bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from p21 Loss Cooperates with INK4 Inactivation Facilitating Immortalization and Bcl-2–Mediated Anchorage-Independent Growth of Oncogene-Transduced Primary Mouse Fibroblasts
Authors: Carbone Christopher J. , Graña Xavier , Reddy E. Premkumar , Haines Dale S.
Published: March 2023

Abstract
The INK4 and CIP cyclin-dependent kinase (Cdk) inhibitors (CKI) activate pocket protein function by suppressing Cdk4 and Cdk2, respectively. Although these inhibitors are lost in tumors, deletion of individual CKIs results in modest proliferation defects in murine models. We have evaluated cooperativity between loss of all INK4 family members (using cdk4r24c mutant alleles that confer resistant to INK4 inhibitors) and p21Waf1/Cip1 in senescence and transformation of mouse embryo fibroblasts (MEF). We show that mutant cdk4r24c and p21 loss cooperate in pRb inactivation and MEF immortalization. Our studies suggest that cdk4r24c mediates resistance to p15INK4B/p16INK4A that accumulates over passage, whereas loss of p21 suppresses hyperoxia-induced Cdk2 inhibition and pRb dephosphorylation on MEF explantation in culture. Although cdk4r24c and p21 loss cooperate in H-rasV12/c-myc–induced foci formation, they are insufficient for oncogene-induced anchorage-independent growth. Interestingly, p21−/−; cdk4r24c MEFs expressing H-rasV12 and c-myc display detachment-induced apoptosis and are transformed by c-myc, H-rasV12, and Bcl-2. We conclude that the INK4 family and p21 loss cooperate in promoting pRb inactivation, cell immortalization, and H-rasV12/c-myc–induced loss of contact inhibition. In addition, absence of pRb function renders H-rasV12 + c-myc–transduced fibroblasts prone to apoptosis when deprived of the extracellular matrix, and oncogene-induced anchorage-independent growth of pocket protein–deficient cells requires apoptotic suppression. [Cancer Res 2007;67(9):4130–7]
Data from SMAC Mimetics Sensitize Nonsteroidal Anti-inflammatory Drug–Induced Apoptosis by Promoting Caspase-3–Mediated Cytochrome c Release
Authors: Bank Alexander , Wang Peng , Du Chunying , Yu Jian , Zhang Lin
Published: March 2023

Abstract
Nonsteroidal anti-inflammatory drugs (NSAID) are effective in suppressing the formation of colorectal tumors. However, the mechanisms underlying the antineoplastic effects of NSAIDs remain unclear. The effects of NSAIDs are incomplete, and resistance to NSAIDs is often developed. Growing evidence has indicated that the chemopreventive activity of NSAIDs is mediated by induction of apoptosis. Our previous studies showed that second mitochondria-derived activator of caspase (SMAC)/Diablo, a mitochondrial apoptogenic protein, plays an essential role in NSAID-induced apoptosis in colon cancer cells. In this study, we found that SMAC mediates NSAID-induced apoptosis through a feedback amplification mechanism involving interactions with inhibitor of apoptosis proteins, activation of caspase-3, and induction of cytosolic release of cytochrome c. Small-molecule SMAC mimetics at nanomolar concentrations significantly sensitize colon cancer cells to NSAID-induced apoptosis by promoting caspase-3 activation and cytochrome c release. Furthermore, SMAC mimetics overcome NSAID resistance in Bax-deficient or SMAC-deficient colon cancer cells by restoring caspase-3 activation and cytochrome c release. Together, these results suggest that SMAC is useful as a target for the development of more effective chemopreventive strategies and agents. [Cancer Res 2008;68(1):276–84]
Data from Inhibitors of the Proteasome Suppress Homologous DNA Recombination in Mammalian Cells
Authors: Murakawa Yasuhiro , Sonoda Eiichiro , Barber Louise J. , Zeng Weihua , Yokomori Kyoko , Kimura Hiroshi , Niimi Atsuko , Lehmann Alan , Zhao Guang Yu , Hochegger Helfrid , Boulton Simon J. , Takeda Shunichi
Published: March 2023

Abstract
Proteasome inhibitors are novel antitumor agents against multiple myeloma and other malignancies. Despite the increasing clinical application, the molecular basis of their antitumor effect has been poorly understood due to the involvement of the ubiquitin-proteasome pathway in multiple cellular metabolisms. Here, we show that treatment of cells with proteasome inhibitors has no significant effect on nonhomologous end joining but suppresses homologous recombination (HR), which plays a key role in DNA double-strand break (DSB) repair. In this study, we treat human cells with proteasome inhibitors and show that the inhibition of the proteasome reduces the efficiency of HR-dependent repair of an artificial HR substrate. We further show that inhibition of the proteasome interferes with the activation of Rad51, a key factor for HR, although it does not affect the activation of ATM, γH2AX, or Mre11. These data show that the proteasome-mediated destruction is required for the promotion of HR at an early step. We suggest that the defect in HR-mediated DNA repair caused by proteasome inhibitors contributes to antitumor effect, as HR plays an essential role in cellular proliferation. Moreover, because HR plays key roles in the repair of DSBs caused by chemotherapeutic agents such as cisplatin and by radiotherapy, proteasome inhibitors may enhance the efficacy of these treatments through the suppression of HR-mediated DNA repair pathways. [Cancer Res 2007;67(18):8536–43]
Data from Autoantibody Profiles Reveal Ubiquilin 1 as a Humoral Immune Response Target in Lung Adenocarcinoma
Authors: Chen Guoan , Wang Xiaoju , Yu Jianjun , Varambally Sooryanarayana , Yu Jindan , Thomas Dafydd G. , Lin Mu-Yen , Vishnu Prakash , Wang Zhuwen , Wang Rui , Fielhauer Jeff , Ghosh Debashis , Giordano Thomas J. , Giacherio Donald , Chang Andrew C. , Orringer Mark B. , El-Hefnawy Talal , Bigbee William L. , Beer David G. , Chinnaiyan Arul M.
Published: March 2023

Abstract
There is considerable evidence that the presence of cancer can elicit a humoral immune response to specific proteins in the host, and these resulting autoantibodies may have potential as noninvasive biomarkers. To characterize the autoantibody repertoire present in the sera of patients with lung adenocarcinoma, we developed a high-density peptide microarray derived from biopanning a lung cancer phage display library. Using a 2,304-element microarray, we interrogated a total of 250 sera from Michigan lung cancer patients and noncancer controls to develop an “autoantibody profile” of lung adenocarcinoma. A set of 22 discriminating peptides derived from a training set of 125 serum samples from lung adenocarcinoma patients and control subjects was found to predict cancer status with 85% sensitivity and 86% specificity in an independent test set of 125 sera. Sequencing of the immunoreactive phage-peptide clones identified candidate humoral immune response targets in lung adenocarcinoma, including ubiquilin 1, a protein that regulates the degradation of several ubiquitin-dependent proteasome substrates. An independent validation set of 122 serum samples from Pittsburgh was examined using two overlapping clones of ubiquilin 1 that showed 0.79 and 0.74 of the area under the receiver operating characteristics curve, respectively. Significantly increased levels of both ubiquilin 1 mRNA and protein, as well as reduced levels of the phosphorylated form of this protein, were detected in lung tumors. Immunofluorescence using anti–ubiquilin 1 antibodies confirmed intracellular expression within tumors cells. These studies indicate that autoantibody profiles, as well as individual candidates, may be useful for the noninvasive detection of lung adenocarcinoma. [Cancer Res 2007;67(7):3461–7]
Data from Induction of Cdc25B Regulates Cell Cycle Resumption after Genotoxic Stress
Authors: Bansal Pallavi , Lazo John S.
Published: March 2023

Abstract
Cdc25 phosphatases propel cell cycle progression by activating cyclin-dependent kinases (Cdk). DNA damage is generally thought to inhibit Cdc25 functionality by inducing proteasomal degradation of Cdc25A and phosphorylation-mediated sequestration of Cdc25B and Cdc25C to the cytoplasm. More recently, a critical role for Cdc25B in the resumption of cell cycle progression through mitosis after DNA damage has been identified. In this study, the fate of Cdc25B after mechanistically distinct DNA-damaging agents (etoposide, cisplatin, bleomycin, ionizing irradiation, or UV irradiation) was examined, and surprisingly a rapid increase in cellular Cdc25B levels was observed after DNA damage. Using UV irradiation as the prototypic damaging agent, we found that the increase in Cdc25B levels was checkpoint dependent and was controlled by a p53-independent mechanism. Cdc25B levels controlled the number of cells progressing into mitosis after UV, but they did not affect G2-M checkpoint engagement immediately after DNA damage. Increased Cdc25B reduced the time required for cell cycle resumption. These data support a model in which Cdc25B accumulation is an important anticipatory event for cell cycle resumption after DNA damage. [Cancer Res 2007;67(7):3356–63]
Data from Deregulated Overexpression of hCdt1 and hCdc6 Promotes Malignant Behavior
Authors: Liontos Michalis , Koutsami Marilena , Sideridou Maria , Evangelou Konstantinos , Kletsas Dimitris , Levy Brynn , Kotsinas Athanassios , Nahum Odelia , Zoumpourlis Vassilis , Kouloukoussa Mirsini , Lygerou Zoi , Taraviras Stavros , Kittas Christos , Bartkova Jirina , Papavassiliou Athanasios G. , Bartek Jiri , Halazonetis Thanos D. , Gorgoulis Vassilis G.
Published: March 2023

Abstract
The accurate execution of DNA replication requires a strict control of the replication licensing factors hCdt1 and hCdc6. The role of these key replication molecules in carcinogenesis has not been clarified. To examine how early during cancer development deregulation of these factors occurs, we investigated their status in epithelial lesions covering progressive stages of hyperplasia, dysplasia, and full malignancy, mostly from the same patients. Abnormal accumulation of both proteins occurred early from the stage of dysplasia. A frequent cause of unregulated hCdc6 and hCdt1 expression was gene amplification, suggesting that these components can play a role per se in cancer development. Overexpression of hCdt1 and hCdc6 promoted rereplication and generated a DNA damage response, which activated the antitumor barriers of senescence and apoptosis. Generating an inducible hCdt1 cellular system, we observed that continuous stimulus by deregulated hCdt1 led to abrogation of the antitumor barriers and resulted in the selection of clones with more aggressive properties. In addition, stable expression of hCdc6 and hCdt1 in premalignant papilloma cells led to transformation of the cells that produced tumors upon injection into nude mice depicting the oncogenic potential of their deregulation. [Cancer Res 2007;67(22):10899–909]
Data from Hepatocellular Carcinoma Associated with Liver-Gender Disruption in Male Mice
Authors: Rogers Arlin B. , Theve Elizabeth J. , Feng Yan , Fry Rebecca C. , Taghizadeh Koli , Clapp Kristen M. , Boussahmain Chakib , Cormier Kathleen S. , Fox James G.
Published: March 2023

Abstract
Hepatocellular carcinoma (HCC) is a male-predominant cancer associated with chronic hepatitis. Like human viral hepatitis, murine Helicobacter hepaticus infection produces inflammation and HCC with a masculine bias. We used this model to identify potential mechanisms of male HCC predisposition. Male weanling A/JCr mice (n = 67) were gavaged with H. hepaticus or vehicle. At 1 year, mice were distributed into four groups: surgical castration, chemical castration, castration followed by dihydrotestosterone supplementation, or sexually intact controls. Responses to infection were compared with IFN-γ challenge alone. At 21 months, there was no significant difference in hepatitis between groups. Neither castration nor androgen receptor agonism altered tumor incidence. Infected mice with severe, but not mild, disease exhibited a mosaic of alterations to sexually dimorphic genes and microsomal long-chain fatty acids. By microarray, tumorigenic hepatitis was strongly associated with liver-gender disruption, defined as the loss of a gender-identifying hepatic molecular signature. IFN-γ alone produced similar changes, demonstrating a role for proinflammatory cytokines in this process. In conclusion, hepatocarcinogenesis in male mice with chronic hepatitis is maturationally imprinted and androgen-independent. Proinflammatory cytokines may promote HCC in a male-predominant fashion due to high sensitivity of the masculinized liver to loss of sex-specific transcriptional balance. Liver-gender disruption has pleiotropic implications for hepatic enzyme activity, lipid processing, nuclear receptor activation, apoptosis, and proliferation. We propose a multistep model linking chronic hepatitis to liver cancer through cytokine-mediated derangement of gender-specific cellular metabolism. This model introduces a novel mechanism of inflammation-associated carcinogenesis consistent with male-predominant HCC risk. [Cancer Res 2007;67(24):11536–46]
Data from Differential Involvement of Vascular Endothelial Growth Factor in the Survival of Hypoxic Colon Cancer Cells
Authors: Calvani Maura , Trisciuoglio Daniela , Bergamaschi Cristina , Shoemaker Robert H. , Melillo Giovanni
Published: March 2023

Abstract
The recent approval of bevacizumab (Avastin), a humanized anti–vascular endothelial growth factor (VEGF) monoclonal antibody, in combination with chemotherapy for the treatment of patients with metastatic colorectal cancer, has provided proof of principle of the efficacy of antiangiogenic strategies for cancer therapy. The activity of bevacizumab is primarily attributed to its ability to inhibit endothelial cell survival. Whether anti-VEGF strategies may also have a direct effect on cancer cell survival is poorly understood. We show that serum-starved colon cancer cells differentially respond to autocrine production of VEGF with the induction of hypoxia inducible factor-1α (HIF-1α) and survival under hypoxic conditions. Inhibition of VEGF or VEGF receptor 2 (VEGFR2)/KDR, but not VEGFR1/Flt-1, was sufficient to abrogate VEGF-mediated induction of HIF-1α and survival in sensitive HCT116, but not in resistant HT29, colon cancer cells. These results provide evidence that a VEGF/KDR/HIF-1α autocrine loop differentially mediates survival of hypoxic colon cancer cells, and they suggest that colon cancer cells may be intrinsically sensitive or resistant to anti-VEGF strategies, which may determine the therapeutic efficacy of bevacizumab. [Cancer Res 2008;68(1):285–91]
Data from A Macrophage Gene Expression Signature Defines a Field Effect in the Lung Tumor Microenvironment
Authors: Stearman Robert S. , Dwyer-Nield Lori , Grady Michael C. , Malkinson Alvin M. , Geraci Mark W.
Published: March 2023

Abstract
One area of intensive investigation is to understand complex cellular and signaling interactions in the tumor microenvironment. Using a novel, although straightforward, microarray approach, we defined a gene expression signature from the lung tumor microenvironment in the murine A/J-urethane model of human lung adenocarcinoma. The tumor microenvironment is reflected by the composition of the cell types present and alterations in mRNA levels, resulting in a “Field Effect” around the tumor. The genes composing the Field Effect expression signature include proteases and their inhibitors, inflammation markers, and immune signaling molecules. By several criteria, the Field Effect expression signature can be attributed to the macrophage lineage, suggesting a qualitative change in the expression pattern of tumor-associated macrophages (TAM) observed in lung tumors. The protein expression levels for a number of Field Effect genes were verified by Western blot analysis of lung homogenates, and for their expression in macrophages and parenchymal cells outside of the tumors by immunohistochemistry. In addition, the Field Effect expression signature was used to classify bronchoalveolar lavage (BAL) cells from tumor-bearing or age-matched control mice. Using a variety of statistical measures, the Field Effect expression signature correctly classified the BAL cells >94% of the time. Finally, the protein levels for several Field Effect genes were higher in cell-free BAL fluid, indicating they may be secreted by the TAMs. This work suggests that TAMs generate a unique gene expression signature within the tumor microenvironment, and this signature could potentially be used for identifying lung cancer from BAL cells and/or fluid. [Cancer Res 2008;68(1):34–43]
Data from Identification of Tumor-Initiating Cells in a p53-Null Mouse Model of Breast Cancer
Authors: Zhang Mei , Behbod Fariba , Atkinson Rachel L. , Landis Melissa D. , Kittrell Frances , Edwards David , Medina Daniel , Tsimelzon Anna , Hilsenbeck Susan , Green Jeffrey E. , Michalowska Aleksandra M. , Rosen Jeffrey M.
Published: March 2023

Abstract
Using a syngeneic p53-null mouse mammary gland tumor model that closely mimics human breast cancer, we have identified, by limiting dilution transplantation and in vitro mammosphere assay, a Lin−CD29HCD24H subpopulation of tumor-initiating cells. Upon subsequent transplantation, this subpopulation generated heterogeneous tumors that displayed properties similar to the primary tumor. Analysis of biomarkers suggests the Lin−CD29HCD24H subpopulation may have arisen from a bipotent mammary progenitor. Differentially expressed genes in the Lin−CD29HCD24H mouse mammary gland tumor-initiating cell population include those involved in DNA damage response and repair, as well as genes involved in epigenetic regulation previously shown to be critical for stem cell self-renewal. These studies provide in vitro and in vivo data that support the cancer stem cell (CSC) hypothesis. Furthermore, this p53-null mouse mammary tumor model may allow us to identify new CSC markers and to test the functional importance of these markers. [Cancer Res 2008;68(12):4674–82]
Data from Activated Cholinergic Signaling Provides a Target in Squamous Cell Lung Carcinoma
Authors: Song Pingfang , Sekhon Harmanjatinder S. , Fu Xiao Wen , Maier Michelle , Jia Yibing , Duan Jie , Proskosil Becky J. , Gravett Courtney , Lindstrom Jon , Mark Gregory P. , Saha Saurabh , Spindel Eliot R.
Published: March 2023

Abstract
The binding of exogenous nicotine to nicotinic acetylcholine (ACh) receptors (nAChR) and the binding of endogenous ACh to both nAChR and muscarinic ACh receptors (mAChR) stimulate growth of both small cell and non–small cell lung carcinomas. Understanding how cholinergic signaling is up-regulated in lung cancer may suggest new therapeutic approaches. Analysis of 28 squamous cell lung carcinomas (SCC) showed increased levels of α5 and β3 nAChR mRNA and increased levels of ACh associated with increased levels of choline acetyltransferase mRNA and decreased cholinesterase mRNAs. Lynx1, an allosteric inhibitor of nAChR activity, was also decreased in SCC. Thus, cholinergic signaling is broadly increased in SCC caused by increased levels of receptors, increased levels of ligands, and decreased levels of receptor inhibitors. Partially explaining the cholinergic up-regulation seen in SCC, incubation of the H520 SCC cell line with nicotine increased levels of ACh secretion, increased expression of nAChR, and, as measured by electrophysiologic recording, increased activity of the expressed nAChR. Consistent with these effects, nicotine stimulated proliferation of H520 cells. One approach to blocking proliferative effects of nicotine and ACh on growth of lung cancers may be through M3 mAChR antagonists, which can limit the activation of mitogen-activated protein kinase that is caused by both nicotinic and muscarinic signaling. This was tested with the M3-selective muscarinic antagonist darifenacin. Darifenacin blocked nicotine-stimulated H520 growth in vitro and also blocked H520 growth in nude mice in vivo. Thus, cholinergic signaling is broadly up-regulated in SCC and blocking cholinergic signaling can limit basal and nicotine-stimulated growth of SCC. [Cancer Res 2008;68(12):4693–700]
Data from An Effective Vaccine Strategy Protective against Antigenically Distinct Tumor Variants
Authors: Pavelko Kevin D. , Heckman Karin L. , Hansen Michael J. , Pease Larry R.
Published: March 2023

Abstract
Antigenically distinct tumor variants can emerge in response to selective pressures inherent to host-tumor interactions. The development of successful immunotherapeutic strategies can be limited by these disparate antigenic profiles. Using the immunomodulator B7-DC XAb to activate cytolytic T cells specific for tumor-associated antigens, we found that the specificity of immune responses elicited by live tumors are distinct from the specificity of the responses elicited by soluble proteins derived from the same tumors. Remarkably, whereas the induced antitumor immunity generated against live variants of the B16 melanoma and EL4 thymic lymphoma tumors were highly specific for the original tumor variant used in the challenge, immunity generated using soluble proteins derived from tumor lysates was broadly reactive, recognizing the challenge tumor, as well as antigenically distinct variants. The antigens detected using live tumor and tumor lysate vaccines could be distinguished biochemically, demonstrating that they are structurally distinct. We show that vaccines using antigens present in tumor cell lysates induce protective immunity with strong memory against distantly related tumor variants. The existence of a class of antigens shared among tumor variants provides an attractive target for vaccine development. [Cancer Res 2008;68(7):2471–8]
Data from Genome-Wide, High-Resolution Detection of Copy Number, Loss of Heterozygosity, and Genotypes from Formalin-Fixed, Paraffin-Embedded Tumor Tissue Using Microarrays
Authors: Jacobs Sharoni , Thompson Ella R. , Nannya Yasuhito , Yamamoto Go , Pillai Raji , Ogawa Seishi , Bailey Dione K. , Campbell Ian G.
Published: March 2023

Abstract
Formalin-fixed, paraffin-embedded (FFPE) material tends to yield degraded DNA and is thus suboptimal for use in many downstream applications. We describe an integrated analysis of genotype, loss of heterozygosity (LOH), and copy number for DNA derived from FFPE tissues using oligonucleotide microarrays containing over 500K single nucleotide polymorphisms. A prequalifying PCR test predicted the performance of FFPE DNA on the microarrays better than age of FFPE sample. Although genotyping efficiency and reliability were reduced for FFPE DNA when compared with fresh samples, closer examination revealed methods to improve performance at the expense of variable reduction in resolution. Important steps were also identified that enable equivalent copy number and LOH profiles from paired FFPE and fresh frozen tumor samples. In conclusion, we have shown that the Mapping 500K arrays can be used with FFPE-derived samples to produce genotype, copy number, and LOH predictions, and we provide guidelines and suggestions for application of these samples to this integrated system. [Cancer Res 2007;67(6):2544–51]
Data from Phosphorylation and Activation of Cell Division Cycle Associated 8 by Aurora Kinase B Plays a Significant Role in Human Lung Carcinogenesis
Authors: Hayama Satoshi , Daigo Yataro , Yamabuki Takumi , Hirata Daizaburo , Kato Tatsuya , Miyamoto Masaki , Ito Tomoo , Tsuchiya Eiju , Kondo Satoshi , Nakamura Yusuke
Published: March 2023

Abstract
Through genome-wide gene expression analysis of lung carcinomas, we detected in the great majority of lung cancer samples cotransactivation of cell division cycle associated 8 (CDCA8) and aurora kinase B (AURKB), which were considered to be components of the vertebrate chromosomal passenger complex. Immunohistochemical analysis of lung cancer tissue microarrays showed that overexpression of CDCA8 and AURKB was significantly associated with poor prognosis of lung cancer patients. AURKB directly phosphorylated CDCA8 at Ser154, Ser219, Ser275, and Thr278 and seemed to stabilize CDCA8 protein in cancer cells. Suppression of CDCA8 expression with small interfering RNA against CDCA8 significantly suppressed the growth of lung cancer cells. In addition, functional inhibition of interaction between CDCA8 and AURKB by a cell-permeable peptide corresponding to 20-amino acid sequence of a part of CDCA8 (11R-CDCA8261–280), which included two phosphorylation sites by AURKB, significantly reduced phosphorylation of CDCA8 and resulted in growth suppression of lung cancer cells. Our data imply that selective suppression of the CDCA8-AURKB pathway could be a promising therapeutic strategy for treatment of lung cancer patients. [Cancer Res 2007;67(9):4113–22]
Data from Relaxin-Expressing, Fiber Chimeric Oncolytic Adenovirus Prolongs Survival of Tumor-Bearing Mice
Authors: Ganesh Shanthi , Gonzalez Edick Melissa , Idamakanti Neeraja , Abramova Marina , VanRoey Melinda , Robinson Michael , Yun Chae-Ok , Jooss Karin
Published: March 2023

Abstract
Selective replication of oncolytic viruses in tumor cells provides a promising approach for the treatment of human cancers. One of the limitations observed with oncolytic viruses currently used in the treatment of solid tumors is the inefficient spread of virus throughout the tumor mass following intratumoral injection. Data are presented showing that oncolytic adenoviruses expressing the relaxin gene and containing an Ad5/Ad35 chimeric fiber showed significantly enhanced transduction and increased virus spread throughout the tumor when compared with non–relaxin-expressing, Ad5-based viruses. The increased spread of such viruses throughout tumors correlated well with improved antitumor efficacy and overall survival in two highly metastatic tumor models. Furthermore, nonreplicating viruses expressing relaxin did not increase metastases, suggesting that high level expression of relaxin will not enhance metastatic spread of tumors. In summary, the data show that relaxin may play a role in rearranging matrix components within tumors, which helps recombinant oncolytic adenoviruses to spread effectively throughout the tumor mass and thereby increase the extent of viral replication within the tumor. Expressing relaxin from Ad5/Ad35 fiber chimeric adenoviruses may prove a potent and novel approach to treating patients with cancer. [Cancer Res 2007;67(9):4399–406]
Data from Genetic Variation in the One-Carbon Transfer Pathway and Ovarian Cancer Risk
Authors: Kelemen Linda E. , Sellers Thomas A. , Schildkraut Joellen M. , Cunningham Julie M. , Vierkant Robert A. , Pankratz V. Shane , Fredericksen Zachary S. , Gadre Madhura K. , Rider David N. , Liebow Mark , Goode Ellen L.
Published: March 2023

Abstract
Dysfunction in enzymes involved in one-carbon (1-C) metabolism can lead to increased chromosomal strand breaking and abnormal methylation patterns, which are both associated with cancer risk. Availability of 1-C units may modify risk. We investigated the association of single-nucleotide polymorphisms (SNP) in 21 genes in the 1-C transfer pathway among 829 Caucasian cases with primary epithelial ovarian cancer and 941 frequency-matched unaffected controls enrolled at Mayo Clinic (Rochester, MN) and Duke University (Durham, NC) and examined risk modification by multivitamin supplement use. Multivariable-adjusted SNP-specific logistic regression and haplotype analyses were done for 180 SNPs and false positive report probabilities (FPRP) were calculated. Each copy of the minor allele in SHMT1 intron 5 A>G (rs9909104) was associated with epithelial ovarian cancer [odds ratio (OR), 1.2; 95% confidence interval (95% CI), 1.0–1.4; P trend = 0.02; FPRP = 0.16] and a 5-SNP SHMT1 haplotype was associated with decreased risk (P = 0.01; FPRP = 0.09). Three SNPs in DNMT3A were associated with risk among multivitamin supplement users: 3′ untranslated region (UTR) C>G (rs13420827: OR, 0.8; 95% CI, 0.6–1.0; P interaction = 0.006; FPRP = 0.54), intron 6 G>A (rs11887120: OR, 0.8; 95% CI, 0.7–1.0; P interaction = 0.007; FPRP = 0.57), and intron 22 A>T (rs11695471: OR, 1.2; 95% CI, 1.0–1.5; P interaction = 0.01; FPRP = 0.66). These data extend previous findings from other cancers of a role for SHMT1 in ovarian cancer, and provide evidence that SNPs in methylation and DNA synthesis reactions are associated with risk of ovarian cancer. Interventions with modifiable factors such as multivitamin intake may reduce risk. [Cancer Res 2008;68(7):2498–506]
Data from Aurora-A, a Negative Prognostic Marker, Increases Migration and Decreases Radiosensitivity in Cancer Cells
Authors: Guan Zhong , Wang Xian-ren , Zhu Xiao-feng , Huang Xue-fei , Xu Jie , Wang Li-hui , Wan Xiang-bo , Long Zi-jie , Liu Jian-nan , Feng Gong-kan , Huang Wenlin , Zeng Yi-xin , Chen Fu-jin , Liu Quentin
Published: March 2023

Abstract
Centrosomal Aurora-A (Aur-A) kinase ensures proper spindle assembly and accurate chromosome segregation in mitosis. Overexpression of Aur-A leads to centrosome amplification, aberrant spindle, and consequent genetic instability. In the present study, Aur-A was found to be overexpressed in laryngeal squamous cell carcinoma (LSCC). Moreover, Aur-A expression was adversely correlated with median survival, and further identified as a potential independent factor for disease prognosis. Suppression of Aurora kinase activity chemically or genetically led to LSCC Hep2 cell cycle arrest and apoptotic cell death. Importantly, we found that Aur-A increases cell migration and this novel function was correlated with Akt1 activation. The enhanced cell migration induced by Aur-A overexpression could be abrogated by either small-molecule Akt1 inhibitor or short interfering RNA. VX-680, a selective Aurora kinase inhibitor, decreased Akt1 phosphorylation at Ser473 and inhibited cell migration, but failed to do so in constitutive active Akt1 (myr-Akt1)–overexpressed cells. Moreover, our data suggested that overexpression of Aur-A kinase might also contribute to radioresistance of LSCC. Inhibiting Aur-A by VX-680 induced expression of p53 and potently sensitized cells to radiotherapy, leading to significant cell death. Ectopic overexpression of Aur-A, however, reduced p53 level and rendered cells more resistant to irradiation. Taken together, we showed that Aur-A kinase, a negative prognostic marker, promotes migration and reduces radiosensitivity in laryngeal cancer cells. [Cancer Res 2007;67(21):10436–44]
Data from Recombinant Immunoproapoptotic Proteins with Furin Site Can Translocate and Kill HER2-Positive Cancer Cells
Authors: Wang Tao , Zhao Jing , Ren Jun-Lin , Zhang Li , Wen Wei-Hong , Zhang Rui , Qin Wei-Wei , Jia Lin-Tao , Yao Li-Bo , Zhang Ying-Qi , Chen Si-Yi , Yang An-Gang
Published: March 2023

Abstract
We previously reported the selective killing of HER2-positive tumor cells by a class of immunoproapoptotic proteins containing single-chain antibody, translocation domain of Pseudomonas exotoxin A (domain II; PEA II), and constitutively active human apoptotic molecules. In this study, a novel class of antitumor immunoproapoptotic proteins was explored to mediate tumor-specific apoptosis both in vitro and in vivo. Three furin cleavage sequences, including a synthetic polyarginine tract, and two furin cleavable sequences from PEA and diphtheria toxin were respectively used to replace PEA II in the previously constructed immunoproapoptotic protein. When produced and secreted by the genetically modified Jurkat cells, the novel targeted proapoptotic proteins selectively bound to HER2, which is often overexpressed on tumor cell surface. Followed by receptor-mediated endocytosis and furin cleavage in the endosome, the recombinant proteins could translocate into the cytosol, leading to irreversible cell death. Moreover, delivery of these proteins by either i.m. plasmid injection or i.v. injection of plasmid-expressing Jurkat cells led to tumor regression and prolonged animal survival in a nude mouse xenograft tumor model, indicating in vivo antitumor activity of the recombinant proteins. We conclude that the new class of immunoproapoptotic proteins show comparable activity with PEA II–containing counterpart and provide an attractive therapeutic alternative as they contain much less exogenous fragments. [Cancer Res 2007;67(24):11830–39]
Data from Cyclooxygenase-2 Is a Target Gene of Rho GDP Dissociation Inhibitor β in Breast Cancer Cells
Authors: Schunke Dario , Span Paul , Ronneburg Henrike , Dittmer Angela , Vetter Martina , Holzhausen Hans-Jürgen , Kantelhardt Eva , Krenkel Sylke , Müller Volkmar , Sweep Fred C.G.J. , Thomssen Christoph , Dittmer Jürgen
Published: March 2023

Abstract
Rho GDP dissociation inhibitor β (Rho-GDIβ), an inhibitor of Rho GTPases, is primarily expressed by hematopoietic cells but is also found in epithelial cancer cells. Recently, we have identified Rho-GDIβ as a target of the transcription factor Ets1. Here, we show that, in breast cancer cells, Ets1 regulates Rho-GDIβ expression and binds to the upstream region of the Rho-GDIβ gene. Furthermore, in primary breast cancer, Rho-GDIβ is coexpressed with Ets1. Studying the function of Rho-GDIβ in breast cancer, we found that a Rho-GDIβ–specific small interfering RNA increased cellular migration but also decreased the expression of cyclooxygenase-2 (Cox-2) oncogene as shown by microarray, quantitative reverse transcription-PCR, and Western blot analyses. Further studies revealed that Rho-GDIβ regulates Cox-2 gene at least partly on the transcriptional level, most likely by activating nuclear factor of activated T cells 1 (NFAT-1). Vav-1, an interaction partner of Rho-GDIβ, was also found to interfere with Cox-2 expression and NFAT-1 cellular distribution, suggesting a cooperative action of Rho-GDIβ and Vav-1 on Cox-2 expression. To explore the importance of Rho-GDIβ for the survival of breast cancer patients, two cohorts, including 263 and 117 patients, were analyzed for clinical outcome in relation to Rho-GDIβ RNA and protein levels, respectively. Expression of Rho-GDIβ was not associated with either disease-free or overall survival in the two patient population. Our data suggest that the expression of Rho-GDIβ in breast cancer is neither beneficial nor disadvantageous to the patient. This may be the net effect of two opposing activities of Rho-GDIβ, one that suppresses tumor progression by inhibiting migration and the other that stimulates it by enhancing Cox-2 expression. [Cancer Res 2007;67(22):10694–702]
Data from Cell Division Cycle 25B Phosphatase Is Essential for Benzo(a)Pyrene-7,8-Diol-9,10-Epoxide–Induced Neoplastic Transformation
Authors: Srivastava Sanjay K. , Bansal Pallavi , Oguri Tetsuya , Lazo John S. , Singh Shivendra V.
Published: March 2023

Abstract
Cell division cycle 25B (Cdc25B) phosphatase controls entry into mitosis and regulates recovery from G2-M checkpoint-induced arrest. In the present study, we show that exposure of diploid mouse embryonic fibroblasts (MEF) to the ultimate carcinogen anti-benzo(a)pyrene (BP)-7,8-diol-9,10-epoxide (anti-BPDE) resulted in a concentration- and time-dependent increase in Cdc25B protein levels. Chronic exposure of wild-type (Cdc25B+/+) MEFs to anti-BPDE (0.1 μmol/L) caused neoplastic transformation characterized by colony formation in culture and tumor production in nude mice. In contrast, the Cdc25B null MEFs were resistant to anti-BPDE–induced transformation. Furthermore, a carcinogenic dose of the parent hydrocarbon (BP) increased Cdc25B protein levels in the target organ, lung. The biological importance of elevated Cdc25B levels was documented by the early reentry into mitosis of cells overexpressing ectopic Cdc25B levels even in the presence of DNA damage following anti-BPDE exposure, whereas control cells resumed only after DNA damage was repaired. We conclude that Cdc25B has an essential role in anti-BPDE–induced neoplastic transformation, including regulation of cell cycle resumption in the presence of DNA damage. [Cancer Res 2007;67(19):9150–7]
Data from Proteasome Inhibition Up-regulates p53 and Apoptosis-Inducing Factor in Chondrocytes Causing Severe Growth Retardation in Mice
Authors: Zaman Farasat , Menendez-Benito Victoria , Eriksson Emma , Chagin Andrei S. , Takigawa Masaharu , Fadeel Bengt , Dantuma Nico P. , Chrysis Dionisios , Sävendahl Lars
Published: March 2023

Abstract
Proteasome inhibitors (PI), a novel class of anticancer drugs, are relatively well tolerated and have recently been introduced into the clinic for the treatment of multiple myeloma. The tumor selectivity and low toxicity of PIs are surprising, given the crucial role of the ubiquitin/proteasome system in a multitude of cellular processes. Here, we show that systemic administration of PIs specifically impairs the ubiquitin/proteasome system in growth plate chondrocytes. Importantly, young mice displayed severe growth retardation during treatment as well as 45 days after the cessation of treatment with clinically relevant amounts of MG262 (0.2 μmol/kg body weight/injection) or bortezomib (1.0 mg/kg body weight/injection). Dysfunction of the ubiquitin/proteasome system was accompanied by the induction of apoptosis of stem-like and proliferative chondrocytes in the growth plate. These results were recapitulated in cultured fetal rat metatarsal bones and chondrocytic cell lines (rat, human). Apoptosis was associated with up-regulation of the proapoptotic molecules, p53 and apoptosis-inducing factor (AIF), both in vitro and in vivo. In addition to the observation that AIF is expressed in the growth plate, we also provide evidence that AIF serves as a direct target protein for ubiquitin, thus explaining its prominent up-regulation upon proteasome inhibition. Suppression of p53 or AIF expression with small interfering RNAs partly rescued chondrocytes from proteasome inhibition–induced apoptosis (35% and 41%, respectively). Our observations show that proteasome inhibition may selectively target essential cell populations in the growth plate causing significant growth failure. These findings could have important implications for the use of proteasome inhibitors in the treatment of childhood cancer. [Cancer Res 2007;67(20):10078–86]
Data from Genome-Wide Loss of Heterozygosity and Copy Number Analysis in Melanoma Using High-Density Single-Nucleotide Polymorphism Arrays
Authors: Stark Mitchell , Hayward Nicholas
Published: March 2023

Abstract
Although a number of genes related to melanoma development have been identified through candidate gene screening approaches, few studies have attempted to conduct such analyses on a genome-wide scale. Here we use Illumina 317K whole-genome single-nucleotide polymorphism arrays to define a comprehensive allelotype of melanoma based on loss of heterozygosity (LOH) and copy number changes in a panel of 76 melanoma cell lines. In keeping with previous reports, we found frequent LOH on chromosome arms 9p (72%), 10p (55%), 10q (55%), 9q (49%), 6q (43%), 11q (43%), and 17p (41%). Tumor suppressor genes (TSGs) can be identified through homozygous deletion (HD). We detected 174 HDs, the most common of which targeted CDKN2A (n = 33). The second highest frequency of HD occurred in PTEN (n = 8), another well known melanoma TSG. HDs were also common for PTPRD (n = 7) and HDAC4 (n = 3), TSGs recently found to be mutated or deleted in other cancer types. Analysis of other HDs and regions of LOH that we have identified might lead to the characterization of further melanoma TSGs. We noted 197 regional amplifications, including some centered on the melanoma oncogenes MITF (n = 9), NRAS (n = 3), BRAF (n = 3), and CCND1 (n = 3). Other amplifications potentially target novel oncogenes important in the development of a subset of melanomas. The numerous focal amplifications and HDs we have documented here are the first step toward identifying a comprehensive catalog of genes involved in melanoma development, some of which may be useful prognostic markers or targets for therapies to treat this disease. [Cancer Res 2007;67(6):2632–42]
Data from mTORC2 Activity Is Elevated in Gliomas and Promotes Growth and Cell Motility via Overexpression of Rictor
Authors: Masri Janine , Bernath Andrew , Martin Jheralyn , Jo Oak D. , Vartanian Raffi , Funk Alexander , Gera Joseph
Published: March 2023

Abstract
mTORC2 is a multimeric kinase composed of the mammalian target of rapamycin kinase (mTOR), mLST8, mSin1, and rictor. The complex is insensitive to acute rapamycin exposure and has shown functions in controlling cell growth and actin cytoskeletal assembly. mTORC2 has recently been shown to phosphorylate and activate Akt. Because ∼70% of gliomas harbor high levels of activated Akt, we investigated whether mTORC2 activity was elevated in gliomas. In this study, we found that mTORC2 activity was elevated in glioma cell lines as well as in primary tumor cells as compared with normal brain tissue (P < 0.05). Moreover, we found that rictor protein and mRNA levels were also elevated and correlated with increased mTORC2 activity. Overexpression of rictor in cell lines led to increased mTORC2 assembly and activity. These lines exhibited increased anchorage-independent growth in soft agar, increased S-phase cell cycle distribution, increased motility, and elevated integrin β1 and β3 expression. In contrast, small interfering RNA–mediated knockdown of rictor inhibited these oncogenic activities. Protein kinase Cα (PKCα) activity was shown to be elevated in rictor-overexpressing lines but reduced in rictor-knockdown clones, consistent with the known regulation of actin organization by mTORC2 via PKCα. Xenograft studies using these cell lines also supported a role for increased mTORC2 activity in tumorigenesis and enhanced tumor growth. In summary, these data suggest that mTORC2 is hyperactivated in gliomas and functions in promoting tumor cell proliferation and invasive potential due to increased complex formation as a result of the overexpression of rictor. [Cancer Res 2007;67(24):11712–20]
Data from TTI-237: A Novel Microtubule-Active Compound with In vivo Antitumor Activity
Authors: Beyer Carl F. , Zhang Nan , Hernandez Richard , Vitale Danielle , Lucas Judy , Nguyen Thai , Discafani Carolyn , Ayral-Kaloustian Semiramis , Gibbons James J.
Published: March 2023

Abstract
5-Chloro-6-[2,6-difluoro-4-[3-(methylamino)propoxy]phenyl]-N-[(1S)-2,2,2-trifluoro-1-methylethyl]-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine butanedioate (TTI-237) is a microtubule-active compound of novel structure and function. Structurally, it is one of a class of compounds, triazolo[1,5a]pyrimidines, previously not known to bind to tubulin. Functionally, TTI-237 inhibited the binding of [3H]vinblastine to tubulin, but it caused a marked increase in turbidity development that more closely resembled the effect observed with docetaxel than that observed with vincristine. The morphologic character of the presumptive polymer is unknown at present. When applied to cultured human tumor cells at concentrations near its IC50 value for cytotoxicity (34 nmol/L), TTI-237 induced multiple spindle poles and multinuclear cells, as did paclitaxel, but not vincristine or colchicine. Flow cytometry experiments revealed that, at low concentrations (20–40 nmol/L), TTI-237 produced sub-G1 nuclei and, at concentrations above 50 nmol/L, it caused a strong G2-M block. The compound was a weak substrate of multidrug resistance 1 (multidrug resistance transporter or P-glycoprotein). In a cell line expressing a high level of P-glycoprotein, the IC50 of TTI-237 increased 25-fold whereas those of paclitaxel and vincristine increased 806-fold and 925-fold, respectively. TTI-237 was not recognized by the MRP or MXR transporters. TTI-237 was active in vivo in several nude mouse xenograft models of human cancer, including LoVo human colon carcinoma and U87-MG human glioblastoma, when dosed i.v. or p.o. Thus, TTI-237 has a set of properties that distinguish it from other classes of microtubule-active compounds. [Cancer Res 2008;68(7):2292–300]
Data from Regression of Lung and Colon Cancer Xenografts by Depleting or Inhibiting RLIP76 (Ral-Binding Protein 1)
Authors: Singhal Sharad S. , Singhal Jyotsana , Yadav Sushma , Dwivedi Seema , Boor Paul J. , Awasthi Yogesh C. , Awasthi Sanjay
Published: March 2023

Abstract
Ral-binding protein 1 (RALBP1) is a stress-responsive and stress-protective multispecific transporter of glutathione conjugates (GS-E) and xenobiotic toxins. It is frequently overexpressed in malignant cells and plays a prominent antiapoptotic role selectively in cancer cells through its ability to control cellular concentration of proapoptotic oxidized lipid byproducts. In the absence of chemotherapy, depletion or inhibition of RALBP1 causes regression of syngeneic mouse B16 melanoma. Because RALBP1 transports anthracycline and Vinca alkaloid drugs, as well as GS-E, and because it confers resistance to these drugs, we proposed that depletion or inhibition of RALBP1 should cause regression of human solid tumors that overexpress RALBP1 and augment chemotherapy efficacy. Non–small-cell lung cancer (NSCLC) H358 and H520 and colon SW480 cell lines were used. Cytotoxic synergy between anti-RALBP1 immunoglobulin G (IgG), cis-diammine-dichloroplatinum (II) [CDDP], and vinorelbine was examined in cell culture and xenografts of NSCLC cells. Effects of RALBP1 depletion by antisense were examined in xenografts of NSCLC H358, NSCLC H520, and colon SW480 cells. RALBP1 depletion by phosphorothioate antisense was confirmed and was associated with rapid, complete, and sustained remissions in established s.c. human lung and colon xenografts. RALBP1 inhibition by anti-RALBP1 IgG was equally as effective as antisense and enhanced CDDP-vinorelbine in lung cancer xenografts. These studies show that RALBP1 is a transporter that serves as a key effector function in cancer cell survival and is a valid target for cancer therapy, and confirm that inhibitory modulation of RALBP1 transport activity at the cell surface is sufficient for antitumor effects. [Cancer Res 2007;67(9):–9] [Cancer Res 2007;67(9):4382–9]
Data from A Novel Bispecific, Trivalent Antibody Construct for Targeting Pancreatic Carcinoma
Authors: Gold David V. , Goldenberg David M. , Karacay Habibe , Rossi Edmund A. , Chang Chien-Hsing , Cardillo Thomas M. , McBride William J. , Sharkey Robert M.
Published: March 2023

Abstract
Preclinical and clinical studies have demonstrated the application of radiolabeled mAb-PAM4 for nuclear imaging and radioimmunotherapy of pancreatic carcinoma. We have now examined the ability of a novel PAM4-based, bispecific monoclonal antibody (mAb) construct, TF10, to pretarget a radiolabeled peptide for improved imaging and therapy. TF10 is a humanized, bispecific mAb, divalent for mAb-PAM4 and monovalent for mAb-679, reactive against the histamine-succinyl-glycine hapten. Biodistribution studies and nuclear imaging of the radiolabeled TF10 and/or TF10-pretargeted hapten-peptide (IMP-288) were conducted in nude mice bearing CaPan1 human pancreatic cancer xenografts. 125I-TF10 cleared rapidly from the blood, with levels decreasing to <1% injected dose per gram (ID/g) by 16 hours. Tumor uptake was 3.47 ± 0.66% ID/g at this time point with no accumulation in any normal tissue. To show the utility of the pretargeting approach, 111In-IMP-288 was administered 16 hours after TF10. At 3 hours postadministration of radiolabeled peptide, imaging showed intense uptake within the tumors and no evidence of accretion in any normal tissue. No targeting was observed in animals given only the 111In-peptide. Tumor uptake of the TF10-pretargeted 111In-IMP-288 was 24.3 ± 1.7% ID/g, whereas for 111In-IMP-288 alone it was only 0.12 ± 0.002% ID/g at 16 hours. Tumor/blood ratios were significantly greater for the pretargeting group (∼1,000:1 at 3 hours) compared with 111In-PAM4-IgG (∼5:1 at 24 hours; P < 0.0003). Radiation dose estimates suggested that TF10/90Y-peptide pretargeting would provide a greater antitumor effect than 90Y-PAM4-IgG. Thus, the results suggest that TF10 pretargeting may provide improved imaging for early detection, diagnosis, and treatment of pancreatic cancer as compared with directly radiolabeled PAM4-IgG. [Cancer Res 2008;68(12):4819–26]