bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Epidermal Growth Factor Receptor and Mutant p53 Expand an Esophageal Cellular Subpopulation Capable of Epithelial-to-Mesenchymal Transition through ZEB Transcription Factors
Authors: Ohashi Shinya , Natsuizaka Mitsuteru , Wong Gabrielle S. , Michaylira Carmen Z. , Grugan Katharine D. , Stairs Douglas B. , Kalabis Jiri , Vega Maria E. , Kalman Ross A. , Nakagawa Momo , Klein-Szanto Andres J. , Herlyn Meenhard , Diehl J. Alan , Rustgi Anil K. , Nakagawa Hiroshi
Published: March 2023

Abstract
Transforming growth factor-β (TGF-β) is a potent inducer of epithelial to mesenchymal transition (EMT). However, it remains elusive about which molecular mechanisms determine the cellular capacity to undergo EMT in response to TGF-β. We have found that both epidermal growth factor receptor (EGFR) overexpression and mutant p53 tumor suppressor genes contribute to the enrichment of an EMT-competent cellular subpopulation among telomerase-immortalized human esophageal epithelial cells during malignant transformation. EGFR overexpression triggers oncogene-induced senescence, accompanied by the induction of cyclin-dependent kinase inhibitors p15INK4B, p16INK4A, and p21. Interestingly, a subpopulation of cells emerges by negating senescence without loss of EGFR overexpression. Such cell populations express increased levels of zinc finger E-box binding (ZEB) transcription factors ZEB1 and ZEB2, and undergo EMT on TGF-β stimulation. Enrichment of EMT-competent cells was more evident in the presence of p53 mutation, which diminished EGFR-induced senescence. RNA interference directed against ZEB resulted in the induction of p15INK4B and p16INK4A, reactivating the EGFR-dependent senescence program. Importantly, TGF-β–mediated EMT did not take place when cellular senescence programs were activated by either ZEB knockdown or the activation of wild-type p53 function. Thus, senescence checkpoint functions activated by EGFR and p53 may be evaded through the induction of ZEB, thereby allowing the expansion of an EMT-competent unique cellular subpopulation, providing novel mechanistic insights into the role of ZEB in esophageal carcinogenesis. Cancer Res; 70(10); 4174–84. ©2010 AACR.
Data from TP53 Cancerous Mutations Exhibit Selection for Translation Efficiency
Authors: Waldman Yedael Y. , Tuller Tamir , Sharan Roded , Ruppin Eytan
Published: March 2023

Abstract
The tumor suppressor gene TP53 is known to be a key regulator in cancer, and more than half of human cancers exhibit mutations in this gene. Recent evidence shows that point mutations in TP53 not only disrupt its function but also possess gain-of-function and dominant-negative effects on wild-type copies, thus making the mutated gene an oncogene. Hence, this brings about the possibility that TP53 mutations may be under selection for increasing the overall translation efficiency (TE) of defected TP53 in cancerous cells. Here, we perform the first large-scale analysis of TE in human cancer mutated TP53 variants, identifying a significant increase in TE that is correlated with the frequency of TP53 mutations. Furthermore, mutations with a known oncogenic effect significantly increase their TE compared with the other TP53 mutations. Further analysis shows that TE may have influence both on selecting the location of the mutation and on its outcome: codons with lower TE show stronger selection toward nonsynonymous mutations and, for each codon, frequent mutations show stronger increase in TE compared with less frequent mutations. Additionally, we find that TP53 mutations have significantly higher TE increase in progressive versus primary tumors. Finally, an analysis of TP53 NCI-60 cell lines points to a coadaptation between the mutations and the tRNA pool, increasing the overall TP53 TE. Taken together, these results show that TE plays an important role in the selection of TP53 cancerous mutations. [Cancer Res 2009;69(22):8807–13]
Data from Suppression of Casein Kinase 1α in Melanoma Cells Induces a Switch in β-Catenin Signaling to Promote Metastasis
Authors: Sinnberg Tobias , Menzel Moritz , Kaesler Susanne , Biedermann Tilo , Sauer Birgit , Nahnsen Sven , Schwarz Michael , Garbe Claus , Schittek Birgit
Published: March 2023

Abstract
Casein kinase 1 α (CK1α) is a multifunctional Ser/Thr kinase that phosphorylates several substrates. Among those is β-catenin, an important player in cell adhesion and Wnt signaling. Phosphorylation of β-catenin by CK1α at Ser45 is the priming reaction for the proteasomal degradation of β-catenin. Interestingly, aside from this role in β-catenin degradation, very little is known about the expression and functional role of CK1α in tumor cells. Here, we show that CK1α expression in different tumor types is either strongly suppressed or completely lost during tumor progression and that CK1α is a key factor determining β-catenin stability and transcriptional activity in tumor cells. CK1α reexpression in metastatic melanoma cells reduces growth in vitro and metastasis formation in vivo, and induces cell cycle arrest and apoptosis, whereas suppression of CK1α in primary melanoma cells induces invasive tumor growth. Inactivation of CK1α promotes tumor progression by regulating a switch in β-catenin–mediated signaling. These results show that melanoma cells developed an efficient new mechanism to activate the β-catenin signaling pathway and define CK1α as a novel tumor suppressor. Cancer Res; 70(17); 6999–7009. ©2010 AACR.
Data from Oncogene-Induced Sensitization to Chemotherapy-Induced Death Requires Induction as well as Deregulation of E2F1
Authors: Helgason G. Vignir , O'Prey Jim , Ryan Kevin M.
Published: March 2023

Abstract
The analysis of DNA tumor viruses has provided landmark insights into the molecular pathogenesis of cancer. A paradigm for this field has been the study of the adenoviral E1a protein, which has led to the identification of proteins such as p300, p400, and members of the retinoblastoma family. Through binding Rb family members, E1a causes deregulation of E2F proteins—an event common to most human cancers and a central pathway in which oncogenes, including E1a, sensitize cells to chemotherapy-induced programmed cell death. We report here, however, that E1a not only causes deregulation of E2F, but importantly that it also causes the posttranscriptional upregulation of E2F1 protein levels. This effect is distinct from the deregulation of E2F1, however, as mutants of E2F1 impaired in pRb binding are induced by E1a and E2F1 induction can also be observed in Rb-null cells. Analysis of E1a mutants selectively deficient in cellular protein binding revealed that induction of E2F1 is instead intrinsically linked to p400. Mutants unable to bind p400, despite being able to deregulate E2F1, do not increase E2F1 protein levels and they do not sensitize cells to apoptotic death. These mutants can, however, be complemented by either the knockdown of p400, resulting in the restoration of the ability to induce E2F1, or by the overexpression of E2F1, with both events reenabling sensitization to chemotherapy-induced death. Due to the frequent deregulation of E2F1 in human cancer, these studies reveal potentially important insights into E2F1-mediated chemotherapeutic responses that may aid the development of novel targeted therapies for malignant disease. Cancer Res; 70(10); 4074–80. ©2010 AACR.
Data from FOXO1A Is a Target for HER2-Overexpressing Breast Tumors
Authors: Wu Yanyuan , Shang Xiying , Sarkissyan Marianna , Slamon Dennis , Vadgama Jaydutt V.
Published: March 2023

Abstract
Trastuzumab treatment has improved the overall survival of HER2-overexpressing breast cancer patients. However, many of these patients will eventually become resistant to treatment. The mechanisms that contribute to resistance to trastuzumab are unknown. In this study, we tested the hypothesis that targeting of the FKHR transcription factor FOXO1A in HER2-overexpressing breast tumor cells can overcome the trastuzumab resistance in vitro. We have shown that overexpression of HER2 leads to activation of phosphatidylinositol 3-kinase (PI3K)/Akt pathway and subsequent inactivation of FOXO1A in HER2-overexpressing breast cancer cells SKBR3, BT474, and MCF7-HER2. In wild-type SKBR3 and BT474 cells, trastuzumab downregulates active Akt and increases FOXO1A expression that leads to increase in p27kip1 and decrease in cyclin D1 and finally inhibits cell proliferation. In contrast, the effect of trastuzumab was eliminated by the reduction of FOXO1A in HER2-overexpressing cells with constitutively active Akt1 (SKBR3/AA28 and BT474/AA9). The downregulation of FOXO1A resulted in nuclear export of p27kip1. Blocking the constitutively active Akt by a specific Akt/protein kinase B signaling inhibitor-2 (API-2) significantly increased FOXO1A expression and rendered the cells more responsive to trastuzumab-induced growth inhibition. Reactivation of FOXO1A by stable or transient transfection also restored the growth-inhibitory effects of trastuzumab in SKBR3/AA28, BT474/AA9, and MCF7-HER2 cells. Knocking down FOXO1A by small interfering RNA resulted in reducing trastuzumab-induced growth inhibition. In summary, trastuzumab can inhibit proliferation of HER2-overexpressing breast cancer cells by reactivating FOXO1A through inhibition of the PI3K/Akt pathway. FOXO1A may therefore serve as a target for HER2-overexpressing breast tumors. Cancer Res; 70(13); 5475–85. ©2010 AACR.
Data from The Bisecting GlcNAc on N-Glycans Inhibits Growth Factor Signaling and Retards Mammary Tumor Progression
Authors: Song Yinghui , Aglipay Jason A. , Bernstein Joshua D. , Goswami Sumanta , Stanley Pamela
Published: March 2023

Abstract
The branching of complex N-glycans attached to growth factor receptors promotes tumor progression by prolonging growth factor signaling. The addition of the bisecting GlcNAc to complex N-glycans by Mgat3 has varying effects on cell adhesion, cell migration, and hepatoma formation. Here, we show that Chinese hamster ovary cells expressing Mgat3 and the polyoma middle T (PyMT) antigen have reduced cell proliferation and growth factor signaling dependent on a galectin lattice. The Mgat3 gene is not expressed in virgin mammary gland but is upregulated during lactation and is expressed in mouse mammary tumor virus (MMTV)/PyMT tumors. Mice lacking Mgat3 that cannot transfer the bisecting GlcNAc to N-glycans acquire PyMT-induced mammary tumors more rapidly and have an increased tumor burden, increased migration of tumor cells, and increased early metastasis to lung. Tumors and tumor-derived cells lacking Mgat3 exhibit enhanced signaling through the Ras pathway and reduced amounts of functionally glycosylated α-dystroglycan. Constitutive overexpression of an MMTV/Mgat3 transgene inhibits early mammary tumor development and tumor cell migration. Thus, the addition of the bisecting GlcNAc to complex N-glycans of mammary tumor cell glycoprotein receptors is a cell autonomous mechanism serving to retard tumor progression by reducing growth factor signaling. Cancer Res; 70(8); 3361–71. ©2010 AACR.
Data from BRAF Inactivation Drives Aneuploidy by Deregulating CRAF
Authors: Kamata Tamihiro , Hussain Jahan , Giblett Susan , Hayward Robert , Marais Richard , Pritchard Catrin
Published: March 2023

Abstract
Aspartate-594 is the third most common BRAF residue mutated in human cancer. Mutants of this residue are kinase inactive, and the mechanism(s) by which they contribute to cancer has remained perplexing. Using a conditional knock-in mouse model, we show that the D594ABraf mutant does not drive tumor development per se but is able to induce aneuploidy in murine splenocytes and mouse embryonic fibroblasts and contributes to immortalization through the propagation of aneuploid cells. D594ABraf lacks kinase activity but induces the related gene product Craf as well as the mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathway. Here, we show that the aneuploid phenotype is dependent on Craf. Treatment with the MEK inhibitor U0126 did not attenuate the emergence of aneuploidy but prevented the growth of aneuploid cells. These results provide a previously unidentified link between Craf and chromosomal stability, with important implications for our understanding of the development of cancers with driver mutations that hyperactivate Craf. Cancer Res; 70(21); 8475–86. ©2010 AACR.
Data from Small Molecule Inhibition of GDC-0449 Refractory Smoothened Mutants and Downstream Mechanisms of Drug Resistance
Authors: Dijkgraaf Gerrit J. P. , Alicke Bruno , Weinmann Lasse , Januario Thomas , West Kristina , Modrusan Zora , Burdick Dan , Goldsmith Richard , Robarge Kirk , Sutherlin Dan , Scales Suzie J. , Gould Stephen E. , Yauch Robert L. , de Sauvage Frederic J.
Published: March 2023

Abstract
Inappropriate Hedgehog (Hh) signaling has been directly linked to medulloblastoma (MB), a common malignant brain tumor in children. GDC-0449 is an Hh pathway inhibitor (HPI) currently under clinical investigation as an anticancer agent. Treatment of a MB patient with GDC-0449 initially regressed tumors, but this individual ultimately relapsed with a D473H resistance mutation in Smoothened (SMO), the molecular target of GDC-0449. To explore the role of the mutated aspartic acid residue in SMO function, we substituted D473 with every amino acid and found that all functional mutants were resistant to GDC-0449, with positively charged residues conferring potential oncogenic properties. Alanine scan mutagenesis of SMO further identified E518 as a novel prospective mutation site for GDC-0449 resistance. To overcome this form of acquired resistance, we screened a panel of chemically diverse HPIs and identified several antagonists with potent in vitro activity against these GDC-0449–resistant SMO mutants. The bis-amide compound 5 was of particular interest, as it was able to inhibit tumor growth mediated by drug resistant SMO in a murine allograft model of MB. However, focal amplifications of the Hh pathway transcription factor Gli2 and the Hh target gene cyclin D1 (Ccnd1) were observed in two additional resistant models, indicating that resistance may also occur downstream of SMO. Importantly, these HPI resistant MB allografts retained their sensitivity to PI3K inhibition, presenting additional opportunities for the treatment of such tumors. Cancer Res; 71(2); 435–44. ©2010 AACR.
Data from In Vivo Magnetic Resonance Imaging of the Estrogen Receptor in an Orthotopic Model of Human Breast Cancer
Authors: Pais Adi , Gunanathan Chidambaram , Margalit Raanan , Eti Biton Inbal , Yosepovich Ady , Milstein David , Degani Hadassa
Published: March 2023

Abstract
Histologic overexpression of the estrogen receptor α (ER) is a well-established prognostic marker in breast cancer. Noninvasive imaging techniques that could detect ER overexpression would be useful in a variety of settings where patients' biopsies are problematic to obtain. This study focused on developing, by in vivo MRI, strategies to measure the level of ER expression in an orthotopic mouse model of human breast cancer. Specifically, novel ER-targeted contrast agents based on pyridine-tetra-acetate-Gd(III) chelate (PTA-Gd) conjugated to 17β-estradiol (EPTA-Gd) or to tamoxifen (TPTA-Gd) were examined in ER-positive or ER-negative tumors. Detection of specific interactions of EPTA-Gd with ER were documented that could differentiate ER-positive and ER-negative tumors. In vivo competition experiments confirmed that the enhanced detection capability of EPTA-Gd was based specifically on ER targeting. In contrast, PTA-Gd acted as an extracellular probe that enhanced ER detection similarly in either tumor type, confirming a similar vascular perfusion efficiency in ER-positive and ER-negative tumors in the model. Finally, TPTA-Gd accumulated selectively in muscle and could not preferentially identify ER-positive tumors. Together, these results define a novel MRI probe that can permit selective noninvasive imaging of ER-positive tumors in vivo. Cancer Res; 71(24); 7387–97. ©2011 AACR.
Data from Neuropilin-1–Dependent Regulation of EGF-Receptor Signaling
Authors: Rizzolio Sabrina , Rabinowicz Noa , Rainero Elena , Lanzetti Letizia , Serini Guido , Norman Jim , Neufeld Gera , Tamagnone Luca
Published: March 2023

Abstract
Neuropilin-1 (NRP1) is a coreceptor for multiple extracellular ligands. NRP1 is widely expressed in cancer cells and in advanced human tumors; however, its functional relevance and signaling mechanisms are unclear. Here, we show that NRP1 expression controls viability and proliferation of different cancer cells, independent of its short intracellular tail. We found that the extracellular domain of NRP1 interacts with the EGF receptor (EGFR) and promotes its signaling cascade elicited upon EGF or TGF-α stimulation. Upon NRP1 silencing, the ability of ligand-bound EGFR to cluster on the cell surface, internalize, and activate the downstream AKT pathway is severely impaired. EGFR is frequently activated in human tumors due to overexpression, mutation, or sustained autocrine/paracrine stimulation. Here we show that NRP1-blocking antibodies and NRP1 silencing can counteract ligand-induced EGFR activation in cancer cells. Thus our findings unveil a novel molecular mechanism by which NRP1 can control EGFR signaling and tumor growth. Cancer Res; 72(22); 5801–11. ©2012 AACR.
Data from Unphosphorylated STAT1 Promotes Sarcoma Development through Repressing Expression of Fas and Bad and Conferring Apoptotic Resistance
Authors: Zimmerman Mary A. , Rahman Nur-Taz , Yang Dafeng , Lahat Guy , Lazar Alexander J. , Pollock Raphael E. , Lev Dina , Liu Kebin
Published: March 2023

Abstract
STAT1 exists in phosphorylated (pSTAT1) and unphosphorylated (uSTAT1) forms each regulated by IFN-γ. Although STAT1 is a key mediator of the IFN-γ signaling pathway, an essential component of the host cancer immunosurveillance system, STAT1 is also overexpressed in certain human cancers where the functions of pSTAT1 and uSTAT1 are ill defined. Using a murine model of soft tissue sarcoma (STS), we show that disruption of the IFN effector molecule IRF8 decreases pSTAT1 and increases uSTAT1 in STS cells, thereby increasing their metastatic potential. We determined that the IRF8 gene promoter was hypermethylated frequently in human STS. An analysis of 123 human STS specimens revealed that high uSTAT1 levels in tumor cells was correlated with a reduction in disease-specific survival (DSS), whereas high pSTAT1 levels in tumor cells were correlated with an increase in DSS. In addition, uSTAT1 levels were negatively correlated with pSTAT1 levels in these STS specimens. Mechanistic investigations revealed that IRF8 suppressed STAT1 transcription by binding the STAT1 promoter. RNAi-mediated silencing of STAT1 in STS cells was sufficient to increase expression of the apoptotic mediators Fas and Bad and to elevate the sensitivity of STS cells to Fas-mediated apoptosis. Together, our findings show how the phosphorylation status of pSTAT1 determines its function as a tumor suppressor, with uSTAT1 acting as a tumor promoter that acts by elevating resistance to Fas-mediated apoptosis to promote immune escape. Cancer Res; 72(18); 4724–32. ©2012 AACR.
Data from The Metabolomic Signature of Malignant Glioma Reflects Accelerated Anabolic Metabolism
Authors: Chinnaiyan Prakash , Kensicki Elizabeth , Bloom Gregory , Prabhu Antony , Sarcar Bhaswati , Kahali Soumen , Eschrich Steven , Qu Xiaotao , Forsyth Peter , Gillies Robert
Published: March 2023

Abstract
Although considerable progress has been made toward understanding glioblastoma biology through large-scale genetic and protein expression analyses, little is known about the underlying metabolic alterations promoting their aggressive phenotype. We conducted global metabolomic profiling on patient-derived glioma specimens and identified specific metabolic programs differentiating low- and high-grade tumors, with the metabolic signature of glioblastoma reflecting accelerated anabolic metabolism. When coupled with transcriptional profiles, we identified the metabolic phenotype of the mesenchymal subtype to consist of accumulation of the glycolytic intermediate phosphoenolpyruvate and decreased pyruvate kinase activity. Unbiased hierarchical clustering of metabolomic profiles identified three subclasses, which we term energetic, anabolic, and phospholipid catabolism with prognostic relevance. These studies represent the first global metabolomic profiling of glioma, offering a previously undescribed window into their metabolic heterogeneity, and provide the requisite framework for strategies designed to target metabolism in this rapidly fatal malignancy. Cancer Res; 72(22); 5878–88. ©2012 AACR.
Data from Critical Role of STAT3 in IL-6–Mediated Drug Resistance in Human Neuroblastoma
Authors: Ara Tasnim , Nakata Rie , Sheard Michael A. , Shimada Hiroyuki , Buettner Ralf , Groshen Susan G. , Ji Lingyun , Yu Hua , Jove Richard , Seeger Robert C. , DeClerck Yves A.
Published: March 2023

Abstract
Drug resistance is a major cause of treatment failure in cancer. Here, we have evaluated the role of STAT3 in environment-mediated drug resistance (EMDR) in human neuroblastoma. We determined that STAT3 was not constitutively active in most neuroblastoma cell lines but was rapidly activated upon treatment with interleukin (IL)-6 alone and in combination with the soluble IL-6 receptor (sIL-6R). Treatment of neuroblastoma cells with IL-6 protected them from drug-induced apoptosis in a STAT3-dependent manner because the protective effect of IL-6 was abrogated in the presence of a STAT3 inhibitor and upon STAT3 knockdown. STAT3 was necessary for the upregulation of several survival factors such as survivin (BIRC5) and Bcl-xL (BCL2L1) when cells were exposed to IL-6. Importantly, IL-6–mediated STAT3 activation was enhanced by sIL-6R produced by human monocytes, pointing to an important function of monocytes in promoting IL-6–mediated EMDR. Our data also point to the presence of reciprocal activation of STAT3 between tumor cells and bone marrow stromal cells including not only monocytes but also regulatory T cells (Treg) and nonmyeloid stromal cells. Thus, the data identify an IL-6/sIL-6R/STAT3 interactive pathway between neuroblastoma cells and their microenvironment that contributes to drug resistance. Cancer Res; 73(13); 3852–64. ©2013 AACR.
Data from G Protein–Coupled Receptor Kinase GRK5 Phosphorylates Moesin and Regulates Metastasis in Prostate Cancer
Authors: Chakraborty Prabir Kumar , Zhang Yushan , Coomes Alexandra S. , Kim Wan-Ju , Stupay Rachel , Lynch Lauren D. , Atkinson Tamieka , Kim Jae I. , Nie Zhongzhen , Daaka Yehia
Published: March 2023

Abstract
G protein–coupled receptor kinases (GRK) regulate diverse cellular functions ranging from metabolism to growth and locomotion. Here, we report an important contributory role for GRK5 in human prostate cancer. Inhibition of GRK5 kinase activity attenuated the migration and invasion of prostate cancer cells and, concordantly, increased cell attachment and focal adhesion formation. Mass spectrometric analysis of the phosphoproteome revealed the cytoskeletal-membrane attachment protein moesin as a putative GRK5 substrate. GRK5 regulated the subcellular distribution of moesin and colocalized with moesin at the cell periphery. We identified amino acid T66 of moesin as a principal GRK5 phosphorylation site and showed that enforcing the expression of a T66-mutated moesin reduced cell spreading. In a xenograft model of human prostate cancer, GRK5 silencing reduced tumor growth, invasion, and metastasis. Taken together, our results established GRK5 as a key contributor to the growth and metastasis of prostate cancer. Cancer Res; 74(13); 3489–500. ©2014 AACR.
Data from LEO1 Is Regulated by PRL-3 and Mediates Its Oncogenic Properties in Acute Myelogenous Leukemia
Authors: Chong Phyllis S.Y. , Zhou Jianbiao , Cheong Lip-Lee , Liu Shaw-Cheng , Qian Jingru , Guo Tiannan , Sze Siu Kwan , Zeng Qi , Chng Wee Joo
Published: March 2023

Abstract
PRL-3, an oncogenic dual-specificity phosphatase, is overexpressed in 50% of acute myelogenous leukemia (AML) and associated with poor survival. We found that stable expression of PRL-3 confers cytokine independence and growth advantage of AML cells. However, how PRL-3 mediates these functions in AML is not known. To comprehensively screen for PRL3-regulated proteins in AML, we performed SILAC-based quantitative proteomics analysis and discovered 398 significantly perturbed proteins after PRL-3 overexpression. We show that Leo1, a component of RNA polymerase II–associated factor (PAF) complex, is a novel and important mediator of PRL-3 oncogenic activities in AML. We described a novel mechanism where elevated PRL-3 protein increases JMJD2C histone demethylase occupancy on Leo1 promoter, thereby reducing the H3K9me3 repressive signals and promoting Leo1 gene expression. Furthermore, PRL-3 and Leo1 levels were positively associated in AML patient samples (N = 24; P < 0.01). On the other hand, inhibition of Leo1 reverses PRL-3 oncogenic phenotypes in AML. Loss of Leo1 leads to destabilization of the PAF complex and downregulation of SOX2 and SOX4, potent oncogenes in myeloid transformation. In conclusion, we identify an important and novel mechanism by which PRL-3 mediates its oncogenic function in AML. Cancer Res; 74(11); 3043–53. ©2014 AACR.
Data from Novel Strategies to Enforce an Epithelial Phenotype in Mesenchymal Cells
Authors: Dragoi Ana-Maria , Swiss Rachel , Gao Beile , Agaisse Hervé
Published: March 2023

Abstract
E-cadherin downregulation in cancer cells is associated with epithelial-to-mesenchymal transition (EMT) and metastatic prowess, but the underlying mechanisms are incompletely characterized. In this study, we probed E-cadherin expression at the plasma membrane as a functional assay to identify genes involved in E-cadherin downregulation. The assay was based on the E-cadherin–dependent invasion properties of the intracellular pathogen Listeria monocytogenes. On the basis of a functional readout, automated microscopy and computer-assisted image analysis were used to screen siRNAs targeting 7,000 human genes. The validity of the screen was supported by its definition of several known regulators of E-cadherin expression, including ZEB1, HDAC1, and MMP14. We identified three new regulators (FLASH, CASP7, and PCGF1), the silencing of which was sufficient to restore high levels of E-cadherin transcription. In addition, we identified two new regulators (FBXL5 and CAV2), the silencing of which was sufficient to increase E-cadherin expression at a posttranscriptional level. FLASH silencing regulated the expression of E-cadherin and other ZEB1-dependent genes, through posttranscriptional regulation of ZEB1, but it also regulated the expression of numerous ZEB1-independent genes with functions predicted to contribute to a restoration of the epithelial phenotype. Finally, we also report the identification of siRNA duplexes that potently restored the epithelial phenotype by mimicking the activity of known and putative microRNAs. Our findings suggest new ways to enforce epithelial phenotypes as a general strategy to treat cancer by blocking invasive and metastatic phenotypes associated with EMT. Cancer Res; 74(14); 3659–72. ©2014 AACR.
Data from Cancer Affects microRNA Expression, Release, and Function in Cardiac and Skeletal Muscle
Authors: Chen Daohong , Goswami Chirayu P. , Burnett Riesa M. , Anjanappa Manjushree , Bhat-Nakshatri Poornima , Muller William , Nakshatri Harikrishna
Published: March 2023

Abstract
Circulating microRNAs (miRNA) are emerging as important biomarkers of various diseases, including cancer. Intriguingly, circulating levels of several miRNAs are lower in patients with cancer compared with healthy individuals. In this study, we tested the hypothesis that a circulating miRNA might serve as a surrogate of the effects of cancer on miRNA expression or release in distant organs. Here we report that circulating levels of the muscle-enriched miR486 is lower in patients with breast cancer compared with healthy individuals and that this difference is replicated faithfully in MMTV-PyMT and MMTV-Her2 transgenic mouse models of breast cancer. In tumor-bearing mice, levels of miR486 were relatively reduced in muscle, where there was elevated expression of the miR486 target genes PTEN and FOXO1A and dampened signaling through the PI3K/AKT pathway. Skeletal muscle expressed lower levels of the transcription factor MyoD, which controls miR486 expression. Conditioned media (CM) obtained from MMTV-PyMT and MMTV-Her2/Neu tumor cells cultured in vitro were sufficient to elicit reduced levels of miR486 and increased PTEN and FOXO1A expression in C2C12 murine myoblasts. Cytokine analysis implicated tumor necrosis factor α (TNFα) and four additional cytokines as mediators of miR486 expression in CM-treated cells. Because miR486 is a potent modulator of PI3K/AKT signaling and the muscle-enriched transcription factor network in cardiac/skeletal muscle, our findings implicated TNFα-dependent miRNA circuitry in muscle differentiation and survival pathways in cancer. Cancer Res; 74(16); 4270–81. ©2014 AACR.
Data from ERK1/2 Blockade Prevents Epithelial–Mesenchymal Transition in Lung Cancer Cells and Promotes Their Sensitivity to EGFR Inhibition
Authors: Buonato Janine M. , Lazzara Matthew J.
Published: March 2023

Abstract
Overcoming cellular mechanisms of de novo and acquired resistance to drug therapy remains a central challenge in the clinical management of many cancers, including non–small cell lung cancer (NSCLC). Although much work has linked the epithelial–mesenchymal transition (EMT) in cancer cells to the emergence of drug resistance, it is less clear where tractable routes may exist to reverse or inhibit EMT as a strategy for drug sensitization. Here, we demonstrate that extracellular signal-regulated kinase (ERK) 1/2 (mitogen-activated protein kinase 3/1, MAPK3/1) signaling plays a key role in directing the mesenchymal character of NSCLC cells and that blocking ERK signaling is sufficient to heighten therapeutic responses to EGF receptor (EGFR) inhibitors. MEK1/2 (MAPKK1/2) inhibition promoted an epithelial phenotype in NSCLC cells, preventing induction of EMT by exogenous TGF-β. Moreover, in cells exhibiting de novo or acquired resistance to the EGFR inhibitor gefitinib, MEK inhibition enhanced the sensitivity to gefitinib and slowed cell migration. These effects only occurred, however, if MEK was inhibited for a period sufficient to trigger changes in EMT marker expression. Consistent with these findings, changes in EMT phenotypes and markers were also induced by the expression of mutant KRAS in a MEK-dependent manner. Our results suggest that prolonged exposure to MEK or ERK inhibitors may not only restrain EMT but also overcome naïve or acquired resistance of NSCLC to EGFR-targeted therapy in the clinic. Cancer Res; 74(1); 309–19. ©2013 AACR.
Data from Cyclophilin B Supports Myc and Mutant p53-Dependent Survival of Glioblastoma Multiforme Cells
Authors: Choi Jae Won , Schroeder Mark A. , Sarkaria Jann N. , Bram Richard J.
Published: March 2023

Abstract
Glioblastoma multiforme is an aggressive, treatment-refractory type of brain tumor for which effective therapeutic targets remain important to identify. Here, we report that cyclophilin B (CypB), a prolyl isomerase residing in the endoplasmic reticulum (ER), provides an essential survival signal in glioblastoma multiforme cells. Analysis of gene expression databases revealed that CypB is upregulated in many cases of malignant glioma. We found that suppression of CypB reduced cell proliferation and survival in human glioblastoma multiforme cells in vitro and in vivo. We also found that treatment with small molecule inhibitors of cyclophilins, including the approved drug cyclosporine, greatly reduced the viability of glioblastoma multiforme cells. Mechanistically, depletion or pharmacologic inhibition of CypB caused hyperactivation of the oncogenic RAS–mitogen-activated protein kinase pathway, induction of cellular senescence signals, and death resulting from loss of MYC, mutant p53, Chk1, and Janus-activated kinase/STAT3 signaling. Elevated reactive oxygen species, ER expansion, and abnormal unfolded protein responses in CypB-depleted glioblastoma multiforme cells indicated that CypB alleviates oxidative and ER stresses and coordinates stress adaptation responses. Enhanced cell survival and sustained expression of multiple oncogenic proteins downstream of CypB may thus contribute to the poor outcome of glioblastoma multiforme tumors. Our findings link chaperone-mediated protein folding in the ER to mechanisms underlying oncogenic transformation, and they make CypB an attractive and immediately targetable molecule for glioblastoma multiforme therapy. Cancer Res; 74(2); 484–96. ©2013 AACR.
Data from TLR7 Promotes Tumor Progression, Chemotherapy Resistance, and Poor Clinical Outcomes in Non–Small Cell Lung Cancer
Authors: Chatterjee Saradiya , Crozet Lucile , Damotte Diane , Iribarren Kristina , Schramm Catherine , Alifano Marco , Lupo Audrey , Cherfils-Vicini Julien , Goc Jeremy , Katsahian Sandrine , Younes Mohammad , Dieu-Nosjean Marie Caroline , Fridman Wolf Herman , Sautès-Fridman Catherine , Cremer Isabelle
Published: March 2023

Abstract
Toll-like receptors (TLR) recognize pathogen molecules and danger-associated signals that stimulate inflammatory processes. TLRs have been studied mainly in antigen-presenting cells, where they exert important immune regulatory functions, but they are also expressed by epithelial tumor cells, where they have been implicated in tumor progression. In this study, we demonstrate that the injection of TLR7 agonist in NOD/SCID mice, in C57BL/6 wild-type, and TLR7-deficient mice grafted with lung adenocarcinoma tumor cells leads to increased tumor progression and chemotherapeutic resistance. In patients with non–small cell lung cancer, expression analyses revealed that high TLR7 expression was strongly associated with resistance to neoadjuvant chemotherapy and poor clinical outcomes. Our findings delineate a crucial role for TLR7 in lung cancer physiopathology. Cancer Res; 74(18); 5008–18. ©2014 AACR.
Data from Survival in Patients with High-Risk Prostate Cancer Is Predicted by miR-221, Which Regulates Proliferation, Apoptosis, and Invasion of Prostate Cancer Cells by Inhibiting IRF2 and SOCS3
Authors: Kneitz Burkhard , Krebs Markus , Kalogirou Charis , Schubert Maria , Joniau Steven , van Poppel Hein , Lerut Evelyne , Kneitz Susanne , Scholz Claus Jürgen , Ströbel Philipp , Gessler Manfred , Riedmiller Hubertus , Spahn Martin
Published: March 2023

Abstract
A lack of reliably informative biomarkers to distinguish indolent and lethal prostate cancer is one reason this disease is overtreated. miR-221 has been suggested as a biomarker in high-risk prostate cancer, but there is insufficient evidence of its potential utility. Here we report that miR-221 is an independent predictor for cancer-related death, extending and validating earlier findings. By mechanistic investigations we showed that miR-221 regulates cell growth, invasiveness, and apoptosis in prostate cancer at least partially via STAT1/STAT3-mediated activation of the JAK/STAT signaling pathway. miR-221 directly inhibits the expression of SOCS3 and IRF2, two oncogenes that negatively regulate this signaling pathway. miR-221 expression sensitized prostate cancer cells for IFN-γ–mediated growth inhibition. Our findings suggest that miR-221 offers a novel prognostic biomarker and therapeutic target in high-risk prostate cancer. Cancer Res; 74(9); 2591–603. ©2014 AACR.
Data from Potassium Channel KCNA1 Modulates Oncogene-Induced Senescence and Transformation
Authors: Lallet-Daher Hélène , Wiel Clotilde , Gitenay Delphine , Navaratnam Naveenan , Augert Arnaud , Le Calvé Benjamin , Verbeke Stéphanie , Carling David , Aubert Sébastien , Vindrieux David , Bernard David
Published: March 2023

Abstract
Oncogene-induced senescence (OIS) constitutes a failsafe program that restricts tumor development. However, the mechanisms that link oncogenesis to senescence are not completely understood. We carried out a loss-of-function genetic screen that identified the potassium channel KCNA1 as a determinant of OIS escape that can license tumor growth. Oncogenic stress triggers an increase in KCNA1 expression and its relocation from the cytoplasm to the membrane. Mechanistically, this relocation is due to a loss of protein kinase A (PKA)-induced phosphorylation at residue S446 of KCNA1. Accordingly, sustaining PKA activity or expressing a KCNA1 phosphomimetic mutant maintained KCNA1 in the cytoplasm and caused escape from OIS. KCNA1 relocation to the membrane induced a change in membrane potential that invariably resulted in cellular senescence. Restoring KCNA1 expression in transformation-competent cells triggered variation in membrane potential and blocked RAS-induced transformation, and PKA activation suppressed both effects. Furthermore, KCNA1 expression was reduced in human cancers, and this decrease correlated with an increase in breast cancer aggressiveness. Taken together, our results identify a novel pathway that restricts oncogenesis through a potassium channel-dependent senescence pathway. Cancer Res; 73(16); 5253–65. ©2013 AACR.
Data from Acquired Expression of NFATc1 Downregulates E-Cadherin and Promotes Cancer Cell Invasion
Authors: Oikawa Tsukasa , Nakamura Atsuko , Onishi Nobuyuki , Yamada Taketo , Matsuo Koichi , Saya Hideyuki
Published: March 2023

Abstract
NFATc1 is a transcription factor that regulates T-cell development, osteoclastogenesis, and macrophage function. Given that T cells, osteoclasts, and macrophages in the tumor microenvironment are thought to modulate tumor progression, tumor cells may acquire NFATc1 expression through fusion with these NFATc1-expressing normal cells. We here revealed that a small proportion of tumor cells in human carcinoma specimens expressed NFATc1. To investigate the consequences of NFATc1 acquisition by tumor cells, we established A549 and MCF7 cell lines expressing a constitutively active form of NFATc1 (NFATc1CA) in an inducible manner. The expression of NFATc1CA promoted cancer cell invasion in association with changes in cell morphology. Analysis of gene expression and RNA interference experiments revealed that NFATc1CA suppressed E-cadherin expression by upregulating the transcriptional repressors Snail and Zeb1 in a manner independent of TGF-β signaling. Induced expression of NFATc1CA also downregulated E-cadherin expression and increased invasive activity in tumor xenografts in vivo. Our results thus suggest that the acquisition of NFATc1 expression contributes to tumor progression. Cancer Res; 73(16); 5100–9. ©2013 AACR.
Data from Invasive Lobular Carcinoma Cell Lines Are Characterized by Unique Estrogen-Mediated Gene Expression Patterns and Altered Tamoxifen Response
Authors: Sikora Matthew J. , Cooper Kristine L. , Bahreini Amir , Luthra Soumya , Wang Guoying , Chandran Uma R. , Davidson Nancy E. , Dabbs David J. , Welm Alana L. , Oesterreich Steffi
Published: March 2023

Abstract
Invasive lobular carcinoma (ILC) is a histologic subtype of breast cancer that is frequently associated with favorable outcomes, as approximately 90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that patients with ILC receiving adjuvant endocrine therapy may not benefit as much as patients with invasive ductal carcinoma. On the basis of these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome via gene expression microarray analyses and ER ChIP-Seq, and to examine response to endocrine therapy. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. We identified 915 genes that were uniquely E2 regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also E2 regulated in vivo in HCI-013. MM134 cells were de novo tamoxifen resistant and were induced to grow by 4-hydroxytamoxifen, as well as other antiestrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required fibroblast growth factor receptor (FGFR)-1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance. Cancer Res; 74(5); 1463–74. ©2014 AACR.
Data from Crosstalk between Glioma-Initiating Cells and Endothelial Cells Drives Tumor Progression
Authors: Jeon Hye-Min , Kim Sung-Hak , Jin Xun , Park Jong Bae , Kim Se Hoon , Joshi Kaushal , Nakano Ichiro , Kim Hyunggee
Published: March 2023

Abstract
Glioma-initiating cells (GIC), which reside within the perivascular microenvironment to maintain self-renewal capacity, are responsible for glioblastoma initiation, progression, and recurrence. However, the molecular mechanisms controlling crosstalk between GICs and endothelial cells are poorly understood. Here, we report that, in both GICs and endothelial cells, platelet-derived growth factor (PDGF)–driven activation of nitric oxide (NO) synthase increases NO-dependent inhibitor of differentiation 4 (ID4) expression, which in turn promotes JAGGED1–NOTCH activity through suppression of miR129 that specifically represses JAGGED1 suppression. This signaling axis promotes tumor progression along with increased GIC self-renewal and growth of tumor vasculature in the xenograft tumors, which is dramatically suppressed by NOTCH inhibitor. ID4 levels correlate positively with NOS2 (NO synthase-2), HES1, and HEY1 and negatively with miR129 in primary GICs. Thus, targeting the PDGF–NOS–ID4–miR129 axis and NOTCH activity in the perivascular microenvironment might serve as an efficacious therapeutic modality for glioblastoma. Cancer Res; 74(16); 4482–92. ©2014 AACR.
Data from Axon Guidance Factor SLIT2 Inhibits Neural Invasion and Metastasis in Pancreatic Cancer
Authors: Göhrig Andreas , Detjen Katharina M. , Hilfenhaus Georg , Körner Jan L. , Welzel Martina , Arsenic Ruza , Schmuck Rosa , Bahra Marcus , Wu Jane Y. , Wiedenmann Bertram , Fischer Christian
Published: March 2023

Abstract
Pancreatic ductal adenocarcinoma (PDAC) metastasizes by neural, vascular, and local invasion routes, which limit patient survival. In nerves and vessels, SLIT2 and its ROBO receptors constitute repellent guidance cues that also direct epithelial branching. Thus, the SLIT2–ROBO system may represent a key pinch point to regulate PDAC spread. In this study, we examined the hypothesis that escaping from repellent SLIT2–ROBO signaling is essential to enable PDAC cells to appropriate their local stromal infrastructure for dissemination. Through immunohistochemical analysis, we detected SLIT2 receptors ROBO1 and ROBO4 on epithelia, nerves, and vessels in healthy pancreas and PDAC specimens, respectively. SLIT2 mRNA expression was reduced in PDAC compared with nontransformed pancreatic tissues and cell lines, suggesting a reduction in SLIT2–ROBO pathway activity in PDAC. In support of this interpretation, restoring the SLIT2 expression in SLIT2-deficient PDAC cells inhibited their bidirectional chemoattraction with neural cells, and more specifically, impaired unidirectional PDAC cell navigation along outgrowing neurites in models of neural invasion. Restoring autocrine/paracrine SLIT2 signaling was also sufficient to inhibit the directed motility of PDAC cells, but not their random movement. Conversely, RNA interference–mediated silencing of ROBO1 stimulated the motility of SLIT2-competent PDAC cells. Furthermore, culture supernatants from SLIT2-competent PDAC cells impaired migration of endothelial cells (human umbilical vein endothelial cells), whereas an N-terminal SLIT2 cleavage fragment stimulated such migration. In vivo investigations of pancreatic tumors with restored SLIT2 expression demonstrated reduced invasion, metastasis, and vascularization, with opposing effects produced by ROBO1 silencing in tumor cells or sequestration of endogenous SLIT2. Analysis of clinical specimens of PDAC showed that those with low SLIT2 mRNA expression exhibited a higher incidence and a higher fraction of tumor-infiltrated lymph nodes. Taken together, our findings argue that disrupting SLIT2–ROBO signaling in PDAC may enhance metastasis and predispose PDAC cells to neural invasion. Cancer Res; 74(5); 1529–40. ©2014 AACR.
Data from HDAC2 Provides a Critical Support to Malignant Progression of Hepatocellular Carcinoma through Feedback Control of mTORC1 and AKT
Authors: Noh Ji Heon , Bae Hyun Jin , Eun Jung Woo , Shen Qingyu , Park Se Jin , Kim Hyung Seok , Nam Boas , Shin Woo Chan , Lee Eun Kyung , Lee Kyungbun , Jang Ja-Jun , Park Won Sang , Lee Jung Young , Nam Suk Woo
Published: March 2023

Abstract
Aberrant regulation of histone deacetylase 2 (HDAC2) contributes to malignant progression in various cancers, but the underlying mechanism leading to the activation of oncogenic HDAC2 remains unknown. In this study, we show that HDAC2 expression is upregulated in a large cohort of patients with human hepatocellular carcinoma, and that high expression of HDAC2 was significantly associated with poor prognosis of patients with hepatocellular carcinoma. We found that mTORC1/NF-κBp50 signaling is necessary for the growth factor–induced HDAC2 and is sustained in hepatocellular carcinoma, but not in normal hepatic cells. Growth factor–induced mTORC1 activates the nuclear translocation of NF-κBp50, where it binds to the intragenic sequences of the HDAC2 gene and promotes its transcription. Hepatocellular carcinoma tissues derived from chemical-induced mouse and rat liver cancer models validated that mTORC1 activation and NF-κBp50 nuclear translocation are essential for the transcriptional activation of oncogenic HDAC2 in hepatocellular carcinoma. In addition, we demonstrate that HDAC2 is required to maintain mTORC1 activity by stabilizing the mTOR/RAPTOR complex. Elevated expression of HDAC2 triggers a positive feedback loop that activates AKT phosphorylation via the transcriptional modulation of phosphoinositide signaling molecules. Bioinformatics analysis of HDAC2 signature and immunoblot analysis of mesenchymal genes also evidenced that HDAC2 plays a role in the malignant behavior of tumor cells by Snail induction and simultaneously E-cadherin suppression in hepatocellular carcinoma cells. These findings establish a molecular mechanism responsible for the activation of oncogenic HDAC2, which explains how growth factor–induced HDAC2 maintains mitogenic signaling and function during hepatocellular malignant progression and provide a novel strategy for therapeutic intervention in liver cancer. Cancer Res; 74(6); 1728–38. ©2014 AACR.
Data from BRCA2 Phosphorylated by PLK1 Moves to the Midbody to Regulate Cytokinesis Mediated by Nonmuscle Myosin IIC
Authors: Takaoka Miho , Saito Hiroko , Takenaka Katsuya , Miki Yoshio , Nakanishi Akira
Published: March 2023

Abstract
Cytokinesis is the critical final step in cell division. BRCA2 disruption during cytokinesis is associated with chromosome instability, but mechanistic information is lacking that could be used to prevent cancer cell division. In this study, we report that BRCA2 phosphorylation by the mitotic polo-like kinase (PLK1) governs the localization of BRCA2 to the Flemming body at the central midbody, permitting an interaction with nonmuscle myosin IIC (NM-IIC). Formation of an NM-IIC ring-like structure at the Flemming body shows that the IIC-ring relies on its ATPase activity stimulated by interaction with BRCA2 and associated proteins. Notably, inhibiting this binding inactivated the ATPase activity, causing disassembly of the IIC-ring, defective formation of the midbody, and interruption of cytokinesis. An analysis of cancer-associated mutations in BRCA2 at the PLK1-binding site suggests that they may contribute to cytokinetic defects by altering BRCA2 localization. Our findings suggest that BRCA2-dependent IIC-ring formation is a critical step in proper formation of the midbody, offering an explanation for how chromosome instability may arise in breast cancer. Cancer Res; 74(5); 1518–28. ©2014 AACR.