bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4988: Cis-acting genetic variation is associated with altered allele-specific expression of CEBPG transcript in normal human bronchial epithelium
Authors: Blomquist Thomas M. , Brown Ron , Crawford Erin L. , Willey James C.
Published: February 2011

CEBPG (CCAAT/enhancer binding protein gamma) is one of six known members of the CEBP family of bZIP transcription factors. Gene targeted knock-out of CEBPG transcription factor in mice results in early perinatal death, presumably due to observed emphysematous lung histology and abnormal development of alveolar pneumocytes (Kaisho et al, 1999). In recent studies, we observed that: 1) CEBPG transcript expression in normal human bronchial epithelial cells (NBEC) varies greater than 20-fold among individuals (Mullins et al, 2005), 2) the pattern of CEBPG transcript expression in NBEC is different between lung cancer cases and controls (Blomquist et al, 2009), and 3) transcript expression of a key DNA repair gene, ERCC5 (XPG), is partly regulated by CEBPG in NBEC (Crawford et al, 2007). In this study we hypothesized that variation in CEBPG transcript expression patterns in NBEC may, in part, be due to cis-acting genetic variation. In order to test this hypothesis, Allele-Specific Expression (ASE) was measured at transcribed polymorphic site rs2772 in Exon 2 of CEBPG in NBEC cDNA of fifteen individuals heterozygous at rs2772 using allele-specific competitive PCR. ASE at rs2772 was then assessed for association with genotype at the seven polymorphic sites (rs736682, rs17530479, rs17530508, rs1469084, rs16968029, rs3745968, rs36101103) representing the most common haplotypes in the promoter, intron and 3′-untranslated regions of CEBPG gene. CEBPG rs2772 A allele was expressed, on average, 2.34 fold greater than C allele (p < 0.001) in 20% (3 out of 15) of NBEC cDNA samples, among individuals heterozygous at both rs2772 and rs17530479 in the 3′-untranslated and promoter regions of CEBPG, respectively. These findings are consistent with previous reports that in 20% of samples, CEBPG rs2772 A allele was expressed 2.42 fold greater than C allele (Lo et al, 2003). We also observed that 3 out of 9 NBEC samples obtained from individuals diagnosed with lung cancer exhibited rs2772 A:C allelic ratios significantly higher than genomic DNA controls, while 0 out 6 samples from individuals without lung cancer exhibited altered ASE. Of note, rs2772 and rs17530479 polymorphic sites are in linkage disequilibrium with rs10518275 polymorphic site, which was recently associated with severity of cystic fibrosis lung disease (Gu et al, 2009). Here we demonstrate that cis-acting variation in linkage with rs2772 and rs17530479 polymorphic sites is associated with variation in ASE of CEBPG and lung cancer diagnosis.

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 4988.
Abstract 499: EGFR expression correlates with response to photodynamic therapy in esophageal cancer cells
Authors: Yang Pei-Wen , Hung Mien-Chie , Hung Mien-Chie , Wang Ying-Hao , Tung En-Chi , Lee Yung-Chie , Lee Jang-Ming
Published: February 2011

Photodynamic therapy (PDT) has been demonstrated as an effect treatment modality for early esophageal cancer by using a photo-sensitizer which induces a cytotoxic photoreaction in tumor cells after exposure to a specific wave-length of light. However, the mechanism is still poorly understood regarding the response to PDT for the patients with esophageal cancer. Epidermal growth factor receptor (EGFR) activation is known to induce resistance to many anti-cancer treatments. In this study, we intend to investigate the role of EGFR in esophageal cancer treated with PDT. The PDT-induced cell death is based on the accumulation of a photosensitizing drug in specific cells. Followed by irradiation with visible light (usually red light), the drug-accumulation cells will induce apoptosis or necrosis. In our study, we observed PDT induced cell death of human esophageal carcinoma cells, CE48T/VGH in a dose-dependent manner by incubating increasing amounts of photosensitizer photofrin (0 to 20 μg/ml) under the expose of 630 nm red light (0 to 180 mJ/ cm2) by MTT assay. We found the protein expression of EGFR was decreased with increased amounts of photofrin. The phenomenon was more obvious under light treatments. EGFR expression was not recovered in the presence of proteasome inhibitors indicating that the reduction of EGFR was not mediated by proteasome-dependent pathway. However, the amount of EGFR mRNA was similar in PDT treated and un-treated cells by RT-PCR analysis. To further clarify the role of EGFR expression in PDT resistant ECa cells, we selected the PDT resistant esophageal cancer (CE48T/VGH) cells by incubated with 15 μg /ml photofrin under the 54 mJ/ cm2 or 108 mJ/ cm2 of red light exposure. At 25 days post PDT treatment, the cells was collected and indicated as PDTR 1-1 and PDTR 1-2 respectively. Compared to wild type CE48T/VGH cells, PDTR 1-1 and PDTR 1-2 display 16% and 13 % resistances respectively when incubated with 15 μg /ml photofrin under 108 mJ/ cm2 light treatment. Correlated with the resistance, we found that EGFR protein expression was increased in both PDTR 1-1 and PDTR 1-2 (about 18% compared to wild type cells). Based on our preliminary findings, EGFR expression may be involved in PDT resistance in esophageal cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 499.
Abstract 4991: Functional significance of potential oncogene YAP and its isoforms in esophageal squamouse cell carcinoma (ESCC)
Authors: Muramatsu Tomoki , Imoto Issei , Matsui Takeshi , Kozaki Ken-ichi , Tsuda Hitoshi , Shimada Yutaka , Inazawa Johji
Published: February 2011

Previously, we reported cIAP1 to be overexpressed through 11q22 amplification in some ESCC cell lines. YAP, a key molecule in Hippo pathway reported as a possible oncogene in some cancers, locates within the same amplicon in those ESCC lines. Since YAP overexpression was frequently observed in primary ESCC, YAP may work as an oncogene for ESCC. Through expression analyses of mRNA and protein, we identified two novel isoforms of YAP other than two known isoforms. Expression pattern of YAP isoforms was different between normal esophagus and ESCCs, suggesting each isoform to have different function as an oncogene. We constructed stably-transfected cells with siRNA-resistant construct of each of YAP isoforms. We then performed knockdown of endogenous YAP to investigate whether any difference in growth-promoting effect exists among these isoforms. Growth inhibition of ESCC cells with induction of p21 was observed by knockdown of YAP, and each isoform partially rescued siRNA-induced p21 elevation and growth inhibition, although only the small difference was observed among isoforms. Those results suggest that induction of p21 might be regulated by transcriptional repressor YAP, directly or indirectly. Detail analysis of functional significance of YAP will provide not only new avenues for understanding the esophageal carcinogenesis, but also development of YAP-targeted cancer therapy in ESCC.

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 4991.
Abstract 4993: ARHI is required for induction of beclin-1/PI(3)K class III-mediated autophagy
Authors: Lu Zhen , Liao Warren S. L. , Bast Robert C.
Published: February 2011

The maternally imprinted Ras-related tumor suppressor gene Aplasia Ras homolog member I (ARHI; also known as DiRAS3) is downregulated in more than 60% of ovarian cancers. We reported that re-expression of ARHI in vitro at physiologic levels induces autophagy by blocking PI(3)K-Akt signaling and inhibiting mTOR activity, and participated directly in the formation of autophagic vesicles, co-localizing with MAP-LC3-II in the vesicle membrane. Nucleation of autophagic vesicles requires the activity of multi-protein complexes that include Beclin-1 and PI(3) kinase Class III lipid kinase [PI(3)KC3]. A number of proteins have been reported to interact with Beclin-1 and positively or negatively regulate its function in autophagy. One prominent Beclin-1-interacting protein is Bcl-2, which inhibits Beclin-1-dependent autophagy. In this study, we show by indirect immunofluorescence microscopy that ARHI is colocalized with Beclin-1 at the trans-Golgi network. Further, ARHI can be co-immunoprecipitated with Beclin-1 and elimination of ARHI expression by RNA interference compromised Beclin-1-induced autophagy. Concomitant with increased ARHI-Beclin-1 interaction, there was a decreased association between Beclin-1 and its negative regulator Bcl-2. Consistent with its role in Beclin-1-mediated autophagy, knockdown of ARHI also decreased PI(3)KC3 activity, whereas overexpression of ARHI promoted GFP-FYVE co-localization with RFP-LC3. Taken together, our results suggest that ARHI is a positive and necessary regulator of Beclin-1/PI(3)KC3 complex and that ARHI regulates Beclin-1-mediated autophagy by forming a complex at the trans-Golgi network.

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 4993.
Abstract 5: Frequent translocations and overexpression of multiple full-length ETV1 transcripts in prostate cancer
Authors: Gasi Delila , van der Korput Hetty , Trapman Jan
Published: February 2011

In prostate cancer the fusion between TMPRSS2 and the ETS transcription factor gene ERG causes over-expression of truncated ERG. This gene fusion is found in up to 60% of clinical samples. We show that the related gene ETV1 is overexpressed in ∼10% of prostate cancer samples: not only as a fusion transcript with many different partners, but in approximately half of the samples as a full-length transcript. Primary tumors with over-expression of full length ETV1 tend to have a worse prognosis. We showed in a novel fusion event that the complete ETV1 gene is integrated adjacent to the first exon of the poorly characterized ncRNA gene EST14 on chromosome 14. Further characterization of the translocation revealed that not only EST14-ETV1 fusion transcripts were formed, but that also wild-type ETV1 transcripts were over-expressed. These transcripts started at four different alternative first exons and gave rise to production of slightly different ETV1 proteins. However, all proteins have essentially the same properties. Investigation by break-apart in situ hybridization of 7 prostate cancer samples overexpressing full-length ETV1 showed that in at least 5 samples the gene is translocated. This translocation is not to chromosome 14, which seems a hot spot of ETV1 translocations. Chromosome spreads from a xenograft derived from one clinical sample, locate the translocation of ETV1 to a novel site on chromosome 4.

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 5.
Abstract 500: Efficacy of UVC irradiation on GFP-expressing melanoma growth and vascularity in the ear of nude mice
Authors: Aki Ryoichi , Amoh Yasuyuki , Kishimoto Hiroyuki , Kimura Hiroaki , Suetsugu Atsushi , Momiyama Masashi , Katsuoka Kensei , Hoffman Robert M.
Published: February 2011

Our laboratory has developed the use of fluorescent proteins for in vivo imaging (Nature Reviews Cancer 5, 796-806, 2005). We have developed melanoma cell lines that stably express GFP and nude mice that ubiquitously express RFP to study tumor interaction by dual-color imaging. In the present study, we examined the efficacy of UVC irradiation on the growth of murine melanoma expressing GFP in the ear of GFP mice. We also evaluated the efficacy of UVC irradiation against blood vessels vascularizing the melanoma. RFP-expressing blood vessels from transgenic mice expressing RFP used as hosts were readily visible in GFP melanoma. B16F10 melanoma expressing GFP were injected subcutaneously in the ear of the RFP mice. The ears of the mice were observed before and 24 hours after irradiation with UVC. UVC was effective on B16F10 GFP growth and also damaged blood vessels in the tumor. Thus, UVC irradiation has a direct effect on melanoma growth as well as an anti-angiogenesis effect. This dual-color tumor-host model is useful for evaluation of efficacy on melanoma growth and tumor blood vessels, which is readily discernable with fluorescent protein imaging. UVC irradiation is a promising therapeutic for melanoma expressing fluorescent proteins which can be effected in vivo (Proc. Natl. Acad. Sci. USA, 1-6, 14514-14517, 2009).

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 500.
Abstract 5006: Pdcd4 as a prognostic factor and a modulator of cell proliferation, migration and invasion in ovarian cancer
Authors: Wei Na , Liu Stephanie S. , Leung Thomas HL , Tam Kar-Fai , Liao Xiao-yun , Cheung Annie NY , Chan Karen KL , Ngan Hextan YS
Published: February 2011

Programmed cell death 4 (Pdcd4), a novel gene and originally identified as the neoplastic transformation inhibitor, is down regulated in human colon, breast and lung cancer cells and considered as a diagnostic and prognostic marker in lung cancer. It has been shown to have tumor suppressor properties such as inhibition of cell invasion and proliferation, as well as induction of apoptosis. However, those properties of Pdcd4 are tissue specific. The mechanisms of function of Pdcd4 are largely unknown and its function and modulation in ovarian cancer is still elusive. The objectives of our present study are firstly to investigate the expression of Pdcd4 in normal and malignant ovarian tissues and the role of Pdcd4 in ovarian carcinogenesis; and secondly, to study the function of Pdcd4 in the regulation of cell proliferation, migration and invasion and modulation of Pdcd4 in ovarian cancer.

Using both western blot and real-time quantitative PCR analyses, we demonstrated that Pdcd4 expression was continuously down-regulated in the sequence of normal-borderline-malignant ovarian tissue samples. Higher Pdcd4 expression was found to be associated with longer disease-free survival (p=0.037). Using immunohistochemical staining approach, we found the subcellular localization of Pdcd4 differed in the way that, normal ovarian tissues showed distinctive nuclear localization while malignant ovarian tissues showed mainly cytoplasmic staining.

To further explore the function of Pdcd4 in ovarian cancer cells, we developed Pdcd4 over-expression stable clones in ovarian cancer cell lines. Our in vitro studies demonstrated that ectopic Pdcd4 expression significantly inhibited ovarian cancer cell proliferation by inducing cell cycle arrest at G0/G1 stage and the upregulation of cell cycle regulators p27 and p21. The induction of p21 by Pdcd4 was not mediated through p53. Using wound healing, transwell migration and invasion assay, we demonstrated Pdcd4 significantly inhibited ovarian cancer cell migration and invasion.

In conclusion, loss of Pdcd4 was a common abnormality at molecular level in ovarian cancer and it might be a potential prognostic factor in ovarian cancer patients. In addition, our results also provided first evidence for the tumor suppressor properties of Pdcd4 in inhibition of cell proliferation by inducing cell cycle arrest and modulating cell cycle regulators, as well as inhibition of cell migration and invasion in ovarian cancer cells.

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 5006.
Abstract 5007: Nuclear targeted Deleted in liver cancer 1 exhibited reduced tumor suppressive function both in vitro and in vivo
Authors: Chan Lo Kong , Ko Frankie Chi Fat , Ng Irene Oi Lin , Yam Judy Wai Ping
Published: February 2011

The tumor suppressor Deleted in liver cancer 1 (DLC1) protects cell from transformation by catalyzing the GTP hydrolysis of active RhoA. Besides the RhoGAP activity, accumulating evidences have supported that localization at focal adhesions and interaction with tensin protein are key factors guiding the tumor suppressive activity of DLC1. In this study, we provided new evidence that DLC1 was a dynamic protein which shuttles between cytoplasm and nucleus instead of statically staying in the cytoplasm. Subcellular fractionation assay showed that DLC1 protein can be detected in cytoplasmic and nuclear fractions. Treatment of Leptomycin B (LMB), a nuclear export blocker, could lead to the nuclear retention of exogenous and endogenous DLC1 in different human cancer cell lines. Detail examination of relevant DLC1 mutants had shown that the center region of DLC1 was necessary and sufficient for its nuclear localization. We transiently expressed a NLS fusion DLC1 (NLS-DLC1) with preferential nuclear localization in SMMC HCC cells and found that NLS-DLC1 was less potent in suppressing colony formation and actin stress fiber formation. To study the tumor suppressive function of nuclear DLC1 both in vitro and in vivo, we employed retroviral transduction to stably express NLS-DLC1 in a p53−/− RasV12 hepatoblast model. We found that NLS-DLC1 expressing cells proliferated faster in vitro and exhibited increased tumorigenicity upon nude mice injection when compared with the non-nuclear targeted DLC1. Although the function of nuclear DLC1 remains to be answered, our results clearly demonstrated that nuclear localization of DLC1 may serve as a potential mechanism in negatively regulating its tumor suppressive activity.

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 5007.
Abstract 5009: Analyses of human specimens and knockout mouse model reveal a tumor suppressor function of EphA2 in liver
Authors: Guo Hong , Miao Hui , Chen Xin , Iida Hiroshi , Kaneko Shuichi , Wang Bingcheng
Published: February 2011

EphA2 kinase is highly expressed in normal mammalian liver, but its functions are poorly defined. Here we show that EphA2 expression was down-regulated in majority of human hepatocellular carcinoma (HCC) from three different populations. In mice, EphA2 deletion led to enhanced susceptibility to hepatocarcinogenesis induced by diethylnitrosamine (DEN) in tumor multiplicity and burden compared with wild type mice. Acute DEN treatment induced EphA2 expression upregulation, concomitant with mitotic arrest in wild type liver. EphA2-null liver displayed significantly increased apoptosis compared with wild type. Further, acute DEN treatment caused substantially elevated Akt and ERK1/2 kinase activities in EphA2-null but not in wild type liver. Ephrin-A1 stimulation inhibited AKT and ERK1/2 and suppressed cell proliferation in vitro. Re-expression of EphA2 fully restored its function. Liver development displayed stable EphA2 expression and kinase activation increase by age coinciding with upregulated ephrin-A1. Human HCC and the mouse model show that EphA2 suppresses hepatocarcinogenesis by facilitating mitotic arrest in response to carcinogenic insults; inhibition of Akt and ERK is one possible mechanism involved in tumor progression. Together, these finding provide a mechanistic link between EphA2 and liver tumor development.

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 5009.
Abstract 501: A novel PDT system consisting of a DDS-type photosensitizer and a newly developed fiber probe for homogenous irradiation
Authors: MIYAZAKI Kozo , MORIMOTO Yuji , MURAOKA Miho , KUMAGAI Michiaki , HORIE Souta , FUKUSHIMA Shigeto , SHINOMIYA Nariyoshi , NISHIYAMA Nobuhiro , KATAOKA Kazunori
Published: February 2011

Introduction:

Photodynamic therapy (PDT) has already been established as anti-cancer therapy. However, since some types of cancer proliferate multifocally and/or diffusely, topical irradiation of light by a conventional optical fiber results in an insufficient PDT effect. Moreover, using a conventional fiber, we cannot irradiate minimal tumors that escape from detection by conventional diagnostic approaches. When PDT is applied to the lesions of hollow organs, if we homogenously irradiate a wide area of the organ wall, undetectable minimal tumors and multifocally proliferating tumors can be treated simultaneously. In order to realize this concept, we have developed a novel fiber probe that provides homogenous light irradiation on the mucosa of hollow organs. In this study, we fabricated a homogenous irradiation fiber probe (HIFP) for illuminating the bladder by the use of state-of-the-art processing technology (torsional deformation of a fiber core, conical shaping of fiber tip, etc). We evaluated the PDT effect on a rat orthotopic bladder tumor model using the HIFP and a dendrimer phthalocyanine micelle (DPc/m) that we developed as a DDS-type photosensitizer.

Materials and Methods:

The property of spatial distribution of light emitted from the HIFP was measured. Using the HIFP, PDT was carried out on a rat orthotopic bladder tumor model 24 h after administration of a photosensitizer (Photofrin or DPc/M) and PDT effects were pathologically evaluated.

Results:

Preliminarily examination of ultrasonic imaging revealed that the shape of the rat bladder approximates an ellipsoidal body with a long radius of 7.5 mm and a short radius of 5 mm. Analysis of spatial distribution showed that the light emitted from the HIFP covered 90% of the whole luminal area of the approximate ellipsoidal body, while the light emitted from a control fiber (CF) (NA=0.41; flat cleaved end) covered only 15%. Pathological study of the PDT-treated rat using the CF revealed that an anti-tumor effect occurred only in the local area proximate to the focal point of the CF with no anti-tumor effect in tumors in other areas of the bladder wall. In contrast, pathological study of the PDT-treated rat using the HIFP revealed that light was distributed over 60 −80% of the mucosa of the bladder and tumor proliferation was widely suppressed.

Conclusion:

Widespread and homogenous irradiation in the mucosa of the bladder was achieved using the newly developed fiber probe. PDT using a combination of the fiber probe and DPc/M enhanced the anti-tumor effect without bladder shrinking.

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 501.
Abstract 5011: Potential tumor suppressor role of PHD2 : functional study of mutations identified in germline DNA of patients with congenital polycythemia with or without paraganglioma
Authors: Gardie Betty , Ladroue Charline , Carcenac Romain , Gad Sophie , Barrois Michel , Bombled Johny , Hermine Olivier , Leporrier Michel , Baruchel André , Jean-Claude Kiladjian , Giraud Sophie , Mazure Nathalie , Pouyssegur Jacques , Richard Stéphane
Published: February 2011

The Hypoxia Inducible Factor (HIF) plays a major role in tissue response to hypoxia. HIF induces expression of many genes involved in anaerobic glycolysis, angiogenesis, erythropoiesis and cell proliferation. HIF-alpha subunit is tightly regulated by a family of specific hydroxylases in normoxia. PHD (prolyl-hydroxylase domain) proteins hydroxylate HIF-alpha, thereby allowing its attachment to the VHL protein, a component of an E3 ubiquitin ligase complex involved in protein ubiquitination and degradation. Mutations in HIF regulators have been described and lead to the stabilization of HIF, activation of target genes and development of either tumors or polycythemia. Heterozygous germline mutations in the VHL gene predispose to the von Hippel-Lindau disease characterized by a panel of highly vascularized tumors (central nervous system and retinal hemangioblastomas, pheochromocytomas, renal cell carcinoma, pancreatic endocrine tumors) whereas homozygous or compound heterozygous VHL mutations are responsible for isolated polycythemia (”Chuvash polycythemia”) with high circulating erythropoietin levels. Recently, heterozygous germline mutations in the PHD2 gene have been described in few patients with such congenital polycythemia and a particular mutation (H374R) has been identified in a patient with a polycythemia and a recurrent paraganglioma1. This observation raised the question of a possible role of PHD2 loss of function in the genesis of tumors usually seen in the VHL disease. We report here four new heterozygous PHD2 germline mutations in patients with familial or apparently sporadic polycythemia. We performed a functional study of these mutants compared to the H374R mutant and we showed differences in the capacity of the PHD2 mutants to downregulate HIF-alpha. These differences, tested in various conditions, are highly reproducible and suggest that there may be a genotype/phenotype correlation for the PHD2 mutants like the VHL mutants with their different ability to regulate HIF associated with different phenotypes in the VHL disease.

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 5011.
Abstract 5013: FOXP3 is an X-linked prostate tumor suppressor gene that represses MYC
Authors: Lizhong Wang , Liu Runhua , Katoh Hiroto , Liu Yang , Zheng Pan
Published: February 2011

Despite clear epidemiological and genetic evidence for X-linked prostate cancer risk, all prostate cancer genes identified are autosomal. Here we report somatic inactivating mutations and deletion of the X-linked FOXP3 gene in human prostate cancer. We first evaluated expression of FOXP3 in both normal and prostate tissue and a reduced FOXP3 expression was wide-spread among prostate cancer samples. We then used fluorescence in situ hybridization (FISH) and determined the deletion of the FOXP3 in the 14% prostate cancer tissues. Our sequencing analyses identified single base-pair changes in 5/20 prostate cancer samples and these somatic mutations of the FOXP3 are functionally inactivating. Lineage-specific ablation of FoxP3 in the mouse prostate epithelial cells leads to prostate hyperplasia and prostate intraepithelial neoplasia. The targeted mutation of the FoxP3 in prostate tissue is sufficient to initiate the process of prostate cancer development. In both normal and malignant prostate tissues, FOXP3 is both necessary and sufficient to transcriptionally repress cMYC, the most commonly over-expressed oncogene in prostate cancer as well as among the aggregates of other cancers. FOXP3 is the first X-linked prostate tumor suppressor in the male. Since the male has only one X chromosome, our data represents a new paradigm of “single-genetic-hit” inactivation-mediated carcinogenesis.

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 5013.
Abstract 5014: Identification and analysis of critical domains within the neuroblastoma tumor suppressor gene CASZ1
Authors: Virden Ryan A. , Liu Zhihui , Thiele Carol J.
Published: February 2011

Neuroblastoma (NB) is an enigmatic pediatric cancer for which highly successful therapies have been developed for tumors displaying favorable characteristics, while poor prognoses persist for unfavorable tumors. Chromosome 1p36 is frequently lost in the tumors of many patients with unfavorable prognoses and harbors the locus of the zinc finger (ZF) transcription factor CASZ1. Low CASZ1 expression is significantly associated with lower overall patient survival in NB. Functionally, CASZ1 suppresses NB tumor cell growth and regulates a number of key genes important in neural development (e.g. TrkA, p75 and tyrosine hydoxylase [TH]). It has been shown that high expression of TrkA and p75 are both independently associated with good prognoses in NB patients. Despite the important role of CASZ1 in neural development and NB tumor suppression, the key domains that mediate the activation role of CASZ1 have never been elucidated. In order to address this question, we performed a detailed analysis of CASZ1 protein isoform A (CASZ1a), which contains five ZF's. Abrogation of CASZ1a function was determined by loss of the ability to induce endogenous TrkA, p75 and TH mRNA transcription as well as by loss of the ability to activate a TH promoter-luciferase reporter construct. Using site-directed mutagenesis, we individually mutated each of the five ZF's and discovered that loss of any one of ZF1-4 resulted in a 72-98% loss of function compared to wild-type CASZ1a (p < 0.001), without altering protein stability or nuclear localization. Also, deletion of the C-terminal sequence AA728-1166 (a 38% truncation of the protein) did not appreciably alter function. However, a series of N-terminal truncations revealed a novel nuclear localization signal (NLS) at AA23-29, and it was found that CASZ1a depends on this NLS to localize to the nucleus. In addition, a critical activation domain was mapped to AA31-185 of the N-terminus, which also coincides with a newly identified CASZ1a homodimerization domain. Loss of this activation domain resulted in a complete loss of CASZ1a-mediated induction of the target genes TrkA, p75 and TH (p < 0.001), without affecting protein stability or nuclear localization. Therefore, the discovery and analysis of critical domains in this study has linked CASZ1a loss of function to the loss of induction of the positive NB prognostic factors p75 and TrkA. This demonstrates how the loss of CASZ1a may contribute to the pathogenesis and abysmal survivability of high stage neuroblastoma.

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 5014.
Abstract 5018: Transcriptional and functional analysis of the CHD5 gene in Colorectal Cancer
Authors: Fatemi Mehrnaz , Brim Hassan , kumar Krisham , Ashktorab Hassan
Published: February 2011

Background: CHD5 is a family member of chromatin remodeling factors that functions as a tumor suppressor in neuroblastoma and ovarian cancer. The transcriptional activity of CHD5 is silenced by hypermethylation. It has been found that CHD5 is a biomarker in colon carcinogenesis. In this study, we have investigated the transcriptional regulation and function of the CHD5 in CRC.

Methods: The transcriptional activity of CHD5 was tested by reporter luciferase assay. The 1kb large fragment upstream of CHD5 transcription start site (TSS) showed luciferase activity; while the 400 bp subfragment upstream of TSS was inactive in both RKO (CHD5 endogenous non-expressing) and HCT116 (CHD5 endogenous expressing) cell lines. This suggests that the transcriptionally active sites of CHD5 are located within −400 to −1000. There are two consensus TCF binding sites in the 1 kb promoter region. In order to investigate whether Wnt pathway affects the CHD5 transcriptional activity, we treated the RKO and HCT116 cell lines with 6-bromoindirubin-3′oxime (BIO), the GSK-3a inhibitor, which activates the β-Catenin. We tested the Wnt pathway activity in RKO and HCT116 cell lines by using the TCF/LEF responsive luciferase construct. Methylation profiles of CHD5 in 51 CRC and 6 adenomas from African Americans analyzed by MSP. Microdeletion analysis of the CHD5 region (1p36) was performed by aCGH.

Results: The activity of TCF/LEF responsive element increased by 17.5 folds in RKO cell line and by 7.3 in HCT116 cell line after BIO treatment. Interestingly, the luciferase activity of 1kb CHD5 promoter increased after treating with BIO, and no changes were observed in activity of the 400 bp fragment. This suggests that the TCF/LEF and β-Catenin might act as coactivators for CHD5 transcriptional regulation. We also analyzed the proliferation of the RKO cell line after stably transfecting with CHD5 expressing plasmid (pcDNA). The results showed that the exogenous expression of CHD5 reduces the proliferation of the RKO cell line by two folds compared to the wild type and the mock controls. CHD5 was hypermethylated in 78% of the tested patients samples and deleted in 36%.

Conclusion: The function of CHD5 is not well understood in CRC. Here, we suggest that the wnt/β-catenin pathway may be involved in the transcriptional regulation of CHD5. In addition in vivo CHD5 microdeletion and methylation excrement suggest that CHD5 act as tumor suppressor in CRC.

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 5018.
Abstract 5019: Loss of the ETS transcription factor ESE3 induces epithelial-mesenchimal transition and generates cells with stem cell-like properties
Authors: Albino Domenico , Longoni Nicole , Ortelli Erica , Kunderfranco Paolo , Malek Anastasia , Catapano Carlo V. , Carbone Giuseppina MR
Published: February 2011

ETS transcription factors have emerged as important elements in the pathogenesis of prostate cancer. Most ETS factors promote cell proliferation, survival and transformation, while few others act as tumor suppressors. We have recently reported that the epithelial-specific ETS factor ESE3 is frequently down-regulated in prostate cancer, affects negatively cell proliferation and survival, and acts as tumor suppressor in prostate epithelial cells. ESE3 signatures extracted from prostate cancer clinical samples indicated a broad dedifferentiation program. Thus, we hypothesized that ESE3 maintains the differentiation state of prostate epithelial cells and that its loss leads to cell transformation. In this study, we report that stable knock-down of ESE3 in immortalized human prostate epithelial LHS cells (LHS-ESE3kd) resulted in the induction of epithelial-mesenchymal transition (EMT) with the acquisition of a fibroblast-like appearance. Concomitantly, LHS-ESE3kd cells acquired also ability to grow in anchorage-independent conditions in soft-agar and to form prostatosheres in sphere-forming assays. Expression of various stem-cell markers was also increased in LHS-ESE3kd compared to LHS cells. In a panel of prostate cell lines the ability to form prostatospheres was inversely correlated with ESE3 expression level, providing further support to the idea that the gene is an important regulator of the stem cell compartment. Consistently, re-expression of ESE3 in DU145 cells, which do not express ESE3, induced morphological changes consistent with a mesenchymal-epithelial transition, reduced the ability of the cells to migrate and to form prostatospheres. Cancer stem cells are reportedly to be drug resistant and drugs like taxol can select for drug-resistant cells with stem cell properties. We observed that resistance to taxol was inversely correlated with ESE3 expression in prostate cell lines. Furthermore, treatment of LHS-ESE3kd cells with taxol increased sphere formation, consistent with an enlargement of the stem-cell compartment by the ESE3 knock-down and increased selection by the drug. Collectively, these findings implicate that ESE3 controls the differentiation state and stem cell properties of prostate epithelial cells and that loss of ESE3 can be an important event in prostate tumorigenesis.

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 5019.
Abstract 502: Cytokeratin staining for complete remission in rectal cancer after chemoradiation
Authors: Cho Yong Beom , Kim Hee Cheol , Yun Hae Ran , Kim Seok Hyung , Shin Hee Jeong , Yun Seong Hyeon , Lee Woo Yong , Chun Ho-Kyung
Published: February 2011

Purpose: Generally, pathologic complete remission (CR) of rectal cancer after neoadjuvant chemoradiation therapy (CRT) is confirmed by routine hematoxylin and eosin (H & E) staining. The aim of this study was to identify residual rectal cancer cells in primary lesions in patients with pathologic CR by staining immunohistochemically for cytokeratin.

Methods: The medical records of 358 rectal cancer patients that underwent neoadjuvant CRT prior to radical surgery between October 2002 and August 2007 were reviewed. The authors stained sections of resected specimens of the 58 (15.9%) patients (42 males; mean age 54 years) that achieved pathologic CR (as determined originally by H&E staining) with H&E and performed IHC using monoclonal cytokeratin antibody. These stained sections were then reviewed by a pathologist for residual rectal cancer cells.

Results: Of the 58 patients that achieved CR by initial pathologic examinations, 8 (13.8%) were found to contain tumor by cytokeratin IHC. Our H&E study in these 8, revealed that 6 were positive for cancer cells, but that the remaining 2, were negative for residual rectal cancer cells.

Conclusion: By better enabling the identification of residual rectal cancer cells cytokeratin IHC offers a means of improving staging accuracy, and thus, would be use to provide information for actual prognosis and treatment decision making of patients who had clinically CR in rectal cancer after CRT.

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 502.
Abstract 5024: Sorafenib in combination with modifiers of epigenetic mechanism induce synergistic cytotoxicity in human liver cancer cell lines
Authors: Gaur Shikha , Chen Linling , Yen Yun
Published: February 2011

Background: Hepatocellular carcinoma (HCC) is the third most important cause of cancer death worldwide. Sorafenib, a multikinase inhibitor improved outcomes in patients with hepatocellular carcinoma (HCC) by inhibiting angiogenesis. Epigenetic research suggests that many cancers may not be caused by mutations in genes but by chemical modifications that change how the genes function. DNA methylation and histone deacetylation are two of the more widely studied epigenetic mechanisms. Inhibitors of DNA methylation (Vidaza) and histone deacetylation (SAHA) have shown inhibited cell growth and induced apoptosis in liver cancer cells. We investigated the cytotoxicity of combination of Sorafenib with SAHA or Vidaza in two liver cancer cell lines HepG2 and Hep3B. METHODS: HepG2 and Hep3B cells in log phase growth were treated simultaneously with sorafenib (0.5-10 µM) and/or vidaza (1.25-10 µM) or SAHA (1.25-10 µM) for 72 hours. Following drug treatment, MTS assay was used as the endpoint for cell proliferation and the IC50 values and combination indices (CI) were derived using Calcusyn software (Biosoft, Cambridge, UK). Each combination was repeated at least three times.

RESULTS: The mean single agent IC50's for Sorafenib, Vidaza and SAHA were 6.83±0.44 µM, 10.33±2.91µM, and 11.5±4.25 µM, respectively in HepG2 cells and 6.25±0.20 µM, 11.50±0.41 µM, and 4.25±0.20 µM, respectively in Hep3B cells. The combination indices were:CombinationsHepG2Hep3BSorafenib and Vidaza0.72+0.130.73+0.12Sorafenib and SAHA0.77+0.130.68+0.05

CONCLUSIONS: The CI's for both combinations demonstrated synergistic effects in each of the cell lines. The molecular mechanism behind the synergistic effect of sorafenib in combination with vidaza or SAHA in liver cancer in underway.

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 5024.
Abstract 503: Curcumin protects UV-induced skin damage in SKH-1 hairless mouse
Authors: Cherng Jaw-Ming , Yu Alice Yu-whay , Lin Jung-Chung
Published: February 2011

Exposure to ultraviolet (UV) light is the major etiologic factor leading to the development of cutaneous squamous and basal cell carcinoma and is also a risk factor for melanomas. UV elicits inflammation, epidermal hyperplasia and changes in the expression of numerous genes associated with proliferation and differentiation. Curcumin has been shown to exert an anti-inflammatory activity, interfere with multiple cell signaling pathways, and possess potential preventive effect against various cancers. The purpose of this study was to determine whether curcumin can protect UV-induced skin damage in hairless SKH-1 mice. Oral or topical application of curcumin prior to, or immediately after, UV irradiation resulted in a very strong protective effect against UV-induced thymine dimer expression in epidermis, accounting for 69-74% inhibition (p < 0.00). Curcumin treatment also resulted in upregulation of p53 and p21/Cip1 protein levels by 33-41% (p < 0.005) and 46-50% (p < 0.005), respectively. Oral or topical application of curcumin prior to, or immediately after UV irradiation strongly decreased the expression of proliferative cell nuclear antigen by 47- 56% (p < 0.005). In addition, curcumin treatment significantly suppressed UV-induced apoptosis as measured by TUNEL assays (p < 0.005). Furthermore, curcumin treatment also significantly inhibited NF-κB, cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and nitric oxide (NO) levels. Our results suggest that curcumin possesses strong protective effect against UV-caused damage in epidermis. Taken together, these results provide a focus for the rational development of curcumin as a novel chemopreventive agent against UV-induced human skin 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 503.
Abstract 5034: Both host and tumor cells group VIA phospholipase A2 are involved in ovarian cancer development, and lysophosphatidic acid restores the lost activities
Authors: Li Hui , Zhao Zhenwen , Wei Gang , Wang Dongmei , Zhang Hong , Turk John , Xu Yan
Published: February 2011

Host-tumor cell interactions are recognized to be critical in tumor development. We have shown that group VIA phospholipase A2 (calcium-independent phospholipase A2beta, iPLA2β) is important in regulating extracellular lysophosphatidic acid (LPA) levels around human epithelial ovarian cancer (EOC) cells. To explore the role of iPLA2β in host-tumor cell interactions, we have used immunocompetent iPLA2β knockout (KO) mice and the mouse EOC cell line ID8. Tumorigenesis and ascites formation were reduced in iPLA2β-KO mice compared to wild type (WT) mice and were reduced further when ID8 cell iPLA2β levels were lowered with shRNA. LPA and lysophosphatidylcholine (LPC) levels in the tumor microenvironment were reduced in KO mice. LPA, but not LPC, restored ID8 cell migration, invasion, and colony formation with cells in which iPLA2β expression had been suppressed in vitro. LPA, but not LPC, also enhanced in vivo ascites formation and tumorigenesis in iPLA2β-KO mice. Autotaxin (ATX) activity in the tumor microenvironment correlated with tumor loading and was reduced in KO mice and enhanced by LPA in vivo. This is the first demonstration of a role for host cell iPLA2β in cancer, and these findings suggest that iPLA2β is a potential target for developing novel antineoplastic therapeutic strategies.

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 5034.
Abstract 5036: NF-κB pathway inhibition delays the onset of MYC-induced liver cancer
Authors: Bellovin David I. , Adam Stacey J. , Yang Qiwei , Felsher Dean W.
Published: February 2011

Liver cancer is one of the most lethal forms of cancer worldwide. Hence, it is critical to identify pathways that may be essential for the genesis of liver cancer and can thus be considered as targets for therapeutic intervention. Previously, our laboratory developed a conditional transgenic murine model of MYC-induced liver cancer that is dependent upon the expression of this oncogene and regresses following its inactivation. Here, we present evidence of an important role for the nuclear factor-kappa B (NF-κB) pathway in MYC-induced hepatocarcinogenesis. In order to examine whether NF-κB activation is necessary for MYC-induced liver cancer, we established a transgenic system in which MYC can be activated in hepatocytes concomitantly with a mutant form of IκB, thereby inhibiting the NF-κB pathway. Our approach has revealed that suppression of NF-κB activation can significantly inhibit MYC-induced hepatocellular carcinoma (HCC) in adult hosts. Indeed, animals with hepatocyte-inhibited NF-κB remain tumor free up to 8 months after oncogene activation compared to mortality in 100% within 6 months in animals expressing MYC alone. Moreover, inhibition of NF-κB reduces disease penetrance from 100% to 75%. In hosts that do develop liver tumors, there is evidence for activation of the NF-κB pathway, suggesting a necessity for NF-κB activation in MYC-induced HCC. Importantly, suppression of NF-κB activation in neonatal hosts is not only able to similarly suppress MYC-induced tumor formation, but animals that develop liver cancer in this context demonstrate a strikingly altered tumor phenotype. In addition, MYC inactivation results in a concomitant decrease in expression of NF-κB target genes, suggesting a direct role of MYC in the activation of NF-κB in hepatocytes. The inhibition of NF-κB did not result in increased apoptosis upon MYC activation. Rather, NF-κB activation may be important for MYC to evade oncogene-induced senescence, thereby facilitating tumorigenesis. Our data suggests that the inhibition of the NF-κB pathway may be sufficient to abrogate MYC's ability to induce tumorigenesis in the liver and thereby establish NF-κB activation as an attractive therapeutic target for liver 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 5036.