bluuebunny/crossref_metadata_2025 huggingface dataset:
Progesterone inhibits glucose uptake by affecting diverse steps of insulin signaling in 3T3-L1 adipocytes
Authors: Wada Tsutomu , Hori Satoko , Sugiyama Maine , Fujisawa Eriko , Nakano Tetsuro , Tsuneki Hiroshi , Nagira Kiyofumi , Saito Shigeru , Sasaoka Toshiyasu
Published: January 2010

Maternal insulin resistance is essential for efficient provision of glucose to the fetus. Although elevation of placental hormones is known to relate to the development of insulin resistance, the precise underlying mechanism of maternal insulin resistance is unknown. Therefore, we examined the molecular mechanisms of progesterone causing insulin resistance in 3T3-L1 adipocytes. Progesterone at 10−4 M, but not 10−5 M, reduced the amount of IRS-1. As a result, insulin-induced phosphorylation of IRS-1, the association of IRS-1 with p85α, and subsequent phosphorylation of Akt1 and -2 was decreased moderately by 10−4 M progesterone. Subsequently, insulin-induced translocation of GLUT4 to the plasma membrane evaluated by immunostaining on the plasma membrane sheet by confocal laser microscope was also decreased by 10−4 M progesterone. In contrast, 2-[3H]deoxyglucose (2DG) uptake was markedly inhibited by both 10−5 and 10−4 M progesterone in a dose-dependent manner. Surprisingly, 2DG uptake elicited by adenovirus-mediated expression of constitutive-active mutant of PI 3-kinase (myr-p110) and Akt (myr-Akt) was suppressed by progesterone. Interestingly, insulin-induced tyrosine phosphorylation of Cbl and activation of TC10 were inhibited by progesterone at 10−5 M. These results indicate that progesterone is implicated in insulin resistance during pregnancy by inhibiting the PI 3-kinase pathway at the step of 1) IRS-1 expression and 2) distal to Akt and 3) by suppressing the PI 3-kinase-independent pathway of TC10 activation by affecting Cbl phosphorylation.
Effects of Unilateral Motor Cortex Lesion on Ipsilesional Hand's Reach and Grasp Performance in Monkeys: Relationship With Recovery in the Contralesional Hand
Authors: Kaeser Mélanie , Wyss Alexander F. , Bashir Shahid , Hamadjida Adjia , Liu Yu , Bloch Jocelyne , Brunet Jean-François , Belhaj-Saif Abderaouf , Rouiller Eric M.
Published: January 2010

Manual dexterity, a prerogative of primates, is under the control of the corticospinal (CS) tract. Because 90–95% of CS axons decussate, it is assumed that this control is exerted essentially on the contralateral hand. Consistently, unilateral lesion of the hand representation in the motor cortex is followed by a complete loss of dexterity of the contralesional hand. During the months following lesion, spontaneous recovery of manual dexterity takes place to a highly variable extent across subjects, although largely incomplete. In the present study, we tested the hypothesis that after a significant postlesion period, manual performance in the ipsilesional hand is correlated with the extent of functional recovery in the contralesional hand. To this aim, ten adult macaque monkeys were subjected to permanent unilateral motor cortex lesion. Monkeys' manual performance was assessed for each hand during several months postlesion, using our standard behavioral test (modified Brinkman board task) that provides a quantitative measure of reach and grasp ability. The ipsilesional hand's performance was found to be significantly enhanced over the long term (100–300 days postlesion) in six of ten monkeys, with the six exhibiting the best, though incomplete, recovery of the contralesional hand. There was a statistically significant correlation ( r = 0.932; P < 0.001) between performance in the ipsilesional hand after significant postlesion period and the extent of recovery of the contralesional hand. This observation is interpreted in terms of different possible mechanisms of recovery, dependent on the recruitment of motor areas in the lesioned and/or intact hemispheres.
Fine-mapping a locus for glucose tolerance using heterogeneous stock rats
Authors: Woods Leah C. Solberg , Holl Katie , Tschannen Michael , Valdar William
Published: January 2010

Heterogeneous stock (HS) animals provide the ability to map quantitative trait loci at high resolution [<5 Megabase (Mb)] in a relatively short time period. In the current study, we hypothesized that the HS rat colony would be useful for fine-mapping a region on rat chromosome 1 that has previously been implicated in glucose regulation. We administered a glucose tolerance test to 515 HS rats and genotyped these animals with 69 microsatellite markers, spaced an average distance of <1 Mb apart, on a 67 Mb region of rat chromosome 1. Using regression modeling of inferred haplotypes based on a hidden Markov model reconstruction and mixed model analysis in which we accounted for the complex family structure of the HS, we identified one sharp peak within this region. Using positional bootstrapping, we determined the most likely location of this locus is from 205.04 to 207.48 Mb. This work demonstrates the utility of HS rats for fine-mapping complex traits and emphasizes the importance of taking into account family structure when using highly recombinant populations.
On a Class of Ky Fan‐Type Inequalities
Authors: Gao Peng
Published: January 2010

We study one class of Ky Fan‐type inequalities, which has ties with the
original Ky Fan inequality. Our result extends the known ones.
Existence of Solutions to Boundary Value Problems for the Discrete Generalized Emden‐Fowler Equation
Authors: He Tieshan , Yang Fengjian
Published: January 2010

We consider the existence of solutions to boundary value problems for the discrete generalized Emden‐Fowler equation. By means of the minimax methods in the critical point theory, some new results are obtained. Two examples are also given to illustrate the main results.
Lattice Operators and Topologies
Authors: Cogan Eva
Published: January 2010

Working within a complete (not necessarily atomic) Boolean algebra, we use a sublattice to define a topology on that algebra. Our operators generalize complement on a lattice which in turn abstracts the set theoretic operator. Less restricted than those of Banaschewski and Samuel, the operators exhibit some surprising behaviors. We consider properties of such lattices and their interrelations. Many of these properties are abstractions and generalizations of topological spaces. The approach is similar to that of Bachman and Cohen. It is in the spirit of Alexandroff, Frolík, and Nöbeling, although the setting is more general. Proceeding in this manner, we can handle diverse topological theorems systematically before specializing to get as corollaries as the
topological results of Alexandroff, Alo and Shapiro, Dykes, Frolík, and Ramsay.
The Inflammatory Response to Miniaturised Extracorporeal Circulation: A Review of the Literature
Authors: Vohra Hunaid A. , Whistance Robert , Modi Amit , Ohri Sunil K.
Published: January 2010

Conventional cardiopulmonary bypass can trigger a systemic inflammatory response syndrome similar to sepsis. Aetiological factors include surgical trauma, reperfusion injury, and, most importantly, contact of the blood with the synthetic surfaces of the heart-lung machine. Recently, a new cardiopulmonary bypass system, mini-extracorporeal circulation (MECC), has been developed and has shown promising early results in terms of reducing this inflammatory response. It has no venous reservoir, a reduced priming volume, and less blood-synthetic interface. This review focuses on the inflammatory and clinical outcomes of using MECC and compares these to conventional cardio-pulmonary bypass (CCPB). MECC has been shown to reduce postoperative cytokines levels and other markers of inflammation. In addition, MECC reduces organ damage, postoperative complications and the need for blood transfusion. MECC is a safe and viable perfusion option and in certain circumstances it is superior to CCPB.
Targeted Therapies in Epithelial Ovarian Cancer
Authors: Barrena Medel Nicanor I. , Wright Jason D. , Herzog Thomas J.
Published: January 2010

Epithelial ovarian cancer remains a major women's health problem due to its high lethality. Despite great efforts to develop effective prevention and early detection strategies, most patients are still diagnosed at advanced stages of disease. This pattern of late presentation has resulted in significant challenges in terms of designing effective therapies to achieve long-term cure. One potential promising strategy is the application of targeted therapeutics that exploit a myriad of critical pathways involved in tumorigenesis and metastasis. This review examines three of the most provocative targeted therapies with current or future applicability in epithelial ovarian cancer.
Effect of Butachlor Herbicide on EarthwormEisenia fetida—Its Histological Perspicuity
Authors: Gobi Muthukaruppan , Gunasekaran Paramasamy
Published: January 2010

With the advent of the Green Revolution, there has been a quantum leap in the use of synthetic herbicides and pesticides throughout the world to sustain high yielding crop varieties. Continuous use of these synthetic chemicals leads to loss of soil fertility and soil organisms. To explore the effect of exposure to commercial herbicide (Butachlor) on the life history parameters (biomass, clitellum development, and cocoon production) and the histological changes in the earthwormEisenia fetidaover 60 days, the dried cow dung was contaminated with 0.2575 mgkg−1, 0.5150 mgkg−1, and 2.5750 mgkg−1of butachlor based on theLC50value, and a control was maintained. The mean earthworm biomass was found to be decreased with increasing herbicide concentration. Similarly, cocoon production was also reduced by the increasing herbicide concentration. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of herbicide. All earthworms in the exposed group were found to have glandular cell enlargement and to be vacuolated.
JNK1 Mediates Degradation HIF-1α by a VHL-Independent Mechanism that Involves the Chaperones Hsp90/Hsp70
Authors: Zhang Dongyun , Li Jingxia , Costa Max , Gao Jimin , Huang Chuanshu
Published: January 2010

Hypoxia-inducible factor-1α (HIF-1α) is a master transcription factor that is critical for the regulation of a variety of cellular functions. HIF-1α is rapidly degraded under normoxic conditions by ubiquitin-mediated proteasome pathway controlled by the tumor suppressor von Hippel Lindau (VHL). Several recent studies reveal that heat-shock proteins (Hsp) can regulate HIF-1α protein degradation by a VHL-independent pathway. Here, we demonstrate that the stress kinase c-Jun NH2-terminal kinase 1 (JNK1) is required for Hsp-dependent regulation of HIF-1α. Stabilization of HIF-1α was impaired in JNK1−/− cells but could be rescued by JNK1 reconstitution under hypoxic conditions. These effects could be phenocopied in other cell settings by JNK1 silencing. Accordingly, HIF-1 transcriptional activity and target gene expression were dramatically reduced in JNK1−/− cells. Further, decreased levels of endogenous Hsp90/Hsp70 proteins in JNK1−/− cells affected the protective roles of these chaperones in stabilizing newly synthesized HIF-1α, whereas enforced expression of Hsp90/Hsp70 in JNK1−/− cells increased HIF-1α stability relative to parental control cells. Furthering this connection, we also found that defective expression of the Hsp90 acetyltransferase HDAC6 in JNK1−/− cells was associated with reduced Hsp90 chaperone activity. Taken together, our studies define a novel function for JNK1 in regulating HIF-1α turnover by a VHL-independent mechanism. Cancer Res; 70(2); 813–23
Prognosis of Hormone-Dependent Breast Cancers: Implications of the Presence of Dysfunctional Transcriptional Networks Activated by Insulin via the Immune Transcription Factor T-bet
Authors: McCune Kasi , Bhat-Nakshatri Poornima , Thorat Mangesh A. , Nephew Kenneth P. , Badve Sunil , Nakshatri Harikrishna
Published: January 2010

Estrogen receptor α (ERα)–positive breast cancers that co-express transcription factors GATA-3 and FOXA1 have a favorable prognosis. These transcription factors form an autoregulatory hormonal network that influences estrogen responsiveness and sensitivity to hormonal therapy. Disruption of this network may be a mechanism whereby ERα-positive breast cancers become resistant to therapy. The transcription factor T-bet is a negative regulator of GATA-3 in the immune system. In this study, we report that insulin increases the expression of T-bet in breast cancer cells, which correlates with reduced expression of GATA-3, FOXA1, and the ERα:FOXA1:GATA-3 target gene GREB-1. The effects of insulin on GATA-3 and FOXA1 could be recapitulated through overexpression of T-bet in MCF-7 cells (MCF-7-T-bet). Chromatin immunoprecipitation assays revealed reduced ERα binding to GREB-1 enhancer regions in MCF-7-T-bet cells and in insulin-treated MCF-7 cells. MCF-7-T-bet cells were resistant to tamoxifen in the presence of insulin and displayed prolonged extracellular signal–regulated kinase and AKT activation in response to epidermal growth factor treatment. ERα-positive cells with intrinsic tamoxifen resistance as well as MCF-7 cells with acquired tamoxifen and fulvestrant resistance expressed elevated levels of T-bet and/or reduced levels of FOXA1 and GATA-3. Analysis of publicly available databases revealed ERα-positive/T-bet–positive breast cancers expressing lower levels of FOXA1 (P = 0.0137) and GATA-3 (P = 0.0063) compared with ERα-positive/T-bet–negative breast cancers. Thus, T-bet expression in primary tumors and circulating insulin levels may serve as surrogate biomarkers to identify ERα-positive breast cancers with a dysfunctional hormonal network, enhanced growth factor signaling, and resistance to hormonal therapy. Cancer Res; 70(2); 685–96
The AC133 Epitope, but not the CD133 Protein, Is Lost upon Cancer Stem Cell Differentiation
Authors: Kemper Kristel , Sprick Martin R. , de Bree Martijn , Scopelliti Alessandro , Vermeulen Louis , Hoek Maarten , Zeilstra Jurrit , Pals Steven T. , Mehmet Huseyin , Stassi Giorgio , Medema Jan Paul
Published: January 2010

Colon cancer stem cells (CSC) can be identified with AC133, an antibody that detects an epitope on CD133. However, recent evidence suggests that expression of CD133 is not restricted to CSCs, but is also expressed on differentiated tumor cells. Intriguingly, we observed that detection of the AC133 epitope on the cell surface decreased upon differentiation of CSC in a manner that correlated with loss of clonogenicity. However, this event did not coincide with a change in CD133 promoter activity, mRNA, splice variant, protein expression, or even cell surface expression of CD133. In contrast, we noted that with CSC differentiation, a change occured in CD133 glycosylation. Thus, AC133 may detect a glycosylated epitope, or differential glycosylation may cause CD133 to be retained inside the cell. We found that AC133 could effectively detect CD133 glycosylation mutants or bacterially expressed unglycosylated CD133. Moreover, cell surface biotinylation experiments revealed that differentially glycosylated CD133 could be detected on the membrane of differentiated tumor cells. Taken together, our results argue that CD133 is a cell surface molecule that is expressed on both CSC and differentiated tumor cells, but is probably differentially folded as a result of differential glycosylation to mask specific epitopes. In summary, we conclude that AC133 can be used to detect cancer stem cells, but that results from the use of this antibody should be interpreted with caution. Cancer Res; 70(2); 719–29
ETS-1 Oncogenic Activity Mediated by Transforming Growth Factor α
Authors: Holterman Chet E. , Franovic Aleksandra , Payette Josianne , Lee Stephen
Published: January 2010

Inappropriate expression of Ets-1 is observed in a variety of human cancers, and its forced expression in cultured cells results in transformation, autonomous proliferation, and tumor formation. The basis by which Ets-1 confers autonomous growth, one of the primary hallmarks of cancer cells and a critical component of persistent proliferation, has yet to be fully explained. Using a variety of cancer cell lines, we show that inhibition of Ets-1 blocks tumor formation and cell proliferation in vivo and autonomous growth in culture. A screen of multiple diffusible growth factors revealed that inhibition of Ets-1 results in the specific downregulation of transforming growth factor α (TGFα), the proximal promoter region of which contains multiple ETS family DNA binding sites that can be directly bound and regulated by Ets-1. Notably, rescuing TGFα expression in Ets-1–silenced cells was sufficient to restore tumor cell proliferation in vivo and autonomous growth in culture. These results reveal a previously unrecognized mechanism by which Ets-1 oncogenic activity can be explained in human cancer through its ability to regulate the important cellular mitogen TGFα. Cancer Res; 70(2); 730–40
HEF1 Is a Crucial Mediator of the Proliferative Effects of Prostaglandin E2 on Colon Cancer Cells
Authors: Xia Dianren , Holla Vijaykumar R. , Wang Dingzhi , Menter David G. , DuBois Raymond N.
Published: January 2010

Prostaglandin E2 (PGE2), one of the downstream products of cyclooxygenase-2 enzymatic activity, promotes colorectal carcinogenesis in part by stimulating cell division. In this study, we define a critical mechanism in this process by showing that the prometastatic adapter protein human enhancer of filamentation 1 (HEF1; NEDD9) links PGE2 to the cell cycle machinery in colorectal cancer cells. PGE2 rapidly induced expression of HEF1 mRNA and protein in colorectal cancer cells. HEF1 overexpression elicited the same effects as PGE2 treatment on cell proliferation, cell cycle progression, and tumor growth. Conversely, HEF1 knockdown suppressed PGE2-driven cell proliferation and cell cycle progression. Cell cycle alterations involved HEF1 fragmentation as well as co-distribution of HEF1 and cell cycle kinase Aurora A along spindle asters during cell division. Moreover, Aurora A co-immunoprecipitated with HEF1 and was activated by HEF1. Consistent with a role for HEF1 in colorectal carcinogenesis, we found elevated expression of HEF1 expression in 50% of human colorectal cancers examined, relative to paired normal tissues. These findings establish that PGE2 induces HEF1 expression, which in turn promotes cell cycle progression through its interaction with and activation of Aurora A. Further, they establish that HEF1 is a crucial downstream mediator of PGE2 action during colorectal carcinogenesis. Cancer Res; 70(2); 824–31
Insulin-Mediated Acceleration of Breast Cancer Development and Progression in a Nonobese Model of Type 2 Diabetes
Authors: Novosyadlyy Ruslan , Lann Danielle E. , Vijayakumar Archana , Rowzee Anne , Lazzarino Deborah A. , Fierz Yvonne , Carboni Joan M. , Gottardis Marco M. , Pennisi Patricia A. , Molinolo Alfredo A. , Kurshan Naamit , Mejia Wilson , Santopietro Stefania , Yakar Shoshana , Wood Teresa L. , LeRoith Derek
Published: January 2010

Epidemiologic studies suggest that type 2 diabetes (T2D) increases breast cancer risk and mortality, but there is limited experimental evidence supporting this association. Moreover, there has not been any definition of a pathophysiological pathway that diabetes may use to promote tumorigenesis. In the present study, we used the MKR mouse model of T2D to investigate molecular mechanisms that link T2D to breast cancer development and progression. MKR mice harbor a transgene encoding a dominant-negative, kinase-dead human insulin-like growth factor-I receptor (IGF-IR) that is expressed exclusively in skeletal muscle, where it acts to inactivate endogenous insulin receptor (IR) and IGF-IR. Although lean female MKR mice are insulin resistant and glucose intolerant, displaying accelerated mammary gland development and enhanced phosphorylation of IR/IGF-IR and Akt in mammary tissue, in the context of three different mouse models of breast cancer, these metabolic abnormalities were found to accelerate the development of hyperplastic precancerous lesions. Normal or malignant mammary tissue isolated from these mice exhibited increased phosphorylation of IR/IGF-IR and Akt, whereas extracellular signal-regulated kinase 1/2 phosphorylation was largely unaffected. Tumor-promoting effects of T2D in the models were reversed by pharmacological blockade of IR/IGF-IR signaling by the small-molecule tyrosine kinase inhibitor BMS-536924. Our findings offer compelling experimental evidence that T2D accelerates mammary gland development and carcinogenesis,and that the IR and/or the IGF-IR are major mediators of these effects. Cancer Res; 70(2); 741–51
Reversing HOXA9 Oncogene Activation by PI3K Inhibition: Epigenetic Mechanism and Prognostic Significance in Human Glioblastoma
Authors: Costa Bruno M. , Smith Justin S. , Chen Ying , Chen Justin , Phillips Heidi S. , Aldape Kenneth D. , Zardo Giuseppe , Nigro Janice , James C. David , Fridlyand Jane , Reis Rui M. , Costello Joseph F.
Published: January 2010

HOXA genes encode critical transcriptional regulators of embryonic development that have been implicated in cancer. In this study, we documented functional relevance and mechanism of activation of HOXA9 in glioblastoma (GBM), the most common malignant brain tumor. Expression of HOXA genes was investigated using reverse transcription–PCR in primary gliomas and glioblastoma cell lines and was validated in two sets of expression array data. In a subset of GBM, HOXA genes are aberrently activated within confined chromosomal domains. Transcriptional activation of the HOXA cluster was reversible by a phosphoinostide 3-kinase (PI3K) inhibitor through an epigenetic mechanism involving histone H3K27 trimethylation. Functional studies of HOXA9 showed its capacity to decrease apoptosis and increase cellular proliferation along with tumor necrosis factor–related apoptosis-including ligand resistance. Notably, aberrant expression of HOXA9 was independently predictive of shorter overall and progression-free survival in two GBM patient sets and improved survival prediction by MGMT promoter methylation. Thus, HOXA9 activation is a novel, independent, and negative prognostic marker in GBM that is reversible through a PI3K-associated epigenetic mechanism. Our findings suggest a transcriptional pathway through which PI3K activates oncogenic HOXA expression with implications for mTOR or PI3K targeted therapies. Cancer Res; 70(2); 453–62
NF-κB–Dependent Plasticity of the Epithelial to Mesenchymal Transition Induced by Von Hippel-Lindau Inactivation in Renal Cell Carcinomas
Authors: Pantuck Allan J. , An Jiabin , Liu Huiren , Rettig Matthew B.
Published: January 2010

The critical downstream signaling consequences contributing to renal cancer as a result of loss of the tumor suppressor gene von Hippel-Lindau (VHL) have yet to be fully elucidated. Here, we report that VHL loss results in an epithelial to mesenchymal transition (EMT). In studies of paired isogenic cell lines, VHL silencing increased the levels of N-cadherin and vimentin and reduced the levels of E-cadherin relative to the parental VHL+ cell line, which displayed the opposite profile. VHL+ cells grew as clusters of cuboidal and rhomboid cells, whereas VHL-silenced cells took on an elongated, fibroblastoid morphology associated with a more highly invasive character in Matrigel chamber assays. Based on earlier evidence that VHL loss can activate NF-κB, a known mediator of EMT, we tested whether NF-κB contributed to VHL-mediated effects on EMT. On pharmacologic or molecular inhibition of NF-κB, VHL-silenced cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive phenotype. Introducing a pVHL-resistant hypoxia-inducible factor 1α (HIF1α) mutant (HIFαM) into VHL+ cells heightened NF-κB activity, phenocopying EMT effects produced by VHL silencing. Conversely, inhibiting the heightened NF-κB activity in this setting reversed the EMT phenotype. Taken together, these results suggest that VHL loss induces an EMT that is largely dependent on HIFα-induced NF-κB. Our findings rationalize targeting the NF-κB pathway as a therapeutic strategy to treat renal tumors characterized by biallelic VHL inactivation. Cancer Res; 70(2); 752–61
Apoptotic Sensitivity of Colon Cancer Cells to Histone Deacetylase Inhibitors Is Mediated by an Sp1/Sp3-Activated Transcriptional Program Involving Immediate-Early Gene Induction
Authors: Wilson Andrew J. , Chueh Anderly C. , Tögel Lars , Corner Georgia A. , Ahmed Naseem , Goel Sanjay , Byun Do-Sun , Nasser Shannon , Houston Michele A. , Jhawer Minaxi , Smartt Helena J.M. , Murray Lucas B. , Nicholas Courtney , Heerdt Barbara G. , Arango Diego , Augenlicht Leonard H. , Mariadason John M.
Published: January 2010

Histone deacetylase inhibitors (HDACi) induce growth arrest and apoptosis in colon cancer cells and are being considered for colon cancer therapy. The underlying mechanism of action of these effects is poorly defined with both transcription-dependent and -independent mechanisms implicated. We screened a panel of 30 colon cancer cell lines for sensitivity to HDACi-induced apoptosis and correlated the differences with gene expression patterns induced by HDACi in the five most sensitive and resistant lines. A robust and reproducible transcriptional response involving coordinate induction of multiple immediate-early (fos, jun, egr1, egr3, atf3, arc, nr4a1) and stress response genes (Ndrg4, Mt1B, Mt1E, Mt1F, Mt1H) was selectively induced in HDACi sensitive cells. Notably, a significant percentage of these genes were basally repressed in colon tumors. Bioinformatics analysis revealed that the promoter regions of the HDACi-induced genes were enriched for KLF4/Sp1/Sp3 transcription factor binding sites. Altering KLF4 levels failed to modulate apoptosis or transcriptional responses to HDACi treatment. In contrast, HDACi preferentially stimulated the activity of Spl/Sp3 and blocking their action attenuated both the transcriptional and apoptotic responses to HDACi treatment. Our findings link HDACi-induced apoptosis to activation of a Spl/Sp3-mediated response that involves derepression of a transcriptional network basally repressed in colon cancer. Cancer Res; 70(2); 609–20
Characterization of Phosphoglycerate Kinase-1 Expression of Stromal Cells Derived from Tumor Microenvironment in Prostate Cancer Progression
Authors: Wang Jianhua , Ying Gigi , Wang Jingchen , Jung Younghun , Lu Jian , Zhu Jiang , Pienta Kenneth J. , Taichman Russell S.
Published: January 2010

Tumor and stromal interactions in the tumor microenvironment are critical for oncogenesis and cancer progression. Our understanding of the molecular events by which reactive stromal fibroblasts—myofibroblast or cancer-associated fibroblasts (CAF)—affect the growth and invasion of prostate cancer remains unclear. Laser capture microdissection and cDNA microarray analysis of CAFs in prostate tumors revealed strong upregulation of phosphoglycerate kinase-1 (PGK1), an ATP-generating glycolytic enzyme that forms part of the glycolytic pathway and is directly involved in CXCL12-CXCR4 signaling. Normal fibroblasts overexpressing PGK1 resembled myofibroblasts in their expression of smooth muscle α-actin, vimentin, and high levels of CXCL12. These cells also displayed a higher proliferative index and the capability to contribute to prostate tumor cell invasion in vitro, possibly through expression of MMP-2 and MMP-3 and activation of the AKT and ERK pathways. Coimplantation of PGK1-overexpressing fibroblasts with prostate tumor cells promoted tumor cell growth in vivo. Collectively, these observations suggest that PGK1 helps support the interactions between cancer and its microenvironment. Cancer Res; 70(2); 471–80
The Somatostatin Analogue Octreotide Confers Sensitivity to Rapamycin Treatment on Pituitary Tumor Cells
Authors: Cerovac Vesna , Monteserin-Garcia Jose , Rubinfeld Hadara , Buchfelder Michael , Losa Marco , Florio Tullio , Paez-Pereda Marcelo , Stalla Günter K. , Theodoropoulou Marily
Published: January 2010

Rapamycin and its analogues have significant antiproliferative action against a variety of tumors. However, sensitivity to rapamycin is reduced by Akt activation that results from the ablative effects of rapamycin on a p70 S6K–induced negative feedback loop that blunts phosphoinositide 3-kinase (PI3K)–mediated support for Akt activity. Thus, sensitivity to rapamycin might be increased by imposing an upstream blockade to the PI3K/Akt pathway. Here, we investigated this model using the somatostatin analogue octreotide as a tool to decrease levels of activated Ser473-phosphorylated Akt (pAkt-Ser473) in pituitary tumor cells that express somatostatin receptors. Octreotide increased levels of phosphorylated insulin receptor substrate-1 that were suppressed by rapamycin, subsequently decreasing levels of pAkt-Ser473 through effects on phosphotyrosine phosphatase SHP-1. Octreotide potentiated the antiproliferative effects of rapamycin in immortalized pituitary tumor cells or human nonfunctioning pituitary adenoma cells in primary cell culture, sensitizing tumor cells even to low rapamycin concentrations. Combined treatment of octreotide and rapamycin triggered G1 cell cycle arrest, decreasing E2F transcriptional activity and cyclin E levels by increasing levels of p27/Kip1. These findings show that adjuvant treatment with a somatostatin analogue can sensitize pituitary tumor cells to the antiproliferative effects of rapamycin. Cancer Res; 70(2); 666–74
Matrix Metalloproteinase-9 Functions as a Tumor Suppressor in Colitis-Associated Cancer
Authors: Garg Pallavi , Sarma Dittakavi , Jeppsson Sabrina , Patel Neal R. , Gewirtz Andrew T. , Merlin Didier , Sitaraman Shanthi V.
Published: January 2010

There is a well-documented association of matrix metalloproteinase-9 (MMP-9) and receptor Notch-1 overexpression in colon cancer. We recently showed that MMP-9 is also upregulated in colitis, where it modulates tissue damage and goblet cell differentiation via proteolytic cleavage of Notch-1. In this study, we investigated whether MMP-9 is critical for colitis-associated colon cancer (CAC). Mice that are wild type (WT) or MMP-9 nullizygous (MMP-9−/−) were used for in vivo studies and the human enterocyte cell line Caco2-BBE was used for in vitro studies. CAC was induced in mice using an established carcinogenesis protocol that involves exposure to azoxymethane followed by treatment with dextran sodium sulfate. MMP-9−/− mice exhibited increased susceptibility to CAC relative to WT mice. Elevations in tumor multiplicity, size, and mortality were associated with increased proliferation and decreased apoptosis. Tumors formed in MMP-9−/− mice exhibited expression of p21WAF1/Cip1 and increased expression of β-catenin relative to WT mice. In vitro studies of MMP-9 overexpression showed increased Notch-1 activation with a reciprocal decrease in β-catenin. Notch and β-catenin/Wnt signaling have crucial roles in determining differentiation and carcinogenesis in gut epithelia. Despite being a mediator of proinflammatory responses in colitis, MMP-9 plays a protective role and acts as a tumor suppressor in CAC by modulating Notch-1 activation, thereby resulting in activation of p21WAF1/Cip1 and suppression of β-catenin. Cancer Res; 70(2); 792–801
A Single Nucleotide Change in the Mouse Genome Accelerates Breast Cancer Progression
Authors: Seitzer Nina , Mayr Thomas , Streit Sylvia , Ullrich Axel
Published: January 2010

In the growth factor receptor gene FGFR4 the presence of the common single nucleotide polymorphism Arg388 has been associated with progression of various types of cancer including breast cancer. However, a causative relationship is not readily assigned due to genetic heterogeneity in different patient cohorts. To address this issue, we compared the effects of this allele on malignant progression in the WAP-TGFα transgenic mouse model of breast cancer. A knock-in strain was generated to introduce an analogous Arg385 allele into the murine FGFR4 gene. Mouse embryonic fibroblasts derived from this strain displayed accelerated cell transformation, with transformed cells exhibiting greater motility and invasive behavior. In the in vivo context of TGFα-induced mammary carcinogenesis, tumor development and progression was significantly advanced in tumor mass, size, and onset of pulmonary metastases. Our findings definitively identify the FGFR4 Arg388 allele as a functional prognostic marker for breast cancer progression. Cancer Res; 70(2); 802–12
Targeting Specific Regions of the Notch3 Ligand-Binding Domain Induces Apoptosis and Inhibits Tumor Growth in Lung Cancer
Authors: Lin Luping , Mernaugh Ray , Yi Fuming , Blum David , Carbone David P. , Dang Thao P.
Published: January 2010

Like many signaling pathways in development, the Notch receptor pathway plays an important role in cancer pathobiology when it is dysregulated. Potential ligand-binding sites within the epidermal growth factor (EGF)–like repeats of Notch1 have been identified, but the ligand-binding domains in Notch3, which is implicated in lung cancer, are not known. In screening a library of 155 peptides representing all 34 EGF-like repeats in Notch3, we discovered two distinct ligand-binding regions involving the 7–10 and 21–22 repeats that are distinct from the putative ligand-binding domain of Notch1. In cell-based assays, peptides from these regions induced apoptosis and reduced expression of the Notch3-dependent gene Hey1. They also bound directly to the Notch ligand Jagged1, suggesting that their mechanism of action involves disrupting interactions between Notch3 and Jagged1. Recombinant Fc fusion peptides engineered for in vivo testing showed that the Notch3 peptides defined could trigger apoptosis and suppress tumor growth in tumor xenograft assays. These findings rationalize a mechanistic approach to lung cancer treatment based on Notch3 receptor–targeted therapeutic development. Cancer Res; 70(2); 632–8
Use of Four Biomarkers to Evaluate the Risk of Breast Cancer Subtypes in the Women's Contraceptive and Reproductive Experiences Study
Authors: Ma Huiyan , Wang Yaping , Sullivan-Halley Jane , Weiss Linda , Marchbanks Polly A. , Spirtas Robert , Ursin Giske , Burkman Ronald T. , Simon Michael S. , Malone Kathleen E. , Strom Brian L. , McDonald Jill A. , Press Michael F. , Bernstein Leslie
Published: January 2010

Epidemiologic studies suggest that some hormone-related risk factors in breast cancer differentially influence risk for disease subtypes classified by the status of the estrogen and progesterone receptors (ER/PR). However, it remains unclear whether human epidermal growth factor receptor 2 (HER2) or p53 expression status further differentiates these exposure-risk group associations. We evaluated the associations of oral contraceptive (OC) use and reproductive factors with incident invasive breast cancer subtypes among 1,197 population-based cases and 2,015 controls from the Los Angeles County or Detroit components of the Women's Contraceptive and Reproductive Experiences Study. Case-control comparisons by ER/PR/HER2/p53 status were conducted by multivariable polychotomous unconditional logistic regression methods. We found that OC use was not associated with any breast cancer subtype as defined by ER/PR/HER2/p53 status, except for a 2.9-fold increased risk of so-called triple-negative tumors (ER−/PR−/HER2−) among women of 45 to 64 years of age who started OC use before age 18. Parity was associated with a decreased risk of luminal A (ER+ or PR+, HER2−), luminal B (ER+ or PR+/HER2+), and ER−/PR−/HER2+ tumors. Age at first full-term pregnancy was positively associated with luminal A tumors among older women. Neither of these reproductive factors was associated with triple-negative tumors. Long duration of breast-feeding lowered the risk of triple-negative and luminal A tumors. p53 status did not define further differential risk patterns. Our findings offer evidence of differences in the hormone-related risk factors between triple-negative cancers and other ER/PR/HER2-defined subtypes of breast cancer. Cancer Res; 70(2); 575–87
Integration of DNA Copy Number Alterations and Prognostic Gene Expression Signatures in Breast Cancer Patients
Authors: Horlings Hugo M. , Lai Carmen , Nuyten Dimitry S.A. , Halfwerk Hans , Kristel Petra , van Beers Erik , Joosse Simon A. , Klijn Christiaan , Nederlof Petra M. , Reinders Marcel J.T. , Wessels Lodewyk F.A. , van de Vijver Marc J.
Published: January 2010

Purpose: Several prognostic gene expression profiles have been identified in breast cancer. In spite of this progress in prognostic classification, the underlying mechanisms that drive these gene expression patterns remain unknown. Specific genomic alterations, such as copy number alterations, are an important factor in tumor development and progression and are also associated with changes in gene expression.

Experimental Design: We carried out array comparative genomic hybridization in 68 human breast carcinomas for which gene expression and clinical data were available. We used a two-class supervised algorithm, Supervised Identification of Regions of Aberration in aCGH data sets, for the identification of regions of chromosomal alterations that are associated with specific sample labeling. Using gene expression data from the same tumors, we identified genes in the altered regions for which the expression level is significantly correlated with the copy number and validated our results in public available data sets.

Results: Specific chromosomal aberrations are related to clinicopathologic characteristics and prognostic gene expression signatures. The previously identified poor prognosis, 70-gene expression signature is associated with the gain of 3q26.33-27.1, 8q22.1-24.21, and 17q24.3-25.1; the 70-gene good prognosis profile is associated with the loss at 16q12.1-13 and 16q22.1-24.1; basal-like tumors are associated with the gain of 6p12.3-23, 8q24.21-22, and 10p12.33-14 and losses at 4p15.31, 5q12.3-13.1, 5q33.1, 10q23.33, 12q13.13-3, 15q15.1, and 15q21.1; HER2+ breast show amplification at 17q11.1-12 and 17q21.31-23.2 (including HER2 gene).

Conclusions: There is a strong correlation between the different gene expression signatures and underlying genomic changes. These findings help to establish a link between genomic changes and gene expression signatures, enabling a better understanding of the tumor biology that causes poor prognosis. Clin Cancer Res; 16(2); 651–63
NVP-BEZ235 as a New Therapeutic Option for Sarcomas
Authors: Manara Maria C. , Nicoletti Giordano , Zambelli Diana , Ventura Selena , Guerzoni Clara , Landuzzi Lorena , Lollini Pier-Luigi , Maira Saveur-Michel , García-Echeverría Carlos , Mercuri Mario , Picci Piero , Scotlandi Katia
Published: January 2010

Purpose: To evaluate the in vitro and in vivo effects of NVP-BEZ235, a dual pan-phosphoinositide 3-kinase–mammalian target of rapamycin inhibitor in the three most common musculoskeletal tumors (osteosarcoma, Ewing's sarcoma, and rhabdomyosarcoma).

Experimental Design: Antiproliferative activity as well as the effects on migration and metastasis were evaluated in a panel of osteosarcoma, Ewing's sarcoma, as well as rhabdomyosarcoma cell lines. Moreover, simultaneous and sequential treatments were done in association with two of the most important conventional drugs in the treatment of sarcoma, doxorubicin and vincristine.

Results: NVPBEZ235 effectively blocked the pathway in in vitro and in vivo settings. Under the experimental conditions tested, the compound induced disease stasis, by arresting cells in G1 phase of cell cycle, without remarkable effects on apoptosis. As a consequence, to obtain the maximum exploitation of its therapeutic potential, NVP-BEZ235 has been evaluated in combination with conventional cytotoxic agents, thus showing promising efficacy with either doxorubicin and vincristine. Inhibition of the phosphoinositide 3-kinase/mammalian target of rapamycin pathway increased activation of extracellular signal-regulated kinase 1/2, likely due to the presence of autocrine circuits shifting growth factor signaling toward the mitogen-activated protein kinase pathway. This supports the combined use of NVP-BEZ235 with other small signaling inhibitors. Here, we showed synergistic effects when the compound was associated with a anti–insulin-like growth factor-I receptor tyrosine kinase inhibitor. NVP-BEZ235 also inhibited cell migration and metastasis. Combination with vincristine further potentiated the antimetastatic effects.

Conclusions: NVP-BEZ235 displays the features to be considered for sarcoma therapy to potentiate the activity of other anticancer agents. The drug is currently undergoing phase I/II clinical trials in advanced cancer patients. Clin Cancer Res; 16(2); 530–40
Identification of Markers of Taxane Sensitivity Using Proteomic and Genomic Analyses of Breast Tumors from Patients Receiving Neoadjuvant Paclitaxel and Radiation
Authors: Bauer Joshua A. , Chakravarthy A. Bapsi , Rosenbluth Jennifer M. , Mi Deming , Seeley Erin H. , De Matos Granja-Ingram Nara , Olivares Maria G. , Kelley Mark C. , Mayer Ingrid A. , Meszoely Ingrid M. , Means-Powell Julie A. , Johnson Kimberly N. , Tsai Chiaojung Jillian , Ayers Gregory D. , Sanders Melinda E. , Schneider Robert J. , Formenti Silvia C. , Caprioli Richard M. , Pietenpol Jennifer A.
Published: January 2010

Purpose: To identify molecular markers of pathologic response to neoadjuvant paclitaxel/radiation treatment, protein and gene expression profiling were done on pretreatment biopsies.

Experimental Design: Patients with high-risk, operable breast cancer were treated with three cycles of paclitaxel followed by concurrent paclitaxel/radiation. Tumor tissue from pretreatment biopsies was obtained from 19 of the 38 patients enrolled in the study. Protein and gene expression profiling were done on serial sections of the biopsies from patients that achieved a pathologic complete response (pCR) and compared to those with residual disease, non-pCR (NR).

Results: Proteomic and validation immunohistochemical analyses revealed that α-defensins (DEFA) were overexpressed in tumors from patients with a pCR. Gene expression analysis revealed that MAP2, a microtubule-associated protein, had significantly higher levels of expression in patients achieving a pCR. Elevation of MAP2 in breast cancer cell lines led to increased paclitaxel sensitivity. Furthermore, expression of genes that are associated with the basal-like, triple-negative phenotype were enriched in tumors from patients with a pCR. Analysis of a larger panel of tumors from patients receiving presurgical taxane-based treatment showed that DEFA and MAP2 expression as well as histologic features of inflammation were all statistically associated with response to therapy at the time of surgery.

Conclusion: We show the utility of molecular profiling of pretreatment biopsies to discover markers of response. Our results suggest the potential use of immune signaling molecules such as DEFA as well as MAP2, a microtubule-associated protein, as tumor markers that associate with response to neoadjuvant taxane–based therapy. Clin Cancer Res; 16(2); 681–90
Targeting Polo-like Kinase in Cancer Therapy
Authors: Degenhardt Yan , Lampkin Thomas
Published: January 2010

Polo-like kinases (Plk) function in mitosis and maintaining DNA integrity. There are four family members, of which Plk1 represents a target for anticancer therapy. Plk1 is only expressed in dividing cells with peak expression during G2/M. Plk1 functions in multiple steps of mitosis, and is overexpressed in many tumor types. Mitotic arrest and inhibition of proliferation, apoptosis, and tumor growth inhibition have been observed in preclinical studies using small interfering RNAs (siRNA) or small molecules that inhibit Plk1. Preclinical studies also show that Plk1 inhibitors may be active against tumors with RAS mutations and that tumor cells with mutations in TP53 are more sensitive to inhibition of Plk1. Several Plk inhibitors are in phase I or II clinical studies. As expected, hematologic toxicity is the primary dose-limiting toxicity. Some patients have achieved clinical response, although in some studies only at doses above the maximum tolerated dose defined in the study. Further evaluation is necessary to discern the clinical utility of Plk1 inhibitors. Clin Cancer Res; 16(2); 384–9
Tumor O6-methylguanine-DNA Methyltransferase Inactivation by Oral Lomeguatrib
Authors: Watson Amanda J. , Sabharwal Ami , Thorncroft Mary , McGown Gail , Kerr Richard , Bojanic Stana , Soonawalla Zahir , King Alexandra , Miller Andrea , Waller Sue , Leung Hing , Margison Geoffrey P. , Middleton Mark R.
Published: January 2010

Purpose: A major mechanism of resistance to chlorethylnitrosureas and methylating agents involves the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). We sought to determine the dose of oral 6-(4-bromo-2-thienyl) methoxy purin-2-amine (lomeguatrib), a pseudosubstrate inactivator of MGMT, required to render active protein undetectable 12 hours after dosing in prostate, primary central nervous system (CNS), and colorectal cancer patients.

Experimental Design: Lomeguatrib was administered orally as a single dose (20-160 mg) ∼12 hours before tumor resection. Dose escalation was projected to continue until grade 2 toxicity or until complete inactivation of tumor MGMT was encountered. Total MGMT protein levels were quantified by ELISA, and active protein levels were quantified by biochemical assay. MGMT promoter methylation was determined in glioblastoma DNA by methylation-specific PCR.

Results: Thirty-seven patients were dosed with lomeguatrib, and 32 informative tumor samples were obtained. Mean total MGMT level varied between tumor types: 554 ± 404 fmol/mg protein (±SD) for prostate cancer, 87.4 ± 40.3 fmol/mg protein for CNS tumors, and 244 ± 181 fmol/mg protein for colorectal cancer. MGMT promoter hypermethylation did not correlate with total protein expression. Consistent total MGMT inactivation required 120 mg of lomeguatrib in prostate and colorectal cancers. Complete consistent inactivation in CNS tumors was observed only at the highest dose of lomeguatrib (160 mg).

Conclusions: Total MGMT inactivation can be achieved in prostate, primary CNS, and colorectal cancers with a single administration of 120 or 160 mg lomeguatrib. The dose needed did not correlate with mean total MGMT protein concentrations. One hundred twenty to 160 mg/d of lomeguatrib should be administered to achieve total MGMT inactivation in future studies. Clin Cancer Res; 16(2); 743–9