bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Alendronate Use Not without Consequences?
Authors: Somford M. P. , Geurts G. F. A. E. , den Teuling J. W. A. M. , Thomassen B. J. W. , Draijer W. F.
Published: January 2010

A previously unknown side effect of biphosphonate use is emerging. In a specific patient group on long term biphosphonate therapy stress femur fractures seem to occur. The typical presentation consists of prodromal pain in the affected leg and/or a discrete cortical thickening on the lateral side of the femur in conventional radiological examination or the presentation with a spontaneous transverse subtrochanteric femur with typical features. We present three cases of this stress fracture in patients on bisphosphonate therapy. One of these patients suffered a bilateral femur fracture of the same type. In our opinion, in patients on bisphosphonate therapy who present with a spontaneous femur fracture, seizing therapy is advisable. In bilateral cases preventive nailing should be considered.
Isolation and Characterization of a Novel Facultative Anaerobic Filamentous Fungus from Japanese Rice Field Soil
Authors: Tonouchi Akio
Published: January 2010

A novel filamentous fungus strain designated RB-1 was isolated into pure culture from Japanese rice field soil through an anaerobic role tube technique. The strain is a mitosporic fungus that grows in both aerobic and strict anaerobic conditions using various mono-, di-, tri-, and polysaccharides with acetate and ethanol productions. The amount of acetate produced was higher than that of ethanol in both aerobic and anaerobic cultures. The characteristic verrucose or punctuate conidia of RB-1 closely resembled those of some strains of the genusThermomyces, a thermophilic or mesophilic anamorphic ascomycete. However, based on phylogenetic analysis with the small subunit (SSU) and large subunit (LSU) rDNA sequences, RB-1 was characterized as a member of the class Lecanoromycetes of the phylum Ascomycota. Currently, RB-1 is designated as an anamorphic ascomycete and is phylogenetically considered anincertae sediswithin the class Lecanoromycetes.
Bi‐Lipschitz Mappings and Quasinearly Subharmonic Functions
Authors: Dovgoshey Oleksiy , Riihentaus Juhani
Published: January 2010

After considering a variant of the generalized mean value inequality of quasinearly subharmonic
functions, we consider certain invariance properties of quasinearly subharmonic functions. Kojić has shown
that in the plane case both the class of quasinearly subharmonic functions and the class of regularly oscillating
functions are invariant under conformal mappings. We give partial generalizations to her results by showing that
in ℝn, n ≥ 2, these both classes are invariant under bi‐Lipschitz mappings.
Gauge Symmetry and Howe Duality in 4D Conformal Field Theory Models
Authors: Todorov Ivan
Published: January 2010

It is known that there are no local scalar Lie fields in more than
two dimensions. Bilocal fields, however, which naturally arise in conformal operator product expansions, do generate infinite Lie algebras. It is demonstrated that these Lie algebras of local observables admit (highly reducible) unitary positive energy representations in a Fock space. The
multiplicity of their irreducible components is governed by a compact gauge group. The mutually commuting observable algebra and gauge group form a dual pair in the sense of Howe. In a theory of local scalar fields of conformal dimension two in four space‐time dimensions the associated dual pairs are constructed and classified.
Cooperative Signaling with Soft Information Combining
Authors: Lin Rui , Martin Philippa A. , Taylor Desmond P.
Published: January 2010

We propose a Decode‐and‐Forward (DF) scheme using distributed Turbo code (DTC) for a three‐node (source, relay, and destination) wireless cooperative communication system. The relay decodes, then interleaves, and reencodes the decoded data. It then forwards the reencoded packet and its instantaneous receive SNR to the destination. The performances using both ideal and quantized SNR are studied. The destination uses a modified metric within a Turbo decoding algorithm to scale the soft information calculated for the relay code. The proposed scheme is simple to implement and performs well.
Receptor-Mediated and Fluid-Phase Transcytosis of Horseradish Peroxidase across Rat Hepatocytes
Authors: Ellinger Isabella , Fuchs Renate
Published: January 2010

Horseradish peroxidase (HRP) is often used as a fluid-phase marker to characterize endocytic and transcytotic processes. Likewise, it has been applied to investigate the mechanisms of biliary secretion of fluid in rat liver hepatocytes. However, HRP contains mannose residues and thus binds to mannose receptors (MRs) on liver cells, including hepatocytes. To study the role of MR-mediated endocytosis of HRP transport in hepatocytes, we determined the influence of the oligosaccharid mannan on HRP biliary secretion in the isolated perfused rat liver. A 1-minute pulse of HRP was applied followed by marker-free perfusion. HRP appeared in bile with biphasic kinetics: a first peak at 7 minutes and a second peak at 15 minutes after labeling. Perfusion with 0.8 mg/mL HRP in the presence of a twofold excess of mannan reduced the first peak by 41% without effect on the second one. Together with recently published data on MR expression in rat hepatocytes this demonstrates two different mechanisms for HRP transcytosis: a rapid, receptor-mediated transport and a slower fluid-phase transport.
Novel Candidate Cancer Genes Identified by a Large-Scale Cross-Species Comparative Oncogenomics Approach
Authors: Mattison Jenny , Kool Jaap , Uren Anthony G. , de Ridder Jeroen , Wessels Lodewyk , Jonkers Jos , Bignell Graham R. , Butler Adam , Rust Alistair G. , Brosch Markus , Wilson Catherine H. , van der Weyden Louise , Largaespada David A. , Stratton Michael R. , Futreal P. Andy , van Lohuizen Maarten , Berns Anton , Collier Lara S. , Hubbard Tim , Adams David J.
Published: January 2010

Comparative genomic hybridization (CGH) can reveal important disease genes but the large regions identified could sometimes contain hundreds of genes. Here we combine high-resolution CGH analysis of 598 human cancer cell lines with insertion sites isolated from 1,005 mouse tumors induced with the murine leukemia virus (MuLV). This cross-species oncogenomic analysis revealed candidate tumor suppressor genes and oncogenes mutated in both human and mouse tumors, making them strong candidates for novel cancer genes. A significant number of these genes contained binding sites for the stem cell transcription factors Oct4 and Nanog. Notably, mice carrying tumors with insertions in or near stem cell module genes, which are thought to participate in cell self-renewal, died significantly faster than mice without these insertions. A comparison of the profile we identified to that induced with the Sleeping Beauty (SB) transposon system revealed significant differences in the profile of recurrently mutated genes. Collectively, this work provides a rich catalogue of new candidate cancer genes for functional analysis. Cancer Res; 70(3); 883–95
EWS/FLI1 Oncogene Activates Caspase 3 Transcription and Triggers Apoptosis In vivo
Authors: Sohn Eun Jung , Li Hongjie , Reidy Karen , Beers Lisa F. , Christensen Barbara L. , Lee Sean Bong
Published: January 2010

EWS/FLI1 is a fusion gene product generated by a chromosomal translocation t(11;22)(q24;q12) found in Ewing sarcoma. EWS/FLI1 encodes an aberrant transcription factor with oncogenic properties in vitro. Paradoxically, expression of EWS/FLI1 in nontransformed primary cells results in apoptosis, but the exact mechanism remains unclear. In primary mouse embryonic fibroblasts derived from conditional EWS/FLI1 knock-in embryos, expression of EWS/FLI1 resulted in apoptosis with concomitant increase in the endogenous Caspase 3 (Casp3) mRNA. EWS/FLI1 directly bound and activated the CASP3 promoter, whereas small interfering RNA–mediated knockdown of EWS/FLI1 led to a marked decrease in CASP3 transcripts in Ewing sarcoma cell lines. Ectopic expression of EWS/FLI1 resulted in an increased expression of CASP3 protein in heterologous cell lines. Importantly, expression of EWS/FLI1 in the mouse triggered an early onset of apoptosis in kidneys and acute lethality. These findings suggest that EWS/FLI1 induces apoptosis, at least partially, through the activation of CASP3 and show the cell context–dependent roles of EWS/FLI1 in apoptosis and tumorigenesis. Cancer Res; 70(3); 1154–63
Role of Cationic Channel TRPV2 in Promoting Prostate Cancer Migration and Progression to Androgen Resistance
Authors: Monet Michaël , Lehen'kyi V'yacheslav , Gackiere Florian , Firlej Virginie , Vandenberghe Matthieu , Roudbaraki Morad , Gkika Dimitra , Pourtier Albin , Bidaux Gabriel , Slomianny Christian , Delcourt Philippe , Rassendren François , Bergerat Jean-Pierre , Ceraline Jocelyn , Cabon Florence , Humez Sandrine , Prevarskaya Natalia
Published: January 2010

Castration resistance in prostate cancer (PCa) constitutes an advanced, aggressive disease with poor prognosis, associated with uncontrolled cell proliferation, resistance to apoptosis, and enhanced invasive potential. The molecular mechanisms involved in the transition of PCa to castration resistance are obscure. Here, we report that the nonselective cationic channel transient receptor potential vanilloid 2 (TRPV2) is a distinctive feature of castration-resistant PCa. TRPV2 transcript levels were higher in patients with metastatic cancer (stage M1) compared with primary solid tumors (stages T2a and T2b). Previous studies of the TRPV2 channel indicated that it is primarily involved in cancer cell migration and not in cell growth. Introducing TRPV2 into androgen-dependent LNCaP cells enhanced cell migration along with expression of invasion markers matrix metalloproteinase (MMP) 9 and cathepsin B. Consistent with the likelihood that TRPV2 may affect cancer cell aggressiveness by influencing basal intracellular calcium levels, small interfering RNA–mediated silencing of TRPV2 reduced the growth and invasive properties of PC3 prostate tumors established in nude mice xenografts, and diminished expression of invasive enzymes MMP2, MMP9, and cathepsin B. Our findings establish a role for TRPV2 in PCa progression to the aggressive castration-resistant stage, prompting evaluation of TRPV2 as a potential prognostic marker and therapeutic target in the setting of advanced PCa. Cancer Res; 70(3); 1225–35
FKBPL Regulates Estrogen Receptor Signaling and Determines Response to Endocrine Therapy
Authors: McKeen Hayley D. , Byrne Christopher , Jithesh Puthen V. , Donley Christopher , Valentine Andrea , Yakkundi Anita , O'Rourke Martin , Swanton Charles , McCarthy Helen O. , Hirst David G. , Robson Tracy
Published: January 2010

The HSP90 chaperone and immunophilin FKBPL is an estrogen-responsive gene that interacts with estogen receptor α (ERα) and regulates its levels. In this study, we explored the effects of FKBPL on breast cancer proliferation. Breast cancer cells stably overexpressing FKBPL became dependent on estrogen for their growth and were dramatically more sensitive to the antiestrogens tamoxifen and fulvestrant, whereas FKBPL knockdown reverses this phenotype. FKBPL knockdown also decreased the levels of the cell cycle inhibitor p21WAF1 and increased ERα phosphorylation on Ser118 in response to 17β-estradiol and tamoxifen. In support of the likelihood that these effects explained FKBPL-mediated cell growth inhibition and sensitivity to endocrine therapies, FKBPL expression was correlated with increased overall survival and distant metastasis-free survival in breast cancer patients. Our findings suggest that FKBPL may have prognostic value based on its impact on tumor proliferative capacity and sensitivity to endocrine therapies, which improve outcome. Cancer Res; 70(3); 1090–100
RBCK1 Drives Breast Cancer Cell Proliferation by Promoting Transcription of Estrogen Receptor α and Cyclin B1
Authors: Gustafsson Nina , Zhao Chunyan , Gustafsson Jan-Åke , Dahlman-Wright Karin
Published: January 2010

Cell cycle regulatory pathways in breast cancer are incompletely described. Here, we report an important role in estrogen receptor α (ERα)–positive breast cancer cells for the protein kinase C1 (PKC1)–interacting protein RBCK1 in supporting cell cycle progression by driving transcription of ERα and cyclin B1. RBCK1-depleted cells exhibited increased accumulation in G2-M phase of the cell cycle, decreased proliferation, and reduced mRNA levels for ERα and its target genes cyclin D1 and c-myc. Chromatin immunoprecipitation revealed that ERα transcription is associated with RBCK1 recruitment to the ERα promoter, suggesting that transcriptional regulation is one mechanism by which RBCK1 affects ERα mRNA levels. G2-M phase arrest was mediated independently from reduced ERα levels, instead associated with transcriptional inhibition of the key G2-M regulator cyclin B1. In breast tumor samples, there was a positive correlation between levels of RBCK1, ERα, and cyclin B1 mRNA levels. Our findings suggest that RBCK1 regulates cell cycle progression and proliferation of ERα-positive breast cancer cells by supporting transcription of ERα and cyclin B1. Cancer Res; 70(3); 1265–74
Identification of Breast Tumor Mutations in BRCA1 That Abolish Its Function in Homologous DNA Recombination
Authors: Ransburgh Derek J.R. , Chiba Natsuko , Ishioka Chikashi , Toland Amanda Ewart , Parvin Jeffrey D.
Published: January 2010

Effects of breast cancer–associated gene 1 (BRCA1) missense mutations on the function of BRCA1 protein in DNA recombination have been little studied. In this report, we adapted a homology-directed recombination (HDR) assay to analyze the effects of BRCA1 mutations on this function. Using a HeLa-derived cell line with a genomically integrated recombination substrate, we expressed an endonuclease creating a double-stranded break in the substrate that the HDR assay scores by generation of green fluorescent protein–positive cells. By combining RNA interference (RNAi) that targets cellular BRCA1 mRNA with expression of RNAi-resistant BRCA1 mutants, we could effectively substitute selected point mutants to test these in the cellular recombination assay. We found that ∼300 residues at both termini of the BRCA1 protein were essential for HDR. Whereas some mutations analyzed were neutral, mutations that altered any zinc-coordinating residue or generated M18T and T37R alterations were defective for recombination. This study established a robust assay system to analyze the function of BRCA1 in regulating homologous recombination, which is critical for its tumor suppressor function. Cancer Res; 70(3); 988–95
Caffeine-Mediated Inhibition of Calcium Release Channel Inositol 1,4,5-Trisphosphate Receptor Subtype 3 Blocks Glioblastoma Invasion and Extends Survival
Authors: Kang Sang Soo , Han Kyung-Seok , Ku Bo Mi , Lee Yeon Kyung , Hong Jinpyo , Shin Hye Young , Almonte Antoine G. , Woo Dong Ho , Brat Daniel J. , Hwang Eun Mi , Yoo Seung Hyun , Chung Chun Kee , Park Sung-Hye , Paek Sun Ha , Roh Eun Joo , Lee Sung joong , Park Jae-Yong , Traynelis Stephen F. , Lee C. Justin
Published: January 2010

Calcium signaling is important in many signaling processes in cancer cell proliferation and motility including in deadly glioblastomas of the brain that aggressively invade neighboring tissue. We hypothesized that disturbing Ca2+ signaling pathways might decrease the invasive behavior of giloblastoma, extending survival. Evaluating a panel of small-molecule modulators of Ca2+ signaling, we identified caffeine as an inhibitor of glioblastoma cell motility. Caffeine, which is known to activate ryanodine receptors, paradoxically inhibits Ca2+ increase by inositol 1,4,5-trisphospate receptor subtype 3 (IP3R3), the expression of which is increased in glioblastoma cells. Consequently, by inhibiting IP3R3-mediated Ca2+ release, caffeine inhibited migration of glioblastoma cells in various in vitro assays. Consistent with these effects, caffeine greatly increased mean survival in a mouse xenograft model of glioblastoma. These findings suggest IP3R3 as a novel therapeutic target and identify caffeine as a possible adjunct therapy to slow invasive growth of glioblastoma. Cancer Res; 70(3); 1173–83
Inactivation of the Quinone Oxidoreductases NQO1 and NQO2 Strongly Elevates the Incidence and Multiplicity of Chemically Induced Skin Tumors
Authors: Shen Jun , Barrios Roberto J. , Jaiswal Anil K.
Published: January 2010

The cytosolic quinone oxidoreductases NQO1 and NQO2 protect cells against oxidative stress by detoxifying quinones and preventing redox cycling. In this study, we used double knockout (DKO) mice deficient for NQO1 and NQO2 to investigate the role of these antioxidative enzymes in a two-stage model of inflammatory skin carcinogenesis. In this model, tumors are caused by exposure to topical carcinogen dimethylbenz(a)anthracene or benzo(a)pyrene (BP) followed by twice weekly application of proinflammatory phorbol 12-myristate 13-acetate. On this classic chemical carcinogenesis protocol, DKO mice showed a significantly higher skin tumor frequency and multiplicity compared with control wild-type or single knockout mice. Analysis of skin from wild-type and DKO mice exposed to BP for 6, 12, or 24 hours revealed a relative delay in the activation of p53, p63, p19ARF, and apoptosis in DKO mice, consistent with a negative modifier role for NQO1/NQO2 in carcinogenesis. Our findings offer genetic evidence of the significance of quinone oxidoreductases NQO1 and NQO2 in limiting chemical skin carcinogenesis. Cancer Res; 70(3); 1006–14
Increased Expression of Annexin A3 Is a Mechanism of Platinum Resistance in Ovarian Cancer
Authors: Yan Xuedong , Yin Jie , Yao Huiyu , Mao Ning , Yang Yili , Pan Lingya
Published: January 2010

Resistance to platinum drugs has emerged as a major obstacle in the treatment of ovarian cancers. Through proteomic analysis, we have found that the expression of annexin A3, a member of the Ca2+ and phospholipid-binding annexin family, is significantly increased in platinum-resistant ovarian cell lines. Anti–annexin A3 immunostaining indicated that cancers from platinum-resistant patients also possess higher levels of annexin A3 than those from platinum-sensitive patients. Although expression of annexin A3 made susceptible ovarian cancer cells more resistant to platinum, expression of antisense annexin A3 downregulated its expression and rendered the resistant cells more sensitive to platinum. In athymic mice, the growth of tumors from inoculated SKOV3 cells was inhibited by the administration of platinum, whereas tumors from annexin A3–expressing SKOV3/Ann were resistant to platinum treatment. Interestingly, the intracellular platinum concentration and platinum-DNA binding are significantly lower in annexin A3–overexpressing cells than those in parental cells. The lower cisplatin concentration was also accompanied by reduced induction of p53, which could be restored by downregulation of annexin A3. These results indicate that increased expression of annexin A3 is a mechanism of platinum resistance in ovarian cancer. It seems to act by preventing uptake or accumulation of platinum in cells. Therefore, it is conceivable that annexin A3 could be a target for therapeutic intervention and may also serve as a biomarker for drug resistance in ovarian cancer patients. Cancer Res; 70(4); 1616–24
Lung Metastasis Fails in MMTV-PyMT Oncomice Lacking S100A4 Due to a T-Cell Deficiency in Primary Tumors
Authors: Grum-Schwensen Birgitte , Klingelhöfer Jörg , Grigorian Mariam , Almholt Kasper , Nielsen Boye Schnack , Lukanidin Eugene , Ambartsumian Noona
Published: January 2010

Interactions between tumor and stroma cells are essential for the progression of cancer from its initial growth at a primary site to its metastasis to distant organs. The metastasis-stimulating protein S100A4 exerts its function as a stroma cell–derived factor. Genetic depletion of S100A4 significantly reduced the metastatic burden in lungs of PyMT-induced mammary tumors. In S100A4+/+ PyMT mice, massive leukocyte infiltration at the site of the growing tumor at the stage of malignant transition was associated with increased concentration of extracellular S100A4 in the tumor microenvironment. In contrast, in S100A4−/− PyMT tumors, a significant suppression of T-cell infiltration was documented at the transition period. In vitro, the S100A4 protein mediated the attraction of T cells. Moreover, S100A4+/+, but not S100A4−/−, fibroblasts stimulated the invasion of T lymphocytes into fibroblast monolayers. In vivo, the presence of S100A4+/+, but not S100A4−/−, fibroblasts significantly stimulated the attraction of T lymphocytes to the site of the growing tumor. Increased levels of T cells were also observed in the premetastatic lungs of tumor-bearing mice primed to metastasize by S100A4+/+ fibroblasts. Treatment of T cells with the S100A4 protein stimulated production of cytokines, particularly granulocyte colony-stimulating factor and eotaxin-2. The same cytokines were detected in the fluid of S100A4+/+ PyMT tumors at the transition period. We suggest that release of S100A4 in the primary tumor stimulates infiltration of T cells and activates secretion of cytokines, thus triggering sequential events that fuel tumor cells to metastasize. Similar processes could occur in the premetastatic lungs, facilitating generation of inflammatory milieu favorable for metastasis formation. Cancer Res; 70(3); 936–47
Heterotrimerization of the Growth Factor Receptors erbB2, erbB3, and Insulin-like Growth Factor-I Receptor in Breast Cancer Cells Resistant to Herceptin
Authors: Huang Xiaoping , Gao Lizhi , Wang Shuiliang , McManaman James L. , Thor Ann D. , Yang XiaoHe , Esteva Francisco J. , Liu Bolin
Published: January 2010

Primary and acquired resistance to the breast cancer drug trastuzumab (Herceptin) is a significant clinical problem. Here, we report enhanced activation of downstream signaling pathways emanating from the growth factor receptors erbB2, erbB3, and insulin-like growth factor-I receptor (IGF-IR) in trastuzumab-resistant breast cancer cells. Interactions between IGF-IR and erbB2 or erbB3 occur exclusively in trastuzumab-resistant cells, where enhanced erbB2-erbB3 interactions are also observed. Moreover, these three receptors form a heterotrimeric complex in resistant cells. erbB3 or IGF-IR knockdown by short hairpin RNA–mediated strategies upregulates p27kip1, inactivates downstream receptor signaling, and resensitizes resistant cells to trastuzumab. Our findings reveal a heterotrimer complex with a key role in trastuzumab resistance. On the basis of our results, we propose that trastuzumab resistance in breast cancer might be overcome by therapeutic strategies that jointly target erbB3, erbB2, and IGF-IR. Cancer Res; 70(3); 1204–14
Vascular Endothelial Growth Factor—A Positive and Negative Regulator of Tumor Growth
Authors: Vecchiarelli-Federico Laura M. , Cervi David , Haeri Mehran , Li Yanmei , Nagy Andras , Ben-David Yaacov
Published: January 2010

Over the past decade, the well-documented role of vascular endothelial growth factor (VEGF) in tumor angiogenesis has led it to become one of the leading therapeutic targets for the treatment of cancer. Emerging evidence from genetically modified animal models, however, suggests that elevated levels of VEGF, or a proangiogenic phenotype, may impede, rather than promote, early tumor development and progression. For example, hypermorph VEGF transgenic mice display delayed progression of a retroviral-induced murine leukemia, and knockdown of VEGF expression within the myeloid compartment accelerates tumor progression. Several mechanisms have been proposed to explain this paradox, whereby VEGF induces changes within the hematopoietic compartment and tumor microenvironment through recruitment of tumor inhibitory monocytic cells and the negative regulation of tumor angiogenesis. Thus, it is apparent that the levels of VEGF expression in both tumor and nontumor tissues, as well as the context and timing of its modulation relative to cancer induction, play an important role in determining the effects of VEGF expression on tumorigenicity. In light of these recent findings, the various mechanisms underlying the negative role of VEGF during early tumor development, progression, and metastasis will be discussed. Cancer Res; 70(3); 863–7
Sunitinib Acts Primarily on Tumor Endothelium rather than Tumor Cells to Inhibit the Growth of Renal Cell Carcinoma
Authors: Huang Dan , Ding Yan , Li Yan , Luo Wang-Mei , Zhang Zhong-Fa , Snider John , VandenBeldt Kristin , Qian Chao-Nan , Teh Bin Tean
Published: January 2010

Sunitinib is a broad-spectrum small-molecule inhibitor of receptor tyrosine kinases (RTK) that serves as the present standard of care for first-line therapy of advanced clear cell renal cell carcinoma (ccRCC). A full understanding of the targets and mechanism of action of sunitinib in ccRCC treatment remains incomplete. In this study, we evaluated several tumor cell and endothelial targets of sunitinib and investigated which RTK(s) may specifically contribute to its therapeutic effects. Microarray expression profiling and Western blot analysis revealed that among known sunitinib targets, only platelet-derived growth factor receptor-β and vascular endothelial growth factor receptor-2 (VEGFR-2) were overexpressed in ccRCCs relative to normal tissues. Sunitinib was unable to inhibit survival or proliferation of ccRCC cells at pharmacologically relevant concentrations (∼0.1 μmol/L) that inhibit RTK targets. In contrast, sunitinib inhibited endothelial cell proliferation and motility at the same concentrations by suppressing VEGFR-2 signaling. Moreover, whereas sunitinib inhibited the growth of ccRCC xenograft tumors and decreased tumor microvessel density as soon as 12 hours after treatment, sunitinib showed no significant effects on tumor cell proliferation or apoptosis up to 72 hours after treatment. Our findings indicate that sunitinib inhibits ccRCC growth primarily through an antiangiogenic mechanism and not through direct targeting of ccRCC tumor cells. Cancer Res; 70(3); 1053–62
Interleukin-8 Mediates Resistance to Antiangiogenic Agent Sunitinib in Renal Cell Carcinoma
Authors: Huang Dan , Ding Yan , Zhou Ming , Rini Brian I. , Petillo David , Qian Chao-Nan , Kahnoski Richard , Futreal P. Andrew , Furge Kyle A. , Teh Bin Tean
Published: January 2010

The broad spectrum kinase inhibitor sunitinib is a first-line therapy for advanced clear cell renal cell carcinoma (ccRCC), a deadly form of kidney cancer. Unfortunately, most patients develop sunitinib resistance and progressive disease after about 1 year of treatment. In this study, we evaluated the mechanisms of resistance to sunitinib to identify the potential tactics to overcome it. Xenograft models were generated that mimicked clinical resistance to sunitinib. Higher microvessel density was found in sunitinib-resistant tumors, indicating that an escape from antiangiogenesis occurred. Notably, escape coincided with increased secretion of interleukin-8 (IL-8) from tumors into the plasma, and coadministration of an IL-8 neutralizing antibody resensitized tumors to sunitinib treatment. In patients who were refractory to sunitinib treatment, IL-8 expression was elevated in ccRCC tumors, supporting the concept that IL-8 levels might predict clinical response to sunitinib. Our results reveal IL-8 as an important contributor to sunitinib resistance in ccRCC and a candidate therapeutic target to reverse acquired or intrinsic resistance to sunitinib in this malignancy. Cancer Res; 70(3); 1063–71
Nuclear Factor-κB and Tumor-Associated Macrophages
Authors: Mancino Alessandra , Lawrence Toby
Published: January 2010

Tumor-associated macrophages (TAM) have been linked with the progression of cancer by favoring tumor angiogenesis, growth, and metastasis. The precise mechanisms that maintain the protumor phenotype of TAM are poorly understood, but recent research has highlighted a number of signaling pathways that are important in TAM phenotype and function. Nuclear factor-κB (NF-κB) is considered the master regulator of inflammatory and immune responses. Recently several genetic studies have indicated NF-κB is an important pathway in TAM for the integration of signals from the tumor microenvironment that promote carcinogenesis. This review will focus on the role of NF-κB in TAM and the potential of targeting this pathway as a novel therapeutic strategy against cancer. Clin Cancer Res; 16(3); 784–9
Delta-Like Ligand 4 Plays a Critical Role in Pericyte/Vascular Smooth Muscle Cell Formation during Vasculogenesis and Tumor Vessel Expansion in Ewing's Sarcoma
Authors: Schadler Keri L. , Zweidler-McKay Patrick A. , Guan Hui , Kleinerman Eugenie S.
Published: January 2010

Purpose: Bone marrow (BM) cells contribute to tumor vessel formation that supports the growth of Ewing's sarcoma. These BM cells migrate into the tumor and differentiate into endothelial cells and pericytes. We investigated whether delta-like ligand 4 (DLL4) played a role in the formation of BM-derived pericytes/vascular smooth muscle cells (vSMC) during tumor vessel formation.

Experimental Design: Using immunohistochemistry, we examined the expression pattern of DLL4 in 14 patient samples and two xenograft mouse models of Ewing's sarcoma. We then used intratumor injections of short hairpin RNA to inhibit DLL4 expression in Ewing's sarcoma tumors in mice, and evaluated the effect on BM-derived pericytes/vSMCs.

Results: DLL4 was expressed by perivascular cells in 12 of 14 human samples and in BM-derived pericytes/vSMCs in both A4573 and TC71 xenograft tumors. Inhibition of DLL4 expression by short hairpin RNA correlated with the decreased numbers of BM-derived cells in tumor vessels and the decreased numbers of α-SMA+, desmin+, and NG2+ pericytes/vSMCs, as well as increased tumor hypoxia.

Conclusions: DLL4 is important for the formation of BM-derived pericytes/vSMCs during vasculogenesis in Ewing's sarcoma. DLL4 may be a therapeutic target for treatment of Ewing's sarcoma by inhibition of blood vessel formation. Clin Cancer Res; 16(3); 848–56
Antitumor Activity of Targeting Src Kinases in Endothelial and Myeloid Cell Compartments of the Tumor Microenvironment
Authors: Liang Wei , Kujawski Maciej , Wu Jun , Lu Jianming , Herrmann Andreas , Loera Sofia , Yen Yun , Lee Frank , Yu Hua , Wen Wei , Jove Richard
Published: January 2010

Purpose: Several Src family kinase (SFK) inhibitors have entered clinical trials based on their direct effects against tumor cells. Here, we characterize the effects of targeting Src kinases on the tumor microenvironment and how these effects influence tumor growth.

Experimental Design: Human cancer cells grown in cell culture or in mice were treated with dasatinib, a small-molecule inhibitor of SFKs. Tumor cell, endothelial cell, and myeloid cell compartments within the tumor microenvironment were analyzed. Primary human endothelial cells and freshly isolated CD11b+/CD11c− myeloid cells from mice were treated with dasatinib in cell culture. Cellular functions and signaling pathways affected by dasatinib were evaluated.

Results: Dasatinib was not cytotoxic in cell culture against the human cancer cell lines investigated here. However, dasatinib administration in human tumor–bearing mice suppressed tumor growth associated with increased tumor cell apoptosis, decreased microvessel density, and reduced intratumoral CD11b+ myeloid cells. Dasatinib directly inhibited motility and other functions of endothelial and myeloid cells, accompanied by the inhibition of phosphorylation of SFKs and downstream signaling. Tumor-infiltrating myeloid cells were identified as the major source of matrix metalloproteinase (MMP)-9 in the tumor microenvironment. Dasatinib treatment reduced MMP-9 levels in the tumor microenvironment through the simultaneous inhibition of recruitment of MMP9+ myeloid cells and MMP-9 gene expression in tumor-infiltrating myeloid cells.

Conclusions: These findings suggest that Src kinase inhibitors such as dasatinib possess a previously unrecognized anticancer mechanism of action by targeting both host-derived endothelial and myeloid cell compartments within the tumor microenvironment. Clin Cancer Res; 16(3); 924–35
Validation of SAG/RBX2/ROC2 E3 Ubiquitin Ligase as an Anticancer and Radiosensitizing Target
Authors: Jia Lijun , Yang Jie , Hao Xinbao , Zheng Min , He Hongbin , Xiong Xiufang , Xu Liang , Sun Yi
Published: January 2010

Purpose: Sensitive to apoptosis gene (SAG; also known as RBX2 or ROC2) was originally cloned as a redox-inducible antioxidant protein and was later characterized as a RING component of SCF E3 ubiquitin ligases. SAG overexpression inhibits apoptosis induced by many stimuli both in vitro and in vivo. SAG mRNA was overexpressed in human lung tumor tissues with a correlation to poor patient survival. To investigate whether SAG serves as an anticancer target, we determined the effect of SAG silencing on cell proliferation, survival, and radiosensitivity.

Experimental Design: SAG protein expression in human tumors was evaluated by immunohistochemical staining using tumor tissue arrays. SAG expression in cancer cells was knocked down by siRNA silencing. The anticancer effects of SAG silencing were evaluated by in vitro assays for cell growth and survival and by an in vivo orthotopic xenograft tumor model. Radiosensitization by SAG silencing of human cancer cells was determined by clonogenic survival assay. Apoptosis induction was evaluated by fluorescence-activated cell sorting analysis, caspase-3 activation assay, and Western blotting of apoptosis-associated proteins.

Results: SAG was overexpressed in multiple human tumor tissues compared with their normal counterparts. SAG silencing selectively inhibited cancer cell proliferation, suppressed in vivo tumor growth, and sensitized radiation-resistant cancer cells to radiation. Mechanistically, SAG silencing induced apoptosis with accumulation of NOXA, whereas SAG overexpression reduced NOXA levels and shortened NOXA protein half-life.

Conclusions: The findings showed that SAG E3 ubiquitin ligase plays an essential role in cancer cell proliferation and tumor growth and may serve as a promising anticancer and radiosensitizing target. Clin Cancer Res; 16(3); 814–24
MiR-222 Overexpression Confers Cell Migratory Advantages in Hepatocellular Carcinoma through Enhancing AKT Signaling
Authors: Wong Queenie W-L. , Ching Arthur K-K. , Chan Anthony W-H. , Choy Kwong-Wai , To Ka-Fai , Lai Paul B-S. , Wong Nathalie
Published: January 2010

Purpose: This study aims to profile the expressions of 156 microRNAs (miRNA) in hepatocellular carcinoma (HCC) and to characterize the functions of miR-222, the most significantly upregulated candidate identified.

Experimental Design: miRNA expression profile in HCC tumors, matching adjacent cirrhotic livers, and cell lines was conducted using quantitative PCR. Common miR-222 upregulations were further validated in a larger cohort of tumors. The functional effects of miR-222 inhibition on HCC cell lines were examined. The downstream modulated pathways and target of miR-222 were investigated by coupling gene expression profiling and pathway analysis, and by in silico prediction, respectively. Luciferase reporter assay was done to confirm target interaction.

Results: We identified a 40-miRNA signature that could discriminate tumors from adjacent cirrhotic liver tissue, and further corroborated common miR-222 overexpression in tumors relative to its premalignant counterpart (55.3%; P < 0.0001). Increased miR-222 expression correlated significantly with advanced stage HCC and with the shorter disease-free survival of patients (P ≤ 0.01). Inhibition of miR-222 in Hep3B and HKCI-9 significantly retarded cell motility (P < 0.05). Further investigations suggested that AKT signaling was the major pathway influenced by miR-222. A consistent reduction of AKT phosphorylation in Hep3B and HKCI-9 was shown following miR-222 suppression. The protein phosphatase 2A subunit B (PPP2R2A) was predicted as a putative miR-222 target in silico. We found that miR-222 inhibition could augment the tumor protein level and restore luciferase activity in reporter construct containing the PPP2R2A 3′ untranslated region (P = 0.0066).

Conclusions: Our study showed that miR-222 overexpression is common in HCC and could confer metastatic potentials in HCC cells, possibly through activating AKT signaling. Clin Cancer Res; 16(3); 867–75
Clinical Pharmacokinetics of Amifostine and WR1065 in Pediatric Patients with Medulloblastoma
Authors: McKibbin Trevor , Panetta John C. , Fouladi Maryam , Gajjar Amar , Bai Feng , Okcu M. Fatih , Stewart Clinton F.
Published: January 2010

Purpose: We evaluated the pharmacokinetics of amifostine and WR1065 in pediatric patients with newly diagnosed medulloblastoma to assess the influence of patient covariates, including demographics, clinical characteristics, and genetic polymorphisms, on amifostine and WR1065 pharmacokinetic parameters.

Experimental Design: We assessed the pharmacokinetics of amifostine and WR1065 in 33 children who received amifostine (1-minute infusion, 600 mg/m2) just before the start of and 3 hours into a 6-hour cisplatin infusion. Serial blood samples were collected after doses 1 (0 hour) and 2 (3 hours) of course 1. Amifostine and WR1065 were quantitated by high performance liquid chromatography with electrochemical detection. A pharmacokinetic model was simultaneously fit to amifostine and WR1065 plasma or whole blood concentration-versus-time data. The influence of demographic, biochemical, and pharmacogenetic covariates on amifostine and WR1065 disposition was evaluated.

Results: Body surface area was the primary size-based covariate for amifostine pharmacokinetics explaining 53% and 56% of interindividual variability in plasma and whole-blood amifostine clearance, respectively. The population-predicted values for amifostine clearance, volume, and apparent WR1065 clearance from the plasma data were 107 L/h/m2, 5.53 L/m2, and 30.6 L/h/m2. The population-predicted values for amifostine clearance, volume, and apparent WR1065 clearance from whole blood data were 136 L/h/m2, 7.23 L/m2, and 12.5 L/h/m2.

Conclusions: These results support using body surface area for calculating doses of amifostine in children. Similar to data in adults, amifostine and WR1065 are rapidly cleared from plasma and whole blood in children. Clin Cancer Res; 16(3); 1049–57
TKTL1 Is Activated by Promoter Hypomethylation and Contributes to Head and Neck Squamous Cell Carcinoma Carcinogenesis through Increased Aerobic Glycolysis and HIF1α Stabilization
Authors: Sun Wenyue , Liu Yan , Glazer Chad A. , Shao Chunbo , Bhan Sheetal , Demokan Semra , Zhao Ming , Rudek Michelle A. , Ha Patrick K. , Califano Joseph A.
Published: January 2010

Purpose: This study aims to investigate the role of the aberrant expression of Transkelolase-like 1 (TKTL1) in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and to characterize TKTL1 contribution to HNSCC tumorigenesis through aerobic glycolysis and HIF1α stabilization.

Experimental Design: TKTL1 promoter hypomethylation and mRNA/protein aberrant expression were studied in human HNSCC tumor samples and normal mucosas. Oncogenic functions of TKTL1 were examined in HNSCC cell line panels and tumor xenograft models with TKTL1 expression construct. The metabolite levels of fructose-6-phosphate, glyceraldehydes-3-phosphate, pyruvate, lactate, and the levels of HIF1α protein and its downsteam glycolytic targets were compared between the TKTL1-expressing and vehicle-expressing HNSCC cells. Meanwhile, the effects of HIF1α/glycolytic inhibitors were evaluated on the TKTL1 transfectants.

Results: TKTL1 exhibits high frequency of promoter hypomethylation in HNSCC tumors compared with the normal mucosas, correlating with its overexpression in HNSCC. Overexpression of TKTL1 in HNSCC cells promoted cellular proliferation and enhanced tumor growth in vitro and in vivo. Overexpression of TKTL1 increased the production of fructose-6-phosphate and glyceraldehyde-3-phosphate, in turn elevating the production of pyruvate and lactate, resulting in the normoxic stabilization of the malignancy-promoting transcription factor HIF1α and the upregulation of downstream glycolytic enzymes. Notably, the reduction of TKTL1 expression decreased HIF1α accumulation and inhibition with HIF1α and/or the glycolysis inhibitor could abrogate the growth effects mediated by TKTL1 overexpression.

Conclusion: TKTL1 is a novel candidate oncogene that is epigenetically activated by aberrant hypomethlation and contributes to a malignant phenotype through altered glycolytic metabolism and HIF1α accumulation. Clin Cancer Res; 16(3); 857–66
Plasma EBV DNA Clearance Rate as a Novel Prognostic Marker for Metastatic/Recurrent Nasopharyngeal Carcinoma
Authors: Wang Wen-Yi , Twu Chih-Wen , Chen Hsin-Hong , Jan Jian-Sheng , Jiang Rong-San , Chao Jeffrey Y.C. , Liang Kai-Li , Chen Kuan-Wen , Wu Ching-Te , Lin Jin-Ching
Published: January 2010

Purpose: To investigate the prognostic effect of the concentrations and clearance rates of plasma EBV DNA in metastatic/recurrent nasopharyngeal carcinoma (NPC).

Experimental Design: Thirty relapsed and four previously nontreated metastatic NPC patients were treated according to the consensus guidelines of the head and neck cancer team in our hospital (i.v. chemotherapy first, followed by local irradiation boost and oral maintenance chemotherapy where applicable). Multiple plasma samples were collected during the first month of chemotherapy. Circulating EBV DNA concentrations were measured by a real-time quantitative PCR. The half-life values (t1/2) of plasma EBV DNA clearance were calculated. The associations between clinical outcome and plasma EBV DNA assays were analyzed.

Results: Tumor response evaluated after 12 weeks of treatment showed 14 complete responses (41.2%), 12 partial responses (35.3%), 7 stable diseases (20.6%), and 1 progression disease (2.9%). The plasma EBV DNA concentrations have no significant effects on outcome prediction. The t1/2 of plasma EBV DNA clearance ranged from 1.85 to 28.29 days (median, 3.99). Patients with a short t1/2 of plasma EBV DNA clearance have significantly higher complete response rate and overall survival than those with long t1/2. Multivariate analysis revealed a significant effect of the t1/2 of plasma EBV DNA clearance on survival.

Conclusions: The clearance rates of plasma EBV DNA during the first month of chemotherapy can predict tumor response and patient survival. Early change of chemotherapy regimen may be considered for patients with slow plasma EBV DNA clearance rate. Clin Cancer Res; 16(3); 1016–24
Targeting the Tumor Microenvironment With Src Kinase Inhibition
Authors: Chung Alicia S. , Ferrara Napoleone
Published: January 2010

Although most cancer therapies are directed against tumor cells, an emerging area of cancer therapeutics focuses on targeting cells of the tumor microenvironment. Inhibiting the Src family kinase with dasatinib decreases tumor growth through inhibiting growth of tumor-associated endothelial and myeloid cells. Clin Cancer Res; 16(3); 775–7
Interleukin-29 Binds to Melanoma Cells Inducing Jak-STAT Signal Transduction and Apoptosis
Authors: Guenterberg Kristan D. , Grignol Valerie P. , Raig Ene T. , Zimmerer Jason M. , Chan Anthony N. , Blaskovits Farriss M. , Young Gregory S. , Nuovo Gerard J. , Mundy Bethany L. , Lesinski Gregory B. , Carson William E.
Published: January 2010

Interleukin-29 (IL-29) is a member of the type III IFN family that has been shown to have antiviral activity and to inhibit cell growth. Melanoma cell lines were tested for expression of the IL-29 receptor (IL-29R) and their response to IL-29. Expression of IL-28R1 and IL-10R2, components of IL-29R, was evaluated using reverse transcription-PCR. A combination of immunoblot analysis and flow cytometry was used to evaluate IL-29–induced signal transduction. U133 Plus 2.0 Arrays and real-time PCR were used to evaluate gene expression. Apoptosis was measured using Annexin V/propridium iodide staining. In situ PCR for IL-29R was done on paraffin-embedded melanoma tumors. Both IL-28R1 and IL-10R2 were expressed on the A375, 1106 MEL, Hs294T, 18105 MEL, MEL 39, SK MEL 5, and F01 cell lines. Incubation of melanoma cell lines with IL-29 (10–1,000 ng/mL) led to phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT2. Microarray analysis and quantitative reverse transcription-PCR showed a marked increase in transcripts of IFN-regulated genes after treatment with IL-29. In the F01 cell line, bortezomib-induced and temozolomide-induced apoptosis was synergistically enhanced following the addition of IL-29. In situ PCR revealed that IL-10R2 and IL-28R1 were present in six of eight primary human melanoma tumors but not in benign nevi specimens. In conclusion, IL-29 receptors are expressed on the surface of human melanoma cell lines and patient samples, and treatment of these cell lines with IL-29 leads to signaling via the Jak-STAT pathway, the transcription of a unique set of genes, and apoptosis. Mol Cancer Ther; 9(2); 510–20
Ligand-Specific Antibodies to Insulin-Like Growth Factors Suppress Intestinal Polyp Formation in Apc+/− Mice
Authors: Matsunaka Toshihiro , Miyamoto Shin'ichi , Shitara Kenya , Ochiai Atsushi , Chiba Tsutomu
Published: January 2010

Insulin-like growth factors (IGF-I and IGF-II) play important roles in intestinal tumorigenesis. To investigate the effectiveness of IGF-targeting strategies, we conducted an in vivo study using anti-mouse neutralizing antibodies IGF-I (KM3168) and IGF-II (KM1468). Six- and 10-week-old Apc+/− mice were given KM3168 and/or KM1468 i.p. at two doses (0.01 or 0.1 μg/g weight) once or twice weekly for 4 weeks. To clarify the source of IGFs in vivo, we evaluated the expression levels of IGFs in the liver, normal small intestine, and polyps of the small intestine of Apc+/− mice. The phosphorylation status of IGF signal–related molecules was examined using immunostaining to understand the mechanism underlying the effects of IGF-neutralizing antibody. The plasma half-life was 168 for KM3168 and 85 hours for KM1468. In two lineages of Apc+/− mice (Apc1309 and ApcMin/+), a low dose (0.01 μg/g weight) of KM3168 and KM1468 significantly reduced the number of polyps when given once and twice weekly, respectively. Combined administration of the effective dose of each antibody had an additive effect. The liver was the main source of IGF-I, whereas the polyps of the small intestine and normal small intestine were the main source of IGF-II. IGF-neutralizing antibodies decreased the phosphorylation of IGF type 1 receptor and inhibited the signal transduction of the Akt pathway. These results suggest that IGF-I and IGF-II play important roles in polyp formation in Apc+/− mice and that specific antibodies to IGF-I and IGF-II may be promising antitumor agents. Mol Cancer Ther; 9(2); 419–28