bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3535: A novel tumor-specific oncolytic biological therapy against invasive pancreatic cancer
Authors: Koujima Takeshi , Tazawa Hiroshi , Hori Naoto , Tamura Shuta , Kuroda Shinji , Kishimoto Hiroyuki , Nishizaki Masahiko , Urata Yasuo , Kagawa Shunsuke , Fujiwara Toshiyoshi
Published: August 2015

Pancreatic cancer is one of the worst prognosis disease all over the world and has an overall 5-year survival rate of less than 5%. At the time of diagnosis, more than 80% of patients are not eligible for curative surgical resection due to extensive local tumor invasion and early systemic metastasis. Moreover, even after curative surgery, pancreatic cancers still show poor prognosis due to local recurrence and systemic metastasis. Gemcitabine is the standard chemotherapeutic agent to treat advanced pancreatic cancers, but median overall survival ranged from 5.0 to 7.2 months, suggesting that standard chemotherapy is less effective to most of pancreatic cancer patients. Therefore, the development of novel therapeutic strategy is needed for the treatment of pancreatic cancers. We developed a novel oncolytic adenovirus, OBP-702, in which a human telomerase reverse transcriptase gene promoter drives viral E1 gene for virus replication, and armed with the wild-type tumor suppressor p53 gene. Precise antitumor effects of OBP-702 have been evaluated in human pancreatic cancer cells. We used four pancreatic cancer cell lines with different invasion ability, including non-invasive type (MIA PaCa-2, Panc-1) and invasive type (BxPC-3, Capan-1). The antitumor effect of OBP-702 for each cell line was assessed using XTT assay. OBP-702 induced profound anti-tumor effect in all human pancreatic cancer cells, whereas OBP-301 lacking the p53 tumor suppressor gene showed differential effects among the cell types. OBP-301 induced moderate anti-tumor effect in MIA Paca-2, BxPC-3 and Capan-1 cells and strong anti-tumor effect in Panc-1 cells in a dose-dependent manner, suggesting the broad spectrum of OBP-702's efficacy. The molecular mechanism of anti-tumor effect was assessed by Western blot analysis. OBP-301 induced autophagy-related cell death, whereas OBP-702 induced autophagy- and apoptosis-related cell deaths. These results suggest that an oncolytic adenovirus, OBP-702, is a promising antitumor agent to induce profound cell death in invasive human pancreatic cancer cells. The clinical trial of intratumoral administration of OBP-702 in patients with invasive pancreatic cancer is warranted.

Citation Format: Takeshi Koujima, Hiroshi Tazawa, Naoto Hori, Shuta Tamura, Shinji Kuroda, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. A novel tumor-specific oncolytic biological therapy against invasive pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3535. doi:10.1158/1538-7445.AM2015-3535
Abstract 3537: Stem-cell based selective delivery of alpha keto reductases for therapeutic targeting of residual androgens in prostate cancer
Authors: Ranjan Manish , Abd Elmageed Zakaria , Kim Hogyoung , Datta Amrita , Bhasin Nobel , Braun Steven E. , Mondal Debasis , Abdel-Mageed Asim B.
Published: August 2015

The twice as high incidence and mortality among African Americans (AA) compared to Caucasian Americans and other ethnic minorities remains elusive. The de novo synthesis of androgens by prostate tumors provides a significant survival advantage leading to outgrowth of castration resistant tumors. The “intracrine” production of androgens in the tumor microenvironment is greatly influenced by the synthesis of androgen metabolizing enzymes (AMEs) and the level of circulating hormones. Currently, targeting de novo synthesis of androgens in tumor microenvironment is singularly the toughest challenge presented to oncologists. Our present research attempts to identify and exploit the key players among the AMEs for targeting the backdoor pathway of DHT synthesis in castration resistant prostate cancer (CRPC). Comparative analysis of gene expression of AMEs in microdissected cells versus the adjacent normal tissue revealed AKR1C4 to be the most promising candidate for targeting the backdoor pathway in DHT synthesis. Existing literature supports this view since Type 1 3a-HSD enzyme has been shown to readily oxidize testosterone to Δ4-androstene-3, 17-dione in a substrate dependent reaction. Our analysis using recombinant AKR1C4 induced cytotoxicity and apoptosis in androgen dependent PC cells in vitro. Next, using a lentivirus construct, we genetically engineered tumor-tropic adipose-derived stem cells (ASCs) to express and secreted AKR1C14 (mouse homolog of AKR1C4). The results showed that ASCs are capable of expressing the enzyme, which can catabolize DHT in vitro and induce apoptosis in androgen dependent prostate cancer cells as shown by DHT Elisa, psPSA reporter assays and cytotoxicity and survival assays. Our current research plan is to examine the efficacy of tumor-tropic AKR1C14-expressing ASCs in targeting and inhibiting prostate metastatic growth in an animal model system.

Citation Format: Manish Ranjan, Zakaria Abd Elmageed, Hogyoung Kim, Amrita Datta, Nobel Bhasin, Steven E. Braun, Debasis Mondal, Asim B. Abdel-Mageed. Stem-cell based selective delivery of alpha keto reductases for therapeutic targeting of residual androgens in prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3537. doi:10.1158/1538-7445.AM2015-3537
Abstract 3538: Quorum-sensing Salmonella selectively trigger protein expression within tumors
Authors: Swofford Charles A. , Van Dessel Nele , Forbes Neil S.
Published: August 2015

Salmonella that secrete anti-cancer proteins have the potential to eliminate tumors, but nonspecific expression causes damage to healthy tissue. Salmonella, integrated with a density-dependent switch, would only express proteins in tightly packed colonies within tumors, reducing side-effects after the initial bacterial administration. To test this, we cloned the lux quorum-sensing (QS) system and a GFP reporter into the attenuated Salmonella strain VNP20009. Fluorescence and bacterial density were measured in culture and a tumor-on-a-chip device to determine the critical density necessary to initiate expression. QS Salmonella were injected into 4T1 tumor-bearing mice to quantify GFP expression in vivo. At densities below 0.6×1010 CFU/g in tumors, less than 3% of QS Salmonella expressed GFP. Above densities of 4.2×1010 CFU/g, QS Salmonella had similar expression levels to constitutive controls. GFP expression by QS colonies was dependent upon the distance to neighboring bacteria. No colonies expressed GFP when the average distance to neighbors was greater than 155 μm. Calculations of autoinducer concentrations showed that expression was sigmoidally dependent on density and inversely dependent on average radial distance. Based on bacterial counts from excised tissue, the liver density (0.0079×1010 CFU/g) was less than the critical density (0.11×1010 CFU/g) necessary to initiate expression, indicating that expression of a therapeutic protein would not be induced in healthy organs. Inserting the bacterial toxin S. Aureus α-hemolysin (SAH) under the control of the QS system resulted in the expression of SAH only at high bacterial dosage. In vitro, supernatant from cultures of QS-SAH Salmonella reduced cancer cell viability by 70%. When administered to the microfluidic tumor-on-a-chip, QS-SAH Salmonella killed 43% of the tissue, 12 times greater (P<0.05) than induced by control bacteria. QS Salmonella are a promising tool for cancer treatment that will target drugs to tumors, while preventing damage to healthy tissue.

Citation Format: Charles A. Swofford, Nele Van Dessel, Neil S. Forbes. Quorum-sensing Salmonella selectively trigger protein expression within tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3538. doi:10.1158/1538-7445.AM2015-3538
Abstract 3544: Clinical applicable human adipose tissue-derived mesenchymal stem cells delivering therapeutic genes to brainstem glioma
Authors: Choi Seung Ah , Lee Young Eun , Kwak Phil Ae , Moon Youn Joo , Phi Ji Hoon , Wang Kyu-Chang , Kim Sung Su , Wang Kyu-Chang , Joo Kyeung Min , Kim Seung-Ki
Published: August 2015

Brainstem glioma is one of incurable malignancies in children due to its unique inoperable location. Regarding the extensive migratory ability toward cancer and the possible autologous transplantation, human adipose-derived mesenchymal stem cells (hAT-MSC) are attractive vehicles to deliver therapeutic genes to brainstem glioma. In this study, we established clinically applicable hAT-MSCs expressing therapeutic genes in a GMP facility and investigated the therapeutic efficacy against brainstem glioma preclinically. For the feasible clinical application, 1) hAT-MSCs were primarily cultured from the human subcutaneous adipose tissue for making autologous transplantation possible, 2) hAT-MSCs were genetically engineered to express two therapeutic genes, carboxyl esterase (CE) and a secreted form of the TNF-related apoptosis-inducing ligand (sTRAIL) for synergistic effects, 3) human CE and sTRAIL sequences were utilized to avoid immunological side effects, and 4) sTRAIL expression vector was delivered by non-gDNA integrating gene transfer technology. hAT-MSCs expressing sTRAIL ± CE showed significant therapeutic effects against brainstem gliomas in vitro and in vivo. However, simultaneous sTRAIL and CE expression failed to show synergistic effects in vivo. The results indicate that non-viral transient sTRAIL gene transfer to autologous hAT-MSCs is a clinically applicable stem cell-based gene therapy for brainstem gliomas in terms of therapeutic effects and safety.

Citation Format: Seung Ah Choi, Young Eun Lee, Phil Ae Kwak, Youn Joo Moon, Ji Hoon Phi, Kyu-Chang Wang, Sung Su Kim, Kyu-Chang Wang, Kyeung Min Joo, Seung-Ki Kim. Clinical applicable human adipose tissue-derived mesenchymal stem cells delivering therapeutic genes to brainstem glioma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3544. doi:10.1158/1538-7445.AM2015-3544
Abstract 3583: Drug-resistant NPM/ALK mutants show different sensitivity to second generation tyrosine kinase inhibitors
Authors: Mologni Luca , Ceccon Monica , Fontana Diletta , Pirola Alessandra , Piazza Rocco , Gambacorti-Passerini Carlo
Published: August 2015

Rearranged or mutated forms of the Anaplastic Lymphoma Kinase (ALK) are involved in the pathogenesis of various cancers, in particular anaplastic large cell lymphoma (ALCL), non-small-cell lung cancer (NSCLC) and neuroblastoma. ALK-positive tumors are currently treated with crizotinib (XalkoriTM, Pfizer) or ceritinib (ZykadiaTM, Novartis), two oral ALK inhibitors (ALKi). Additional inhibitors are in clinical trial. Despite high response rates, drug-resistant disease often develops in patients. In order to study the mechanisms that underlie resistance, we generated several ALKi-resistant cell lines in vitro. Here we present the selection of novel NPM/ALK-positive ALCL cells resistant to ASP3026 (Astellas) that grow in the presence of up to 2 μM ASP3026 and show 10 to 60 fold shift in IC50. The established ASP3026-resistant cell lines carry several point mutations in the ALK kinase domain (G1128S, C1156F, I1171N/T, F1174I, N1178H, E1210K, and C1156F/D1203N) that confer resistance to ASP3026 when reintroduced in a Ba/F3 cell model. Furthermore, the activity profile of ASP3026, crizotinib, ceritinib, alectinib, AP26113 and PF-06463922 against a panel of 20 NPM/ALK drug-resistant mutants will be presented. We report for each ALKi the IC50 value against the mutants, the IC50 fold increase over wild-type NPM/ALK (relative resistance, RR) and the IC50 ratio between parental Ba/F3 cells and mutants (therapeutic index, TI). From our screen, the G1202R and C1156F/D1203N mutations appear to be highly resistant to all tested inhibitors, therefore they are predicted to be the most challenging mutants for ALKi therapy.

Citation Format: Luca Mologni, Monica Ceccon, Diletta Fontana, Alessandra Pirola, Rocco Piazza, Carlo Gambacorti-Passerini. Drug-resistant NPM/ALK mutants show different sensitivity to second generation tyrosine kinase inhibitors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3583. doi:10.1158/1538-7445.AM2015-3583
Abstract 3586: The use of kinome profiling to determine potential resistance pathways in pancreatic cancer cells treated with PIM kinase inhibitors
Authors: Singh Vandana , Nixon Brittany , Gilbert T.S. Karim , Warner Steve , Bearss David , Graves Lee M. , Baines Antonio T.
Published: August 2015

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent cancer of the pancreas with a 5-year survival rate of 6%, making it the 4th most common cause of cancer deaths in the United States. One of the challenges related to this cancer is the issue of chemoresistance. Chemoresistance renders most drugs ineffective in the treatment of PDAC, including kinase inhibitors and the chemotherapeutic drug gemcitabine. PIM (Proviral Integration site for the Moloney murine leukemia virus) kinases are a family of proteins shown to play an important role in the chemoresistance of many cancers, including pancreatic cancer. PIMs act downstream of the JAK-STAT cytokine signaling pathway and phosphorylate substrates involved in numerous cell functions including cell cycle progression and apoptosis. One objective of our research was to determine the role of PIM kinases on transformed phenotypes of PDAC cells. We were able to demonstrate that the PIM kinase inhibitor SGI-1776 and TP-3654, a second generation PIM kinase inhibitor, were able to inhibit growth in cell viability assay. Also, the PIM inhibitors were able to decrease various phenotypes such as anchorage-dependent and anchorage-independent growth in MIA PaCa-2 and PANC-1 cells. A second objective was to determine if PIM kinase inhibitors could reduce chemoresistance in PDAC cells. PIM inhibitors in combination with gemcitabine decreased cell viability in PDAC cells significantly more than when administered separately. To investigate resistance pathways activated in PDAC cells after treatment with PIM kinase inhibitors, we applied multiplexed inhibitor beads (MIBs) mass spectrometry (MS) to profile the kinome. We observed numerous kinases that were downregulated or upregulated after treatment. One of the kinases upregulated was IKKα, a key kinase in the anti-apoptotic NF-κB signaling pathway. Our results suggest that PIM kinases are an important target for cell growth and chemoresistance in pancreatic cancer. Also, these results suggest that treating PDAC cells with a PIM inhibitor simultaneously with an IKK inhibitor might prevent the effects of resistance pathways. Overall, our studies demonstrate that kinome profiling is an effective strategy to identify cellular responses to PIM kinase inhibitors as well as other drugs for treating pancreatic and other cancers.

Citation Format: Vandana Singh, Brittany Nixon, T.S. Karim Gilbert, Steve Warner, David Bearss, Lee M. Graves, Antonio T. Baines. The use of kinome profiling to determine potential resistance pathways in pancreatic cancer cells treated with PIM kinase inhibitors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3586. doi:10.1158/1538-7445.AM2015-3586
Abstract 3587: Developing targeted therapy for the treatment of drug-resistant ovarian cancer
Authors: Kreitzburg Kelly M. , Dobbins Zacchary , Katre Ashwini , Anwer Tooba , Alvarez Ronald , Landen Charles N. , Yoon Karina J.
Published: August 2015

Despite therapeutic approaches that combine surgical cytoreduction with chemotherapy, ovarian cancer remains the principal cause of death among women with gynecological malignancies. Virtually all patients relapse with drug-resistant disease. To elucidate the biological mechanisms that contribute to this resistance, we established a repository of patient-derived xenograft (PDX) models of ovarian cancer in mice. We used RNA-seq and Ingenuity Canonical Pathway software to analyze chemotherapy induced changes in expression patterns of six of these models. We found that the sphingosine-1-phosphate (S1P) signaling pathway is one of the pathways most affected by paclitaxel and cisplatin treatment, with altered expression in seven genes associated with the S1P pathway (p<0.05). The biologically active lipid S1P contributes to cell growth, survival/apoptosis, angiogenesis, migration and metastasis in normal and tumor tissue. The S1P pathway has also been reported to be involved in chemoresistance in several types of solid tumors.

The S1P pathway depends predominately on three core lipids: ceramide, sphingosine, and S1P. These molecules are termed the ceramide-sphingosine-S1P rheostat, and their expression is tightly regulated both intra- and extra-cellularly. Recent studies suggest a correlation between aberrations in the S1P pathway and poor prognosis, advanced stage, and resistance to chemotherapy and radiation.

Preliminary data using the sphingosine analog FTY-720 is consistent with the hypothesis that the S1P pathway regulates cell survival by effecting changes in the relative levels of ceramide, sphingosine, and S1P, as a cytoprotective autophagic mechanism to evade chemotherapy-induced cytotoxic effects. Cell proliferation assays, immunoblots, and fluorescence microscopy results of ovarian cancer cells exposed to FTY-720 in combination with carboplatin or paclitaxel treatment provide evidence that the S1P pathway may evade cell death through the induction of cytoprotective autophagy. Our data suggest that the S1P pathway contributes to the chemoresistance of ovarian cancer cells to conventional chemotherapeutic agents.

Citation Format: Kelly M. Kreitzburg, Zacchary Dobbins, Ashwini Katre, Tooba Anwer, Ronald Alvarez, Charles N. Landen, Karina J. Yoon. Developing targeted therapy for the treatment of drug-resistant ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3587. doi:10.1158/1538-7445.AM2015-3587
Abstract 3599: Resistance mechanisms to HER2-targeting treatment in HER2-positive gastric cancer
Authors: Kang Kyo Hwa , Nam Ah-Rong , Park Ji Eun , Bang Ju-Hee , Ling Jin , Jin Mei Hua , Kim Tae Yong , Han Sae-Won , Song Sang-Hyun , Im Seock-Ah , Kim Tae-You , Oh Do-Youn , Bang Yung-Jue
Published: August 2015

Background: HER2 is the first validated therapeutic target in advanced gastric cancer (GC). Trastuzumab in combination with chemotherapy is used as a first-line treatment of GC. The resistance mechanisms to trastuzumab have not been widely known in GC. We investigated the resistance mechanisms to HER2-targeting agents in HER2-positive gastric cancer cells.

Methods: SNU216 and NCI-N87 are HER2 amplified gastric cancer cells. Using these cells, we established trastuzumab-resistant cells (SNU216-HR, N87-HR) and dacomitinib (panHER inhibitor)-resistant cells (SNU216-PR). Acquired resistance of the established cell lines was verified by MTT assay and western blotting. We compared various receptor tyrosine kinase activities and protein expression levels between parental and resistant cells by RTK arrays and western blotting. We used many targeted agents (HER family inhibitor, PI3K inhibitor, mTOR inhibitor, MEK inhibitor, Src inhibitor, HSP90 inhibitor, etc) to overcome the resistance.

Results: Resistant cells displayed more rapid growth rate and different morphology compared with parent cells. Resistant cells showed increased levels of pEGFR, pHER2, pHER3, pMET, pIGF1R, pAXL, pSTAT3, pAKT, pFAK, and TS compared with the parental cells in western blot. With the treatment of trastuzumab, HR cells showed elevated levels of EGFR, pHER2, AXL, pAXL, pMEK, pSRC, pSTAT3, pAKT, pERK and TS compared with the parental cells. With the treatment of dacominitib, PR cells showed elevated levels of pEGFR, pAXL, pIGF1R, pMEK, pSRC, pERK and TS compared with the parental cells in western blot. The RTK arrays also showed the similar findings. These resistant cells were more sensitive to Src inhibitor and PI3K inhibitor than parent cells.

Conclusion: Resistance mechanisms to HER2-targeting strategy in gastric cancer include activation of HER, MET, FAK and Src pathway. Targeting these pathways is needed to overcome resistance.

Citation Format: Kyo Hwa Kang, Ah-Rong Nam, Ji Eun Park, Ju-Hee Bang, Jin Ling, Mei Hua Jin, Tae Yong Kim, Sae-Won Han, Sang-Hyun Song, Seock-Ah Im, Tae-You Kim, Do-Youn Oh, Yung-Jue Bang. Resistance mechanisms to HER2-targeting treatment in HER2-positive gastric cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3599. doi:10.1158/1538-7445.AM2015-3599
Abstract 3602: Cross-resistance to 1st, 2nd, and 3rd generation EGFR tyrosine kinase inhibitors in vitro is characterized by MET amplification and PTEN loss
Authors: Paul Sarah M. , Nickles Dorothee , Ye Xioafen , Yauch Robert L. , Shames David S.
Published: August 2015

Reversible EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib offer significant clinical benefit to patients with EGFR mutation positive non-small cell lung cancer (NSCLC) compared to chemotherapy alone, but high rates of resistance especially at EGFR T790M (50-60% of resistant cases) underscore the need for better targeted treatments for NSCLC patients. Third generation irreversible TKIs–AZD9291 and CO-1686–were developed for efficacy in the T790M setting. However, resistance to the new class of EGFR TKIs is inevitable, prompting us to investigate the relationship between erlotinib and AZD9291 resistance mechanisms and explore novel ones. NSCLC cell lines harboring activating EGFR mutations with (NCI-H1975) or without T790M (HCC4006, HCC827, and PC-9) were exposed to erlotinib, dacomitnib, or AZD9291 at IC 75 or greater for three months to generate resistance. We observed cross-resistance to other EGFR TKIs in nearly all resistant lines, suggesting that T790M was not the main driver of resistance in the erlotinib-treated lines and that a common mechanism might account for resistance in each cell line set. An epithelial to mesenchymal transition (EMT) was observed and a corresponding increase in vimentin staining was seen in resistant lines, consistent with cross-resistance. Previous studies showed that MET amplification caused erlotinib resistance in HCC827; our data suggest MET amplification also accounted for the AZD9291 and dacomitnib resistance in HCC827. In AZD9291-resistant HCC4006 and H1975 lines, PTEN levels were substantially reduced compared to the parental line, with a corresponding increase in PIK3 pathway markers. Whole exome sequencing data support homozygous deletion of PTEN loss as a mechanism of acquired resistance to AZD9291 in NCI-H1975. The PTEN null line NCI-H1650 was found to be resistant to all three TKIs without long-term drug exposure, implicating PTEN loss as a mechanism of de novo resistance. An analysis of EGFR mutation status, PTEN status, MET expression, and the kinetics of acquired resistance will be presented and clinical implications will be discussed.

Citation Format: Sarah M. Paul, Dorothee Nickles, Xioafen Ye, Robert L. Yauch, David S. Shames. Cross-resistance to 1st, 2nd, and 3rd generation EGFR tyrosine kinase inhibitors in vitro is characterized by MET amplification and PTEN loss. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3602. doi:10.1158/1538-7445.AM2015-3602
Abstract 3606: Increase of MET gene copy number confers resistance to a monovalent MET antibody and establishes drug dependence
Authors: Martin Valentina , Corso Simona , Comoglio Paolo Maria , Giordano Silvia
Published: August 2015

The tyrosine kinase receptor encoded by the MET oncogene is one of the most frequently altered oncogenes in human cancer. The relevant role played by the MET oncogene in cancer progression led to the development of specific inhibitors targeting MET, some of which are now in advanced phases of clinical trials.

Previous experience has shown that the main limit to the efficacy of most targeted treatments is the advent of resistance. Mechanisms underlying resistance to MET-specific small tyrosine kinase inhibitors (TKIs) have been already described, while nothing is known about resistance to MET monoclonal antibodies, nor about bypassing resistance to chemical TKIs by antibodies or vice-versa.

A monovalent form of an anti-MET monoclonal antibody (MV-DN30) was previously generated to target MET by promoting receptor “shedding”, inactivation and by inhibiting the MET-mediated invasive growth program both in vitro and in vivo cancer models. In our study EBC1 lung cancer cells that are MET-addicted as a consequence of gene amplification and thus sensitive to MET inhibitors, including the MV-DN30 were used as cell model. Upon prolonged treatment of these cells with the MV-DN30 we generated EBC1 cells resistant to this antibody and found that resistance was due to a further increase of MET gene copy number and a dramatic over-expression of the MET receptor. Such an excess of expression saturated the ‘shedding’ activity of MV-DN30, and prevented both the efficient down-regulation of the MET receptor from the surface and the inhibition of the ensuing constitutive activation.

Notably, antibody-resistant cells became ‘drug-dependent’, since the removal of MV-DN30 led them to death due to an excess of MET signal and a concomitant p38MAPK activation. Moreover, antibody-resistant cells remained MET-’addicted’ and were still sensitive to MET TKIs.

Finally, cells made resistant to MET specific TKIs were still sensitive to treatment with the antibody MV-DN30.

These findings suggest that a discontinuous or combined treatment by antibodies and chemical kinase inhibitors may increase the clinical response and bypass resistance to anti-MET targeted therapies.

Citation Format: Valentina Martin, Simona Corso, Paolo Maria Comoglio, Silvia Giordano. Increase of MET gene copy number confers resistance to a monovalent MET antibody and establishes drug dependence. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3606. doi:10.1158/1538-7445.AM2015-3606
Abstract 3624: A novel, selective DNA-PK inhibitor sensitizes poor prognosis chronic lymphocytic leukemia (CLL) cells to mitoxantrone
Authors: Junge Gesa
Published: August 2015

Approximately 20% of Chronic Lymphocytic Leukaemia (CLL) cases carry 11q deletions and 10% carry 17p deletions (associated with loss of p53 function), both of which are poor prognostic markers. Ataxia telangiectasia mutated kinase (ATM) is located on chromosome 11q23 and 30% of del11q patients lack ATM function. Previous work has shown that the DNA-PK inhibitor NU7441 chemosensitises CLL cells to fludarabine ex vivo (Willmore E et al 2008), and monotherapy with KU60648, a dual inhibitor of PI3kδ and DNA-PK has been shown to be effective in ATM deficient cells (Riabinska A et al 2013). Furthermore, a dual DNA-PK/mTOR inhibitor, CC-115, is now in clinical trials (NCT01353625).

Here, we aimed to validate the selective inhibition of DNA-PK over related kinases as a therapeutic approach in CLL, using a novel, more selective compound (NDD0004, cell-free IC50 10nM). Both primary CLL cells and an isogenic pair of DNA-PK-deficient and proficient HCT116 cells were used as models.

Primary CLL cells were cultured ex vivo and treated with the topoisomerase II poison mitoxantrone in the presence and absence of NU7441 and NDD0004. Cell viability was determined after 48h by XTT assay. Apoptosis and DNA damage (yH2AX foci) were measured by caspase 3/7GloAssay and immunofluorescence, respectively. ATM function was determined by the cells ability to autophosphorylate ATM on serine 1981 after ionising radiation.

Chemosensitisation to mitoxantrone in primary CLL cells was substantial and it was higher with NDD0004 than with NU7441 (mean 202- vs. 69-fold, ranges 1-1000 vs. 1-543-fold). Intriguingly, cells lacking ATM or p53 function were also sensitised by DNA-PK inhibition (mean 15- and 21-fold, respectively). HCT116 cells lacking DNA-PK were not chemosensitised by NDD0004 but DNA-PK proficient cells were sensitised 5-fold. Mitoxantrone-induced DSBs (as measured by yH2AX foci) were repaired by 24h, but persisted in the presence of DNA-PK inhibitors. In keeping with this observation, apoptosis as measured by caspase 3/7 activity was potentiated by DNA-PK inhibitors.

NDD0004 and KU60648 were also evaluated in a panel of ATM deficient (HT144, H1395) and ATM proficient (A549, A375) cell lines. ATM status had no impact on (a) the level of chemosensitisation to mitoxantrone by both inhibitors and (b) single agent activity for NDD0004 and KU60648.

In conclusion, our data show that selective inhibition of DNA-PK chemosensitises primary CLL cells even when p53 is mutated or ATM function is lost. Current work is focused on identifying biomarkers which predict good response to DNA-PK inhibitors.

Citation Format: Gesa Junge. A novel, selective DNA-PK inhibitor sensitizes poor prognosis chronic lymphocytic leukemia (CLL) cells to mitoxantrone. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3624. doi:10.1158/1538-7445.AM2015-3624
Abstract 3637: Delivery of an epigenetic agent using a microparticle drug delivery system
Authors: Do Duc P. , Soluade Keane O.
Published: August 2015

Conventional cancer treatment protocols are either toxic or of minimal therapeutic value, necessitating investigation of new modalities for efficacious treatment and management of cancers. Among the various novel compounds, histone deacetylase inhibitors (HDACIs) target cancer cells over-expressing deacetylases (HDACs). The inhibition of HDACs changes gene expression without altering the DNA sequence. In the present study, an albumin-based microparticulate drug delivery system containing vorinostat was formulated and evaluated for breast cancer therapy. Drug-loaded microparticles were prepared by a microencapsulation method through spray drying. Prepared microparticles containing the active drug were characterized for their physiochemical properties, including size, surface morphology, Zeta potential and surface properties. Dissolution studies were carried out to examine the release profile of the drug from the delivery system. For in vitro characterization and efficacy studies, breast carcinoma HTB-126 wells were used. Histone deacetylase (HDAC) activity was determined from cancer cells, and the efficacy of the free vorinostat and microparticle formulations was compared. Global histone changes in cells were analyzed using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Western blot was also utilized to detect acetylation marks in cells. Uptake studies were carried out in cancer cells to examine the internalization capability of microparticle drug formulations. Data indicated that microparticles were approximately 2-μm in size with Zeta potential measurements of about -30 mV. Release studies in cells showed that the drug released from the microparticulate delivery system at an extended rate over a period of over 24 hours. In vitro data in cancer cell line indicated that there was at least 10% more inhibition of cell viability when vorinostat was used with the microparticles. Similar results were observed from clonogenic studies. Additionally, in vitro data suggested that cell death induced by the drug-loaded microparticles was caused by apoptosis. Drug-loaded microparticle formulations were able to be internalized into cancer cells. Microparticles were shown to be a promising targeting strategy for cancer epigenetic therapy by providing an extended-release of the drug in the body.

Citation Format: Duc P. Do, Keane O. Soluade. Delivery of an epigenetic agent using a microparticle drug delivery system. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3637. doi:10.1158/1538-7445.AM2015-3637
Abstract 3640: Discovery of quinazolinones as fibroblast growth factor receptor (FGFR1-4) kinase inhibitors
Authors: Querolle Olivier , Angibaud Patrick , Colombel Hélène , Caron Virginie , Pilatte Isabelle , Poncelet Virginie , Esser Norbert , Gilissen Ron , King Peter , Meerpoel Lieven , Verhulst Tinne , Wroblowski Berthold , Vialard Jorge , Murray Chris W. , Rees David C. , Reningovolo Anita , Saxty Gordon
Published: August 2015

Recent data obtained in several tumor types have identified Fibroblast Growth Factor signaling as a key factor in the molecular pathology of a number of cancers1. This has stimulated the development of a number of agents that block this pathway, including FGFR kinase inhibitors with diverse inhibition and pharmacological profiles that are currently being evaluated in clinical studies.

We recently reported that a quinoxaline moiety can efficiently bind the hinge region of FGFR kinase catalytic sites. In continuation of our efforts to discover additional FGFR1-4 inhibitors, we have identified a quinazolinone scaffold as a novel FGFR kinase hinge binder. Initial hits were optimized into compounds displaying nanomolar affinity for FGFR1-4, potent activity in FGFR driven cells and efficacy in a Ba/F3-FGFR3 xenograft model.

This report represents the first disclosure of the structure-activity relationships as well as the chemical synthesis pathways of these novel quinazolinone-based FGFR1-4 inhibitors.

Turner N. and Grose R. Nature Reviews-Cancer 2010, 10, 116-129

Citation Format: Olivier Querolle, Patrick Angibaud, Hélène Colombel, Virginie Caron, Isabelle Pilatte, Virginie Poncelet, Norbert Esser, Ron Gilissen, Peter King, Lieven Meerpoel, Tinne Verhulst, Berthold Wroblowski, Jorge Vialard, Chris W. Murray, David C. Rees, Anita Reningovolo, Gordon Saxty. Discovery of quinazolinones as fibroblast growth factor receptor (FGFR1-4) kinase inhibitors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3640. doi:10.1158/1538-7445.AM2015-3640
Abstract 3641: Identification of naphthyridines as potent inhibitors of fibroblast growth factor receptor kinase family
Authors: Angibaud Patrick R. , Obringer Michel , Marin Julien , Jeanty Matthieu , Esser Norbert , Gilissen Ron , King Peter , Meerpoel Lieven , Querolle Olivier , Rees David C. , Roux Bruno , Saxty Gordon , Verhulst Tinne , Wroblowski Berthold , Murray Christopher C. , Vialard Jorge
Published: August 2015

The fibroblast growth factor receptor (FGFR) tyrosine kinase family members, FGFR1, 2, 3 and 4, have roles in a variety of key cellular processes, including proliferation, migration, survival, and differentiation1. Aberrant activation of FGFRs through mutation, amplification, chromosomal translocation, and ligand up-regulation being strongly implicated in oncogenic signalling in many tumour types, has triggered efforts to identify selective FGFR inhibitors. As a result, several potent FGFR kinase inhibitors are currently being evaluated in clinical studies across many tumor types, including non-small cell lung, breast and bladder cancers.

We have designed novel 1,5 and 1,7-naphthyridine derivatives that are potent kinase inhibitors of all FGFR family members in enzymatic and cellular systems. Initial hits were further optimized to increase potency and ADME properties leading to identification of a novel 1,5-naphthyridine-based chemical series with nanomolar affinity for FGFR1, 2, 3, and 4, activity in cells, and selectivity with respect to VEGFR-2. In vivo screening using an FGFR3-driven xenograft model revealed efficacious compounds that could be explored further as antitumoral agents.

This report represents the first disclosure of the structure-activity relationship and synthesis pathway of novel naphthyridine chemical series displaying nanomolar affinity for FGFRs1, 2, 3 and 4.

1 Dieci M. V., Ardenos M., Andre F., Soria J.C. Cancer Discovery. 2013, 3(3) 264-279.

Citation Format: Patrick R. Angibaud, Michel Obringer, Julien Marin, Matthieu Jeanty, Norbert Esser, Ron Gilissen, Peter King, Lieven Meerpoel, Olivier Querolle, David C. Rees, Bruno Roux, Gordon Saxty, Tinne Verhulst, Berthold Wroblowski, Christopher C. Murray, Jorge Vialard. Identification of naphthyridines as potent inhibitors of fibroblast growth factor receptor kinase family. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3641. doi:10.1158/1538-7445.AM2015-3641
Abstract 3645: A non-ATP competitive IKKβ inhibitor for cancer therapy
Authors: Rana Sandeep , Blowers Elizabeth , Natarajan Amarnath
Published: August 2015

Kinases are promising targets in cancer drug discovery. IKKβ is an important kinase in the canonical NF-κB pathway, which promotes survival of cancer cells and is constitutively active in number of cancers including pancreatic cancer. Inflammatory stimulus such as tumor necrosis factor-α (TNFα) is known to activate the canonical IKKβ-NF-κB pathway. Upon TNFα stimulation, serine residues 177 and 181 in the activation loop of IKKβ undergo phosphorylation resulting in activated IKKβ. Immunohistochemistry (IHC) studies showed the presence of the proinflammatory cytokine TNFα in ∼50% of surgically resected tumor specimens but in only ∼10% of corresponding normal tissues. Consistently, IHC studies by us with patient samples obtained from the UNMC rapid autopsy pancreatic cancer program showed elevated levels of phosphorylated S181 IKKβ in the tumor and liver metastases samples when compared to the stroma and ductal cells for normal pancreas.

Several small molecule IKKβ inhibitors were developed by pharmaceutical industry to treat chronic inflammatory diseases. Despite complete preclinical characterization of many candidates, to date none of them has been approved by the FDA for clinical use. Nearly all the small molecule IKKβ inhibitors reported are ATP competitive. These inhibitors completely block IKKβ mediated NF-κB activity as a result chronic administration in mice leads to granulocytosis and increased susceptibility to infection-mediated death. Here we report the discovery a non-ATP competitive IKKβ inhibitor that allows transient activation but blocks the sustained activation of IKKβ mediated NF-κB activity. We present a model that has a novel-binding site, which is accessible upon activation of IKKβ and explains the observed experimental results. Our IKKβ inhibitor does not share the toxicity profile of the ATP competitive IKKβ inhibitors. In an orthotopic pancreatic tumor model mice treated with our inhibitor showed reduced tumor growth and metastasis compared to vehicle controls. We also showed that in a mantle cell lymphoma model the median survival of mice treated with our inhibitor nearly doubled when compared vehicle treated mice. Our results suggest that non-ATP competitive IKKβ inhibitors are viable lead candidates for cancer therapy.

Citation Format: Sandeep Rana, Elizabeth Blowers, Amarnath Natarajan. A non-ATP competitive IKKβ inhibitor for cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3645. doi:10.1158/1538-7445.AM2015-3645
Abstract 3652: Development of novel chemical inhibitors targeting the N-terminal domain (NTD) of androgen receptor variants as anti-prostate cancer agents
Authors: Wu Jian Hui
Published: August 2015

The androgen receptor (AR) signaling is a driver of prostate cancer. Current therapeutic strategy for advanced prostate cancer is to suppress the AR signaling by androgen deprivation therapy (ADT) via castration and by antiandrogens to stop androgens from working. However, prostate cancer cells are very versatile in circumventing the ADT and reactivate the AR via multiple mechanisms, resulting in lethal castration-resistant prostate cancer (CRPC). An alarming problem is the emergence of AR variants that lack the ligand-binding domain (such as AR-V7) in CRPC patients, which are constitutively active without the need for androgens. Studies revealed that AR-v7 expression level was correlated with the risk of tumor recurrence after radical prostatectomy and was associated with short patient survival. In addition, mutations in full-length AR is another important mechanism of aberrant AR activation in CRPC cells. Recently, it was found that the F876L mutation is sufficient to confer enzalutamide resistance in cell lines and xenograft model. The AR F876L mutant is detected in CRPC patients treated with an enzalutamide analogue (ARN-509). The AR W741C mutant was detected in CRPC patient treated with bicalutamide and was found to be paradoxically activated by bicalutamide. In this project, we propose to develop novel AR inhibitors that target the AR N-terminal domain (NTD). The rationale for this has at least three fold: i) All of the FDA-approved antiandrogens are targeting the AR-LBD and thereby all of them are inactive against AR-v7; ii) All of the known mechanisms that could account for AR reactivation in CRPC cells are critically depending on the AR-NTD to reactivate AR; and iii) Among the NTD, DNA-binding domain (DBD) and LBD domains, the NTD is the most different domain between the AR and other members of steroid receptors. By a panel of in vitro assays, we have discovered a series of compounds that target the AR-NTD and potently inhibit all forms of the AR variants in our assays, including AR-V7, the wild-type and multiple clinically-relevant mutants of full-length ARs. Our inhibitors showed selectivity towards AR as they are inactive against the close homology proteins within the same steroid family (such as GR and PR). This project could lead to novel AR-NTD inhibitors as drug candidates for treating CRPC patients who have acquired resistance to AR-LBD-directed therapies, such as enzalutamide and abiraterone.

Citation Format: Jian Hui Wu. Development of novel chemical inhibitors targeting the N-terminal domain (NTD) of androgen receptor variants as anti-prostate cancer agents. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3652. doi:10.1158/1538-7445.AM2015-3652
Abstract 3680: Albumin-chitosan hybrid onconase nanocarriers for mesothelioma therapy
Authors: Tekade Rakesh K. , Youngren-Ortiz Susanne R. , Yang Haining , Haware Rahul , Chougule Mahavir B.
Published: August 2015

Onconase (ONC) is a member of a ribonuclease superfamily that has potent cytostatic activity against malignant mesothelioma (MM). However, the recent clinical trials have failed due to unfavorable biopharmaceutical characteristics. The objective of this investigation was to develop BSA-chitosan based hybrid nanoformulations for the efficient delivery of ONC to MM while minimizing the exposure to normal tissues. Taguchi Orthogonal Array L9 type design was used to formulate ONC loaded albumin nanocarriers (ONC-ANC). The ONC-ANC surface was hybridized using varying chitosan concentrations ranging between 0.100-0.175%w/v to form various ONC loaded hybrid nanocarriers (ONC-HNC). The obtained data set was analyzed by principal component analysis (PCA) and principal component regressions (PCR) to decode the effects of investigated design variables. ONC-ANC were found to have a mean particle size of 15.78 ± 0.24 nm (ζ = -21.89 ± 0.11 mV). PCA showed positive correlations between investigated design variables like the bovine serum albumin (BSA) concentration, ethanol dilution, and total ethanol with formulated nanocarrier particle size and entrapment efficiency (EE). PCR showed that the particle size depends on BSA, ethanol dilution, and total ethanol content, while EE was only influenced by BSA content. Further analysis of chitosan and TPP effects used for coating of ONC-ANC by PCR confirmed their positive impacts on the particle size, zeta potential, and prolongation of ONC release compared to uncoated ONC-ANC. PCR analysis of preliminary stability studies showed increase in the particle size and zeta potential at lower pH. However, particle size, zeta potential, and EE of developed HNC were below 63 nm, 31 mV, and 96%, respectively, indicating their stability under subjected buffer conditions. Out of the developed formulations, HNC showed enhanced inhibition of cell viability with lower IC50 against human MM-REN cells compared to ONC and ONC-ANC. This might be attributed to the better cell uptake of HNC, which was confirmed in the cell uptake fluorescence studies. These studies indicated that a developed nanotherapeutic approach might prove beneficial in reducing the therapeutic dose of ONC, minimizing adverse side effects by limiting the exposure of ONC to normal tissues, and help in the development of new therapeutic formulations and routes of administration.

Citation Format: Rakesh K. Tekade, Susanne R. Youngren-Ortiz, Haining Yang, Rahul Haware, Mahavir B. Chougule. Albumin-chitosan hybrid onconase nanocarriers for mesothelioma therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3680. doi:10.1158/1538-7445.AM2015-3680
Abstract 3691: A chemical therapeutic screen identifies new targets for wt/wt melanoma
Authors: Verduzco Daniel , Smalley Keiran
Published: August 2015

Once advanced, melanoma is one of the deadliest forms of cancer. Metastatic melanoma has a 5-year survival rate of about 15%. Treatment of melanoma is based by driver mutation - BRAF-mutant, NRAS-mutant, and melanomas wild-type for BRAF and NRAS, termed “wt/wt melanomas”. While targeted therapies are available for BRAF or NRAS mutant melanomas, no effective targeted therapeutic options are available for wt/wt melanomas. Furthermore, chemotherapy rapidly fails for this third subtype prioritizing the need for novel therapies. We seek to overcome this problem by identifying compounds to target wt/wt melanoma. To this end, we have performed a chemical screen of clinically relevant compounds against 8 wt/wt melanoma cell lines. In our screen, we have identified compounds that specifically target critical proteins, such as ALK, PLK1, and PI3K. Exome sequencing of each wt/wt melanoma line is being performed to uncover specific genetic signatures that would allow for specific susceptibility to each hit from the screen. This work will allow us to develop personalized therapies for the treatment of patients with wt/wt melanoma.

Citation Format: Daniel Verduzco, Keiran Smalley. A chemical therapeutic screen identifies new targets for wt/wt melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3691. doi:10.1158/1538-7445.AM2015-3691