bluuebunny/crossref_metadata_2025 huggingface dataset:
GABAergic and glycinergic inhibition modulate monaural auditory response properties in the avian superior olivary nucleus
Authors: Coleman W. L. , Fischl M. J. , Weimann S. R. , Burger R. M.
Published: March 2011

The superior olivary nucleus (SON) is the primary source of inhibition in the avian auditory brainstem. While much is known about the role of inhibition at the SON's target nuclei, little is known about how the SON itself processes auditory information or how inhibition modulates these properties. Additionally, the synaptic physiology of inhibitory inputs within the SON has not been described. We investigated these questions using in vivo and in vitro electrophysiological techniques in combination with immunohistochemistry in the chicken, an organism for which the auditory brainstem has otherwise been well characterized. We provide a thorough characterization of monaural response properties in the SON and the influence of inhibitory input in shaping these features. We found that the SON contains a heterogeneous mixture of response patterns to acoustic stimulation and that in most neurons these responses are modulated by both GABAergic and glycinergic inhibitory inputs. Interestingly, many SON neurons tuned to low frequencies have robust phase-locking capability and the precision of this phase locking is enhanced by inhibitory inputs. On the synaptic level, we found that evoked and spontaneous inhibitory postsynaptic currents (IPSCs) within the SON are also mediated by both GABAergic and glycinergic inhibition in all neurons tested. Analysis of spontaneous IPSCs suggests that most SON cells receive a mixture of both purely GABAergic terminals, as well as terminals from which GABA and glycine are coreleased. Evidence for glycinergic signaling within the SON is a novel result that has important implications for understanding inhibitory function in the auditory brainstem.
Rho Kinase Phosphorylation Promotes Ezrin-Mediated Metastasis in Hepatocellular Carcinoma
Authors: Chen Yong , Wang Dongmei , Guo Zhen , Zhao Jun , Wu Bing , Deng Hui , Zhou Ti , Xiang Hongjun , Gao Fei , Yu Xue , Liao Jian , Ward Tarsha , Xia Peng , Emenari Chibuzo , Ding Xia , Thompson Winston , Ma Kelong , Zhu Jingde , Aikhionbare Felix , Dou Kefen , Cheng Shi-Yuan , Yao Xuebiao
Published: March 2011

During progression of hepatocellular carcinoma, multiple genetic and epigenetic alterations act to posttranslationally modulate the function of proteins that promote cancer invasion and metastasis. To define such abnormalities that contribute to liver cancer metastasis, we carried out a proteomic comparison of primary hepatocellular carcinoma and samples of intravascular thrombi from the same patient. Mass spectrometric analyses of the liver cancer samples revealed a series of acidic phospho-isotypes associated with the intravascular thrombi samples. In particular, we found that Thr567 hyperphosphorylation of the cytoskeletal protein ezrin was tightly correlated to an invasive phenotype of clinical hepatocellular carcinomas and to poor outcomes in tumor xenograft assays. Using phospho-mimicking mutants, we showed that ezrin phosphorylation at Thr567 promoted in vitro invasion by hepatocarcinoma cells. Phospho-mimicking mutant ezrinT567D, but not the nonphosphorylatable mutant ezrinT567A, stimulated formation of membrane ruffles, suggesting that Thr567 phosphorylation promotes cytoskeletal-membrane remodeling. Importantly, inhibition of Rho kinase, either by Y27632 or RNA interference, resulted in inhibition of Thr567 phosphorylation and a blockade to cell invasion, implicating Rho kinase-ezrin signaling in hepatocellular carcinoma cell invasion. Our findings suggest a strategy to reduce liver tumor metastasis by blocking Rho kinase-mediated phosphorylation of ezrin. Cancer Res; 71(5); 1721–9. ©2011 AACR.
Comprehensive Pathway-Based Association Study of DNA Repair Gene Variants and the Risk of Nasopharyngeal Carcinoma
Authors: Qin Hai-De , Shugart Yin Yao , Bei Jin-Xin , Pan Qing-Hua , Chen Lina , Feng Qi-Sheng , Chen Li-Zhen , Huang Wei , Liu Jian Jun , Jorgensen Timothy J. , Zeng Yi-Xin , Jia Wei-Hua
Published: March 2011

DNA repair plays a central role in protecting against environmental carcinogenesis, and genetic variants of DNA repair genes have been reported to be associated with several human malignancies. To assess whether DNA gene variants were associated with nasopharyngeal carcinoma (NPC) risk, a candidate gene association study was conducted among the Cantonese population within the Guangdong Province, China, the ethnic group with the highest risk for NPC. A 2-stage study design was utilized. In the discovery stage, 676 tagging SNPs covering 88 DNA repair genes were genotyped in a matched case-control study (cases/controls = 755/755). Eleven SNPs with Ptrend < 0.01 were identified. Seven of these SNPs were located within 3 genes, RAD51L1, BRCA2, and TP53BP1. In the validation stage, these 11 SNPs were genotyped in a separate Cantonese population (cases/controls = 1,568/1,297). Two of the SNPs (rs927220 and rs11158728), both in RAD51L1, remained strongly associated with NPC. The SNP rs927220 had a significant Pcombined of 5.55 × 10−5, with OR = 1.20 (95% CI = 1.10–1.30), Bonferroni corrected P = 0.0381. The other SNP (rs11158728), which is in strong linkage disequilibrium with rs927220 (r2 = 0.7), had a significant Pcombined of 2.0 × 10−4, Bonferroni corrected P = 0.1372. Gene–environment interaction analysis suggested that the exposures of salted fish consumption and cigarette smoking had potential interactions with DNA repair gene variations, but need to be further investigated. Our findings support the notion that DNA repair genes, in particular RAD51L1, play a role in NPC etiology and development. Cancer Res; 71(8); 3000–8. ©2011 AACR.
Ulcerative Colitis–Associated Colorectal Cancer Arises in a Field of Short Telomeres, Senescence, and Inflammation
Authors: Risques Rosa Ana , Lai Lisa A. , Himmetoglu Cigdem , Ebaee Anoosheh , Li Lin , Feng Ziding , Bronner Mary P. , Al-Lahham Bassel , Kowdley Kris V. , Lindor Keith D. , Rabinovitch Peter S. , Brentnall Teresa A.
Published: March 2011

Inflammation plays a role in the progression to cancer and it is linked to the presence of senescent cells. Ulcerative colitis (UC) is a chronic inflammatory disease that predisposes to colorectal cancer. Tumorigenesis in this setting is associated with telomere shortening that can be observed in the nondysplastic epithelium of UC patients with high-grade dysplasia (HGD) or cancer (UC progressors). We hypothesized that a preneoplastic field of inflammation, telomere shortening, and senescence underlies tumor progression in UC progressors. Multiple biopsies of varying histologic grade were collected along the colon of nine UC progressors and analyzed for telomere length, DNA damage, senescence, p53, p16, and chronic and acute inflammation. Twenty biopsies from four UC nonprogressors and twenty-one biopsies from control individuals without UC were also analyzed. Short telomeres and increased DNA damage, senescence, and infiltrating leukocytes were observed in biopsies located less than 10 cm from HGD or cancer. Low-grade dysplasia (LGD) had the shortest telomeres along with the highest levels of senescence and infiltrating leukocytes, whereas HGD biopsies showed the opposite pattern. The expression of p16 and p53 was low in nondysplastic biopsies but progressively increased in LGD and HGD. In addition, high levels of infiltrating leukocytes were associated with telomere shortening, senescence, and reduced p53 expression. These results suggest that dysplasia arises in a preneoplastic field of chronic inflammation, which leads to telomere shortening, DNA damage, and senescence. Our findings argue that senescence acts as a tumor suppressor mechanism that is abrogated during the transition from LGD to HGD in UC. Cancer Res; 71(5); 1669–79. ©2011 AACR.
Identification of N-Terminally Truncated Stable Nuclear Isoforms of CDC25B That Are Specifically Involved in G2/M Checkpoint Recovery
Authors: Jullien Denis , Bugler Beatrix , Dozier Christine , Cazales Martine , Ducommun Bernard
Published: March 2011

CDC25B phosphatases must activate cyclin B-CDK1 complexes to restart the cell cycle after an arrest in G2 phase caused by DNA damage. However, little is known about the precise mechanisms involved in this process, which may exert considerable impact on cancer susceptibility and therapeutic responses. Here we report the discovery of novel N-terminally truncated CDC25B isoforms, referred to as ΔN-CDC25B, with an exclusively nuclear and nonredundant function in cell cycle re-initiation after DNA damage. ΔN-CDC25B isoforms are expressed from a distinct promoter not involved in expression of canonical full-length isoforms. Remarkably, in contrast to the high lability and spatial dynamism of the full-length isoforms, ΔN-CDC25B isoforms are highly stable and exclusively nuclear, strongly suggesting the existence of two pools of CDC25B phosphatases in the cell that have functionally distinct properties. Using isoform-specific siRNA, we found that depleting full-length isoforms, but not ΔN-CDC25B isoforms, delays entry into mitosis. Thus, in an unperturbed cell cycle, the full-length isoforms are exclusively responsible for activating cyclin B-CDK1. Strikingly, in the late response to DNA damage, we found a CHK1-dependent shift in accumulation of CDC25B isoforms toward the ΔN-CDC25B species. Under this physiological stress condition, the ΔN-CDC25B isoform was found to play a crucial, nonredundant function in restarting the cell cycle after DNA damage-induced G2 phase arrest. Our findings reveal the existence of a previously unrecognized CDC25B isoform that operates specifically in the nucleus to reinitiate G2/M transition after DNA damage. Cancer Res; 71(5); 1968–77. ©2011 AACR.
The ΔNp63 Proteins Are Key Allies of BRCA1 in the Prevention of Basal-Like Breast Cancer
Authors: Buckley Niamh E. , Conlon Susan J. , Jirstrom Karin , Kay Elaine W. , Crawford Nyree T. , O'Grady Anthony , Sheehan Katherine , Mc Dade Simon S. , Wang Ching-Wei , McCance Dennis J. , Johnston Patrick G. , Kennedy Richard D. , Harkin D. Paul , Mullan Paul B.
Published: March 2011

Little is known about the origin of basal-like breast cancers, an aggressive disease that is highly similar to BRCA1-mutant breast cancers. p63 family proteins that are structurally related to the p53 suppressor protein are known to function in stem cell regulation and stratified epithelia development in multiple tissues, and p63 expression may be a marker of basal-like breast cancers. Here we report that ΔNp63 isoforms of p63 are transcriptional targets for positive regulation by BRCA1. Our analyses of breast cancer tissue microarrays and BRCA1-modulated breast cancer cell lines do not support earlier reports that p63 is a marker of basal-like or BRCA1 mutant cancers. Nevertheless, we found that BRCA1 interacts with the specific p63 isoform ΔNp63γ along with transcription factor isoforms AP-2α and AP-2γ. BRCA1 required ΔNp63γ and AP-2γ to localize to an intronic enhancer region within the p63 gene to upregulate transcription of the ΔNp63 isoforms. In mammary stem/progenitor cells, siRNA-mediated knockdown of ΔNp63 expression resulted in genomic instability, increased cell proliferation, loss of DNA damage checkpoint control, and impaired growth control. Together, our findings establish that transcriptional upregulation of ΔNp63 proteins is critical for BRCA1 suppressor function and that defects in BRCA1-ΔNp63 signaling are key events in the pathogenesis of basal-like breast cancer. Cancer Res; 71(5); 1933–44. ©2011 AACR.
LPS-Induced TLR4 Signaling in Human Colorectal Cancer Cells Increases β1 Integrin-Mediated Cell Adhesion and Liver Metastasis
Authors: Hsu Rich Y.C. , Chan Carlos H.F. , Spicer Jonathan D. , Rousseau Mathieu C. , Giannias Betty , Rousseau Simon , Ferri Lorenzo E.
Published: March 2011

Infectious complications resulting from resection of colorectal cancer (CRC) elevates the risk of cancer recurrence and metastasis, but the reason for this risk relationship is unknown. Defining the mechanisms responsible may offer opportunities to improve outcomes in a majority of patients whose tumors are resected as part of their therapy. The complex formed between Toll receptor TLR4 and myeloid differentiation factor MD2 defines a major cell surface receptor for lipopolysaccharide (LPS), a gram-negative bacterial antigen that has been implicated in infectious complications after CRC resection. As the TLR4/MD2 complex is expressed on CRC cells, we hypothesized that LPS may promote liver metastasis in CRC by stimulating TLR4 signaling. In support of this hypothesis, we report here that LPS enhances liver metastasis of human CRC cells that express TLR4/MD2 after intrasplenic graft of immunocompromised nude mice. Compared with TLR4 nonexpressing, nonmetastatic CRC cells, we observed increased in vitro adherence to different extracellular matrices and human umbilical vein endothelial cells (HUVEC). Furthermore, we observed an increased likelihood of in vivo capture within hepatic sinusoids after LPS treatment. No differences were apparent in phosphorylation of p38 and MAPK isoforms, but in metastatic CRC cells expressing surface TLR4 treatment with LPS increased Ser473 phosphorylation of AKT kinase. We showed that enhanced adherence elicited by LPS in these cells could be blocked at three different levels, using Eritoran (TLR4 small molecule antagonist), PI-103 (PI3K inhibitor), or anti-β1 integrin blocking antibodies. Taken together, the results indicate that stimulation of the TLR4/MD2 complex by LPS activates PI3K/AKT signaling and promotes downstream β1 integrin function, thereby increasing the adhesiveness and metastatic capacity of CRC cells. Our findings suggest that inhibiting LPS-induced TLR4 signaling could improve therapeutic outcomes by preventing cancer metastasis during the perioperative period of CRC resection. Cancer Res; 71(5); 1989–98. ©2011 AACR.
Stromal Deletion of the APC Tumor Suppressor in Mice Triggers Development of Endometrial Cancer
Authors: Tanwar Pradeep S. , Zhang LiHua , Roberts Drucilla J. , Teixeira Jose M.
Published: March 2011

The contribution of the stromal microenvironment to the progression of endometrial cancer has not been well explored. We have conditionally expressed a mutant allele of adenomatous polyposis coli (APCcKO) in murine uterine stroma cells to study its effect on uterine development and function. In addition to metrorrhagia, the mice develop complex atypical endometrial gland hyperplasia that progresses to endometrial carcinoma in situ and endometrial adenocarcinoma as evidenced by myometrial invasion. Stromal cells subjacent to the carcinoma cells express alpha-smooth muscle actin (αSMA) with fewer cells expressing platelet-derived growth factor α compared with normal stromal cells, suggesting that the mutant stromal cells have acquired a more myofibroblastic phenotype, which have been described as cancer-associated fibroblasts and have been shown to induce carcinogenesis in other organ systems. Analyses of human endometrial cancer specimens showed substantial αSMA expression in the stroma compared with normal endometrial stroma cells. We also show that APCcKO mutant uteri and human endometrial cancer have decreased stromal levels of transforming growth factor β and bone morphogenetic protein activities and that the mutant uteri failed to respond to exogenous estradiol stimulation. The mutant stroma cells also had higher levels of vascular endothelial growth factor and stromal derived factor signaling components and diminished expression of estrogen receptor α and progesterone receptor, which is common in advanced stages of human endometrial cancer and is an indicator of poor prognosis. Our results indicate that de novo mutation or loss of heterozygosity in stromal APC is sufficient to induce endometrial hyperplasia and endometrial carcinogenesis by mechanisms that are consistent with unopposed estrogen signaling in the endometrial epithelium. Cancer Res; 71(5); 1584–96. ©2011 AACR.
Enhanced Efficacy of Therapeutic Cancer Vaccines Produced by Co-Treatment withMycobacterium tuberculosisHeparin-Binding Hemagglutinin, a Novel TLR4 Agonist
Authors: Jung In Duk , Jeong Soo Kyung , Lee Chang-Min , Noh Kyung Tae , Heo Deok Rim , Shin Yong Kyoo , Yun Cheol-Heui , Koh Won-Jung , Akira Shizuo , Whang Jake , Kim Hwa-Jung , Park Won Sun , Shin Sung Jae , Park Yeong-Min
Published: March 2011

Effective activation of dendritic cells (DCs) toward T helper (Th)-1 cell polarization would improve DC-based antitumor immunotherapy, helping promote the development of immunotherapeutic vaccines based on T-cell immunity. To achieve this goal, it is essential to develop effective immune adjuvants that can induce powerful Th1 cell immune responses. The pathogenic organism Mycobacterium tuberculosis includes certain constitutes, such as heparin-binding hemagglutinin (HBHA), that possess a strong immunostimulatory potential. In this study, we report the first clarification of the functions and precise mechanism of HBHA in immune stimulation settings relevant to cancer. HBHA induced DC maturation in a TLR4-dependent manner, elevating expression of the surface molecules CD40, CD80, and CD86, MHC classes I and II and the proinflammatory cytokines IL-6, IL-12, IL-1β, TNF-α, and CCR7, as well as stimulating the migratory capacity of DCs in vitro and in vivo. Mechanistic investigations established that MyD88 and TRIF signaling pathways downstream of TLR4 mediated secretion of HBHA-induced proinflammatory cytokines. HBHA-treated DCs activated naïve T cells, polarized CD4+ and CD8+ T cells to secrete IFN-γ, and induced T-cell–mediated cytotoxicity. Notably, systemic administration of DCs that were HBHA-treated and OVA251–264-pulsed ex vivo greatly strengthened immune priming in vivo, inducing a dramatic regression of tumor growth associated with long-term survival in a murine E.G7 thymoma model. Together, our findings highlight HBHA as an immune adjuvant that favors Th1 polarization and DC function for potential applications in DC-based antitumor immunotherapy. Cancer Res; 71(8); 2858–70. ©2011 AACR.
Chromosomal Instability Confers Intrinsic Multidrug Resistance
Authors: Lee Alvin J.X. , Endesfelder David , Rowan Andrew J. , Walther Axel , Birkbak Nicolai J. , Futreal P. Andrew , Downward Julian , Szallasi Zoltan , Tomlinson Ian P.M. , Howell Michael , Kschischo Maik , Swanton Charles
Published: March 2011

Aneuploidy is associated with poor prognosis in solid tumors. Spontaneous chromosome missegregation events in aneuploid cells promote chromosomal instability (CIN) that may contribute to the acquisition of multidrug resistance in vitro and heighten risk for tumor relapse in animal models. Identification of distinct therapeutic agents that target tumor karyotypic complexity has important clinical implications. To identify distinct therapeutic approaches to specifically limit the growth of CIN tumors, we focused on a panel of colorectal cancer (CRC) cell lines, previously classified as either chromosomally unstable (CIN+) or diploid/near-diploid (CIN−), and treated them individually with a library of kinase inhibitors targeting components of signal transduction, cell cycle, and transmembrane receptor signaling pathways. CIN+ cell lines displayed significant intrinsic multidrug resistance compared with CIN− cancer cell lines, and this seemed to be independent of somatic mutation status and proliferation rate. Confirming the association of CIN rather than ploidy status with multidrug resistance, tetraploid isogenic cells that had arisen from diploid cell lines displayed lower drug sensitivity than their diploid parental cells only with increasing chromosomal heterogeneity and isogenic cell line models of CIN+ displayed multidrug resistance relative to their CIN− parental cancer cell line derivatives. In a meta-analysis of CRC outcome following cytotoxic treatment, CIN+ predicted worse progression-free or disease-free survival relative to patients with CIN− disease. Our results suggest that stratifying tumor responses according to CIN status should be considered within the context of clinical trials to minimize the confounding effects of tumor CIN status on drug sensitivity. Cancer Res; 71(5); 1858–70. ©2011 AACR.
Aberrations of EZH2 in Cancer
Authors: Chase Andrew , Cross Nicholas C.P.
Published: March 2011

Control of gene expression is exerted at a number of different levels, one of which is the accessibility of genes and their controlling elements to the transcriptional machinery. Accessibility is dictated broadly by the degree of chromatin compaction, which is influenced in part by polycomb group proteins. EZH2, together with SUZ12 and EED, forms the polycomb repressive complex 2 (PRC2), which catalyzes trimethylation of histone H3 lysine 27 (H3K27me3). PRC2 may recruit other polycomb complexes, DNA methyltransferases, and histone deacetylases, resulting in additional transcriptional repressive marks and chromatin compaction at key developmental loci. Overexpression of EZH2 is a marker of advanced and metastatic disease in many solid tumors, including prostate and breast cancer. Mutation of EZH2 Y641 is described in lymphoma and results in enhanced activity, whereas inactivating mutations are seen in poor prognosis myeloid neoplasms. No histone demethylating agents are currently available for treatment of patients, but 3-deazaneplanocin (DZNep) reduces EZH2 levels and H3K27 trimethylation, resulting in reduced cell proliferation in breast and prostate cancer cells in vitro. Furthermore, synergistic effects are seen for combined treatment with DNA demethylating agents and histone deacetylation inhibitors, opening up the possibility of refined epigenetic treatments in the future. Clin Cancer Res; 17(9); 2613–8. ©2011 AACR.
Prevention of Radiation-Induced Salivary Hypofunction Following hKGF Gene Delivery to Murine Submandibular Glands
Authors: Zheng Changyu , Cotrim Ana P. , Rowzee Anne , Swaim William , Sowers Anastasia , Mitchell James B. , Baum Bruce J.
Published: March 2011

Purpose: Salivary glands are significantly affected when head and neck cancer patients are treated by radiation. We evaluated the effect of human keratinocyte growth factor (hKGF) gene transfer to murine salivary glands on the prevention of radiation-induced salivary hypofunction.

Experimental Design: A hybrid serotype 5 adenoviral vector encoding hKGF (AdLTR2EF1α-hKGF) was constructed. Female C3H mice, 8 weeks old, were irradiated by single (15 Gy) or fractionated (6 Gy for 5 days) doses to induce salivary hypofunction. AdLTR2EF1α-hKGF or AdControl was administered (108 – 1010 particles per gland) to both submandibular glands (SG) by retrograde ductal instillation before irradiation (IR). Salivary flow was measured following pilocarpine stimulation. Human KGF levels were measured by ELISA. SG cell proliferation was measured with bromodeoxyuridine labeling. Endothelial and progenitor or stem cells in SGs were measured by flow cytometry. The effect of SG hKGF production on squamous cell carcinoma (SCC VII) tumor growth was assessed.

Results: In 3 separate single-dose IR experiments, salivary flow rates of mice administered the AdLTR2EF1α-hKGF vector were not significantly different from nonirradiated control mice (P > 0.05). Similarly, in 3 separate fractionated IR experiments, the hKGF-expressing vector prevented salivary hypofunction dramatically. Transgenic hKGF protein was found at high levels in serum and SG extracts. AdLTR2EF1α-hKGF–treated mice showed increased cell proliferation and numbers of endothelial cells, compared with mice treated with AdControl. hKGF gene transfer had no effect on SCC VII tumor growth ± radiation.

Conclusions: hKGF gene transfer prevents salivary hypofunction caused by either single or fractionated radiation dosing in mice. The findings suggest a potential clinical application. Clin Cancer Res; 17(9); 2842–51. ©2011 AACR.
Melanoma Prevention Using Topical PBISe
Authors: Chung Chin-Ying , Madhunapantula SubbaRao V. , Desai Dhimant , Amin Shantu , Robertson Gavin P.
Published: March 2011

Malignant melanoma is the deadliest form of skin cancer, known for its drug resistance and high metastatic potential. Deregulated PI3 and mitogen activated protein (MAP) kinase pathways promote early melanocytic lesion development and confer drug resistance. No agent exists to target these deregulated pathways to prevent cutaneous noninvasive melanocytic cells or invasive melanomas from developing into more aggressive widely disseminated metastatic disease. In this study, a selenium containing isosteric analogue of PBIT [S, S′-1,4-phenylenebis(1,2-ethanediyl)bis-isothiourea] called PBISe [Se, Se′-1,4-phenylenebis(1,2-ethanediyl)bis-isoselenourea] is shown to moderate these 2 major signaling pathways to prevent cutaneous melanocytic lesion or melanoma development. Topical application of PBISe retarded melanocytic lesion development in laboratory-generated skin by 70% to 80% and in animal skin by approximately 50%. Mechanistically, prevention of lesion development occurred due to decreased Akt3 signaling, which increased MAP kinase pathway activity to inhibitory levels. The combined effect of targeting these pathways led to decreased cell proliferation and increased apoptotic cell death thereby preventing melanoma development. Thus, topically applied PBISe treatment has potential to prevent noninvasive melanocytic lesion and invasive metastatic melanoma development in skin. Cancer Prev Res; 4(6); 935–48. ©2011 AACR.
Effect of Suppressive Oligodeoxynucleotides on the Development of Inflammation-Induced Papillomas
Authors: Ikeuchi Hidekazu , Kinjo Takeshi , Klinman Dennis M.
Published: March 2011

Inflammation contributes to the development of papillomas and squamous cell carcinomas in the well-established 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-l3-acetate (TPA) model of skin carcinogenesis. Synthetic oligonucleotides (ODN) containing repetitive TTAGGG motifs have been shown to block deleterious inflammatory reactions in murine models of autoimmunity, pneumonitis, and shock. This article examines whether treatment with suppressive (Sup) ODN can interfere with DMBA/TPA-induced inflammation, thereby reducing papilloma formation. Results indicate that Sup ODN block TPA-dependent skin hyperplasia, edema, and leukocytic infiltration. Sup ODN also inhibit the upregulation of genes encoding pro-oncogenic chemokines and other markers of inflammation including CXCL2, CCL2, COX-2, and ODC (ornithine decarboxylase). Of greatest import, Sup ODN reduce papilloma formation in a dose- and sequence-dependent manner. These findings suggest that Sup ODN may provide a novel means of preventing inflammation and associated oncogenesis. Cancer Prev Res; 4(5); 752–7. ©2011 AACR.
Zerumbone Induces Heme Oxygenase-1 Expression in Mouse Skin and Cultured Murine Epidermal Cells through Activation of Nrf2
Authors: Shin Jun-Wan , Ohnishi Kohta , Murakami Akira , Lee Jeong-Sang , Kundu Joydeb Kumar , Na Hye-Kyung , Ohigashi Hajime , Surh Young-Joon
Published: March 2011

Zerumbone, a sesquiterpene derived from tropical ginger, contains an electrophilic α,β-unsaturated carbonyl moiety and was found to suppress chemically induced papilloma formation in mouse skin. Here, we report that topical application of zerumbone onto dorsal skin of hairless mice induces activation of NF-E2–related factor 2 (Nrf2) and expression of heme oxygenase-1 (HO-1). We compared the levels of HO-1 protein in the skin of zerumbone-treated Nrf2 wild-type and Nrf2 knockout mice, and nrf2-deficient mice expressed HO-1 protein to a much lesser extent than the wild-type animals following topical application of zerumbone. Treatment of mouse epidermal JB6 cells with zerumbone caused a marked increase of Nrf2 nuclear translocation followed by the promoter activity of HO-1, and also enhanced direct binding of Nrf2 to the antioxidant response element. Moreover, knockdown of Nrf2 in JB6 cells diminished the zerumbone-induced upregulation of HO-1. Notably, α-humulene and 8-hydroxy-α-humulene, the structural analogues of zerumbone that lack the α,β-unsaturated carbonyl group, failed to activate Nrf2 and were unable to increase HO-1 expression. Unlike zerumbone, these nonelectrophilic analogues could not suppress the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced JB6 cell transformation and the intracellular accumulation of reactive oxygen species (ROS). Interestingly, when JB6 cells were treated with carbon monoxide–releasing molecule that mimics the HO-1 activity, the TPA-induced ROS production was markedly reduced. Taken together, these findings suggest that upregulation of HO-1 expression by zerumbone is mediated through activation of Nrf2 signaling, which provides a mechanistic basis for the chemopreventive effects of this sesquiterpene on mouse skin carcinogenesis. Cancer Prev Res; 4(6); 860–70. ©2011 AACR.
Evaluation of Different Perfusion Durations in Direct Hemoperfusion with Polymyxin B-Immobilized Fiber Column Therapy for Acute Exacerbation of Interstitial Pneumonias
Authors: Kono Masato , Suda Takafumi , Enomoto Noriyuki , Nakamura Yutaro , Kaida Yusuke , Hashimoto Dai , Inui Naoki , Mizuguchi Tomoaki , Kato Akihiko , Shirai Toshihiro , Nakamura Hirotoshi , Chida Kingo
Published: March 2011

Background: Recently, the potential therapeutic effect of direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) has been reported for acute exacerbation of interstitial pneumonia (AE-IP), a highly morbid clinical event; however, there is no consensus on the appropriate procedure for PMX-DHP. We examined the appropriate perfusion duration of PMX-DHP for AE-IP. Methods: AE-IP patients receiving PMX-DHP were divided into two groups: short-duration group (≤6 h) (n = 5) and long-duration group (12 h) (n = 12). Results: ThePaO2/FiO2 (P/F) ratio increased immediately after PMX-DHP in the two groups. In the long-duration group, the P/F ratio continued to increase over the following 7 days, while, in the short-duration group, the P/F ratio declined again 3 days after therapy. The survival rate 30 days after PMX-DHP was significantly higher in the long-duration group than in the short-duration group. Conclusions: A long perfusion duration of PMX-DHP is more efficacious for AE-IP than a short perfusion duration.
Immunological Effects of Bevacizumab-Based Treatment in Metastatic Colorectal Cancer
Authors: Manzoni M. , Rovati B. , Ronzoni M. , Loupakis F. , Mariucci S. , Ricci V. , Gattoni E. , Salvatore L. , Tinelli C. , Villa E. , Danova M.
Published: March 2011

Objective: The efficacy of bevacizumab in metastatic colorectal cancer (mCRC) could be related not only to its well-known antiangiogenetic properties but also to a hypothetical effect on the immune system of the host. Methods: We enrolled mCRC patients treated with a bevacizumab-based first-line therapy. Lymphocyte and dendritic cell subsets were evaluated at baseline, 3rd and 6th cycle. The clinical efficacy was estimated as response rate and progression-free survival. Forty healthy subjects were used as reference. Results: Fifty-one patients were enrolled. In comparison with healthy subjects, they showed a decrease of T and B cell compartments. Bevacizumab ameliorated the impairment of lymphocyte subsets, especially for T cells. Responders showed a trend toward an increase of CD3 (p = 0.07) and CD4 (p = 0.05). Among patients with a progression-free survival >1 year, only CD19 (p = 0.033) and CD20 (p = 0.013) showed a significant increase. No baseline impairment and no significant modification of dendritic cells were found. Conclusion: Bevacizumab-based therapy is able to increase B and T cell compartments. The expansion of T lymphocytes could imply an amelioration of dendritic cell-presenting capacity. These effects correlate with a more favourable clinical outcome and could be taken into account in clinical protocols aimed at combining antiangiogenetic-therapy with immunotherapy in mCRC.
Prospective Multicenter Randomized Phase III Study of Weekly versus Standard Docetaxel plus Doxorubicin (D4) for First-Line Treatment of Metastatic Breast Cancer
Authors: Stemmler Hans-Joachim , Harbeck Nadia , Gröll de Rivera Isolde , Vehling Kaiser Ursula , Rauthe Gerhard , Abenhardt Wolfgang , Artmann Almut , Sommer Harald , Meerpohl Hans-Gerd , Kiechle Marion , Heinemann Volker
Published: March 2011

Purpose: Previous phase II studies have indicated a greatly reduced hematotoxicity of docetaxel-based regimens administered on weekly schedules. The present trial was initiated to compare the toxicity and efficacy of weekly docetaxel versus its standard 3-weekly application in combination with doxorubicin. Methods: Patients previously untreated with chemotherapy for metastatic disease were recruited. Inclusion criteria were age <65 years or a Karnofsky Performance Status of 70–100%. All patients in the D4 study received doxorubicin (50 mg/m2) on the first day of treatment in addition to docetaxel given either at a 3-weekly dose of 75 mg/m2 every 3 weeks (q3w) or at a weekly dose of 35 mg/m2 (days 1, 8, and 15; q4w). Treatment was continued until a maximum of 8 cycles, unacceptable toxicity, or disease progression. All patients received standard corticosteroid prophylaxis. Results: Since interim analysis showed failure to reach a significant difference for the primary endpoint (hematotoxicity, i.e. leukopenia), the study was closed according to the study protocol (85 of 242 patients). A lower-than-expected rate of leukopenia ≧grade 3 was observed in the standard arm of the D4 study compared to the weekly schedule (per-patient analysis: 61.9% q3w vs. 65.1% q1w; p > 0.05). Grade 3 and grade 4 fever, diarrhea, and infections occurred more frequently in the standard arm, whereas neurotoxicity and skin/nail disorders were observed more frequently in the weekly arm. Except for fever, none of these differences reached a level of significance. Dose delays, dose reductions, and the rate of omitted doses were increased in the weekly arm. The overall response rate was 44.2% in the weekly arm compared to 52.4% in the standard arm (p = 0.52). Time to progression was 6.2 (q1w) versus 10.3 (q3w) months (p = 0.36), and overall survival was 20.5 (q1w) versus 28.7 (q3w) months (p = 0.98). Conclusion: The present data support the feasibility of both weekly and 3-weekly application of docetaxel in combination with doxorubicin. Nevertheless, given that leukopenia was similar in both arms and the efficacy parameters were at least numerically inferior with the weekly schedule, standard 3-weekly application seems to be preferable for patients requiring combination chemotherapy.
Prospective Multicenter Randomized Phase III Study of Weekly versus Standard Docetaxel (D2) for First-Line Treatment of Metastatic Breast Cancer
Authors: Stemmler Hans-Joachim , Harbeck Nadia , Gröll de Rivera Isolde , Vehling Kaiser Ursula , Rauthe Gerhard , Abenhardt Wolfgang , Artmann Almut , Sommer Harald , Meerpohl Hans-Gerd , Kiechle Marion , Heinemann Volker
Published: March 2011

Purpose: Previous phase II studies have indicated a greatly reduced hematotoxicity of docetaxel-based regimens administered on weekly schedules. The present trial was initiated to randomly compare the toxicity and efficacy of weekly docetaxel versus its standard 3-weekly application. Methods: Patients previously untreated with chemotherapy for metastatic disease were recruited. Patients aged >60 years or with a Karnofsky Perfomance Status (KPS) of 60–80% were eligible for the D2 study. Patients were randomized to receive docetaxel either on a 3-weekly [75 mg/m2 every 3 weeks (q3w)] or on a weekly (30 mg/m2 on days 1, 8, and 15; q4w) schedule. Treatment was continued until a maximum of 8 cycles, unacceptable toxicity, or disease progression. All patients received standard corticosteroid prophylaxis. Results: Since statistical significance for the primary endpoint (toxicity) was achieved in the interim analysis, the study was closed according to the study protocol (102 of 162 patients). Compared to the standard arm, leukopenia ≧grade 3 was a rare event in the weekly arm of the D2 study (per-patient analysis: 4.2% q1w vs. 51.9% q3w; p < 0.0001). No difference was observed between the 2 schedules regarding the occurrence of anemia or thrombocytopenia. With regard to nonhematological toxicity, there was a higher incidence of skin/nail and hepatological toxicity with the weekly schedule, whereas neurotoxicity was observed more often in the standard arm. The rate of omitted doses was significantly increased in the weekly arm (8.6% q1w vs. 0% q3w). The overall response rate was 22.9% in the weekly arm compared to 42.6% in the standard arm (p = 0.039). Time to progression was 5.4 (q1w) versus 6.3 (q3w) months (p = 0.91), and overall survival was 22.7 (q1w) versus 15.8 (q3w) months (p = 0.24). Conclusion: The present data support the feasibility of both weekly and 3-weekly application of docetaxel. As expected, severe leukopenia seems avoidable in weekly scheduled single-agent docetaxel and may serve as an important treatment option, particularly in elderly patients and patients with a reduced performance status.
Improvement of Oral Intake following Chemotherapy in Gastric Cancer Patients with an Inability to Eat
Authors: Shitara Kohei , Ito Seiji , Sawaki Akira , Tajika Masahiro , Kawai Hiroki , Yokota Tomoya , Takahari Daisuke , Ura Takashi , Muro Kei
Published: March 2011

Background: Based on several phase III studies, oral S-1-based chemotherapy has become the standard for treatment of advanced gastric cancer in Japan. However, these studies included patients able to maintain sufficient oral intake, and the effectiveness of chemotherapy for patients unable to eat remained unclear. Methods: We retrospectively analyzed the effect of chemotherapy on patients with advanced gastric cancer who presented with inability to eat. We defined ‘inability to eat’ as requirement for daily intravenous fluids or hyperalimentation and ‘improvement of oral intake’ as no such requirement >1 week. Results: Among the 777 patients who received first-line chemotherapy, 100 patients (12.8%) were considered unable to eat and required daily intravenous fluids or hyperalimentation. Performance status was 0–1 in 26 patients and ≧2 in the other 74 patients. Seventy-eight patients (78%) had peritoneal metastasis and 62 patients (62%) had ascites. First-line chemotherapy with 5-fluorouracil-based regimens was used in 46 patients, taxane-based chemotherapy in 34 patients, oral fluoropyrimidine-based therapy in 19 patients, and irinotecan-cisplatin combination treatment in 2 patients. Median survival time was 5.0 months (95% confidence interval, CI, 3.9–6.6). Improvement in oral intake with duration for >1 week was achieved in 40 patients (40%) with the median duration of nutritional-support-free time of 3.1 months (95% CI 2.5–4.6). Conclusion: Chemotherapy is moderately effective in improving oral intake in patients with advanced gastric cancer with inability to eat. Further study is required to improve its prognosis.
Characterization of Physical Binding between Human Papillomavirus 18 Protein E7 and Centromere Protein C
Authors: Yaginuma Yuji , Yoda Kinya , Ogawa Katsuhiro
Published: March 2011

Human papillomaviruses (HPVs) have been linked to a variety of human diseases, most notably cancer of the cervix. In the majority of cases, HPV proteins E6 and E7 are continuously expressed and bind a variety of cellular proteins. The precise mechanism of HPV-induced carcinogenesis has not been fully elucidated; therefore, we attempted to identify the cellular proteins that interact with HPV18 E7 to better understand the function of this important protein. Using yeast 2-hybrid screening, we identified centromere protein C (CENP-C) as one of the proteins that interact with HPV18 E7. CENP-C interacted with E7 from HPV18 but not from HPV11. The CR2 domain of HPV18 E7 and the C-terminal region of CENP-C were found to be involved in the binding of these proteins. CENP-C is a component of the inner kinetochore and plays an essential role in proper chromosome segregation, mitotic checkpoint function, and kinetochore assembly. HPV18 E7–CENP-C binding may therefore impair centromere function, in turn causing cancers. We speculate that altered function of CENP-C as a result of interactions with HPV E7 may be associated with chromosomal abnormalities in HPV18-positive cancers.
Dual, Constrictor-to-Dilator, Response of the Mouse Ductus Arteriosus to the Microsomal Prostaglandin E Synthase-1 Inhibitor, 2-(6-Chloro-1H-phenanthro[9,10d]imidazole- 2-yl)isophthalonitrile
Authors: Baragatti Barbara , Scebba Francesca , Sodini Daria , Pagni Eleonora , Ciofini Enrica , Xu Daigen , Coceani Flavio
Published: March 2011

Background: Microsomal prostaglandin E synthase-1 (mPGES1) is critical for prostaglandin E2 formation in ductus arteriosus (DA) and, accordingly, in its patency. We previously reported that mPGES1 deletion, unlike cyclo-oxygenase (COX) suppression, is not followed by upregulation of relaxant nitric oxide (NO). Consequently, we proposed that a mPGES1 inhibitor may be better than currently used COX inhibitors in managing premature infants with persistent DA (PDA). Objective: To assess the effect of the mPGES1 inhibitor, 2-(6-chloro-1H-phenanthro[9,10d]imidazole-2-yl)isophthalonitrile (MF63) on DA ex vivo and in vivo (p.o. to the mother). Methods: Experiments were carried out with mice bearing human mPGES1. We utilized isolated, wire-mounted DA for isometric recording and a whole-body freezing technique to assess the DA caliber as it occurs in vivo. Results: MF63 (10 µM) contracted the isolated DA. DA constriction was also seen in vivo after a single 10-mg kg–1 dose. Conversely, a 30-mg kg–1 dose gave inconsistent results, combining constriction with no effect. DA dilatation followed instead a repeated lower dose (twice daily for 3 days), and postnatal closure of the vessel was also delayed. Chronic pretreatment had no effect on endothelial NO synthase mRNA expression in fetal DA, nor did it modify the contraction to NO synthase inhibitor NG-nitro-L-arginine methyl ester (100 µM). Conclusions: MF63 has a dual action on DA, the constriction being associated with accessory dilatation. The latter effect should be explained before considering further a mPGES1 inhibitor for management of PDA.
Network of Endocardial Vessels
Authors: Lee Byung-Cheon , Kim Hong Bae , Sung Baeckkyoung , Kim Ki Woo , Sohn Jamin , Son Boram , Chang Byung-Joon , Soh Kwang-Sup
Published: March 2011

Background: Although there have been reports on threadlike structures inside the heart, they have received little attention. We aimed to develop a method for observing such structures and to reveal their ultrastructures. Methods:An in situ staining method, which uses a series of procedures of 0.2–0.4% trypan blue spraying and washing, was applied to observe threadlike structures on the surfaces of endocardia. The threadlike structures were isolated and observed by using confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). Results: Networks of endocardial vessels (20 µm in thickness) with expansions (40–100 µm in diameter) were visualized; they were movable on the endocardium of the bovine atrium and ventricle. CLSM showed that (1) rod-shaped nuclei were aligned along the longitudinal direction of the endocardial vessel and (2) there were many cells inside the expansion. TEM on the endocardial vessel revealed that (1) there existed multiple lumens (1–7 µm in diameter) and (2) the extracellular matrices mostly consisted of collagen fibers, which were aligned along the longitudinal direction of the endocardial vessel or were locally organized in reticular structures. Conclusion: We investigated the endocardial circulatory system in bovine cardiac chambers and its ultrastructures, such as nucleic distributions, microlumens, and collagenous extracellular matrices.
Timing of Renal Replacement Therapy after Cardiac Surgery: A Retrospective Multicenter Spanish Cohort Study
Authors: García-Fernández Nuria , Pérez-Valdivieso José Ramón , Bes-Rastrollo Maira , Vives Marc , Lavilla Javier , Herreros Jesús , Monedero Pablo ,   on behalf of the GEDRCC (Grupo Español de Disfunción Renal en Cirugía Cardiaca)
Published: March 2011

Background: The optimal time to initiate renal replacement therapy (RRT) in cardiac surgery-associated acute kidney injury (CSA-AKI) is unknown. Evidence suggests that the early use of RRT in critically ill patients is associated with improved outcomes. We studied the effects of time to initiation of RRT on outcome in patients with CSA-AKI. Methods: This was a retrospective observational multicenter study (24 Spanish hospitals). We analyzed data on 203 patients who required RRT after cardiac surgery in 2007. The cohort was divided into 2 groups based on the time at which RRT was initiated: in the early RRT group, therapy was initiated within the first 3 days after cardiac surgery; in the late group, RRT was begun after the 3rd day. Multivariate nonconditional logistic and linear regression models were used to adjust for potential confounders. Results: In-hospital mortality was significantly higher in the late RRT group compared with early RRT patients (80.4 vs. 53.2%; p < 0.001; adjusted odds ratio of 4.1, 95% CI: 1.6–10.0). Also, patients in the late RRT group had longer adjusted hospital stays by 11.6 days (95% CI: 1.4–21.9) and higher adjusted percentage increases in creatinine at discharge compared with baseline by 67.7% (95% CI: 28.5–106.4). Conclusions: Patients who undergo early initiation of RRT after CSA-AKI have improved survival rates and renal function at discharge and decreased lengths of hospital stay.
A Modified in vivo Flow Variation Technique of Microdialysis for Sampling Uremic Toxins in the Subcutaneous Interstitial Compartment
Authors: Ebah Leonard , Brenchley Paul , Coupes Beatrice , Mitra Sandip
Published: March 2011

Background: Uremic toxins are typically measured in plasma and little is known of their interstitial concentrations. We undertook experiments to validate a microdialysis technique for simultaneous recovery of small and large uremic toxins in the subcutaneous interstitial fluid (ISF). Methods: Microdialysis catheters were inserted into the subcutaneous interstitium of 8 subjects (controls and uremic patients) and perfused using two different solutions at incremental flow rates to determine analyte recovery and ISF concentrations of urea and protein. Results: 10% dextran-40 perfusate allowed the determination of interstitial concentrations of urea and protein reliably, by virtue of the exponential decay of their concentrations in the microdialysate with incremental flow rates (R2 = 0.63–0.99). Interstitial and plasma urea correlated well (r = 0.95), as did interstitial urea from distant anatomical sites (r = 0.96). Conclusion: Cutaneous microdialysis with dextran-40 allows measurement of small and large molecule concentrations in ISF, creating an opportunity to characterize ISF in uremia.
A Method to Estimate Total Entry to Hard Drug Use: The Case of Intravenous Drug Use in Norway
Authors: Amundsen Ellen J. , Bretteville-Jensen Anne Line , Kraus Ludwig
Published: March 2011

Background/Aims: Epidemiological measures such as the prevalence and incidence of hard drug use are important tools for evaluating drug situations and drug policies. Models for drug use trajectories illustrate how temporary and lasting cessation of and relapse into hard drug use are other important elements in the overall picture of change in hard drug use over time. Estimating the total entry to hard drug use broadens the knowledge of the change in such use. Methods: The entry rate for hard drug use is defined as the sum of incident cases and relapses and estimated based on successive prevalence estimates and cessation rates. Results: The entry rate, as applied to the Norwegian case of intravenous drug use, increased from the mid-1980s to a peak in 2000, decreased up to 2003 and stabilized thereafter. The peak in Oslo appeared earlier (1998). The estimated level of the entry rate is sensitive to the rate of cessation. Conclusion: We conclude that it is possible to expand the description of hard drug use epidemics beyond estimates of prevalence and incidence. The entry rate supplies a useful tool for our understanding of drug situations and decision making regarding drug policies.