bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Wnt/β-Catenin Signaling Contributes to Activation of Normal and Tumorigenic Liver Progenitor Cells
Authors: Yang Wen , Yan He-Xin , Chen Lei , Liu Qiong , He Ya-Qin , Yu Le-Xing , Zhang Shu-Hui , Huang Dan-Dan , Tang Liang , Kong Xiao-Ni , Chen Chao , Liu Shu-Qin , Wu Meng-Chao , Wang Hong-Yang
Published: March 2024

Abstract
Adult hepatic progenitor (oval) cells are facultative stem cells in liver, which participate in a range of human liver diseases, including hepatocellular carcinoma (HCC). However, the molecular pathways regulating the expansion and differentiation of these cells are poorly understood. We show that active Wnt/β-catenin signaling occurs preferentially within the oval cell population, and forced expression of constitutively active β-catenin mutant promotes expansion of the oval cell population in the regenerated liver. More importantly, we identify a subpopulation of less differentiated progenitor-like cells in HCC cell lines and primary HCC tissues, which are defined by expression of the hepatic progenitor marker OV6 and endowed with endogenously active Wnt/β-catenin signaling. These OV6+ HCC cells possess a greater ability to form tumor in vivo and show a substantial resistance to standard chemotherapy compared with OV6− tumor cells. The fraction of tumor cells expressing OV6 is enriched after Wnt pathway activation, whereas inhibition of β-catenin signaling leads to a decrease in the proportion of OV6+ cells. In addition, the chemoresistance of OV6+ HCC progenitor-like cells can be reversed by lentivirus-delivered stable expression of microRNA targeting β-catenin. These results highlight the importance of the Wnt/β-catenin pathway in activation and expansion of oval cells in normal rodent models and human HCCs. OV6+ tumor cells may represent the cellular population that confers HCC chemoresistance, and therapies targeted to the Wnt/β-catenin signaling may provide a specific method to disrupt this resistance mechanism to improve overall tumor control with chemotherapy. [Cancer Res 2008;68(11):4287–95]
Data from A Novel Mechanism of Late Gene Silencing Drives SV40 Transformation of Human Mesothelial Cells
Authors: Carbone Michele , Pannuti Antonio , Zhang Lei , Testa Joseph R. , Bocchetta Maurizio
Published: March 2024

Abstract
Suppression of the late gene expression, usually by integration of the viral DNA into the host genome, is a critical step in DNA tumor virus carcinogenesis. SV40 induces high rates of transformation in infected primary human mesothelial cells in tissue culture, leading to the formation of immortal cell lines (SV40-transformed human mesothelial cell lines, S-HML). The studies described here were designed to elucidate the unusual susceptibility of primary human mesothelial cells to SV40 carcinogenesis. We found that S-HML contained wild-type, mostly episomal SV40 DNA. In these cells, the early genes that code for the viral oncogenes are expressed; at the same time, the synthesis of the late genes, capsid proteins, is suppressed and S-HML are not lysed. Late gene suppression is achieved through the production of antisense RNA molecules. These antisense RNA molecules originate in the early region of the SV40 circular chromosome and proceed in antisense orientation into the late gene region, leading to the formation of highly unstable double-strand RNA, which is rapidly degraded. Our results reveal a novel biological mechanism responsible for the suppression of late viral gene products, an important step in viral carcinogenesis in humans. [Cancer Res 2008;68(22):9488–96]
Data from ERRγ Mediates Tamoxifen Resistance in Novel Models of Invasive Lobular Breast Cancer
Authors: Riggins Rebecca B. , Lan Jennifer P-J. , Klimach Uwe , Zwart Alan , Cavalli Luciane R. , Haddad Bassem R. , Chen Li , Gong Ting , Xuan Jianhua , Ethier Stephen P. , Clarke Robert
Published: March 2024

Abstract
One-third of all estrogen receptor (ER)–positive breast tumors treated with endocrine therapy fail to respond, and the remainder is likely to relapse in the future. Almost all data on endocrine resistance has been obtained in models of invasive ductal carcinoma (IDC). However, invasive lobular carcinomas (ILC) comprise up to 15% of newly diagnosed invasive breast cancers each year and, whereas the incidence of IDC has remained relatively constant during the last 20 years, the prevalence of ILC continues to increase among postmenopausal women. We report a new model of Tamoxifen (TAM)-resistant invasive lobular breast carcinoma cells that provides novel insights into the molecular mechanisms of endocrine resistance. SUM44 cells express ER and are sensitive to the growth inhibitory effects of antiestrogens. Selection for resistance to 4-hydroxytamoxifen led to the development of the SUM44/LCCTam cell line, which exhibits decreased expression of ERα and increased expression of the estrogen-related receptor γ (ERRγ). Knockdown of ERRγ in SUM44/LCCTam cells by siRNA restores TAM sensitivity, and overexpression of ERRγ blocks the growth-inhibitory effects of TAM in SUM44 and MDA-MB-134 VI lobular breast cancer cells. ERRγ-driven transcription is also increased in SUM44/LCCTam, and inhibition of activator protein 1 (AP1) can restore or enhance TAM sensitivity. These data support a role for ERRγ/AP1 signaling in the development of TAM resistance and suggest that expression of ERRγ may be a marker of poor TAM response. [Cancer Res 2008;68(21):8908–17]
Data from TGFBR1 Haplotypes and Risk of Non–Small-Cell Lung Cancer
Authors: Lei Zhe , Liu Reng-Yun , Zhao Jun , Liu Zeyi , Jiang Xiefang , You Weiming , Chen Xiao-Feng , Liu Xia , Zhang Kui , Pasche Boris , Zhang Hong-Tao
Published: March 2024

Abstract
Transforming growth factor β (TGF-β) receptors are centrally involved in TGF-β–mediated cell growth and differentiation and are frequently inactivated in non–small-cell lung cancer (NSCLC). Constitutively decreased type I TGF-β receptor (TGFBR1) expression is emerging as a novel tumor-predisposing phenotype. The association of TGFBR1 haplotypes with risk for NSCLC has not yet been studied. We tested the hypothesis that single-nucleotide polymorphisms (SNP) and/or TGFBR1 haplotypes are associated with risk of NSCLC. We genotyped six TGFBR1 haplotype-tagging SNPs (htSNP) by PCR-RFLP assays and one htSNP by PCR-single-strand conformation polymorphism assay in two case-control studies. Case-control study 1 included 102 NSCLC patients and 104 healthy controls from Suzhou. Case-control study 2 included 131 patients with NSCLC and 133 healthy controls from Wuxi. Individuals included in both case-control studies were Han Chinese. Haplotypes were reconstructed according to the genotyping data and linkage disequilibrium status of these seven htSNPs. None of the htSNP was associated with NSCLC risk in either study. However, a four-marker CTGC haplotype was significantly more common among controls than among cases in both studies (P = 0.014 and P = 0.010, respectively), indicating that this haplotype is associated with decreased NSCLC risk {adjusted odds ratio [OR], 0.09 [95% confidence interval (95% CI), 0.01–0.61] and 0.11 [95% CI, 0.02–0.59], respectively}. Combined analysis of both studies shows a strong association of this four-marker haplotype with decreased NSCLC risk (adjusted OR, 0.11; 95% CI, 0.03–0.39). This is the first evidence of an association between a TGFBR1 haplotype and risk for NSCLC. [Cancer Res 2009;69(17):7046–52]
Data from Lin−Sca-1+CD49fhigh Stem/Progenitors Are Tumor-Initiating Cells in the Pten-Null Prostate Cancer Model
Authors: Mulholland David J. , Xin Li , Morim Ashkan , Lawson Devon , Witte Owen , Wu Hong
Published: March 2024

Abstract
We have shown previously that Pten deletion leads to the expansion of subset of prostate cancer cells positive for CK5 and p63. Although this subpopulation may be involved in tumor initiation or progression, studies to date have not functionally validated this hypothesis. Using in vitro sphere-forming assay and in vivo prostate reconstitution assay, we show here the presence of a tumor-initiating subpopulation in the Pten prostate cancer mouse model. Specifically, we show that the Lin−Sca-1+CD49fhigh (LSC) subpopulation overlaps with CK5+;p63+ cells and is significantly increased during prostate cancer initiation and progression and after castration. Mutant spheres mimic the structural organization of the epithelial compartment in the Pten-null primary tumor. Sorted LSC cells from either Pten-null spheres or primary tumors are able to regenerate prostate epithelial structure with cancerous morphology, closely mimicking that of primary cancers. Therefore, the LSC subpopulation is capable of initiating a cancerous phenotype that recapitulates the pathology seen in the primary lesions of the Pten mutant prostate model. [Cancer Res 2009;69(22):8555–62]
Data from Osteoblast-Derived Factors Induce an Expression Signature that Identifies Prostate Cancer Metastasis and Hormonal Progression
Authors: Wang Gang , Haile Simon , Comuzzi Barbara , Tien Amy H. , Wang Jun , Yong Theresa M.K. , Jelescu-Bodos Anca E. , Blaszczyk Natalie , Vessella Robert L. , Masri Bassam A. , Sadar Marianne D.
Published: March 2024

Abstract
Identification of gene expression signatures associated with metastases provides a tool to discern mechanisms and potential therapeutic targets and may lead toward a molecular classification system in pathology. Prostate cancer (CaP) frequently metastasizes to the bone to form osteoblastic lesions. Correlative clinical data and in vitro evidence have led to the hypothesis that osteoblast-derived factors promote hormonal progression of CaP cells. Here, the gene expression signature of CaP exposed to osteoblast-derived factors was identified. This signature included known androgen-regulated genes, oncogenes, tumor suppressors, and genes whose products are involved in apoptosis and cell cycle. A comparative functional genomic approach involved the application of this responsive gene expression signature to clinical samples of human CaP, melanomas, and oral cancers. Cluster analysis revealed that this gene expression signature had specificity for CaP and could resolve clinical specimens according to stage (benign, localized, and metastatic) and androgen sensitivity with an accuracy of 100% and 80%, respectively. Together, these results suggest that factors derived from osteoblasts induce a more advanced phenotype of CaP and promotes hormonal progression. [Cancer Res 2009;69(8):3433–42]
Data from Inhibition of the Sodium Potassium Adenosine Triphosphatase Pump Sensitizes Cancer Cells to Anoikis and Prevents Distant Tumor Formation
Authors: Simpson Craig D. , Mawji Imtiaz A. , Anyiwe Kika , Williams Moyo A. , Wang Xiaoming , Venugopal Amudha L. , Gronda Marcela , Hurren Rose , Cheng Sonia , Serra Stefano , Zavareh Reza Beheshti , Datti Alessandro , Wrana Jeffrey L. , Ezzat Shereen , Schimmer Aaron D.
Published: March 2024

Abstract
Normal epithelial cells undergo apoptosis upon detachment from the extracellular matrix, a process termed “anoikis.” However, malignant epithelial cells with metastatic potential resist anoikis and can survive in an anchorage-independent fashion. Molecules that sensitize resistant cells to anoikis will be useful chemical probes to understand this pathway. To identify novel anoikis sensitizers in anoikis-resistant PPC-1 prostate adenocarcinoma cells, a library of 2,000 off-patent drugs and natural products was screened for their ability to preferentially induce cell death in suspension over adherent culture conditions. This screen identified five members of the family of cardiac glycosides as anoikis sensitizers, including ouabain, peruvoside, digoxin, digitoxin, and strophanthidin. We conducted further studies with ouabain to discern the mechanism of cardiac glycoside-induced anoikis sensitization. Ouabain initiated anoikis through the mitochondrial pathway of caspase activation. In addition, ouabain sensitized cells to anoikis by inhibiting its known target, the Na+/K+ ATPase pump, and inducing hypoosmotic stress. Resistance to anoikis permits cancer cells to survive in the circulation and facilitates their metastasis to distant organs, so we tested the effects of Na+/K+ ATPase inhibition on distant tumor formation in mouse models. In these mouse models, ouabain inhibited tumor metastases but did not alter the growth of subcutaneous tumors. Thus, we have identified a novel mechanism to sensitize resistant cells to anoikis and decrease tumor metastasis. These results suggest a potential mechanism for the observed clinical reduction in metastasis and relapse in breast cancer patients who have undergone treatments with cardiac glycosides. [Cancer Res 2009;69(7):2739–47]
Data from A Novel Prostate Cancer Susceptibility Locus at 19q13
Authors: Hsu Fang-Chi , Sun Jielin , Wiklund Fredrik , Isaacs Sarah D. , Wiley Kathleen E. , Purcell Lina D. , Gao Zhengrong , Stattin Pär , Zhu Yi , Kim Seong-Tae , Zhang Zheng , Liu Wennuan , Chang Bao-Li , Walsh Patrick C. , Duggan David , Carpten John D. , Isaacs William B. , Grönberg Henrik , Xu Jianfeng , Zheng S. Lilly
Published: March 2024

Abstract
A two-stage genome-wide association study (GWAS) of the Cancer Genetic Markers of Susceptibility (CGEMS) initiative identified single nucleotide polymorphisms (SNP) in 150 regions across the genome that may be associated with prostate cancer (PCa) risk. We filtered these results to identify 43 independent SNPs where the frequency of the risk allele was consistently higher in cases than in controls in each of the five CGEMS study populations. Genotype information for 22 of these 43 SNPs was obtained either directly by genotyping or indirectly by imputation in our PCa GWAS of 500 cases and 500 controls selected from a population-based case-control study in Sweden [Cancer of the Prostate in Sweden (CAPS)]. Two of these 22 SNPs were significantly associated with PCa risk (P < 0.05). We then genotyped these two SNPs in the remaining cases (n = 2,393) and controls (n = 1,222) from CAPS and found that rs887391 at 19q13 was highly associated with PCa risk (P = 9.4 × 10−4). A similar trend of association was found for this SNP in a case-control study from Johns Hopkins Hospital (JHH), albeit the result was not statistically significant. Altogether, the frequency of the risk allele of rs887391 was consistently higher in cases than controls among each of seven study populations examined, with an overall P = 3.2 × 10−7 from a combined allelic test. A fine-mapping study in a 110-kb region at 19q13 among CAPS and JHH study populations revealed that rs887391 was the most strongly associated SNP in the region. Additional confirmation studies of this region are warranted. [Cancer Res 2009;69(7):2720–3]
Data from Pegylated Kunitz Domain Inhibitor Suppresses Hepsin-Mediated Invasive Tumor Growth and Metastasis
Authors: Li Wei , Wang Bu-Er , Moran Paul , Lipari Terry , Ganesan Rajkumar , Corpuz Racquel , Ludlam Mary J.C. , Gogineni Alvin , Koeppen Hartmut , Bunting Stuart , Gao Wei-Qiang , Kirchhofer Daniel
Published: March 2024

Abstract
The transmembrane serine protease hepsin is one of the most highly upregulated genes in prostate cancer. Here, we investigated its tumor-promoting activity by use of a mouse orthotopic prostate cancer model. First, we compared the tumor growth of low hepsin-expressing LnCaP-17 cells with hepsin-overexpressing LnCaP-34 cells. After implantation of cells into the left anterior prostate lobe, LnCaP-34 tumors not only grew faster based on increased serum prostate-specific antigen levels but also metastasized to local lymph nodes and, most remarkably, invaded the contralateral side of the prostate at a rate of 100% compared with only 18% for LnCaP-17 tumors. The increased tumor growth was not due to nonspecific gene expression changes and was not predicted from the unaltered in vitro growth and invasion of LnCaP-34 cells. A likely explanation is that the in vivo effects of hepsin were mediated by specific hepsin substrates present in the tumor stroma. In a second study, mice bearing LnCaP-34 tumors were treated with a PEGylated form of Kunitz domain-1, a potent hepsin active site inhibitor derived from hepatocyte growth factor activator inhibitor-1 (Kiapp 0.30 ± 0.02 nmol/L). Treatment of established tumors with PEGylated Kunitz domain-1 decreased contralateral prostate invasion (46% weight reduction) and lymph node metastasis (50% inhibition). Moreover, serum prostate-specific antigen level remained reduced during the entire treatment period, reaching a maximal reduction of 76% after 5 weeks of dosing. The findings show that hepsin promotes invasive prostate tumor growth and metastasis and suggest that active site-directed hepsin inhibition could be effective in prostate cancer therapy. [Cancer Res 2009;69(21):8395–402]
Data from Perifosine Inhibits Mammalian Target of Rapamycin Signaling through Facilitating Degradation of Major Components in the mTOR Axis and Induces Autophagy
Authors: Fu Lei , Kim Young-Ae , Wang Xuerong , Wu Xiaoyun , Yue Ping , Lonial Sagar , Khuri Fadlo R. , Sun Shi-Yong
Published: March 2024

Abstract
Perifosine is an alkylphospholipid exhibiting antitumor activity as shown in both preclinical studies and clinical trials. This activity is partly associated with its ability to inhibit Akt activity. It has been shown that the mammalian target of rapamycin (mTOR) axis plays a critical role in regulation of cell proliferation and survival primarily through functioning both downstream and upstream of Akt. The current study reveals a novel mechanism by which perifosine inhibits Akt and the mTOR axis. In addition to inhibition of Akt, perifosine inhibited the assembly of both mTOR/raptor and mTOR/rictor complexes. Strikingly, perifosine reduced the levels of Akt and other major components including mTOR, raptor, rictor, 70-kDa ribosomal S6 kinase, and 4E-binding protein 1 in the mTOR axis by promoting their degradation through a GSK3/FBW7-dependent mechanism. These results thus suggest that perifosine inhibits the mTOR axis through a different mechanism from inhibition of mTOR signaling by classic mTOR inhibitors such as rapamycin. Moreover, perifosine substantially increased the levels of type II light chain 3, a hallmark of autophagy, in addition to increasing poly(ADP-ribose) polymerase cleavage, suggesting that perifosine induces both apoptosis and autophagy. The combination of perifosine with a lysosomal inhibitor enhanced apoptosis and inhibited the growth of xenografts in nude mice, suggesting that perifosine-induced autophagy protects cells from undergoing apoptosis. Collectively, we conclude that perifosine inhibits mTOR signaling and induces autophagy, highlighting a novel mechanism accounting for the anticancer activity of perifosine and a potential strategy to enhance the anticancer efficacy of perifosine by preventing autophagy. [Cancer Res 2009;69(23):8967–76]
Data from Overactivation of the MEK/ERK Pathway in Liver Tumor Cells Confers Resistance to TGF-β–Induced Cell Death through Impairing Up-regulation of the NADPH Oxidase NOX4
Authors: Caja Laia , Sancho Patricia , Bertran Esther , Iglesias-Serret Daniel , Gil Joan , Fabregat Isabel
Published: March 2024

Abstract
Transforming growth factor-β (TGF-β) induces apoptosis in hepatocytes, being considered a liver tumor suppressor. However, many human hepatocellular carcinoma (HCC) cells escape from its proapoptotic effects, gaining response to this cytokine in terms of malignancy. We have recently reported that the apoptosis induced by TGF-β in hepatocytes requires up-regulation of the NADPH oxidase NOX4, which mediates reactive oxygen species (ROS) production. TGF-β–induced NOX4 expression is inhibited by antiapoptotic signals, such as the phosphatydilinositol-3-phosphate kinase or the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways. The aim of the present work was to analyze whether resistance to TGF-β–induced apoptosis in HCC cells is related to the impairment of NOX4 up-regulation due to overactivation of survival signals. Results indicate that inhibition of the MAPK/ERK kinase (MEK)/ERK pathway in HepG2 cells, which are refractory to the proapoptotic effects of TGF-β, sensitizes them to cell death through a mitochondrial-dependent mechanism, coincident with increased levels of BIM and BMF, decreased levels of BCL-XL and MCL1, and BAX/BAK activation. Regulation of BMF, BCL-XL, and MCL1 occurs at the mRNA level, whereas BIM regulation occurs post-transcriptionally. ROS production and glutathione depletion are only observed in cells treated with TGF-β and PD98059, which correlates with NOX4 up-regulation. Targeting knockdown of NOX4 impairs ROS increase and all the mitochondrial-dependent apoptotic features by a mechanism that is upstream from the regulation of BIM, BMF, BCL-XL, and MCL1 levels. In conclusion, overactivation of the MEK/ERK pathway in liver tumor cells confers resistance to TGF-β–induced cell death through impairing NOX4 up-regulation, which is required for an efficient mitochondrial-dependent apoptosis. [Cancer Res 2009;69(19):7595–602]
Data from Cancer Prevention: From 1727 to Milestones of the Past 100 Years
Authors: Lippman Scott M. , Hawk Ernest T.
Published: March 2024

Abstract
The rich, multidisciplinary history of cancer prevention recounted here begins with surgical and workplace recommendations of the 1700s and ends with 2009 results of the enormous (35,535 men) Selenium and Vitamin E [prostate] Cancer Prevention Trial (SELECT). This history comprises a fascinating array of chemopreventive, vaccine, surgical, and behavioral science research, both preclinical and clinical. Preclinical milestones of cancer prevention include the 1913 and 1916 mouse studies by Lathrop and Loeb of cancer development associated with pregnancy or cancer prevention through castration (oophorectomy), preventing chemically induced mouse carcinogenesis as early as 1929, energy restriction studies in the 1940s, the 1950s discoveries and later molecular characterizations of field cancerization and multistep carcinogenesis, and the effects of angiogenesis inhibition in genetically engineered mice reported in 2009. The extraordinary panoply of clinical research includes numerous large and smaller chemoprevention studies of nutritional supplements, other dietary approaches, a Bacillus Calmette-Guérin trial in 1976, molecular-targeted agents, and agents to prevent infection-related cancers such as hepatitis B virus vaccine to prevent liver cancer in 1984. Clinical surgical prevention includes removal of intraepithelial neoplasia detected by screening (including Pap testing developed in 1929 and culposcopy for cervical premalignancy and colonoscopy and polypectomy to prevent colorectal cancer begun in the 1960s) and prophylactic surgeries, such as in Lynch syndrome patients begun in 1977. Behavioral studies include smoking cessation and control beginning in the 1950s, obesity control rooted in studies of 1841, and genetic-counseling and cancer-survivorship studies. This history of pioneering events may help in better understanding who we are and what we want to achieve as cancer prevention researchers and practitioners. [Cancer Res 2009;69(13):5269–84]
Data from Metastasis-Associated Protein 1 Short Form Stimulates Wnt1 Pathway in Mammary Epithelial and Cancer Cells
Authors: Kumar Rakesh , Balasenthil Seetharaman , Pakala Suresh B. , Rayala Suresh K. , Sahin Aysegul A. , Ohshiro Kazufumi
Published: March 2024

Abstract
Although Wnt1 downstream signaling components as well as cytoplasmic level of metastatic tumor antigen 1 short form (MTA1s) are elevated in human breast cancer, it remains unknown whether a regulatory cross-talk exists between these two pathways. Here, we provide evidence of a remarkable correlation between the levels of MTA1s and stimulation of the Wnt1 signaling components, leading to increased stabilization of β-catenin and stimulation of Wnt1 target genes in the murine mammary epithelial and human breast cancer cells. We found that MTA1s influences Wnt1 pathway through extracellular signal-regulated kinase (ERK) signaling as selective silencing of the endogenous MTA1s or ERK, or its target glycogen synthase kinase 3β resulted in a substantial decrease in β-catenin expression, leading to the inhibition of Wnt1 target genes. Furthermore, downregulation of β-catenin in cells with elevated MTA1s level was accompanied by a corresponding decrease in the expression of Wnt1 target genes, establishing a mechanistic role for the ERK/glycogen synthase kinase 3β/β-catenin pathway in the stimulation of the Wnt1 target genes by MTA1s in mammary epithelial cells. In addition, mammary glands from the virgin MTA1s transgenic mice mimicked the phenotypic changes found in the Wnt1 transgenic mice and exhibited an overall hyperactivation of the Wnt1 signaling pathway, leading to increased stabilization and nuclear accumulation of β-catenin. Mammary glands from the virgin MTA1s-TG mice revealed ductal hyperplasia and ductal carcinoma in situ, and low incidence of palpable tumors. These findings reveal a previously unrecognized role for MTA1s as an important modifier of the Wnt1 signaling in mammary epithelial and cancer cells. Cancer Res; 70(16); 6598–608. ©2010 AACR.
Data from NPM-ALK Oncogenic Tyrosine Kinase Controls T-Cell Identity by Transcriptional Regulation and Epigenetic Silencing in Lymphoma Cells
Authors: Ambrogio Chiara , Martinengo Cinzia , Voena Claudia , Tondat Fabrizio , Riera Ludovica , di Celle Paola Francia , Inghirami Giorgio , Chiarle Roberto
Published: March 2024

Abstract
Transformed cells in lymphomas usually maintain the phenotype of the postulated normal lymphocyte from which they arise. By contrast, anaplastic large cell lymphoma (ALCL) is a T-cell lymphoma with aberrant phenotype because of the defective expression of the T-cell receptor and other T-cell–specific molecules for still undetermined mechanisms. The majority of ALCL carries the translocation t(2;5) that encodes for the oncogenic tyrosine kinase NPM-ALK, fundamental for survival, proliferation, and migration of transformed T cells. Here, we show that loss of T-cell–specific molecules in ALCL cases is broader than reported previously and involves most T-cell receptor–related signaling molecules, including CD3ϵ, ZAP70, LAT, and SLP76. We further show that NPM-ALK, but not the kinase-dead NPM-ALKK210R, downregulated the expression of these molecules by a STAT3-mediated gene transcription regulation and/or epigenetic silencing because this downregulation was reverted by treating ALCL cells with 5-aza-2-deoxycytidine or by knocking down STAT3 through short hairpin RNA. Finally, NPM-ALK increased the methylation of ZAP70 intron 1-exon 2 boundary region, and both NPM-ALK and STAT3 regulated the expression levels of DNA methyltransferase 1 in transformed T cells. Thus, our data reveal that oncogene-deregulated tyrosine kinase activity controls the expression of molecules that determine T-cell identity and signaling. [Cancer Res 2009;69(22):8611–9]
Data from Down-regulation of c-FLIP Enhances Death of Cancer Cells by Smac Mimetic Compound
Authors: Cheung Herman H. , Mahoney Douglas J. , LaCasse Eric C. , Korneluk Robert G.
Published: March 2024

Abstract
Smac mimetic compounds (SMC) are novel small molecules being developed for cancer therapy. The mechanism of SMC-induced sensitivity in cancer cells depends on autocrine release of tumor necrosis factor α (TNFα); however, potential mechanisms of resistance remain unknown. Here, we investigated the molecular profile and cytotoxic responsiveness of a diverse panel of 51 cancer cell lines to combinations of a dimeric SMC (AEG40730), death ligand TNFα, and tumor necrosis factor-related apoptosis-inducing ligand. Synergy was seen in combination with death receptor agonists in some cells, although single-agent activity was limited to a fewsensitive lines. Unexpectedly, the majority of cell lines resistant to combinations of SMC-AEG40730 and death ligands expressed caspase-8, FADD, RIP1, and ligand receptors necessary for apoptosis execution. Furthermore, TNFα-mediated ubiquitination of RIP1 was repressed by SMC-AEG40730 treatment, leading to the formation of the proapoptosis complex II. However, in resistant cancer cells, SMC-AEG40730 repressed TNFα-mediated c-jun-NH2-kinase activation and the levels of caspase-8 inhibitor c-FLIP were persistently elevated, in contrast to SMC-responsive cancer cells. Importantly, the silencing of c-FLIP restored SMC sensitivity in previously resistant cancer cells by allowing ligand-mediated activation of caspase-8 and caspase-3 to proceed. Together, these results provide mechanistic insight into the action of SMCs, demonstrating that the deciphering of the relevant molecular signature in cancer cells leads to the prediction of cancer cell responsiveness to SMC treatment. Furthermore, a majority of resistant cancer cells were sensitized to SMC-AEG40730 and TNFα by down-regulating c-FLIP, suggesting novel approaches in the use of SMCs and c-FLIP antagonists in treating cancer. [Cancer Res 2009;69(19):7729–38]
Data from Concurrent Suppression of Integrin α5, Radixin, and RhoA Phenocopies the Effects of miR-31 on Metastasis
Authors: Valastyan Scott , Chang Amelia , Benaich Nathan , Reinhardt Ferenc , Weinberg Robert A.
Published: March 2024

Abstract
miR-31 inhibits breast cancer metastasis via the pleiotropic suppression of a cohort of prometastatic target genes that include integrin α5 (ITGA5), radixin (RDX), and RhoA. We previously showed that the concomitant overexpression of ITGA5, RDX, and RhoA was capable of overriding the antimetastatic effects of ectopically expressed miR-31 in vivo. However, these prior studies failed to investigate whether the combined suppression of the endogenous mRNAs encoding these three proteins recapitulated the in vivo consequences of miR-31 expression on metastasis. We show here that short hairpin RNA–mediated concurrent downregulation of ITGA5, RDX, and RhoA is sufficient to phenocopy the full spectrum of described influences of miR-31 on metastasis in vivo, including the effects of this microRNA (miRNA) on local invasion, early post-intravasation events, and metastatic colonization. These findings provide mechanistic insights into the metastatic process and have implications about the importance of pleiotropy for the biological actions of miRNAs. Cancer Res; 70(12); 5147–54. ©2010 AACR.
Data from Human Suppressor of Cytokine Signaling 1 Controls Immunostimulatory Activity of Monocyte-Derived Dendritic Cells
Authors: Hong Bangxing , Ren Wenhong , Song Xiao-Tong , Evel-Kabler Kevin , Chen Si-Yi , Huang Xue F.
Published: March 2024

Abstract
Dendritic cell (DC)–based tumor vaccines have only achieved limited clinical efficacy, underscoring the limitation of stimulatory strategies to elicit effective cytotoxic T lymphocyte (CTL) responses against self-tumor–associated antigens. Here, we investigate the role of human suppressor of cytokine signaling 1 (SOCS1), a feedback inhibitor of the Janus-activated kinase/signal transducer and activator of transcription signaling pathway, in regulating antigen presentation by human DCs (hDC). We find that human SOCS1 (hSOCS1)–silenced DCs have an enhanced stimulatory ability to prime self-antigen–specific CTLs in vitro and in a severe combined immunodeficient-hu mouse model. Human CTLs activated by SOCS1-silenced DCs, but not wild-type DCs, have an active lytic activity to natural antigen-expressing tumor cells. We further find that the capacity of hDCs to prime CTLs is likely controlled by SOCS1-restricted production and signaling of proinflammatory cytokines, such as interleukin-12. These results indicate a critical role of hSOCS1 in negatively regulating the immunostimulatory capacity of DCs and imply a translational potential of this alternative SOCS1 silencing strategy to develop effective DC vaccines. [Cancer Res 2009;69(20):8076–84]
Data from Epigenetic Silencing of the Sulfate Transporter Gene DTDST Induces Sialyl Lewisx Expression and Accelerates Proliferation of Colon Cancer Cells
Authors: Yusa Akiko , Miyazaki Keiko , Kimura Naoko , Izawa Mineko , Kannagi Reiji
Published: March 2024

Abstract
Colon cancer cells express the carbohydrate determinant sialyl Lewisx, while they exhibit markedly decreased the expression of its sulfated derivative, sialyl 6-sulfo Lewisx. In contrast, normal colonic epithelial cells strongly express sialyl 6-sulfo Lewisx, but they virtually do not express sialyl Lewisx. Impaired sulfation was therefore suggested to occur during the course of malignant transformation of colonic epithelial cells and was assumed to be responsible for the increased sialyl Lewisx expression in cancers. To elucidate the molecular biological background of the impaired sulfation in cancers, we studied the expression levels of mRNA for 6-O-sulfotransferase isoenzymes, PAPS synthases and transporters, and a cell membrane sulfate transporter, DTDST, in cancer tissues. The most striking decrease in cancer cells compared with nonmalignant epithelial cells was noted in the transcription of the DTDST gene (P = 0.0000014; n = 20). Most cultured colon cancer cells had a diminished DTDST transcription, which was restored when cultured with histone deacetylase inhibitors. Suppression of DTDST transcription under the control of a tet-off inducible promoter resulted in increased sialyl Lewisx expression and reduced sialyl 6-sulfo Lewisx expression. Unexpectedly, the growth rate of the cancer cells was markedly enhanced when transcription of DTDST was suppressed. These results show that the decrease in the transcription of the sulfate transporter gene is the major cause of decreased expression of sialyl 6-sulfo Lewisx and increased expression of sialyl Lewisx in colon cancers. The results also suggest that the diminished DTDST expression is closely related to enhanced proliferation of cancer cells. Cancer Res; 70(10); 4064–73. ©2010 AACR.
Data from Estrogen Receptor β1 Expression Is Regulated by miR-92 in Breast Cancer
Authors: Al-Nakhle Hakeemah , Burns Philip A. , Cummings Michele , Hanby Andrew M. , Hughes Thomas A. , Satheesha Sampoorna , Shaaban Abeer M. , Smith Laura , Speirs Valerie
Published: March 2024

Abstract
Estrogen receptor β1 (ERβ1) downregulation occurs in many breast cancers, but the responsible molecular mechanisms remain unclear. Here, we report that levels of ERβ1 expression are negatively regulated by the microRNA miR-92. Expression analysis in a cohort of primary breast tumors confirmed a significant negative correlation between miR-92 and both ERβ1 mRNA and protein. Inhibition of miR-92 in MCF-7 cells increased ERβ1 expression in a dose-dependent manner, whereas miR-92 overexpression led to ERβ1 downregulation. Reporter constructs containing candidate miR-92 binding sites in the 3′-untranslated region (UTR) of ERβ1 suggested by bioinformatics analysis confirmed that miR-92 downregulated ERβ1 via direct targeting of its 3′-UTR. Our results define a potentially important mechanism for downregulation of ERβ1 expression in breast cancer. Cancer Res; 70(11); 4778–84. ©2010 AACR.
Data from Regulation of Protein Citrullination through p53/PADI4 Network in DNA Damage Response
Authors: Tanikawa Chizu , Ueda Koji , Nakagawa Hidewaki , Yoshida Nobuaki , Nakamura Yusuke , Matsuda Koichi
Published: March 2024

Abstract
Upon a wide range of cellular stresses, p53 is activated and inhibits malignant transformation through the transcriptional regulation of its target genes related to apoptosis, cell cycle arrest, and DNA repair. However, its involvement in posttranslational modifications of proteins has not yet been well characterized. Here, we report the novel role of p53 in the regulation of protein citrullination. p53 transactivated peptidylarginine deiminase type 4 (PADI4) through an intronic p53-binding site. The PADI4 gene encodes an enzyme catalyzing the citrullination of arginine residues in proteins, and ectopic expression of p53 or PADI4 induced protein citrullination. In addition, various proteins were citrullinated in response to DNA damage, but knockdown of PADI4 or p53 remarkably inhibited their citrullination, indicating the regulation of protein citrullination in a p53/PADI4-dependent manner. We found that PADI4 citrullinated the histone chaperone protein, nucleophosmin (NPM1), at the arginine 197 residue in vivo under physiologic conditions. Citrullination of NPM1 by PADI4 resulted in its translocation from the nucleoli to the nucleoplasm, whereas PADI4 did not alter the localization of mutant NPM1 (R197K). Furthermore, ectopic expression of PADI4 inhibited tumor cell growth, and concordantly, the knockdown of PADI4 attenuated p53-mediated growth-inhibitory activity, demonstrating the significance of PADI4-mediated protein citrullination in the p53 signaling pathway.[Cancer Res 2009;69(22):8761–9]
Data from Antigen-Experienced CD4+ T Cells Limit Naïve T-Cell Priming in Response to Therapeutic Vaccination In vivo
Authors: Schiering Chris , Guarnerio Jlenia , Basso Veronica , Muzio Luca , Mondino Anna
Published: March 2024

Abstract
CD4+ T cells play a central role in protective immunity. In a mouse tumor model, we previously found that tumor growth elicits natural CD4+ T-cell responses, but impedes therapeutic vaccination. We show here that inhibition of vaccine-mediated naïve T-cell priming is due to the presence of a minor but distinct population of tumor-reactive CD4+ T cells. These cells are generated in the tumor draining lymph nodes (LN), are capable of systemic redistribution, and act to limit the representation of antigen-bearing MHC II+ antigen-presenting cells (APC) in contralateral LNs or when transferred to tumor-free mice. Surgical tumor resection, which lowers the representation of tumor primed CD4+ T cells, restored to some extent vaccine-induced CD4+ T-cell activation. Likewise, vaccination with artificial APCs (latex beads) or higher numbers of dendritic cells allowed comparable CD4+ T-cell priming in tumor-free and tumor-bearing mice. Together, our results emphasize the ability of antigen-experienced CD4+ T lymphocytes to interfere with therapeutic vaccination and highlight the need for alternative strategies able to surmount limitations imposed by ongoing immune responses. Cancer Res; 70(15); 6161–70. ©2010 AACR.
Data from Autotaxin Promotes Cancer Invasion via the Lysophosphatidic Acid Receptor 4: Participation of the Cyclic AMP/EPAC/Rac1 Signaling Pathway in Invadopodia Formation
Authors: Harper Kelly , Arsenault Dominique , Boulay-Jean Stephanie , Lauzier Annie , Lucien Fabrice , Dubois Claire M.
Published: March 2024

Abstract
The ability of cancer cells to invade and metastasize is the major cause of death in cancer patients. Autotaxin (ATX) is a secreted lysophospholipase whose level of expression within tumors correlates strongly with their aggressiveness and invasiveness. ATX is the major enzyme involved in the production of lysophosphatidic acid (LPA), a phospholipid that is known to act mostly through its three first characterized receptors (LPA1, LPA2, and LPA3). Tumor cell invasion across tissue boundaries and metastasis are dependent on the capacity of invasive cancer cells to breach the basement membrane. This process can be initiated by the formation of the actin-rich cell protrusions, invadopodia. In this study, we show that ATX is implicated in the formation of invadopodia in various cancer cells types and this effect is dependent on the production of LPA. We further provide evidence that LPA4 signaling in fibrosarcoma cells regulates invadopodia formation downstream of ATX, a process mediated through the activation of EPAC by cyclic AMP and subsequent Rac1 activation. Results using LPA4 shRNA support the requirement of the LPA4 receptor for cell invasion and in vivo metastasis formation. This work presents evidence that blocking the LPA receptor, LPA4, in fibrosarcoma cells could provide an additional tool to improve the efficacy of treatment of metastasis in patients. Because LPA receptors and ATX are currently being targeted in preclinical trials, the current findings should stimulate future studies to evaluate the expression pattern and clinical outcome of LPA4, together with other LPA receptors, in various cancer patients. Cancer Res; 70(11); 4634–43. ©2010 AACR.
Data from High DNA Methyltransferase 3B Expression Mediates 5-Aza-Deoxycytidine Hypersensitivity in Testicular Germ Cell Tumors
Authors: Beyrouthy Maroun J. , Garner Kristen M. , Hever Mary P. , Freemantle Sarah J. , Eastman Alan , Dmitrovsky Ethan , Spinella Michael J.
Published: March 2024

Abstract
Testicular germ cell tumors (TGCT) are the most common solid tumors of 15- to 35-year-old men. TGCT patients are frequently cured with cytotoxic cisplatin-based therapy. However, TGCT patients refractory to cisplatin-based chemotherapy have a poor prognosis, as do those having a late relapse. Pluripotent embryonal carcinomas (EC) are the malignant counterparts to embryonic stem cells and are considered the stem cells of TGCTs. Here, we show that human EC cells are highly sensitive to 5-aza-deoxycytidine (5-aza-CdR) compared with somatic solid tumor cells. Decreased proliferation and survival with low nanomolar concentrations of 5-aza-CdR is associated with ATM activation, H2AX phosphorylation, increased expression of p21, and the induction of genes known to be methylated in TGCTs (MGMT, RASSF1A, and HOXA9). Notably, 5-aza-CdR hypersensitivity is associated with markedly abundant expression of the pluripotency-associated DNA methyltransferase 3B (DNMT3B) compared with somatic tumor cells. Knockdown of DNMT3B in EC cells results in substantial resistance to 5-aza-CdR, strongly indicating that 5-aza-CdR sensitivity is mechanistically linked to high levels of DNMT3B. Intriguingly, cisplatin-resistant EC cells retain an exquisite sensitivity to low-dose 5-aza-CdR treatment, and pretreatment of 5-aza-CdR resensitizes these cells to cisplatin-mediated toxicity. This resensitization is also partially dependent on high DNMT3B levels. These novel findings indicate that high expression of DNMT3B, a likely byproduct of their pluripotency and germ cell origin, sensitizes TGCT-derived EC cells to low-dose 5-aza-CdR treatment. [Cancer Res 2009;69(24):9360–6]
Data from Diagnosing Cervical Cancer and High-Grade Precursors by HPV16 Transcription Patterns
Authors: Schmitt Markus , Dalstein Véronique , Waterboer Tim , Clavel Christine , Gissmann Lutz , Pawlita Michael
Published: March 2024

Abstract
Infections with high-risk human papillomaviruses (HPV), mainly HPV type 16, can cause malignant transformation of the human cervical epithelium and the development of cervical cancer (CxCa). A rapid and precise diagnosis of the precancerous lesions by conventional cytology or HPV DNA tests remains difficult and often leads to overtreatment. We quantitatively analyzed the HPV16 transcriptome of 80 HPV16 DNA-positive cervical scrapes classified as mild cytologic grade, including no intraepithelial lesion or malignancy (NIL/M; normal, n = 25) and low-grade squamous intraepithelial lesion (LSIL; n = 24), and severe cytologic grade, including high-grade squamous intraepithelial lesion (HSIL; n = 24) and CxCa (n = 7), with novel nucleic acid sequence-based amplification–Luminex assays. In severe lesions, HPV16 E6*II and E1C encoding transcripts were strongly upregulated, whereas spliced E1^E4 and L1 encoding transcripts were markedly downregulated. Using a combination of the four marker transcripts, 100% of CxCa and 67% of HSIL cases were correctly identified as severe, and 74% of LSIL and 92% of NIL/M samples as mild cytologic grade. Compared with a commercially available HPV E6/E7 mRNA assay, the specificity of the marker combination for discriminating severe and mild cytologic lesions increased from 23% to 83%. In conclusion, we identified a novel HPV16 RNA pattern for grading of cervical lesions with a potentially high diagnostic value for the primary screening of CxCa precursors and the triage of cervical lesions. Cancer Res; 70(1); 249–56
Data from CDX2 Regulates Multidrug Resistance 1 Gene Expression in Malignant Intestinal Epithelium
Authors: Takakura Yuji , Hinoi Takao , Oue Naohide , Sasada Tatsunari , Kawaguchi Yasuo , Okajima Masazumi , Akyol Aytekin , Fearon Eric R. , Yasui Wataru , Ohdan Hideki
Published: March 2024

Abstract
The caudal-related homeobox transcription factor CDX2 has a key role in intestinal development and differentiation. CDX2 heterozygous mutant mice develop colonic polyps, and loss of CDX2 expression is seen in a subset of colon carcinomas in humans. Ectopic CDX2 expression in the stomach of transgenic mice promotes intestinal metaplasia, and CDX2 expression is frequently detected in intestinal metaplasia in the stomach and esophagus. We sought to define CDX2-regulated genes to enhance knowledge of CDX2 function. HT-29 colorectal cancer cells have minimal endogenous CDX2 expression, and HT-29 cells with ectopic CDX2 expression were generated. Microarray-based gene expression studies revealed that the Multidrug Resistance 1 (MDR1/P-glycoprotein/ABCB1) gene was activated by CDX2. Evidence that the MDR1 gene was a direct transcriptional target of CDX2 was obtained, including analyses with MDR1 reporter gene constructs and chromatin immunoprecipitation assays. RNA interference–mediated inhibition of CDX2 decreased endogenous MDR1 expression. In various colorectal cancer cell lines and human tissues, endogenous MDR1 expression was well correlated to CDX2 expression. Overexpression of CDX2 in HT-29 cells revealed increased resistance to the known substrate of MDR1, vincristine and paclitaxel, which was reversed by an MDR1 inhibitor, verapamil. These data indicate that CDX2 directly regulates MDR1 gene expression through binding to elements in the promoter region. Thus, CDX2 is probably important for basal expression of MDR1, regulating drug excretion and absorption in the lower gastrointestinal tract, as well as for multidrug resistance to chemotherapy reagent in CDX2-positive gastrointestinal cancers. Cancer Res; 70(17); 6767–78. ©2010 AACR.
Data from Mechanism by Which Mcl-1 Regulates Cancer-Specific Apoptosis Triggered by mda-7/IL-24, an IL-10–Related Cytokine
Authors: Dash Rupesh , Richards Joanna E. , Su Zhao-zhong , Bhutia Sujit K. , Azab Belal , Rahmani Mohamed , Dasmahapatra Girija , Yacoub Adly , Dent Paul , Dmitriev Igor P. , Curiel David T. , Grant Steven , Pellecchia Maurizio , Reed John C. , Sarkar Devanand , Fisher Paul B.
Published: March 2024

Abstract
Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), a cytokine belonging to the IL-10 family, selectively induces apoptosis in cancer cells without harming normal cells by promoting an endoplasmic reticulum (ER) stress response. The precise molecular mechanism by which the ER stress response culminates in cell death requires further clarification. The present study shows that in prostate carcinoma cells, the mda-7/IL-24–induced ER stress response causes apoptosis by translational inhibition of the antiapoptotic protein myeloid cell leukemia-1 (Mcl-1). Forced expression of Mcl-1 blocked mda-7/IL-24 lethality, whereas RNA interference or gene knockout of Mcl-1 markedly sensitized transformed cells to mda-7/IL-24. Mcl-1 downregulation by mda-7/IL-24 relieved its association with the proapoptotic protein Bak, causing oligomerization of Bak and leading to cell death. These observations show the profound role of the Bcl-2 protein family member Mcl-1 in regulating cancer-specific apoptosis induced by this cytokine. Thus, our studies provide further insights into the molecular mechanism of ER stress–induced cancer-selective apoptosis by mda-7/IL-24. As Mcl-1 is overexpressed in the majority of prostate cancers, mda-7/IL-24 might provide an effective therapeutic for this disease. Cancer Res; 70(12); 5034–45. ©2010 AACR.