bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2976: Array comparative genomic hybridization analysis reveals distinct genetic alterations in African Americans with colon cancer
Authors: Brim Hassan , Lee Edward L. , Smoot Duane T. , Ashktorab Hassan
Published: February 2011

Purpose: Microsatellite Instability (MIN), CpG Island Methylation phenotype (CIMP) and Chromosomal Instability (CIN) are known processes through which colorectal cancer (CRC) can occur. In a given tumor, one or more of these events might be responsible for tumor development. We previously reported the results of our MSI and CIMP analysis of colorectal tumors in African Americans (AA), a group at high risk. Here, we report our array Comparative Genomic Hybridization (aCGH) analysis of 30 AA colorectal tumors and its implication for the understanding of CRC development in this population.

Experimental design: We applied aCGH using a 105k chip to identify copy number aberrations in samples from 30 AA colon cancer patients. In addition, we did a population comparative analysis with aCGH data in Caucasians as well as with a widely publicized list of colon cancer candidate genes (CAN genes). Bioinformatics analysis was done to calculate the chromosomal imbalance using Agilent Genomic Workbench 5.0.

Results: There was an average of 30 aberrations per patient with all samples displaying some level of chromosomal instability. Analysis of DNA copy number of frequently altered chromosomes revealed that deletions occurred primarily in chromosomes 4, 8 and 18. Chromosomal duplications occurred in more than 50% of cases on chromosomes 7, 8, 13, 20 and X. The CIN profile showed some differences when compared to alterations in Caucasians (22 cases).

Conclusions: Prominent chromosome X amplification in male patients and chromosome 4, 8 and 18 deletions were the primary targets in AAs. Most CAN genes were altered at high frequencies in AAs with EXOC4, EPHB6, GNAS, MLL3 and TBX22 as the most frequently deleted genes and HAPLN1, ADAM29, SMAD2 and SMAD4 as the most frequently amplified genes. CIN seems to be more prominent in AAs and may play a distinctive role in CRC development in this population.

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 2976.
Abstract 2979: Tumor suppressor ING1b maintains genomic stability through PCNA monoubiquitination and histone H4 acetylation
Authors: Wong Ronald PC , Lin Hanyang , Chen David W. , Li Gang
Published: February 2011

Unrepaired lesion on DNA template blocks replication fork progression and causes replication stress. Prolonged stalling of replication may give rise to serious consequences such as replication collapse, DNA double strand breaks (DSBs), recombination and genomic instability. The lesion bypass pathway, which is regulated by PCNA monoubiquitination, is essential for resolving replication stalling. We demonstrated a novel tumor suppressive function of p33ING1b (ING1b) in preserving genomic stability upon replication stress. We found that ING1b knockdown cells exhibit defects in S phase recovery and enhanced genomic instability due to UV-induced replication blockage. We showed that ING1b is required for PCNA monoubiquitination upon replication stress. Enhanced PCNA monoubiquitination due to overexpression of the E3 ligase Rad18 or knockdown of the deubiquitinating enzyme USP1 is abrogated in ING1b depleted cells. Furthermore, ING1b is required for Rad18 foci formation, localization to chromatin and interaction with PCNA after UV. In addition, ING1b is required for foci formation of Polη, a translesion DNA polymerase, indicating that ING1b is involved in regulation of the lesion bypass mechanism. We found that ING1b depleted cells display hypoacetylation of histone H4 at S phase and treatment with class I and II histone deacetylase inhibitors restores histone H4 acetylation and PCNA monoubiquitination in ING1b knockdown cells. These data suggest that ING1b regulates PCNA monoubiquitination through histone H4 acetylation to facilitate lesion bypass and recovery from replication blockage. This provides insights into a novel mechanism regulating lesion bypass through chromatin remodeling in maintaining genomic stability upon replication stress. It has implications in developing new strategies for cancer prevention and treatment.

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 2979.
Abstract 2982: Activation of checkpoint kinase Chk2 by cisplatin and its role in cisplatin resistance
Authors: Liang Xiaobing , Mueller Michael D. , Yu Jing Jie
Published: February 2011

One of the mechanisms of platinum resistance in cancer chemotherapy is the activation of DNA damage checkpoint pathways. Chk2 is a multifunctional key component of the DNA replication-monitoring S/G2 checkpoint system, which mediates DNA damage signaling following genotoxic stress and leads to DNA repair or apoptosis. Developing checkpoint kinase inhibitors for better treatment of cancer has been a major target in drug discovery over the past decade. In our study, flow cytometric experiments show that cisplatin induces an initial accumulation of cells at S phase of cell cycle followed by an increase of cell fraction at G2 phase, suggesting cisplatin-induced cell cycle arrest. Treatment of cisplatin in human ovarian carcinoma cells resulted in Chk2 phosphorylation at Thr-68 and p53 phosphorylation at Ser-15. The observed cisplatin-induced increase in p53 phosphorylation preceded (by about 12 hours) the observed increase in Chk2 phosphorylation. Elevated protein levels of ATM, p53 and P21 by cisplatin in these cells appear in a dose-dependent manner. In addition, overexpression of p53 by cDNA transfection in cells with wild type p53-function doubled the amount of Chk2 phosphorylation 48 hours after cisplatin treatment, whereas p53 knock-down by specific siRNA greatly reduced Chk2 phosphorylation. Furthermore, selective Chk2 Inhibitor (C3742) potentiated the cell-killing effect of cisplatin in both sensitive and resistant ovarian cancer cells. In conclusion, our results suggest that after cisplatin exposure the DNA damage response pathway is activated with greatly increased Chk2 phosphorylation which is modulated by p53. Inhibition of Chk2 with a small-molecule inhibitor may overcome cisplatin resistance in cancer chemotherapy.

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 2982.
Abstract 2987: Oncogenic Wip1 is activated and negatively regulates DNA-damage induced apoptosis in p53-null cancer cells
Authors: PARK JIYOUNG , Jang Se Jin , Seol Hyang sook , Choi Jene
Published: February 2011

Wip1 (wild-type p53-induced phosphatase, or PPM1D) belongs to the protein phosphatase type 2C family and its expression is induced by p53 in response to various stresses. Wip1 is known to dephosphorylate cellular target proteins such as p38 MAPK, p53, and uracil DNA glycosylase that are involved in DNA-repair and cell-cycle-checkpoint pathways. Here, we show that after methylmethane sulfonate (MMS) treatment Wip1 is induced in various breast-cancer cell lines in the absence of wild-type p53 and p38 MAPK activity. Wip1 expression in response to MMS was not blocked by the p38 MAPK inhibitor SB202190 or in p38-silenced MCF-7 cells using p38 MAPK small-interfering RNA (siRNA). The Wip1 promoter displayed great induction in breast cancer cell lines, which have DNA-binding deficient p53 mutants, and p53-null cancer cells such as Saos-2, A549-E6 and HCT116(p53−/−), whereas a control promoter, p53-Luc, showed the least promoter activity after MMS treatment. The mutation of p53 response element in the Wip1 promoter decreased its activity in both unstressed and stressed cells, but the overall level of fold-induction was similar. In addition, cell death was greatly increased in Wip1-siRNA and MMS treated cells in comparison with scrambled siRNA and MMS treated cells in the both cell lines of HCT116 (p53 +/+) and HCT116 (p53−/−). Our data indicate that Wip1 induction in response to various stimuli is not solely controlled by p53, and other damage response signaling appears to compensate for p53. Furthermore, Wip1 negatively regulates DNA-damage induced cell death regardless of the presence wild-type p53.

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 2987.
Abstract 2995: MicroRNA expression and outcome of adjuvant chemotherapy in patients with completely resected non-small cell lung cancer: International Adjuvant Lung Cancer Trial Biologic Program (IALT-Bio)
Authors: Voortman Johannes , Goto Akiteru , Mendiboure Jean , Sohn Jane J. , Schetter Aaron J. , Dunant Ariane , Khan Mohamed , Pham Trung C. , Petrini Iacopo , Lee Alan , Hainaut Pierre , Pignon Jean-Pierre , Brambilla Elisabeth , Popper Helmut H. , Filipits Martin , Harris Curtis C. , Giaccone Giuseppe
Published: February 2011

The aim of our study was to assess whether expression levels of a panel of biologically relevant microRNAs can be used as prognostic and/or predictive biomarkers in patients who participated in the International Adjuvant Lung Cancer Trial (IALT), the largest randomized study conducted so far of adjuvant chemotherapy in patients with radically resected NSCLC stage I-III.

Expression of miR-21, miR-29b, miR-34a/b/c, miR-155 and Let-7a was determined by quantitative real-time PCR in paraffin embedded formalin fixed tumor specimens from 639 IALT patients, using small nuclear RNA U66 as the endogenous normalization control. From 79 patients sufficient tumor adjacent normal tissue was available as well. The prognostic and predictive value of microRNA expression and chemotherapy for survival were studied using a Cox model, which included every factor used in the stratified randomization plus clinical and histological prognostic factors as well as other factors statistically related to microRNA expression. Association of p53 mutation status and miR-34a/b/c expression was analyzed, as well as association of EGFR and K-Ras mutation status with miR-21 and Let-7a expression, respectively. Finally association of p16 and miR-29b expression was assessed. In situ hybridization was performed for validation and to determine histological expression patterns.

Overall, we found that there was no significant association between the expression profile of any of the tested microRNAs and survival. However, for miR-21, miR-34b and miR-34c, there is a suggested deleterious prognostic effect of lower values on survival. No single microRNA expression profile or a combination of microRNA expression profiles, as determined by cluster analysis, predicted response to adjuvant cisplatin-based chemotherapy.

Concluding, expression levels of the tested microRNAs were neither predictive nor prognostic in this patient cohort.

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 2995.
Abstract 3006: Alterations of the microRNA genes targeting MYCC are frequent in medulloblastomas with MYCC overexpression
Authors: Lv Sheng-Qing , Kim Young-Ho , Nobusawa Sumihito , Grotzer Michael , Ohgaki Hiroko
Published: February 2011

MicroRNAs (miRNAs) regulate a variety of cellular processes (including differentiation, proliferation and apoptosis) via the regulation of multiple target genes, including oncogenes and tumor suppressors. Abnormal miRNA expression may therefore play a significant role in tumor development. Medulloblastoma is a common malignant brain tumor in children. Several studies have shown abnormal miRNA-expression profiles in medulloblastomas, but little is known as to whether such profiles are caused by alterations in miRNA genes. In the present study, we screened 48 medulloblastomas for mutation, deletion, and amplification of nine miRNA genes (miR-33b, miR-135a-1, miR-135a-2, miR-135b, miR-186, miR-200b, miR-512-2, miR-548d-1, and miR-548d-2). These miRNAs were selected on the basis of the presence of potential target sequences within the 3’-untranslated region of the MYCC messenger RNA, since MYCC is frequently overexpressed without MYCC gene amplification in medulloblastoma. Differential PCR revealed deletions in miR-186 (15%), miR-135a-1 (33%), miR-548d-1 (42%), miR-548d-2 (21%) and miR-512-2 (33%) genes, whereas deletion or amplification was detected in miR-135b (23%) and miR-135a-2 (15%). In miR-33b, deletion, amplification or a mutation at the precursor miRNA were detected in 10% of medulloblastomas. Overall, 35 out of 48 (73%) medulloblastomas had at least one alteration in the miRNA genes analyzed. Real-time RT-PCR revealed MYCC overexpression in 11 out of 37 medulloblastomas analyzed (30%), and there was a significant correlation between MYCC overexpression and miR-512-2 gene deletion (P = 0.0084). These results suggest that deletion or amplification in miRNA genes is frequent, and may play a role in the pathogenesis of medulloblastomas.

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 3006.
Abstract 3008: PNA based microarray for cancer & stem cell related miRNAs profiling from low total RNA with on-chip labeling
Authors: Hyunsun Kim , Choi Jae-Jin , cho Minhye , Park Heekyung
Published: February 2011

MicroRNAs(miRNAs) are short non-coding RNAs that play a critical role in many important biological processes. MiRNA expression profiling is important to understand the biological mechanisms, develop drugs, and diagnose. However, analyzed method of expression profiling is limited for short base of miRNA. Microarray which is hybridization based technique is the best for detection tool on miRNA characteristic. So, we have developed a PNA-based microarray that is highly sensitive, specific and reproducible to analyze miRNA expression profiles with direct miRNA labeling on chip after hybridization. PNA probes are well known to have stronger binding affinity, specificity to its complementary DNA or RNA strand and stability to biological enzymes. Unlabeled total RNA is hybridized to the PNA-based microarray for 4 hours and then only hybridized miRNA labeling is performed by using enzymatic ligation with pCp-Cy3. Labeling method of only hybridized miRNAs is an important technique for reproducibility and reliable results of microarray. Our data showed very low cross hybridization for miRNAs differing by single nucleotide such as human let7 family and miR-181 family. We used this microarray to determine the profile of microRNAs expressed in the developing cancer cell lines and Tissue. Array results have been validated by subsequent confirmation of miRNA expression using TaqMan qRT-PCR analysis. The results from the TaqMan qRT-PCR and PNA based microarray are shown that the range of correlation were 0.904-0.989. PNA-based microarray platform can detect small amounts of individual miRNAs from <400ng of total RNA with above 99% correlation between independent replicates in 6hrs. Therefore, PANArrayTM miRNA can be a powerful tool to analyze miRNA expression profiling in cancer diagnosis and prognosis for high throughput screening with high accuracy.

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 3008.
Abstract 3015: The miR-21:miR-221 ratio as a serum-based diagnostic for non-small cell lung cancer
Authors: Karkera Jayaprakash , Gaffney Dana S. , Londhe Puja , Wu Xiaoying , Fan Hongtao , Raponi Mitch
Published: February 2011

MicroRNAs (miRNA) are small (21-25 nucleotides) non-coding regulatory RNAs that control protein expression at the transcriptional level through various mechanisms. Previous studies have shown that circulating miRNA can be utilized as a tool to gain a better understanding of both benign and malignant tumor conditions. Their altered expression has been linked with several cancers including lung cancer. Lung cancer is the leading cause of death worldwide with approximately 85% of diagnoses being attributed to non-small cell lung cancer (NSCLC). The goal of this study was to determine if the presence of circulating miRNAs from NSCLC patients can serve as non-invasive diagnostic biomarkers of disease and therapy monitoring. We initially evaluated the expression of 16 NSCLC-specific miRNAs (miR-146b, miR-155, miR-205, miR-21, miR-221, miR-199a-5p, miR-222, miR-320, miR-223, miR-25, miR-16, miR-191, miR-20a, miR-24, miR-145, and miR-152) in 46 NSCLC serum samples ranging from stage I to IV, including 20 adenocarcinoma and 26 squamous cell carcinoma samples. Eighteen healthy controls were used for comparison. RNA was extracted from serum using the single-step Trizol method and real-time PCR (Taqman). Of the 16 miRNAs tested, six miRNAs were significantly upregulated in the NSCLC when compared to the normals (p<0.0001 with AUROCs of 0.80 to 0.93). Top Scoring Pair analyses identified the ratio of miR-21 to miR-221 as the most robust predictor of NSCLC status compared to healthy subjects with an AUROC of 0.95 (95% CI; 0.91-0.99, p < 0.001) and 17% error rate (leave-one-out cross validation). This miRNA pair was then validated in an independent set of 19 NSCLC and 26 normal serum samples with overall accuracy of 80% (89% and 73% for NSCLC and normal, respectively) and AUC of 0.88 (95%CI: 0.78-0.98). These findings demonstrate the potential of using miR-21 and miR-221 in detecting NSCLC from the serum. Furthermore, these miRNAs could lead to the development of non-invasive biomarkers for early diagnosis, prognosis, and therapy monitoring in NSCLC.

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 3015.
Abstract 3019: MicroRNAs as a powerful diagnostic tools for the differential diagnosis of kidney tumors
Authors: Spector Yael , Fridman Eddie , Barshack Iris , Dotan Zohar , Ramon Jacob , Rosenwald Nitzan , Aharonov Ranit , Tabak Sarit , Banjamin Sima , Dov Avital , David Miriam Ben , Zion Orit , Banjamin Hila , Faerman Alexander
Published: February 2011

Background: Renal cell tumors are a group of tumors which differ both in morphologic appearance and biological behavior. In some cases, despite morphologic and immunohistochemical assessment, the pathological differential diagnosis might be difficult. Since accurate diagnosis might change the management of the patient, additional tools for exact diagnosis are required. In this work we propose microRNAs, a family of small non-coding regulatory RNAs involved in human development and pathology, as an emerging class of effective biomarkers for Renal cell tumors.

Patients and Methods: Two independent sets of kidney tumors FFPE samples were collected and reviewed by a pathologist with special experience in uropathology. Historically, renal cell tumors includes: clear cell RCC, chromophobe RCC, papillary RCC (both subtypes) and oncocytoma and are classified histologically using H&E stained slides. High-quality totalRNA was extracted from the FFPE samples using a proprietary protocol developed to preserve the fraction of small RNAs and the expression levels of microRNAs were measured on a microarray and verified on qRT-PCR platforms both developed at Rosetta Genomics.

Results: Expression levels of about 800 microRNAs in a training set of more than 70 kidney tumors identified differentially expressed microRNAs between the different histological types of renal cell tumors. We defined a simple algorithm for classification based on a set of only 6 microRNAs to classify clear cell, chromophobe, papillary and oncocytoma tumors. The classifier was then tested on an independent validation set including samples from the same histological types, and the classifier diagnosed correctly 91% of the tumors. Technical validation was performed using qRT-PCR showing a high correlation to the results obtained by the microarrays.

Conclusions: Expression levels of certain microRNAs are highly specific to subtypes of kidney tumors. A combination of 6 microRNAs can successfully answer specific differential diagnosis of morphologically similar renal cell tumors. The results we present provide a basis for the development of microRNA based diagnostic assay for renal neoplasia.

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 3019.
Abstract 303: Developing predictive biomarkers of PI3K/AKT pathway activation
Authors: Savage Heidi M. , Mullappally Berny , Mohan Sankar , Pandita Ajay , Shames David , Lackner Mark , Punnoose Elizabeth
Published: February 2011

The PI3K/AKT pathway is frequently up-regulated in cancer. This occurs through activation of growth factor receptors, PI3K (p110α) mutations and amplifications, PTEN loss, and more rarely mutations and amplifications of the AKT genes. These pathway alterations could be useful as predictive biomarkers to identify the tumors that are dependent on the PI3K/AKT pathway and therefore, most likely to respond to PI3K/AKT targeted agents. PTEN is frequently inactivated in tumors from various tissues especially brain, endometrium, prostate, ovary, and breast. Developing a predictive biomarker assay PTEN status is challenging because PTEN is lost in cancer by multiple mechanisms including gene deletion, mutations, and DNA methylation. Here we evaluate multiple assays to detect PTEN loss in breast, ovarian, and prostate cancer cell lines as well as tumors to assess the prevalence by which loss occurs by these different mechanisms.

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 303.
Abstract 3032: MicroRNA profiling in head and neck cancer
Authors: Lu Ya-Ching , Cheng Ann-Joy
Published: February 2011

Endogenous small non-coding RNA molecules, such as micorRNAs (miRNAs) are thought to play an important role in human carcinogenesis. These 21-23 nucleotides of miRNAs will silence gene expressions through binding to the 3’UTR of their target mRNAs. Previous evidence with differential expression of microRNA in cancer and normal samples suggests that they are involved in the development of cancer. To identify the miRNA expression specific for head-neck cancer (HNC), the miRNA profiling of 6 cancer cell lines, 2 immortalized normal cell lines and 3 lines of primary normal cell were performed by miRNA microarray. Total of 470 human miRNA were screened for the differential expressions between cancer and normal cell lines. There were 23 miRNAs expressed significantly between two groups (P < 0.05), with 19 elevated and 4 decreased in HNC cell lines. Of which, 9 miRNAs were further validated using RT-qPCR analysis, including miR-10b. The biological function of miR-10b was investigated. Suppression of miR-10b expression by anti-sense oligonucleotide led to repression of cell migration and invasion phenotype. However, there is no significant effect on cell growth, apoptosis or chemo/radio-sensitivity. In conclusion, we have identified at least 9 miRNAs which associated with HNC. miR-10b plays role in the carcinogenesis through promoting cancer cell migrating and invasive, while no effect on cell viability or stress responses.

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 3032.
Abstract 3046: Differential microRNA patterns in prostate carcinoma cells after single and fractionated radiation
Authors: Aryankalayil Molykutty J. , Palayoor Sanjeewani T. , Cerna David , Coleman C. Norman
Published: February 2011

Our previous mRNA microarray analysis showed that fractionated radiation induced more differentially expressed genes compared to single dose radiation in PC3 and DU145 cells. MicroRNAs (miRNAs) are an important class of non-coding small RNAs capable of regulating gene expression at the translational level. To understand the role of miRNAs in regulation of radiation-induced gene expression patterns, we studied the expression levels of miRNAs by microarray analysis in prostate cancer cells. Methods: PC3 and DU145 cells were exposed to 5 Gy and 10Gy either as a single dose radiation or multi-fractionated (0.5Gyx10 and 1Gyx10) radiation. RNA was extracted at 24h after the final dose of radiation and miRNA microarray analysis was done using Agilent human miRNA Microarray Kit (V2). The chip contains probes for 723 human and 76 human viral microRNAs from the Sanger database v.10.1. Data were analyzed using GeneSpring software (Agilent technologies). Results: Of the total 723 miRNAs represented in the array, 141 miRNAs were differentially expressed (> 1.5 fold change) by the 4 radiation protocols. Significant difference in the miRNA expression pattern was noted between the two cell lines. The number of radiation - induced miRNAs was higher in PC3 cells than in DU145 cells. In PC3 cells fractionated radiation resulted in more down regulated miRNAs compared to single dose radiation. In our previous study immune response genes were significantly up regulated by fractionated radiation in PC3 cells but not in DU145 cells. In the present study Mir-146a was significantly up regulated in DU145 cells after fractionated radiation but not in PC3 cells suggesting an inverse correlation between the differential expression of mir-146a and immune response genes in both cell lines. This study also demonstrated significant differences in let-7 family of miRNAs in the two cell lines and also between single and fractionated radiation. In PC3 cells, 8 of the let-7 miRNAs were upregulated after fractionated radiation whereas in DU145 cells they were either downregulated or not changed. Conclusion: Fractionated radiation resulted in expression of more number of miRNAs compared to single dose radiation. We are currently in the process of evaluating radiation-induced differential gene expression changes by a combined approach of mRNA, miRNA and protein array analysis to identify radiation induced molecular targets for cancer therapy.

This work was supported by the Intramural Research Program of Center for Cancer Research, National Cancer Institute, National Institutes of Health.

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 3046.
Abstract 3059: The Tmeff2 protein functions as a tumor suppressor and interacts with Sarcosine dehydrogenase
Authors: Overcash Ryan , Chen Xiaofei , Harris Mitchel , Hoffman Donald , Ruiz-Echevarria Maria J.
Published: February 2011

Tmeff2 is a gene with an expression profile limited to the brain and the prostate but shown to be frequently upregulated in prostate cancer. It encodes a type I transmembrane protein with a short cytoplasmic tail containing a potential G-protein activation domain and an extracellular domain containing two follistatin (FS) modules and an epidermal growth factor-like (EGF) domain. Although these features are suggestive of a function in signal transduction, the role of the Tmeff2 in prostate cancer, or the mechanism(s) that lead to its overexpression during the disease are unclear. In the present study, we evaluated the functional role of Tmeff2 in prostate tumorigenesis.

To investigate the function of the gene, Tmeff2 was overexpressed in TRAMP C1 murine prostate cancer cells and HEK293T cells, and the effects of overexpression on cellular growth and tumorigenicity were assessed. Tmeff2 overexpression in HEK293T cells almost completely abolished the ability of these cells to form colonies in soft agar and resulted in a 20-30% reduction in proliferation rates in these and TRAMP C1 cells, indicating that the gene may function as a tumor suppressor in prostate cancer cells. Moreover, although TMEFF2 overexpression alone did not induce apoptosis, it sensitized these cell lines to staurosporine or rapamycin-induced apoptosis, causing nearly a three-fold increase in the percentage of apoptotic cells.

In order to assess the molecular mechanism(s) by which Tmeff2 may suppress cellular growth and tumorigenicity, we screened Tmeff2 affinity complexes by mass spectrometry to search for candidate functional partner(s) of Tmeff2. Our results showed an interaction with Sarcosine Dehydrogenase (SARDH) an enzyme involved in the metabolism of sarcosine. This interaction was further confirmed by co-immunoprecipitation analysis. Importantly, sarcosine has recently been described as a biomarker for prostate cancer as it was shown to be highly increased in prostate and metastatic prostate cancer. In addition, it may also play a role in the biology of the cancer since it promotes cell invasion when added to benign prostate epithelial cells.

In summary, the results presented here suggest that Tmeff2 functions as a tumor suppressor for prostate cancer. Its interaction with SARDH may represent a mechanism by which Tmeff2 modulates tumorigenicity by altering the levels of sarcosine. Further analyses are necessary to determine the value of Tmeff2 as a prognostic marker.

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 3059.
Abstract 3067: Differential proteomic profilingidentifies HNSCCinvasion genes: GANAB is negative regulator in HNSCC invasion
Authors: Chiu Ching-Chi , Li Hsiao-Fang , Chen Yin-Ju , Chen Ann-Joy
Published: February 2011

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancer worldwide, however, highly invasive or metastatic characteristics are the common cause of treatment failure. In order to investigate the invasive mechanism of cancer, we established highly invasive sublines of five HNC cell lines by using Matrigel and Transwell selection method. After confirmed the invasion phenotype, the differential proteomes were determined using proteomic methods. Total of 420 protein bands were identified by mass spectrometry analysis, which corresponds to 184 proteins. There were 52 proteins identified more than twice of the four independent experiments, indicating the significance of these proteins in regulation of invasion phenotype. In which, 18 (35%) functions as cytoskeleton or adhesion molecules, 10 (19%) function as molecular chaperone, 9 (17%) belongs to metabolic enzymes, 8 (15%) involve in transcriptional or translational regulation, 7 (13%) involve in cellular signalling pathway. RT-PCR analysis revealed 13 genes that were consistently differentially expressed in the HNSCC invasion sublines. One of the most significantly change genes is GANAB. The treatment of GANAB-shRNA also resulted in augment of cell growth in all HNSCC cell lines, with approximately increase to 1.34 fold at day 5 (p < 0.05). GANAB-shRNA transfected cells migrated 1.78 fold faster than control cells in in vitro wound healing assay. The GANAB silencing cell increase to 12.33 fold (p=0.005) in HNSCC cell lines. These results suggest that plays an important role in negative regulation of cell growth, migration and invasion. Using a cut-off value of a 1.5-fold differential expression in tumor verse normal tissues, 14 (44%) patients were found under-expressed in GANAB proteins. These results support our cellular findings and indicate that HNSCC.

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 3067.
Abstract 3071: Frequent silencing of protocadherin 17, a candidate tumour suppressor for esophageal squamous-cell carcinoma
Authors: Imoto Issei , Haruki Shigeo , Kozaki Ken-ich , Matsui Takeshi , Kawachi Hiroshi , Komatsu Shuhei , Muramatsu Tomoki , Shimada Yutaka , Kawano Tatsuyuki , Inazawa Johji
Published: February 2011

Protocadherins are a subfamily of the cadherin superfamily, but little is known about their functions. We identified a homozygous loss of protocadherin 17 (PCDH17) in the course of a program to screen a panel of esophageal squamous-cell carcinoma (ESCC) cell lines for genomic copy-number aberrations. PCDH17 mRNA was expressed in normal esophageal tissue but not in the majority of ESCC cell lines without a homozygous deletion of this gene, and restored in gene-silenced ESCC cells after treatment with 5-aza-2′-deoxycytidine. The DNA methylation status of the PCDH17 CpG-island correlated inversely with the PCDH17 expression, and a putative methylation-target region showed promoter activity. The methylation of the PCDH17 promoter was also associated with the silencing of gene expression in primary ESCC at least partly. Among primary ESCC cases, the silencing of PCDH17 protein expression was associated with a poorer differentiation status of ESCC cells, and possibly with prognosis in a subset of this tumour. Restoration of PCDH17 expression in ESCC cells reduced cell proliferation and migration/invasion. These results suggest that silencing of PCDH17 expression through hypermethylation of the promoter or other mechanisms leads to loss of its tumour-suppressive activity, which may be a factor in the carcinogenesis of at least some ESCCs.

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 3071.
Abstract 3084: Chfr in breast cancer development
Authors: Jha Saheli , Banerjee Snigdha , Mehta Smita , Kambhampati Suman , Haque Inamul , Banerjee Sushanta K.
Published: February 2011

Breast cancer is a common malignancy and is the most frequently diagnosed cancer in USA. It can be developed when genes that control the cell cycle and genomic stability are aberrantly expressed or non-functional. Where CHFR encodes an ubiquitin ligase that reportedly delays mitosis in response to microtubule-targeting drugs (i.e. nocodazoles and taxanes). CHFR (Checkpoint with FHA and Ring Finger) is hypothesized to mediate a delay in cell cycle progression, early in mitosis, in response to microtubule stress, independent of the spindle assembly checkpoint. As a potential regulator of cell cycle progression, CHFR naturally becomes an interesting target for understanding cancer cells. Low or moderate CHFR mRNA expression has been already reported in many cancers including breast cancer with some relevance to tumor suppressor activities. In this study we analyzed the expression profiles of CHFR in different breast cancer cell lines at mRNA and protein levels using real-time PCR and immuno-Western blot analysis. We also analyzed its expression in various breast tissue samples using immunohistochemistry. We found CHFR mRNA was significantly higher in BT474 and MCF-7 cells as compared to MDA-MB-231 cells. Two isoforms (i.e.,) of CHFR protein were detected in these cells. High molecular weight (∼89kD) isoform was markedly elevated in MDA-MB-231 cells as compared to MCF-7 cells while low molecular weight (∼52kD) isoform markedly reduced in MDA-MB-231 cells. Moreover, in normal breast sample CHFR expression is nuclear while in adenocarcinoma samples CHFR was prominent expression in cytoplasmic. Finally, we found that high molecular weight CHFR isoform expression can be regulated negatively by CCN5/WISP-2, an anti-invasive gene. Collectively, these studies suggest that CHFR may play dual roles in the genesis of breast cancer and possibly, the high molecular weight isoform may play critical role in progression of breast cancer.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

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 3084.
Abstract 3096: c-Myc regulates MAP4K1 expression and AP-1 activity in Pdcd4 knock-down cells
Authors: Yang Hsin-Sheng , Wang Qing
Published: February 2011

Programmed Cell Death 4 (Pdcd4) is a novel tumor suppressor that frequently exhibits down-regulated expression in several types of cancer. In colon cancer tissues, expression level of Pdcd4 is continuously down-regulated in the order of normal-adenoma-carcinoma. Over-expression of Pdcd4 has been demonstrated to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced transformation and tumor phenotype. In addition to cultured cells, Pdcd4 transgenic mice that over-express Pdcd4 in the epidermis show significant reductions in 7,12-dimethylbenz(a)anthracene (DMBA)/TPA induced skin papilloma formation and carcinoma incidence. Knock-out of Pdcd4 expression in mice resulted in induction of lymphomas with frequent metastases to the liver and kidneys, and an increase in DMBA/TPA induced skin papilloma formation and carcinoma incidence. These findings suggest that Pdcd4 suppresses carcinogenesis not only at an early stage (tumor promotion), but also at a late stage (tumor progression) in both cultured cells and transgenic mice.

Recently, we demonstrated that over-expression of Pdcd4 inhibits invasion and MAP4K1 expression in colon tumor cells. Conversely, knock-down of Pdcd4 promotes invasion, activates AP-1 and β-catenin/Tcf dependent transcription, and up-regulates c-Myc expression in colon tumor cells. However, how MAP4K1 expression is regulated by Pdcd4 remains unknown. MAP4K1, a kinase upstream of JNK signaling pathway, is also known as HPK1 (haematopoietic progenitor kinase 1) whose function and expression regulation in solid tumors is not well studied. It has been known that activation of MAP4K1 results in activation of JNK, c-Jun and AP-1 dependent transcription. In the present study, we found that MAP4K1 expression is up-regulated by Pdcd4 knock-down. Concurrently, the phosphorylation of JNK and c-Jun is increased in Pdcd4 knock-down cells. c-Myc is a direct downstream target gene of β-catenin/Tcf dependent transcription and is up-regulated by Pdcd4 knock-down. To investigate the role of c-Myc in regulating MAP4K1 expression, we over-expressed c-Myc in HEK293 cells and found that over-expression of c-Myc induces MAP4K1 expression and activates c-Jun. Using chromatin immunoprecipitation, we demonstrate that c-Myc directly binds to MAP4K1 promoter in Pdcd4 knock-down cells. Down-regulation of c-Myc using c-myc RNAi reverses MAP4K1 expression and c-Jun activation in Pdcd4 knock-down cells. Thus, these results provide an insight into how Pdcd4 regulates MAP4K1 expression and AP-1 dependent transcription.

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 3096.
Abstract 3101: Pituitary homeobox 2 (PITX2) promotes thyroid carcinogenesis by activation of cyclin D2
Authors: Huang Yue , Zhu Guozhang
Published: February 2011

Pituitary homeobox 2 (PITX2), a Paired-like homeodomain transcription factor and a downstream effector of β-catenin signaling, plays substantial roles in normal embryonic development but its possible involvement in tumorigenesis was unknown. In this study, we extend its function in human cancer. Remarkably, we found that PITX2 was frequently overexpressed in human cancerous (papillary, follicular, and anaplastic) thyroid tissues, indicating for the first time that overactivated PITX2 may contribute to thyroid cancer. Cell-based and biochemical studies were performed to uncover the molecular mechanism of PITX2 action in thyroid cancer. Knockdown of PITX2 gene expression in human thyroid cancer cells significantly reduced cell proliferation and soft-agar colony formation. Biochemical analysis of cell cycle regulators upon PITX2 knockdown revealed down-regulation of all three D-type Cyclins (Cyclin D1, Cyclin D2 and Cyclin D3), dephosphorylation of Rb, and up-regulation of p15(INK4B) and p27(Kip1). Chromatin immunoprecipitation and promoter reporter assay indicated that Cyclin D2 was a direct target gene of PITX2. Consistently, we observed that high expression levels of Cyclin D2 were frequently associated with PITX2 overexpression in thyroid cancer tissues. To confirm our results in vivo, we took advantage of a mouse model of thyroid cancer (TRbetaPV/PV mouse). Consistently, the aberrant elevation of Pitx2 levels in the thyroid cancer of TRbetaPV/PV mice was accompanied by up-regulation of Cyclin Ds, increased phosphorylation of Rb, and down-regulation of p15(INK4B). Collectively, our findings demonstrate that the overactivated PITX2-Cyclin D2 pathway promotes thyroid tumorigenesis, and they provide the first evidence implicating an oncogenic role of PITX2 in human cancer.

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 3101.
Abstract 3105: Expression of Wip1, a homeostatic regulator, is competitively controlled by c-Jun and p53 in response to UV irradiation
Authors: Song Ji-young , Park Ji-young , Kim Hyun-mi , Kim Jae-yong , Choi Jene
Published: February 2011

Wild-type p53-induced phosphatase (Wip1) is induced by p53 in response to various stresses, resulting in the dephosphorylation of proteins (i.e., p38 MAPK, p53, and uracil DNA glycosylase) involved in DNA repair and cell cycle checkpoint pathways. The p38 MAPK-p53 pathway has been a unique way for Wip1 induction as a stress responder. Here, we show that c-Jun directly binds to and activates the Wip1 promoter in response to UV irradiation. Mutation of the p53 response element (p53RE) or c-Jun consensus sites reduced promoter activities in both non-stressed and stressed A549 cells. Intriguingly, overexpression of p53 significantly decreased Wip1 expression in HCT116 p53+/+ cells but increased Wip1 expression in HCT116 p53−/− cells. Adenovirus-mediated p53 overexpression greatly decreased JNK activity. Up-regulation of Wip1 via the p38 MAPK-p53 and JNK-c-Jun pathways is specific, as demonstrated by our findings that p38 MAPK and JNK inhibitors affected the expression of Wip1 protein, whereas an ERK inhibitor did not. The JNK-c-Jun and p38 MAPK-p53 pathways were activated concomitantly in A549 cells; however, c-Jun activation occurred much more quickly, and to a greater extent, in A549-E6 cells, with delayed but fully induced Wip1 expression. Collectively, these data indicate that Wip1 is activated via both the JNK-c-Jun and p38 MAPK-p53 signaling pathways and that temporal induction of Wip1 largely depends on the balance between c-Jun and p53, because of their competition for JNK binding. Moreover, our results suggest that JNK-c-Jun-mediated Wip1 induction could serve as a major signaling pathway in human tumors, because of frequent p53 mutation.

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 3105.
Abstract 3127: Protein kinase D1 downregulation facilities PMA-induced apoptosis in LNCaP prostate cancer cells
Authors: Chen Jun , Giridhar Karthik V. , Wang Qiming Jane
Published: February 2011

Phorbol esters, analogs of diacylglycerol, induce apoptosis in androgen-sensitive LNCaP prostate cancer cells. Although the apoptotic pathways induced by PMA are well characterized, little is known of PMA-regulated pro-survival pathways such as ERK1/2 and Akt. We now provide experimental evidence to indicate that PKD1 promotes survival signals in LNCaP cells in response to PMA treatment. In turn, PMA induces dose- and time-dependent downregulation of PKD1 to facilitate apoptosis. This effect can be blocked by PKC inhibitor Ro 31-8220, indicating that PKC activation is required for PKD1 downregulation. Depletion of endogenous PKCδ and PKCε reveals that PKD1 activation and subsequent downregulation are mainly controlled by PKCδ. Knockdown of endogenous PKD1 and PKD2 decreases ERK1/2 and Akt activities and potentiates PMA-induced apoptosis as measured by cleaved PARP and sub-G0/G1 population, whereas overexpression of wild-type and constitutive-active PKD1 enhances ERK1/2 and Akt activities and suppresses PMA-induced apoptosis. Further analysis shows that the downregulation of PKD1 is mediated by ubiquitin/proteasome degradation pathway. In summary, our data indicate that PKD1 plays a pro-survival role in PMA-induced apoptosis by modulating downstream ERK1/2 and Akt activities.

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 3127.
Abstract 3134: Oncogenic functions of Secreted Frizzled-Related Protein 2 (sFRP2) in human renal cancer
Authors: Yamamura Soichiro , Kawakami Kazumori , Hirata Hiroshi , Ueno Koji , Saini Sharanjot , Majid Shahana , Carroll Peter , Dahiya Rajvir
Published: February 2011

The secreted Frizzled-related proteins (sFRPs) are modulators of the Wnt signaling pathway which is involved in embryonic development and tumor progression. The functions of secreted frizzled-related protein 2 (sFRP2) have not been studied in renal cancer. Human renal cancer tissue microarray revealed that the level of sFRP2 expression was high in normal kidney, low in primary renal cancer tissues and high in metastatic renal cancer tissues, suggesting different roles of the sFRP2 gene in different grades of renal cancer. To study the functions of sFRP2 gene in renal carcinoma cells, we established A498 renal cancer cell lines which stably expressed sFRP2. Stably expressed sFRP2 significantly promoted cell proliferation in vitro and in vivo tumor growth. The stably expressed sFRP2 cells were also found to reduce UV-induced apoptosis and increase in the G2 phase of the cell cycle. In the stable sFRP2 cell lines, expression of c-Fos, Bcl2, Bcl-w, cyclinB2 and cyclinE2 genes was significantly increased and p53 expression was decreased. In metastatic Caki1 cells, sFRP2 knockdown inhibited invasion and reduced expression of CD146, MMP2 and Rac1/2/3 genes. This is the first report documenting that sFRP2 modulates proliferation and invasion pathways by altering various genes in renal cancer cells. This data may provide better strategies for the management of renal cancer through regulation of sFRP2 pathways.

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 3134.