bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3312: Molecular profiling of melanoma primary tumors
Authors: Essner Richard
Published: February 2011

Objectives: A number of pathologic features have been identified from primary melanoma that are useful for determining patient prognosis including tumor thickness, ulceration, mitotic rate and Clark level; and the tumor status of the sentinel nodes (SN). Because none of these factors is useful for evaluating the outcome of individual patients we used a cDNA microarray to determine the relevance of molecular profiling of the primaries to determine the presence of lymph node metastases.

Methods: We obtained intact melanoma primaries and SN from 12 patients and microdissected both for molecular analysis. RNA was extracted and purified by RNeasy (Qiagen, Valencia, CA). GEArray Q series-Human Tumor Metastasis Gene Array Kits (Superarray, Bethesda, MD) were used to evaluate gene expression from biotinylated cDNA and images were acquired on the Molecular Dynamics storm 860 imaging station (Amersham Pharmacia Biotech, United Kingdom, Ltd). The signal intensity which corresponds to the quantity of cDNA bound to the array was analyzed by the ScanAlyze V2.50 image analysis software (Covance, Berkeley, CA).

Results: RNA was evaluated from 12 primary melanoma and matching SN, 7 with metastases. Four genes: caveolin (CAV1), Lim kinase (LIMK), matrix metalloproteinase 15 (MMP15) and vascular endothelial growth factor (VEGF) demonstrated consistent up-regulation in primary melanoma associated with SN metastases identified by H & E and the presence of these genes expressed in SN. Human melanoma cell lines and tumor-negative SN served as controls. Receiver operator curves (ROC) for genes: CAV1, LIMK, MMP15 and VEGF were constructed and the area under the curves (AUC) were determined as: 0.956+0.056, 0.978+0.039, 0.822+0.114 and 0.91+0.08, respectively. The combined concordance of LIMK and VEGF to predict metastases was 0.94

Conclusions: Gene expression profiling of primary melanoma can be used for predicting the presence of SN metastases. Up-regulation of LIMK and VEGF from the primary tumors may be an important first step to understand the early mechanism for patients developing lymph node metastases.

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 3312.
Abstract 3319: Human triple-negative breast cancer stem cells utilized for drug discovery therapeutics for triple-negative breast cancer patients
Authors: Sharma Cristian V.R , Passarini Jenna D. , Majdoub Mariam W. , DiMaggio Christina M. , Sobhy Omar M. , Punzalan Rubio R. , Sharma Michael V.R. , Harris-White Marni E. , Warden Michael W. , Sharma Sherven P. , Sharma Jay P.
Published: February 2011

Breast cancer is the most common malignancy among women in developed countries, affecting more than a million women per year worldwide. Of these, triple negative breast carcinoma represents 10-17 %. Triple negative breast carcinomas, characterized by estrogen, progesterone and HER2 receptor negativity are very aggressive tumors with poor prognosis. Breast Cancer Stem derived from triple negative parental Breast Cancer tumors, are a subpopulation of cells within the parental breast cancer population within the individual which are positive for the following markers: CD133+CD44+CD24+ESA+SSEA-1+TRA-1-61+& TRA1-81+ and Oct ¾ these Breast Cancer Stem cells are highly tumorigenic and possess the stem cell-like properties of self-renewal and the ability to produce differentiated progeny. Breast Cancer Stem cells also demonstrate up regulation of SSEA3+, SSEA4+ upon differentiation into parental cancer phenotype. Individualized treatment (tailored therapy) based on molecular biology markers of tumor and patient is the trend in clinical practice these days. However, molecular targets and predictors for the treatment of triple negative breast carcinoma do not currently exist. With the identification and characterization of Breast Cancer Stem Cells from parental triple negative tumors, enables one to screen novel drug candidates for potential development of therapeutics for triple negative Breast Cancer Patients. In this study we have utilized Breast Cancer Stem Cells from triple negative Tumors to screen potential drug candidates. The Breast Cancer Stem Cell based assay system may provide novel therapeutic approaches into treatment of triple negative breast cancer patients, which are resistant to standard chemotherapy and radiation.

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 3319.
Abstract 333: FISH markers in oral tongue squamous cell carcinoma
Authors: Wangsa Darawalee , Ryott Michael , Elmberger Göran , Schäffer Alejandro A. , Auer Gert , Lundqvist Elisabeth Åvall , Munck-Wikland Eva , Ried Thomas , Heselmeyer-Haddad Kerstin
Published: February 2011

Oral tongue squamous cell carcinoma (OTSCC) is a continued health problem worldwide, and is associated with poor prognosis. Genetic alterations in head and neck cancers have frequently been shown, however, reports about alterations in OTSCC and their correlation with clinical and histopathological parameters are limited. We investigated OTSCC by analyzing five probe markers (TERC, CCND1, EGFR, P53 and CEP®4) by means of fluorescence in situ hybridization (FISH) in sixty-five patients (Stage I, n=15; Stage II, n=30; Stage III, n=7; Stage IV, n=13). Higher copy number gains in all five markers was found to be significantly (P=0.002) correlated to non-smoking habits while low-level copy number gains corresponded to smokers in OTSCC patients. Of the five markers, CCND1 was found to have the highest mean copy number gain in comparison to all other markers used in this study. The percentage of cells with elevated (>3 signals) CCND1 copy number gain increased with stage. In Stage II OTSCC, CCND1 copy number gain correlated significantly (P=0.03) with a better prognosis in patients. Of the patients with increased CCND1 copy number gains (>3 signals in at least 5% of cells), all were non-smokers. In conclusion, high copy number gain using FISH correlated with non-smoking habits, making it particularly interesting to explore the mechanism of how these patients develop 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 333.
Abstract 3333: Therapeutic efficacy and safety of TRAIL-producing human adipose tissue-derived mesenchymal stem cells against experimental brainstem glioma
Authors: Kim Seung-Ki , Choi Seung Ah , Hwang Sung-Kyun , Wang Kyu-Chang , Cho Byung-Kyu , Phi Ji Hoon , Lee Ji Yeoun , Jung Hee Won , Lee Do-Hun
Published: February 2011

Mesenchymal stem cells (MSCs) have an extensive migratory capacity for gliomas, which is comparable to that of neural stem cells. Among the various types of MSCs, human adipose tissue-derived MSCs (hAT-MSC) emerge as one of the most attractive vehicles for gene therapy because of their high throughput, lack of ethical concerns, and availability and ease of isolation. We evaluated the therapeutic potential and safety of genetically engineered hAT-MSCs encoding the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) against brainstem gliomas.

hAT-MSCs were isolated from human fat tissue, characterized, and transfected with TRAIL using nucleofector. The therapeutic potential of TRAIL-producing hAT-MSCs (hAT-MSC.TRAIL) was confirmed using in vitro and in vivo studies. The final fate of injected hAT-MSCs was traced in long-survival animals. The characterization of hAT-MSCs revealed the expression of MSC-specific cell-type markers and their differentiation potential into neuronal lineage. Short-term outcomes included a 56.3% reduction of tumor volume (P < 0.001) with increased apoptosis (3.03-fold, P < 0.05) in animals treated with hAT-MSC.TRAIL compared with the control groups. Long-term outcomes included a significant survival benefit in the hAT-MSC.TRAIL-treated group (26 days of median survival in the control group vs 84 days in the hAT-MSC.TRAIL-treated group, P < 0.0001), without any evidence of mesenchymal differentiation in vivo. Our study demonstrated the therapeutic efficacy and safety of nonvirally engineered hAT-MSCs against brainstem gliomas.

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 3333.
Abstract 3339: Elimination of cancer stem cells in pancreatic cancer cell lines by a combinatorial therapy
Authors: Visús Carmen , Lozano-Leon Antonio , Wang YangYang , Chang YooJung , Whitcomb David C. , Brand Randall E. , DeLeo Albert B.
Published: February 2011

Cancer stem cells (CSC) are tumor initiating cells and considered resistant to current conventional chemo and radio therapies. Consequently, novel strategies are needed to target these cells. Tumor cells expressing elevated levels of aldehyde dehydrogenase 1 family member A1 activity (ALDHbright cells) have been shown to have many properties attributed to CSC, including tumorigenicity in immunodeficient mice. We used FACS analysis to identify and sort ALDHbright cells from several human pancreatic cell lines using ALDEFLUOR (Stem Cell Technologies, Vancouver Canada). We show that ALDHbright but not ALDHnegative cells sorted from the human MiaPaCa-2 pancreatic adenocarcinoma cell are highly tumorigenic at low inoculum of 500 cells in immunodeficient NOD.SCID mice, a critical property of CSC. Previously, we identified the ALDH1A188–96 peptide as an HLA-A2-restricted, cytotoxic T cell (CTL)-defined tumor antigen. Using a flow cytometry-based assay, ALDHbright cells in the HLA-A2+ MiaPaCa-2 cell line were selectively eliminated in vitro by ALDH1A188–96 peptide-specific CTL. The Hedgehog (Hh) stem cell signaling pathway has been shown to play a critical role in invasion and metastasis in pancreatic cancer. Treatment of the MiaPaCa-2 cell line with the Hg inhibitor, cyclopamine, significantly eliminated ALDH+ MiaPaCA-2 cells compared to treatment with conventional chemotherapeutic agents. The efficacy of a combinatorial therapy consisting of adoptive transfer of ALDH1A1-specific CTL combined with systemic administration of cyclopamine in vitro and in vivo on ALDHbright cells and in vivo growth inhibition of MIA PaCa-2-derived xenografts is detailed.

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 3339.
Abstract 3355: Comparison of CD133, uPAR, and CXCR4 expression in lung cancer cell lines under normal and spheroid culture conditions
Authors: Lee Alan J. , Sarfaraz Sami , Voeller Donna M. , Giaccone Giuseppe
Published: February 2011

Background: Cancer stem cells (CSC) have been identified in several solid tumors including breast, brain, and recently lung cancers, etc. In the CSC model, CSCs are thought to be able to self-renew extensively, grow as spheroids in vitro, and be resistant to conventional cancer therapies. CD133, uPAR and CXCR4 have been reported as putative markers that can be used to mark enriched cancer stem cell populations. Although CD133, uPAR and CXCR4 have been implicated in CSC biology and identification, their application as lung CSC (LCSC) markers have not been fully explored. In this study we examined and compared CD133, uPAR and CXCR4 expression in non-spheroid cells and CSC-like spheroid cells derived from several lung and non-lung cancer cell lines.

Methods: We cultured four classic small cell lung cancer (SCLC) lines, two variant SCLC lines, three non-small cell lung cancer (NSCLC) lines, one primary lung cancer line derived in our lab, three lymphoma cell lines, one thymoma cell line, and one breast cancer cell line. Cell lines were maintained in RPMI or DMEM with 10% fetal calf serum. Spheroids were cultured and maintained in low-attachment flasks in serum free media supplemented with EGF and FGF. CD133, CXCR4, and uPAR expression were evaluated by immunostaining followed by flow cytometry analysis.

Results: Under spheroid culture conditions, CD133 expression tends to remain the same or increases in most of the cell lines tested. SCLC and lymphoma lines tend to express more CD133 than NSCLC and non-lung cancer lines in both normal and spheroid culture conditions. uPAR expression is generally low, however when detectable, it only shows up in cell lines grown in spheroid culture conditions. CXCR4 expression generally increases in spheroid culture conditions with greater expression seen in SCLC lines and lymphoma lines.

Conclusion: Spheroid cells tend to exhibit higher CD133 expression than cells under regular culture conditions. This finding supports the idea that CD133 is enriched in LCSC populations. SCLC and lymphoma lines in normal and spheroid culture conditions express more CD133, uPAR, and CXCR4. This does not appear to be tied to adherent growth properties as two adherent SCLC lines displayed no striking difference in expression compared with other non-adherent SCLC lines. However the tendency for SCLC cells and lymphoma cells to grow in regular culture conditions as clumps may offer some insight into the increased expression of these markers.

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 3355.
Abstract 3405: Caveolin-1 modulates the metastatic ability of Ewing's sarcoma
Authors: Sainz-Jaspeado Miguel , Lagares-Tena Laura , Lasheras Jaime , Navid Fariba , Rodriguez-Galindo Carlos , Mateo-Lozano Silvia , Notario Vicente , Sanjuan Xavier , del Muro Xavier Garcia , Fabra Angels , Tirado Oscar M.
Published: February 2011

Metastasis is the final stage of tumor progression and is thought to be responsible for up to 90% of deaths associated with solid tumors. Caveolin-1 (CAV1) regulates multiple cancer-associated processes including cellular transformation, tumor growth, cell death and survival, multidrug resistance, angiogenesis, cell migration and metastasis. Although CAV1 was previously identified as a metastasis-associated gene that is a transcriptional target of EWS/FLI1 as well as an important determinant of Ewing's sarcoma family of tumors (ESFT) malignant phenotype, the possible involvement of CAV1 in regulating the ability of ESFT to metastasize has not been established. Therefore, in the present study we tested the hypothesis that CAV1 modulates the metastatic ability of ESFT cells. First, we analyzed the expression of CAV1 by immunostaining a tissue microarray (TMA) containing 43 paraffin-embedded ESFT tumors with known EWS translocations. Even though no evidence was found for a significant association between CAV1 expression with stage, size or tumor site, all metastatic samples (10/10) had significantly high CAV1 expression, suggesting that high CAV1 content makes it easier for ESFT cells to metastasize. To determine the effect of CAV1 on the migratory and invasive capabilities of ESFT cells, we knocked down CAV1 expression in TC252 and A673 cells by stably transfecting a previously validated shRNA construct. In vitro, wound healing and transwell migration and invasion assays showed that, in both cell lines. CAV1 knocked-down cells migrated significantly less (p≤0.01) than parental and vector-transfected control cells. Moreover, control transfected A673 cells introduced into balb/c nude mice by tail vein injection strongly colonized the lungs. In contrast, about 40% of animals injected with low CAV1 cells had no incidence of metastasis to any organ, and the other 60% suffered a significant delay in lung colonization (P=0.0005). These data demonstrate that CAV1 plays a key role in regulating the ability of ESFT cells to metastasize. Ongoing experiments are designed to elucidate the CAV1-regulated signalling pathways responsible for the development of ESFT metastases.

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 3405.
Abstract 3411: Targeting of EWS-FLI1 with small molecule YK-4-279 reduces xenograft growth by disruption of disordered protein-protein interactions
Authors: Toretsky Jeffrey A. , Erkizan Hayriye V. , Kong Yali , Merchant Melinda , Barber-Rotenberg Julie S. , Brown Milton L. , Üren Aykut
Published: February 2011

Introduction: EWS-FLI1 oncoprotein is expressed as a result of a tumor-specific translocation that occurs in patients with Ewing's Sarcoma. Development of strategies to therapeutically target EWS-FLI1 revealed its significant intrinsically disordered regions. The intrinsically disordered regions enhance protein-protein interactions while presenting an opportunity for small molecule targeting. We hypothesized that a small molecule could bind to EWS-FLI1 and prevent a key protein-protein interaction with RNA Helicase A (RHA) leading to decreased cell growth. Methods: Small molecule library screening was performed using surface plasmon resonance. Chemical optimization followed by fluorescence polarization enhanced and confirmed compound binding to EWS-FLI1, respectively. Testing of compounds included co-immunoprecipitation, cell growth, caspase-3, and xenografts. Results: A library of 3000 compounds (NCI, DTP) was screened for EWS-FLI1 binding. NSC635437 had an RUactual: RUtheorhetic of 0.9 and was chosen for further evaluation based upon potential for chemical derivatization. One optimized compound, YK-4-279, significantly reduced the protein-protein interaction between EWS-FLI1 and GST-RHA(647-1075). SPR measurement of the KD was 9.48 microM for the affinity of YK-4-279 with EWS-FLI1. YK-4-279 has an IC50 of 1 microM for a series of ESFT cell lines, while cell lines that lack EWS-FLI1 are 10-30 fold more resistant to the compound. YK-4-279 reduced the growth of Ewing's Sarcoma xenografts while not affecting the growth of PC3 prostate tumors. PONDR analysis of EWS-FLI1 and RHA indicate that their interaction is occurring in an ordered-disordered transition region of RHA. Conclusions: The lead compound derivative YK-4-279 demonstrates that the EWS-FLI1/RHA interaction can be blocked with a detrimental effect on Ewing's Sarcoma cells both in vitro and in vivo. These findings both validate the interaction of EWS-FLI1 with RHA as an oncogenic target and provide a lead compound for therapeutic development. Additional studies are underway to evaluate the contributions of the disordered regions to small molecule binding and developing strategies of optimization.

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 3411.
Abstract 3432: A green tea polyphenol epigallocatechin-3 gallate specifically targets tumor-associated endothelial cells
Authors: Hida Yasuhiro , Ohga Noritaka , Muraki Chikara , Akiyama Kousuke , Kondoh Miyako , Maishi Nako , Kurosu Takuro , Ishikawa Shuhei , Hirata Naoya , Shindoh Masanobu , Hida Kyoko
Published: February 2011

A green tea polyphenol, epigallocatechin-3 gallate (EGCG) suppresses tumor growth in vivo. We investigated mechanisms of specific tumor angiogenesis inhibition using tumor-associated endothelial cells (TECs), peripheral blood-derived ECs, and normal endothelial cells (NECs). TECs were isolated and cultured from human tumor xenografts in nude mice. Peripheral blood-derived ECs were isolated from peripheral blood of nude mice. EGCG suppressed migration of TECs and peripheral blood-derived ECs. EGCG also inhibited the phosphorylation of Akt in TECs and peripheral blood-derived ECs. The PI3K inhibitor, LY294002 blocked the migration of TECs induced by VEGF. Furthermore, VEGF-induced mobilization of CD133/VEGFR-2 double-positive cells into circulation was inhibited by EGCG. MMP-9 in the bone marrow is involved in mobilizing bone marrow-derived VEGFR-2 positive cells into peripheral circulation. Expression of MMP-9 mRNA was suppressed in bone marrow stromal cells by EGCG. In vivo model, EGCG reduced melanoma growth. Our study showed that EGCG specifically inhibits TEC and circulating EC through PI3K in EC and MMP-9 expression in bone marrow stroma. EGCG is a promising angiogenesis inhibitor for cancer therapy.

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 3432.
Abstract 3447: Identification of Gastric Cancer-Specific Helicobacter Pylori Genes Using Suppression Subtractive Hybridization
Authors: Gong Yue-hua , Jun Liu , Yuan Yuan
Published: February 2011

Helicobacter pylori (H. pylori), a microaerophilic Gram negative bacterium, is known to cause chronic gastritis, peptic ulcer, and gastric cancer. Genes that are present in certain isolates may determine strain-specific traits such as drug resistance. In order to understand the pathogenic mechanisms of gastric diseases, identify the molecule markers of the diseases associated with H.pylori strains, and provide clue for the target treatment of H. pylori related diseases, a subtracted DNA library was constructed from a gastric cancer-associated H. pylori strain and a superficial gastritis-associated H. pylori strain by suppression subtractive hybridization. Differentially expressed genes were identified by dot blot hybridization and DNA sequencing. Twelve high copy genes and 9 low-copy genes were found in gastric cancer-associated strain compare to superficial gastritis strain. These differentially expressed genes were confirmed by PCR analysis of bacteria isolates. Interestingly, PPIase was detected positively in 13 out of 26 H pylori strains derived from gastric cancer patients. In contrast, less than 24% of H pylori strains from superficial gastritis showed positive. Our results suggest that PPIase may represent a novel marker and potential therapeutic target for gastric 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 3447.
Abstract 345: Prostaglandin receptors differentially regulate prostate cancer growth: A novel treatment target
Authors: Huang Hosea F. , Shu Ping , Murphy Thomas F. , King Sherita , Wright Chris , Jordan Mark L.
Published: February 2011

INTRODUCTION AND OBJECTIVE: Prostaglandin E2 (PGE2) acts through a series of distinct prostanoid receptors, EPR 1-4. Since PGE2 is implicated in prostate cancer (CaP) tumorigenesis and metastasis, we hypothesized that EP receptor expression may influence CaP growth.

METHODS: 27 consecutive radical prostatectomy specimens were assessed by immunohistochemistry (IHC) for EPR expression and compared with normal human prostate epithelium (NP) from the same specimen as control. As a corollary, the expression of EP receptors in both normal (PrEC, PWR1E and PZ-HPV7) and CaP cells (LNCaP, PC3 and CA-HPV10) were assessed by RT-PCR and Western blot. The functional significance of EPR was assessed by growth of malignant and benign cell lines in vitro after siRNA EPR knockdown. All studies were approved by the local institutional review board (IRB) and all in vitro experiments performed a minimum of 3 times.

RESULTS: EP1, EP2, EP3 and EP4 receptors were detected by IHC in all NP clinical specimens. Compared with NP, EP4 and EP2 were over-expressed in 74% (20/27) and 63% (17/27) of CaP specimens, respectively; in contrast, EP3 expression was reduced in 93% (25/27) clinical samples (Figure). EP1 showed no specific differential expression pattern. Western blot showed increased EP4 but reduced EP3 in CaP lines (CA-HPV10, LNCaP and PC3) compared with NP lines; EP2 and EP4 knockdown significantly suppressed whereas EP3 knockdown stimulated in vitro growth of CA-HPV10 vs PZ-HPV7 cells. Expression of Runx 2 and MMP9, (known to contribute to CaP metastatic potential) was also reduced after EP2 and EP4 knockdown in CaP cells.

CONCLUSION: We observed EP4 and EP2 over-expression and reduced EP3 expression in 27 consecutive resected CaP specimens and in 6 representative cell lines. These observations were corroborated by the effects of EP4, EP2 and EP3 knockdown on tumor cell growth in vitro. These data suggest that EP receptor subtypes may regulate CaP growth which may represent a novel therapeutic approach.

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 345.
Abstract 3452: Role of P-glycoprotein in carcinogenesis
Authors: Wang Lihua , Jiang Weiwu , Moorthy Bhagavatula , Kondraganti Sudha Rani
Published: February 2011

Cancer accounts for nearly one-quarter of deaths in the United States, exceeded only by heart diseases. Polycyclic aromatic hydrocarbons (PAHs) are commonly found in our environment and appear to be carcinogenic by genotoxic mechanisms. Several studies show that over-expression of P-glycoprotein (Pg-p, coded by mdr1) is associated with the development of various cancers. High expression of the mdr1 gene has been reported in many human cancers such as in breast, liver, colon, kidney and brain. Many molecular and cellular studies have revealed the ability of dietary phytochemicals in vegetables and fruits to reduce the risk of cancer. The abundant and inexpensive dietary phytochemicals are being explored as Pg-p modulators in cancer chemoprevention and chemotherapy.

In the present study, we investigated the role of P-gp in cancer development. We also studied whether the inhibition of P-gp function could reduce the development of cancer. The wild type (C57BL/6J) mice were exposed to the environmental PAH, 7, 12-dimethylbenz(a)anthracene (DMBA) and dietary phytochemicals, alone and in combination. The hepatic and mammary gene expressions of P-gp, Pregnane X receptor (PXR), and CYP3A11 were analyzed. The environmental PAHs induced hepatic and mammary expressions of P-gp and associated genes in mice, compared to controls. Administration of dietary phytochemicals inhibited the P-gp expression significantly. Induction of specific DNA adducts were also observed in hepatic and mammary tissues of mice treated with PAHs and phytochemicals.

These studies show a potential for development of dietary phytochemicals as Pg-p modulators in chemoprevention and chemotherapy of human cancers.

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 3452.
Abstract 346: Aspirin blocks EGF responsiveness in ovarian cancer cells
Authors: Cho May , Khabele Dineo , Son Deok-Soo
Published: February 2011

Many ovarian cancers overexpress epidermal growth factor receptor (EGFR). EGFR over-expression in ovarian cancer has been associated with poor prognosis. EGFR inhibitors alone do not produce positive clinical results in ovarian tumors that lack a tyrosine kinase mutation or over-express EGFR. This suggests that downstream signaling pathways remained active. In other tumors, efficacy of EGFR inhibitors is improved with combination therapy . Recent evidence suggests that human epithelial ovarian cancers express elevated levels of COX-1, indicating COX-1 is a potential target for therapy. Aspirin (acetylsalicylate, ASA) is a more selective COX-1 inhibitor and is also known to have anti-tumor and anti-angiogenic properties. Our objective was to investigate the effects of ASA on EGF-induced ovarian cancer cell growth. ASA inhibited cell proliferation induced by EGF with a dose dependent manner in COX-1 positive OVCAR-3 ovarian cancer cells. In particular, ASA decreased phosphorylated Akt and Erk activated by EGF. Furthermore, we made COX-1 expressing cell line (SKCOX-1) by stably transfecting COX-1 expression vector into COX-1 negative SKOV-3 cells. SKCOX-1 cells were more responsive to ASA compared to cells transfected with pcDNA-3 (SKpcDNA). Taken together, ASA inhibits proliferation of COX-1 positive ovarian cancer cells by blocking phosphorylation of Akt and Erk, probably potentiating the efficacy to treat ovarian 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 346.
Abstract 3462: A DNA methyltransferase inhibitor and all-trans retinoic acid reduce oral cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide
Authors: Tang Xiaohan , Albert Martin , Scognamiglio Theresa , Gudas Lorraine
Published: February 2011

The transcriptional silencing of some cell cycle inhibitors and tumor suppressors, such as p16 and RARβ2, by DNA hypermethylation at CpG islands is commonly found in human oral squamous carcinoma cells. We examined the effects of the DNA methyltransferase (Dnmt) inhibitor 5-Aza-2′-deoxycytidine (5-Aza, 0.25 mg/kg body weight), all-trans retinoic acid (RA, given at 100 μg/kg body weight and 1 mg/kg body weight, respectively), and the combination of 5-Aza and the low dose RA on murine oral cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO) in a mouse model. All the drug treatments were performed for 15 weeks after a 10-week 4-NQO treatment. Mice in all drug treatment groups showed decreases in the average numbers of neoplastic tongue lesions. The combination of 5-Aza and RA effectively attenuated tongue lesion severity. While all drug treatments limited the increase in the percentage of PCNA positive cells and the decrease in the percentage of p16 positive cells caused by the 4-NQO treatment in mouse tongue epithelial regions without visible lesions and in the neoplastic tongue lesions, the combination of 5-Aza and RA was the most effective. Collectively, our results show that the combination of a DNA demethylating drug and RA has potential as a strategy to reduce oral cavity cancer in this 4-NQO model.

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 3462.
Abstract 347: Inhibition of ERK1/2 can sensitize human malignant mesothelioma cells and tumors to doxorubicin
Authors: Shukla Arti , Hillegass Jedd M. , MacPherson Maximilian B. , Beuschel Stacie L. , Heintz Nicholas H. , Vacek Pamela M. , Pass Harvey I. , Carbone Michele , Testa Joseph R. , Mossman Brooke T.
Published: February 2011

Malignant mesothelioma (MM) has a poor prognosis because of its resistance towards different drugs. Extracellular signal regulated kinase (ERK) family is known to have important roles in tumorigenesis and drug resistance. Here we show that Doxorubicin (Dox) treatment activates ERK1/2 in different MM lines. Activated ERK1/2 play a significant role in cell survival as inhibition of ERK1/2 by U0126 in the presence of Dox results in significantly enhanced cell killing. We show here using small molecule inhibitor and RNA silencing approaches that ERK1/2 inhibition sensitizes human MM cells to Dox treatment. ERK1/2 inhibition by U0126 significantly inhibited certain important drug resistance and proapoptotic genes in human MM cells as measured by PCR Array using human drug resistance and metabolism template. MM cell lines stably transfected with shERK1 or shERK2 exhibited significant increases in the accumulation of Dox and decreases in the cell viability when treated with Dox as compared to shCon line. Microarray analysis performed on stable shERK1 and shERK2 lines showed more than 2 fold inhibitions in selected ATP binding cassette genes, which may be responsible in part for increased Dox accumulation and sensitivity. Finally, subcutaneous injection of stable human MM lines inhibited for ERK1 or ERK2 into SCID mice showed that inhibition of ERK1/2 sensitizes in vivo tumors to Dox. These studies demonstrate a key role of ERK1/2 in MM tumor drug resistance. This work is supported by National Cancer Institute grant P01CA114047 and VCC/LCCRO grant.

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 347.
Abstract 3496: SYK inhibition results in increased sensitivity of OVCAR-3 cells to paclitaxel
Authors: Sultan Aya , Wang Cindy Y. , Duran George E. , Francisco E. Brian , Berek Jonathan S. , Sikic Branimir I.
Published: February 2011

In order to identify novel drug targets in ovarian cancers, we examined our ovarian cancer gene expression microarray data for expression of genes in the tyrosine kinase family. The spleen tyrosine kinase (SYK) gene was expressed in 73% of 55 ovarian cancer specimens, compared to 26% of 60 breast cancer specimens. Previous studies established the role of SYK in lymphocyte development, immune cell activation, and tumor progression. We found SYK to be expressed in 6 of 10 ovarian carcinoma cell lines. Among its many targets, SYK can bind microtubules and other molecules associated with the cytoskeleton. Because of this ability, we studied the relationship of SYK expression to cellular sensitivity to taxanes. We focused on the OVCAR-3 cell line, which was one of the highest SYK-expressing cell lines, to elucidate the potential effects of SYK on taxane sensitivity. Our results demonstrate that knockdown of SYK expression by siRNA resulted in a one log-fold increased sensitivity of OVCAR-3 cells to the taxane, paclitaxel. Furthermore, this effect was durable, as knockdown of SYK and sensitization to paclitaxel persisted over 128 hours. The potential effects of SYK on tubulin polymerization are currently being investigated. We will evaluate potential upstream and downstream targets to elucidate the pathway(s) responsible for SYK effects and determine whether SYK levels contribute to tumor resistance to chemotherapeutic agents. Understanding the growth signals in drug sensitive and resistant ovarian cancer cell lines and tumor samples may eventually lead to new therapeutic approaches for ovarian cancers.

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 3496.
Abstract 3500: Nucleolytic processing of Topoisomerase 2 covalent complexes
Authors: Nitiss John L. , Bahmed Karim , Mishina Margarita , Berk Jeffrey , Nitiss Karin C.
Published: February 2011

The generation of elevated levels of enzyme: DNA covalent complexes is the key event in cell killing by many drugs targeting DNA topoisomerases. These agents, termed topoisomerase poisons generate protein linked DNA strand that block transcription and replication, leading to cell death. A critical step in the repair of topoisomerase mediated DNA damage is the removal of protein that is covalently attached to DNA. Several specialized repair enzymes, including Tdp1 (tyrosyl DNA phosphodiesterase I) and TTRAP (TRAF and TNF receptor-associated protein) can hydrolyze phosphotyrosyl: DNA linkages. We previously reported that yeast Tdp1 could hydrolyze 5′ as well as 3′ phosphotyrosyl linkages. Human Tdp1 can also hydrolyze 5′ phosphotyrosyl linkages, although the efficiency of the reaction with the human enzyme is much less than that seen with the yeast enzyme. Interestingly, the human enzyme processes adducts bearing a seven amino acid peptide linked to an oligonucleotide with greater efficiency than a 5′ biotin linked oligonucleotide, suggesting that the nature of the adduct at DNA ends influences Tdp1 reaction kinetics. We also used substrates derived from Top2 trapped covalent complexes to assess the ability of other DNA repair enzymes to remove peptides covalently bound to DNA. We found that the heterodimeric nuclease Slx1/Slx4 is able to remove Top2 peptides that are covalently bound to DNA. This result is consistent with our genetic data from yeast that a mutation in the subunit that includes the nuclease (Slx1) is hypersensitive to Top2 poisons, but not sensitive to other DNA damaging agents. Our results indicate that there are multiple pathways for repairing Top2 covalent complexes and suggest that the Slx1/Slx4 dependent pathway may be particularly relevant to repairing topoisomerase mediated damage at replication forks.

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 3500.
Abstract 3503: CCT241533 is a novel, potent and selective inhibitor of CHK2 and potentiates the cellular effects of PARP inhibitors
Authors: Anderson Victoria E. , Eve Paul D. , Walton Michael I. , Caldwell John J. , Pearl Laurence H. , Oliver Antony W. , Collins Ian , Garrett Michelle D.
Published: February 2011

CHK2 is a checkpoint kinase involved in the ATM-mediated response to double stranded DNA breaks (DSB). Detection of DSB by the MRE11-RAD50-NBS1 (MRN) complex leads to activation of ataxia telangiectasia mutated (ATM) kinase, which can then phosphorylate CHK2 on threonine 68. This facilitates CHK2 to dimerisation and autophosphorylation in trans at threonine 383/387, resulting in full activation and subsequent phosphorylation in cis at serine 516, a biomarker read out of CHK2 activation. Once activated, CHK2 phosphorylates a range of targets involved in DNA damage repair, cell cycle arrest and apoptosis.

It has been suggested that inhibitors of CHK2 may increase the efficacy of genotoxic cancer therapies. However, the evidence so far is inconsistent. We have therefore developed a CCT241533, a potent and selective inhibitor of CHK2, as a molecular tool and potential therapeutic agent (the structure will be disclosed in the presentation). The co-crystal structure of CCT241533 bound to the kinase domain of CHK2 confirms that the compound binds the ATP binding pocket. CCT241533 inhibits CHK2 with an IC50 of 3 nM and shows minimal inhibitory activity against a panel of known kinases at 1 μM, including CHK1 (IC50 = 245 nM). We show that CCT241533 blocks CHK2 activity in three human tumor cell lines (HT29, HeLa, MCF7) in which we have confirmed functional activation of CHK2. We also show that CCT241533 potentiates the growth inhibitory effect of two structurally distinct Poly (ADP-ribose) polymerase (PARP) inhibitors in p53 defective human cancer cells. We further demonstrate that this cellular effect correlates with inhibition of PARP inhibitor-mediated induction of CHK2 activity, as assessed by the phospho-serine 516 biomarker and CHK2 mobility shift. This adds strength to the conclusion that the potentiation between the two compounds is due to their effects on CHK2.

To summarize, we have developed a potent and selective CHK2 inhibitor and show, for the first time, potentiation between CHK2 inhibition and PARP inhibition.

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 3503.
Abstract 3515: Gefitinib-resistant cell line derived from PC-9 has high sensitivity to SN-38
Authors: Sakai Asao , Kimura Hideharu , Sone Takashi , Ohmori Tohru , Kasahara Kazuo , Fujimura Masaki
Published: February 2011

Most non-small cell lung cancer (NSCLC) tumors with EGFR mutations are responsive to EGFR tyrosine kinase inhibitors such as gefitinib. Preliminary experiments with PC-9/MET, a gefitinib resistant cell line derived from PC-9 showed a higher sensitivity to SN-38, which is an active metabolite of CPT-11, in comparison to parental PC-9. The mechanisms of the collateral sensitivity to SN-38 were investigated in the resistant cell line. The WST-1 assay showed that PC-9/MET was more sensitive, with an IC50 of 0.027 ± 0.014 μM, to SN-38 than that to PC-9 with an IC50 of 0.093 ± 0.049 μM. Topoisomerase-I (Topo-I) mRNA expression value in PC-9/MET to increase 9.2 times in comparison to that of PC-9. The Topo-I activity of PC-9/MET was higher than that of PC-9 and the Topo-I protein expression was also higher in PC-9/MET. PC-9/MET has a greater expression of MET in comparison to PC-9. The suppression of MET expression by an MET-specific siRNA resulted in a decrease in the Topo-I activity and Topo-I protein expression in PC-9/MET.

In conclusion, the Topo-I activity and protein expression in PC-9/MET is elevated via the mRNA expression, thus resulting in collateral sensitivity to SN-38. The MET over-expression in PC-9/MET may therefore be one of the mechanisms which cause an increase in the Topo-I activity and expression.

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 3515.
Abstract 3518: Preclinical pharmacology of the novel, potent & selective CHK1 inhibitor SAR-020106
Authors: Walton Michael I. , Eve Paul D. , Hayes Angela , Valenti Melanie , Brandon Alexis De Haven , Box Gary , Aherne G Wynne , Eccles Suzanne A. , Raynaud Florence I. , Williams David H. , Reader John C. , Collins Ian , Garrett Michelle D.
Published: February 2011

Genotoxic antitumor agents continue to be the mainstay of current cancer chemotherapy. These drugs cause DNA damage and activate numerous cell cycle checkpoints facilitating DNA repair and the maintenance of genomic integrity. Most human tumors lack functional p53 and consequently have compromized G1/S checkpoint control. This has led to the hypothesis that S and G2/M checkpoint abrogation may selectively enhance genotoxic cell killing in a p53 deficient background, as normal cells would be rescued at the G1/S checkpoint. CHK1 is a serine/threonine kinase associated with DNA damage linked S and G2/M checkpoint control. SAR-020106 (the structure will be shown on the poster) is an ATP competitive, potent and selective CHK1 inhibitor with an IC50 of 13.3nM on the isolated human enzyme. This compound abrogates an etoposide-induced G2 arrest with an IC50 of 55nM in HT29 cells, and significantly enhances the cell killing of gemcitabine and SN38 by 3.0 to 29-fold in a number of colon tumor lines in vitro and in a p53 dependent fashion. Biomarker studies have shown that SAR-020106 inhibits cytotoxic drug induced autophosphorylation of CHK1 at S296 and blocks phosphorylation of CDK1 at Y15 in a dose-dependent fashion both in vitro and in vivo. Cytotoxic drug combinations were associated with increased γH2AX and PARP cleavage consistent with SAR-020106 enhanced DNA damage and tumor cell death. Irinotecan and gemcitabine antitumor activity was enhanced by SAR-020106 in vivo with minimal toxicity. Orally bioavailable analogues of SAR-02106 are currently under development. In conclusion SAR-020106 represents a novel class of CHK1 inhibitors which can enhance antitumor activity with selected anticancer drugs in vivo and may therefore have clinical utility.

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 3518.
Abstract 3522: A Phase 0 microdosing trial to identify chemoresistance: From bench to bedside
Authors: Wang Sisi , He Miaoling , Li Tao , de Vere White Ralph , Lara Primo N. , Gandara David , Mack Philip C. , Turteltaub Kenneth , Henderson Paul T. , Pan Chong-xian
Published: February 2011

BACKGROUND: DNA damage is the critical step in cancer cell response to platinum (Pt) chemotherapy. We hypothesize that low levels of Pt-induced DNA damage are predictive of chemoresistance. Accelerator mass spectrometry (AMS) is an ultrasensitive method for measuring radiocarbon. By measuring 14C bound to DNA, AMS can detect carboplatin-induced DNA damage after patients receive one subtoxic microdose of 14C-labeled carboplatin.

METHODS: Cancer cells and mice bearing tumor xenografts were treated with one microdose (1/100th of the therapeutic dose) or one therapeutic dose of [14C]carboplatin. Carboplatin-DNA adducts and other relevant parameters such as drug influx/efflux, intracellular drug inactivation, and repair of DNA damage, were measured and correlated with response to chemotherapy.

RESULTS: AMS detected Pt-DNA damage when cancer cells and mice with tumor xenografts were exposed to one subtoxic microdose of [14C]carboplatin. The levels of microdose-induced DNA damage were linearly proportional to the DNA damage caused by the therapeutic drug dose (R2=0.92, p<0.001); and these levels of DNA damage correlated with chemoresistance. Low DNA damage predicts chemoresistance. Measuring drug uptake/efflux, intracellular inactivation and DNA repair allowed insight into some resistance mechanisms. A Phase 0 microdosing trial has been designed to study patients with non-small cell lung cancer or bladder cancer who are scheduled to receive Pt-based chemotherapy. One subtoxic microdose of 14C-carboplatin will be administered to these patients before biopsy. Pt-induced DNA damage and repair in left-over tumor biopsy specimens and other relevant parameters will be measured and correlated with the response and toxicity of chemotherapy. Molecular analysis of genes such as ERCC1 and RRM1 will be analyzed and compared with this Phase 0 results.

CONCLUSION: The levels of DNA damage induced by nontoxic microdosing carboplatin can potentially predict chemoresistance in patients. A phase 0 microdosing trial is under the IRB review to identify chemoresistance and determine the underlying resistant mechanisms for personalized therapy before patients receive toxic Pt 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 3522.