bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5469: SAR650984, an anti-CD38 antibody, shows anti-tumor activity in a preclinical model of multiple myeloma.
Authors: Hann Byron , Cai Ti , Wang Donghui , Hom Yun-Kit , Aftab Blake T. , Martin Tom , Wolf Jeffrey
Published: August 2014

Multiple myeloma (MM) is the second most common cancer of the blood and one that is difficult to treat. Although survival has greatly improved over the past decade, MM remains fatal, necessitating development of novel therapies. CD38 is a promising target for antibody therapeutics for the treatment MM and various other hematological malignancies. CD38 is a type II transmembrane glycoprotein with ectozyme activity that has been implicated in Ca2+ mobilization and is found highly expressed on malignant plasma cells of MM. CD38 expression correlates with poor disease prognosis in a subset of hematological malignancies, including MM, where CD38 expression in circulating cells is associated with decreased progression free survival. Previous studies have identified several potential mechanisms of action in the context of anti-myeloma activity, including antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and pro-apoptotic activity in cancer cell lines.

To determine the potential therapeutic value of targeting CD38 in the context of MM, a humanized anti-CD38 antibody, SAR650984, was generated and evaluated for anti-tumor activity. We evaluated anti-tumor activity of SAR650984 in xenograft-based models of multiple myeloma . SAR650984 demonstrated potent anti-tumor activity in NCI-H929 and RPMI-8226 MM xenograft models.

These results strongly support continued clinical examination of the therapeutic potential for SAR650984 in the treatment of MM and further demonstrates that targeting CD38 with SAR650984 has potential to impact MM disease.

Citation Format: Byron Hann, Ti Cai, Donghui Wang, Yun-Kit Hom, Blake T. Aftab, Tom Martin, Jeffrey Wolf. SAR650984, an anti-CD38 antibody, shows anti-tumor activity in a preclinical model of multiple myeloma. [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 5469. doi:10.1158/1538-7445.AM2013-5469
Abstract 5473: Anti-EGFR monoclonal antibody nimotuzumab enhances temozolomide-induced growth suppression of mutant EGFR expressing glioma xenografts.
Authors: Nagane Motoo , Nitta Yusuke , Shimizu Saki , Shishido-Hara Yukiko , Shiokawa Yoshiaki
Published: August 2014

A mutant form of EGFR, EGFRvIII or ΔEGFR, is common in glioblastoma (GBM) conferring enhanced tumorigenic activity as well as resistance to chemotherapeutic drugs. Nimotuzumab, a humanized monoclonal EGFR antibody, has been shown to exert a modest activity in patients with GBM, but its specific activity against ΔEGFR has not been fully investigated. We treated human glioma cells overexpressing either wild-type (wt) EGFR or ΔEGFR with nimotuzumab with or without temozolomide (TMZ). Nimotuzumab treatment resulted in reduction in tyrosine phosphorylation at C-terminal of ΔEGFR more preferentially than that of wtEGFR, albeit to a lesser extent than tyrosine kinase inhibitor AG1478. Nimotuzumab-induced EGFR tyrosine dephosphorylation was associated with a decrease in AKT phosphorylation, suggesting suppression of downstream signaling pathways. In animal models, growth of subcutaneous xenografts was suppressed by TMZ, but was not affected by nimotuzumab monotreatment. However, antitumor activity was synergistically enhanced when TMZ was combined with nimotuzumab in both U87MG.ΔEGFR and LNZ308.ΔEGFR xenografts, while such an effect was limited in wtEGFR-overexpressing xenografts. Similarly, compared with nimotuzumab or TMZ monotherapy, the combination treatment of TMZ with nimotuzumab significantly elongated survival of mice bearing intracerebral xenografts derived from U87MG.ΔEGFR (p < 0.001, logrank test), and U87MG.wtEGFR to a lesser extent (p = 0.006). These anti-tumor effects by the combination treatment were associated with a decreased proliferation rate and an increase in apoptosis rate in treated xenografts. The U87MG.ΔEGFR intracerebral tumors which had re-grown after the combination treatment with TMZ and nimotuzumab (“escapers”) exhibited an increase expression of MGMT as well as a decrease in mismatch repair (MMR) proteins, MSH6 and MLH1. The reduction of MMR expression was further retained in subcultured escaper cells. These expression changes were not observed in xenografts treated with any of vehicles or monotherapies. These results suggest that nimotuzumab has antitumor activity against mutant EGFR-expressing glioma in vivo when combined with TMZ, and the resistance to this combination treatment might involve expression change of both MGMT and MMR.

Citation Format: Motoo Nagane, Yusuke Nitta, Saki Shimizu, Yukiko Shishido-Hara, Yoshiaki Shiokawa. Anti-EGFR monoclonal antibody nimotuzumab enhances temozolomide-induced growth suppression of mutant EGFR expressing glioma 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 5473. doi:10.1158/1538-7445.AM2013-5473

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 5489: CRK protein domains diminish cell invasiveness of non-small cell lung cancer.
Authors: Rettig Matthew , Mortazavi Fariborz (Fred)
Published: August 2014

CRK (c-Crk) as an adaptor protein is involved in several oncogenic signal transduction pathways, conveying oncogenic signals to its downstream effectors, and thereby affecting multiple cellular processes including proliferation, differentiation and migration. For example, CRK expression and phosphorylation have been linked to heightened invasiveness of non-small cell lung cancer (NSCLC) cells. In order to intervene in CRK signaling pathway, we examined whether CRK protein domains can be used as a therapeutic tool to interrupt CRK signaling thereby influencing cell invasiveness in NSCLC. For this purpose, Src homology domains of CRK-I (i.e., SH2 and SH3 domains) were overexpressed in H157, Rh2 and A549 cells. CRK-I SH3 domain expression induced epithelial morphology in H157 cells and enhanced epithelial morphology of A549 and Rh2 cells as compared to cells transfected with SH2 domain or control vector. In addition, CRK-I SH3 domain expression induced E-cadherin expression in H157 cells. Furthermore, CRK-I SH3 domain expression significantly decreased the motility of A549 and H157 cells and also decreased the invasiveness of H157 cells. In summary, these data provide evidence that CRK protein domains can be utilized to influence the malignant phenotype of NSCLC cells and also reduce the metastatic potential of these cells.

Citation Format: Matthew Rettig, Fariborz (Fred) Mortazavi. CRK protein domains diminish cell invasiveness of non-small cell lung 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 5489. doi:10.1158/1538-7445.AM2013-5489
Abstract 5502: Vintafolide: a first-in-class small molecule drug conjugate targeting folate receptor positive tumors.
Authors: Leamon Christopher P. , Reddy Joseph A. , Haines Brian B. , Dussault Isabelle
Published: August 2014

Targeted anti-cancer therapies offer the promise of more efficacious treatments with fewer side effects. Vintafolide (also known as EC145) is a rationally designed small molecule drug conjugate consisting of one folic acid moiety which serves as a stable high affinity binding ligand for the folate receptor, and one vinca alkaloid unit (desacetylvinblastine hydrazide; DAVLBH), which serves as the cytotoxic warhead. Vintafolide is thus designed to target cancer cells by binding with high affinity to folate receptors which are more commonly expressed at high levels on tumors compared to normal tissues. Vintafolide is internalized following binding to folate receptors and is cleaved in endosomes to release DAVLBH. Like all vinca alkaloids, DAVLBH binds to tubulin and disrupts the mitotic spindle which leads to cell death. Pre-clinical in vitro and in vivo experiments show that vintafolide requires interaction with the folate receptor for its activity and that it is more efficacious and better tolerated than untargeted DAVLBH. Vintafolide is currently being investigated in clinical trials in ovarian (Phase III) and lung (Phase II) cancer patients who express folate receptors on their tumors as determined by the investigational companion imaging agent, etarfolatide. Etarfolatide is also a folate-based conjugate consisting of folic acid linked to a peptidic metal-chelating moiety labeled with 99mTechnetium. In a randomized Phase II study in patients with advanced ovarian cancer, patients treated with vintafolide had a significantly longer period of progression free survival compared with the control. This was driven by patients who were identified by etarfolatide as having tumors with functional folate receptors. Vintafolide and etarfolatide is the first pair of therapeutic and non-invasive, imaging diagnostic to be co-developed for the treatment of cancer.

Citation Format: Christopher P. Leamon, Joseph A. Reddy, Brian B. Haines, Isabelle Dussault. Vintafolide: a first-in-class small molecule drug conjugate targeting folate receptor positive tumors. [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 5502. doi:10.1158/1538-7445.AM2013-5502
Abstract 5503: Targeting thymidine metabolic pathways in cancer cells with a novel thymidine conjugate.
Authors: Zhou Qibing , Wei Qiong , Zhang Dejun
Published: August 2014

Cellular thymidine metabolism involves two pathways: the catabolic and salvage pathways. The catabolic pathway breaks down thymidine to carbon dioxide for energy while the salvage pathway converts thymidine to its 5′-triphosphate as one of building blocks for DNA synthesis. Cytosolic level of thymidine is regulated by both thymidine phosphorylase (TYMP) of the catabolic pathway and thymidine kinase (TK) of the salvage pathway. In tumor tissues and cancer cells, abnormally high levels of these two proteins have been consistently reported. Therefore, thymidine metabolic pathways in cancer cells are a potential therapeutic target for novel drug design and development. We recently developed a novel thymidine analog, 3′-deoxythymidine phenylquinoxaline conjugate (dT-QX) that selectively killed a series of cancer cell lines including human liver carcinoma HepG2 and Hep3B, breast adenocarcinoma MCF-7, rat brain glioma C6 and mouse liver cancer H22 cells and showed low cytotoxicity on the normal liver hepatocyte HL-7702 cells. dT-QX is a conjugate of 3′-deoxythymidine and a DNA intercalating moiety with a triazole linkage achieved by click chemistry. The selective killing of cancer cells was attributed to the selective inhibition of DNA synthesis in the cancer cells but not in normal liver HL-7702 cells, resulting in extensive production of mitochondrial superoxide stress. The conjugation of 3′-deoxythymidine was found to be critical for dT-QX to achieve the selective killing of cancer cells. The killing by dT-QX was revealed to be directly due to the expression levels of TYMP and TKs in cancer cells, confirming that dT-QX successfully targeted the thymidine metabolic pathways as designed. Finally, a preliminary mouse study with subcutaneous liver tumors confirmed that dT-QX effectively inhibited the growth of tumors in vivo.

Citation Format: Qibing Zhou, Qiong Wei, Dejun Zhang. Targeting thymidine metabolic pathways in cancer cells with a novel thymidine conjugate. [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 5503. doi:10.1158/1538-7445.AM2013-5503
Abstract 5525: Development of novel high-throughput screening assay system for exploring EMT inhibitors.
Authors: Arai Kazuya , Sakamoto Ruriko , Itoh Manabu , Miura Hiromi , Shimomura Manami , Nakatsura Tetsuya
Published: August 2014

Background: EMT (Epitherial-Mesenchymal transition) is a significant event in tumor metastasis and malignancy. Cancer cells are stimulated by EMT-inducible agonists from the surrounding stromal cells, and cause transformation such as weakening of cell-cell adhesion and the accompanying acceleration of cell migration and invasion. Inhibition of EMT is considered to enable controlling of malignant transformation. In this study, we developed a high-throughput assay system of EMT inhibitor screen in 3D cell culture.

Method: We adopted 3D cell culture method on NanoCulture® Plate (NCP), a scaffold type spheroid culture plate, as a culture method which can confirm spheroid morphologies. TGF-β and its inhibitor, SB431542, were used as an EMT inducer and as a positive control for EMT inhibitor, respectively. Expressions of E-cadherin, N-cadherin, vimentin and zeb-1, represent EMT maker genes, were evaluated by qRT-PCR. As hypoxia inside the spheroids reflected the spheroid size and cell-cell adhesion strength, we visualized the intra-spheroid hypoxia, and used it as an indicator for EMT induction and inhibition.

Result: A549 cell spheroids gradually collapsed, by the weakening of cell-cell adhesion, and cells migrating out from the spheroids, by treating with TGF-β. This collapse of the spheroids was inhibited by SB431542 treatment. SB431542 treatment also accompanied inhibition of E-cadherin down-regulation, and N-cadherin, vimentin and zeb-1 up-regulation. These results indicate that this method is clearly reproducing EMT and its inhibition. And we elucidated that intra-spheroid hypoxicity was closely correlated with spheroid morphology. From this, it is demonstrated that this method is simple but high-precision assay.

Conclusion: We developed a high-throughput assay system for EMT inhibitor screen, by evaluating intra-spheroid hypoxicity as an indicator for alternation of the spheroid morphology. This method is an unique method which enables to evaluate EMT condition, by monitoring the collapse of spheroids directly. We are now running a screen for EMT inhibitor candidate compounds, by using this assay system.

Citation Format: Kazuya Arai, Ruriko Sakamoto, Manabu Itoh, Hiromi Miura, Manami Shimomura, Tetsuya Nakatsura. Development of novel high-throughput screening assay system for exploring EMT inhibitors. [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 5525. doi:10.1158/1538-7445.AM2013-5525
Abstract 5533: Novel targets and monoclonal antibodies for cancer therapy.
Authors: Grandi Alberto , Parri Matteo , Campagnoli Susanna , Nogarotto Renzo , De Camilli Elisa , Naldi Ilaria , Cinti Caterina , Sarmientos Paolo , Grandi Guido , Terracciano Luigi , Viale Giuseppe , Pileri Piero , Grifantini Renata Maria
Published: August 2014

Cancer therapeutic targets is an extremely active research field in both academia and pharmaceutical companies. In our recent research activities we identified by a high-throughput immunohistochemistry screening of Tissue microarray (TMA), a panel of 89 novel candidate tumor markers for prevalent cancers representing breast, lung colon ovary and prostate carcinomas. The novel marker candidates were found over-expressed in one or more of the five tumors under analysis, with significant frequency. Three of them seems to be promising therapeutic targets for monoclonal antibody therapy, being exposed on the surface of cancer cells. They include: 1) a lectin binding protein, over-expressed in breast, lung and ovary cancer; 2) a protein involved in iron homoeostasis and over-expressed in breast, colon, lung and ovary cancers, 3) a cadherin homologous protein detected in colon, lung and ovary cancers. Gene silencing using siRNA technology and/or over-expression experiments using marker-encoding plasmids significantly alter cell proliferation, migration, invasiveness and clonal growth in vitro, indicating that expression of the three proteins confers cell phenotypes relevant for tumor progression. Highly specific murine monoclonal antibodies (mAbs) were generated against the three proteins and proved to bind the surface of cancer cells lines. Of particular interest is a murine mAb targeting the cadherin-like protein that, upon binding to the cell surface, is efficiently internalized by cancer cells, suggesting that it is amenable to the development of antibody-drug conjugates. This mAb did not show any relevant IHC cross-reactivity in the 35 human tissues requested by FDA to demonstrate antibody specificity. Furthermore this mAb significantly inhibited tumor growth in athymic nude mice bearing HCT15 and HT29 colon cancer xenograft models. Finally, IHC analysis of approximately 300 colon cancer clinical samples indicates that the antibody stains a large fraction of colon cancer samples, and gives intense membranous staining in specific patients’ group. Overall, data indicate that this antibody could be developed as a novel tool for a targeted therapy of colo-rectal cancer, alone or in combination with other treatments

Citation Format: Alberto Grandi, Matteo Parri, Susanna Campagnoli, Renzo Nogarotto, Elisa De Camilli, Ilaria Naldi, Caterina Cinti, Paolo Sarmientos, Guido Grandi, Luigi Terracciano, Giuseppe Viale, Piero Pileri, Renata Maria Grifantini. Novel targets and monoclonal antibodies for cancer therapy. [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 5533. doi:10.1158/1538-7445.AM2013-5533
Abstract 5556: Discovery of RKI-18, a small molecule that inhibits Rho kinases 1 and 2, migration and invasion of human tumors.
Authors: Patel Ronil A. , Lui Yan , Wang Binglin , Li Ronshi , Sebti Said M.
Published: August 2014

Signal transduction pathways that are mediated by ROCK1 and ROCK2 trigger cell migration, invasion and metastasis. This prompted us to design and synthesize novel Rho-kinase inhibitors (RKIs). Here, we show that one of our most potent RKIs, RKI-18 (IC50 397 nM (ROCK1) and 349 nM (ROCK2)) but not its inactive closely related analogue RKI-11 suppresses potently the phosphorylation of the ROCK substrate MLC2 in intact human cancer cells. Furthermore, RKI-18 is highly selective at inhibiting P-MLC2 over P-Akt, P-S6 and P-Erk ½ levels. RKI-18 suppresses ROCK-mediated actin fiber formation following stimulation with LPA as well as PAK-mediated lamelipodia and filopodia formation following bradykinin or PDGF stimulation. Furthermore, RKI-18 but not RKI-11 inhibits migration, invasion and anchorage-independent growth of human breast cancer cells. The fact that RKI-18, the active ROCK inhibitor, but not RKI-11, its inactive analogue, is effective at suppressing malignant transformation suggests that preventing migration, invasion and anchorage-independent growth with RKI-18 is likely due to inhibition of ROCK. Further advanced preclinical studies are required to determine the potential of RKI-18 as an anti-metastatic agent.

Citation Format: Ronil A. Patel, Yan Lui, Binglin Wang, Ronshi Li, Said M. Sebti. Discovery of RKI-18, a small molecule that inhibits Rho kinases 1 and 2, migration and invasion of human tumors. [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 5556. doi:10.1158/1538-7445.AM2013-5556
Abstract 5558: Lurbinectedin (PM01183) specifically targets RNA Pol II for degradation via the proteasome pathway in a TC-NER-dependent fashion.
Authors: Santamaria Gema , Martinez-Leal Juan F. , Cuevas Carmen , Garcia-Fernandez Luis F. , Galmarini Carlos M.
Published: August 2014

Lurbinectedin (PM01183), a new synthetic tetrahydroisoquinoline alkaloid, is a minor groove specific DNA binder that interacts directly with specific factors involved in DNA repair and transcription pathways. In living cells, PM01183-DNA adducts stall replication and transcription giving rise to double strand breaks, inducing accumulation of cells in the S-phase of the cell cycle and triggering apoptosis. In both the ongoing phase II trials (pancreas and platinum-resistant ovarian cancer) the first stage was concluded with positive results in clinical activity, ensuring the continuity of the studies. Also, phase I trials in combination with doxorubicin and gemcitabine as well as in advanced acute leukemia are ongoing. Here, we examined the effects of PM01183 on the activity and stability of the RNAPol II as well as on other factors of the transcriptional machinery, including TBP (TFIID), p62 (TFIIH), XPG and XPF. Our results showed that PM01183 induced a rapid, time- and concentration-dependent degradation of RNA Pol II in a panel of different human tumor cell lines, including HCT-116 (colon), A549 (NSCLC), HeLa (cervix) and A763 (sarcoma). This degradative process was efficiently abrogated in the presence of transcriptional (DRB or Actinomycin D) or proteasome inhibitors (MG132), demonstrating that PM01183 specifically targets the transcriptionally active RNA Pol II for degradation via the proteasome pathway. In addition, it was also shown that the effect of PM01183 on the RNA Pol II was dependent on the presence of a functional TC NER repair machinery. PM01183 induced degradation of RNA Pol II in global NER (XPC) deficient cells, but failed to do it in TC NER (CSB, XPD and XPG) deficient cells. Importantly, these effects were confirmed to be specific for the RNA Pol II, since other factors of the transcriptional machinery, such as TBP (TFIID), p62 (TFIIH), XPG or XPF or the RPA194 subunit of the RNA Pol I were not affected. Together, these results show up the complex mechanism of action of the drug on tumor cells.

Citation Format: Gema Santamaria, Juan F. Martinez-Leal, Carmen Cuevas, Luis F. Garcia-Fernandez, Carlos M. Galmarini. Lurbinectedin (PM01183) specifically targets RNA Pol II for degradation via the proteasome pathway in a TC-NER-dependent fashion. [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 5558. doi:10.1158/1538-7445.AM2013-5558
Abstract 5559: Molecular mechanisms of elesclomol cytotoxicity.
Authors: Hasinoff Brian B. , Yalowich Jack C. , Patel Daywin , Yadav Aron , Wu Xing
Published: August 2014

Elesclomol is an anticancer drug that has received both fast track and orphan drug status from the FDA and is currently undergoing clinical trials. Elesclomol forms a strong 1:1 complex with Cu2+ and may exert its anticancer activity through the induction of oxidative stress or its ability to transport Cu2+ into the cell. The complexes of elesclomol with redox inactive Pt2+ and Ni2+ were much less cytotoxic than its Cu2+ complex which suggests a role for Cu2+-induced oxidative stress. Elesclomol and Cu2+-elesclomol inhibited the growth of human erythroleukemic K562 cells in the low nanomolar concentrations with even a brief 1.5 hr exposure. The cell growth inhibitory effects of elesclomol were decreased with an increase in cell density, likely due to Cu2+ depletion of the medium. Consistent with this, the addition of the Cu2+ chelator Trien to the medium decreased cytotoxicity. Cu2+-elesclomol induced caspase 3/7 in K562 cells, indicating it was apoptosis inducing. The Cu2+-elesclomol complex inhibited topoisomerase I activity and induced topoisomerase I-covalent complexes in K562 cells at a relatively high concentration of 50 μM. It did not, however, inhibit or poison topoisomerase II or produce topoisomerase II-covalent complexes in cells. Cu2+-elesclomol, but not elesclomol, was able to induce γH2AX formation in K562 cells, indicative of DNA double strand breaks. Ascorbic acid, GSH and NADH were all able to slowly reduce the Cu2+-elesclomol complex. However, EPR spin trapping experiments, either in the presence or absence of added H2O2, showed that the reduced copper complex could not directly generate damaging hydroxyl radicals. Depletion of GSH in K562 cells by treatment with BSO sensitized cells to elesclomol and its copper complex, indicating oxidative stress may be responsible for cytotoxicity. In conclusion, these results show that elesclomol may inhibit cell growth through Cu2+-mediated oxidative stress. Support: CIHR, a Canada Research Chair in Drug Development to B.B.H., and a National Institutes of Health grant CA090787 to J.C.Y.

Citation Format: Brian B. Hasinoff, Jack C. Yalowich, Daywin Patel, Aron Yadav, Xing Wu. Molecular mechanisms of elesclomol cytotoxicity. [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 5559. doi:10.1158/1538-7445.AM2013-5559
Abstract 5562: Generation and characterization of highly selective cathepsin S inhibitors with potentials against pancreatic cancer.
Authors: Chang Wun-Shaing W. , Liao Chien-Yu , Chang Yi-Hsun , Wu Tzu Chin , Wu Rou-Jhen , Chang Tien-Ning , Chang Jang-Yang , Lin Chun-Cheng
Published: August 2014

Cathepsin S (CTSS) is a critical cellular protease required for cancer development and metastasis. This proteolytic enzyme is often over-expressed by malignant tumor cells and secreted into the extracellular milieu to degrade surrounding matrix components. Here, we attempted to systematically generate and evaluate potential CTSS inhibitors in hope to identify potent candidates for use as antitumor agents. Detailed kinetic analysis revealed several lead compounds possess very low Ki values and high specificity against target CTSS protease. Results from ECM degradation assays demonstrated that these small molecules could protect fibronectin from CTSS-mediated degradation and consequently hinder tumor cell movement. Treating various pancreatic tumor cell lines with these CTSS inhibitors further resulted in a drastic decrease in cell migration and invasion. The test compounds also reduced the spread of pancreatic tumor cells in orthotopic animal model and thus prolonged mice survival. Finally, these lead molecules exhibited reasonable pharmacokinetic (PK) profiles, suggesting their potential as antitumor agents against pancreatic cancer.

Citation Format: Wun-Shaing W. Chang, Chien-Yu Liao, Yi-Hsun Chang, Tzu Chin Wu, Rou-Jhen Wu, Tien-Ning Chang, Jang-Yang Chang, Chun-Cheng Lin. Generation and characterization of highly selective cathepsin S inhibitors with potentials against pancreatic 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 5562. doi:10.1158/1538-7445.AM2013-5562
Abstract 5563: Targeting the PH domain of TIAM1 to inhibit prostate cancer metastasis.
Authors: Meuillet Emmanuelle J. , Moses Sylvestor A. , Jandova Jana , Mash Eugene A. , Zhang Shuxing
Published: August 2014

TIAM1 (T-lymphoma invasion and metastasis-inducing protein-1) is a highly conserved guanine nucleotide exchange factor and contains an Dbl Homology (DH)/C-terminal Pleckstrin Homology (PH) domain. The crystal structure of DH-PH of TIAM1 in complex with Rac-1 has been reported. TIAM1 has been found to be over-expressed cancers such as breast, colon and prostate cancers. An increase in TIAM1 expression has been shown to be associated with increased metastatic potential of breast cancer cell lines and is also correlated with poor prognosis of patients with prostate cancer. TIAM1 is thus a novel PH domain-containing drug target directly related to cancer progression, metastasis and patient survival. We have identified and characterized novel small molecule inhibitors targeting the phosphoinositide lipid binding PH domain of TIAM1 in order to selectively inhibit cell migration, invasion and survival. An In Silico screen of our internal and Maybridge library using the crystal structure of TIAM1 has identified 11 compounds that bind to the PH domain. In vitro assays revealed that compounds TPH-3 and TPH-15 significantly reduced the amount of active Rac1 in PC-3 prostate cancer cells (EC50 of 2.73±0.13 and 2.38±0.98 μM) by binding to PH-TIAM1 with high affinity (KD in the micromolar range) using surface plasmon resonance (SPR) spectrometry. Both compounds displaced PtdIns-3,4,5-P3 in a SPR competitive binding assay. TPH-3 and TPH-15 inhibited cell proliferation with EC50 of 19.8±3.2 and 28.7±1.7 μM in prostate cancer cells LnCaP and EC50 of 18.6±1.8 and 33.3±6.7 μM in PC-3. Wound healing assays and lamellipodia formation were both inhibited by the compounds. TPH-15 inhibited ≈70% of PC-3 invasion using a matrigel invasion assay. Finally, TPH-15 exhibits anti-tumor properties in a PC-3 mouse xenograft study (%T/C≈38.8) with good pharmacokinetic properties (T1/2≈5 hours). Cardio-injection of prostate PC-3 cells in SCID mice was used to test the effects of TPH-15 in the prevention of bone metastasis. Mice were treated with 50mg/kg ip of TPH-15 once a day for 5 days. TPH-15-treated mice developed significantly less pelvic bone lesions than the untreated group and TPH-15 treated mice lived longer, on average, than the untreated group. Overall, we have identified novel compounds which exhibit the ability to reduce prostate cancer bone metastasis by binding to the PH domain of TIAM1, an important GEF in the process of metastasis.

Citation Format: Emmanuelle J. Meuillet, Sylvestor A. Moses, Jana Jandova, Eugene A. Mash, Shuxing Zhang. Targeting the PH domain of TIAM1 to inhibit prostate cancer metastasis. [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 5563. doi:10.1158/1538-7445.AM2013-5563
Abstract 5567: Development of a novel magnetic anti-cancer drug for hyperthermic therapy.
Authors: Umemura Masanari , Fukumura Hidenobu , Sato Itaru , Feng Xianfeng , Eguchi Haruki , Ishikawa Yoshihiro
Published: August 2014

Background: Hyperthermic therapy is a type of cancer treatment in which body tissue is exposed to high temperature (up to 113°F). Despite of its effectiveness, it has not been widely used. One reason is that it is technically difficult to increase high temperature only in a target cancer site. To address this issue, we have developed a novel nano-magnetic particle, i.e., EI236. EI236 exhibits not only anti-cancer effect, but also ferromagnetic property. Because of its magnetism, this drug can generate heat by itself when it is exposed to an alternating current magnetic field (ACMF).

Method: We established a rabbit model of VX2 cells (rabbit osteosarcoma) grafted on legs to examine the anti-cancer and hyperthermal effects of EI236 in vivo. Rabbits were divided into five groups; 1) no treatment group 2) intra-venous (iv.) EI236 injection group 3) intra-arterial (ia.) EI236 group 4) ia. Methotrexate (MTX) injection group, and 5) ia. EI236+ACMF group. The volume of tumor was measured daily, and then the samples were harvested and evaluated histologically by HE, Ki67, and TUNEL staining.

Results: The effect of EI236 was similar to that of MTX when EI236 was injected via intra-arterial infusion. Via intra-arterial infusion was more effective than iva intra-venous infusion. When EI236 was injected and the tumor was exposed to ACMF for simultaneous chemotherapeutic and hyperthermal effects, it showed the greatest regression of tumor among all the groups examined. EI236 significantly increased necrosis as determined by HE staining, and further increased it by ACMF. Similarly, EI236 decreased cell proliferation as determined by Ki67, and further decreased it by ACMF. Moreover EI236 increased apoptosis as determined by TUNEL staining, and further increased it by ACMF. These results demonstrated that the exposure of ACMF greatly enhanced the anti-cancer effect of EI236. Taken together, EI236 exhibited simultaneous effects of anti-cancer and thyperthermia.

Conclusion: These results demonstrate that EI236 can provide us in developing a new strategy of simultaneous hyperthermo-chemotherapy in the future.

Citation Format: Masanari Umemura, Hidenobu Fukumura, Itaru Sato, Xianfeng Feng, Haruki Eguchi, Yoshihiro Ishikawa. Development of a novel magnetic anti-cancer drug for hyperthermic therapy. [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 5567. doi:10.1158/1538-7445.AM2013-5567
Abstract 5573: Discovery of potent oridonin derivatives for the treatment of breast cancer.
Authors: Zhang Yusong , Ding Chunyong , Yang Zhengduo , Chen Haijun , Chu Lili , Zhou Jia , Shen Qiang
Published: August 2014

Oridonin, a diterpenoid derived from the herbal Rabdosia rubescens, has been reported to have antitumor effects on various types of cancer cells. However, its relatively low aqueous solubility and bioavailability have limited its development into clinical applications. Herein, we chemically modified oridonin and generated a series of novel analogues. We then employed MTT assay to detect their effects on cell growth and a number of new and potent molecules have been identified. Among them, compounds CYD-6-86 and CYD-6-92 significantly inhibited the proliferation of human breast cancer MDA-MB-231 and MCF-7 cells. Furthermore, both compounds induced enhanced apoptosis in a dose- and time-dependent fashion when compared with oridonin. Cell cycle analysis indicated that both CYD-6-86 and CYD-6-92 induced S phase arrest in MDA-MB-231 cells and G0/G1 phase arrest in MCF-7 cells, while oridonin induced G2/M phase arrest in MDA-MB-231 and MCF-7 cells. Consistent with oridonin, Western blot analysis showed that CYD-6-86 and CYD-6-92 inhibited the expression of NF-κB and Bcl-2, and increased expression of Bax and cleaved PARP. Intriguingly, compounds CYD-6-86 and CYD-6-92 have demonstrated to suppress the growth of adriamycin-resistant MCF-7 clone, while at the same dosage oridonin displayed no effect on these cells. Our findings suggest that these new analogues may be superior to the natural product oridonin to overcome the chemo-resistance, and have great potential to be developed as novel therapeutics for the treatment of breast cancer.

Citation Format: Yusong Zhang, Chunyong Ding, Zhengduo Yang, Haijun Chen, Lili Chu, Jia Zhou, Qiang Shen. Discovery of potent oridonin derivatives for the treatment of breast 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 5573. doi:10.1158/1538-7445.AM2013-5573
Abstract 5576: Pharmacologic targeting of CtBP by established and newly designed inhibitors.
Authors: Byun Jung S. , Gardner Kevin L.
Published: August 2014

Breast cancer is not one single entity but a collection of multiple diseases that affect different populations with varying incidence, morbidity and mortality. Thus finding a unified marker and associated biological processes that provide an overall indication of prognosis with clear insights into therapy opportunities is critically needed. Previous our studies showed that CtBP drives invasion and metastasis by governing a mode of gene regulation that is not only reversible and strongly influenced by environmental factors, like metabolic status, but can be stably passed on to expanding clones of tumor cells. Recent studies indicate that this form of “epigenetic regulation” plays a critical role in tumor progression. Our most recent finding that CtBP expression can function as a single predictor of overall poor survival from breast cancer, independent of current criteria such as hormone receptor status, suggests that inhibiting CtBP and the pathways it controls may provide a unifying concept for improving breast cancer diagnosis and treatment.

Using Computer Assisted Drug Design (CADD), we have identified multiple potential CtBP inhibitors from a panel of library of commercially available compounds. To validate the efficacy of these inhibitors, we have used targeted assessment by quantitative gene expression and ChIP analysis of established CtBP targets. We then scored compounds that disrupt CtBP controlled processes including EMT and genome instability at a low micromolar range. We found that some compounds were able to displace CtBP from endogenous genes and reactivate repressed gene expression. A smaller subset of these was able to inhibit cellular reprogramming associated with EMT and the wound healing response.

These findings suggest that CtBP may be an effective target of pharmacological inhibition to impair tumor invasion and metastasis, and offers a proof-of-principle that will provide a foundation for more effective treatment strategies against aggressive forms of breast cancer.

Citation Format: Jung S. Byun, Kevin L. Gardner. Pharmacologic targeting of CtBP by established and newly designed inhibitors. [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 5576. doi:10.1158/1538-7445.AM2013-5576
Abstract 5591: Clinical significance of EML4-ALK fusion gene and association with EGFR and KRAS gene mutations in 208 Chinese patients with non-small cell lung cancer.
Authors: Chen Jun , Liu Hongyu , Li Ying , Li Yongwen , Yang Tong , Wei Sen , Wang Jing , Zhou Qinghua
Published: August 2014

EML4-ALK fusion gene has been recently identified in a small subset of non-small cell lung cancer (NSCLC) patients who respond positively to ALK inhibitors. The characteristics of EML4-ALK fusion gene in Chinese patients with NSCLC are poorly understood. Here, we report on the prevalence of EML4-ALK, EGFR status and KRAS mutations in 208 Chinese patients with NSCLC. EGFR mutations were found in 24.5% (51/208) of patients. In concordance with previous reports, these mutations were identified at high frequencies in females (47.5% vs 15.0% in males; P > 0.05); never-smokers (42.3% vs 13.9% in smokers; P < 0.05), and adenocarcinoma patients (44.2% vs 8.0% in non-adenocarcinoma patients; P < 0.05). There were only 2.88% (6/208) patients with KRAS mutations in our study group. We identified 7 patients who harbored the EML4-ALK fusion gene (3.37%, 7/208), including 4 cases with variant 3 (57.1%), 2 with variant 1, and 1 with variant 2. All positive cases corresponded to female patients (11.5%, 7/61). Six of the positive cases were non-smokers (7.69%, 6/78). The incidence of EML4-ALK translocation in female, non-smoking adenocarcinoma patients was as high as 15.2% (5/33). No EGFR/KRAS mutations were detected among the EML4-ALK positive patients. Pathological analysis showed no difference between solid signet-ring cell pattern (4/7) and mucinous cribriform pattern (3/7) in ALK-positive patients. Immunostaining showed intratumor heterogeneity of ALK rearrangement in primary carcinomas and 50% (3/6) of metastatic tumors with ALK-negative staining. Meta-analysis demonstrated that EML4-ALK translocation occurred in 4.84% (125/2580) of unselected patients with NSCLC, and was also predominant in non-smoking patients with adenocarcinoma. Taken together, EML4-ALK translocations were infrequent in the entire NSCLC patient population, but were frequent in the NSCLC subgroup of female, non-smoker, adenocarcinoma patients. There was intratumor heterogeneity of ALK rearrangement in primary carcinomas and at metastatic sites.

Citation Format: Jun Chen, Hongyu Liu, Ying Li, Yongwen Li, Tong Yang, Sen Wei, Jing Wang, Qinghua Zhou. Clinical significance of EML4-ALK fusion gene and association with EGFR and KRAS gene mutations in 208 Chinese patients with non-small cell lung 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 5591. doi:10.1158/1538-7445.AM2013-5591
Abstract 5598: A comprehensive study to analyze tumor sensitivity to HSP90 inhibition therapy.
Authors: Riolo Matthew , Modi Shanu , Corben Adriana , Hudis Clifford , Alpaugh Mary , Chiosis Gabriela
Published: August 2014

There have been great advances in receptor-targeted breast cancer therapeutics. However, limited sensitivity and tumor resistance remain significant problems for many patients. To overcome these obstacles our laboratory has focused on targeting HSP90, a global mediator of oncogenic pathways involved in nearly all cancer types. Our laboratory has developed PU-H71 which selectively inhibits oncogenic HSP90 and is one of the first targeted therapies to show preclinical potent activity in the treatment of triple negative breast cancers. Here, we investigate how the complex biology of different types of breast tumors influences response to HSP90 inhibition. Our preliminary data indicate that sensitivity to PU-H71 goes beyond a tumor's receptor status and is highly driven by its intracellular protein composition. Our objective is to identify specific pharmacodynamic changes in select HSP90 onco-client proteins and regulators of apoptosis associated with HSP90 inhibition as a tool to monitor therapeutic response. Using several different breast cancer cell lines we evaluate how alterations in specific onco-client phosphorylated species as well as the induction of pro-apoptotic protein cleavage correlates to a tumor's sensitivity to HSP90 inhibition. In addition to testing cell lines, we have developed a system to investigate PU-H71 on primary tumors by treating surgery specimens ‘ex vivo’ (fresh tissue sectioning) to determine response and pharmacodynamic alterations in patient samples. Our long term goal is to establish specific pharmacodynamic changes (PD markers) that correlate to tumor sensitivity allowing us to better predict those patients more likely to benefit from HSP90 inhibition i.e. PU-H71 therapy.

Citation Format: Matthew Riolo, Shanu Modi, Adriana Corben, Clifford Hudis, Mary Alpaugh, Gabriela Chiosis. A comprehensive study to analyze tumor sensitivity to HSP90 inhibition therapy. [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 5598. doi:10.1158/1538-7445.AM2013-5598
Abstract 5625: Targeting different LRP receptors and sulfated proteoglycan by branched neurotensin provide high cancer selectivity.
Authors: Bracci Luisa , Falciani Chiara , Brunetti Jlenia , Lelli Barbara , Ravenni Niccolò , Lozzi Luisa , Depau Lorenzo , Pini Alessandro
Published: August 2014

In previous paper we reported on the much higher selectivity toward cancer cells and tissues of tetra-branched neurotensin peptides (NT4) compared to monomeric NT peptide. We also demonstrated that NT4 can be coupled to many different functional units for cancer cell tracing and drug delivery and can induce tumor growth reduction in animal studies. We then proposed NT4 as promising cancer selective theranostics for different human cancers, including CRC, pancreas adenocarcinoma and urinary bladder cancer. Nonetheless, multimeric binding of tetrabranched peptides, together with the chemical modification produced by coupling to the branched core, might have modified receptor selectivity of NT4 with respect to native monomeric NT and actually we had no conclusive indication on which receptor our branched NT4 peptides were binding to.

Data reported in the present paper demonstrate that synthesis of neurotensin sequence in a tetra-branched form induce a switching of receptor selectivity, by decreasing affinity to the NT high affinity receptor NTR1 and contemporarily acquiring binding to additional receptors, which produces a much higher cancer cell selectivity of NT4 with respect to monomeric NT peptides. We demonstrate here that NT4 binds sortilin and SorLa and also acquire the ability to bind different receptors belonging to the Low Density Lipoprotein Receptor Related Protein (LRP) family as well as heparin and other Heparan Sulfate Proteoglycans (HSPG).

The much higher binding of NT4 in respect to native NT to either cancel cell lines or human cancer surgical samples, as well as the higher selectivity toward human cancer tissues of NT4 is due to binding to different membrane receptors, which are very selectively expressed by many different human cancers. Moreover, our results confirm that sulfated proteoglycan can mimic the ligand binding site of different LRP receptors and indicate that targeting of multiple LRP receptors together with sulfated proteoglycans produce an extremely high selectivity towards many different human cancers.

Citation Format: Luisa Bracci, Chiara Falciani, Jlenia Brunetti, Barbara Lelli, Niccolò Ravenni, Luisa Lozzi, Lorenzo Depau, Alessandro Pini. Targeting different LRP receptors and sulfated proteoglycan by branched neurotensin provide high cancer selectivity. [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 5625. doi:10.1158/1538-7445.AM2013-5625
Abstract 5629: Prolyl isomerase Pin1 negatively regulates CDK10 stability to induce tamoxifen resistance in breast cancer.
Authors: Kharam Prem , Choi Hong Seok
Published: August 2014

Endocrine therapies that inhibit estrogen receptor (ER)-α signaling are the most common and effective treatment for ER-α-positive breast cancer. However, the use of these agents is limited by the frequent development of resistance. The aim of this study was to elucidate the mechanisms by which downregulation of CDK10 expression confers resistance to tamoxifen in breast cancer. Here, we show that peptidyl-prolyl isomerase Pin1 downregulates CDK10 protein as a result of its interaction with and ubiquitination of CDK10, thereby affecting CDK10-dependent Raf-1 phosphorylation (S338). Pin1-/- mouse embryonic fibroblasts (MEFs) show higher CDK10 expression than Pin1+/+ MEFs, whereas CDK10 protein was downregulated in the rescued Pin1-/- MEFs after reexpression of Pin1. Pin1 silencing in SKBR-3 and MCF7 cells increased the CDK10 expression. In human tamoxifen-resistant breast cancer and tamoxifen-resistant MCF7 cells, immunohistochemical staining and immunoblotting analysis shows an inverse correlation between the expression of CDK10 and the degree of tamoxifen resistance. There was also a positive correlation between the high level of P-Raf-1 (Ser338) and Pin1 in human tamoxifen-resistant breast cancer and tamoxifen-resistant MCF7 (TAMR-MCF7) cells. Importantly, 4-OH tamoxifen (4-OHT), when used in combination with overexpressed CDK10 or Raf-1 inhibitor, increased cleaved PARP and DNA fragmentation to inhibit cologenic growth of MCF7 cells and tamoxifen-resistant MCF7 cells, respectively. On the basis of these findings, we suggest that the Pin1-mediated CDK10 ubiquitination is a major regulator of tamoxifen-resistant breast cancer cell growth and survival.

Citation Format: Prem Kharam, Hong Seok Choi. Prolyl isomerase Pin1 negatively regulates CDK10 stability to induce tamoxifen resistance in breast 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 5629. doi:10.1158/1538-7445.AM2013-5629

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