bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Extracellular Signal–Regulated Kinase Signaling Pathway Regulates Breast Cancer Cell Migration by Maintaining slug Expression
Authors: Chen Haoming , Zhu Genfeng , Li Yong , Padia Ravi N. , Dong Zheng , Pan Zhixing K. , Liu Kebin , Huang Shuang
Published: March 2023

Abstract
Cell migration is a critical step in cancer cell invasion. Recent studies have implicated the importance of the extracellular signal–regulated kinase (ERK) signaling pathway in cancer cell migration. However, the mechanism associated with ERK-regulated cell migration is poorly understood. Using a panel of breast cancer cell lines, we detected an excellent correlation between ERK activity and cell migration. Interestingly, we noticed that a 48-hour treatment with U0126 [specific mitogen-activated protein/ERK kinase (MEK)-1/2 inhibitor] was needed to significantly inhibit breast cancer cell migration, whereas this inhibitor blocked ERK activity within 1 hour. This observation suggests that ERK-dependent gene expression, rather than direct ERK signaling, is essential for cell migration. With further study, we found that ERK activity promoted the expression of the activator protein-1 (AP1) components Fra-1 and c-Jun, both of which were necessary for cell migration. Combination of U0126 treatment and Fra-1/c-Jun knockdown did not yield further reduction in cell migration than either alone, indicating that ERKs and Fra-1/c-Jun act by the same mechanism to facilitate cell migration. In an attempt to investigate the role of Fra-1/c-Jun in cell migration, we found that the ERK-Fra-1/c-Jun axis regulated slug expression in an AP1-dependent manner. Moreover, the occurrence of U0126-induced migratory inhibition coincided with slug reduction, and silencing slug expression abrogated breast cancer cell migration. These results suggest an association between ERK-regulated cell migration and slug expression. Indeed, cell migration was not significantly inhibited by U0126 treatment or Fra-1/c-Jun silencing in cells expressing slug transgene. Our study suggests that the ERK pathway regulates breast cancer cell migration by maintaining slug expression. [Cancer Res 2009;69(24):9228–35]
Data from PTPL1/PTPN13 Regulates Breast Cancer Cell Aggressiveness through Direct Inactivation of Src Kinase
Authors: Glondu-Lassis Murielle , Dromard Mathilde , Lacroix-Triki Magali , Nirdé Philippe , Puech Carole , Knani Dora , Chalbos Dany , Freiss Gilles
Published: March 2023

Abstract
The protein tyrosine phosphatase PTPL1/PTPN13, the activity of which is decreased through allelic loss, promoter methylation, or somatic mutations in some tumors, has been proposed as a tumor suppressor gene. Moreover, our recent clinical study identified PTPL1 expression level as an independent prognostic indicator of a favorable outcome for patients with breast cancer. However, how PTPL1 can affect tumor aggressiveness has not been characterized. Here, we first show that PTPL1 expression, assessed by immunohistochemistry, is decreased in breast cancer and metastasis specimens compared with nonmalignant tissues. Second, to evaluate whether PTPL1 plays a critical role in breast cancer progression, RNA interference experiments were performed in poorly tumorigenic MCF-7 breast cancer cells. PTPL1 inhibition drastically increased tumor growth in athymic mice and also enhanced several parameters associated with tumor progression, including cell proliferation on extracellular matrix components and cell invasion. Furthermore, the inhibition of Src kinase expression drastically blocked the effects of PTPL1 silencing on cell growth. In PTPL1 knockdown cells, the phosphorylation of Src on tyrosine 419 is increased, leading to the activation of its downstream substrates Fak and p130cas. Finally, substrate-trapping experiments revealed that Src tyrosine 419 is a direct target of the phosphatase. Thus, by identification of PTPL1 as the first phosphatase able to inhibit Src through direct dephosphorylation in intact cells, we presently describe a new mechanism by which PTPL1 inhibits breast tumor aggressiveness. Cancer Res; 70(12); 5116–26. ©2010 AACR.
Data from Mutant p53 Disrupts the Stress MAPK Activation Circuit Induced by ASK1-Dependent Stabilization of Daxx
Authors: Kitamura Tetsuya , Fukuyo Yayoi , Inoue Masahiro , Horikoshi Nobuko T. , Shindoh Masanobu , Rogers Buck E. , Usheva Anny , Horikoshi Nobuo
Published: March 2023

Abstract
Daxx is a regulatory protein for apoptosis signal–regulating kinase 1 (ASK1) which activates c-Jun NH2-terminal kinase (JNK) and p38 pathways in response to stressors such as tumor necrosis factor-α (TNFα). Here, we show that TNFα treatment induces the accumulation of Daxx protein through ASK1 activation by preventing its proteasome-dependent degradation. ASK1 directly phosphorylates Daxx at Ser176 and Ser184 and Daxx is required for the sustained activation of JNK. Tumorigenic mutant p53, which binds to Daxx and inhibits Daxx-dependent activation of ASK1, prevents Daxx phosphorylation and stabilization. When mutant p53 was depleted in cancer cells, Daxx was accumulated and the cell-killing effect of TNFα was restored. Our results indicate that Daxx not only activates ASK1 but also is a downstream target of ASK1 and that accumulated Daxx further activates ASK1. Thus, the Daxx-ASK1 positive feedback loop amplifying JNK/p38 signaling plays an important role in the cell-killing effects of stressors, such as TNFα. Tumorigenic mutant p53 disrupts this circuit and makes cells more tolerable to stresses, as its gain-of-function mechanism. [Cancer Res 2009;69(19):7681–8]
Data from Immature Immunosuppressive CD14+HLA-DR−/low Cells in Melanoma Patients Are Stat3hi and Overexpress CD80, CD83, and DC-Sign
Authors: Poschke Isabel , Mougiakakos Dimitrios , Hansson Johan , Masucci Giuseppe V. , Kiessling Rolf
Published: March 2023

Abstract
Myeloid-derived suppressor cells (MDSC) have emerged as key immune modulators in various tumor models and human malignancies, but their characteristics in humans remain to be unequivocally defined. In this study, we have examined circulating CD14+HLA-DR−/low MDSC in 34 advanced malignant melanoma (MM) patients. Their frequency is significantly increased and associated with disease activity. Contrary to the common notion that MDSC are a heterogeneous population of exclusively immature cells, we find the coexpression of markers associated with mature phenotype. We show for the first time the overexpression of CD80, CD83, and DC-Sign in human MDSC. Further, increased levels of signal transducer and activator of transcription 3 (Stat3), an important regulator in MDSC development and function, were noted in MM-MDSC. Stat3 was altered toward an active, phosphorylated state in the HLA-DR− population of CD14+ cells and was more reactive to activating stimuli in patients. Importantly, inhibition of Stat3 abolished their suppressive activity almost completely. The described MM-MDSC use arginase in conjunction with other yet undefined mechanisms to suppress CD4+ and CD8+ T cells. Several observations suggest a redox imbalance in MDSC and indicate an important role of Stat3-dependent oxidative stress in MDSC-mediated T-cell suppression. These results emphasize the diversity of MDSC in human cancer and provide potential targets for therapeutic interventions. Cancer Res; 70(11); 4335–45. ©2010 AACR.
Data from Inhibition of the Sodium-Potassium-Chloride Cotransporter Isoform-1 Reduces Glioma Invasion
Authors: Haas Brian R. , Sontheimer Harald
Published: March 2023

Abstract
Malignant gliomas metastasize throughout the brain by infiltrative cell migration into peritumoral areas. Invading cells undergo profound changes in cell shape and volume as they navigate extracellular spaces along blood vessels and white matter tracts. Volume changes are aided by the concerted release of osmotically active ions, most notably K+ and Cl−. Their efflux through ion channels along with obligated water causes rapid cell shrinkage. Suitable ionic gradients must be established and maintained through the activity of ion transport systems. Here, we show that the Sodium-Potassium-Chloride Cotransporter Isoform-1 (NKCC1) provides the major pathway for Cl− accumulation in glioma cells. NKCC1 localizes to the leading edge of invading processes, and pharmacologic inhibition using the loop diuretic bumetanide inhibits in vitro Transwell migration by 25% to 50%. Short hairpin RNA knockdowns of NKCC1 yielded a similar inhibition and a loss of bumetanide-sensitive cell volume regulation. A loss of NKCC1 function did not affect cell motility in two-dimensional assays lacking spatial constraints but manifested only when cells had to undergo volume changes during migration. Intracranial implantation of human gliomas into severe combined immunodeficient mice showed a marked reduction in cell invasion when NKCC1 function was disrupted genetically or by twice daily injection of the Food and Drug Administration–approved NKCC1 inhibitor Bumex. These data support the consideration of Bumex as adjuvant therapy for patients with high-grade gliomas. Cancer Res; 70(13); 5597–606. ©2010 AACR.
Data from Circadian Rhythm of Transferrin Receptor 1 Gene Expression Controlled by c-Myc in Colon Cancer–Bearing Mice
Authors: Okazaki Fumiyasu , Matsunaga Naoya , Okazaki Hiroyuki , Utoguchi Naoki , Suzuki Ryo , Maruyama Kazuo , Koyanagi Satoru , Ohdo Shigehiro
Published: March 2023

Abstract
The abundance of cell surface levels of transferrin receptor 1 (TfR1), which regulates the uptake of iron-bound transferring, correlates with the rate of cell proliferation. Because TfR1 expression is higher in cancer cells than in normal cells, it offers a target for cancer therapy. In this study, we found that the expression of TfR1 in mouse colon cancer cells was affected by the circadian organization of the molecular clock. The core circadian oscillator is composed of an autoregulatory transcription-translation feedback loop, in which CLOCK and BMAL1 are positive regulators and the Period (Per), Cryptochrome (Cry), and Dec genes act as negative regulators. TfR1 in colon cancer–bearing mice exhibited a 24-hour rhythm in mRNA and protein levels. Luciferase reporter analysis and chromatin immunoprecipitation experiments suggested that the clock-controlled gene c-MYC rhythmically activated the transcription of the TfR1 gene. Platinum incorporation into tumor DNA and the antitumor efficacy of transferrin-conjugated liposome-delivered oxaliplatin could be enhanced by drug administration at times when TfR1 expression increased. Our findings suggest that the 24-hour rhythm of TfR1 expression may form an important aspect of strategies for TfR1-targeted cancer therapy. Cancer Res; 70(15); 6238–46. ©2010 AACR.
Data from GlcNAcylation Plays an Essential Role in Breast Cancer Metastasis
Authors: Gu Yuchao , Mi Wenyi , Ge Yuqing , Liu Haiyan , Fan Qiong , Han Cuifang , Yang Jing , Han Feng , Lu Xinzhi , Yu Wengong
Published: March 2023

Abstract
GlcNAcylation, a dynamic posttranslational modification, is involved in a wide range of biological processes and some human diseases. Although there is emerging evidence that some tumor-associated proteins are modified by GlcNAcylation, the role of GlcNAcylation in tumor progression remains unclear. Here, we show that GlcNAcylation enhances the migration/invasion of breast cancer cells in vitro and lung metastasis in vivo. The decrease of cell surface E-cadherin is the molecular mechanism underlying GlcNAcylation-induced breast cancer metastasis. p120 and β-catenin, but not E-cadherin, are GlcNAcylated; the GlcNAcylation of p120 and β-catenin might play roles in the decrease of cell surface E-cadherin. Moreover, immunohistochemistry analysis indicated that the global GlcNAcylation level in breast tumor tissues is elevated significantly as compared with that in the corresponding adjacent tissues; further, GlcNAcylation was significantly enhanced in metastatic lymph nodes compared with their corresponding primary tumor tissues. This is the first report to clearly elucidate the roles and mechanisms whereby GlcNAcylation influences the malignant properties of breast cancer cells. These results also suggest that GlcNAcylation might be a potential target for the diagnosis and therapy of breast cancer. Cancer Res; 70(15); 6344–51. ©2010 AACR.
Data from ATAD2 Is a Novel Cofactor for MYC, Overexpressed and Amplified in Aggressive Tumors
Authors: Ciró Marco , Prosperini Elena , Quarto Micaela , Grazini Ursula , Walfridsson Julian , McBlane Fraser , Nucifero Paolo , Pacchiana Giovanni , Capra Maria , Christensen Jesper , Helin Kristian
Published: March 2023

Abstract
The E2F and MYC transcription factors are critical regulators of cell proliferation and contribute to the development of human cancers. Here, we report on the identification of a novel E2F target gene, ATAD2, the predicted protein product of which contains both a bromodomain and an ATPase domain. The pRB-E2F pathway regulates ATAD2 expression, which is limiting for the entry into the S phase of the cell cycle. We show that ATAD2 binds the MYC oncogene and stimulates its transcriptional activity. ATAD2 maps to chromosome 8q24, 4.3 Mb distal to MYC, in a region that is frequently found amplified in cancer. Consistent with this, we show that ATAD2 expression is high in several human tumors and that the expression levels correlate with clinical outcome of breast cancer patients. We suggest that ATAD2 links the E2F and MYC pathways and contributes to the development of aggressive cancer through the enhancement of MYC-dependent transcription. [Cancer Res 2009;69(21):8491–8]
Data from Widespread Estrogen-Dependent Repression of microRNAs Involved in Breast Tumor Cell Growth
Authors: Maillot Gérard , Lacroix-Triki Magali , Pierredon Sandra , Gratadou Lise , Schmidt Sabine , Bénès Vladimir , Roché Henri , Dalenc Florence , Auboeuf Didier , Millevoi Stefania , Vagner Stéphan
Published: March 2023

Abstract
Altered expression of microRNAs (miRNA), an abundant class of small nonprotein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here, we analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. We set out to thoroughly describe miRNA expression, by using miRNA microarrays and real-time reverse transcription-PCR (RT-PCR) experiments, in various breast tumor cell lines in which estrogen signaling has been induced by 17β-estradiol (E2). We show that the expression of a broad set of miRNAs decreases following E2 treatment in an ER-dependent manner. We further show that enforced expression of several of the repressed miRNAs reduces E2-dependent cell growth, thus linking expression of specific miRNAs with estrogen-dependent cellular response. In addition, a transcriptome analysis revealed that the E2-repressed miR-26a and miR-181a regulate many genes associated with cell growth and proliferation, including the progesterone receptor gene, a key actor in estrogen signaling. Strikingly, miRNA expression is also regulated in breast cancers of women who had received antiestrogen neoadjuvant therapy. Overall, our data indicate that the extensive alterations in miRNA regulation upon estrogen signaling pathway play a key role in estrogen-dependent functions and highlight the utility of considering miRNA expression in the understanding of antiestrogen resistance of breast cancer. [Cancer Res 2009;69(21):8332–40]
Data from Activation of the PI3K/AKT Pathway Induces Urothelial Carcinoma of the Renal Pelvis: Identification in Human Tumors and Confirmation in Animal Models
Authors: Qian Chao-Nan , Furge Kyle A. , Knol Jared , Huang Dan , Chen Jindong , Dykema Karl J. , Kort Eric J. , Massie Aaron , Khoo Sok Kean , Vanden Beldt Kristin , Resau James H. , Anema John , Kahnoski Richard J. , Morreau Hans , Camparo Philippe , Comperat Eva , Sibony Mathilde , Denoux Yves , Molinie Vincent , Vieillefond Annick , Eng Charis , Williams Bart O. , Teh Bin Tean
Published: March 2023

Abstract
Urothelial carcinoma of the renal pelvis is a deadly disease with an unclear tumorigenic mechanism. We conducted gene expression profiling on a set of human tumors of this type and identified a phosphatidylinositol 3-kinase (PI3K)/AKT activation expression signature in 76.9% (n = 13) of our samples. Sequence analysis found both activating mutations of PIK3CA (13.6%, n = 22) and loss of heterozygosity at the PTEN locus (25%, n = 8). In contrast, none of the other subtypes of kidney neoplasms (e.g., clear-cell renal cell carcinoma) harbored PIK3CA mutations (n = 87; P < 0.001). Immunohistochemical analysis of urothelial carcinoma samples found loss of PTEN protein expression (36.4%, n = 11) and elevation of phosphorylated mammalian target of rapamycin (mTOR; 63.6%, n = 11). To confirm the role of the PI3K/AKT pathway in urothelial carcinoma, we generated mice containing biallelic inactivation of Pten in the urogenital epithelia. These mice developed typical renal pelvic urothelial carcinomas, with an incidence of 57.1% in mice older than 1 year. Laser capture microdissection followed by PCR confirmed the deletion of Pten exons 4 and 5 in the animal tumor cells. Immunohistochemical analyses showed increased phospho-mTOR and phospho-S6K levels in the animal tumors. Renal lymph node metastases were found in 15.8% of the animals with urothelial carcinoma. In conclusion, we identified and confirmed an important role for the PI3K/AKT pathway in the development of urothelial carcinoma and suggested that inhibitors of this pathway (e.g., mTOR inhibitor) may serve as effective therapeutic agents. [Cancer Res 2009;69(21):8256–64]
Data from Disruption of Sphingosine 1-Phosphate Lyase Confers Resistance to Chemotherapy and Promotes Oncogenesis through Bcl-2/Bcl-xL Upregulation
Authors: Colié Sandra , Van Veldhoven Paul P. , Kedjouar Blandine , Bedia Carmen , Albinet Virginie , Sorli Sonia-Caroline , Garcia Virginie , Djavaheri-Mergny Mojgan , Bauvy Chantal , Codogno Patrice , Levade Thierry , Andrieu-Abadie Nathalie
Published: March 2023

Abstract
Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite involved in cancer development through stimulation of cell survival, proliferation, migration, and angiogenesis. Irreversible degradation of S1P is catalyzed by S1P lyase (SPL). The human SGPL1 gene that encodes SPL maps to a region often mutated in cancers. To investigate the effect of SPL deficiency on cell survival and transformation, the susceptibility to anticancer drugs of fibroblasts generated from SPL-deficient mouse embryos (Sgpl1−/−) was compared with that of cells from heterozygous (Sgpl1+/−) or wild-type (Sgpl1+/+) embryos. First, loss of SPL caused resistance to the toxic effects of etoposide and doxorubicin. Interestingly, heterozygosity for the Sgpl1 gene resulted in partial resistance to apoptosis. Secondly, doxorubicin-induced apoptotic signaling was strongly inhibited in Sgpl1−/− cells (phosphatidylserine externalization, caspase activation, and cytochrome c release). This was accompanied by a strong increase in Bcl-2 and Bcl-xL protein content. Whereas correction of SPL deficiency in Sgpl1−/− cells led to downregulation of antiapoptotic proteins, Bcl-2 and Bcl-xL small interfering RNA–mediated knockdown in SPL-deficient cells resulted in increased sensitivity to doxorubicin, suggesting that Bcl-2 upregulation mediates SPL protective effects. Moreover, SPL deficiency led to increased cell proliferation, anchorage-independent cell growth, and formation of tumors in nude mice. Finally, transcriptomic studies showed that SPL expression is downregulated in human melanoma cell lines. Thus, by affecting S1P metabolism and the expression of Bcl-2 members, the loss of SPL enhances cell resistance to anticancer regimens and results in an increased ability of cells to acquire a transformed phenotype and become malignant. [Cancer Res 2009;69(24):9346–53]
Data from Activating Peroxisome Proliferator-Activated Receptor γ Mutant Promotes Tumor Growth In vivo by Enhancing Angiogenesis
Authors: Tian Lifeng , Zhou Jie , Casimiro Mathew C. , Liang Bing , Ojeifo John O. , Wang Min , Hyslop Terry , Wang Chenguang , Pestell Richard G.
Published: March 2023

Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is expressed in a variety of cancer cells. The addition of ligand activates the receptor by inducing a conformational change in the receptor, which can be recapitulated by mutation. To investigate the role of activated PPARγ signaling in breast cancer, we compared the function of a constitutively active PPARγ (PγCA) mutant with the wild-type PPARγ in ErbB2-induced mammary tumorigenesis in vivo. Tumor cells transduced with either PPARγ or PγCA were implanted into immunocompetent FVB mice. Enhanced tumor growth was observed in PγCA-transduced cells, which was associated with increased angiogenesis and endothelial stem cells as evidenced by increased number of cells stained with von Willebrand factor, c-Kit, CD133, and CD31. Genome-wide expression profiling identified a group of genes within the angiogenesis pathway, including Angptl4, as targets of activated PPARγ; PγCA also induced Angptl4 protein secretion in ErbB2-transformed mammary epithelial cells. Angptl4 promoted vascular endothelial cell migration; conversely, immunodepletion of Angptl4 reduced PγCA-mediated cellular migration. Collectively, these studies suggest that activated PPARγ induces Angptl4 to promote tumor growth through enhanced angiogenesis in vivo. [Cancer Res 2009;69(24):9236–44]
Data from Wip1 Directly Dephosphorylates γ-H2AX and Attenuates the DNA Damage Response
Authors: Cha Hyukjin , Lowe Julie M. , Li Henghong , Lee Ji-Seon , Belova Galina I. , Bulavin Dmitry V. , Fornace Albert J.
Published: March 2023

Abstract
The integrity of DNA is constantly challenged throughout the life of a cell by both endogenous and exogenous stresses. A well-organized rapid damage response and proficient DNA repair, therefore, become critically important for maintaining genomic stability and cell survival. When DNA is damaged, the DNA damage response (DDR) can be initiated by alterations in chromosomal structure and histone modifications, such as the phosphorylation of the histone H2AX (the phosphorylated form is referred to as γ-H2AX). γ-H2AX plays a crucial role in recruiting DDR factors to damage sites for accurate DNA repair. On repair completion, γ-H2AX must then be reverted to H2AX by dephosphorylation for attenuation of the DDR. Here, we report that the wild-type p53–induced phosphatase 1 (Wip1) phosphatase, which is often overexpressed in a variety of tumors, effectively dephosphorylates γ-H2AX in vitro and in vivo. Ectopic expression of Wip1 significantly reduces the level of γ-H2AX after ionizing as well as UV radiation. Forced premature dephosphorylation of γ-H2AX by Wip1 disrupts recruitment of important DNA repair factors to damaged sites and delays DNA damage repair. Additionally, deletion of Wip1 enhances γ-H2AX levels in cells undergoing constitutive oncogenic stress. Taken together, our studies show that Wip1 is an important mammalian phosphatase for γ-H2AX and shows an additional mechanism for Wip1 in the tumor surveillance network. Cancer Res; 70(10); 4112–22. ©2010 AACR.
Data from DNA Methylation Analysis Determines the High Frequency of Genic Hypomethylation and Low Frequency of Hypermethylation Events in Plasma Cell Tumors
Authors: Salhia Bodour , Baker Angela , Ahmann Gregory , Auclair Daniel , Fonseca Rafael , Carpten John
Published: March 2023

Abstract
Multiple myeloma (MM) is a plasma cell malignancy of the bone marrow, which evolves from a premalignant stage called monoclonal gammopathy of undetermined significance (MGUS). In some patients, an intermediate stage referred to as smoldering multiple myeloma (SMM) is clinically recognized, with the full-bore malignancy termed MM. We conducted a study to assess differential CpG methylation at 1,500 genic loci during MM progression and profiled CD138+ plasma cells from MGUS, SMM, and MM specimens; human myeloma cell lines; and normal plasma cell (NPC) samples. We showed that the number of differentially methylated loci (DML) increased with tumor grade, and the vast majority were due to hypomethylation. Hierarchical clustering analysis revealed samples that coclustered tightly with NPC. These cases, referred to as “normal-like,” contained significantly fewer DML when compared with their non–normal-like counterparts and displayed overall methylation levels resembling NPC. This study represents one of the first methylome interrogation studies in MM and points toward global hypomethylation at genic CpG loci as an important and early mechanism driving myelomagenesis. Determining the set of critical genes and pathways based on the myeloma methylome is expected to lead to an improved understanding of biological mechanisms involved in myelomagenesis. Cancer Res; 70(17); 6934–44. ©2010 AACR.
Data from CUB Domain–Containing Protein 1, a Prognostic Factor for Human Pancreatic Cancers, Promotes Cell Migration and Extracellular Matrix Degradation
Authors: Miyazawa Yuri , Uekita Takamasa , Hiraoka Nobuyoshi , Fujii Satoko , Kosuge Tomoo , Kanai Yae , Nojima Yoshihisa , Sakai Ryuichi
Published: March 2023

Abstract
CUB domain–containing protein 1 (CDCP1) is a membrane protein that is highly expressed in several solid cancers. We reported previously that CDCP1 regulates anoikis resistance as well as cancer cell migration and invasion, although the underlying mechanisms have not been elucidated. In this study, we found that expression of CDCP1 in pancreatic cancer tissue was significantly correlated with overall survival and that CDCP1 expression in pancreatic cancer cell lines was relatively high among solid tumor cell lines. Reduction of CDCP1 expression in these cells suppressed extracellular matrix (ECM) degradation by inhibiting matrix metalloproteinase-9 secretion. Using the Y734F mutant of CDCP1, which lacks the tyrosine phosphorylation site, we showed that CDCP1 regulates cell migration, invasion, and ECM degradation in a tyrosine phosphorylation–dependent manner and that these CDCP1-associated characteristics were inhibited by blocking the association of CDCP1 and protein kinase Cδ (PKCδ). CDCP1 modulates the enzymatic activity of PKCδ through the tyrosine phosphorylation of PKCδ by recruiting PKCδ to Src family kinases. Cortactin, which was detected as a CDCP1-dependent binding partner of PKCδ, played a significant role in migration and invasion but not in ECM degradation of pancreatic cells. These results suggest that CDCP1 expression might play a crucial role in poor outcome of pancreatic cancer through promotion of invasion and metastasis and that molecules blocking the expression, phosphorylation, or the PKCδ-binding site of CDCP1 are potential therapeutic candidates. Cancer Res; 70(12); 5136–46. ©2010 AACR.
Data from Matrix Metalloproteinase-14 (MT1-MMP)–Mediated Endoglin Shedding Inhibits Tumor Angiogenesis
Authors: Hawinkels Lukas J.A.C. , Kuiper Patricia , Wiercinska Eliza , Verspaget Hein W. , Liu Zhen , Pardali Evangelia , Sier Cornelis F.M. , ten Dijke Peter
Published: March 2023

Abstract
Endoglin is a transforming growth factor-β coreceptor with a crucial role in angiogenesis. A soluble form of endoglin is present in the circulation, but the role of soluble endoglin (sEndoglin) is poorly understood. In addition, the endoglin shedding mechanism is not known. Therefore, we examined the role of sEndoglin in tumor angiogenesis and the mechanism by which the extracellular domain of endoglin is released from the membrane.In colorectal cancer specimens, we observed high endothelial endoglin protein expression, accompanied with slightly lower sEndoglin levels in the circulation, compared with healthy controls. In vitro analysis using endothelial sprouting assays revealed that sEndoglin reduced spontaneous and vascular endothelial growth factor–induced endothelial sprouting. Human umbilical vascular endothelial cells were found to secrete high levels of sEndoglin. Endoglin shedding was inhibited by matrix metalloproteinase (MMP) inhibitors and MMP-14 short hairpin RNA, indicating MMP-14 as the major endoglin shedding protease. Coexpression of endoglin and membrane-bound MMP-14 led to a strong increase in sEndoglin levels. Endoglin shedding required a direct interaction between endoglin and membrane-localized MMP-14. Using cleavage site mutants, we determined that MMP-14 cleaved endoglin at a site in close proximity to the transmembrane domain. Taken together, this study shows that MMP-14 mediates endoglin shedding, which may regulate the angiogenic potential of endothelial cells in the (colorectal) tumor microenvironment. Cancer Res; 70(10); 4141–50. ©2010 AACR.
Data from A Novel Role of Interleukin-13 Receptor α2 in Pancreatic Cancer Invasion and Metastasis
Authors: Fujisawa Toshio , Joshi Bharat , Nakajima Atsushi , Puri Raj K.
Published: March 2023

Abstract
Whereas interleukin-13 receptor α2 chain (IL-13Rα2) is overexpressed in a variety of human solid cancers including pancreatic cancer, we investigated its significance in cancer invasion and metastasis. We used two pancreatic cancer cell lines, IL-13Rα2–negative HPAF-II and IL-13Rα2–positive HS766T, and generated IL-13Rα2 stably transfected HPAF-II as well as IL-13Rα2 RNA interference knocked-down HS766T cells. Ability of invasion and signal transduction was compared between IL-13Rα2–negative and IL-13Rα2–positive cells and tumor metastasis was assessed in murine model for human pancreatic cancer with orthotopic implantation of tumors. IL-13 treatment enhanced cell invasion in IL-13Rα2–positive cancer cell lines but not in IL-13Rα2–negative cell lines. Furthermore, gene transfer of IL-13Rα2 in negative cell lines enhanced invasion, whereas its silencing downmodulated invasion of pancreatic cell lines in a Matrigel invasion assay. In vivo study revealed that IL-13Rα2–positive cancer metastasized to lymph nodes, liver, and peritoneum at a significantly higher rate compared with IL-13Rα2–negative tumors. The expression of IL-13Rα2 in metastatic lesions was found to be increased compared with primary tumors, and mice with IL-13Rα2–positive cancer displayed cachexia and poor prognosis. Invasion and metastasis also correlated with increased matrix metalloproteinase protease activity in these cells. Mechanistically, IL-13 activated extracellular signal-regulated kinase 1/2 and activator protein-1 nuclear factors in IL-13Rα2–positive pancreatic cancer cell lines but not in IL-13Rα2–negative cell lines. Taken together, our results show for the first time that IL-13 can signal through IL-13Rα2 in pancreatic cancer cells and IL-13Rα2 may serve as a prognostic biomarker of invasion and metastasis in pancreatic cancer. [Cancer Res 2009;69(22):8678–85]
Data from Insulin-Like Growth Factor-I Regulates the Liver Microenvironment in Obese Mice and Promotes Liver Metastasis
Authors: Wu Yingjie , Brodt Pnina , Sun Hui , Mejia Wilson , Novosyadlyy Ruslan , Nunez Nomeli , Chen Xiaoli , Mendoza Arnulfo , Hong Sung-Hyeok , Khanna Chand , Yakar Shoshana
Published: March 2023

Abstract
Among the mechanisms implicated in the tumor-promoting effects of obesity, signaling by insulin-like growth factor-I (IGF-I) and insulin has received considerable attention. However, the emerging realization that obesity is associated with chronic inflammation has prompted other consideration of how the IGF-I axis may participate in cancer progression. In the present study, we used two mouse models of chronic (LID) and inducible (iLID) igf-1 gene deficiency in the liver to investigate the role of IGF-I in regulating the host microenvironment and colorectal carcinoma growth and metastasis in obese mice. Obese mice had a heightened inflammatory response in the liver, which was abolished in mice with chronic IGF-I deficiency (LID). In control animals changes to the hepatic microenvironment associated with obesity sustained the presence of tumor cells in the liver and increased the incidence of hepatic metastases after intrasplenic/portal inoculation of colon carcinoma cells. These changes did not occur in LID mice with chlonic IGF-1 deficiency. In contrast, these changes occured in iLID mice with acute IGF-1 deficiency, in the same manner as the control animals, revealing a fundamental difference in the nature of the requirement for IGF-1 on tumor growth and metastasis. In the setting of obesity, our findings imply that IGF-1 is critical to activate and sustain an inflammatory response in the liver that is needed for hepatic metastasis, not only through direct, paracrine effect on tumor cell growth, but also through indirect effects involving the tumor microenvironment. Cancer Res; 70(1); 57–67
Data from Positive Cross-Talk between Estrogen Receptor and NF-κB in Breast Cancer
Authors: Frasor Jonna , Weaver Aisha , Pradhan Madhumita , Dai Yang , Miller Lance D. , Lin Chin-Yo , Stanculescu Adina
Published: March 2023

Abstract
Estrogen receptors (ER) and nuclear factor-κB (NF-κB) are known to play important roles in breast cancer, but these factors are generally thought to repress each other's activity. However, we have recently found that ER and NF-κB can also act together in a positive manner to synergistically increase gene transcription. To examine the extent of cross-talk between ER and NF-κB, a microarray study was conducted in which MCF-7 breast cancer cells were treated with 17β-estradiol (E2), tumor necrosis factor α (TNFα), or both. Follow-up studies with an ER antagonist and NF-κB inhibitors show that cross-talk between E2 and TNFα is mediated by these two factors. We find that although transrepression between ER and NF-κB does occur, positive cross-talk is more prominent with three gene-specific patterns of regulation: (a) TNFα enhances E2 action on ∼30% of E2-upregulated genes; (b) E2 enhances TNFα activity on ∼15% of TNFα-upregulated genes; and (c) E2 + TNFα causes a more than additive upregulation of ∼60 genes. Consistent with their prosurvival roles, ER and NF-κB and their target gene, BIRC3, are involved in protecting breast cancer cells against apoptosis. Furthermore, genes positively regulated by E2 + TNFα are clinically relevant because they are enriched in luminal B breast tumors and their expression profiles can distinguish a cohort of patients with poor outcome following endocrine treatment. Taken together, our findings suggest that positive cross-talk between ER and NF-κB is more extensive than anticipated and that these factors may act together to promote survival of breast cancer cells and progression to a more aggressive phenotype. [Cancer Res 2009;69(23):8918–25]
Data from Lipid Rafts and Caveolin-1 Are Required for Invadopodia Formation and Extracellular Matrix Degradation by Human Breast Cancer Cells
Authors: Yamaguchi Hideki , Takeo Yukiko , Yoshida Shuhei , Kouchi Zen , Nakamura Yoshikazu , Fukami Kiyoko
Published: March 2023

Abstract
Invadopodia are ventral membrane protrusions through which invasive cancer cells degrade the extracellular matrix. They are thought to function in the migration of cancer cells through tissue barriers, which is necessary for cancer invasion and metastasis. Although many protein components of invadopodia have been identified, the organization and the role of membrane lipids in invadopodia are not well understood. In this study, the role of lipid rafts, which are cholesterol-enriched membrane microdomains, in the assembly and function of invadopodia in human breast cancer cells was investigated. Lipid rafts are enriched, internalized, and dynamically trafficked at invadopodia sites. Perturbation of lipid raft formation due to depleting or sequestering membrane cholesterol blocked the invadopodia-mediated degradation of the gelatin matrix. Caveolin-1 (Cav-1), a resident protein of lipid rafts and caveolae, accumulates at invadopodia and colocalizes with the internalized lipid raft membranes. Membrane type 1 matrix metalloproteinase (MT1-MMP), a matrix proteinase associated with invadopodia, is localized at lipid raft-enriched membrane fractions and cotrafficked and colocalized with Cav-1 at invadopodia. The small interfering RNA–mediated silencing of Cav-1 inhibited the invadopodia-mediated and MT1-MMP–dependent degradation of the gelatin matrix. Furthermore, Cav-1 and MT1-MMP are coexpressed in invasive human breast cancer cell lines that have an ability to form invadopodia. These results indicate that invadopodia are the sites where enrichment and trafficking of lipid rafts occur and that Cav-1 is an essential regulator of MT1-MMP function and invadopodia-mediated breast cancer cell invasion. [Cancer Res 2009;69(22):8594–602]
Data from Genome-Wide Identification of PAX3-FKHR Binding Sites in Rhabdomyosarcoma Reveals Candidate Target Genes Important for Development and Cancer
Authors: Cao Liang , Yu Yunkai , Bilke Sven , Walker Robert L. , Mayeenuddin Linnia H. , Azorsa David O. , Yang Fan , Pineda Marbin , Helman Lee J. , Meltzer Paul S.
Published: March 2023

Abstract
The PAX3-FKHR fusion protein is present in a majority of alveolar rhabdomyosarcomas associated with increased aggressiveness and poor prognosis. To better understand the molecular pathogenesis of PAX3-FKHR, we carried out the first, unbiased genome-wide identification of PAX3-FKHR binding sites and associated target genes in alveolar rhabdomyosarcoma. The data shows that PAX3-FKHR binds to the same sites as PAX3 at both MYF5 and MYOD enhancers. The genome-wide analysis reveals that the PAX3-FKHR sites are (a) mostly distal to transcription start sites, (b) conserved, (c) enriched for PAX3 motifs, and (d) strongly associated with genes overexpressed in PAX3-FKHR–positive rhabdomyosarcoma cells and tumors. There is little evidence in our data set for PAX3-FKHR binding at the promoter sequences. The genome-wide analysis further illustrates a strong association between PAX3 and E-box motifs in these binding sites, suggestive of a common coregulation for many target genes. We also provide the first direct evidence that FGFR4 and IGF1R are the targets for PAX3-FKHR. The map of PAX3-FKHR binding sites provides a framework for understanding the pathogenic roles of PAX3-FKHR, as well as its molecular targets to allow a systematic evaluation of agents against this aggressive rhabdomyosarcoma. Cancer Res; 70(16); 6497–508. ©2010 AACR.
Data from Suppression of Cyclin D1 by Hypoxia-Inducible Factor-1 via Direct Mechanism Inhibits the Proliferation and 5-Fluorouracil–Induced Apoptosis of A549 Cells
Authors: Wen Wen , Ding Jin , Sun Wen , Wu Kun , Ning Beifang , Gong Wenfeng , He Guoping , Huang Shanna , Ding Xinyu , Yin Peipei , Chen Lei , Liu Qiong , Xie Weifen , Wang Hongyang
Published: March 2023

Abstract
Hypoxia-inducible factor (HIF) and cyclin D1 are both key mediators of cell growth and proliferation in normal and cancer cells. However, the interrelation between HIF and cyclin D1 remains unclear. In the present study, we observed the inverse correlation between cyclin D1 and HIF-1 in hypoxia condition. Overexpression of the dominant negative mutant of HIF-1α (DN-HIF) significantly enhanced cyclin D1 expression upon hypoxia or arsenite exposure, suggesting the negative regulation of cyclin D1 by HIF-1. Furthermore, we found that the impairment of HIF-1 increased cyclin D1 expression in A549 pulmonary cancer cells, which in turn promoted G1-S cell cycle transition and cell proliferation. Cyclin D1 expression was increased in s.c. xenograft of DN-HIF stably transfected A549 cells in nude mice compared with that of control cells. Chromatin immunoprecipitation assay revealed that HIF-1 was able to directly bind to the promoter region of cyclin D1, which indicates that the negative regulation of cyclin D1 by HIF-1 is through a direct mechanism. Inhibition of histone deacetylase (HDAC) by pretreatment of cells with trichostatin A or specific knockdown of HDAC7 by its shRNA antagonized the suppression of cyclin D1 by HIF-1, suggesting that HDAC7 is required for HIF-1–mediated cyclin D1 downregulation. Moreover, we found that 5-fluorouracil–triggered apoptosis of DN-HIF–transfected A549 cells was reduced by sicyclin D1 (cyclin D1–specific interference RNA) introduction, suggesting that clinical observation of HIF-1 overexpression–associated chemoresistance might be, at least partially, due to the negative regulation of cyclin D1. Cancer Res; 70(5); 2010–9
Data from Estrogen-Dependent and Estrogen-Independent Mechanisms Contribute to AIB1-Mediated Tumor Formation
Authors: Torres-Arzayus Maria I. , Zhao Jin , Bronson Roderick , Brown Myles
Published: March 2023

Abstract
We have previously reported the oncogenic properties of the gene amplified in breast cancer 1 (AIB1), a member of the p160 family of hormone receptor coactivators. In a transgenic mouse model, AIB1 overexpression resulted in a high incidence of tumors in various tissues, including mammary gland, uterus, lung, and pituitary. To determine whether the AIB1 oncogenicity in this model depended on its function as an estrogen receptor (ER) coactivator, we abolished ER signaling through two independent approaches, by performing ovariectomy on AIB1 transgenic (AIB1-tg) mice to prevent gonadal estrogen production and by crossing AIB1-tg mice with ERα-null mutant mice. Ovariectomized (ovx) mice, but not AIB1 × ERα−/− mice, still developed mammary gland hyperplasia and ductal carcinoma in situ. Both approaches, however, completely prevented the development of invasive mammary tumors, indicating that invasive mammary tumor formation is strictly estrogen dependent. Once developed, AIB1-induced mammary tumors can subsequently lose their dependence on estrogen: Injection of ERα(+) tumor cell lines derived from such tumors into ovx or untreated wild-type mice resulted in a similar rate of tumor growth in both groups. Surprisingly, however, ovx mice had an ∼4-fold higher rate of metastasis formation, suggesting that estrogen provided some protection from metastasis formation. Lastly, our experiments identified oncogenic functions of AIB1 that are independent of its ER coactivation, as both approaches, ovariectomy and ER−/− crosses, still resulted in a high incidence of tumors in the lung and pituitary. We therefore conclude that AIB1 can exert its oncogenicity through tissue-specific estrogen-dependent and estrogen-independent functions. Cancer Res; 70(10); 4102–11. ©2010 AACR.
Data from Epigenetic Regulation of Vitamin D 24-Hydroxylase/CYP24A1 in Human Prostate Cancer
Authors: Luo Wei , Karpf Adam R. , Deeb Kristin K. , Muindi Josephia R. , Morrison Carl D. , Johnson Candace S. , Trump Donald L.
Published: March 2023

Abstract
Calcitriol, a regulator of calcium homeostasis with antitumor properties, is degraded by the product of the CYP24A1 gene, which is downregulated in human prostate cancer by unknown mechanisms. We found that CYP24A1 expression is inversely correlated with promoter DNA methylation in prostate cancer cell lines. Treatment with the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (DAC) activates CYP24A1 expression in prostate cancer cells. In vitro methylation of the CYP24A1 promoter represses its promoter activity. Furthermore, inhibition of histone deacetylases by trichostatin A (TSA) enhances the expression of CYP24A1 in prostate cancer cells. Quantitative chromatin immunoprecipitation-PCR (ChIP-qPCR) reveals that specific histone modifications are associated with the CYP24A1 promoter region. Treatment with TSA increases H3K9ac and H3K4me2 and simultaneously decreases H3K9me2 at the CYP24A1 promoter. ChIP-qPCR assay reveals that treatment with DAC and TSA increases the recruitment of vitamin D receptor to the CYP24A1 promoter. Reverse transcriptase-PCR analysis of paired human prostate samples revealed that CYP24A1 expression is downregulated in prostate malignant lesions compared with adjacent histologically benign lesions. Bisulfite pyrosequencing shows that CYP24A1 gene is hypermethylated in malignant lesions compared with matched benign lesions. Our findings indicate that repression of CYP24A1 gene expression in human prostate cancer cells is mediated in part by promoter DNA methylation and repressive histone modifications. Cancer Res; 70(14); 5953–62. ©2010 AACR.
Data from Glomus Tumors in Neurofibromatosis Type 1: Genetic, Functional, and Clinical Evidence of a Novel Association
Authors: Brems Hilde , Park Caroline , Maertens Ophélia , Pemov Alexander , Messiaen Ludwine , Upadhyaya Meena , Claes Kathleen , Beert Eline , Peeters Kristel , Mautner Victor , Sloan Jennifer L. , Yao Lawrence , Lee Chyi-Chia Richard , Sciot Raf , De Smet Luc , Legius Eric , Stewart Douglas R.
Published: March 2023

Abstract
Neurofibromatosis type 1 (NF1) is a common disorder that arises secondary to mutations in the tumor suppressor gene NF1. Glomus tumors are small, benign but painful tumors that originate from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. We report 11 individuals with NF1 who harbored 20 glomus tumors of the fingers and 1 in the toe; 5 individuals had multiple glomus tumors. We hypothesized that biallelic inactivation of NF1 underlies the pathogenesis of these tumors. In 12 NF1-associated glomus tumors, we used cell culture and laser capture microdissection to isolate DNA. We also analyzed two sporadic (not NF1-associated) glomus tumors. Genetic analysis showed germ line and somatic NF1 mutations in seven tumors. RAS mitogen-activated protein kinase hyperactivation was observed in cultured NF1−/− glomus cells, reflecting a lack of inhibition of the pathway by functional neurofibromin, the protein product of NF1. No abnormalities in NF1 or RAS mitogen-activated protein kinase activation were found in sporadic glomus tumors. By comparative genomic hybridization, we observed amplification of the 3′-end of CRTAC1 and a deletion of the 5′-end of WASF1 in two NF1-associated glomus tumors. For the first time, we show that loss of neurofibromin function is crucial in the pathogenesis of glomus tumors in NF1. Glomus tumors of the fingers or toes should be considered as part of the tumor spectrum of NF1. [Cancer Res 2009;69(18):7393–401]
Data from A Chemosensitization Screen Identifies TP53RK, a Kinase that Restrains Apoptosis after Mitotic Stress
Authors: Peterson David , Lee James , Lei Xingye C. , Forrest William F. , Davis David P. , Jackson Peter K. , Belmont Lisa D.
Published: March 2023

Abstract
Taxanes are very effective at causing mitotic arrest; however, there is variability among cancer cells in the apoptotic response to mitotic arrest. The variability in clinical efficacy of taxane-based therapy is likely a reflection of this variability in apoptotic response, thus elucidation of the molecular mechanism of the apoptotic response to mitotic stress could lead to improved clinical strategies. To identify genes whose expression influences the rate and extent of apoptosis after mitotic arrest, we screened a kinase-enriched small interfering RNA library for effects on caspase activation in response to maximally effective doses of paclitaxel, a PLK1 inhibitor, or cisplatin. Small interfering RNA oligonucleotides directed against an atypical protein kinase, TP53RK, caused the greatest increase in caspase-3/7 activation in response to antimitotic agents. Time-lapse microscopy revealed that cells entered mitosis with normal kinetics, but died after entry into mitosis in the presence of paclitaxel more rapidly when TP53RK was depleted. Because expression levels of TP53RK vary in cancers, TP53RK levels could provide a molecular marker to predict response to antimitotic agents. TP53RK inhibition may also sensitize cancers to taxanes. Cancer Res; 70(15); 6325–35. ©2010 AACR.