bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Par-4 Binds to Topoisomerase 1 and Attenuates Its DNA Relaxation Activity
Authors: Goswami Anindya , Qiu Shirley , Dexheimer Thomas S. , Ranganathan Padhma , Burikhanov Ravshan , Pommier Yves , Rangnekar Vivek M.
Published: March 2024

Abstract
The regulation of DNA relaxation by topoisomerase 1 (TOP1) is essential for DNA replication, transcription, and recombination events. TOP1 activity is elevated in cancer cells, yet the regulatory mechanism restraining its activity is not understood. We present evidence that the tumor suppressor protein prostate apoptosis response-4 (Par-4) directly binds to TOP1 and attenuates its DNA relaxation activity. Unlike camptothecin, which binds at the TOP1-DNA interface to form cleavage complexes, Par-4 interacts with TOP1 via its leucine zipper domain and sequesters TOP1 from the DNA. Par-4 knockdown by RNA interference enhances DNA relaxation and gene transcription activities and promotes cellular transformation in a TOP1-dependent manner. Conversely, attenuation of TOP1 activity either by RNA interference or Par-4 overexpression impedes DNA relaxation, cell cycle progression, and gene transcription activities and inhibits transformation. Collectively, our findings suggest that Par-4 serves as an intracellular repressor of TOP1 catalytic activity and regulates DNA topology to suppress cellular transformation. [Cancer Res 2008;68(15):6190–8]
Data from Focal Gains of VEGFA and Molecular Classification of Hepatocellular Carcinoma
Authors: Chiang Derek Y. , Villanueva Augusto , Hoshida Yujin , Peix Judit , Newell Philippa , Minguez Beatriz , LeBlanc Amanda C. , Donovan Diana J. , Thung Swan N. , Solé Manel , Tovar Victoria , Alsinet Clara , Ramos Alex H. , Barretina Jordi , Roayaie Sasan , Schwartz Myron , Waxman Samuel , Bruix Jordi , Mazzaferro Vincenzo , Ligon Azra H. , Najfeld Vesna , Friedman Scott L. , Sellers William R. , Meyerson Matthew , Llovet Josep M.
Published: March 2024

Abstract
Hepatocellular carcinomas represent the third leading cause of cancer-related deaths worldwide. The vast majority of cases arise in the context of chronic liver injury due to hepatitis B virus or hepatitis C virus infection. To identify genetic mechanisms of hepatocarcinogenesis, we characterized copy number alterations and gene expression profiles from the same set of tumors associated with hepatitis C virus. Most tumors harbored 1q gain, 8q gain, or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 of 103 tumors, 4 tumors harbored focal gains at 6p21 incorporating vascular endothelial growth factor A (VEGFA). Fluorescence in situ hybridization on an independent validation set of 210 tumors found 6p21 high-level gains in 14 tumors, as well as 2 tumors with 6p21 amplifications. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain in hepatocellular carcinomas suggested a novel, non–cell-autonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 of these tumors identified five classes, including “CTNNB1”, “proliferation”, “IFN-related”, a novel class defined by polysomy of chromosome 7, and an unannotated class. These class labels were further supported by molecular data; mutations in CTNNB1 were enriched in the “CTNNB1” class, whereas insulin-like growth factor I receptor and RPS6 phosphorylation were enriched in the “proliferation” class. The enrichment of signaling pathway alterations in gene expression classes provides insights on hepatocellular carcinoma pathogenesis. Furthermore, the prevalence of VEGFA high-level gains in multiple tumor types suggests indications for clinical trials of antiangiogenic therapies. [Cancer Res 2008;68(16):6779–88]
Data from Transforming Growth Factor-β1 and CD105 Promote the Migration of Hepatocellular Carcinoma–Derived Endothelium
Authors: Benetti Anna , Berenzi Angiola , Gambarotti Marco , Garrafa Emirena , Gelati Maurizio , Dessy Enrico , Portolani Nazario , Piardi Tullio , Giulini Stefano Maria , Caruso Arnaldo , Invernici Gloria , Parati Eugenio Agostino , Nicosia Roberto , Alessandri Giulio
Published: March 2024

Abstract
Hepatocellular carcinoma (HCC) is one of most malignant and aggressive human tumors. Transforming growth factor-β1 (TGF-β1) and its coreceptor CD105 have been shown to contribute to HCC malignant progression. TGF-β1 and CD105 have also been implicated in angiogenesis, but their role in the vascularization of HCC has not been investigated. To fill this gap, we studied the effect of TGF-β1 and CD105 on HCC-derived endothelium. By using immunomagnetic beads, we isolated and cultured endothelial cells (ECs) from HCC (HCC-EC) and adjacent nonneoplastic tissue (nNL-ECs) obtained from 24 liver biopsies. HCC and nNL biopsies were also analyzed by immunohistochemistry for the expression of CD105, TGF-β1, Ve-cadherin (Ve-cad), CD44, β-catenin, and E-cadherin. Compared with nNL-ECs, HCC-ECs had higher expression of CD105, enhanced spontaneous motility, and greater capacity to migrate in response to TGF-β1 (5 ng/mL), particularly in the presence of a fibronectin matrix. The chemotactic effect of TGF-β1 was blocked by anti-CD105 antibodies and correlated with the grade of HCC malignancy. Histologic examination of HCC biopsies showed that HCCs with the worse malignant features had the highest expression of TGF-β1, CD105, and angiogenic markers (Ve-cad and CD44). Because CD105 was highly expressed in microvessels at the tumor periphery and TGF-β1 staining was only found in neoplastic hepatocytes, we conclude that HCC-derived TGF-β1 may act as a chemoattractant for CD105-expressing ECs and as a promoter of tumor angiogenesis. Thus, drugs that selectively target the TGF-β1/CD105 axis may interfere with HCC-related angiogenesis and HCC progression. [Cancer Res 2008;68(20):8626–34]
Data from The Role of ATF4 Stabilization and Autophagy in Resistance of Breast Cancer Cells Treated with Bortezomib
Authors: Milani Manuela , Rzymski Tomasz , Mellor Howard R. , Pike Luke , Bottini Alberto , Generali Daniele , Harris Adrian L.
Published: March 2024

Abstract
The ubiquitin-proteasome system plays a key regulatory role in cellular homeostasis. The inhibition of the 26S proteasome by Bortezomib leads to the accumulation of misfolded proteins, resulting in endoplasmic reticulum stress followed by a coordinated cellular response called unfolded protein response (UPR). Endoplasmic reticulum stress is also a potent inducer of macroautophagy. Bortezomib is a selective and potent inhibitor of the 26S proteasome and is approved for the treatment of multiple myeloma. Clinical trials with Bortezomib have shown promising results for some types of cancers, but not for some others, including those of the breast. In this study, we show that Bortezomib induces the UPR and autophagy in MCF7 breast cancer cells. Surprisingly, Bortezomib did not induce phosphorylation of PERK, a key initial step of the UPR. We show that induction of autophagy by Bortezomib is dependent on the proteasomal stabilisation of ATF4 and up-regulation of LC3B by ATF4. We show that ATF4 and LC3B play a critical role in activating autophagy and protecting cells from Bortezomib-induced cell death. Our experiments also reveal that HDAC6 knockdown results in decreased LC3B protein and reduced autophagy. Our work shows that the induction of autophagy through ATF4 may be an important resistance mechanism to Bortezomib treatment in breast cancer, and targeting autophagy may represent a novel approach to sensitize breast cancers to Bortezomib. [Cancer Res 2009;69(10):4415–23]
Data from F14512, a Potent Antitumor Agent Targeting Topoisomerase II Vectored into Cancer Cells via the Polyamine Transport System
Authors: Barret Jean-Marc , Kruczynski Anna , Vispé Stéphane , Annereau Jean-Philippe , Brel Viviane , Guminski Yves , Delcros Jean-Guy , Lansiaux Amélie , Guilbaud Nicolas , Imbert Thierry , Bailly Christian
Published: March 2024

Abstract
The polyamine transport system (PTS) is an energy-dependent machinery frequently overactivated in cancer cells with a high demand for polyamines. We have exploited the PTS to selectively deliver a polyamine-containing drug to cancer cells. F14512 combines an epipodophyllotoxin core-targeting topoisomerase II with a spermine moiety introduced as a cell delivery vector. The polyamine tail supports three complementary functions: (a) facilitate formulation of a water-soluble compound, (b) increase DNA binding to reinforce topoisomerase II inhibition, and (c) facilitate selective uptake by tumor cells via the PTS. F14512 is 73-fold more cytotoxic to Chinese hamster ovary cells compared with CHO-MG cells with a reduced PTS activity. A decreased sensitivity of L1210 leukemia cells to F14512 was observed in the presence of putrescine, spermidine, and spermine. In parallel, the spermine moiety considerably enhances the drug-DNA interaction, leading to a reinforced inhibition of topoisomerase II. The spermine tail of F14512 serves as a cell delivery vehicle as well as a DNA anchor, and this property translates at the cellular level into a distinct pharmacologic profile. Twenty-nine human solid or hematologic cell lines were used to characterize the high cytotoxic potential of F14512 (median IC50 of 0.18 μmol/L). Finally, the potent antitumor activity of F14512 in vivo was evidenced with a MX1 human breast tumor xenograft model, with partial and complete tumor regressions. This work supports the clinical development of F14512 as a novel targeted cytotoxic drug and sheds light on the concept of selective delivery of drugs to tumor cells expressing the PTS. [Cancer Res 2008;68(23):9845–53]
Data from p53 Small-Molecule Inhibitor Enhances Temozolomide Cytotoxic Activity against Intracranial Glioblastoma Xenografts
Authors: Dinca Eduard B. , Lu Kan V. , Sarkaria Jann N. , Pieper Russell O. , Prados Michael D. , Haas-Kogan Daphne A. , VandenBerg Scott R. , Berger Mitchel S. , James C. David
Published: March 2024

Abstract
In this study, we investigated the precursor and active forms of a p53 small-molecule inhibitor for their effects on temozolomide (TMZ) antitumor activity against glioblastoma (GBM), using both in vitro and in vivo experimental approaches. Results from in vitro cell viability analysis showed that the cytotoxic activity of TMZ was substantially increased when p53 wild-type (p53wt) GBMs were cotreated with the active form of p53 inhibitor, and this heightened cytotoxic response was accompanied by increased poly(ADP-ribose) polymerase cleavage as well as elevated cellular phospho-H2AX. Analysis of the same series of GBMs, as intracranial xenografts in athymic mice, and administering corresponding p53 inhibitor precursor, which is converted to the active compound in vivo, yielded results consistent with the in vitro analyses: TMZ + p53 inhibitor precursor cotreatment of three distinct p53wt GBM xenografts resulted in significant enhancement of TMZ antitumor effect relative to treatment with TMZ alone, as indicated by serial bioluminescence monitoring as well as survival analysis (P < 0.001 for cotreatment survival benefit in each case). Mice receiving intracranial injection with p53null GBM showed similar survival benefit from TMZ treatment regardless of the presence or absence of p53 inhibitor precursor. In total, our results indicate that the p53 active and precursor inhibitor pair enhances TMZ cytotoxicity in vitro and in vivo, respectively, and do so in a p53-dependent manner. [Cancer Res 2008;68(24):10034–8]
Data from Enhancing Mammalian Target of Rapamycin (mTOR)–Targeted Cancer Therapy by Preventing mTOR/Raptor Inhibition-Initiated, mTOR/Rictor-Independent Akt Activation
Authors: Wang Xuerong , Yue Ping , Kim Young Ae , Fu Haian , Khuri Fadlo R. , Sun Shi-Yong
Published: March 2024

Abstract
It has been shown that mammalian target of rapamycin (mTOR) inhibitors activate Akt while inhibiting mTOR signaling. However, the underlying mechanisms and the effect of the Akt activation on mTOR-targeted cancer therapy are unclear. The present work focused on addressing the role of mTOR/rictor in mTOR inhibitor-induced Akt activation and the effect of sustained Akt activation on mTOR-targeted cancer therapy. Thus, we have shown that mTOR inhibitors increase Akt phosphorylation through a mechanism independent of mTOR/rictor because the assembly of mTOR/rictor was inhibited by mTOR inhibitors and the silencing of rictor did not abrogate mTOR inhibitor-induced Akt activation. Moreover, Akt activation during mTOR inhibition is tightly associated with development of cell resistance to mTOR inhibitors. Accordingly, cotargeting mTOR and phosphatidylinositol 3-kinase/Akt signaling prevents mTOR inhibition-initiated Akt activation and enhances antitumor effects both in cell cultures and in animal xenograft models, suggesting an effective cancer therapeutic strategy. Collectively, we conclude that inhibition of the mTOR/raptor complex initiates Akt activation independent of mTOR/rictor. Consequently, the sustained Akt activation during mTOR inhibition will counteract the anticancer efficacy of the mTOR inhibitors. [Cancer Res 2008;68(18):7409–18]
Data from Aging and Cancer-Related Loss of Insulin-like Growth Factor 2 Imprinting in the Mouse and Human Prostate
Authors: Fu Vivian X. , Dobosy Joseph R. , Desotelle Joshua A. , Almassi Nima , Ewald Jonathan A. , Srinivasan Rajini , Berres Mark , Svaren John , Weindruch Richard , Jarrard David F.
Published: March 2024

Abstract
Loss of imprinting (LOI) is an epigenetic alteration involving loss of parental origin-specific expression at normally imprinted genes. A LOI for Igf2, a paracrine growth factor, is important in cancer progression. Epigenetic modifications may be altered by environmental factors. However, is not known whether changes in imprinting occur with aging in prostate and other tissues susceptible to cancer development. We found a LOI for Igf2 occurs specifically in the mouse prostate associated with increased Igf2 expression during aging. In older animals, expression of the chromatin insulator protein CTCF and its binding to the Igf2-H19 imprint control region was reduced. Forced down-regulation of CTCF leads to Igf2 LOI. We further show that Igf2 LOI occurs with aging in histologically normal human prostate tissues and that this epigenetic alteration was more extensive in men with associated cancer. This finding may contribute to a postulated field of cancer susceptibility that occurs with aging. Moreover, Igf2 LOI may serve as a marker for the presence of prostate cancer. [Cancer Res 2008;68(16):6797–802]
Data from Pim Kinases Promote Cell Cycle Progression by Phosphorylating and Down-regulating p27Kip1 at the Transcriptional and Posttranscriptional Levels
Authors: Morishita Daisuke , Katayama Ryohei , Sekimizu Kazuhisa , Tsuruo Takashi , Fujita Naoya
Published: March 2024

Abstract
The serine/threonine kinase Pim is known to promote cell cycle progression and to inhibit apoptosis leading to tumorigenesis. However, the precise mechanisms remain unclear. We show, herein, that all the Pim family members (Pim1, Pim2, and Pim3) bind to and directly phosphorylate the cyclin-dependent kinase inhibitor p27Kip1 at threonine-157 and threonine-198 residues in cells and in vitro. The Pim-mediated phosphorylation induced p27Kip1 binding to 14-3-3 protein, resulting in its nuclear export and proteasome-dependent degradation. Ectopic expression of Pim kinases overcome the G1 arrest mediated by wild-type p27Kip1 but not by phosphorylation-resistant T157A-p27Kip1 or T198A-p27Kip1. In addition to the posttranslational regulations, p27Kip1 promoter assay revealed that Pim kinases also had the ability to suppress p27Kip1 transcription. Pim-mediated phosphorylation and inactivation of forkhead transcription factors, FoxO1a and FoxO3a, was involved in the transcriptional repression of the p27Kip1 gene. In contrast, inhibition of Pim signaling by expressing the dominant-negative form of Pim1 increased nuclear p27Kip1 level and attenuated cell proliferation. Because the CDK inhibitor p27Kip1 plays a crucial role in tumor suppression by inhibiting abnormal cell cycle progression, Pim kinases promote cell cycle progression and tumorigenesis by down-regulating p27Kip1 expression at both transcriptional and posttranslational levels. [Cancer Res 2008;68(13):5076–85]
Data from Prolyl Isomerase Cyclophilin A Regulation of Janus-Activated Kinase 2 and the Progression of Human Breast Cancer
Authors: Zheng Jiamao , Koblinski Jennifer E. , Dutson Laura V. , Feeney Yvonne B. , Clevenger Charles V.
Published: March 2024

Abstract
The activation of the Janus-activated kinase 2 (Jak2) tyrosine kinase following ligand binding has remained incompletely characterized at the mechanistic level. We report that the peptidyl-prolyl isomerase (PPI) cyclophilin A (CypA), which is implicated in the regulation of protein conformation, is necessary for the prolactin (PRL)-induced activation of Jak2 and the progression of human breast cancer. A direct correlation was observed between the levels or activity of CypA and the extent of PRL-induced signaling and gene expression. Loss of PRLr-CypA binding, following treatment with the PPI inhibitor cyclosporine A (CsA), or overexpression of a dominant-negative PRLr mutant (P334A) resulted in a loss of PRLr/Jak2–mediated signaling. In vitro, CsA treatment of breast cancer cells inhibited their growth, motility, invasion, and soft agar colony formation. In vivo, CsA treatment of nude mice xenografted with breast cancer cells induced tumor necrosis and completely inhibited metastasis. These studies reveal that a CypA-mediated conformational change within the PRLr/Jak2 complex is required for PRL-induced transduction and function and indicate that the inhibition of prolyl isomerases may be a novel therapeutic strategy in the treatment of human breast cancer. [Cancer Res 2008;68(19):7769–78]
Data from A Novel Diterpene Suppresses CWR22Rv1 Tumor Growth In vivo through Antiproliferation and Proapoptosis
Authors: Lin Feng-Min , Tsai Chin-Hsien , Yang Yu-Chih , Tu Wei-Chun , Chen Li-Ru , Liang Yun-Sa , Wang Sheng-Yang , Shyur Lie-Fen , Chien Shih-Chang , Cha Tai-Lung , Hsiao Pei-Wen
Published: March 2024

Abstract
Androgen receptor (AR) is the main therapeutic target for treatment of metastatic prostate cancers (PCa). As recurrent tumors restore AR activity independent of hormones, new therapies that abolish AR activity have been sought to prevent or delay the emergence of ablation-resistant disease. Here, we report that a novel abietane diterpene, 6-hydroxy-5,6-dehydrosugiol (HDHS), isolated from the stem bark of Cryptomeria japonica, was a potent AR antagonist in PCa cells. HDHS treatment of androgen-dependent LNCaP and androgen-responsive 22Rv1 cells induced apoptosis as shown by nucleosome release, activation of caspase-3 and caspase-7, and cleavage of poly(ADP-ribose) polymerase accompanied with concomitant up-regulation of tumor suppressor p53. HDHS also decreased the protein expression of cyclins (D1 and E), cyclin-dependent kinases (CDK2, CDK4, and CDK6), and retinoblastoma phosphorylation in PCa cells, which suggest cell cycle arrest in the G1 phase. Oral administration of HDHS at 0.5 and 2.5 mg/kg once daily for 24 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 22% and 39%, respectively, in association with decreased proliferation and increased apoptosis in tumor cells, which further correlated with increased levels of HDHS in plasma and tumors. Overall, our data suggest that HDHS has potential for use in chemoprevention and chemotherapy of PCa. [Cancer Res 2008;68(16):6634–42]
Data from Premature Cell Cycle Entry Induced by Hepatitis B Virus Regulatory HBx Protein during Compensatory Liver Regeneration
Authors: Hodgson Amanda J. , Keasler Victor V. , Slagle Betty L.
Published: March 2024

Abstract
The cycles of cell death and compensatory regeneration that occur during chronic hepatitis B virus (HBV) infection are central to viral pathogenesis and are a risk factor for the development of liver cancer. The HBV genome encodes one regulatory protein, HBx, which is required for virus replication, although its precise role in replication and pathogenesis is unclear. Because HBx can induce the G0-G1 transition in cultured cells, the purpose of this study was to examine the effect of HBx during liver regeneration. Transgenic mice expressing HBx (ATX) and their wild-type (WT) littermates were used in the partial hepatectomy (PH) model for compensatory regeneration. Liver tissues collected from ATX and WT mice at varying sacrifice time points after PH were examined for markers of cell cycle progression. When compared with WT liver tissues, ATX livers had evidence of premature cell cycle entry as assessed by several variables (BrdUrd incorporation, proliferating cell nuclear antigen and mitotic indices, and reduced steady-state p21 protein levels). However, HBx did not affect apoptosis, glycogen storage, or PH-induced steatosis. Together, these results show that HBx expression can induce cell cycle progression within the regenerating liver. Our data are consistent with a model in which HBx expression contributes to liver disease and cancer formation by affecting early steps in liver regeneration. [Cancer Res 2008;68(24):10341–8]
Data from Chromosome 12p Deletions in TEL-AML1 Childhood Acute Lymphoblastic Leukemia Are Associated with Retrotransposon Elements and Occur Postnatally
Authors: Wiemels Joseph L. , Hofmann Jerry , Kang Michelle , Selzer Rebecca , Green Roland , Zhou Mi , Zhong Sheng , Zhang Luoping , Smith Martyn T. , Marsit Carmen , Loh Mignon , Buffler Patricia , Yeh Ru-Fang
Published: March 2024

Abstract
TEL-AML1 (ETV6-RUNX1) is the most common translocation in the childhood leukemias, and is a prenatal mutation in most children. This translocation has been detected at a high rate among newborns (∼1%); therefore, the rate-limiting event for leukemia seems to be secondary mutations. One such frequent mutation in this subtype is partial deletion of chromosome 12p, trans from the translocation. Nine del(12p) breakpoints within six leukemia cases were sequenced to explore the etiology of this genetic event, and most involved cryptic sterile translocations. Twelve of 18 del(12p) parent sequences involved in these breakpoints were located in repeat regions (8 of these in long interspersed nuclear elements). This stands in contrast with TEL-AML1, in which only 21 of 110 previously assessed breakpoints (19%) occur in DNA repeats (P = 0.0001). An exploratory assessment of archived neonatal blood cards revealed significantly more long interspersed nuclear element CpG methylations in individuals at birth who were later diagnosed with TEL-AML1 leukemia, compared with individuals who did not contract leukemia (P = 0.01). Nontemplate nucleotides were also more frequent in del(12p) than in TEL-AML1 junctions (P = 0.004), suggesting formation by terminal deoxynucleotidyl transferase. Assessment of six archived neonatal blood cards indicated that no del(12p) rearrangements backtracked to birth, although two of these patients were previously positive for TEL-AML1 using the same assay with comparable sensitivity. These data are compatible with a two-stage natural history: TEL-AML1 occurs prenatally, and del(12p) occurs postnatally in more mature cells with a structure that suggests the involvement of retrotransposon instability. [Cancer Res 2008;68(23):9935–44]
Data from PEA-15 Induces Autophagy in Human Ovarian Cancer Cells and Is Associated with Prolonged Overall Survival
Authors: Bartholomeusz Chandra , Rosen Daniel , Wei Caimiao , Kazansky Anna , Yamasaki Fumiyuki , Takahashi Takeshi , Itamochi Hiroaki , Kondo Seiji , Liu Jinsong , Ueno Naoto T.
Published: March 2024

Abstract
Phospho-enriched protein in astrocytes (PEA-15) is a 15-kDa phosphoprotein that slows cell proliferation by binding to and sequestering extracellular signal–regulated kinase (ERK) in the cytoplasm, thereby inhibiting ERK-dependent transcription and proliferation. In previous studies of E1A human gene therapy for ovarian cancer, we discovered that PEA-15 induced the antitumor effect of E1A by sequestering activated ERK in the cytoplasm of cancer cells. Here, we investigated the role of PEA-15 in ovarian cancer tumorigenesis, the expression levels of PEA-15 in human ovarian cancer, and whether PEA-15 expression correlated with overall survival in women with ovarian cancer. We overexpressed PEA-15 in low-PEA-15-expressing cells and knocked down PEA-15 in high-PEA-15-expressing cells and analyzed the effects on proliferation, anchorage-independent growth, and cell cycle progression. We then assessed PEA-15 expression in an annotated tissue microarray of tumor samples from 395 women with primary epithelial ovarian cancer and tested whether PEA-15 expression was linked with overall survival. PEA-15 expression inhibited proliferation, and cell cycle analysis did not reveal apoptosis but did reveal autophagy, which was confirmed by an increase in LC3 cleavage. Inhibition of the ERK1/2 pathway decreased PEA-15–induced autophagy. These findings suggest that the antitumor activity of PEA-15 is mediated, in part, by the induction of autophagy involving activation of the ERK1/2 pathway. Multivariable analyses indicated that the women with high-PEA-15-expressing tumors survived longer than those with low-PEA-15-expressing tumors (hazard ratio, 1.973; P = 0.0167). Our findings indicate that PEA-15 expression is an important prognostic marker in ovarian cancer. [Cancer Res 2008;68(22):9302–10]
Data from The Activated Notch1 Signal Pathway Is Associated with Gastric Cancer Progression through Cyclooxygenase-2
Authors: Yeh Tien-Shun , Wu Chew-Wun , Hsu Kai-Wen , Liao Wan-Jung , Yang Min-Chieh , Li Anna Fen-Yau , Wang An-Ming , Kuo Min-Liang , Chi Chin-Wen
Published: March 2024

Abstract
Gastric carcinoma is one of the most common cancers and lethal malignancies worldwide. Thus far, the regulatory mechanisms of its aggressiveness are still poorly understood. To understand the pathogenesis and to develop new therapeutic strategies, it is essential to dissect the molecular mechanisms that regulate progression of gastric cancer. Herein, we sought to address whether Notch1 signal pathway is involved in the control of progression in gastric cancer. We found that expression of Notch ligand Jagged1 was correlated with aggressiveness of human gastric cancer. Patients with Jagged1 expression in gastric cancer tissues had a poor survival rate compared with those without Jagged1 expression. The Notch1 receptor intracellular domain (N1IC), the activated form of Notch1 receptor, promoted the colony-forming ability and xenografted tumor growth of human stomach adenocarcinoma SC-M1 cells. Migration and invasion abilities of SC-M1 cells were enhanced by N1IC. Furthermore, N1IC and C promoter–binding factor 1 (CBF1) bound to cyclooxygenase-2 (COX-2) promoter and elevated COX-2 expression in SC-M1 cells through a CBF1-dependent manner. The colony-forming, migration, and invasion abilities enhanced by N1IC were suppressed in SC-M1 cells after treatment with the COX-2 inhibitor NS-398 or knockdown of COX-2. These cellular processes inhibited by Notch1 knockdown were restored by prostaglandin E2 or exogenous COX-2. Taken together, these results suggest that activation of Notch1 signal pathway promotes progression of gastric cancer, at least in part through COX-2. [Cancer Res 2009;69(12):5039–48]
Data from The Dendritic Cell–like Functions of IFN-Producing Killer Dendritic Cells Reside in the CD11b+ Subset and Are Licensed by Tumor Cells
Authors: Terme Magali , Mignot Grégoire , Ullrich Evelyn , Bonmort Mathieu , Minard-Colin Véronique , Jacquet Alexandra , Schultze Joachim L. , Kroemer Guido , Leclerc Claude , Chaput Nathalie , Zitvogel Laurence
Published: March 2024

Abstract
IFN producing killer dendritic cells (IKDC) were originally defined as CD11cint B220+NK1.1+ (or CD49b+) cells that exert a potent tumoricidal activity in animals lacking B, T, and conventional natural killer effectors. MHC class II expression on tumor infiltrating IKDC prompted us to investigate their putative antigen presenting function. Here, we show that tumor cells license IKDC to acquire the properties of antigen presenting cells, i.e., expression of MHC class II and costimulatory CD86 molecules. We show that the CD11b+ subset of IKDC are able to prime naïve CD4+ T cells and cross-prime naïve CD8+ T lymphocytes. Licensing of IKDC by tumor cells was mandatory for the full differentiation of T cells into polarized effectors. IKDC could engulf and process soluble Ova protein in a CD206-dependent manner. Finally, we show that CD11b+IKDC is selectively endowed with CTLA4Ig-inhibitable antigen presenting capacities and that targeting this subset with the detoxified adenylate cyclase toxin of Bordetella pertussis fused to antigen resulted in efficient cross-presentation of antigen by IKDC to specific TCR transgenic CD8+T cells in vivo. Collectively, our data indicate that upon exposure to tumor cells, IKDC subserve DC-like functions. [Cancer Res 2009;69(16):6590–7]
Data from The mRNA-Destabilizing Protein Tristetraprolin Is Suppressed in Many Cancers, Altering Tumorigenic Phenotypes and Patient Prognosis
Authors: Brennan Sarah E. , Kuwano Yuki , Alkharouf Nadim , Blackshear Perry J. , Gorospe Myriam , Wilson Gerald M.
Published: March 2024

Abstract
AU-rich element-binding proteins (ARE-BP) regulate the stability and/or translational efficiency of mRNAs containing cognate binding sites. Many targeted transcripts encode factors that control processes such as cell division, apoptosis, and angiogenesis, suggesting that dysregulated ARE-BP expression could dramatically influence oncogenic phenotypes. Using several approaches, we evaluated the expression of four well-characterized ARE-BPs across a variety of human neoplastic syndromes. AUF1, TIA-1, and HuR mRNAs were not systematically dysregulated in cancers; however, tristetraprolin mRNA levels were significantly decreased across many tumor types, including advanced cancers of the breast and prostate. Restoring tristetraprolin expression in an aggressive tumor cell line suppressed three key tumorgenic phenotypes: cell proliferation, resistance to proapoptotic stimuli, and expression of vascular endothelial growth factor mRNA. However, the cellular consequences of tristetraprolin expression varied across different cell models. Analyses of gene array data sets revealed that suppression of tristetraprolin expression is a negative prognostic indicator in breast cancer, because patients with low tumor tristetraprolin mRNA levels were more likely to present increased pathologic tumor grade, vascular endothelial growth factor expression, and mortality from recurrent disease. Collectively, these data establish that tristetraprolin expression is frequently suppressed in human cancers, which in turn can alter tumorigenic phenotypes that influence patient outcomes. [Cancer Res 2009;69(12):5168–76]
Data from Helicobacter pylori Cytotoxin-Associated Gene A Activates the Signal Transducer and Activator of Transcription 3 Pathway In vitro and In vivo
Authors: Bronte-Tinkew Dana M. , Terebiznik Mauricio , Franco Aime , Ang Michelle , Ahn Diane , Mimuro Hitomi , Sasakawa Chihiro , Ropeleski Mark J. , Peek Richard M. , Jones Nicola L.
Published: March 2024

Abstract
Persistent infection with Helicobacter pylori confers an increased risk for the development of gastric cancer. However, the exact mechanisms whereby this bacterium causes carcinogenesis have not been completely elucidated. Recent evidence indicates that aberrant activation of the signal transducers and activators of transcription 3 (STAT3) signaling pathway may play a role in gastric carcinogenesis. Therefore, we hypothesized that H. pylori infection modulates STAT3 signaling, favoring gastric cancer development. In epithelial cells infected with H. pylori, STAT3 was activated, as assessed by immunoblotting for phosphorylated STAT3, immunofluorescence of translocated STAT3, fluorescence recovery after photobleaching, and luciferase activation in transfected cells. Activation was dependent on translocation but not phosphorylation of cytotoxin-associated gene A (CagA) in host cells. Activation seemed to be receptor-mediated because preincubation of cells with the interleukin-6 (IL-6) receptor superantagonist sant7 or inhibition of gp130 by a monoclonal antibody prevented H. pylori–mediated STAT3 activation. However, activation was not related to autocrine activation by IL-6 or IL-11. CagA+ wild-type H. pylori, but not the noncarcinogenic cagA− mutant, activated STAT3 in gastric epithelial cells in vivo in the gerbil model of H. pylori–mediated gastric carcinogenesis. Collectively, these results indicate that H. pylori CagA activates the STAT3 signaling pathway in vitro and in vivo, providing a potential mechanism by which chronic H. pylori infection promotes the development of gastric cancer. [Cancer Res 2009;69(2):632–9]
Data from T-Regulatory Cells Shift from a Protective Anti-Inflammatory to a Cancer-Promoting Proinflammatory Phenotype in Polyposis
Authors: Gounaris Elias , Blatner Nichole R. , Dennis Kristen , Magnusson Fay , Gurish Michael F. , Strom Terry B. , Beckhove Philipp , Gounari Fotini , Khazaie Khashayarsha
Published: March 2024

Abstract
T-regulatory (Treg) cells play a major role in cancer by suppressing protective antitumor immune responses. A series of observations (from a single laboratory) suggest that Treg cells are protective in cancer by virtue of their ability to control cancer-associated inflammation in an interleukin (IL)-10–dependent manner. Here, we report that the ability of Treg cells to produce IL-10 and control inflammation is lost in the course of progressive disease in a mouse model of hereditary colon cancer. Treg cells that expand in adenomatous polyps no longer produce IL-10 and instead switch to production of IL-17. Aberrant Treg cells from polyp-ridden mice promote rather than suppress focal mastocytosis, a critical tumor-promoting inflammatory response. The cells, however, maintain other Treg characteristics, including their inability to produce IL-2 and ability to suppress proliferation of stimulated CD4 T cells. By promoting inflammation and suppressing T-helper functions, these cells act as a double-edged knife propagating tumor growth. [Cancer Res 2009;69(13):5490–7]
Data from Epigenetic Loss of Mucosa-Associated Lymphoid Tissue 1 Expression in Patients with Oral Carcinomas
Authors: Chiba Tadashige , Maeda Genta , Kawashiri Shuichi , Kato Koroku , Imai Kazushi
Published: March 2024

Abstract
Mucosa-associated lymphoid tissue 1 (MALT1), which is located in a genomic region that encodes unknown tumor suppressor gene(s), activates nuclear factor-κB in lymphocyte lineages. However, its expression and role in the pathology of malignant tumors of epithelial origin is not known. In the present study, we examined MALT1 expression and its implications for the pathology of oral carcinomas. Immunostaining localized MALT1 in the nucleus of normal oral epithelial cells, but the expression was absent in 45.0% of carcinomas (49 of 109 cases) especially at the invasive front. The loss of expression was correlated with tumor recurrence (P = 0.007) and poor patient survival (P < 0.001), and it was an independent prognostic determinant (P < 0.001). MALT1-negative carcinomas exhibited microsatellite instability at the MALT1 locus and a specific cytosine methylation positioned at −256 from the gene, and the expression was recovered by demethylation treatment. In contrast to lymphocyte lineages, carcinoma cells showed MALT1 located at the nucleus independent of its domain structures, and its loss of expression induced the epithelial-mesenchymal transition. These results show that MALT1 is expressed in the nucleus of oral epithelial cells and that its expression is epigenetically inactivated during tumor progression, suggesting that the detection of MALT1 expression is a useful predictive and prognostic determinant in the clinical management of oral carcinomas. [Cancer Res 2009;69(18):7216–23]
Data from Candidate Gene Association Study of Esophageal Squamous Cell Carcinoma in a High-Risk Region in Iran
Authors: Akbari Mohammad R. , Malekzadeh Reza , Shakeri Ramin , Nasrollahzadeh Dariush , Foumani Maryam , Sun Yulong , Pourshams Akram , Sadjadi Alireza , Jafari Elham , Sotoudeh Masoud , Kamangar Farin , Boffetta Paolo , Dawsey Sanford M. , Ghadirian Parviz , Narod Steven A.
Published: March 2024

Abstract
There is a region with a high risk for esophageal squamous cell carcinoma (ESCC) in the northeast of Iran. Previous studies suggest that hereditary factors play a role in the high incidence of cancer in the region. We selected 22 functional variants (and 130 related tagSNPs) from 15 genes that have been associated previously with the risk of ESCC. We genotyped a primary set of samples from 451 Turkmens (197 cases and 254 controls). Seven of 152 variants were associated with ESCC at the P = 0.05 level; these single nucleotide polymorphisms were then studied in a validation set of 549 cases and 1,119 controls, which included both Turkmens and non-Turkmens. The association observed for a functional variant in ADH1B was confirmed in the validation set, and that of a tagSNP in MGMT, the association was borderline significant in the validation set, after correcting for multiple testing. The other 5 variants that were associated in the primary set were not significantly associated in the validation set. The histidine allele at codon 48 of ADH1B gene was associated with a significantly decreased risk of ESCC in the joint data set (primary and validation set) under a recessive model (odds ratio, 0.41; 95% confidence interval, 0.29-0.76; P = 4 × 10−4). The A allele of the rs7087131 variant of MGMT gene was associated with a decreased risk of ESCC under a dominant model (odds ratio, 0.79; 95% confidence interval, 0.64-0.96; P = 0.02). These results support the hypothesis that genetic predisposition plays a role in the high incidence of ESSC in Iran. [Cancer Res 2009;69(20):7994–8000]
Data from Inhibition of Transforming Growth Factor-β–Mediated Immunosuppression in Tumor-Draining Lymph Nodes Augments Antitumor Responses by Various Immunologic Cell Types
Authors: Fujita Takuya , Teramoto Koji , Ozaki Yoshitomo , Hanaoka Jun , Tezuka Noriaki , Itoh Yasushi , Asai Tohru , Fujino Shozo , Kontani Keiichi , Ogasawara Kazumasa
Published: March 2024

Abstract
Tumor-draining lymph nodes (DLN) are the most important priming sites for generation of antitumor immune responses. They are also the location where an immunosuppressive cytokine, transforming growth factor-β (TGF-β), plays a critical role in suppressing these antitumor immune responses. We focused on TGF-β–mediated immunosuppression in DLNs and examined whether local inhibition of TGF-β augmented antitumor immune responses systemically in tumor-bearing mice models. For inhibition of TGF-β–mediated immunosuppression in DLNs, C57BL/6 mice subcutaneously bearing E.G7 tumors were administered plasmid DNA encoding the extracellular domain of TGF-β type II receptor fused to the human IgG heavy chain (TGFR DNA) i.m. near the established tumor. In DLNs, inhibition of TGF-β suppressed the proliferation of regulatory T cells and increased the number of tumor antigen-specific CD4+ or CD8+ cells producing IFN-γ. Enhancement of antitumor immune responses in DLNs were associated with augmented tumor antigen-specific cytotoxic and natural killer activity in spleen as well as elevated levels of tumor-specific antibody in sera. The growth of the established metastatic as well as primary tumors was effectively suppressed via augmented antitumor immune responses. Inhibition of TGF-β–mediated immunosuppression in DLNs is significantly associated with augmented antitumor responses by various immunocompetent cell types. This animal model provides a novel rationale for molecular cancer therapeutics targeting TGF-β. [Cancer Res 2009;69(12):5142–50]
Data from Positive Feedback Activation of Estrogen Receptors by the CXCL12-CXCR4 Pathway
Authors: Sauvé Karine , Lepage Julie , Sanchez Mélanie , Heveker Nikolaus , Tremblay André
Published: March 2024

Abstract
Induction of estrogen-regulated gene transcription by estrogen receptors ERα and ERβ plays an important role in breast cancer development and growth. High expression of the chemokine receptor CXCR4 and its ligand CXCL12/stromal cell-derived factor 1 (SDF-1) has also been correlated with aggressive breast tumor phenotypes. Here, we describe a positive regulatory loop between the CXCR4/SDF-1 signaling pathway and ER transcriptional competence in human breast cancer cells. Treatment of breast carcinoma MCF-7 cells with SDF-1 increased ER transcriptional activity and expression of ER target genes, including SDF-1 itself. These effects were blocked by the antiestrogen ICI-182780 and by CXCR4 silencing and, conversely, estrogen-induced gene expression and growth of MCF-7 cells were impaired on CXCR4 inhibition. Both ERα and ERβ were activated by SDF-1 in the presence of CXCR4 and by overexpression of a constitutively active CXCR4, indicating that CXCR4 signals to both receptors. In particular, ERβ was able to translate the effects of SDF-1 on its own expression, as well as enhance activator protein 1 (AP-1) containing genes cyclin D1 and c-Myc in the presence of tamoxifen. This correlated with an increased ERβ occupancy of responsive promoters at both estrogen-responsive and AP-1 elements. Ser-87, a conserved mitogen-activated protein kinase site in ERβ, was highly phosphorylated by SDF-1, revealing an essential role of the AF-1 domain in response to CXCR4 activation. These results identify a complete autocrine loop between the CXCR4/SDF-1 and ERα/ERβ signaling pathways that dictates ER-dependent gene expression and growth of breast cancer cells. [Cancer Res 2009;69(14):5793–800]
Data from Malignant B Cells Skew the Balance of Regulatory T Cells and TH17 Cells in B-Cell Non-Hodgkin's Lymphoma
Authors: Yang Zhi-Zhang , Novak Anne J. , Ziesmer Steven C. , Witzig Thomas E. , Ansell Stephen M.
Published: March 2024

Abstract
Using biopsy specimens from patients with B-cell non-Hodgkin's lymphoma, we observed a significantly low frequency of TH17 cells, including several samples with no detectable amount of interleukin (IL)-17–producing cells present in the tumor microenvironment. We found that, in the absence of lymphoma B cells, treatment with IL-1β/IL-6 or lipopolysaccharide (LPS) enhanced IL-17 expression in CD4+ T cells and this enhancement was attenuated when CD4+ T cells were cocultured with lymphoma B cells. Blockade of CD27-CD70 or CD28-CD80/86 interactions by anti-CD70 or anti-CD80/86 antibodies restored LPS-mediated induction of IL-17 expression in CD4+ T cells cocultured with lymphoma B cells. Because a subset of lymphoma B cells express IL-2 and given that IL-2 signaling is critically important in the development of regulatory T (Treg) cells, we tested the role of IL-2 signaling in TH17 cell development. We found that treatment with anti-IL-2 antibody to interrupt IL-2 signaling significantly inhibited Foxp3 expression in CD4+ T cells. In contrast, interruption of IL-2 signaling up-regulated IL-17 expression in CD4+ T cells and restored lymphoma-mediated down-regulation of IL-17–producing cells. Furthermore, the reversal of Treg cell activity by LPS or CpG-A resulted in an enhancement of IL-17–producing cells. Taken together, our study indicated that lymphoma B cells play an important role in skewing the balance between Treg and TH17 cells resulting in the establishment of a profoundly inhibitory tumor microenvironment. [Cancer Res 2009;69(13):5522–30]
Data from Increased Expression of Androgen Receptor Sensitizes Prostate Cancer Cells to Low Levels of Androgens
Authors: Waltering Kati K. , Helenius Merja A. , Sahu Biswajyoti , Manni Visa , Linja Marika J. , Jänne Olli A. , Visakorpi Tapio
Published: March 2024

Abstract
Androgen receptor (AR) is known to be overexpressed in castration-resistant prostate cancer. To interrogate the functional significance of the AR level, we established two LNCaP cell sublines expressing in a stable fashion two to four times (LNCaP-ARmo) and four to six times (LNCaP-ARhi) higher level of AR than the parental cell line expressing the empty vector (LNCaP-pcDNA3.1). LNCaP-ARhi cell line grew faster than the control line in low concentrations, especially in 1 nmol/L 5α-dihydrotestosterone (DHT). Microarray-based transcript profiling and subsequent unsupervised hierarchical clustering showed that LNCaP-ARhi cells clustered together with VCaP cells, containing endogenous AR gene amplification and overexpression, indicating the central role of AR in the overall regulation of gene expression in prostate cancer cells. Two hundred forty genes showed >2-fold changes on DHT treatment in LNCaP-ARhi at 4 h time point, whereas only 164 and 52 showed changes in LNCaP-ARmo and LNCaP-pcDNA3.1, respectively. Many androgen-regulated genes were upregulated in LNCaP-ARhi at 10-fold lower concentration of DHT than in control cells. DHT (1 nmol/L) increased expression of several cell cycle–associated genes in LNCaP-ARhi cells. ChIP-on-chip assay revealed the presence of chromatin binding sites for AR within ±200 kb of most of these genes. The growth of LNCaP-ARhi cells was also highly sensitive to cyclin-dependent kinase inhibitor, roscovitine, at 1nmol/L DHT. In conclusion, our results show that overexpression of AR sensitizes castration-resistant prostate cancer cells to the low levels of androgens. The activity of AR signaling pathway is regulated by the levels of both ligand and the receptor. [Cancer Res 2009;69(20):8141–9]
Data from Intravital Imaging Reveals Transient Changes in Pigment Production and Brn2 Expression during Metastatic Melanoma Dissemination
Authors: Pinner Sophie , Jordan Peter , Sharrock Kirsty , Bazley Laura , Collinson Lucy , Marais Richard , Bonvin Elise , Goding Colin , Sahai Erik
Published: March 2024

Abstract
How melanoma acquire a metastatic phenotype is a key issue. One possible mechanism is that metastasis is driven by microenvironment-induced switching between noninvasive and invasive states. However, whether switching is a reversible or hierarchical process is not known and is difficult to assess by comparison of primary and metastatic tumors. We address this issue in a model of melanoma metastasis using a novel intravital imaging method for melanosomes combined with a reporter construct in which the Brn-2 promoter drives green fluorescent protein (GFP) expression. A subpopulation of cells containing little or no pigment and high levels of Brn2::GFP expression are motile in the primary tumor and enter the vasculature. Significantly, the less differentiated state of motile and intravasated cells is not maintained at secondary sites, implying switching between states as melanoma cells metastasize. We show that melanoma cells can switch in both directions between high- and low-pigment states. However, switching from Brn2::GFP high to low was greatly favored over the reverse direction. Microarray analysis of high- and low-pigment populations revealed that transforming growth factor (TGF)β2 was up-regulated in the poorly pigmented cells. Furthermore, TGFβ signaling induced hypopigmentation and increased cell motility. Thus, a subset of less differentiated cells exits the primary tumor but subsequently give rise to metastases that include a range of more differentiated and pigment-producing cells. These data show reversible phenotype switching during melanoma metastasis. [Cancer Res 2009;69(20):7969–77]