bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 211: Control of integrin expression and signaling by claudin-3 and claudin-4 in ovarian cancer.
Authors: Lin Xinjian , Shang Xiying , Manorek Gerald , Howell Stephen
Published: August 2014

Changes in cell-cell and cell-matrix adhesion are central to ovarian cancer metastasis. We have previously demonstrated that the two major tight junction proteins claudin-3 (CLDN3) and claudin-4 (CLDN4) function to restrain in vivo growth and metastatic potential of ovarian cancer cells by sustaining expression of E-cadherin and limiting β-catenin signaling. Here we report that CLDN3 and CLDN4 control integrin αvβ3 expression and signaling through which they regulate cell-matrix adhesion and anchorage-dependent growth. Knockdown of CLDN3 or CLDN4 in human ovarian carcinoma cells reduced their ability to adhere to fibronectin whereas increased expression of CLDN3 or CLDN4 enhanced adherence to the extracellular matrix protein. A flow cytometric analysis revealed that CLDN3 and CLDN4 knockdown reduced αvβ3 complex formation at the cell surface by a factor of 1.7- and 12.4-fold, respectively, relative to the parental 2008 cells. Deconvoluting microscopic analysis of immunocytochemically stained cells confirmed the reduction in αvβ3 expression in the CLDN3KD and CLDN4KD cells. Measurement of β3 mRNA levels by qRT-PCR demonstrated a 55 ± 11.0% reduction in the CLDN3KD cells and a 51 ± 13.7% decrease in the CLDN4KD cells while the αv mRNA level was not affected. Interestingly, ablation of αvβ3 increased CLDN3 and CLDN4 expression at both the mRNA and protein level. Anchorage-independent growth was markedly reduced in both CLDN3KD and CLDN4KD cells with respect to the number and the size distribution of the colonies that formed in soft agar. Moreover, loss of either CLDN3 or CLDN4 resulted in activation of focal adhesion kinase (FAK) as the phosphorylation of Tyr-397 residue within FAK, which reflects FAK activity, was significantly increased in the CLDN3 and CLDN4 knockdown cells. Taken together, these results indicate a novel role for CLDN3 and CLDN4 in regulating integrin αvβ3 expression and signaling that control cell-matrix adhesion and aggressiveness of the ovarian carcinoma cells.

Citation Format: Xinjian Lin, Xiying Shang, Gerald Manorek, Stephen Howell. Control of integrin expression and signaling by claudin-3 and claudin-4 in ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 211. doi:10.1158/1538-7445.AM2013-211

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 2110: Realgar exerts cytotoxic killing of gastric cancer cells through Bax apoptotic pathway.
Authors: Chen Siyu , Tian Wei , Ding Wenping , Zheng Leizhen , Li Xiaoping , Zhang Li , Gu Jianchun , Tao shuangfen , Kim Sungkyoung , Gu Wenhua
Published: August 2014

Background:Arsenic compound has shown excellent activity in APL. Its anticancer activity in solid tumors is still being explored. We have tested realgar, arsenic sulfide (As4A4), in gastric cancer cells to understand its anticancer activity and mechanism.

Methods: The effects of the realgar on cell proliferation and apoptosis of AGS and MGC803 cell lines were determined using methyl thiazolyl tetrazolium (MTT) assay and Annexin V assay. Western blot analysis was used to detect the related pathways by measuring the expression levels of apoptotic proteins such as Bax, Bcl-2, c-myc, p53 and mdm2. Real-time PCR analysis was used to measure the mRNA levels of the related genes.

Results: Realgar significantly inhibited proliferation and induced apoptosis in gastric cancer cell lines AGS and MGC803 in a dose- and time-dependent manner, particularly in AGS cells. Realgar up-regulated the expression of p53 and p53 target genes MDM2 and Bax, down-regulated the expression of Bcl-2 and c-Myc in AGS cell lines, indicating that realgar could induce apoptosis via p53-bax pathway in AGS cell lines. However, similar dose of realgar up-regulated the expression of Bax, down-regulated the expression of Bcl-2 and c-Myc in MGC803 cell lines, with much less effect on the expression of p53.

Conclusion: Realgar has significant anti-cancer effect on gastric cancer cell lines through inhibiting cell proliferation and inducing apoptosis. Our findings suggest a potential therapeutic effect of realgar in gastric cancer and further study in this area is needed.

Citation Format: Siyu Chen, Wei Tian, Wenping Ding, Leizhen Zheng, Xiaoping Li, Li Zhang, Jianchun Gu, shuangfen Tao, Sungkyoung Kim, Wenhua Gu. Realgar exerts cytotoxic killing of gastric cancer cells through Bax apoptotic pathway. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2110. doi:10.1158/1538-7445.AM2013-2110
Abstract 2115: A chemicogenetic interrogation of colorectal cancer identifies a shared chemical vulnerability in Wnt signaling and telomere length maintenance.
Authors: Kulak Ozlem , Holohan Brody , Wu Xiaofeng , Lum Lawrence
Published: August 2014

Despite the general acceptance that loss of the APC tumor suppressor is the predominant cancer-initiating event in colorectal cancer (CRC), a therapeutic strategy premised upon disabling deviant gene transcription associated with this phenomenon currently does not exist. Chemical antagonism of the poly-ADP ribosylase enzymes Tankyrase 1 and 2 (Tnks1&2) results in the destruction of the transcriptional co-activator β-catenin by promoting the stability of a β-catenin destruction complex. We have evaluated the consequences of disrupting β-catenin activity on the CRC signaling network using faithful reporters of the most frequently corrupted cellular processes (Wnt/β-catenin, p53, and Kras signaling), and a portfolio of Tnks inhibitors identified from a chemical library screen. In addition to inducing loss of β-catenin activity, the exposure of cells to Tnks inhibitors resulted in increased p53 activity. We demonstrated that this unexpected cellular response is due to loss of Tnks ability to regulate the shelterin complex that protects the telomeric sequences found at the ends of chromosomes. Long term culturing of cancerous cells with Tnks inhibitors resulted in telomere shortening and cellular senescence. Our findings reveal a single agent strategy for targeting two cellular processes that support the renewal of cancer initiating cells - Wnt signaling and telomere length maintenance.

Citation Format: Ozlem Kulak, Brody Holohan, Xiaofeng Wu, Lawrence Lum. A chemicogenetic interrogation of colorectal cancer identifies a shared chemical vulnerability in Wnt signaling and telomere length maintenance. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2115. doi:10.1158/1538-7445.AM2013-2115
Abstract 212: Are there cell cycle-dependent variations in cadherin-mediated cell adhesion.
Authors: Cimpean Maria , Yu Yangjinqi , Laperle Brenna , Corey Edie , Thomas William A.
Published: August 2014

Cell adhesion makes possible the development of tissues and organs. It has thus been an important topic in biomedical research, cancer research in particular. One method used to quantify cell adhesion, the dual pipette assay, has shown persistent variability in the force required to separate adherent cells despite efforts to minimize variability through strict protocols and assay automation. We are using FUCCI (fluorescence ubiquitination cell cycle indicator) to determine if cell-cycle dependent changes might account for the observed variability in separation force. The FUCCI technique involves antiphase oscillating proteins that mark the cell-cycle transitions with corresponding fluorescent probes. Initial comparison of fluorescence distributions in aggregated and unaggregated FUCCI E cad cells showed no preferential accumulation in aggregates of cells in a particular stage of the cell cycle. Work continues to improve the resolution and reproducibility of the tests.

Citation Format: Maria Cimpean, Yangjinqi Yu, Brenna Laperle, Edie Corey, William A. Thomas. Are there cell cycle-dependent variations in cadherin-mediated cell adhesion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 212. doi:10.1158/1538-7445.AM2013-212

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 2120: Platinum-based cancer chemotherapeutics inhibit STAT signaling by blocking the SH2 domain.
Authors: Lesterhuis W. Joost , Hato Stanleyson V. , Figdor Carl G. , Takahashi Susumu , Punt Cornelis J.A. , Asai Akira , De Vries I. Jolanda M.
Published: August 2014

Platinum-based drugs form the corner stone of many treatment schedules in cancer. Their main mechanism of actions is the covalent binding to DNA, leading to the formation of platinum-DNA adducts and thereby inducing apoptosis. Recently, other so called off-target effects of these drugs have been described. These include the induction of immunogenic cell death and the downregulation of inhibitory molecule Programmed Death-Ligand 2 by inactivation of signaling molecule/transcription factor STAT6, a member of the Signal Transducer and Activator of Transcription (STAT) protein family. STAT proteins play crucial roles in the pathogenesis and progression of cancer and much research is being conducted to identify inhibitors of STAT signaling for use in cancer treatment.

Here, we investigated the potential of platinum-based chemotherapeutics to inhibit STAT signaling. We found that treatment of tumor cells of various origins with platinum drugs inhibit the activation of STAT proteins and leads to loss of cytokine-induced and constitutive STAT protein phosphorylation. Concurrently, a decrease of STAT protein nuclear accumulation was evident by confocal microscopy analysis. This resulted in a downregulation of STAT-regulated tumorigenic genes such as Bcl-xL, MCL-1, VEGF and survivin. Non-STAT target genes were not affected. Analysis of the known STAT inactivation pathways showed that these were not activated nor enhanced by treatment with platinum drugs. Finally, using a biochemical alphascreen-based assay, we demonstrated that platinum compounds directly interact with STAT proteins and inhibit binding to the SH2 domain.

These findings provide novel insight into the mechanism of action of platinum drugs and show for the first time that these clinically used compounds directly affect important cellular signaling pathways. These results indicate that part of the efficacy of these drugs may be derived from their inhibition of STAT signaling and they provide important leads for the development of novel innovative treatment schedules in cancer that exploit the STAT-inhibiting effect of platinum drugs, for example by potentiating targeted therapies or immunotherapy.

Citation Format: W. Joost Lesterhuis, Stanleyson V. Hato, Carl G. Figdor, Susumu Takahashi, Cornelis J.A. Punt, Akira Asai, I. Jolanda M. De Vries. Platinum-based cancer chemotherapeutics inhibit STAT signaling by blocking the SH2 domain. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2120. doi:10.1158/1538-7445.AM2013-2120
Abstract 2123: Tetrandrine impairs prostate cancer cell survival in part by inhibiting AR signaling pathway.
Authors: Koul Sweaty , Koul Hari K.
Published: August 2014

Prostate cancer (PCa) is the second leading cause of cancer deaths in men, and the majority of prostate cancer deaths are a result of emergence of castrate resistant phenotype. Our previous studies indicated that Tetrandrine (TET), a bis-benzylisoquinoline alkaloid isolated from the root of Stephania tetrandra inhibited cell cycle progression and promoted growth arrest at lower concentrations and promoted apoptosis at higher concentrations and at longer time points. AR signaling is known to play a critical role in androgen responsive prostate cancer cells. In the present studies we evaluated the effects of TET on AR signaling in androgen dependent (LNCaP cells) as well as castrate resistant (C4 and C42B cells, castrate resistant lineages of LNCaP cells) prostate cancer cells. Exposure of LNCaP cells to Tet resulted in a dose and time dependent decrease in PSA protein (cell associated as well as secreted PSA). Further analysis revealed that Tet also decreased PSA mRNA as well as PSA promoter activity, suggesting that Tet induced decrease in PSA was a result of inhibition of PSA transcription. Since PSA is known to be an AR responsive gene, these results led us to investigate the effects of Tet on AR signaling. Results from these studies revealed that Tet inhibited AR activity as measured by TARP promoter assay. Taken together these studies suggest that Tet targets AR signaling pathway effectively blocking AR target genes. In summary our results suggest that Tet by inhibiting AR signaling pathway may work as an effective therapeutic agent in prostate cancer, for which there is no cure to date.

Grant Support: Studies supported in part by VA Merit Award-01BX001258 (HK), NIH/NCI R01CA161880 (HK) and Department of Surgery, School of Medicine chair commitment (HK).

Citation Format: Sweaty Koul, Hari K. Koul. Tetrandrine impairs prostate cancer cell survival in part by inhibiting AR signaling pathway. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2123. doi:10.1158/1538-7445.AM2013-2123
Abstract 2127: Synergistic effect of carboxyl-modified magnetic nanoparticles and docetaxel on prostate cancer cells in vitro.
Authors: Watanabe Masatoshi , Sato Akiko , Okamoto Daiki , Kurioka Daisuke , Ishiguro Hitoshi , Uemura Hiroji , Kubota Yoshinobu
Published: August 2014

Chemotherapy is used for castration-resistant prostate cancer as one of treatment options. In this regard, docetaxel-based chemotherapy has been shown to improve the quality of life in patients with the advanced disease. However, this needs to be improved because of limitations by lack of specificity, systemic toxicity, and progression of docetaxel-resistance. Nanotechnology has served a new role in medical sciences by a variety of nanotechnology platforms, leading to therapy and diagnostics. Among these platforms, magnetic nanoparticles (Fe3O4) have potential applications in drug delivery, cancer diagnosis and therapy. We have shown that magnetic nanoparticles (MgNPs) would modify the effect of chemotherapy in cancer cells. In this study, we analyzed the combined effect of docetaxel and carboxyl-modified magnetic nanoparticles (MgNPs-COOH) on a prostate cancer cell line, DU145 and their mechanisms compared with the effect of MgNPs and docetaxel. The combination of docetaxel and MgNPs/MgNPs-COOH more effectively inhibited cancer cell growth and induced apoptosis. While only MgNPs produced reactive oxygen species (ROS) and inhibited cancer cell growth slightly, MgNPs-COOH did neither produce ROS nor inhibit cancer cell growth. In addition, these two MgNPs appear to inhibit the different cellular pathways involving apoptosis and inflammation. These results suggest that MgNPs-COOH may induce different responses compared with MgNPs, and result in favorable development of current chemotherapy for the advanced disease and leading to new tumor ablation therapies.

Citation Format: Masatoshi Watanabe, Akiko Sato, Daiki Okamoto, Daisuke Kurioka, Hitoshi Ishiguro, Hiroji Uemura, Yoshinobu Kubota. Synergistic effect of carboxyl-modified magnetic nanoparticles and docetaxel on prostate cancer cells in vitro. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2127. doi:10.1158/1538-7445.AM2013-2127
Abstract 2132: Analysis of adenylate cyclase 6 in HMBA induced K562 cell megakaryocyte differentiation.
Authors: Jiang Shin Hua , Ho Chiu Yi , Lee Tai Lin , Chang Yun Shiang , Huang Wei Tung , Tsai Meng Feng , Yuan Ang
Published: August 2014

Leukemia is a hematopoietic stem cell disorder and leukemia patients suffer their lost in functional blood cell and the ratio of non-function cell increased. K562 cell was isolated from the pleural effusion of the leukemia patient and was used as

a model cell line to study the relationship between the blood cell differentiation and signal transduction. In this report, three different inducers, huangqi (Astragalus membranaceus) extract, chemicals Hemin and HMBA were used to induce K562 cell differentiation and several cluster of differentiation (CD) marker were used to identify the cell linage. Two megakaryocyte markers were up-regulated in these treatments. The CD61, a late marker, was highly expressed in HMBA treated cell and CD41, an earlier marker, was identified in huangqi and HMBA treated cell. In former report, the Gi2α and Gsα was induced by the HMBA administration. Since both G proteins affect their downstream effector, adenylate cyclases (ADCYs), the

ADCYs that could be participated in the pathway were examined by RT-PCR. The

ADCY1 and ADCY6 were up-regulated in the HMBA-induced K562 cell. The ADCY6 was further studied because it coupled to calcium ion channel. The recombinant

ADCY6 transfected cells were treated with three inducers, the results showed that all inducers induceed CD61 expression especially in HMBA treated sample.

Also, the CD61 gene was 25 times higher expression as the parental cell. The results imply that the signals activated from HMBA and ADCY6 together may participate in the megakaryocyte differentiation. The study suggested that K562 cells can change the cell destination through the ADCY isoforms expression and other signal genes. These results may be used as the reference of the drug discover for leukemia treatment.

Citation Format: Shin Hua Jiang, Chiu Yi Ho, Tai Lin Lee, Yun Shiang Chang, Wei Tung Huang, Meng Feng Tsai, Ang Yuan. Analysis of adenylate cyclase 6 in HMBA induced K562 cell megakaryocyte differentiation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2132. doi:10.1158/1538-7445.AM2013-2132
Abstract 2146: Development of functional assays for p97/VCP inhibition.
Authors: Shi Yihui , Liu Xiaohe , Calaoagan Joy , Samuelsson Steven , Chou Tsui-Fen , Deshaies Raymond J. , Sambucetti Lidia C.
Published: August 2014

p97 (also called VCP in metazoans and CDC48 in yeast) is a highly conserved, ubiquitously expressed, and essential AAA ATPase. p97 plays a key role in endoplasmic reticulum-associated degradation of misfolded secretory and membrane proteins as well as ubiquitin-dependent turnover of a subset of cytoplasmic substrates of the ubiquitin-proteasome system. p97 also plays a critical role in specific cellular processes including Golgi membrane reassembly, membrane fusion, autophagy and DNA repair mechanisms. p97 expression is elevated in a number of cancer types including prostate cancer, non-small-cell lung carcinoma and leukemia. Given its cellular functions in protein homeostasis and the successful clinical development of proteasome inhibitors, p97 has emerged as an exciting new target for cancer therapy. We used p97 siRNA and a recently identified small molecule p97 inhibitor, N2,N4-dibenzylquinazoline- 2,4-diamine (DBeQ) as tools to develop functional assays suitable for further evaluating the activity of potential p97 inhibitors. A panel of unfolded protein response marker genes that are consistently modulated by p97 siRNA or DBeQ treatment has been identified. In addition, methods to monitor autophagic activity have been developed, including high content analysis of LC3B-GFP puncta formation. Cell viability assays were used to determine the susceptibility of various cancer cell lines to p97 inhibition. These assays will be used to evaluate the effects of potential p97 inhibitors on p97-dependent pathways and anti-proliferative activity.

Acknowledgement: Funded by NExT Chemical Biology Consortium, NCI Contract No. HHSN261200800001E.

Citation Format: Yihui Shi, Xiaohe Liu, Joy Calaoagan, Steven Samuelsson, Tsui-Fen Chou, Raymond J. Deshaies, Lidia C. Sambucetti. Development of functional assays for p97/VCP inhibition. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2146. doi:10.1158/1538-7445.AM2013-2146
Abstract 2158: Evaluation of the efficacy of dasatinib, a Src/Abl inhibitor, in a preclinical model of colorectal cancer.
Authors: Song Eun-Kee , Purkey Alicia , Quackenbush Kevin , Cross Benjamin , Bagby Stacey , Arcaroli John J. , Messersmith Wells
Published: August 2014

Background: Dysregulation of c-Src has been shown to modulate many different tumor cell processes. Downstream targets of Src include focal adhesion kinase (FAK), which is important for migration and invasion, and Stat-3, a kinase that enhances survival of cells and angiogenesis. Dysregulation of Src has been shown to be important at various stages of cancer development. Dasatinib is a potent Src/Abl inhibitor and has been shown to have anti-proliferative and anti-invasive activity in many preclinical models. The objective was to determine the anti-proliferative and anti-tumor effects of dasatinib in our preclinical model of colorectal cancer (CRC). Experimental Design: We used colorectal cancer cell lines and patient-derived explants to investigate the efficacy of dasatinib. We treated 45 CRC cell lines with dasatinib for 72 hours and proliferation was assayed by a sulforhodamine B (SRB) assay; an IC50 < 0.1 μM was considered sensitive. We treated 10 patient-derived CRC explants with dasatinib (50 mg/kg/day, administered once-daily) for 28 days to determine in vivo efficacy; a tumor growth inhibition inhibition (TGI) ≥ 50% was considered sensitive. Results: We found that 17 out of 41 CRC cell lines reached an IC50 < 1 uM with dasatinib treatment. The cell lines: HCT116, LS174T, SW1417, WiDR, KM20 and SNU977 all reached an IC50 < 0.08 μM, which is considered to be an achievable dose in the clinic setting. Of 10 CRC explants, grown as xenografts, one showed sensitivity to dasatinib, with a tumor growth inhibiton of 55%. Conclusion: Dasatinib has significant anti-proliferative activity in a subset of CRC cell lines in vitro, but shows moderate efficacy in one out of ten explants treated. We plan on treating an additional 10 CRC explants (20 total) with dasatinib and developing biomarkers of sensitivity or resistance.

Citation Format: Eun-Kee Song, Alicia Purkey, Kevin Quackenbush, Benjamin Cross, Stacey Bagby, John J. Arcaroli, Wells Messersmith. Evaluation of the efficacy of dasatinib, a Src/Abl inhibitor, in a preclinical model of colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2158. doi:10.1158/1538-7445.AM2013-2158
Abstract 216: HMGB1 regulates homing capacity of human mesenchymal stromal cells into colon cancer.
Authors: Hoshino Go , Yagi Hiroshi , Hasegawa Hirotoshi , Ishii Yoshiyuki , Endo Takashi , Okabayashi Koji , Yasuda Akimasa , Nakamura Masaya , Okano Hideyuki , Matsuzaki Yumi , Kitagawa Yuko
Published: August 2014

Recently a growing corpus of studies has highlighted the important aspect of Mesenchymal Stem Cell (MSC) therapy: systemically administered MSCs home to sites of cancer. In this study, we focused on a homing mechanism of human MSCs into cancer. First, we examined if cultured medium from cancer cell lines could modulate migration of MSCs, the secretion level of HMGB1 from six different colon cancer cell lines affected the migration capacity of MSCs. In addition, recombinant HMGB1 could increase the migration capacity in dose dependent manner. Finally, we applied MSCs intracutaneously into mice bearing colon cancer using a cell line which secreted high level of HMGB1. The in vivo bioluminescence live-image showed that MSCs surrounded the tumors within 48hours after their injection, additionally the immunohistochemistry revealed the existence of MSCs in the tumors. These findings are critical in understanding the role of MSCs in solid cancer, further they might facilitate therapeutic application of MSCs in the treatment of cancer.

Citation Format: Go Hoshino, Hiroshi Yagi, Hirotoshi Hasegawa, Yoshiyuki Ishii, Takashi Endo, Koji Okabayashi, Akimasa Yasuda, Masaya Nakamura, Hideyuki Okano, Yumi Matsuzaki, Yuko Kitagawa. HMGB1 regulates homing capacity of human mesenchymal stromal cells into colon cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 216. doi:10.1158/1538-7445.AM2013-216
Abstract 2168: Dual targeting of the AKT/mTOR signaling pathwayinhibits mesothelioma: Targeted therapies against multiple activated receptor tyrosine kinases.
Authors: Zhou Shengmei , Liu Li , Hu Weijiang , Li Hailong , Meng Fanguo , Zhou Haimeng , Fletcher Jonathan A. , Ou Wenbin
Published: August 2014

Mesothelioma is a notoriously chemotherapy-resistant neoplasm, as is evident in the dismal overall survival for patients with this asbestos-associated disease. The receptor tyrosine kinases EGFR and MET are activated in subsets of mesothelioma, suggesting these kinases might represent novel therapeutic targets. However, clinical trials have not shown activity for EGFR inhibitors in mesothelioma. We had previously demonstrated activation of multiple receptor tyrosine kinases, including EGFR, MET, and AXL, in individual mesothelioma cell lines, targeting HSP90 suppressed the multiple activated RTKs in mesothelioma cell lines, resulting in apo-apoptotic and anti-proliferative effects. Thus, we hypothesized that a coordinated network of multi-RTK activation contributes collectively to activate PI3-K/AKT/mTOR and/or RAF/MAPK signalings for the tumorigenesis of mesothelioma. Herein, we demonstrate abnormal activation of the PI3-K/AKT/p70S6K and RAF/MEK/MAPK pathways in mesothelioma, as compared with normal mesothelial cells. Multiple receptor tyrosine kinases, including EGFR, MET, and AXL, in individual mesothelioma cell lines, collectively activated survival signaling intermediate AKT, but not MAPK. The anti-proliferative responses of the coordinate inhibition of these multi-kinase signaling were comparable with suppression of PI3-K/AKT/mTOR pathway. Dual targeting AKT/mTOR signaling has substantially greater effect on mesothelioma proliferation and survival, compared to inhibition of individual activated kinases and downstream signaling alone, suggesting that no one activated RTK is the predominant oncogenic control mechanism in mesothelioma and PI3-K/AKT/mTOR is a crucial survival pathway. The AKT/mTOR signaling inhibition by BEZ235 resulting in pro-apoptotic and anti-proliferative effects in mesothelioma, was associated with the blockage of MDM2-p53 interaction.

Citation Format: Shengmei Zhou, Li Liu, Weijiang Hu, Hailong Li, Fanguo Meng, Haimeng Zhou, Jonathan A. Fletcher, Wenbin Ou. Dual targeting of the AKT/mTOR signaling pathwayinhibits mesothelioma: Targeted therapies against multiple activated receptor tyrosine kinases. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2168. doi:10.1158/1538-7445.AM2013-2168
Abstract 2172: Effects of RAD001 on the protein expression pattern and function of tumor and immune cells.
Authors: Stehle Franziska , Schulz Kristin , Kalich Jana , Fahldieck Corinna , Seliger Barbara
Published: August 2014

The crucial role of the PI3K/Akt/mTOR pathway in the pathogenesis of cancer has led to the development of various therapeutics targeting this signaling cascade. The serine/threonine kinase mTOR is involved in the regulation of the different growth properties of both tumor and immune cells. Furthermore, mTOR forms two macromolecular complexes: (i) the rapamycin-sensitive mTORC1, which contains RAPTOR and (ii) mTORC2, which is rapamycin-insensitive and contains RICTOR. Downstream targets of these complexes like HIF-1alpha and HIF-2alpha or cyclin D1 are responsible for the activation of various intracellular processes leading to the activation of cell proliferation, induction of angiogenesis, and metastasis. The effects of mTOR inhibitors have been most studied in T cells, although recently it has been shown that renal cell carcinoma (RCC) is tightly controlled by mTOR and that mTOR pathway activation represents an adverse prognostic factor. Thus targeted inhibition of mTOR represents a promising therapeutic approach for the treatment of RCC patients. Since it is currently discussed whether the RAD001-mediated effect on T cells might negatively interfere with its anti-tumoral activity in RCC we here analyzed the effects of RAD001 on the immune cell repertoire as well as the growth properties and protein expression pattern of RCC cells. We could show a decrease in the frequency of T cells which was associated with an altered expression of chemokines/ chemokine receptors suggesting an altered T cell homing. Furthermore, RAD001 exerts a dose-dependent growth inhibitory effect in RCC cells. This was accompanied by distinct expression levels of various proteins in RCC cells. So far, 11 differentially expressed proteins were identified by MALDI-TOF analysis, which are involved in cell proliferation and gene regulation. Currently functional analysis of RAD001-regulated proteins in T lymphocytes and RCC cells are performed providing better insights into the consequences of the mTOR inhibition.

Citation Format: Franziska Stehle, Kristin Schulz, Jana Kalich, Corinna Fahldieck, Barbara Seliger. Effects of RAD001 on the protein expression pattern and function of tumor and immune cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2172. doi:10.1158/1538-7445.AM2013-2172

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 2175: Src homology region 2 domain-containing phosphatase-1 is a major target of sorafenib in hepatocellular carcinoma.
Authors: Tai Wei-Tien , Shiau Chung-Wai , Chen Pei-Jer , Cheng Ann-Lii , Chen Kuen-Feng
Published: August 2014

Sorafenib is the only clinical approved drug in hepatocellular carcinoma (HCC). Previously, we have investigated that Signal transducer and activator of transcription 3 (STAT3) is a kinase-independent target of sorafenib (Journal of Hepatology, 2012). Here, we report that sorafenib relieves the anto-inhibited Src homology region 2 domain-containing phosphatase-1 (SHP-1) to increase its phosphatase activity and inhibit p-STAT3-related signaling. Sorafenib increases SHP-1 activity either in HCC cell-based test or purified recombinant SHP-1 protein directly. Deletion of N-SH2 domain (dN1) or point mutation (D61A) of SHP-1 abolished the effect of sorafenib on SHP-1 and phospho-STAT3 (p-STAT3) and apoptosis in HCC, suggesting that sorafenib may affect SHP-1 by switching the transformation from auto-inhibition to the active form. The significant correlation between inhibited SHP-1 and overexpression of p-STAT3 was demonstrated in immunohistochemistry of clinical HCC samples. Novel sorafenib derivatives, SC-43 and SC-40, showed more potent effects than sorafenib on enhancing the activity of SHP-1 activity, inhibiting p-STAT3, induction apoptosis and overcoming sorafenib resistance in HCC. SC-43 showed better survival benefits than sorafenib in orthotopic HCC tumors. SHP-1 represents a major target of sorafenib in HCC. Sorafenib derivatives (SC-43 and SC-40) show better anti-HCC effects than sorafenib by targeting SHP-1. Further clinical investigations may be warranted.

Citation Format: Wei-Tien Tai, Chung-Wai Shiau, Pei-Jer Chen, Ann-Lii Cheng, Kuen-Feng Chen. Src homology region 2 domain-containing phosphatase-1 is a major target of sorafenib in hepatocellular carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2175. doi:10.1158/1538-7445.AM2013-2175
Abstract 2182: Novel ATP-competitive protein kinase D inhibitors: in vitro characterization and SAR analysis.
Authors: Tandon Manuj , Johnson James , Farber Elisa , Carder Evan , Wipf Peter , Wang Qiming J.
Published: August 2014

Protein Kinase Ds (PKDs) are serine/threonine kinases targeted by the second messenger diacylglycerol. The three isoforms of PKD (PKD1, PKD2, and PKD3) have emerged as key mediators in diverse cellular processes pertaining to cancer development including proliferation, apoptosis, migration/invasion and angiogenesis. Potent and selective PKD inhibitors are powerful tools in dissecting PKD-mediated cellular pathways and promising leads for developing effective anticancer agents. From targeted kinase inhibitor library screens we identified three highly potent novel ATP-competitive PKD inhibitors, IKK 16, 1-naphthyl PP1 and SD 208 with in vitro PKD inhibitory activity in low nanomolar range. All inhibitors except IKK 16 showed high selectivity for PKD relative to the related kinase family PKC and CAMK. When tested in LNCaP prostate cancer cells the compounds inhibited phorbol ester-induced PKD1 activation in a concentration dependent manner. SD 208 was found to be most specific for PKD and it did not affect the PKC mediated trans-phosphorylation of PKD1 at S744/748. Importantly, 1-naphthyl PP1 and SD 208 potently blocked prostate cancer cell proliferation and concentration-dependently induced cell death. SAR analysis of SD 208 and 1-naphthyl PP1 led to identification of key structural elements that are important for PKD inhibitory activity. In summary, we have identified and evaluated a panel of structurally divergent novel ATP-competitive PKD small molecule inhibitors with potent PKD inhibitory activities that could be further developed as potential antitumor agents in prostate cancer.

Citation Format: Manuj Tandon, James Johnson, Elisa Farber, Evan Carder, Peter Wipf, Qiming J. Wang. Novel ATP-competitive protein kinase D inhibitors: in vitro characterization and SAR analysis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2182. doi:10.1158/1538-7445.AM2013-2182
Abstract 2191: GABA but not baclofen prevents gemcitabine resistance induced by low dose nicotine in pancreatic cancer xenografts.
Authors: Banerjee Jheelam , Al-Wadei Mohammed H. , Al-Wadei Hussein A. N. , Schuller Hildegard M.
Published: August 2014

Pancreatic ductal adenocarinoma (PDAC) is a leading cause of cancer deaths in developed countries. The nucleoside analog Gemcitabine, which induces apoptosis, is widely used for the therapy of pancreatic cancer. Smoking and alcoholism are risk factors for pancreatic cancer. Nicotine replacement therapy often accompanies chemotherapy while the GABA-B receptor (GABA-B-R) agonist Baclofen has recently been suggested as an effective agent for the treatment of alcohol dependence. Our laboratory has shown that the proliferation and migration of PDAC and pancreatic duct epithelial cells in vitro is regulated by the nicotinic receptor-mediated synthesis and release of stress neurotransmitters that bind to beta-adrenoreceptors (beta-ARs). We have additionally shown that nicotine in the drinking water at a high dose (432 μmole/L) comparable to nicotine exposure in heavy smokers significantly stimulated the growth of PDAC xenografts whereas identical exposure of mice to low dose nicotine (1 μmole/L) reduced gemcitabine-induced apoptosis, thus significantly increasing resistance to gemcitabine. In the current study, we have investigated the potential prevention of nicotine-induced gemcitabine resistance by γ-aminobutyric acid (GABA) and Baclofen in PDAC xenografts. We found that GABA significantly reduced nicotine-induce drug resistance. By contrast, Baclofen failed to reduce nicotine-induced resistance to gemcitabine while even slightly increasing xenograft growth in mice not exposed to nicotine. Investigation of xenograft tissues for the expression levels of the GABA-B-R, intracellular cAMP and signaling proteins associated with cell proliferation, apoptosis and metastasis by immunoassays and western blots revealed effective inhibition of cAMP-dependent signaling in xenografts of mice treated with GABA. By contrast, Baclofen did not inhibit cAMP-dependent signaling and decreased the protein expression of the GABA-R, suggesting downregulation of the receptor. Our findings identify GABA as a promising agent for the prevention of nicotine-induced resistance to gemcitabine in PDAC. On the other hand, our data suggest that treatment of alcohol dependence by Baclofen should be avoided in PDAC patients. Supported by grants RO1CA130888 and RO1CA042829 with the National Cancer Institute.

Citation Format: Jheelam Banerjee, Mohammed H. Al-Wadei, Hussein A. N. Al-Wadei, Hildegard M. Schuller. GABA but not baclofen prevents gemcitabine resistance induced by low dose nicotine in pancreatic cancer xenografts. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2191. doi:10.1158/1538-7445.AM2013-2191
Abstract 2198: Possible circadian modulation of dihydropyrimidine dehydrogenase by mir-27a and mir-27b.
Authors: Butterfield Gabriel L. , Offer Steven M. , Diasio Robert B.
Published: August 2014

5-fluorouracil (5-FU) is a commonly administered chemotherapy drug used for the treatment of various aggressive cancers. Dihydropyrimidine dehydrogenase (DPD, encoded by the DPYD gene) is the rate limiting enzyme of the 5-flourouracil (5-FU) catabolic pathway, and as such limits the amount of drug available for conversion into active metabolites. Reduced expression of DPD has been linked to severe adverse toxicity to 5-FU, including mucositis, diarrhea, hematological toxicities, and, in extreme cases, death. DPD has been previously shown to follow circadian patterns of expression in rodent models and in humans. Many microRNAs also exhibit circadian variations in expression and have been suggested to control oscillations in target protein expression. Using in silico prediction, we identified two putative binding domains for the microRNAs mir-27a and mir-27b within the DPYD gene. One of these sites is located in the 3’ untranslated region (UTR) and the other is located within the coding region just upstream from the stop codon. Using a reporter system, we show that mir-27a and mir-27b are able to bind to both predicted binding sites. Furthermore, over-expression of either microRNA reduced endogenous DPD protein levels in the HT-29 colon cancer cell line. To investigate mir-27a/b as a potential circadian regulator of DPD expression, expression was measured in livers collected at 4-hour intervals from chrono-synchronized mice. As expected, the circadian pattern of DPD enzyme activity closely matched that of DPD expression. The expression patterns for mir-27a and mir-27b were inverse of those for DPD expression and activity. These data suggest that mir-27a and mir-27b may direct circadian variations in DPD enzyme activity.

Citation Format: Gabriel L. Butterfield, Steven M. Offer, Robert B. Diasio. Possible circadian modulation of dihydropyrimidine dehydrogenase by mir-27a and mir-27b. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2198. doi:10.1158/1538-7445.AM2013-2198
Abstract 2199: Associations of genetic polymorphisms in VEGFR1 with progression-free and overall survival in patients with neuroendocrine tumors treated with the VEGFA inhibitor bevacizumab.
Authors: Ter-Minassian Monica , Qian ZhiRong R. , Chan Jennifer A. , Hooshmand Susanne M. , Brais Lauren K. , Heafield Rachel , Lin Xihong , Liu Geoffrey , Christiani David C. , Kulke Matthew H.
Published: August 2014

Background:

Neuroendocrine tumors (NET) have been shown to be responsive to treatment with VEGF pathway inhibitors. We hypothesized that genetic variation in VEGFA, VEGFR1 or VEGFR2 is associated with progression free survival (PFS) and/or overall survival (OS) in patients with metastatic NET treated with bevacizumab, a monoclonal antibody targeting VEGFA.

Methods:

We selected 61 functional and tagging SNPs with a minor allele frequency of 5% or greater, with full gene coverage of VEGFA, VEGFR1 and VEGFR2. We pooled data from two genotyped datasets, selecting 82 patients with metastatic NET who received bevacizumab administered either as a single agent or as part of a combination regimen. Using a Cox proportional hazards regression analysis, and an additive genetic model, we tested the SNPs’ associations with PFS and OS adjusting for age and stage at diagnosis, gender, tumor origin, grade of differentiation, and genotyping dataset.

Results:

We found that 4 intronic tagging SNPs in VEGFR1, rs7987649, rs9508021, rs9513095 and rs2104330 were associated with PFS at p<0.05. The association between rs7987649 and PFS (multivariate Hazard Ratio 0.55 (0.38, 0.81) p=0.002) remained significant after adjusting for multiple testing. One of the four SNPs associated with PFS, rs7987649, as well as another SNP in VEGFR1, rs3794339, were associated with OS at p<0.05 although these associations did not remain significant after multiple testing adjustment. No SNPs in either VEGFR2 or VEGFA were associated with PFS or OS.

Conclusions:

In patients with neuroendocrine tumors treated with bevacizumab, the VEGFR1 SNP rs7987649 appears to be associated with progression-free survival. We note that three SNPs identified in our analysis, rs9508021, rs9513095 and rs2104330, are in strong linkage disequilibrium with SNPs rs7993418 and rs9582036, which have been associated with increased VEGFR1 expression and with PFS and OS in pancreatic adenocarcinoma (Lambrechts, 2012). Further study of loci within this region of VEGFR1 is warranted to discover potential causal variants affecting NET survival.

Citation Format: Monica Ter-Minassian, ZhiRong R. Qian, Jennifer A. Chan, Susanne M. Hooshmand, Lauren K. Brais, Rachel Heafield, Xihong Lin, Geoffrey Liu, David C. Christiani, Matthew H. Kulke. Associations of genetic polymorphisms in VEGFR1 with progression-free and overall survival in patients with neuroendocrine tumors treated with the VEGFA inhibitor bevacizumab. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2199. doi:10.1158/1538-7445.AM2013-2199
Abstract 222: Anticancer effects of Withaferin A on UP-LN1 carcinoma cells through the inhibition of STAT3 phosphorylation and IFN-γ-mediated induction of metastatic cancer stem cells .
Authors: Yeh Chi-Tai , Wu Alexander TH , Chen Hung-Chang , Chuang Cheng-Keng , Pang See-Tong , Liao Shuen-Kuei
Published: August 2014

Cancer stem cells (CSCs) have been defined as a subpopulation of cancer cells with the ability of self-renewal, giving rise to different progenies, and transition between epithelial and mesenchymal status in response to the tumor microenvironment. Due to the lack of an appropriate cell model, our understanding of CSC biology remains poor and the development of CSC antagonists is challenging. We herein used the UP-LN1 cell line as a CSC model which was derived from a gastrointestinal tumor-to-lymph node metastasis lesion. UP-LN1 cells constitute two major components, the floating (F) and adherent (A) cells. F cells were identified as the primary niche of CSCs, and could be serially subcultured while maintaining their stem-like properties including high self-renewal potential, formation of suspended grape-like aggregates and/or spheres, resistance to multiple drugs and NK/LAK effectors, as well as an increased CDY1 (a novel iPS probe) dye retention. Using this cell model, we demonstrated that Withaferin A (WA) dramatically reduced the proliferation of F cells and their ability to form aggregates in vitro. WA also dose-dependently reduced the side population cells. Mechanistically, WA treatment resulted in the down-regulation of two axes, CXCR4 and STAT3, both instrumental in the acquisition of metastatic ability and the development/maintenance of CSCs. We validated the in vitro results using non-invasive imaging technique in a xenograft mouse model. WA-treated animals demonstrated a marked decrease in tumor burden and metastasis, indicating that WA is potentially an effective agent for targeting CSCs.

Citation Format: Chi-Tai Yeh, Alexander TH Wu, Hung-Chang Chen, Cheng-Keng Chuang, See-Tong Pang, Shuen-Kuei Liao. Anticancer effects of Withaferin A on UP-LN1 carcinoma cells through the inhibition of STAT3 phosphorylation and IFN-γ-mediated induction of metastatic cancer stem cells . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 222. doi:10.1158/1538-7445.AM2013-222
Abstract 224: Targeting reprogramming the stemness in breast carcinogenesis by 2-Methoxyestradiol.
Authors: Maity Gargi , Banerjee Snigdha , De Archana , Sarkar Sandipto , Das Amlan , Banerjee Sushanta
Published: August 2014

2-Methoxyestradiol (2ME2), a natural metabolite of estradiol is a potent antitumor and antiangiogenic agent. 2ME2 inhibits the proliferation of a wide variety of cancer cell and primary cultures and blocks tumor growth in the tumor xenograft model. 2-ME2 is currently undergoing Phase I and II clinical trial under the commercial name Panzem. Although various molecular targets have been proposed for this compound, the impact of 2ME2 on reprogramming of stemness is unknown. Thus, the purpose of this was to determine whether 2ME2 can modulate pathophysiological events like epithelial to mesenchymal transition (EMT), cell migration and stemness in breast cancer cell. Our study indicated that 2ME2 inhibits EMT by down regulating mesenchymal markers like vimentin, Snail, Twist and upregulating epithelial markers like keratin-19, E-cadherin in both low metastatic (MCF-7) and high metastatic (MDA-MB-231) breast cancer cells. We found that 2ME2 significantly reduced in vitro breast cancer cell proliferation and migration. We also showed that 2ME2 not only decreased expression of stem cell markers CD44 and oct4 and increased CD24 expression in breast cancer cells it also inhibits stemness or self -renewal property of breast cancer stem cell as observed from mammosphere assay. Overall our results may help to understand the role of 2ME2 in EMT process followed by stemness, which may facilitate to develop new therapeutic targets in breast cancer management.

Citation Format: Gargi Maity, Snigdha Banerjee, Archana De, Sandipto Sarkar, Amlan Das, Sushanta Banerjee. Targeting reprogramming the stemness in breast carcinogenesis by 2-Methoxyestradiol. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 224. doi:10.1158/1538-7445.AM2013-224

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.