bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B54: Role and underlying mechanism of Runx3-Lgr5 in colon cancer cell lines.
Authors: Kim Bo Ram , Kang Myoung Hee , Kim Jun Suk , Oh Sang Cheul
Published: August 2014

The cancer stem cells (CSCs) are thought to be responsible for recurrence and drug resistance after chemotherapy. CSCs markers are mostly studied in breast cancer and other cancers but study of CSCs marker is insufficient in GI cancers. LGR5 (Leucine-rich-repeat-containing G protein-coupled receptor5) is Wnt target gene that marks dividing stem cells such as hair follicle, intestine and stomach. Recently, the various evidences suggest LGR5 as cancer stem cell marker in colon cancer. However, its function and mechanism remain unclear. RUNX3(runt[[Unable to Display Character: ‑]]related transcription factor 3) is known as tumor suppressor gene in gastrointestinal epithelium. It is reported that loss of RUNX3 induces EMT, makes stem cell like subpopulation and reveals remarkable LGR5. But It is unclear whether upregulation of LGR5 influences tumorigenesis in colon CSC. Here we found that LGR5 is down-regulated when RUNX3 endogenously expressed whereas LGR5 is up-regulated when RUNX3 don't endogenously expressed in colon cancer. So, we confirm that overexpression of RUNX3 decrease proteinexpression of epithelial-mesenchymal transition(EMT) markers by western blotting and mRNA expression of LGR5, SOX2, OCT4, and NANOG by Real Time-PCR. We knockdown RUNX3 by siRNA in colon cancer cells that endogenously expressed RUNX3. The siRNA increases expression of LGR5. We performed colonosphere culture to measure size and number. Overexpression of RUNX3 decreases size, number and CSCs marker level whereas, knockdown of RUNX3 increases size, number and CSCs marker level in colonosphere formation.

These studies suggest that role of Lgr5 as colon cancer stem cell marker and Runx3 known as tumor suppressor gene and aim to identify the mechanism of the metastasis of colon cancer and recurrence with Lgr5 and RUNX3.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B54.

Citation Format: Bo Ram Kim, Myoung Hee Kang, Jun Suk Kim, Sang Cheul Oh. Role and underlying mechanism of Runx3-Lgr5 in colon cancer cell lines. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B54.
Abstract B60: FUCCI cell cycle imaging identifies drug-resistant quiescent cancer cells within tumors.
Authors: Yano Shuya , Tome Yasunori , Zhang Yong , Miwa Shinji , Suetsugu Atsushi , Kishimoto Hiroyuki , Tazawa Hiroshi , Bouvet Michael , Fujiwara Toshiyoshi , Hoffman Robert M.
Published: August 2014

Fluorescence ubiquitination cell cycle indicator (FUCCI) imaging was used to identify the cell cycle phase of cancer cells in small and large tumors. In nascent tumors in nude mice, approximately 30% of the cells in the center of the tumor were in G0/G1 and 70% were in S/G2/M. In contrast in a large tumor, approximately 90% of cancer cells were in G0/G1 phase. Similarly, approximately 75% of cancer cells far from (>100 µm) tumor blood vessels were in G0/G1. Longitudinal real-time imaging demonstrated that cytotoxic drugs used in the clinic killed only proliferating cancer cells at the surface of the tumors and, in contrast, had little effect on quiescent cancer cells that are the vast majority of an established tumor. These results demonstrate why solid tumors are usually drug resistant in the clinic. The results also suggest that drugs that target quiescent cancer cells are urgently needed.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B60.

Citation Format: Shuya Yano, Yasunori Tome, Yong Zhang, Shinji Miwa, Atsushi Suetsugu, Hiroyuki Kishimoto, Hiroshi Tazawa, Michael Bouvet, Toshiyoshi Fujiwara, Robert M. Hoffman. FUCCI cell cycle imaging identifies drug-resistant quiescent cancer cells within tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B60.
Abstract B71: DNA damage responses to cisplatin and dicycloplatin, a new platinum analog.
Authors: Yu Jing Jie , Yang Xuqing , Song Qinhua , Mueller Michael D. , Remick Scot C.
Published: August 2014

Background: Dicycloplatin (DCP), a new platinum compound approved by the Chinese FDA in March of 2012, shows better water solubility, greater stability, and lower toxicity, compared to cisplatin and carboplatin. Preclinical in vitro and in vivo studies and a Phase I clinical trial demonstrated that DCP possesses strong antitumor activity and lower adverse events than carboplatin. Phase II clinical trials using dicycloplatin plus paclitaxel in chemotherapy-naïve patients with advanced NSCLC found that efficacy and safety of DCP plus paclitaxel regimen were comparable to those of carboplatin plus paclitaxel regimen, with slightly better tolerance. Materials and Methods: Pharmacokinetic study of DCP characteristics was conducted using AP-4000TM LC-MS/MS System in patient blood samples. Molecular mechanism studies of dicycloplatin-induced gene-signature profiling were determined by Immunoblotting and compared to cisplatin profiling in human ovarian cancer cells. Results: Pharmacokinetic mass spectrometry shows different spectrums of dicycloplatin and of carboplatin in plasma. Two hours after administration, plasma concentration of dicycloplatin prototype is still high (17.1 μg/ml), following a peak concentration of 26.9 µg/ml at 0.5-h. Molecular mechanism investigation showed DCP-induced activation of several kinases including phosphorylations of Chk2 at threonine 68, p53 at serine 15 and BRCA1 at serine 1497. The increases in p-Chk2 and p-BRCA1 showed that the amount of DCP-induced phosphorylation doubled at 48-h and tripled for p-p53 at 24-h, compared to controls. Conclusion: Dicycloplatin appears to activate DNA damage-repair pathways through mechanisms similar to cisplatin.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B71.

Citation Format: Jing Jie Yu, Xuqing Yang, Qinhua Song, Michael D. Mueller, Scot C. Remick. DNA damage responses to cisplatin and dicycloplatin, a new platinum analog. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B71.
Abstract C105: Development and utilization of a cell morphology database, MorphoBase, for drug target identification.
Authors: Futamura Yushi , Kawatani Makoto , Muroi Makoto , Aono Harumi , Osada Hiroyuki
Published: August 2014

Background: Tumor cells often dynamically and specifically change shape depending on the mode of action of a drug. It prompted us to accumulate information on morphological changes induced by various compounds with known mechanisms and construct a database linking morphology to drug function, termed “MorphoBase,” which may be helpful in the target identification of a drug and the discovery of unique bioactive compounds.

Material and Methods: We designed a high-content imaging algorithm to segment the cells and quantify the effects of various authentic compounds on morphological changes in 2 cancer cell lines, srcts-NRK and HeLa cells, against 12 morphological parameters. We also developed a data analysis program that incorporated multivariate statistical tools to analyze the similarities in morphological changes; principal component analysis (PCA) was applied to visualize phenotypic responses, and the similarities in morphological changes were ranked by 2 statistical computations: “Similarity ranking” determined by Euclidean distances and “Probability scores.”

Results: A test set of 208 authentic compounds was created and their multiparametric phenotype responses were analyzed. As a result, inhibitors with a common mode of action formed clusters in PCA and were mutually ranked in their top 20 nearest neighbors, suggesting that MorphoBase can be used to successfully profile phenotypes by drug function. The importance of this database was verified by establishing the molecular targets of three antimitotic drugs and a new cytotoxic fungal metabolite pyrrolizilactone. When compared the similarity in induction of each morphologic feature with those in the dataset, their molecular targets were predicted to be tubulin and proteasome, respectively. We thus demonstrated that these compounds actually inhibit plausible targets in vitro and in a cell-based system.

Conclusions: As an alternative to current high-content approaches, we developed a phenotype profiling system, based on MorphoBase. Our new system classifies the compounds by mode of action and predicts the molecular target of compounds with unknown mechanisms. This sensitive and convenient profiling tool has the potential to significantly cut the time it takes to establish on- and off-target effects of novel anticancer drugs, and will facilitate the discovery of bioactive compounds with unique mechanisms of action as well.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C105.

Citation Format: Yushi Futamura, Makoto Kawatani, Makoto Muroi, Harumi Aono, Hiroyuki Osada. Development and utilization of a cell morphology database, MorphoBase, for drug target identification. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C105.
Abstract C107: Isolation and characterization of human breast epithelial cells.
Authors: Hoynowski Steven
Published: August 2014

Breast cancer is one of the most common cancers among women in the United States and it is the second leading cause of cancer deaths in this population. Roughly 232,000 women in the U.S. were diagnosed with malignant breast cancer in 2013 and approximately 40,000 of these patients will die. The majority of breast cancers originate in the lobular or ductal cells of the milk-producing glands. In these structures, there are two main cell types: the inner luminal cells, which are surrounded by basal myoepithelium. These cells are structurally distinct and are the precursors to variable forms of breast cancer. As such, it is important to study them not only separately but also together. Current methods for culturing human mammary epithelial cells select for those of a basal phenotype. Isolation of pure basal and luminal cell populations was accomplished by using antibody-linked magnetic beads to isolate essentially pure populations of both basal (CALLA/CD10) and luminal mammary (MUC1/CD227) epithelial cells from organoid explant cultures. Organoids were isolated and plated on collagen I coated flasks in either DFCI (basal) or MBCM (luminal) media and cultured at 37°C in 5% CO2 to induce cell migration. The media was replenished every 2 - 3 days until the cells reached confluence. Cultured cells were harvested and immunopurified using a CALLA/CD10 or MUC1/CD227 antibody and magnetic beads. Positively selected cells were seeded in tissue culture treated flasks and propagated with medium exchange every 2 - 3 days. Each cell population was analyzed using flow cytometry to determine their purity. The DFCI/CD10 cells were over 98% CD10 positive with very little MUC1 reactivity, suggesting that they are an essentially pure basal epithelial cell population. The cells isolated using MBCM/MUC1 appear to be a mixed population with 86% MUC1 positive luminal cells and the remainder being CD10 positive basal cells. A second round of immunopurification resulted in an isolated cell population that was greater than 95% MUC1 positive, suggesting a pure luminal epithelial cell population. This procedure has been used on several organoid preparations and has generated high cell yields in addition to high cell purity. These isolated cell types can now be tested individually for drug sensitivity.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C107.

Citation Format: Steven Hoynowski. Isolation and characterization of human breast epithelial cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C107.
Abstract C12: Beta-catenin enhances synovial sarcomagenesis and provides a therapeutic target.
Authors: Jones Kevin B. , Illum Benjamin , Jin Huifeng , Zhu Mu Julie , Monument Michael , Grossmann Allie , Capecchi Mario R.
Published: August 2014

β-catenin is a master regulator in the cellular biology of development and neoplasia. Its dysregulation is implicated as a driver of colorectal carcinogenesis and the epithelial-mesenchymal transition in other cancers. Nuclear β-catenin is known to be a poor prognostic sign in synovial sarcoma, the most common soft-tissue sarcoma in adolescents and young adults. Beyond this prognostic correlation, the biology of β-catenin's role in synovial sarcoma has not been explored. We show through genetic experiments in mice demonstrate that loss of β-catenin hampers SS18-SSX2-driven synovial sarcomagenesis. Expression of a stabilized form of β-catenin greatly enhances synovial sarcomagenesis. Stabilization of β-catenin specifically enables transformation under the influence of the SS18-SSX2 fusion oncogene by blocking differentiation and apoptosis. As part of the mechanism of this impact, β-catenin recruits BRG1-containing SWI/SNF chromatin remodeling complexes to activated target genes. Compounds disrupting the transcriptional activity of β-catenin are toxic to human and mouse synovial sarcoma cell lines.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C12.

Citation Format: Kevin B. Jones, Benjamin Illum, Huifeng Jin, Julie Zhu Mu, Michael Monument, Allie Grossmann, Mario R. Capecchi. Beta-catenin enhances synovial sarcomagenesis and provides a therapeutic target. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C12.
Abstract C123: Frameshift mutations of chromosome cohesion-related genes SGOL1 and PDS5B in gastric and colorectal cancers with high microsatellite instability.
Authors: An Changhyeok , Kim Min Sung , Lee Jae Im , Yoo Nam Jin , Lee Sug Hyung
Published: August 2014

Background: Cohesin is a protein complex that regulates chromatid cohesion and plays roles in preventing aneuploidy and maintaining chromosomal stability. SGOL1 encodes a cohesin protector and PDS5B encodes a regulatory cohesion factor. Both SGOL1 and PDS5B are considered putative tumor suppressor genes.

Purpose: Aim of this study was to explore whether SGOL1 and PDS5B genes are mutated and expressionally altered in gastric (GC) and colorectal cancers (CRC).

Method: In a database, we found that both genes possessed mononucleotide repeats in coding sequences that could be mutation targets in cancers with microsatellite instability (MSI). We analyzed mutations in them in 91 GC and 100 CRC with high MSI (MSI-H) or stable MSI/low MSI (MSS/MSI-L) by single-strand conformation polymorphism analysis and DNA sequencing. We also analyzed SGOL1 and PDS5B expressions in the GC and CRC by immunohistochemistry.

Results: Overall, we found 21 SGOL1 frameshift mutations in 21 cancers and 18 PDS5B frameshift mutations in 16 cancers. SGOL1 and PDS5B frameshift mutation were detected in 26.6% and 20.3% of MSI-H respectively, but not in MSS/MSI-L (0/112). In immunohistochemistry, losses of SGOL1 and PDS5B were identified in 19 - 47% of the GC and CRC irrespective of MSI status. The losses were more common in those with the frameshift mutations or MSI-H than those without the mutations or MSI-H.

Conclusion: The data indicate that frameshift mutations of SGOL1 and PDS5B, and their losses may be a feature of GC and CRC with MSI-H. Also, the data suggest that these alterations might contribute to cancer pathogenesis by deregulating cohesin-related functions.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C123.

Citation Format: Changhyeok An, Min Sung Kim, Jae Im Lee, Nam Jin Yoo, Sug Hyung Lee. Frameshift mutations of chromosome cohesion-related genes SGOL1 and PDS5B in gastric and colorectal cancers with high microsatellite instability. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C123.
Abstract C131: HSP27 is necessary in cells showing oncogene hyper-activation.
Authors: Konda Johndavid , Olivero Martina , Musiani Daniele , Lamba Simona , Bardelli Alberto , Di Nicolantonio Federica , Di Renzo Maria Flavia
Published: August 2014

The small heat shock protein of 27 KDa (HSP27) encoded by the HSPB1 gene, is a molecular chaperone with anti-aggregation property, it participates in sequestering damaged proteins, and is involved in the proteasomal degradation of certain proteins under stress conditions. Besides its role in stressed condition, HSP27 plays crucial roles within the cell under unstressed conditions and it provides cytoskeletal structural stability and exerts important anti-apoptotic function by binding apoptotic proteins. Clinically, Hsp27 is highly expressed in many cancers including breast, ovarian and prostate carcinomas and is associated with aggressive tumor behaviour, metastasis, poor prognosis and resistance to chemotherapeutics. Using LV driven expression of HSP27 specific shRNA, HSP27 suppression in three gastric cancer cell lines (GTL-16, MKN-45 and EBC-1) showing addiction to MET because of MET gene amplification was able to induce cell death. Moreover, HSP27 silencing synergized in inducing apoptosis with the MET inhibitor JNJ-38877605, which alone was only able to induce cell cycle blockade. Similarly, (H3255) lung carcinoma and (DiFi) colorectal carcinoma cell lines which carry EGFR amplification and are susceptible to EGFR inhibition were exquisitely susceptible to HSP27 silencing, that induced cell death. HSP27 silenced in twenty human colorectal (CRC) cell lines with either wt KRAS or harbouring KRAS mutations (SW620, LS513, LS1034) or BRAF mutations (OXCO-1, COLO741, COLO-201, COLO-205), Among them the LS513 and LS1034 cells and the COLO-201 and COLO-205, addicted to KRAS and BRAF, respectively, came out to be also addicted to HSP27, as they undergo apoptosis by HSP27 silencing. Taken together, these data suggest that cells addicted to oncogene over-activation require HSP27 for survival and that HSP27 interferes with the effectiveness of targeted agents. Due to its involvement in cancer development, the inhibition of HSP27 has been proposed as a potential cancer treatment strategy. Antisense and peptide aptamer strategies have shown that targeting HSP27 increases cancer cell death in vitro and in vivo in preclinical models. More important, an antisense drug inhibiting HSP27 is available for human therapy and is ongoing Phase II clinical trials. Therefore, HSP27 knockdown in combination with targeted therapies can be envisaged as a viable therapeutic approach for clinical application.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C131.

Citation Format: Johndavid Konda, Martina Olivero, Daniele Musiani, Simona Lamba, Alberto Bardelli, Federica Di Nicolantonio, Maria Flavia Di Renzo. HSP27 is necessary in cells showing oncogene hyper-activation. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C131.
Abstract C153: New approaches to target mevalonate biosynthesis in cancer.
Authors: Brodsky Alexander , Casella Cinzia
Published: August 2014

To support rapid growth, tumors need to synthesize lipids and cholesterol, and stopping production of these metabolites can inhibit tumors. Statins are among the most prescribed and well-tolerated drugs in the world to treat cardiovascular disease by inhibiting cholesterol synthesis. Statins are known to be toxic to cancer cells and have attracted renewed attention because of the increased appreciation of the importance of the regulation of metabolism in tumors. Statins have not progressed beyond clinical trials because some patients significantly benefit, while others do not in a range of cancers. Our strategy is to improve our understanding of the mechanisms of tumor responses to statins and thereby enhance statin toxicity to cancer cells. We have found that combining statins with oxysterols synergistically enhances statin toxicity by 10-fold. Oxysterols are oxidized cholesterol metabolites that naturally occur during cholesterol synthesis. We hypothesize that oxysterols inhibit the expression of cholesterol synthesis through a master regulator of metabolism, SREBP-2, making cells more sensitive to statins. We find that oxysterols enhance statin induced apoptosis and suppress the expression of SREBP-2 along with SREBP-2 targets including HMGCR. We have tested a number of oxysterols that work with a range of efficacies in seven representative ovarian cancer cell lines. P53 status is not a major factor in mediating oxysterol activity. Oxysterols inhibit expression of SREBP-2 leading to lower expression of the statin target, HMGCR, along with lower expression of most of the mevalonate and cholesterol biosynthesis pathways. These observations suggests that the cell's response to statins and not initial expression levels may be most critical to determine which patients may benefit from statin therapy. Current studies are testing the combination in mouse models and evaluating the function and regulation of SREBP-2 in ovarian cancer. In summary, we have discovered an approach to suppress cancer cell's response to statins leading to greatly improved statin efficacy highlighting the importance of the mevalonate and cholesterol pathways in mediating growth and survival.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C153.

Citation Format: Alexander Brodsky, Cinzia Casella. New approaches to target mevalonate biosynthesis in cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C153.
Abstract C159: A human monoclonal antibody targeting the stem cell factor receptor (c-Kit) blocks tumor cell signaling and inhibits tumor growth.
Authors: Lebron Maria , Brennan Laura , Damoci Chris , Prewett Marie , Starodubtseva Marina , Amatulli Michael , Zhang Yiwei , Burtrum Douglas , Balderes Paul , Persaud Kris , Surguladze David , Loizos Nick , Paz Keren , Kotanides Helen
Published: August 2014

Stem cell factor receptor also known as c-Kit is a receptor tyrosine kinase that mediates cell growth, survival, and differentiation signals in response to its ligand stem cell factor (SCF). Aberrant c-Kit expression and/or activation through mutations or autocrine/paracrine signaling mechanisms occur in various malignancies and promote tumor development. Specific therapeutic targeting of c-Kit in cancer is warranted given its cancer role. In this study, we characterize the biological properties of CK6, a fully human IgG1 monoclonal antibody against the extracellular region of human c-Kit. CK6 specifically binds human c-Kit receptor with high affinity (EC50= 0.06nM) and strongly blocks its interaction with SCF (IC50= 0.41nM) in solid phase assays. Flow cytometry shows CK6 binding to the cell surface of small cell lung carcinoma (SCLC), melanoma, leukemia, and other human c-Kit expressing tumor cell lines. Furthermore, exposure to CK6 inhibits SCF stimulation of c-Kit tyrosine kinase activity and downstream signaling pathways in these tumor cell lines. Reduced levels of phosphorylated c-Kit, mitogen-activated protein kinase (MAPK) and protein kinase B/Akt were observed. Given these findings, we evaluated the antitumor growth efficacy of CK6 in several human xenograft tumor models in vivo. CK6 monotherapy treatment significantly suppressed tumor growth of NCI-H526 SCLC (T/C%= 50) and Malme-3M Melanoma (T/C%= 58) xenograft models. The combination of CK6 with standard of care (SOC) chemotherapy agents, cisplatin and etoposide for SCLC or dacarbazine for melanoma, led to enhanced tumor growth inhibition (SCLC T/C%= 12; melanoma T/C%= 38) compared to CK6 monotherapy or SOC alone. In summary, our results demonstrate that CK6 is a c-Kit antagonist antibody with tumor growth neutralizing properties and are highly suggestive of potential therapeutic application in treating human cancers harboring c-Kit receptor.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C159.

Citation Format: Maria Lebron, Laura Brennan, Chris Damoci, Marie Prewett, Marina Starodubtseva, Michael Amatulli, Yiwei Zhang, Douglas Burtrum, Paul Balderes, Kris Persaud, David Surguladze, Nick Loizos, Keren Paz, Helen Kotanides. A human monoclonal antibody targeting the stem cell factor receptor (c-Kit) blocks tumor cell signaling and inhibits tumor growth. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C159.
Abstract C192: Protein L-isoaspartyl methyltransferase negatively regulates p53 activity.
Authors: Lee Min-Gyu , Lee Jae-Cheol , Nam Ki-Hong , Yoo Jihee , Park Jeehun , Han Jeung-Whan
Published: August 2014

Protein L-isoaspartyl methyltransferase (PIMT), the “protein repair enzyme,” specifically methylates the isoaspartyl residue generated by the spontaneous deamidation of asparagine, and this methylation is an essential step for converting isoaspartate to aspartate. However, the role of the PIMT in the regulation of protein functions is relatively less understood. Here, we show that PIMT negatively regulates the tumor suppressor protein p53 by reducing the p53 protein levels, thereby suppressing the p53-mediated transcription of target genes. In addition, PIMT depletion up-regulates the proapoptotic and checkpoint activation functions of p53. Moreover, PIMT destabilizes p53 by enhancing the p53-HDM2 interaction. These PIMT effects on p53 stability and activity are attributed to the PIMT-mediated methylation of p53 at isoaspartate residues 29 and 30. Our study provides a new insight into molecular mechanisms by which PIMT suppresses the p53 activity through carboxyl methylation, and suggests a novel therapeutic target for cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C192.

Citation Format: Min-Gyu Lee, Jae-Cheol Lee, Ki-Hong Nam, Jihee Yoo, Jeehun Park, Jeung-Whan Han. Protein L-isoaspartyl methyltransferase negatively regulates p53 activity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C192.
Abstract C22: The effect of irinotecan-induced in k-Ras wild and mutant type colon cancer cell lines.
Authors: Kang Myoung Hee , Kim Bo Ram , Lee Sun il , Kim Jun Suk , Oh Sang Cheul
Published: August 2014

Irinotecan (IRI) prevents DNA from unwinding by inhibition of topoisomerase [[Unable to Display Character: І]]. Its main use is in colon cancer, in particular, in combination with other chemotherapy agents. Recent studies, those with irinotecan treatment has a synergistic effect appears. However, there is no study on the effect of the irinotecan mono-treatment. In addition their roles and the underlying mechanism in anti-tumorigenic function of solid tumor, especially kras wild and mutant type colon cancer, are not yet known. Bax protein is a key mediator of apoptosis and might be related to chemosensitivity. In this work, we evaluated the anti-tumorigenic action of these irinotecan anti-cancer agents with especially k-ras wild and mutant type colon cancer cell lines, and investigated their apoptosis-inducing effects as the potential mechanism in this process. The results show that the growth inhibitory effects of 5-fuorouracil (5-FU), Oxaliplatin(OX) produced a dose- and time dependent fashion in k-ras wild (HT29, Colo205) and mutant type (HCT116, DLD-1) colon cancer cell lines. Otherwise, irinotecan produced a cell growth of k-ras wild type cell lines were resistant versus that shown in the sensitive k-ras mutant type cell lines. Cell cycle analysis by FACS indicated that IRI-treated cell lines showed an increase in the proportion of cells in sub-G1 phase, compared to untreated cells. Exposure of colon cancer cells to IRI also resulted in the increase in the percentage of annexin V- positive and PI-negative cells. The results by multiple in vitro experimental model, showed that IRI induces these k-ras mutant type colon cancer cells to undergo apoptosis with increased the Bax protein and a release of cytochrome C from mitochondria, the activation of caspase9, the cleavage of PARP. But Bax protein was inactivation in k-ras wild type colon cancer cell lines. Importantly, inhibition of ERK kinase activity demonstrated that IRI-induced apoptotic pathway was regulated by the ERK signaling cascade. These data indicate that anti-cancer agent, irinotecan, promotes Bax-mediate apoptosis of colon cancer cell lines by sequential activation of the ERK signaling pathway followed by the up-regulation of intrinsic pathway of caspase 9.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C22.

Citation Format: Myoung Hee Kang, Bo Ram Kim, Sun il Lee, Jun Suk Kim, Sang Cheul Oh. The effect of irinotecan-induced in k-Ras wild and mutant type colon cancer cell lines. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C22.
Abstract C239: Development of EphA10/CD3 bispecific tandem scFv as a drug candidate against breast cancer.
Authors: Taki Shintaro
Published: August 2014

Background: Monoclonal antibodies (mAbs) are clinically used to treat several types of cancer due to their high specificity and potential to activate immune systems. The therapeutic effects of mAbs are unsatisfactory, however, in cases of aggressive cancer or low expression level of target protein. Recently, various antibody formats has been developed through genetic engineering technologies to improve therapeutic effect. Most notably bispecific antibodies (BsAb) are a highly promising form of target therapy. A BsAb that simultaneously targets the antigens on cancer cells and activated T-cells reportedly has the potential to show cytotoxicity more effectively than conventional mAbs. In our efforts to develop a new bispecific monoclonal antibody drug against breast cancer, we attempted to generate a tandem single-chain variable fragment (taFv) targeting both the T-cell CD3 antigen and Ephrin receptor A10 (EphA10), which were previously identified as breast cancer novel biomarker proteins.

Methods: We constructed the taFv (EphA10/CD3) expression vector that contain two single chain Fv (scFv) derived from the anti-EphA10 antibody and anti-CD3 antibody joined by a flexible five amino acid linker (G4S). The taFv was expressed transiently in CHO-S cells and verified for identity by Western blot analysis, was purified via its C-terminal His tag by metal ion affinity chromatography (IMAC). Flow cytometry was used to confirm dual specificity of taFv against cells expressing the appropriate targets. The ability of cytotoxic for taFv from PBMC was analyzed by lactate dehydrogenase (LDH) release assay.

Results: The taFv monomer was purified from CHO-S cells together with the taFv dimer. By flow cytometry analysis, each monomer and dimer bound both antigens EphA10 and CD3 while binding to CD3 was lower than full-body IgG. And each taFvs showed highly cytotoxicity specifically against EphA10 over-expression cancer cell line. Most notably, the cytotoxicity of taFv dimer was higher than taFv monomer at low Effector/Target ratio and low concentration.

Conclusion: In this research, it's proved that this taFv (EphA10/CD3) could induce EphA10 specific cytotoxicity. So, we are now ongoing to evaluate the therapeutic effects of each taFvs (monomer and dimer) in vivo.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C239.

Citation Format: Shintaro Taki. Development of EphA10/CD3 bispecific tandem scFv as a drug candidate against breast cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C239.
Abstract C248: Novel PORCN inhibitors are safe and effective in the treatment of WNT-dependent cancers.
Authors: Madan Babita , Ke Zhiyuan , Lim Shermaine Q.y. , Alam Jenefer , Ho Soo Yei , Jeyaraj Duraiswamy A. , Ghosh Kakaly , Chew Yun Shan , Aliyev Jamal , Ding Li Jun , Pendharkar Vishal , Wang Sifang , Sangthongpitag Kanda , Keller Thomas , Lee May Ann , Virshup David M.
Published: August 2014

Dysregulation of the Wnt signaling cascades is implicated in multiple disorders. There are 19 human Wnts that mediate signaling through diverse downstream pathways. To achieve maximum benefit from inhibition of Wnt signaling, targeting all of these pathways may be useful. The secretion and biological activity of all human Wnts requires palmitoylation mediated by Porcupine (PORCN), an endoplasmic reticulum-localized membrane bound O-acyltransferase. Several small molecule inhibitors of PORCN have been developed. Here we report a novel pharmacophore with derivatives that are nanomolar inhibitors of Wnt signaling. By a number of criteria, these compounds potently inhibit PORCN catalytic activity and hence suppress downstream Wnt-activated signaling pathways. The compounds effectively reduce autocrine Wnt signaling activity in selected cancer cell lines. The inhibitory activity is stereospecific, as an (R) enantiomer is inactive. Compounds with good oral bioavailability were tested for their in vivo activity and found to be highly efficacious in reversing tumor growth in both MMTV-WNT1 mice and of tumor xenografts. Treated tumors showed marked nuclear exclusion and decreased cytoplasmic staining of beta-catenin compared to vehicle controls. Importantly the treatment modulated downstream markers of Wnt signaling. No signs of toxicity were observed in mice at therapeutically effective doses. These results and our published results on C59 demonstrate that inhibiting the Wnt/beta-catenin pathway by targeting PORCN with small-molecule inhibitors is a feasible and nontoxic strategy. Use of porcupine inhibitors overcomes the problem of redundancy of Wnts, thereby, providing new options for therapy in diseases with high Wnt activity.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C248.

Citation Format: Babita Madan, Zhiyuan Ke, Shermaine Q.y. Lim, Jenefer Alam, Soo Yei Ho, Duraiswamy A. Jeyaraj, Kakaly Ghosh, Yun Shan Chew, Jamal Aliyev, Li Jun Ding, Vishal Pendharkar, Sifang Wang, Kanda Sangthongpitag, Thomas Keller, May Ann Lee, David M. Virshup. Novel PORCN inhibitors are safe and effective in the treatment of WNT-dependent cancers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C248.
Abstract C250: Concurrent targeting Bcl-2/Bcl-xL and MDM2 as a new therapeutic strategy for acute leukemia.
Authors: Hoffman-Luca C. Gianna , McEachern Donna , Ziazadeh Daniel , Zhao Yu-Jun , Sun Wei , Debussche Laurent , Wang Shaomeng
Published: August 2014

Acquired resistance of tumor cells to anticancer drugs is a major cause of cancer therapy failure in the clinic. In this study, we have investigated the acquired resistance mechanisms in vitro and in vivo for two novel anticancer drugs currently in clinical trials, a Bcl-2/Bcl-xL inhibitor ABT-263 and a MDM2-p53 interaction inhibitor MI-77301/SAR405838. In adult relapsed ALL (RS4;11) xenograft model, both ABT-263 and SAR405838 induced rapid and complete tumor regression but tumors regrew shortly after treatment cessation for both drugs. In pediatric AML (MV4;11) xenograft model, ABT-263 induced tumor growth inhibition and SAR405838 induced rapid and complete tumor regression but tumors also regrew after treatment stopped. Analysis of RS4;11 and MV4;11 resistant tumors to both drugs show that tumor cells evade apoptosis induction by the MDM2 inhibitor by mutation of p53 gene or compromised p53 function, whereas in RS4;11 tumor cells lose their sensitivity to the Bcl-2/Bcl-xL inhibitor through down-regulation of pro-apoptotic Bcl-2 family member BAX. Interestingly, RS4;11 tumors which became resistant to SAR405838, retained sensitivity to ABT-263 and rapid tumor regression was observed upon treatment with ABT-263. Similarly, in both RS4;11 and MV4;11 models, tumor cells which became highly resistant to ABT-263 were still very sensitive to SAR405838 and tumors resistant to the treatment of ABT-263 underwent rapid and complete tumor regression upon treatment with SAR405838. Furthermore, in both leukemia xenograft mouse models, sequential treatment with ABT-263 followed by SAR405838 achieved rapid and complete tumor regression with extended tumor free survival compared to the single agents. Additionally, the combination of SAR405838 and ABT-263 achieved a higher degree of long-term tumor regression than either agent alone. Our study provides new insights into the resistant mechanisms for both Bcl-2/Bcl-xL and MDM2 inhibitors in acute leukemia. Importantly, our preclinical data suggest that the combination and sequential treatment of these two distinct classes of novel apoptosis-inducing agents should be explored as an innovative treatment strategy for acute leukemia in the clinic with the goal to overcome acquired drug resistance and to improve the long-term clinical outcome for acute leukemia patients.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C250.

Citation Format: C. Gianna Hoffman-Luca, Donna McEachern, Daniel Ziazadeh, Yu-Jun Zhao, Wei Sun, Laurent Debussche, Shaomeng Wang. Concurrent targeting Bcl-2/Bcl-xL and MDM2 as a new therapeutic strategy for acute leukemia. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C250.
Abstract C270: In vitro and in vivo antitumor activity of DCBCI0901, a potent PI3K/mTORC1/mTORC2 inhibitor.
Authors: Lee Ying-Shuan E. , Kuo Mann-Yan , Huang Yi-Ting , Tseng Yu-Wen , Lin Yu Jie , Liu Yen His , Chiou Shian-Yi , Chen Li Jung , Lu Y.-Y. , Yang Chih-Hsin , Yang Pan-Chyr
Published: August 2014

The mammalian target of rapamycin (mTOR) is a highly conserved Ser/Thr protein kinase and a central controller of cell growth, proliferation, and survival. Studies have linked the hyperactive PI3K-AKT-mTOR signaling pathway in a variety of human cancers. Drugs targeting to PI3K and mTOR are likely to be an effective treatment for human malignancies that rely on these targets for their growth. Institute of Pharmaceutics at Development Center for Biotechnology in Taiwan has developed a novel and potent small molecule DCBCI0901 as PI3K/mTORC1/mTORC2 inhibitor. DCBCI0901 attenuated cell survival and proliferation in both in vitro and in vivo models. DCBCI0901 possessed IC50 of 8.4 nM against mTOR kinase and IC50 of 78 nM against PI3Kα (p110α/p85α) while exerting high selectivity against a panel of 20 other serine/ threonine and tyrosine kinases. In addition, DCBCI0901 is highly active in cellular assays. It causes a significant reduction in phospho-p70S6K (mTORC1 substrate), phospho-AKT (S473) (mTORC2 substrate), and phospho-AKT (T308) (PI3K substrate) levels. The antitumor efficacy of DCBCI0901 was evaluated in diverse human tumor cell lines. DCBCI0901 effectively inhibits cell proliferation of five well-established cell lines (one NSCLC, A549; two prostate cancers, PC-3 and LNCap; two breast cancers, HCC1954 and BT474), with IC50 values ranging from 6 to 48 nM. Notably, DCBCI0901 is effective against a panel of nine lung cancer cell lines (one cell line is EGFR-TKI sensitive model and eight cell lines are EGFR-TKI resistant model), with IC50 in the ten of nanomolar range. DCBCI0901 showed significant antitumor efficacy in mouse xenograft models including lung cancer, prostate cancer, and leukemia with tumor growth inhibition greater than 65%. DCBCI0901 also demonstrated effective suppression of tumor growth in advanced-stage xenograft models (lung cancer (A549), mean tumor volume > 350mm3 at the start of treatment). Furthermore, in an EGFR-TKI resistant lung cancer H1975 xenograft model, DCBCI0901 effectively suppressed tumor growth. Based on the in vitro/in vivo pharmacology data, DCBCI0901 was selected as a drug candidate for further development as anticancer agent.

This publication is dedicated to the memory of Dr. Paonien Chen.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C270.

Citation Format: Ying-Shuan E. Lee, Mann-Yan Kuo, Yi-Ting Huang, Yu-Wen Tseng, Yu Jie Lin, Yen His Liu, Shian-Yi Chiou, Li Jung Chen, Y.-Y. Lu, Chih-Hsin Yang, Pan-Chyr Yang. In vitro and in vivo antitumor activity of DCBCI0901, a potent PI3K/mTORC1/mTORC2 inhibitor. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C270.
Abstract C282: The carcinogen cadmium is a HIF1A stabilizer that reduces HIF1 activity through cytosolic sequestration of HIF1A within K63-linked ubiquitinated aggregates.
Authors: Chargui Abderrahman , Belaid Amine , Vouret Valérie , Tauc Michel , Pouysségur Jacques , El May Michèle Véronique , Hofman Paul , Poujeol Philippe , Mograbi Baharia
Published: August 2014

Hypoxia-inducible factor-1 (HIF1) is a master transcription factor that orchestrates the adaptation of tumor cells to hypoxia by activating the expression of a broad range of genes promoting neoangiogenesis, tumor growth, glycolysis, metastasis, and resistance to treatments. Accumulating evidence now suggests that this adaptation depends on the stabilization or the increased synthesis of the HIF1A subunit. To have a better understanding of HIF1A regulation, we focused our attention on the environmental carcinogen cadmium (Cd). Our data now challenge these hypotheses and reveal unique and opposing activities of Cd on HIF1A expression and activity. Instead of a mere action on synthesis, Cd increases by itself the stability of HIF1A protein under normoxia; independently of proteasome impairment, oxidative damage or endoplasmic reticulum stress. However, little if any HIF1A is able to translocate to the nucleus of Cd-treated cells where it activates barely HIF1 transcriptional function. Consistently, Cd dominantly inhibited hypoxia-induced HIF1 activity. Interestingly, HIF1A stabilization and inhibition of activity coincided with its association with cytosolic K63-linked ubiquitinated aggregates. We therefore propose that Cd would stabilize HIF1A but the exaggerated K63 ubiquitination would foster aggregation of HIF1A with ubiquitinated proteins, thus precluding HIF1A from interacting with its downstream nuclear targets. The unique stabilization and sequestration of HIF1A we highlighted with cadmium unravels a novel regulatory mechanism of HIF1 activity.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C282.

Citation Format: Abderrahman Chargui, Amine Belaid, Valérie Vouret, Michel Tauc, Jacques Pouysségur, Michèle Véronique El May, Paul Hofman, Philippe Poujeol, Baharia Mograbi. The carcinogen cadmium is a HIF1A stabilizer that reduces HIF1 activity through cytosolic sequestration of HIF1A within K63-linked ubiquitinated aggregates. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C282.
Abstract C285: TLR9 signaling in the tumor microenvironment initiates cancer recurrence after radiation therapy.
Authors: Gao Chan
Published: August 2014

Recent studies suggested that cancer radiotherapy is potentially immunogenic. However, it is unclear why such effects rarely prevent tumor recurrence. Here, we uncover a novel Toll-like Receptor 9 (TLR9)-dependent mechanism initiating tumor regrowth after local radiotherapy. Systemic inhibition of TLR9, but not TLR4, delayed the recurrence of B16 melanoma, MB49 bladder, and CT26 colon cancers after localized, high dose tumor irradiation. We demonstrate that soluble factors present in the microenvironment of regressing tumors trigger TLR9 signaling in freshly recruited myeloid cells within four days after radiotherapy. The tumorigenic effects of TLR9 depended on rapid upregulation of IL-6 expression, which in turn resulted in downstream activation of Jak/STAT3 signaling in myeloid cells. By comparing global gene expression in wild-type, Tlr9-, or Stat3-deficient myeloid cells derived from irradiated tumors, we identified a unique set of TLR9/STAT3-regulated genes involved in tumor-promoting inflammation and revascularization. To assess whether blocking STAT3 can correct the aberrant TLR9 signaling, we used mice with a myeloid cell-specific Stat3 gene ablation or we treated mice using CpG-Stat3 siRNA to target TLR9-positive cells. Both approaches confirmed that targeting STAT3 in myeloid cells abrogates TLR9-mediated cancer recurrence after radiation therapy. Our results suggest that combining localized tumor irradiation with myeloid cell-specific inhibition of TLR9/STAT3 signaling can generate new strategies for the elimination of radiation resistant cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C285.

Citation Format: Chan Gao. TLR9 signaling in the tumor microenvironment initiates cancer recurrence after radiation therapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C285.