bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from ESE3/EHF Controls Epithelial Cell Differentiation and Its Loss Leads to Prostate Tumors with Mesenchymal and Stem-like Features
Authors: Albino Domenico , Longoni Nicole , Curti Laura , Mello-Grand Maurizia , Pinton Sandra , Civenni Gianluca , Thalmann George , D'Ambrosio Gioacchino , Sarti Manuela , Sessa Fausto , Chiorino Giovanna , Catapano Carlo V. , Carbone Giuseppina M.
Published: March 2024

Abstract
Cancer stem cells (CSC) play a significant role in tumor progression, disease recurrence, and treatment failure. Here, we show that the endogenously expressed ETS transcription factor ESE3/EHF controls prostate epithelial cell differentiation and stem-like potential. We found that loss of ESE3/EHF induced epithelial-to-mesenchymal transition (EMT), stem-like features, and tumor-initiating and metastatic properties in prostate epithelial cells, and reexpression of ESE3/EHF inhibited the stem-like properties and tumorigenic potential of prostate cancer cells. Mechanistically, ESE3/EHF repressed the expression of key EMT and CSC genes, including TWIST1, ZEB2, BMI1, and POU5F1. Analysis of human tissue microarrays showed that reduced ESE3/EHF expression is an early event in tumorigenesis, frequently occurring independently of other ETS gene alterations. Additional analyses linked loss of ESE3/EHF expression to a distinct group of prostate tumors with distinctive molecular and biologic characteristics, including increased expression of EMT and CSC genes. Low ESE3/EHF expression was also associated with increased biochemical recurrence of prostate cancer and reduced overall survival after prostatectomy. Collectively, our findings define a key role for ESE3/EHF in the development of a subset of prostate tumors and highlight the clinical importance of identifying molecularly defined tumor subgroups. Cancer Res; 72(11); 2889–900. ©2012 AACR.
Data from An NMR Metabolomics Approach for the Diagnosis of Leptomeningeal Carcinomatosis
Authors: Cho Hye Rim , Wen He , Ryu Young Jin , An Yong Jin , Kim Hyo Cheol , Moon Woo Kyung , Han Moon Hee , Park Sunghyouk , Choi Seung Hong
Published: March 2024

Abstract
Leptomeningeal carcinomatosis (LC) is the third most common metastatic complication of the central nervous system. However, the current modalities to reliably diagnose this condition are not satisfactory. Here, we report a preclinical proof of concept for a metabolomics-based diagnostic strategy using a rat LC model incorporating glioma cells that stably express green fluorescent protein. Cytologic diagnoses gave 66.7% sensitivity for the 7-day LC group and 0% for the 3-day LC group. MR imaging could not diagnose LC at these stages. In contrast, nuclear magnetic resonance–based metabolomics on cerebrospinal fluid detected marked differences between the normal and LC groups. Predictions based on the multivariate model provided sensitivity, specificity, and overall accuracy of 88% to 89% in both groups for LC diagnosis. Further statistical analyses identified lactate, acetate, and creatine as specific for the 7-day LC group, with glucose a specific marker of the normal group. Overall, we showed that the metabolomics approach provided both earlier and more accurate diagnostic results than cytology and MR imaging in current use. Cancer Res; 72(20); 5179–87. ©2012 AACR.
Data from Augmentation of Therapeutic Responses in Melanoma by Inhibition of IRAK-1,-4
Authors: Srivastava Ratika , Geng Degui , Liu Yingjia , Zheng Liqin , Li Zhaoyang , Joseph Mary Ann , McKenna Colleen , Bansal Navneeta , Ochoa Augusto , Davila Eduardo
Published: March 2024

Abstract
Toll-like receptors (TLR) are expressed by a variety of cancers, including melanoma, but their functional contributions in cancer cells are uncertain. To approach this question, we evaluated the effects of stimulating or inhibiting the TLR/IL-1 receptor-associated kinases IRAK-1 and IRAK-4 in melanoma cells where their functions are largely unexplored. TLRs and TLR-related proteins were variably expressed in melanoma cell lines, with 42% expressing activated phospho-IRAK-1 constitutively and 85% expressing high levels of phospho-IRAK-4 in the absence of TLR stimulation. Immunohistochemical evaluation of melanoma tumor biopsies (n = 242) revealed two distinct patient populations, one that expressed p-IRAK-4 levels similar to normal skin (55%) and one with significantly higher levels than normal skin (45%). Levels of p-IRAK-4 levels did not correlate with clinical stage, gender, or age, but attenuated IRAK-1,-4 signaling with pharmacologic inhibitors or siRNA-enhanced cell death in vitro in combination with vinblastine. Moreover, in a xenograft mouse model of melanoma, the combined pharmacologic treatment delayed tumor growth and prolonged survival compared with subjects receiving single agent therapy. We propose p-IRAK-4 as a novel inflammation and prosurvival marker in melanoma with the potential to serve as a therapeutic target to enhance chemotherapeutic responses. Cancer Res; 72(23); 6209–16. ©2012 AACR.
Data from Smac Mimetic LBW242 Sensitizes XIAP-Overexpressing Neuroblastoma Cells for TNF-α–Independent Apoptosis
Authors: Eschenburg Georg , Eggert Angelika , Schramm Alexander , Lode Holger N. , Hundsdoerfer Patrick
Published: March 2024

Abstract
Despite intensive treatment regimens, high-risk and late-stage neuroblastoma tends to have a poor survival outcome. Overexpression of the apoptotic regulator, X-linked inhibitor of apoptosis protein (XIAP), has been associated with chemotherapy resistance in several cancers including neuroblastoma. Here, we report preclinical evidence that XIAP offers an effective therapeutic target in neuroblastoma. Human and murine neuroblastoma cells were treated with the Smac mimetic LBW242 alone or in combination with cytotoxic drugs used clinically to treat neuroblastoma. Expression of XIAP protein, but not mRNA, was highly increased in neuroblastoma cells compared to healthy adrenal gland tissue, consistent with a posttranscriptional regulation of XIAP expression. Treatment with LBW242 sensitized human and murine neuroblastoma cells to chemotherapy-induced apoptosis, which was mediated by activation of both the intrinsic and extrinsic apoptosis pathways. Although Smac mimetics have been reported to stimulate TNF-α–induced apoptosis by degradation of cellular IAP (cIAP)-1/2, we found that LBW242-mediated sensitization in neuroblastoma cells occurred in a TNF-α–independent manner, despite induction of cIAP-1/2 degradation and TNF-α expression. Together, our findings show that XIAP targeting sensitizes neuroblastoma to chemotherapy-induced apoptosis, suggesting a novel therapeutic approach to treat this childhood malignancy. Cancer Res; 72(10); 2645–56. ©2012 AACR.
Data from SMYD3 Promotes Cancer Invasion by Epigenetic Upregulation of the Metalloproteinase MMP-9
Authors: Cock-Rada Alicia M. , Medjkane Souhila , Janski Natacha , Yousfi Nadhir , Perichon Martine , Chaussepied Marie , Chluba Johanna , Langsley Gordon , Weitzman Jonathan B.
Published: March 2024

Abstract
Upregulation of the matrix metalloproteinase (MMP)–9 plays a central role in tumor progression and metastasis by stimulating cell migration, tumor invasion, and angiogenesis. To gain insights into MMP-9 expression, we investigated its epigenetic control in a reversible model of cancer that is initiated by infection with intracellular Theileria parasites. Gene induction by parasite infection was associated with trimethylation of histone H3K4 (H3K4me3) at the MMP-9 promoter. Notably, we found that the H3K4 methyltransferase SMYD3 was the only histone methyltransferase upregulated upon infection. SMYD3 is overexpressed in many types of cancer cells, but its contributions to malignant pathophysiology are unclear. We found that overexpression of SMYD3 was sufficient to induce MMP-9 expression in transformed leukocytes and fibrosarcoma cells and that proinflammatory phorbol esters further enhanced this effect. Furthermore, SMYD3 was sufficient to increase cell migration associated with MMP-9 expression. In contrast, RNA interference–mediated knockdown of SMYD3 decreased H3K4me3 modification of the MMP-9 promoter, reduced MMP-9 expression, and reduced tumor cell proliferation. Furthermore, SMYD3 knockdown also reduced cellular invasion in a zebrafish xenograft model of cancer. Together, our results define SMYD3 as an important new regulator of MMP-9 transcription, and they provide a molecular link between SMYD3 overexpression and metastatic cancer progression. Cancer Res; 72(3); 810–20. ©2011 AACR.
Data from Transcriptional Signatures of Ral GTPase Are Associated with Aggressive Clinicopathologic Characteristics in Human Cancer
Authors: Smith Steven C. , Baras Alexander S. , Owens Charles R. , Dancik Garrett , Theodorescu Dan
Published: March 2024

Abstract
RalA and RalB are small GTPases that support malignant development and progression in experimental models of bladder, prostate, and squamous cancer. However, demonstration of their clinical relevance in human tumors remains lacking. Here, we developed tools to evaluate Ral protein expression, activation, and transcriptional output and evaluated their association with clinicopathologic parameters in common human tumor types. To evaluate the relevance of Ral activation and transcriptional output, we correlated RalA and RalB activation with the mutational status of key human bladder cancer genes. We also identified and evaluated a transcriptional signature of genes that correlates with depletion of RalA and RalB in vivo. The Ral transcriptional signature score, but not protein expression as evaluated by immunohistochemistry, predicted disease stage, progression to muscle invasion, and survival in human bladder cancers and metastatic and stem cell phenotypes in bladder cancer models. In prostate cancer, the Ral transcriptional signature score was associated with seminal vesicle invasion, androgen-independent progression, and reduced survival. In squamous cell carcinoma, this score was decreased in cancer tissues compared with normal mucosa, validating the experimental findings that Ral acts as a tumor suppressor in this tumor type. Together, our findings show the clinical relevance of Ral in human cancer and provide a rationale for the development of Ral-directed therapies. Cancer Res; 72(14); 3480–91. ©2012 AACR.
Data from miR-23b Represses Proto-oncogene Src Kinase and Functions as Methylation-Silenced Tumor Suppressor with Diagnostic and Prognostic Significance in Prostate Cancer
Authors: Majid Shahana , Dar Altaf A. , Saini Sharanjot , Arora Sumit , Shahryari Varahram , Zaman Mohd Saif , Chang Inik , Yamamura Soichiro , Tanaka Yuichiro , Deng Guoren , Dahiya Rajvir
Published: March 2024

Abstract
The miRNAs have great potential as biomarkers and therapeutic agents owing to their ability to control multiple genes and potential to influence cellular behavior. Here, we identified that miR-23b is a methylation-silenced tumor suppressor in prostate cancer. We showed that miR-23b expression is controlled by promoter methylation and has great promise as a diagnostic and prognostic biomarker in prostate cancer. High levels of miR-23b expression are positively correlated with higher overall and recurrence-free survival in patients with prostate cancer. Furthermore, we elucidated the tumor suppressor role of miR-23b using in vitro and in vivo models. We showed that proto-oncogene Src kinase and Akt are direct targets of miR-23b. Increased expression of miR-23b inhibited proliferation, colony formation, migration/invasion, and triggered G0–G1 cell-cycle arrest and apoptosis in prostate cancer. Overexpression of miR-23b inhibited epithelial-to-mesenchymal transition (EMT) causing a decline in mesenchymal markers Vimentin and Snail and increasing the epithelial marker, E-cadherin. Depletion of Src by RNA interference conferred similar functional effects as that of miR-23b reconstitution. miR-23b expression caused a dramatic decrease in tumor growth in nude mice and attenuated Src expression in excised tumors compared with a control miR. These findings suggest that miR-23b is a methylation-silenced tumor suppressor that may be a useful biomarker in prostate cancer. Loss of miR-23b may confer proliferative advantage and promote prostate cancer migration and invasion, and reexpression of miR-23b may contribute to the epigenetic therapy for prostate cancer. Cancer Res; 72(24); 6435–46. ©2012 AACR.
Data from CDK8 Maintains Tumor Dedifferentiation and Embryonic Stem Cell Pluripotency
Authors: Adler Adam S. , McCleland Mark L. , Truong Tom , Lau Shari , Modrusan Zora , Soukup Tim M. , Roose-Girma Merone , Blackwood Elizabeth M. , Firestein Ron
Published: March 2024

Abstract
CDK8 is a cyclin-dependent kinase that mediates transcriptional control of pathways linked to both cancer and stem cells. In this study, we show that CDK8 is required for both tumor growth and maintenance of tumor dedifferentiation in vivo and uncover a common role for CDK8 in controlling cancer and stem cell function. Acute CDK8 loss in vivo strongly inhibited tumor growth and promoted differentiation. Transcriptional profiling identified a set of embryonic stem cell–related genes that are activated by CDK8 in cancer. Consistent with this, we found that CDK8 expression correlated to the embryonic stem cell pluripotency state and loss of CDK8 caused embryonic stem cells to differentiate. This effect was, at least partially, mediated by the ability of CDK8 to regulate MYC protein and downstream MYC target gene expression. Similar regulation of MYC target genes by CDK8 was observed in colon tumor cells, and increased expression of a CDK8-regulated, embryonic stem cell MYC target gene signature was associated with loss of differentiation and poor outcome in primary human colon cancers. Together, these observations reveal that CDK8 acts, at least in part, through MYC to maintain both tumors and embryonic stem cells in an undifferentiated state. This raises the intriguing possibility that targeting CDK8 therapeutically may specifically inhibit the stem-like properties of cancer cells. Cancer Res; 72(8); 2129–39. ©2012 AACR.
Data from Differential WNT Activity in Colorectal Cancer Confers Limited Tumorigenic Potential and Is Regulated by MAPK Signaling
Authors: Horst David , Chen Justina , Morikawa Teppei , Ogino Shuji , Kirchner Thomas , Shivdasani Ramesh A.
Published: March 2024

Abstract
Colorectal cancers (CRC) express the WNT effector protein β-catenin in a heterogeneous subcellular pattern rather than uniformly in the nucleus. In this study, we investigated this important aspect of molecular heterogeneity in CRCs by analyzing its basis and relationship with tumor-initiating capability. CRC cells with the highest WNT levels showed only a marginal increase in tumor initiation capacity. Notably, high WNT activity correlated with a coincident activation of robust mitogen-activated protein kinase (MAPK) signaling, which when upregulated by KRAS expression or downregulated by epidermal growth factor receptor inhibition elicited parallel effects on WNT activity. These findings suggested that on its own high WNT activity may not be a reliable signifier of tumor-initiating potential or stem-like potential. Furthermore, they suggest that MAPK signaling is a critical modifier of intratumoral heterogeneity that contributes significantly to determining the impact of WNT activity on stemness phenotypes in colon cancer cells. Cancer Res; 72(6); 1547–56. ©2012 AACR.
Data from MEK1/2 Inhibition Decreases Lactate in BRAF-Driven Human Cancer Cells
Authors: Falck Miniotis Maria , Arunan Vaitha , Eykyn Thomas R. , Marais Richard , Workman Paul , Leach Martin O. , Beloueche-Babari Mounia
Published: March 2024

Abstract
The RAS/BRAF/MEK/ERK signaling pathway is a central driver in cancer with many BRAF and MEK inhibitors being evaluated in clinical trials. Identifying noninvasive biomarkers of early pharmacodynamic responses is important for development of these targeted drugs. As increased aerobic glycolysis is often observed in cancer, we hypothesized that MEK1/2 (MAP2K1/MAP2K2) inhibitors may reduce lactate levels as detected by magnetic resonance spectroscopy (MRS), as a metabolic biomarker for the pharmacodynamic response. MRS was used to monitor intracellular and extracellular levels of lactate in human cancer cells in vitro and in melanoma tumors ex vivo. In addition, we used 1H MRS and a fluorescent glucose analog to evaluate the effect of MEK inhibition on glucose uptake. MEK1/2 signaling inhibition reduced extracellular lactate levels in BRAF-dependent cells but not BRAF-independent cells. The reduction in extracellular lactate in BRAF-driven melanoma cells was time-dependent and associated with reduced expression of hexokinase-II driven by c-Myc depletion. Taken together, these results reveal how MEK1/2 inhibition affects cancer cell metabolism in the context of BRAF oncogene addiction. Furthermore, they offer a preclinical proof-of-concept for the use of MRS to measure lactate as a noninvasive metabolic biomarker for pharmacodynamic response to MEK1/2 inhibition in BRAF-driven cancers. Cancer Res; 73(13); 4039–49. ©2013 AACR.
Data from Oxidative Stress-Regulated Lentiviral TK/GCV Gene Therapy for Lung Cancer Treatment
Authors: Leinonen Hanna M. , Ruotsalainen Anna-Kaisa , Määttä Ann-Marie , Laitinen Heidi M. , Kuosmanen Suvi M. , Kansanen Emilia , Pikkarainen Jere T. , Lappalainen Jari P. , Samaranayake Haritha , Lesch Hanna P. , Kaikkonen Minna U. , Ylä-Herttuala Seppo , Levonen Anna-Liisa
Published: March 2024

Abstract
Nuclear factor erythroid-2 related factor 2 (Nrf2) is a transcription factor that regulates protection against a wide variety of toxic insults to cells, including cytotoxic cancer chemotherapeutic drugs. Many lung cancer cells harbor a mutation in either Nrf2 or its inhibitor Keap1 resulting in permanent activation of Nrf2 and chemoresistance. In this study, we sought to examine whether this attribute could be exploited in cancer suicide gene therapy by using a lentiviral (LV) vector expressing herpes simplex virus thymidine kinase (HSV-TK/GCV) under the regulation of antioxidant response element (ARE), a cis-acting enhancer sequence that binds Nrf2. In human lung adenocarcinoma cells in which Nrf2 is constitutively overexpressed, ARE activity was found to be high under basal conditions. In this setting, ARE-HSV-TK was more effective than a vector in which HSV-TK expression was driven by a constitutively active promoter. In a mouse xenograft model of lung cancer, suicide gene therapy with LV-ARE-TK/GCV was effective compared with LV-PGK-TK/GCV in reducing tumor size. We conclude that ARE-regulated HSV-TK/GCV therapy offers a promising approach for suicide cancer gene therapy in cells with high constitutive ARE activity, permitting a greater degree of therapeutic targeting to those cells. Cancer Res; 72(23); 6227–35. ©2012 AACR.
Data from B-Raf Activation Cooperates with PTEN Loss to Drive c-Myc Expression in Advanced Prostate Cancer
Authors: Wang Jingqiang , Kobayashi Takashi , Floc'h Nicolas , Kinkade Carolyn Waugh , Aytes Alvaro , Dankort David , Lefebvre Celine , Mitrofanova Antonina , Cardiff Robert D. , McMahon Martin , Califano Andrea , Shen Michael M. , Abate-Shen Cory
Published: March 2024

Abstract
Both the PI3K → Akt → mTOR and mitogen-activated protein kinase (MAPK) signaling pathways are often deregulated in prostate tumors with poor prognosis. Here we describe a new genetically engineered mouse model of prostate cancer in which PI3K-Akt-mTOR signaling is activated by inducible disruption of PTEN, and extracellular signal-regulated kinase 1/2 (ERK1/2) MAPK signaling is activated by inducible expression of a BRAFV600E oncogene. These tissue-specific compound mutant mice develop lethal prostate tumors that are inherently resistant to castration. These tumors bypass cellular senescence and disseminate to lymph nodes, bone marrow, and lungs where they form overt metastases in approximately 30% of the cases. Activation of PI3K → Akt → mTOR and MAPK signaling pathways in these prostate tumors cooperate to upregulate c-Myc. Accordingly, therapeutic treatments with rapamycin and PD0325901 to target these pathways, respectively, attenuate c-Myc levels and reduce tumor and metastatic burden. Together, our findings suggest a generalized therapeutic approach to target c-Myc activation in prostate cancer by combinatorial targeting of the PI3K → Akt → mTOR and ERK1/2 MAPK signaling pathways. Cancer Res; 72(18); 4765–76. ©2012 AACR.
Data from Genetic Polymorphisms and Protein Expression of NRF2 and Sulfiredoxin Predict Survival Outcomes in Breast Cancer
Authors: Hartikainen Jaana M. , Tengström Maria , Kosma Veli-Matti , Kinnula Vuokko L. , Mannermaa Arto , Soini Ylermi
Published: March 2024

Abstract
NRF2 activates several protective genes, such as sulfiredoxin (SRXN1), as a response to oxidative and xenobiotic stress. Defects in NRF2 pathway may increase cancer susceptibility. In tumor cells, activation of NRF2 may lead to chemo- and radioresistance and thus affect patient outcome. Nine single-nucleotide polymorphisms on NRF2 gene and eight on SRXN1 were genotyped in 452 patients with breast cancer and 370 controls. Protein expression of NRF2 and SRXN1 was studied in 373 breast carcinomas by immunohistochemistry. Statistical significance of the associations between genotypes, protein expression, clinicopathologic variables, and survival was assessed. A high level (>25%) of cytoplasmic NRF2 positivity was observed in 237 of 361 (66%) and SRXN1 positivity was observed in 82 of 363 (23%) cases. The NRF2 rs6721961 genotype TT was associated with increased risk of breast cancer [P = 0.008; OR, 4.656; confidence interval (CI), 1.350–16.063] and the T allele was associated with a low extent of NRF2 protein expression (P = 0.0003; OR, 2.420; CI, 1.491–3.926) and negative SRXN1 expression (P = 0.047; OR, 1.867; CI = 1.002–3.478). The NRF2 rs2886162 allele A was associated with low NRF2 expression (P = 0.011; OR, 1.988; CI, 1.162–3.400) and the AA genotype was associated with a worse survival (P = 0.032; HR, 1.687; CI, 1.047–2.748). The NRF2 rs1962142 T allele was associated with a low level of cytoplasmic NRF2 expression (P = 0.036) and negative sulfiredoxin expression (P = 0.042). The NRF2 rs2706110 AA genotype was associated with an increased risk of breast cancer, and the SRXN1 rs6053666 C allele was associated with a decrease in breast cancer risk (P = 0.011 and 0.017). NRF2 and SRXN1 genetic polymorphisms are associated with breast cancer risk and survival, implicating that mechanisms associated with reactive oxygen species and NRF2 pathway are involved in breast cancer initiation and progression. Cancer Res; 72(21); 5537–46. ©2012 AACR.
Data from Monofunctional Platinum–DNA Adducts Are Strong Inhibitors of Transcription and Substrates for Nucleotide Excision Repair in Live Mammalian Cells
Authors: Zhu Guangyu , Myint MyatNoeZin , Ang Wee Han , Song Lina , Lippard Stephen J.
Published: March 2024

Abstract
To overcome drug resistance and reduce the side effects of cisplatin, a widely used antineoplastic agent, major efforts have been made to develop next generation platinum-based anticancer drugs. Because cisplatin–DNA adducts block RNA polymerase II unless removed by transcription-coupled excision repair, compounds that react similarly but elude repair are desirable. The monofunctional platinum agent pyriplatin displays antitumor activity in mice, a cytotoxicity profile in cell cultures distinct from that of cisplatin, and a unique in vitro transcription inhibition mechanism. In this study, we incorporated pyriplatin globally or site specifically into luciferase reporter vectors to examine its transcription inhibition profiles in live mammalian cells. Monofunctional pyriplatin reacted with plasmid DNA as efficiently as bifunctional cisplatin and inhibited transcription as strongly as cisplatin in various mammalian cells. Using repair-defective nucleotide excision repair (NER)-, mismatch repair-, and single-strand break repair–deficient cells, we show that NER is mainly responsible for removal of pyriplatin–DNA adducts. These findings reveal that the mechanism by which pyriplatin generates its antitumor activity is very similar to that of cisplatin, despite the chemically different nature of their DNA adducts, further supporting a role for monofunctional platinum anticancer agents in human cancer therapy. This information also provides support for the validity of the proposed mechanism of action of cisplatin and provides a rational basis for the design of more potent platinum anticancer drug candidates using a monofunctional DNA-damaging strategy. Cancer Res; 72(3); 790–800. ©2011 AACR.
Data from Basal but not Luminal Mammary Epithelial Cells Require PI3K/mTOR Signaling for Ras-Driven Overgrowth
Authors: Plichta Kristin A. , Mathers Jessica L. , Gestl Shelley A. , Glick Adam B. , Gunther Edward J.
Published: March 2024

Abstract
The mammary ducts of humans and mice are comprised of two main mammary epithelial cell (MEC) subtypes: a surrounding layer of basal MECs and an inner layer of luminal MECs. Breast cancer subtypes show divergent clinical behavior that may reflect properties inherent in their MEC compartment of origin. How the response to a cancer-initiating genetic event is shaped by MEC subtype remains largely unexplored. Using the mouse mammary gland, we designed organotypic three-dimensional culture models that permit challenge of discrete MEC compartments with the same oncogenic insult. Mammary organoids were prepared from mice engineered for compartment-restricted coexpression of oncogenic H-RASG12V together with a nuclear fluorescent reporter. Monitoring of H-RASG12V-expressing MECs during extended live cell imaging permitted visualization of Ras-driven phenotypes via video microscopy. Challenging either basal or luminal MECs with H-RASG12V drove MEC proliferation and survival, culminating in aberrant organoid overgrowth. In each compartment, Ras activation triggered modes of collective MEC migration and invasion that contrasted with physiologic modes used during growth factor–initiated branching morphogenesis. Although basal and luminal Ras activation produced similar overgrowth phenotypes, inhibitor studies revealed divergent use of Ras effector pathways. Blocking either the phosphoinositide 3-kinase or the mammalian target of rapamycin pathway completely suppressed Ras-driven invasion and overgrowth of basal MECs, but only modestly attenuated Ras-driven phenotypes in luminal MECs. We show that MEC subtype defines signaling pathway dependencies downstream of Ras. Thus, cells-of-origin may critically determine the drug sensitivity profiles of mammary neoplasia. Cancer Res; 72(22); 5856–66. ©2012 AACR.
Data from Regulation of ERBB2 Receptor by t-DARPP Mediates Trastuzumab Resistance in Human Esophageal Adenocarcinoma
Authors: Hong Jun , Katsha Ahmed , Lu Pengcheng , Shyr Yu , Belkhiri Abbes , El-Rifai Wael
Published: March 2024

Abstract
Esophageal adenocarcinoma (EAC) is an aggressive malignancy with a poor outcome. Although targeting ERBB2 with trastuzumab has been evaluated in clinical trials, the molecular mechanisms of trastuzumab resistance remain uncharacterized in EAC. The dopamine and cyclic AMP-regulated phosphoprotein of MR 32000 (DARPP-32), also known as PPP1R1B, is located together with ERBB2 at the 17q12-q21 amplicon. We evaluated the expression of a transcript variant of DARPP-32 (t-DARPP) and ERBB2 in 141 primary tumors and investigated the role of t-DARPP in trastuzumab resistance using OE19 and OE33 EAC cell models. Overexpression of t-DARPP mRNA was detected in two-thirds of tumors with a correlation between ERBB2 and t-DARPP overexpression levels (r = 0.58, P = 0.003). Cell viability and clonogenic survival assays showed that t-DARPP increased survival by 40% in response to trastuzumab (P < 0.01). The Annexin-V staining and Western blot analysis indicated that t-DARPP effectively abrogated trastuzumab-induced apoptosis, inhibited cleavage of caspase-3, and blocked trastuzumab-induced dephosphorylation of ERBB2 and AKT proteins. The knockdown of endogenous t-DARPP reversed these effects and sensitized cells to trastuzumab (P < 0.01). The cycloheximide-based protein degradation analysis indicated that t-DARPP extended the half-life of ERBB2, explaining the increase in the basal levels of ERBB2, p-ERBB2(Y1248), and p-AKT(S473). Coimmunoprecipitation and Western blot analysis showed that t-DARPP associated with ERBB2 in a protein complex, and interfered with trastuzumab binding to the ERBB2 receptor. Using EAC-xenografted mouse model, t-DARPP enhanced tumor growth and rendered tumors unresponsive to trastuzumab. This study establishes t-DARPP as a mediator of trastuzumab resistance and underscores its potential importance in clinical trials of EAC. Cancer Res; 72(17); 4504–14. ©2012 AACR.
Data from Dysregulation of Ezrin Phosphorylation Prevents Metastasis and Alters Cellular Metabolism in Osteosarcoma
Authors: Ren Ling , Hong Sung-Hyeok , Chen Qing-Rong , Briggs Joseph , Cassavaugh Jessica , Srinivasan Satish , Lizardo Michael M. , Mendoza Arnulfo , Xia Ashley Y. , Avadhani Narayan , Khan Javed , Khanna Chand
Published: March 2024

Abstract
Ezrin links the plasma membrane to the actin cytoskeleton where it plays a pivotal role in the metastatic progression of several human cancers; however, the precise mechanistic basis for its role remains unknown. Here, we define transitions between active (phosphorylated open) and inactive (dephosphorylated closed) forms of Ezrin that occur during metastatic progression in osteosarcoma. In our evaluation of these conformations we expressed C-terminal mutant forms of Ezrin that are open (phosphomimetic T567D) or closed (phosphodeficient T567A) and compared their biologic characteristics to full-length wild-type Ezrin in osteosarcoma cells. Unexpectedly, cells expressing open, active Ezrin could form neither primary orthotopic tumors nor lung metastases. In contrast, cells expressing closed, inactive Ezrin were also deficient in metastasis but were unaffected in their capacity for primary tumor growth. By imaging single metastatic cells in the lung, we found that cells expressing either open or closed Ezrin displayed increased levels of apoptosis early after their arrival in the lung. Gene expression analysis suggested dysregulation of genes that are functionally linked to carbohydrate and amino acid metabolism. In particular, cells expressing closed, inactive Ezrin exhibited reduced lactate production and basal or ATP-dependent oxygen consumption. Collectively, our results suggest that dynamic regulation of Ezrin phosphorylation at amino acid T567 that controls structural transitions of this protein plays a pivotal role in tumor progression and metastasis, possibly in part by altering cellular metabolism. Cancer Res; 72(4); 1001–12. ©2011 AACR.
Data from Elevation of Receptor Tyrosine Kinases by Small Molecule AKT Inhibitors in Prostate Cancer Is Mediated by Pim-1
Authors: Cen Bo , Mahajan Sandeep , Wang Wenxue , Kraft Andrew S.
Published: March 2024

Abstract
The PI3K/AKT pathway is hyperactivated in prostate cancer but its effective therapeutic targeting has proven difficult. In particular, the antitumor activity of AKT inhibitors is attenuated by upregulation of receptor tyrosine kinases (RTK) through an uncharacterized feedback mechanism. In this report, we show that RNA interference-mediated silencing or pharmacologic inhibition of Pim-1 activity curtails AKT inhibitor-induced upregulation of RTKs in prostate cancer cells. Although Pim kinases have been implicated in cap-dependent translational control, we find that in the context of AKT inhibition, the expression of RTKs is controlled by Pim-1 in a cap-independent manner by controlling internal ribosome entry. Combination of Pim and AKT inhibitors resulted in synergistic inhibition of prostate tumor growth in vitro and in vivo. Together, our results show that Pim-1 mediates resistance to AKT inhibition and suggest its targeting to improve the efficacy of AKT inhibitors in anticancer therapy. Cancer Res; 73(11); 3402–11. ©2013 AACR.
Data from Intravital FLIM-FRET Imaging Reveals Dasatinib-Induced Spatial Control of Src in Pancreatic Cancer
Authors: Nobis Max , McGhee Ewan J. , Morton Jennifer P. , Schwarz Juliane P. , Karim Saadia A. , Quinn Jean , Edward Mike , Campbell Andrew D. , McGarry Lynn C. , Evans T.R. Jeffry , Brunton Valerie G. , Frame Margaret C. , Carragher Neil O. , Wang Yingxiao , Sansom Owen J. , Timpson Paul , Anderson Kurt I.
Published: March 2024

Abstract
Cancer invasion and metastasis occur in a complex three-dimensional (3D) environment, with reciprocal feedback from the surrounding host tissue and vasculature-governing behavior. In this study, we used a novel intravital method that revealed spatiotemporal regulation of Src activity in response to the anti-invasive Src inhibitor dasatinib. A fluorescence lifetime imaging microscopy–fluorescence resonance energy transfer (FLIM-FRET) Src biosensor was used to monitor drug-targeting efficacy in a transgenic p53-mutant mouse model of pancreatic cancer. In contrast to conventional techniques, FLIM-FRET analysis allowed for accurate, time-dependent, live monitoring of drug efficacy and clearance in live tumors. In 3D organotypic cultures, we showed that a spatially distinct gradient of Src activity exists within invading tumor cells, governed by the depth of penetration into complex matrices. In parallel, this gradient was also found to exist within live tumors, where Src activity is enhanced at the invasive border relative to the tumor cortex. Upon treatment with dasatinib, we observed a switch in activity at the invasive borders, correlating with impaired metastatic capacity in vivo. Src regulation was governed by the proximity of cells to the host vasculature, as cells distal to the vasculature were regulated differentially in response to drug treatment compared with cells proximal to the vasculature. Overall, our results in live tumors revealed that a threshold of drug penetrance exists in vivo and that this can be used to map areas of poor drug-targeting efficiency within specific tumor microenvironments. We propose that using FLIM-FRET in this capacity could provide a useful preclinical tool in animal models before clinical translation. Cancer Res; 73(15); 4674–86. ©2013 AACR.
Data from Bone Marrow Stromal Cells Create a Permissive Microenvironment for Myeloma Development: A New Stromal Role for Wnt Inhibitor Dkk1
Authors: Fowler Jessica A. , Mundy Gregory R. , Lwin Seint T. , Edwards Claire M.
Published: March 2024

Abstract
The rapid progression of multiple myeloma is dependent upon cellular interactions within the bone marrow microenvironment. In vitro studies suggest that bone marrow stromal cells (BMSC) can promote myeloma growth and survival and osteolytic bone disease. However, it is not possible to recreate all cellular aspects of the bone marrow microenvironment in an in vitro system, and the contributions of BMSCs to myeloma pathogenesis in an intact, immune competent, in vivo system are unknown. To investigate this, we used a murine myeloma model that replicates many features of the human disease. Coinoculation of myeloma cells and a BMSC line, isolated from myeloma-permissive mice, into otherwise nonpermissive mice resulted in myeloma development, associated with tumor growth within bone marrow and osteolytic bone disease. In contrast, inoculation of myeloma cells alone did not result in myeloma. BMSCs inoculated alone induced osteoblast suppression, associated with an increase in serum concentrations of the Wnt signaling inhibitor, Dkk1. Dkk1 was highly expressed in BMSCs and in myeloma-permissive bone marrow. Knockdown of Dkk1 expression in BMSCs decreased their ability to promote myeloma and the associated bone disease in mice. Collectively, our results show novel roles of BMSCs and BMSC-derived Dkk1 in the pathogenesis of multiple myeloma in vivo. Cancer Res; 72(9); 2183–9. ©2012 AACR.
Data from STAT5 Is Crucial to Maintain Leukemic Stem Cells in Acute Myelogenous Leukemias Induced by MOZ-TIF2
Authors: Tam Winnie F. , Hähnel Patricia S. , Schüler Andrea , Lee Benjamin H. , Okabe Rachel , Zhu Nan , Pante Saskia V. , Raffel Glen , Mercher Thomas , Wernig Gerlinde , Bockamp Ernesto , Sasca Daniel , Kreft Andreas , Robinson Gertraud W. , Hennighausen Lothar , Gilliland D. Gary , Kindler Thomas
Published: March 2024

Abstract
MOZ-TIF2 is a leukemogenic fusion oncoprotein that confers self-renewal capability to hematopoietic progenitor cells and induces acute myelogenous leukemia (AML) with long latency in bone marrow transplantation assays. Here, we report that FLT3-ITD transforms hematopoietic cells in cooperation with MOZ-TIF2 in vitro and in vivo. Coexpression of FLT3-ITD confers growth factor independent survival/proliferation, shortens disease latency, and results in an increase in the number of leukemic stem cells (LSC). We show that STAT5, a major effector of aberrant FLT3-ITD signal transduction, is both necessary and sufficient for this cooperative effect. In addition, STAT5 signaling is essential for MOZ-TIF2–induced leukemic transformation itself. Lack of STAT5 in fetal liver cells caused rapid differentiation and loss of replating capacity of MOZ-TIF2–transduced cells enriched for LSCs. Furthermore, mice serially transplanted with Stat5−/− MOZ-TIF2 leukemic cells develop AML with longer disease latency and finally incomplete penetrance when compared with mice transplanted with Stat5+/+ MOZ-TIF2 leukemic cells. These data suggest that STAT5AB is required for the self-renewal of LSCs and represents a combined signaling node of FLT3-ITD and MOZ-TIF2 driven leukemogenesis. Therefore, targeting aberrantly activated STAT5 or rewired downstream signaling pathways may be a promising therapeutic option. Cancer Res; 73(1); 373–84. ©2012 AACR.
Data from IFNβ Produced by TLR4-Activated Tumor Cells Is Involved in Improving the Antitumoral Immune Response
Authors: Núñez Nicolás Gonzalo , Andreani Virginia , Crespo María Inés , Nocera David Andrés , Breser María Laura , Morón Gabriel , Dejager Lien , Libert Claude , Rivero Virginia , Maccioni Mariana
Published: March 2024

Abstract
Toll-like receptor (TLR) ligands may be a valuable tool to promote antitumor responses by reinforcing antitumor immunity. In addition to their expression in immune cells, functional TLRs are also expressed by many cancer cells, but their significance has been controversial. In this study, we examined the action of TLR ligands on tumor pathophysiology as a result of direct tumor cell effects. B16 murine melanoma cells were stimulated in vitro with a TLR4 ligand (LPS-B16) prior to inoculation into TLR4-deficient mice (Tlr4 lps-del). Under such conditions, B16 cells yielded smaller tumors than nonstimulated B16 cells. The apoptosis/proliferation balance of the cells was not modified by TLR ligand treatment, nor was this effect compromised in immunocompromised nude mice. Mechanistic investigations revealed that IFNβ was the critical factor produced by TLR4-activated tumor cells in mediating their in vivo outgrowth. Transcriptional analysis showed that TLR4 activation on B16 cells induced changes in the expression of type I IFN and type I IFN-related genes. Most importantly, culture supernatants from LPS-B16 cells improved the maturation of bone marrow–derived dendritic cells (BMDC) from TLR4-deficient mice, upregulating the expression of interleukin-12 and costimulatory molecules on those cells. BMDC maturation was blunted by addition of an IFNβ-neutralizing antibody. Moreover, tumor growth inhibition observed in LPS-B16 tumors was abrogated in IFNAR1-deficient mice lacking a functional type I IFN receptor for binding IFN. Together, our findings show that tumor cells can be induced through the TLR4 pathway to produce IFN and positively contribute to the antitumoral immune response. Cancer Res; 72(3); 592–603. ©2011 AACR.
Data from NLRR1 Enhances EGF-Mediated MYCN Induction in Neuroblastoma and Accelerates Tumor Growth In Vivo
Authors: Hossain Shamim , Takatori Atsushi , Nakamura Yohko , Suenaga Yusuke , Kamijo Takehiko , Nakagawara Akira
Published: March 2024

Abstract
Neuronal leucine-rich repeat protein-1 (NLRR1), a type-1 transmembrane protein highly expressed in unfavorable neuroblastoma, is a target gene of MYCN that is predominately expressed in primary neuroblastomas with MYCN amplification. However, the precise biological role of NLRR1 in cell proliferation and tumor progression remains unknown. To investigate its functional importance, we examined the role of NLRR1 in EGF and insulin growth factor-1 (IGF-1)–mediated cell viability. We found that NLRR1 positively regulated cell proliferation through activation of extracellular signal–regulated kinase mediated by EGF and IGF-1. Interestingly, EGF stimulation induced endogenous MYCN expression through Sp1 recruitment to the MYCN promoter region, which was accelerated in NLRR1-expressing cells. The Sp1-binding site was identified on the promoter region for MYCN induction, and phosphorylation of Sp1 was important for EGF-mediated MYCN regulation. In vivo studies confirmed the proliferation-promoting activity of NLRR1 and established an association between NLRR1 expression and poor prognosis in neuroblastoma. Together, our findings indicate that NLRR1 plays an important role in the development of neuroblastoma and therefore may represent an attractive therapeutic target for cancer treatment. Cancer Res; 72(17); 4587–96. ©2012 AACR.
Data from Carbonyl Reductase 1 Offers a Novel Therapeutic Target to Enhance Leukemia Treatment by Arsenic Trioxide
Authors: Jang Miran , Kim Yeonghwan , Won Hyeran , Lim Sangbin , K.R Jyothi , Dashdorj Amarjargal , Min Yoo Hong , Kim Si-Young , Shokat Kevan M. , Ha Joohun , Kim Sung Soo
Published: March 2024

Abstract
Arsenic trioxide (As2O3) is used, in current practice, as an effective chemotherapeutic agent for acute promyelocytic leukemia (APL). However, the side effects and relatively low efficacy of As2O3 in treating other leukemias have limited its wider use in therapeutic applications. In the present study, we found that the expression of carbonyl reductase 1 (CBR1) affects the resistance to As2O3 in leukemias, including APL; As2O3 upregulated CBR1 expression at the transcriptional level by stimulating the activity of the transcription factor activator protein-1. Moreover, CBR1 overexpression was sufficient to protect cells against As2O3 through modulation of the generation of reactive oxygen species, whereas the attenuation of CBR1 was sufficient to sensitize cells to As2O3. A combination treatment with the specific CBR1 inhibitor hydroxy-PP-Me remarkably increased As2O3-induced apoptotic cell death compared with As2O3 alone, both in vitro and in vivo. These results were confirmed in primary cultured human acute and chronic myeloid leukemia cells, with no significant cell death observed in normal leukocytes. Taken together, our findings indicate that CBR1 contributes to the low efficacy of As2O3 and, therefore, is a rational target for the development of combination chemotherapy with As2O3 in diverse leukemias including APL. Cancer Res; 72(16); 4214–24. ©2012 AACR.
Data from In Vivo Regulation of TGF-β by R-Ras2 Revealed through Loss of the RasGAP Protein NF1
Authors: Patmore Deanna M. , Welch Sara , Fulkerson Patricia C. , Wu Jianqiang , Choi Kwangmin , Eaves David , Kordich Jennifer J. , Collins Margaret H. , Cripe Timothy P. , Ratner Nancy
Published: March 2024

Abstract
Ras superfamily proteins participate in TGF-β—mediated developmental pathways that promote either tumor suppression or progression. However, the specific Ras proteins, which integrate in vivo with TGF-β signaling pathways, are unknown. As a general approach to this question, we activated all Ras proteins in vivo by genetic deletion of the RasGAP protein Nf1 and examined mice doubly deficient in a Ras protein to determine its requirement in formation of TGF-β—dependent neurofibromas that arise in Nf1-deficient mice. Animals lacking Nf1 and the Ras-related protein R-Ras2/TC21 displayed a delay in formation of neurofibromas but an acceleration in formation of brain tumors and sarcomas. Loss of R-Ras2 was associated with elevated expression of TGF-β in Nf1-deficient Schwann cell precursors, blockade of a Nf1/TGFβRII/AKT-dependent autocrine survival loop in tumor precursor cells, and decreased precursor cell numbers. Furthermore, the increase in size of sarcomas from xenografts doubly deficient in these genes was also found to be TGF-β—dependent, in this case resulting from cell nonautonomous effects on endothelial cells and myofibroblasts. Extending these findings in clinical specimens, we documented an increase in TGF-β ligands and an absence of TGF-β receptor II in malignant peripheral nerve sheath tumors, which correspond to tumors in the Nf1-deficient mouse model. Together, our findings reveal R-Ras2 as a critical regulator of TGF-β signaling in vivo. Cancer Res; 72(20); 5317–27. ©2012 AACR.
Data from CD24 Offers a Therapeutic Target for Control of Bladder Cancer Metastasis Based on a Requirement for Lung Colonization
Authors: Overdevest Jonathan B. , Thomas Shibu , Kristiansen Glen , Hansel Donna E. , Smith Steven C. , Theodorescu Dan
Published: March 2024

Abstract
Metastasis is lethal in most bladder cancer patients. Expression of CD24, a glycosyl phosphatidylinositol (GPI)-linked sialoglycoprotein and cancer stem cell marker, is associated with metastatic progression in multiple cancer types, yet the role of CD24 in this process remains unclear. While developing a murine model of human metastatic bladder cancer, we observed that tumor cell CD24 expression correlated with a propensity to metastasize to the lung. Our immunohistochemical evaluation of 60 paired primary and metastatic human bladder cancer samples revealed increased intensity (P < 0.001) and frequency (P < 0.001) of CD24 expression in metastases. To directly evaluate the role of CD24 in metastatic colonization, we manipulated CD24 expression in human bladder cancer cell lines using short hairpin RNA depletion, cDNA overexpression, and fluorescence-activated cell sorting selection. Although suppression of CD24 reduced acute tumor cell retention in the lungs of mice inoculated intravenously with cancer cells, this differential retention was no longer apparent after 24 hours, prompting us to evaluate the role of CD24 in lung colonization. Here, CD24 was found necessary for subsequent development of lung metastases. We next treated clinically detectable lung metastases in mice with anti-CD24 antibody and observed reduced tumor growth and prolonged survival. These findings suggest that CD24 is a lynchpin of metastatic progression and a promising therapeutic target for antimetastatic therapy. Cancer Res; 71(11); 3802–11. ©2011 AACR.
Data from Autophagy Induced by Conventional Chemotherapy Mediates Tumor Cell Sensitivity to Immunotherapy
Authors: Ramakrishnan Rupal , Huang Chun , Cho Hyun-Il , Lloyd Mark , Johnson Joseph , Ren Xiubao , Altiok Soner , Sullivan Daniel , Weber Jeffrey , Celis Esteban , Gabrilovich Dmitry I.
Published: March 2024

Abstract
Autophagy attenuates the efficacy of conventional chemotherapy but its effects on immunotherapy have been little studied. Here, we report that chemotherapy renders tumor cells more susceptible to lysis by CTL in vivo. Moreover, bystander tumor cells that did not express antigen were killed by CTL. This effect was mediated by transient but dramatic upregulation of the mannose-6-phosphate receptor (MPR) on the tumor cell surface. Antitumor effects of combined treatment related to the kinetics of MPR upregulation and abrogation of this event abolished the combined effect of immunotherapy and chemotherapy. MPR accumulation on the tumor cell surface during chemotherapy was observed in different mouse tumor models and in patients with multiple myeloma. Notably, this effect was the result of redistribution of the receptor caused by chemotherapy-inducible autophagy. Together, our findings reveal one molecular mechanism through which the antitumor effects of conventional cancer chemotherapy and immunotherapy are realized. Cancer Res; 72(21); 5483–93. ©2012 AACR.