bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 487: Invasion characteristics of tumor cells in a glioblastoma model of genetically modified neural stem cells
Authors: Sampetrean Oltea , Saga Isako , Osuka Satoru , Saya Hideyuki
Published: August 2012

Background: Although several types of cells in the brain are able to migrate during development or even in adulthood, only cells of high grade malignancies exhibit an invasive phenotype. The present study aims to characterize the differences between infiltrating tumor cells and their cells of origin using a model of genetically-induced glioblastoma-initiating cells (GICs) in the syngeneic mouse adult brain. Methods: Neural stem cells/ multipotent progenitor cells (NSCs/NPCs) were isolated from the subventricular zone of adult C57BL/6 mice with a homozygous deletion of the Ink4a/ARF locus and cultured as neurospheres. GICs were established by overexpression of H-RasV12 in the NSCs/NPCs. Tumor cells were isolated from the tumors formed by orthotopic implantation of the GICs into 6-week-old wild type mice and propagated as tumorspheres (TS). The motility of each type of cells and their response to various chemoattractants was assessed using in vitro migration assays. Their preference for anatomical structures and their ability to infiltrate the surrounding normal brain was analyzed by tracking the cells in cultured coronal brain slices established from stereotactically-implanted mice. Results: In vitro, both tumor cells and NSCs exhibited a similar degree of motility, but consistently varied in their response to a panel of chemoattractants. Compared to NSCs, GICs and TS responded only slightly to single growth factors or cytokines, but showed significant responses to combinations of chemoattractants. The most marked increase in migration was triggered by the supernatant of cultured tumor cells. Supernatants obtained from GICs, TS or human glioma cell lines induced migration to a similar degree. Timelapse microscopy confirmed motility of both normal and tumor cells, with all three groups being able to move both within the cortex and within the striatum, and both along blood vessels and fiber tracts. However, NSCs/NPCs did not leave the injection site as single cells, while GICs and TS entered and infiltrated the normal brain as solitary cells. This pattern of migration was greatly reduced by the administration of epithelial-to-mesenchymal transition (EMT) inhibitors, both in vitro and in vivo. Conclusion: Our results show that tumor invasion is multifactorial, with both autocrine secretion of several factors, as well as a mesenchymal phenotype being key regulators. Moreover, the mesenchymal phenotype in itself is a targetable attribute and should be assessed in patient samples in order to adjust anti-invasive therapy when warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 487. doi:1538-7445.AM2012-487
Abstract 4874: Small molecule inhibitor of ezrin inhibits metastasis in a transgenic mouse model of osteosarcoma
Authors: Murdoch Jared T. , Hong Sung-Hyeok , Bulut Gulay , Kosturko George W. , Drebing Lauren E. , Toretsky Jeffrey A. , Uren Aykut
Published: August 2012

Osteosarcoma is the predominant primary bone cancer in children with a low survival rate due to pulmonary metastasis. Research on the molecular mechanism driving pulmonary metastasis implicates the cytoskeletal protein ezrin as the critical component of the disease pathology. Ezrin links the actin cytoskeleton to the plasma membrane proteins, and its overexpression is associated with poor survival in patients and increased invasion in osteosarcoma cell lines. We used surface plasmon resonance technology to screen small molecule libraries for compounds directly binding to ezrin. Two molecules, NSC305787 and NSC668394, were chosen based on their ezrin binding affinities and ability to inhibit ezrin in multiple functional, biochemical, cellular, and in vivo assays. To test the anti-metastatic activity of these molecules in vivo, we utilized a tissue-specific transgenic mouse model expressing Cre recombinase to excise the Retinoblastoma (Rb) and p53 tumor suppressor genes in osteoblast progenitor cells. These animals develop spontaneous osteosarcoma with 100% penetrance and high frequency of liver and lung metastases, mimicking human disease. We tested the anti-metastatic potential of ezrin inhibitors that we discovered, NSC305787 and NSC668394, in this clinically relevant mouse model. We started the treatment on one group of animals at 2 months of age before any detectable tumor is present and on a second group of animals only after detection of smallest palpable tumor. Animals in each group were randomly assigned to one of three treatment options: DMSO (Control), NSC305787, or NSC668394. Animals were observed for primary tumor growth and metastasis formation. All animals were euthanized when primary tumor volume reached 2.0cm3, when animals had severe cachexia, or when animals showed signs of pulmonary insufficiency. Mice treated with NSC305787 and NSC668394 did not show any changes in the growth of their primary tumors and experienced similar survival times. However, our results suggest that NSC305787 inhibits osteosarcoma metastasis to lungs as confirmed by histopathological analysis. Therefore, when combined with adjuvant chemotherapy and surgical resection of the primary tumor, targeting ezrin with small molecules may yield a positive outcome and greater survival in a clinical setting.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4874. doi:1538-7445.AM2012-4874
Abstract 4881: Induction of Bim by the BRAF inhibitor PLX4720 sensitizes human melanoma cells to the BH3 mimetic ABT-737
Authors: Wroblewski David , Zhang Xu Dong , Hersey Peter
Published: August 2012

Once melanoma has metastasized to distant sites it has proved difficult to treat by a variety of chemotherapeutic and biological agents. Significant advances have been made in identifying subgroups of patients with activating mutations in signalling pathway proteins. In particular, the finding that approximately 50% of melanoma have V600E mutations in the BRAF serine/threonine kinase has resulted in the generation of a number of new drugs which target the mutated active form of BRAF. One of these drugs, Vemurafenib (PLX4032/RG704) has shown significant promise in prolonging survival compared to standard chemotherapy, however reports of patient relapse has prompted investigation into means of overcoming acquired resistance to the agent. We report here that efficacy of the PLX4032 analogue, PLX4720, is greatly enhanced by co-treatment with the BH3 mimetic, ABT-737. Treatment with either agent is able to induce apoptosis in melanoma cells, however the kinetics are typically slow, with cell death occurring 48 or 72 hours post treatment. In this study, while either agent was largely ineffective as a single treatment 24 hours following treatment, addition of the combination of drugs rapidly induced significant killing. We show that apoptosis was caspase-dependent, in that inhibition of caspase activation almost totally blocked induction of cell death by the combination of agents. Apoptosis was also associated with activation of the intrinsic apoptotic pathway, with reduction of mitochondrial membrane potential and activation of caspase-9. Exposure of melanoma cells to PLX4720 rapidly decreased phosphorylation of the pro-apoptotic BH3-only protein Bim, resulting in strong upregulation as early as 6 hours after addition of the compound. Strong upregulation of Bim was shown by RNAi knockdown to play an important role in sensitizing cells to co-treatment with ABT-737, by assisting in the inhibition of anti-apoptotic Bcl-2 family proteins. Further, the combination of agents induced significant levels of apoptosis in melanoma cells derived from patients harbouring the BRAFV600E mutation. Collectively, these results show that the BRAF inhibitor PLX4720 sensitizes melanoma cells to apoptosis by the BH3 mimetic ABT-737 in a Bim- and caspase-dependent manner. Additionally, these studies identify a potential clinical application for BH3 mimetics in overcoming resistance of melanoma to treatment with BRAF inhibitors, increasing efficacy of this class of agent and improving patient outcomes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4881. doi:1538-7445.AM2012-4881
Abstract 4883: YM155 potentiates chemosensitivity to gemcitabine in human pancreatic cancer cell line, MiaPaCa-2
Authors: Jung Kyungah , Yoon Dokhyun , Shin Jaesik , Kim Taewon
Published: August 2012

Pancreatic cancer is a highly aggressive malignancy with a median overall survival of less than 1 year. Although gemcitabine is a standard chemotherapeutic agent, response rates range only from 20% to 40% and ultimately all patients acquire resistance to the chemotherapy. In this study, we evaluated the potential efficacy of YM155, a selective survivin suppressant, in pancreatic cancer cell line, MiaPaCa-2 showing resistance to gemcitabine. YM155 inhibited the expression of survivin in the pancreatic cancer cell line and gemcitabine upregulated survivin on the contrary. However, YM155 enhanced chemosensitivity to gemcitabine resulting in apoptotic cell death, which accompanied a decrease in survivin expression. Knockdown of endogenous survivin via RNA interference also enhanced sensitivity to gemcitabine. In addition, YM155 potentiated the anti-tumor effect of gemcitabine in the xenograft tumors of MiaPaCa-2. While gemcitabine induced cell cycle arrest at S-phase, co-treatment of YM155 bypassed the cell cycle arrest resulting in apoptotic cell death. Therefore, our results suggest that YM155 potentiates chemosensitivity to gemcitabine in pancreatic cancer cells through suppression of survivin, which is induced by gemcitabine. Combination of gemcitabine and YM155 might be a potential therapeutic strategy for the treatment of pancreatic cancer to be explored in clinical investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4883. doi:1538-7445.AM2012-4883
Abstract 4884: The oncogenic phosphatase PPM1D confers cisplatin resistance in ovarian carcinoma cells by attenuating checkpoint kinase 1 and p53 activation
Authors: Ali Ahmed Y. , Abedini Mohammad R. , Tsang Benjamin K.
Published: August 2012

Cisplatin (CDDP: cis-diamminedichloroplatinum) resistance is a major hurdle in the treatment of human ovarian cancer (OVCA). A better understanding of the mechanisms of CDDP resistance can greatly improve therapeutic outcome for patients. p53, a determinant of CDDP sensitivity in ovarian cancer, is activated by Chk1 in response to DNA damage. Although the oncogenic phosphatase Protein Phosphatase Magnesium-dependent 1 (PPM1D) can deactivate both p53 and Chk1 through site-specific dephosphorylation, whether PPM1D plays a role in CDDP resistance is unknown. Here, using pair-matched wt-p53 CDDP-sensitive (OV2008) and -resistant (C13*) cells, and p53-compromised CDDP-resistant cells (A2780cp, OCC-1, OVCAR-3, and SKOV3), we have demonstrated (i) the existence of site-specific differences in phospho-Ser-Checkpoint kinase 1 (Chk1) content between sensitive and resistant cells in response to CDDP; (ii) PPM1D, but not phosphoinositide-3-kinase-related kinase (ATR), is important in the regulation of CDDP-induced Chk1 activation and ovarian cancer cell chemosensitivity; (iii) PPM1D down-regulation sensitizes resistant cells to CDDP primarily by activating Chk1 and p53. Our findings establish for the first time that PPM1D confers CDDP resistance in ovarian cancer cells through attenuating CDDP-induced, Chk1-mediated, p53-dependent apoptosis. These findings extend the current knowledge on the molecular and cellular basis of cisplatin resistance and offer the rationale for PPMID as a potential target for treatment of chemoresistant ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4884. doi:1538-7445.AM2012-4884
Abstract 4887: Curcuminoid CLEFMA induces autophagy-associated apoptosis in lung cancer
Authors: Sahoo Kaustuv K. , Yadav Vivek R. , Awasthi Vibhudutta
Published: August 2012

CLEFMA (4-[3,5-bis(2-chlorobenzylidene-4-oxo-piperidine-1-yl)-4-oxo-2-butenoic acid) is a novel curcuminoid discovered in our laboratory. Earlier we showed that CLEFMA induces oxidative stress-dependent cell death in lung adenocarcinoma H441 cells. Although apoptosis is the desired mechanism for chemotherapy-induced cell death, the associated pathways are often defective in lung cancers resulting in high levels of chemoresistance. Therefore, drugs that induce alternate modes of cell death, such as autophagy, may be beneficial. Drug-induced hyperinduction of autophagy is classified as type 2 programmed cell death. In most circumstances, autophagy parallels apoptosis, and such composite cell death is described as “autophagy-associated apoptosis”. Whether autophagy plays a synergistic or antagonistic role in overall cell death response to anticancer drugs is an important focus in cancer research. In this study, we have investigated the interaction between autophagy and apoptosis in CLEFMA mediated cell death. Methods: The human non-small cell lung carcinoma (H441) cell line was treated with CLEFMA (10 µM) and the molecular mechanisms of cell death were investigated. Growth inhibition was assessed by MTT or hexosaminidase assay. Apoptosis was measured by flow cytometry of annexin V-stained cells, RT-PCR and immunoblotting for apoptosis-related biomarkers. Induction of autophagy was established by electron microscopy and immunobloting for LC3B, ATG, beclin1, AKT and mTOR. Autophagy was inhibited by 3-methyladenine (3-MA 1 mM) as well as chloroquine and E64D+pepstatin combination. The tumor suppressive efficacy of CLEFMA was demonstrated in H441 xenograft mice intraperitoneally receiving 0, 5 and 10 µg/day of CLEFMA for 32 days. The mice were imaged for F-18-fluorodeoxyglucose uptake in tumor tissue. Results: CLEFMA suppressed the viability of H441 cell line in a dose-dependent manner (IC50 = 6.25 µM). It induced cell cycle arrest at G2/M phase with accompanying accumulation of p21 protein. Caspase 3/7 immunoblotting and annexin V flow cytometry confirmed the induction of apoptosis. At the same time, we observed induction of LC3BII and suppression of AKT/mTOR phosphorylation. The suppression of autophagy significantly increased CLEFMA-induced cell death and increased caspase cleavage. In the xenograft model, 5 and 10 µg CLEFMA significantly reduced the tumor volume by 72% and 96.2%, respectively; the tumor uptake of F-18-fluorodeoxyglucose was also reduced. Conclusions: We demonstrate the efficacy of CLEFMA as a potent tumor suppressive agent. The mechanistic results suggest that autophagy is a survival mechanism in CLEFMA-treated lung cancer cells and it antagonizes apoptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4887. doi:1538-7445.AM2012-4887
Abstract 4904: Acetaminophen enhances the chemotherapeutic effect of cisplatin and paclitaxel on human ovarian carcinoma cells in vitro
Authors: Wu Jeffrey J. , Neuwelt Alexander J. , Muldoon Leslie L. , Neuwelt Edward A.
Published: August 2012

Chemoresistance is commonly found in treating cancer patients. Acetaminophen enhances the cytotoxicity of cisplatin in human liver cancer cells by depleting glutathione and increasing production of toxic metabolites in vitro. The objective of this study was to investigate potential molecular mechanisms for chemoenhancement in non-hepatic cells. Human ovarian carcinoma SKOV3 cells were treated with cisplatin or paclitaxel with or without acetaminophen in vitro. Cellular mitochondrial membrane potential and reactive oxygen species concentration was measured by using JC-1 and DHR123 stain, respectively. Cellular platinum level was analyzed using ICP-MS. Apoptosis and signaling pathways were examined by immunoblotting and immunohistochemical analyses. A 2 h incubation with acetaminophen (10 mM) decreased cellular glutathione levels and increased mitochondrial membrane potential without affecting reactive oxygen species. Overnight acetaminophen treatment increased reactive oxygen species and enhanced both cisplatin- and paclitaxel-induced apoptosis. In contrast, the combination of acetaminophen with cisplatin but not paclitaxel blocked nuclear translocation of nrf2, a transcription factor that has been implicated in regulation of the antioxidant response. Pretreatment with acetaminophen for 2 h did not affect cellular platinum uptake when compared to cisplatin alone. Regardless of different oxidative stress pathways involved between cisplatin and paclitaxel, the addition of acetaminophen enhanced the cytotoxic effects of both chemotherapeutic drugs in human ovarian carcinoma cells. Our results suggest that acetaminophen could be used as a chemoenhancing adjuvant for conventional chemotherapy drugs in treating ovarian and other malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4904. doi:1538-7445.AM2012-4904
Abstract 4905: The BH3 mimetic navitoclax (ABT-263) selectively induces apoptosis in cholangiocarcinoma-associated fibroblasts thereby reducing tumor growth
Authors: Mertens Joachim C. , Fingas Christian D. , Christensen John D. , Kakisaka Keisuke , Smoot Rory L. , Bronk Steven F. , Mott Justin L. , Gustafson Michael P. , Dietz Allan B. , Roberts Lewis R. , Sirica Alphonse E. , Gores Gregory J.
Published: August 2012

Background and Aims: Cholangiocarcinomas (CCA) are highly desmoplastic tumors containing abundant cancer associated myofibroblasts (CAF). An inverse association between the abundance of CAF and survival has been demonstrated in CCA, suggesting that CAF play a pivotal role in CCA development and progression. The CAF phenotype represents an ‘activated cell state’ and as such may be uniquely susceptible to apoptosis. BH3 mimetics induce apoptosis in cells ‘primed’ for cell death, representing a therapeutic strategy for cancer. Herein we examine whether CAF display a selective sensitivity to the BH3 mimetic ABT-263 and whether ABT-263 induced ablation of CAF reduces tumor growth and progression. Methods: We employed human and rat CAF, myofibroblastic human LX2 cells, human and rat control fibroblasts, the rat cholangiocarcinoma cell line BDEneu and human CCA cell lines for these studies. In-vivo experiments were conducted using a syngeneic, orthotopic rat CCA model. Results: We observed a significant and dose dependent induction of apoptosis by ABT-263 in human and rat primary CAF as well as activated LX2 cells as compared to rat BDEneu and human CCA cell lines. Comparison of Bcl-2 protein expression in quiescent fibroblasts versus CAF demonstrated a consistent upregulation of Bax in the CAF, likely explaining their enhanced sensitivity to pro-death stimuli. Indeed, ABT-263 treatment of CAF was associated with Bax activation as compared to human CCA cell lines. Finally, administration of ABT-263 decreased tumor size and metastasis in a human-like in-vivo rat model of CCA. Analysis of the rat tumors revealed a decrease in Tenascin C positive tumor stroma and an increase of TUNEL-positive apoptotic stromal cells. Conclusions: CCA associated CAF appear to be ‘primed’ for cell death, possibly due to overexpression of the pro-apoptotic Bcl-2 protein Bax. Consequently CAF display increased sensitivity to the BH3 mimetic ABT-263, which selectively depletes them from a rat in-vivo model of CCA, thereby reducing tumor growth and metastasis. Thus targeting CCA tumor stroma by inducing apoptosis in CAF may represent a new therapeutic approach in human CCA.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4905. doi:1538-7445.AM2012-4905
Abstract 4972: Phosphorylation of caspase-3 and caspase-7 by p21-activated protein kinase (PAK)2 inhibits chemotherapeutic drug-induced apoptosis of breast cancer cell lines
Authors: Li Xiang , Zhu Feng , Bode Ann M. , Dong Ziming , Dong Zigang
Published: August 2012

P21-activated kinase (PAK)2, a member of PAK family of serine/threonine protein kinases, plays an important role in physiological processes such as motility, survival, mitosis, and apoptosis. However, the role of PAK2 in chemotherapy resistance remains unclear. Here we report that PAK2 is highly expressed in human breast cancer cell lines and human breast invasive carcinoma tissue compared with human non-tumorigenic mammary epithelial cell lines and adjacent normal breast tissue respectively. Interestingly, we found that PAK2 can phosphorylate caspase-3 at Thr77, Thr152 and Thr245. Moreover, PAK2 can bind with caspase-7 and phosphorylate caspase-7 at Ser30, Thr173 and Ser239. Functionally, the phosphorylation of caspase-3 and caspase-7 decreases their activity, thereby inhibiting staurosporine and doxorubicin HCl-induced cellular apoptosis. Our data indicate that highly expressed PAK2 mediates chemotherapy resistance in human breast invasive ductal carcinoma by negatively regulating caspase-3 and caspase-7 activity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4972. doi:1538-7445.AM2012-4972
Abstract 4975: Api6/AIM/SPα/CD5L overexpression in alveolar type II epithelial cells induces spontaneous lung adenocarcinoma
Authors: Du Hong , Li Yuan , Qu Peng , Wu Lingyan , Li Beilin , Yan Cong
Published: August 2012

Chronic inflammation is an important contributor to the development of lung cancers, one of the most common malignancies worldwide, but the underlying molecular mechanisms of inflammation that specifically cue cancer risk remains poorly understood. We have previously found that blocking neutral lipid metabolism in lysosomal acid lipase knock-out mice (lal-/-) leads to severe tissue inflammation and diseases in multiple organs, including the lung. In an effort to identify downstream target genes of LAL to promote lung inflammation, Affymetrix GeneChip microarray analysis were performed and identified apoptosis inhibitor 6 (Api6, AIM, Sp-alpha, CD5L) as one of top increased expression gene (70 folds in the lal-/- lung). This aberrant up-regulation of Api6 occurs primarily in alveolar type II (AT II) epithelial cells of lal-/- mice and this up-regulation of Api6 can be reduced by treatment of ligands for peroxisome proliferator-activated receptor gamma (PPARgamma) in lal-/- mice. To determine the functional role of Api6 in AT II epithelial cells, an epithelial-specific CCSP-rtTA/(TetO)7-CMV-Api6 bitransgenic mouse model has been generated. Here we report that Api6 is a pro-inflammatory and oncogenic molecule. Api6 overexpression inhibited apoptosis and activated oncogenic signaling in AT II lung epithelial cells, inducing emphysema and adenocarcinoma. Additionally, Api6 overexpression in AT II cells increased the concentrations of pro-inflammatory cytokines/chemokines in bronchoalveolar lavage fluid and serum, which promote expansion of myeloid derived suppressor cells (MDSCs) in the lung and blood but not in bone marrow or spleen. Lung MDSCs suppressed T cell proliferation and activity in vitro and reduced levels of T cells in vivo following doxycycline treatment to activate Api6. Together, our findings establish that Api6 promotes lung tumorigenesis by blocking a mechanism of epithelial apoptosis that would normally support immunosurveillance. In humans, expression of the Api6 gene is up-regulated in chronic obstructive pulmonary disease (COPD, the major phenotype is emphysema) and lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4975. doi:1538-7445.AM2012-4975
Abstract 498: Anti-invasive potential of alginate microcapsule encapsulating TIMP 2-engineered cells against malignant glioma cells
Authors: Jung Shin , Jung Young-il , Jang Woo-Youl , Jung Tae-Young , Moon Kyung-Sub , Kim In-Young
Published: August 2012

Objectives. 293T was genetically modified to secrete tissue inhibitor of metalloproteinase-2 (TIMP-2) (abbreviated as 293TIMP2 cells) and 293TIMP2 cells were encapsulated into alginate microcapsules to produce TIMP-2 protien continuously. Since TIMP-2 is known to inhibit matrix metalloproteinase-2 (MMP-2) expression of tumor cells, it could be inhibit invasion of tumor cells through extracellular matrix. The anti-invasive potential of the microcapsules was studied in vitro against U87MG glioma cells. Experimental. The TIMP-2 gene was transfected to 293T cells and the genetically engineered 293TIMP2 cells were encapsulted into alginate microcapsules. The released TIMP-2 protein was examined with Western blot analysis and the anti-invasive potential against U86MG glioma cells was tested with gelatin zymography for matrix metalloproteinase-2 (MMP-2) and a Matrigel assay for invasion. Results. Cell viability within the alginate microcapsules was properly maintained at a cell density of 5×106 cell density. Since polycationic polymers are helpful to maintain mechanical strength of microcapsules with good cell viability, alginate microcapsules were reinforced with chitosan (0.1 % wt/vol). Expression of TIMP-2 protein in cell lysate and the secreted TIMP-2 into conditioned media were confirmed with Western blot analysis. Alginate microcapsules encapsulating 293TIMP2 cells properly released TIMP-2 protein into the medium and the released TIMP-2 protein was effective in inhibiting MMP-2 expression and invasion of U87MG glioma cells. Conclusion. These results indicated that alginate microcapsules encapsulating 293TIMP2 cells are superior candidates for anti-invasive therapy of glioma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 498. doi:1538-7445.AM2012-498
Abstract 4986: Nuclear PRAS40 regulates the cellular response to nucleolar stress
Authors: Havel Jonathan Joseph , Li Zenggang , Fu Haian
Published: August 2012

The Proline-rich Akt Substrate of 40kDA (PRAS40) has recently been identified as a binding partner and inhibitor of the mammalian Target of Rapamycin Complex 1 (mTORC1), a growth factor- and nutrient-sensitive kinase whose activity promotes protein synthesis and cell growth. Despite its inhibitory effect on mTORC1, PRAS40 has been shown to promote cell survival in rodent models of spinal cord injury and tumorigenesis. Importantly, PRAS40 levels have also been found to correlate with poor prognosis in lung cancer patients, an effect not readily explained by mTORC1 inhibition. Here we demonstrate that in addition to its known cytoplasmic role in inhibiting mTORC1, PRAS40 also actively shuttles to the nucleus, where it congregates at the periphery of nucleoli and exists in a high-molecular weight complex void of mTORC1 components. Through immunoprecipitation and mass spectrometry analyses we have begun to identify members of this nuclear PRAS40 complex. Furthermore, we demonstrate that PRAS40 overexpression attenuates Actinomycin D-mediated induction of nucleolar stress markers. These findings may help to explain the apparent pro-tumorigenic effects of PRAS40 and identify the PRAS40 nuclear complex as a potential target for anti-cancer drug discovery.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4986. doi:1538-7445.AM2012-4986
Abstract 499: NFATc1 is a novel invasion promoter in colorectal cancer
Authors: Tripathi Manish K. , Mima Shinji , Freeman Tanner J. , Weaver Connie , Deane Natasha G. , Zhang Bing , Beauchamp R. Daniel
Published: August 2012

Colorectal carcinoma is the third leading cause of cancer-related death in the United States. In order to understand the mechanism/signaling pathways responsible for invasion, migration and metastasis in colorectal cancer, our lab successfully modeled human cancer invasion/metastasis using mouse colon cancer cells. We have developed an integrative and comparative computational approach to reveal transcriptional regulatory mechanisms underlying colon cancer progression. Applying this approach to fourteen human colorectal cancer (CRC) microarray data sets and to one microarray dataset from an immunocompetent mouse model of metastasis, we identified known and novel transcriptional regulators in CRC. Among these transcriptional regulators, the Nuclear Factor of Activated T cells (NFAT) family of transcription factors play a central role in inducible gene transcription in various signaling pathways including regulation of cell differentiation, development, adaption, immune system response, inflammation, adipocyte metabolism, and lipolysis, and carcinogenesis. We found that an NFAT-driven transcriptional program significantly correlates with disease-free survival in multiple CRC Stage II patients. Using quantitative real time RT-PCR, we validated high NFATc1 expression in a subgroup of stage II colorectal cancer patients and differential expression of predicted NFATc1 targets in the same patients. The tumor-associated NFATc1 co-regulated gene signature was associated with worse clinical survival outcomes in stage II colorectal cancer patients. In comparison with parental MC38 mouse colon cancer cells, NFATc1 expression is increased in MC38met cells selected for invasive and metastatic ability, RNAi-based inhibition of NFATc1 expression in the MC38met cells resulted in decreased invasiveness in a transendothelial invasion model. Our studies suggest a role for NFATc1 as a tumor promoting transcription factor that contributes to invasion in colon cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 499. doi:1538-7445.AM2012-499
Abstract 5: Frequency of FGFR2 gene amplification in gastric cancer
Authors: Matsumoto Kazuko , Arao Tokuzo , Hamaguchi Tetsuya , Shimada Yasuhiro , Kato Ken , Oda Ichiro , Taniguchi Hirokazu , Koizumi Fumiaki , Yanagihara Kazuyoshi , Sasaki Hiroki , Yamada Yasuhide , Nishio Kazuto
Published: August 2012

Background: FGFR2 amplification confers hypersensitivity to FGFR inhibitor in gastric cancer cell lines. However, the frequency of FGFR2 amplification, its clinicopathological features, and the results of high throughput screening assays in a large cohort of gastric clinical samples remain largely unclear. Patients and methods: The expression levels of FGFR2 mRNA and proteins, the drug sensitivity to an FGFR inhibitor, and the genomic copy numbers of FGFR1-4 were evaluated in gastric cancer cell lines. The gene amplification of the FGFRs in formalin-fixed, paraffin-embedded (FFPE) gastric cancer tissues was determined by a real-time PCR-based copy number assay. For confirming the results, fluorescence in situ hybridization (FISH) was conducted. Results: All of the four gastric cancer cell lines with FGFR2 amplification were sensitive to an FGFR inhibitor. The above copy number assay and FISH analysis revealed that 4.1% (11/267) of the gastric cancers harbored FGFR2 amplification (intestinal type, n=2; diffuse type, n=8 and unclassified type, n=1). No amplification of the three other family members was detected. A FISH analysis showed that six of these seven cases were highly amplified, while the remaining one had a relatively low grade of amplification. Although the difference was not significant, patients with FGFR2 amplification tended to exhibit a shorter overall survival period. Conclusions: FGFR2 amplification was observed in 4.1% of gastric cancers and our established PCR-based copy number assay could be a powerful tool for detecting FGFR2 amplification using FFPE samples. Our results strongly encourage the development of FGFR-targeted therapy for gastric cancers with FGFR2 amplification.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5. doi:1538-7445.AM2012-5
Abstract 5018: Genetic and epigenetic investigation of breast carcinoma arising in Lynch syndrome families
Authors: Lotsari Johanna E. , Gylling Annette , Abdel-Rahman Wael M. , Friman Marjukka , Aarnio Markku , Jarvinen Heikki J. , Mecklin Jukka-Pekka , Kuopio Teijo , Peltomaki Paivi
Published: August 2012

Breast carcinoma is the most common cancer type in females, but its incidence is generally not increased in Lynch syndrome (LS). Deficient DNA mismatch repair (MMR) is a hallmark of LS tumors that are unequivocal manifestations of the syndrome (e.g., colorectal and breast carcinoma). Because of controversial study results, it is unclear at present whether or not breast carcinoma is specifically associated with LS. We addressed this question by determining the genetic and epigenetic profiles for all available breast carcinomas from LS families from a nation-wide registry, including 24 tumors from MMR gene mutation carriers and 17 tumors from non-carriers. The average age at breast carcinoma diagnosis was similar in mutation carriers and non-carriers (56 years for each). Among breast carcinomas from mutation carriers, 43% showed loss of MMR protein corresponding to the germline mutation, and high-degree microsatellite instability (MSI-H) was present in 36%. Moreover, in mutation carriers, the age at diagnosis was lower for breast carcinomas that were MMR-deficient (by absent MMR protein and/or MSI present) compared to MMR proficient tumors (51 vs. 60 years, p= 0.031). Breast carcinomas showed frequent inactivation of tumor suppressor genes (TSG) by promoter methylation. The average number of methylated TSGs out of 24 per tumor was 3.1 for mutation carriers and 2.8 for non-carriers. The gene-specific distribution of methylation was also similar between the two breast tumor sets. In mutation carriers, the most frequently methylated TSGs were RASSF1 (77%), APC (45%), CDH13 (45%), GSTP1 (32%) and CDKN2B (27%). In non-carriers, the respective frequencies were 75%, 47%, 59%, 35%, and 29%. When compared to tumors arising in other organs from LS mutation carriers, methylation of CDKN2B was seen as a particular characteristic of breast tumorigenesis. Our investigation shows that TSG promoter methylation is a common characteristic of breast carcinomas arising in LS and affects mutation carriers and non-carriers with comparable overall rates and gene-specific distributions. Analysis of MMR protein expression and MSI revealed that while many breast carcinomas from LS mutation carriers follow MMR-driven tumorigenesis characteristic of tumors of the LS spectrum in general, a significant subset of breast tumors also exists that appears to arise and progress along separate pathways.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5018. doi:1538-7445.AM2012-5018
Abstract 502: Schwann cells promote tumor cell invasion through regulation of the laminin receptorA6B1
Authors: Chopra Harsharon , Riquer Zyanya P. Espinosa , Cress Anne E. , Sroka Isis C.
Published: August 2012

Tumor cell migration and invasion of nerves, a process known as perineural nerve invasion (PNI), is a major metastatic route for neurotropic cancers including prostate and pancreatic cancer. The laminin family of extracellular matrix glycoproteins derived from myelinating Schwann cells coat nerve axons and play a prominent role in the development and maintenance of the peripheral nervous system. Tumor cells undergoing PNI utilize the laminin rich nerves as they migrate and invade during metastasis. Evidence has shown that the A6B1 laminin receptor promotes tumor cell migration and invasion following cleavage of the receptor to form the variant A6pB1 by the serine protease urokinase plasminogen activator (uPA). Here we demonstrate Schwann cell regulation of A6pB1 formation on prostate and pancreatic tumor cell lines. Conditioned medium from the S16 and S16Y cell lines, which are immortalized Schwann cells of the myelinating and non-myelinating phenotype, respectively was provided to the prostate and pancreatic tumor cell lines. It was observed that S16Y conditioned medium inhibited A6 conversion to A6p while the myelinating S16 cells increased cleavage of the receptor in DU-145, CF-PAC1 and PC-3 cancer cells. This effect was reversible as replenishing standard media conditions following a 24 hour treatment with S16 or S16Y media brought integrin cleavage levels back to steady state levels by 24 hours. Further, conditioned medium from S16 cells significantly increased pancreatic tumor cell invasion while S16Y conditioned medium decreased invasion in a modified Boyden chamber Matrigel assay. The increased invasion mediated by myelinating Schwann cells was dependent on A6 since a function blocking antibody targeting A6 inhibited invasion. Taken together these results suggest that myelinating Schwann cells (S16Y) in the pancreatic and prostatic nerve environment promote A6B1 and A6pB1 receptor dependent tumor cell invasion during PNI. (Supported in part by NIH CA23074 and CA159406 and HHMI Grant 52005889)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 502. doi:1538-7445.AM2012-502
Abstract 5027: MicroRNA profiling of diagnostic fine needle aspirates of pancreatic cancer preserved as formalin-fixed paraffin-embedded cell blocks
Authors: Ali Shadan S. , Saleh Husain , Sethi Seema , Sarkar Fazlul H. , Philip Philip A.
Published: August 2012

MicroRNA (miRNA) expression profiling and quantitative real-time PCR (qRT-PCR) from fine needle aspirates (FNA) of formalin-fixed paraffin-embedded cell blocks (FFPE) could be a major improvement for prognosis and predicting treatment response in inoperable tumors of pancreatic cancer (PC). MicroRNA (miRNA) profiling provides a more comprehensive molecular interrogation of tumors. In the present study, miRNA expression profiling was performed on formalin-fixed paraffin-embedded cell blocks (FFPE) from FNA of suspicious pancreatic masses. Subjects were retrospectively studied and included those who had a pathological diagnosis of pancreatic adenocarcinoma and others with no histological proof of any cancer. We compared the expression profile of miRNAs in the pooled samples of FNA blocks from patients diagnosed with PC (n=29) with normal controls (n=15). MicroRNA profiling confirmed the deregulation of over 228 miRNAs of which, the top seven were validated by qRT-PCR. The expression of let-7c, let-7f, and miR-200c were significantly lower in almost all of the 29 patients compared to normal samples. On the contrary, the expression level of miR-486-5p, and miR-451 were significantly higher in all PC samples. Interestingly, two of the miRNAs, let-7d and miR-423-5p, that showed significant down-regulation or up-regulation in pooled sample showed a differential expression between the samples with individual qRT-PCR. These results suggest that identifying seven-miRNA signatures for PC in FNA cell blocks and validating with qRT-PCR can provide a strategy for improving the diagnosis of PC by using minimally invasive procedures.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5027. doi:1538-7445.AM2012-5027
Abstract 5038: Non-cording microRNA hsa-miR-199a expression in hepatocellular carcinoma correlates with patient survival
Authors: Nakajima Go , Kuramochi Hidekazu , Kondo Yurin , Okuyama Ryuji , Yamamoto Masakazu , Kanemura Toshinori , Hayashi Kazuhiko
Published: August 2012

[Aim] MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at a post-transcriptional level. Previous study from our group identified forty nine miRNAs that are expressed differentially by comparing 26 pair samples of hepatocellular carcinoma (HCC) tumor tissue and non-tumor liver tissue using next-generation sequencer system. In this study, the expression of hsa-miR-199a and hsa-miR-199b, one of the extracted targets from our study, were investigated by real-time PCR using validation set HCC samples, and were examined the correlation between the miRNA expression and clinical data. [Patients and Methods] Forty-eight patients diagnosed as HCC had undergone surgical removal from 1991 to 1997 at the Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Japan. The formalin-fixed paraffin embedded samples were prepared using the standard protocol. The paraffin blocks were cut into 10μm sections, and the tumor samples were collected using Laser-captured microdissection and total RNA including miRNA fraction were isolated. After synthesized cDNA using miRNA specific primer, real-time PCR was performed using miRNA specific primer/probe. [Results] The expression level of hsa-miR-199a and hsa-miR-199b were down-regulated in tumor compared to non-tumor (P<0.0001, P=0.0002, respectively). The patients were divided into two groups, higher/lower expression of each miRNA, the group of the higher hsa-miR-199a expression was significantly longer overall survival time compared to the lower expression group (P=0.0303). However, hsa-miR-199b was not significant difference (P=0.3801). [Conclusion] The hsa-miR-199a may be potential prognostic factor for HCC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5038. doi:1538-7445.AM2012-5038
Abstract 504: Metformin potently inhibits cell proliferation, adhesion and invasion in ovarian cancer cells
Authors: Suri Anuj , Schuler Kevin , Zhou Chunxiao , Malloy Kim , Dickens Hallum , Steplowski Tara , Huh Gene , Gehrig Paola A. , Bae-Jump Victoria
Published: August 2012

ABSTRACT Objectives: Metformin is an anti-diabetic drug that has been shown to have anti-tumorgenic effects by behaving as a novel mTOR inhibitor. Metformin has been shown to suppress cancer cell growth, but little is known of its potential to halt metastatic spread. Thus, our goal was to assess the effect of metformin on proliferation, adhesion and invasion in ovarian cancer cell lines. Methods: Four ovarian cancer cell lines, SKOV3, CAOV3, OVCAR3 and IGROV1 were used. Cell proliferation was assessed by MTT assay after exposure to metformin. Cell cycle progression was evaluated by flow cytometry. Apoptosis was assessed by Annexin V-FITC assay. hTERT expression was determined by real-time RT-PCR. Western immunoblotting was performed to determine the expression of the downstream targets of metformin, including AMPK and the ribosomal protein S6. Inhibition of adhesion and invasion by metformin was assessed by in vitro adhesion assay and ChemoTx® invasion assay. Results: Metformin potently inhibited growth in a dose-dependent manner in all four ovarian cancer cell lines (IC50 of 0.1-1 mM) (p=0.00001-0.0121). Treatment with metformin resulted in G1 arrest, induction of apoptosis and decreased hTERT expression. Western immunoblot analysis demonstrated that metformin induced phosphorylation of AMPK, its immediate downstream mediator, and decreased phosphorylation of the S6 protein, a key target of the mTOR pathway, within 24 hours of exposure. Metformin inhibited cellular adhesion in the ovarian cancer cell lines by 10-23% at 1 mM (p=0.04-0.00001) and 25-35% at 10 mM (p=0.05-0.00001). In addition, metformin decreased invasion by 7-21% at 1 mM (p=0.03-0.0009) and 29-42% at 10 mM (p=0.03-0.0012). Conclusions: We report that metformin is a potent inhibitor of cell proliferation and exhibits anti-metastatic effects in ovarian cancer cells. Thus, metformin may have potential as a targeted chemotherapeutic agent in the treatment of ovarian cancer. More work is needed to determine if metformin will be universally beneficial in all ovarian cancer patients versus selectively efficacious in a subset of ovarian cancer patients, such as those women who are obese and/or diabetic.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 504. doi:1538-7445.AM2012-504