bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Association of the von Hippel–Lindau Protein with AUF1 and Posttranscriptional Regulation of VEGFA mRNA
Authors: Xin Hong , Brown Julie A. , Gong Changning , Fan Hao , Brewer Gary , Gnarra James R.
Published: March 2024

Abstract
The von Hippel–Lindau (VHL) tumor suppressor gene product is the recognition component of an E3 ubiquitin ligase and is inactivated in patients with VHL disease and in most sporadic clear-cell renal cell carcinomas (RCC). pVHL controls oxygen-responsive gene expression at the transcriptional and posttranscriptional levels. The VEGFA mRNA contains AU-rich elements (ARE) in the 3′–untranslated region, and mRNA stability or decay is determined through ARE-associated RNA-binding factors. We show here that levels of the ARE-binding factor, AUF1, are regulated by pVHL and by hypoxia. pVHL and AUF1 stably associate with each other in cells and AUF1 is a ubiquitylation target of pVHL. AUF1 and another RNA-binding protein, HuR, bind to VEGFA ARE RNA. Ribonucleoprotein (RNP) immunoprecipitations showed that pVHL associates indirectly with VEGFA mRNA through AUF1 and/or HuR, and this complex is associated with VEGFA mRNA decay under normoxic conditions. Under hypoxic conditions pVHL is downregulated, whereas AUF1 and HuR binding to VEGF mRNA is maintained, and this complex is associated with stabilized mRNA. These studies suggest that AUF1 and HuR bind to VEGFA ARE RNA under both normoxic and hypoxic conditions, and that a pVHL–RNP complex determines VEGFA mRNA decay. These studies further implicate the ubiquitin–proteasome system in ARE-mediated RNA degradation. Mol Cancer Res; 10(1); 108–20. ©2011 AACR.
Data from Constitutive K-RasG12D Activation of ERK2 Specifically Regulates 3D Invasion of Human Pancreatic Cancer Cells via MMP-1
Authors: Botta Gregory P. , Reginato Mauricio J. , Reichert Maximilian , Rustgi Anil K. , Lelkes Peter I.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinomas (PDAC) are highly invasive and metastatic neoplasms commonly unresponsive to current drug therapy. Overwhelmingly, PDAC harbors early constitutive, oncogenic mutations in K-RasG12D that exist prior to invasion. Histologic and genetic analyses of human PDAC biopsies also exhibit increased expression of extracellular signal-regulated kinase (ERK) 1/2 and proinvasive matrix metalloproteinases (MMP), indicators of poor prognosis. However, the distinct molecular mechanisms necessary for K-Ras/ERK1/2 signaling and its influence on MMP-directed stromal invasion in primary human pancreatic ductal epithelial cells (PDEC) have yet to be elucidated in three-dimensions. Expression of oncogenic K-RasG12D alone in genetically defined PDECs reveals increased invadopodia and epithelial-to-mesenchymal transition markers, but only when cultured in a three-dimensional model incorporating a basement membrane analog. Activation of ERK2, but not ERK1, also occurs only in K-RasG12D–mutated PDECs cultured in three-dimensions and is a necessary intracellular signaling event for invasion based upon pharmacologic and short hairpin RNA (shRNA) inhibition. Increased active invasion of K-RasG12D PDECs through the basement membrane model is associated with a specific microarray gene expression signature and induction of MMP endopeptidases. Specifically, MMP-1 RNA, its secreted protein, and its proteolytic cleavage activity are amplified in K-RasG12D PDECs when assayed by real-time quantitative PCR, ELISA, and fluorescence resonance energy transfer (FRET). Importantly, shRNA silencing of MMP-1 mimics ERK2 inhibition and disrupts active, vertical PDEC invasion. ERK2 isoform and MMP-1 targeting are shown to be viable strategies to attenuate invasion of K-RasG12D–mutated human pancreatic cancer cells in a three-dimensional tumor microenvironment. Mol Cancer Res; 10(2); 183–96. ©2011 AACR.
Data from Role of Plasminogen Activator Inhibitor-1 in Urokinase's Paradoxical In Vivo Tumor Suppressing or Promoting Effects
Authors: Jing Yuqi , Kovacs Krisztina , Kurisetty Vittal , Jiang Zhijie , Tsinoremas Nick , Merchan Jaime R.
Published: March 2024

Abstract
Tumor proteases and inhibitors have been associated with paradoxical effects on tumor progression in preclinical and clinical settings. We previously reported that urokinase (uPA) overexpression delays tumor progression in mammary cancer. This study aimed to determine the role of plasminogen activator inhibitor-1 (PAI-1) on uPA's paradoxical in vivo effects. Using syngeneic murine models, we found that stable uPA overexpression promoted in vivo growth of colon tumors (MC-38) naturally expressing high PAI-1, whereas growth inhibition was observed in renal tumors (RENCA) expressing lower PAI-1 levels. In murine mammary carcinoma (4T1), uPA overexpression shifted the uPA/PAI-1 balance in favor of the protease, resulting in significantly reduced tumor growth and metastases in vivo. Conversely, increased tumor progression was observed in stable PAI-1 overexpressing 4T1 tumors as compared with uPA-overexpressing and control tumors. These effects were associated with downregulation of metastases promoting genes in uPA-overexpressing tumors, such as metalloproteinases, CXCL-1, c-Fos, integrin α-5, VEGF-A, PDGF-α, and IL-1β. In PAI-1–overexpressing tumors, many of the above genes were upregulated. PAI-1 overexpressing tumors had increased total and new tumor microvessels, and increased tumor cell proliferation, whereas the opposite effects were found in uPA-overexpressing tumors. Finally, PAI-1 downregulation led to significant inhibition of 4T1 tumor growth and metastases in vivo. In conclusion, uPA's dual effects on tumor progression occur in the context of its interactions with endogenous PAI-1 expression. Our studies uncover novel mechanisms of in vivo tumor control by modulation of the balance between tumor proteases and inhibitors, which may be exploited therapeutically. Mol Cancer Res; 10(10); 1271–81. ©2012 AACR.
Data from ECM Composition and Rheology Regulate Growth, Motility, and Response to Photodynamic Therapy in 3D Models of Pancreatic Ductal Adenocarcinoma
Authors: Cramer Gwendolyn M. , Jones Dustin P. , El-Hamidi Hamid , Celli Jonathan P.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma is characterized by prominent stromal involvement, which plays complex roles in regulating tumor growth and therapeutic response. The extracellular matrix (ECM)-rich stroma associated with this disease has been implicated as a barrier to drug penetration, although stromal depletion strategies have had mixed clinical success. It remains less clear how interactions with ECM, acting as a biophysical regulator of phenotype, not only a barrier to drug perfusion, regulate susceptibilities and resistance to specific therapies. In this context, an integrative approach is used to evaluate invasive behavior and motility in rheologically characterized ECM as determinants of chemotherapy and photodynamic therapy (PDT) responses. We show that in 3D cultures with ECM conditions that promote invasive progression, response to PDT is markedly enhanced in the most motile ECM-infiltrating populations, whereas the same cells exhibit chemoresistance. Conversely, drug-resistant sublines with enhanced invasive potential were generated to compare differential treatment response in identical ECM conditions, monitored by particle tracking microrheology measurements of matrix remodeling. In both scenarios, ECM-infiltrating cell populations exhibit increased sensitivity to PDT, whether invasion is consequent to selection of chemoresistance, or whether chemoresistance is correlated with acquisition of invasive behavior. However, while ECM-invading, chemoresistant cells exhibit mesenchymal phenotype, induction of EMT in monolayers without ECM was not sufficient to enhance PDT sensitivity, yet does impart chemoresistance as expected. In addition to containing platform development with broader applicability to inform microenvironment-dependent therapeutics, these results reveal the efficacy of PDT for targeting the most aggressive, chemoresistant, invasive pancreatic ductal adenocarcinoma associated with dismal outcomes for this disease.

Implications: ECM-infiltrating and chemoresistant pancreatic tumor populations exhibit increased sensitivity to PDT. Mol Cancer Res; 15(1); 15–25. ©2016 AACR.
Data from PRMT6 Promotes Lung Tumor Progression via the Alternate Activation of Tumor-Associated Macrophages
Authors: Avasarala Sreedevi , Wu Pei-Ying , Khan Samia Q. , Yanlin Su , Van Scoyk Michelle , Bao Jianqiang , Di Lorenzo Alessandra , David Odile , Bedford Mark T. , Gupta Vineet , Winn Robert A. , Bikkavilli Rama Kamesh
Published: March 2024

Abstract
Increased expression of protein arginine methyl transferase 6 (PRMT6) correlates with worse prognosis in lung cancer cases. To interrogate the in vivo functions of PRMT6 in lung cancer, we developed a tamoxifen-inducible lung-targeted PRMT6 gain-of-function mouse model, which mimics PRMT6 amplification events in human lung tumors. Lung-targeted overexpression of PRMT6 accelerated cell proliferation de novo and potentiated chemical carcinogen (urethane)-induced lung tumor growth. To explore the molecular mechanism/s by which PRMT6 promotes lung tumor growth, we used proteomics-based approaches and identified interleukin-enhancer binding protein 2 (ILF2) as a novel PRMT6-associated protein. Furthermore, by using a series of in vitro gain-of-function and loss-of-function experiments, we defined a new role for the PRMT6–ILF2 signaling axis in alternate activation of tumor-associated macrophages (TAM). Interestingly, we have also identified macrophage migration inhibitory factor, which has recently been shown to regulate alternate activation of TAMs, as an important downstream target of PRMT6–ILF2 signaling. Collectively, our findings reveal a previously unidentified noncatalytic role for PRMT6 in potentiating lung tumor progression via the alternate activation of TAMs.
Implications:
This is the first study to demonstrate an in vivo role for PRMT6 in lung tumor progression via the alternate activation of TAMs.
Data from Deletion or Epigenetic Silencing of AJAP1 on 1p36 in Glioblastoma
Authors: Lin Ningjing , Di Chunhui , Bortoff Kathy , Fu Jinrong , Truszkowski Peter , Killela Patrick , Duncan Chris , McLendon Roger , Bigner Darell , Gregory Simon , Adamson David Cory
Published: March 2024

Abstract
Glioblastoma is universally fatal because of its propensity for rapid recurrence due to highly migratory tumor cells. Unraveling the genomic complexity that underlies this migratory characteristic could provide therapeutic targets that would greatly complement current surgical therapy. Using multiple high-resolution genomic screening methods, we identified a single locus, adherens junctional associated protein 1 (AJAP1) on chromosome 1p36 that is lost or epigenetically silenced in many glioblastomas. We found AJAP1 expression absent or reduced in 86% and 100% of primary glioblastoma tumors and cell lines, respectively, and the loss of expression correlates with AJAP1 methylation. Restoration of AJAP1 gene expression by transfection or demethylation agents results in decreased tumor cell migration in glioblastoma cell lines. This work shows the significant loss of expression of AJAP1 in glioblastoma and provides evidence of its role in the highly migratory characteristic of these tumors. Mol Cancer Res; 10(2); 208–17. ©2012 AACR.
Data from Autophagy Induction with RAD001 Enhances Chemosensitivity and Radiosensitivity through Met Inhibition in Papillary Thyroid Cancer
Authors: Lin Chi-Iou , Whang Edward E. , Donner David B. , Du Jinyan , Lorch Jochen , He Frank , Jiang Xiaofeng , Price Brendan D. , Moore Francis D. , Ruan Daniel T.
Published: March 2024

Abstract
Although autophagy is generally considered a prosurvival mechanism that preserves viability, there is evidence that it could drive an alternative programmed cell death pathway in cells with defects in apoptosis. Because the inhibition of autophagic activity promotes resistance to both chemotherapy and external beam radiation in papillary thyroid cancer (PTC), we determined if RAD001, a potent activator of autophagy, improves the efficacy of either therapy. We found that RAD001 increased the expression level of light chain 3-II, a marker for autophagy, as well as autophagosome formation in cell lines and in human PTC ex vivo. RAD001 sensitized PTC to doxorubicin and external beam radiation in a synergistic fashion, suggesting that combination therapy could improve therapeutic response at less toxic concentrations. The effects of RAD001 were abrogated by RNAi knockdown of the autophagy-related gene 5, suggesting that RAD001 acts, in part, by enhancing autophagy. Because the synergistic activity of RAD001 with doxorubicin and external radiation suggests distinct and complementary mechanisms of action, we characterized how autophagy modulates signaling pathways in PTC. To do so, we performed kinome profiling and discovered that autophagic activation resulted in Src phosphorylation and Met dephosphorylation. Src inhibition did not reverse the effects of RAD001, whereas Met inhibition reversed the effects of autophagy blockade on chemosensitivity. These results suggest that the anticancer effects of autophagic activation are mediated largely through Met. We conclude that RAD001 induces autophagy, which enhances the therapeutic response to cytotoxic chemotherapy and external beam radiation in PTC. Mol Cancer Res; 8(9); 1217–26. ©2010 AACR.
Data from Interactions with Fibroblasts Are Distinct in Basal-Like and Luminal Breast Cancers
Authors: Camp J. Terese , Elloumi Fathi , Roman-Perez Erick , Rein Jessica , Stewart Delisha A. , Harrell J. Chuck , Perou Charles M. , Troester Melissa A.
Published: March 2024

Abstract
Basal-like breast cancers have several well-characterized distinguishing molecular features, but most of these are features of the cancer cells themselves. The unique stromal–epithelial interactions, and more generally, microenvironmental features of basal-like breast cancers have not been well characterized. To identify characteristic microenvironment features of basal-like breast cancer, we performed cocultures of several basal-like breast cancer cell lines with fibroblasts and compared these with cocultures of luminal breast cancer cell lines with fibroblasts. Interactions between basal-like cancer cells and fibroblasts induced expression of numerous interleukins and chemokines, including IL-6, IL-8, CXCL1, CXCL3, and TGFβ. Under the influence of fibroblasts, basal-like breast cancer cell lines also showed increased migration in vitro. Migration was less pronounced for luminal lines; but, these lines were more likely to have altered proliferation. These differences were relevant to tumor biology in vivo, as the gene set that distinguished luminal and basal-like stromal interactions in coculture also distinguishes basal-like from luminal tumors with 98% accuracy in 10-fold cross-validation and 100% accuracy in an independent test set. However, comparisons between cocultures where cells were in direct contact and cocultures where interaction was solely through soluble factors suggest that there is an important impact of direct cell-to-cell contact. The phenotypes and gene expression changes invoked by cancer cell interactions with fibroblasts support the microenvironment and cell–cell interactions as intrinsic features of breast cancer subtypes. Mol Cancer Res; 9(1); 3–13 ©2010 AACR.
Data from Phosphoproteomic Screen Identifies Potential Therapeutic Targets in Melanoma
Authors: Tworkoski Kathryn , Singhal Garima , Szpakowski Sebastian , Zito Christina Ivins , Bacchiocchi Antonella , Muthusamy Viswanathan , Bosenberg Marcus , Krauthammer Michael , Halaban Ruth , Stern David F.
Published: March 2024

Abstract
Therapies directed against receptor tyrosine kinases are effective in many cancer subtypes, including lung and breast cancer. We used a phosphoproteomic platform to identify active receptor tyrosine kinases that might represent therapeutic targets in a panel of 25 melanoma cell strains. We detected activated receptors including TYRO3, AXL, MERTK, EPHB2, MET, IGF1R, EGFR, KIT, HER3, and HER4. Statistical analysis of receptor tyrosine kinase activation as well as ligand and receptor expression indicates that some receptors, such as FGFR3, may be activated via autocrine circuits. Short hairpin RNA knockdown targeting three of the active kinases identified in the screen, AXL, HER3, and IGF1R, inhibited the proliferation of melanoma cells and knockdown of active AXL also reduced melanoma cell migration. The changes in cellular phenotype observed on AXL knockdown seem to be modulated via the STAT3 signaling pathway, whereas the IGF1R-dependent alterations seem to be regulated by the AKT signaling pathway. Ultimately, this study identifies several novel targets for therapeutic intervention in melanoma. Mol Cancer Res; 9(6); 801–12. ©2011 AACR.
Data from Pan-Cancer Analysis Reveals Recurrent BCAR4 Gene Fusions across Solid Tumors
Authors: Nickless Andrew , Zhang Jin , Othoum Ghofran , Webster Jace , Inkman Matthew J. , Coonrod Emily , Fontes Sherron , Rozycki Emily B. , Maher Christopher A. , White Nicole M.
Published: March 2024

Abstract
Chromosomal rearrangements often result in active regulatory regions juxtaposed upstream of an oncogene to generate an expressed gene fusion. Repeated activation of a common downstream partner–with differing upstream regions across a patient cohort–suggests a conserved oncogenic role. Analysis of 9,638 patients across 32 solid tumor types revealed an annotated long noncoding RNA (lncRNA), Breast Cancer Anti-Estrogen Resistance 4 (BCAR4), was the most prevalent, uncharacterized, downstream gene fusion partner occurring in 11 cancers. Its oncogenic role was confirmed using multiple cell lines with endogenous BCAR4 gene fusions. Furthermore, overexpressing clinically prevalent BCAR4 gene fusions in untransformed cell lines was sufficient to induce an oncogenic phenotype. We show that the minimum common region to all gene fusions harbors an open reading frame that is necessary to drive proliferation.
Implications:
BCAR4 gene fusions represent an underappreciated class of gene fusions that may have biological and clinical implications across solid tumors.
Data from Combinatorial Treatment with PARP-1 Inhibitors and Cisplatin Attenuates Cervical Cancer Growth through Fos-Driven Changes in Gene Expression
Authors: Gupte Rebecca , Lin Ken Y. , Nandu Tulip , Lea Jayanthi S. , Kraus W. Lee
Published: March 2024

Abstract
Cervical cancer continues to be a significant cause of cancer-related deaths in women. The most common treatment for cervical cancer involves the use of the drug cisplatin in conjunction with other therapeutics. However, the development of cisplatin resistance in patients can hinder the efficacy of these treatments, so alternatives are needed. In this study, we found that PARP inhibitors (PARPi) could attenuate the growth of cells representing cervical adenocarcinoma and cervical squamous cell carcinoma. Moreover, a combination of PARPi with cisplatin increased cisplatin-mediated cytotoxicity in cervical cancer cells. This was accompanied by a dramatic alteration of the transcriptome. The FOS gene, which encodes the transcription factor Fos, was one of the most highly upregulated genes in the dual treatment condition, leading to increased Fos protein levels, greater Fos binding to chromatin, and the subsequent induction of Fos target genes. Increased expression of Fos was sufficient to hinder cervical cancer growth, as shown by ectopic expression of Fos in cervical cancer cells. Conversely, Fos knockdown enhanced cell growth. Collectively, these results indicate that by inducing FOS expression, PARPi treatment in combination with cisplatin leads to inhibition of cervical cancer proliferation, likely through a Fos-specific gene expression program.
Implications:
Our observations, which link the gene regulatory effects of PARPi + cisplatin to the growth inhibitory effects of FOS expression in cervical cancer cells, strengthen the rationale for using PARPi with cisplatin as a therapy for cervical cancer.
Data from ATF6-Mediated Signaling Contributes to PARP Inhibitor Resistance in Ovarian Cancer
Authors: McMellen Alexandra , Yamamoto Tomomi M. , Qamar Lubna , Sanders Brooke E. , Nguyen Lily L. , Ortiz Chavez Daniela , Bapat Jaidev , Berning Amber , Post Miriam D. , Johnson Joshua , Behbakht Kian , Nurmemmedov Elmar , Chuong Edward B. , Bitler Benjamin G.
Published: March 2024

Abstract
High-grade serous ovarian cancer (HGSOC) is the deadliest ovarian cancer histotype due in-part to the lack of therapeutic options for chemotherapy-resistant disease. PARP inhibitors (PARPi) represent a targeted treatment. However, PARPi resistance is becoming a significant clinical challenge. There is an urgent need to overcome resistance mechanisms to extend disease-free intervals. We established isogeneic PARPi-sensitive and -resistant HGSOC cell lines. In three PARPi-resistant models, there is a significant increase in AP-1 transcriptional activity and DNA repair capacity. Using RNA-sequencing and an shRNA screen, we identified activating transcription factor 6 (ATF6) as a mediator of AP-1 activity, DNA damage response, and PARPi resistance. In publicly available datasets, ATF6 expression is elevated in HGSOC and portends a poorer recurrence-free survival. In a cohort of primary HGSOC tumors, higher ATF6 expression significantly correlated to PARPi resistance. In PARPi-resistant cell lines and a PDX model, inhibition of a known ATF6 regulator, p38, attenuated AP-1 activity and RAD51 foci formation, enhanced DNA damage, significantly inhibited tumor burden, and reduced accumulation of nuclear ATF6.
Implications:
This study highlights that a novel p38-ATF6-mediated AP-1 signaling axis contributes to PARPi resistance and provides a clinical rationale for combining PARPi and AP-1 signaling inhibitors.
Data from Multi-omics Profiling Shows BAP1 Loss Is Associated with Upregulated Cell Adhesion Molecules in Uveal Melanoma
Authors: Baqai Usman , Purwin Timothy J. , Bechtel Nelisa , Chua Vivian , Han Anna , Hartsough Edward J. , Kuznetsoff Jeffim N. , Harbour J. William , Aplin Andrew E.
Published: March 2024

Abstract
BRCA1-associated protein 1 (BAP1) is a tumor suppressor gene that is mutated in cancer, including uveal melanoma. Loss-of-function BAP1 mutations are associated with uveal melanoma metastasis and poor prognosis, but the mechanisms underlying these effects remain unclear. Upregulation of cell–cell adhesion proteins is involved with collective migration and metastatic seeding of cancer cells. Here, we show that BAP1 loss in uveal melanoma patient samples is associated with upregulated gene expression of multiple cell adhesion molecules (CAM), including E-cadherin (CDH1), cell adhesion molecule 1 (CADM1), and syndecan-2 (SDC2). Similar findings were observed in uveal melanoma cell lines and single-cell RNA-sequencing data from uveal melanoma patient samples. BAP1 reexpression in uveal melanoma cells reduced E-cadherin and CADM1 levels. Functionally, knockdown of E-cadherin decreased spheroid cluster formation and knockdown of CADM1 decreased growth of BAP1-mutant uveal melanoma cells. Together, our findings demonstrate that BAP1 regulates the expression of CAMs which may regulate metastatic traits.
Implications:
BAP1 mutations and increased metastasis may be due to upregulation of CAMs.
Data from Diurnal Expression of PD-1 on Tumor-Associated Macrophages Underlies the Dosing Time-Dependent Antitumor Effects of the PD-1/PD-L1 Inhibitor BMS-1 in B16/BL6 Melanoma-Bearing Mice
Authors: Tsuruta Akito , Shiiba Yuki , Matsunaga Naoya , Fujimoto Marina , Yoshida Yuya , Koyanagi Satoru , Ohdo Shigehiro
Published: March 2024

Abstract
Cancer cells have acquired several pathways to escape from host immunity in the tumor microenvironment. Programmed death 1 (PD-1) receptor and its ligand PD-L1 are involved in the key pathway of tumor immune escape, and immune checkpoint therapy targeting PD-1 and PD-L1 has been approved for the treatment of patients with certain types of malignancies. Although PD-1 is a well-characterized receptor on T cells, the immune checkpoint receptor is also expressed on tumor-associated macrophages (TAM), a major immune component of the tumor microenvironment. In this study, we found significant diurnal oscillation in the number of PD-1–expressing TAMs collected from B16/BL6 melanoma-bearing mice. The levels of Pdcd1 mRNA, encoding PD-1, in TAMs also fluctuated in a diurnal manner. Luciferase reporter and bioluminescence imaging analyses revealed that a NF-κB response element in the upstream region of the Pdcd1 gene is responsible for its diurnal expression. A circadian regulatory component, DEC2, whose expression in TAMs exhibited diurnal oscillation, periodically suppressed NF-κB–induced transactivation of the Pdcd1 gene, resulting in diurnal expression of PD-1 in TAMs. Furthermore, the antitumor efficacy of BMS-1, a small molecule inhibitor of PD-1/PD-L1, was enhanced by administering it at the time of day when PD-1 expression increased on TAMs. These findings suggest that identification of the diurnal expression of PD-1 on TAMs is useful for selecting the most appropriate time of day to administer PD-1/PD-L1 inhibitors.
Implications:
Selecting the most appropriate dosing time of PD-1/PD-L1 inhibitors may aid in developing cancer immunotherapy with higher efficacy.
Data from BRAFV600E-Driven Lung Adenocarcinoma Requires Copper to Sustain Autophagic Signaling and Processing
Authors: Tsang Tiffany , Gu Xingxing , Davis Caroline I. , Posimo Jessica M. , Miller Zoey A. , Brady Donita C.
Published: March 2024

Abstract
The transition metal copper (Cu) is an essential micronutrient required for development and proliferation, but the molecular mechanisms by which Cu contributes to these processes is not fully understood. Although traditionally studied as a static cofactor critical for the function of Cu-dependent enzymes, an expanding role for Cu is emerging to include its novel function as a dynamic mediator of signaling processes through the direct control of protein kinase activity. We now appreciate that Cu directly binds to and influences MEK1/2 and ULK1/2 kinase activity, and show here that reductions in MAPK and autophagic signaling are associated with dampened growth and survival of oncogenic BRAF-driven lung adenocarcinoma cells upon loss of Ctr1. Efficient autophagy, clonogenic survival, and tumorigenesis of BRAF-mutant cells required ULK1 Cu-binding. Although treatment with canonical MAPK inhibitors resulted in the upregulation of protective autophagy, mechanistically, the Cu chelator tetrathiomolybdate (TTM) was sufficient to target both autophagic and MAPK signaling as a means to blunt BRAF-driven tumorigenic properties. These findings support leveraging Cu chelation with TTM as an alternative therapeutic strategy to impair autophagy and MAPK signaling. As traditional MAPK monotherapies initiate autophagy signaling and promote cancer cell survival.
Implications:
We establish that copper chelation therapy inhibits both autophagy and MAPK signaling in BRAFV600E-driven lung adenocarcinoma, thus overcoming the upregulation of protective autophagy elicited by canonical MAPK pathway inhibitors.
Data from Nicotine Does Not Enhance Tumorigenesis in Mutant K-Ras–Driven Mouse Models of Lung Cancer
Authors: Maier Colleen R. , Hollander M. Christine , Hobbs Evthokia A. , Dogan Irem , Linnoila R. Ilona , Dennis Phillip A.
Published: March 2024

Abstract
Smoking is the leading cause of preventable cancer deaths in the United States. Nicotine replacement therapies (NRT) have been developed to aid in smoking cessation, which decreases lung cancer incidence. However, the safety of NRT is controversial because numerous preclinical studies have shown that nicotine enhances tumor cell growth in vitro and in vivo. We modeled NRT in mice to determine the effects of physiologic levels of nicotine on lung tumor formation, tumor growth, or metastasis. Nicotine administered in drinking water did not enhance lung tumorigenesis after treatment with the tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Tumors that develop in this model have mutations in K-ras, which is commonly observed in smoking-related, human lung adenocarcinomas. In a transgenic model of mutant K-ras–driven lung cancer, nicotine did not increase tumor number or size and did not affect overall survival. Likewise, in a syngeneic model using lung cancer cell lines derived from NNK-treated mice, oral nicotine did not enhance tumor growth or metastasis. These data show that nicotine does not enhance lung tumorigenesis when given to achieve levels comparable with those of NRT, suggesting that nicotine has a dose threshold, below which it has no appreciable effect. These studies are consistent with epidemiologic data showing that NRT does not enhance lung cancer risk in former smokers. Cancer Prev Res; 4(11); 1743–51. ©2011 AACR.
Data from Physical Activity Is Associated with Reduced Risk of Gastric Cancer: A Systematic Review and Meta-analysis
Authors: Singh Siddharth , Varayil Jithinraj Edakkanambeth , Devanna Swapna , Murad Mohammad Hassan , Iyer Prasad G.
Published: March 2024

Abstract
Physical activity may be associated with reduced risk of gastric cancer. We performed a systematic review and meta-analysis to evaluate the magnitude of the association and the quality of supporting evidence. After a comprehensive search of bibliographic databases and conference proceedings through February 2013 for observational studies that examined associations between recreational and/or occupational physical activity and gastric cancer risk, we identified 16 studies (seven cohort, nine case control) reporting 11,111 cases of gastric cancer among 1,606,760 patients. Summary adjusted-OR estimates with 95% confidence intervals (CI) were estimated using the random-effects model. Meta-analysis demonstrated that the risk of gastric cancer was 21% lower among the most physically active people as compared with the least physically active people (OR = 0.79; 95% CI, 0.71–0.87) with moderate heterogeneity among studies (I2 = 55%). This protective effect was seen for gastric cancers in the cardia (four studies; OR = 0.80; 95% CI, 0.63–1.00) and distal stomach (five studies; OR = 0.63; 95% CI, 0.52–0.76). The effect size was significantly smaller in high-quality studies (six studies; OR = 0.86; 95% CI, 0.75–0.99), as compared with low-quality studies (10 studies; OR = 0.74; 95% CI, 0.69–0.81). The results were consistent across sex, study quality, study design, and geographic location. In conclusion, meta-analysis of published observational studies indicates that physical activity is associated with reduced risk of gastric cancer. Lifestyle interventions focusing on increasing physical activity may decrease the global burden of gastric cancer, in addition to a myriad of other health benefits. Cancer Prev Res; 7(1); 12–22. ©2013 AACR.
Data from DNA Damage Drives an Activin A–Dependent Induction of Cyclooxygenase-2 in Premalignant Cells and Lesions
Authors: Fordyce Colleen , Fessenden Tim , Pickering Curtis , Jung Jason , Singla Veena , Berman Hal , Tlsty Thea
Published: March 2024

Abstract
Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step in the synthesis of prostaglandins. Its overexpression induces numerous tumor-promoting phenotypes and is associated with cancer metastasis and poor clinical outcome. Although COX-2 inhibitors are promising chemotherapeutic and chemopreventative agents for cancer, the risk of significant cardiovascular and gastrointestinal complications currently outweighs their potential benefits. Systemic complications of COX-2 inhibition could be avoided by specifically decreasing COX-2 expression in epithelial cells. To that end, we have investigated the signal transduction pathway regulating the COX-2 expression in response to DNA damage in breast epithelial cells. In variant human mammary epithelial cells that have silenced p16 (vHMEC), double-strand DNA damage or telomere malfunction results in a p53- and activin A–dependent induction of COX-2 and continued proliferation. In contrast, telomere malfunction in HMEC with an intact p16/Rb pathway induces cell cycle arrest. Importantly, in ductal carcinoma in situ lesions, high COX-2 expression is associated with high γH2AX, TRF2, activin A, and telomere malfunction. These data show that DNA damage and telomere malfunction can have both cell-autonomous and cell-nonautonomous consequences and can provide a novel mechanism for the propagation of tumorigenesis. Cancer Prev Res; 3(2); 190–201
Data from The State of Molecular Biomarkers for the Early Detection of Lung Cancer
Authors: Hassanein Mohamed , Callison J. Clay , Callaway-Lane Carol , Aldrich Melinda C. , Grogan Eric L. , Massion Pierre P.
Published: March 2024

Abstract
Using biomarkers to select the most at-risk population, to detect the disease while measurable and yet not clinically apparent has been the goal of many investigations. Recent advances in molecular strategies and analytic platforms, including genomics, epigenomics, proteomics, and metabolomics, have identified increasing numbers of potential biomarkers in the blood, urine, exhaled breath condensate, bronchial specimens, saliva, and sputum, but none have yet moved to the clinical setting. Therefore, there is a recognized gap between the promise and the product delivery in the cancer biomarker field. In this review, we define clinical contexts where risk and diagnostic biomarkers may have use in the management of lung cancer, identify the most relevant candidate biomarkers of early detection, provide their state of development, and finally discuss critical aspects of study design in molecular biomarkers for early detection of lung cancer. Cancer Prev Res; 5(8); 992–1006. ©2012 AACR.
Data from Chemoprevention of Esophageal Cancer with Black Raspberries, Their Component Anthocyanins, and a Major Anthocyanin Metabolite, Protocatechuic Acid
Authors: Peiffer Daniel S. , Zimmerman Noah P. , Wang Li-Shu , Ransom Benjamin W.S. , Carmella Steven G. , Kuo Chieh-Ti , Siddiqui Jibran , Chen Jo-Hsin , Oshima Kiyoko , Huang Yi-Wen , Hecht Stephen S. , Stoner Gary D.
Published: March 2024

Abstract
Diets containing either freeze-dried black raspberries (BRBs) or their polyphenolic anthocyanins (ACs) have been shown to inhibit the development of N-nitrosomethylbenzylamine (NMBA)–induced esophageal cancer in rats. The present study was conducted to determine whether PCA, a major microbial metabolite of black raspberry (BRB) ACs, also prevents NMBA-induced esophageal cancer in rats. F344 rats were injected with NMBA three times a week for 5 weeks and then fed control or experimental diets containing 6.1% BRBs, an anthocyanin (AC)-enriched fraction derived from BRBs, or protocatechuic acid (PCA). Animals were exsanguinated at weeks 15, 25, and 35 to quantify the development of preneoplastic lesions and tumors in the esophagus, and to relate this to the expression of inflammatory biomarkers. At weeks 15 and 25, all experimental diets were equally effective in reducing NMBA-induced esophageal tumorigenesis, as well as in reducing the expression of pentraxin-3 (PTX3), a cytokine produced by peripheral blood mononuclear cells in response to interleukin (IL)-1β and TNF-α. All experimental diets were also active at reducing tumorigenesis at week 35; however, the BRB diet was significantly more effective than the AC and PCA diets. Furthermore, all experimental diets inhibited inflammation in the esophagus via reducing biomarker (COX-2, iNOS, p-NF-κB, and sEH) and cytokine (PTX3) expression. Overall, our data suggest that BRBs, their component ACs, and PCA inhibit NMBA-induced esophageal tumorigenesis, at least in part, by their inhibitory effects on genes associated with inflammation. Cancer Prev Res; 7(6); 574–84. ©2014 AACR.
Data from The Effect of HIV and HPV Coinfection on Cervical COX-2 Expression and Systemic Prostaglandin E2 Levels
Authors: Fitzgerald Daniel W. , Bezak Karl , Ocheretina Oksana , Riviere Cynthia , Wright Thomas C. , Milne Ginger L. , Zhou Xi Kathy , Du Baoheng , Subbaramaiah Kotha , Byrt Erin , Goodwin Matthew L. , Rafii Arash , Dannenberg Andrew J.
Published: March 2024

Abstract
Human immunodeficiency virus (HIV-1) infection causes chronic inflammation. COX-2–derived prostaglandin E2 (PGE2) has been linked to both inflammation and carcinogenesis. We hypothesized that HIV-1 could induce COX-2 in cervical tissue and increase systemic PGE2 levels and that these alterations could play a role in AIDS-related cervical cancer. Levels of cervical COX-2 mRNA and urinary PGE-M, a biomarker of systemic PGE2 levels, were determined in 17 HIV-negative women with a negative cervical human papilloma virus (HPV) test, 18 HIV-infected women with a negative HPV test, and 13 HIV-infected women with cervical HPV and high-grade squamous intraepithelial lesions on cytology. Cervical COX-2 levels were significantly associated with HIV and HPV status (P = 0.006 and 0.002, respectively). Median levels of urinary PGE-M were increased in HIV-infected compared with uninfected women (11.2 vs. 6.8 ng/mg creatinine, P = 0.02). Among HIV-infected women, urinary PGE-M levels were positively correlated with plasma HIV-1 RNA levels (P = 0.003). Finally, levels of cervical COX-2 correlated with urinary PGE-M levels (P = 0.005). This study shows that HIV-1 infection is associated with increased cervical COX-2 and elevated systemic PGE2 levels. Drugs that inhibit the synthesis of PGE2 may prove useful in reducing the risk of cervical cancer or systemic inflammation in HIV-infected women. Cancer Prev Res; 5(1); 34–40. ©2011 AACR.
Data from Prevention of Mutagenesis: New Potential Mechanisms of Metformin Action in Neoplastic Cells
Authors: Bost Frédéric , Ben-Sahra Issam , Tanti Jean-François
Published: March 2024

Abstract
Several experimental and epidemiologic studies have shown that the antidiabetes drug metformin has antitumor properties. The report by Algire and colleagues in this issue of the journal (beginning on page 536) shows for the first time that metformin reduces mutagenesis induced by reactive oxygen species. This report offers new perspectives on metformin in cancer prevention and provides a new mechanism for the reduction of cancer risk in diabetic patients treated with this drug. Cancer Prev Res; 5(4); 503–6. ©2012 AACR.
Data from A Dietary Tomato Supplement Prevents Prostate Cancer in TRAMP Mice
Authors: Pannellini Tania , Iezzi Manuela , Liberatore Marcella , Sabatini Federica , Iacobelli Stefano , Rossi Cosmo , Alberti Saverio , Di Ilio Carmine , Vitaglione Paola , Fogliano Vincenzo , Piantelli Mauro
Published: March 2024

Abstract
Transgenic adenocarcinoma of the mouse prostate (TRAMP) is a model for progressive prostate cancer that mirrors the stages of the human form. In this study, the effects of a diet enriched with processed whole tomatoes on survival, tumorigenesis, and progression of prostate cancer, and the antioxidant and inflammatory status of TRAMP mice were investigated. Tomato diet significantly increased overall survival (P < 0.01), delayed progression from prostatic intraepithelial neoplasia to adenocarcinoma, and decreased the incidence of poorly differentiated carcinoma. Biochemical data disclosed an increase in serum antioxidant activity and a reduction of serum inflammation/angiogenesis biomarkers of particular importance in prostate carcinogenesis. Cancer Prev Res; 3(10); 1284–91. ©2010 AACR.
Data from A Migration Signature and Plasma Biomarker Panel for Pancreatic Adenocarcinoma
Authors: Balasenthil Seetharaman , Chen Nanyue , Lott Steven T. , Chen Jinyun , Carter Jennifer , Grizzle William E. , Frazier Marsha L. , Sen Subrata , Killary Ann McNeill
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma is a disease of extremely poor prognosis for which there are no reliable markers of asymptomatic disease. To identify pancreatic cancer biomarkers, we focused on a genomic interval proximal to the most common fragile site in the human genome, chromosome 3p12, which undergoes smoking-related breakage, loss of heterozygosity, and homozygous deletion as an early event in many epithelial tumors, including pancreatic cancers. Using a functional genomic approach, we identified a seven-gene panel (TNC, TFPI, TGFBI, SEL-1L, L1CAM, WWTR1, and CDC42BPA) that was differentially expressed across three different expression platforms, including pancreatic tumor/normal samples. In addition, Ingenuity Pathways Analysis (IPA) and literature searches indicated that this seven-gene panel functions in one network associated with cellular movement/morphology/development, indicative of a “migration signature” of the 3p pathway. We tested whether two secreted proteins from this panel, tenascin C (TNC) and tissue factor pathway inhibitor (TFPI), could serve as plasma biomarkers. Plasma ELISA assays for TFPI/TNC resulted in a combined area under the curve (AUC) of 0.88 and, with addition of CA19-9, a combined AUC for the three-gene panel (TNC/TFPI/CA19-9), of 0.99 with 100% specificity at 90% sensitivity and 97.22% sensitivity at 90% specificity. Validation studies using TFPI only in a blinded sample set increased the performance of CA19-9 from an AUC of 0.84 to 0.94 with the two-gene panel. Results identify a novel 3p pathway–associated migration signature and plasma biomarker panel that has utility for discrimination of pancreatic cancer from normal controls and promise for clinical application. Cancer Prev Res; 4(1); 137–49. ©2010 AACR.
Data from Dietary Fish Oil Promotes Colonic Apoptosis and Mitochondrial Proton Leak in Oxidatively Stressed Mice
Authors: Fan Yang-Yi , Ran Qitao , Toyokuni Shinya , Okazaki Yasumasa , Callaway Evelyn S. , Lupton Joanne R. , Chapkin Robert S.
Published: March 2024

Abstract
An alteration of mitochondrial function can result in disruption of redox homeostasis and is associated with abnormal cancer cell growth. Manganese superoxide dismutase (SOD2) and glutathione peroxidase 4 (Gpx4) are two of the most important antioxidant defense enzymes that protect cells against oxidative stress. We had previously shown that n-3 polyunsaturated fatty acids (PUFA) promote colonocyte apoptosis, a marker of colon cancer risk, in part by enhancing phospholipid oxidation. To elucidate the mechanisms regulating oxidative stress-induced apoptosis in vivo, we fed heterozygous SOD2Het, Gpx4Het, and transgenic Gpx4Tg mice diets containing either 15% corn oil by weight (CO, enriched in n-6 PUFA) or 3.5% CO + 11.5% fish oil (FO, enriched in n-3 PUFA) for 4 weeks. Our data showed that (i) genetic predeposition to oxidative stress facilitates apoptosis in the mouse colon (Gpx4Het > SOD2Het > Wt > Gpx4Tg), (ii) dietary n-3 PUFA have an additive effect on the induction of apoptosis in Gpx4Het and SOD2Het mice; and (iii) dietary n-3 PUFA reverse the phenotype in oxidatively protected Gpx4Tg mice by elevating apoptosis to a level observed in wild-type (Wt; control) animals. Complimentary experiments examining colonic mitochondrial bioenergetic profiles indicate that FO-fed mice exhibit a significantly (P < 0.05) increased respiration-induced proton leak relative to control CO treatment. This finding was consistent with a loss of membrane potential in response to chronic oxidative stress and supports the contention that n-3 PUFA alter mitochondrial metabolic activity, thereby enhancing apoptosis and reducing colon cancer risk. Cancer Prev Res; 4(8); 1267–74. ©2011 AACR.
Data from Synergistic Effects of Combined Phytochemicals and Skin Cancer Prevention in SENCAR Mice
Authors: Kowalczyk Magdalena C. , Kowalczyk Piotr , Tolstykh Olga , Hanausek Margaret , Walaszek Zbigniew , Slaga Thomas J.
Published: March 2024

Abstract
The purpose of our study was to determine the inhibitory effect of combined phytochemicals on chemically induced murine skin tumorigenesis. Our hypothesis was that concurrent topical and dietary treatment with selected compounds would lead to more efficient prevention of skin cancer. We tested ellagic acid and calcium D-glucarate as components of diets, while resveratrol was applied topically; grape seed extract was applied topically or in the diet. The 4-week inflammatory-hyperplasia assay based on the 7,12-dimethylbenz[a]anthracene (DMBA)–induced skin carcinogenesis model in SENCAR mice was used. We have found that all the selected combinations caused a marked decrease of epidermal thickness compared with the DMBA-treated group and also with groups treated with a single compound and DMBA. All combinations of resveratrol with other compounds showed a synergistic effect on hyperplasia and Ha-ras mutations. Skin tissue of mice receiving the combinations showed decreased cell proliferation and Bcl2 expression; decreased p21, a regulator of cell cycle; and decreased marker of inflammation cyclooxygenase-2. All the selected combinations diminished the DMBA-induced mRNA expression of the CYP1B1 level, and also caused a marked decrease of proto-oncogenes c-jun and c-fos, components of transcription factor activator protein. In conclusion, all combinations showed either additive or synergistic effects and their joint actions allowed for decreasing the doses of the compounds. Especially, resveratrol combinations with ellagic acid, grape seed extract, and other phytochemicals are very potent inhibitors of skin tumorgenesis, based on the suppression of epidermal hyperplasia as well as on the modulation of intermediate biomarkers of cell proliferation, cell survival, inflammation, oncogene mutation, and apoptosis. Cancer Prev Res; 3(2); 170–8
Data from Risk Modification of Colorectal Adenoma by CYP7A1 Polymorphisms and the Role of Bile Acid Metabolism in Carcinogenesis
Authors: Wertheim Betsy C. , Smith Jeffrey W. , Fang Changming , Alberts David S. , Lance Peter , Thompson Patricia A.
Published: March 2024

Abstract
Cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in the conversion of cholesterol to bile acids, is a postulated gene modifier of colorectal cancer risk and target for the therapeutic bile acid, ursodeoxycholic acid (UDCA). We investigated associations between CYP7A1 polymorphisms and fecal bile acids, colorectal adenoma (CRA), and UDCA efficacy for CRA prevention. Seven tagging, single-nucleotide polymorphisms (SNP) in CYP7A1 were measured in 703 (355 UDCA, 348 placebo) participants of a phase III chemoprevention trial, of which 495 had known baseline fecal bile acid concentrations. In the placebo arm, participants with two minor Grs8192871 alleles (tag for a low activity promoter polymorphism at −204) had lower odds of high secondary bile acids (OR = 0.26, 95% CI: 0.10–0.69), and CRA at 3 years' follow-up (OR = 0.41, 95% CI: 0.19–0.89), than AA carriers. Haplotype construction from the six polymorphic SNPs showed participants with the third most common haplotype (Crs10957057Crs8192879Grs8192877Trs11786580Ars8192871Grs13251096) had higher odds of high primary bile acids (OR = 2.34, 95% CI: 1.12–4.89) and CRA (OR = 1.89, 95% CI: 1.00–3.57) than those with the most common CTACAG haplotype. Furthermore, three SNPs (rs8192877, rs8192871, and rs13251096) each modified UDCA efficacy for CRA prevention, and CCGTAG-haplotype carriers experienced 71% lower odds of CRA recurrence with UDCA treatment, an effect not present for other haplotypes (test for UDCA–haplotype interaction, P = 0.020). Our findings support CYP7A1 polymorphisms as determinants of fecal bile acids and risk factors for CRA. Furthermore, UDCA efficacy for CRA prevention may be modified by genetic variation in CYP7A1, limiting treatment benefit to a subgroup of the population. Cancer Prev Res; 5(2); 197–204. ©2011 AACR.