bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Breast Cancer Lung Metastasis Requires Expression of Chemokine Receptor CCR4 and Regulatory T Cells
Authors: Olkhanud Purevdorj B. , Baatar Dolgor , Bodogai Monica , Hakim Fran , Gress Ronald , Anderson Robin L. , Deng Jie , Xu Mai , Briest Susanne , Biragyn Arya
Published: March 2024

Abstract
Cancer metastasis is a leading cause of cancer morbidity and mortality. More needs to be learned about mechanisms that control this process. In particular, the role of chemokine receptors in metastasis remains controversial. Here, using a highly metastatic breast cancer (4T1) model, we show that lung metastasis is a feature of only a proportion of the tumor cells that express CCR4. Moreover, the primary tumor growing in mammary pads activates remotely the expression of TARC/CCL17 and MDC/CCL22 in the lungs. These chemokines acting through CCR4 attract both tumor and immune cells. However, CCR4-mediated chemotaxis was not sufficient to produce metastasis, as tumor cells in the lung were efficiently eliminated by natural killer (NK) cells. Lung metastasis required CCR4+ regulatory T cells (Treg), which directly killed NK cells using β-galactoside–binding protein. Thus, strategies that abrogate any part of this process should improve the outcome through activation of effector cells and prevention of tumor cell migration. We confirm this prediction by killing CCR4+ cells through delivery of TARC-fused toxins or depleting Tregs and preventing lung metastasis. [Cancer Res 2009;69(14):5996–6004]
Data from Tuberous Sclerosis Complex Suppression in Cerebellar Development and Medulloblastoma: Separate Regulation of Mammalian Target of Rapamycin Activity and p27Kip1 Localization
Authors: Bhatia Bobby , Northcott Paul A. , Hambardzumyan Dolores , Govindarajan Baskaran , Brat Daniel J. , Arbiser Jack L. , Holland Eric C. , Taylor Michael D. , Kenney Anna Marie
Published: March 2024

Abstract
During development, proliferation of cerebellar granule neuron precursors (CGNP), candidate cells-of-origin for the pediatric brain tumor medulloblastoma, requires signaling by Sonic hedgehog (Shh) and insulin-like growth factor (IGF), the pathways of which are also implicated in medulloblastoma. One of the consequences of IGF signaling is inactivation of the mammalian target of rapamycin (mTOR)–suppressing tuberous sclerosis complex (TSC), comprised of TSC1 and TSC2, leading to increased mRNA translation. We show that mice, in which TSC function is impaired, display increased mTOR pathway activation, enhanced CGNP proliferation, glycogen synthase kinase-3α/β (GSK-3α/β) inactivation, and cytoplasmic localization of the cyclin-dependent kinase inhibitor p27Kip1, which has been proposed to cause its inactivation or gain of oncogenic functions. We observed the same characteristics in wild-type primary cultures of CGNPs in which TSC1 and/or TSC2 were knocked down, and in mouse medulloblastomas induced by ectopic Shh pathway activation. Moreover, Shh-induced mouse medulloblastomas manifested Akt-mediated TSC2 inactivation, and the mutant TSC2 allele synergized with aberrant Shh signaling to increase medulloblastoma incidence in mice. Driving exogenous TSC2 expression in Shh-induced medulloblastoma cells corrected p27Kip1 localization and reduced proliferation. GSK-3α/β inactivation in the tumors in vivo and in primary CGNP cultures was mTOR-dependent, whereas p27Kip1 cytoplasmic localization was regulated upstream of mTOR by TSC2. These results indicate that a balance between Shh mitogenic signaling and TSC function regulating new protein synthesis and cyclin-dependent kinase inhibition is essential for the normal development and prevention of tumor formation or expansion. [Cancer Res 2009;69(18):7224–34]
Data from Regulation of HSulf-1 Expression by Variant Hepatic Nuclear Factor 1 in Ovarian Cancer
Authors: Liu Peng , Khurana Ashwani , Rattan Ramandeep , He Xiaoping , Kalloger Steve , Dowdy Sean , Gilks Blake , Shridhar Viji
Published: March 2024

Abstract
We recently identified HSulf-1 as a down-regulated gene in ovarian carcinomas. Our previous analysis indicated that HSulf-1 inactivation in ovarian cancers is partly mediated by loss of heterozygosity and epigenetic silencing. Here, we show that variant hepatic nuclear factor 1 (vHNF1), encoded by transcription factor 2 gene (TCF2, HNF1β), negatively regulates HSulf-1 expression in ovarian cancer. Immunoblot assay revealed that vHNF1 is highly expressed in HSulf-1–deficient OV207, SKOV3, and TOV-21G cell lines but not in HSulf-1–expressing OSE, OV167, and OV202 cells. By short hairpin RNA–mediated down-regulation of vHNF1 in TOV-21G cells and transient enhanced vHNF1 expression in OV202 cells, we showed that vHNF1 suppresses HSulf-1 expression in ovarian cancer cell lines. Reporter assay and chromatin immunoprecipitation experiments showed that vHNF1 is specifically recruited to HSulf-1 promoter at two different vHNF1-responsive elements in OV207 and TOV-21G cells. Additionally, down-regulation of vHNF1 expression in OV207 and TOV-21G cells increased cisplatin- or paclitaxel-mediated cytotoxicity as determined by both 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and clonogenic assays and this effect was reversed by down-regulation of HSulf-1. Moreover, nude mice bearing TOV-21G cell xenografts with stably down-regulated vHNF1 were more sensitive to cisplatin- or paclitaxel-induced cytotoxicity compared with xenografts of TOV-21G clonal lines with nontargeted control short hairpin RNA. Finally, immunohistochemical analysis of 501 ovarian tumors including 140 clear-cell tumors on tissue microarrays showed that vHNF1 inversely correlates to HSulf-1 expression. Collectively, these results indicate that vHNF1 acts as a repressor of HSulf-1 expression and might be a molecular target for ovarian cancer therapy. [Cancer Res 2009;69(11):4843–50]
Data from p38δ Mitogen-Activated Protein Kinase Is Essential for Skin Tumor Development in Mice
Authors: Schindler Eva M. , Hindes Anna , Gribben Erin L. , Burns Carole J. , Yin Yan , Lin Meei-Hua , Owen Robert J. , Longmore Gregory D. , Kissling Grace E. , Arthur J. Simon C. , Efimova Tatiana
Published: March 2024

Abstract
Activating Ras mutations occur in a large portion of human tumors. Yet, the signaling pathways involved in Ras-induced tumor formation remain incompletely understood. The mitogen-activated protein kinase pathways are among the best studied Ras effector pathways. The p38 mitogen-activated protein kinase isoforms are important regulators of key biological processes including cell proliferation, differentiation, survival, inflammation, senescence, and tumorigenesis. However, the specific in vivo contribution of individual p38 isoforms to skin tumor development has not been elucidated. Recent studies have shown that p38δ, a p38 family member, functions as an important regulator of epidermal keratinocyte differentiation and survival. In the present study, we have assessed the effect of p38δ deficiency on skin tumor development in vivo by subjecting p38δ knockout mice to a two-stage 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate chemical skin carcinogenesis protocol. We report that mice lacking p38δ gene exhibited a marked resistance to development of 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin papillomas, with increased latency and greatly reduced incidence, multiplicity, and size of tumors compared with wild-type mice. Our data suggest that the underlying mechanism for reduced susceptibility to skin carcinogenesis in p38δ-null mice involves a defect in proliferative response associated with aberrant signaling through the two major transformation-promoting pathways: extracellular signal-regulated kinase 1/2-activator protein 1 and signal transducer and activator of transcription 3. These findings strongly suggest an in vivo role for p38δ in promoting cell proliferation and tumor development in epidermis and may have therapeutic implication for skin cancer. [Cancer Res 2009;69(11):4648–55]
Data from MYC Activity Mitigates Response to Rapamycin in Prostate Cancer through Eukaryotic Initiation Factor 4E–Binding Protein 1–Mediated Inhibition of Autophagy
Authors: Balakumaran Bala S. , Porrello Alessandro , Hsu David S. , Glover Wayne , Foye Adam , Leung Janet Y. , Sullivan Beth A. , Hahn William C. , Loda Massimo , Febbo Phillip G.
Published: March 2024

Abstract
Loss of PTEN and activation of phosphoinositide 3-kinase are commonly observed in advanced prostate cancer. Inhibition of mammalian target of rapamycin (mTOR), a downstream target of phosphoinositide 3-kinase signaling, results in cell cycle arrest and apoptosis in multiple in vitro and in vivo models of prostate cancer. However, single-agent use of mTOR inhibition has limited clinical success, and the identification of molecular events mitigating tumor response to mTOR inhibition remains a critical question. Here, using genetically engineered human prostate epithelial cells (PrEC), we show that MYC, a frequent target of genetic gain in prostate cancers, abrogates sensitivity to rapamycin by decreasing rapamycin-induced cytostasis and autophagy. Analysis of MYC and the mTOR pathway in human prostate tumors and PrEC showed selective increased expression of eukaryotic initiation factor 4E–binding protein 1 (4EBP1) with gain in MYC copy number or forced MYC expression, respectively. We have also found that MYC binds to regulatory regions of the 4EBP1 gene. Suppression of 4EBP1 expression resulted in resensitization of MYC-expressing PrEC to rapamycin and increased autophagy. Taken together, our findings suggest that MYC expression abrogates sensitivity to rapamycin through increased expression of 4EBP1 and reduced autophagy. [Cancer Res 2009;69(19):7803–10]
Data from Cytogenetic and cDNA Microarray Expression Analysis of MCF10 Human Breast Cancer Progression Cell Lines
Authors: Marella Narasimharao V. , Malyavantham Kishore S. , Wang Jianmin , Matsui Sei-ichi , Liang Ping , Berezney Ronald
Published: March 2024

Abstract
We used a combination of spectral karyotyping, array comparative genomic hybridization, and cDNA microarrays to gain insights into the structural and functional changes of the genome in the MCF10 human breast cancer progression model cell lines. Spectral karyotyping data showed several chromosomal aberrations and array comparative genomic hybridization analysis identified numerous genomic gains and losses that might be involved in the progression toward cancer. Analysis of the expression levels of genes located within these genomic regions revealed a lack of correlation between chromosomal gains and losses and corresponding up-regulation or down-regulation for the majority of the ∼1,000 genes analyzed in this study. We conclude that other mechanisms of gene regulation that are not directly related to chromosomal gains and losses play a major role in breast cancer progression. [Cancer Res 2009;69(14):5946–53]
Data from The G Protein–Coupled Receptor 87 Is Necessary for p53-Dependent Cell Survival in Response to Genotoxic Stress
Authors: Zhang Yanhong , Qian Yingjuan , Lu Wenfu , Chen Xinbin
Published: March 2024

Abstract
p53 regulates an array of target genes, which mediates p53 tumor suppression by inducing cell cycle arrest, apoptosis, and cell survival. G protein–coupled receptors belong to a superfamily of cell surface molecules and are known to regulate cell proliferation, migration, and survival. Here, we found that G protein–coupled receptor 87 (GPR87) was up-regulated by p53 and by DNA damage in a p53-dependent manner. We also found that p53 directly regulated GPR87 potentially via a p53-responsive element in the GPR87 gene. To investigate the role of GPR87 in the p53 pathway, we generated multiple RKO and MCF7 cell lines in that GPR87 can be inducibly overexpressed or knocked down by a tetracycline-inducible system. We found that overexpression of GPR87 had little effect on cell growth. However, GPR87 knockdown sensitized cancer cells to DNA damage–induced growth suppression via enhanced p53 stabilization and activation. Importantly, the prosurvival activity of GPR87 can be reversed by knockdown of p53. Together, our results suggested that GPR87 is essential for p53-dependent cell survival in response to DNA damage. Thus, due to its expression on the cell surface and its role in cell survival, GPR87 may be explored as a novel therapeutic target for cancer treatment and prevention. [Cancer Res 2009;69(15):6049–56]
Data from HOXA13 Promotes Cancer Cell Growth and Predicts Poor Survival of Patients with Esophageal Squamous Cell Carcinoma
Authors: Gu Zhen-Dong , Shen Lu-Yan , Wang Hua , Chen Xiao-Mei , Li Yong , Ning Tao , Chen Ke-Neng
Published: March 2024

Abstract
Homeobox genes are known to be classic examples of the intimate relationship between embryogenesis and tumorigenesis. Here, we investigated whether inhibition of HOXA13, a member of the homeobox genes, was sufficient to affect the proliferation of esophageal cancer cells in vitro and in vivo, and studied the association between HOXA13 expression and survival of patients with esophageal squamous cell carcinoma (ESCC). HOXA13 expression was permanently knocked down using an RNA interference technique, and cell strain with stable knockdown of HOXA13 protein was established. Colony formation assay showed that the number of colonies in HOXA13 protein–deficient cells was significantly less than that of control cells (P < 0.01). Tumor growth in nude mice showed that the weight and volume of tumors from the HOXA13 knockdown cells was significantly less than that from the control cells (P < 0.01). Then, HOXA13 expression in ESCC specimens and paired noncancerous mucosa was detected by immunohistochemistry, and overexpression of HOXA13 was found to be more pronounced in ESCCs than paired noncancerous mucosa (P < 0.05). Furthermore, the association of HOXA13 expression and disease-free survival time was analyzed in 155 ESCC cases. The median survival time of patients expressing HOXA13 was significantly shorter than HOXA13-negative patients (P = 0.0006). Multivariate analysis indicated that tumor-node-metastasis (TNM) stage and HOXA13 expression were independent predictors of disease-free survival time of patients with ESCC. Our results showed that HOXA13 expression enhanced tumor growth in vitro and in vivo, and was a negative independent predictor of disease-free survival of patients with ESCC. [Cancer Res 2009;69(12):4969–73]
Data from A Multicenter, Double-Blinded Validation Study of Methylation Biomarkers for Progression Prediction in Barrett's Esophagus
Authors: Jin Zhe , Cheng Yulan , Gu Wen , Zheng Yingye , Sato Fumiaki , Mori Yuriko , Olaru Alexandru V. , Paun Bogdan C. , Yang Jian , Kan Takatsugu , Ito Tetsuo , Hamilton James P. , Selaru Florin M. , Agarwal Rachana , David Stefan , Abraham John M. , Wolfsen Herbert C. , Wallace Michael B. , Shaheen Nicholas J. , Washington Kay , Wang Jean , Canto Marcia Irene , Bhattacharyya Achyut , Nelson Mark A. , Wagner Paul D. , Romero Yvonne , Wang Kenneth K. , Feng Ziding , Sampliner Richard E. , Meltzer Stephen J.
Published: March 2024

Abstract
Esophageal adenocarcinoma risk in Barrett's esophagus (BE) is increased 30- to 125-fold versus the general population. Among all BE patients, however, neoplastic progression occurs only once per 200 patient-years. Molecular biomarkers are therefore needed to risk-stratify patients for more efficient surveillance endoscopy and to improve the early detection of progression. We therefore performed a retrospective, multicenter, double-blinded validation study of eight BE progression prediction methylation biomarkers. Progression or nonprogression were determined at 2 years (tier 1) and 4 years (tier 2). Methylation was assayed in 145 nonprogressors and 50 progressors using real-time quantitative methylation-specific PCR. Progressors were significantly older than nonprogressors (70.6 versus 62.5 years; P < 0.001). We evaluated a linear combination of the eight markers, using coefficients from a multivariate logistic regression analysis. Areas under the ROC curve (AUC) were high in the 2-year, 4-year, and combined data models (0.843, 0.829, and 0.840; P < 0.001, <0.001, and <0.001, respectively). In addition, even after rigorous overfitting correction, the incremental AUCs contributed by panels based on the 8 markers plus age versus age alone were substantial (Δ-AUC = 0.152, 0.114, and 0.118, respectively) in all 3 models. A methylation biomarker–based panel to predict neoplastic progression in BE has potential clinical value in improving both the efficiency of surveillance endoscopy and the early detection of neoplasia. [Cancer Res 2009;69(10):4112–5]
Data from Epigenetic Inactivation of the Circadian Clock Gene BMAL1 in Hematologic Malignancies
Authors: Taniguchi Hiroaki , Fernández Agustin F. , Setién Fernando , Ropero Santiago , Ballestar Esteban , Villanueva Alberto , Yamamoto Hiroyuki , Imai Kohzoh , Shinomura Yasuhisa , Esteller Manel
Published: March 2024

Abstract
Disruption of circadian rhythms, daily oscillations in biological processes that are regulated by an endogenous clock, has been linked to tumorigenesis. Normal and malignant tissues often show asynchronies in cell proliferation and metabolic rhythms. Cancer chronotherapy takes biological time into account to improve the therapy. However, alterations of the circadian clock machinery genes have rarely been reported in human cancer. Herein, we show that the BMAL1 gene, a core component of the circadian clock, is transcriptionally silenced by promoter CpG island hypermethylation in hematologic malignancies, such as diffuse large B-cell lymphoma and acute lymphocytic and myeloid leukemias. We also describe how BMAL1 reintroduction in hypermethylated leukemia/lymphoma cells causes growth inhibition in colony assays and nude mice, whereas BMAL1 depletion by RNA interference in unmethylated cells enhances tumor growth. We also show that BMAL1 epigenetic inactivation impairs the characteristic circadian clock expression pattern of genes such as C-MYC, catalase, and p300 in association with a loss of BMAL1 occupancy in their respective promoters. Furthermore, the DNA hypermethylation–associated loss of BMAL1 also prevents the recruitment of its natural partner, the CLOCK protein, to their common targets, further enhancing the perturbed circadian rhythm of the malignant cells. These findings suggest that BMAL1 epigenetic inactivation contributes to the development of hematologic malignancies by disrupting the cellular circadian clock. [Cancer Res 2009;69(21):8447–54]
Data from Genetic Alterations in the Phosphoinositide 3-Kinase/Akt Signaling Pathway Confer Sensitivity of Thyroid Cancer Cells to Therapeutic Targeting of Akt and Mammalian Target of Rapamycin
Authors: Liu Dingxie , Hou Peng , Liu Zhi , Wu Guojun , Xing Mingzhao
Published: March 2024

Abstract
We investigated the genotype-dependent therapeutic potential of targeting the phosphoinositide 3-kinase (PI3K)/Akt pathway for thyroid cancer. Proliferation of TPC1, Hth7, FTC133, OCUT1, K1, and BCPAP cells that harbored PI3K/Akt-activating genetic alterations was potently inhibited by the Akt inhibitor perifosine, whereas SW1736, Hth74, WRO, KAT18, and TAD2 cells that harbored no genetic alterations had no or only modest responses. Inhibition of Akt phosphorylation by perifosine was seen in these cells. Genetic-dependent apoptosis was induced by perifosine in cells selectively tested. Similarly, potent inhibition of cell proliferation by the mammalian target of rapamycin (mTOR) inhibitor temsirolimus occurred in virtually all the cells harboring genetic alterations, whereas modest inhibition was seen in some of the cells not harboring genetic alterations. Temsirolimus inhibited the phosphorylation of p70S6K, a substrate of mTOR. Knockdown of Akt1/2 or mTOR by shRNA approach inhibited the proliferation and colony formation of FTC133 and OCUT1 cells that harbored genetic alterations in the PI3K/Akt pathway but had no effect on SW1736 and KAT18 cells that did not. Transfection with PIK3CA mutants greatly sensitized SW1736 cells to perifosine and temsirolimus. Growth of xenograft tumors derived from FTC133 cells but not SW1736 cells in nude mice was dramatically inhibited by perifosine. Thus, this work for the first time shows that genetic alterations in the PI3K/Akt pathway confer thyroid cancer cells addiction to this pathway and their sensitivity to inhibition by targeting Akt and mTOR. This genotype-based targeting of the PI3K/Akt pathway using Akt and mTOR inhibitors may offer an effective therapeutic strategy for thyroid cancer and warrants further studies. [Cancer Res 2009;69(18):7311–9]
Data from Kupffer Cell Suppression of CD8+ T Cells in Human Hepatocellular Carcinoma Is Mediated by B7-H1/Programmed Death-1 Interactions
Authors: Wu Ke , Kryczek Ilona , Chen Lieping , Zou Weiping , Welling Theodore H.
Published: March 2024

Abstract
B7-H1 is a recently identified B7 family member that, along with one of its receptors, programmed death-1 (PD-1), has been involved in multiple immunopathologic scenarios. However, the nature of B7-H1 and PD-1 in human hepatocellular carcinoma (HCC) remains poorly defined. We investigated the expression and functional relevance of this pathway in patients with HCC. We showed that B7-H1 expression on Kupffer cells (KC) was increased in tumor tissues compared with surrounding nontumor liver tissues in patients with HCC and this correlated with poorer survival. Coculture of HCC cells with monocytes showed that tumor-associated interleukin-10 contributed to the induction of B7-H1 in the HCC environment. We further observed that the levels of PD-1+CD8+ T cells were higher in tumor tissues than in nontumor tissues. B7-H1+ KCs and PD-1+ T cells were colocalized in the HCC stroma. PD-1+CD8+ T cells had decreased proliferative ability and effector function as shown by reduced granule and cytokine expression compared with PD-1− T cells. Importantly, blocking KC B7-H1 interaction with PD-1+CD8+ cells using neutralizing antibodies recovered effector T-cell function. Our data indicate that the B7-H1/PD-1 axis contributes to immune suppression in human HCC, with blockade of this pathway carrying important therapeutic implications. [Cancer Res 2009;69(20):8067–75]
Data from Phosphorylation and Degradation of MdmX Is Inhibited by Wip1 Phosphatase in the DNA Damage Response
Authors: Zhang Xinna , Lin Lin , Guo Huarong , Yang Jianhua , Jones Stephen N. , Jochemsen Aart , Lu Xiongbin
Published: March 2024

Abstract
MdmX and Mdm2 regulate p53 tumor suppressor functions by controlling p53 transcriptional activity and/or stability in cells exposed to DNA damage. Accumulating evidence indicates that ATM-mediated phosphorylation and degradation of Mdm2 and MdmX may be the initial driving force that induces p53 activity during the early phase of the DNA damage response. We have recently determined that a novel protein phosphatase, Wip1 (or PPM1D), contributes to p53 regulation by dephosphorylating Mdm2 to close the p53 activation loop initiated by the ATM/ATR kinases. In the present study, we determine that Wip1 directly dephosphorylates MdmX at the ATM-targeted Ser403 and indirectly suppresses phosphorylation of MdmX at Ser342 and Ser367. Wip1 inhibits the DNA damage–induced ubiquitination and degradation of MdmX, leading to the stabilization of MdmX and reduction of p53 activities. Our data suggest that Wip1 is an important component in the ATM-p53-MdmX regulatory loop. [Cancer Res 2009;69(20):7960–8]
Data from Peptidyl-Prolyl Isomerase Pin1 Markedly Enhances the Oncogenic Activity of the Rel Proteins in the Nuclear Factor-κB Family
Authors: Fan Gaofeng , Fan Yongjun , Gupta Nupur , Matsuura Isao , Liu Fang , Zhou Xiao Zhen , Lu Kun Ping , Gélinas Céline
Published: March 2024

Abstract
The peptidyl-prolyl isomerase Pin1 is frequently up-regulated in human cancers in which Rel/nuclear factor-κB (NF-κB) is constitutively activated, but its role in these cancers remains to be determined, and evidence is still lacking to show that Pin1 contributes to cell transformation by Rel/NF-κB. Rel/NF-κB transcriptional and oncogenic activities are modulated by several posttranslational modifications and coregulatory proteins, and previous studies showed that cytokine treatment induces binding of Pin1 to the RelA subunit of NF-κB, thereby enhancing RelA nuclear localization and stability. Here we show that Pin1 associates with the Rel subunits of NF-κB that are implicated in leukemia/lymphomagenesis and modulates their transcriptional and oncogenic activities. Pin1 markedly enhanced transformation of primary lymphocytes by the human c-Rel protein and also increased cell transformation by the potent viral Rel/NF-κB oncoprotein v-Rel, in contrast to a Pin1 mutant in the WW domain involved in interaction with NF-κB. Pin1 promoted nuclear accumulation of Rel proteins in the absence of activating stimuli. Importantly, inhibition of Pin1 function with the pharmacologic inhibitor juglone or with Pin1-specific shRNA led to cytoplasmic relocalization of endogenous c-Rel in human lymphoma-derived cell lines, markedly interfered with lymphoma cell proliferation, and suppressed endogenous Rel/NF-κB–dependent gene expression. Together, these results show that Pin1 is an important regulator of Rel/NF-κB transforming activity and suggest that Pin1 may be a potential therapeutic target in Rel/NF-κB–dependent leukemia/lymphomas. [Cancer Res 2009;69(11):4589–97]
Data from Identification of Candidate Biomarkers of Therapeutic Response to Docetaxel by Proteomic Profiling
Authors: Zhao Liangli , Lee Brian Y. , Brown David A. , Molloy Mark P. , Marx Gavin M. , Pavlakis Nick , Boyer Michael J. , Stockler Martin R. , Kaplan Warren , Breit Samuel N. , Sutherland Robert L. , Henshall Susan M. , Horvath Lisa G.
Published: March 2024

Abstract
Docetaxel chemotherapy improves symptoms and survival in men with metastatic hormone-refractory prostate cancer (HRPC). However, ∼50% of patients do not respond to Docetaxel and are exposed to significant toxicity without direct benefit. This study aimed to identify novel therapeutic targets and predictive biomarkers of Docetaxel resistance in HRPC. We used iTRAQ-mass spectrometry analysis to identify proteins associated with the development of Docetaxel resistance using Docetaxel-sensitive PC3 cells and Docetaxel-resistant PC3-Rx cells developed by Docetaxel dose escalation. Functional validation experiments were performed using recombinant protein treatment and siRNA knockdown experiments. Serum/plasma levels of the targets in patient samples were measured by ELISA. The IC50 for Docetaxel in the PC3-Rx cells was 13-fold greater than the parent PC-3 cell line (P = 0.004). Protein profiling identified MIC-1 and AGR2 as respectively up-regulated and down-regulated in Docetaxel-resistant cells. PC-3 cells treated with recombinant MIC-1 also became resistant to Docetaxel (P = 0.03). Conversely, treating PC3-Rx cells with MIC-1 siRNA restored sensitivity to Docetaxel (P = 0.02). Knockdown of AGR2 expression in PC3 cells resulted in Docetaxel resistance (P = 0.007). Furthermore, increased serum/plasma levels of MIC-1 after cycle one of chemotherapy were associated with progression of the cancer (P = 0.006) and shorter survival after treatment (P = 0.002). These results suggest that both AGR2 and MIC-1 play a role in Docetaxel resistance in HRPC. In addition, an increase in serum/plasma MIC-1 level after cycle one of Docetaxel may be an indication to abandon further treatment. Further investigation of MIC-1 as a biomarker and therapeutic target for Docetaxel resistance in HRPC is warranted. [Cancer Res 2009;69(19):7696–7703]
Data from Fibulin-5 Suppresses Lung Cancer Invasion by Inhibiting Matrix Metalloproteinase-7 Expression
Authors: Yue Wen , Sun Quanhong , Landreneau Rodney , Wu Chuanyue , Siegfried Jill M. , Yu Jian , Zhang Lin
Published: March 2024

Abstract
The high mortality rate of lung cancer is largely due to the spread of disease to other organs. However, the molecular changes driving lung cancer invasion and metastasis remain unclear. In this study, we identified fibulin-5, a vascular ligand for integrin receptors, as a suppressor of lung cancer invasion and metastasis. Fibulin-5 was silenced by promoter hypermethylation in a majority of lung cancer cell lines and primary tumors. It inhibited lung cancer cell invasion and down-regulated matrix metalloproteinase-7 (MMP-7), which promoted lung cancer cell invasion. Knockdown of fibulin-5 was sufficient to stimulate cell invasion and MMP-7 expression. The expression levels of fibulin-5 and MMP-7 were inversely correlated in lung tumors. Suppression of MMP-7 expression by fibulin-5 was mediated by an integrin-binding RGD motif via the extracellular signal-regulated kinase (ERK) pathway. Furthermore, overexpression of fibulin-5 in H460 lung cancer cells inhibited metastasis in mice. Collectively, these results suggest that epigenetic silencing of fibulin-5 promotes lung cancer invasion and metastasis by activating MMP-7 expression through the ERK pathway. [Cancer Res 2009;69(15):6339–46]
Data from A Risk Variant in an miR-125b Binding Site in BMPR1B Is Associated with Breast Cancer Pathogenesis
Authors: Sætrom Pål , Biesinger Jacob , Li Sierra M. , Smith David , Thomas Laurent F. , Majzoub Karim , Rivas Guillermo E. , Alluin Jessica , Rossi John J. , Krontiris Theodore G. , Weitzel Jeffrey , Daly Mary B. , Benson Al B. , Kirkwood John M. , O'Dwyer Peter J. , Sutphen Rebecca , Stewart James A. , Johnson David , Larson Garrett P.
Published: March 2024

Abstract
MicroRNAs regulate diverse cellular processes and play an integral role in cancer pathogenesis. Genomic variation within miRNA target sites may therefore be important sources for genetic differences in cancer risk. To investigate this possibility, we mapped HapMap single nucleotide polymorphisms (SNP) to putative miRNA recognition sites within genes dysregulated in estrogen receptor–stratified breast tumors and used local linkage disequilibirum patterns to identify high-ranking SNPs in the Cancer Genetic Markers of Susceptibility (CGEMS) breast cancer genome-wide association study for further testing. Two SNPs, rs1970801 and rs11097457, scoring in the top 100 from the CGEMS study, were in strong linkage disequilibrium with rs1434536, an SNP that resides within a miR-125b target site in the 3′ untranslated region of the bone morphogenic receptor type 1B (BMPR1B) gene encoding a transmembrane serine/threonine kinase. We validated the CGEMS association findings for rs1970801 in an independent cohort of admixture-corrected cases identified from families with multiple case histories. Subsequent association testing of rs1434536 for these cases and CGEMS controls with imputed genotypes supported the association. Furthermore, luciferase reporter assays and overexpression of miR-125b–mimics combined with quantitative reverse transcription-PCR showed that BMPR1B transcript is a direct target of miR-125b and that miR-125b differentially regulates the C and T alleles of rs1434536. These results suggest that allele-specific regulation of BMPR1B by miR-125b explains the observed disease risk. Our approach is general and can help identify and explain the mechanisms behind disease association for alleles that affect miRNA regulation. [Cancer Res 2009;69(18):7459–65]
Data from c-Jun Protects Hypoxia-Inducible Factor-1α from Degradation via Its Oxygen-Dependent Degradation Domain in a Nontranscriptional Manner
Authors: Yu Bing , Miao Ze-Hong , Jiang Yi , Li Mei-Hong , Yang Na , Li Ting , Ding Jian
Published: March 2024

Abstract
Although hypoxia-inducible factor-1α (HIF-1α) has long been intensively investigated as a drug target by interfering with its expression or transcriptional function, the regulatory mechanisms of HIF-1α remain to be further clarified. We report here that c-Jun associates with HIF-1α via its oxygen-dependent degradation domain, masks the sites for ubiquitination, and thus protects HIF-1α from proteasome-executing degradation. All of these together resulted in the stabilization and accumulation of HIF-1α, consequently promoting the transcription of its target gene and driving angiogenesis-related events. The stabilization of HIF-1α was dependent on the domains of c-Jun for DNA binding and heterodimerization but independent of the Ser63/73 phosphorylation that is critical for transcriptional function. These findings highlight a previously unrecognized nontranscriptional function of c-Jun on the one hand and a distinct regulatory mechanism of HIF-1α activity on the other, consequently offering profound mechanistic insights into multiple events simultaneously involving both c-Jun and HIF-1α in tumor progression. [Cancer Res 2009;69(19):7704–12]
Data from MicroRNA-661, a c/EBPα Target, Inhibits Metastatic Tumor Antigen 1 and Regulates Its Functions
Authors: Reddy Sirigiri Divijendra Natha , Pakala Suresh B. , Ohshiro Kazufumi , Rayala Suresh K. , Kumar Rakesh
Published: March 2024

Abstract
MicroRNAs (miR) have been identified as posttranscriptional modifiers of target gene regulation and control the expression of gene products important in cancer progression. Here, we show that miR-661 inhibits the expression of metastatic tumor antigen 1 (MTA1), a widely up-regulated gene product in human cancer, by targeting the 3′ untranslated region (UTR) of MTA1 mRNA. We found that endogenous miR-661 expression was positively regulated by the c/EBPα transcription factor, which is down-regulated during cancer progression. c/EBPα directly interacted with the miR-661 chromatin and bound to miR-661 putative promoter that contains a c/EBPα-consensus motif. In addition, we found that the level of MTA1 protein was progressively up-regulated, whereas that of miR-661 and its activator, c/EBPα, were down-regulated in a breast cancer progression model consisting of MCF-10A cell lines whose phenotypes ranged from noninvasive to highly invasive. c/EBPα expression in breast cancer cells resulted in increased miR-661 expression and reduced MTA1 3′UTR-luciferase activity and MTA1 protein level. We also provide evidence that the introduction of miR-661 inhibited the motility, invasiveness, anchorage-independent growth, and tumorigenicity of invasive breast cancer cells. We believe our findings show for the first time that c/EBPα regulates the level of miR-661 and in turn modifies the functions of the miR661-MTA1 pathway in human cancer cells. Based on these findings, we suggest that miR-661 be further investigated for therapeutic use in down-regulating the expression of MTA1 in cancer cells. [Cancer Res 2009;69(14):5639–42]
Data from Proteasome Inhibition Potentiates Antitumor Effects of Photodynamic Therapy in Mice through Induction of Endoplasmic Reticulum Stress and Unfolded Protein Response
Authors: Szokalska Angelika , Makowski Marcin , Nowis Dominika , Wilczyński Grzegorz M. , Kujawa Marek , Wójcik Cezary , Młynarczuk-Biały Izabela , Salwa Pawel , Bil Jacek , Janowska Sylwia , Agostinis Patrizia , Verfaillie Tom , Bugajski Marek , Gietka Jan , Issat Tadeusz , Głodkowska Eliza , Mrówka Piotr , Stoklosa Tomasz , Hamblin Michael R. , Mróz Paweł , Jakóbisiak Marek , Golab Jakub
Published: March 2024

Abstract
Photodynamic therapy (PDT) is an approved therapeutic procedure that exerts cytotoxic activity toward tumor cells by inducing production of reactive oxygen species such as singlet oxygen. PDT leads to oxidative damage of cellular macromolecules, including proteins that undergo multiple modifications such as fragmentation, cross-linking, and carbonylation that result in protein unfolding and aggregation. Because the major mechanism for elimination of carbonylated proteins is their degradation by proteasomes, we hypothesized that a combination of PDT with proteasome inhibitors might lead to accumulation of carbonylated proteins in endoplasmic reticulum (ER), aggravated ER stress, and potentiated cytotoxicity toward tumor cells. We observed that Photofrin-mediated PDT leads to robust carbonylation of cellular proteins and induction of unfolded protein response. Pretreatment of tumor cells with three different proteasome inhibitors, including bortezomib, MG132, and PSI, gave increased accumulation of carbonylated and ubiquitinated proteins in PDT-treated cells. Proteasome inhibitors effectively sensitized tumor cells of murine (EMT6 and C-26) as well as human (HeLa) origin to PDT-mediated cytotoxicity. Significant retardation of tumor growth with 60% to 100% complete responses was observed in vivo in two different murine tumor models (EMT6 and C-26) when PDT was combined with either bortezomib or PSI. Altogether, these observations indicate that combination of PDT with proteasome inhibitors leads to potentiated antitumor effects. The results of these studies are of immediate clinical application because bortezomib is a clinically approved drug that undergoes extensive clinical evaluations for the treatment of solid tumors. [Cancer Res 2009;69(10):4235–43]
Data from Kinome Profiling in Pediatric Brain Tumors as a New Approach for Target Discovery
Authors: Sikkema Arend H. , Diks Sander H. , den Dunnen Wilfred F.A. , ter Elst Arja , Scherpen Frank J.G. , Hoving Eelco W. , Ruijtenbeek Rob , Boender Piet J. , de Wijn Rik , Kamps Willem A. , Peppelenbosch Maikel P. , de Bont Eveline S.J.M.
Published: March 2024

Abstract
Progression in pediatric brain tumor growth is thought to be the net result of signaling through various protein kinase-mediated networks driving cell proliferation. Defining new targets for treatment of human malignancies, without a priori knowledge on aberrant cell signaling activity, remains exceedingly complicated. Here, we introduce kinome profiling using flow-through peptide microarrays as a new concept for target discovery. Comprehensive tyrosine kinase activity profiles were identified in 29 pediatric brain tumors using the PamChip kinome profiling system. Previously reported activity of epidermal growth factor receptor, c-Met, and vascular endothelial growth factor receptor in pediatric brain tumors could be appreciated in our array results. Peptides corresponding with phosphorylation consensus sequences for Src family kinases showed remarkably high levels of phosphorylation compared with normal tissue types. Src activity was confirmed applying Phos-Tag SDS-PAGE. Furthermore, the Src family kinase inhibitors PP1 and dasatinib induced substantial tumor cell death in nine pediatric brain tumor cell lines but not in control cell lines. Thus, this study describes a new high-throughput technique to generate clinically relevant tyrosine kinase activity profiles as has been shown here for pediatric brain tumors. In the era of a rapidly increasing number of small-molecule inhibitors, this approach will enable us to rapidly identify new potential targets in a broad range of human malignancies. [Cancer Res 2009;69(14):5987–95]
Data from Activating Transcription Factor 2 and c-Jun–Mediated Induction of FoxP3 for Experimental Therapy of Mammary Tumor in the Mouse
Authors: Liu Yan , Wang Yin , Li Weiquan , Zheng Pan , Liu Yang
Published: March 2024

Abstract
FOXP3 is inactivated in breast cancer cells by a number of mechanisms, including somatic mutations, deletion, and epigenetic silencing. Because the mutation and deletion are usually heterozygous in the cancer samples, it is of interest to determine whether the gene can be induced for the purpose of cancer therapy. Here, we report that anisomycin, a potent activator of activating transcription factor (ATF) 2, and c-Jun-NH2-kinase, induces expression of FoxP3 in both normal and malignant mammary epithelial cells. The induction is mediated by ATF2 and c-Jun. Targeted mutation of ATF2 abrogates both constitutive and inducible expression of FoxP3 in normal epithelial cells. Both ATF2 and c-Jun interact with a novel enhancer in the intron 1 of the FoxP3 locus. Moreover, shRNA silencing of ATF2 and FoxP3 reveals an important role of ATF2-FoxP3 pathway in the anisomycin-induced apoptosis of breast cancer cells. A low dose of anisomycin was also remarkably effective in treating established mammary tumor in the mice. Our data showed that FoxP3 can be reactivated for cancer therapy. [Cancer Res 2009;69(14):5954–60]
Data from Tumor Necrosis Factor-α and Interleukin-1 Antagonists Alleviate Inflammatory Skin Changes Associated with Epidermal Growth Factor Receptor Antibody Therapy in Mice
Authors: Surguladze David , Deevi Dhanvanthri , Claros Nidia , Corcoran Erik , Wang Su , Plym Mary Jane , Wu Yan , Doody Jacqueline , Mauro David J. , Witte Larry , Busam Klaus J. , Pytowski Bronek , Rodeck Ulrich , Tonra James R.
Published: March 2024

Abstract
Cancer patients receiving epidermal growth factor receptor (EGFR) antibody therapy often experience an acneiform rash of uncertain etiology in skin regions rich in pilosebaceous units. Currently, this condition is treated symptomatically with very limited, often anecdotal success. Here, we show that a monoclonal antibody targeting murine EGFR, ME1, caused a neutrophil-rich hair follicle inflammation in mice, similar to that reported in patients. This effect was preceded by the appearance of lipid-filled hair follicle distensions adjacent to enlarged sebaceous glands. The cytokine tumor necrosis factor-α (TNFα), localized immunohistochemically to this affected region of the pilosebaceous unit, was specifically up-regulated by ME1 in skin but not in other tissues examined. Moreover, skin inflammation was reduced by cotreatment with the TNFα signaling inhibitor, etanercept, indicating the involvement of TNFα in this inflammatory process. Interleukin-1, a cytokine that frequently acts in concert with TNFα, is also involved in this process given the efficacy of the interleukin-1 antagonist Kineret. Our results provide a mechanistic framework to develop evidence-based trials for EGFR antibody–induced skin rash in patients with cancer. [Cancer Res 2009;69(14):5643–7]
Data from Angiopoietin-1 Overexpression Modulates Vascular Endothelium to Facilitate Tumor Cell Dissemination and Metastasis Establishment
Authors: Holopainen Tanja , Huang Huilian , Chen Caiping , Kim Kyung Eun , Zhang Luqing , Zhou Fei , Han Wencan , Li Chaojun , Yu Jun , Wu Jun , Koh Gou Young , Alitalo Kari , He Yulong
Published: March 2024

Abstract
The angiopoietin-1 (Ang1)/Tie2 signaling pathway is known to play an important role in the regulation of vascular maturation and maintenance of vessel integrity. In this study, we have investigated the effect of systemic Tie2 activation or inhibition on tumor growth and metastasis. We found that treatment with Ang1 delivered via an adenoviral vector promoted s.c. implanted tumor metastasis to the lungs. Ang1 treatment did not significantly increase vascular density in the tumors but induced enlargement of blood vessels in both the tumor and normal tissues, which increased tumor cell dissemination into the blood circulation. Ang1 also enhanced the formation of metastatic foci in the lungs when tumor cells were injected into the circulation via the tail vein. The effect of Ang1 on metastasis was validated by a simultaneous treatment with a soluble form of Tie2 (sTie2), which led to the suppression of Ang1-induced increase of tumor metastasis. Furthermore, using a highly metastatic tumor model, we confirmed that systemic treatment with sTie2 suppressed tumor metastasis to the lungs and lymph nodes, whereas tumor-associated angiogenesis and lymphangiogenesis were not significantly affected. This suggests that the Ang1/Tie2 signals contribute to tumor progression by increasing vascular entry and exit of tumor cells to facilitate tumor dissemination and establishment of metastases. [Cancer Res 2009;69(11):4656–64]
Data from Compartment-Specific Roles of ATP-Binding Cassette Transporters Define Differential Topotecan Distribution in Brain Parenchyma and Cerebrospinal Fluid
Authors: Shen Jun , Carcaboso Angel M. , Hubbard K. Elaine , Tagen Michael , Wynn Henry G. , Panetta John C. , Waters Christopher M. , Elmeliegy Mohamed A. , Stewart Clinton F.
Published: March 2024

Abstract
Topotecan is a substrate of the ATP-binding cassette transporters P-glycoprotein (P-gp/MDR1) and breast cancer resistance protein (BCRP). To define the role of these transporters in topotecan penetration into the ventricular cerebrospinal fluid (vCSF) and brain parenchymal extracellular fluid (ECF) compartments, we performed intracerebral microdialysis on transporter-deficient mice after an intravenous dose of topotecan (4 mg/kg). vCSF penetration of unbound topotecan lactone was measured as the ratio of vCSF-to-plasma area under the concentration-time curves. The mean ± SD ratios for wild-type, Mdr1a/b−/−, Bcrp1−/−, and Mdr1a/b−/−Bcrp1−/− mice were 3.07 ± 0.09, 2.57 ± 0.17, 1.63 ± 0.12, and 0.86 ± 0.05, respectively. In contrast, the ECF-to-plasma ratios for wild-type, Bcrp1−/−, and Mdr1a/b−/−Bcrp1−/− mice were 0.36 ± 0.06, 0.42 ± 0.06, and 0.88 ± 0.07. Topotecan lactone was below detectable limits in the ECF of Mdr1a/b−/− mice. When gefitinib (200 mg/kg) was preadministered to inhibit Bcrp1 and P-gp, the vCSF-to-plasma ratio decreased to 1.29 ± 0.09 in wild-type mice and increased to 1.13 ± 0.13 in Mdr1a/b−/−Bcrp1−/− mice, whereas the ECF-to-plasma ratio increased to 0.74 ± 0.14 in wild-type and 1.07 ± 0.03 in Mdr1a/b−/−Bcrp1−/− mice. Preferential active transport of topotecan lactone over topotecan carboxylate was shown in vivo by vCSF lactone-to-carboxylate area under the curve ratios for wild-type, Mdr1a/b−/−, Bcrp1−/−, and Mdr1a/b−/−Bcrp1−/− mice of 5.69 ± 0.83, 3.85 ± 0.64, 3.61 ± 0.46, and 0.78 ± 0.19, respectively. Our results suggest that Bcrp1 and P-gp transport topotecan into vCSF and out of brain parenchyma through the blood-brain barrier. These findings may help to improve pharmacologic strategies to treat brain tumors. [Cancer Res 2009;69(14):5885–92]
Data from Identification of Las2, a Major Modifier Gene Affecting the Pas1 Mouse Lung Tumor Susceptibility Locus
Authors: Liu Peng-Yuan , Vikis Haris , James Michael , Lu Yan , Wang Dao-Long , Liu Hong-Bo , Wen Wei-Dong , Wang Yian , You Ming
Published: March 2024

Abstract
Lung cancer is the leading cause of cancer death worldwide. Here, we describe a genome-wide association study of chemically induced lung tumorigenesis on 593 mice from 21 inbred strains using 115,904 genotyped and 1,952,918 imputed single nucleotide polymorphisms (SNPs). Using a genetic background–controlled genome search, we identified a novel lung tumor susceptibility gene Las2 (Lung adenoma susceptibility 2) on distal chromosome 18. Las2 showed strong association with resistance to tumor induction (rs30245983; P = 1.87 × 10−9) as well as epistatic interactions (P = 1.71 × 10−3) with the pulmonary adenoma susceptibility 1 locus, a major locus affecting mouse lung tumor development (rs13459098, P = 5.64 × 10−27). Sequencing analysis revealed four nonsynonymous SNPs and two insertions/deletions in the susceptible allele of Las2, resulting in the loss of tumor suppressor activities in both cell colony formation and nude mouse tumorigenicity assays. Deletion of LAS2 was observed in ∼40% of human lung adenocarcinomas, implying that loss of function of LAS2 may be a key step for lung tumorigenesis. [Cancer Res 2009;69(15):6290–8]