bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B192: Selective induction of apoptosis in TSC2-null cells.
Authors: Alayev Anya , Snyder Rose B. , Holz Marina K.
Published: August 2014

Mammalian target of rapamycin complex 1 (mTORC1) is an important regulator of cell cycle progression and proliferation, and is a target of the inhibitor rapamycin. The mTORC1 pathway is hyperactivated in many types of cancer, as a consequence of inappropriately regulated growth factor signaling pathways, and in diseases with Tuberous Sclerosis Complex (TSC) 1/2 loss, such as TS and lymphangioleiomyomatosis (LAM). Thus, use of rapamycin analogs has emerged as a viable therapeutic option in treatment of these diseases. However, rapamycin is not an effective monotherapy agent because it is cytostatic, and promotes autophagy induction and Akt reactivation, which may contribute to malignant cell survival, impeding tumor regression. We have observed that the combination of rapamycin with the plant-derived polyphenol resveratrol prevents rapamycin-induced autophagy and Akt activation, and selectively promotes apoptosis of TSC2-null cells, such as TSC2-/- MEFs and LAM-derived cells. This combination may be an effective option for targeted killing of cells with dysregulated mTORC1 signaling.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B192.

Citation Format: Anya Alayev, Rose B. Snyder, Marina K. Holz. Selective induction of apoptosis in TSC2-null 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 B192.
Abstract B204: Targeting key DNA/RNA heteroduplex of telomerase by small-molecule ligands.
Authors: Islam Mohammad K. , Thurston David E. , Rahman Khondaker M.
Published: August 2014

Small molecules can be designed to target the DNA/RNA hybrid (DRH) duplex that forms during the catalytic cycle of telomerase. Formation of this unique heteroduplex, which is typically between 4-11 base pairs long, is a key step in the mechanism of telomerase extension. Small molecules that bind to this duplex may inhibit telomerase by either stabilizing the structure thereby preventing strand dissociation (a key step in the catalytic cycle of telomerase), or by sufficiently distorting the substrate duplex causing misalignment of key catalytic groups. As telomerase is frequently over-expressed in cancer cells, the DRH duplex is a good therapeutic target. Thus we initiated a screening programme initially based on the National Cancer Institute (NCI) compound libraries which provide a high degree of structural diversity. Three novel scaffolds were identified in a Fluorescent Resonance Energy Transfer (FRET) based assay that showed at least a 5°C selective stabilization of the DNA/RNA hybrid duplex at 5μM ligand concentration. Medicinal chemistry modifications were then employed on these scaffolds to generate focused libraries of analogues with drug like properties. In total, 30 molecules were synthesized based on the identified scaffolds and subsequently screened against seven different DNA sequences including telomeric and promoter G-quadruplexes, and DRH sequences. A number of compounds showed selective DNA/RNA hybrid stabilization potential without significant affinity for G-quadruplex or duplex DNA sequences. These ligands provided hybrid DNA/RNA stabilization in the range of 5.2-9.5°C at 1μM ligand concentration. A second generation molecules where amides have been replaced by secondary amines are currently being synthesized to obtain SAR. Selected analogues from both compounds set are currently being evaluated in a variety of biological assays to confirm selective telomerase inhibition, and in cell based experiments to assess their potential as antitumour agents.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B204.

Citation Format: Mohammad K. Islam, David E. Thurston, Khondaker M. Rahman. Targeting key DNA/RNA heteroduplex of telomerase by small-molecule ligands. [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 B204.
Abstract B228: Short hairpin RNA targeting SET suppresses cell proliferation and induces apoptosis in human gastric carcinoma cells.
Authors: Hairong Shi , Lijiang Liu
Published: August 2014

Background: SET is overexpressed in multiple tumors, including human gastric cancer. In this study, we examined the role of SET in regulating gastric cancer cell apoptosis.

Material and Methods: Expression of SET was investigated after transfection with SET short hairpin RNA (shRNA) in gastric cancer cells by Western blotting and immunofluorescence analysis. Next, the effects of SET shRNA on cell proliferation and apoptosis were evaluated by the 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium Bromide assay and flow cytometric analysis. To investigate the precise mechanism of these effects, a comprehensive analysis was performed using a cDNA microarray.

Results: shRNA targeting SET resulted in a significant decrease in SET expression, and cell proliferation. Meanwhile, increased cell apoptosis was confirmed. The comprehensive analysis showed that shRNA targeting SET upregulated a number of apoptosis-related genes (including IL18, TFPI, DKK1 and HSPA5).

Conclusions: Attenuation of SET by shRNA resulted in suppressed cell proliferation and apparent apoptosis, suggesting that SET may be a target for therapy of gastric cancer.

Supported by: National Natural Science Foundation of China (81001082)

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B228.

Citation Format: Shi Hairong, Liu Lijiang. Short hairpin RNA targeting SET suppresses cell proliferation and induces apoptosis in human gastric carcinoma 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 B228.
Abstract B252: The unique mechanism of action of VAL-083 may provide a new treatment option for some chemo-resistant cancers.
Authors: Steino Anne , Bacha Jeffrey A. , Garner William J. , Kanekal Sarath , Siddik Zahid H. , Brown Dennis M.
Published: August 2014

Poor outcomes in cancer therapy due to chemo-resistance remain a significant unmet clinical problem for many solid tumors and leukemias. VAL-083 (dianhydrogalactitol) represents a structurally unique first-in-class N7-bifunctional DNA alkylating agent. VAL-083 primarily mediates guanine N7 DNA cross-links, which separates it from other DNA alkylating chemotherapeutics (e.g. temozolomide) that have their primary cytotoxicity by targeting DNA at the O6 position of guanine. As expected from its mechanism, VAL-083 overcomes resistance associated with O6-methylguanine-DNA methyltransferase (MGMT) overexpression in vitro. Furthermore, unlike other N7-acting drugs, such as cisplatin which primarily induces intrastrand crosslinks, VAL-083 mediates interstrand DNA crosslinks. When tested side-by-side in a standard syngeneic mouse fibrosarcoma model (RIF-1 cell-line in C3H mice), VAL-083 demonstrated superiority to cisplatin in tumor growth delay. For mice treated with a single injection of cisplatin of 4 mg/kg, the tumor growth delay was 1.45 days compared to untreated controls. Single IP injection of VAL-083 at a dose of 10 mg/kg delayed tumor growth by 5.6 days. Combination treatment of VAL-083 followed immediately by cisplatin produced a more than additive effect by delaying growth 8.65 days. VAL-083 readily crosses the blood-brain barrier, accumulates in brain tissue and is effective against brain tumor cells both in vitro and in vivo, and against brain cancer stem cells in vitro. VAL-083 is currently in Phase I/II clinical trials for glioblastoma and recurrent metastatic brain tumors. Studies are underway to further characterize the efficacy of VAL-083 in various tumor cell-lines resistant to chemotherapy. Previous clinical studies showing VAL-083 activity in several tumor models, combined with the new data on MGMT-chemo-resistance and synergy with cisplatin makes VAL-083 a promising alternative for both primary and secondary brain tumors as well as cisplatin-resistant tumors.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B252.

Citation Format: Anne Steino, Jeffrey A. Bacha, William J. Garner, Sarath Kanekal, Zahid H. Siddik, Dennis M. Brown. The unique mechanism of action of VAL-083 may provide a new treatment option for some chemo-resistant 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 B252.
Abstract B256: Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer cells.
Authors: Goldberg Alexander A. , Montes-Grajales Diana , Olivero Jesus , Beach Adam , Titorenko Vladimir , Safe Steven , Sanderson Thomas
Published: August 2014

We have previously shown that a series of brominated and chlorinated analogs of 3,3'-diindolylmethane (DIM) can inhibit can induce apoptosis and necrosis in androgen-dependent and androgen-independent prostate cancer cells and that addition of bromine to the 4 and 4’ position of the indole ring of DIM maximally increases the potency of the anticancer compound. To understand the upstream events leading to the activation of caspases in response to treatment with ring-DIMs in androgen-dependent LNCaP and androgen-independent LNCaP C4-2B cells by monitoring the onset of endoplasmic reticulum (ER) stress and the dysregulation of mitochondrial respiration. We found that 4,4'-dibromo- and 7,7'-dichloroDIM and DIM itself induced ER stress-dependent upregulation of CHOP, ATF4, and GRP78, while only 4,4'-dibromo and 7,7'-dichloroDIM induced phosphorylation of eIF2alpha and JNK. Both ER stress and loss of mitochondrial membrane potential were observed after treatment with 4,4'-dihaloDIMs and DIM, but not 7,7'-dihaloDIMs within 1 hour of exposure, before the appearance of later stage apoptotic events such as condensed chromatin. Salubrinal inhibited cell death induced by 4,4'-dihaloDIMs, but facilitated cell death induced by 7,7'-dihaloDIMs or DIM. Interestingly, salubrinal did not increase eIF2alpha phosphorylation after co-treatment with either DIM or ring-DIMs. However, it did restore mitochondrial membrane potential in cells treated with 4,4'dihaloDIMs and further decreased mitochondrial activity after co-treatment with 7,7'-dihaloDIMs or DIM. Moreover, cyclosporin A inhibited cell death induced by both 4,4’-dihalo and 7,7’-dihaloDIMs but not DIM. Taken together, these data suggest that the ring-DIMs induce cell death via mitochondrial dysfunction and ER stress, and that because salubrinal either stimulates or inhibits cell death in combination with specific ring-DIMs, its effects are related to mitochondrial membrane integrity and not to phosphorylation of eIF2alpha.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B256.

Citation Format: Alexander A. Goldberg, Diana Montes-Grajales, Jesus Olivero, Adam Beach, Vladimir Titorenko, Steven Safe, Thomas Sanderson. Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer 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 B256.
Abstract B270: Discovery and preliminary characterization of novel tyrosine kinase inhibitors with selectivity to BTK.
Authors: Namdev Nivedita D. , Cornell-Kennon Susan , Yu Yi , Hill Jason , Bull Cathy , Volak Laurie , Wang Jianqiang , Lowe Deirdre , Gu Xuibin , Koerner Steffi , Moussa Magdi , Vensel David , Liu Yanbin , Wu Hui , Chen Chang-Rung , Dransfield Daniel T. , Ashwell Mark A.
Published: August 2014

Bruton's tyrosine kinase (BTK) is a non receptor tyrosine kinase and belongs to the SRC-related TEC subfamily. The role of BTK in the B cell receptor (BCR) signaling pathway is well defined and is critical for full activation of phospholipase-C γ and MAPK as well as calcium mobilization. More than 95% of human lymphomas are B cell lymphoma and among them over 70% expresses BCR. Studies in lymphoma cell lines in vitro have demonstrated the role of BTK in BCR signaling.

We have performed in vitro kinase profiling to determine percent inhibition and IC50 for kinase families of interest. An extensive cellular characterization including anti-proliferative assays, Western blot analysis for evaluation of phospho BTK (pY223) and cell cycle analysis was performed in DLBCL TMD8 cells. An in vivo tumor xenograft model was employed to further evaluate the target knockdown and efficacy against tumor growth.

Compounds 1 and 2 were found to exhibit potent inhibition of BTK (IC50 0.6 nM), Src family (IC50 0.6-10 nM) and Trk isoforms (IC50 2-4 nM). Inhibition of cell proliferation was accompanied by reduction of phosphorylation of BTK. In addition to the anti-proliferative activity, following a single oral dose, inhibition of BTK phosphorylation (pY223) was observed in vivo in a TMD8 tumor xenograft model. The growth of TMD8 tumor xenografts was markedly suppressed after daily oral administration for 12 days of these two compounds.

A series of potent multi non-receptor tyrosine kinase inhibitors targeting the Tec, Src and Trk family of kinases have been discovered and characterized.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B270.

Citation Format: Nivedita D. Namdev, Susan Cornell-Kennon, Yi Yu, Jason Hill, Cathy Bull, Laurie Volak, Jianqiang Wang, Deirdre Lowe, Xuibin Gu, Steffi Koerner, Magdi Moussa, David Vensel, Yanbin Liu, Hui Wu, Chang-Rung Chen, Daniel T. Dransfield, Mark A. Ashwell. Discovery and preliminary characterization of novel tyrosine kinase inhibitors with selectivity to BTK. [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 B270.
Abstract B290: Activation of the PD-1 pathway contributes to immune escape in EGFR-driven lung tumors.
Authors: Akbay Esra A. , Koyama Shohei , Carretero Julian , Altabef Abigail , Tchaicha Jeremy , Christensen Camilla , Shimamura Takeshi , Sholl Lynette , Rodig Scott , Freeman Gordon , Hammerman Peter , Dranoff Glenn , Wong Kwok-Kin
Published: August 2014

The recent clinical success of therapeutic blockade of the immune checkpoint Programmed Death (PD)-1 in advanced lung cancer patients suggests that mechanisms of immune escape may contribute to lung tumor pathogenesis. We identified a correlation between Epidermal Growth Factor Receptor (EGFR) pathway activation and a gene signature indicative of immunosuppression manifested by upregulation of PD-1, PD-L1, cytotoxic T lymphocyte antigen-4 (CTLA-4) and multiple tumor-promoting inflammatory cytokines. Accordingly, we identified a decrease in the number of cytotoxic T cells and an increase in markers of T cell exhaustion in genetically engineered mouse models (GEMMs) of EGFR-driven lung cancer. PD-1 antibody blockade significantly improved the survival of mice with EGFR-driven lung adenocarcinomas by enhancing effector T cell function and lowering the levels of tumor promoting cytokines. Expression of mutant EGFR in human bronchial epithelial cells induced PD-L1 expression, and PD-L1 expression was reduced by treatment with EGFR tyrosine kinase inhibitors (TKIs) in human non-small cell lung cancer (NSCLC) cell lines with an activated EGFR pathway. These data suggest that oncogenic EGFR signaling remodels the tumor microenvironment to trigger immune escape, in addition to established effects on cell proliferation, and mechanistically link treatment response to PD-1 inhibition.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B290.

Citation Format: Esra A. Akbay, Shohei Koyama, Julian Carretero, Abigail Altabef, Jeremy Tchaicha, Camilla Christensen, Takeshi Shimamura, Lynette Sholl, Scott Rodig, Gordon Freeman, Peter Hammerman, Glenn Dranoff, Kwok-Kin Wong. Activation of the PD-1 pathway contributes to immune escape in EGFR-driven lung 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 B290.
Abstract B46: Soluble AXL is a candidate circulating biomarker for predicting acquired and intrinsic resistance to molecular-targeted agents in NSCLC cells.
Authors: Ise Nobuyuki , Takemori Nobuaki , Omi Kazuya , Goishi Katsutoshi , Higashiyama Shigeki
Published: August 2014

Background: Drug resistance is an important factor that compromise therapeutic effect of most anti-cancer drugs including molecular-targeted agents. Non-invasive assessment of drug resistance by circulating biomarkers would therefore be useful for determining therapeutic options for resistant patients. Recently, a receptor tyrosine kinase AXL has been implicated in acquired resistance to EGFR inhibitors in NSCLC cells. In this study, we examined the potential utility of AXL as a circulating biomarker to predict acquired or intrinsic drug resistance using NSCLC cells.

Materials and methods: Drug resistant NSCLC cell lines were developed by exposing NSCLC cells with either EGFR inhibitor gefitinib or MET inhibitor PHA-665752. AXL-positive cells in parent and established resistant cell lines were isolated by anti-AXL antibody-immobilized magnetic beads. Drug resistance was assessed by MTS growth inhibition assay. Immunoblot analysis was performed on cell lysate and conditioned medium to evaluate expression and release of AXL. The role of AXL in cell growth and motility was examined by MTS growth inhibition assay and transwell migration assay.

Results: Drug-resistant NSCLC cell lines were successfully established, and increased release of fragmented soluble form of AXL was observed in these cell lines. They showed increased cell motility, which was effectively inhibited by AXL knockdown using siRNA. In contrast, their cell growth was not affected by AXL knockdown, even when these cells were simultaneously treated with molecular-targeted agents. Furthermore, cells highly expressing AXL were immunologically isolated from a gefitinib-sensitive parent cell line. These cells showed partial resistance to gefitinib, indicating that such cells intrinsically exist in NSCLC cell populations.

Conclusions: Soluble form of AXL is a candidate circulating biomarker for predicting acquired and intrinsic resistance to molecular-targeted agents in NSCLC cells. It may also be used to predict AXL-mediated increased motility of resistant cells. Patients harboring such resistant cells may have increased chance of responding to AXL-targeted anti-metastasis therapy.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B46.

Citation Format: Nobuyuki Ise, Nobuaki Takemori, Kazuya Omi, Katsutoshi Goishi, Shigeki Higashiyama. Soluble AXL is a candidate circulating biomarker for predicting acquired and intrinsic resistance to molecular-targeted agents in NSCLC 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 B46.
Abstract B59: Zhangfei/CREBZF arrests the growth of osteosarcoma cells by displacing Mdm2 and stabilizing p53.
Authors: Zhang Rui , Misra Vikram
Published: August 2014

Osteosarcomas (OS) are the most common malignant bone tumors in humans and dogs. Although there has been dramatic progress in treating OS in both species by surgery and chemotherapy, these therapies often fail, leading to recurrence of the tumor and metastatic spread. Our previous studies showed that Zhangfei/CREBZF, a basic region-leucine zipper (bLZip) transcription factor, is a potent suppressor of growth in some cancer cell lines, including the canine osteosarcoma cell line D-17. However, the mechanisms underlying the suppressive effects of Zhangfei have not been fully elucidated. Furthermore, the effects of Zhangfei are not universal and it has no obvious effects on untransformed cells and some cancer cell lines, suggesting that Zhangfei may act through an intermediary that is either not induced or is defective in cells that it does not affect. The objective of this study was to identify such an intermediary and to determine how Zhangfei exerts its effect. By monitoring the mRNA levels, protein, localization, and transcription activity of tumor suppressor protein p53 and its target genes in D-17 cells infected with adenovirus vectors expressing Zhangfei, we found Zhangfei stabilizes p53 and co-localizes with it in cellular nuclei and that the basic-leucine zipper domain of Zhangfei is required for its profound effects on cell growth and interaction with p53. Suppression of p53 by siRNA at least partially inhibited the effects of Zhangfei on the growth of cells. The effects of Zhangfei on dog osteosarcoma cells (D-17 cells) is mirrored by its effects on the p53 expressing human osteosarcoma cell line U2OS while Zhangfei has no effect on the p53-null osteosarcoma cell line MG63. In U2OS cells Zhangfei displaces the ubiquitin ligase, MDM2, from its association with p53 suggesting a mechanism for the effects of Zhangfei on p53. Overall, we identified that Zhangfei suppressed cell growth in osteosarcoma cells through direct interaction with tumor suppressor protein p53. We demonstrated that Zhangfei stabilized p53 and promoted its nuclear retention by displacing the E3 ubiquitin ligase, Mdm2. Our findings reveal a novel mechanism by which Zhangfei may inhibit tumor growth and metastasis. This may provide a potential application to gene therapy of certain types of osteosarcoma, and perhaps other tumors containing functional p53.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B59.

Citation Format: Rui Zhang, Vikram Misra. Zhangfei/CREBZF arrests the growth of osteosarcoma cells by displacing Mdm2 and stabilizing p53. [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 B59.
Abstract B86: Potent antitumor effect of TAS-102, a novel oral anti-neoplastic nucleoside agent, on both cetuximab-sensitive KRAS wild-type and cetuximab-resistant KRAS mutated colorectal cancer cells via trifluorothymidine incorporation into DNA.
Authors: Tanaka Nozomu , Yamada Yukari , Fujioka Akio , Yamamura Keisuke , Ito Satoko , Matsuo Kenichi , Utsugi Teruhiro
Published: August 2014

Background: The KRAS gene is mutated in approximately 40% of colorectal cancer (CRC). Patients with KRAS mutant CRC do not benefit from treatment with anti-EGFR antibody cetuximab and panitumumab. TAS-102 is a novel oral anti-neoplastic nucleoside agent, consisting of trifluorothymidine (FTD) as the antitumor component and thymidine phosphorylase inhibitor which prevents degradation of FTD. In a previous report, TAS-102 showed a broad spectrum of antitumor effect against various types of tumors via FTD incorporation into DNA followed by possible DNA dysfunction. Here, we investigated TAS-102 antitumor potency against colorectal cancer cell lines with differing KRAS status.

Materials and Methods: Cytotoxicity of FTD and cetuximab by 72h treatment was evaluated using cancer cell lines with varying of KRAS gene status. The antitumor effect of TAS-102 and cetuximab was compared in mice subcutaneously implanted with colorectal cancer cell lines with KRAS wild-type or mutation. In the same models, the amount of FTD incorporated into DNA was analyzed by HPLC in the TAS-102-treated tumors. EGFR downstream signaling pathways were analyzed by immunoblotting in the cetuximab-treated tumors.

Results: KRAS wild-type cell lines were sensitive to cetuximab in vitro, while some of the KRAS mutants were not. Cetuximab showed antitumor effect against KRAS wild-type tumors with downregulation of EGFR downstream signaling pathways, and it didn't show antitumor effect against KRAS mutants. In contrast to cetuximab, FTD exhibited a broad spectrum of cytotoxicity in vitro irrespective of KRAS status. Additionally, TAS-102 exerted significant antitumor effect against KRAS wild-type and mutant tumors. FTD incorporation into DNA was observed in both tumor types.

Conclusion: TAS-102 appears to exert significant antitumor effects on CRC cell lines irrespective of KRAS status which is consistent with preliminary clinical findings.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B86.

Citation Format: Nozomu Tanaka, Yukari Yamada, Akio Fujioka, Keisuke Yamamura, Satoko Ito, Kenichi Matsuo, Teruhiro Utsugi. Potent antitumor effect of TAS-102, a novel oral anti-neoplastic nucleoside agent, on both cetuximab-sensitive KRAS wild-type and cetuximab-resistant KRAS mutated colorectal cancer cells via trifluorothymidine incorporation into DNA. [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 B86.
Abstract C121: Genomic characterization of invasive cervical cancer in Guatemala and Venezuela: Common activation of the PIK3CA pathway.
Authors: Dean Michael , Gharzouzi Eduardo , Alvirez Enrique , Villagran Guillermo , Odey Ushie , Sawitzke Julie , Boland Joe , Lou Hong , Yeager Meredith
Published: August 2014

Cervical cancer represents the most dramatic cancer health disparity of women in the world, with over 270,000 deaths annually, concentrated in poor, rural, and indigenous populations. Guatemala and Venezuela are illustrative of this disparity as cervical cancer is the predominant cause of cancer cases and deaths in women. The average age of the subjects is 50, and smoking and oral contraceptive use is low. The affected women have an average of 6 children and adeno- or adenosquamous pathologies represent 25% of the tumors. To determine the genomic changes in invasive tumors, we initiated a prospective collection of invasive cervical cancer tissue. To determine the most frequently mutated genes we sequenced the exomes of 23 tumors in the Ion Torrent Proton and followed up with targeted sequencing of genes by Ampliseq in an additional 280 tumors. The exome sequence revealed potential driver mutations in several known cancer genes such as PTEN, PIK3CA, TSC1, SETD2, HRAS, PTCH, ARID1A, ARID4A and RB1. Targeted resequencing in a larger set of tumors of commonly mutated genes in the COSMIC database (PIK3CA, TP53, STK11, PTEN, KRAS, HRAS, and CDKN2A) revealed 40% mutation in PIK3CA and 11% in PTEN (a negative regulator of the PI kinase pathway). TP53 and STK11 were significantly mutated (10 and 8% of tumors, respectively) but HRAS, KRAS and CDKN2A at a very low level (0-2%). The PIK3CA mutations were concentrated in the known activating sites in the helical domain (E542K and E545K). To determine HPV stain types we amplified the HPV L1 gene found detectable in HPV in 96% of samples with HPV16 in 53%, HPV18 in 12%, HPV45 in 10% and HPV 26, 31, 33, 35, 39, 52, 56, 58, 67, 68, 69, and 73 in 0.8-4.9% of samples. In conclusion, invasive cervical cancers display frequent mutation of the helical domain of PIK3CA and activation of the PI kinase pathway, suggesting that targeted inhibition of this pathway may provide an avenue for therapy in this largely untreatable, common cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C121.

Citation Format: Michael Dean, Eduardo Gharzouzi, Enrique Alvirez, Guillermo Villagran, Ushie Odey, Julie Sawitzke, Joe Boland, Hong Lou, Meredith Yeager. Genomic characterization of invasive cervical cancer in Guatemala and Venezuela: Common activation of the PIK3CA pathway. [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 C121.
Abstract C187: Salicylates suppress tumor growth via inhibition of HMGB1.
Authors: Napolitano Andrea , Pellegrini Laura , Jube Sandro , Jennings Cormac J. , Flores Erin G. , Larson David , Negi Vishal S. , Pagano Ian , Tanji Mika , Powers Amy , Pastorino Sandra , Pass Harvey I. , Bianchi Marco E. , Carbone Michele , Yang Haining
Published: August 2014

High-Mobility Group Box 1 (HMGB1) is a chromatin-associated protein critically involved in nucleosome assembly. During cell necrosis, HMGB1 is first translocated from the nucleus to the cytoplasm, and then passively released to the extracellular space, where it initiates and propagates the inflammatory response. Immune cells (e.g. macrophages) and cancer cells are also able to actively secrete HMGB1. Extracellular HMGB1 is therefore considered a crucial molecule for both chronic inflammation and cancer development, and a promising therapeutic target.

In this study, using a malignant mesothelioma (MM) model, we tested the hypothesis that the known anti-cancer effects of aspirin (acetyl salicylic acid), the most widely used anti-inflammatory drug, and salicylic acid, its major metabolite, could be due to HMGB1 inhibition.

In vitro, we analyzed the effects of salicylates on HMGB1-induced MM cell proliferation, wound healing, migration, invasion and anchorage-independent colony formation. Moreover, using a MM xenograft model, we tested whether in vivo suppression of HMGB1 signaling by salicylates or BoxA, a specific HMGB1 inhibitor, resulted in reduced MM growth and increased survival.

Our results demonstrated that salicylates, at doses normally used in clinical practice (≤1 mM), significantly suppress HMGB1-induced in vitro pro-tumorigenic effects on MM cells and inhibits in vivo MM growth, significantly extending mice survival.

Our findings are critically relevant to the understanding of the poorly known anti-cancer effects of salicylates. From this perspective, they apply to more than 50 million people in the USA alone currently taking aspirin. Finally, these preclinical results could be translated to improve the current treatment of the usually lethal MM, and of other HMGB1-related malignancies as well.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C187.

Citation Format: Andrea Napolitano, Laura Pellegrini, Sandro Jube, Cormac J. Jennings, Erin G. Flores, David Larson, Vishal S. Negi, Ian Pagano, Mika Tanji, Amy Powers, Sandra Pastorino, Harvey I. Pass, Marco E. Bianchi, Michele Carbone, Haining Yang. Salicylates suppress tumor growth via inhibition of HMGB1. [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 C187.
Abstract C231: Novel, fully-human GrB-containing constructs targeting the Fn14 receptor for TWEAK on solid tumor cells.
Authors: Zhou Hong , Migliorini Mary , Hittelman Walter , Ekmekcioglu Suhendan , Tran Nhan , LoBello Janine , Winkles Jeffrey A. , Rosenblum Michael G.
Published: August 2014

The TNFR superfamily member Fn14, the receptor for TNF-like weak inducer of apoptosis (TWEAK), has emerged as a potentially clinically valuable target for cancer therapy. Fn14 expression was relatively low in normal tissues but was found to be elevated in various human solid tumor types, including brain, breast and melanoma, and can be a negative prognostic indicator. TMAs of melanoma patient tumors found elevated Fn14 expression in 173/190(92%) of primary specimens and 86/150(58%) of metastases. Studies are underway examining expression vs survival. Studies are also underway examining TNBC microarrays for expression as well. To target the Fn14 receptor, we constructed a novel chimeric protein designated granzyme B (GrB)-TWEAK, using the human TWEAK receptor-binding domain as a targeting moiety and the human Granzyme B as a cytotoxic domain. In addition, we developed a high mw(160kDa) fusion protein composed of a single-chain anti-Fn14 scFv and GrB(designated scIGB). Both fusion construct was expressed in mammalian cells and purified to homogeneity. BiaCore analysis of TWEAK, GrB-TWEAK and scIGB binding to the Fn14 extracellular domain indicated that these proteins bound to Fn14 with similar affinities(Kds of ∼ 3-8 nM). Confocal immunofluoresence studies showed that GrB-TWEAK and scIGB specifically and rapidly (within 3 hrs) internalized into Fn14-expressing MDA-MB-231 breast cancer and HT-29 colorectal adenocarcinoma cells. Against a panel of 26 human cancer cell lines in culture, GrB-TWEAK demonstrated impressive and selective cytotoxicity to Fn14-expressing cells in the low nanomolar range (IC50 ranged from 0.4 nM-330 nM) and were 6 to 1117 fold more potent than free GrB. Treatment of cells expressing the multidrug resistance protein MDR1 showed no cross-resistance to the fusion construct in vitro. Mechanistic studies demonstrated that GrB-TWEAK activated caspase cascades and cytochrome C related pro-apoptotic mechanisms in keeping with the known intracellular functions of GrB in target cells. Preliminary mouse xenograft tumor model studies are ongoing.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C231.

Citation Format: Hong Zhou, Mary Migliorini, Walter Hittelman, Suhendan Ekmekcioglu, Nhan Tran, Janine LoBello, Jeffrey A. Winkles, Michael G. Rosenblum. Novel, fully-human GrB-containing constructs targeting the Fn14 receptor for TWEAK on solid tumor 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 C231.
Abstract C292: Inhibition of carbonic anhydrase (9 and 12) decreases cell proliferation and gene expression in human glioblastoma cell.
Authors: Teixeira Silvia A. , Pezuk Julia A. , Brassesco Maria S. , Carlotti Carlos G. , Tone Luiz G. , Scrideli Carlos A.
Published: August 2014

Propose: Glioblastoma (GB) is the most common and lethal malignant primary brain tumor, representing up to 50% of all primary brain gliomas, and carries the poorest prognosis. An important factor for tumor progression is the acidification of the environment that is promoted by carbonic anhydrases (CAs) 9 and 12, directing to the acquisition of metastatic phenotype and chemoresistance to anticancer drugs. Indisulam is a novel anticancer drug with potent inhibition of CAs. It has in vitro and in vivo activity and prevents cell cycle progression in tumor cells, downregulates genes involved in cytotoxic drug resistence and cell proliferation. The aim this study was to evaluate the expression and the effects of inhibition of the 9/12 CAs by indisulam in proliferation and in gene expression of GB cell lines subjected to normoxia or hypoxia.

Materials and Method: The U87-MG, U251, U138-MG, U343-MG-a adult GB cell lines were cultured in conditions of hypoxia or normoxia. Functional studies of cell proliferation and clonogenic capacity were performed in triplicate with Indisulan at different concentrations during 24, 48 and 72h. Gene expression of CA9, CA12, VEGF and HIF1α was assessed using qRT-PCR. Statistical analysis was made by one-way ANOVA and Bonferoni post-hoc.

Results: Indisulam displayed inhibitory characteristics to hypoxia induced CA9/CA12 expression in the four GBM cell lines. All experiments showed that the inhibition of CA9/12 with indisulam were dose- and time-dependent (p<0.05) and caused a decreased on cell proliferation and the capacity clonogenic. The evaluation of gene expression in conditions of hypoxia (1%) compared to normoxia (preliminary experiments) showed increased expression to the genes CA9, CA12, HIF-1α and VEGF with decreased expression when the cells were treated with Indisulam.

Conclusion: Our results indicate antiproliferative and inhibitory effect of the indisulam in GB cell line on condition of normoxic and hypoxic. It suggests that indisulam may be an interesting candidate for the development antitumor therapies based on the inhibition of tumor-associated carbonic anhydrase.

Financial Support: FAPESP

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C292.

Citation Format: Silvia A. Teixeira, Julia A. Pezuk, Maria S. Brassesco, Carlos G. Carlotti, Luiz G. Tone, Carlos A. Scrideli. Inhibition of carbonic anhydrase (9 and 12) decreases cell proliferation and gene expression in human glioblastoma cell. [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 C292.
Abstract C52: A novel combinatorial treatment for glioblastoma of temozolomide and JLK1486.
Authors: Weatherbee Jessica L. , Kraus Jean-Louis , Moser Richard P. , Ross Alonzo H.
Published: August 2014

Background: Glioblastoma multiforme (GBM) is a grade IV brain tumor characterized by a heterogeneous population of cells that are highly invasive and resistant to chemotherapeutic treatments. The current standard of care, comprised of surgical resection followed by radiation and chemotherapy, only provides GBM patients with a 12-14 month survival period. Our lab is currently investigating the potential therapeutic combination of temozolomide, the chemotherapeutic agent currently used to treat GBM patients, with a novel agent, JLK1486, to determine if this combination decreases or inhibits tumor recurrence in vitro.

Materials and Methods: GBM neurospheres and primary lines were treated with single or combination treatments of temozolomide (TMZ) and/or JLK1486. Spheres were counted on day 7 to determine initial sphere formation, re-counted on day 14 to determine recovery, and were then pH dissociated and counted on day 21 to determine secondary sphere formation.

Results: Our lab found that neither TMZ nor JLK1486 alone eliminated secondary sphere formation. When cells were treated with a single dose of both TMZ+JLK1486 on day 0 secondary sphere formation was not inhibited. However, when cells where treated with TMZ+JLK1486 on day 0 and then dosed a second time with JLK1486 on day 7, secondary sphere formation was significantly reduced in double versus single agent treated cells. At least part of the enhanced efficacy of TMZ and JLK1486 involves activation of the unfolded protein response (UPR), which in turn increases expression of CHOP and induces apoptosis.

Conclusion: Combining novel chemotherapeutic agents with the current standard of chemotherapeutic care, TMZ, may not only inhibit tumor growth but also tumor recurrence. Our lab found that when a novel chemotherapeutic agent, JLK1486, was combined with TMZ, secondary sphere formation was inhibited, suggesting that dual treatment is more efficacious than single agent in inhibiting secondary sphere formation and may reduce tumor recurrence. Combined therapy of UPR-inducing agents with chemotherapy is a promising approach to enhance efficacy by eliminating the few surviving cells that allow formation of secondary spheres and, perhaps, tumor recurrence.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C52.

Citation Format: Jessica L. Weatherbee, Jean-Louis Kraus, Richard P. Moser, Alonzo H. Ross. A novel combinatorial treatment for glioblastoma of temozolomide and JLK1486. [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 C52.
Abstract CN03-03: Use of the zebrafish for studying cancer genetics.
Authors: Zon Leonard I.
Published: August 2014

Melanoma is a devastating disease and there are few therapies that lead to substantial long-term remission for metastatic disease. We have created a zebrafish model of melanoma by overexpressing BRAF-V600E in the combination of P53 mutation. This fish develops melanoma at a characteristic rate and the tumors greatly resemble those of human melanomas. Examination of gene expression in the melanomas demonstrated neural crest transcription factor expression in the zebrafish melanomas. A neural crest marker called Crestin was substantially upregulated in the tumors compared to adjacent skin. A chemical screen was undertaken to find small molecules that prevent neural crest development during embryogenesis in the zebrafish, hoping to find a small molecule that would inhibit the gene expression signature in the tumor. A drug called leflunomide was found to inhibit transcription elongation in the crest and also in human melanomas. Combination of a BRAF inhibitor plus leflunomide led to a substantial decrease in human tumors when placed into nude mice. A Phase II clinical trial has been undertaken using the combination of BRAF inhibitor and leflunomide. Leflunomide has an important effect on transcription elongation that is dependent on a new tumor suppressor complex called the HEXIM complex. Inactivation of the HEXIM complex interferes with the effect of the drug. HEXIM has also been shown to be a tumor suppressor in our zebrafish model system. In an effort to understand the effects of leflunomide, we undertook a screen for a chemical suppressor of leflunomide. This demonstrated pathways that affected drug metabolism as well as transcription elongation. Our studies demonstrate a novel pathway for interrupting cancer development by blocking transcription elongation in combination with BRAF inhibitors.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN03-03.

Citation Format: Leonard I. Zon. Use of the zebrafish for studying cancer genetics. [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 CN03-03.
Abstract CN04-01: Poking cancer cells with BH3 profiling to personalize cancer therapy.
Authors: Montero Joan , Ni Chonghaile Triona , Sarosiek Kris , Ryan Jeremy A. , Leah Hogdal , Letai Anthony G.
Published: August 2014

Nearly all attempts to understand and predict response of patient cancer cells to therapeutics rely on measurements of static properties at a single time point such as protein abundance, gene expression profiling, or genetic code. While these approaches have doubtless yielded useful information to guide therapy, it is often the case that observing how a system responds to systematic perturbation can be a more powerful guide to understanding and predicting behavior. Using BH3 profiling, we systematically perturb the mitochondria of cancer cells with BH3 peptides and can make predictions about response to therapy based on the response observed. So far, we have successfully applied BH3 profiling to understanding and predicting clinical response to conventional chemotherapy, targeted pathway inhibitors and direct inhibitors of anti-apoptotic proteins like BCL-2. Since BH3 profiling can provide results within a single day, it is applicable to studying primary cancer cells from patient biopsies without the need for prolonged ex vivo culture. BH3 profiling has the potential to provide a predictive biomarker for any cancer therapeutic that kills cancer cells via the mitochondrial pathway of apoptosis.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN04-01.

Citation Format: Joan Montero, Triona Ni Chonghaile, Kris Sarosiek, Jeremy A. Ryan, Hogdal Leah, Anthony G. Letai. Poking cancer cells with BH3 profiling to personalize cancer 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 CN04-01.
Abstract CN05-03: Targeting oncogene-induced DNA damage for cancer therapy.
Authors: Fernandez-Capetillo Oscar
Published: August 2014

Our laboratory has focused much of its research in trying to understand how cells respond to "replicative stress" (RS), a type of DNA damage which arises unavoidably every time that a cell replicates its DNA, and which is mainly prevented by a RS-Response (RSR) coordinated by ATR and Chk1 kinases.

Given that certain oncogenes can generate substantial amounts of RS, we hypothesized that cells carrying these oncogenes might be “addicted” to a proficient RSR. To explore these ideas, we have generated several cellular, animal and chemical tools for the study of ATR function in mammals. These include (1) a cell system in which ATR can be selectively activated at will; (2) mice with a reduced or increased RSR, and (3) chemical inhibitors of ATR. Our early works suggested that ATR inhibitors would indeed be particularly deleterious for tumors with high levels of RS, such as those induced by the Myc oncogene. Our ideas and new results in this area will be presented.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN05-03.

Citation Format: Oscar Fernandez-Capetillo. Targeting oncogene-induced DNA damage for cancer 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 CN05-03.
Abstract PL03-03: Designing p300/CBP histone acetyltransferase inhibitors for cancer.
Authors: Cole Philip A.
Published: August 2014

The transcriptional coactivator p300/CBP catalyzes protein lysine acetylation on histones and other proteins and has been implicated in a wide array of physiologic and pathologic processes including cancer. In contrast to HDACS, methyltransferases, and bromodomains, it has historically been difficult to identify drug-like small molecules as potent histone acetyltransferase inhibitors. We will discuss our longstanding effort to design selective p300/CBP acetyltransferase inhibitors using enzymologic and structural considerations. We will provide current pharmacodynamic and pharmacokinetic properties of our most recent p300/CBP inhibitors and future directions related to anticancer therapies. We will also highlight the use of protein microarrays as a tool to understand the regulation and substrate profile of p300/CBP protein acetylation.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):PL03-03.

Citation Format: Philip A. Cole. Designing p300/CBP histone acetyltransferase inhibitors for 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 PL03-03.