bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Dynamics of the Immune Reaction to Pancreatic Cancer from Inception to Invasion
Authors: Clark Carolyn E. , Hingorani Sunil R. , Mick Rosemarie , Combs Chelsea , Tuveson David A. , Vonderheide Robert H.
Published: March 2023

Abstract
The dynamics of cancer immunosurveillance remain incompletely understood, hampering efforts to develop immunotherapy of cancer. We evaluated the evolving in vivo immune response to a spontaneous tumor in a genetically defined mouse model of pancreatic ductal adenocarcinoma from the inception of preinvasive disease to invasive cancer. We observed a prominent leukocytic infiltration even around the lowest grade preinvasive lesions, but immunosuppressive cells, including tumor-associated macrophages, myeloid-derived suppressor cells (MDSC), and regulatory T cells (Treg), dominated the early response and persisted through invasive cancer. Effector T cells, however, were scarce in preinvasive lesions, found in only a subset of advanced cancers, and showed no evidence of activation. The lack of tumor-infiltrating effector T cells strongly correlated with the presence of intratumoral MDSC with a near mutual exclusion. In vitro, we found that MDSC suppressed T-cell proliferation. Overall, our results show that suppressive cells of the host immune system appear early during pancreatic tumorigenesis, preceding and outweighing antitumor cellular immunity, and likely contribute to disease progression. Thus, in contrast to the hypothesis that an early “elimination phase” of cancer immunosurveillance is eventually overwhelmed by a growing invasive tumor, our findings suggest that productive tumor immunity may be undermined from the start. Efforts to test potent inhibitors of MDSC, tumor-associated macrophages, and Treg, particularly early in the disease represent important next steps for developing novel immunotherapy of cancer. [Cancer Res 2007;67(19):9518–27]
Data from Lin-7C/VELI3/MALS-3: An Essential Component in Metastasis of Human Squamous Cell Carcinoma
Authors: Onda Takeshi , Uzawa Katsuhiro , Nakashima Dai , Saito Kengo , Iwadate Yasuo , Seki Naohiko , Shibahara Takahiko , Tanzawa Hideki
Published: March 2023

Abstract
Using proteomic selection, functional verification, and clinical validation, we identified specific down-regulation of Lin-7C/VELI3/MALS-3 (Lin-7C), which marks oral squamous cell carcinoma (OSCC) metastasis. Despite a rarity of sequence variations in the Lin-7C gene in both primary OSCC and OSCC-derived cells, a high prevalence of hypermethylation was detected in the CpG island region that strongly correlated with its down-regulation. Inducible Lin-7C mRNA by experimental demethylation was found in all OSCC cells tested. Overexpression of the Lin-7C gene in an OSCC cell clone does not contribute to underproliferation but results in a noninvasive phenotype with elevated β-catenin expression. Experimental metastases in multiple organs of immunodeficient mice were inhibited in cells expressing Lin-7C. Finally, the Lin-7C expression status in primary tumors afforded significantly (P < 0.001) high accuracy for predicting lymph node metastasis. These results establish Lin-7C as a novel target of early detection, prevention, and therapy for OSCC metastasis. [Cancer Res 2007;67(20):9643–8]
Data from Tumor-Secreted Vascular Endothelial Growth Factor-C Is Necessary for Prostate Cancer Lymphangiogenesis, but Lymphangiogenesis Is Unnecessary for Lymph Node Metastasis
Authors: Wong Sunny Y. , Haack Herbert , Crowley Denise , Barry Marc , Bronson Roderick T. , Hynes Richard O.
Published: March 2023

Abstract
Dissemination to draining lymph nodes is a frequent first step in prostate cancer metastasis. Although tumors metastasize to lymph nodes via the lymphatics, the importance of lymphangiogenesis in mediating the process remains controversial. Here, we inhibit intratumoral lymphangiogenesis in s.c. and surgical orthotopic implantation mouse models of human prostate cancer using several strategies. Stable expression of small interfering RNAs (siRNA) targeted against human vascular endothelial growth factor-C (VEGF-C) in PC-3 cells reduced intratumoral lymphatics by 99% in s.c. tumors, indicating that tumor-secreted VEGF-C is necessary for lymphangiogenesis. Expression of siRNAs against human VEGF-A somewhat reduced tumor lymphangiogenesis. Secretion of a soluble VEGF receptor-3/Flt4 fusion protein by PC-3 cells reduced intratumoral lymphatics by 100% in s.c. tumors. Combination of soluble Flt4 and VEGF-C siRNA yielded >92% reduction of intratumoral lymphatics in orthotopic prostate tumors. However, metastasis to lymph nodes was not significantly affected regardless of intratumoral lymphatic vessel density. The abundance of marginal lymphatics at the tumor-stromal interface was unchanged in orthotopic tumors whose intratumoral lymphatics were inhibited, suggesting that these marginal vessels could be sufficient for lymph node metastasis. Hematogenous metastasis (blood tumor burden, lung metastasis) correlated with degree of lymph node invasion. We also analyzed the lymphatics in spontaneous transgenic adenocarcinomas of the mouse prostate which metastasize to lymph nodes. Progression from well-differentiated prostate intraepithelial neoplasia to metastatic, undifferentiated adenocarcinoma was accompanied by loss of lymphatics. These results suggest that tumor-secreted VEGF-C and, to a lesser extent, VEGF-A, are important for inducing prostate cancer intratumoral lymphangiogenesis but are unnecessary for lymph node metastasis.
Data from Retroviral Insertional Mutagenesis Identifies Genes that Collaborate with NUP98-HOXD13 during Leukemic Transformation
Authors: Slape Christopher , Hartung Helge , Lin Ying-Wei , Bies Juraj , Wolff Linda , Aplan Peter D.
Published: March 2023

Abstract
The t(2;11)(q31;p15) chromosomal translocation results in a fusion between the NUP98 and HOXD13 genes and has been observed in patients with myelodysplastic syndrome (MDS) or acute myelogenous leukemia. We previously showed that expression of the NUP98-HOXD13 (NHD13) fusion gene in transgenic mice results in an invariably fatal MDS; approximately one third of mice die due to complications of severe pancytopenia, and about two thirds progress to a fatal acute leukemia. In the present study, we used retroviral insertional mutagenesis to identify genes that might collaborate with NHD13 as the MDS transformed to an acute leukemia. Newborn NHD13 transgenic mice and littermate controls were infected with the MOL4070LTR retrovirus. The onset of leukemia was accelerated, suggesting a synergistic effect between the NHD13 transgene and the genes neighboring retroviral insertion events. We identified numerous common insertion sites located near protein-coding genes and confirmed dysregulation of a subset of these by expression analyses. Among these genes were Meis1, a known collaborator of HOX and NUP98-HOX fusion genes, and Mn1, a transcriptional coactivator involved in human leukemia through fusion with the TEL gene. Other putative collaborators included Gata2, Erg, and Epor. Of note, we identified a common insertion site that was >100 kb from the nearest coding gene, but within 20 kb of the miR29a/miR29b1 microRNA locus. Both of these miRNA were up-regulated, demonstrating that retroviral insertional mutagenesis can target miRNA loci as well as protein-coding loci. Our data provide new insights into NHD13-mediated leukemogenesis as well as retroviral insertional mutagenesis mechanisms. [Cancer Res 2007;67(11):5148–55]
Data from The Role of Protein Binding in Induction of Apoptosis by Phenethyl Isothiocyanate and Sulforaphane in Human Non–Small Lung Cancer Cells
Authors: Mi Lixin , Wang Xiantao , Govind Sudha , Hood Brian L. , Veenstra Timothy D. , Conrads Thomas P. , Saha Daniel T. , Goldman Radoslav , Chung Fung-Lung
Published: March 2023

Abstract
Induction of apoptosis underlies a mechanism for inhibiting tumorigenesis by phenethyl isothiocyanate (PEITC) and sulforaphane (SFN). However, the upstream events by which isothiocyanates (ITC) induce apoptosis have not been fully investigated. As electrophiles, ITCs could trigger apoptosis by binding to DNA or proteins or by inducing oxidative stress. To better understand the molecular mechanisms of apoptosis by ITCs, we examined, as a first step, the role of these events in human non–small lung cancer A549 cells. PEITC was a more potent inducer than SFN; it induced apoptosis at 20 μmol/L, whereas SFN induced at 40 μmol/L but not at 20 μmol/L. To study binding with cellular proteins and DNA, cells were treated with 14C-ITCs; the initial protein binding by PEITC was almost 3-fold than that of SFN. The binding by PEITC increased with time, whereas binding by SFN remained low. Therefore, 4 h after incubation proteins became the predominant targets for PEITC with a 6-fold binding than that of SFN. To characterize the chemical nature of binding by the ITCs, we used bovine serum albumin (BSA) as a surrogate protein. PEITC also modified BSA covalently to a greater extent than SFN occurring exclusively at cysteine residues. Surprisingly, neither PEITC nor SFN bound to DNA or RNA at detectable levels or caused significant DNA strand breakage. The levels of oxidative damage in cells, measured as reactive oxygen species, 8-oxo-deoxyguanosine, and protein carbonyls formation, were greater in cells treated with SFN than PEITC. Because PEITC is a stronger inducer of apoptosis than SFN, these results indicate that direct covalent binding to cellular proteins is an important early event in the induction of apoptosis by the ITCs. [Cancer Res 2007;67(13):6409–16]
Data from Autophagy Is Activated in Colorectal Cancer Cells and Contributes to the Tolerance to Nutrient Deprivation
Authors: Sato Kazunori , Tsuchihara Katsuya , Fujii Satoshi , Sugiyama Masanori , Goya Tomoyuki , Atomi Yutaka , Ueno Takashi , Ochiai Atsushi , Esumi Hiroyasu
Published: March 2023

Abstract
Several types of cancer cells, including colorectal cancer–derived cell lines, show austerity, the resistance to nutrient starvation, but exactly how cancer cells obtain energy sources under conditions in which their external nutrient supply is extremely limited remains to be clarified. Because autophagy is a catabolic process by which cells supply amino acids from self-digested organelles, cancer cells are likely to use autophagy to obtain amino acids as alternative energy sources. Amino acid deprivation-induced autophagy was assessed in DLD-1 and other colorectal cancer–derived cell lines. The autophagosome-incorporated LC3-II protein level increased after treatment with a combination of autolysosome inhibitors, which interferes with the consumption of autophagosomes. Autophagosome formation was also morphologically confirmed using ectopically expressed green fluorescent protein-LC3 fusion proteins in DLD-1 and SW480 cells. These data suggest that autophagosomes were actively produced and promptly consumed in colorectal cancer cells under nutrient starvation. Autolysosome inhibitors and 3-methyl adenine, which suppresses autophagosome formation, remarkably enhanced apoptosis under amino acid–deprived and glucose-deprived condition. Similar results were obtained in the cells with decreased ATG7 level by the RNA interference. These data suggest that autophagy is pivotal for the survival of colorectal cancer cells that have acquired austerity. Furthermore, autophagosome formation was seen only in the tumor cells but not in the adjacent noncancerous epithelial cells of colorectal cancer specimens. Taken together, autophagy is activated in colorectal cancers in vitro and in vivo, and autophagy may contribute to the survival of the cancer cells in their microenvironment. [Cancer Res 2007;67(20):9677–84]
Data from Insertional Mutagenesis Reveals Progression Genes and Checkpoints in MYC/Runx2 Lymphomas
Authors: Stewart Monica , Mackay Nancy , Hanlon Linda , Blyth Karen , Scobie Linda , Cameron Ewan , Neil James C.
Published: March 2023

Abstract
In this study, we have exploited the power of insertional mutagenesis to elucidate tumor progression pathways in mice carrying two oncogenes (MYC/Runx2) that collaborate to drive early lymphoma development. Neonatal infection of these mice with Moloney murine leukemia virus resulted in accelerated tumor onset with associated increases in clonal complexity and lymphoid dissemination. Large-scale analysis of retroviral integration sites in these tumors revealed a profound bias towards a narrow range of target genes, including Jdp2 (Jundm2), D cyclin, and Pim family genes. Remarkably, direct PCR analysis of integration hotspots revealed that every progressing tumor consisted of multiple clones harboring hits at these loci, giving access to large numbers of independent insertion events and uncovering the contrasting mutagenic mechanisms operating at each target gene. Direct PCR analysis showed that high-frequency targeting occurs only in the tumor environment in vivo and is specific for the progression gene set. These results indicate that early lymphomas in MYC/Runx2 mice remain dependent on exogenous growth signals, and that progression can be achieved by constitutive activation of pathways converging on a cell cycle checkpoint that acts as the major rate-limiting step for lymphoma outgrowth. [Cancer Res 2007;67(11):5126–33]
Data from A Novel Strategy for the Discovery of MHC Class II–Restricted Tumor Antigens: Identification of a Melanotransferrin Helper T-Cell Epitope
Authors: Röhn Till A. , Reitz Annette , Paschen Annette , Nguyen Xuan D. , Schadendorf Dirk , Vogt Anne B. , Kropshofer Harald
Published: March 2023

Abstract
CD4+ helper T cells play a critical role in orchestrating host immune responses, including antitumor immunity. The limited availability of MHC class II–associated tumor antigens is still viewed as a major obstacle in the use of CD4+ T cells in cancer vaccines. Here, we describe a novel approach for the identification of MHC class II tumor-associated antigens (TAAs). By combining two-dimensional liquid chromatography and nanoelectrospray ionization tandem mass spectrometry, we developed a highly sensitive method for the detection of human leukocyte antigen (HLA)-DR–associated peptides of dendritic cells upon exposure to necrotic tumor cells. This approach led to the identification of a novel MHC class II–restricted TAA epitope derived from melanotransferrin. The epitope stimulated T cells derived from melanoma patients and healthy individuals and displayed promiscuity in HLA-DR restriction. Moreover, the same peptide was also presented by MHC class II–positive melanoma cells. This strategy may contribute to increase the number of tumor epitopes presented by MHC class II molecules and may support the development of more efficacious vaccines against cancer.
Data from Dual Role of Inactivating Lef1 Mutations in Epidermis: Tumor Promotion and Specification of Tumor Type
Authors: Niemann Catherin , Owens David M. , Schettina Peter , Watt Fiona M.
Published: March 2023

Abstract
The NH2 terminus of LEF1 is frequently mutated in human sebaceous tumors. To investigate how this contributes to cancer, we did two-stage chemical carcinogenesis on K14ΔNLef1 transgenic mice, which express NH2-terminally truncated Lef1 in the epidermal basal layer. Transgenic mice developed more tumors, more rapidly than littermate controls, even without exposure to tumor promoter. They developed sebaceous tumors, whereas controls developed squamous cell carcinomas. K14ΔNLef1 epidermis failed to up-regulate p53 and p21 proteins during tumorigenesis or in response to UV irradiation, and this correlated with impaired p14ARF induction. We propose that LEF1 NH2-terminal mutations play a dual role in skin cancer, specifying tumor type by inhibiting Wnt signaling and acting as a tumor promoter by preventing induction of p53. [Cancer Res 2007;67(7):2916–21]
Data from A Role for Endoglin as a Suppressor of Malignancy during Mouse Skin Carcinogenesis
Authors: Pérez-Gómez Eduardo , Villa-Morales María , Santos Javier , Fernández-Piqueras José , Gamallo Carlos , Dotor Javier , Bernabéu Carmelo , Quintanilla Miguel
Published: March 2023

Abstract
Endoglin is a membrane glycoprotein that acts as a coreceptor for transforming growth factor-β. We and others have previously suggested a function of endoglin as a tumor suppressor in epithelial cancer. Here, we study the expression of endoglin during chemical mouse skin carcinogenesis. We find that shedding of membrane endoglin, allowing the secretion of a soluble endoglin form, is a late event associated with progression from squamous to spindle cell carcinomas. Knockdown of endoglin in transformed keratinocytes activates the Smad2/3 signaling pathway resulting in cell growth arrest, delayed tumor latencies, and a squamous to spindle phenotypic conversion. Forced expression of the long endoglin isoform in spindle carcinoma cells blocks transforming growth factor-β1 stimulation of Smad2/3 signaling and prevents tumor formation. In contrast, expression of the short endoglin isoform has no effect on spindle cell growth in vitro or in vivo. Our results show that endoglin behaves as a suppressor of malignancy during the late stages of carcinogenesis. Therefore, disruption of membrane endoglin emerges as a crucial event for progression to spindle cell carcinomas. [Cancer Res 2007;67(21):10268–77]
Data from Repression of RUNX1 Activity by EVI1: A New Role of EVI1 in Leukemogenesis
Authors: Senyuk Vitalyi , Sinha Kislay K. , Li Donglan , Rinaldi Ciro R. , Yanamandra Sastry , Nucifora Giuseppina
Published: March 2023

Abstract
Recurring chromosomal translocations observed in human leukemia often result in the expression of fusion proteins that are DNA-binding transcription factors. These altered proteins acquire new dimerization properties that result in the assembly of inappropriate multimeric transcription complexes that deregulate hematopoietic programs and induce leukemogenesis. Recently, we reported that the fusion protein AML1/MDS1/EVI1 (AME), a product of a t(3;21)(q26;q22) associated with chronic myelogenous leukemia and acute myelogenous leukemia, displays a complex pattern of self-interaction. Here, we show that the 8th zinc finger motif of MDS1/EVI1 is an oligomerization domain involved not only in interaction of AME with itself but also in interactions with the parental proteins, RUNX1 and MDS1/EVI1, from which AME is generated. Because the 8th zinc finger motif is also present in the oncoprotein EVI1, we have evaluated the effects of the interaction between RUNX1 and EVI1 in vitro and in vivo. We found that in vitro, this interaction alters the ability of RUNX1 to bind to DNA and to regulate a reporter gene, whereas in vivo, the expression of the isolated 8th zinc finger motif of EVI1 is sufficient to block the granulocyte colony-stimulating factor–induced differentiation of 32Dcl3 cells, leading to cell death. As EVI1 is not detected in normal bone marrow cells, these data suggest that its inappropriate expression could contribute to hematopoietic transformation in part by a new mechanism that involves EVI1 association with key hematopoietic regulators, leading to their functional impairment. [Cancer Res 2007;67(12):5658–66]
Data from Scavenger Receptor-A–Targeted Leukocyte Depletion Inhibits Peritoneal Ovarian Tumor Progression
Authors: Bak S. Peter , Walters Julie Jo , Takeya Motohiro , Conejo-Garcia Jose R. , Berwin Brent L.
Published: March 2023

Abstract
Immunosuppressive leukocytes are emerging as a critical factor in facilitating tumor progression. These leukocytes are converted by the tumor microenvironment to become tolerogenic, facilitate metastasis, and to aid in neovascularization. The predominant variety of suppressive leukocytes found in human and murine ovarian cancer are called vascular leukocytes (VLC), due to sharing functions and cell surface markers of both dendritic cells and endothelial cells. Using the ID8 murine model of ovarian cancer, the aim of this study was to test the efficacy of VLC elimination as an ovarian tumor therapy. We show that carrageenan-mediated depletion of peritoneal tumor-associated leukocytes inhibits ovarian tumor progression. We then identified scavenger receptor-A (SR-A) as a cell surface receptor that is robustly and specifically expressed within human and murine ovarian tumor ascites upon VLCs. Administration of anti–SR-A immunotoxin to mice challenged with peritoneal ID8 tumors eliminated tumor-associated VLCs and, importantly, substantially inhibited peritoneal tumor burden and ascites accumulation. Moreover, the toxin required targeting to SR-A because mice that received untargeted toxin did not exhibit inhibition of tumor progression. We conclude that SR-A constitutes a novel and specific target for efficacious immunotherapeutic treatment of peritoneal ovarian cancer. [Cancer Res 2007;67(10):4783–9]
Data from Loss of Heterozygosity and Somatic Mutations of the Glucocorticoid Receptor Gene Are Rarely Found at Relapse in Pediatric Acute Lymphoblastic Leukemia but May Occur in a Subpopulation Early in the Disease Course
Authors: Irving Julie A.E. , Minto Lynne , Bailey Simon , Hall Andy G.
Published: March 2023

Abstract
Glucocorticoids are pivotal in the treatment of children with acute lymphoblastic leukemia (ALL) and have significant antileukemic effects in the majority of children. However, clinical resistance is a significant problem. Although cell line models implicate somatic mutations and loss of heterozygosity (LOH) of the glucocorticoid receptor (GR) gene as a mechanism of in vitro glucocorticoid resistance, the relevance of this mechanism as a cause of clinical resistance in children with ALL is not known. Mutational screening of all coding exons of the GR gene and LOH analyses were done in a large cohort of relapsed ALL. We show that somatic mutations and LOH of the GR rarely contribute to relapsed disease in children with ALL. However, we report the second case of ALL with a somatic mutation of the GR involving a 29-bp deletion in exon 8 and resulting in a truncated protein with loss of part of the ligand-binding domain. There was no evidence of a remaining wild-type allele. Allele-specific PCR detected the mutated clone at day 28 after presentation, which persisted at a low level throughout the disease course before relapse several years later. We hypothesize that the mutated allele present in a leukemic subclone at initial diagnosis was selected for during remission induction with glucocorticoids and contributed to the emergence of a glucocorticoid-resistant cell population.
Data from Sensitization to the Lysosomal Cell Death Pathway by Oncogene-Induced Down-regulation of Lysosome-Associated Membrane Proteins 1 and 2
Authors: Fehrenbacher Nicole , Bastholm Lone , Kirkegaard-Sørensen Thomas , Rafn Bo , Bøttzauw Trine , Nielsen Christina , Weber Ekkehard , Shirasawa Senji , Kallunki Tuula , Jäättelä Marja
Published: March 2023

Abstract
Expression and activity of lysosomal cysteine cathepsins correlate with the metastatic capacity and aggressiveness of tumors. Here, we show that transformation of murine embryonic fibroblasts with v-H-ras or c-srcY527F changes the distribution, density, and ultrastructure of the lysosomes, decreases the levels of lysosome-associated membrane proteins (LAMP-1 and LAMP-2) in an extracellular signal-regulated kinase (ERK)- and cathepsin-dependent manner, and sensitizes the cells to lysosomal cell death pathways induced by various anticancer drugs (i.e., cisplatin, etoposide, doxorubicin, and siramesine). Importantly, K-ras and erbb2 elicit a similar ERK-mediated activation of cysteine cathepsins, cathepsin-dependent down-regulation of LAMPs, and increased drug sensitivity in human colon and breast carcinoma cells, respectively. Notably, reconstitution of LAMP levels by ectopic expression or by cathepsin inhibitors protects transformed cells against the lysosomal cell death pathway. Furthermore, knockdown of either lamp1 or lamp2 is sufficient to sensitize the cells to siramesine-induced cell death and photo-oxidation–induced lysosomal destabilization. Thus, the transformation-associated ERK-mediated up-regulation of cysteine cathepsin expression and activity leads to a decrease in the levels of LAMPs, which in turn contributes to the enhanced sensitivity of transformed cells to drugs that trigger lysosomal membrane permeabilization. These data indicate that aggressive cancers with high cysteine cathepsin levels are especially sensitive to lysosomal cell death pathways and encourage the further development of lysosome-targeting compounds for cancer therapy. [Cancer Res 2008;68(16):6623–33]
Data from A Six-Gene Signature Predicting Breast Cancer Lung Metastasis
Authors: Landemaine Thomas , Jackson Amanda , Bellahcène Akeila , Rucci Nadia , Sin Soraya , Abad Berta Martin , Sierra Angels , Boudinet Alain , Guinebretière Jean-Marc , Ricevuto Enrico , Noguès Catherine , Briffod Marianne , Bièche Ivan , Cherel Pascal , Garcia Teresa , Castronovo Vincent , Teti Anna , Lidereau Rosette , Driouch Keltouma
Published: March 2023

Abstract
The lungs are a frequent target of metastatic breast cancer cells, but the underlying molecular mechanisms are unclear. All existing data were obtained either using statistical association between gene expression measurements found in primary tumors and clinical outcome, or using experimentally derived signatures from mouse tumor models. Here, we describe a distinct approach that consists of using tissue surgically resected from lung metastatic lesions and comparing their gene expression profiles with those from nonpulmonary sites, all coming from breast cancer patients. We show that the gene expression profiles of organ-specific metastatic lesions can be used to predict lung metastasis in breast cancer. We identified a set of 21 lung metastasis–associated genes. Using a cohort of 72 lymph node–negative breast cancer patients, we developed a 6-gene prognostic classifier that discriminated breast primary cancers with a significantly higher risk of lung metastasis. We then validated the predictive ability of the 6-gene signature in 3 independent cohorts of breast cancers consisting of a total of 721 patients. Finally, we show that the signature improves risk stratification independently of known standard clinical variables and a previously established lung metastasis signature based on an experimental breast cancer metastasis model. [Cancer Res 2008;68(15):6092–9]
Data from Pediatric Malignant Germ Cell Tumors Show Characteristic Transcriptome Profiles
Authors: Palmer Roger D. , Barbosa-Morais Nuno L. , Gooding Emma L. , Muralidhar Balaji , Thornton Claire M. , Pett Mark R. , Roberts Ian , Schneider Dominik T. , Thorne Natalie , Tavaré Simon , Nicholson James C. , Coleman Nicholas
Published: March 2023

Abstract
Malignant germ cell tumors (GCT) of childhood are rare and heterogeneous neoplasms thought to arise from primordial germ cells. They vary substantially in their natural history and show important clinical differences from their adult counterparts. To address the biological basis for these observations, we have undertaken a comprehensive analysis of global gene expression patterns in pediatric malignant GCTs and compared these findings with published data on adult testicular GCTs (TGCT). Our study included 27 primary tumors and assessed the principal malignant histologic types of pediatric GCT, yolk sac tumor (YST; n = 18), and seminoma (n = 9). Analysis of Affymetrix U133A GeneChip data was performed using the statistical software environment R, including gene set enrichment analysis, with cross-validation at the RNA and protein level. Unsupervised analysis showed complete separation of YSTs and seminomas by global gene expression profiles and identified a robust set of 657 discriminatory transcripts. There was no segregation of tumors of the same histology arising at different sites or at different ages within the pediatric range. In contrast, there was segregation of pediatric malignant GCTs and adult malignant TGCTs, most notably for the YSTs. The pediatric seminomas were significantly enriched for genes associated with the self-renewing pluripotent phenotype, whereas the pediatric YSTs were significantly enriched for genes associated with a differentiation and proliferation phenotype. We conclude that histologic type is the key discriminator in pediatric malignant GCTs and that the observed clinical differences between malignant GCTs of children and adults are mirrored by significant differences in global gene expression. [Cancer Res 2008;68(11):4239–47]
Data from CARM1 Regulates Estrogen-Stimulated Breast Cancer Growth through Up-regulation of E2F1
Authors: Frietze Seth , Lupien Mathieu , Silver Pamela A. , Brown Myles
Published: March 2023

Abstract
Estrogen receptor α (ERα) mediates breast cancer proliferation through transcriptional mechanisms involving the recruitment of specific coregulator complexes to the promoters of cell cycle genes. The coactivator-associated arginine methyltransferase CARM1 is a positive regulator of ERα-mediated transcriptional activation. Here, we show that CARM1 is essential for estrogen-induced cell cycle progression in the MCF-7 breast cancer cell line. CARM1 is specifically required for the estrogen-induced expression of the critical cell cycle transcriptional regulator E2F1 whereas estrogen stimulation of cyclin D1 is CARM1 independent. Upon estrogen stimulation, the E2F1 promoter is subject to CARM1-dependent dimethylation on histone H3 arginine 17 (H3R17me2) in a process that parallels the recruitment of ERα. Additionally, we find that the recruitment of CARM1 and subsequent histone arginine dimethylation are dependent on the presence of the oncogenic coactivator AIB1. Thus, CARM1 is a critical factor in the pathway of estrogen-stimulated breast cancer growth downstream of ERα and AIB1 and upstream of the cell cycle regulatory transcription factor E2F1. These studies identify CARM1 as a potential new target in the treatment of estrogen-dependent breast cancer. [Cancer Res 2008;68(1):301–6]
Data from Peptide Aptamers Targeting Mutant p53 Induce Apoptosis in Tumor Cells
Authors: Guida Elisa , Bisso Andrea , Fenollar-Ferrer Cristina , Napoli Marco , Anselmi Claudio , Girardini Javier E. , Carloni Paolo , Del Sal Giannino
Published: March 2023

Abstract
Mutations in the p53 tumor suppressor gene frequently result in expression of p53 point mutants that accumulate in cancer cells and actively collaborate with tumor progression through the acquisition of novel properties. Interfering with mutant p53 functions may represent a valid alternative for blocking tumor growth and development of aggressive phenotypes. The interactions and activities of selected proteins can be specifically modulated by the binding of peptide aptamers (PA). In the present work, we isolated PAs able to interact more efficiently with p53 conformational mutants compared with wild-type p53. The interaction between mutant p53 and PAs was further characterized using molecular modeling. Transient expression of PAs was able to reduce the transactivation activity of mutant p53 and to induce apoptosis specifically in cells expressing mutant p53. These PAs could provide a potential strategy to inhibit the oncogenic functions of mutant p53 and improve mutant p53-targeted cancer therapies. [Cancer Res 2008;68(16):6550–8]
Data from Immunoediting Sculpts Tumor Epitopes during Immunotherapy
Authors: Singh Reshma , Paterson Yvonne
Published: March 2023

Abstract
Immunoediting of tumor-associated antigens occurs in response to immune pressure. We show that the mutation of residues within epitopes of HER-2/neu leads to the outgrowth of autochthonous tumors after immunizing HER-2/neu transgenic mice with Listeria monocytogenes therapeutic vaccines expressing fragments of HER-2/neu. Three of these vaccines target the extracellular domain (LmLLO-EC1, LmLLO-EC2, and LmLLO-EC3), and two of these vaccines target the intracellular domain (Lm-LLO-IC1 and Lm-LLO-IC2). Mutations occurred in the regions of the HER-2/neu molecule targeted by the Listeria strain expressing that region, which suggests that the rate of generation of escape mutants was a significant factor in the efficacy of each vaccine. A longer delay in the onset of tumors after immunotherapy occurred with the vaccine that targeted the kinase domain. We verified that the mutations in this domain occurred within novel CD8+ T-cell epitopes, and that the mutation of these residues abrogated CTL responses to these epitopes. The long delay in the onset of tumors after immunotherapy targeting the kinase domain may be because this region of HER-2/neu cannot undergo extensive mutations without impairing its ability to signal cell growth. [Cancer Res 2007;67(5):1887–92]
Data from Human Cancer Cells Commonly Acquire DNA Damage during Mitotic Arrest
Authors: Dalton W. Brian , Nandan Mandayam O. , Moore Ryan T. , Yang Vincent W.
Published: March 2023

Abstract
The mitotic checkpoint is a mechanism that arrests the progression to anaphase until all chromosomes have achieved proper attachment to mitotic spindles. In cancer cells, satisfaction of this checkpoint is frequently delayed or prevented by various defects, some of which have been causally implicated in tumorigenesis. At the same time, deliberate induction of mitotic arrest has proved clinically useful, as antimitotic drugs that interfere with proper chromosome-spindle interactions are effective anticancer agents. However, how mitotic arrest contributes to tumorigenesis or antimitotic drug toxicity is not well defined. Here, we report that mitotic chromosomes can acquire DNA breaks during both pharmacologic and genetic induction of mitotic arrest in human cancer cells. These breaks activate a DNA damage response, occur independently of cell death, and subsequently manifest as karyotype alterations. Such breaks can also occur spontaneously, particularly in cancer cells containing mitotic spindle abnormalities. Moreover, we observed evidence of some breakage in primary human cells. Our findings thus describe a novel source of DNA damage in human cells. They also suggest that mitotic arrest may promote tumorigenesis and antimitotic toxicity by provoking DNA damage. [Cancer Res 2007;67(24):11487–92]
Data from Molecular Dissection of Hyperdiploid Multiple Myeloma by Gene Expression Profiling
Authors: Chng Wee J. , Kumar Shaji , VanWier Scott , Ahmann Greg , Price-Troska Tammy , Henderson Kim , Chung Tae-Hoon , Kim Seungchan , Mulligan George , Bryant Barbara , Carpten John , Gertz Morie , Rajkumar S. Vincent , Lacy Martha , Dispenzieri Angela , Kyle Robert , Greipp Philip , Bergsagel P. Leif , Fonseca Rafael
Published: March 2023

Abstract
Hyperdiploid multiple myeloma (H-MM) is the most common form of myeloma. In this gene expression profiling study, we show that H-MM is defined by a protein biosynthesis signature that is primarily driven by a gene dosage mechanism as a result of trisomic chromosomes. Within H-MM, four independently validated patient clusters overexpressing nonoverlapping sets of genes that form cognate pathways/networks that have potential biological importance in multiple myeloma were identified. One prominent cluster, cluster 1, is characterized by high expression of cancer testis antigen and proliferation-associated genes. Tumors from these patients were more proliferative than tumors in other clusters (median plasma cell labeling index, 3.8; P < 0.05). Another cluster, cluster 3, is characterized by genes involved in tumor necrosis factor/nuclear factor-κB signaling and antiapoptosis. These patients have better response to bortezomib as compared with patients within other clusters (70% versus 29%; P = 0.02). Furthermore, for a group of patients generally thought to have better prognosis, a cluster of patients with short survival (cluster 1; median survival, 27 months) could be identified. This analysis illustrates the heterogeneity within H-MM and the importance of defining specific cytogenetic prognostic factors. Furthermore, the signatures that defined these clusters may provide a basis for tailoring treatment to individual patients. [Cancer Res 2007;67(7):2982–9]
Data from Selective Inhibition of Growth of Tuberous Sclerosis Complex 2–Null Cells by Atorvastatin Is Associated with Impaired Rheb and Rho GTPase Function and Reduced mTOR/S6 Kinase Activity
Authors: Finlay Geraldine A. , Malhowski Amy J. , Liu Yingling , Fanburg Barry L. , Kwiatkowski David J. , Toksoz Deniz
Published: March 2023

Abstract
Inactivating mutations in the tuberous sclerosis complex 2 (TSC2) gene, which encodes tuberin, result in the development of TSC and lymphangioleiomyomatosis (LAM). The tumor suppressor effect of tuberin lies in its GTPase-activating protein activity toward Ras homologue enriched in brain (Rheb), a Ras GTPase superfamily member. The statins, 3-hydroxy-3-methylglutaryl CoA reductase inhibitors, have pleiotropic effects which may involve interference with the isoprenylation of Ras and Rho GTPases. We show that atorvastatin selectively inhibits the proliferation of Tsc2−/− mouse embryo fibroblasts and ELT-3 smooth muscle cells in response to serum and estrogen, and under serum-free conditions. The isoprenoids farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP) significantly reverse atorvastatin-induced inhibition of Tsc2−/− cell growth, suggesting that atorvastatin dually targets a farnesylated protein, such as Rheb, and a geranylgeranylated protein, such as Rho, both of which have elevated activity in Tsc2−/− cells. Atorvastatin reduced Rheb isoprenylation, GTP loading, and membrane localization. Atorvastatin also inhibited the constitutive phosphorylation of mammalian target of rapamycin, S6 kinase, and S6 found in Tsc2−/− cells in an FPP-reversible manner and attenuated the high levels of phosphorylated S6 in Tsc2-heterozygous mice. Atorvastatin, but not rapamycin, attenuated the increased levels of activated RhoA in Tsc2−/− cells, and this was reversed by GGPP. These results suggest that atorvastatin may inhibit both rapamycin-sensitive and rapamycin-insensitive mechanisms of tuberin-null cell growth, likely via Rheb and Rho inhibition, respectively. Atorvastatin may have potential therapeutic benefit in TSC syndromes, including LAM. [Cancer Res 2007;67(20):9878–86]
Data from TFAP2C Controls Hormone Response in Breast Cancer Cells through Multiple Pathways of Estrogen Signaling
Authors: Woodfield George W. , Horan Annamarie D. , Chen Yizhen , Weigel Ronald J.
Published: March 2023

Abstract
Breast cancers expressing estrogen receptor-α (ERα) are associated with a favorable biology and are more likely to respond to hormonal therapy. In addition to ERα, other pathways of estrogen response have been identified including ERβ and GPR30, a membrane receptor for estrogen, and the key mechanisms regulating expression of ERs and hormone response remain controversial. Herein, we show that TFAP2C is the key regulator of hormone responsiveness in breast carcinoma cells through the control of multiple pathways of estrogen signaling. TFAP2C regulates the expression of ERα directly by binding to the ERα promoter and indirectly via regulation of FoxM1. In so doing, TFAP2C controls the expression of ERα target genes, including pS2, MYB, and RERG. Furthermore, TFAP2C controlled the expression of GPR30. In distinct contrast, TFAP2A, a related factor expressed in breast cancer, was not involved in estrogen-mediated pathways but regulated expression of genes controlling cell cycle arrest and apoptosis including p21CIP1 and IGFBP-3. Knockdown of TFAP2C abrogated the mitogenic response to estrogen exposure and decreased hormone-responsive tumor growth of breast cancer xenografts. We conclude that TFAP2C is a central control gene of hormone response and is a novel therapeutic target in the design of new drug treatments for breast cancer. [Cancer Res 2007;67(18):8439–43]
Data from Amino-Biphosphonate–Mediated MMP-9 Inhibition Breaks the Tumor-Bone Marrow Axis Responsible for Myeloid-Derived Suppressor Cell Expansion and Macrophage Infiltration in Tumor Stroma
Authors: Melani Cecilia , Sangaletti Sabina , Barazzetta Francesca M. , Werb Zena , Colombo Mario P.
Published: March 2023

Abstract
BALB-neuT mice expressing an activated rat c-erbB-2/neu transgene under the mouse mammary tumor virus long terminal repeat show enhanced hematopoiesis with hyperproduction of myeloid-derived suppressor cells (MDSC) because of vascular endothelial growth factor (VEGF) secreted by the tumor. Here, we show that both tumor and stromal cells express matrix metalloproteinase-9 (MMP-9), thereby increasing the levels of pro–MMP-9 in the sera of tumor-bearing mice. Treatment with amino-biphosphonates impaired tumor growth, significantly decreased MMP-9 expression and the number of macrophages in tumor stroma, and reduced MDSC expansion both in bone marrow and peripheral blood by dropping serum pro–MMP-9 and VEGF. We dissected the role of tumor-derived MMP-9 from that secreted by stromal leukocytes by transplanting bone marrow from MMP-9 knockout mice into BALB-neuT mice. Although bone marrow progenitor–derived MMP-9 had a major role in driving MDSC expansion, amino-biphosphonate treatment of bone marrow chimeras further reduced both myelopoiesis and the supportive tumor stroma, thus enhancing tumor necrosis. Moreover, by reducing MDSC, amino-biphosphonates overcome the tumor-induced immune suppression and improved the generation and maintenance of antitumor immune response induced by immunization against the p185/HER-2. Our data reveal that suppression of MMP-9 activity breaks the vicious loop linking tumor growth and myeloid cell expansion, thus reducing immunosuppression. Amino-biphosphonates disclose a specific MMP-9 inhibitory activity that may broaden their application above their current usage. [Cancer Res 2007;67(23):11438–46]
Data from RASSF1A Polymorphism A133S Is Associated with Early Onset Breast Cancer in BRCA1/2 Mutation Carriers
Authors: Gao Boning , Xie Xian-Jin , Huang Chunxian , Shames David S. , Chen Tina T-L. , Lewis Cheryl M. , Bian Aihua , Zhang Bifeng , Olopade Olufunmilayo I. , Garber Judy E. , Euhus David M. , Tomlinson Gail E. , Minna John D.
Published: March 2023

Abstract
The tumor suppressor gene RASSF1A regulates cell cycle progression, apoptosis, and microtubule stability and is inactivated by promoter methylation in ∼50% of breast cancers. It has been shown previously that the polymorphism A133S in RASSF1A reduces its ability to regulate cell cycle progression and this polymorphism is associated with an increased risk of breast cancer. We analyzed the frequency of RASSF1A A133S in 190 Caucasian women without breast cancer and 653 patients with breast cancer including 138 BRCA1 and BRCA2 (BRCA1/2) mutation carriers, 395 non–BRCA1/2 mutations carriers, and 120 untested for BRCA1/2 mutations. Patients with breast cancer had a higher frequency of A133S than the controls [P = 0.017; odds ratios (OR), 1.71; 95% confidence intervals (95% CI), 1.10–2.66]. There is also a higher frequency of A133S in patients with higher familial breast cancer risk (P = 0.029; OR, 1.76; 95% CI, 1.06–2.92) and patients carrying BRCA1/2 mutations (P = 0.037, OR, 1.82; 95% CI, 1.04–3.18). Importantly, we found that the co-occurrence of a BRCA1 or BRCA2 mutation and A133S in RASSF1A was associated with earlier onset of breast cancer compared with those individuals with either a BRCA1/2 mutation or the A133S polymorphism alone (36.0 versus 42.0 years old, P = 0.002). Our data suggest that the presence of the RASSF1A A133S polymorphism is associated with breast cancer pathogenesis in general and modifies breast cancer age of onset in BRCA1/2 mutations carriers. Our results warrant a large-scale study to examine the effect of the A133S polymorphism in the development of breast and other types of cancers. [Cancer Res 2008;68(1):22–5]
Data from Traf1 Induction and Protection from Tumor Necrosis Factor by Nuclear Factor-κB p65 Is Independent of Serine 536 Phosphorylation
Authors: Sasaki Carl Y. , Slemenda Colin F. , Ghosh Paritosh , Barberi Theresa J. , Longo Dan L.
Published: March 2023

Abstract
Abnormal nuclear factor-κB (NF-κB) signaling has been attributed to the initiation and progression of cancer. Posttranslational modification of p65 facilitates optimal NF-κB signaling after activation. Here, we show that the phosphorylation of serine 536 was required for p65-mediated transcription and IκBα expression in fibroblasts. Furthermore, tumor necrosis factor (TNF) treatment slightly induced p65 phosphorylation, and both unphosphorylated and phosphorylated p65 translocated into the nucleus. The phosphorylation of serine 536 was not required for p65-mediated protection from TNF cytotoxicity and Traf1 induction in fibroblasts. Also, the corecruitment of p65 and RNA polymerase II to the Traf1 enhancer region did not require p65 phosphorylation. However, the corecruitment of p65 and RNA polymerase II to the Csf2 promoter required the phosphorylation of serine 536. These findings suggested that the requirement of serine phosphorylation at residue 536 and the distance between the NF-κB response element and the start of transcription may influence which genes will be transcribed. [Cancer Res 2007;67(23):11218–25]
Data from Novel Indenoisoquinolines NSC 725776 and NSC 724998 Produce Persistent Topoisomerase I Cleavage Complexes and Overcome Multidrug Resistance
Authors: Antony Smitha , Agama Keli K. , Miao Ze-Hong , Takagi Kazutaka , Wright Mollie H. , Robles Ana I. , Varticovski Lyuba , Nagarajan Muthukaman , Morrell Andrew , Cushman Mark , Pommier Yves
Published: March 2023

Abstract
Camptothecin (CPT) derivatives are effective anticancer drugs, especially against solid tumors. As CPTs are chemically unstable and have clinical limitations, we have synthesized indenoisoquinolines as novel topoisomerase I (Top1) inhibitors. We presently report two indenoisoquinoline derivatives, NSC 725776 and NSC 724998, which have been selected for therapeutic development. Both are potent Top1 inhibitors and induce Top1 cleavage at unique genomic positions compared with CPT. Consistent with Top1 poisoning, protein-linked DNA breaks were detected in cells treated with NSC 725776 and NSC 724998 at nanomolar concentrations. Those drug-induced protein-linked DNA breaks persisted longer after drug removal than those produced by CPT. Studies in human cells in culture show that NSC 725776 and NSC 724998 exert antiproliferative activity at submicromolar concentrations. Furthermore, NSC 725776 and NSC 724998 show cross-resistance in cells deficient or silenced for Top1, which is consistent with their selective Top1 targeting. Similar to other known Top1 inhibitors, NSC 725776–treated and NSC 724998–treated cells show an arrest of cell cycle progression in both S and G2-M and a dependence on functional p53 for their cytotoxicity. Dose-dependent γ-H2AX foci formation was readily observed in cells treated with NSC 725776 and NSC 724998. These γ-H2AX foci were detectable at pharmacologically relevant doses for up to 24 h and thus could be used as biomarkers for clinical trials (phase 0). [Cancer Res 2007;67(21):10397–405]