinum and gold are retained in the human body. The newestin vivoapplications include zinc in prostate gland and arsenic in skin.
Inhibition of Tumor Growth and Metastasis by Depletion of Vesicular Sorting Protein Hrs: Its Regulatory Role on E-Cadherin and β-Catenin
Authors: Toyoshima Masafumi , Tanaka Nobuyuki , Aoki Jun , Tanaka Yoshinori , Murata Kazuko , Kyuuma Masanao , Kobayashi Hideyuki , Ishii Naoto , Yaegashi Nobuo , Sugamura Kazuo
Published: June 2007

Abnormally high signals from receptor tyrosine kinases (RTK) are associated with carcinogenesis, and impaired deactivation of RTKs may also be a mechanism in cancer. Hepatocyte growth factor–regulated tyrosine kinase substrate (Hrs) is one of the master regulators that sort activated receptors toward lysosomes and shut down their signals. Hrs contains a ubiquitin-interacting motif and is involved in the endosomal sorting of monoubiquitinated membrane proteins, such as growth factor receptor and E-cadherin. Here, we investigated the role of Hrs in determining the malignancy of cancer cells and discovered that the targeted disruption of Hrs by small interfering RNA effectively attenuated the proliferation, anchorage-independent growth, tumorigenesis, and metastatic potential of HeLa cells in vitro and in vivo. The restoration of Hrs expression increased cell proliferation and anchorage-independent growth in a mouse embryonic fibroblast line established from a Hrs knockout mouse. Further analysis revealed that Hrs depletion was associated with the up-regulation of E-cadherin and reduced β-catenin signaling. The aberrant accumulation of E-cadherin most likely resulted from impaired E-cadherin degradation in lysosomes. These results suggest that Hrs may play a critical role in determining the malignancy of cancer cells by regulating the degradation of E-cadherin. [Cancer Res 2007;67(11):5162–71]
Oncogenic Potential of the Nuclear Receptor Coregulator Proline-, Glutamic Acid–, Leucine-Rich Protein 1/Modulator of the Nongenomic Actions of the Estrogen Receptor
Authors: Rajhans Rajib , Nair Sujit , Holden Alan H. , Kumar Rakesh , Tekmal Rajeshwar Rao , Vadlamudi Ratna K.
Published: June 2007

Proline-, glutamic acid–, leucine-rich protein 1 (PELP1), a novel nuclear receptor coactivator, and its expression is deregulated in hormone-dependent cancers, including those of the breast, endometrium, and ovary. PELP1 interacts with estrogen receptor and modulates its genomic and nongenomic functions. In this study, we examined whether PELP1 functions as an oncogene. The overexpression of PELP1 in fibroblasts and epithelial model cells resulted in cellular transformation. PELP1 also enhanced the transformation potential of c-Src kinase in focus formation assays, and PELP1 overexpression potentiated estradiol-mediated cell migratory potential and anchorage-independent growth. Using PELP1-small interfering RNA, we provided evidence that endogenous PELP1 plays an essential role in E2-mediated anchorage-independent growth, cell migration, and cytoskeletal changes. When compared with control vector transfectants, breast cancer cells stably overexpressing PELP1 showed a rapid tumor growth in xenograft studies. Immunohistochemical analysis of PELP1 expression using a tumor progression array of 252 breast carcinomas and normal breast tissue specimens revealed that PELP1 expression is deregulated to a greater degree in higher grade node-positive invasive tumors than in normal breast tissue or ductal carcinoma in situ. Our data suggest that PELP1 is a potential oncogene, that its expression is deregulated during cancer progression, and that PELP1 may play a role in oncogenesis. [Cancer Res 2007;67(11):5505–12]
Molecular Features of Hormone-Refractory Prostate Cancer Cells by Genome-Wide Gene Expression Profiles
Authors: Tamura Kenji , Furihata Mutsuo , Tsunoda Tatsuhiko , Ashida Shingo , Takata Ryo , Obara Wataru , Yoshioka Hiroki , Daigo Yataro , Nasu Yasutomo , Kumon Hiromi , Konaka Hiroyuki , Namiki Mikio , Tozawa Keiichi , Kohri Kenjiro , Tanji Nozomu , Yokoyama Masayoshi , Shimazui Toru , Akaza Hideyuki , Mizutani Yoichi , Miki Tsuneharu , Fujioka Tomoaki , Shuin Taro , Nakamura Yusuke , Nakagawa Hidewaki
Published: June 2007

One of the most critical issues in prostate cancer clinic is emerging hormone-refractory prostate cancers (HRPCs) and their management. Prostate cancer is usually androgen dependent and responds well to androgen ablation therapy. However, at a certain stage, they eventually acquire androgen-independent and more aggressive phenotype and show poor response to any anticancer therapies. To characterize the molecular features of clinical HRPCs, we analyzed gene expression profiles of 25 clinical HRPCs and 10 hormone-sensitive prostate cancers (HSPCs) by genome-wide cDNA microarrays combining with laser microbeam microdissection. An unsupervised hierarchical clustering analysis clearly distinguished expression patterns of HRPC cells from those of HSPC cells. In addition, primary and metastatic HRPCs from three patients were closely clustered regardless of metastatic organs. A supervised analysis and permutation test identified 36 up-regulated genes and 70 down-regulated genes in HRPCs compared with HSPCs (average fold difference > 1.5; P < 0.0001). We observed overexpression of AR, ANLN, and SNRPE and down-regulation of NR4A1, CYP27A1, and HLA-A antigen in HRPC progression. AR overexpression is likely to play a central role of hormone-refractory phenotype, and other genes we identified were considered to be related to more aggressive phenotype of clinical HRPCs, and in fact, knockdown of these overexpressing genes by small interfering RNA resulted in drastic attenuation of prostate cancer cell viability. Our microarray analysis of HRPC cells should provide useful information to understand the molecular mechanism of HRPC progression and to identify molecular targets for development of HRPC treatment. [Cancer Res 2007;67(11):5117–25]
Proton Pump Inhibitors Induce Apoptosis of Human B-Cell Tumors through a Caspase-Independent Mechanism Involving Reactive Oxygen Species
Authors: De Milito Angelo , Iessi Elisabetta , Logozzi Mariantonia , Lozupone Francesco , Spada Massimo , Marino Maria Lucia , Federici Cristina , Perdicchio Maurizio , Matarrese Paola , Lugini Luana , Nilsson Anna , Fais Stefano
Published: June 2007

Proton pumps like the vacuolar-type H+ ATPase (V-ATPase) are involved in the control of cellular pH in normal and tumor cells. Treatment with proton pump inhibitors (PPI) induces sensitization of cancer cells to chemotherapeutics via modifications of cellular pH gradients. It is also known that low pH is the most suitable condition for a full PPI activation. Here, we tested whether PPI treatment in unbuffered culture conditions could affect survival and proliferation of human B-cell tumors. First, we showed that PPI treatment increased the sensitivity to vinblastine of a pre-B acute lymphoblastic leukemia (ALL) cell line. PPI, per se, induced a dose-dependent inhibition of proliferation of tumor B cells, which was associated with a dose- and time-dependent apoptotic-like cytotoxicity in B-cell lines and leukemic cells from patients with pre-B ALL. The effect of PPI was mediated by a very early production of reactive oxygen species (ROS), that preceded alkalinization of lysosomal pH, lysosomal membrane permeabilization, and cytosol acidification, suggesting an early destabilization of the acidic vesicular compartment. Lysosomal alterations were followed by mitochondrial membrane depolarization, release of cytochrome c, chromatin condensation, and caspase activation. However, inhibition of caspase activity did not affect PPI-induced cell death, whereas specific inhibition of ROS by an antioxidant (N-acetylcysteine) significantly delayed cell death and protected both lysosomal and mitochondrial membranes. The proapoptotic activity of PPI was consistent with a clear inhibition of tumor growth following PPI treatment of B-cell lymphoma in severe combined immunodeficient mice. This study further supports the importance of acidity and pH gradients in tumor cell homeostasis and suggests new therapeutic approaches for human B-cell tumors based on PPI. [Cancer Res 2007;67(11):5408–17]
MUC1 Oncoprotein Promotes Refractoriness to Chemotherapy in Thyroid Cancer Cells
Authors: Siragusa Mauro , Zerilli Monica , Iovino Flora , Francipane Maria Giovanna , Lombardo Ylenia , Ricci-Vitiani Lucia , Di Gesù Giuseppe , Todaro Matilde , De Maria Ruggero , Stassi Giorgio
Published: June 2007

Overexpression of MUC1 oncoprotein is frequently observed in cancer and contributes to confer resistance to genotoxic agents. Papillary, follicular, and anaplastic thyroid carcinomas are the three forms of thyroid epithelial cancer. Anaplastic tumors are less differentiated and extremely aggressive, characterized by a poor prognosis. Little is known about the role of MUC1 in thyroid cancer. We recently showed that autocrine production of interleukin (IL)-4 and IL-10 controls thyroid cancer cell survival, growth, and resistance to chemotherapy through activation of Janus-activated kinase/signal transducers and activators of transcription (JAK/STAT) and phosphatidylinositide 3′-OH kinase (PI3K)/Akt pathways. In the present study, we showed that MUC1 COOH-terminal subunit (MUC1-C) is overexpressed in all the histologic variants of thyroid cancer cells and localizes to mitochondria where it interferes with the release of mitochondrial proapoptotic proteins. Moreover, IL-4 and IL-10 promote the increase of MUC1-C expression levels in normal thyroid cells, whereas blockage of both cytokines or neutralization of JAK/STAT and PI3K/Akt pathways through the exogenous expression of SOCS-1 and AktK179M leads to a significant decrease of MUC1-C in primary thyroid cancer cells. Interestingly, down-regulation of MUC1 expression by direct targeting with RNA interference sensitizes anaplastic thyroid cancer cells to chemotherapy-induced apoptosis in vitro. Thus, MUC1 is a main component of the survival network acting in thyroid cancer and could be considered a key molecular target for sensitizing cancer cells to conventional or novel treatments. [Cancer Res 2007;67(11):5522–30]
Noxa Up-regulation and Mcl-1 Cleavage Are Associated to Apoptosis Induction by Bortezomib in Multiple Myeloma
Authors: Gomez-Bougie Patricia , Wuillème-Toumi Soraya , Ménoret Emmanuelle , Trichet Valérie , Robillard Nelly , Philippe Moreau , Bataille Régis , Amiot Martine
Published: June 2007

Targeting the ubiquitin-proteasome pathway has emerged as a potent anticancer strategy. Bortezomib, a specific proteasome inhibitor, has been approved for the treatment of relapsed or refractory multiple myeloma. Multiple myeloma cell survival is highly dependent on Mcl-1 antiapoptotic molecules. In a recent study, proteasome inhibitors induced Mcl-1 accumulation that slowed down their proapoptotic effects. Consequently, we investigated the role of Bcl-2 family members in bortezomib-induced apoptosis. We found that bortezomib induced apoptosis in five of seven human myeloma cell lines (HMCL). Bortezomib-induced apoptosis was associated with Mcl-1 cleavage regardless of Mcl-1L accumulation. Furthermore, RNA interference mediated Mcl-1 decrease and sensitized RPMI-8226 HMCL to bortezomib, highlighting the contribution of Mcl-1 in bortezomib-induced apoptosis. Interestingly, an important induction of Noxa was found in all sensitive HMCL both at protein and mRNA level. Concomitant to Mcl-1 cleavage and Noxa induction, we also found caspase-3, caspase-8, and caspase-9 activation. Under bortezomib treatment, Mcl-1L/Noxa complexes were highly increased, Mcl-1/Bak complexes were disrupted, and there was an accumulation of free Noxa. Finally, we observed a dissociation of Mcl-1/Bim complexes that may be due to a displacement of Bim induced by Noxa. Thus, in myeloma cells, the mechanistic basis for bortezomib sensitivity can be explained mainly by the model in which the sensitizer Noxa can displace Bim, a BH3-only activator, from Mcl-1, thus leading to Bax/Bak activation. [Cancer Res 2007;67(11):5418–24]
Estrogen Receptor α Mediates Breast Cancer Cell Resistance to Paclitaxel through Inhibition of Apoptotic Cell Death
Authors: Sui Meihua , Huang Yi , Park Ben Ho , Davidson Nancy E. , Fan Weimin
Published: June 2007

Estrogen receptors (ER) are expressed in ∼65% of human breast cancer. Cumulative data from clinical trials and retrospective analyses suggest that some chemotherapeutic agents may be less effective in patients with ER-positive (ER+) tumors than those with ER-negative (ER−) tumors. Paclitaxel is an active agent used in breast cancer chemotherapy. To investigate the possible influence of ER on the therapeutic efficacy of paclitaxel and its underlying mechanism, we established several isogenic ER+ cell lines by stable transfection of ERα expression vectors into ER− breast cancer BCap37 cells. We showed that 17-β estradiol significantly reduces the overall cytotoxicity of paclitaxel in BCap37-expressing ERα but has no influence on the ER− parental cells. Further analyses indicate that expression of ERα in BCap37 cells mainly interferes with paclitaxel-induced apoptotic cell death, without affecting paclitaxel-induced microtubule bundling and mitotic arrest. Moreover, we found that the addition of ICI 182,780 (Fulvestrant), a selective ER down-regulator, could completely reverse the resistance of ER+ BCap37 cells to paclitaxel. These findings showed that ERα-mediated breast tumor cell resistance to paclitaxel was through selective inhibition of paclitaxel-induced tumor cell apoptosis. Additionally, the combination of ICI 182,780 also sensitizes MCF-7 and T47D cell lines to the treatment of paclitaxel, which further confirmed the correlation between ERα and drug resistance in ER+ tumor cells. The results obtained from this study provide useful information for understanding ER-mediated resistance to paclitaxel and possibly other antineoplastic agents. [Cancer Res 2007;67(11):5337–44]
Distinctive Features of Angiogenesis and Lymphangiogenesis Determine Their Functionality during De novo Tumor Development
Authors: Eichten Alexandra , Hyun William C. , Coussens Lisa M.
Published: June 2007

Blood and lymphatic vasculature are essential components of all organs, responsible for maintaining organ fluid dynamics and tissue homeostasis. Although both vessel systems are composed of similar lineages of endothelial cells whose crude functions include fluid and cell transport, each system also possesses distinctive physiologic properties, enabling their distinctive functions in tissues. The role of hematogenous vasculature and development of angiogenic blood vessels during cancer development is well established; however, the role of lymphangiogenesis and structural/functional alterations occurring within lymphatic vessels during cancer development are incompletely understood. To assess premalignant versus malignant alterations in blood and lymphatic vasculature associated with squamous epithelial skin carcinogenesis, we assessed architectural and functional features of both vascular systems using a mouse model of de novo carcinoma development. We report that, as vasculature acquires angiogenic and/or lymphangiogenic properties, angiogenic blood vessels become leaky in premalignant tissue and at peripheries of carcinomas, where enlarged lymphatic capillaries efficiently drain increased tissue fluid, thereby maintaining tissue hemodynamics. In contrast, central regions of carcinomas exhibit elevated tissue fluid levels, compressed lymphatic lumina, and decreased vascular leakage, thus indicating impaired hemodynamics within solid tumors. Together, these data support the notion that therapeutic delivery of anticancer agents is best realized in premalignant tissues and/or at the peripheries of solid tumors where hemodynamic forces support drug delivery. Strategies to normalize intratumoral hemodynamics would therefore enhance therapeutic delivery to otherwise poorly accessible central regions of solid tumors. [Cancer Res 2007;67(11):5211–20]
Docosahexaenoic Acid and Butyrate Synergistically Induce Colonocyte Apoptosis by Enhancing Mitochondrial Ca2+ Accumulation
Authors: Kolar Satya Sree N. , Barhoumi Rola , Lupton Joanne R. , Chapkin Robert S.
Published: June 2007

We have previously shown that butyrate, a short-chain fatty acid fiber fermentation product, induces colonocyte apoptosis via a nonmitochondrial, Fas-mediated, extrinsic pathway. Interestingly, fermentable fiber when combined with fish oil containing docosahexaenoic acid (DHA, 22:6n-3) exhibits an enhanced ability to induce apoptosis and protect against colon tumorigenesis. To determine the molecular mechanism of action, the effect of DHA and butyrate cotreatment on intracellular Ca2+ homeostasis was examined. Mouse colonocytes were treated with 50 μmol/L DHA or linoleic acid (LA) for 72 h ± butyrate (0–10 mmol/L) for the final 24 h. Cytosolic and mitochondrial Ca2+ levels were measured using Fluo-4 and Rhod-2. DHA did not alter basal Ca2+ or the intracellular inositol trisphosphate (IP3) pool after 6 h butyrate cotreatment. In contrast, at 12 and 24 h, DHA- and butyrate-treated cultures exhibited a 25% and 38% decrease in cytosolic Ca2+ compared with LA and butyrate. Chelation of extracellular Ca2+ abolished the effect of thapsigargin on the IP3-releasable Ca2+ pool. DHA and butyrate cotreatment compared with untreated cells increased the mitochondrial-to-cytosolic Ca2+ ratio at 6, 12, and 24 h by 73%, 18%, and 37%, respectively. The accumulation of mitochondrial Ca2+ preceded the onset of apoptosis. RU-360, a mitochondrial-uniporter inhibitor, abrogated mitochondrial Ca2+ accumulation and also partially blocked apoptosis in DHA and butyrate cotreated cells. Collectively, these data show that the combination of DHA and butyrate, compared with butyrate alone, further enhances apoptosis by additionally recruiting a Ca2+-mediated intrinsic mitochondrial pathway. [Cancer Res 2007;67(11):5561–8]
Expression and Functional Analysis of Human Leukocyte Antigen Class I Antigen-Processing Machinery in Medulloblastoma
Authors: Raffaghello Lizzia , Nozza Paolo , Morandi Fabio , Camoriano Marta , Wang Xinhui , Garrè Maria Luisa , Cama Armando , Basso Giuseppe , Ferrone Soldano , Gambini Claudio , Pistoia Vito
Published: June 2007

Defects in the expression and/or function of the human leukocyte antigen (HLA) class I antigen-processing machinery (APM) components are found in many tumor types. These abnormalities may have a negative impact on the interactions of tumor cells with host's immune system and on the outcome of T cell–based immunotherapy. To the best of our knowledge, no information is available about APM component expression and functional characteristics in human medulloblastoma cells (Mb). Therefore, in the present study, we have initially compared the expression of APM components in Mb, an embryonal pediatric brain tumor with a poor prognosis, with that in noninfiltrating astrocytic pediatric tumors, a group of differentiated brain malignancies with favorable prognosis. LMP2, LMP7, calnexin, β2-microglobulin–free heavy chain (HC) and β2-microglobulin were down-regulated or undetectable in Mb lesions, but not in astrocytic tumors or normal fetal cerebellum. Two Mb cell lines (DAOI and D283) displayed similar but not superimposable defects in APM component expression as compared with primary tumors. To assess the functional implications of HLA class I APM component down-regulation in Mb cell lines, we tested their recognition by HLA class I antigen-restricted, tumor antigen (TA)–specific CTL, generated by stimulations with dendritic cells that had been transfected with Mb mRNA. The Mb cell lines were lysed by TA-specific CTL in a HLA-restricted manner. Thus, defective expression of HLA class I–related APM components in Mb cells does not impair their ability to present TA to TA-specific CTL. In conclusion, these results can contribute to optimize T cell–based immunotherapeutic strategies for Mb treatment. [Cancer Res 2007;67(11):5471–8]
Chemoresistant KM12C Colon Cancer Cells Are Addicted to Low Cyclic AMP Levels in a Phosphodiesterase 4–Regulated Compartment via Effects on Phosphoinositide 3-Kinase
Authors: McEwan David G. , Brunton Valerie G. , Baillie George S. , Leslie Nicholas R. , Houslay Miles D. , Frame Margaret C.
Published: June 2007

One of the major problems in treating colon cancer is chemoresistance to cytotoxic chemotherapeutic agents. There is therefore a need to devise new strategies to inhibit colon cancer cell growth and survival. Here, we show that a combination of low doses of the adenylyl cyclase activator forskolin together with the specific cyclic AMP (cAMP) phosphodiesterase-4 (PDE4) inhibitor rolipram, but not the cAMP phosphodiesterase-3 (PDE3) inhibitor cilostamide, causes profound growth arrest of chemoresistant KM12C colon cancer cells. Low-dose forskolin causes KM12C cells to exit the cell cycle in G1 by inducing p27Kip1 and primes cells for apoptosis on addition of rolipram. The effect of the low-dose forskolin/rolipram combination is mediated by displacement of the phosphatidylinositol 3,4,5-trisphosphate/phosphoinositide 3-kinase signaling module from the plasma membrane and suppression of the Akt/protein kinase-B oncogene pathway, to which KM12C cells are addicted for growth. The cAMP and phosphoinositide 3-kinase pathways form a critical intersection in this response, and reexpression of the tumor suppressor lipid phosphatase, phosphatase and tensin homologue, which is commonly lost or mutated in colon cancer, sensitizes KM12C cells to growth inhibition by challenge with low-dose forskolin. Certain chemoresistant colon cancer cells are therefore exquisitely sensitive to subtle elevation of cAMP by a synergistic low-dose adenylyl cyclase activator/PDE4 inhibitor combination. Indeed, these cells are addicted to maintenance of low cAMP concentrations in a compartment that is regulated by PDE4. Well-tolerated doses of PDE4 inhibitors that are already in clinical development for other therapeutic indications may provide an exciting new strategy for the treatment of colon cancer. [Cancer Res 2007;67(11):5248–57]
ACTIBIND, a T2 RNase, Competes with Angiogenin and Inhibits Human Melanoma Growth, Angiogenesis, and Metastasis
Authors: Schwartz Betty , Shoseyov Oded , Melnikova Vladislava O. , McCarty Marya , Leslie Michael , Roiz Levava , Smirnoff Patricia , Hu Guo-fu , Lev Dina , Bar-Eli Menashe
Published: June 2007

Melanoma is a very aggressive and highly angiogenic tumor in which standard treatments have had only limited success. Patients with advanced disease have a 5-year survival rate of 5%. In search for alternatives, we identified a natural product extracted from the fungus Aspergillus niger, termed ACTIBIND, that inhibits tumor growth and metastasis of melanoma in vivo. ACTIBIND, a T2 RNase, exerts antitumorigenic and antiangiogenic activities by competing with the angiogenic factor angiogenin (itself an RNase homologue). Thus, there was decreased expression and activity of the matrix metalloproteinase 2 in melanoma and vascular endothelial cells, decreased vascularization, and increased tumor cell apoptosis in vivo. ACTIBIND significantly inhibited angiogenesis in an in vivo angiogenesis assay with sponges containing angiogenin. In vitro, ACTIBIND was internalized by both melanoma and human umbilical vein endothelial cells, reached the cell nuclei, and inhibited the activity of angiogenin response elements in a dose-dependent manner. Collectively, our data indicate that ACTIBIND should be tested for its potential as a new antiangiogenic modality for the treatment of melanoma. [Cancer Res 2007;67(11):5258–66]
Mainstream Tobacco Smoke Causes Paternal Germ-Line DNA Mutation
Authors: Yauk Carole L. , Berndt M. Lynn , Williams Andrew , Rowan-Carroll Andrea , Douglas George R. , Stämpfli Martin R.
Published: June 2007

Despite the presence of known mutagens and carcinogens in cigarette smoke, there is currently no evidence to show that smoking, or exposure to cigarette smoke, can result in heritable genetic mutation. We show that male mice exposed to mainstream tobacco smoke (MTS) exhibit a significant increase in germ-line mutation frequency in spermatogonial stem cells. We exposed mature male mice to MTS for 6 or 12 weeks and investigated mutations arising in exposed spermatogonial stem cells at the expanded simple tandem repeat locus Ms6-hm. A generalized score test showed a significant treatment effect (P = 0.0214). Ms6-hm mutation frequency was 1.4 and 1.7 times higher in mice exposed to MTS for 6 and 12 weeks, respectively, compared with sham controls. The data suggest that mutations accumulate in the spermatogonial stem cells with extended exposures. Mutation spectra were identical between exposed and sham individuals, supporting the hypothesis that tandem repeat mutations arise through indirect mechanisms of mutation. Mutations in sperm that are passed on to offspring cause permanent, irreversible changes in genetic composition and can persist in future generations. Our research suggests that the consequences of smoking extend beyond the smoker to their nonsmoking descendents. [Cancer Res 2007;67(11):5103–4]
Insertional Mutagenesis Reveals Progression Genes and Checkpoints in MYC/Runx2 Lymphomas
Authors: Stewart Monica , Mackay Nancy , Hanlon Linda , Blyth Karen , Scobie Linda , Cameron Ewan , Neil James C.
Published: June 2007

In this study, we have exploited the power of insertional mutagenesis to elucidate tumor progression pathways in mice carrying two oncogenes (MYC/Runx2) that collaborate to drive early lymphoma development. Neonatal infection of these mice with Moloney murine leukemia virus resulted in accelerated tumor onset with associated increases in clonal complexity and lymphoid dissemination. Large-scale analysis of retroviral integration sites in these tumors revealed a profound bias towards a narrow range of target genes, including Jdp2 (Jundm2), D cyclin, and Pim family genes. Remarkably, direct PCR analysis of integration hotspots revealed that every progressing tumor consisted of multiple clones harboring hits at these loci, giving access to large numbers of independent insertion events and uncovering the contrasting mutagenic mechanisms operating at each target gene. Direct PCR analysis showed that high-frequency targeting occurs only in the tumor environment in vivo and is specific for the progression gene set. These results indicate that early lymphomas in MYC/Runx2 mice remain dependent on exogenous growth signals, and that progression can be achieved by constitutive activation of pathways converging on a cell cycle checkpoint that acts as the major rate-limiting step for lymphoma outgrowth. [Cancer Res 2007;67(11):5126–33]
X Inactive–Specific Transcript RNA Coating and Genetic Instability of the X Chromosome in BRCA1 Breast Tumors
Authors: Vincent-Salomon Anne , Ganem-Elbaz Carine , Manié Elodie , Raynal Virginie , Sastre-Garau Xavier , Stoppa-Lyonnet Dominique , Stern Marc-Henri , Heard Edith
Published: June 2007

Identification among breast tumors of those arising in a hereditary BRCA1 context remains a medical challenge. Abnormalities in X chromosome copy number and in the epigenetic stability of the inactive X chromosome (Xi) have been proposed to characterize BRCA1 breast tumors. In particular, it has been proposed that loss of BRCA1 function can lead to loss of X inactive–specific transcript (XIST) RNA association with the Xi. However, few studies have addressed this issue in a sufficiently large series of BRCA1 primary tumors. Here we assess X-chromosome status using single-cell (RNA and DNA fluorescence in situ hybridization) and global genomic (array-comparative genomic hybridization and allelotyping) approaches on a series of 11 well-defined BRCA1 tumors. We show that many or most cells of the tumors contain one or more XIST RNA domains. Furthermore, the number of XIST RNA domains per cell varied considerably even within a single tumor. Frequent X-chromosome allelic and copy number aberrations were found, in agreement with aberrant XIST RNA domain numbers. In summary, by combining multiple approaches to assess the genetics and epigenetics of a large series of BRCA1 primary tumors, we can conclude definitively that BRCA1 is not required for XIST RNA coating of the X chromosome. The intratumoral and intertumoral variability in XIST RNA domain number in BRCA1 tumors correlates with chromosomal genetic abnormalities, including gains, losses, reduplications, and rearrangements of the X-chromosome. Finally, we also show the necessity for combined global and single-cell approaches in the assessment of tumors with such a high degree of heterogeneity. [Cancer Res 2007;67(11):5134–40]
Methylation and Silencing of Protein Tyrosine Phosphatase Receptor Type O in Chronic Lymphocytic Leukemia
Authors: Motiwala Tasneem , Majumder Sarmila , Kutay Huban , Smith David Spencer , Neuberg Donna S. , Lucas David M. , Byrd John C. , Grever Michael , Jacob Samson T.
Published: June 2007

Purpose: Previous studies in our laboratory have shown the progressive methylation and suppression of the gene encoding protein tyrosine phosphatase, PTPRO, in the livers of rats fed a methyl-deficient diet that induces hepatocarcinogenesis. Subsequently, we observed the methylation of PTPRO in primary human lung tumors and also showed its potential tumor suppressor characteristics. The present study was undertaken to investigate whether the truncated form of PTPRO (PTPROt), specifically expressed in naïve B lymphocytes, was also methylated and suppressed in chronic lymphocytic leukemia (CLL), a disease generally affecting B lymphocytes.

Experimental Design and Results: Initial screening showed that 60% of the 52 CLL samples analyzed using methylation-specific PCR assay were methylated compared with B lymphocytes from normal individuals, which were not methylated. The expression of PTPROt, as measured by semiquantitative reverse transcription-PCR, inversely correlated with methylation in the few samples tested. Analysis of additional samples (n = 50) by combined bisulfite restriction analysis showed that the PTPRO CpG island was methylated in 82% of patients with CLL compared with B lymphocytes from normal individuals. Furthermore, overall expression of PTPRO was reduced in CLL relative to normal lymphocytes. The PTPRO gene was also suppressed by methylation in the CLL cell line WaC3CD5, where it could be reactivated upon treatment with the DNA hypomethylating agent 5-AzaC. Ectopic expression of PTPROt in a nonexpressing cell line increased growth inhibition with fludarabine treatment, a therapy commonly used for CLL.

Conclusion: This study reveals the potential role of PTPRO methylation and silencing in CLL tumorigenesis and also provides a novel molecular target in the epigenetic therapy.
Identification and Characterization of T-Cell Epitopes Deduced from RGS5, a Novel Broadly Expressed Tumor Antigen
Authors: Boß Cristina N. , Grünebach Frank , Brauer Katharina , Häntschel Maik , Mirakaj Valbona , Weinschenk Toni , Stevanovic Stefan , Rammensee Hans-Georg , Brossart Peter
Published: June 2007

Purpose: Identification of tumor-associated antigens and advances in tumor immunology resulted in the development of vaccination strategies to treat patients with malignant diseases. In a novel experimental approach that combined comparative mRNA expression analysis of defined cell types with the characterization of MHC ligands by mass spectrometry, we found that regulator of G protein signaling 5 (RGS5) is extensively up-regulated in a broad variety of malignant cells, and we identified two HLA-A2– and HLA-A3–binding peptides derived from the RGS5 protein. Interestingly, RGS5 was recently shown to be involved in tumor angiogenesis.

Experimental Design: We used monocyte-derived dendritic cells pulsed with these novel antigenic peptides or transfected with RGS5-mRNA for the in vitro induction of CTLs, generated from healthy donors, to analyze the presentation of RGS5-deduced epitopes by malignant cells.

Results: The generated CTL lines elicited an antigen-specific and HLA-restricted cytolytic activity against tumor cells endogenously expressing the RGS5 protein. Furthermore, we were able to induce RGS5-specific CTLs using peripheral blood mononuclear cells from a patient with acute myeloid leukemia capable of recognizing the autologous leukemic blasts while sparing nonmalignant cells.

Conclusions: These results indicate that the RGS5 peptides represent interesting candidates for the development of cancer vaccines designed to target malignant cells and tumor vessels.
Scheduling of Radiation with Angiogenesis Inhibitors Anginex and Avastin Improves Therapeutic Outcome via Vessel Normalization
Authors: Dings Ruud P.M. , Loren Melissa , Heun Hanke , McNiel Elizabeth , Griffioen Arjan W. , Mayo Kevin H. , Griffin Robert J.
Published: June 2007

Purpose: To test whether a direct antiangiogenic peptide (anginex) and a vascular endothelial growth factor antibody (bevacizumab, Avastin) can transiently normalize vasculature within tumors to improve oxygen delivery, alleviate hypoxia, and increase the effect of radiation therapy.

Experimental Design: Tumor oxygenation levels, microvessel density and pericyte coverage were monitored in three different solid tumor models (xenograft human ovarian carcinoma MA148, murine melanoma B16F10, and murine breast carcinoma SCK) in mice. Multiple treatment schedules were tested in these models to assess the influence on the effect of radiation therapy.

Results: In all three tumor models, we found that tumor oxygenation levels, monitored daily in real time, were increased during the first 4 days of treatment with both anginex and bevacizumab. From treatment day 5 onward, tumor oxygenation in treated mice decreased significantly to below that in control mice. This “tumor oxygenation window” occurred in all three tumor models varying in origin and growth rate. Moreover, during the treatment period, tumor microvessel density decreased and pericyte coverage of vessels increased, supporting the idea of vessel normalization. We also found that the transient modulation of tumor physiology caused by either antiangiogenic therapy improved the effect of radiation treatment. Tumor growth delay was enhanced when single dose or fractionated radiotherapy was initiated within the tumor oxygenation window as compared with other treatment schedules.

Conclusions: The results are of immediate translational importance because the clinical benefits of bevacizumab therapy might be increased by more precise treatment scheduling to ensure radiation is given during periods of peak radiosensitivity. The oxygen elevation in tumors by non–growth factor–mediated peptide anginex suggests that vessel normalization might be a general phenomenon of agents directed at disrupting the tumor vasculature by a variety of mechanisms.
Multicenter Clinical Trial of Bortezomib in Relapsed/Refractory Waldenstrom's Macroglobulinemia: Results of WMCTG Trial 03-248
Authors: Treon Steven P. , Hunter Zachary R. , Matous Jeffrey , Joyce Robin M. , Mannion Brian , Advani Ranjana , Cook David , Songer Joseph , Hill John , Kaden Bruce R. , Sharon David , Steiss Ronald , Leleu Xavier , Branagan Andrew R. , Badros Ashraf
Published: June 2007

Purpose: Waldenstrom's macroglobulinemia (WM) is a B-cell disorder. Despite advances in the therapy, WM remains incurable. As such, novel therapeutic agents are needed for the treatment of WM.

Experimental Design: In this multicenter study, 27 patients with WM received up to eight cycles of bortezomib at 1.3 mg/m2 on days 1, 4, 8, and 11. All but one patient had relapsed/or refractory disease.

Results: Following therapy, median serum IgM levels declined from 4,660 to 2,092 mg/dL (P < 0.0001). The overall response rate was 85%, with 10 and 13 patients achieving minor and major responses, respectively. Responses were prompt and occurred at median of 1.4 months. The median time to progression for all responding patients was 7.9 (range, 3-21.4+) months. The most common grade III/IV toxicities occurring in ≥5% of patients were sensory neuropathies (22.2%), leukopenia (18.5%), neutropenia (14.8%), dizziness (11.1%), and thrombocytopenia (7.4%). Sensory neuropathies resolved or improved in nearly all patients following cessation of therapy.

Conclusions: The results of these studies show that bortezomib is an active agent in relapsed and refractory WM.
DNA Copy Number Gains at Loci of Growth Factors and Their Receptors in Salivary Gland Adenoid Cystic Carcinoma
Authors: Vékony Hedy , Ylstra Bauke , Wilting Saskia M. , Meijer Gerrit A. , van de Wiel Mark A. , Leemans C. René , van der Waal Isaäc , Bloemena Elisabeth
Published: June 2007

Purpose: Adenoid cystic carcinoma (ACC) is a malignant salivary gland tumor with a high mortality rate due to late, distant metastases. This study aimed at unraveling common genetic abnormalities associated with ACC. Additionally, chromosomal changes were correlated with patient characteristics and survival.

Experimental Design: Microarray-based comparative genomic hybridization was done to a series of 18 paraffin-embedded primary ACCs using a genome-wide scanning BAC array.

Results: A total of 238 aberrations were detected, representing more gains than losses (205 versus 33, respectively). Most frequent gains (>60%) were observed at 9q33.3-q34.3, 11q13.3, 11q23.3, 19p13.3-p13.11, 19q12-q13.43, 21q22.3, and 22q13.33. These loci harbor numerous growth factor [fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF)] and growth factors receptor (FGFR3 and PDGFRβ) genes. Gains at the FGF(R) regions occurred significantly more frequently in the recurred/metastasized ACCs compared with indolent ACCs. Furthermore, patients with 17 or more chromosomal aberrations had a significantly less favorable outcome than patients with fewer chromosomal aberrations (log-rank = 5.2; P = 0.02).

Conclusions: Frequent DNA copy number gains at loci of growth factors and their receptors suggest their involvement in ACC initiation and progression. Additionally, the presence of FGFR3 and PDGFRβ in increased chromosomal regions suggests a possible role for autocrine stimulation in ACC tumorigenesis.
Molecular Characterization of Inflammatory Genes in Sentinel and Nonsentinel Nodes in Melanoma
Authors: Torisu-Itakura Hitoe , Lee Jonathan H. , Scheri Randall P. , Huynh Young , Ye Xing , Essner Richard , Morton Donald L.
Published: June 2007

Purpose: Identification of regional node metastasis is important for accurate staging and optimal treatment of early melanoma. We hypothesize that the nodal profile of immunoregulatory cytokines can confirm the identity of the first tumor-draining regional node, i.e., the sentinel node (SN) and indicate its tumor status.

Experimental Design: RNA was extracted from freshly dissected and preserved nodal tissue of 13 tumor-negative SNs, 10 tumor-positive SNs (micrometastases <2 mm), and 11 tumor-negative non-SNs (NSN). RNA was converted into cDNA and then amplified by PCR. Expression of 96 cytokines and chemokines was assessed using cDNA microarray and compared by using hierarchical clustering.

Results: Fifty-seven genes were expressed at significantly (P < 0.05) different levels in SNs and NSNs (4 genes had higher expression, and 53 genes had lower expression in SNs). Expression levels of interleukin-13 (IL-13), leptin, lymphotoxin β receptor (LTbR), and macrophage inflammatory protein 1b (MIP1b) were significantly higher (P < 0.04, P < 0.01, P < 0.05, and P < 0.01, respectively), and expression level of IL-11Ra was lower (P < 0.03) for tumor-positive as compared with tumor-negative SN. Receiver-operator characteristics curve analyses showed that the area under the curve (AUC) for IL-13, leptin, LTbR, MIP1b, and IL-11Ra was 0.79, 0.83, 0.75, 0.81, and 0.77, respectively. The AUC for the five genes in combination was 0.973, suggesting high concordance of gene-expression profiles with SN staging.

Conclusions: SNs have a different immunoregulatory cytokine profile than NSNs. The cytokine profile of tumor-positive SNs; increased expression of IL-13, leptin, LTbR, and MIP1b and decreased expression of IL-11Ra, may provide clues to the local tumor lymph node interaction seen in the earliest steps of melanoma metastasis.
Strong Time Dependence of the 76-Gene Prognostic Signature for Node-Negative Breast Cancer Patients in the TRANSBIG Multicenter Independent Validation Series
Authors: Desmedt Christine , Piette Fanny , Loi Sherene , Wang Yixin , Lallemand Françoise , Haibe-Kains Benjamin , Viale Giuseppe , Delorenzi Mauro , Zhang Yi , d'Assignies Mahasti Saghatchian , Bergh Jonas , Lidereau Rosette , Ellis Paul , Harris Adrian L. , Klijn Jan G.M. , Foekens John A. , Cardoso Fatima , Piccart Martine J. , Buyse Marc , Sotiriou Christos ,   on behalf of the TRANSBIG Consortium
Published: June 2007

Purpose: Recently, a 76-gene prognostic signature able to predict distant metastases in lymph node–negative (N−) breast cancer patients was reported. The aims of this study conducted by TRANSBIG were to independently validate these results and to compare the outcome with clinical risk assessment.

Experimental Design: Gene expression profiling of frozen samples from 198 N− systemically untreated patients was done at the Bordet Institute, blinded to clinical data and independent of Veridex. Genomic risk was defined by Veridex, blinded to clinical data. Survival analyses, done by an independent statistician, were done with the genomic risk and adjusted for the clinical risk, defined by Adjuvant! Online.

Results: The actual 5- and 10-year time to distant metastasis were 98% (88-100%) and 94% (83-98%), respectively, for the good profile group and 76% (68-82%) and 73% (65-79%), respectively, for the poor profile group. The actual 5- and 10-year overall survival were 98% (88-100%) and 87% (73-94%), respectively, for the good profile group and 84% (77-89%) and 72% (63-78%), respectively, for the poor profile group. We observed a strong time dependence of this signature, leading to an adjusted hazard ratio of 13.58 (1.85-99.63) and 8.20 (1.10-60.90) at 5 years and 5.11 (1.57-16.67) and 2.55 (1.07-6.10) at 10 years for time to distant metastasis and overall survival, respectively.

Conclusion: This independent validation confirmed the performance of the 76-gene signature and adds to the growing evidence that gene expression signatures are of clinical relevance, especially for identifying patients at high risk of early distant metastases.
The Mammalian Target of Rapamycin Signaling Pathway: Twists and Turns in the Road to Cancer Therapy
Authors: Abraham Robert T. , Gibbons James J.
Published: June 2007

The immunosuppressive drug rapamycin played a key role in the functional characterization of mammalian target of rapamycin (mTOR), an unusual protein kinase that coordinates growth factor and nutrient availability with cell growth and proliferation. Several rapamycin-related compounds are now in various stages of clinical development as anticancer agents. This article highlights recent advances in our understanding of the mTOR signaling pathway and the implications of these findings for the clinical application of mTOR inhibitors in cancer patients.
Methylation ofCASP8, DCR2, andHIN-1in Neuroblastoma Is Associated with Poor Outcome
Authors: Yang Qiwei , Kiernan Colleen M. , Tian Yufeng , Salwen Helen R. , Chlenski Alexandre , Brumback Babette A. , London Wendy B. , Cohn Susan L.
Published: June 2007

Purpose: Epigenetic aberrations have been shown to play an important role in the pathogenesis of most cancers. To investigate the clinical significance of epigenetic changes in neuroblastoma, we evaluated the relationship between clinicopathologic variables and the pattern of gene methylation in neuroblastoma cell lines and tumors.

Experimental Design: Methylation-specific PCR was used to evaluate the gene methylation status of 19 genes in 14 neuroblastoma cell lines and 8 genes in 70 primary neuroblastoma tumors. Associations between gene methylation, established prognostic factors, and outcome were evaluated. Log-rank tests were used to identify the number of methylated genes that was most predictive of overall survival.

Results: Epigenetic changes were detected in the neuroblastoma cell lines and primary tumors, although the pattern of methylation varied. Eight of the 19 genes analyzed were methylated in >70% of the cell lines. Epigenetic changes of four genes were detected in only small numbers of cell lines. None of the cell lines had methylation of the other seven genes analyzed. In primary neuroblastoma tumors, high-risk disease and poor outcome were associated with methylation of DCR2, CASP8, and HIN-1 individually. Although methylation of the other five individual genes was not predictive of poor outcome, a trend toward decreased survival was seen in patients with a methylation phenotype, defined as ≥4 methylated genes (P = 0.055).

Conclusion: Our study indicates that clinically aggressive neuroblastoma tumors have aberrant methylation of multiple genes and provides a rationale for exploring treatment strategies that include demethylating agents.