bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Novel Matrix Metalloproteinase Inhibitor [18F]Marimastat-Aryltrifluoroborate as a Probe for In vivo Positron Emission Tomography Imaging in Cancer
Authors: auf dem Keller Ulrich , Bellac Caroline L. , Li Ying , Lou Yuanmei , Lange Philipp F. , Ting Richard , Harwig Curtis , Kappelhoff Reinhild , Dedhar Shoukat , Adam Michael J. , Ruth Thomas J. , Bénard François , Perrin David M. , Overall Christopher M.
Published: March 2024

Abstract
Matrix metalloproteinases (MMP), strongly associated pathogenic markers of cancer, have undergone extensive drug development programs. Marimastat, a noncovalent MMP inhibitor, was conjugated with FITC to label cellular metalloproteinase cancer targets in MDA-MB-231 cells in vitro. Punctate localization of active transmembrane MMP14 was observed. For molecular-targeted positron emission tomography imaging of syngeneic 67NR murine mammary carcinoma in vivo, marimastat was 18F-labeled using a shelf-stable arylboronic ester conjugate as a captor for aqueous [18F]fluoride in a novel, rapid one-step reaction at ambient temperature. [18F]Marimastat-aryltrifluoroborate localized to the tumors, with labeling being blocked in control animals first loaded with >10-fold excess unlabeled marimastat. The labeled drug cleared primarily via the hepatobiliary and gastrointestinal tract, with multiple animals imaged in independent experiments, confirming the ease of this new labeling strategy. Cancer Res; 70(19); 7562–9. ©2010 AACR.
Data from Inactivation of the Orphan Nuclear Receptor TR3/Nur77 Inhibits Pancreatic Cancer Cell and Tumor Growth
Authors: Lee Syng-Ook , Abdelrahim Maen , Yoon Kyungsil , Chintharlapalli Sudhakar , Papineni Sabitha , Kim Kyounghyun , Wang Huamin , Safe Stephen
Published: March 2024

Abstract
Activation of the orphan nuclear receptor TR3/Nur77 (NR4A1) promotes apoptosis and inhibits pancreatic tumor growth, but its endogenous function and the effects of its inactivation have yet to be determined. TR3 was overexpressed in human pancreatic tumors compared with nontumor tissue. Small interfering RNA–mediated knockdown of TR3 or cell treatment with the TR3 antagonist 1,1-bis(3′-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH) decreased proliferation, induced apoptosis, and decreased expression of antiapoptotic genes including Bcl-2 and survivin in pancreatic cancer cells. Survivin suppression was mediated by formation of a TR3-Sp1-p300 DNA binding complex on the proximal GC-rich region of the survivin promoter. When administered in vivo, DIM-C-pPhOH induced apoptosis and inhibited tumor growth in an orthotopic model of pancreatic cancer, associated with inhibition of the same antiapoptotic markers observed in vitro. Our results offer preclinical validation of TR3 as a drug target for pancreatic cancer chemotherapy, based on the ability of TR3 inhibitors to block the growth of pancreatic tumors. Cancer Res; 70(17); 6824–36. ©2010 AACR.
Data from E6-Associated Protein Is Required for Human Papillomavirus Type 16 E6 to Cause Cervical Cancer in Mice
Authors: Shai Anny , Pitot Henry C. , Lambert Paul F.
Published: March 2024

Abstract
High-risk human papillomaviruses (HPV) cause certain anogenital and head and neck cancers. E6, one of three potent HPV oncogenes that contribute to the development of these malignancies, is a multifunctional protein with many biochemical activities. Among these activities are its ability to bind and inactivate the cellular tumor suppressor p53, induce expression of telomerase, and bind to various other proteins, including Bak, E6BP1, and E6TP1, and proteins that contain PDZ domains, such as hScrib and hDlg. Many of these activities are thought to contribute to the role of E6 in carcinogenesis. The interaction of E6 with many of these cellular proteins, including p53, leads to their destabilization. This property is mediated at least in part through the ability of E6 to recruit the ubiquitin ligase E6-associated protein (E6AP) into complexes with these cellular proteins, resulting in their ubiquitin-mediated degradation by the proteasome. In this study, we address the requirement for E6AP in mediating acute and oncogenic phenotypes of E6, including induction of epithelial hyperplasia, abrogation of DNA damage response, and induction of cervical cancer. Loss of E6AP had no discernible effect on the ability of E6 to induce hyperplasia or abrogate DNA damage responses, akin to what we had earlier observed in the mouse epidermis. Nevertheless, in cervical carcinogenesis studies, there was a complete loss of the oncogenic potential of E6 in mice nulligenic for E6AP. Thus, E6AP is absolutely required for E6 to cause cervical cancer. Cancer Res; 70(12); 5064–73. ©2010 AACR.
Data from Colorectal Tumors Are Effectively Eradicated by Combined Inhibition of β-Catenin, KRAS, and the Oncogenic Transcription Factor ITF2
Authors: Mologni Luca , Dekhil Hafedh , Ceccon Monica , Purgante Stefania , Lan Cathy , Cleris Loredana , Magistroni Vera , Formelli Franca , Gambacorti-Passerini Carlo B.
Published: March 2024

Abstract
Colorectal carcinomas (CRC) harbor well-defined genetic abnormalities, including aberrant activation of β-catenin (β-cat) and KRAS, but independent targeting of these molecules seems to have limited therapeutic effect. In this study, we report therapeutic effects of combined targeting of different oncogenes in CRC. Inducible short hairpin RNA (shRNA)–mediated silencing of β-cat, ITF2, or KRAS decreased proliferation by 88%, 72%, and 45%, respectively, with no significant apoptosis in any case. In contrast, combined blockade of β-cat and ITF2 inhibited proliferation by 99% with massive apoptosis. Similar effects occurred after combined shRNA against β-cat and KRAS. In vivo, single oncogene blockade inhibited the growth of established tumors by up to 30%, whereas dual β-cat and ITF2 targeting caused 93% inhibition. Similar tumor growth suppression was achieved by double β-cat/KRAS shRNA in vivo. Our findings illustrate an effective therapeutic principle in CRC based on a combination targeting strategy that includes the ITF2 oncogene, which represents a novel therapeutic target. Cancer Res; 70(18); 7253–63. ©2010 AACR.
Data from Apoptotic Sensitivity of Colon Cancer Cells to Histone Deacetylase Inhibitors Is Mediated by an Sp1/Sp3-Activated Transcriptional Program Involving Immediate-Early Gene Induction
Authors: Wilson Andrew J. , Chueh Anderly C. , Tögel Lars , Corner Georgia A. , Ahmed Naseem , Goel Sanjay , Byun Do-Sun , Nasser Shannon , Houston Michele A. , Jhawer Minaxi , Smartt Helena J.M. , Murray Lucas B. , Nicholas Courtney , Heerdt Barbara G. , Arango Diego , Augenlicht Leonard H. , Mariadason John M.
Published: March 2024

Abstract
Histone deacetylase inhibitors (HDACi) induce growth arrest and apoptosis in colon cancer cells and are being considered for colon cancer therapy. The underlying mechanism of action of these effects is poorly defined with both transcription-dependent and -independent mechanisms implicated. We screened a panel of 30 colon cancer cell lines for sensitivity to HDACi-induced apoptosis and correlated the differences with gene expression patterns induced by HDACi in the five most sensitive and resistant lines. A robust and reproducible transcriptional response involving coordinate induction of multiple immediate-early (fos, jun, egr1, egr3, atf3, arc, nr4a1) and stress response genes (Ndrg4, Mt1B, Mt1E, Mt1F, Mt1H) was selectively induced in HDACi sensitive cells. Notably, a significant percentage of these genes were basally repressed in colon tumors. Bioinformatics analysis revealed that the promoter regions of the HDACi-induced genes were enriched for KLF4/Sp1/Sp3 transcription factor binding sites. Altering KLF4 levels failed to modulate apoptosis or transcriptional responses to HDACi treatment. In contrast, HDACi preferentially stimulated the activity of Spl/Sp3 and blocking their action attenuated both the transcriptional and apoptotic responses to HDACi treatment. Our findings link HDACi-induced apoptosis to activation of a Spl/Sp3-mediated response that involves derepression of a transcriptional network basally repressed in colon cancer. Cancer Res; 70(2); 609–20
Data from Matrix Metalloproteinase-9 Regulates Tumor Cell Invasion through Cleavage of Protease Nexin-1
Authors: Xu Danmei , McKee Chad M. , Cao Yunhong , Ding Yunchuan , Kessler Benedikt M. , Muschel Ruth J.
Published: March 2024

Abstract
Matrix metalloproteinase-9 (MMP-9) expression is known to enhance the invasion and metastasis of tumor cells. In previous work based on a proteomic screen, we identified the serpin protease nexin-1 (PN-1) as a potential target of MMP-9. Here, we show that PN-1 is a substrate for MMP-9 and establish a link between PN-1 degradation by MMP-9 and regulation of invasion. PN-1 levels increased in prostate carcinoma cells after downregulation of MMP-9 and in tissues of MMP-9–deficient mice, consistent with PN-1 degradation by MMP-9. We identified three MMP-9 cleavage sites in PN-1 and showed that mutations in those sites made PN-1 more resistant to MMP-9. Urokinase plasminogen activator (uPA) is inhibited by PN-1. MMP-9 augmented uPA activity in the medium of PC3-ML cells by degrading PN-1. Prostate cancer cells, overexpressing PN-1 or treated with MMP-9 shRNA, had reduced cell invasion in Matrigel. PN-1 siRNA restored uPA activity and the invasive capacity. PN-1 mutated in the serpin inhibitory domain, the reactive center loop, failed to inhibit uPA and to reduce Matrigel invasion. This study shows a novel molecular pathway in which MMP-9 regulates uPA activity and tumor cell invasion through cleavage of PN-1. Cancer Res; 70(17); 6988–98. ©2010 AACR.
Data from SLIT2 Attenuation during Lung Cancer Progression Deregulates β-Catenin and E-Cadherin and Associates with Poor Prognosis
Authors: Tseng Ruo-Chia , Lee Shih-Hua , Hsu Han-Shui , Chen Ben-Han , Tsai Wan-Ching , Tzao Ching , Wang Yi-Ching
Published: March 2024

Abstract
Chromosome 4p15.3 is frequently deleted in late-stage lung cancer. We investigated the significance of the SLIT2 gene located in this region to lung cancer progression. SLIT2 encodes an extracellular glycoprotein that can suppress breast cancer by regulating β-catenin. In this study, we examined alterations in the structure or expression of SLIT2, its receptor ROBO1, and β-catenin, along with the AKT/glycogen synthase kinase 3β (GSK3β)/β-transducin repeat-containing protein (βTrCP) pathway in lung cancer cell lines and patients. Low SLIT2 expression correlated with an upward trend of pathological stage and poorer survival in lung cancer patients. Importantly, SLIT2, βTrCP, and β-catenin expression levels predicted postoperative recurrence of lung cancer in patients. Stimulating SLIT2 expression by various methods increased the level of E-cadherin caused by attenuation of its transcriptional repressor SNAI1. Conversely, knocking down SLIT2 expression increased cell migration and reduced cell adhesion through coordinated deregulation of β-catenin and E-cadherin/SNAI1 in the AKT/GSK3β/βTrCP pathway. Our findings indicate that SLIT2 suppresses lung cancer progression, defining it as a novel “theranostic” factor with potential as a therapeutic target and prognostic predictor in lung cancer. Cancer Res; 70(2); 543–51
Data from Tuberous Sclerosis Complex 1: An Epithelial Tumor Suppressor Essential to Prevent Spontaneous Prostate Cancer in Aged Mice
Authors: Kladney Raleigh D. , Cardiff Robert D. , Kwiatkowski David J. , Chiang Gary G. , Weber Jason D. , Arbeit Jeffrey M. , Lu Zhi Hong
Published: March 2024

Abstract
The phosphoinositide 3-kinase (PI3K) pathway regulates mammalian cell growth, survival, and motility and plays a major pathogenetic role in human prostate cancer (PCa). However, the oncogenic contributions downstream of the PI3K pathway made by mammalian target of rapamycin complex 1 (mTORC1)–mediated cell growth signal transduction in PCa have yet to be elucidated in detail. Here, we engineered constitutive mTORC1 activation in prostate epithelium by a conditional genetic deletion of tuberous sclerosis complex 1 (Tsc1), a potent negative regulator of mTORC1 signaling. Epithelial inactivation was not immediately tumorigenic, but Tsc1-deficient mice developed prostatic intraepithelial neoplasia (mPIN) in lateral and anterior prostates by 6 months of age, with increasing disease penetrance over time. Lateral prostate lesions in 16- to 22-month-old mutant mice progressed to two types of more advanced lesions, adenomatous gland forming lesion (Type 1) and atypical glands embedded in massively expanded reactive stroma (Type 2). Both Type 1 and Type 2 lesions contained multiple foci of microinvasive carcinoma. Epithelial neoplastic and atypical stromal lesions persisted despite 4 weeks of RAD001 chemotherapy. Rapalogue resistance was not due to AKT or extracellular signal-regulated kinase 1/2 activation. Expression of the homeobox gene Nkx3.1 was lost in Tsc1-deficient mPIN, and it cooperated with TSC1 loss in mPIN initiation in doubly mutant Tsc1:Nkx3.1 prostatic epithelial knockout mice. Thus, TSC1 inactivation distal to PI3K and AKT activation is sufficient to activate a molecular signaling cascade producing prostatic neoplasia and focal carcinogenesis. Cancer Res; 70(21); 8937–47. ©2010 AACR.
Data from RasGRP3 Contributes to Formation and Maintenance of the Prostate Cancer Phenotype
Authors: Yang Dazhi , Kedei Noemi , Li Luowei , Tao Juan , Velasquez Julia F. , Michalowski Aleksandra M. , Tóth Balázs I. , Marincsák Rita , Varga Attila , Bíró Tamás , Yuspa Stuart H. , Blumberg Peter M.
Published: March 2024

Abstract
RasGRP3 mediates the activation of the Ras signaling pathway that is present in many human cancers. Here, we explored the involvement of RasGRP3 in the formation and maintenance of the prostate cancer phenotype. RasGRP3 expression was elevated in multiple human prostate tumor tissue samples and in the human androgen-independent prostate cancer cell lines PC-3 and DU 145 compared with the androgen-dependent prostate cancer cell line LNCaP. Downregulation of endogenous RasGRP3 in PC-3 and DU 145 cells reduced Ras-GTP formation, inhibited cell proliferation, impeded cell migration, and induced apoptosis. Anchorage-independent growth of the PC-3 cells and tumor formation in mouse xenografts of both cell lines were likewise inhibited. Inhibition of RasGRP3 expression reduced AKT and extracellular signal-regulated kinase 1/2 phosphorylation and sensitized the cells to killing by carboplatin. Conversely, exogenous RasGRP3 elevated Ras-GTP, stimulated proliferation, and provided resistance to phorbol 12-myristate 13-acetate–induced apoptosis in LNCaP cells. RasGRP3-overexpressing LNCaP cells displayed a markedly enhanced rate of xenograft tumor formation in both male and female mice compared with the parental line. Suppression of RasGRP3 expression in these cells inhibited downstream RasGRP3 responses, caused the cells to resume the LNCaP morphology, and suppressed growth, confirming the functional role of RasGRP3 in the altered behavior of these cells. We conclude that RasGRP3 contributes to the malignant phenotype of the prostate cancer cells and may constitute a novel therapeutic target for human prostate cancer. Cancer Res; 70(20); 7905–17. ©2010 AACR.
Data from Myeloid-Derived Suppressor Cells Inhibit T-Cell Activation by Depleting Cystine and Cysteine
Authors: Srivastava Minu K. , Sinha Pratima , Clements Virginia K. , Rodriguez Paulo , Ostrand-Rosenberg Suzanne
Published: March 2024

Abstract
Myeloid-derived suppressor cells (MDSC) are present in most cancer patients and are potent inhibitors of T-cell–mediated antitumor immunity. Their inhibitory activity is attributed to production of arginase, reactive oxygen species, inducible nitric oxide synthase, and interleukin-10. Here we show that MDSCs also block T-cell activation by sequestering cystine and limiting the availability of cysteine. Cysteine is an essential amino acid for T-cell activation because T cells lack cystathionase, which converts methionine to cysteine, and because they do not have an intact xc− transporter and therefore cannot import cystine and reduce it intracellularly to cysteine. T cells depend on antigen-presenting cells (APC), such as macrophages and dendritic cells, to export cysteine, which is imported by T cells via their ASC neutral amino acid transporter. MDSCs express the xc− transporter and import cystine; however, they do not express the ASC transporter and do not export cysteine. MDSCs compete with APC for extracellular cystine, and in the presence of MDSCs, APC release of cysteine is reduced, thereby limiting the extracellular pool of cysteine. In summary, MDSCs consume cystine and do not return cysteine to their microenvironment, thereby depriving T cells of the cysteine they require for activation and function. Cancer Res; 70(1); 68–77
Data from microRNA Signature and Expression of Dicer and Drosha Can Predict Prognosis and Delineate Risk Groups in Neuroblastoma
Authors: Lin Ruey-Jen , Lin You-Chin , Chen Jeremy , Kuo Huan-Hsien , Chen Yuan-Yan , Diccianni Mitchell B. , London Wendy B. , Chang Chih-Hao , Yu Alice L.
Published: March 2024

Abstract
Neuroblastoma is a common childhood tumor and accounts for 15% of pediatric cancer deaths. To investigate the microRNA (miRNA) profile and role of Dicer and Drosha in neuroblastoma, we assessed the expression of 162 human miRNAs, Dicer and Drosha in 66 neuroblastoma tumors by using real-time PCR methods. We found global downregulation of miRNA expression in advanced neuroblastoma and identified 27 miRNAs that can clearly distinguish low- from high-risk patients. Furthermore, expression levels of Dicer or Drosha were low in high-risk neuroblastoma tumors, which accounted for global downregulation of miRNAs in advanced disease and correlated with poor outcome. Notably, for patients with non–MYCN-amplified tumors, low expression of Dicer can serve as a significant and independent predictor of poor outcome (hazard ratio, 9.6; P = 0.045; n = 52). Using plausible neural networks to select a combination of 15 biomarkers that consist of 12 miRNAs' signature, expression levels of Dicer and Drosha, and age at diagnosis, we were able to segregate all patients into four distinct patterns that were highly predictive of clinical outcome. In vitro studies also showed that knockdown of either Dicer or Drosha promoted the growth of neuroblastoma cell lines. Our results reveal that a combination of 15 biomarkers can delineate risk groups of neuroblastoma and serve as a powerful predictor of clinical outcome. Moreover, our findings of growth promotion by silencing Dicer/Drosha implied their potential use as therapeutic targets for neuroblastoma. Cancer Res; 70(20); 7841–50. ©2010 AACR.
Data from Estrogen Suppresses MLK3-Mediated Apoptosis Sensitivity in ER+ Breast Cancer Cells
Authors: Rangasamy Velusamy , Mishra Rajakishore , Mehrotra Suneet , Sondarva Gautam , Ray Rajarshi S. , Rao Arundhati , Chatterjee Malay , Rana Basabi , Rana Ajay
Published: March 2024

Abstract
Little knowledge exists about the mechanisms by which estrogen can impede chemotherapy-induced cell death of breast cancer cells. 17β-Estradiol (E2) hinders cytotoxic drug–induced cell death in estrogen receptor–positive (ER+) breast cancer cells. We noted that the activity of the proapoptotic mixed lineage kinase 3 (MLK3) kinase was relatively higher in estrogen receptor–negative (ER−) breast tumors, suggesting that E2 might inhibit MLK3 activity. The kinase activities of MLK3 and its downstream target, c-Jun NH2-terminal kinase, were rapidly inhibited by E2 in ER+ but not in ER− cells. Specific knockdown of AKT1/2 prevented MLK3 inhibition by E2, indicating that AKT mediated this event. Furthermore, MLK3 inhibition by E2 involved phosphorylation of MLK3 Ser674 by AKT, attenuating the proapoptotic function of MLK3. We found that a pan-MLK inhibitor (CEP-11004) limited Taxol-induced cell death and that E2 accentuated this limitation. Taken together, our findings indicate that E2 inhibits the proapoptotic function of MLK3 as a mechanism to limit cytotoxic drug–induced death of ER+ breast cancer cells. Cancer Res; 70(4); 1731–40
Data from High-Throughput Screening for Salmonella Avirulent Mutants That Retain Targeting of Solid Tumors
Authors: Arrach Nabil , Cheng Pui , Zhao Ming , Santiviago Carlos A. , Hoffman Robert M. , McClelland Michael
Published: March 2024

Abstract
Salmonella has a natural ability to target a wide range of tumors in animal models. However, strains used for cancer therapy have generally been selected only for their avirulence rather than their tumor-targeting ability. To select Salmonella strains that are avirulent and yet efficient in tumor targeting, a necessary criterion for clinical applications, we measured the relative fitness of 41,000 Salmonella transposon insertion mutants growing in mouse models of human prostate and breast cancer. Two classes of potentially safe mutants were identified. Class 1 mutants showed reduced fitness in normal tissues and unchanged fitness in tumors (e.g., mutants in htrA, SPI-2, and STM3120). Class 2 mutants showed reduced fitness in tumors and normal tissues (e.g., mutants in aroA and aroD). In a competitive fitness assay in human PC-3 tumors growing in mice, class 1 mutant STM3120 had a fitness advantage over class 2 mutants aroA and aroD, validating the findings of the initial screening of a large pool of transposon mutants and indicating a potential advantage of class 1 mutants for delivery of cancer therapeutics. In addition, an STM3120 mutant successfully targeted tumors after intragastric delivery, opening up the oral route as an option for therapy administration. Cancer Res; 70(6); 2165–70
Data from Bile Acid Reflux Contributes to Development of Esophageal Adenocarcinoma via Activation of Phosphatidylinositol-Specific Phospholipase Cγ2 and NADPH Oxidase NOX5-S
Authors: Hong Jie , Behar Jose , Wands Jack , Resnick Murray , Wang Li Juan , DeLellis Ronald A. , Lambeth David , Cao Weibiao
Published: March 2024

Abstract
Gastroesophageal reflux disease complicated by Barrett's esophagus (BE) is a major risk factor for esophageal adenocarcinoma (EA). However, the mechanisms of the progression from BE to EA are not fully understood. Besides acid reflux, bile acid reflux may also play an important role in the progression from BE to EA. In this study, we examined the role of phosphatidylinositol-specific phospholipase C (PI-PLC) and a novel NADPH oxidase NOX5-S in bile acid–induced increase in cell proliferation. We found that taurodeoxycholic acid (TDCA) significantly increased NOX5-S expression, hydrogen peroxide (H2O2) production, and cell proliferation in EA cells. The TDCA-induced increase in cell proliferation was significantly reduced by U73122, an inhibitor of PI-PLC. PI-PLCβ1, PI-PLCβ3, PI-PLCβ4, PI-PLCγ1, and PI-PLCγ2, but not PI-PLCβ2 and PI-PLCδ1, were detectable in FLO cells by Western blot analysis. Knockdown of PI-PLCγ2 or extracellular signal-regulated kinase (ERK) 2 mitogen-activated protein (MAP) kinase with small interfering RNAs (siRNA) significantly decreased TDCA-induced NOX5-S expression, H2O2 production, and cell proliferation. In contrast, knockdown of PI-PLCβ1, PI-PLCβ3, PI-PLCβ4, PI-PLCγ1, or ERK1 MAP kinase had no significant effect. TDCA significantly increased ERK2 phosphorylation, an increase that was reduced by U73122 or PI-PLCγ2 siRNA. We conclude that TDCA-induced increase in NOX5-S expression and cell proliferation may depend on sequential activation of PI-PLCγ2 and ERK2 MAP kinase in EA cells. It is possible that bile acid reflux present in patients with BE may increase reactive oxygen species production and cell proliferation via activation of PI-PLCγ2, ERK2 MAP kinase, and NADPH oxidase NOX5-S, thereby contributing to the development of EA. Cancer Res; 70(3); 1247–55
Data from In situ Vaccination Combined with Androgen Ablation and Regulatory T-Cell Depletion Reduces Castration-Resistant Tumor Burden in Prostate-Specific Pten Knockout Mice
Authors: Akins Elizabeth J. , Moore Miranda L. , Tang Shuai , Willingham Mark C. , Tooze Janet A. , Dubey Purnima
Published: March 2024

Abstract
There is no effective treatment for prostate cancer arising after androgen ablation. Previous studies have analyzed the short-term effects of androgen ablation on the immune system and suggest an abatement of immune suppression by hormone removal. Because castration-resistant disease can arise years after treatment, it is crucial to determine the duration of immune potentiation by castration. Because immunotherapeutic efficacy is determined by the balance of immune cell subsets and their location within the tumor, we assessed the acute and chronic effect of androgen ablation on the localization of T-cell subsets within castration-resistant murine prostate cancer. We observed a transient increase in CD4+ and CD8+ T-cell numbers at the residual tumor after androgen ablation. More than 2 months later, regulatory T cells (Treg) were increasingly found within prostate epithelium, whereas CTLs, which were evenly distributed before androgen ablation, became sequestered within stroma. Anti-CD25 antibody administration along with castration enhanced CTL access to cancerous glands but did not increase effector function. Intraprostatic injection of LIGHT-expressing tumor cells increased the proportion of CD8+ T cells with functional capacity within the cancerous gland. In addition, Treg depletion within the tumor was enhanced. Together, these manipulations significantly reduced castration-resistant tumor burden. Thus, our results indicate that immune modulations, which prevent Treg accumulation and augment effector cell infiltration of prostatic epithelium, may be effective in reducing tumor burden or preventing tumor recurrence after androgen ablation therapy. Cancer Res; 70(9); 3473–82. ©2010 AACR.
Data from Caffeine-Mediated Inhibition of Calcium Release Channel Inositol 1,4,5-Trisphosphate Receptor Subtype 3 Blocks Glioblastoma Invasion and Extends Survival
Authors: Kang Sang Soo , Han Kyung-Seok , Ku Bo Mi , Lee Yeon Kyung , Hong Jinpyo , Shin Hye Young , Almonte Antoine G. , Woo Dong Ho , Brat Daniel J. , Hwang Eun Mi , Yoo Seung Hyun , Chung Chun Kee , Park Sung-Hye , Paek Sun Ha , Roh Eun Joo , Lee Sung joong , Park Jae-Yong , Traynelis Stephen F. , Lee C. Justin
Published: March 2024

Abstract
Calcium signaling is important in many signaling processes in cancer cell proliferation and motility including in deadly glioblastomas of the brain that aggressively invade neighboring tissue. We hypothesized that disturbing Ca2+ signaling pathways might decrease the invasive behavior of giloblastoma, extending survival. Evaluating a panel of small-molecule modulators of Ca2+ signaling, we identified caffeine as an inhibitor of glioblastoma cell motility. Caffeine, which is known to activate ryanodine receptors, paradoxically inhibits Ca2+ increase by inositol 1,4,5-trisphospate receptor subtype 3 (IP3R3), the expression of which is increased in glioblastoma cells. Consequently, by inhibiting IP3R3-mediated Ca2+ release, caffeine inhibited migration of glioblastoma cells in various in vitro assays. Consistent with these effects, caffeine greatly increased mean survival in a mouse xenograft model of glioblastoma. These findings suggest IP3R3 as a novel therapeutic target and identify caffeine as a possible adjunct therapy to slow invasive growth of glioblastoma. Cancer Res; 70(3); 1173–83
Data from Activation of Endothelial Ras Signaling Bypasses Senescence and Causes Abnormal Vascular Morphogenesis
Authors: Bajaj Anshika , Zheng Qingxia , Adam Alejandro , Vincent Peter , Pumiglia Kevin
Published: March 2024

Abstract
Angiogenesis is crucial for embryogenesis, reproduction, and wound healing and is a critical determinant of tumor growth and metastasis. The multifunctional signal transducer Ras is a proto-oncogene and frequently becomes mutated in a variety of human cancers, including angiosarcomas. Regulation of Ras is important for endothelial cell function and angiogenesis. Hyperactivation of Ras is linked with oncogene-induced senescence in many cell types. Given links between vascular malformations and angiosarcoma with activated Ras signaling, we sought to determine the consequence of sustained Ras activation on endothelial cell function. We find that sustained Ras activation in primary endothelial cells leads to prolonged activation of progrowth signaling, accompanied by a senescence bypass, enhanced proliferation, autonomous growth, and increased survival. Moreover, Ras severely compromises the ability of these cells to organize into vascular structures, instead promoting formation of planar endothelial sheets. This abnormal phenotype is regulated by phosphoinositide 3-kinase signaling, highlighting the therapeutic potential of agents targeting this axis in dealing with vascular morphogenic disorders and vascular normalization of tumors. Cancer Res; 70(9); 3803–12. ©2010 AACR.
Data from EWS/FLI1 Oncogene Activates Caspase 3 Transcription and Triggers Apoptosis In vivo
Authors: Sohn Eun Jung , Li Hongjie , Reidy Karen , Beers Lisa F. , Christensen Barbara L. , Lee Sean Bong
Published: March 2024

Abstract
EWS/FLI1 is a fusion gene product generated by a chromosomal translocation t(11;22)(q24;q12) found in Ewing sarcoma. EWS/FLI1 encodes an aberrant transcription factor with oncogenic properties in vitro. Paradoxically, expression of EWS/FLI1 in nontransformed primary cells results in apoptosis, but the exact mechanism remains unclear. In primary mouse embryonic fibroblasts derived from conditional EWS/FLI1 knock-in embryos, expression of EWS/FLI1 resulted in apoptosis with concomitant increase in the endogenous Caspase 3 (Casp3) mRNA. EWS/FLI1 directly bound and activated the CASP3 promoter, whereas small interfering RNA–mediated knockdown of EWS/FLI1 led to a marked decrease in CASP3 transcripts in Ewing sarcoma cell lines. Ectopic expression of EWS/FLI1 resulted in an increased expression of CASP3 protein in heterologous cell lines. Importantly, expression of EWS/FLI1 in the mouse triggered an early onset of apoptosis in kidneys and acute lethality. These findings suggest that EWS/FLI1 induces apoptosis, at least partially, through the activation of CASP3 and show the cell context–dependent roles of EWS/FLI1 in apoptosis and tumorigenesis. Cancer Res; 70(3); 1154–63
Data from Downregulation of Rap1GAP through Epigenetic Silencing and Loss of Heterozygosity Promotes Invasion and Progression of Thyroid Tumors
Authors: Zuo Hui , Gandhi Manoj , Edreira Martin M. , Hochbaum Daniel , Nimgaonkar Vishwajit L. , Zhang Ping , DiPaola James , Evdokimova Viktoria , Altschuler Daniel L. , Nikiforov Yuri E.
Published: March 2024

Abstract
Thyroid cancer is the most common type of endocrine malignancy, encompassing tumors with various levels of invasive growth and aggressiveness. Rap1GAP, a Rap1 GTPase-activating protein, inhibits the RAS superfamily protein Rap1 by facilitating hydrolysis of GTP to GDP. In this study, we analyzed 197 thyroid tumor samples and showed that Rap1GAP was frequently lost or downregulated in various types of tumors, particularly in the most invasive and aggressive forms of thyroid cancer. The downregulation was due to promoter hypermethylation and/or loss of heterozygosity, found in the majority of thyroid tumors. Treatment with demethylating agent 5-aza-deoxycytidine and/or histone deacetylation inhibitor trichostatin A induced gene reexpression in thyroid cells. A genetic polymorphism, Y609C, was seen in 7% of thyroid tumors but was not related to gene downregulation. Loss of Rap1GAP expression correlated with tumor invasiveness but not with specific mutations activating the mitogen-activated protein kinase pathway. Rap1GAP downregulation was required in vitro for cell migration and Matrigel invasion. Recovery of Rap1GAP expression inhibited thyroid cell proliferation and colony formation. Overall, our findings indicate that epigenetic or genetic loss of Rap1GAP is very common in thyroid cancer, where these events are sufficient to promote cell proliferation and invasion. Cancer Res; 70(4); 1389–97
Data from Cyr61 Mediates Hepatocyte Growth Factor–Dependent Tumor Cell Growth, Migration, and Akt Activation
Authors: Goodwin C. Rory , Lal Bachchu , Zhou Xin , Ho Sandra , Xia Shuli , Taeger Alexandra , Murray Jamie , Laterra John
Published: March 2024

Abstract
Certain tumor cell responses to the growth factor–inducible early response gene product CCN1/Cyr61 overlap with those induced by the hepatocyte growth factor (HGF)/c-Met signaling pathway. In this study, we investigate if Cyr61 is a downstream effector of HGF/c-Met pathway activation in human glioma cells. A semiquantitative immunohistochemical analysis of 112 human glioma and normal brain specimens showed that levels of tumor-associated Cyr61 protein correlate with tumor grade (P < 0.001) and with c-Met protein expression (r2 = 0.4791, P < 0.0001). Purified HGF rapidly upregulated Cyr61 mRNA (peak at 30 minutes) and protein expression (peak at 2 hours) in HGF−/c-Met+ human glioma cell lines via a transcription- and translation-dependent mechanism. Conversely, HGF/c-Met pathway inhibitors reduced Cyr61 expression in HGF+/c-Met+ human glioma cell lines in vitro and in HGF+/c-Met+ glioma xenografts. Targeting Cyr61 expression with small interfering RNA (siRNA) inhibited HGF-induced cell migration (P < 0.01) and cell growth (P < 0.001) in vitro. The effect of Cyr61 on HGF-induced Akt pathway activation was also examined. Cyr61 siRNA had no effect on the early phase of HGF-induced Akt phosphorylation (Ser473) 30 minutes after stimulation with HGF. Cyr61 siRNA inhibited a second phase of Akt phosphorylation measured 12 hours after cell stimulation with HGF and also inhibited HGF-induced phosphorylation of the Akt target glycogen synthase kinase 3α. We treated preestablished subcutaneous glioma xenografts with Cyr61 siRNA or control siRNA by direct intratumoral delivery. Cyr61 siRNA inhibited Cyr61 expression and glioma xenograft growth by up to 40% in a dose-dependent manner (P < 0.05). These results identify a Cyr61-dependent pathway by which c-Met activation mediates cell growth, cell migration, and long-lasting signaling events in glioma cell lines and possibly astroglial malignancies. Cancer Res; 70(7); 2932–41
Data from Phase I Assessment of New Mechanism-Based Pharmacodynamic Biomarkers for MLN8054, a Small-Molecule Inhibitor of Aurora A Kinase
Authors: Chakravarty Arijit , Shinde Vaishali , Tabernero Josep , Cervantes Andres , Cohen Roger B. , Dees E. Claire , Burris Howard , Infante Jeffrey R. , Macarulla Teresa , Elez Elena , Andreu Jordi , Rodriguez-Braun Edith , Rosello Susana , von Mehren Margaret , Meropol Neal J. , Langer Corey J. , ONeil Bert , Bowman Douglas , Zhang Mengkun , Danaee Hadi , Faron-Yowe Laura , Gray Gary , Liu Hua , Pappas Jodi , Silverman Lee , Simpson Chris , Stringer Bradley , Tirrell Stephen , Veiby Ole Petter , Venkatakrishnan Karthik , Galvin Katherine , Manfredi Mark , Ecsedy Jeffrey A.
Published: March 2024

Abstract
The mitotic kinase Aurora A is an important therapeutic target for cancer therapy. This study evaluated new mechanism-based pharmacodynamic biomarkers in cancer patients in two phase I studies of MLN8054, a small-molecule inhibitor of Aurora A kinase. Patients with advanced solid tumors received MLN8054 orally for 7 consecutive days in escalating dose cohorts, with skin and tumor biopsies obtained before and after dosing. Skin biopsies were evaluated for increased mitotic cells within the basal epithelium. Tumor biopsies were assessed for accumulation of mitotic cells within proliferative tumor regions. Several patients in the highest dose cohorts showed marked increases in the skin mitotic index after dosing. Although some tumors exhibited increases in mitotic cells after dosing, others displayed decreases, a variable outcome consistent with dual mechanisms of mitotic arrest and mitotic slippage induced by antimitotics in tumors. To provide a clearer picture, mitotic cell chromosome alignment and spindle bipolarity, new biomarkers of Aurora A inhibition that act independently of mitotic arrest or slippage, were assessed in the tumor biopsies. Several patients, primarily in the highest dose cohorts, had marked decreases in the percentage of mitotic cells with aligned chromosomes and bipolar spindles after dosing. Evidence existed for an exposure–effect relationship for mitotic cells with defects in chromosome alignment and spindle bipolarity that indicated a biologically active dose range. Outcomes of pharmacodynamic assays from skin and tumor biopsies were concordant in several patients. Together, these new pharmacodynamic assays provide evidence for Aurora A inhibition by MLN8054 in patient skin and tumor tissues. Cancer Res; 71(3); 675–85. ©2010 AACR.
Data from Comprehensive Pathway-Based Association Study of DNA Repair Gene Variants and the Risk of Nasopharyngeal Carcinoma
Authors: Qin Hai-De , Shugart Yin Yao , Bei Jin-Xin , Pan Qing-Hua , Chen Lina , Feng Qi-Sheng , Chen Li-Zhen , Huang Wei , Liu Jian Jun , Jorgensen Timothy J. , Zeng Yi-Xin , Jia Wei-Hua
Published: March 2024

Abstract
DNA repair plays a central role in protecting against environmental carcinogenesis, and genetic variants of DNA repair genes have been reported to be associated with several human malignancies. To assess whether DNA gene variants were associated with nasopharyngeal carcinoma (NPC) risk, a candidate gene association study was conducted among the Cantonese population within the Guangdong Province, China, the ethnic group with the highest risk for NPC. A 2-stage study design was utilized. In the discovery stage, 676 tagging SNPs covering 88 DNA repair genes were genotyped in a matched case-control study (cases/controls = 755/755). Eleven SNPs with Ptrend < 0.01 were identified. Seven of these SNPs were located within 3 genes, RAD51L1, BRCA2, and TP53BP1. In the validation stage, these 11 SNPs were genotyped in a separate Cantonese population (cases/controls = 1,568/1,297). Two of the SNPs (rs927220 and rs11158728), both in RAD51L1, remained strongly associated with NPC. The SNP rs927220 had a significant Pcombined of 5.55 × 10−5, with OR = 1.20 (95% CI = 1.10–1.30), Bonferroni corrected P = 0.0381. The other SNP (rs11158728), which is in strong linkage disequilibrium with rs927220 (r2 = 0.7), had a significant Pcombined of 2.0 × 10−4, Bonferroni corrected P = 0.1372. Gene–environment interaction analysis suggested that the exposures of salted fish consumption and cigarette smoking had potential interactions with DNA repair gene variations, but need to be further investigated. Our findings support the notion that DNA repair genes, in particular RAD51L1, play a role in NPC etiology and development. Cancer Res; 71(8); 3000–8. ©2011 AACR.
Data from PSF1, a DNA Replication Factor Expressed Widely in Stem and Progenitor Cells, Drives Tumorigenic and Metastatic Properties
Authors: Nagahama Yumi , Ueno Masaya , Miyamoto Satoru , Morii Eiichi , Minami Takashi , Mochizuki Naoki , Saya Hideyuki , Takakura Nobuyuki
Published: March 2024

Abstract
PSF1 (partner of sld five 1) is an evolutionarily conserved DNA replication factor implicated in DNA replication in lower species that is strongly expressed in a wide range of normal stem cell populations and progenitor cell populations. Because stem and progenitor cells possess high proliferative capacity, we hypothesized that PSF1 may play an important role in tumor growth. To begin to investigate PSF1 function in cancer cells, we cloned the mouse PSF1 promoter and generated lung and colon carcinoma cells that stably express a PSF1 promoter-reporter gene. Reporter expression in cells correlated with endogenous PSF1 mRNA expression. In a tumor cell xenograft model, high levels of reporter expression correlated with high proliferative activity, serial transplantation potential, and metastatic capability. Notably, cancer cells expressing reporter levels localized to perivascular regions in tumors and displayed expression signatures related to embryonic stem cells. RNAi-mediated silencing of endogenous PSF1 inhibited cancer cell growth by disrupting DNA synthesis and chromosomal segregation. These findings implicate PSF1 in tumorigenesis and offer initial evidence of its potential as a theranostic target. Cancer Res; 70(3); 1215–24
Data from NOTCH Signaling Is Required for Formation and Self-Renewal of Tumor-Initiating Cells and for Repression of Secretory Cell Differentiation in Colon Cancer
Authors: Sikandar Shaheen S. , Pate Kira T. , Anderson Scott , Dizon Diana , Edwards Robert A. , Waterman Marian L. , Lipkin Steven M.
Published: March 2024

Abstract
NOTCH signaling is critical for specifying the intestinal epithelial cell lineage and for initiating colorectal adenomas and colorectal cancers (CRC). Based on evidence that NOTCH is important for the maintenance and self-renewal of cancer-initiating cells in other malignancies, we studied the role of NOTCH signaling in colon cancer–initiating cells (CCIC). Tumors formed by CCICs maintain many properties of the primary CRCs from which they were derived, such as glandular organization, cell polarity, gap junctions, and expression of characteristic CRC molecular markers. Furthermore, CCICs have the property of self-renewal. In this study, we show that NOTCH signaling is 10- to 30-fold higher in CCIC compared with widely used colon cancer cell lines. Using small-molecule inhibition and short hairpin RNA knockdown, we show that NOTCH prevents CCIC apoptosis through repression of cell cycle kinase inhibitor p27 and transcription factor ATOH1. NOTCH is also critical to intrinsic maintenance of CCIC self-renewal and the repression of secretory cell lineage differentiation genes such as MUC2. Our findings describe a novel human cell system to study NOTCH signaling in CRC tumor initiation and suggest that inhibition of NOTCH signaling may improve CRC chemoprevention and chemotherapy. Cancer Res; 70(4); 1469–78
Data from Lactate Dehydrogenase B Is Critical for Hyperactive mTOR-Mediated Tumorigenesis
Authors: Zha Xiaojun , Wang Fang , Wang Ying , He Shaozong , Jing Yanling , Wu Xueyan , Zhang Hongbing
Published: March 2024

Abstract
Mammalian target of rapamycin (mTOR) is a major downstream effector of the receptor tyrosine kinase (RTK)–phosphoinositide 3-kinase (PI3K)–v-akt murine thymoma viral oncogene homologue 1 (AKT) signaling pathway. Although this signaling network is frequently altered in cancer, the underlying mechanisms that cause tumorigenesis as a result of activated mTOR remain largely unknown. We report here that expression of lactate dehydrogenase B (LDHB), a critical enzymatic activator of glycolysis, was upregulated in an mTOR-dependent manner in TSC1−/−, TSC2−/−, PTEN−/−, or activated AKT1-expressing mouse embryonic fibroblasts (MEF). LDHB gene expression was transactivated by signal transducer and activator of transcription 3 (STAT3), a key tumorigenic driver in many cancers, acting as a downstream mTOR effector in both mouse MEFs and human cancer cells. LDHB attenuation blunted the tumorigenic potential of oncogenic TSC2-null cells in nude mice. We concluded that LDHB is a downstream target of mTOR that is critical for oncogenic mTOR-mediated tumorigenesis. Our findings offer proof of concept for targeting LDHB as a therapeutic strategy in cancers driven by aberrant activation of the RTK-PI3K-AKT-mTOR signaling cascade. Cancer Res; 71(1); 13–8. ©2011 AACR.
Data from Variability in the Androgen Response of Prostate Epithelium to 5α-Reductase Inhibition: Implications for Prostate Cancer Chemoprevention
Authors: Mostaghel Elahe A. , Geng Linda , Holcomb Ilona , Coleman Ilsa M. , Lucas Jared , True Lawrence D. , Nelson Peter S.
Published: March 2024

Abstract
Inhibitors of 5α-reductase (SRD5A) that lower intraprostatic levels of dihydrotestosterone (DHT) reduce the overall incidence of prostate cancer (PCa), but there is significant variation in chemopreventive activity between individual men. In seeking molecular alterations that might underlie this variation, we compared gene expression patterns in patients with localized PCa who were randomized to prostatectomy alone versus treatment with two different doses of the SRD5A inhibitor dutasteride. Prostatic levels of DHT were decreased by >90% in both dutasteride-treated patient groups versus the untreated patient group. Despite significant and uniform suppression of tissue DHT, unsupervised clustering based on prostatic gene expression did not discriminate these groups. However, subjects could be resolved into distinct cohorts characterized by high or low expression of genes regulated by the androgen receptor (AR), based solely on AR transcript expression. The higher-dose dutasteride treatment group was found to include significantly fewer cancers with TMPRSS2-ERG genetic fusions. Dutasteride treatment was associated with highly variable alterations in benign epithelial gene expression. Segregating subjects based on expression of AR and androgen-regulated genes revealed that patients are differentially sensitive to SRD5A inhibition. Our findings suggest that AR levels may predict the chemopreventive efficacy of SRD5A inhibitors. Cancer Res; 70(4); 1286–95
Data from miR-31 Ablates Expression of the HIF Regulatory Factor FIH to Activate the HIF Pathway in Head and Neck Carcinoma
Authors: Liu Chung-Ji , Tsai Meng-Miao , Hung Pei-Shih , Kao Shou-Yen , Liu Tsung-Yun , Wu Kou-Juey , Chiou Shih-Hwa , Lin Shu-Chun , Chang Kuo-Wei
Published: March 2024

Abstract
MicroRNAs (miRNA) are endogenously expressed noncoding RNAs with important biological and pathological functions that are yet to be fully defined. This study investigated alterations in miRNA expression in head and neck squamous cell carcinoma (HNSCC), the incidence of which is rising throughout the world. Initial screening and subsequent analysis identified a panel of aberrantly expressed miRNAs in HNSCC tissues, with miR-31 among the most markedly upregulated. Ectopic expression of miR-31 increased the oncogenic potential of HNSCC cells under normoxic conditions in cell culture or tumor xenografts. Conversely, blocking miR-31 expression reduced the growth of tumor xenografts. The in silico analysis suggested that miR-31 may target the 3′ untranslated region (UTR) of factor-inhibiting hypoxia-inducible factor (FIH), a hypoxia-inducible factor (HIF) regulatory factor that inhibits the ability of HIF to act as a transcriptional regulator under normoxic conditions. In support of this likelihood, miR-31 expression repressed FIH expression and mutations within the predictive miR-31 target site in the FIH 3′ UTR abrogated FIH repression. Furthermore, miR-31 expression increased HIF transactivation activity. We found that FIH suppressed oncogenic phenotypes under normoxic conditions and that this activity was abrogated by functional mutations. Lastly, increased miR-31 expression was correlated with decreased levels of FIH in tumor tissues. Our findings suggest that miR-31 contributes to the development of HNSCC by impeding FIH to activate HIF under normoxic conditions. Cancer Res; 70(4); 1635–44