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Hepatocellular carcinoma (HCC) is a heterogeneous disease. Mouse models are commonly used as preclinical models to study hepatocarcinogenesis, but how well these models recapitulate molecular subtypes of human HCC is unclear. Here, integration of genomic signatures from molecularly and clinically defined human HCC (n = 11) and mouse models of HCC (n = 9) identified the mouse models that best resembled subtypes of human HCC and determined the clinical relevance of each model. Mst1/2 knockout (KO), Sav1 KO, and SV40 T antigen mouse models effectively recapitulated subtypes of human HCC with a poor prognosis, whereas the Myc transgenic model best resembled human HCCs with a more favorable prognosis. The Myc model was also associated with activation of β-catenin. E2f1, E2f1/Myc, E2f1/Tgfa, and diethylnitrosamine (DEN)-induced models were heterogeneous and were unequally split into poor and favorable prognoses. Mst1/2 KO and Sav1 KO models best resemble human HCC with hepatic stem cell characteristics. Applying a genomic predictor for immunotherapy, the six-gene IFNγ score, the Mst1/2 KO, Sav1 KO, SV40, and DEN models were predicted to be the least responsive to immunotherapy. Further analysis showed that elevated expression of immune-inhibitory genes (Cd276 and Nectin2/Pvrl2) in Mst1/2 KO, Sav1 KO, and SV40 models and decreased expression of immune stimulatory gene (Cd86) in the DEN model might be accountable for the lack of predictive response to immunotherapy. Implication: The current genomic approach identified the most relevant mouse models to human liver cancer and suggests immunotherapeutic potential for the treatment of specific subtypes. Mol Cancer Res; 16(11); 1713–23. ©2018 AACR.

Myeloid-derived suppressor cells (MDSC) are an immunosuppressive population of immature myeloid cells found in advanced-stage cancer patients and mouse tumor models. Production of inducible nitric oxide synthase (iNOS) and arginase, as well as other suppressive mechanisms, allows MDSCs to suppress T-cell–mediated tumor clearance and foster tumor progression. Using an unbiased global gene expression approach in conditional p120-catenin knockout mice (L2-cre;p120ctnf/f), a model of oral–esophageal cancer, we have identified CD38 as playing a vital role in MDSC biology, previously unknown. CD38 belongs to the ADP-ribosyl cyclase family and possesses both ectoenzyme and receptor functions. It has been described to function in lymphoid and early myeloid cell differentiation, cell activation, and neutrophil chemotaxis. We find that CD38 expression in MDSCs is evident in other mouse tumor models of esophageal carcinogenesis, and CD38high MDSCs are more immature than MDSCs lacking CD38 expression, suggesting a potential role for CD38 in the maturation halt found in MDSC populations. CD38high MDSCs also possess a greater capacity to suppress activated T cells, and promote tumor growth to a greater degree than CD38low MDSCs, likely as a result of increased iNOS production. In addition, we have identified novel tumor–derived factors, specifically IL6, IGFBP3, and CXCL16, which induce CD38 expression by MDSCs ex vivo. Finally, we have detected an expansion of CD38+ MDSCs in peripheral blood of advanced-stage cancer patients and validated targeting CD38 in vivo as a novel approach to cancer therapy. Cancer Res; 75(19); 4074–85. ©2015 AACR.

DNMT3A, the gene encoding the de novo DNA methyltransferase 3A, is among the most frequently mutated genes in hematologic malignancies. However, the mechanisms through which DNMT3A normally suppresses malignancy development are unknown. Here, we show that DNMT3A loss synergizes with the FLT3 internal tandem duplication (ITD) in a dose-influenced fashion to generate rapid lethal lymphoid or myeloid leukemias similar to their human counterparts. Loss of DNMT3A leads to reduced DNA methylation, predominantly at hematopoietic enhancer regions in both mouse and human samples. Myeloid and lymphoid diseases arise from transformed murine hematopoietic stem cells. Broadly, our findings support a role for DNMT3A as a guardian of the epigenetic state at enhancer regions, critical for inhibition of leukemic transformation.

Purpose: An improved understanding of the molecular pathogenesis of brain metastases, one of the most common and devastating complications of advanced melanoma, may identify and prioritize rational therapeutic approaches for this disease. In particular, the identification of molecular differences between brain and extracranial metastases would support the need for the development of organ-specific therapeutic approaches. Experimental Design: Hotspot mutations, copy number variations (CNV), global mRNA expression patterns, and quantitative analysis of protein expression and activation by reverse-phase protein array (RPPA) analysis were evaluated in pairs of melanoma brain metastases and extracranial metastases from patients who had undergone surgical resection for both types of tumors. Results: The status of 154 previously reported hotspot mutations, including driver mutations in BRAF and NRAS, were concordant in all evaluable patient-matched pairs of tumors. Overall patterns of CNV, mRNA expression, and protein expression were largely similar between the paired samples for individual patients. However, brain metastases demonstrated increased expression of several activation-specific protein markers in the PI3K/AKT pathway compared with the extracranial metastases. Conclusions: These results add to the understanding of the molecular characteristics of melanoma brain metastases and support the rationale for additional testing of the PI3K/AKT pathway as a therapeutic target in these highly aggressive tumors. Clin Cancer Res; 20(21); 5537–46. ©2014 AACR.

nc886 is a 101 nucleotide long non-coding RNA that has been designated as a precursor microRNA or a vault RNA based upon it sequence. nc886 has also been suggested to be a tumor suppressor, mainly inferred by its expression pattern as well as its genomic location at human chromosome 5q31, a locus for a tumor suppressor gene(s). However, legitimate data based on nc886's correct identity for its functional cellular roles as a tumor suppressor have not been provided yet. Here we have investigated nc886 in gastric cancer where its expression is suppressed due to CpG DNA hypermethylation at its promoter region in a cohort of paired tumor/normal tissues from 88 gastric cancer patients. CpG hypermethylation of nc886 and thus its diminished expression is significantly associated with poor survival in these cancer patients. nc886 inhibits cell proliferation when ectopically expressed in gastric cancer cells. nc886's tumor suppressive role is corroborated by the induction of well-known oncogenes such as FOS, NF-κB, and MYC upon its knockdown. All these activities of nc886 are undoubtedly independent of mature microRNA or vault RNA. Our data indicate that nc886 is a putative tumor suppressor and could potentially be used as a diagnostic marker in gastric cancer.

NR4A1 (Nur77, TR3) is an orphan nuclear receptor that is overexpressed in pancreatic cancer and exhibits pro-oncogenic activity. RNA interference of NR4A1 expression in Panc-1 cells induced apoptosis and subsequent proteomic analysis revealed the induction of several markers of endoplasmic reticulum stress, including glucose-related protein 78 (GRP78), CCAAT/enhancer-binding protein-homologous protein (CHOP), and activating transcription factor-4 (ATF-4). Treatment of pancreatic cancer cells with the NR4A1 antagonist 1,1-bis(3′-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH) gave similar results. Moreover, both NR4A1 knockdown and DIM-C-pPhOH induced reactive oxygen species (ROS), and induction of ROS and endoplasmic reticulum stress by these agents was attenuated after cotreatment with antioxidants. Manipulation of NR4A1 expression coupled with gene expression profiling identified a number of ROS metabolism transcripts regulated by NR4A1. Knockdown of one of these transcripts, thioredoxin domain containing 5 (TXNDC5), recapitulated the elevated ROS and endoplasmic reticulum stress; thus, demonstrating that NR4A1 regulates levels of endoplasmic reticulum stress and ROS in pancreatic cancer cells to facilitate cell proliferation and survival. Finally, inactivation of NR4A1 by knockdown or DIM-C-pPhOH decreased TXNDC5, resulting in activation of the ROS/endoplasmic reticulum stress and proapoptotic pathways. Implications: The NR4A1 receptor is pro-oncogenic, regulates the ROS/endoplasmic reticulum stress pathways, and inactivation of the receptor represents a novel pathway for inducing cell death in pancreatic cancer. Mol Cancer Res; 12(4); 527–38. ©2014 AACR.

Leukemia cells are protected by various components of their microenvironment, including marrow stromal cells (MSCs). To understand the molecular mechanisms underlying this protection, we cultured acute lymphoblastic leukemia (ALL) cells with MSCs and studied the effect of the latter on the molecular profiling of ALL cells at the mRNA and protein levels. Our results indicated that activated Wnt signaling in ALL cells is involved in MSC-mediated drug resistance. Blocking the Wnt pathway sensitized the leukemia cells to chemotherapy and improved overall survival in a mouse model. Targeting the Wnt pathway may be an innovative approach to the treatment of ALL.

Clinical application of the prognostic gene expression signature has been delayed due to the large number of genes and complexity of prediction algorithms. In the current study we aimed to develop an easy-to-use risk score with a limited number of genes that can robustly predict prognosis of patients with hepatocellular carcinoma (HCC). The risk score was developed using Cox coefficient values of 65 genes in the training set (n = 139) and its robustness was validated in test sets (n = 292). The risk score was a highly significant predictor of overall survival (OS) in the first test cohort (P = 5.6 × 10−5, n = 100) and the second test cohort (P = 5.0 × 10−5, n = 192). In multivariate analysis, the risk score was a significant risk factor among clinical variables examined together (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.13-1.64; P = 0.001 for OS). Conclusion: The risk score classifier we have developed can identify two clinically distinct HCC subtypes at early and late stages of the disease in a simple and highly reproducible manner across multiple datasets. (HEPATOLOGY 2011)

Purpose: This study was aimed at developing and validating a quantitative multigene assay for predicting tumor recurrence after gastric cancer surgery. Experimental Design: Gene expression data were generated from tumor tissues of patients who underwent surgery for gastric cancer (n = 267, training cohort). Genes whose expression was significantly associated with activation of YAP1 (a frequently activated oncogene in gastrointestinal cancer), 5-year recurrence-free survival, and 5-year overall survival were first identified as candidates for prognostic genes (156 genes, P < 0.001). We developed the recurrence risk score (RRS) by using quantitative RT-PCR to identify genes whose expression levels were significantly associated with YAP1 activation and patient survival in the training cohort. Results: We based the RRS assay on 6 genes, IGFBP4, SFRP4, SPOCK1, SULF1, THBS, and GADD45B, whose expression levels were significantly associated with YAP1 activation and prognosis in the training cohort. The RRS assay was further validated in an independent cohort of 317 patients. In multivariate analysis, the RRS was an independent predictor of recurrence [HR, 1.6; 95% confidence interval (CI), 1.02–2.4; P = 0.03]. In patients with stage II disease, the RRS had an HR of 2.9 (95% CI, 1.1–7.9; P = 0.03) and was the only significant independent predictor of recurrence. Conclusions: The RRS assay was a valid predictor of recurrence in the two cohorts of patients with gastric cancer. Independent prospective studies to assess the clinical utility of this assay are warranted. Clin Cancer Res; 22(24); 6228–35. ©2016 AACR.

Aims Despite continual efforts to develop prognostic and predictive models of colorectal cancer by using clinicopathological and genetic parameters, a clinical test that can discriminate between patients with good or poor outcome after treatment has not been established. Thus, the authors aim to uncover subtypes of colorectal cancer that have distinct biological characteristics associated with prognosis and identify potential biomarkers that best reflect the biological and clinical characteristics of subtypes. Methods Unsupervised hierarchical clustering analysis was applied to gene expression data from 177 patients with colorectal cancer to determine a prognostic gene expression signature. Validation of the signature was sought in two independent patient groups. The association between the signature and prognosis of patients was assessed by Kaplan–Meier plots, log-rank tests and the Cox model. Results The authors identified a gene signature that was associated with overall survival and disease-free survival in 177 patients and validated in two independent cohorts of 213 patients. In multivariate analysis, the signature was an independent risk factor (HR 3.08; 95% CI 1.33 to 7.14; p=0.008 for overall survival). Subset analysis of patients with AJCC (American Joint Committee on Cancer) stage III cancer revealed that the signature can also identify the patients who have better outcome with adjuvant chemotherapy (CTX). Adjuvant chemotherapy significantly affected disease-free survival in patients in subtype B (3-year rate, 71.2% (CTX) vs 41.9% (no CTX); p=0.004). However, such benefit of adjuvant chemotherapy was not significant for patients in subtype A. Conclusion The gene signature is an independent predictor of response to chemotherapy and clinical outcome in patients with colorectal cancer.

Human squamous cell cancers are the most common epithelially derived malignancies. One example is esophageal squamous cell carcinoma (ESCC), which is associated with a high mortality rate that is related to a propensity for invasion and metastasis. Here, we report that periostin, a highly expressed cell adhesion molecule, is a key component of a novel tumor-invasive signature obtained from an organotypic culture model of engineered ESCC. This tumor-invasive signature classifies with human ESCC microarrays, underscoring its utility in human cancer. Genetic modulation of periostin promotes tumor cell migration and invasion as revealed in gain-of-loss and loss-of-function experiments. Inhibition of epidermal growth factor receptor signaling and restoration of wild-type p53 function were each found to attenuate periostin, suggesting the interdependence of two common genetic alterations with periostin function. Collectively, our studies reveal periostin as an important mediator of ESCC tumor invasion and they indicate that organotypic (three-dimensional) culture can offer an important tool to discover novel biological effectors in cancer. Cancer Res; 70(13); 5281–92. ©2010 AACR.

Aberrations in oncogenes and tumor suppressors frequently affect the activity of critical signal transduction pathways. To analyze systematically the relationship between the activation status of protein networks and other characteristics of cancer cells, we did reverse phase protein array (RPPA) profiling of the NCI60 cell lines for total protein expression and activation-specific markers of critical signaling pathways. To extend the scope of the study, we merged those data with previously published RPPA results for the NCI60. Integrative analysis of the expanded RPPA data set revealed five major clusters of cell lines and five principal proteomic signatures. Comparison of mutations in the NCI60 cell lines with patterns of protein expression showed significant associations for PTEN, PIK3CA, BRAF, and APC mutations with proteomic clusters. PIK3CA and PTEN mutation enrichment were not cell lineage-specific but were associated with dominant yet distinct groups of proteins. The five RPPA-defined clusters were strongly associated with sensitivity to standard anticancer agents. RPPA analysis identified 27 protein features significantly associated with sensitivity to paclitaxel. The functional status of those proteins was interrogated in a paclitaxel whole genome small interfering RNA (siRNA) library synthetic lethality screen and confirmed the predicted associations with drug sensitivity. These studies expand our understanding of the activation status of protein networks in the NCI60 cancer cell lines, demonstrate the importance of the direct study of protein expression and activation, and provide a basis for further studies integrating the information with other molecular and pharmacological characteristics of cancer. Mol Cancer Ther; 9(2); 257–67

Purpose: The Hippo pathway is a tumor suppressor in the liver. However, the clinical significance of Hippo pathway inactivation in HCC is not clearly defined. We analyzed genomic data from human and mouse tissues to determine clinical relevance of Hippo pathway inactivation in HCC. Experimental Design: We analyzed gene expression data from Mst1/2−/− and Sav1−/− mice and identified a 610-gene expression signature reflecting Hippo pathway inactivation in the liver [silence of Hippo (SOH) signature]. By integrating gene expression data from mouse models with those from human HCC tissues, we developed a prediction model that could identify HCC patients with an inactivated Hippo pathway and used it to test its significance in HCC patients, via univariate and multivariate Cox analyses. Results: HCC patients (National Cancer Institute cohort, n = 113) with the SOH signature had a significantly poorer prognosis than those without the SOH signature [P < 0.001 for overall survival (OS)]. The significant association of the signature with poor prognosis was further validated in the Korean (n = 100, P = 0.006 for OS) and Fudan University cohorts (n = 242, P = 0.001 for OS). On multivariate analysis, the signature was an independent predictor of recurrence-free survival (HR, 1.6; 95% confidence interval, 1.12–2.28: P = 0.008). We also demonstrated significant concordance between the SOH HCC subtype and the hepatic stem cell HCC subtype that had been identified in a previous study (P < 0.001). Conclusions: Inactivation of the Hippo pathway in HCC is significantly associated with poor prognosis. Clin Cancer Res; 22(5); 1256–64. ©2015 AACR.

In this study, Lee and colleagues develop a genomic predictor that can identify patients at high risk for late recurrence of hepatocellular carcinoma (HCC) and provided new biomarkers for risk stratification., Background Typically observed at 2 y after surgical resection, late recurrence is a major challenge in the management of hepatocellular carcinoma (HCC). We aimed to develop a genomic predictor that can identify patients at high risk for late recurrence and assess its clinical implications. Methods and Findings Systematic analysis of gene expression data from human liver undergoing hepatic injury and regeneration revealed a 233-gene signature that was significantly associated with late recurrence of HCC. Using this signature, we developed a prognostic predictor that can identify patients at high risk of late recurrence, and tested and validated the robustness of the predictor in patients (n = 396) who underwent surgery between 1990 and 2011 at four centers (210 recurrences during a median of 3.7 y of follow-up). In multivariate analysis, this signature was the strongest risk factor for late recurrence (hazard ratio, 2.2; 95% confidence interval, 1.3–3.7; p = 0.002). In contrast, our previously developed tumor-derived 65-gene risk score was significantly associated with early recurrence (p = 0.005) but not with late recurrence (p = 0.7). In multivariate analysis, the 65-gene risk score was the strongest risk factor for very early recurrence (, Editors' Summary Background Primary liver cancer—a tumor that starts when a liver cell acquires genetic changes that allow it to grow uncontrollably—is the second-leading cause of cancer-related deaths worldwide, killing more than 600,000 people annually. If hepatocellular cancer (HCC; the most common type of liver cancer) is diagnosed in its early stages, it can be treated by surgically removing part of the liver (resection), by liver transplantation, or by local ablation, which uses an electric current to destroy the cancer cells. Unfortunately, the symptoms of HCC, which include weight loss, tiredness, and jaundice (yellowing of the skin and eyes), are vague and rarely appear until the cancer has spread throughout the liver. Consequently, HCC is rarely diagnosed before the cancer is advanced and untreatable, and has a poor prognosis (likely outcome)—fewer than 5% of patients survive for five or more years after diagnosis. The exact cause of HCC is unclear, but chronic liver (hepatic) injury and inflammation (caused, for example, by infection with hepatitis B virus [HBV] or by alcohol abuse) promote tumor development. Why Was This Study Done? Even when it is diagnosed early, HCC has a poor prognosis because it often recurs. Patients treated for HCC can experience two distinct types of tumor recurrence. Early recurrence, which usually happens within the first two years after surgery, arises from the spread of primary cancer cells into the surrounding liver that left behind during surgery. Late recurrence, which typically happens more than two years after surgery, involves the development of completely new tumors and seems to be the result of chronic liver damage. Because early and late recurrence have different clinical courses, it would be useful to be able to predict which patients are at high risk of which type of recurrence. Given that injury, inflammation, and regeneration seem to prime the liver for HCC development, might the gene expression patterns associated with these conditions serve as predictive markers for the identification of patients at risk of late recurrence of HCC? Here, the researchers develop a genomic predictor for the late recurrence of HCC by examining gene expression patterns in tissue samples from livers that were undergoing injury and regeneration. What Did the Researchers Do and Find? By comparing gene expression data obtained from liver biopsies taken before and after liver transplantation or resection and recorded in the US National Center for Biotechnology Information Gene Expression Omnibus database, the researchers identified 233 genes whose expression in liver differed before and after liver injury (the hepatic injury and regeneration, or HIR, signature). Statistical analyses indicate that the expression of the HIR signature in archived tissue samples was significantly associated with late recurrence of HCC in three independent groups of patients, but not with early recurrence (a significant association between two variables is one that is unlikely to have arisen by chance). By contrast, a tumor-derived 65-gene signature previously developed by the researchers was significantly associated with early recurrence but not with late recurrence. Notably, as few as four genes from the HIR signature were sufficient to construct a reliable predictor for late recurrence of HCC. Finally, the researchers report that many of the genes in the HIR signature encode proteins involved in inflammation and cell death, but that others encode proteins involved in cellular growth and proliferation such as STAT3, a protein with a well-known role in liver regeneration. What Do These Findings Mean? These findings identify a gene expression signature that was significantly associated with late recurrence of HCC in three independent groups of patients. Because most of these patients were infected with HBV, the ability of the HIR signature to predict late occurrence of HCC may be limited to HBV-related HCC and may not be generalizable to HCC related to other causes. Moreover, the predictive ability of the HIR signature needs to be tested in a prospective study in which samples are taken and analyzed at baseline and patients are followed to see whether their HCC recurs; the current retrospective study analyzed stored tissue samples. Importantly, however, the HIR signature associated with late recurrence and the 65-gene signature associated with early recurrence provide new insights into the biological differences between late and early recurrence of HCC at the molecular level. Knowing about these differences may lead to new treatments for HCC and may help clinicians choose the most appropriate treatments for their patients. Additional Information Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001770. The US National Cancer Institute provides information about all aspects of cancer, including detailed information for patients and professionals about primary liver cancer (in English and Spanish) The American Cancer Society also provides information about liver cancer (including information on support programs and services; available in several languages) The UK National Health Service Choices website provides information about primary liver cancer (including a video about coping with cancer) Cancer Research UK (a not-for-profit organization) also provides detailed information about primary liver cancer (including information about living with primary liver cancer) MD Anderson Cancer Center provides information about symptoms, diagnosis, treatment, and prevention of primary liver cancer MedlinePlus provides links to further resources about liver cancer (in English and Spanish)

Purpose: Activation of YAP1, a novel oncogene in the Hippo pathway, has been observed in many cancers, including colorectal cancer. We investigated whether activation of YAP1 is significantly associated with prognosis or treatment outcomes in colorectal cancer. Experimental Design: A gene expression signature reflecting YAP1 activation was identified in colorectal cancer cells, and patients with colorectal cancer were stratified into two groups according to this signature: activated YAP1 colorectal cancer (AYCC) or inactivated YAP1 colorectal cancer (IYCC). Stratified patients in five test cohorts were evaluated to determine the effect of the signature on colorectal cancer prognosis and response to cetuximab treatment. Results: The activated YAP1 signature was associated with poor prognosis for colorectal cancer in four independent patient cohorts with stage I–III disease (total n = 1,028). In a multivariate analysis, the impact of the YAP1 signature on disease-free survival was independent of other clinical variables [hazard ratio (HR), 1.63; 95% confidence interval (CI), 1.25–2.13; P < 0.001]. In patients with stage IV colorectal cancer and wild-type KRAS, IYCC patients had a better disease control rate and progression-free survival (PFS) after cetuximab monotherapy than did AYCC patients; however, in patients with KRAS mutations, PFS duration after cetuximab monotherapy was not different between IYCC and AYCC patients. In multivariate analysis, the effect of YAP1 activation on PFS was independent of KRAS mutation status and other clinical variables (HR, 1.82; 95% CI, 1.05–3.16; P = 0.03). Conclusions: Activation of YAP1 is highly associated with poor prognosis for colorectal cancer and may be useful in identifying patients with metastatic colorectal cancer resistant to cetuximab. Clin Cancer Res; 21(2); 357–64. ©2014 AACR.

nc886 (= vtRNA2-1 or pre-miR-886) is a recently discovered noncoding RNA that is a cellular PKR (Protein Kinase RNA-activated) ligand and repressor. nc886 has been suggested to be a tumor suppressor, solely based on its expression pattern and genomic locus. In this report, we have provided sufficient evidence that nc886 is a putative tumor suppressor in esophageal squamous cell carcinoma (ESCC). In 84 paired specimens from ESCC patients, nc886 expression is significantly lower in tumors than their normal adjacent tissues. More importantly, decreased expression of nc886 is significantly associated with shorter recurrence-free survival of the patients. Suppression of nc886 is mediated by CpG hypermethylation of its promoter, as evidenced by its significant negative correlation to nc886 expression in ESCC tumors and by induced expression of nc886 upon demethylation of its promoter. Knockdown of nc886 and consequent PKR activation induce FOS and MYC oncogenes as well as some inflammatory genes including oncogenic NF-κB. When ectopically expressed, nc886 inhibits proliferation of ESCC cells, further demonstrating that nc886 could be a tumor suppressor. All these findings implicate nc886 as a novel, putative tumor suppressor that is epigenetically silenced and regulates the expression of oncogenes in ESCC.

Affiliation number 9 for the 11th and last authors is incorrect. The correct affiliation is: Department of Biochemistry and Molecular Biology, Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Kyunghee University, Seoul, Korea.

Platinum compounds display clinical activity against a wide variety of solid tumors; however, resistance to these agents is a major limitation in cancer therapy. Reduced platinum uptake and increased platinum export are examples of resistance mechanisms that limit the extent of DNA damage. Here, we report the discovery and characterization of the role of ATP11B, a P-type ATPase membrane protein, in cisplatin resistance. We found that ATP11B expression was correlated with higher tumor grade in human ovarian cancer samples and with cisplatin resistance in human ovarian cancer cell lines. ATP11B gene silencing restored the sensitivity of ovarian cancer cell lines to cisplatin in vitro. Combined therapy of cisplatin and ATP11B-targeted siRNA significantly decreased cancer growth in mice bearing ovarian tumors derived from cisplatin-sensitive and -resistant cells. In vitro mechanistic studies on cellular platinum content and cisplatin efflux kinetics indicated that ATP11B enhances the export of cisplatin from cells. The colocalization of ATP11B with fluorescent cisplatin and with vesicular trafficking proteins, such as syntaxin-6 (STX6) and vesicular-associated membrane protein 4 (VAMP4), strongly suggests that ATP11B contributes to secretory vesicular transport of cisplatin from Golgi to plasma membrane. In conclusion, inhibition of ATP11B expression could serve as a therapeutic strategy to overcome cisplatin resistance.

Thrombocytosis, characterized by high platelet counts, and anemia, caused by low numbers of red blood cells, are associated with poor outcomes in solid tumors and occur in several types of myeloid disorders. The megakaryocyte and erythroid lineages give rise to platelets and red blood cells, respectively, but the mechanisms that cause increased megakaryopoiesis and concurrently decreased erythropoiesis are poorly understood. In this study, we identified that expression of DLX4, a transcription factor encoded by a homeobox gene, increases during megakaryopoiesis and decreases during erythropoiesis. Overexpression and knockdown experiments using normal CD34+ stem/progenitor cells and bipotent K562 cells demonstrated that DLX4 induces lineage markers and morphologic features of megakaryocytes, and concomitantly represses erythroid marker expression and hemoglobin levels. Gene Ontology and Gene Set Enrichment Analyses of genome-wide changes in gene expression induced by DLX4 showed that DLX4 induces a megakaryocytic transcriptional program and inhibits an erythroid transcriptional program. Bioinformatic analysis also revealed that DLX4 induces gene signatures that are associated with NF-kappaB signaling. The ability of DLX4 to promote megakaryocyte development and to inhibit erythroid differentiation was diminished by blocking NF-kappaB activity or by repressing IL1B, a transcriptional target of DLX4. These findings indicate that DLX4 promotes megakaryocyte development at the expense of erythroid generation in part by inducing inflammatory signaling. Studies are ongoing to investigate the transcriptional control by homeobox genes of inflammatory signaling in thrombocytosis and anemia that are associated with solid tumors and myeloproliferative diseases. Citation Format: Bon Q. Trinh, Nicolas Barengo, Sang Bae Kim, Ju-Seog Lee, Patrick A. Zweidler-McKay, Honami Naora. Transcriptional control of inflammatory signaling in the megakaryocyte and erythroid lineages. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr A25.

Thrombocytosis, characterized by high platelet counts, and anemia, caused by low numbers of red blood cells, are associated with poor outcomes in various solid tumors and also occur in several myeloid disorders. The megakaryocyte and erythroid lineages give rise to platelets and red blood cells, respectively, but the mechanisms that cause increased megakaryopoiesis and concurrently decreased erythropoiesis in malignancies are poorly understood. We and others have previously identified that DLX4, a developmental transcription factor encoded by a homeobox gene, is aberrantly expressed in several types of solid tumors and myeloid malignancies but the mechanisms of DLX4 are poorly understood. In this study, we identified that DLX4 expression increases during megakaryopoiesis and decreases during erythropoiesis. Overexpression and knockdown experiments using normal CD34+ stem/progenitor cells and bipotent K562 cells demonstrated that DLX4 induces lineage markers and morphologic features of megakaryocytes, and concomitantly represses erythroid marker expression and hemoglobin levels. Gene Ontology and Gene Set Enrichment Analyses of genome-wide changes in gene expression induced by DLX4 showed that DLX4 induces a megakaryocytic transcriptional program and inhibits an erythroid transcriptional program. Bioinformatic analysis also revealed that DLX4 induces gene signatures that are associated with NF-kappaB signaling. The ability of DLX4 to promote megakaryocyte development and to inhibit erythroid differentiation was diminished by blocking NF-kappaB activity or by repressing IL1B, a transcriptional target of DLX4. These findings indicate that DLX4 promotes megakaryocyte development at the expense of erythroid generation in part by inducing inflammatory signaling. Studies are ongoing to investigate the transcriptional control by homeobox genes of inflammatory signaling in thrombocytosis and anemia that are associated with solid tumors and myeloid disorders. Citation Format: Bon Q. Trinh, Nicolas Barengo, Sang Bae Kim, Ju-Seog Lee, Patrick A. Zweidler-McKay, Honami Naora. Transcriptional control of inflammatory signaling in the megakaryocyte and erythroid lineages: implications for the tumor microenvironment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 731.

Although several prognostic signatures have been developed in lung cancer, their application in clinical practice has been limited because they have not been validated in multiple independent data sets. Moreover, the lack of common genes between the signatures makes it difficult to know what biological process may be reflected or measured by the signature. By using classical data exploration approach with gene expression data from patients with lung adenocarcinoma (n = 186), we uncovered two distinct subgroups of lung adenocarcinoma and identified prognostic 193-gene gene expression signature associated with two subgroups. The signature was validated in 4 independent lung adenocarcinoma cohorts, including 556 patients. In multivariate analysis, the signature was an independent predictor of overall survival (hazard ratio, 2.4; 95% confidence interval, 1.2 to 4.8; p = 0.01). An integrated analysis of the signature revealed that E2F1 plays key roles in regulating genes in the signature. Subset analysis demonstrated that the gene signature could identify high-risk patients in early stage (stage I disease), and patients who would have benefit of adjuvant chemotherapy. Thus, our study provided evidence for molecular basis of clinically relevant two distinct two subtypes of lung adenocarcinoma.

The aims of this study were to compare the performance of six different genomic prognostic markers to predict long-term survival and chemotherapy response on the same patient cohort and assess if clinicopathological variables carry independent prognostic and predictive values. We examined seven clinical variables and six previously described prognostic signatures on 228 tumors from patients who received homogeneous preoperative chemotherapy and had long-term follow-up information for survival. We used the area under the receiver operator characteristic curve (AUC) to compare predictors and also performed univariate and multivariate analyses including the genomic and clinical variables and plotted Kaplan-Meir survival curves. All genomic prognostic markers had statistically similar AUCs and sensitivity to predict 5-year progression-free survival (PFS, sensitivities ranged from 0.591 to 0.773, and AUCs: 0.599-0.673), overall survival (OS, sensitivities: 0.590-0.769, AUCs: 0.596-0.684) and pathologic complete response (pCR, sensitivities: 0.596-0.851, AUCs: 0.614-0.805). In multivariate analysis, the genomic markers were not independent from one another; however, estrogen receptor (Odds Ratio [OR] 7.63, P < 0.001) and HER2 status (OR: 0.37, P = 0.021) showed significant independent predictive values for pCR. Nodal status remained an independent prognostic, but not predictive, variable (OR for PFS: 2.77, P = 0.021, OR for OS: 3.62, P = 0.01). There was moderate to good agreement between different prediction results in pair-wise comparisons. First-generation prognostic-gene signatures predict both chemotherapy response and long-term survival. When multiple predictors are applied to the same case discordant risk prediction frequently occurs.

Purpose: Despite continual efforts to develop a prognostic model of gastric cancer by using clinical and pathologic parameters, a clinical test that can discriminate patients with good outcomes from those with poor outcomes after gastric cancer surgery has not been established. We aim to develop practical biomarker-based risk score that can predict relapse of gastric cancer after surgical treatment. Experimental Design: Microarray technologies were used to generate and analyze gene expression profiling data from 65 gastric cancer patients to identify biomarker genes associated with relapse. The association of expression patterns of identified genes with relapse and overall survival was validated in independent gastric cancer patients. Results: We uncovered two subgroups of gastric cancer that were strongly associated with the prognosis. For the easy translation of our findings into practice, we developed a scoring system based on the expression of six genes that predicted the likelihood of relapse after curative resection. In multivariate analysis, the risk score was an independent predictor of relapse in a cohort of 96 patients. We were able to validate the robustness of the six-gene signature in an additional independent cohort. Conclusions: The risk score derived from the six-gene set successfully prognosticated the relapse of gastric cancer patients after gastrectomy. Clin Cancer Res; 17(7); 1850–7. ©2011 AACR.

Background Despite many attempts to establish pre-treatment prognostic markers to understand the clinical biology of esophageal adenocarcinoma (EAC), validated clinical biomarkers or parameters remain elusive. We generated and analyzed tumor transcriptome to develop a practical biomarker prognostic signature in EAC. Methodology/Principal Findings Untreated esophageal endoscopic biopsy specimens were obtained from 64 patients undergoing surgery and chemoradiation. Using DNA microarray technology, genome-wide gene expression profiling was performed on 75 untreated cancer specimens from 64 EAC patients. By applying various statistical and informatical methods to gene expression data, we discovered distinct subgroups of EAC with differences in overall gene expression patterns and identified potential biomarkers significantly associated with prognosis. The candidate marker genes were further explored in formalin-fixed, paraffin-embedded tissues from an independent cohort (52 patients) using quantitative RT-PCR to measure gene expression. We identified two genes whose expression was associated with overall survival in 52 EAC patients and the combined 2-gene expression signature was independently associated with poor outcome (P

Purpose In approximately 20% of patients with superficial bladder tumors, the tumors progress to invasive tumors after treatment. Current methods of predicting the clinical behavior of these tumors prospectively are unreliable. We aim to identify a molecular signature that can reliably identify patients with high-risk superficial tumors that are likely to progress to invasive tumors. Patients and Methods Gene expression data were collected from tumor specimens from 165 patients with bladder cancer. Various statistical methods, including leave-one-out cross-validation methods, were applied to identify a gene expression signature that could predict the likelihood of progression to invasive tumors and to test the robustness of the expression signature in an independent cohort. The robustness of the gene expression signature was validated in an independent (n = 353) cohort. Results Supervised analysis of gene expression data revealed a gene expression signature that is strongly associated with invasive bladder tumors. A molecular classifier based on this gene expression signature correctly predicted the likelihood of progression of superficial tumor to invasive tumor. Conclusion We present a molecular signature that can predict, at diagnosis, the likelihood of bladder cancer progression and, possibly, lead to improvements in patient therapy.

Hepatocellular carcinoma (HCC) is the fifth most common tumor and the third leading cause of cancer-related deaths. Loss of TGF-β signaling has been associated with development of HCC. Cancer preventive effects of Vitamin D (VD) have been implicated in multiple cancers, however a clear role for Vitamin D in specific high risk populations remains undefined for HCC. Therefore, we examined for a potential chemopreventive role of VD in HCC in the context of TGF-β inactivation. Methods: (1) We screened for somatic mutation of the TGF-β pathway and VD related genes in 202 HCCs from The Cancer Genome Atlas (TCGA). (2) Wild type, Sptbn1+/- and Smad3+/- mice were fed with low VD (200 IU VD/kg) or high VD diet (10,000 IU VD/kg) for 9 weeks. Liver tissues were subjected to microarray analyses and further evaluation by quantitative PCR. (3) Wild type, Sptbn1+/- and Smad3+/- mice were injected Diethylnitrosamine (DEN) and at 8 month, 26 mice receiving low VD (200 IU VD/kg) and 26 mice receiving high VD (10,000 IU VD/kg) chow. HCC development was assessed at 4 months after VD treatment. (4) Reverse Phase Protein Array (RPPA) was performed to analyze expression profiles of 164 proteins of mouse liver tumors. (5) Liver samples from patients with HCV cirrhosis receiving VD supplements were examined to evaluate expression of TGF-β, Wnt and VD pathway molecules by immunohistochemistry. Results: (1) We observed a high rate of somatic mutation in TGF-β and VD pathway related genes in the TCGA genomic analysis. (2) None of the VD treated mice developed HCC but high VD treatment increased TLR7 mRNA expression about 3-fold in liver from Smad3+/- mice compared with livers from WT mice. (3) Smad3+/- mice with low VD showed 3-fold larger HCC formation, compared to the high VD group (Smad3+/-) that did not develop significant tumors. However, correction of VD in the Chow after 10 months did not reverse HCC formation. (4) RPPA data revealed that the tumor suppressor protein PDCD4 was reduced in Smad3+/- mice with low VD treatment. However, oncoproteins such as β-catenin, Stat5A and Bcl2-XL were induced in the same sample. (5) Expression of β2SP and TβRII were higher in HCV cirrhosis patients receiving VD supplementation compared to non-treated group. Conclusions: Loss of TGF-β signaling pathway developed HCC and VD deficiency promotes tumor growth in the context of Smad3 disruption potentially through regulation of TLR7 expression. However, after 10 months restoring VD does not have any significant effect on altering tumors. Therefore VD could be a potential candidate for prevention in early identified HCC high risk individuals who has inactivation of TGF-β/Smad3 signaling. Citation Format: Ji-hyun Shin, Lior H. Katz, Nina M. Munoz, Andrea Cortes, Vivek Shukla, Sang-Bae Kim, Franklin Herlong, Keigo Machida, Hidekazu Tsukamoto, Kirti Shetty, Aiwu R. He, Lynt B. Johnson, Asif Rashid, Jian Chen, Ju-Seog Lee, Lopa Mishra. Vitamin D deficiency regulates TLR7 to promote hepatocellular cancer in TGF-β/Smad3 heterozygous mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 892. doi:10.1158/1538-7445.AM2015-892

Purpose: To investigate the clinical significance of activation of YAP1, a newly identified oncogene in colorectal cancer (CRC). Patients and Methods: A gene expression signature reflecting YAP1 activation was identified in CRC cells, and CRC patients were stratified into two groups according to this signature: activated YAP1 CRC (AYCC) or inactivated YAP1 CRC (IYCC). Stratified patients in six test cohorts were evaluated to determine the effect of the signature on CRC prognosis and response to treatment with cetuximab. Results: The activated YAP1 signature was associated with poor prognosis for CRC in four independent patient cohorts with stage I-III disease (total n = 1,028). In a multivariate analysis, the impact of the YAP1 signature on the disease-free survival rate was independent of other clinical variables [hazard ratio (HR), 1.63; 95% confidence interval (CI), 1.25-2.13; P < .001]. In patients with stage IV CRC, AYCC patients had a poorer disease control rate and progression-free survival duration after cetuximab-based monotherapy than did IYCC patients (HR, 1.82; 95% CI, 1.05-3.16; P = .03). In multivariate analysis, the effect of YAP1 activation on PFS was independent of KRAS mutation status and cetuximab-based therapy was effective only in IYCC patients without KRAS mutations. Conclusion: Activation of YAP1 is highly associated with poor prognosis for CRC and may be useful in identifying patients with CRC resistant to treatment with cetuximab. Citation Format: Keun-Wook Lee, Sung Sook Lee, Sang-Bae Kim, Yun-Yong Park, Bo Hwa Sohn, Hyun-Sung Lee, Ju-Seog Lee. Activation of yap1 is significantly associated with poor prognosis and cetuximab resistance in colorectal cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4734. doi:10.1158/1538-7445.AM2014-4734

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. Vitamin D (VD) has been implicated in the prevention of multiple cancers, some of which are characterized by inactivation of TGF-β signaling. Recently, inactivation of TGF-β signaling has been associated with development of HCC. We examined the potential role of VD in HCC chemoprevention in the context of TGF-β inactivation in a mouse model. Methods: Wild type, Sptbn1+/- and Smad3+/- male mice were treated with 50 mg/kg of the chemical carcinogen diethylnitrosamine (DEN) via i.p. injection at 14 days of age. At 8 months, the animals were changed from regular chow (2,200 IU/kg VD) to one of two diets: lower than normal VD (200 IU/kg) or high VD (10,000 IU/kg). At one year of age, the livers were harvested for tissue analysis. Several metrics were assessed including expression levels of 164 proteins from liver tumors by Reverse Phase Protein Array (RPPA). Results: Twenty three mice were treated with lower than normal dose VD while 26 received high dose VD. We did not find significant differences in blood calcium levels in animals on either diet. As expected, high VD intervention after 8 months of DEN injection did not affect the total number of tumors the mice developed; however, the lower than normal VD regimen promoted tumor growth in the context of Smad3 disruption (liver-to-body weight ratio 18.37% in Smad3+/- mice treated with low dose VD vs. 6.25% in Smad3+/- animals treated with high dose, p=0.028). Furthermore, RPPA data revealed that the lower than normal VD intake in DEN-treated Smad3 heterozygous null mice results in repression of tumor suppressing genes such as PDCD4 and concomitant up-regulation of tumor promoting genes like Stat5A, Bcl2-XL, PDGFRB and PEA15. Conclusions: Remarkably, lower than normal VD in the context of Smad3 disruption promotes tumor growth possibly through repression of tumor suppressing genes such as PDCD4 and up-regulation of oncogenes like Stat5A, Bcl2-XL, PDGFRB and PEA15. These results suggest that VD treatment strategies could potentially be significant for chemoprevention and treatment of HCC in the context of inactivation of TGF-β signaling in patient populations with underlying deficiency of VD. Citation Format: Nina M. Muñoz, Lior H. Katz, Keigo Machida, Hidekazu Tsukamoto, Kirty Shetty, Aiwu R. He, Lynt B. Johnson, Asif Rashid, Sang Bae Kim, Ju-Seog Lee, Lopa Mishra. Vitamin D deficiency promotes hepatocellular carcinoma tumor growth in TGF-β impaired mice by Smad3 heterozygous deletion. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 248. doi:10.1158/1538-7445.AM2014-248

BackgroundAlthough several prognostic genomic predictors have been identified from independent studies, it remains unclear whether these predictors are actually concordant with respect to their predictions for individual patients and which predictor performs best. We compared five prognostic genomic predictors, the V7RHS, the ColoGuideEx, the Meta163, the OncoDX, and the MDA114, in terms of predicting disease-free survival in two independent cohorts of patients with colorectal cancer.Study designUsing original classification algorithms, we tested the predictions of five genomic predictors for disease-free survival in two cohorts of patients with colorectal cancer (n = 229 and n = 168) and evaluated concordance of predictors in predicting outcomes for individual patients.ResultsWe found that only two predictors, OncoDX and MDA114, demonstrated robust performance in identifying patients with poor prognosis in 2 independent cohorts. These two predictors also had modest but significant concordance of predicted outcome (r>0.3, PConclusionsFurther validation of developed genomic predictors is necessary. Despite the limited number of genes shared by OncoDX and MDA114, individual-patient outcomes predicted by these two predictors were significantly concordant.

Metabolic changes are common features of many cancer cells and are frequently associated with the clinical outcome of patients with various cancers including hepatocellular carcinoma (HCC). Thus, aberrant metabolic pathways in cancer cells are attractive targets for cancer therapy. However, our understanding of cancer-specific regulatory mechanisms of cell metabolism is still very limited. We found that Tat activating regulatory DNA-binding protein (TARDBP) is a novel regulator of glycolysis in HCC cells. TARDBP regulates expression of the platelet isoform of phosphofructokinase (PFKP), the rate-limiting enzyme of glycolysis that catalyzes the irreversible conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. Silencing of TARDBP expression in multiple HCC cell lines leads to impaired glucose metabolism and inhibition of in vitro and in vivo growth of HCC cells. Notably, the miR-520 family is an intermediate regulator of TARDBP-mediated regulation of glycolysis. Mechanistically, TARDBP suppressed expression of the miR-520 family, which in turn inhibited expression of PFKP. We further showed that expression of PFKP is significantly associated with the overall survival of patients with HCC. Our study provides new mechanistic insights into the regulation of glycolysis in HCC cells and reveals TARDBP as a potential therapeutic target for HCC. Citation Format: Yun-Yong Park, Sang Bae Kim, Hee Dong Han, Bo-Hwa Sohn, Jiyong Liang, Yiling Lu, Gordon Mills, Anil Sood, Ju-Seog Lee. TARDBP regulates glycolysis in hepatocellular carcinoma by regulating PFKP through miR-520. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5398. doi:10.1158/1538-7445.AM2013-5398

Transcription factors (TFs) are direct effectors of altered signaling pathways in cancer. To uncover new TFs that would determine clinical outcomes in breast cancer patients, we systematically analyzed gene expression data from breast cancer patients. Our results revealed that forkhead box protein M1 (FOXM1) is the top-ranked survival-associated TF with triple-negative breast cancer. Surprisingly, silencing FOXM1 expression led breast cancer cells to become more sensitive to doxorubicin (Dox). We found that FOXM1-dependent resistance to Dox is mediated by regulating DNA repair genes. We further demonstrated that NF-κB1 interacts with FOXM1 in the presence of Dox to protect breast cancer cells from DNA damage. Finally, silencing FOXM1 expression in a mouse xenograft model significantly sensitized the cells to Dox. Our systematic approaches identified an unexpected role of FOXM1 in Dox resistance by regulating DNA repair genes and FOXM1 may be a promising therapeutic target for sensitizing breast cancer cells to Dox. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2962. doi:1538-7445.AM2012-2962

Although the importance of the cellular microenvironment (soil) during invasion and metastasis of cancer cells (seed) has been well-recognized, technical challenges have limited the ability to assess the influence of the microenvironment on cancer cells at the molecular level. Here, we show that an experimental strategy, competitive cross-species hybridization of microarray experiments, can characterize the influence of different microenvironments on cancer cells by independently extracting gene expression data of cancer and host cells when human cancer cells were xenografted into different organ sites of immunocompromised mice. Surprisingly, the analysis of gene expression data showed that the brain microenvironment induces complete reprogramming of metastasized cancer cells, resulting in a gain of neuronal cell characteristics and mimicking neurogenesis during development. We also show that epigenetic changes coincide with transcriptional reprogramming in cancer cells. These observations provide proof of principle for competitive cross-species hybridization of microarray experiments to characterize the effect of the microenvironment on tumor cell behavior Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4283. doi:1538-7445.AM2012-4283

Wnt/β-catenin signaling has been known to be involved in many cellular processes including cell proliferation, migration, and survival. Aberrant activation of Wnt/β-catenin signaling has been widely reported in many cancers and associated with poor outcome after treatments. However, activation of Wnt/β-catenin signaling in hepatocellular carcinoma (HCC) has been known to be significantly associated with favorable outcome. In this study, we identified 82 genes as a β-catenin signature by analyzing expression data from tumor tissues of patients with HCC and liver tissues from active β-catenin mutant transgenic mice. HCC patients with the β-catenin signature have significantly better prognosis in both overall survival and recurrence-free survival than those without the signature. Further analysis of β-catenin signature revealed over-expression of glutamine synthetase (GS), liver-specific β-catenin target gene, and shift of glutamine metabolism. Cell growth rate were highly dependent on GS expression levels. Cell proliferation rate was increased by GS knockdown using shRNAs but decreased by GS overexpression in HCC cell lines. Intracellular glutamate concentrations were severely decreased by GS overexpression. GS overexpression in HCC cells also led to decrease intracellular α-ketoglutarate levels impeding TCA cycle, and intracellular glutathione levels accumulating high reactive oxygen species (ROS). In conclusion, we found GS up-regulation in HCC cells inhibited cell growth by glutamate depletion and thereby lower anaplerotic metabolic activity and higher ROS levels. Our results present molecular mechanisms for the favorable outcome in HCC patients with CTNNB1 mutations and importance of glutamine metabolism in cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5142. doi:1538-7445.AM2012-5142

MicroRNAs (miRNAs) are single-stranded, non-coding RNA molecules and on average only 22 nucleotides long that regulate gene expression at the post-transcriptional level. The current approaches with miRNA-mRNA association were not enough to verify real functional targets at protein level, which could affect on biological signaling pathway. In this study, we developed a correlation based approach (sequence-independence) to predict potential miRNA targets with genomic and proteomic data including the expression of phosphorylated proteins in NCI-60 cells. To do this we calculated the number of correlated probe-pairs between miRNA(439)-mRNA(22k) and protein(222)-mRNA probe pairs. Then, two significant output pair sets were combined by mRNA probes and then counted the number of common probes. With these count numbers, finally we generated Association score matrix between miRNA and protein probes. Using those score matrix, we evaluated the highly associated miRNAs with 36 biological pathways, which play critical roles in cell cycle, proliferation and metastasis. Among these associations, we found that miR-500 cluster is highly associated with ERK/MAPK signaling pathway through activating MEK1/2 phosphorylation in Melanoma and breast cancer cells. In conclusion, we developed a novel expression profile based approach to systematically predict potential miRNA functional targets which play critical roles in cell signaling pathways from the NCI-60 genomic and proteomic data at whole genomic scale. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 135. doi:1538-7445.AM2012-135

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor with poor prognosis due in part to drug resistance and high incidence of tumor recurrence. The drug resistant and cancer recurrence phenotype may be ascribed to the presence of cancer stem cells, which seem to reside in special stem-cell niches in vivo and require special culture conditions including certain growth factors and serum-free medium to maintain their stemness in vitro. In this study, we used several stem-like glioblastoma cell lines (GSC11, GSC23 and GBM3752) derived from patients’ tissues by typical neurosphere culture system, and showed that addition of fetal bovine serum (FBS) to the medium induced an increase of ROS, leading to aberrant differentiation and decreases of stem cell markers such as CD133. We found that exposure of glioblastoma stem cells (GSCs) to serum induces their differentiation through activation of mitochondrial respiration, leading to an increase in superoxide (O2−) generation and a profound reactive oxygen species (ROS) stress response manifested by upregulation of oxidative stress response pathway. This increase in mitochondrial ROS leads to a down-regulation of molecules including SOX2, and Olig2, and Notch1 that are important for stem cell function and an upregulation of mitochondrial superoxide dismutase SOD2 that converts O2− to H2O2. Neutralization of ROS by antioxidant N-acetylcysteine in the serum-treated GSCs suppresses the increase of superoxide and largely rescues the expression of SOX2, Olig2, and Notch1, and prevents the serum-induced differentiation phenotype. Upregulation of ROS by chemical disruption of mitochondrial electron respiration chain induced further decrease of CD133. Our study suggests that mitochondrial function and cellular redox status may profoundly affect the fates of glioblastoma stem cells, and that modulation of ROS generation may be an effective way to impact CSCs, which may provide a new basis for developing novel therapeutic approaches. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 999. doi:1538-7445.AM2012-999

Background Gastric cancer continues to be one of the deadliest cancers in the world and therefore identification of new drugs targeting this type of cancer is thus of significant importance. The purpose of this study was to identify and validate a therapeutic agent which might improve the outcomes for gastric cancer patients in the future. Methodology/Principal Findings Using microarray technology, we generated a gene expression profile of human gastric cancer–specific genes from human gastric cancer tissue samples. We used this profile in the Broad Institute's Connectivity Map analysis to identify candidate therapeutic compounds for gastric cancer. We found the histone deacetylase inhibitor vorinostat as the lead compound and thus a potential therapeutic drug for gastric cancer. Vorinostat induced both apoptosis and autophagy in gastric cancer cell lines. Pharmacological and genetic inhibition of autophagy however, increased the therapeutic efficacy of vorinostat, indicating that a combination of vorinostat with autophagy inhibitors may therapeutically be more beneficial. Moreover, gene expression analysis of gastric cancer identified a collection of genes (ITGB5, TYMS, MYB, APOC1, CBX5, PLA2G2A, and KIF20A) whose expression was elevated in gastric tumor tissue and downregulated more than 2-fold by vorinostat treatment in gastric cancer cell lines. In contrast, SCGB2A1, TCN1, CFD, APLP1, and NQO1 manifested a reversed pattern. Conclusions/Significance We showed that analysis of gene expression signature may represent an emerging approach to discover therapeutic agents for gastric cancer, such as vorinostat. The observation of altered gene expression after vorinostat treatment may provide the clue to identify the molecular mechanism of vorinostat and those patients likely to benefit from vorinostat treatment.

ESR1 is one of the most important oncogenes and therapeutic targets in breast cancer. By applying systems-level re-analysis of publicly available gene expression data, we uncovered potential regulator of ESR1. We demonstrated that orphan nuclear receptor NR2E3 regulates ESR1 via direct binding to the ESR1 promoter with concomitant recruitment of PIAS3 to promoter in breast cancer cells, and is essential for physiological cellular activity of ESR1 in estrogen receptor (ER)-positive breast cancer cells. Moreover, expression of NR2E3 was significantly associated with recurrence-free survival and favorable response to tamoxifen treatment in women with ER-positive breast cancer. Our results provide mechanistic insight into how ESR1 is regulated by NR2E3 and clinical relevance of NR2E3 in breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 356. doi:10.1158/1538-7445.AM2011-356

MicroRNAs (miRNAs) are single-stranded, non-coding RNA molecules and on average only 22 nucleotides long that regulate gene expression at the post-transcriptional level. Target predictions of miRNA based on sequence are limited due to too many candidates resulting in high false positives. To overcome this limitation functional target prediction approaches have been investigated by using mRNA and miRNA expression data. These approaches used in the computational assessment of functional miRNA-target association. However, these approaches with miRNA-mRNA association were not enough to verify real functional targets at protein level, which could affect on biological signaling pathway. Therefore, in order to overcome current limitation we developed a novel correlation-based approach (sequence-independence) that predict the association of miRNAs with signaling pathways by using genomics and proteomics data from NCI-60 cancer cell lines (mRNA, miRNA, and protein expression data). To identify miRNA-protein association, we used two correlation-based methods: direct comparison (miRNA-protein pairs) and indirect comparison (miRNA-mRNA and protein-mRNA pairs), then compared their outputs. In direct comparison, we calculated Pearson correlation coefficients for 96k probe pairs and found over 3 k significant correlated pairs (3.2 %) at the cut-off p-value < 0.005: among them 53.4 % were negative and 46.6% were positive. In indirect comparison, we ranked the number of correlated mRNA probes between miRNA-mRNA and protein-mRNA pairs, in which we calculated over 11 and 5.7 million probe pairs respectively. Then, two significant output pair sets were combined by intersection of mRNA probes and then determined the number of common probes. With these determined numbers, finally we generated association score matrix between miRNA and protein probes. Using those score matrix, we evaluated the highly associated miRNAs with 40 biological pathways, which play critical roles in cell cycle, proliferation and metastasis. In conclusion, we developed a noble expression profile-based approach to systematically predict potential miRNA functional targets which play critical roles in cell signaling pathways from the NCI-60 genomic and proteomic data at whole genomic scale. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3995. doi:10.1158/1538-7445.AM2011-3995

Esophageal adenocarcinoma (EAC) is thought to arise from the metaplastic condition known as Barrett's esophagus (BE), which is caused by chronic inflammation due to gastroesophageal reflux disease. Since the molecular mechanisms underlying the pathogenesis of EAC are unknown, understanding EAC development mechanisms and their regulation is crucial for the treatment of EAC. Comparative genomic studies of evolutionarily similar and dissimilar species have been suggested as a means of studying the evolutionary biology in the species. Thus, we performed a cross-species comparison of gene expression patterns in human and rat tissues, uncovering the evolutionarily conserved gene expression patterns during EAC progression across both species. Using a non-carcinogenic rat model that progresses from normal esophagus to BE to EAC, we were able to identify the biological mechanisms of EAC development. We analyzed gene expression data from rat specimens (15 NE, 18 BE, and 30 EAC) as well as from human tissues (28NE, 72BE, and 75EAC). Using the presence of orthologous genes in both microarray platforms and various statistical tests, we uncovered a number of genes whose expression patterns were well conserved during progression from NE to BE in humans and rats. The expression of 869 genes was commonly altered when NE progressed to BE in both humans and rats (P During BE to EAC progression in both species, 541 gene expressions were altered (P In conclusion, systems-level characterization of gene expression data from humans and a rodent model shows evolutionarily conserved genes and pathways during EAC progression, and these genes and pathways could become reliable biomarkers for early detection, or therapeutic targets for the treatment of EAC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2005.

Prostate cancer is the most common cancer in men around the world, with a high incidence of bone metastasis, which is the major determinant of mortality in prostate cancer. The survival and proliferation of prostate cancer cells metastatic to bone result from the cross-talk between carcinoma cells and the stromal cells. In contrast to skeletal metastases resulting from breast or lung cancer that are most often osteolytic, metastases from prostate carcinoma are nearly always osteoblastic, suggesting that interactions between prostate cancer cells and stroma in bone might be different from those of lung or breast cancer cells and bone stroma. Therefore, gene expression patterns that are unique to osteoblastic prostate cancer will help to identify genes involved in the bidirectional cross-talk between prostate cancer cells and bone cells in microenvironment niche. However, because gene expression signatures from human cancer tissues are a mixture of those from carcinoma and stromal cells, it has been impossible to delineate stromal cell specific gene expression signatures from carcinoma cell signatures. Thus, we have devised a novel experimental strategy: “competitive cross-species hybridization of microarray”, which can simultaneously extract gene expression patterns of carcinoma cells and stromal cells from a single xenograft sample. In the current study, we xenografted human prostate cancer cells (PC3, PCA118b, 10A) into mouse bone and prostate and used these tissues for microarray experiments. Total RNAs were purified from three different tissue groups: normal bones (mouse RNA only), tumor-bearing bones (mixture of mouse and human RNA), and tumor-bearing prostates (mixture of mouse and human RNA). Labeled cRNA from normal bones and tumor-bearing bones were hybridized to mouse microarray slide to measure gene expression of mouse bone cells. Likewise, labeled cRNA from tumor-bearing prostate and tumor-bearing bone were hybridized to human microarray slide to measure gene expression of human prostate cancer cells. Gene expression data from mouse microarrays identified gene expression patterns unique to bone cells that interact with prostate cancer cells in bone. When same analysis applied to human data, it also uncovered prostate cancer cell gene expression signatures associated with different microenvironment (prostate vs. bone). In order to uncover gene networks involved in cross-talk between prostate cancer cells and bone cells in metastatic bone microenvironment, gene network analysis using Ingenuity Pathway Analysis (IPA) was applied to combined gene lists from human and mouse data. In conclusion, by applying novel experimental strategy, “competitive cross-species hybridization of microarray”, we uncovered critical gene network involved in bidirectional cellular communication that drives the survival of prostate cancer cells in metastatic bone microenvironment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 546.

Glioblastoma multiforme (GBM) is a common and highly aggressive primary brain tumor with poor prognosis due in part to drug resistance and high incidence of tumor recurrence. The drug resistant and cancer recurrence phenotype may be ascribed to the presence of cancer stem cells, which seem to reside in special stem-cell niches in vivo and require special culture conditions including certain growth factors and serum-free medium to maintain their stemness in vitro. In this study, we used two lines of stem-like cancer cells (GSC11 and GSC23) derived from the tumor tissues of two GBM patients by classical neurosphere culture system, and showed that addition of serum (FBS) to the medium induced an increase of ROS, leading to aberrant differentiation and eventual cell death. Although both GBM stem-like cell lines showed high percentage of CD133-positive cells (20% in GSC11 and 70% in GSC23), exposure to serum only caused a moderate decrease of CD133 expression at later time points. Several methods were used to further test the role of ROS in affecting the stemness of the GSC cells and their self-renewal capacity. Addition of 5% FBS or removal of the antioxidant supplements (B27) from the culture medium caused the spheroid GSC cells to attach to the culture surface, exhibit differentiation morphology, decrease expression of certain stem-cell markers, and eventually die within two weeks. Serum exposure also resulted in a decrease of the GSC ability to form colonies in soft agar assay and to grow tumors in a mouse xenograft model. Although an increase of general cellular ROS could be detected when GSC cells were exposed to FBS, the mitochondrial superoxide appeared to be prominent and likely to be a primary event, which led to a compensatory increase of the mitochondrial SOD2 expression and upregulation of glutathione synthesis. Interestingly, addition of the antioxidant N-Acetylcysteine to the FBS-containing medium partially blocked the FBS-induced aberrant differentiation and improved cell viability and self-renewal capacity, suggesting that ROS may play an important role in affecting stemness and differentiation status of the cancer stem cells. We postulate that during tumor development, only the progeny cells that acquire the ability to counteract the impact of ROS increase induced by serum may eventually proliferate and grow as the tumor bulk, and that proper redox-modulation may be a potential novel strategy to block tumor formation and possibly kill the stem-like cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4266.

Gene-expression profiling has been applied in specific settings such as to elucidate the mechanisms of biological pathways, to classify subtypes of a disease, and to predict cancer prognosis. Furthermore, the Connectivity Map using gene-expression signature can categorize the biological responses to a large number of diverse small molecule therapeutics. To find new agents targeting gastric cancer, we analyzed global human gastric cancer gene expression profile using the Connectivity Map. From 3360 gastric cancer specific genes, it was revealed that the candidate compounds for targeting gastric cancer were histone deacetylase inhibitors (HDACi) such as vorinostat. We validated the therapeutic efficacy of vorinostat in gastric cancer cell lines. Vorinostat induced both apoptosis and autophagy in gastric cancer cell lines, but showed a different pattern in each cell line. Pharmacological or genetic inhibition of autophagy respectively by chloroquine and a siRNA against Beclin 1 increased the therapeutic efficacy of vorinostat, indicating a mechanism of drug resistance. Further transcriptome analysis will make it possible to find a predictive biomarker gene signature for vorinostat and as such can help in the future to better understand the action mechanisms of vorinostat. In conclusion, we showed that systems analysis using Connectivity Map with a human gastric cancer gene signature can be novel approach to find targeting agents for gastric cancer. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C163.

4113 Background: Clinical heterogeneity in gastric cancer is likely due to biological differences among patients. Molecular subtypes and their associated biomarkers need to be established to improve treatment of this disease. We aimed to uncover subgroups of gastric cancer that have distinct biological characteristics associated with clinical outcome and to identify potential best treatments or therapeutic targets for each subgroup. Methods: We analyzed gene expression profiling data from gastric cancer cell lines and 267 patients with gastric cancer to uncover tumor subtypes and identify a gene expression signature associated with prognosis and response to adjuvant chemotherapy. The association of the signature with prognosis was validated in an independent cohort of 200 patients, and its association with response to adjuvant therapy was validated by cell culture experiments. Results: We identified an expression signature of 88 genes that specifically reflected activation of the oncogene YAP1. Compared with patients without this signature, patients with the YAP1 signature had significantly poorer prognosis. In multivariate analysis, the signature was the strongest indicator of overall survival among all demographic and clinical variables examined together (hazard ratio, 2.1; 95% confidence interval, 1.3-3.3;P = .002). Activation of YAP1 was significantly associated with resistance to adjuvant chemotherapy. We also demonstrated that the Notch pathway is a potential therapeutic target for overcoming chemoresistance mediated by YAP1. Conclusions: Activation of the oncogene YAP1 is significantly associated with poorer survival of patients with gastric cancer and induces chemoresistance to this disease. Therefore, YAP1 may be highly attractive therapeutic target for patients with gastric cancer resistant to standard chemotherapy.