bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4118: Hypoxia affects the metabolic activation and detoxification of the environmental mutagen benzo(a)pyrene
Authors: Schooten Frederik-Jan Van , Schults Marten , Sanen Kathleen , Godschalk Roger , Theys Jan , Chiu Roland
Published: August 2012

Hypoxia is characteristic for a number of pathologies and promotes genetic instability, as exposure to low oxygen levels results in an elevated mutation frequency. We have previously shown that activation of the hypoxia responsive transcription factor HIF-1α, in the presence of sufficient oxygen, enhanced mutation frequencies induced by the environmental mutagen benzo[a]pyrene (BaP). Since proper carcinogen metabolism depends on oxygen we examined how varying oxygen levels influenced BaP metabolism by studying its activation and deactivation. The human lung carcinoma cell line A549 was treated with BaP under different oxygen concentrations (20%, 5%, and 0.2%) for 18 hours and alterations in BaP-metabolism were determined. First, we analyzed the BaP induced expression of key metabolic enzymes; expression levels of CYP1A1 and CYP1B1 was higher under hypoxia, while expression of the detoxifying enzymes UGT1A6 and UGT2B7 were significantly reduced by hypoxia. Then, several BaP metabolites in supernatants were determined by HPLC-fluorescence detection. In general, low oxygen levels lead to slower metabolism of BaP leaving more of the parent molecule intact. At the same time, BaP-7,8-dihydrodiol, the pre-cursor metabolite of the reactive metabolite BaP-7,8-dihydroxy-9,10-epoxide (BPDE), was formed in higher concentrations under hypoxia. Finally, under hypoxia DNA adducts accumulated over a period of 168 hours, whereas DNA adducts were efficiently removed under 20% oxygen, eventually leading to 1.6 times higher adduct levels under hypoxic conditions. These data indicate that the metabolism has shifted towards increased activation of BaP instead of detoxification under hypoxic conditions. These data support the idea that modulation of carcinogen metabolism may be an important additional mechanism for the observed HIF1 mediated genetic instability.

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 4118. doi:1538-7445.AM2012-4118
Abstract 4121: Glycine N-methyltransferase deficiency affects hepatic cholesterol homeostasis and steatosis-associated inflammation
Authors: Fang Cheng-Chieh , Liao Yi-Jen , Chen Yi-Ming
Published: August 2012

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder with excess accumulation of lipid within hepatocyte. Severe NAFLD is associated with inflammation and contributes to the development of hepatocellular carcinoma (HCC). Previously, we reported that glycine N-methyltransferase knockout (Gnmt-/-) mice develop chronic hepatitis and HCC. The aim of this study was to understand the role of GNMT and its interactive proteins play in the pathogenesis of NAFLD. Firstly, we found that Gnmt-/- mice had hyperlipidemia and steatohepatitis and GNMT was down-regulated in the liver tissues from patients with NAFLD as well as from mice fed with high fat diet, high cholesterol diet or methionine/choline deficient diet. Besides, Q-PCR showed that the liver tissues of Gnmt-/- mice had higher levels of TNF-α, IL-6, IL-12p40 and IL-1α than the wild-type mice. Single photon emission computed tomography images demonstrated that Gnmt-/- mice had slower hepatic cholesterol uptake and excretion rates than the wild-type mice. Yeast two-hybrid screenings and co-immunoprecipitation assays elucidated that the Niemann-Pick type C2 protein (NPC2) interacts with GNMT. Confocal microscopy demonstrated that NPC2 was released from lysosomes and interacts with GNMT in the cytosol when cells were treated with low density lipoprotein. Over-expression of GNMT prolonged the half-lives of both NPC2 isoforms and reduced cholesterol accumulation in cells. In conclusion, we demonstrated that GNMT regulates the homeostasis of cholesterol metabolism and steatosis-associated inflammation. This study provides novel targets for the prevention and treatment of steatohepatitis and HCC.

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 4121. doi:1538-7445.AM2012-4121
Abstract 4122: Induction of steroid sulfatase expression by bacterial lipopolysaccharides in human prostate cancer cells: Possible role of STS in tumor cell migration
Authors: Im Hee-Jung , Park Nahee , Chun Young-Jin
Published: August 2012

Steroid sulfatase (STS) is responsible for the conversion of estrone sulfate to estrone that can stimulate growth in endocrine-dependent tumors such as breast and prostate cancer. Although STS is considered as a therapeutic target for the estrogen-dependent diseases, cellular function of STS are still not clear. Previously, we found that tumor necrosis factor (TNF)-α significantly enhances steroid sulfatase expression in PC-3 human prostate cancer cells through PI3K/Akt-dependent pathways. Here, we studied whether bacterial lipopolysaccharides (LPS) which are known to induce TNF-α may increase STS expression. Treatment with LPS in PC-3 cells induces STS mRNA and protein in concentration- and time-dependent manners. Because LPS-induced STS mRNA expression was strongly suppressed by NF-κB inhibitors such as Bay 11-7082 and bortezomib, the involvement of NF-κB pathways on STS expression was suggested. To determine whether IkBα is involved in NF-κB-dependent STS expression, the effect of IKKα siRNA was elucidated. IKKα siRNA significantly suppressed STS mRNA and protein expression. Interestingly, overexpression of STS by transfecting expression vector induced wound healing effect whereas knockdown of STS by siRNA significantly decreased wound healing effect in PC-3 cells. Moreover, treatment with LPS in STS knockdowned cells recovered wound healing effect. Taken together, these results strongly suggest that STS may contribute tumor cell migration.

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 4122. doi:1538-7445.AM2012-4122
Abstract 4123: Cholesterol and breast cancer
Authors: Danilo Christiane , Mainieri Maria Antonietta , Lisanti Michael P. , Frank Philippe G.
Published: August 2012

Breast cancer is the most commonly diagnosed type of cancer among women with an incidence rate five times greater in the Western world than elsewhere. Relocation studies have ruled out genetics as the sole factor in this discrepancy, since immigrant populations develop breast cancer at rates similar to indigenous Western populations, thus indicating an environmental effect on breast cancer incidence. Amongst possible environmental factors, diet and obesity have long been considered likely risk factors for cancer development. Despite this probability, a specific role of cholesterol in breast cancer has not yet been specifically examined. Cholesterol is an integral component of the plasma membrane and is the precursor to biomolecules such as steroid hormones and vitamins. Epidemiologic evidence indicates that cancer patients display abnormal levels of the cholesterol carrying lipoproteins, high density lipoprotein (HDL) and low density lipoprotein (LDL), thus suggesting a role for cholesterol in breast cancer. Recent research in our laboratory shows that when fed a high fat, high cholesterol diet, PyMT Tg mice, a model of breast cancer, develop larger, more advanced tumor lesions. These mice also develop a significant increase in HDL-cholesterol levels and an increase in the expression of the HDL-C receptor, SR-BI compared to PyMT Tg mice fed a control chow diet. In the present study, we aim to elucidate the role of SR-BI in breast cancer. To do so we manipulate cellular levels of SR-BI in human breast cancer cell lines. In vitro, we show that ablation of SR-BI in human breast cancer cells leads to a decrease in cellular proliferation, migration, and invasion. Xenograft mouse models indicate that SR-BI depletion confers protection against tumor growth in vivo with concomitant dysregulation of key mitogenic signaling pathways. These results suggest a role for SR-BI in breast cancer.

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 4123. doi:1538-7445.AM2012-4123
Abstract 4125: Suppression of the mevalonate pathway and oncogenic signaling may underlie the tumor-suppressing effects of KLK5 in breast cancer
Authors: Pampalakis Georgios , Obasuyi Osahon , Papadodima Olga , Chatziioannou Aristotelis , Zoumpourlis Vassileios , Sotiropoulou Georgia
Published: August 2012

Kallikrein-related peptidase 5 (KLK5) has been implicated in different types of cancer based on its aberrant expression in tumor cell lines and tissue specimens and in vitro data, however, functional association is missing. Here, we confirmed that KLK5 is very frequently down-regulated or inactivated in breast cancers of different subtypes. Reconstitution of KLK5 expression by stable transfection in KLK5-negative MDA-MB-231 cells remarkably reversed their malignant phenotype both in vitro (wound scratch and soft agar assay) and in vivo (orthotopic xenograft growth in SCID mice). We found that in KLK5 transfectants Snail1 and the mesenchymal marker vimentin were highly downregulated, pointing to a potential involvement of KLK5 in mesenchymal-to-epithelial transdifferentiation, however, re-expression of E-cadherin could not be demonstrated. Importantly, it appears that KLK5 may severely affect the overall output of the proteolytic web as it minimized the proteolytic activities of MMP9 and MMP3. Unexpectedly, transcriptomic profiling revealed that reconstitution of KLK5 expression suppresses the mevalonate pathway of cholesterol biosynthesis by highly up-regulating INSIG1 (insulin induced gene 1), a major negative regulator of HMGCR (3-hydroxy-3-methylgluratyl-CoA reductase), while KLK5 may also affect cholesterol uptake, as the LDLR (LDL receptor) and PCSK9 (proprotein convertase subtilisin-like/kexin type 9), the main regulator of LDLR, were both found significantly upregulated in KLK5 transfectants. A functional role of KLK5 in the regulation of the mevalonate pathway and protein-prenylation circuitries was demonstrated by reduced cellular cholesterol and prenylation levels, end products of this pathway. Reduced prenylation was shown by the remarkable reduction in the levels of activated RhoA, which must be subjected to isoprenylation (mainly geranyl-geranylation) for activation. To our knowledge, this is the first demonstration of a protease involved in the crosstalk between metabolic pathways and oncogenic signaling. Moreover, among the genes found up or down-regulated upon KLK5 re-expression (i.e. the “KLK5 signature”) were several genes known to be involved in atherosclerosis and other lipid-related metabolic disorders. Overall, KLK5 may represent a nodal interconnection of proteolytic and signaling pathways in cancer but may also participate in pathways associated with metabolic diseases, in support of the emerging concept of common genetic networks governing both cancer and lipid-associated disorders.

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 4125. doi:1538-7445.AM2012-4125
Abstract 4126: Synergism of polyamine synthesis inhibition and AMP kinase activation on human melanoma proliferation and migration
Authors: Hsueh Eddy C. , Zhang Yanping , Guangyong Peng
Published: August 2012

Introduction: Metformin has been shown to inhibit human cancer cell growth via activation of MAP kinase with resultant inhibition of mTOR signaling pathway. We have reported the over-expression of ornithine decarboxylase (ODC) in human melanoma cell lines. ODC is a key enzyme in polyamine biosynthesis. We determined the effect of metformin in combination with DMFO, an ODC inhibitor, on tumor proliferation and migration, and the possible mechanisms, using human melanoma cells. Methods: Human melanoma cells were treated with Metformin, DFMO, or combination. Cell proliferation assay was performed using Cell Titer Blue proliferation assay. Cell migration assay was performed by seeding melanoma cells in 24-well plate. After overnight incubation, an artificial homogenous wound was created onto the monolayer with a plastic micropipette tip. After wounding, the migration of cells into the wound was observed at 0- and 48-hour time points. Quantitative RT-PCR for ODC1 detection was performed using Assay-on-Demand Hs00159739-ml. GAPDH served as housekeeping control. Western blotting was performed to determine the expression of AMP kinase, mTOR, p70S6K and 4E-BP1, Raf-1 and Raf-B. Data were presented as means ± SD for the three separate experiments. For comparison between groups, the student's t test was used and p< 0.05 was considered to be statically significant. Results: There was dose-dependent inhibition of melanoma cell proliferation and migration with either metformin or DFMO. Synergistic inhibition was observed with the combination treatment on both cell migration and proliferation. There was synergistic inhibition of ODC expression with the combined treatment compared with DFMO alone (p<0.01). The combination treatment also lead to significant enhancement of AMPK activation and increased phosphorylation of AMPKΨ at Thr-172 compared with metformin alone (p<0.01). The combination treatment resulted in inhibition of mTOR signaling with decreased phosphorylation of mTOR, p70S6K and 4E-BP1, Raf-1 and Raf-B in treated cancer cells, when compared with individual drug treatments. Conclusion: We have observed a synergistic effect of AMP kinase activation and polyamine synthesis inhibition on suppressing human melanoma proliferation and migration. The synergism is due to enhanced inhibition of both polyamine synthesis and mTOR signaling pathways.

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 4126. doi:1538-7445.AM2012-4126
Abstract 4127: MiR-183/96/182 cluster confers cell motile advantages in hepatocellular carcinoma
Authors: Leung Wilson , He Mian , Law Priscilla , Ching Arthur , Chan Anthony , Wong Nathalie
Published: August 2012

Profilings of microRNA expressions in hepatocellular carcinoma (HCC) have highlighted common upregulations of the miR-183/96/182 cluster. We showed in this study concordant over-expression of miR-183, miR-96 and miR-182 can be frequently detected in primary HCC tumors (59%; n=47/80). In addition, miR-183/96/182 up-regulation correlated with metastatic features including presence of microvascular invasion (P<0.05) and advanced tumor differentiation (P<0.01), and poorer disease-free survival of patients (P<0.05). Univariate and multivariate analyses further establish miR-183/96/182 over-expression as an independent prognostic factor (Relative Risk: 2.0471; P=0.0289). Functional knockdown of individual miR-183, miR-96 and miR-182 in two invasive HCC cells indicated significant inhibition on cell migration and invasion (P<0.01), although an effect on cell viability was not apparent. In silico TargetScan analysis showed putative target seed sequences of miR-183, miR-96 and miR-182 on the FOXO1 3′UTR. To verify the possible interaction between miR-183/96/182 and FOXO1 in HCC, we conducted Western blot analysis which showed knockdown of miR-183, miR-96 and miR-182 concomitantly enhanced FOXO1 protein expression. Subsequent reporter assay indicated knockdown of miR-183/96/182 could significantly augmented the luciferase signal of wild-type FOXO1 3′UTR but not mutant (P<0.01). Our finding highlighted over-expression of miR-183/96/182 as an independent prognostic predictor for HCC patients, and the oncogenic role of this miRNA cluster in promoting HCC cell motility, possibly via FOXO1 repression.

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 4127. doi:1538-7445.AM2012-4127
Abstract 413: Genome-wide microarray expression and array-CGH analysis in neuroblastoma stem-like cells by use of the neurosphere-formation assay
Authors: Gallo Gabriel , Legarra Sheila , Fan Xing , Pata-Merci Noemie , Guegan Justine , Danglot Gisele , Bernheim Alain , Castresana Javier S.
Published: August 2012

In this work, we aimed at analyzing genome-wide gene expression and DNA gains and losses in neuroblastoma cell lines and in neurospheres containing stem-like cells. SKNDZ and SIMA neuroblastoma cell lines were grown in DMEM cell culture medium, and in DMEM-F12 selective serum free medium (with EGF, bFGF and B27; to induce the neurosphere-forming phenotype). After RNA and genomic DNA extractions from the 4 cell lines (2 standard, 2 neurosphere-forming cell lines), expression microarrays and array-CGH analyses were performed (Aligent Technologies). Array-CGH did not show any significant differences between standard and neurosphere-forming cell lines, both in SKNDZ and in SIMA. Microarray expression analysis demonstrated a total of 425 upregulated and 170 downregulated genes in neurosphere-forming cell lines. The differentially expressed genes were classified using the PANTHER classification system (www.pantherdb.org). As a result, apoptosis, cell adhesion, cell communication, cell cycle, and immune system processes appeared upregulated and downregulated in neurospheres. Some of those genes participate in pathways related with cancer (Table 1). In conclusion, the stem-like phenotype does not seem to be linked to anatomic changes at the level of deletions/gains of DNA, but to changes in expression of genes, like those of the TGF-beta, Notch and Sonic Hedgehog pathways. Those pathways, specially TGF-beta, widely described as an important therapeutic target against cancer, should be further studied to determine their real implication in the neurosphere-formation process in neuroblastoma, and therefore, as candidate targets for the treatment of neuroblastoma stem-like 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 413. doi:1538-7445.AM2012-413
Abstract 4130: Bariatric surgery profoundly changes circulating MicroRNA profile in the rat
Authors: Wu Qianxin , Li Jia V. , Seyfried Florian , Ashrafian Hutan , Gooderham Nigel John
Published: August 2012

Obesity is a worldwide public health issue which can lead to cardiovascular disease, type 2 diabetes, and cancers. Bariatric surgery can provide sustained weight loss and a significant reduction of cancer risk. MicroRNAs are approximately 22 nucleotide long post transcription regulators. MicroRNAs are suggested to play important roles in obesity and metabolic syndrome related biological processes, but also are involved in different types of cancer. Recently microRNAs have been shown to be present in blood, and it is proposed that circulating microRNAs may be biomarker of tissue biochemistry and pathology. The aim of this study is to investigate if the circulation microRNA profile is changed by bariatric surgery and whether the altered microRNA expression could contribute to the long term reduced predisposition cancer risk associated with such surgery. Total plasma RNA from 53 days post bariatric surgery and sham operated rats were isolated and then examined using Taqman Rodent MicroRNA A+B Cards which have the capacity to evaluate expression levels of 373 rat microRNAs. Four different normalization methods (Global, cel-miR-39 spiked in, U6 endogenous and five endogenous microRNAs normalization) were tested. Five endogenous microRNAs normalization was found to be optimal and selected for all downstream analysis. Our preliminary data showed that 113 microRNAs were expressed in the plasma of bariatric surgical rats and 92 in sham operated rats. Furthermore, an OPLS-DA model clearly showed that bariatric surgery changed the circulating microRNA expression profile. Among nineteen of the most significantly changed microRNAs, nine of them are relevant to cancer. In summary, our data suggest that bariatric surgery fundamentally changed circulating microRNA expression. Understanding the significance of these changes in circulating microRNA may give clues to the mechanisms whereby bariatric surgery affords health benefits to individual undergoing such surgery, including a reduced predisposition to disease such as cancer.

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 4130. doi:1538-7445.AM2012-4130
Abstract 4131: Serum miRNA profiles of patients with oral cancer and pre-cancer
Authors: MacLellan Sara A. , Lawson James , Baik Jonathan , Guillaud Martial , Poh Catherine F. , Garnis Cathie
Published: August 2012

Oral cancer is one of the most commonly diagnosed cancers worldwide. Those diagnosed with this disease are often diagnosed at late stage with poor 5-year survival rate and/or suffer from a high rate of local recurrence or second primary tumor. Novel approaches for early detection for treatment stratification are needed to improve these statistics. MicroRNAs (miRNAs), a group of small, non-coding RNAs, can be isolated from blood serum samples and have shown the potential to be used as a non-invasive detection method in several cancer types. The purpose of this study is to examine the expression profiles of circulating miRNAs in the serum of patients with high-risk oral lesions (HRLs; oral cancer/carcinoma in situ) and to explore their utility as potential oral cancer biomarkers. Methods: Serum samples were collected from 33 patients with HRL (17 oral cancer and 16 carcinoma in situ) undergoing intent-to-cure surgical treatment and from a demographically matched (for age, sex, and smoking status) normal control group (N=15). RNA was extracted from serum samples using a modified miRNeasy (Qiagen) protocol. The miRCURY LNA™ Universal RT miRNA PCR system was used to profile all serum samples. The system allowed for the profiling of 742 miRNAs plus required controls within a single experiment. Statistical tests were carried out using Statistica 64 and Microsoft Excel. Results: Using analysis of variance, we detected 37 miRNAs that showed a significant differential expression between the three groups (oral squamous cell carcinoma, carcinoma in situ, and controls). Among these 37 miRNAs, miR-223, miR-342-3p, miR-423-5p, and miR-451 were the most differentially expressed. Conclusions: By examining circulating miRNA expression profiles, we have identified potential biomarkers that can be obtained from a simple blood test. The differential expression of serum miRNAs between disease stages suggests the possible utility of these miRNAs as biomarkers for the early detection of oral cancer and its progression. Blood samples are easily collected from patients, and combining serum miRNA profiles with other screening techniques could greatly improve the sensitivity in oral cancer detection. Early detection to facilitate treatment decision making for those with oral cancer or premalignant disease would have a great impact on disease survival.

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 4131. doi:1538-7445.AM2012-4131
Abstract 4134: miR1288 in colorectal cancers: Altered expression and its clinicopathological significance
Authors: Gopalan Vinod , Salajegheh Ali , Smith Robert A. , Lam Alfred K-Y
Published: August 2012

Introduction: MicroRNA-1288 (miR-1288) is a non-coding RNA located in 17p11.2 and not been studied solely in cancer. We aim to examine the miR-1288 expression in a large cohort of patients with colorectal carcinoma, adenoma and non-neoplastic colorectal tissues. The implications of miR-1288 expression and clinicopathological features were also studied. Methods: Tissues from 102 patients with surgical resection of colorectum (82 adenocarcinomas, 10 adenomas and 10 non-neoplastic tissues), two colon cancer cell lines (SW480 and SW48) and one normal colonic epithelial cell line (FHC) were recruited. miRNA was extracted from all these samples and were converted in to cDNA. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for the detection of miR-1288 expression. The results were correlated with the clinical and pathological data. Results: miR-1288 expression was decreased in majority of colorectal adenocarcinoma when compared to colorectal adenoma and non-neoplastic tissues. Reduced or absence expression of miR-1288 was noted in 78% (n=64) of the cancers. The colon cancer cell lines showed reduced expression of miR-1288 compared to normal colonic epithelial cell line. Distal colorectal cancers showed higher expression levels of miR-1288 than proximal cancers (p= 0.007). The expression levels of miR-1288 were significantly altered in different levels of cancer invasion (T staging) (p= 0.023). Conclusions: Altered expression pattern of miR-1288 in colorectal cancers compare to non-neoplastic tissues was identified. Also, differential regulation of miR-1288 was found to be related to location and pathological staging of colorectal cancers.

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 4134. doi:1538-7445.AM2012-4134
Abstract 4135: Plasma miRNAs as potential predictive/prognostic biomarker for ovarian cancer
Authors: Chen Kexin
Published: August 2012

Background: Ovarian cancer is the fifth leading cause of cancer death in women worldwide. While the survival rates of women with early stage ovarian cancer are high, most cases are diagnosed late. Due to asymptomatic development and few screening options, almost 70% of women present at late stages of carcinogenesis. Sensitive, non-invasive biomarkers that can facilitate disease detection, staging and prediction of therapeutic outcome are highly desirable to improve survival rate and help to determine optimized treatment for ovarian cancer. The small non-coding RNAs, microRNAs (miRNAs), have recently been identified as critical regulators for various diseases including cancer and may represent a novel class of cancer biomarkers. The purpose of this study was to identify and validate circulating microRNAs in human plasma for use as such biomarkers in ovarian cancer. Methods/ Principle findings: We scan the circulating plasma miRNAs by Taqman Low Density Array, then identify and validated 30 markers in plasma samples among 70 cases and 70 controls by real-time PCR assay. Promising associations were evaluated in a second stage, comprising 150 cases and 150 controls. We found that compared with normal, there are 9 miRNAs (miR-205, miR-200a, miR-184, miR-34a*, miR-141, miR-483-5p, miR-193b*, let-7e*, miR-363*) expressed higher in ovarian cancer group, while the miR-98 and let-7f have the lower levels in ovarian cancer. Compared with early stage cases (stage I), there is only miR-483-5p expressed higher in advanced stages (stage II-IV). Receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of candidate plasma microRNA markers. We observed that combination of these identified miRNAs and CA-125, a widely used marker for ovarian cancer, further improved the accuracy of detection. Furthermore, our analysis showed that high levels of plasma miR-483-5p or low levels of let-7f predicted poor prognosis of ovarian cancer patients, consistent with the expression of miRNAs in ovarian cancer tissues. Conclusions/Significance: We propose that plasma miRNAs (miR-205, miR-200a, miR-184, miR-34a*, miR-141, miR-483-5p, miR-193b*, let-7e*, miR-363*) are potential biomarkers that complements CA-125 in detecting ovarian cancer; miR-483-5p and let-7f may predict the prognosis of ovarian cancer. It may provide new avenues for the detection, diagnosis, and therapy of this deadly disease.

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 4135. doi:1538-7445.AM2012-4135
Abstract 4138: miRNA-362-3p is associated with recurrence of colorectal cancer and targets E2F1, USF2 and PTPN1
Authors: Tobiasen Heidi , Christensen Lise Lotte , Holm Anja , Schepeler Troels , Thorsen Kasper , Rasmussen Mads H. , Birkenkamp-Demtroeder Karin , Sieber Oliver M. , Gibbs Peter , Lamy Philippe , Laurberg Søren , Øster Bodil , Hansen Kristian Q. , Hagemann-Madsen Rikke , Byskov Kristina , Ørntoft Torben F. , Andersen Claus L.
Published: August 2012

Colorectal cancer (CRC) is one of the leading causes of cancer death in Western countries. A significant number of CRC patients undergoing curative-intented surgery subsequently develop recurrence and die from the disease. MicroRNAs (miRNAs) are aberrantly expressed in cancers and appear to have both diagnostic and prognostic significance. In this study we identified novel miRNAs associated with recurrence of CRC. TaqMan® Human MicroRNA Array Set v2.0 was used to profile the expression of 667 miRNAs in 14 normal colon mucosas and 46 microsatellite stable CRC tumors. Four miRNAs (miR-362-3p, miR-570, miR-148a* and miR-944) were expressed at a lower level in the tumors from patients with recurrence (p < 0.015) compared to tumors from patients with no recurrence. A significant association of low expression with reduced disease free survival was confirmed for miR-362-3p in a second independent cohort of 43 CRC patients using single TaqMan® microRNA assays. In vitro functional analysis showed that over-expression of miR-362-3p in colon cancer cell lines (HCT116, LS174T, and DLD1) reduced cell viability and proliferation mainly due to cell cycle arrest. E2F1, USF2 and PTPN1 were identified as potential miR-362-3p targets by mRNA profiling of HCT116 cells over-expressing miR-362-3p. Subsequently, these genes were confirmed as direct targets by Luciferase reporter assays. In vitro knock-down confirmed that these targets are important players in the miR-362-3p target network. We conclude that miR-362-3p may be a novel prognostic marker in CRC and hypothesize that augmented expression of miR-362-3p may prevent the development of distant metastasis by targeting E2F1, USF2 and PTPN1.

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 4138. doi:1538-7445.AM2012-4138
Abstract 4149: Pathway-based serum microRNA profiling and late-stage non-small cell lung cancer survival
Authors: Wang Yan , Lippman Scott M. , Minna John D. , Roth Jack A. , Wu Xifeng
Published: August 2012

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer mortality in the world. Nearly half of NSCLC patients are diagnosed with late-stage (stage III or stage IV) disease with an overall 5-year survival rate of less than 15%. Deregulation of microRNAs (miRNAs) is involved in cancer development, progression, and prognosis. Circulating miRNAs have been suggested as promising biomarkers for early detection, diagnosis, and prognosis of cancer. This ongoing study is to utilize a pathway-based approach to screen and validate serum miRNA profiles as predictors of survival using a large patient cohort of 348 late-stage NSCLC patients. In the testing set, pre-treatment serum miRNA profiles of four good- (survival time > 24 months) and four poor-survival (survival time < 6 months) patients were compared by Taqman miRNA microarray. 145 highly expressed serum miRNAs were identified from initial screening and 37 of them were mapped onto the 3′UTRs of a panel of 23 genes in TGF-β signaling pathway using computer-assisted miRNA target prediction program. All 37 miRNA candidates were subject to large-scale single-probe quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The expression level of serum miR-30d, which targets TGFBR2 and was a previously reported serum marker for early-stage lung cancer survival, was significantly higher in the poor-survival group than the good-survival group (P = 0.0208) in our study population of late-stage lung cancer. The level of serum miR-93-3p that targets SMAD7 was significantly higher in the poor-survival group than the good-survival group (P = 9x10−6). The 2-year overall survival rate in patients with high serum miR-93-3p expression was significantly lower than that in those with low expression with an adjusted HR of 1.59 (95% CI, 1.24 - 2.03) (P = 2x10−4). In contrast, serum level of let-7g, that targets SMAD2, TGFBR1 and the activin A receptor family was significantly lower in the poor-survival group than in the good-survival group (P = 7x10−4), and patients with high serum let-7g expression was associated with a significantly better two-year survival (HR=0.48, 95% CI, 0.37 - 0.62, P = 1x10−8). Our results suggest that serum miR-30d, miR-93-3p and let-7g may become valuable biomarkers for survival in late-stage NSCLC patients.

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 4149. doi:1538-7445.AM2012-4149
Abstract 415: Human embryonic stem cell-derived endothelial cells as cellular delivery vehicles for targeting therapy of metastatic breast cancer
Authors: Su Weijun , Wang Lina , Zhou Manqian , Tong Lingling , Xiang Rong , Li Zongjin
Published: August 2012

Recent reports revealed that endothelial progenitor cells (EPCs) isolated from bone marrow, cord blood or embryos have been experimentally utilized to deliver therapeutic agents for cancer treatment. Their potential in cancer therapy highlights the need for a consistent and renewable source of endothelial cells for clinical applications. Moreover, one of the most critical issues for ensuring success of endothelial therapy is the development of technologies for non-invasive monitoring of the distribution of transplanted cells and kinetic of tumor progression or regression. We generated human embryonic stem cell-derived endothelial cells (hESC-ECs) from H9 cell line. The hESC-ECs resemble adult endothelial cells HUVEC in endothelial markers and angiogenesis potential. In vitro study revealed the paracrine effects of hESC-ECs on tumor cells using conditioned medium (EC-CM). After treated with EC-CM, human breast cancer cells MDA-MB-231 proliferated slower and exhibited a higher apoptosis rate in low-serum condition, and the migration ability was impaired. Furthermore, we introduced a multitude of non-invasive, quantitative, functional imaging techniques with reporter gene methods to probe breast cancer model processes, and to track the hESC-ECs for targeting therapy in vivo by firefly luciferase (Fluc)/renilla luciferase (Rluc) imaging. We transduced hESC-ECs with triple fusion (TF) reporter gene containing the herpes simplex virus truncated thymidine kinase (HSV-ttk), renilla luciferase (Rluc) and RFP (RL-RFP-HSV-ttk). The NOD/SCID mice breast cancer metastasis model was established by tail vein injection of 1.5×106 MDA-MB-231 cells, which carry a reporter system encoding the gene of Fluc and GFP. Bioluminescence imaging (BLI) revealed that hESC-ECs can be sequenced in tumor sites for more than 72 hours. When given pro-drug ganciclovir (GCV), targeting HSV-ttk gene, the MDA-MB-231 tumor was inhibited by the indication of Fluc imaging. And immunofluorescence staining also confirmed that hESC-EC can exclusively home to tumor lesions instead of normal lung tissue. Taken together, our results revealed that hESC-ECs can specifically target tumor sites and kill nearby tumor cells by bystander effect when GCV is given. These finds suggest that hESC-ECs are attractive targeting vehicles for cancer therapy, and molecular imaging in small animals is an invaluable part of cancer diagnosis, prediction of tumor response to available therapies and monitoring response to therapy as well as developing drugs prior to clinical translation.

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 415. doi:1538-7445.AM2012-415
Abstract 4161: Rab25 cooperates with RIN1 to suppress p21 Ras
Authors: Cheng Jiming , Ayyagari Vijayalakshmi , Rao Krishna
Published: August 2012

Introduction: Our previous work has shown that the loss of Rab25 occurs in estrogen receptor (ER) and progesterone receptor (PR) negative breast cancer cell lines and human tumor samples and seems to correlate with an active Ras pathway. Loss of Rab25 cooperates with mutant Ras to promote tumorigenesis. RIN1 is a protein inhibitor of Ras, and our current works confirms that Rab25 binds to RIN1 and cooperates to inhibit Ras. Rab25 also has multiple effects on microRNAs. Materials and Methods: Cell culture -RAO-1-4 cell lines was grown in DFCI-1 medium. Immunoprecipitation- Protein extracts from RAO-1, RAO-2, and RAO-3/Rab25 were tested for RIN1expression. Immunoprecipitated extracts were then assayed by western blot for RAB25 expression. Chemiluminescence Assay- Cell extract from MDA-MB-231 cells with shRIN1 was used. These cells contained no Rab25 as well. Recombinant RIN1 and recombinant Rab25 were tested in various combinations for ras inhibition using the Active Motif kit. MicroRNA assay- RNA was extracted from RAO-2, RAO-4, and RAO-4/Rab25 and sent to Phalanx Biotech for microRNA profiling. Results: 1. Rab25 binds to RIN1 in a ternary complex with Ras. 2. Rab25 coopeates with RIN1 in an additive manner to inhibit Ras. 3. Rab25 expression impacts several microRNAs including 29b, 100, 138, 146a, 205, 524-5p, 762, 1246, 1260b, 1307, 1826, 3172, 3175, and 3178. Conclusions: 1. Rab25 is a tumor modulator. It can regulate tumor growth and angiogenesis through inhibition of ras in cooperation with RIN1. 2. Our data previous indicated that Rab25 could localize to the nucleus, and it appears to effect the expression of several microRNAs.

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 4161. doi:1538-7445.AM2012-4161
Abstract 4177: Synergistic role of ecdysoneless with oncogenic Ras in transformation of human mammary epithelial cells
Authors: Bele Aditya , Gurumurthy Channabasavaiah Basavaraju , Zhao Xiangshan , Wang Jun , Mirza Sameer , Mohibi Shakur , Band Hamid , Band Vimla
Published: August 2012

Precisely regulated cell proliferation is essential for embryonic development as well as homeostasis in adult organs and tissues, whereas uncontrolled cell proliferation is a hallmark of cancer. Thus, elucidating how the cell cycle machinery is controlled is an important area of research in cancer cell biology. A large body of evidence has established a basic paradigm of the control of cell cycle progression involving the Retinoblastoma (Rb) protein family in conjunction with the E2F family of transcription factors. During G0/G1, interaction of hypo-phosphorylated Rb proteins with E2Fs prevents the transcription of E2F target genes. Cyclin-CDK complexes generated during cell cycle progression hyper-phosphorylate Rb, leading to release of Rb from E2Fs; this allows E2F target gene transcription and cell cycle progression. We previously identified the mammalian ortholog of Drosophila ecdysoneless (Ecd) protein as a novel and essential regulator of Rb-E2F-dependent cell cycle progression. Loss of Ecd retards the separation of Rb from E2F, arrests cells at G1/S boundary and prevents cell cycle progression. Consistent with role of Ecd in cell cycle, our recent studies show Ecd is overexpressed in breast cancer cell lines as well as in ductal carcinoma in situ and infiltrating ductal carcinomas of the breast. To understand the mechanism of Ecd overexpression and its correlation with oncogenesis, we overexpressed either Ecd alone, 61L-HRas alone or both genes together in hTERT-immortalized hMECs. These transfectants were then examined for their oncogenic properties. We observed while vector infected cells do not exhibit anchorage independence, all three transfectants showed anchorage independent proliferation, particularly Ecd+Ras showed a dramatic increase in anchorage independence in comparison with either Ecd or H-Ras. Similarly, other oncogenic traits such as proliferation on matrigel, invasion and migration were dramatically increased when both genes were expressed in comparison with individual genes. Considering the known oncogenic role of Ras in human cancer and the known role of Ecd in cell cycle, these data are highly significant and present a novel synergistic pathway for mammary cell transformation. We are currently defining the molecular mechanism of this synergistic oncogenic effect. In addition, we are generating Ecd overexpressed transgenic mice to examine the role of Ecd in oncogenesis in in vivo models.

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 4177. doi:1538-7445.AM2012-4177
Abstract 4185: Identifying transcriptional start sites of human microRNAs based on high-throughput sequencing data
Authors: Tsou Ann-Ping , Chien Chia-Hung , Chiang-Hsieh Pei-Yun , Tsai Wei-Chih , Huang Hsien-Da
Published: August 2012

MicroRNAs (miRNAs) are critical small non-coding RNAs that regulate gene expression by hybridizing to the 3′-untranslated regions (3′ UTR) of target mRNAs, subsequently controlling diverse biological processes at posttranscriptional level. How miRNA genes are regulated receives considerable attention because it directly affects miRNA-mediated gene regulatory networks. Although numerous prediction models were developed for identifying miRNA promoters or transcriptional start sites (TSSs), most of them lack experimental validation and are inadequate to elucidate relationships between miRNA genes and transcription factors (TFs). Here, we integrate three experimental datasets, including Cap analysis of gene expression (CAGE) tags, TSS Seq libraries, and H3K4me3 chromatin signature derived from high-throughput sequencing analysis of gene initiation, to provide direct evidence of miRNA TSSs, thus establishing an experimental-based resource of human miRNA TSSs, named miRStart. Moreover, a machine learning based Support Vector Machine (SVM) model is developed to systematically identify representative TSSs for each miRNA gene. Finally, to demonstrate the effectiveness of the proposed resource, an important human intergenic miRNA, hsa-miR-122, is selected to experimentally validate putative TSS owing to its high expression in a normal liver. In conclusion, this work successfully identify 847 human miRNA TSSs (292 of them are clustered to 70 TSSs of miRNA clusters) based on the utilization of high-throughput sequencing data from TSS-relevant experiments, and establish a valuable resource for biologists in advanced research in miRNA-mediated regulatory networks.

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 4185. doi:1538-7445.AM2012-4185
Abstract 4190: Ezrin plays a key role in the regulation of translation in metastatic osteosarcoma
Authors: Morrow James J. , Briggs Joseph , Ren Ling , Chakrabarti Kristi , Cassavaugh Jessica , Veenstra Timothy D. , Chen Qingrong , Khan Javed , Uren Aykut , Khanna Chand
Published: August 2012

Our previous studies have demonstrated the association between Ezrin and the metastatic biology of pediatric sarcomas including osteosarcoma (OS) and rhabdomyosarcoma. Mechanistic studies exploring this association have shown that Ezrin expression enhances the survival of metastatic cells upon their arrival to the secondary metastatic site. In order to better understand this role in metastasis, we undertook two non-candidate analyses of Ezrin function including a microarray subtraction of high and low Ezrin expressing cells and a proteomic approach to identify proteins that bind the N-terminus of Ezrin in tumor lysates. Functional analyses of these data led to a novel and unifying hypothesis that Ezrin contributes to the efficiency of metastasis through regulation of protein translation. In support of this hypothesis we found Ezrin to be part of a ribonucleoprotein complex and to bind with poly A binding protein 1 (PABA1; PABPC1). Using luciferase reporter-based assays, we have shown that OS cells expressing high levels of Ezrin are able to translate mRNAs containing a stem loop 5′ UTR structure, so called “weakly translated mRNAs,” more efficiently than low Ezrin OS cells. This finding suggests that Ezrin's contribution to the metastatic phenotype may be due in part to enhanced translation of specific mRNAs during metastasis that are normally expressed at low levels outside of the metastatic context. Ongoing studies will now assess the ability of Ezrin to enhance the expression of specific mRNAs in 3-dimensional contexts more relevant to cancer cell growth in vivo. We have developed stable high and low Ezrin osteosarcoma cell lines that express a GFP reporter with or without a complex 5′ UTR stem loop structure in the mRNA transcript and with and without protein destabilizing elements. Initial studies have shown that the addition of the 5′ UTR structure and destabilizing elements progressively limits GFP reporter expression. We plan to confirm that this reduction in expression is due to reduced translation and to assess whether 3-D culture conditions or the in vivo environment enhance expression of these tunable reporters of translation in an Ezrin-dependant manner. We expect these results to provide a novel mechanistic basis to consider how Ezrin may contribute to metastasis.

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 4190. doi:1538-7445.AM2012-4190