bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from EphB1 Suppression in Acute Myelogenous Leukemia: Regulating the DNA Damage Control System
Authors: Kampen K.R. , Scherpen F.J.G. , Garcia-Manero G. , Yang H. , Kaspers G.J.L. , Cloos J. , Zwaan C.M. , van den Heuvel-Eibrink M.M. , Kornblau S.M. , De Bont E.S.J.M.
Published: March 2024

Abstract
Loss of ephrin receptor (EphB1) expression may associate with aggressive cancer phenotypes; however, the mechanism of action remains unclear. To gain detailed insight into EphB1 function in acute myelogenous leukemia (AML), comprehensive analysis of EphB1 transcriptional regulation was conducted. In AML cells, EphB1 transcript was inversely correlated with EphB1 promoter methylation. The presence of EphB1 allowed EfnB1 ligand–mediated p53 DNA binding, leading to restoration of the DNA damage response (DDR) cascade by the activation of ATR, Chk1, p53, p21, p38, CDK1tyr15, and Bax, and downregulation of HSP27 and Bcl2. Comparatively, reintroduction of EphB1 expression in EphB1-methylated AML cells enhanced the same cascade of ATR, Chk1, p21, and CDK1tyr15, which consequently enforced programmed cell death. Interestingly, in pediatric AML samples, EphB1 peptide phosphorylation and mRNA expression were actively suppressed as compared with normal bone marrow, and a significant percentage of the primary AML specimens had EphB1 promoter hypermethylation. Finally, EphB1 repression associated with a poor overall survival in pediatric AML. Combined, the contribution of EphB1 to the DDR system reveals a tumor-suppressor function for EphB1 in pediatric AML.

Implications: The tumor-suppressor function of EphB1 is clinically relevant across many malignancies, suggesting that EphB1 is an important regulator of common cancer cell transforming pathways. Mol Cancer Res; 13(6); 982–92. ©2015 AACR.
Data from Base Excision Repair Defects Invoke Hypersensitivity to PARP Inhibition
Authors: Horton Julie K. , Stefanick Donna F. , Prasad Rajendra , Gassman Natalie R. , Kedar Padmini S. , Wilson Samuel H.
Published: March 2024

Abstract
PARP-1 is important for the recognition of both endogenous and exogenous DNA damage, and binds to DNA strand breaks including intermediates of base excision repair (BER). Once DNA-bound, PARP-1 becomes catalytically activated synthesizing PAR polymers onto itself and other repair factors (PARylation). As a result, BER repair proteins such as XRCC1 and DNA polymerase β (pol β) are more efficiently and rapidly recruited to sites of DNA damage. In the presence of an inhibitor of PARP activity (PARPi), PARP-1 binds to sites of DNA damage, but PARylation is prevented. BER enzyme recruitment is hindered, but binding of PARP-1 to DNA is stabilized, impeding DNA repair and leading to double-strand DNA breaks (DSB). Deficiencies in pol β−/− and Xrcc1−/− cells resulted in hypersensitivity to the PARP inhibitor 4-AN and reexpression of pol β or XRCC1, in these contexts, reversed the 4-AN hypersensitivity phenotype. BER deficiencies also showed evidence of replication defects that lead to DSB-induced apoptosis upon PARPi treatment. Finally, the clinically relevant PARP inhibitors olaparib and veliparib also exhibited hypersensitivity in both pol β−/− and Xrcc1−/− BER-deficient cells. These results reveal heightened sensitivity to PARPi as a function of BER deficiency.

Implications: BER deficiency represents a new therapeutic opportunity to enhance PARPi efficacy.

Visual Overview: http://mcr.aacrjournals.org/content/12/8/1128/F1.large.jpg.

Mol Cancer Res; 12(8); 1128–39. ©2014 AACR.
Data from Systemic Ablation of MMP-9 Triggers Invasive Growth and Metastasis of Pancreatic Cancer via Deregulation of IL6 Expression in the Bone Marrow
Authors: Grünwald Barbara , Vandooren Jennifer , Gerg Michael , Ahomaa Kaarin , Hunger Annique , Berchtold Sonja , Akbareian Sophia , Schaten Susanne , Knolle Percy , Edwards Dylan R. , Opdenakker Ghislain , Krüger Achim
Published: March 2024

Abstract
Matrix metalloproteinase 9 (MMP-9/Gelatinase B) is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and plays a central role in tumor cell invasion and metastasis. Here we complemented mechanistic insights in the cancer biology of MMP-9 and investigated the effects of specific long-term loss-of-function, by genetic ablation, of MMP-9 on PDAC initiation and progression in the well-established KPC mouse model of spontaneous PDAC. Tumor growth and progression were analyzed by histopathology and IHC. Invasive growth of PDAC cells was analyzed by both in vitro (proliferation, survival, migration, invasion assays) and in vivo (experimental metastasis assays) methods. Retroviral shRNAi was used to knockdown target genes (MMP-9, IL6R). Gene expression was analyzed by qRT-PCR, immunoblot, ELISA, in situ hybridization, and zymography. PDAC tumors from MMP-9–deficient mice were dramatically larger, more invasive, and contained more stroma. Yet, ablation of MMP-9 in PDAC cells did not directly promote invasive growth. Interestingly, systemic ablation of MMP-9 led to increased IL6 levels resulting from abrogation of MMP-9–dependent SCF signaling in the bone marrow. IL6 levels in MMP-9−/− mice were sufficient to induce invasive growth and STAT3 activation in PDAC cells via IL6 receptor (IL6R). Interference with IL6R blocked the increased invasion and metastasis of PDAC cells in MMP-9–deficient hosts. In conclusion, ablation of systemic MMP-9 initiated fatal communication between maintenance of physiological functions of MMP-9 in the bone marrow and invasive growth of PDAC via the IL6/IL6R/STAT3 axis.

Implications: Thus, the beneficial effects of host MMP-9 on PDAC are an important caveat for the use of systemic MMP-9 inhibitors in cancer. Mol Cancer Res; 14(11); 1147–58. ©2016 AACR.
Data from Telomere-Regulating Genes and the Telomere Interactome in Familial Cancers
Authors: Robles-Espinoza Carla Daniela , del Castillo Velasco-Herrera Martin , Hayward Nicholas K. , Adams David J.
Published: March 2024

Abstract
Telomeres are repetitive sequence structures at the ends of linear chromosomes that consist of double-stranded DNA repeats followed by a short single-stranded DNA protrusion. Telomeres need to be replicated in each cell cycle and protected from DNA-processing enzymes, tasks that cells execute using specialized protein complexes such as telomerase (that includes TERT), which aids in telomere maintenance and replication, and the shelterin complex, which protects chromosome ends. These complexes are also able to interact with a variety of other proteins, referred to as the telomere interactome, to fulfill their biological functions and control signaling cascades originating from telomeres. Given their essential role in genomic maintenance and cell-cycle control, germline mutations in telomere-regulating proteins and their interacting partners have been found to underlie a variety of diseases and cancer-predisposition syndromes. These syndromes can be characterized by progressively shortening telomeres, in which carriers can present with organ failure due to stem cell senescence among other characteristics, or can also present with long or unprotected telomeres, providing an alternative route for cancer formation. This review summarizes the critical roles that telomere-regulating proteins play in cell-cycle control and cell fate and explores the current knowledge on different cancer-predisposing conditions that have been linked to germline defects in these proteins and their interacting partners. Mol Cancer Res; 13(2); 211–22. ©2014 AACR.
Data from The Lipid Kinase PI4KIIIβ Is Highly Expressed in Breast Tumors and Activates Akt in Cooperation with Rab11a
Authors: Morrow Anne A. , Alipour Mohsen Amir , Bridges Dave , Yao Zemin , Saltiel Alan R. , Lee Jonathan M.
Published: March 2024

Abstract
Emerging evidence now implicates phosphatidylinositol 4-kinases (PI4K), enzymes that generate PI(4)P from phosphatidylinositol (PtdIns), in cancer. In this study, we investigate the role of PI4KIIIβ, one of four mammalian PI4Ks, in breast cancer. Although PI4KIIIβ protein levels are low in normal breast tissue, we find that approximately 20% of primary human breast tumors overexpress it. Expression of PI4KIIIβ in breast carcinoma cells leads to increased Akt activation, dependent on increased PI(3,4,5)P3 production. However, a kinase-inactive version of PI4KIIIβ also led to increased Akt activation, and no changes in PI(4)P or PI(4,5)P2 lipid abundance were detected in the PI4KIIIβ-overexpressing cells. This implies that PI4KIIIβ regulates PI(3,4,5)P3 and Akt independent of PI(4)P production. We find that the PI4KIIIβ-binding protein, Rab11a, a small GTPase that regulates endosomal recycling, is involved in PI4KIIIβ-mediated activation of Akt, as RNAi depletion of Rab11a impairs Akt activation. Furthermore, ectopic PI4KIIIβ expression alters cellular Rab11a distribution and enhances recruitment of PI4KIIIβ and Rab11a to recycling endosomes. This work suggests that PI4KIIIβ affects PI3K/Akt signaling through Rab11a and endosomal trafficking, independent of its lipid kinase activity. Thus, PI4KIIIβ likely plays a role in breast oncogenesis and that cooperation between Rab11a and PI4KIIIβ represents a novel Akt activation pathway. Mol Cancer Res; 12(10); 1492–508. ©2014 AACR.
Data from 27-Hydroxycholesterol Impairs Plasma Membrane Lipid Raft Signaling as Evidenced by Inhibition of IL6–JAK–STAT3 Signaling in Prostate Cancer Cells
Authors: Dambal Shweta , Alfaqih Mahmoud , Sanders Sergio , Maravilla Erick , Ramirez-Torres Adela , Galvan Gloria C. , Reis-Sobreiro Mariana , Rotinen Mirja , Driver Lucy M. , Behrove Matthew S. , Talisman Tijana Jovanovic , Yoon Junhee , You Sungyong , Turkson James , Chi Jen-Tsan , Freeman Michael R. , Macias Everardo , Freedland Stephen J.
Published: March 2024

Abstract
We recently reported that restoring the CYP27A1–27hydroxycholesterol axis had antitumor properties. Thus, we sought to determine the mechanism by which 27HC exerts its anti–prostate cancer effects. As cholesterol is a major component of membrane microdomains known as lipid rafts, which localize receptors and facilitate cellular signaling, we hypothesized 27HC would impair lipid rafts, using the IL6–JAK–STAT3 axis as a model given its prominent role in prostate cancer. As revealed by single molecule imaging of DU145 prostate cancer cells, 27HC treatment significantly reduced detected cholesterol density on the plasma membranes. Further, 27HC treatment of constitutively active STAT3 DU145 prostate cancer cells reduced STAT3 activation and slowed tumor growth in vitro and in vivo. 27HC also blocked IL6-mediated STAT3 phosphorylation in nonconstitutively active STAT3 cells. Mechanistically, 27HC reduced STAT3 homodimerization, nuclear translocation, and decreased STAT3 DNA occupancy at target gene promoters. Combined treatment with 27HC and STAT3 targeting molecules had additive and synergistic effects on proliferation and migration, respectively. Hallmark IL6–JAK–STAT gene signatures positively correlated with CYP27A1 gene expression in a large set of human metastatic castrate-resistant prostate cancers and in an aggressive prostate cancer subtype. This suggests STAT3 activation may be a resistance mechanism for aggressive prostate cancers that retain CYP27A1 expression. In summary, our study establishes a key mechanism by which 27HC inhibits prostate cancer by disrupting lipid rafts and blocking STAT3 activation.
Implications:
Collectively, these data show that modulation of intracellular cholesterol by 27HC can inhibit IL6–JAK–STAT signaling and may synergize with STAT3-targeted compounds.
Data from Grainyhead-like 2 Reverses the Metabolic Changes Induced by the Oncogenic Epithelial–Mesenchymal Transition: Effects on Anoikis
Authors: Farris Joshua C. , Pifer Phillip M. , Zheng Liang , Gottlieb Eyal , Denvir James , Frisch Steven M.
Published: March 2024

Abstract
Resistance to anoikis is a prerequisite for tumor metastasis. The epithelial-to-mesenchymal transition (EMT) allows tumor cells to evade anoikis. The wound-healing regulatory transcription factor Grainyhead-like 2 (GRHL2) suppresses/reverses EMT, accompanied by suppression of the cancer stem cell (CSC) phenotype and by resensitization to anoikis. Here, the effects of GRHL2 upon intracellular metabolism in the context of reversion of the EMT/CSC phenotype, with a view toward understanding how these effects promote anoikis sensitivity, were investigated. EMT enhanced mitochondrial oxidative metabolism. Although this was accompanied by higher accumulation of superoxide, the overall level of reactive oxygen species (ROS) declined, due to decreased hydrogen peroxide. Glutamate dehydrogenase 1 (GLUD1) expression increased in EMT, and this increase, via the product α-ketoglutarate (α-KG), was important for suppressing hydrogen peroxide and protecting against anoikis. GRHL2 suppressed GLUD1 gene expression, decreased α-KG, increased ROS, and sensitized cells to anoikis.

Implications: These results demonstrate a mechanistic role for GRHL2 in promoting anoikis through metabolic alterations. Mol Cancer Res; 14(6); 528–38. ©2016 AACR.
Data from c-Src Phosphorylates and Inhibits the Function of the CIC Tumor Suppressor Protein
Authors: Bunda Severa , Heir Pardeep , Li Annie Si Cong , Mamatjan Yasin , Zadeh Gelareh , Aldape Kenneth
Published: March 2024

Abstract
Capicua (CIC) is a transcriptional repressor that counteracts activation of genes in response to receptor tyrosine kinase (RTK)/Ras/ERK signaling. Following activation of RTK, ERK enters the nucleus and serine-phosphorylates CIC, releasing it from its targets to permit gene expression. We recently showed that ERK triggers ubiquitin-mediated degradation of CIC in glioblastoma (GBM). In this study, we examined whether another important downstream effector of RTK/EGFR, the non-RTK c-Src, affects CIC repressor function in GBM. We found that c-Src binds and tyrosine-phosphorylates CIC on residue 1455 to promote nuclear export of CIC. On the other hand, CIC-mutant allele (CIC-Y1455F), that escapes c-Src–mediated tyrosine phosphorylation, remains localized to the nucleus and retains strong repressor function against CIC targets, the oncogenic transcription factors ETV1 and ETV5. Furthermore, we show that the orally available Src family kinase inhibitor, dasatinib, which prevents EGF-mediated tyrosine phosphorylation of CIC and attenuates elevated ETV1 and ETV5 levels, reduces viability of GBM cells and glioma stem cells (GSC), but not of their control cells with undetectable c-Src activity. In fact, GBM cells and GSC expressing the tyrosine-defective CIC mutant (Y1455F) lose sensitivity to dasatinib, further endorsing the effect of dasatinib on Src-mediated tyrosine phosphorylation of CIC. These findings elucidate important mechanisms of CIC regulation and provide the rationale to target c-Src alongside ERK pathway inhibitors as a way to fully restore CIC tumor suppressor function in neoplasms such as GBM.
Implications:
c-Src tyrosine-phosphorylates CIC exports to cytoplasm and inactivates its repressor function in GBM.
Data from DNA Replication Stress Induced by Trifluridine Determines Tumor Cell Fate According to p53 Status
Authors: Kataoka Yuki , Iimori Makoto , Fujisawa Ryo , Morikawa-Ichinose Tomomi , Niimi Shinichiro , Wakasa Takeshi , Saeki Hiroshi , Oki Eiji , Miura Daisuke , Tsurimoto Toshiki , Maehara Yoshihiko , Kitao Hiroyuki
Published: March 2024

Abstract
DNA replication stress (DRS) is a predominant cause of genome instability, a driver of tumorigenesis and malignant progression. Nucleoside analogue-type chemotherapeutic drugs introduce DNA damage and exacerbate DRS in tumor cells. However, the mechanisms underlying the antitumor effect of these drugs are not fully understood. Here, we show that the fluorinated thymidine analogue trifluridine (FTD), an active component of the chemotherapeutic drug trifluridine/tipiracil, delayed DNA synthesis by human replicative DNA polymerases by acting both as an inefficient deoxyribonucleotide triphosphate source (FTD triphosphate) and as an obstacle base (trifluorothymine) in the template DNA strand, which caused DRS. In cells, FTD decreased the thymidine triphosphate level in the dNTP pool and increased the FTD triphosphate level, resulting in the activation of DRS-induced cellular responses during S-phase. In addition, replication protein A–coated single-stranded DNA associated with FancD2 and accumulated after tumor cells completed S-phase. Finally, FTD activated the p53–p21 pathway and suppressed tumor cell growth by inducing cellular senescence via mitosis skipping. In contrast, tumor cells that lost wild-type p53 underwent apoptotic cell death via aberrant late mitosis with severely impaired separation of sister chromatids. These results demonstrate that DRS induced by a nucleoside analogue–type chemotherapeutic drug suppresses tumor growth irrespective of p53 status by directing tumor cell fate toward cellular senescence or apoptotic cell death according to p53 status.
Implications:
Chemotherapeutic drugs that increase DRS during S-phase but allow tumor cells to complete S-phase may have significant antitumor activity even when functional p53 is lost.
Data from Downregulation of the Deiminase PADI2 Is an Early Event in Colorectal Carcinogenesis and Indicates Poor Prognosis
Authors: Cantariño Neus , Musulén Eva , Valero Vanesa , Peinado Miquel Angel , Perucho Manuel , Moreno Victor , Forcales Sònia-Vanina , Douet Julien , Buschbeck Marcus
Published: March 2024

Abstract
Peptidyl arginine deiminases (PADI) are a family of enzymes that catalyze the poorly understood posttranslational modification converting arginine residues into citrullines. In this study, the role of PADIs in the pathogenesis of colorectal cancer was investigated. Specifically, RNA expression was analyzed and its association with survival in a cohort of 98 colorectal cancer patient specimens with matched adjacent mucosa and 50 controls from donors without cancer. Key results were validated in an independent collection of tumors with matched adjacent mucosa and by mining of a publicly available expression data set. Protein expression was analyzed by immunoblotting for cell lines or IHC for patient specimens that further included 24 cases of adenocarcinoma with adjacent dysplasia and 11 cases of active ulcerative colitis. The data indicate that PADI2 is the dominantly expressed PADI enzyme in colon mucosa and is upregulated during differentiation. PADI2 expression is low or absent in colorectal cancer. Frequently, this occurs already at the stage of low-grade dysplasia. Mucosal PADI2 expression is also low in ulcerative colitis. The expression level of PADI2 in tumor and adjacent mucosa correlates with differential survival: low levels associate with poor prognosis.

Implications: Downregulation of PADI2 is an early event in the pathogenesis of colorectal cancer associated with poor prognosis and points toward a possible role of citrullination in modulating tumor cells and their microenvironment. Mol Cancer Res; 14(9); 841–8. ©2016 AACR.
Data from CD44 Regulates Formation of Spheroids and Controls Organ-Specific Metastatic Colonization in Epithelial Ovarian Carcinoma
Authors: Sacks Suarez Joelle , Gurler Main Hilal , Muralidhar Goda G. , Elfituri Osama , Xu Hao-Liang , Kajdacsy-Balla Andre A. , Barbolina Maria V.
Published: March 2024

Abstract
Disseminating epithelial ovarian cancer cells often become assembled into spheroids prior to their arrival at metastatic sites within the peritoneal cavity. Although epithelial ovarian carcinoma (EOC) is the deadliest gynecologic malignancy, the mechanisms regulating formation and metastatic potential of spheroids are poorly understood. We show that expression of a cell surface glycoprotein CD44 is an important contributing factor for spheroid formation and spheroid adhesion to mesothelial cells, and its loss impairs mesenteric metastasis. In contrast, loss of CD44 resulted in significant increase of tumor burden at several locoregional sites, including liver, and unleashed distant metastases to the thoracic cavity. Altogether our studies suggest that CD44 regulates metastatic progression of EOC in an organ-specific manner.
Implications:
Expression of CD44 promotes spheroid formation, mesothelial adhesion, and formation of mesenteric metastasis, but it suppresses development of metastasis to several peritoneal sites, including liver, and the thoracic cavity.
Data from DNA Methylome Analyses Implicate Fallopian Tube Epithelia as the Origin for High-Grade Serous Ovarian Cancer
Authors: Klinkebiel David , Zhang Wa , Akers Stacey N. , Odunsi Kunle , Karpf Adam R.
Published: March 2024

Abstract
High-grade serous ovarian cancer (HGSC) is the most common and lethal form of epithelial ovarian cancer (EOC). Two distinct tissues have been suggested as the tissue of origin: ovarian surface epithelia (OSE) and fallopian tube epithelia (FTE). We hypothesized that the DNA methylome of HGSC should more closely resemble the methylome of its tissue of origin. To this end, we profiled HGSC (n = 10), and patient-matched OSE and FTE (n = 5) primary fresh-frozen tissues, and analyzed the DNA methylome using Illumina 450K arrays (n = 20) and Agilent Sure Select methyl-seq (n = 7). Methylomes were compared using statistical analyses of differentially methylated CpG sites (DMC) and differentially methylated regions (DMR). In addition, methylation was evaluated within a variety of different genomic contexts, including CpG island shores and Homeobox (HOX) genes, due to their roles in tissue specification. Publicly available HGSC methylome data (n = 628) were interrogated to provide additional comparisons with FTE and OSE for validation. These analyses revealed that HGSC and FTE methylomes are significantly and consistently more highly conserved than are HGSC and OSE. Pearson correlations and hierarchal clustering of genes, promoters, CpG islands, CpG island shores, and HOX genes all revealed increased relatedness of HGSC and FTE methylomes. Thus, these findings reveal that the landscape of FTE more closely resembles HGSC, the most common and deadly EOC subtype.

Implications: DNA methylome analyses support the hypothesis that HGSC arise from the fallopian tube and that due to its tissue-specificity and biochemical stability, interrogation of the methylome may be a valuable approach to examine cell/tissue lineage in cancer. Mol Cancer Res; 14(9); 787–94. ©2016 AACR.
Data from Secreted Factors from Adipose Tissue Reprogram Tumor Lipid Metabolism and Induce Motility by Modulating PPARα/ANGPTL4 and FAK
Authors: Blücher Christina , Iberl Sabine , Schwagarus Nancy , Müller Silvana , Liebisch Gerhard , Höring Marcus , Hidrobo Maria Soledad , Ecker Josef , Spindler Nick , Dietrich Arne , Burkhardt Ralph , Stadler Sonja C.
Published: March 2024

Abstract
Recent studies indicate that adipose tissue in obesity promotes breast cancer progression by secreting protumorigenic chemokines, growth factors, and fatty acids. However, the detailed mechanisms by which hypertrophic adipose tissue influences breast cancer cells are still not well understood. Here we show that co-culture with adipose tissue from high-fat diet induced obese C57BL/6 mice alters transcriptome profiles in triple-negative breast cancer (TNBC) cells, leading to upregulation of genes involved in inflammation and lipid metabolism, such as IL1B, PLIN2, and ANGPTL4. Similar results were obtained by treating TNBC cells with adipose tissue conditioned media (ACM) generated from fat tissue of obese female patients. Many of the upregulated genes were activated by PPAR nuclear receptors, as shown by pathway analyses and gene expression experiments using PPAR agonists and antagonists. Metabolic analysis revealed that TNBC cells cultivated with ACM had significantly higher levels of β-oxidation. Furthermore, ACM-treated TNBC cells displayed a pronounced aggressive cell phenotype, with enhanced wound healing, proliferation, and invasion capabilities. ACM-induced invasion was dependent on the PPAR-target ANGPTL4 and activated FAK signaling, as shown by ANGPTL4 depletion and FAK inhibition. Together, our data suggest that factors released by adipose tissue change PPAR-regulated gene expression and lipid metabolism and induce a more aggressive TNBC cell phenotype. These effects are, at least in parts, mediated by fatty acids provided by the adipose tissue.
Implications:
Adipose tissue provides factors for increased progression of TNBC cells, identifying PPAR- and FAK-signaling as potential novel targets for treatment of TNBC, especially in obese women.
Data from Palmitate-Induced IRE1–XBP1–ZEB Signaling Represses Desmoplakin Expression and Promotes Cancer Cell Migration
Authors: Nath Aritro , Oak Amrita , Chen Kevin Y. , Li Irene , Splichal R. Chauncey , Portis Jason , Foster Sean , Walton S. Patrick , Chan Christina
Published: March 2024

Abstract
Elevated uptake of saturated fatty acid palmitate is associated with metastatic progression of cancer cells; however, the precise signaling mechanism behind the phenomenon is unclear. The loss of cell adhesion proteins, such as desmoplakin (DSP), is a key driving event in the transformation of cancer cells to more aggressive phenotypes. Here, we investigated the mechanism by which palmitate induces the loss of DSP in liver and breast cancer cells. We propose that palmitate activates the IRE1–XBP1 branch of the endoplasmic reticulum (ER) stress pathway to upregulate the ZEB transcription factor, leading to transcriptional repression of DSP. Using liver and breast cancer cells treated with palmitate, we found loss of DSP leads to increased cell migration independent of E-cadherin. We report that the ZEB family of transcription factors function as direct transcriptional repressors of DSP. CRISPR-mediated knockdown of IRE1 confirmed that the transcription of ZEB, loss of DSP, and enhanced migration in the presence of palmitate is dependent on the IRE1–XBP1 pathway. In addition, by analyzing the somatic expression and copy number variation profiles of over 11,000 tumor samples, we corroborate our hypothesis and establish the clinical relevance of DSP loss via ZEB in human cancers.
Implications:
Provides mechanistic link on palmitate-induced activation of IRE1α to cancer cell migration.
Data from Tumor Cell–Derived MMP3 Orchestrates Rac1b and Tissue Alterations That Promote Pancreatic Adenocarcinoma
Authors: Mehner Christine , Miller Erin , Khauv Davitte , Nassar Aziza , Oberg Ann L. , Bamlet William R. , Zhang Lizhi , Waldmann Jens , Radisky Evette S. , Crawford Howard C. , Radisky Derek C.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDA) arises at the convergence of genetic alterations in KRAS with a fostering microenvironment shaped by immune cell influx and fibrotic changes; identification of the earliest tumorigenic molecular mediators evokes the proverbial chicken and egg problem. Matrix metalloproteinases (MMP) are key drivers of tumor progression that originate primarily from stromal cells activated by the developing tumor. Here, MMP3, known to be expressed in PDA, was found to be associated with expression of Rac1b, a tumorigenic splice isoform of Rac1, in all stages of pancreatic cancer. Using a large cohort of human PDA tissue biopsies specimens, both MMP3 and Rac1b are expressed in PDA cells, that the expression levels of the two markers are highly correlated, and that the subcellular distribution of Rac1b in PDA is significantly associated with patient outcome. Using transgenic mouse models, coexpression of MMP3 with activated KRAS in pancreatic acinar cells stimulates metaplasia and immune cell infiltration, priming the stromal microenvironment for early tumor development. Finally, exposure of cultured pancreatic cancer cells to recombinant MMP3 stimulates expression of Rac1b, increases cellular invasiveness, and activation of tumorigenic transcriptional profiles.

Implications: MMP3 acts as a coconspirator of oncogenic KRAS in pancreatic cancer tumorigenesis and progression, both through Rac1b-mediated phenotypic control of pancreatic cancer cells themselves, and by giving rise to the tumorigenic microenvironment; these findings also point to inhibition of this pathway as a potential therapeutic strategy for pancreatic cancer. Mol Cancer Res; 12(10); 1430–9. ©2014 AACR.
Data from Urothelial Carcinoma of the Bladder Induces Endothelial Cell Activation and Hypercoagulation
Authors: John Axel , Robador José R. , Vidal-y-Sy Sabine , Houdek Pia , Wladykowski Ewa , Günes Cagatay , Bolenz Christian , Schneider Stefan W. , Bauer Alexander T. , Gorzelanny Christian
Published: March 2024

Abstract
Cancer-related venous thromboembolisms (VTE) are associated with metastasis and reduced survival in patients with urothelial cancer of the bladder. Although previous reports suggest the contribution of tissue factor and podoplanin, the mechanistic linkage between VTE and bladder cancer cell–derived molecules is unknown. Therefore, we compared distinct procoagulant pathways in four different cell lines. In vitro findings were further confirmed by microfluidic experiments mimicking the pathophysiology of tumor blood vessels and in tissue samples of patients with bladder cancer by transcriptome analysis and immunohistology. In vitro and microfluidic experiments identified bladder cancer–derived VEGF-A as highly procoagulant because it promoted the release of von Willebrand factor (VWF) from endothelial cells and thus platelet aggregation. In tissue sections from patients with bladder cancer, we found that VWF-mediated blood vessel occlusions were associated with a poor outcome. Transcriptome data further indicate that elevated expression levels of enzymes modulating VEGF-A availability were significantly connected to a decreased survival in patients with bladder cancer. In comparison with previously postulated molecular players, we identified tumor cell–derived VEGF-A and endothelial VWF as procoagulant mediators in bladder cancer. Therapeutic strategies that prevent the VEGF-A–mediated release of VWF may reduce tumor-associated hypercoagulation and metastasis in patients with bladder cancer.
Implications:
We identified the VEGF-A–mediated release of VWF from endothelial cells to be associated with bladder cancer progression.
Data from Decreased Expression of Cystathionine β-Synthase Promotes Glioma Tumorigenesis
Authors: Takano Naoharu , Sarfraz Yasmeen , Gilkes Daniele M. , Chaturvedi Pallavi , Xiang Lisha , Suematsu Makoto , Zagzag David , Semenza Gregg L.
Published: March 2024

Abstract
Cystathionine β-synthase (CBS) catalyzes metabolic reactions that convert homocysteine to cystathionine. To assess the role of CBS in human glioma, cells were stably transfected with lentiviral vectors encoding shRNA targeting CBS or a nontargeting control shRNA, and subclones were injected into immunodeficient mice. Interestingly, decreased CBS expression did not affect proliferation in vitro but decreased the latency period before rapid tumor xenograft growth after subcutaneous injection and increased tumor incidence and volume following orthotopic implantation into the caudate–putamen. In soft-agar colony formation assays, CBS knockdown subclones displayed increased anchorage-independent growth. Molecular analysis revealed that CBS knockdown subclones expressed higher basal levels of the transcriptional activator hypoxia-inducible factor 2α (HIF2α/EPAS1). HIF2α knockdown counteracted the effect of CBS knockdown on anchorage-independent growth. Bioinformatic analysis of mRNA expression data from human glioma specimens revealed a significant association between low expression of CBS mRNA and high expression of angiopoietin-like 4 (ANGPTL4) and VEGF transcripts, which are HIF2 target gene products that were also increased in CBS knockdown subclones. These results suggest that decreased CBS expression in glioma increases HIF2α protein levels and HIF2 target gene expression, which promotes glioma tumor formation.

Implications: CBS loss-of-function promotes glioma growth. Mol Cancer Res; 12(10); 1398–406. ©2014 AACR.
Data from Transposon Mutagenesis Screen Identifies Potential Lung Cancer Drivers and CUL3 as a Tumor Suppressor
Authors: Dorr Casey , Janik Callie , Weg Madison , Been Raha A. , Bader Justin , Kang Ryan , Ng Brandon , Foran Lindsey , Landman Sean R. , O'Sullivan M. Gerard , Steinbach Michael , Sarver Aaron L. , Silverstein Kevin A.T. , Largaespada David A. , Starr Timothy K.
Published: March 2024

Abstract
Non–small cell lung cancers (NSCLC) harbor thousands of passenger events that hide genetic drivers. Even highly recurrent events in NSCLC, such as mutations in PTEN, EGFR, KRAS, and ALK, are detected, at most, in only 30% of patients. Thus, many unidentified low-penetrant events are causing a significant portion of lung cancers. To detect low-penetrance drivers of NSCLC, a forward genetic screen was performed in mice using the Sleeping Beauty (SB) DNA transposon as a random mutagen to generate lung tumors in a Pten-deficient background. SB mutations coupled with Pten deficiency were sufficient to produce lung tumors in 29% of mice. Pten deficiency alone, without SB mutations, resulted in lung tumors in 11% of mice, whereas the rate in control mice was approximately 3%. In addition, thyroid cancer and other carcinomas, as well as the presence of bronchiolar and alveolar epithelialization, in mice deficient for Pten were also identified. Analysis of common transposon insertion sites identified 76 candidate cancer driver genes. These genes are frequently dysregulated in human lung cancers and implicate several signaling pathways. Cullin3 (Cul3), a member of a ubiquitin ligase complex that plays a role in the oxidative stress response pathway, was identified in the screen and evidence demonstrates that Cul3 functions as a tumor suppressor.

Implications: This study identifies many novel candidate genetic drivers of lung cancer and demonstrates that CUL3 acts as a tumor suppressor by regulating oxidative stress. Mol Cancer Res; 13(8); 1238–47. ©2015 AACR.
Data from Cooperativity of E-cadherin and Smad4 Loss to Promote Diffuse-Type Gastric Adenocarcinoma and Metastasis
Authors: Park Jun Won , Jang Seok Hoon , Park Dong Min , Lim Na Jung , Deng Chuxia , Kim Dae Yong , Green Jeffrey E. , Kim Hark Kyun
Published: March 2024

Abstract
Loss of E-cadherin (CDH1), Smad4, and p53 has been shown to play an integral role in gastric, intestinal, and breast cancer formation. Compound conditional knockout mice for Smad4, p53, and E-cadherin were generated to define and compare the roles of these genes in gastric, intestinal, and breast cancer development by crossing with Pdx-1-Cre, Villin-Cre, and MMTV-Cre transgenic mice. Interestingly, gastric adenocarcinoma was significantly more frequent in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice than in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1+/+ mice, demonstrating that Cdh1 heterozygosity accelerates the development and progression of gastric adenocarcinoma, in combination with loss of Smad4 and p53. Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice developed gastric adenocarcinomas without E-cadherin expression. However, intestinal and mammary adenocarcinomas with the same genetic background retained E-cadherin expression and were phenotypically similar to mice with both wild-type Cdh1 alleles. Lung metastases were identified in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice, but not in the other genotypes. Nuclear β-catenin accumulation was identified at the invasive tumor front of gastric adenocarcinomas arising in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice. This phenotype was less prominent in mice with intact E-cadherin or Smad4, indicating that the inhibition of β-catenin signaling by E-cadherin or Smad4 downregulates signaling pathways involved in metastases in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice. Knockdown of β-catenin significantly inhibited the migratory activity of Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ cell lines. Thus, loss of E-cadherin and Smad4 cooperates with p53 loss to promote the development and metastatic progression of gastric adenocarcinomas, with similarities to human gastric adenocarcinoma.

Implications: This study demonstrates that inhibition of β-catenin is a converging node for the antimetastatic signaling pathways driven by E-cadherin and Smad4 in Pdx-1-Cre;Smad4F/F;Trp53F/F;Cdh1F/+ mice, providing novel insights into mechanisms for gastric cancer metastasis. Mol Cancer Res; 12(8); 1088–99. ©2014 AACR.
Data from Combined Targeting of G9a and Checkpoint Kinase 1 Synergistically Inhibits Pancreatic Cancer Cell Growth by Replication Fork Collapse
Authors: Urrutia Guillermo , Salmonson Ann , Toro-Zapata Jorge , de Assuncao Thiago M. , Mathison Angela , Dusetti Nelson , Iovanna Juan , Urrutia Raul , Lomberk Gwen
Published: March 2024

Abstract
Because of its dismal outcome, pancreatic ductal adenocarcinoma (PDAC) remains a therapeutic challenge making the testing of new pharmacologic tools a goal of paramount importance. Here, we developed a rational approach for inhibiting PDAC growth based on leveraging cell-cycle arrest of malignant cells at a phase that shows increased sensitivity to distinct epigenomic inhibitors. Specifically, we simultaneously inhibited checkpoint kinase 1 (Chk1) by prexasertib and the G9a histone methyltransferase with BRD4770, thereby targeting two key pathways for replication fork stability. Methodologically, the antitumor effects and molecular mechanisms of the combination were assessed by an extensive battery of assays, utilizing cell lines and patient-derived cells as well as 3D spheroids and xenografts. We find that the prexasertib–BRD4770 combination displays a synergistic effect on replication-associated phenomena, including cell growth, DNA synthesis, cell-cycle progression at S phase, and DNA damage signaling, ultimately leading to a highly efficient induction of cell death. Moreover, cellular and molecular data reveal that the synergistic effect of these pathways can be explained, at least in large part, by the convergence of both Chk1 and G9a functions at the level of the ATR–RPA–checkpoint pathway, which is operational during replication stress. Thus, targeting the epigenetic regulator G9a, which is necessary for replication fork stability, combined with inhibition of the DNA damage checkpoint, offers a novel approach for controlling PDAC growth through replication catastrophe.
Implications:
This study offers an improved, context-dependent, paradigm for the use of epigenomic inhibitors and provides mechanistic insight into their potential therapeutic use against PDAC.
Data from Augmented TME O-GlcNAcylation Promotes Tumor Proliferation through the Inhibition of p38 MAPK
Authors: Moriwaki Kazumasa , Asahi Michio
Published: March 2024

Abstract
O-GlcNAcylation is a dynamic O-linked glycosylation event that plays a crucial role in regulating cellular signaling. Recent studies indicate that increased O-GlcNAcylation is a general feature in cancer and contributes to various cancer phenotypes, including cell proliferation, survival, invasion, metastasis, and energy metabolism. However, the role of O-GlcNAcylation in the tumor microenvironment (TME) is not fully elucidated. Here, B16 melanoma cells were subcutaneously transplanted into O-GlcNAc transferase transgenic (Ogt-Tg) mice exhibiting elevated O-GlcNAcylation to examine the effect of O-GlcNAcylation in the TME on tumor progression. In this model system, B16 tumor growth was significantly higher in Ogt-Tg/+ mice compared with wild-type (WT) mice. The tumors grown in Ogt-Tg/+ mice showed significant downregulation of p38 MAPK activity and upregulation of the ERK1/2 signaling pathway. In addition, proinflammatory cytokine production was significantly lower in the tumor tissues from Ogt-Tg/+ mice than in those from WT mice. Activation of NF-κB, a key regulator in the cytokine production, was downregulated in the macrophages of the tumor tissues grown in Ogt-Tg/+ mice. These data reveal that elevated O-GlcNAcylation in the TME reduces the production of inflammatory cytokines and promotes cancer progression through downregulation of p38 MAPK activity and subsequent upregulation of the ERK1/2 signaling pathway.

Implications: The reduced production of inflammatory cytokines by augmented O-GlcNAcylation in the TME, mainly macrophages, promotes tumor proliferation through the inhibition of p38 MAPK and suggests a possible cause of increased morbidity and mortality rates for various cancers in diabetic patients. Mol Cancer Res; 15(9); 1287–98. ©2017 AACR.
Data from Circadian Oscillations Persist in Cervical and Esophageal Cancer Cells Displaying Decreased Expression of Tumor-Suppressing Circadian Clock Genes
Authors: van der Watt Pauline J. , Roden Laura C. , Davis Kate T. , Parker M. Iqbal , Leaner Virna D.
Published: March 2024

Abstract
There is accumulating evidence for a link between circadian clock disruption and cancer progression. In this study, the circadian clock was investigated in cervical and esophageal cancers, to determine whether it is disrupted in these cancer types. Oncomine datamining revealed downregulation of multiple members of the circadian clock gene family in cancer patient tissue compared with matched normal epithelium. Real-time RT-PCR analysis confirmed significant downregulation of CLOCK, PER1, PER2, PER3, CRY1, CRY2, REV-ERBα, and RORα in esophageal tumor tissue. In cell line models, expression of several circadian clock genes was significantly decreased in transformed and cancer cells compared with noncancer controls, and protein levels were dysregulated. These effects were mediated, at least in part, by methylation, where CLOCK, CRY1, and RORα gene promoter regions were found to be methylated in cancer cells. Overexpression of CLOCK and PER2 in cancer cell lines inhibited cell proliferation and activation of RORα and REV-ERBα using agonists resulted in cancer cell death, while having a lesser effect on normal epithelial cells. Despite dysregulated circadian clock gene expression, cervical and esophageal cancer cells maintain functional circadian oscillations after Dexamethasone synchronization, as revealed using real-time bioluminescence imaging, suggesting that their circadian clock mechanisms are intact.
Implications:
This study is a first to describe dysregulated, yet oscillating, circadian clock gene expression in cervical and esophageal cancer cells, and knowledge of circadian clock functioning in these cancer types has the potential to inform chronotherapy approaches, where the timing of administration of chemotherapy is optimized on the basis of the circadian clock.
Data from The Chemokine (CCL2–CCR2) Signaling Axis Mediates Perineural Invasion
Authors: He Shizhi , He Shuangba , Chen Chun-Hao , Deborde Sylvie , Bakst Richard L. , Chernichenko Natalya , McNamara William F. , Lee Sei Young , Barajas Fernando , Yu Zhenkun , Al-Ahmadie Hikmat A. , Wong Richard J.
Published: March 2024

Abstract
Perineural invasion is a form of cancer progression where cancer cells invade along nerves. This behavior is associated with poor clinical outcomes; therefore, it is critical to identify novel ligand–receptor interactions between nerves and cancer cells that support the process of perineural invasion. A proteomic profiler chemokine array was used to screen for nerve-derived factors secreted from tissue explants of dorsal root ganglion (DRG), and CCL2 was identified as a lead candidate. Prostate cancer cell line expression of CCR2, the receptor to CCL2, correlated closely with MAPK and Akt pathway activity and cell migration towards CCL2 and DRG. In vitro nerve and cancer coculture invasion assays of perineural invasion demonstrated that cancer cell CCR2 expression facilitates perineural invasion. Perineural invasion is significantly diminished in coculture assays when using DRG harvested from CCL2−/− knockout mice as compared with control CCL2+/+ mice, indicating that CCR2 is required for perineural invasion in this murine model of perineural invasion. Furthermore, 20 of 21 (95%) patient specimens of prostate adenocarcinoma with perineural invasion exhibited CCR2 expression by immunohistochemistry, while just 3 of 13 (23%) lacking perineural invasion expressed CCR2. In summary, nerve-released CCL2 supports prostate cancer migration and perineural invasion though CCR2-mediated signaling.

Implications: These results reveal CCL2–CCR2 signaling as a key ligand–receptor mechanism that mediates cancer cell communication with nerves during perineural invasion and highlight a potential future therapeutic target. Mol Cancer Res; 13(2); 380–90. ©2014 AACR.
Data from The Histone Demethylase Jumonji Coordinates Cellular Senescence Including Secretion of Neural Stem Cell–Attracting Cytokines
Authors: Perrigue Patrick M. , Silva Michael E. , Warden Charles D. , Feng Nathan L. , Reid Michael A. , Mota Daniel J. , Joseph Lauren P. , Tian Yangzi Isabel , Glackin Carlotta A. , Gutova Margarita , Najbauer Joseph , Aboody Karen S. , Barish Michael E.
Published: March 2024

Abstract
Jumonji domain-containing protein 3 (JMJD3/KDM6B) demethylates lysine 27 on histone H3 (H3K27me3), a repressive epigenetic mark controlling chromatin organization and cellular senescence. To better understand the functional consequences of JMJD3 its expression was investigated in brain tumor cells. Querying patient expression profile databases confirmed JMJD3 overexpression in high-grade glioma. Immunochemical staining of two glioma cell lines, U251 and U87, indicated intrinsic differences in JMJD3 expression levels that were reflected in changes in cell phenotype and variations associated with cellular senescence, including senescence-associated β-galactosidase (SA-β-gal) activity and the senescence-associated secretory phenotype (SASP). Overexpressing wild-type JMJD3 (JMJD3wt) activated SASP-associated genes, enhanced SA-β-gal activity, and induced nuclear blebbing. Conversely, overexpression of a catalytically inactive dominant negative mutant JMJD3 (JMJD3mut) increased proliferation. In addition, a large number of transcripts were identified by RNA-seq as altered in JMJD3 overexpressing cells, including cancer- and inflammation-related transcripts as defined by Ingenuity Pathway Analysis. These results suggest that expression of the SASP in the context of cancer undermines normal tissue homeostasis and contributes to tumorigenesis and tumor progression. These studies are therapeutically relevant because inflammatory cytokines have been linked to homing of neural stem cells and other stem cells to tumor loci.

Implications: This glioma study brings together actions of a normal epigenetic mechanism (JMJD3 activity) with dysfunctional activation of senescence-related processes, including secretion of SASP proinflammatory cytokines and stem cell tropism toward tumors. Mol Cancer Res; 13(4); 636–50. ©2015 AACR.