bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Transcriptome Analysis Reveals that p53 and β-Catenin Alterations Occur in a Group of Aggressive Adrenocortical Cancers
Authors: Ragazzon Bruno , Libé Rossella , Gaujoux Sébastien , Assié Guillaume , Fratticci Amato , Launay Pierre , Clauser Eric , Bertagna Xavier , Tissier Frédérique , de Reyniès Aurélien , Bertherat Jérôme
Published: March 2024

Abstract
Adrenocortical carcinoma (ACC) is a rare disease with an overall poor but heterogeneous prognosis. This heterogeneity could reflect different mechanisms of tumor development. Gene expression profiling by transcriptome analysis led to ACC being divided into two groups of tumors with very different outcomes. Somatic inactivating mutations of the tumor suppressor gene TP53 and activating mutations of the proto-oncogene β-catenin (CTNNB1) are the most frequent mutations identified in ACC. This study investigates the correlation between p53 and β-catenin alterations and the molecular classification of ACC by transcriptome analysis of 51 adult sporadic ACCs. All TP53 and CTNNB1 mutations seemed to be mutually exclusive and were observed only in the poor-outcome ACC group. Most of the abnormal p53 and β-catenin immunostaining was also found in this group. Fifty-two percent of the poor-outcome ACC group had TP53 or CTNNB1 mutations and 60% had abnormal p53 or β-catenin immunostaining. Unsupervised clustering transcriptome analysis of this poor-outcome group revealed three different subgroups, two of them being associated with p53 or β-catenin alterations, respectively. Analysis of p53 and β-catenin target gene expressions in each cluster confirmed a profound and anticipated effect on tumor biology, with distinct profiles logically associated with the respective pathway alterations. The third group had no p53 or β-catenin alteration, suggesting other unidentified molecular defects. This study shows the important respective roles of p53 and β-catenin in ACC development, delineating subgroups of ACC with different tumorigenesis and outcomes. Cancer Res; 70(21); 8276–81. ©2010 AACR.
Data from Signal Transducers and Activators of Transcription-3 Binding to the Fibroblast Growth Factor Receptor Is Activated by Receptor Amplification
Authors: Dudka Anna A. , Sweet Steve M.M. , Heath John K.
Published: March 2024

Abstract
Fibroblast growth factor receptors (FGFR) are cell surface tyrosine kinases that function in cell proliferation and differentiation. Aberrant FGFR signaling occurs in diverse cancers due to gene amplification, but the associated oncogenic mechanisms are poorly understood. Using a proteomics approach, we identified signal transducers and activators of transcription-3 (STAT3) as a receptor-binding partner that is mediated by Tyr677 phosphorylation on FGFR. Binding to activated FGFR was essential for subsequent tyrosine phosphorylation and nuclear translocation of STAT3, along with activation of its downstream target genes. Tyrosine phosphorylation of STAT3 was also dependent on concomitant FGFR-dependent activity of SRC and JAK kinases. Lastly, tyrosine (but not serine) phosphorylation of STAT3 required amplified FGFR protein expression, generated either by enforced overexpression or as associated with gene amplification in cancer cells. Our findings show that amplified FGFR expression engages the STAT3 pathway, and they suggest therapeutic strategies to attack FGFR-overexpressing cancers. Cancer Res; 70(8); 3391–401. ©2010 AACR.
Data from Downregulation of HtrA1 Promotes Resistance to Anoikis and Peritoneal Dissemination of Ovarian Cancer Cells
Authors: He Xiaoping , Ota Takayo , Liu Peng , Su Changqing , Chien Jeremy , Shridhar Viji
Published: March 2024

Abstract
We previously identified serine protease HtrA1 as a downregulated gene in epithelial ovarian cancer (EOC), but the functional consequence of loss of HtrA1 in EOC remains largely unclear. Here, we report that loss of HtrA1 attenuates anoikis—a critical physiologic barrier for tumor metastasis. In response to loss of anchorage, HtrA1 expression was upregulated in SKOV3 cells, resulting in autocatalytic activation of HtrA1. Stable knockdown of HtrA1 in SKOV3 and TOV21G cells resulted in resistance to anoikis due to enhanced activation of epidermal growth factor receptor (EGFR)/AKT pathway. In suspended SKOV3 cells, enhanced expression of HtrA1 inhibited EGFR/AKT pathway, leading to increased cell death, whereas protease-inactive mutant HtrA1 failed to result in either the inhibition of EGFR/AKT pathway or increased cell death, suggesting the requirement of HtrA1 protease activity in regulating anoikis. Immunoprecipitation and immunofluorescence assays revealed that HtrA1 interacted with EGFR not only on the cell membrane but also in the nucleus. Most importantly, downregulation of HtrA1 significantly enhanced the peritoneal dissemination of SKOV3ip1 cells in nonobese diabetic/severe combined immunodeficient mice, with increased phospho-EGFR level in corresponding tumor nodules compared with that in xenografts originated from the control cells. Taken together, these data reveal for the first time a novel function of HtrA1 in promoting anoikis by attenuating activation of EGFR/AKT pathway that may contribute to its metastasis suppression capacity, thus providing a possible explanation for the aggressive nature of human ovarian tumors with downregulated HtrA1. Cancer Res; 70(8); 3109–18. ©2010 AACR.
Data from Tumor Stroma–Derived Wnt5a Induces Differentiation of Basal Cell Carcinoma of Ptch-Mutant Mice via CaMKII
Authors: Nitzki Frauke , Zibat Arne , König Simone , Wijgerde Mark , Rosenberger Albert , Brembeck Felix H. , Carstens Per-Ole , Frommhold Anke , Uhmann Anja , Klingler Stefan , Reifenberger Julia , Pukrop Tobias , Aberger Fritz , Schulz-Schaeffer Walter , Hahn Heidi
Published: March 2024

Abstract
Basal cell carcinoma (BCC) is the most common skin tumor in humans. Although BCCs rarely metastasize, they can cause significant morbidity due to local aggressiveness. Approximately 20% of BCCs show signs of spontaneous regression. The understanding of molecular events mediating spontaneous regression has the potential to reduce morbidity of BCC and, potentially, other tumors, if translated into tumor therapies. We show that BCCs induced in conditional Ptchflox/floxERT2+/− knockout mice regress with time and show a more differentiated phenotype. Differentiation is accompanied by Wnt5a expression in the tumor stroma, which is first detectable at the fully developed tumor stage. Coculture experiments revealed that Wnt5a is upregulated in tumor-adjacent macrophages by soluble signals derived from BCC cells. In turn, Wnt5a induces the expression of the differentiation marker K10 in tumor cells, which is mediated by Wnt/Ca2+ signaling in a CaMKII-dependent manner. These data support a role of stromal Wnt5a in BCC differentiation and regression, which may have important implications for development of new treatment strategies for this tumor. Taken together, our results establish BCC as an easily accessible model of tumor regression. The regression of BCC despite sustained Hedgehog signaling activity seems to be mediated by tumor-stromal interactions via Wnt5a signaling. Cancer Res; 70(7); 2739–48
Data from Deoxycytidine Kinase Modulates the Impact of the ABC Transporter ABCG2 on Clofarabine Cytotoxicity
Authors: Nagai Shinjiro , Takenaka Kazumasa , Nachagari Deepa , Rose Charles , Domoney Kali , Sun Daxi , Sparreboom Alex , Schuetz John D.
Published: March 2024

Abstract
Purine nucleoside antimetabolites, such as clofarabine, are effective antileukemic agents. However, their effectiveness depends on an initial activation step in which they are monophosphorylated by deoxycytidine kinase (dCK). Some purine nucleoside antimetabolites and their monophosphate derivatives are exported by the ABC transporter ABCG2. Because clofarabine is a dCK substrate, and we show substantial variation in dCK and ABCG2 in myeloid leukemia, we hypothesized that the activity of dCK may modulate ABCG2-mediated resistance to clofarabine by regulating the formation of clofarabine monophosphate. We show that ABCG2 influence on clofarabine cytotoxicity was markedly influenced by dCK activity. When dCK expression was reduced by siRNA, clofarabine cytotoxicity was strongly reduced by enhanced ABCG2-mediated efflux. Conversely, dCK overexpression blunted ABCG2-mediated efflux of clofarabine by increasing the formation of clofarabine nucleotides. The use of an ABCG2 inhibitor confirmed that ABCG2 export of clofarabine is maximal when dCK levels are minimal. Analysis of intracellular clofarabine metabolites suggested that ABCG2 exported clofarabine more readily than clofarabine monophosphate. That ABCG2 primarily effluxes clofarabine, but not chlorfarabine-monophosphate, was confirmed by HPLC analysis of drug exported from ABCG2-overexpressing cells. Because the level and function of dCK and ABCG2 vary substantially among other types of cancer, these findings have important implications not only for clofarabine therapy but for purine nucleoside therapy in general. Therefore, we propose that addition of ABCG2 inhibitors would effectively increase the antitumor efficacy of purine nucleosides by blocking drug efflux that may be a significant mode of resistance when dCK levels are low. Cancer Res; 71(5); 1781–91. ©2011 AACR.
Data from Transcription Factor KLF11 Integrates Progesterone Receptor Signaling and Proliferation in Uterine Leiomyoma Cells
Authors: Yin Ping , Lin Zhihong , Reierstad Scott , Wu Ju , Ishikawa Hiroshi , Marsh Erica E. , Innes Joy , Cheng Youhong , Pearson Kerry , Coon John Sayler , Kim J. Julie , Chakravarti Debabrata , Bulun Serdar E.
Published: March 2024

Abstract
Uterine leiomyoma is the most common tumor of the female genital tract and the leading cause of hysterectomy. Although progesterone stimulates the proliferation of uterine leiomyoma cells, the mechanism of progesterone action is not well understood. We used chromatin immunoprecipitation (ChIP)–cloning approach to identify progesterone receptor (PR) target genes in primary uterine leiomyoma smooth muscle cells. We identified 18 novel PR-binding sites, one of which was located 20.5 kb upstream of the transcriptional start site of the Krüppel-like transcription factor 11 (KLF11) gene. KLF11 mRNA levels were minimally downregulated by progesterone but robustly upregulated by the progesterone antagonist RU486. Luciferase reporter assays showed significant baseline and RU486-inducible promoter activity in the KLF11 basal promoter or distal PR-binding region, both of which contained multiple Sp1-binding sequences but lacked classic progesterone response elements. RU486 stimulated recruitment of Sp1, RNA polymerase II, PR, and the coactivators SRC-1 and SRC-2 to the distal region and basal promoter. siRNA knockdown of PR increased KLF11 expression, whereas knockdown of KLF11 increased leiomyoma cell proliferation and abolished the antiproliferative effect of RU486. In vivo, KLF11 expression was significantly lower in leiomyoma tissues compared with adjacent myometrial tissues. Taken together, using a ChIP-cloning approach, we uncovered KLF11 as an integrator of PR signaling and proliferation in uterine leiomyoma cells. Cancer Res; 70(4); 1722–30
Data from Combined Gene Expression and Genomic Profiling Define Two Intrinsic Molecular Subtypes of Urothelial Carcinoma and Gene Signatures for Molecular Grading and Outcome
Authors: Lindgren David , Frigyesi Attila , Gudjonsson Sigurdur , Sjödahl Gottfrid , Hallden Christer , Chebil Gunilla , Veerla Srinivas , Ryden Tobias , Månsson Wiking , Liedberg Fredrik , Höglund Mattias
Published: March 2024

Abstract
In the present investigation, we sought to refine the classification of urothelial carcinoma by combining information on gene expression, genomic, and gene mutation levels. For these purposes, we performed gene expression analysis of 144 carcinomas, and whole genome array-CGH analysis and mutation analyses of FGFR3, PIK3CA, KRAS, HRAS, NRAS, TP53, CDKN2A, and TSC1 in 103 of these cases. Hierarchical cluster analysis identified two intrinsic molecular subtypes, MS1 and MS2, which were validated and defined by the same set of genes in three independent bladder cancer data sets. The two subtypes differed with respect to gene expression and mutation profiles, as well as with the level of genomic instability. The data show that genomic instability was the most distinguishing genomic feature of MS2 tumors, and that this trait was not dependent on TP53/MDM2 alterations. By combining molecular and pathologic data, it was possible to distinguish two molecular subtypes of Ta and T1 tumors, respectively. In addition, we define gene signatures validated in two independent data sets that classify urothelial carcinoma into low-grade (G1/G2) and high-grade (G3) tumors as well as non-muscle and muscle-invasive tumors with high precisions and sensitivities, suggesting molecular grading as a relevant complement to standard pathologic grading. We also present a gene expression signature with independent prognostic effect on metastasis and disease-specific survival. We conclude that the combination of molecular and histopathologic classification systems might provide a strong improvement for bladder cancer classification and produce new insights into the development of this tumor type. Cancer Res; 70(9); 3463–72. ©2010 AACR.
Data from Sp100 as a Potent Tumor Suppressor: Accelerated Senescence and Rapid Malignant Transformation of Human Fibroblasts through Modulation of an Embryonic Stem Cell Program
Authors: Negorev Dmitri G. , Vladimirova Olga V. , Kossenkov Andrew V. , Nikonova Elena V. , Demarest Renee M. , Capobianco Anthony J. , Showe Michael K. , Rauscher Frank J. , Showe Louise C. , Maul Gerd G.
Published: March 2024

Abstract
Identifying the functions of proteins, which associate with specific subnuclear structures, is critical to understanding eukaryotic nuclear dynamics. Sp100 is a prototypical protein of ND10/PML nuclear bodies, which colocalizes with Daxx and the proto-oncogenic PML. Sp100 isoforms contain SAND, PHD, Bromo, and HMG domains and are highly sumoylated, all characteristics suggestive of a role in chromatin-mediated gene regulation. A role for Sp100 in oncogenesis has not been defined previously. Using selective Sp100 isoform-knockdown approaches, we show that normal human diploid fibroblasts with reduced Sp100 levels rapidly senesce. Subsequently, small rapidly dividing Sp100 minus cells emerge from the senescing fibroblasts and are found to be highly tumorigenic in nude mice. The derivation of these tumorigenic cells from the parental fibroblasts is confirmed by microsatellite analysis. The small rapidly dividing Sp100 minus cells now also lack ND10/PML bodies, and exhibit genomic instability and p53 cytoplasmic sequestration. They have also activated MYC, RAS, and TERT pathways and express mesenchymal to epithelial transdifferentiation (MET) markers. Reintroduction of expression of only the Sp100A isoform is sufficient to maintain senescence and to inhibit emergence of the highly tumorigenic cells. Global transcriptome studies, quantitative PCR, and protein studies, as well as immunolocalization studies during the course of the transformation, reveal that a transient expression of stem cell markers precedes the malignant transformation. These results identify a role for Sp100 as a tumor suppressor in addition to its role in maintaining ND10/PML bodies and in the epigenetic regulation of gene expression. Cancer Res; 70(23); 9991–10001. ©2010 AACR.
Data from Targeted Inhibition of Replication Protein A Reveals Cytotoxic Activity, Synergy with Chemotherapeutic DNA-Damaging Agents, and Insight into Cellular Function
Authors: Shuck Sarah C. , Turchi John J.
Published: March 2024

Abstract
Targeting uncontrolled cell proliferation and resistance to DNA-damaging chemotherapeutics with a single agent has significant potential in cancer treatment. Replication protein A (RPA), the eukaryotic ssDNA-binding protein, is essential for genomic maintenance and stability via roles in both DNA replication and repair. We have identified a novel small molecule that inhibits the in vitro and cellular ssDNA-binding activity of RPA, prevents cell cycle progression, induces cytotoxicity, and increases the efficacy of chemotherapeutic DNA-damaging agents. These results provide new insight into the mechanism of RPA-ssDNA interactions in chromosome maintenance and stability. This represents the first molecularly targeted eukaryotic DNA-binding inhibitor and reveals the utility of targeting a protein-DNA interaction as a therapeutic strategy for cancer treatment. Cancer Res; 70(8); 3189–98. ©2010 AACR.
Data from NF-κB–Inhibited Acute Myeloid Leukemia Cells Are Rescued from Apoptosis by Heme Oxygenase-1 Induction
Authors: Rushworth Stuart A. , Bowles Kristian M. , Raninga Prahlad , MacEwan David J.
Published: March 2024

Abstract
Despite high basal NF-κB activity in acute myeloid leukemia (AML) cells, inhibiting NF-κB in these cells has little or no effect on inducing apoptosis. We previously showed that heme oxygenase-1 (HO-1) underlies this resistance of AML to tumor necrosis factor–induced apoptosis. Here, we describe a mechanism by which HO-1 is a silent antiapoptotic factor only revealed when NF-κB is inhibited, thus providing a secondary antiapoptotic mechanism to ensure AML cell survival and chemoresistance. We show that inhibition of NF-κB increased HO-1 expression in primary AML cells compared with that of nonmalignant cells. In addition, we observed this suppressed HO-1 level in AML cells compared with CD34+ nonmalignant control cells. Using chromatin immunoprecipitation assay and small interfering RNA knockdown, we showed that the NF-κB subunits p50 and p65 control this suppression of HO-1 in AML cells. Finally, we showed that inhibition of HO-1 and NF-κB in combination significantly induced apoptosis in AML cells but not in noncancerous control cells. Thus, NF-κB inhibition combined with HO-1 inhibition potentially provides a novel therapeutic approach to treat chemotherapy-resistant forms of AML. Cancer Res; 70(7); 2973–83
Data from Genetic and Structural Variation in the Gastric Cancer Kinome Revealed through Targeted Deep Sequencing
Authors: Zang Zhi Jiang , Ong Choon Kiat , Cutcutache Ioana , Yu Willie , Zhang Shen Li , Huang Dachuan , Ler Lian Dee , Dykema Karl , Gan Anna , Tao Jiong , Lim Siyu , Liu Yujing , Futreal P. Andrew , Grabsch Heike , Furge Kyle A. , Goh Liang Kee , Rozen Steve , Teh Bin Tean , Tan Patrick
Published: March 2024

Abstract
Genetic alterations in kinases have been linked to multiple human pathologies. To explore the landscape of kinase genetic variation in gastric cancer (GC), we used targeted, paired-end deep sequencing to analyze 532 protein and phosphoinositide kinases in 14 GC cell lines. We identified 10,604 single-nucleotide variants (SNV) in kinase exons including greater than 300 novel nonsynonymous SNVs. Family-wise analysis of the nonsynonymous SNVs revealed a significant enrichment in mitogen-activated protein kinase (MAPK)-related genes (P < 0.01), suggesting a preferential involvement of this kinase family in GC. A potential antioncogenic role for MAP2K4, a gene exhibiting recurrent alterations in 2 lines, was functionally supported by siRNA knockdown and overexpression studies in wild-type and MAP2K4 variant lines. The deep sequencing data also revealed novel, large-scale structural rearrangement events involving kinases including gene fusions involving CDK12 and the ERBB2 receptor tyrosine kinase in MKN7 cells. Integrating SNVs and copy number alterations, we identified Hs746T as a cell line exhibiting both splice-site mutations and genomic amplification of MET, resulting in MET protein overexpression. When applied to primary GCs, we identified somatic mutations in 8 kinases, 4 of which were recurrently altered in both primary tumors and cell lines (MAP3K6, STK31, FER, and CDKL5). These results demonstrate that how targeted deep sequencing approaches can deliver unprecedented multilevel characterization of a medically and pharmacologically relevant gene family. The catalog of kinome genetic variants assembled here may broaden our knowledge on kinases and provide useful information on genetic alterations in GC. Cancer Res; 71(1); 29–39. ©2011 AACR.
Data from Effects of Acute versus Chronic Hypoxia on DNA Damage Responses and Genomic Instability
Authors: Pires Isabel M. , Bencokova Zuzana , Milani Manuela , Folkes Lisa K. , Li Ji-Liang , Stratford Mike R. , Harris Adrian L. , Hammond Ester M.
Published: March 2024

Abstract
Questions exist concerning the effects of acute versus chronic hypoxic conditions on DNA replication and genomic stability that may influence tumorigenesis. Severe hypoxia causes replication arrest independent of S-phase checkpoint, DNA damage response, or transformation status. Arrests occur during both the initiation and elongation phases of DNA replication, correlated with a rapid decrease in available deoxynucleotide triphosphates. With fluctuating oxygen tensions in tumors, arrested hypoxic cells may undergo rapid reperfusion and reoxygenation that leads to reoxygenation-induced DNA damage. In cells subjected to chronic hypoxia, we found that replicative restart was inhibited along with numerous replication factors, including MCM6 and RPA, the latter of which limits the hypoxia-induced DNA damage response. In contrast, in cells where replicative restart occurred, it was accompanied by extensive reoxygenation-induced DNA damage and compromised DNA repair. We found that cells reoxygenated after acute hypoxia underwent rapid p53-dependent apoptosis. Our findings suggest that cells lacking functional p53 are more susceptible to genomic instability and potentially tumorigenesis if they experience reoxygenation after acute exposure to hypoxia. Cancer Res; 70(3); 925–35
Data from miR-375 Is Activated by ASH1 and Inhibits YAP1 in a Lineage-Dependent Manner in Lung Cancer
Authors: Nishikawa Eri , Osada Hirotaka , Okazaki Yasumasa , Arima Chinatsu , Tomida Shuta , Tatematsu Yoshio , Taguchi Ayumu , Shimada Yukako , Yanagisawa Kiyoshi , Yatabe Yasushi , Toyokuni Shinya , Sekido Yoshitaka , Takahashi Takashi
Published: March 2024

Abstract
Lung cancers with neuroendocrine (NE) features are often very aggressive but the underlying molecular mechanisms remain elusive. The transcription factor ASH1/ASCL1 is a master regulator of pulmonary NE cell development that is involved in the pathogenesis of lung cancers with NE features (NE-lung cancers). Here we report the definition of the microRNA miR-375 as a key downstream effector of ASH1 function in NE-lung cancer cells. miR-375 was markedly induced by ASH1 in lung cancer cells where it was sufficient to induce NE differentiation. miR-375 upregulation was a prerequisite for ASH1-mediated induction of NE features. The transcriptional coactivator YAP1 was determined to be a direct target of miR-375. YAP1 showed a negative correlation with miR-375 in a panel of lung cancer cell lines and growth inhibitory activities in NE-lung cancer cells. Our results elucidate an ASH1 effector axis in NE-lung cancers that is functionally pivotal in controlling NE features and the alleviation from YAP1-mediated growth inhibition. Cancer Res; 71(19); 6165–73. ©2011 AACR.
Data from Pancreatic Ductal Adenocarcinoma Mice Lacking Mucin 1 Have a Profound Defect in Tumor Growth and Metastasis
Authors: Besmer Dahlia M. , Curry Jennifer M. , Roy Lopamudra D. , Tinder Teresa L. , Sahraei Mahnaz , Schettini Jorge , Hwang Sun-Il , Lee Yong Y. , Gendler Sandra J. , Mukherjee Pinku
Published: March 2024

Abstract
MUC1 is overexpressed and aberrantly glycosylated in more than 60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In this study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared with both KC and KCM. Cell lines derived from KCKO tumors have significantly less tumorigenic capacity compared with cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared with mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor, platelet-derived growth factor, or matrix metalloproteinase 9. Further, significantly less KCKO cells entered the G2–M phase of the cell cycle compared with the KCM cells. Proteomics and Western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of mitogen-activated protein kinase (MAPK), as well as a significant decrease in nestin and tubulin-α2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. Cancer Res; 71(13); 4432–42. ©2011 AACR.
Data from Contribution of Abcc10 (Mrp7) to In Vivo Paclitaxel Resistance as Assessed in Abcc10−/− Mice
Authors: Hopper-Borge Elizabeth A. , Churchill Timothy , Paulose Chelsy , Nicolas Emmanuelle , Jacobs Joely D. , Ngo Olivia , Kuang Yehong , Grinberg Alex , Westphal Heiner , Chen Zhe-Sheng , Klein-Szanto Andres J. , Belinsky Martin G. , Kruh Gary D.
Published: March 2024

Abstract
Recently, we reported that the ATP-binding cassette transporter 10 (ABCC10), also known as multidrug resistance protein 7 (MRP7), is able to confer resistance to a variety of anticancer agents, including taxanes. However, the in vivo functions of the pump have not been determined to any extent. In this study, we generated and analyzed Abcc10−/− mice to investigate the ability of Abcc10 to function as an endogenous resistance factor. Mouse embryo fibroblasts derived from Abcc10−/− mice were hypersensitive to docetaxel, paclitaxel, vincristine, and cytarabine (Ara-C) and exhibited increased cellular drug accumulation, relative to wild-type controls. Abcc10−/− null mice treated with paclitaxel exhibited increased lethality associated with neutropenia and marked bone marrow toxicity. In addition, toxicity in spleen and thymus was evident. These findings indicate that Abcc10 is dispensable for health and viability and that it is an endogenous resistance factor for taxanes, other natural product agents, and nucleoside analogues. This is the first demonstration that an ATP-binding cassette transporter other than P-glycoprotein can affect in vivo tissue sensitivity toward taxanes. Cancer Res; 71(10); 3649–57. ©2011 AACR.
Data from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis
Authors: Hartman Zachary C. , Yang Xiao-Yi , Glass Oliver , Lei Gangjun , Osada Takuya , Dave Sandeep S. , Morse Michael A. , Clay Timothy M. , Lyerly Herbert K.
Published: March 2024

Abstract
HER2 overexpression occurs in approximately 25% of breast cancers, where it correlates with poor prognosis. Likewise, systemic inflammation in breast cancer correlates with poor prognosis, although the process is not understood. In this study, we explored the relationship between HER2 and inflammation, comparing the effects of overexpressing wild-type or mutated inactive forms of HER2 in primary human breast cells. Wild-type HER2 elicited a profound transcriptional inflammatory profile, including marked elevation of interleukin-6 (IL-6) expression, which we established to be a critical determinant of HER2 oncogenesis. Mechanistic investigations revealed that IL-6 secretion induced by HER2 overexpression activated Stat3 and altered gene expression, enforcing an autocrine loop of IL-6/Stat3 expression. Both mouse and human in vivo models of HER2-amplified breast carcinoma relied critically on this HER2–IL-6–Stat3 signaling pathway. Our studies offer the first direct evidence linking HER2 to a systemic inflammatory mechanism that orchestrates HER2-mediated tumor growth. We suggest that the HER2–IL-6–STAT3 signaling axis we have defined in breast cancer could prompt new therapeutic or prevention strategies for treatment of HER2-amplified cancers. Cancer Res; 71(13); 4380–91. ©2011 AACR.
Data from Genome-wide Methylation Analysis Identifies Genes Specific to Breast Cancer Hormone Receptor Status and Risk of Recurrence
Authors: Fackler Mary Jo , Umbricht Christopher B. , Williams Danielle , Argani Pedram , Cruz Leigh-Ann , Merino Vanessa F. , Teo Wei Wen , Zhang Zhe , Huang Peng , Visvananthan Kala , Marks Jeffrey , Ethier Stephen , Gray Joe W. , Wolff Antonio C. , Cope Leslie M. , Sukumar Saraswati
Published: March 2024

Abstract
To better understand the biology of hormone receptor–positive and–negative breast cancer and to identify methylated gene markers of disease progression, we carried out a genome-wide methylation array analysis on 103 primary invasive breast cancers and 21 normal breast samples, using the Illumina Infinium HumanMethylation27 array that queried 27,578 CpG loci. Estrogen and/or progesterone receptor–positive tumors displayed more hypermethylated loci than estrogen receptor (ER)-negative tumors. However, the hypermethylated loci in ER-negative tumors were clustered closer to the transcriptional start site compared with ER-positive tumors. An ER-classifier set of CpG loci was identified, which independently partitioned primary tumors into ER subtypes. A total of 40 (32 novel and 8 previously known) CpG loci showed differential methylation specific to either ER-positive or ER-negative tumors. Each of the 40 ER subtype–specific loci was validated in silico, using an independent, publicly available methylome dataset from the Cancer Genome Atlas. In addition, we identified 100 methylated CpG loci that were significantly associated with disease progression; the majority of these loci were informative particularly in ER-negative breast cancer. Overall, the set was highly enriched in homeobox containing genes. This pilot study shows the robustness of the breast cancer methylome and illustrates its potential to stratify and reveal biological differences between ER subtypes of breast cancer. Furthermore, it defines candidate ER-specific markers and identifies potential markers predictive of outcome within ER subgroups. Cancer Res; 71(19); 6195–207. ©2011 AACR.
Data from HDAC4-Regulated STAT1 Activation Mediates Platinum Resistance in Ovarian Cancer
Authors: Stronach Euan A. , Alfraidi Albandri , Rama Nona , Datler Christoph , Studd James B. , Agarwal Roshan , Guney Tankut G. , Gourley Charlie , Hennessy Bryan T. , Mills Gordon B. , Mai Antonello , Brown Robert , Dina Roberto , Gabra Hani
Published: March 2024

Abstract
Ovarian cancer frequently acquires resistance to platinum chemotherapy, representing a major challenge for improving patient survival. Recent work suggests that resistant clones exist within a larger drug-sensitive cell population prior to chemotherapy, implying that resistance is selected for rather than generated by treatment. We sought to compare clinically derived, intrapatient paired models of initial platinum response and subsequent resistant relapse to define molecular determinants of evolved resistance. Transcriptional analysis of a matched cell line series from three patients with high-grade serous ovarian cancer before and after development of clinical platinum resistance (PEO1/PEO4/PEO6, PEA1/PEA2, PEO14/PEO23) identified 91 up- and 126 downregulated genes common to acquired resistance. Significantly enhanced apoptotic response to platinum treatment in resistant cells was observed following knockdown of histone deacetylase (HDAC) 4, FOLR2, PIK3R1, or STAT1 (P < 0.05). Interestingly, HDAC4 and STAT1 were found to physically interact. Acetyl-STAT1 was detected in platinum-sensitive cells but not in HDAC4 overexpressing platinum-resistant cells from the same patient. In resistant cells, STAT1 phosphorylation/nuclear translocation was seen following platinum exposure, whereas silencing of HDAC4 increased acetyl-STAT1 levels, prevented platinum-induced STAT1 activation, and restored cisplatin sensitivity. Conversely, matched sensitive cells were refractory to STAT1 phosphorylation on platinum treatment. Analysis of 16 paired tumor biopsies taken before and after development of clinical platinum resistance showed significantly increased HDAC4 expression in resistant tumors [n = 7 of 16 (44%); P = 0.04]. Therefore, clinical selection of HDAC4-overexpressing tumor cells upon exposure to chemotherapy promotes STAT1 deacetylation and cancer cell survival. Together, our findings identify HDAC4 as a novel, therapeutically tractable target to counter platinum resistance in ovarian cancer. Cancer Res; 71(13); 4412–22. ©2011 AACR.
Data from Imaging DNA Damage In Vivo Using γH2AX-Targeted Immunoconjugates
Authors: Cornelissen Bart , Kersemans Veerle , Darbar Sonali , Thompson James , Shah Ketan , Sleeth Kate , Hill Mark A. , Vallis Katherine A.
Published: March 2024

Abstract
DNA damage responses (DDR) occur during oncogenesis and therapeutic responses to DNA damaging cytotoxic drugs. Thus, a real-time method to image DNA damage in vivo would be useful to diagnose cancer and monitor its treatment. Toward this end, we have developed fluorophore- and radioisotope-labeled immunoconjugates to target a DDR signaling protein, phosphorylated histone H2A variant H2AX (γH2AX), which forms foci at sites of DNA double-strand breaks. Anti-γH2AX antibodies were modified by the addition of diethylenetriaminepentaacetic acid (DTPA) to allow 111In labeling or the fluorophore Cy3. The cell-penetrating peptide Tat (GRKKRRQRRRPPQGYG) was also added to the immunoconjugate to aid nuclear translocation. In irradiated breast cancer cells, confocal microscopy confirmed the expected colocalization of anti-γH2AX-Tat with γH2AX foci. In comparison with nonspecific antibody conjugates, 111In-anti-γH2AX-Tat was retained longer in cells. Anti-γH2AX-Tat probes were also used to track in vivo DNA damage, using a mouse xenograft model of human breast cancer. After local X-ray irradiation or bleomycin treatment, the anti-γH2AX-Tat probes produced fluorescent and single photon emission computed tomography signals in the tumors that were proportionate to the delivered radiation dose and the amount of γH2AX present. Taken together, our findings establish the use of radioimmunoconjugates that target γH2AX as a noninvasive imaging method to monitor DNA damage, with many potential applications in preclinical and clinical settings. Cancer Res; 71(13); 4539–49. ©2011 AACR.
Data from Activation of Toll-like Receptor 5 on Breast Cancer Cells by Flagellin Suppresses Cell Proliferation and Tumor Growth
Authors: Cai Zhenyu , Sanchez Amir , Shi Zhongcheng , Zhang Tingting , Liu Mingyao , Zhang Dekai
Published: March 2024

Abstract
Increasing evidence showed that Toll-like receptors (TLR), key receptors in innate immunity, play a role in cancer progression and development but activation of different TLRs might exhibit the exact opposite outcome, antitumor or protumor effects. TLR function has been extensively studied in innate immune cells, so we investigated the role of TLR signaling in breast cancer epithelial cells. We found that TLR5 was highly expressed in breast carcinomas and that TLR5 signaling pathway is overly responsive in breast cancer cells. Interestingly, flagellin/TLR5 signaling in breast cancer cells inhibits cell proliferation and an anchorage-independent growth, a hallmark of tumorigenic transformation. In addition, the secretion of soluble factors induced by flagellin contributed to the growth-inhibitory activity in an autocrine fashion. The inhibitory activity was further confirmed in mouse xenografts of human breast cancer cells. These findings indicate that TLR5 activation by flagellin mediates innate immune response to elicit potent antitumor activity in breast cancer cells themselves, which may serve as a novel therapeutic target for human breast cancer therapy. Cancer Res; 71(7); 2466–75. ©2011 AACR.
Data from Combined Gene Expression Profiling and RNAi Screening in Clear Cell Renal Cell Carcinoma Identify PLK1 and Other Therapeutic Kinase Targets
Authors: Ding Yan , Huang Dan , Zhang Zhongfa , Smith Josh , Petillo David , Looyenga Brendan D. , Feenstra Kristin , MacKeigan Jeffrey P. , Furge Kyle A. , Teh Bin T.
Published: March 2024

Abstract
In recent years, several molecularly targeted therapies have been approved for clear cell renal cell carcinoma (ccRCC), a highly aggressive cancer. Although these therapies significantly extend overall survival, nearly all patients with advanced ccRCC eventually succumb to the disease. To identify other molecular targets, we profiled gene expression in 90 ccRCC patient specimens for which tumor grade information was available. Gene set enrichment analysis indicated that cell-cycle–related genes, in particular, Polo-like kinase 1 (PLK1), were associated with disease aggressiveness. We also carried out RNAi screening to identify kinases and phosphatases that when inhibited could prevent cell proliferation. As expected, RNAi-mediated knockdown of PLK1 and other cell-cycle kinases was sufficient to suppress ccRCC cell proliferation. The association of PLK1 in both disease aggression and in vitro growth prompted us to examine the effects of a small-molecule inhibitor of PLK1, BI 2536, in ccRCC cell lines. BI 2536 inhibited the proliferation of ccRCC cell lines at concentrations required to inhibit PLK1 kinase activity, and sustained inhibition of PLK1 by BI 2536 led to dramatic regression of ccRCC xenograft tumors in vivo. Taken together, these findings highlight PLK1 as a rational therapeutic target for ccRCC. Cancer Res; 71(15); 5225–34. ©2011 AACR.
Data from Formation of the eIF4F Translation–Initiation Complex Determines Sensitivity to Anticancer Drugs Targeting the EGFR and HER2 Receptors
Authors: Zindy Pierre , Bergé Yann , Allal Ben , Filleron Thomas , Pierredon Sandra , Cammas Anne , Beck Samantha , Mhamdi Loubna , Fan Li , Favre Gilles , Delord Jean-Pierre , Roché Henri , Dalenc Florence , Lacroix-Triki Magali , Vagner Stéphan
Published: March 2024

Abstract
Elucidating how cancer cells respond to antagonists of HER receptor family members is critical to understanding mechanisms of therapeutic resistance that arise in patients. In large part, resistance to such agents appears to arise from deregulation of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR pathway. mTOR-dependent phosphorylation of the translation repressor 4E-BP1 leads to its dissociation from eIF4E, thereby causing an increase in the formation of the eIF4F complex, which also comprises eIF4G and eIF4A. In this study, we show that trastuzumab, cetuximab, and erlotinib all decrease the formation of the eIF4F complex in breast, colon, and head and neck cancer cells, respectively. Ectopic expression of eIF4E restores the trastuzumab-dependent defect in eIF4F formation, renders cells resistant to the trastuzumab-mediated decrease in cell proliferation, and rescues breast cancer xenografts from inhibition by trastuzumab. In breast tumor specimens, the level of eIF4E expression is associated with the therapeutic response to a trastuzumab-based regimen. Together, our findings suggest that formation of the eIF4F complex may be a critical determinant of the response to anticancer drugs that target HER2 and epidermal growth factor receptor. Cancer Res; 71(12); 4068–73. ©2011 AACR.
Data from Snail2 is an Essential Mediator of Twist1-Induced Epithelial Mesenchymal Transition and Metastasis
Authors: Casas Esmeralda , Kim Jihoon , Bendesky Andrés , Ohno-Machado Lucila , Wolfe Cecily J. , Yang Jing
Published: March 2024

Abstract
To metastasize, carcinoma cells must attenuate cell–cell adhesion to disseminate into distant organs. A group of transcription factors, including Twist1, Snail1, Snail2, ZEB1, and ZEB2, have been shown to induce epithelial mesenchymal transition (EMT), thus promoting tumor dissemination. However, it is unknown whether these transcription factors function independently or coordinately to activate the EMT program. Here we report that direct induction of Snail2 is essential for Twist1 to induce EMT. Snail2 knockdown completely blocks the ability of Twist1 to suppress E-cadherin transcription. Twist1 binds to an evolutionarily conserved E-box on the proximate Snail2 promoter to induce its transcription. Snail2 induction is essential for Twist1-induced cell invasion and distant metastasis in mice. In human breast tumors, the expression of Twist1 and Snail2 is highly correlated. Together, our results show that Twist1 needs to induce Snail2 to suppress the epithelial branch of the EMT program and that Twist1 and Snail2 act together to promote EMT and tumor metastasis. Cancer Res; 71(1); 245–54. ©2010 AACR.
Data from Nm23-H1 Indirectly Promotes the Survival of Acute Myeloid Leukemia Blast Cells by Binding to More Mature Components of the Leukemic Clone
Authors: Lilly Andrew J. , Khanim Farhat L. , Hayden Rachel E. , Luong Quang T. , Drayson Mark T. , Bunce Christopher M.
Published: March 2024

Abstract
Nm23-H1 plays complex roles in the development of diverse cancers including breast carcinoma, high-grade lymphomas, and acute myeloid leukemia (AML). In the case of AML and lymphomas, serum Nm23-H1 protein is elevated with the highest levels correlating with poorest prognosis. A recent study identified that this association is most likely causal in AML and that Nm23-H1 acts as an AML cell survival factor. In this study, we report heterogeneity in the ability of AML samples to bind and respond to Nm23-H1, and we offer evidence that binding is essential for improved survival. Further, we show that the subset of AMLs that bind Nm23-H1 do not do so through the putative Nm23-H1 receptor MUC1*. Although rNm23-H1 promoted the survival of the most primitive blasts within responding AMLs, it was not these cells that actually bound the protein. Instead, rNm23-H1 bound to more mature CD34lo/CD34− and CD11b+ cells, revealing an indirect survival benefit of Nm23-H1 on primitive blasts. In support of this finding, the survival of purified blast cells was enhanced by medium conditioned by more mature cells from the clone that had been stimulated by rNm23-H1. Levels of interleukin 1β (IL1β) and IL6 in rNm23-H1 conditioned medium mirrored the potency of the conditioned media to promote blast cell survival. Furthermore, Nm23-H1 expression was significantly associated with IL1β and IL6 expression in primary uncultured AML samples. These findings have implications for the role of Nm23-H1 in AML and its use as a prognostic marker. Additionally, they offer the first evidence of novel cross-talk between cell populations within the tumor clone. Cancer Res; 71(3); 1177–86. ©2010 AACR.
Data from Expression of Id-1 Is Regulated by MCAM/MUC18: A Missing Link in Melanoma Progression
Authors: Zigler Maya , Villares Gabriel J. , Dobroff Andrey S. , Wang Hua , Huang Li , Braeuer Russell R. , Kamiya Takafumi , Melnikova Vladislava O. , Song Renduo , Friedman Ran , Alani Rhoda M. , Bar-Eli Menashe
Published: March 2024

Abstract
The acquisition of the metastatic melanoma phenotype is associated with increased expression of the melanoma cell adhesion molecule MCAM/MUC18 (CD146). However, the mechanism by which MUC18 contributes to melanoma metastasis remains unclear. Herein, we stably silenced MUC18 expression in two metastatic melanoma cell lines, A375SM and C8161, and conducted cDNA microarray analysis. We identified and validated that the transcriptional regulator, inhibitor of DNA binding-1 (Id-1), previously shown to function as an oncogene in several malignancies, including melanoma, was downregulated by 5.6-fold following MUC18 silencing. Additionally, we found that MUC18 regulated Id-1 expression at the transcriptional level via ATF-3, which itself was upregulated by 6.9-fold in our cDNA microarray analysis. ChIP analysis showed increased binding of ATF-3 to the Id-1 promoter after MUC18 silencing. To complement these studies, we rescued the expression of MUC18, which reversed the expression patterns of Id-1 and ATF-3. Moreover, we showed that MUC18 promotes melanoma invasion through Id-1, as overexpression of Id-1 in MUC18-silenced cells resulted in increased MMP-2 expression and activity. To our knowledge, this is the first demonstration that MUC18 is involved in cell signaling regulating the expression of Id-1 and ATF-3, thus contributing to melanoma metastasis. Cancer Res; 71(10); 3494–504. ©2011 AACR.
Data from Tumor Cell Invasion Is Promoted by Interstitial Flow-Induced Matrix Priming by Stromal Fibroblasts
Authors: Shieh Adrian C. , Rozansky Hallie A. , Hinz Boris , Swartz Melody A.
Published: March 2024

Abstract
Interstitial flow emanates from tumors into the microenvironment where it promotes tumor cell invasion. Fibroblasts are key constituents of the tumor stroma that modulate the mechanical environment by matrix remodeling and contraction. Here, we explore how interstitial fluid flow affects fibroblast–tumor cell interactions. Using a 3-dimensional invasion assay and MDA-MB-435S cells cocultured with dermal fibroblasts in a collagen matrix, we showed a synergistic enhancement of tumor cell invasion by fibroblasts in the presence of interstitial flow. Interstitial flow also drove transforming growth factor (TGF)-β1 and collagenase-dependent fibroblast migration, consistent with previously described mechanisms in which flow promotes invasion through autologous chemotaxis and increased motility. Concurrently, migrating fibroblasts enhanced tumor cell invasion by matrix priming via Rho-mediated contraction. We propose a model in which interstitial flow promotes fibroblast migration through increased TGF-β1 activation and collagen degradation, positioning fibroblasts to locally reorganize collagen fibers via Rho-dependent contractility, in turn enhancing tumor cell invasion via mechanotactic cues. This represents a novel mechanism in which interstitial flow causes fibroblast-mediated stromal remodeling that facilitates tumor invasion. Cancer Res; 71(3); 790–800. ©2011 AACR.