bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1520: Beta-endorphin neuron transplants suppress mammary tumor growth and progression via neuroimmune activation
Authors: Sarkar Dipak K. , Zhang Changqing , Dokur Madhavi , Boyadjieva Nadka I. , Ortigüela Maria , Rafferty Nicole , Mojtehedzadeh Sepideh , Reuhl Kenneth , Sengottuvelan Murugan
Published: June 2012

A review of studies that evaluated psychological factors and outcome in cancer patients suggested an association between certain psychological factors and the growth and progression of cancer. It has been suggested that the effect of stress on the immune system may in turn affect the growth of some tumors. We have previously shown that a set of hormone secreting nerve cells in the hypothalamus, called beta-endorphin (BEP) neurons, plays a role in regulating stress response and immune function. Hence, we tested whether activation of BEP neurons reduces stress hormone levels and prevents the N-nitroso-N-methylurea (NMU)-induced mammary tumor burden and malignancy rate. To test this we differentiated rat neural stem cells from the hypothalamus into BEP neurons in culture, which were later transplanted into the paraventricular nuclei (PVN) of the hypothalamus of 90 day old Sprague-Dawley female rats, which were injected with MNU 4 weeks prior to cells transplantation. Control rats were transplanted with cortical cells or not operated. Animals were palpated every week to check for tumor growth for additional 12 weeks. Tumor length and width were measured with a calibrator. Sixteen weeks after MNU injection, animals were sacrificed, tumors were collected, and slices of tumors were put in formalin and processed for histological staining for pathology. Additionally, the impact of cell transplants on plasma levels of stress hormone corticosterone and cytokines interferon gamma (INF-γ), tumor necrosis factor alpha (TNF-α) in plasma and the levels of natural killer (NK) cell and macrophage cytotoxic activities in peripheral blood and spleen were evaluated. When the BEP neurons were transplanted into the PVN of an adult rat, they integrated well with the surrounding cells and produced BEP and it precursor gene proopiomelanocortin. We found that BEP implanted animals have significantly lower tumor incidence, tumor volume, tumor number and malignancy rate. Rats with BEP neuron transplants also showed reduced plasma corticosterone levels, increased NK cell and macrophage activities in the spleens and peripheral blood mononuclear cells, elevated plasma levels of anti-inflammatory cytokine INF-γ and decreased levels of inflammatory cytokine TNF-α. These results identify a protective role of BEP neurons against MNU-induced mammary tumor (animal model for breast cancer) growth and progression via increasing the innate immune function and reducing the inflammatory milieu. (Supported by NIH Grant AA015718).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1520. doi:10.1158/1538-7445.AM2011-1520
Abstract 1531: HtrA1 sensitizes ovarian cancer cells to cisplatin-induced cytotoxicity by targeting XIAP for degradation
Authors: He Xiaoping , Khurana Ashwani , Maguire Jacie L , Chien Jeremy , Shridhar Viji
Published: June 2012

We have previously identified serine protease HtrA1 as a down-regulated gene in ovarian cancer and loss of HtrA1 may contribute to cell resistance to cisplatin treatment. However, the exact mechanism by which HtrA1 regulates chemosensitivity in ovarian cancer is currently unknown. Here, we used mixture-based oriented peptide library approach and identified XIAP, an important member of the inhibitor of apoptosis (IAP) protein family, as one possible substrate of HtrA1. Recombinant wild type (WT) HtrA1 but not protease-inactive SA mutant HtrA1 can cleave XIAP protein in vitro. Over-expression of HtrA1 led to decreased level of XIAP in OV167 and OV202 ovarian cancer cells, while down-regulation of HtrA1 resulted in increased level of XIAP in SKOV3 ovarian cancer cells. CDDP treatment enhanced the cleavage of XIAP by HtrA1. Immuno-precipitation assay revealed that HtrA1 binds to XIAP directly both in vitro and in vivo. Increased cell resistance to cisplatin treatment was observed in SKOV3 and TOV-21G cells after stable knockdown of HtrA1 with shRNA. In contrast, over-expression of HtrA1 in OV202 cells promotes cell sensitivity to cisplatin treatment which can be reversed by increased expression of XIAP. In conclusion, our experiments reveal XIAP as a novel substrate of HtrA1 and the mechanism by which HtrA1 confers cell sensitivity to cisplatin treatment may be partially through its degradation of XIAP.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1531. doi:10.1158/1538-7445.AM2011-1531
Abstract 1536: UVB-irradiation regulates VLA-4-mediated melanoma cell adhesion to endothelial VCAM-1 under flow conditions
Authors: Liu Wei , Wang Lei , Shirure Venktesh S. , Burdick Monica M. , Wu Shiyong
Published: June 2012

The major aspect contributing to the mortality of melanoma is its ability to spread, or metastasize. Ultraviolet B light (UVB) is considered an indirect cause of melanoma formation. However, little is known about the potential effects of UVB to melanoma metastasis. Integrins, a large family of cell adhesion molecules expressed on the melanoma cell surface, are important for cell signaling, growth, and migration during metastasis. Most critically, tumor cell tissue invasion is dependent on the initial interaction of tumor cells with vascular endothelium at the target organ, and there is increasing evidence for a prominent role of melanoma very late antigen-4 integrin (VLA-4, α4β1 integrin) binding to its endothelial ligand vascular cell adhesion molecule-1 (VCAM-1) in this process. This research focuses on the quantitative modulation of VLA-4 integrin expression and function on melanoma cells after UVB irradiation. The present data show that at 3, 12, and 18 hours post-UVB irradiation, VLA-4 expression was unchanged relative to untreated cells, but adhesion to VCAM-1 decreased significantly. Immunofluorescence studies implied that the spatial organization of α4 integrin on the melanoma cell surface contributed to the changes in avidity for VCAM-1 upon UVB irradiation. Further analysis suggested that the surface level of α4 integrin was maintained by Akt activity after UVB irradiation. The level of cell surface α4 integrin was significantly increased after UVB-irradiation when Akt was inhibited. Inhibition of Akt also reversed the reduction of avidity of cells after the irradiation. Our data also show that UVB reduces the level of Akt. The inhibition of Akt activity correlated with a reduced amount of coupled cNOS and reduced amount of iNOS after UVB-irradiation. However the effect of NOSs on melanoma cell adhesion appears due to their roles in regulation of apoptosis after UVB-irradiation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1536. doi:10.1158/1538-7445.AM2011-1536
Abstract 154: miRNAs in plasma of pancreatic cancer patients
Authors: Ali Shadan , Almhanna Khaldoun , Chen Wei , Philip Philip A. , Sarkar Fazlul H.
Published: June 2012

Pancreatic cancer (PC) has the poorest overall survival rate among all human cancers, which is in part could be due to the lack of early diagnosis; however, there are no reliable tools for early detection of PC, emphasizing the need for the discovery of novel biomarkers. In the current study, we investigated the expression profile of microRNAs (miRNAs) in the plasma of 50 PC patients and compared with 10 normal volunteers. The data was further validated by quantitative real-time PCR and cell-based assays. Moreover, we have tested the biological significance of our findings from plasma miRNAs experimentally by assessing differential expression of miRNAs in two parental and four chemo-resistant human PC cell lines by miRNA profiling and quantitative RT-PCR. We found 37 miRNAs that were down-regulated and 54 were up-regulated in the plasma from patients diagnosed with PC. The expression of miR-21 was significantly higher, and the expression of let-7 family (especially let-7d) and miR-146a was significantly lower in PC. The higher expression of miR-21 predicted worse survival, and although the overall expression of let-7d was lower in PC, the lowest expression predicted better survival compared to PC patients with relatively higher expression of let-7. Interestingly, we also found that miR-21 family was markedly over-expressed in chemo-resistant PC cell lines, which was consistent with the plasma data from PC patients. Our previous studies showed increased expression of miR-21 with concomitant loss of PTEN expression, which is consistent with current findings showing the loss of three additional targets of miR-21 (PDCD4, Maspin and TPM1). These results suggest that identifying and validating the expression of miRNAs in newly diagnosed patients could serve as a potential biomarker for tumor aggressiveness. Based on our findings, we conclude that miR-21 expression may serve as a novel plasma biomarker for early detection of PC. Hence such miRNAs could be useful for the screening of high-risk patients, which may further lead to the development of novel strategies by which miR-21 could be targeted for future drug development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 154. doi:10.1158/1538-7445.AM2011-154
Abstract 1541: Secondary mutations in ALK and resistance to ALK kinase inhibitors
Authors: Sasaki Takaaki , Okuda Katsuhiro , Zheng Wei , Butrynski James , Capelletti Marzia , Wang Liping , Gray Nathanael , Wilner Keith D. , Christensen James G. , Demetri George D. , Shapiro Geoffrey I. , Rodig Scott J. , Eck Michael J. , Jänne Pasi A.
Published: June 2012

Background: The anaplastic lymphoma kinase (ALK) inhibitor crizotinib is clinically effective in cancer patients whose tumors harbor ALK translocations. However, drug resistance will ultimately develop in most if not all patients. We studied drug resistance mechanisms using both in vitro models and analyses from tumors of patients that had developed crizotinib resistance.

Methods and Results: We identified a secondary mutation in ALK, F1174L, as one cause of crizotinib resistance in a patient with an inflammatory myofibroblastic tumor (IMT) harbouring a RANBP2-ALK translocation who progressed while crizotinib therapy. When present in cis with an ALK translocation, this mutation (also detected in neuroblastomas) causes an increase in ALK phosphorylation, cell growth and downstream signaling. Furthermore, the F1174L mutation inhibits crizotinib mediated downregulation of ALK signaling and blocks apoptosis in RANBP2-ALK Ba/F3 cells. We also evaluated the impact of mutations in the ALK gatekeeper residue (L1196) and engineered all possible gatekeeper mutations resulting from a single nucleotide change into the background of EML4-ALK. Three of the mutations (L1196M, L1196Q and L1196V) in the background of EML4-ALK led to IL-3 independent growth. Furthermore the EML4-ALK L1196M mutant resulted in a greater baseline ALK phosphorylation, cell growth and downstream signaling compared to EML4-ALK alone. A chemically distinct ALK inhibitor, TAE684, or the HSP90 inhibitor 17-AAG are both effective in models harbouring the F1174L or the L1196M ALK mutations.

Conclusions: We identify secondary mutations in ALK that confer crizotinib resistance. In addition, we identify therapeutic strategies, alternative ALK inhibitors or HSP90 inhibitors that may be clinically effective in patients that have developed crizotinib resistance. Understanding the mechanistic basis of drug resistance is necessary in order to develop effective clinical treatments for patients with ALK-translocated cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1541. doi:10.1158/1538-7445.AM2011-1541
Abstract 1550: The effect of snail on cellular adhesion in prostate cancer cells
Authors: Neal Corey L. , Mckeithen Danielle , Odero-Marah Valerie
Published: June 2012

PURPOSE: The purpose of the study is to determine the role of Snail transcription factor on cellular adhesion to fibronectin and collagen, in human prostate cancer cells. Adhesion of cells to one another or the extracellular matrix (ECM) is responsible for normal and abnormal cellular activity, such as cell migration, invasion, metastasis of tumor cells, and angiogenesis. Snail transcription factor induces epithelial-mesenchymal transition (EMT) in which epithelial cells loose expression of specific genes and acquire traits of mesenchymal genes. We hypothesized that Snail will lead to decreased cellular adhesion to fibronectin and collagen matrix, concomitant with increased cell migration. DESIGN METHODS: We stably overexpressed Snail in LNCaP (LNCaP-Snail) and ARCaP (ARCaP-Snail) prostate cancer cells, or stably knocked down Snail in C4-2 and ARCaP-Snail cells using shRNA. We performed cell adhesion and migration assays on fibronectin and collagen I matrices using these cell models. Flow cytometry was also used for integrin expression analysis. RESULTS: We found that ARCaP prostate cancer cells transfected with Snail displayed decreased adhesion to fibronectin and collagen I, which was reversed by Snail knockdown. Additionally we have seen a decrease in the expression of the α5 and α2 integrin among ARCaP cell lines over expressing Snail, concomitant with an increased migration in cell lines overexpressing Snail. CONCLUSION: We have shown that Snail decreases cell adhesion to fibronectin and collagen, and inversely increases cell migration. These studies define a new role for Snail transcription factor that may be crucial for cell detachment and subsequent metastasis. Supported by grants P20MD002285-01 & G12RR003062-22

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1550. doi:10.1158/1538-7445.AM2011-1550
Abstract 1568: Plasma-derived circulating microvesicles can both detect and help monitor breast cancer-related pathologies
Authors: Holterman Daniel A. , Duncan Janet E. , Deng Ta , Smith Shannon E. , Spetzler David B. , Kuslich Christine D.
Published: June 2012

Circulating microvesicles (cMV) are membrane-bound structures that play an important role in several biologic processes, including angiogenesis and immune modulation. cMV levels are known to change in response to certain pathologies, and specific subpopulations of cMV can be isolated using antibodies targeted to membrane proteins specific for the secreting cells. We examined whether the levels of specific cMV subpopulations are altered in patients with a disease, specifically breast cancer. In order to characterize individual cancer-associated microvesicles (MVs), advanced breast cancer MVs were compared with normal control MVs. Circulating microvesicles were isolated from breast cancer patients or noncancer control patients, stained with fluorochrome-conjugated antibodies, and analyzed using flow cytometry. Tumor-specific antibodies were paired with process-specific markers, such as DLL4 and VEGFR2 for angiogenic cMV, CTLA4 and FasL for immunosuppressive cMV, and CD80 or CD83 for immunostimulatory cMV, to identify and characterize cMV subpopulations.

Using this approach, distinct and informative cMV subpopulations were identified and quantified between breast cancer patients and healthy controls. For example, immunosuppressive MVs were elevated in the cancer patients compared with noncancer controls (68% vs 44% of CD45+ cMV coexpressed CTLA4). Additionally, angiogenic MVs were elevated in cancer plasma, with 44% coexpressing DLL4 and CD31 compared with 2% of cMV from noncancer controls.

This study suggests that in addition to aiding diagnosis, monitoring specific subpopulations of cMV may offer important information regarding biologic processes perturbed by breast cancer in an individual patient, without the need for an invasive biopsy or a standard pathology evaluation such as immunohistochemistry, and therefore may also aid in prognosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1568. doi:10.1158/1538-7445.AM2011-1568
Abstract 1586: Oral administration of HIV-protease inhibitors reduces ovarian tumor growth in vivo
Authors: Vandeven Natalie A. , Tan Lijun , Sorenson Dorothy , Liu J. Rebecca
Published: June 2012

INTRODUCTION: Ritonavir boosted lopinavir (LPV/r) is an FDA approved HIV-protease inhibitor combination that is a well tolerated and preferred treatment for HIV patients. Ritonavir is a potent irreversible inhibitor of cytochrome P450 isoform 3A (CYP3A) which can substantially increase bioavailability of lopinavir in vivo. This combination of lopinavir and ritonavir has been shown to increase the efficacy of reducing viral load in AIDS patients. HIV patients taking antiretroviral protease inhibitors such as LPV/r have a lower incidence of HIV associated malignancies such as non-Hodgkin's lymphoma, cervical cancer and Kaposi's sarcoma, leading to the hypothesis that these drugs have antineoplastic activity. Given the need for novel treatment approaches in ovarian cancer, we are investigating the antineoplastic effects of LPV/r, in vivo. METHODS: A xenograph model of ovarian cancer is used to assess the antineoplastic effect of LPV/r in vivo. Oral doses of LPV/r dissolved in corn oil are administered to mice over the course of 2-3 weeks. Tumor area and mouse weight are monitored. After 2-3 weeks tumors are harvested and analyzed. RESULTS: Preliminary results indicate that LPV/r administered orally in combination with a high fat diet inhibits tumor growth in vivo without inducing weight loss. In contrast, the dose of intraperitoneal cisplatin required to attain a similar antineoplastic effect resulted in significant weight loss and morbidity. CONCLUSIONS: Because protease inhibitors can induce both apoptotic and non-apoptotic ovarian cancer cell death in vitro and in vivo, these drugs may circumvent chemoresistance due to alterations in apoptotic response. Our data suggests that LPV/r may also have clinical application in the treatment of ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1586. doi:10.1158/1538-7445.AM2011-1586
Abstract 1595: Use of MDV3100 to establish androgen-receptor antagonist resistant LNCaP cells for modelling castrate-resistant progression
Authors: Kuruma Hidetoshi , Matsumoto Hiroaki , Zoubeidi Amina , Thomas Christian , Lamoureux Francois , Gleave Martin
Published: June 2012

Background. The androgen receptor (AR) plays a critical role in the development and progression of prostate cancer. Even in castrate resistant prostate cancer (CRPC), the AR is active and drives progression. MDV3100 is a novel AR antagonist with demonstrated anti-tumour activity in preclinical models and patients with CRPC. To define its anti-cancer effects and features of its recurrent/resistant tumour, we assessed dose-dependent activity of MDV3100 in vivo, and set out to establish MDV3100 resistant cell lines and tumors to characterize its resistant phenotype.

Methods. Androgen sensitive human prostate cancer LNCaP cells were inoculated into male athymic nude mice, and when tumour volume reached 150mm3 and serum PSA was 50ng/ml, mice were castrated. When serum PSA levels returned to pre-castrate level, mice were randomly divided into 4 groups of 1, 10 and 50mg/kg of MDV3100 and vehicle treatment groups. Tumour volume and serum PSA were followed weekly. MDV3100 recurrent tumours were harvested and re-cultured in vitro in the presence of MDV3100, or re-implanted into castrated male nude mice treated daily with 10mg/kg of MDV3100. Established cell lines were characterized for response of androgen and MDV3100, and AR and prostate specific antigen (PSA) expressions in vitro.

Results. Serum PSA declined -60.8% at 2 weeks and -88.0% at 5 weeks from baseline in 10 and 50mg/kg of MDV3100, respectively. Vehicle and 1mg/kg of MDV3100 did not decrease serum PSA levels. Time to PSA progression from baseline was 6 and 12 weeks at 10 and 50mg/kg MDV3100, respectively. While high doses (50mg/kg) of MDV3100 resulted in the most anti-tumour effect, there were no complete responses and 90% of tumours eventually recurred within 10 weeks’ of treatment. Fifteen cell-lines derived from 7 animals in the high dose group and 3 cell-lines from the animal allografts have been generated to date. Eleven of 12 cell lines showed resistance against 10uM of MDV3100, as proliferation rates were suppressed by a mean of 19% (range, 64.4-98.9%) compared to 50.7% in parental LNCaP cells. Eleven of 12 lines expressed AR while two were PSA negative.

Conclusions. While dose-dependent anti-tumour effects of MDV3100 was seen in castrate-resistant LNCaP tumors in vivo, all tumor eventually progressed. Generated MDV3100 resistant cell lines and xenografts were characterized as AR(+)/PSA(+), AR(+)/PSA(−), or AR(−)/PSA(−) and may be useful for modelling resistant phenotypes of MDV3100 in patients. Further characterization is warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1595. doi:10.1158/1538-7445.AM2011-1595
Abstract 1596: Human choriocarcinomas: Placental growth factor-dependent preclinical tumor models
Authors: Bagley Rebecca G. , Ren Yi , Kurtzberg Leslie , Weber William , Bangari Dinesh , Teicher Beverly A.
Published: June 2012

Choriocarcinomas are an aggressive form of cancer that develops in the uterus from tissue that would normally become the placenta. Choriocarcinomas are a trophoblastic gestational disease and the tumors are highly angiogenic. Human placental growth factor (hPlGF) is an angiogenic growth factor that promotes the growth of blood vessels in the placenta. hPlGF levels can be higher under pathological conditions such as cancer. Some human tumor specimens have higher PlGF levels than normal tissue, thus hPlGF is a target for anti-angiogenic therapy. The human choriocarcinoma cell lines BeWo, JAr, and JEG-3 were evaluated as preclinical models of hPlGF overexpression. The levels of hVEGF-A and hPlGF secreted by the choriocarcinomas and 11 human and mouse cancer cell lines in culture were measured by ELISA. The choriocarcinomas secreted higher levels of hPlGF and lower levels of hVEGF-A than 10/11 other cancer cell lines. The hPlGF serum levels in mice bearing subcutaneous choriocarcinoma tumors correlated with tumor volume and reached >2,000 pg/ml. By comparison, no hPlGF was detected in the serum of mice bearing H460 non-small lung carcinoma, HT29 colon carcinoma or MOLM-13 acute myeloid leukemia xenograft tumors. Although choriocarcinoma cells secreted both hPlGF and hVEGF-A in culture, serum levels of hVEGF-A in mice bearing choriocarcinoma xenografts were undetectable or <50 pg/ml at the time points serum was collected indicating that angiogenic factor secretion by the cells in culture was not the same in vivo. JEG-3 tumors grew faster than JAr tumors following the subcutaneous implantantion of 1×106 cells into nude mice. BeWo tumors grew the slowest and had the highest serum PlGF levels. Immunohistochemical methods confirmed expression of hPlGF in the choriocarcinoma xenografts. Studies involving double immunofluorescence on the xenograft tumors are ongoing to investigate endothelial cell and pericyte interactions and stromal involvement in the tumors. sFLT01, a novel fusion protein that neutralizes PlGF and VEGF-A, was added to choriocarcinoma cells in culture and administered to mice bearing choriocarcinoma xenografts in efficacy studies. Exposure of JAr and JEG-3 cells in culture to sFLT01 resulted in a phenotypic change whereby the cells produced less hPlGF and no significant hVEGF-A. In vivo, sFLT01 (25 mg/kg, IP injection, 2x per week) slowed tumor growth in JAr and JEG-3 tumors and increased median survival by 5-30 days compared to vehicle controls. These results indicate that human choriocarcinoma xenograft models are a valuable research tool for evaluating anti-angiogenic agents that target hPlGF.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1596. doi:10.1158/1538-7445.AM2011-1596
Abstract 1604: Development of breast cancer patient-derived xenograft models as preclinical tool for drug discovery
Authors: Rymer Isha C. , Wang Jinwei , Zhu Zhou , Schwab Richard , Wallace Anne M. , Blair Sarah L. , Greenberg Norman , Yang Wei J.
Published: June 2012

Based on gene expression profile and hormone receptor status breast cancer is usually classified into the following subtypes, luminal A, luminal B, Her2 overexpressed, basal, normal-like, and the newly identified subtype, claudin-low. For a long time sub-cutaneous and orthotopic xenograft of established human cancer cell lines have served as the primary in vivo models for drug evaluation preclinically, however their prognostic value to clinical trials has not been to our satisfaction. In an effort to overcome the limitations of traditionally used cell line models and to develop preclinical models that better represent the diversity of human breast cancer, we generated a series of human -in-mouse orthotopic xenograft models using primary tumor specimens from patients. These models are characterized in depth, including tumor histology, genomics, gene expression profiles, and chemosensitivities to standard of care compounds. They will serve as great tools to breast cancer research and discovery.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1604. doi:10.1158/1538-7445.AM2011-1604
Abstract 162: Profiling of microRNA in oral cancer cells identifying miR-10b functions in oncogenesis and up-regulates in plasma of oral cancer patients
Authors: Lu Ya-Ching , Cheng Ann-Joy
Published: June 2012

Oral cancer is the 6th leading cancer, and is still increasing with years. Since this cancer usually occurs in the middle age male, at the high peak of life responsibility, it has tremendous impact of family and society. MicorRNAs (miRNAs) are endogenous, non-coding small RNA, which consist of 21-23 nucleotides. They serve widespread functions as regulatory molecules in post-transcriptional gene silencing for the regulation of cellular bio-functions. And the dysregulation of miRNAs has been implicated in malignancy. Agilent system was used to perform miRNA profiling in 6 cancer cell lines and 5 lines of normal keratinocytes for identification of differently expressed miRNAs. There were 23 miRNAs selected as candidates which were shown more than 2-fold change with the FDR<0.1. Among these miRNAs, 19 of them were elevated and 4 were decreased in oral cancer cell lines. miR-10b was validated by qPCR analysis showed significantly up-regulated in cancer cells. Furthermore, the biological function of miR-10b was investigated after alteration of miR-10b expression. Reduction of miR-10b by antisense oligonucleotide further resulted in retard of cell migratory and invasive ability, however, no significant alterations on cell growth or chemo/radio-sensitivity. In analyzing miR-10b expression in 24 normal and 29 plasma samples from oral cancer patients, miR-10b was up-regulated 3.3 fold in the cancer patients (P<0.0001). Taken together, miR-10b plays a role in the carcinogenesis through promoting cancer cell migratory and invasive function, and plasma miR-10b may serve as a biomarker for oral cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 162. doi:10.1158/1538-7445.AM2011-162
Abstract 1622: Inhibition of the acetyltransferase p300 as a novel pro-apoptotic and anti-invasion approach for treatment of prostate cancer
Authors: Santer Frédéric R. , Höschele Philipp P.S. , Oh Su Jung , Erb Holger , Bouchal Jan , Cavarretta Ilaria T. , Meyers David J. , Cole Philip A. , Culig Zoran
Published: June 2012

Inhibitors of histone deacetylases have been approved for clinical application in cancer treatment. On the other hand, histone acetyltransferase inhibitors have not been investigated for their potential use in cancer therapy. In prostate cancer the histone acetyltransferases and coactivators p300 and CBP are upregulated and induce transcription of androgen-receptor responsive genes, even in the absence or in the presence of low levels of androgen receptor. To discover a potential anti-cancer effect of p300/CBP inhibition we used two different approaches: i) downregulation of p300 and CBP by specific siRNA and ii) chemical inhibition of the acetyltransferase activity by a newly developed small molecule. Knockdown of p300 by specific siRNA, but surprisingly not of CBP led to an increase of caspase-dependent apoptosis involving both extrinsic and intrinsic cell death pathways in androgen-dependent and castration-resistant prostate cancer cells. Induction of apoptosis was mediated by several pathways including inhibition of androgen-receptor responsive genes and decrease of expression levels of the NF-κB subunit p65 due to a higher turnover of the protein. Furthermore, cell invasion was decreased upon p300, but not CBP depletion and was accompanied by a lower MMP-9 transcription. Thus, p300 and CBP have differential roles in the processes of survival and invasion of prostate cancer cells. Induction of apoptosis in prostate cancer cells was confirmed by the use of the cell permeable small molecule inhibitor of p300/CBP′s acetyltransferase domain. Taken together, those results suggest that p300 inhibition is a promising approach for the development of new anti-cancer therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1622. doi:10.1158/1538-7445.AM2011-1622
Abstract 1630: The PKC inhibitor Sotrastaurin selectively inhibits the growth of CD79 mutant diffuse-large B-cell lymphoma
Authors: Naylor Tara , Enns Andreas , Warmuth Markus , Lenz Georg , Stegmeier Frank P.
Published: June 2012

The activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) is characterized by constitutive activation of the oncogenic NF-κB pathway and is associated with poor prognosis. Recent studies demonstrated dependence on NF-κB pathway activation and identified genetic lesions in NF-κB pathway regulators, including CARD11/CARMA1, A20/TNFAIP3, and CD79A/B. In this study, we evaluated the therapeutic potential of the selective PKC inhibitor sotrastaurin (STN) in preclinical models of DLBCL. We found that a significant fraction of ABC DLBCL cell lines exhibited strong sensitivity to sotrastaurin and detected that responsiveness can be predicted based on the molecular nature of NF-κB pathway lesions. While mutations in CD79A/B correlate with sensitivity to PKC inhibitors, mutations in CARD11 render ABC DLBCL cell lines insensitive to PKC inhibitors. The growth inhibitory effect of PKC inhibitors correlates with NF-κB pathway inhibition and is mediated by the induction of a G1 cell cycle arrest and/or apoptosis. Collectively, our study provides a strong rationale for the clinical evaluation of sotrastaurin in ABC DLBCL patients that harbor CD79 mutations, and furthermore illustrates the necessity to stratify DLBCL patients according to their genetic abnormalities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1630. doi:10.1158/1538-7445.AM2011-1630
Abstract 1632: Anti-β1 integrin antibody inhibits osteosarcoma lung seeding and metastasis
Authors: Kimura Hiroaki , Tome Yasunori , Grzesiak John , Momiyama Masashi , Hayashi Katsuhiro , Bouvet Michael , Tsuchiya Hiroyuki , Hoffman Robert M.
Published: June 2012

The efficacy of anti β1 integrin monoclonal antibody (clone AIIB2) to inhibit lung seeding and colony formation of human osteosarcoma cells was imaged in real time. To visualize cancer cell seeding and metastasis in the lung, human osteosarcoma cells were used in which green fluorescent protein (GFP) is expressed in the nucleus and RFP is expressed in the cytoplasm. 143B cells were preincubated with AIIB2 or control antibody, and then injected into the nude mice via tail vein. Twenty four hours later, the lungs were fluorescently-imaged in live mice with the lung exposed. 143B cells which arrested in the lung were counted. Two weeks after the first observation, the animals were sacrificed and the lungs were resected and fluorescently imaged to quantitate resulting lung metastatic colonies. AIIB2 significantly inhibited osteosarcoma cells seeding and colony formation in the lung. This result indicates that β1 integrin plays an important role for osteosarcoma cell adhesion to lung. To evaluate efficacy of the AIIB2 antibody on primary tumor growth and spontaneous metastases, 143B osteosarcoma cells were orthotopically transplanted in the tibia. Two weeks later, mice were treated with either 40 µg or 200 µg AIIB2, or control antibody biweekly. After three weeks treatment, primary tumors and lung metastases were evaluated. Neither 40 µg nor 200 µg of AIIB2 significantly inhibited primary tumor growth. In contrast, both doses of AIIB2 significantly inhibited spontaneous lung metastasis. AIIB2 appears to be a specific anti-metastatic agent since it inhibited lung metastasis while not inhibiting primary tumor growth. This is consistent with AIIB2 inhibition of adhesion of 143B cells to the lung. These results suggest that anti-β1 integrin antibody treatment has clinical potential as an anti-metastatic agent.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1632. doi:10.1158/1538-7445.AM2011-1632
Abstract 1633: C-terminal binding proteins are novel drug targets
Authors: Straza Michael W. , Kovi Ramesh C. , Paliwal Seema , Rajeshkumar Barur , Hilbert Brendan , Doughty Tyler , Parker Daniel , Royer William , Whalen Giles F. , Lyle Stephen , Schiffer Celia A. , Grossman Steven R.
Published: June 2012

The CtBP transcriptional corepressors have been identified as proto-oncogenes. CtBP represses pro-apoptotic genes and promotes cancer cell migration and invasion in a redox sensitive manner through a regulatory dehydrogenase domain. The CtBP dehydrogenase substrate 4-methylthio-2-oxobutyric acid (MTOB) can act as a CtBP inhibitor at high concentrations, and induces apoptosis in the human colorectal cancer cell line HCT116. MTOB induced apoptosis is dependent upon expression of the BH3 only protein BIK, a previously established CtBP target. Treatment of both native and transformed Mouse Embryonic Fibroblasts revealed a wide therapeutic index for CtBP inhibition. In human colon cancer cell peritoneal xenografts, MTOB treatment reduced tumor growth and induced apoptosis in vivo without notable toxicity. To verify the potential utility of CtBP as a therapeutic target in human cancer, the expression of CtBP and its negative regulator ARF was studied in a series of resected human colon adenocarcinomas. CtBP and ARF levels were inversely-correlated, with elevated CtBP levels (compared with adjacent normal tissue) observed in greater than 60% of specimens, with ARF absent in nearly all specimens exhibiting elevated CtBP levels. Thus, CtBP is a viable therapeutic target in human cancer. In order to identify novel CtBP inhibitors, a simple dehydrogenase assay was developed that utilizes the spectrophotometric measurement of enzymatic conversion of NADH to NAD+ by the CtBP dehydrogenase activity. This assay successfully detects MTOB substrate and inhibitor activity, as well as inhibition of CtBP activity by the related compound 4-methylthio-2-hydroxybutyric acid (MTHB). This assay will be adapted for high throughput screening of small molecule libraries for novel CtBP inhibitors that can be further characterized in pre-clinical models.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1633. doi:10.1158/1538-7445.AM2011-1633
Abstract 1638: Potent anticancer actions of the Hsp90 inhibitor STA-9090 in wild-type EGFR models of lung cancer
Authors: Acquaviva Jaime , Sang Jim , Sequeira Manuel , Smith Donald , Zhang Chaohua , Lovly Christine , Wada Yumiko , Blackman Ronald K. , Proia David A.
Published: June 2012

Non-small cell lung cancer (NSCLC) is a heterogeneous disease that can be sub-classified based on the specific alterations in oncogenes that drive it. While EGFR and KRAS are most often implicated in the molecular epidemiology of NSCLC, aberrations in several other genes have been shown to contribute to oncogenesis. These include mutation and/or amplification of MET, mutation in BRAF or chromosomal rearrangements involving ALK. Targeted therapy against these kinases has shown signs of therapeutic success; however, acquired drug resistance universally develops.

Heat Shock Protein 90 (Hsp90) is a molecular chaperone that mediates the post-translational stability of its protein substrates, many of which are validated oncogenes. Hsp90 is emerging as an important target in cancer therapy because its inactivation results in the abrogation of multiple signaling pathways simultaneously, irrespective of the mutational status of its substrate. STA-9090 is a second-generation, synthetic, small-molecule Hsp90 inhibitor that has shown potent and selective activity preclinically and is currently in Phase 2 trials in a number of indications.

We show here that in the presence of STA-9090, upregulation of the MET pathway, either through transient stimulation by its ligand, HGF, or through amplification of MET itself, is incapable of maintaining survival in EGFR-inhibitor-resistant NSCLC. To identify additional genetic lesions sensitive to Hsp90 inhibition, we screened a panel of wild-type EGFR NSCLC cell lines for viability in the presence of STA-9090. All the cell lines assayed, driven by mutations in genes such as PDGFRα, BRAF, PI3K and EML4-ALK or amplification of wild-type EGFR, were sensitive to STA-9090, with IC50 values between 10 and 150 nM. Further analysis demonstrated that STA-9090 potently destabilized the oncogenic driver for each cell line. In vivo, STA-9090 showed strong single-agent activity in xenograft models of human NSCLC carrying either a BRAF mutation or EML4-ALK fusion, in accordance with the sensitivity of these client proteins to the effects of STA-9090 action.

Inhibition of Hsp90 activity therefore presents a promising approach for combating NSCLC induced by mutations in genes other than EGFR, as well as by compensatory pathways upregulated in the context of EGFR-inhibitor resistance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1638. doi:10.1158/1538-7445.AM2011-1638
Abstract 1640: Notch pathway mediates post-treatment repopulation of lung squamous cell carcinoma cells
Authors: Day Chi-Ping , Esposito Dominic , Mahesh Cynthia R. , Merlino Glenn
Published: June 2012

Conventional adjuvant therapies, such as chemotherapy and radiotherapy, usually take intermittent schedule, allowing the recovery of the normal tissues. However, during the recovery period, tumors may resume growth to replenish the lost cells. This phenomenon, known as repopulation, is an important mechanism to mediate post-treatment recurrence. In this study, we examined murine Lewis Lung Carcinoma (LLC) with a panel of subtype markers of non-small cell lung cancer (NSCLC), and characterized it as a murine lung squamous cell carcinoma (SCC), one of the major NSCLC subtypes. To recapitulate post-treatment repopulation, LLC cells were treated with the first-line NSCLC chemotherapeutic agent, paclitaxel, at IC50 dose for 24 hours, and allowed to recover in normal culture medium. Expression of genes involved in Notch pathway and markers of airway epithelial stem cell (basal cell) in LLC cells are upregulated during the recovery phase instead of treated period. Notch pathway inhibitor, DAPT, has no significant effect on growth of LLC cells as single agent or in combination with paclitaxel. However, sequential treatment of paclitaxel for 24 hours followed by DAPT for another 24 hours delays growth of LLC cells during recovery phase, suggesting that Notch pathway mediates the post-treatment repopulation. Moreover, using different labeling markers to track cell growth, we found paclitaxel-treated LLC cells in recovery phase can stimulate the growth of healthy LLC cells in co-culture, while conditioned medium from the culture of treated cells had no significant effect. These results implied that direct contact between damaged and healthy cells is required for repopulation, thus cell-surface Notch ligand such as Jagged-1 may be involved in this mechanism. Here we suggested that treatment of Notch pathway inhibitor following chemotherapy may prevent post-treatment recurrence of lung SCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1640. doi:10.1158/1538-7445.AM2011-1640
Abstract 1651: Targeting Vav3 oncogene enhances docetaxel-induced apoptosis in LNCaP cells under chronic hypoxia
Authors: Nomura Takeo , Hirai Kenichi , Yamasaki Mutsushi , Sato Fuminori , Mimata Hiromitsu
Published: June 2012

Introduction and Objective: We previously reported that chronic hypoxic condition (1% oxygen for over six months) induced Vav3 oncogene expression with androgen-independent growth and malignant behavior in LNCaP cells. And overexpression of Vav3 oncogene promoted the growth of LNCaP cells with increased invasion and migration under normoxic condition. The objective of this study was to examine the effect of Vav3 siRNA on cell proliferation and apoptosis in docetaxel-treated LNCaP cells under chronic hypoxic condition.

Methods: We analyzed the sensitivity of docetaxel in LNCaP cells under normoxic and chronic hypoxic conditions by 2-(4-lodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-1) and flow cytometric analyses. The effects of Vav3 siRNA on cell growth and apoptosis were examined under chronic hypoxia with or without docetaxel treatment. To seek a molecular understanding of Vav3 siRNA induced apoptosis, we analyzed alterations in the growth signaling components in the PI3K/Akt and ERK mediated pathways by immunoblot analysis.

Results: Overexpression of Vav3 was observed in LNCaP cells under chronic hypoxia compared with its expression under normoxia. Although the growth rates were reduced in a dose- and time-dependent manner by docetaxel in LNCaP cells under both normoxic and chronic hypoxic conditions, these effects were significantly decreased in LNCaP cells under chronic hypoxia. In addition, we found that docetaxel induced apoptosis following activation of caspase-3 and cleaved poly (ADP-ribose) polymerase, and that the interrupting the Vav3 signaling pathway using siRNA enhanced docetaxel sensitivity of LNCaP cells under chronic hypoxia and led to apoptosis. A profound activation of PI3K/Akt pathway was observed under chronic hypoxic condition. Treatment with Vav3 siRNA showed weak inhibition of Akt phosphorylation and treatment with Vav3 siRNA plus docetaxel strongly inhibited this signaling.

Conclusions: Our results showed that Vav3 siRNA enhances docetaxel-induced apoptosis in LNCaP cells under chronic hypoxia and that targeting Vav3 oncogene may have important practical implications for managing hormone refractory prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1651. doi:10.1158/1538-7445.AM2011-1651
Abstract 1661: Knockdown of Nrf2 in cancer cells suppresses tumor growth: implication for the inhibitory role in HIF-1α and ErbB2 signaling
Authors: Kwak Mi-Kyoung , Hur Eu-gene , Kim Tae-Hyoung , Manandhar Sarala , Choi Bo-Hyun , Ryu In-geun
Published: June 2012

Nuclear factor-erythroid 2 (Nrf2) is the transcription factor regulating multiple antioxidant proteins and phase 2 detoxifying enzymes, and plays a crucial role in the cytoprotection against oxidative stress-associated damages. However, a potential role of Nrf2 in cancer biology has been emerged recently. In our mouse xenografts study, a stable knockdown of Nrf2 in cancer cells from the colon (HCT116 and HT29) and ovary (SKOV-3) strongly suppressed tumor growth. As an underlying mechanism, it was observed that a vessel formation and vascular endothelial growth factor (VEGF) expression were suppressed in Nrf2-inhibited colon cancer tumors. Suppressive effect of Nrf2 knockdown on angiogenesis was further evidenced by the chicken embryo chorioallantoic membrane assay and endothelial tube formation assay. The subsequent mechanism studies revealed that Nrf2-inhibited HT29 cells failed to accumulate HIF-1α protein under 1% O2 hypoxia, resulting in the limitation of the expression of HIF-1α target genes for angiogenesis. Whereas, a tumor growth suppression shown in SKOV-2 cells was associated with repressed expression of ErbB2 and the consequent increase in p27. Further experimental demonstrations showed that the expression of ErbB2 is inversely related with Nrf2 in other types of cancer cell lines; therefore, the cell growth is attenuated in these Nrf2-inhibited cancer cells. Taken together, our current study suggests that a stable Nrf2 inhibition in cancer cells suppresses tumor growth through the alterations in HIF-1α and ErbB2 signaling. Hence, Nrf2 may be a promising target to control cancer cell growth and chemoresistance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1661. doi:10.1158/1538-7445.AM2011-1661