bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Downregulation of MicroRNA miR-520h by E1A Contributes to Anticancer Activity
Authors: Su Jen-Liang , Chen Poshen B. , Chen Ya-Huey , Chen Shang-Chih , Chang Yi-Wen , Jan Yi-Hua , Cheng Xiaoyun , Hsiao Michael , Hung Mien-Chie
Published: March 2024

Abstract
The leading cause of death in cancer patients is cancer metastasis, for which there is no effective treatment. MicroRNAs (miRNA) have been shown to play a significant role in cancer metastasis through regulation of gene expression. The adenovirus type 5 E1A (E1A) is associated with multiple tumor-suppressing activities including the inhibition of metastasis, and E1A gene therapies have been tested in several clinical trials. However, the mechanisms involved in E1A-mediated tumor-suppressing activities are not yet completely defined. Here, we showed that E1A downregulated the expression of the miRNA miR-520h, which was critical for E1A-mediated cancer cell mobility and in vitro invasion activity. In addition, we identified a signal cascade, namely, E1A→miRNA-520h→PP2A/C→IκB kinase→NF-κB→Twist, in which E1A inhibited the expression of Twist through downregulation of miR-520h and the signal cascade. Our results indicated a functional link between miR-520h and tumorigenicity/invasive ability and provided a new insight into the role of E1A-mediated miRNA regulation in tumor suppression. Therefore, the results identified a new cascade of E1A-mediated tumor suppression activity via downregulation of miRNA-520h expression. Cancer Res; 70(12); 5096–108. ©2010 AACR.
Data from Targeting Wild-Type and Mutant p53 with Small Molecule CP-31398 Blocks the Growth of Rhabdomyosarcoma by Inducing Reactive Oxygen Species–Dependent Apoptosis
Authors: Xu Jianmin , Timares Laura , Heilpern Clay , Weng Zhiping , Li Changzhao , Xu Hui , Pressey Joseph G. , Elmets Craig A. , Kopelovich Levy , Athar Mohammad
Published: March 2024

Abstract
Rhabdomyosarcoma (RMS) is a common soft-tissue sarcoma of childhood in need of more effective therapeutic options. The expression of p53 in RMS is heterogeneous such that some tumors are wild-type whereas others are p53 mutant. The small molecule CP-31398 modulates both the wild-type and the mutant p53 proteins. Here, we show that CP-31398 blocks the growth of RMS cells that have either wild-type or mutant p53 status. In wild-type A204 cells, CP-31398 increased the expression of p53 and its downstream transcriptional targets, p21 and mdm2; enhanced the expression of apoptosis-related proteins; and reduced proliferation biomarkers. Flow profiling of CP-31398–treated cells indicated an enhancement in sub-G0 and G1 populations. CP-31398 inhibited proliferation in a manner associated with co-induction of SOX9 and p21. Apoptosis induced by CP-31398 occurred with translocation of p53 to mitochondria, leading to altered mitochondrial membrane potential, cytochrome c release, and reactive oxygen species release. In vivo, CP-31398 decreased the growth of tumor xenografts composed of wild-type or mutant p53 tumor cells, increasing tumor-free host survival. Our findings indicate that the ability of CP-31398 to modulate wild-type and mutant p53 results in the inhibition of RMS growth and invasiveness. Cancer Res; 70(16); 6566–76. ©2010 AACR.
Data from TP53 Cancerous Mutations Exhibit Selection for Translation Efficiency
Authors: Waldman Yedael Y. , Tuller Tamir , Sharan Roded , Ruppin Eytan
Published: March 2024

Abstract
The tumor suppressor gene TP53 is known to be a key regulator in cancer, and more than half of human cancers exhibit mutations in this gene. Recent evidence shows that point mutations in TP53 not only disrupt its function but also possess gain-of-function and dominant-negative effects on wild-type copies, thus making the mutated gene an oncogene. Hence, this brings about the possibility that TP53 mutations may be under selection for increasing the overall translation efficiency (TE) of defected TP53 in cancerous cells. Here, we perform the first large-scale analysis of TE in human cancer mutated TP53 variants, identifying a significant increase in TE that is correlated with the frequency of TP53 mutations. Furthermore, mutations with a known oncogenic effect significantly increase their TE compared with the other TP53 mutations. Further analysis shows that TE may have influence both on selecting the location of the mutation and on its outcome: codons with lower TE show stronger selection toward nonsynonymous mutations and, for each codon, frequent mutations show stronger increase in TE compared with less frequent mutations. Additionally, we find that TP53 mutations have significantly higher TE increase in progressive versus primary tumors. Finally, an analysis of TP53 NCI-60 cell lines points to a coadaptation between the mutations and the tRNA pool, increasing the overall TP53 TE. Taken together, these results show that TE plays an important role in the selection of TP53 cancerous mutations. [Cancer Res 2009;69(22):8807–13]
Data from Disulfiram Treatment Facilitates Phosphoinositide 3-Kinase Inhibition in Human Breast Cancer Cells In vitro and In vivo
Authors: Zhang Haijun , Chen Di , Ringler Jonathan , Chen Wei , Cui Qiuzhi Cindy , Ethier Stephen P. , Dou Q. Ping , Wu Guojun
Published: March 2024

Abstract
Frequent genetic alterations of the components in the phosphoinositide 3-kinase (PI3K)/PTEN/AKT signaling pathway contribute greatly to breast cancer initiation and progression, which makes targeting this signaling pathway a promising therapeutic strategy for breast cancer treatment. In this study, we showed that in the presence of copper (Cu), disulfiram (DSF), a clinically used antialcoholism drug, could potently inhibit breast cancer cell growth regardless of the PIK3CA status. Surprisingly, the treatment with a mixture of DSF and copper (DSF-Cu) led to the decreased expression of PTEN protein and the activation of AKT in a dose- and time-dependent manner in different cell lines with or without PIK3CA mutations. Treatment of breast cancer cell lines with a combination of DSF-Cu and LY294002, a pan-PI3K inhibitor, resulted in the significant inhibition of cell growth when compared with either drug alone. In addition, the combined treatment of DSF and LY294002 significantly inhibited the growth of the breast tumor xenograft in nude mice induced by MDA-MB-231 cells expressing mutant PIK3CA-H1047R and PIK3CA-E545K, whereas neither DSF nor LY294002 alone could significantly retard tumor growth. Finally, the observed in vivo inhibitory effects are found associated with aberrant signaling alterations and apoptosis-inducing activities in tumor samples. Thus, our finding shows for the first time that treatment of breast cancer with DSF results in a novel feedback mechanism that activates AKT signaling. Our study also suggests that the combination of DSF and a PI3K inhibitor may offer a new combinational treatment model for breast cancer, particularly for those with PIK3CA mutations. Cancer Res; 70(10); 3996–4004. ©2010 AACR.
Data from Systems Biologists Seek Fuller Integration of Systems Biology Approaches in New Cancer Research Programs
Authors: Wolkenhauer Olaf , Auffray Charles , Baltrusch Simone , Blüthgen Nils , Byrne Helen , Cascante Marta , Ciliberto Andrea , Dale Trevor , Drasdo Dirk , Fell David , Ferrell James E. , Gallahan Daniel , Gatenby Robert , Günther Ulrich , Harms Brian D. , Herzel Hanspeter , Junghanss Christian , Kunz Manfred , van Leeuwen Ingeborg , Lenormand Philippe , Levi Francis , Linnebacher Michael , Lowengrub John , Maini Philip K. , Malik Arif , Rateitschak Katja , Sansom Owen , Schäfer Reinhold , Schürrle Karsten , Sers Christine , Schnell Santiago , Shibata Darryl , Tyson John , Vera Julio , White Michael , Zhivotovsky Boris , Jaster Robert
Published: March 2024

Abstract
Systems biology takes an interdisciplinary approach to the systematic study of complex interactions in biological systems. This approach seeks to decipher the emergent behaviors of complex systems rather than focusing only on their constituent properties. As an increasing number of examples illustrate the value of systems biology approaches to understand the initiation, progression, and treatment of cancer, systems biologists from across Europe and the United States hope for changes in the way their field is currently perceived among cancer researchers. In a recent EU-US workshop, supported by the European Commission, the German Federal Ministry for Education and Research, and the National Cancer Institute of the NIH, the participants discussed the strengths, weaknesses, hurdles, and opportunities in cancer systems biology. Cancer Res; 70(1); 12–3
Data from Oncogenic Ras Promotes Reovirus Spread by Suppressing IFN-β Production through Negative Regulation of RIG-I Signaling
Authors: Shmulevitz Maya , Pan Lu-Zhe , Garant Katy , Pan Da , Lee Patrick W.K.
Published: March 2024

Abstract
Reovirus is the first naturally occurring human virus reported to exploit activated Ras signaling in the host cell for infection, and is currently undergoing clinical trials as a cancer therapeutic. Recent evidence suggests that Ras transformation promotes three reoviral replication steps during the first round of infection: uncoating of the incoming virion, generation of progeny viruses with enhanced infectivity, and virus release through enhanced apoptosis. Whether oncogenic Ras also enhances reovirus spread in subsequent rounds of infection through other mechanisms has not been examined. Here, we show that compared with nontransformed cells, Ras-transformed cells are severely compromised not only in their response to IFN-β, but also in the induction of IFN-β mRNA following reovirus infection. Defects in both IFN-β production and response allow for efficient virus spread in Ras-transformed cells. We show that the MEK/ERK pathway downstream of Ras is responsible for inhibiting IFN-β expression by blocking signaling from the retinoic acid–inducible gene I (RIG-I) which recognizes viral RNAs. Overexpression of wild-type RIG-I restores INF-β expression in reovirus-infected Ras-transformed cells. In vitro–synthesized viral mRNAs also invoke robust RIG-I–mediated IFN-β production in transfected nontransformed cells, but not in Ras-transformed cells. Collectively, our data suggest that oncogenic Ras promotes virus spread by suppressing viral RNA–induced IFN-β production through negative regulation of RIG-I signaling. Cancer Res; 70(12); 4912–21. ©2010 AACR.
Data from Paradoxical Dependencies of Tumor Dormancy and Progression on Basic Cell Kinetics
Authors: Enderling Heiko , Anderson Alexander R.A. , Chaplain Mark A.J. , Beheshti Afshin , Hlatky Lynn , Hahnfeldt Philip
Published: March 2024

Abstract
Even after a tumor is established, it can early on enter a state of dormancy marked by balanced cell proliferation and cell death. Disturbances to this equilibrium may affect cancer risk, as they may cause the eventual lifetime clinical presentation of a tumor that might otherwise have remained asymptomatic. Previously, we showed that cell death, proliferation, and migration can play a role in shifting this dynamic, making the understanding of their combined influence on tumor development essential. We developed an individual cell-based computer model of the interaction of cancer stem cells and their nonstem progeny to study early tumor dynamics. Simulations of tumor growth show that three basic components of tumor growth—cell proliferation, migration, and death—combine in unexpected ways to control tumor progression and, thus, clinical cancer risk. We show that increased proliferation capacity in nonstem tumor cells and limited cell migration overall lead to space constraints that inhibit proliferation and tumor growth. By contrast, increasing the rate of cell death produces the expected tumor size reduction in the short term, but results ultimately in paradoxical accelerated long-term growth owing to the liberation of cancer stem cells and formation of self-metastases.[Cancer Res 2009;69(22):8814–21]
Data from Recruitment of Myeloid but not Endothelial Precursor Cells Facilitates Tumor Regrowth after Local Irradiation
Authors: Kozin Sergey V. , Kamoun Walid S. , Huang Yuhui , Dawson Michelle R. , Jain Rakesh K. , Duda Dan G.
Published: March 2024

Abstract
Tumor neovascularization and growth might be promoted by the recruitment of bone marrow–derived cells (BMDC), which include endothelial precursor cells and “vascular modulatory” myelomonocytic (CD11b+) cells. BMDCs may also drive tumor regrowth after certain chemotherapeutic and vascular disruption treatments. In this study, we evaluated the role of BMDC recruitment in breast and lung carcinoma xenograft models after local irradiation (LI). We depleted the bone marrow by including whole-body irradiation (WBI) of 6 Gy as part of a total tumor dose of 21 Gy, and compared the growth delay with the one achieved after LI of 21 Gy. In both models, the inclusion of WBI induced longer tumor growth delays. Moreover, WBI increased lung tumor control probability by LI. Exogenous delivery of BMDCs from radiation-naïve donors partially abrogated the WBI effect. Myeloid BMDCs, primarily macrophages, rapidly accumulated in tumors after LI. Intratumoral expression of stromal-derived factor 1α (SDF-1α), a chemokine that promotes tissue retention of BMDCs, was noted 2 days after LI. Conversely, treatment with an inhibitor of SDF-1α receptor CXCR4 (AMD3100) with LI significantly delayed tumor regrowth. However, when administered starting from 5 days post-LI, AMD3100 treatment was ineffective. Lastly, with restorative bone marrow transplantation of Tie2-GFP–labeled BMDC population, we observed an increased number of monocytes but not endothelial precursor cells in tumors that recurred following LI. Our results suggest that an increase in intratumoral SDF-1α triggered by LI recruits myelomonocytes/macrophages which promotes tumor regrowth. Cancer Res; 70(14); 5679–85. ©2010 AACR.
Data from Suppression of Casein Kinase 1α in Melanoma Cells Induces a Switch in β-Catenin Signaling to Promote Metastasis
Authors: Sinnberg Tobias , Menzel Moritz , Kaesler Susanne , Biedermann Tilo , Sauer Birgit , Nahnsen Sven , Schwarz Michael , Garbe Claus , Schittek Birgit
Published: March 2024

Abstract
Casein kinase 1 α (CK1α) is a multifunctional Ser/Thr kinase that phosphorylates several substrates. Among those is β-catenin, an important player in cell adhesion and Wnt signaling. Phosphorylation of β-catenin by CK1α at Ser45 is the priming reaction for the proteasomal degradation of β-catenin. Interestingly, aside from this role in β-catenin degradation, very little is known about the expression and functional role of CK1α in tumor cells. Here, we show that CK1α expression in different tumor types is either strongly suppressed or completely lost during tumor progression and that CK1α is a key factor determining β-catenin stability and transcriptional activity in tumor cells. CK1α reexpression in metastatic melanoma cells reduces growth in vitro and metastasis formation in vivo, and induces cell cycle arrest and apoptosis, whereas suppression of CK1α in primary melanoma cells induces invasive tumor growth. Inactivation of CK1α promotes tumor progression by regulating a switch in β-catenin–mediated signaling. These results show that melanoma cells developed an efficient new mechanism to activate the β-catenin signaling pathway and define CK1α as a novel tumor suppressor. Cancer Res; 70(17); 6999–7009. ©2010 AACR.
Data from Reprogramming Human Cancer Cells in the Mouse Mammary Gland
Authors: Bussard Karen M. , Boulanger Corinne A. , Booth Brian W. , Bruno Robert D. , Smith Gilbert H.
Published: March 2024

Abstract
The tissue microenvironment directs stem/progenitor cell behavior. Cancer cells are also influenced by the microenvironment. It has been shown that, when placed into blastocysts, cancer cells respond to embryonic cues and differentiate according to the tissue type encountered during ontological development. Previously, we showed that the mouse mammary gland was capable of redirecting adult mouse testicular and neural stem/progenitor cells toward a mammary epithelial cell fate during gland regeneration. Here, we report that human embryonal carcinoma cells proliferate and produce differentiated mammary epithelial cell progeny when mixed with mouse mammary epithelial cells and inoculated into the epithelium-free mammary fat pads of athymic nude mice. Fluorescence in situ hybridization confirmed the presence of human cell progeny in the mammary outgrowths for human centromeric DNA, as well as immunochemistry for human-specific breast epithelial cytokeratins and human-specific milk proteins in impregnated transplant hosts. It was found that the number of human cells increased by 66- to 660-fold during mammary epithelial growth and expansion as determined by human cytokeratin expression. All features found in primary outgrowths were recapitulated in the secondary outgrowths from chimeric implants. These results show that human embryonal carcinoma–derived progeny interact with mouse mammary cells during mammary gland regeneration and are directed to differentiate into cells that exhibit diverse mammary epithelial cell phenotypes. This is the first demonstration that human cells are capable of recognizing the signals generated by the mouse mammary gland microenvironment present during gland regeneration in vivo. Cancer Res; 70(15); 6336–43. ©2010 AACR.
Data from miRNA-96 Suppresses KRAS and Functions as a Tumor Suppressor Gene in Pancreatic Cancer
Authors: Yu Shuangni , Lu Zhaohui , Liu Changzheng , Meng Yunxiao , Ma Yihui , Zhao Wugan , Liu Jianping , Yu Jia , Chen Jie
Published: March 2024

Abstract
Therapeutic applications of microRNA (miRNA) in KRAS-driven pancreatic cancers might be valuable, but few studies have explored this area. Here, we report that miR-96 directly targets the KRAS oncogene and functions as a tumor-suppressing miRNA in pancreatic cancer cells. Ectopic expression of miR-96 through a synthetic miRNA precursor inhibited KRAS, dampened Akt signaling, and triggered apoptosis in cells. In human clinical specimens, miR-96 was downregulated or deleted where an association with KRAS elevations was observed. In vitro and in vivo assays established that miR-96 decreased cancer cell invasion and migration and slowed tumor growth in a manner associated with KRAS downregulation. Our findings identify miR-96 as a potent regulator of KRAS, which may provide a novel therapeutic strategy for treatment of pancreatic cancer and other KRAS-driven cancers. Cancer Res; 70(14); 6015–25. ©2010 AACR.
Data from Deficiency of pRb Family Proteins and p53 in Invasive Urothelial Tumorigenesis
Authors: He Feng , Mo Lan , Zheng Xiao-Yong , Hu Changkun , Lepor Herbert , Lee Eva Y-H.P. , Sun Tung-Tien , Wu Xue-Ru
Published: March 2024

Abstract
Defects in pRb tumor suppressor pathway occur in ∼50% of the deadly muscle-invasive urothelial carcinomas in humans and urothelial carcinoma is the most prevalent epithelial cancer in long-term survivors of hereditary retinoblastomas caused by loss-of-function RB1 mutations. Here, we show that conditional inactivation of both RB1 alleles in mouse urothelium failed to accelerate urothelial proliferation. Instead, it profoundly activated the p53 pathway, leading to extensive apoptosis, and selectively induced pRb family member p107. Thus, pRb loss triggered multiple fail-safe mechanisms whereby urothelial cells evade tumorigenesis. Additional loss of p53 in pRb-deficient urothelial cells removed these p53-dependent tumor barriers, resulting in late-onset hyperplasia, umbrella cell nuclear atypia, and rare-occurring low-grade, superficial papillary bladder tumors, without eliciting invasive carcinomas. Importantly, mice deficient in both pRb and p53, but not those deficient in either protein alone, were highly susceptible to subthreshold carcinogen exposure and developed invasive urothelial carcinomas that strongly resembled the human counterparts. The invasive lesions had a marked reduction of p107 but not p130 of the pRb family. Our data provide compelling evidence, indicating that urothelium, one of the slowest cycling epithelia, is remarkably resistant to transformation by pRb or p53 deficiency; that concurrent loss of these two tumor suppressors is necessary but insufficient to initiate urothelial tumorigenesis along the invasive pathway; that p107 may play a critical role in suppressing invasive urothelial tumor formation; and that replacing/restoring the function of pRb, p107, or p53 could be explored as a potential therapeutic strategy to block urothelial tumor progression. [Cancer Res 2009;69(24):9413–21]
Data from Src Family Kinase Inhibitor Saracatinib (AZD0530) Impairs Oxaliplatin Uptake in Colorectal Cancer Cells and Blocks Organic Cation Transporters
Authors: Morrow Christopher J. , Ghattas Mohammad , Smith Christopher , Bönisch Heinz , Bryce Richard A. , Hickinson D. Mark , Green Tim P. , Dive Caroline
Published: March 2024

Abstract
Elevated Src family kinase (SFK) activity is associated with tumor invasion and metastasis. The SFK inhibitor saracatinib (AZD0530) is currently in phase II trials in patients including those with colorectal cancer (CRC), where links between SFK activity and poor prognosis are particularly striking. Saracatinib is likely to be used clinically in combination regimens, specifically with 5-fluorouracil (5-FU) and oxaliplatin, in CRC. The aim of this study was to determine the effect of saracatinib on oxaliplatin and 5-FU efficacy in CRC cells. Saracatinib did not modulate 5-FU efficacy but antagonized oxaliplatin in a schedule-specific manner through reduced oxaliplatin uptake via an SFK-independent mechanism. Saracatinib resembles the pharmacophore of known organic cation transporter (OCT) inhibitors and reduced oxaliplatin efficacy maximally in cells overexpressing OCT2. These data suggest that oxaliplatin uptake in CRC is attenuated by saracatinib via inhibition of OCT2, a potential consideration for the clinical development of this SFK inhibitor. Cancer Res; 70(14); 5931–41. ©2010 AACR.
Data from The Aryl Hydrocarbon Receptor Functions as a Tumor Suppressor of Liver Carcinogenesis
Authors: Fan Yunxia , Boivin Gregory P. , Knudsen Erik S. , Nebert Daniel W. , Xia Ying , Puga Alvaro
Published: March 2024

Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the biological and toxic effects of its xenobiotic ligands. Previous cell culture studies have shown that, in addition to controlling the xenobiotic detoxification response, AHR activation leads to G0-G1 arrest, diminished capacity for DNA replication, and inhibition of cell proliferation. In fact, recent work from our own and from other laboratories suggests that AHR may function as a tumor suppressor gene that becomes silenced during the process of tumor formation. To test this hypothesis and determine whether the mouse Ahr gene acts as a tumor suppressor gene in vivo, we have examined the role of Ahr ablation in liver tumorigenesis induced by the genotoxic chemical diethylnitrosamine (DEN), a hepatic carcinogen that is not an AHR ligand. In mice given a single i.p. injection of DEN, AHR antagonized liver tumor formation and growth by regulating cell proliferation, inflammatory cytokine expression, and DNA damage, parameters which were significantly elevated in the livers of control and, more so, of DEN-exposed Ahr−/− mice. Ahr−/− hepatocytes also showed significantly higher numbers of 4N cells, increased expression of proliferative markers, and repression of tumor suppressor genes. These data support the concept that in its basal state in the absence of a xenobiotic ligand, the Ahr gene functions as a tumor suppressor gene, and that its silencing may be associated with cancer progression. Cancer Res; 70(1); 212–220
Data from Glioblastoma Proto-oncogene SEC61γ Is Required for Tumor Cell Survival and Response to Endoplasmic Reticulum Stress
Authors: Lu Zheming , Zhou Lei , Killela Patrick , Rasheed Ahmed B. , Di Chunhui , Poe William E. , McLendon Roger E. , Bigner Darell D. , Nicchitta Christopher , Yan Hai
Published: March 2024

Abstract
Glioblastoma multiforme is the most prevalent type of adult brain tumor and one of the deadliest tumors known to mankind. The genetic understanding of glioblastoma multiforme is, however, limited, and the molecular mechanisms that facilitate glioblastoma multiforme cell survival and growth within the tumor microenvironment are largely unknown. We applied digital karyotyping and single nucleotide polymorphism arrays to screen for copy-number changes in glioblastoma multiforme samples and found that the most frequently amplified region is at chromosome 7p11.2. The high resolution of digital karyotyping and single nucleotide polymorphism arrays permits the precise delineation of amplicon boundaries and has enabled identification of the minimal region of amplification at chromosome 7p11.2, which contains two genes, EGFR and SEC61γ. SEC61γ encodes a subunit of a heterotrimeric protein channel located in the endoplasmic reticulum (ER). In addition to its high frequency of gene amplification in glioblastoma multiforme, SEC61γ is also remarkably overexpressed in 77% of glioblastoma multiforme but not in lower-grade gliomas. The small interfering RNA–mediated knockdown of SEC61γ expression in tumor cells led to growth suppression and apoptosis. Furthermore, we showed that pharmacologic ER stress agents induce SEC61γ expression in glioblastoma multiforme cells. Together, these results indicate that aberrant expression of SEC61γ serves significant roles in glioblastoma multiforme cell survival likely via a mechanism that is involved in the cytoprotective ER stress–adaptive response to the tumor microenvironment. [Cancer Res 2009;69(23):9105–11]
Data from EGFR Promotes Lung Tumorigenesis by Activating miR-7 through a Ras/ERK/Myc Pathway That Targets the Ets2 Transcriptional Repressor ERF
Authors: Chou Yu-Ting , Lin Hua-Heng , Lien Yung-Chang , Wang Yuan-Hung , Hong Chun-Fu , Kao Yu-Rung , Lin Sheng-Chieh , Chang Ying-Che , Lin Shu-Yu , Chen Shu-Jen , Chen Hua-Chien , Yeh Shauh-Der , Wu Cheng-Wen
Published: March 2024

Abstract
MicroRNAs (miRNA) mediate distinct gene regulatory pathways triggered by epidermal growth factor receptor (EGFR) activation, which occurs commonly in lung cancers with poor prognosis. In this study, we report the discovery and mechanistic characterization of the miRNA miR-7 as an oncogenic “oncomiR” and its role as a key mediator of EGFR signaling in lung cancer cells. EGFR activation or ectopic expression of Ras as well as c-Myc stimulated miR-7 expression in an extracellular signal-regulated kinase (ERK)–dependent manner, suggesting that EGFR induces miR-7 expression through a Ras/ERK/Myc pathway. In support of this likelihood, c-Myc bound to the miR-7 promoter and enhanced its activity. Ectopic miR-7 promoted cell growth and tumor formation in lung cancer cells, significantly increasing the mortality of nude mice hosts, which were orthotopically implanted with lung cancers. Quantitative proteomic analysis revealed that miR-7 decreased levels of the Ets2 transcriptional repression factor ERF, the coding sequence of which was found to contain a miR-7 complementary sequence. Indeed, ectopic miR-7 inhibited production of ERF messages with a wild-type but not a silently mutated coding sequence, and ectopic miR-7 rescued growth arrest produced by wild-type but not mutated ERF. Together, these results identified that ERF is a direct target of miR-7 in lung cancer. Our findings suggest that miR-7 may act as an important modulator of EGFR-mediated oncogenesis, with potential applications as a novel prognostic biomarker and therapeutic target in lung cancer. Cancer Res; 70(21); 8822–31. ©2010 AACR.
Data from Discovery and Canine Preclinical Assessment of a Nontoxic Procaspase-3–Activating Compound
Authors: Peterson Quinn P. , Hsu Danny C. , Novotny Chris J. , West Diana C. , Kim Dewey , Schmit Joanna M. , Dirikolu Levent , Hergenrother Paul J. , Fan Timothy M.
Published: March 2024

Abstract
A critical event in the apoptotic cascade is the proteolytic activation of procaspases to active caspases. The caspase autoactivating compound PAC-1 induces cancer cell apoptosis and exhibits antitumor activity in murine xenograft models when administered orally as a lipid-based formulation or implanted s.c. as a cholesterol pellet. However, high doses of PAC-1 were found to induce neurotoxicity, prompting us to design and assess a novel PAC-1 derivative called S-PAC-1. Similar to PAC-1, S-PAC-1 activated procaspase-3 and induced cancer cell apoptosis. However, S-PAC-1 did not induce neurotoxicity in mice or dogs. Continuous i.v. infusion of S-PAC-1 in dogs led to a steady-state plasma concentration of ∼10 μmol/L for 24 to 72 hours. In a small efficacy trial of S-PAC-1, evaluation of six pet dogs with lymphoma revealed that S-PAC-1 was well tolerated and that the treatments induced partial tumor regression or stable disease in four of six subjects. Our results support this canine setting for further evaluation of small-molecule procaspase-3 activators, including S-PAC-1, a compound that is an excellent candidate for further clinical evaluation as a novel cancer chemotherapeutic. Cancer Res; 70(18); 7232–41. ©2010 AACR.
Data from Cdc42-Interacting Protein 4 Promotes Breast Cancer Cell Invasion and Formation of Invadopodia through Activation of N-WASp
Authors: Pichot Christina S. , Arvanitis Constadina , Hartig Sean M. , Jensen Samuel A. , Bechill John , Marzouk Saad , Yu Jindan , Frost Jeffrey A. , Corey Seth J.
Published: March 2024

Abstract
In the earliest stages of metastasis, breast cancer cells must reorganize the cytoskeleton to affect cell shape change and promote cell invasion and motility. These events require the cytoskeletal regulators Cdc42 and Rho, their effectors such as N-WASp/WAVE, and direct inducers of actin polymerization such as Arp2/3. Little consideration has been given to molecules that shape the cell membrane. The F-BAR proteins CIP4, TOCA-1, and FBP17 generate membrane curvature and act as scaffolding proteins for activated Cdc42 and N-WASp. We found that expression of CIP4, but not TOCA-1 or FBP17, was increased in invasive breast cancer cell lines in comparison with weakly or noninvasive breast cancer cell lines. Endogenous CIP4 localized to the leading edge of migrating cells and to invadopodia in cells invading gelatin. Because CIP4 serves as a scaffolding protein for Cdc42, Src, and N-WASp, we tested whether loss of CIP4 could result in decreased N-WASp function. Interaction between CIP4 and N-WASp was epidermal growth factor responsive, and CIP4 silencing by small interfering RNA caused decreased tyrosine phosphorylation of N-WASp at a Src-dependent activation site (Y256). CIP4 silencing also impaired the migration and invasion of MDA-MB-231 cells and was associated with decreased formation of invadopodia and gelatin degradation. This study presents a new role for CIP4 in the promotion of migration and invasion of MDA-MB-231 breast cancer cells and establishes the contribution of F-BAR proteins to cancer cell motility and invasion. Cancer Res; 70(21); 8347–56. ©2010 AACR.
Data from NF-κB–Dependent Plasticity of the Epithelial to Mesenchymal Transition Induced by Von Hippel-Lindau Inactivation in Renal Cell Carcinomas
Authors: Pantuck Allan J. , An Jiabin , Liu Huiren , Rettig Matthew B.
Published: March 2024

Abstract
The critical downstream signaling consequences contributing to renal cancer as a result of loss of the tumor suppressor gene von Hippel-Lindau (VHL) have yet to be fully elucidated. Here, we report that VHL loss results in an epithelial to mesenchymal transition (EMT). In studies of paired isogenic cell lines, VHL silencing increased the levels of N-cadherin and vimentin and reduced the levels of E-cadherin relative to the parental VHL+ cell line, which displayed the opposite profile. VHL+ cells grew as clusters of cuboidal and rhomboid cells, whereas VHL-silenced cells took on an elongated, fibroblastoid morphology associated with a more highly invasive character in Matrigel chamber assays. Based on earlier evidence that VHL loss can activate NF-κB, a known mediator of EMT, we tested whether NF-κB contributed to VHL-mediated effects on EMT. On pharmacologic or molecular inhibition of NF-κB, VHL-silenced cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive phenotype. Introducing a pVHL-resistant hypoxia-inducible factor 1α (HIF1α) mutant (HIFαM) into VHL+ cells heightened NF-κB activity, phenocopying EMT effects produced by VHL silencing. Conversely, inhibiting the heightened NF-κB activity in this setting reversed the EMT phenotype. Taken together, these results suggest that VHL loss induces an EMT that is largely dependent on HIFα-induced NF-κB. Our findings rationalize targeting the NF-κB pathway as a therapeutic strategy to treat renal tumors characterized by biallelic VHL inactivation. Cancer Res; 70(2); 752–61
Data from Reduced Levels of IGF-I Mediate Differential Protection of Normal and Cancer Cells in Response to Fasting and Improve Chemotherapeutic Index
Authors: Lee Changhan , Safdie Fernando M. , Raffaghello Lizzia , Wei Min , Madia Federica , Parrella Edoardo , Hwang David , Cohen Pinchas , Bianchi Giovanna , Longo Valter D.
Published: March 2024

Abstract
Inhibitors of the insulin-like growth factor-I (IGF-I) receptor have been widely studied for their ability to enhance the killing of a variety of malignant cells, but whether IGF-I signaling differentially protects the host and cancer cells against chemotherapy is unknown. Starvation can protect mice, but not cancer cells, against high-dose chemotherapy [differential stress resistance (DSR)]. Here, we offer evidence that IGF-I reduction mediates part of the starvation-dependent DSR. A 72-hour fast in mice reduced circulating IGF-I by 70% and increased the level of the IGF-I inhibitor IGFBP-1 by 11-fold. LID mice, with a 70% to 80% reduction in circulating IGF-I levels, were protected against three of four chemotherapy drugs tested. Restoration of IGF-I was sufficient to reverse the protective effect of fasting. Sixty percent of melanoma-bearing LID mice treated with doxorubicin achieved long-term survival whereas all control mice died of either metastases or chemotherapy toxicity. Reducing IGF-I/IGF-I signaling protected primary glia, but not glioma cells, against cyclophosphamide and protected mouse embryonic fibroblasts against doxorubicin. Further, S. cerevisiae lacking homologs of IGF-I signaling proteins were protected against chemotherapy-dependent DNA damage in a manner that could be reversed by expressing a constitutively active form of Ras. We conclude that normal cells and mice can be protected against chemotherapy-dependent damage by reducing circulating IGF-I levels and by a mechanism that involves downregulation of proto-oncogene signals. Cancer Res; 70(4); 1564–72
Data from Cocarcinogenic Effect of Capsaicin Involves Activation of EGFR Signaling but Not TRPV1
Authors: Hwang Mun Kyung , Bode Ann M. , Byun Sanguine , Song Nu Ry , Lee Hyong Joo , Lee Ki Won , Dong Zigang
Published: March 2024

Abstract
Epidemiologic and animal studies revealed that capsaicin can act as a carcinogen or cocarcinogen. However, the molecular mechanisms of the cancer-promoting effects of capsaicin are not clear. Here, we report that capsaicin has a cocarcinogenic effect on 12-O-tetradecanoylphorbol-13-acetate (TPA)–promoted skin carcinogenesis in vivo and is mediated through the epidermal growth factor receptor (EGFR), but not the transient receptor potential vanilloid subfamily member 1 (TRPV1). Topical application of capsaicin on the dorsal skin of 7,12-dimetylbenz(a)anthracene–initiated and TPA-promoted TRPV1 wild-type (WT) and TRPV1 knockout (KO) mice induced more and larger skin tumors in TRPV1/KO mice, suggesting a TRPV1-independent mechanism. Cyclooxygenase-2 (COX-2) was highly elevated by capsaicin treatment in tumors and murine embryonic fibroblasts from TRPV1/KO mice. Inhibitors of EGFR/MEK signaling suppressed TPA/capsaicin-induced COX-2 expression in TRPV1/KO cells, indicating that activation of EGFR and its downstream signaling is involved in COX-2 elevation. Capsaicin induced a further induction of TPA-increased COX-2 expression in EGFR/WT cells, but not in EGFR/KO cells. TPA/capsaicin cotreatment caused EGFR tyrosine phosphorylation and activated EGFR downstream signaling, including ERKs and Akt in EGFR/WT, but not EGFR/KO cells. Specific inhibition of EGFR and TRPV1 indicated that capsaicin-induced ERK activation in A431 cells was dependent on EGFR, but not TRPV1. Together, these findings suggest that capsaicin might act as a cocarcinogen in TPA-induced skin carcinogenesis through EGFR-dependent mechanisms. Cancer Res; 70(17); 6859–69. ©2010 AACR.
Data from PET Imaging of Tumor Neovascularization in a Transgenic Mouse Model with a Novel 64Cu-DOTA-Knottin Peptide
Authors: Nielsen Carsten H. , Kimura Richard H. , Withofs Nadia , Tran Phuoc T. , Miao Zheng , Cochran Jennifer R. , Cheng Zhen , Felsher Dean , Kjær Andreas , Willmann Juergen K. , Gambhir Sanjiv S.
Published: March 2024

Abstract
Due to the high mortality of lung cancer, there is a critical need to develop diagnostic procedures enabling early detection of the disease while at a curable stage. Targeted molecular imaging builds on the positive attributes of positron emission tomography/computed tomography (PET/CT) to allow for a noninvasive detection and characterization of smaller lung nodules, thus increasing the chances of positive treatment outcome. In this study, we investigate the ability to characterize lung tumors that spontaneously arise in a transgenic mouse model. The tumors are first identified with small animal CT followed by characterization with the use of small animal PET with a novel 64Cu–1,4,7,10-tetra-azacylododecane-N,N′,N′′,N′′′-tetraacetic acid (DOTA)–knottin peptide that targets integrins upregulated during angiogenesis on the tumor associated neovasculature. The imaging results obtained with the knottin peptide are compared with standard 18F-fluorodeoxyglucose (FDG) PET small animal imaging. Lung nodules as small as 3 mm in diameter were successfully identified in the transgenic mice by small animal CT, and both 64Cu-DOTA-knottin 2.5F and FDG were able to differentiate lung nodules from the surrounding tissues. Uptake and retention of the 64Cu-DOTA-knottin 2.5F tracer in the lung tumors combined with a low background in the thorax resulted in a statistically higher tumor to background (normal lung) ratio compared with FDG (6.01 ± 0.61 versus 4.36 ± 0.68; P < 0.05). Ex vivo biodistribution showed 64Cu-DOTA-knottin 2.5F to have a fast renal clearance combined with low nonspecific accumulation in the thorax. Collectively, these results show 64Cu-DOTA-knottin 2.5F to be a promising candidate for clinical translation for earlier detection and improved characterization of lung cancer. Cancer Res; 70(22); 9022–30. ©2010 AACR.
Data from Zoledronic Acid Potentiates mTOR Inhibition and Abolishes the Resistance of Osteosarcoma Cells to RAD001 (Everolimus): Pivotal Role of the Prenylation Process
Authors: Moriceau Gatien , Ory Benjamin , Mitrofan Laura , Riganti Chiara , Blanchard Frédéric , Brion Régis , Charrier Céline , Battaglia Séverine , Pilet Paul , Denis Marc G. , Shultz Leonard D. , Mönkkönen Jukka , Rédini Françoise , Heymann Dominique
Published: March 2024

Abstract
Despite recent improvements in therapeutic management of osteosarcoma, ongoing challenges in improving the response to chemotherapy warrants new strategies still needed to improve overall patient survival. In this study, we investigated in vivo the effects of RAD001 (Everolimus), a new orally available mTOR inhibitor, on the growth of human and mouse osteosarcoma cells either alone or in combination with zoledronate (ZOL), an anti-osteoporotic drug used to treat bone metastases. RAD001 inhibited osteosarcoma cell proliferation in a dose- and time-dependent manner with no modification of cell-cycle distribution. Combination with ZOL augmented this inhibition of cell proliferation, decreasing PI3K/mTOR signaling compared with single treatments. Notably, in contrast to RAD001, ZOL downregulated isoprenylated membrane-bound Ras concomitantly with an increase of nonisoprenylated cytosolic Ras in sensitive and resistant osteosarcoma cell lines to both drugs. Moreover, ZOL and RAD001 synergized to decrease Ras isoprenylation and GTP-bound Ras levels. Further, the drug combination reduced tumor development in two murine models of osteoblastic or osteolytic osteosarcoma. We found that ZOL could reverse RAD001 resistance in osteosarcoma, limiting osteosarcoma cell growth in combination with RAD001. Our findings rationalize further study of the applications of mTOR and mevalonate pathway inhibitors that can limit protein prenylation pathways. Cancer Res; 70(24); 10329–39. ©2010 AACR.
Data from Epithelial-to-Mesenchymal Transition Promotes Tubulin Detyrosination and Microtentacles that Enhance Endothelial Engagement
Authors: Whipple Rebecca A. , Matrone Michael A. , Cho Edward H. , Balzer Eric M. , Vitolo Michele I. , Yoon Jennifer R. , Ioffe Olga B. , Tuttle Kimberly C. , Yang Jing , Martin Stuart S.
Published: March 2024

Abstract
Epithelial-to-mesenchymal transition (EMT) is associated with increased breast tumor metastasis; however, the specific mechanisms by which EMT promotes metastasis remain somewhat unclear. Despite the importance of cytoskeletal dynamics during both EMT and metastasis, very few current studies examine the cytoskeleton of detached and circulating tumor cells. Specific posttranslational α-tubulin modifications are critical for adherent cell motility and implicated in numerous pathologies, but also remain understudied in detached cells. We report here that EMT induced through ectopic expression of Twist or Snail promotes α-tubulin detyrosination and the formation of tubulin-based microtentacles in detached HMLEs. Mechanistically, EMT downregulates the tubulin tyrosine ligase enzyme, resulting in an accumulation of detyrosinated α-tubulin (Glu-tubulin), and increases microtentacles that penetrate endothelial layers to facilitate tumor cell reattachment. Confocal microscopy shows that microtentacles are capable of penetrating the junctions between endothelial cells. Suppression of endogenous Twist in metastatic human breast tumor cells is capable of reducing both tubulin detyrosination and microtentacles. Clinical breast tumor samples display high concordance between Glu-tubulin and Twist expression levels, emphasizing the coupling between EMT and tubulin detyrosination in vivo. Coordinated elevation of Twist and Glu-tubulin at invasive tumor fronts, particularly within ductal carcinoma in situ samples, establishes that EMT-induced tubulin detyrosination occurs at the earliest stages of tumor invasion. These data support a novel model where the EMT that occurs during tumor invasion downregulates tubulin tyrosine ligase, increasing α-tubulin detyrosination and promoting microtentacles that could enhance the reattachment of circulating tumor cells to the vascular endothelium during metastasis. Cancer Res; 70(20); 8127–37. ©2010 AACR.
Data from Tumor-Specific CD8+ T Cells Expressing Interleukin-12 Eradicate Established Cancers in Lymphodepleted Hosts
Authors: Kerkar Sid P. , Muranski Pawel , Kaiser Andrew , Boni Andrea , Sanchez-Perez Luis , Yu Zhiya , Palmer Douglas C. , Reger Robert N. , Borman Zachary A. , Zhang Ling , Morgan Richard A. , Gattinoni Luca , Rosenberg Steven A. , Trinchieri Giorgio , Restifo Nicholas P.
Published: March 2024

Abstract
T-cell–based immunotherapies can be effective in the treatment of large vascularized tumors, but they rely on adoptive transfer of substantial numbers (∼20 million) of tumor-specific T cells administered together with vaccination and high-dose interleukin (IL)-2. In this study, we report that ∼10,000 T cells gene-engineered to express a single-chain IL-12 molecule can be therapeutically effective against established tumors in the absence of exogenous IL-2 and vaccine. Although IL-12–engineered cells did not perist long-term in hosts, they exhibited enhanced functionality and were detected in higher numbers intratumorally along with increased numbers of endogenous natural killer and CD8+ T cells just before regression. Importantly, transferred T cells isolated from tumors stably overproduced supraphysiologic amounts of IL-12, and the therapeutic effect of IL-12 produced within the tumor microenvironment could not be mimicked with high doses of exogenously provided IL-12. Furthermore, antitumor effects could be recapitulated by engineering wild-type open-repertoire splenocytes to express both the single-chain IL-12 and a recombinant tumor-specific T-cell receptor (TCR), but only when individual cells expressed both the TCR and IL-12, indicating that arrested migration of T cells at the tumor site was required for their activities. Successful tumor eradication was dependent on a lymphodepleting preconditioning regimen that reduced the number of intratumoral CD4+ Foxp3+ T regulatory cells. Our findings reveal an approach to genetically modify T cells to reduce the cell number needed, eliminate the need for vaccines or systemic IL-2, and improve immunotherapy efficacy based on adoptive transfer of gene-engineered T cells. Cancer Res; 70(17); 6725–34. ©2010 AACR.
Data from Melanoma Cells Express ICOS Ligand to Promote the Activation and Expansion of T-Regulatory Cells
Authors: Martin-Orozco Natalia , Li Yufeng , Wang Yijun , Liu Shijuan , Hwu Patrick , Liu Yong-Jun , Dong Chen , Radvanyi Laszlo
Published: March 2024

Abstract
CD4+CD25+Foxp3+ T-regulatory cells (Tregs) accumulate in tumors; however, little is known about how the tumor environment influences this process. Here we show that human melanomas express inducible T-cell costimulator ligand (ICOS-L/B7H) that can provide costimulation through ICOS for the expansion of activated Tregs maintaining high Foxp3 and CD25 expression as well as a suppressive function. Thus, ICOS-L expression by melanoma tumor cells may directly drive Treg activation and expansion in the tumor microenvironment as another mechanism of immune evasion. Cancer Res; 70(23); 9581–90. ©2010 AACR.
Data from Recruitment of Phosphorylated NPM1 to Sites of DNA Damage through RNF8-Dependent Ubiquitin Conjugates
Authors: Koike Ayaka , Nishikawa Hiroyuki , Wu Wenwen , Okada Yukinori , Venkitaraman Ashok R. , Ohta Tomohiko
Published: March 2024

Abstract
Protein accumulation at DNA double-strand breaks (DSB) is essential for genome stability; however, the mechanisms governing these events are not fully understood. Here, we report a new role for the nucleophosmin protein NPM1 in these mechanisms. Thr199-phosphorylated NPM1 (pT199-NPM1) is recruited to nuclear DNA damage foci induced by ionizing radiation (IR). Foci formation is impaired by depletion of the E3 ubiquitin ligases RNF8 and RNF168 or the E2 Ubc13, and pT199-NPM1 binds to Lys63-linked ubiquitin polymers in vitro. Thus, phosphorylated NPM1 may interact with RNF8-dependent ubiquitin conjugates at sites of DNA damage. The interaction was found to rely on T199 phosphorylation, an acidic tract, and an adjacent ubiquitin-interacting motif–like domain. Depletion of the breast cancer suppressor BRCA1 or its partner, RAP80, enhanced IR-induced NPM1 foci and prolonged persistence of the foci, possibly implicating BRCA1 in pT199-NPM1 action and dynamics. Replacement of endogenous NPM1 with its nonphosphorylable T199A mutant prolonged persistence of IR-induced RAD51 foci accompanied by unrepaired DNA damage. Collectively, our findings suggest that phosphorylated NPM1 is a novel component in DSB repair that is recruited by ubiquitin conjugates downstream of RNF8 and RNF168. Cancer Res; 70(17); 6746–56. ©2010 AACR.