bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from CYP1A1/2 Haplotypes and Lung Cancer and Assessment of Confounding by Population Stratification
Authors: Aldrich Melinda C. , Selvin Steve , Hansen Helen M. , Barcellos Lisa F. , Wrensch Margaret R. , Sison Jennette D. , Kelsey Karl T. , Buffler Patricia A. , Quesenberry Charles P. , Seldin Michael F. , Wiencke John K.
Published: March 2023

Abstract
Prior studies of lung cancer and CYP1A1/2 in African-American and Latino populations have shown inconsistent results and have not yet investigated the haplotype block structure of CYP1A1/2 or addressed potential population stratification. To investigate haplotypes in the CYP1A1/2 region and lung cancer in African-Americans and Latinos, we conducted a case-control study (1998–2003). African-Americans (n = 535) and Latinos (n = 412) were frequency matched on age, sex, and self-reported race/ethnicity. We used a custom genotyping panel containing 50 single nucleotide polymorphisms in the CYP1A1/2 region and 184 ancestry informative markers selected to have large allele frequency differences between Africans, Europeans, and Amerindians. Latinos exhibited significant haplotype main effects in two blocks even after adjusting for admixture [odds ratio (OR), 2.02; 95% confidence interval (95% CI), 1.28–3.19 and OR, 0.55; 95% CI, 0.36–0.83], but no main effects were found among African-Americans. Adjustment for admixture revealed substantial confounding by population stratification among Latinos but not African-Americans. Among Latinos and African-Americans, interactions between smoking level and haplotypes were not statistically significant. Evidence of population stratification among Latinos underscores the importance of adjusting for admixture in lung cancer association studies, particularly in Latino populations. These results suggest that a variant occurring within the CYP1A2 region may be conferring an increased risk of lung cancer in Latinos. [Cancer Res 2009;69(6):2340–8]
Data from Rat Umbilical Cord Stem Cells Completely Abolish Rat Mammary Carcinomas with No Evidence of Metastasis or Recurrence 100 Days Post–Tumor Cell Inoculation
Authors: Ganta Chanran , Chiyo Doi , Ayuzawa Rie , Rachakatla Rajashekar , Pyle Marla , Andrews Gordon , Weiss Mark , Tamura Masaaki , Troyer Deryl
Published: March 2023

Abstract
Genetically engineered stem cells efficiently deliver therapeutic proteins to cancer and other sites of inflammation. However, a major advantage would be realized if tumor-trafficking stem cells that have not been genetically modified exhibit an inherent antitumor effect, thus circumventing the necessity of the expression of exogenous genes by the cells. We transplanted Fisher 344 rat–derived mammary adenocarcinoma cells (Mat B III) orthotopically into syngeneic F344 rats with an intact immune system. Rat umbilical cord matrix stem (rUCMS) cells derived from Wharton's jelly were then administered intratumoral (i.t) or i.v. 4 days later. The tumor attenuation effect was significantly evident starting from day 14 in i.v. and i.t. rUCMS cell–transplanted rats compared with sham-transplanted rats. In addition, unmodified rUCMS cell–transplanted rats showed complete regression of tumors to undetectable levels by 34 to 38 days with no evidence of metastasis or recurrence 100 days post–tumor cell inoculation. Dye-loaded rUCMS cells were identified within tumors only 4 days after their i.v. transplantation. In vitro colony assays with rUCMS cells as feeder layers markedly reduced Mat B III colony size and number. Growth attenuation of Mat B III cells exposed to either rUCMS cells directly or to the conditioned medium derived from rUCMS cells was associated with apoptosis indicators, including increased activated caspase-3. In addition, rUCMS cells cocultured with Mat B III cells had a dose-dependent antiproliferative effect on Mat B III cells. These findings suggest that unmodified human UCMS cells could be used for targeted cytotherapy for breast cancer. [Cancer Res 2009;69(5):1815–20]
Data from Heat-Induced Perturbations of DNA Damage Signaling Pathways are Modulated by Molecular Chaperones
Authors: Laszlo Andrei , Fleischer Ilona
Published: March 2023

Abstract
Heat is one of the most potent radiosensitizers known. Several randomized trials have shown that hyperthermia is a good adjuvant for radiotherapy at several different cancer sites. However, the mechanism(s) involved in the interaction of heat and radiation that lead to radiosensitization remain to be elucidated. In this report, we have determined that heat induces perturbations in some of the earliest events in the cellular response to DNA damage induced by ionizing radiation. We studied the effect of heat on the formation of complexes containing γ-H2AX/MDC1/53BP1 in heated-irradiated cells. We found that the formation of this complex was delayed in heated-irradiated cells, in a heat but not radiation dose–dependent manner. The length of the heat-induced delay of complex formation was attenuated in thermotolerant and heat radiosensitization–resistant cells. The length of the delay of γ-H2AX/MDC1/53BP1 complex formation correlated with the magnitude of heat radiosensitization and was modulated by the molecular chaperone Hsc70. Heat radiosensitization was attenuated in 53BP1-null cells, implying that the delay of the formation of the γ-H2AX/MDC1/53BP1 complex plays a role in heat radiosensitization. Heat also induced a delay of events in the DNA damage response that are downstream from 53BP1. Our results support the notion that heat-induced perturbations in the earliest events of the cellular response to ionizing radiation–induced DNA damage play a role in heat radiosensitization. [Cancer Res 2009;69(5):2042–9]
Data from Gene Expression Profiles in Peripheral Blood Mononuclear Cells Can Distinguish Patients with Non–Small Cell Lung Cancer from Patients with Nonmalignant Lung Disease
Authors: Showe Michael K. , Vachani Anil , Kossenkov Andrew V. , Yousef Malik , Nichols Calen , Nikonova Elena V. , Chang Celia , Kucharczuk John , Tran Bao , Wakeam Elliot , Yie Ting An , Speicher David , Rom William N. , Albelda Steven , Showe Louise C.
Published: March 2023

Abstract
Early diagnosis of lung cancer followed by surgery presently is the most effective treatment for non–small cell lung cancer (NSCLC). An accurate, minimally invasive test that could detect early disease would permit timely intervention and potentially reduce mortality. Recent studies have shown that the peripheral blood can carry information related to the presence of disease, including prognostic information and information on therapeutic response. We have analyzed gene expression in peripheral blood mononuclear cell samples including 137 patients with NSCLC tumors and 91 patient controls with nonmalignant lung conditions, including histologically diagnosed benign nodules. Subjects were primarily smokers and former smokers. We have identified a 29-gene signature that separates these two patient classes with 86% accuracy (91% sensitivity, 80% specificity). Accuracy in an independent validation set, including samples from a new location, was 78% (sensitivity of 76% and specificity of 82%). An analysis of this NSCLC gene signature in 18 NSCLCs taken presurgery, with matched samples from 2 to 5 months postsurgery, showed that in 78% of cases, the signature was reduced postsurgery and disappeared entirely in 33%. Our results show the feasibility of using peripheral blood gene expression signatures to identify early-stage NSCLC in at-risk populations. [Cancer Res 2009;69(24):9202–10]
Data from CTL Activation Using the Natural Low-Affinity Epitope 222-229 from Tyrosinase-Related Protein 1 Leads to Tumor Rejection
Authors: Pavelko Kevin D. , Hansen Michael J. , Pease Larry R.
Published: March 2023

Abstract
Vaccine strategies for cancer immunotherapy have focused on peptide ligands with high affinity for MHC class I. Largely, these vaccines have not been therapeutic. We have examined the peptide specificity of a strongly protective T-cell response that eradicates established B16 melanoma and find that the recognized epitope is generated by a low-affinity MHC class I ligand from tyrosinase-related protein 1 (TRP1). Cytotoxic T-cell responses are induced against TRP1222-229 by several vaccination schemes using a Toll-like receptor agonist, T regulatory cell depletion, or the immune modulator B7-DCXAb to drive immunity. TRP1222 CTL are generated from multiple antigen sources, including antigens expressed by tumors growing in situ, tumor cell lysates, and peptide vaccines. The key finding in this study is that protection from freshly implanted or established B16 tumors is primarily mediated by TRP1222-specific CTL and not by CTL specific for more traditional melanoma antigens such as TRP2 or gp100. This finding challenges the assumption that the optimal peptide antigens for cancer vaccines are high-affinity MHC ligands. We propose that when administered appropriately, native low-affinity MHC ligands are optimal inducers of immunotherapeutic CTL. [Cancer Res 2009;69(7):3114–20]
Data from NADPH Oxidase 4 Contributes to Transformation Phenotype of Melanoma Cells by Regulating G2-M Cell Cycle Progression
Authors: Yamaura Maki , Mitsushita Junji , Furuta Shuichi , Kiniwa Yukiko , Ashida Atsuko , Goto Yasuhumi , Shang Wei H. , Kubodera Makoto , Kato Masayoshi , Takata Minoru , Saida Toshiaki , Kamata Tohru
Published: March 2023

Abstract
Generation of reactive oxygen species (ROS) has been implicated in carcinogenic development of melanoma, but the underlying molecular mechanism has not been fully elucidated. We studied the expression and function of the superoxide-generating NADPH oxidase (Nox)4 in human melanoma cells. Nox4 was up-regulated in 13 of 20 melanoma cell lines tested. Silencing of Nox4 expression in melanoma MM-BP cells by small interfering RNAs decreased ROS production and thereby inhibited anchorage-independent cell growth and tumorigenecity in nude mice. Consistently, a general Nox inhibitor, diphenylene iodonium, and antioxidants vitamine E and pyrrolidine dithiocarbamate blocked cell proliferation of MM-BP cells. Flow cytometric analysis indicated that Nox4 small interfering RNAs and diphenylene iodonium induced G2-M cell cycle arrest, which was also observed with another melanoma cell line, 928mel. This was accompanied by induction of the Tyr-15 phosphorylated, inactive form of cyclin-dependent kinase 1 (a hallmark of G2-M checkpoint) and hyperphosphorylation of cdc25c leading to its increased binding to 14-3-3 proteins. Ectopic expression of catalase, a scavenger of ROS, also caused accumulation of cells in G2-M phase. Immunohistochemistry revealed that expression of Nox4 was detected in 31.0% of 13 melanoma patients samples, suggesting the association of Nox4 expression with some steps of melanoma development. The findings suggest that Nox4-generated ROS are required for transformation phenotype of melanoma cells and contribute to melanoma growth through regulation of G2-M cell cycle progression. [Cancer Res 2009;69(6):2647–54]
Data from Akt Phosphorylation of Merlin Enhances Its Binding to Phosphatidylinositols and Inhibits the Tumor-Suppressive Activities of Merlin
Authors: Okada Masashi , Wang Yanru , Jang Sung-Wuk , Tang Xiaoling , Neri Luca M. , Ye Keqiang
Published: March 2023

Abstract
The NF2 tumor suppressor gene encodes an intracellular membrane-associated protein, called merlin, which belongs to the band 4.1 family of cytoskeleton-associated proteins that link cell surface glycoproteins to the actin cytoskeleton. Merlin suppresses phosphatidylinositol 3-kinase (PI3K)/Akt signaling by directly binding and inhibiting the stimulatory activity of PIKE-L on PI3K. Akt feeds back and phosphorylates merlin and provokes its polyubiquitination and degradation. Here, we show that Akt phosphorylation and PI(3,4,5)P3 binding mediate the tumor-suppressive activity of merlin. The extreme NH2 terminus of merlin directly interacts with phosphatidylinositols, for which the unfolded conformation is required. Moreover, Akt phosphorylation enhances merlin binding affinity to phosphatidylinositols and inhibits its proapoptotic actions. Furthermore, Akt phosphorylation and phosphatidylinositols increase merlin binding to CD44. Epidermal growth factor treatment and Akt phosphorylation provoke merlin to aggregate in the ruffled plasma membrane and promote cell migration. Thus, these results suggest that PI3K signaling regulates the tumor-suppressive activity of merlin via both Akt phosphorylation and phosphatidylinositol lipids binding to merlin. [Cancer Res 2009;69(9):4043–51]
Data from Regulatory T Cells Recruited through CCL22/CCR4 Are Selectively Activated in Lymphoid Infiltrates Surrounding Primary Breast Tumors and Lead to an Adverse Clinical Outcome
Authors: Gobert Michael , Treilleux Isabelle , Bendriss-Vermare Nathalie , Bachelot Thomas , Goddard-Leon Sophie , Arfi Vanessa , Biota Cathy , Doffin Anne Claire , Durand Isabelle , Olive Daniel , Perez Solène , Pasqual Nicolas , Faure Christelle , Ray-Coquard Isabelle , Puisieux Alain , Caux Christophe , Blay Jean-Yves , Ménétrier-Caux Christine
Published: March 2023

Abstract
Immunohistochemical analysis of FOXP3 in primary breast tumors showed that a high number of tumor-infiltrating regulatory T cells (Ti-Treg) within lymphoid infiltrates surrounding the tumor was predictive of relapse and death, in contrast to those present within the tumor bed. Ex vivo analysis showed that these tumor-infiltrating FOXP3+ T cells are typical Treg based on their CD4+CD25highCD127lowFOXP3+ phenotype, their anergic state on in vitro stimulation, and their suppressive functions. These Ti-Treg could be selectively recruited through CCR4 as illustrated by (a) selective blood Treg CCR4 expression and migration to CCR4 ligands, (b) CCR4 down-regulation on Ti-Treg, and (c) correlation between Ti-Treg in lymphoid infiltrates and intratumoral CCL22 expression. Importantly, in contrast to other T cells, Ti-Treg are selectively activated locally and proliferate in situ, showing T-cell receptor engagement and suggesting specific recognition of tumor-associated antigens (TAA). Immunohistochemical stainings for ICOS, Ki67, and DC-LAMP show that Ti-Treg were close to mature DC-LAMP+ dendritic cells (DC) in lymphoid infiltrates but not in tumor bed and were activated and proliferating. Furthermore, proximity between Ti-Treg, CD3+, and CD8+ T cells was documented within lymphoid infiltrates. Altogether, these results show that Treg are selectively recruited within lymphoid infiltrates and activated by mature DC likely through TAA presentation, resulting in the prevention of effector T-cell activation, immune escape, and ultimately tumor progression. This study sheds new light on Treg physiology and validates CCR4/CCL22 and ICOS as therapeutic targets in breast tumors, which represent a major health problem. [Cancer Res 2009;69(5):2000–9]
Data from Proapoptotic Activity of Bortezomib in Gastrointestinal Stromal Tumor Cells
Authors: Bauer Sebastian , Parry Joshua A. , Mühlenberg Thomas , Brown Matthew F. , Seneviratne Danushka , Chatterjee Payel , Chin Anna , Rubin Brian P. , Kuan Shih-Fan , Fletcher Jonathan A. , Duensing Stefan , Duensing Anette
Published: March 2023

Abstract
Gastrointestinal stromal tumors (GIST) are caused by activating mutations in the KIT or PDGFRA receptor tyrosine kinase genes. Although >85% of GIST patients treated with the small-molecule inhibitor imatinib mesylate (Gleevec) achieve disease stabilization, complete remissions are rare and a substantial proportion of patients develop resistance to imatinib over time. Upregulation of soluble, non–chromatin-bound histone H2AX has an important role in imatinib-induced apoptosis of GIST cells. Additionally, H2AX levels in untreated GIST are maintained at low levels by a pathway that involves KIT, phosphoinositide 3-kinase, and the ubiquitin-proteasome system. In this study, we asked whether bortezomib-mediated inhibition of the ubiquitin-proteasome machinery could lead to upregulation of histone H2AX and GIST cell death. We show that bortezomib rapidly triggers apoptosis in GIST cells through a combination of mechanisms involving H2AX upregulation and loss of KIT protein expression. Downregulation of KIT transcription was an underlying mechanism for bortezomib-mediated inhibition of KIT expression. In contrast, the nuclear factor-κB signaling pathway did not seem to play a major role in bortezomib-induced GIST cell death. Significantly, we found that bortezomib would induce apoptosis in two imatinib-resistant GIST cell lines as well as a short-term culture established from a primary imatinib-resistant GIST. Collectively, our results provide a rationale to test the efficacy of bortezomib in GIST patients with imatinib-sensitive or -resistant tumors. Cancer Res; 70(1); 150–9
Data from p53-Altered FBXW7 Expression Determines Poor Prognosis in Gastric Cancer Cases
Authors: Yokobori Takehiko , Mimori Koshi , Iwatsuki Masaaki , Ishii Hideshi , Onoyama Ichiro , Fukagawa Takeo , Kuwano Hiroyuki , Nakayama Keiichi I. , Mori Masaki
Published: March 2023

Abstract
A molecular target associated with the progression of gastric cancer has not yet been uncovered. FBXW7 is a tumor suppressor gene transcriptionally controlled by p53 that plays a role in the regulation of cell cycle exit and reentry via c-Myc degradation. Few studies have addressed the clinical significance of FBXW7 expression in gastric cancer. Therefore, we examined FBXW7 mRNA expression to determine its clinicopathologic significance in 100 cases of gastric cancer. Low expression levels of FBXW7 in primary gastric cancer contributed to malignant potential, such as lymph node metastasis (P = 0.0012), tumor size (P = 0.0003), and poor prognosis (P = 0.018). In comparison with 52 cases of gastric cancer without the p53 mutation, 29 cases with the mutation exhibited lower expression levels of FBXW7 (P = 0.0034), revealing a significant relationship between p53 mutation and FBXW7 expression. Furthermore, we found that gastric cancer patients who had low FBXW7 expression levels and p53 mutation had a distinctively poor prognosis in comparison with other subgroups (P = 0.0033). In conclusion, we showed a role for p53 in the transcriptional regulation of FBXW7 expression in clinical gastric cancer cases and showed that disruption of both p53 and FBXW7 contributes to poor prognosis. [Cancer Res 2009;69(9):3788–94]
Data from Pivotal Roles of Snail Inhibition and RKIP Induction by the Proteasome Inhibitor NPI-0052 in Tumor Cell Chemoimmunosensitization
Authors: Baritaki Stavroula , Yeung Kam , Palladino Michael , Berenson James , Bonavida Benjamin
Published: March 2023

Abstract
The novel proteasome inhibitor NPI-0052 has been shown to sensitize tumor cells to apoptosis by various chemotherapeutic drugs and tumor necrosis factor–related apoptosis-inducing ligand (TRAIL), although the mechanisms involved are not clear. We hypothesized that NPI-0052–mediated sensitization may result from NF-κB inhibition and downstream modulation of the metastasis inducer Snail and the metastasis suppressor/immunosurveillance cancer gene product Raf-1 kinase inhibitory protein (RKIP). Human prostate cancer cell lines were used as models, as they express different levels of these proteins. We show that NPI-0052 inhibits both NF-κB and Snail and induces RKIP expression, thus resulting in cell sensitization to CDDP and TRAIL. The direct role of NF-κB inhibition in sensitization was corroborated with the NF-κB inhibitor DHMEQ, which mimicked NPI-0052 in sensitization and inhibition of Snail and induction of RKIP. The direct role of Snail inhibition by NPI-0052 in sensitization was shown with Snail small interfering RNA, which reversed resistance and induced RKIP. Likewise, the direct role of RKIP induction in sensitization was revealed by both overexpression of RKIP (mimicking NPI-0052) and RKIP small interfering RNA that inhibited NPI-0052–mediated sensitization. These findings show that NPI-0052 modifies the NF-κB-Snail-RKIP circuitry in tumor cells and results in downstream inhibition of antiapoptotic gene products and chemoimmunosensitization. The findings also identified Snail and RKIP as targets for reversal of resistance. [Cancer Res 2009;69(21):8376–85]
Data from Human Glioblastoma–Derived Cancer Stem Cells: Establishment of Invasive Glioma Models and Treatment with Oncolytic Herpes Simplex Virus Vectors
Authors: Wakimoto Hiroaki , Kesari Santosh , Farrell Christopher J. , Curry William T. , Zaupa Cecile , Aghi Manish , Kuroda Toshihiko , Stemmer-Rachamimov Anat , Shah Khalid , Liu Ta-Chiang , Jeyaretna Deva S. , Debasitis Jason , Pruszak Jan , Martuza Robert L. , Rabkin Samuel D.
Published: March 2023

Abstract
Glioblastoma, the most malignant type of primary brain tumor, is one of the solid cancers where cancer stem cells have been isolated, and studies have suggested resistance of those cells to chemotherapy and radiotherapy. Here, we report the establishment of CSC-enriched cultures derived from human glioblastoma specimens. They grew as neurospheres in serum-free medium with epidermal growth factor and fibroblast growth factor 2, varied in the level of CD133 expression and very efficiently formed highly invasive and/or vascular tumors upon intracerebral implantation into immunodeficient mice. As a novel therapeutic strategy for glioblastoma-derived cancer stem–like cells (GBM-SC), we have tested oncolytic herpes simplex virus (oHSV) vectors. We show that although ICP6 (UL39)–deleted mutants kill GBM-SCs as efficiently as wild-type HSV, the deletion of γ34.5 significantly attenuated the vectors due to poor replication. However, this was significantly reversed by the additional deletion of α47. Infection with oHSV G47Δ (ICP6−, γ34.5−, α47−) not only killed GBM-SCs but also inhibited their self-renewal as evidenced by the inability of viable cells to form secondary tumor spheres. Importantly, despite the highly invasive nature of the intracerebral tumors generated by GBM-SCs, intratumoral injection of G47Δ significantly prolonged survival. These results for the first time show the efficacy of oHSV against human GBM-SCs, and correlate this cytotoxic property with specific oHSV mutations. This is important for designing new oHSV vectors and clinical trials. Moreover, the new glioma models described in this study provide powerful tools for testing experimental therapeutics and studying invasion and angiogenesis. [Cancer Res 2009;69(8):3472–81]
Data from Activation of DNA Methyltransferase 1 by EBV Latent Membrane Protein 2A Leads to Promoter Hypermethylation of PTEN Gene in Gastric Carcinoma
Authors: Hino Rumi , Uozaki Hiroshi , Murakami Noriko , Ushiku Tetsuo , Shinozaki Aya , Ishikawa Shumpei , Morikawa Teppei , Nakaya Takeo , Sakatani Takashi , Takada Kenzo , Fukayama Masashi
Published: March 2023

Abstract
CpG island promoter methylation of tumor suppressor genes is one of the most characteristic abnormalities in EBV-associated gastric carcinoma (GC). Aberrant promoter methylation and expression loss of PTEN were evaluated in cancer tissues of GC by methylation-specific PCR and immunohistochemistry, respectively, showing that both abnormalities occurred concurrently in EBV-associated GC. PTEN abnormalities were reiterated in GC cell lines MKN-1 and MKN-7 infected with recombinant EBV, and DNA methyltransferase 1 (DNMT1) was commonly overexpressed in both cell lines. Stable and transient transfection systems in MKN-1 similarly showed that viral latent membrane protein 2A (LMP2A) up-regulated DNMT1, leading to an increase in methylation of the PTEN promoter. Importantly, the level of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) increased in the nuclei of LMP2A-expressing GC cells, and knockdown of STAT3 counteracted LMP2A-mediated DNMT1 overexpression. Immunohistochemistry for both pSTAT3 and DNMT1 showed diffuse labeling in the nuclei of the cancer cells in GC tissues, especially in EBV-associated GC. Taken together, LMP2A induces the phosphorylation of STAT3, which activates DNMT1 transcription and causes PTEN expression loss through CpG island methylation of the PTEN promoter in EBV-associated GC. LMP2A plays an essential role in the epigenetic abnormalities in host stomach cells and in the development and maintenance of EBV-associated cancer. [Cancer Res 2009;69(7):2766–74]
Data from Lysine-Specific Demethylase 1 Is Strongly Expressed in Poorly Differentiated Neuroblastoma: Implications for Therapy
Authors: Schulte Johannes H. , Lim Soyoung , Schramm Alexander , Friedrichs Nicolaus , Koster Jan , Versteeg Rogier , Ora Ingrid , Pajtler Kristian , Klein-Hitpass Ludger , Kuhfittig-Kulle Steffi , Metzger Eric , Schüle Roland , Eggert Angelika , Buettner Reinhard , Kirfel Jutta
Published: March 2023

Abstract
Aberrant epigenetic changes in DNA methylation and histone acetylation are hallmarks of most cancers, whereas histone methylation was previously considered to be irreversible and less versatile. Recently, several histone demethylases were identified catalyzing the removal of methyl groups from histone H3 lysine residues and thereby influencing gene expression. Neuroblastomas continue to remain a clinical challenge despite advances in multimodal therapy. Here, we address the functional significance of the chromatin-modifying enzyme lysine-specific demethylase 1 (LSD1) in neuroblastoma. LSD1 expression correlated with adverse outcome and was inversely correlated with differentiation in neuroblastic tumors. Differentiation of neuroblastoma cells resulted in down-regulation of LSD1. Small interfering RNA–mediated knockdown of LSD1 decreased cellular growth, induced expression of differentiation-associated genes, and increased target gene–specific H3K4 methylation. Moreover, LSD1 inhibition using monoamine oxidase inhibitors resulted in an increase of global H3K4 methylation and growth inhibition of neuroblastoma cells in vitro. Finally, targeting LSD1 reduced neuroblastoma xenograft growth in vivo. Here, we provide the first evidence that a histone demethylase, LSD1, is involved in maintaining the undifferentiated, malignant phenotype of neuroblastoma cells. We show that inhibition of LSD1 reprograms the transcriptome of neuroblastoma cells and inhibits neuroblastoma xenograft growth. Our results suggest that targeting histone demethylases may provide a novel option for cancer therapy. [Cancer Res 2009;69(5):2065–71]
Data from Characterization of the HDAC1 Complex That Regulates the Sensitivity of Cancer Cells to Oxidative Stress
Authors: Kato Takuya , Shimono Yohei , Hasegawa Masaki , Jijiwa Mayumi , Enomoto Atsushi , Asai Naoya , Murakumo Yoshiki , Takahashi Masahide
Published: March 2023

Abstract
Histone deacetylases (HDAC) are involved in carcinogenesis through their regulation of cell proliferation, differentiation, and survival. The inhibitors of HDAC exhibit profound synergistic effects in cancer treatment when combined with other anticancer drugs. However, the molecular mechanisms underlying this synergy are not fully understood. Here, we show that HDAC1 increases the resistance of cancer cells to oxidative stress by negatively regulating the expression of thioredoxin binding protein 2 (TBP-2). We found that the recruitment of HDAC1 to the TBP-2 promoter is mediated by a protein complex consisting of RET finger protein (RFP; also called TRIM27) and the trimeric transcription factor NF-Y. Accordingly, RNA interference–mediated depletion of RFP led to the disruption of the protein complex and a marked increase in the sensitivity of cancer cells to cisplatin, a potent inducer of oxidative stress. Furthermore, high levels of RFP expression correlated with down-regulation of TBP-2 in human colon cancers and were associated with poor clinical outcome. These findings reveal the diverse cancer-promoting activities of HDAC1 and identify RFP as a key regulator that provides cancer cells with resistance to anticancer drugs. [Cancer Res 2009;69(8):3597–604]
Data from Androgen Receptor Controls EGFR and ERBB2 Gene Expression at Different Levels in Prostate Cancer Cell Lines
Authors: Pignon Jean-Christophe , Koopmansch Benjamin , Nolens Gregory , Delacroix Laurence , Waltregny David , Winkler Rosita
Published: March 2023

Abstract
EGFR or ERBB2 contributes to prostate cancer (PCa) progression by activating the androgen receptor (AR) in hormone-poor conditions. Here, we investigated the mechanisms by which androgens regulate EGFR and ERBB2 expression in PCa cells. In steroid-depleted medium (SDM), EGFR protein was less abundant in androgen-sensitive LNCaP than in androgen ablation–resistant 22Rv1 cells, whereas transcript levels were similar. Dihydrotestosterone (DHT) treatment increased both EGFR mRNA and protein levels and stimulated RNA polymerase II recruitment to the EGFR gene promoter, whereas it decreased ERBB2 transcript and protein levels in LNCaP cells. DHT altered neither EGFR or ERBB2 levels nor the abundance of prostate-specific antigen (PSA), TMEPA1, or TMPRSS2 mRNAs in 22Rv1 cells, which express the full-length and a shorter AR isoform deleted from the COOH-terminal domain (ARΔCTD). The contribution of both AR isoforms to the expression of these genes was assessed by small interfering RNAs targeting only the full-length or both AR isoforms. Silencing of both isoforms strongly reduced PSA, TMEPA1, and TMPRSS2 transcript levels. Inhibition of both AR isoforms did not affect EGFR and ERBB2 transcript levels but decreased EGFR and increased ERBB2 protein levels. Proliferation of 22Rv1 cells in SDM was inhibited in the absence of AR and ARΔCTD. A further decrease was obtained with PKI166, an EGFR/ERBB2 kinase inhibitor. Overall, we showed that ARΔCTD is responsible for constitutive EGFR expression and ERBB2 repression in 22Rv1 cells and that ARΔCTD and tyrosine kinase receptors are necessary for sustained 22Rv1 cell growth. [Cancer Res 2009;69(7):2941–9]
Data from The Membrane Mucin Muc4 Inhibits Apoptosis Induced by Multiple Insults via ErbB2-Dependent and ErbB2-Independent Mechanisms
Authors: Workman Heather C. , Sweeney Colleen , Carraway Kermit L.
Published: March 2023

Abstract
The aberrant expression of membrane mucins such as Muc1 and Muc4 by tumor cells has been shown to engage signaling pathways that promote cellular properties associated with tumor progression. Our previous studies have shown that Muc4 interacts with and potentiates signaling by the ErbB2 (HER2) receptor tyrosine kinase through an epidermal growth factor–like domain in its extracellular region. Here, we show that expression of Muc4 in human A375 melanoma cells and MCF7 breast cancer cells confers resistance to apoptosis induced by a variety of stimuli, including chemotherapeutic agents, the absence of serum factors, and the loss of cellular adhesion. Mapping experiments revealed that the O-glycosylation and cytosolic domains of Muc4 are dispensable for its antiapoptotic activity, and are also dispensable for the potentiation of signaling by ErbB2. Knockdown of endogenous Muc4 in JIMT-1 breast cancer cells sensitizes cells to apoptotic stimuli, and this can be rescued by Muc4 forms lacking the O-glycosylation or cytosolic domains. Surprisingly, however, the molecular mechanisms underlying Muc4 antiapoptotic activity vary among cell lines. Although Muc4 in JIMT-1 cells engages ErbB2 to promote cell survival, its antiapoptotic mechanism in MCF7 and A375 cells seems to be independent of ErbB2. However, Muc4 expression in all cell lines culminates in the phosphorylation and inactivation of the proapoptotic protein Bad and the elevation of the prosurvival protein Bcl-xL. Our observations suggest that tumor cells can exploit the versatile antiapoptotic activities of Muc4 to acquire resistance to therapeutic agents, and augment cell survival after the loss of adhesion and microenvironment-derived survival factors. [Cancer Res 2009;69(7):2845–52]
Data from Altered Expression of Neurotensin Receptors Is Associated with the Differentiation State of Prostate Cancer
Authors: Swift Stephanie L. , Burns Julie E. , Maitland Norman J.
Published: March 2023

Abstract
In prostate cancer, traditional treatments such as androgen response manipulation often provide only temporary resolution of disease, with emergence of a more aggressive, androgen-independent tumor following initial therapy. To treat recurrent disease, cell surface proteins that are specifically overexpressed on malignant cells may be useful for generating targeted therapeutics. Recent evidence suggests that neurotensin receptors (NTR) are recruited in advanced prostate cancer as an alternative growth pathway in the absence of androgens. In this study, we assessed the potential use of these receptors as targets by analyzing NTR expression patterns in human prostate cell lines and primary prostate tumor cell cultures derived from patient samples. In primary tumor cell cultures, NTR1 was upregulated in cells with a basal phenotype (cytokeratin 1/5/10/14+), whereas NTR2 and NTR3 were upregulated in cells with luminal phenotype (cytokeratin 18+). Similar patterns of NTR expression occurred in benign prostate tissue sections, implicating differentiation state as a basis for the differences observed in tumor cell lines. Our findings support the use of NTRs as tools for therapeutic targeting in prostate cancers composed of both poorly differentiated and/or well-differentiated cells. Cancer Res; 70(1); 347–56
Data from Epigenetic Regulation of c-ROS Receptor Tyrosine Kinase Expression in Malignant Gliomas
Authors: Jun Hyun Jung , Woolfenden Steve , Coven Shanie , Lane Keara , Bronson Roderick , Housman David , Charest Alan
Published: March 2023

Abstract
The proto-oncogene tyrosine kinase c-ROS is an orphan receptor whose normal expression pattern is tightly spatio-temporally restricted during development. In glioma, c-ROS mRNA expression is frequently ectopically up-regulated. In this study, we determined by immunohistochemical means that c-ROS receptor protein is present in 25% of low-grade and 30% of malignant glioma tumor samples from tissue microarrays. We then explored the molecular basis for the up-regulation of c-ROS expression in these tumors. We identified and characterized the c-ROS gene promoter region and report that the ectopic expression of c-ROS in tumors is tied to hypomethylation of a CpG island in the c-ROS promoter. Bisulfite sequencing analysis in glioma tumor samples revealed that demethylation of the CpG island (−384 to −132 bp) correlated with c-ROS expression. Moreover, c-ROS expression could be activated by treatment of c-ROS–negative cells with the demethylating agent 5-aza-2′-deoxycytidine. These results establish a strong link between c-ROS promoter demethylation and gain of c-ROS expression and function in glioma. Our data suggest that epigenetic activation of c-ROS represents an important oncogenic mechanism for glioma initiation and progression and suggest that cautionary measures in the clinical use of 5-aza-dC for the treatment of glioma be taken into consideration. [Cancer Res 2009;69(6):2180–4]
Data from Preferential Induction of EphB4 over EphB2 and Its Implication in Colorectal Cancer Progression
Authors: Kumar S. Ram , Scehnet Jeffrey S. , Ley Eric J. , Singh Jasbir , Krasnoperov Valery , Liu Ren , Manchanda Parmeet K. , Ladner Robert D. , Hawes Debra , Weaver Fred A. , Beart Robert W. , Singh Gagandeep , Nguyen Cu , Kahn Michael , Gill Parkash S.
Published: March 2023

Abstract
The receptor tyrosine kinase EphB2 is expressed by colon progenitor cells; however, only 39% of colorectal tumors express EphB2 and expression levels decline with disease progression. Conversely, EphB4 is absent in normal colon but is expressed in all 102 colorectal cancer specimens analyzed, and its expression level correlates with higher tumor stage and grade. Both EphB4 and EphB2 are regulated by the Wnt pathway, the activation of which is critically required for the progression of colorectal cancer. Differential usage of transcriptional coactivator cyclic AMP-responsive element binding protein–binding protein (CBP) over p300 by the Wnt/β-catenin pathway is known to suppress differentiation and increase proliferation. We show that the β-catenin-CBP complex induces EphB4 and represses EphB2, in contrast to the β-catenin-p300 complex. Gain of EphB4 provides survival advantage to tumor cells and resistance to innate tumor necrosis factor-related apoptosis-inducing ligand–mediated cell death. Knockdown of EphB4 inhibits tumor growth and metastases. Our work is the first to show that EphB4 is preferentially induced in colorectal cancer, in contrast to EphB2, whereby tumor cells acquire a survival advantage. [Cancer Res 2009;69(9):3736–45]
Data from Blockade of a Chemokine, CCL2, Reduces Chronic Colitis-Associated Carcinogenesis in Mice
Authors: Popivanova Boryana Konstantinova , Kostadinova Feodora Ivanova , Furuichi Kengo , Shamekh Mohamed M. , Kondo Toshikazu , Wada Takashi , Egashira Kensuke , Mukaida Naofumi
Published: March 2023

Abstract
Accumulating evidence indicates the crucial contribution of chronic inflammation to various types of carcinogenesis, including colon carcinoma associated with ulcerative colitis and asbestosis-induced malignant mesothelioma. Ulcerative colitis–associated colon carcinogenesis can be recapitulated in mice by azoxymethane administration followed by repetitive dextran sulfate sodium ingestion. In the course of this carcinogenesis process, the expression of a macrophage-tropic chemokine, CCL2, was enhanced together with intracolonic massive infiltration of macrophages, which were a major source of cyclooxygenase (COX)-2, a crucial mediator of colon carcinogenesis. Mice deficient in CCL2-specific receptor, CCR2, exhibited less macrophage infiltration and lower tumor numbers with attenuated COX-2 expression. Moreover, CCL2 antagonists decreased intracolonic macrophage infiltration and COX-2 expression, attenuated neovascularization, and eventually reduced the numbers and size of colon tumors, even when given after multiple colon tumors have developed. These observations identify CCL2 as a crucial mediator of the initiation and progression of chronic colitis–associated colon carcinogenesis and suggest that targeting CCL2 may be useful in treating colon cancers, particularly those associated with chronic inflammation. [Cancer Res 2009;69(19):7884–92]
Data from cIAP1, cIAP2, and XIAP Act Cooperatively via Nonredundant Pathways to Regulate Genotoxic Stress–Induced Nuclear Factor-κB Activation
Authors: Jin Hyung-Seung , Lee Dong-Hee , Kim Dong-Hwan , Chung Ji-Hye , Lee Seul-Ji , Lee Tae H.
Published: March 2023

Abstract
Various genotoxic agents cause monoubiquitination of NEMO/IKKγ—the regulatory subunit of IκB kinase (IKK) complex—in the nucleus. Ubiquitinated NEMO exits from the nucleus and forms a complex with the IKK catalytic subunits IKKα and IKKβ, resulting in IKK activation and, ultimately, nuclear factor-κB (NF-κB) activation. Thus, NEMO ubiquitination is a prerequisite for IKK-dependent activation of NF-κB. However, the IKK activation mechanism is unknown and the NEMO-ubiquitinating E3 enzyme has not been identified. We found that inhibitors of apoptosis protein (IAP) regulate genotoxic stress–induced NF-κB activation at different levels. XIAP mediates activation of the upstream IKK kinase, TAK1, and couples activated TAK1 to the IKK complex. This XIAP-dependent event occurs in response to camptotechin or etoposide/VP16; however, XIAP is dispensable for activation of NF-κB by doxorubicin, which engages a MEK-ERK pathway to activate IKK. We also show that cIAP1 mediates NEMO ubiquitination and cIAP2 regulates an event downstream of NEMO ubiquitination. Our study highlights nonredundant cooperative contributions of IAPs to antiapoptotic NF-κB activation by genotoxic signals beyond their classic caspase inhibitory functions. [Cancer Res 2009;69(5):1782–91]
Data from Nucleolar Targeting of RelA(p65) Is Regulated by COMMD1-Dependent Ubiquitination
Authors: Thoms Hazel C. , Loveridge Carolyn J. , Simpson James , Clipson Alexandra , Reinhardt Karina , Dunlop Malcolm G. , Stark Lesley A.
Published: March 2023

Abstract
Stimulation of the NF-κB pathway can have proapoptotic or antiapoptotic consequences, and one mechanism that determines the outcome is the nuclear distribution of RelA. Certain stress stimuli induce nucleolar accumulation of RelA thereby mediating apoptosis, whereas others induce nucleoplasmic accumulation and inhibition of apoptosis. Here we investigated the mechanisms that regulate the nuclear distribution of RelA, specifically, the role of the ubiquitin/proteasome system. We found that stress-induced nucleolar translocation of RelA is preceded by ubiquitination of the protein. We also found that chemical proteasome inhibitors induce the ubiquitination and nucleolar translocation of RelA and that this is required for the apoptotic response to these agents. We show that the RelA nucleolar localization signal (amino acids 27–30) is a critical domain for ubiquitination of the protein but that the lysine residue within this motif is not a direct target. We show that RelA binds COMMD1, the rate-limiting component of the RelA ubiquitin ligase complex, in response to stress. Furthermore, we show that overexpression of COMMD1 promotes stress-mediated nucleolar targeting of RelA, whereas knockdown of COMMD1 blocks this effect, causing RelA to remain in the nucleoplasm. These data identify a new role for COMMD1 in regulating the nuclear/nucleolar distribution of RelA and suggest that ubiquitination acts as a signal for transport of RelA to the nucleolus. These findings have relevance to the design of chemopreventative/anticancer agents that act by targeting RelA to the nucleolar compartment. Cancer Res; 70(1); 139–49
Data from Magnetovaccination as a Novel Method to Assess and Quantify Dendritic Cell Tumor Antigen Capture and Delivery to Lymph Nodes
Authors: Long Christopher M. , van Laarhoven Hanneke W.M. , Bulte Jeff W.M. , Levitsky Hyam I.
Published: March 2023

Abstract
A major parameter limiting immune responses to vaccination is the number of activated antigen-presenting cells (APC) that capture antigen and migrate to draining lymph nodes (LN). Currently, a quantitative noninvasive technique for monitoring in vivo antigen capture and delivery is lacking. The use of cellular magnetic resonance (MR) imaging (MRI) is a promising approach for this purpose; however, cellular imaging currently requires ex vivo prelabeling of cells with contrast agents followed by reintroduction of cells into the subject being monitored. Here, we describe an in vivo labeling method, which relies upon cell-to-cell transfer of superparamagnetic iron oxide (SPIO) from tumor cells to endogenous APCs, in situ, to quantify APC delivery to LNs in a tumor vaccine model. Mice were immunized with a tumor cell–based vaccine that was irradiated and labeled with SPIO. APCs that had captured SPIO were imaged over time as they accumulated in LNs. We show here that MRI is capable of monitoring, in vivo, the trafficking of magnetically labeled APCs inducing a tumor-specific immune response, and that these cells can be magnetically recovered ex vivo. Excellent correlation was observed between in vivo and ex vivo quantification of APCs, with resolution sufficient to detect increased APC trafficking elicited by an adjuvant. This study shows the potential of magnetovaccination and MRI cell tracking to systematically evaluate a key parameter relevant to the optimization of vaccine therapies through noninvasive MRI-based quantification of APC numbers. [Cancer Res 2009;69(7):3180–7]
Data from Identification of Copy Number Abnormalities and Inactivating Mutations in Two Negative Regulators of Nuclear Factor-κB Signaling Pathways in Waldenström's Macroglobulinemia
Authors: Braggio Esteban , Keats Jonathan J. , Leleu Xavier , Van Wier Scott , Jimenez-Zepeda Victor H. , Valdez Riccardo , Schop Roelandt F.J. , Price-Troska Tammy , Henderson Kimberly , Sacco Antonio , Azab Feda , Greipp Philip , Gertz Morie , Hayman Suzanne , Rajkumar S. Vincent , Carpten John , Chesi Marta , Barrett Michael , Stewart A. Keith , Dogan Ahmet , Bergsagel P. Leif , Ghobrial Irene M. , Fonseca Rafael
Published: March 2023

Abstract
Waldenström's macroglobulinemia (WM) is a distinct clinicobiological entity defined as a B-cell neoplasm characterized by a lymphoplasmacytic infiltrate in bone marrow (BM) and IgM paraprotein production. Cytogenetic analyses were historically limited by difficulty in obtaining tumor metaphases, and the genetic basis of the disease remains poorly defined. Here, we performed a comprehensive analysis in 42 WM patients by using a high-resolution, array-based comparative genomic hybridization approach to unravel the genetic mechanisms associated with WM pathogenesis. Overall, 83% of cases have chromosomal abnormalities, with a median of three abnormalities per patient. Gain of 6p was the second most common abnormality (17%), and its presence was always concomitant with 6q loss. A minimal deleted region, including MIRN15A and MIRN16-1, was delineated on 13q14 in 10% of patients. Of interest, we reported biallelic deletions and/or inactivating mutations with uniparental disomy in tumor necrosis factor (TNF) receptor–associated factor 3 and TNFα-induced protein 3, two negative regulators of the nuclear factor-κB (NF-κB) signaling pathway. Furthermore, we confirmed the association between TRAF3 inactivation and increased transcriptional activity of NF-κB target genes. Mutational activation of the NF-κB pathway, which is normally activated by ligand receptor interactions within the BM microenvironment, highlights its biological importance, and suggests a therapeutic role for inhibitors of NF-κB pathway activation in the treatment of WM. [Cancer Res 2009;69(8):3579–88]
Data from Rho GDP Dissociation Inhibitor 2 Suppresses Metastasis via Unconventional Regulation of RhoGTPases
Authors: Moissoglu Konstadinos , McRoberts Kevin S. , Meier Jeremy A. , Theodorescu Dan , Schwartz Martin A.
Published: March 2023

Abstract
Rho GDP dissociation inhibitor 2 (RhoGDI2) has been identified as a metastasis suppressor in bladder and possibly other cancers. This protein is a member of a family of proteins that maintain Rho GTPases in the cytoplasm and inhibit their activation and function. To understand the mechanism of metastasis suppression, we compared effects of RhoGDI1 and RhoGDI2. Despite showing much stronger inhibition of metastasis, RhoGDI2 is a weak inhibitor of Rho GTPase membrane targeting and function. However, point mutants that increase or decrease the affinity of RhoGDI2 for GTPases abolished its ability to inhibit metastasis. Surprisingly, metastasis suppression correlates with increased rather than decreased Rac1 activity. These data show that RhoGDI2 metastasis inhibition works through Rho GTPases but via a mechanism distinct from inhibition of membrane association. [Cancer Res 2009;69(7):2838–44]