bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Multiple Myeloma Cell Killing by Depletion of the MET Receptor Tyrosine Kinase
Authors: Stellrecht Christine M. , Phillip Cornel J. , Cervantes-Gomez Fabiola , Gandhi Varsha
Published: March 2024

Abstract
Multiple myeloma (MM) is an invariably fatal plasma cell malignancy, primarily due to the therapeutic resistance which ultimately arises. Much of the resistance results from the expression of various survival factors. Despite this, the ribonucleoside analogue, 8-chloro-adenosine (8-Cl-Ado), is cytotoxic to a number of MM cell lines. Previously, we established that the analogue incorporates into the RNA and inhibits mRNA synthesis. Because 8-Cl-Ado is able to overcome survival signals present in MM cells and inhibits mRNA synthesis, it is likely that the drug induces cytotoxicity by depleting the expression of critical MM survival genes. We investigated this question using gene array analysis, real-time reverse transcription-PCR, and immunoblot analysis on 8-Cl-Ado–treated MM.1S cells and found that the mRNA and protein levels of the receptor tyrosine kinase MET decrease prior to apoptosis. To determine MET's role in 8-Cl-Ado cytotoxicity, we generated MM.1S clones stably expressing a MET ribozyme. None of the clones expressed <25% of the basal levels of MET mRNA, suggesting that a threshold level of MET is necessary for their survival. Additionally, the ribozyme knockdown lines were more sensitive to the cytotoxic actions of 8-Cl-Ado as caspase-3 activation and the induction of poly-ADP-ribose polymerase (PARP) cleavage were more pronounced and evident 12 h earlier than in the parental cells. We further established MET's role in MM cell survival by demonstrating that a retroviral MET RNA interference construct induces PARP cleavage in MM.1S cells. These results show that MET provides a survival mechanism for MM cells. 8-Cl-Ado overcomes MM cell survival by a mechanism that involves the depletion of MET. [Cancer Res 2007;67(20):9913–20]
Data from Cancer Immunotherapy Using Irradiated Tumor Cells Secreting Heat Shock Protein 70
Authors: Chang Chih-Long , Tsai Ya-Chea , He Liangmei , Wu T.-C. , Hung Chien-Fu
Published: March 2024

Abstract
Ovarian cancer is responsible for the highest mortality rate among patients with gynecologic malignancies. Therefore, there is an emerging need for innovative therapies for the control of advanced ovarian cancer. Immunotherapy has emerged as a potentially plausible approach for the control of ovarian cancer. In the current study, we have generated heat shock protein 70 (Hsp70)-secreting murine ovarian cancer cells that express luciferase (MOSEC/luc). Hsp70 has been shown to target and concentrate antigenic peptides in dendritic cells and is also able to activate dendritic cells. We characterized the antigen-specific immune response and the antitumor effect of the MOSEC/luc cells expressing Hsp70 using noninvasive luminescence images to measure the amount of ovarian tumors in the peritoneal cavity of mice. We found that mice challenged with MOSEC/luc cells expressing Hsp70 generate significant antigen-specific CD8+ T-cell immune responses. Furthermore, we also found that mice vaccinated with irradiated MOSEC/luc cells expressing Hsp70 generate significant therapeutic effect against MOSEC/luc cells. In addition, we have shown that CD8+, natural killer, and CD4+ cells are important for protective antitumor effect generated by irradiated tumor cell–based vaccines expressing Hsp70. Moreover, we also found that CD40 receptor is most important, followed by Toll-like receptor 4 receptor, for inhibiting in vivo tumor growth of the viable MOSEC/luc expressing Hsp70. Thus, the use of Hsp70-secreting ovarian tumor cells represents a potentially effective therapy for the control of lethal ovarian cancer. [Cancer Res 2007;67(20):10047–57]
Data from Extracellular Redox State Regulates Features Associated with Prostate Cancer Cell Invasion
Authors: Chaiswing Luksana , Zhong Weixiong , Cullen Joseph J. , Oberley Larry W. , Oberley Terry D.
Published: March 2024

Abstract
We have examined the possible role of extracellular reduction-oxidation (redox) state in regulation of biological/biochemical features associated with prostate cancer cell invasion. DU145, PC-3, and RWPE1-derived human prostate cancer (WPE1-NB26) cell lines were used for the present in vitro analysis. Increasing levels of nitric oxide using S-nitroso-N-acetylpenicillamine resulted in a decrease in cell invasion ability, whereas increasing levels of extracellular superoxide radical (O2•−) using xanthine/xanthine oxidase resulted in an increase in cell invasion ability in these three cell lines. WPE1-NB26 cells exhibited an increased glutathione/glutathione disulfide ratio in the medium in comparison with RWPE1 cells (immortalized but nonmalignant prostate epithelial cells), suggesting an alteration of extracellular redox state of WPE1-NB26 cells. We hypothesized that O2•− production at or near the plasma membrane or in the adjacent extracellular matrix at least partially regulated prostate cancer cell invasion. Using adenovirus-mediated extracellular superoxide dismutase (EC-SOD) gene transduction to enzymatically decrease O2•− levels, we showed that in the presence of heparin, adenovirus EC-SOD gene transduction resulted in an increase in the expression of EC-SOD outside the cells with resultant inhibition of cell invasion ability. This inhibition correlated with reduced metalloproteinase [matrix metalloproteinase (MMP) 2/membrane type 1-MMP] activities and increased levels of extracellular nitrite. Our results suggest a prominent role of extracellular redox status in regulation of cell invasion, which may provide opportunities for therapeutic interventions. [Cancer Res 2008;68(14):5820–6]
Data from Association of Genetic Variation in the Transforming Growth Factor β-1 Gene with Serum Levels and Risk of Colorectal Neoplasia
Authors: Saltzman Barbara S. , Yamamoto Jennifer F. , Decker Robert , Yokochi Lance , Theriault Andre G. , Vogt Thomas M. , Le Marchand Loïc
Published: March 2024

Abstract
In the normal intestinal epithelium transforming growth factor β-1 (TGFβ-1) acts as a growth inhibitor, but in malignant cells it may act as a tumor promoter. However, only limited information is available on genetic variation in the TGFB1 gene and its relationship to circulating levels and risk of colorectal cancer. To characterize associations of genetic variation [tagging single-nucleotide polymorphisms (tagSNP) and haplotypes with frequency >0.05] at the TGFB1 locus with circulating TGFβ-1 and risk of colorectal neoplasia, we conducted two case-control studies (including 271 colorectal adenoma cases and 544 controls, and 535 colorectal adenocarcinoma cases and 656 controls) among Japanese Americans, Caucasians, and Native Hawaiians in Hawaii. Serum TGFβ-1 was measured by sandwich ELISA among the subjects of the first study. The variant A allele for tagSNP rs6957 was associated with higher serum TGFβ-1 [means (in ng/mL) and 95% confidence interval (95% CI) for AA or AG, 32.6 (30.6–34.7); GG, 29.0 (25.1–32.9); Pdifference = 0.05] after adjusting for age and other factors. Homozygous carriers of the variant G allele for tagSNP rs11466345 had a statistically significantly lower risk of adenocarcinoma [AG versus AA: odds ratio (OR), 0.9 (95% CI, 0.7–1.2); GG versus AA: OR, 0.4 (95% CI, 0.2–0.7); Ptrend = 0.01]. The haplotype carrying both variants was also statistically significantly associated with a reduced risk of adenocarcinoma (OR, 0.3; 95% CI, 0.1–0.8). Although not statistically significant, the direction and magnitude of the corresponding ORs were similar for adenoma. These results suggest that a haplotype containing SNP rs11466345 at the 3′ end of TGFB1 is associated with genetic susceptibility to colorectal neoplasia. [Cancer Res 2008;68(4):1236–44]
Data from Identification of Pbx1, a Potential Oncogene, as a Notch3 Target Gene in Ovarian Cancer
Authors: Park Joon T. , Shih Ie-Ming , Wang Tian-Li
Published: March 2024

Abstract
Notch3 gene amplification has recently been identified in ovarian cancer but the Notch3 effectors that are involved in the development of ovarian cancer remain elusive. In this study, we have identified Pbx1, a proto-oncogene in hematopoietic malignancy, as a Notch3 target gene. Pbx1 expression is transcriptionally regulated by Notch3 activation, and Notch3/CSL protein complex directly binds to the Pbx1 promoter segment harboring the CSL-binding sequence. The growth-inhibitory effect of γ-secretase inhibitor could be partially reversed by ectopic Pbx1 expression. Furthermore, functional studies by Pbx1 short hairpin RNA knockdown show that Pbx1 is essential for cell proliferation and tumorigenicity. Taken together, the above findings indicate that Pbx1 is a direct Notch3-regulated gene that mediates the survival signal of Notch3 in ovarian cancer. [Cancer Res 2008;68(21):8852–60]
Data from Spontaneous Squamous Cell Carcinoma Induced by the Somatic Inactivation of Retinoblastoma and Trp53 Tumor Suppressors
Authors: Martínez-Cruz Ana Belén , Santos Mirentxu , Lara M. Fernanda , Segrelles Carmen , Ruiz Sergio , Moral Marta , Lorz Corina , García-Escudero Ramón , Paramio Jesús M.
Published: March 2024

Abstract
Squamous cell carcinomas (SCC) represent the most aggressive type of nonmelanoma skin cancer. Although little is known about the causal alterations of SCCs, in organ-transplanted patients the E7 and E6 oncogenes of human papillomavirus, targeting the p53- and pRb-dependent pathways, have been widely involved. Here, we report the functional consequences of the simultaneous elimination of Trp53 and retinoblastoma (Rb) genes in epidermis using Cre-loxP system. Loss of p53, but not pRb, produces spontaneous tumor development, indicating that p53 is the predominant tumor suppressor acting in mouse epidermis. Although the simultaneous inactivation of pRb and p53 does not aggravate the phenotype observed in Rb-deficient epidermis in terms of proliferation and/or differentiation, spontaneous SCC development is severely accelerated in doubly deficient mice. The tumors are aggressive and undifferentiated and display a hair follicle origin. Detailed analysis indicates that the acceleration is mediated by premature activation of the epidermal growth factor receptor/Akt pathway, resulting in increased proliferation in normal and dysplastic hair follicles and augmented tumor angiogenesis. The molecular characteristics of this model provide valuable tools to understand epidermal tumor formation and may ultimately contribute to the development of therapies for the treatment of aggressive squamous cancer. [Cancer Res 2008;68(3):683–92]
Data from Human Endogenous Retrovirus K Triggers an Antigen-Specific Immune Response in Breast Cancer Patients
Authors: Wang-Johanning Feng , Radvanyi Laszlo , Rycaj Kiera , Plummer Joshua B. , Yan Peisha , Sastry K. Jagannadha , Piyathilake Chandrika J. , Hunt Kelly K. , Johanning Gary L.
Published: March 2024

Abstract
Recent evidence indicates that human cancer cells reactivate the expression of latent human endogenous retroviral (HERV) proteins. However, the extent to which cancer patients mount de novo immune responses against expressed HERV elements is unclear. In this study, we determined the extent of HERV-K env expression in human breast cancer (BC) and whether both humoral and cell-mediated immunity against HERV-K can be found in BC patients. We found HERV-K env protein expression in 88% of BC (n = 119) but not in normal breast (n = 76) tissues. ELISA screening assays detected significant titers of anti–HERV-K env IgG in a large proportion of BC patients. T-cell responses against HERV-K were also detected in peripheral blood mononuclear cells (PBMC) from BC patients stimulated with autologous dendritic cells pulsed with HERV-K env SU antigens. These responses included induction of T-cell proliferation (P = 0.0043), IFN-γ production measured by enzyme-linked immunospot (P < 0.0001), and multiplex cytokine secretion (P = 0.0033). Multiplex cytokine analysis found a T-helper 1 cytokine response, including interleukin (IL)-2 (P = 0.0109), IL-6 (P = 0.0396), IL-8 (P = 0.0169), and IP-10 (P = 0.0045) secretion during in vitro stimulation of BC PBMC with HERV-K antigen. We also found HERV-K–specific CTLs that were capable of lysing target cells expressing HERV-K env protein in BC patients but not in normal female controls without cancer. These findings suggest that retroviral gene products are capable of acting as tumor-associated antigens activating both T-cell and B-cell responses in BC patients. [Cancer Res 2008;68(14):5869–77]
Data from Breast Cancer–Associated Fibroblasts Confer AKT1-Mediated Epigenetic Silencing of Cystatin M in Epithelial Cells
Authors: Lin Huey-Jen L. , Zuo Tao , Lin Ching-Hung , Kuo Chieh Ti , Liyanarachchi Sandya , Sun Shuying , Shen Rulong , Deatherage Daniel E. , Potter Dustin , Asamoto Lisa , Lin Shili , Yan Pearlly S. , Cheng Ann-Lii , Ostrowski Michael C. , Huang Tim H.-M.
Published: March 2024

Abstract
The interplay between histone modifications and promoter hypermethylation provides a causative explanation for epigenetic gene silencing in cancer. Less is known about the upstream initiators that direct this process. Here, we report that the Cystatin M (CST6) tumor suppressor gene is concurrently down-regulated with other loci in breast epithelial cells cocultured with cancer-associated fibroblasts (CAF). Promoter hypermethylation of CST6 is associated with aberrant AKT1 activation in epithelial cells, as well as the disabled INNP4B regulator resulting from the suppression by CAFs. Repressive chromatin, marked by trimethyl-H3K27 and dimethyl-H3K9, and de novo DNA methylation is established at the promoter. The findings suggest that microenvironmental stimuli are triggers in this epigenetic cascade, leading to the long-term silencing of CST6 in breast tumors. Our present findings implicate a causal mechanism defining how tumor stromal fibroblasts support neoplastic progression by manipulating the epigenome of mammary epithelial cells. The result also highlights the importance of direct cell-cell contact between epithelial cells and the surrounding fibroblasts that confer this epigenetic perturbation. Because this two-way interaction is anticipated, the described coculture system can be used to determine the effect of epithelial factors on fibroblasts in future studies. [Cancer Res 2008;68(24):10257–66]
Data from Inhibition of Fibroblast Growth Factor 19 Reduces Tumor Growth by Modulating β-Catenin Signaling
Authors: Pai Rama , Dunlap Debra , Qing Jing , Mohtashemi Iman , Hotzel Kathy , French Dorothy M.
Published: March 2024

Abstract
Fibroblast growth factors (FGF) play important roles in development, angiogenesis, and cancer. FGF19 uniquely binds to FGF receptor 4 (FGFR4). Our previous study has shown that FGF19 transgenic tumors have an activated Wnt-pathway phenotype. Wnt signaling is implicated in initiating or promoting FGF signaling in various cell types and organs. In this study, we examined whether FGF19 or inhibition of FGF19 affects the β-catenin signaling pathway using human colon cancer cell lines (HCT116, Colo201). Our results show that FGF19 increases tyrosine phosphorylation of β-catenin and causes loss of β-catenin–E-cadherin binding. FGF19 increases p-GSK3β and active β-catenin levels and anti-FGF19 antibody (1A6) treatment abrogates this effect of FGF19. Anti-FGF19 antibody treatment increases S33/S37/T41 phosphorylation and ubiquitination of β-catenin. Ion-trap mass spectrometric analysis confirmed that 1A6 increases phosphorylation of β-catenin in the NH2 terminus. Using HCT116-paired β-catenin knockout cells, we show that FGF19 induces TCF/LEF reporter activity in parental (WT/Δ45) and in WT/− but not in mutant (−/Δ45) cells, and that inhibition of endogenous FGF19 reduces this reporter activity, indicating that wild-type β-catenin is accessible for modulation. FGFR4 knockdown using inducible short hairpin RNA significantly reduces the colony-forming ability in vitro and tumor growth in vivo. Although cleaved caspase-3 immunoreactivity remains unchanged, the number of ki67-positive nuclei is reduced in FGFR4 knockdown tumor xenograft tissues. Consistent with the reduced β-catenin activation, Taqman analyses show that FGF19/FGFR4 inhibition reduced β-catenin target gene (cyclin D1, CD44, c-jun, Cox-2, UPAR) expression. These findings highlight that FGF19/FGFR4 cross-talk with β-catenin and that pathway intervention reduces tumor growth. [Cancer Res 2008;68(13):5086–95]
Data from Knockdown of the Transforming Growth Factor-β Type III Receptor Impairs Motility and Invasion of Metastatic Cancer Cells
Authors: Criswell Tracy L. , Dumont Nancy , Barnett Joey V. , Arteaga Carlos L.
Published: March 2024

Abstract
The transforming growth factor-β (TGF-β) signaling pathway plays dual roles in epithelial cell tumorigenesis. TGF-β is initially growth inhibitory, but as tumorigenesis progresses, TGF-β becomes prometastatic. Although the role of the types I and II TGF-β receptors is fairly well established, the role of the ubiquitously expressed TGF-β type III receptor (TβRIII) in tumorigenesis is less defined. To examine the role of TβRIII in breast cancer cells, we stably expressed short hairpin RNAs specific to TβRIII in MDA-231 human breast cancer cells and mouse mammary carcinoma cells expressing the polyomavirus middle T oncogene (PMTLuc). MDA-231 and PMTLuc cells with down-regulated TβRIII expression (231-kd; PMTLuc-kd) exhibited decreased growth rate, motility, and invasion into Matrigel, as well as an increase in apoptosis, compared with control cells. MDA-231 xenografts established in nude mice metastasized, whereas tumors made by 231-kd cells did not. Nuclear factor-κB (NF-κB) activity, which is known to regulate cell growth and motility, was lower in the MDA-231 and PMTLuc knockdown cells compared with control cells. Transfection of an expression vector encoding constitutively active IKK2 into the 231-kd cells restored the ability of TβRIII-deficient cells to invade Matrigel and decreased their basal level of apoptosis. These data indicate that TβRIII differentially regulates cell growth, motility, and invasion in tumorigenic MDA-231 and PMTLuc cells and that these growth changes occur through the modulation of NF-κB activity. [Cancer Res 2008;68(18):7304–12]
Data from Development of Cellular Immune Responses against PAX5, a Novel Target for Cancer Immunotherapy
Authors: Yan Mengyong , Himoudi Nourredine , Pule Martin , Sebire Neil , Poon Edmund , Blair Allison , Williams Owen , Anderson John
Published: March 2024

Abstract
PAX5 is a member of the PAX family of developmental transcription factors with an important role in B-cell development. Its expression in normal adult tissue is limited to the hemopoietic system, but it is aberrantly expressed in a number of solid cancers and leukemias where it functions as an oncogene. We therefore hypothesized that anti-PAX5 immune responses could be used to target a number of malignancies without significant toxicity. We screened PAX5 peptides for the ability to bind HLA-A2 and identified a novel sequence, TLPGYPPHV (referred to as TLP). CTL lines against TLP were generated from peripheral blood of five normal HLA-A2–positive blood donors and showed specific HLA-A2–restricted killing against PAX5-expressing target cells. We generated high-avidity CTL clones from these lines capable of killing cells pulsed with <1 nmol/L of TLP and killing a range of PAX5-expressing malignant cell lines. I.v. injection of an anti-PAX5 CTL clone into immunodeficient mice bearing s.c. human tumors resulted in specific growth inhibition of PAX5-expressing tumors. This knowledge can be used for the therapeutic generation of CTL lines or the cloning of high-avidity T-cell receptor genes for use in adoptive immunotherapy. [Cancer Res 2008;68(19):8058–65]
Data from The EGFR-STAT3 Oncogenic Pathway Up-regulates the Eme1 Endonuclease to Reduce DNA Damage after Topoisomerase I Inhibition
Authors: Vigneron Arnaud , Gamelin Erick , Coqueret Olivier
Published: March 2024

Abstract
The epidermal growth factor receptor (EGFR)-src-signal transducers and activators of transcription 3 (STAT3) oncogenic pathway plays a central role in tumorigenesis and is involved not only in cell transformation but also in tumor escape to genotoxic treatments. Despite its importance, the molecular mechanisms by which this signaling pathway induces resistance to DNA damage remain most of the time to be characterized. In this study, we show that the EGFR-src pathway is activated in response to topoisomerase I inhibition. After treatment, this signaling cascade induced the activation of STAT3 and the binding of the transcription factor to the promoter of the Eme1 gene. Eme1 is an endonuclease involved in the processing of DNA damage after topoisomerase I inhibition. These results suggest a model by which the STAT3-mediated activation of Eme1 prevents DNA damage and enhances cell survival in response to topoisomerase inhibition. This survival pathway was inhibited by a combined treatment with a src inhibitor, SKI, and with cetuximab, a monoclonal antibody directed against the EGFR that is widely used in the treatment of colorectal cancers. We therefore propose that the benefit of anti-EGFR therapy relies on an increase of DNA damage generated by topoisomerase I inhibition. [Cancer Res 2008;68(3):815–25]
Data from SerpinB2 Protection of Retinoblastoma Protein from Calpain Enhances Tumor Cell Survival
Authors: Tonnetti Laura , Netzel-Arnett Sarah , Darnell Grant A. , Hayes Tamara , Buzza Marguerite S. , Anglin Ian E. , Suhrbier Andreas , Antalis Toni M.
Published: March 2024

Abstract
The tumor suppressor retinoblastoma protein (Rb) plays a pivotal role in the regulation of cell proliferation and sensitivity to apoptosis through binding to E2F transcription factors. Loss of Rb in response to genotoxic stress or inflammatory cytokines can enhance cell death, in part, by eliminating Rb-mediated repression of proapoptotic gene transcription. Here we show that calpain cleavage of Rb facilitates Rb loss by proteasome degradation and that this may occur during tumor necrosis factor α–induced apoptosis. The cytoprotective, Rb-binding protein SerpinB2 (plasminogen activator inhibitor type 2) protects Rb from calpain cleavage, increasing Rb levels and enhancing cell survival. Chromatin immunoprecipitation assays show that the increased Rb levels selectively enhance Rb repression of proapoptotic gene transcription. This cytoprotective role of SerpinB2 is illustrated by reduced susceptibility of SerpinB2-deficient mice to multistage skin carcinogenesis, where Rb-dependent cell proliferation competes with apoptosis during initiation of papilloma development. These data identify SerpinB2 as a cell survival factor that modulates Rb repression of proapoptotic signal transduction and define a new posttranslational mechanism for selective regulation of the intracellular levels of Rb. [Cancer Res 2008;68(14):5648–57]
Data from Phosphorylated Caveolin-1 Regulates Rho/ROCK-Dependent Focal Adhesion Dynamics and Tumor Cell Migration and Invasion
Authors: Joshi Bharat , Strugnell Scott S. , Goetz Jacky G. , Kojic Liliana D. , Cox Michael E. , Griffith Obi L. , Chan Simon K. , Jones Steven J. , Leung Sher-Ping , Masoudi Hamid , Leung Samuel , Wiseman Sam M. , Nabi Ivan R.
Published: March 2024

Abstract
Rho/ROCK signaling and caveolin-1 (Cav1) are implicated in tumor cell migration and metastasis; however, the underlying molecular mechanisms remain poorly defined. Cav1 was found here to be an independent predictor of decreased survival in breast and rectal cancer and significantly associated with the presence of distant metastasis for colon cancer patients. Rho/ROCK signaling promotes tumor cell migration by regulating focal adhesion (FA) dynamics through tyrosine (Y14) phosphorylation of Cav1. Phosphorylated Cav1 is localized to protrusive domains of tumor cells and Cav1 tyrosine phosphorylation is dependent on Src kinase and Rho/ROCK signaling. Increased levels of phosphorylated Cav1 were associated with elevated GTP-RhoA levels in metastatic tumor cells of various tissue origins. Stable expression and knockdown studies of Cav1 in tumor cells showed that phosphorylated Cav1 expression stimulates Rho activation, stabilizes FAK association with FAs, and promotes cell migration and invasion in a ROCK-dependent and Src-dependent manner. Tyrosine-phosphorylated Cav1, therefore, functions as an effector of Rho/ROCK signaling in the regulation of FA turnover and, thereby, tumor cell migration and invasion. These studies define a feedback loop between Rho/ROCK, Src, and phosphorylated Cav1 in tumor cell protrusions, identifying a novel function for Cav1 in tumor metastasis that may contribute to the poor prognosis of some Cav1-expressing tumors. [Cancer Res 2008;68(20):8210–20]
Data from Oct-3/4 Expression Reflects Tumor Progression and Regulates Motility of Bladder Cancer Cells
Authors: Chang Chao-Ching , Shieh Gia-Shing , Wu Pensee , Lin Chia-Cheng , Shiau Ai-Li , Wu Chao-Liang
Published: March 2024

Abstract
Cancer and embryonic stem cells exhibit similar behavior, including immortal, undifferentiated, and invasive activities. Here, we show that in clinical samples bladder tumors with intense expression of stem cell marker Oct-3/4 (also known as POU5F1) are associated with further disease progression, greater metastasis, and shorter cancer-related survival compared with those with moderate and low expressions. Expression of Oct-3/4 is detected in human bladder transitional cell carcinoma samples and cell lines. Overexpression of Oct-3/4 enhances, whereas knockdown of Oct-3/4 expression by RNA interference reduces, migration and invasion of bladder cancer cells. Oct-3/4 can up-regulate fibroblast growth factor-4 and matrix metalloproteinase-2 (MMP-2), MMP-9, and MMP-13 production, which may contribute to tumor metastasis. Finally, we show that Ad5WS4, an E1B-55 kD–deleted adenovirus driven by the Oct-3/4 promoter, exerts potent antitumor activity against bladder cancer in a syngeneic murine tumor model. Therefore, our results implicate that Oct-3/4 may be useful as a novel tumor biological and prognostic marker and probably as a potential therapeutic target for bladder cancer. [Cancer Res 2008;68(15):6281–91]
Data from Integrated Genomic Profiling of Chronic Lymphocytic Leukemia Identifies Subtypes of Deletion 13q14
Authors: Ouillette Peter , Erba Harry , Kujawski Lisa , Kaminski Mark , Shedden Kerby , Malek Sami N.
Published: March 2024

Abstract
Chronic lymphocytic leukemia (CLL) is a biologically heterogeneous illness with a variable clinical course. Loss of chromosomal material on chromosome 13 at cytoband 13q14 is the most frequent genetic abnormality in CLL, but the molecular aberrations underlying del13q14 in CLL remain incompletely characterized. We analyzed 171 CLL cases for loss of heterozygosity and subchromosomal copy loss on chromosome 13 in DNA from fluorescence-activated cell sorting–sorted CD19+ cells and paired buccal cells using the Affymetrix XbaI 50k SNP array platform. The resulting high-resolution genomic maps, together with array-based measurements of expression levels of RNA in CLL cases with and without del13q14 and quantitative PCR–based expression analysis of selected genes, support the following conclusions: (a) del13q14 is heterogeneous and composed of multiple subtypes, with deletion of Rb or the miR15a/miR16 loci serving as anatomic landmarks, respectively; (b) del13q14 type Ia deletions are relatively uniform in length and extend from breakpoints close to the miR15a/miR16 cluster to a newly identified telomeric breakpoint cluster at the ∼50.2 to 50.5 Mb physical position; (c) LATS2 RNA levels are ∼2.6-fold to 2.8-fold lower in cases with del13q14 type I that do not delete Rb, as opposed to del13q14 type II or all other CLL cases; (d) PHLPP RNA is absent in ∼50% of CLL cases with del13q14; and (e) ∼15% of CLL cases display marked reductions in miR15a/miR16 expression that are often but not invariably associated with bi-allelic miR15a/miR16 loss. These data should aid future investigations into biological differences imparted on CLL by different del13q14 subtypes. [Cancer Res 2008;68(4):1012–21]
Data from A Novel, Macrophage Migration Inhibitory Factor Suicide Substrate Inhibits Motility and Growth of Lung Cancer Cells
Authors: Winner Millicent , Meier Jason , Zierow Swen , Rendon Beatriz E. , Crichlow Gregg V. , Riggs Randall , Bucala Richard , Leng Lin , Smith Ned , Lolis Elias , Trent John O. , Mitchell Robert A.
Published: March 2024

Abstract
Although chemokine and growth factor receptors are attractive and popular targets for cancer therapeutic intervention, structure-based targeting of the ligands themselves is generally not considered practical. New evidence indicates that a notable exception to this is macrophage migration inhibitory factor (MIF). MIF, an autocrine- and paracrine-acting cytokine/growth factor, plays a pivotal role in both the initiation and maintenance of neoplastic diseases. MIF possesses a nonphysiologic enzymatic activity that is evolutionarily well-conserved. Although small molecule antagonists of MIFs enzymatic active site have been reported to inhibit biological activities of MIF, universally high IC50s have limited their clinical appeal. Using a computational virtual screening strategy, we have identified a unique small molecule inhibitor that serves as a suicide substrate for MIF, resulting in the covalent modification of the catalytically active NH2-terminal proline. Our studies further reveal that this compound, 4-iodo-6-phenylpyrimidine (4-IPP), is ∼5× to 10× times more potent in blocking MIF-dependent catalysis and lung adenocarcinoma cell migration and anchorage-independent growth than the prototypical MIF inhibitor, ISO-1. Finally, using an in silico combinatorial optimization strategy, we have identified four unique congeners of 4-IPP that exhibit MIF inhibitory activity at concentrations 10× to 20× lower than that of parental 4-IPP. [Cancer Res 2008;68(18):7253–7]
Data from Attenuation of Melanoma Invasion by a Secreted Variant of Activated Leukocyte Cell Adhesion Molecule
Authors: van Kilsdonk Jeroen W.J. , Wilting Roel H. , Bergers Mieke , van Muijen Goos N.P. , Schalkwijk Joost , van Kempen Léon C.L.T. , Swart Guido W.M.
Published: March 2024

Abstract
Activated leukocyte cell adhesion molecule (ALCAM/CD166/MEMD), a marker of various cancers and mesenchymal stem cells, is involved in melanoma metastasis. We have exploited a secreted NH2-terminal fragment, sALCAM, to test the hypothesis that ALCAM coordinates tissue growth and cell migration. Overexpression of sALCAM in metastatic melanoma cells disturbed clustering of endogenous ALCAM and inhibited activation of matrix metalloproteinase-2 (MMP-2). Exposure of HT1080 fibrosarcoma cells to sALCAM similarly inhibited MMP-2, suggesting a broader effect on ALCAM-positive tumor cells. In contrast to the previously reported, promotive effects of an NH2-terminally truncated, transmembrane variant (ΔN-ALCAM), sALCAM impaired the migratory capacity of transfected cells in vitro, reduced basement membrane penetration in reconstituted human skin equivalents, and diminished metastatic capacity in nude mice. Remarkably, L1 neuronal cell adhesion molecule (L1CAM/CD171), another progression marker of several cancers including melanoma, was suppressed upon sALCAM overexpression but was up-regulated by ΔN-ALCAM. The partially overlapping and opposite effects induced by alternative strategies targeting ALCAM functions collectively attribute an integrative role to ALCAM in orchestrating cell adhesion, growth, invasion, and proteolysis in the tumor tissue microenvironment and disclose a therapeutic potential for sALCAM. [Cancer Res 2008;68(10):3671–9]
Data from Loss of Keap1 Function Activates Nrf2 and Provides Advantages for Lung Cancer Cell Growth
Authors: Ohta Tsutomu , Iijima Kumiko , Miyamoto Mamiko , Nakahara Izumi , Tanaka Hiroshi , Ohtsuji Makiko , Suzuki Takafumi , Kobayashi Akira , Yokota Jun , Sakiyama Tokuki , Shibata Tatsuhiro , Yamamoto Masayuki , Hirohashi Setsuo
Published: March 2024

Abstract
Oxidative and electrophilic stresses are sensed by Keap1, which activates Nrf2 to achieve cytoprotection by regulating the expression of drug-metabolizing and antioxidative stress enzymes/proteins. Because oxidative and electrophilic stresses cause many diseases, including cancer, we hypothesized that an abnormality in the Nrf2-Keap1 system may facilitate the growth of cancer cells. We sequenced the KEAP1 gene of 65 Japanese patients with lung cancer and identified five nonsynonymous somatic mutations at a frequency of 8%. We also identified two nonsynonymous somatic KEAP1 gene mutations and two lung cancer cell lines expressing KEAP1 at reduced levels. In lung cancer cells, low Keap1 activity (due to mutations or low-level expression) led to nuclear localization and constitutive activation of Nrf2. The latter resulted in constitutive expression of cytoprotective genes encoding multidrug resistance pumps, phase II detoxifying enzymes, and antioxidative stress enzymes/proteins. Up-regulation of these target genes in lung cancer cells led to cisplatin resistance. Nrf2 activation also stimulated growth of lung cancer–derived cell lines expressing KEAP1 at low levels and in mutant cell lines and in Keap1-null mouse embryonic fibroblasts under homeostatic conditions. Thus, inhibition of NRF2 may provide new therapeutic approaches in lung cancers with activation of Nrf2. [Cancer Res 2008;68(5):1303–9]
Data from Effects of the Dual Phosphatidylinositol 3-Kinase/Mammalian Target of Rapamycin Inhibitor NVP-BEZ235 on the Tumor Vasculature: Implications for Clinical Imaging
Authors: Schnell Christian R. , Stauffer Frédéric , Allegrini Peter R. , O'Reilly Terence , McSheehy Paul M.J. , Dartois Celine , Stumm Michael , Cozens Robert , Littlewood-Evans Amanda , García-Echeverría Carlos , Maira Sauveur-Michel
Published: March 2024

Abstract
Dysregulated angiogenesis and high tumor vasculature permeability, two vascular endothelial growth factor (VEGF)-mediated processes and hallmarks of human tumors, are in part phosphatidylinositol 3-kinase (PI3K) dependent. NVP-BEZ235, a dual PI3K/mammalian target of rapamycin (mTOR) inhibitor, was found to potently inhibit VEGF-induced cell proliferation and survival in vitro and VEGF-induced angiogenesis in vivo as shown with s.c. VEGF-impregnated agar chambers. Moreover, the compound strongly inhibited microvessel permeability both in normal tissue and in BN472 mammary carcinoma grown orthotopically in syngeneic rats. Similarly, tumor interstitial fluid pressure, a phenomenon that is also dependent of tumor permeability, was significantly reduced by NVP-BEZ235 in a dose-dependent manner on p.o. administration. Because RAD001, a specific mTOR allosteric inhibitor, was ineffective in the preceding experiments, we concluded that the effects observed for NVP-BEZ235 are in part driven by PI3K target modulation. Hence, tumor vasculature reduction was correlated with full blockade of endothelial nitric oxide (NO) synthase, a PI3K/Akt-dependent but mTORC1-independent effector involved in tumor permeability through NO production. In the BN472 tumor model, early reduction of permeability, as detected by Ktrans quantification using the dynamic contrast-enhanced magnetic resonance imaging contrasting agent P792 (Vistarem), was found to be a predictive marker for late-stage antitumor activity by NVP-BEZ235. [Cancer Res 2008;68(16):6598–607]
Data from Small Molecule Targeting the Hec1/Nek2 Mitotic Pathway Suppresses Tumor Cell Growth in Culture and in Animal
Authors: Wu Guikai , Qiu Xiao-Long , Zhou Longen , Zhu Jiewen , Chamberlin Richard , Lau Johnson , Chen Phang-Lang , Lee Wen-Hwa
Published: March 2024

Abstract
Hec1 is a conserved mitotic regulator critical for spindle checkpoint control, kinetochore functionality, and cell survival. Overexpression of Hec1 has been detected in a variety of human cancers and is linked to poor prognosis of primary breast cancers. Through a chemical genetic screening, we have identified a small molecule, N-(4-[2,4-dimethyl-phenyl]-thiazol-2-yl)-benzamide (INH1), which specifically disrupts the Hec1/Nek2 interaction via direct Hec1 binding. Treating cells with INH1 triggered reduction of kinetochore-bound Hec1 as well as global Nek2 protein level, consequently leading to metaphase chromosome misalignment, spindle aberrancy, and eventual cell death. INH1 effectively inhibited the proliferation of multiple human breast cancer cell lines in culture (GI50, 10–21 μmol/L). Furthermore, treatment with INH1 retarded tumor growth in a nude mouse model bearing xenografts derived from the human breast cancer line MDA-MB-468, with no apparent side effects. This study suggests that the Hec1/Nek2 pathway may serve as a novel mitotic target for cancer intervention by small compounds. [Cancer Res 2008;68(20):8393–9]
Data from Genetic Predictors of MEK Dependence in Non–Small Cell Lung Cancer
Authors: Pratilas Christine A. , Hanrahan Aphrothiti J. , Halilovic Ensar , Persaud Yogindra , Soh Junichi , Chitale Dhananjay , Shigematsu Hisayuki , Yamamoto Hiromasa , Sawai Ayana , Janakiraman Manickam , Taylor Barry S. , Pao William , Toyooka Shinichi , Ladanyi Marc , Gazdar Adi , Rosen Neal , Solit David B.
Published: March 2024

Abstract
Hyperactivated extracellular signal-regulated kinase (ERK) signaling is common in human cancer and is often the result of activating mutations in BRAF, RAS, and upstream receptor tyrosine kinases. To characterize the mitogen-activated protein kinase/ERK kinase (MEK)/ERK dependence of lung cancers harboring BRAF kinase domain mutations, we screened a large panel of human lung cancer cell lines (n = 87) and tumors (n = 916) for BRAF mutations. We found that non–small cell lung cancers (NSCLC) cells with both V600E and non-V600E BRAF mutations were selectively sensitive to MEK inhibition compared with those harboring mutations in epidermal growth factor receptor (EGFR), KRAS, or ALK and ROS kinase fusions. Supporting its classification as a “driver” mutation in the cells in which it is expressed, MEK inhibition in V600EBRAF NSCLC cells led to substantial induction of apoptosis, comparable with that seen with EGFR kinase inhibition in EGFR mutant NSCLC models. Despite high basal ERK phosphorylation, EGFR mutant cells were uniformly resistant to MEK inhibition. Conversely, BRAF mutant cell lines were resistant to EGFR inhibition. These data, together with the nonoverlapping pattern of EGFR and BRAF mutations in human lung cancer, suggest that these lesions define distinct clinical entities whose treatment should be guided by prospective real-time genotyping. To facilitate such an effort, we developed a mass spectrometry-based genotyping method for the detection of hotspot mutations in BRAF, KRAS, and EGFR. Using this assay, we confirmed that BRAF mutations can be identified in a minority of NSCLC tumors and that patients whose tumors harbor BRAF mutations have a distinct clinical profile compared with those whose tumors harbor kinase domain mutations in EGFR. [Cancer Res 2008;68(22):9375–83]
Data from Phosphorylated Insulin-Like Growth Factor-I/Insulin Receptor Is Present in All Breast Cancer Subtypes and Is Related to Poor Survival
Authors: Law Jennifer H. , Habibi Golareh , Hu Kaiji , Masoudi Hamid , Wang Michelle Y.C. , Stratford Anna L. , Park Eugene , Gee Julia M.W. , Finlay Pauline , Jones Helen E. , Nicholson Robert I. , Carboni Joan , Gottardis Marco , Pollak Michael , Dunn Sandra E.
Published: March 2024

Abstract
Drugs that target the insulin-like growth factor-I receptor (IGF-IR) and/or insulin receptor (IR) are currently under investigation for a variety of malignancies including breast cancer. Although we have previously reported that IGF-IR expression in primary breast tumors is common, the activation status of this receptor has not been examined in relation to survival. Phosphorylated IGF-IR/IR (P-IGF-IR/IR) and its downstream signaling partner phospho-S6 (P-S6) were evaluated immunohistochemically in tumor tissue microarrays representing 438 cases of invasive breast cancer. P-IGF-IR/IR (n = 114; P = 0.046) and total levels of IR (n = 122; P = 0.009) were indicative of poor survival, whereas total IGF-IR (n = 112; P = 0.304) was not. P-IGF-IR/IR and P-S6 were coordinately expressed in primary breast tumors (likelihood ratio, 11.57; P = 6.70 × 10−4). Importantly, P-IGF-IR/IR was detected in all breast cancer subtypes (luminal, 48.1%; triple negative, 41.9%; and HER2, 64.3%). In vitro, the IGF-IR/IR inhibitor BMS-536924 decreased phospho-RSK and P-S6, and significantly suppressed the growth of breast cancer cell lines MCF-7, SUM149, and AU565 representing the luminal, triple negative, and HER2 subtypes, respectively, in monolayer and soft agar. BMS-536924 also inhibited growth in tamoxifen resistant MCF-7 Tam-R cells while having little effect on immortalized normal breast epithelial cells. Thus, we can determine which patients have the activated receptor and provide evidence that P-IGF-IR/IR is a prognostic factor for breast cancer. Beyond this, P-IGF-IR/IR could be a predictive marker for response to IGF-IR and/or IR-targeted therapies, as these inhibitors may be of benefit in all breast cancer subtypes including those with acquired resistance to tamoxifen. [Cancer Res 2008;68(24):10238–46]
Data from Cyclin-Dependent Kinase 3–Mediated Activating Transcription Factor 1 Phosphorylation Enhances Cell Transformation
Authors: Zheng Duo , Cho Yong-Yeon , Lau Andy T.Y. , Zhang Jishuai , Ma Wei-Ya , Bode Ann M. , Dong Zigang
Published: March 2024

Abstract
Cyclin-dependent kinase (cdk)-3, a member of the cdk family of kinases, plays a critical role in cell cycle regulation and is involved in G0-G1 and G1-S cell cycle transitions. However, the role of cdk3 in cell proliferation, as well as cell transformation, is not yet clearly understood. Here, we report that the protein expression level of cdk3 is higher in human cancer cell lines and human glioblastoma tissue compared with normal brain tissue. Furthermore, we found that cdk3 phosphorylates activating transcription factor 1 (ATF1) at serine 63 and enhances the transactivation and transcriptional activities of ATF1. Results also indicated that siRNA directed against cdk3 (si-cdk3) suppresses ATF1 activity, resulting in inhibition of proliferation and growth of human glioblastoma T98G cells in soft agar. Importantly, we showed that cdk3 enhances epidermal growth factor–induced transformation of JB6 Cl41 cells and si-cdk3 suppresses RasG12V/cdk3/ATF1–induced foci formation in NIH3T3 cells. These results clearly showed that the cdk3-ATF1 signaling axis is critical for cell proliferation and transformation. [Cancer Res 2008;68(18):7650–60]
Data from Runx2 Transcriptional Activation of Indian Hedgehog and a Downstream Bone Metastatic Pathway in Breast Cancer Cells
Authors: Pratap Jitesh , Wixted John J. , Gaur Tripti , Zaidi Sayyed K. , Dobson Jason , Gokul Karthiga Devi , Hussain Sadiq , van Wijnen Andre J. , Stein Janet L. , Stein Gary S. , Lian Jane B.
Published: March 2024

Abstract
Runx2, required for bone formation, is ectopically expressed in breast cancer cells. To address the mechanism by which Runx2 contributes to the osteolytic disease induced by MDA-MB-231 cells, we investigated the effect of Runx2 on key components of the “vicious cycle” of transforming growth factor β (TGFβ)-mediated tumor growth and osteolysis. We find that Runx2 directly up-regulates Indian Hedgehog (IHH) and colocalizes with Gli2, a Hedgehog signaling molecule. These events further activate parathyroid hormone-related protein (PTHrP). Furthermore, Runx2 directly regulates the TGFβ-induced PTHrP levels. A subnuclear targeting deficient mutant Runx2, which disrupts TGFβ-induced Runx2-Smad interactions, failed to induce IHH and downstream events. In addition, Runx2 knockdown in MDA-MB-231 inhibited IHH and PTHrP expression in the presence of TGFβ. In vivo blockade of the Runx2-IHH pathway in MDA-MB-231 cells by Runx2 short hairpin RNA inhibition prevented the osteolytic disease. Thus, our studies define a novel role of Runx2 in up-regulating the vicious cycle of metastatic bone disease, in addition to Runx2 regulation of genes related to progression of tumor metastasis. [Cancer Res 2008;68(19):7795–802]
Data from Global Hypomethylation of Genomic DNA in Cancer-Associated Myofibroblasts
Authors: Jiang Le , Gonda Tamas A. , Gamble Mary V. , Salas Martha , Seshan Venkatraman , Tu Shuiping , Twaddell William S. , Hegyi Peter , Lazar Gyorgy , Steele Islay , Varro Andrea , Wang Timothy C. , Tycko Benjamin
Published: March 2024

Abstract
Global hypomethylation has long been recognized as a feature of the malignant epithelial component in human carcinomas. Here we show evidence for this same type of epigenetic alteration in cancer-associated stromal myofibroblasts. We used methylation-sensitive SNP array analysis (MSNP) to profile DNA methylation in early-passage cultures of stromal myofibroblasts isolated from human gastric cancers. The MSNP data indicated widespread hypomethylation in these cells, with rare focal gains of methylation, conclusions that were independently validated by bisulfite sequencing and by a methylation-sensitive cytosine incorporation assay. Immunohistochemistry with anti–5-methylcytosine (anti–5-methyl-C) in a series of gastrectomy specimens showed frequent loss of methylation in nuclei of both the malignant epithelial cells and α-smooth muscle actin (ASMA)–positive stromal myofibroblasts of both intestinal-type and diffuse carcinomas. We confirmed this phenomenon and established its onset at the stage of noninvasive dysplastic lesions by immunohistochemistry for anti–5-methyl-C in a transgenic mouse model of multistage gastric carcinogenesis. These findings indicate similar general classes of epigenetic alterations in carcinoma cells and their accompanying reactive stromal cells and add to accumulating evidence for biological differences between normal and cancer-associated myofibroblasts. [Cancer Res 2008;68(23):9900–8]
Data from Inducible Cutaneous Inflammation Reveals a Protumorigenic Role for Keratinocyte CXCR2 in Skin Carcinogenesis
Authors: Cataisson Christophe , Ohman Rebecca , Patel Gopal , Pearson Andrea , Tsien Margaret , Jay Steve , Wright Lisa , Hennings Henry , Yuspa Stuart H.
Published: March 2024

Abstract
Transgenic mice that overexpress PKCα in the epidermis (K5-PKCα mice) exhibit acute CXCR2-mediated intraepidermal neutrophilic inflammation and a strong epidermal hyperplasia in response to application of 12-O-tetradecanoylphorbol-13-acetate (TPA). We now show that hyperplasia is independent of infiltrating neutrophils. Furthermore, when K5-PKCα mice were initiated with 7,12-dimethylbenz(a)anthracene (DMBA) and promoted with a low dose of TPA, 58% of K5-PKCα mice developed skin papillomas that progressed to carcinoma, whereas wild-type mice did not develop tumors. We confirmed that CXCR2 is expressed by keratinocytes and showed that transformation by oncogenic ras (a hallmark of DMBA initiation) or TPA exposure induced all CXCR2 ligands. Ras induction of CXCR2 ligands was mediated by autocrine activation of epidermal growth factor receptor and nuclear factor-κB, and potentiated by PKCα. Oncogenic ras also induced CXCR2 ligands in keratinocytes genetically ablated for CXCR2. However, ras transformed CXCR2 null keratinocytes formed only small skin tumors in orthotopic skin grafts to CXCR2 intact hosts, whereas transformed wild-type keratinocytes produced large tumors. In vitro, CXCR2 was essential for CXCR2 ligand-stimulated migration of ras-transformed keratinocytes and for ligand activation of the extracellular signal-regulated kinase (ERK) and Akt pathways. Both migration and activation of ERK and Akt were restored by CXCR2 reconstitution of CXCR2 null keratinocytes. Thus, activation of CXCR2 on ras-transformed keratinocytes has both promigratory and protumorigenic functions. The up-regulation of CXCR2 ligands after initiation by oncogenic ras and promotion with TPA in the mouse skin model provides a mechanism to stimulate migration by both autocrine and paracrine pathways and contribute to tumor development. [Cancer Res 2009;69(1):319–28]