bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1364: Design, synthesis and evaluation of potent antiproliferative and cytotoxic antifolates with selective FRs and PCFT transport over RFC and potent GARFTase inhibition
Authors: Wang Lei , Cherian Christina , Desmoulin Sita Kugel , Hou Zhanjun , Matherly Larry H. , Gangjee Aleem
Published: June 2012

Lack of selectivity for folate transporters is one of the major causes of toxicity and chemotherapy failure with clinically used antifolates. Three folate transporters, the reduced folate carrier (RFC), folate receptors (FR) and the proton-coupled folate transporter (PCFT), account for most of the folate influx activity in mammalian cells. We recently reported potent inhibition of cell proliferation by a classical 2-amino-4-oxo-6-substituted pyrrolo[2,3-d]pyrimidine with a thienoyl for benzoyl-substituted side chain and a 4-carbon bridge (AG71). AG71 was selective for transport by FRs and PCFT over RFC and inhibited glycinamideribonucleotide formyl transferase (GARFTase) in de novo purine biosynthesis. In SCID mice with KB tumors, AG71 was highly active against both early and advanced stage tumors. A series of five thienoyl regioisomers of AG71 with [1,3] (AG117 and AG118) and [1,2] (AG114, AG115, AG116) thienoyl substitutions by the 4-carbon bridge and the L-glutamate were synthesized. Analogs were evaluated for anti-proliferative activities in engineered Chinese hamster ovary (CHO) cells expressing RFC, FR, or PCFT to determine the optimum structures for selective transport by FRs and/or PCFT. Additional studies were performed in KB and IGROV1 tumor cells, using inhibition of cell proliferation or colony formation as metrics. Like AG71, none of the novel thienyol regioisomers were substrates for RFC. AG117 and AG118 were potently active toward FR- and PCFT-expressing CHO cells and toward KB and IGROV1 tumor cells, equivalent or exceeding levels for AG71. In colony-forming assays in KB cells, AG117 and AG118 were cytotoxic. AG114, AG115, and AG116 were substantially less active or completely inert. AG117 and AG118, like AG71, were high affinity ligands for FRα by competitive ligand binding with 3H-folic acid, and were potent substrates for PCFT by direct competition 3H-methotrexate transport. By protection assays, AG71 and AG117 preserved potent anti-proliferative activity even in the presence of 50 nM leucovorin; adenosine and 5-imidazole-4-carboxamide were completely protective, establishing the de novo purine biosynthetic pathway and GARFTase as the principal intracellular targets. GARFTase inhibition was confirmed by in situ GARFTase metabolic assays with 14C-glycine as a radiotracer. Our results identify 6-subsituted pyrrolo[2,3-d]pyrimidine thienoyl regioisomers of AG71 as potent anti-proliferative and cytotoxic antifolates, reflecting selective transport by PCFT and FR over RFC and inhibition of GARFTase.

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 1364. doi:10.1158/1538-7445.AM2011-1364
Abstract 137: MicroRNA-200c restores anoikis sensitivity in breast and gynecological cancers
Authors: Richer Jennifer K. , Howe Erin N. , Cochrane Dawn R.
Published: June 2012

Background: MicroRNA-200c directly targets ZEB1, an epithelial to mesenchymal (EMT)-inducing transcriptional repressor of E-cadherin and other key determinates of epithelial identity and polarity. Therefore, restoration of miR-200c results in repression of ZEB1, dramatic reduction in migration and invasion, and increased sensitivity to microtubule targeting chemotherapeutics. We hypothesized that in addition to ZEB1, miR-200c targets additional genes that contribute to its myriad effects on maintaining the epithelial phenotype by repressing mesenchymal genes.

Results: We performed microarray analysis following restoration of miR-200c to aggressive endometrial cancer cells and identified 18 genes that were both significantly repressed and predicted to be direct targets of miR-200c. These genes, including fibronectin 1 (FN1), class III beta-tubulin (TUBB3), neurotrophic tyrosine receptor kinase type 2 (NTRK2 or TrkB), leptin receptor (LEPR), moesin (MSN1) and Rho GTPase activating protein 19 (ARHGAP19), are all typically expressed only in non-epithelial cells, such as fibroblasts or neurons. Utilizing luciferase reporter assays and mutational analysis, we validate each of these genes as direct targets of miR-200c. We also demonstrate that restoration of miR-200c leads to a dramatic decrease in mRNA and protein levels of these targets. Further we find that restoration of miR-200c restores anoikis sensitivity to suspended cells, leading to over a 1.5 fold increase in cell death. TrkB is a potent suppressor of anoikis in breast and ovarian cancer models. Addition of TrkB lacking the miR-200c binding site reversed the ability of miR-200c to suppress anoikis. Interestingly, neurotrophin 3 (NTF3), a ligand for TrkB, contains 2 putative miR-200c binding sites and is down regulated upon restoration of miR-200c. Thus, loss of miR-200c in carcinoma cells allows inappropriate translation of both TrkB and NTF3, setting up an autocrine loop that results in anoikis resistance.

Conclusions: Our data demonstrate that miR-200c serves as a “guardian of the epithelial phenotype” and suppressor of EMT by directly targeting and repressing a program of genes that should not be on in differentiated epithelial cells. We identify a novel function of miR-200c, the ability to suppress anoikis resistance, an important yet understudied step in the metastatic cascade.

Funding source: DOD Breast Cancer Program Idea Award BC084162 to JKR

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 137. doi:10.1158/1538-7445.AM2011-137
Abstract 1378: Identification and characterization of small molecule inhibitors targeting Eya phosphatase activity for anti-breast cancer therapy
Authors: Krueger Aaron , Dehdashti Seameen , Southhall Noel , Patnaik Samarjit , Marugan Juan , Zheng Wei , Ford Heide , Zhao Rui
Published: June 2012

Eya proteins are transcriptional co-activators of the homeobox gene Six1 and are also unique protein tyrosine phosphatases. Six1 and Eya2 are required for normal development but are down-regulated in most adult tissues. However, Six1 and Eya are over-expressed in a large number of breast tumors and play a causal role in the initiation and development of these tumors. The phosphatase activity of Eya was shown to be important for the transformation, migration, invasion, and metastasis of breast cancer cells. Eya's phosphatase activity therefore provides an attractive enzymatic target for anti-breast cancer therapy. In addition, Eyas also direct cells to a DNA-damage-repair pathway instead of an apoptotic pathway upon DNA damage through the dephosphorylation of histone H2AX. Inhibiting Eya phosphatase activity can therefore potentially sensitize tumor tissue to radiation or chemotherapy treatment. We developed an HTS assay to identify small molecule inhibitors of Eya's phosphatase activity. In collaboration with the NIH Chemical Genomics Center, we have screened over 300,000 compounds and identified several promising lead compounds. These hits are currently being evaluated for their potency, specificity, and mechanism of action using biochemical, structural, and cell-based assays. We believe that Eya is a significant target for cancer therapy through sensitizing cancer cells to radiation and chemotherapy and through the inhibition of Six1-mediated tumorigenesis and metastasis.

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 1378. doi:10.1158/1538-7445.AM2011-1378
Abstract 1382: Use of polarized light spectroscopy (CD) to study STAT3 folding and STAT3:ligand interactions
Authors: Rahman Khondaker M. , Palmer Jonathan , Essex Samantha , Nkansah Edwin , Zinzalla Giovanna , Wilderspin Andrew F. , Bui Tam T.T , Drake Alex F. , Thurston David E.
Published: June 2012

STAT3 is a homodimeric transcription factor that is over-expressed in variety of solid tumours. It is known to trigger transcription of a range of genes associated with tumour growth and metastasis. In order to use the STAT3/STAT3 dimer for drug discovery, the factors affecting dimerisation of the monomeric protein and the interaction with ligands must be understood. In this study, we have demonstrated that Circular Dichroism (CD) can be used as a tool to study these processes. We have found that formation of the dimeric STAT3/STAT3 complex results in an induced CD signal which is absent in monomeric protein. Thus, CD can be used to optimize conditions for the production and storage of un-phosphorylated (un-P-) and phosphorylated (P-) STAT3. A similar induced signal was observed when a small molecule (or peptide ligand) interacted with either un-P- or P-STAT3 due to chiral perturbation of the protein structure or electron rearrangements. Crucially, the intensity of the induced CD signal was found to depend on the strength and geometry of the interaction of the binding partner. CD was also used to determine the secondary structure of un-P- and P-STAT3. HIS- and FLAG-tagged STAT3 were examined using the far-UV spectral region (190-250 nm), and the regular folded environment of the peptidic bonds was used to determine the alpha-helix, beta-sheet, and random coil content of different batches of STAT3 protein. For batches of P-STAT3, the composition was found to be 28.3% α-helix, 22.3% β-sheet and 49.4% random coils. For un-P-STAT3, the β-sheet content was slightly higher (23.2%) while the α-helix content was lower (26.8%). Next, protein:ligand interactions which alter the conformation of the protein were studied. Titration of un-P-STAT monomer with different small-molecule inhibitors produced a significant change in the CD spectrum consistent with modification of secondary structure due to altered folding. In particular, significant effects on the secondary structures of both un-P- and P-STAT3 were observed upon binding of the natural peptidic ligands LKTKF and LPQTV. Crucially, the different complex geometries adopted by the proteins upon interaction with ligands could be used to determine the stoichiometry of interaction and the orientation of the ligands in the binding pocket of the protein. These results demonstrate that CD spectroscopy can be used to evaluate STAT3 structure and ligand interactions at the molecular level, and thus represents a useful analytical tool in the development of small molecule inhibitors for potential therapeutic use.

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 1382. doi:10.1158/1538-7445.AM2011-1382
Abstract 1385: Real-time imaging of paxillin-GFP expression in breast cancer cells in vitro and in vivo
Authors: Suetsugu Atsushi , Digman Michelle , Gratton Enrico , Moriwaki Hisataka , Saji Shigetoyo , Bouvet Michael , Hoffman Robert M.
Published: June 2012

Paxillin is involved in the assembly of focal adhesions. In this study, we describe real-time imaging of paxillin-GFP expression in breast cancer cells (MDA-MB-231) in vitro and in vivo. In vitro, round cancer cells had greater paxilin movement than stretched cancer cells as seen by fluorescence imaging. When paxillin-GFP breast cancer cell (1×106) were injected in the epigastric cranials vein, round cancer cells had GFP-expressing protrusions. Many paxillin-GFP-expressing breast cancer cells stretched. The cancer cells extravasated and subsequently grew around the outer surface of the blood vessel after one week. Migration of single cells in vivo was observed by fluorescence microscopy. Two weeks after cell injection, paxillin-GFP breast cancer cells migrated along the vessel wall. Most of paxillin-GFP cancer cells were stretched and were not mobile. With anti-VEGF treatment, paxillin was observed in round structures rather than stretched structures and paxillin movement within the cell were arrested. The results show that paxillin-GFP allows the imaging of the role of paxillin in vitro and in vivo.

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 1385. doi:10.1158/1538-7445.AM2011-1385
Abstract 1392: CTGF inhibits cell motility in oral cancer cells through reducing COX-2 expression
Authors: Yang Wan-Yu , Tang Chih-Hsin , Chuang Jing-Yuan
Published: June 2012

Oral squamous cell carcinoma (SCC) has a striking tendency to migrate and metastasize. Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin synthase, has been implicated in tumor metastasis. Connective tissue growth factor (CTGF), a secreted protein that binds to integrins, modulates the invasive behavior of certain human cancer cells. However, the effect of CTGF on migration activity and COX-2 expression in human oral cells is mostly unknown. Here we found that CTGF reduced the migration and expression of COX-2 in human oral cancer cells. αvβ5 monoclonal antibody (mAb), phosphatidylinositol 3-kinase inhibitor (PI3K; Ly294002 and wortmannin) and Akt inhibitor reversed the CTGF-inhibited the migration and COX-2 down-regulation of oral cancer cells. CTGF stimulation decreased the phosphorylation of focal adhesion kinase (FAK), PI3K and Akt. In addition, c-Jun siRNA also antagonized the CTGF-inhibited migration and COX-2 expression. Moreover, CTGF decreased the binding of c-Jun to the AP-1 element on the COX-2 promoter. Taken together, our results indicated that CTGF inhibits the migration of oral cancer cells by decreasing COX-2 expression through the αvβ5 integrin receptor, FAK, PI3K, Akt, c-Jun and AP-1 signal transduction pathway.

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 1392. doi:10.1158/1538-7445.AM2011-1392
Abstract 1394: Beta-cryptoxanthin suppresses cancer cell motility and angiogenesis via inhibiting alpha 7-nicotinic acetylcholine receptor-mediated PI3K pathway
Authors: Miao Benchun , Wang Xiang-Dong
Published: June 2012

Epidemiologic studies show that increased dietary intake or higher blood levels of one specific carotenoid, beta-cryptoxanthin (BCX), is strongly associated with a reduced risk of lung cancer. However, the biological activities and molecular targets by which BCX functions as a chemopreventive agent against lung cancer are poorly understood. Recent studies show that both nicotine and nicotinic acetylcholine receptors (nAChRs) play crucial roles in cancer cell survival, proliferation, migration, invasion and angiogenesis. In particular, alpha 7-nAChR is the main subunit mediating the effects of nicotine in lung carcinogenesis. Here we report that BCX suppresses cancer cell motility and angiogenesis by inhibiting the expression of alpha 7-nAChR and its mediated PI3K pathway in vitro. Similar to MG624, an alpha 7-nAChR-specific antagonist, BCX significantly inhibited migration and invasion of alpha 7-nAChR positive lung cancer cells and endothelial cells in both transwell and wound healing assays, but both MG624 and BCX were inactive in alpha 7-nAChR negative cells. Moreover, BCX and MG624 were synergized in suppressing cell migration due to the fact that BCX, but not MG624, is effective at suppressing alpha 7-nAChR at both mRNA expression and protein levels. Furthermore, the inhibition of cell migration by BCX was attenuated in PTEN-deficient U87MG cells or MCF-7 cells which express constitutively active PI3K. BCX also effectively inhibited nicotine and PNU282987, an alpha 7-nAChR-specific agonist-stimulated cell migration, endothelial cell tube formation and microvessel outgrowth in an aortic ring model. Immunocytochemistry analysis showed that BCX effectively suppressed actin reorganization, lamellipodia and stress fiber formation induced by overexpression of wild type PI3K downstream molecules Rac and Rho, while constitutively active Rac and Rho attenuated the inhibition of cell migration by BCX. Moreover, BCX suppressed activities of matrix metalloproteinase (MMP)-2 and MMP9, two downstream molecules of alpha 7-nAChR/PI3K. Conclusively, these data demonstrate that BCX can inhibit cancer cell motility and angiogenesis by suppressing alpha 7-nAChR expression and its downstream PI3K pathway. This could be one of the potential mechanisms for the chemopreventive effect of BCX against lung cancer (Supported by NIH R01CA104932).

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 1394. doi:10.1158/1538-7445.AM2011-1394
Abstract 1398: IFIT2 depletion promotes migration through atypical PKC signaling in oral squamous cell carcinoma
Authors: Lai Kuo Chu , Liu Chung Ji , Lee Te Chang
Published: June 2012

Interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) is one of most responsive interferon-stimulated genes to interferons, viruses, and a variety of agents. However, the biological functions of IFIT2 are poorly understood. Our previous study showed that IFIT2 overexpression was frequently found in tumor tissues of oral squamous cell carcinoma (OSCC). Besides, enhanced IFIT2 expression was inversely associated with poor patient survival. In cultured cell system, we demonstrated that depletion of IFIT2 expression in OSCC cell lines significantly enhanced the motility of cells. In this study, experiments were conducted to explore the underlying mechanisms by which IFIT2 depletion enhanced migration of OSCC cells. We first established stable IFIT2 knockdown and non-silencing control cells by lentivirus transduction system. Our results showed that stable IFIT2 knockdown cells displayed elongated spindle-like morphology, F-actin reorganization, and loss of epithelial markers, such as E-cadherin and keratin 18, as compared to control cells, suggesting the involvement of IFIT2 in epithelial-mesenchymal transition and F-actin cytoskeleton organization. While stable IFIT2 knockdown cells exhibited enhanced cell motility and invasion as compared to control cells, we found that PI3K/Akt or PKC inhibitors significantly inhibited migration of stable IFIT2 knockdown OSCC cells. Notably, PKCζ pseudosubstract significantly abolished IFIT2 depletion-induced migration. Furthermore, atypical PKC phosphorylation (Thr410/403) was enhanced in IFIT2-silencing cells compared to that of control cells. Furthermore, among 25 metastatic OSCC patients, the median survival was 57.4 months in patients expressed high levels of IFIT2 (IFIT2 ≥ 50), whereas the median survival drastically reduced to 13.6 months in patients expressed low IFIT2 (IFIT2 < 50). Taken together, our results revealed that atypical PKC signaling may involve in enhanced migration of IFIT2 knockdown OSCC cells.

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 1398. doi:10.1158/1538-7445.AM2011-1398
Abstract 1405: Mesothelin enhances ovarian cancer invasion of by inducing MMP-7 through MAPK/ERK and JNK pathways
Authors: Chang Ming-Cheng , Chen Chi-An , Chiang Ying-Cheng , Chen Tzer-Ming , Cheng Wen-Fang
Published: June 2012

Ovarian cancer is a cancer of high mortality in women malignancies. Little is known with its property of tumor progression and no effective molecule could monitor the tumor growth or therapeutic responses of this disease. In our previous studies, we first identified that mesothelin, a secreted protein, over-expressed in ovarian cancer tissues with a poor clinical outcome in chemotherapeutic response of ovarian cancer patients. Besides, mesothelin activated PI3K/Akt signaling to inhibit paclitaxel-induced apoptosis. Here, we investigated the mechanism of mesothelin enhancing the invasion of ovarian cancer and the correlation between mesothelin and metastatic diseases. The expression of mesothelin correlated well with expression of MMP-7 in human ovarian cancer tissues. Mesothelin over-expressed or mesothelin-treated ovarian cancer cells could enhance the migration and invasion of cancer cells through the activation of MMP-7. Mesothelin could regulate the expression of MMP-7 through ERK (extracellular-signal-regulated kinase) 1/2, Akt (phosphoinositide 3-kinase), and JNK (c-jun-N-terminal kinase) pathways. The MMP-7 expression and the migrating ability of mesothelin-treated ovarian cancer cells can be suppressed by the ERK1/2 or JNK specific inhibitor, or decoy AP-1 oligonucleotide in in vitro experiments. The in vivo animal experiments also demonstrated that mice treated with MAPK/ERK or JNK- specific inhibitor could decrease the itnratumoral MMP-7 expression and delay the tumor growth. We concluded that mesothelin enhances ovarian cancer invasion by MMP-7 expression through the MAPK/ERK and JNK signal transduction pathways. And blocking these two pathways can be a potential strategy to inhibit the tumor growth 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 1405. doi:10.1158/1538-7445.AM2011-1405
Abstract 1406: Downregulation of uPAR inhibits migration, invasion, proliferation, FAK/PI3K/Akt signaling, and induces senescence in papillary thyroid carcinoma cells
Authors: Nowicki Theodore S. , Zhao Hong , Darzynkiewicz Zbigniew , Moscatello Augustine , Schantz Stimson , Shin Edward , Tiwari Raj K. , Geliebter Jan
Published: June 2012

Papillary thyroid carcinoma (PTC) is the most common endocrine and thyroid malignancy. The urokinase plasminogen activator receptor (uPAR) plays an important role in cancer pathogenesis, including breakdown of the extracellular matrix, invasion, and metastasis. Additionally, there is increasing evidence that uPAR also promotes tumorigenesis via the modulation of multiple signaling pathways. BRAFV600E, the most common initial genetic mutation in PTC, leads to ERK1/2 hyperphosphorylation, which has been shown in numerous cancers to induce uPAR. Treatment of the BRAFV600E-positive PTC cell line, BCPAP, with the MEK/ERK inhibitor U0126 reduced uPAR RNA levels by 90%. siRNA-mediated down-regulation of uPAR in BCPAP cells resulted in drastically reduced proliferation rates and decreased clonigenic survival, as well as demonstrated senescence-associated nuclear morphology and induction of β-galactosidase activity. uPAR-knockdown BCPAP cells also displayed greatly reduced migration and invasion rates, as well as a complete loss of the cells’ plasminogen-enhanced invasiveness. Additionally, uPAR down-regulation lead to greatly decreased activity in the focal adhesion kinase (FAK)/phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, as well as a modest reduction in ERK1/2 signaling (which remained constitutively active secondary to BRAFV600E activation), which suggests the existence of a uPAR signaling feedback loop capable of affecting the various phenotypic changes exhibited by uPAR-knockdown cells. Taken together, these data provide new evidence of a novel role for uPAR induction as a central component in PTC pathogenesis, and highlight the potential of uPAR as a therapeutic target.

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 1406. doi:10.1158/1538-7445.AM2011-1406
Abstract 1407: Mitogen-activated protein kinase kinase 4 (MEK4) is a key regulator of prostate cancer progression
Authors: Pavese Janet M. , Ogden Irene M. , Huang Xiaoke , Xu Li , Bergan Raymond C.
Published: June 2012

Mitogen-activated protein kinase kinase 4 (MEK4) is a dual-specificity kinase that has been implicated in cancer progression in multiple cancer types, including prostate cancer (PCa). MEK4 is upregulated in invasive PCa lesions in human tissue. We hypothesize that increased MEK4 promotes PCa invasion and metastasis. Our group has created PC3-M cells stably transfected with either constitutively-active or increased levels of wild-type MEK4. In a Matrigel Boyden chamber assay, constitutively-active or wild-type MEK4 was shown to increase PCa invasion. Cancer cell invasion requires the coupling of cell migration with increased production of proteases. We hypothesized that MEK4 promoted invasion via production of proteases, but not via cell migration. Using an uncoated boyden chamber, MEK4 was shown not to affect migration. Using quantitative real time polymerase chain reaction (qRT/PCR), we went on to demonstrate that MEK4 increased MMP-2 and MMP-9 transcript expression, but did not affect MMP-10 expression. In addition to these studies, we have also looked at the effect of increased or constitutively-active MEK4 on an orthotopic mouse model of PCa. In this model, PCa cells are injected into the prostates of nude mice and tumor size, circulating tumor cells, and lung metastasis are quantified. Preliminary data shows that constitutively-active MEK4 causes an increase in primary tumor size as well as an increase in circulating tumor cells in both the blood and the bone marrow. In summary, we demonstrated that chronic high expression of MEK4 increases human PCa invasion, that this is not due to increased migration, but is associated with increases in MMP-2 and MMP-9. Further, constitutively-active MEK4 appears to have different biological effects than high levels of wild type MEK4 in vivo. Ongoing studies are evaluating the effect of wild type MEK4 and of constitutively-active MEK4 on the formation of distant soft tissue metastasis in the above murine model. In related studies we are seeking to identify downstream proteins critical for MEK4's effects on cell invasion and metastasis both in vitro and in vivo. We are also seeking to examine the effects of sustained MEK4 knockdown on PCa invasion and metastasis.

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 1407. doi:10.1158/1538-7445.AM2011-1407
Abstract 1408A: Estrogen can stimulate cholangiocarcinoma cells proliferation and invasion and associate with poor prognosis
Authors: Thuwajit Peti , Hunsawong Taweewun , Thuwajit Chanitra
Published: June 2012

Cholangiocarcinoma is defined as a cancer arising from bile duct epithelial cell. The prevalence of cholangiocarcinoma is low among worldwide, however it was raised each year. Moreover, this kind of cancer is endemic in Thailand which associated with liver fluke infection, Opisthorchis viverrini. In Thailand, the prevalence of cholangiocarcinoma was about 20-time higher than in western country and may be more than 400-time in endemic area (northeastern part). Cholangiocarcinoma has poor prognosis with low 5-year survival rate due to its high metastasis rate which caused inadequate surgery while chemotherapy and radiotherapy are resisted. It is a type of chronic liver disease with altered estrogen metabolizing enzyme that could leading to the accumulation of estrogen in plasma. Estrogen was known as a promoting factor in progression of some cancer, eg. breast cancer and endometrial cancer. Our finding indicated the increasing of serum estrogen level in male cholangiocarcinoma patients and correlated with serum alkaline phosphatase and bilirubin and inverse correlated with albumin. The high level of serum estrogen could be determined as poor prognostic factor for survival of cholangiocarcinoma patients with statistically significant. In vitro studies demonstrated the effect of estrogen on cell proliferation and invasion of cholangiocarcinoma cell lines. Real time proliferative assay indicated the growth stimulated effect of estrogen on 4 cholangiocaricinoma cell lines (KKU-100, KKU-M055, KKU-M156 and KKU-M213) in dose dependent manner up to 10 nM. Results from in vitro invasion assay showed the effect of estrogen on cholangiocarcinoma cell invasion with highest effect at concentration 1 nM and this effect could be inhibited by tamoxifen. Metastasis genes expression of KKU-M213 cholangiocarcinoma cell induced by estrogen was measured by RT2 ProlifilerTM PCR array system. Total 84 metastasis genes expression were compared with non-induced cell, 24 genes showed change in expression level more than twice which were 11 genes increased and 13 genes decreased. The pathway of estrogen induced metastasis genes in cholangiocarcinoma cells should be analyzed. The results should indicate the mechanism and control of cholangiocarcinoma invasion and metastasis, which may be introduced to the new therapeutic guideline.

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 1408A. doi:10.1158/1538-7445.AM2011-1408A
Abstract 1411: Overexpression of IFITM1 is associated with gastric cancer and its silencing inhibits migratory and invasive potential of tumor cells
Authors: Lee Jieun , Song Naaleum , Goh Sung-Ho , Choi Il Ju , Jeong Jin Sook , Lee Yeon-Su
Published: June 2012

Gastric cancer is the most common types of human cancer with an annual incidence of approximately 870,000 new cases worldwide (Crew K D, Neugut A I, Epidemiology of gastric cancer, World J Gastroenterol 2006;12(3):354-362). Despite its high prevalence, the risk factors and tumorigenesis of gastric cancer are not clearly identified. Consequently, the identification of the oncogene or tumour suppressor gene in gastric cancer has been the focus of many researches. In our effort to find gastric cancer related genes, we analysed the gene expression profiles in 30 pairs of gastric cancer patient samples (tumour and normal tissue) using microarrays and identified interferon-induced transmembrane protein 1 (IFITM1) as a highly up-regulated gene in tumor tissues. IFITM1, also known as 9-27 or Leu13, is a cell surface molecule and the IFN-inducible transmembrane protein family. However, there have been a few papers of IFITM1 explaining its function, and the role of IFITM1 in cancer is poorly understood. In the present study, we examined the roles of IFITM1 for gastric cancer and its function for tumoringenesis. Quantitative real-time PCR, western blot analysis and immunohistochemical staining were performed to confirm the cancer specific expression pattern of IFITM1. In various gastric cancer cell lines, IFITM1 mRNA expression level was highly up-regulated in comparison human mammary epithelial cell (HMEC). Furthermore, mRNA expression of IFITM1 was significantly up-regulated in cancer tissues than matching normal tissues. In addition, IFITM1 overexpression was observed in gastric adenocarcinoma by immunohistochemistry. Interestingly, cells which overexpressed IFITM1 exhibit an increased migration, invasion and wound healing potential. Consistently, IFITM1 knockdown cells by siRNA showed a decreased invasiveness. Our findings suggest that IFITM1 plays an important role for the migration, invasion and wound healing capacity of cancer cells and associated with progression of gastric 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 1411. doi:10.1158/1538-7445.AM2011-1411
Abstract 1413: Hepatocyte growth factor activator inhibitor-2 inhibits prostate cancer cell migration and invasion
Authors: Wu Shang-Ru , Teng Chen-Hsin , Tsai Chin-Hsien , Tu Ya-Ting , Cheng Tai-Shan , Shyu Hsin-Yi , Ko Chun-Jung , Lan Shao-Wei , Huang Hsiang-Po , Lin Chen-Yong , Hsiao Pei-Wen , Lee Ming-Shyue
Published: June 2012

Dysregulation of proteolysis on cell surface has been strongly implicated in cancer cell migration and invasion. In this study, we delineated the role of hepatocyte growth factor activator inhibitor-2 (HAI-2) in prostate cancer cell migration and invasion within a human prostate cancer progression model, established by a serial of intraprostatic injections of prostate cancer cells and isolation of the invasive cells from nearby lymph nodes. The invasion capability of these cells was increased after the serial isolations. Interestingly, the expression of HAI-2 but not HAI-1 was dramatically decreased following the progression and concurrent with an increase of activated matriptase. Overexpression of HAI-2 reduced prostate cancer cell migration and invasion, at least in part due to its inhibitory role in matriptase. Following the orthotopic tumor growth in mice, the level of matriptase was increased while HAI-2 protein level was decreased. These results indicated that during the progression of human prostate cancer, HAI-2 expression was reduced, leading to constitutive matriptase activation, increased cell migration and invasion. Thus, HAI-2 exerted an inhibitory role in prostate cancer progression partly through inhibiting matripase activity. Imbalance between HAI-2 and matriptase may result in prostate tumor progression.

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 1413. doi:10.1158/1538-7445.AM2011-1413
Abstract 1422: Abrogation of prostate cancer cell metastatic phenotype by cathepsin-L inhibition
Authors: Sudhan Dhivya R. , Siemann Dietmar W.
Published: June 2012

Prostate cancer is the most commonly diagnosed cancer in North America and the second leading cause of cancer death in men. Although highly curable in early stages, ∼90% of patients with advanced prostate cancer develop skeletal metastases; an occurrence that results in a substantial reduction in the quality of life and a drastic worsening of the prognosis. Tumor cells rely on proteolytic enzymes for successful establishment of metastases. Cathepsin-L (Cts-L) is a lysosomal endopeptidase of the papain super family of cysteine protease that is up regulated in a wide range of human cancers including prostate cancer. Cts-L over expression can enhance the invasive/metastatic potential of cancer cells through two distinct mechanisms: (i) degradative proteolysis of extracellular matrix and basement membrane components by secreted Cts-L and (ii) enhanced expression of genes involved in EMT and migration by nuclear Cts-L.

The goal of the present studies was to elucidate whether the administration of the specific small molecule CtsL inhibitor 3-bromophenyl-3-hydroxyphenyl-ketone thiosemicarbazone (KGP-94) could inhibit the metastatic phenotype in prostate cancer cells. PC-3 and its sublines PC-3-ML and PC-3-N which possess moderate, high, and low metastatic potential, respectively, were used. In response to treatment with 25uM of KGP-94, PC-3 and PC-3-ML showed a 45 and 55% decrease in migratory potential respectively as determined by transwell and wound healing assays. KGP-94 also significantly affected the invasive potential of PC-3 and PC-3-ML at 10uM and 25uM dose concentrations. These results occurred in the absence of cytotoxicity as determined using a clonogenic cell survival assay. Cell cycle analysis by flow cytometry did show that KGP-94 treatment induces a G1 arrest but this effect was insufficient to account for the pronounced inhibition of migration and invasion.In order to elucidate whether KGP-94 treatment affected nuclear Cts-L, presence of the nuclear isoform was validated in PC-3 cells through immunoblot analysis of nuclear extracts and confocal imaging. Nuclear Cts-L has been reported to induce epithelial to mesenchymal transition through increasing expression of Vimentin, N-Cadherin with concomitant suppression of E-Cadherin. However, quantitative PCR analysis failed to show an effect on the expression of these genes in response to KGP-94 treatment. These data therefore suggest that the abrogation of migratory and invasive potential observed in the prostate cancer models is a consequence of an inhibitory effect on secreted and not nuclear Cts-L.

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 1422. doi:10.1158/1538-7445.AM2011-1422
Abstract 1424: Cyclophilin A induces head and neck squamous cell carcinoma (HNSCC) invasion by its interaction to EMMPRIN/CD147
Authors: Suzuki Shinsuke , Takahashi Masafumi , Ishikawa Kazuo
Published: June 2012

Extracellular matrix (ECM) remodeling that is crucial in tumorigenesis involves proteolytic enzymes, primarily matrix metalloproteases (MMPs). The production of MMPs is stimulated by different factors, including extracellular matrix metalloprotease inducer (EMMPRIN/CD147). Over-expression of EMMPRIN, a member of the immunoglobulin super-family, promotes invasion, metastasis, growth and survival of malignant cells. Cyclophilin A (CypA) is a multifunction protein and promotes cancer progression in various cancer types. It has been reported CypA can interact and activate EMMPRIN, however the role of EMMPRIN-Cyp A interaction in oncogenicity is not fully understood in malignant cells including head and neck squamous cell carcinoma (HNSCC). In order to evaluate tumorigenicity that are induced by EMMPRIN-CypA interaction, EMMPRIN expressing HNSCC cell lines were stimulated with CypA. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] dye assay revealed that HNSCC cell proliferation was increased, whereas cisplatin induced cell death was declined in the presence of CypA. In addition, CypA induced MMP-9 up-regulation was detected in culture medium by gelatin zymography. Moreover, increment of invaded cells through matrigel-coated membranes was found by CypA stimulation. Interestingly the elevated invasive potential was abrogated by EMMPRIN function blocking antibody. These findings suggest that CypA, by its interaction to EMMPRIN, might contribute to the HNSCC tumorigenesis.

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 1424. doi:10.1158/1538-7445.AM2011-1424
Abstract 1428: Upregulation of IKBKE promotes glioma cell migration and invasion by phosphorylation of Snail
Authors: Guo Jianping , Huang Qiang , Shu Shaokun , Kim Donghwa , Brem Steven S. , Cheng Jin Q.
Published: June 2012

IKBKE is a member of IκB kinase (IKK) family. Previous studies have shown that IKBKE is an oncogene in breast and ovarian cancer. In this study, we demonstrate that IKBKE is frequently upregulated in human glioma and regulates cell invasion, a process that causes incurable surgery for glioma. Increase expression of IKBKE was detected in 7 of 11 glioma cell lines and 41 of 57 primary tumors examined, which closely correlates with high grade tumors and patient poor overall survival. Further, ectopic expression of IKBKE induces and knockdown of IKBKE decreases cell migration and invasion. Notably, E-cadherin protein and mRNA levels were inversely regulated by IKBKE. Moreover, we demonstrated that IKBKE directly binds and phosphorylates Snail at Ser-165. The phosphorylation of Snail induces its stability and nuclear translocation and represses E-cadherin expression. Taken together, these findings indicate that IKBKE could play a pivotal role in gliomagenesis and invasion.

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 1428. doi:10.1158/1538-7445.AM2011-1428
Abstract 1431: An optimized in vitro method to evaluate primary tumor cell invasion using optical imaging technology
Authors: Bockhorn Jessica , Chang Ya-Fang , Liu Huiping , Greene Geoffrey
Published: June 2012

The recent development of human-in-mouse tumor models has provided better representative working models to understand tumor initiation and progression than previous mouse tumor models or cell lines. However, it has not been feasible to use these models for high-throughput functional or therapeutic screening. Our aim was to establish a complementary in vitro culturing system for high-throughput functional studies or therapeutic screening of breast cancer stem cells (BCSCs). We hypothesize that with extracellular matrix and stromal cell support, three-dimensional (3D) cultures can support the survival and invasion of primary human tumors in vitro. We report here a new method to objectively evaluate and quantify invasion of primary breast cancer tumor cells using Transwells and bioluminescence imaging (BLI) technology. We optimized the adhesion and invasion conditions for these primary tumor cells. We also labeled cells using Luc2-EGFP or -tdTomato lentiviral vectors so that the signal of all invaded cells could be quantified using BLI or fluorescence imaging of the entire bottom chamber of the Transwell system. Our results demonstrate that stromal cells are not only necessary for the survival of the primary tumor cells but also facilitate their invasion in vitro. This work establishes a new method for screening candidate genes, miRNAs and compounds that regulate growth, survival, invasion and drug sensitivity of primary tumor cells, including both BCSCs and non-BCSCs.

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 1431. doi:10.1158/1538-7445.AM2011-1431
Abstract 1435: Analyzing the role of CXCR and IGF-IR in modulating actin dynamics in neuroblastoma cells
Authors: Muller James , Sabanayagam Chandran , van Golen Cynthia M.
Published: June 2012

The sensory cues that developing neurons use to control the pattering of neurite outgrowth are currently not well defined. CXCR4 and the insulin like growth factor receptor (IGF1r) have been implicated in the regulation of chemotaxis, neuronal migration, and axonal guidance. In addition to these chemokine receptors role in the guidance of neuronal development, an increasing body of evidence shows they are up-regulated in many late stage and metastatic cancers. Neuroblastoma, a cancer of neural crest origin, often expresses high levels of CXCR4 and IGF1r, and depending upon the level of differentiation, is capable of producing fully extended axons. The mediator of the cytoskeletal changes seen in axonal extension is primarily carried out by actin polymerization. In order to better understand the role of CXCR4 and IGF1r role in mediating these cytoskeletal changes we used western blots and immunocytochemistry / confocal microscopy to analyze the neuroblastoma cell line SHSY-5Y. We were able to show that indeed both receptors are involved in neuronal outgrowth. However, the individual effects of treatment with the receptors ligand resulted in different cellular morphologies. CXCR4 stimulation resulted in a more differentiated neuronal form, while IGF1r stimulation resulted in a very immature neuronal morphology with shorter broader processes. Finally, we were able to quantitate the effects of treatment to a wide array of phenotypic patterns that shows the connection between our observed morphological changes to show that these observations are real effects of treatment.

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 1435. doi:10.1158/1538-7445.AM2011-1435
Abstract 1440: Downregulation of Pdcd4 leads to epithelial to mesenchymal transition and promotes metastasis in nude mice
Authors: Wang Qing , Zhang Yong , Yang Hsin-Sheng
Published: June 2012

Progression of benign tumor into invasive carcinoma is a major cause of death in cancer patients. Programmed cell death 4 (Pdcd4) is a novel tumor suppressor, which inhibits TPA-induced transformation and tumor phenotype in mouse epidermal JB6 cells. It has been reported that overexpression of pdcd4 cDNA significantly reduces invasive ability of colon carcinoma and breast carcinoma cells in Matrigel invasion assays. Conversely, knockdown of Pdcd4 leads to fibroblast-like transition, promotion of Matrigel invasion, and activation of β-catenin dependent transcription. Activation of β-catenin dependent transcription by Pdcd4 knockdown results in up-regulation of urokinase-type plasminogen activator receptor (u-PAR) and c-Myc expression. Knockdown of u-PAR or c-Myc inhibits invasion in Pdcd4 knockdown cells, suggesting that both u-PAR and c-Myc contribute to the enhanced invasion induced by Pdcd4 knockdown. However, it is unclear whether down-regulation of Pdcd4 promotes metastasis in vivo.

In this study, we demonstrated that knockdown of Pdcd4 decreases the expression of epithelial markers (α-catenin and γ-catenin) and increases the protein level of mesenchymal markers (fibronectin and N-cadherin) in colon GEO and HT29 cells. These results indicate that knockdown of Pdcd4 leads to epithelial to mesenchymal transition (EMT). To delineate whether Pdcd4 knockdown promotes cell migration, wound-healing and Boyden chamber migration assays were performed. In wound-healing assay, Pdcd4 knockdown cells showed wound closure approximately 3-fold faster than control cells. In addition, the migration capacity of Pdcd4 knockdown cells is approximately 10-fold higher than that of control cells using the Boyden chamber assay. These findings indicate that knockdown of Pdcd4 promotes migration. To test whether knockdown of Pdcd4 promotes metastasis in vivo, parental, Pdcd4 knockdown, and control cells were injected into the cecal wall (orthotopic implantation) of nude mice (n = 6/group). Six weeks post-injection, samples of lung, liver, lymph node, and cecum were collected and the tumor nodules of each sample were determined. Tumors are formed on cecum in all injected mice. However, only mice injected with Pdcd4 knockdown cells developed hepatic and local lymph node metastases. No pulmonary metastasis was observed. These results indicate that Pdcd4 knockdown promotes metastasis in nude mice. Taken together, our data demonstrated that knockdown of Pdcd4 leads to EMT and promotion of migration and metastasis.

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 1440. doi:10.1158/1538-7445.AM2011-1440