bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2105: Evaluation of antitumor properties of metformin over human multidrug-resistant chronic myeloid leukemia cells
Authors: Oliveira Ligia P. , Renó Débora L. , Curvello Rodrigo S. , Lima Luana P. , Galvão Ana Carolina S.
Published: July 2017

Besides the progress in the knowledge of cancer biology, the rates of mortality due to this disease are still considerably elevated. Therefore, application of new drugs in antitumor therapies has been constantly studied. However, any of them have achieved a considerable success so far. In this work we evaluated the ability of metformin, a traditional hypoglycemic prescribed to treatment of type II diabetes along decades, over programmed cell death and modulation of metastatic potential in multidrug resistant (MDR) human myeloid chronic leukemia cells (Lucena), through MTT reduction test, flow cytometry, western blotting and gelatin zymography. Metformin was able to reduce the cell viability in a concentration and time-dependent manner, but was not able to induce Lucena cells to apoptosis or necrosis, though activation of the apoptotic machinery. Indeed, it was not observed activation of caspase 3, in contrast to an expressive activation of PARP. Interestingly, proteins associated to autophagy were overexpressed by Lucena cells, and an arrest of cell cycle was observed after exposition to the drug. Finally, it was verified that metformin was able to modulate activity of MMP2 and MMP9, enzymes associated to the metastatic process. Taken together these results suggest that the hypoglycemic is able to acts over the first steps of cancers in more aggressive stages. Finally, inhibition of MMPs indicates a promissory action of metformin for the treatment of metastatic disease.

Note: This abstract was not presented at the meeting.

Citation Format: Ligia P. Oliveira, Débora L. Renó, Rodrigo S. Curvello, Luana P. Lima, Ana Carolina S. Galvão. Evaluation of antitumor properties of metformin over human multidrug-resistant chronic myeloid leukemia cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2105. doi:10.1158/1538-7445.AM2017-2105
Abstract 2110: Anti-invasive and antimetastatic actions of omega-3 polyunsaturated fatty acids in glioblastoma cells
Authors: Kim Soyeon , Shin Soyeon , Jeong Soyeon , Han Seung-Hyeon , Yoo Yoon-Seon , Silwal Prashanta , Jeon Young-Joo , Heo Jun-Young , Kweon Gi-Ryang , Park Seung-Kiel , Park Jong-Il , Lim Kyu
Published: July 2017

Glioblastoma (GBM) is the most aggressive and deadliest brain malignancy in adults. Despite of surgical techniques, radiotherapy and chemotherapy, GBM has remained an invariably lethal tumor with a median survival less than 15 months. Although the anticancer mechanisms of omega-3 polyunsaturated fatty acids (ω3-PUFAs) have been reported in several cancers, it is still unclear in brain cancer. Here, our data show the anti-invasive and anti-metastatic effects of ω3-PUFAs in GBM. Invasiveness using transwell chamber was inhibited by docosahexaenoic acid (DHA) treatment in D54MG and GL261 cells. In zymography, MMP-2 activity was suppressed by DHA in a dose dependent manner. MMP-2 promoter activity was also decreased. DHA inhibited both p-STAT3 and β-catenin levels that contribute to invasion by stimulating pro-invasion factors such as MMP-2. Additionally, fat-1 (ω3-desaturease) stable D54MG cell was established and the effect of the high level of ω3-PUFAs was investigated endogenously. The invasiveness were significantly inhibited in the fat-1 stable cells compared to control cell. Moreover, the metastasis in vivo was significantly reduced when GL261 mouse glioma cells were injected through tail vein into the fat-1 transgenic mice. In immunohistochemistry, intensity of p-STAT-3 and β-catenin were significantly weak in metastatic lung tumor from Fat-1 mice compared to wild type mice. These results indicate that anti-invasive and anti-metastatic actions of ω3-PUFA may be correlated with inhibition of MMP-2 through decrease of STAT3 and β-catenin in GBM cells. Thus, these findings provide important preclinical evidence and molecular insight for utilization of ω-3 PUFAs for the chemoprevention and treatment of human GBM. [This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2007-0054932, NRF-2015R1D1A1A01056887) and by the framework of international cooperation program managed by National Research Foundation of Korea (2015K2A2A6002008)].

Citation Format: Soyeon Kim, Soyeon Shin, Soyeon Jeong, Seung-Hyeon Han, Yoon-Seon Yoo, Prashanta Silwal, Young-Joo Jeon, Jun-Young Heo, Gi-Ryang Kweon, Seung-Kiel Park, Jong-Il Park, Kyu Lim. Anti-invasive and antimetastatic actions of omega-3 polyunsaturated fatty acids in glioblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2110. doi:10.1158/1538-7445.AM2017-2110
Abstract 2115: Therapeutic potential of fingolimod against prostate cancer cells is partly attributed to interrupting the cross talk between estrogen and sphingolipid metabolisms
Authors: Allam Rasha M. , Al-Abd Ahmed M. , Khedr Alaa , Sharaf Ola A. , Nofal Salwa M. , Khalifa Amani E. , Mosli Hisham A. , Abdel-Naim Ashraf B.
Published: July 2017

Sphingolipids influence tumor microenvironment in different malignancies. Estrogen and estrogen metabolites are involved in prostate cancer. Fingolimod is Sphingokinase-1 (SphK1) inhibitor which possesses anticancer properties in various tumor types. The aim of the current study is to investigate the interference of Fingolimod with the cross talk between sphingolipid and estrogen metabolisms within prostate cancer cells as a novel therapeutic strategy. The design is based on determining the mutual influence between estrogen metabolism/signaling and sphingolipid metabolism within prostate cancer cells. Cytotoxicity using SRB-U assay; cell cycle analysis using DNA cytometry and intracellular caspase-3 concentration were assessed. Estrogen metabolites and estrogen metabolizing enzymes were determined using LC/MS and RT-PCR, respectively. Estrogen receptor (ERα and ERβ) expression and their downstream signaling (CXCR4 and Cyclin-D1, respectively) were measured using immunocytochemical staining and RT-PCR, respectively. Fingolimod showed antiproliferative/cytotoxic effects against different prostate cancer cells (LNCaP, DU145 and PC3) with IC50 ranging from 3.0±0.3 to 6.8±1.7 µM. Fingolimod induced significant decrease in estradiol, estrone, 4-hydroxyestradiol and 16α-hydroxyestrone concentrations with reciprocal increase in 2-methoxyestrone and 2-methoxyestradiol concentrations. This was mirrored by significant down expression for the enzymes, aromatese, CYP1A1 and CYP1B1 and over expression for the enzyme COMT. Additionally, Fingolimod suppressed the expression of ERα and ERβ within prostate cancer cells as well as their downstream signaling (CXCR4 and Cyclin-D1, respectively). Reciprocally, it was found that estradiol and catechol estrogens induce the expression of SphK1 while methoxylated catechol estrogen suppresses its expression. Our results give compelling evidence that Fingolimod has therapeutic potential by modulating the estrogenic micromilieu and interrupting its cross talk with sphingolipid metabolism in prostate cancer cells.

Citation Format: Rasha M. Allam, Ahmed M. Al-Abd, Alaa Khedr, Ola A. Sharaf, Salwa M. Nofal, Amani E. Khalifa, Hisham A. Mosli, Ashraf B. Abdel-Naim. Therapeutic potential of fingolimod against prostate cancer cells is partly attributed to interrupting the cross talk between estrogen and sphingolipid metabolisms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2115. doi:10.1158/1538-7445.AM2017-2115
Abstract 2125: Flavokawain A, a kava chalcone, inhibits growth and invasion of human osteosarcoma cells by targeting Skp2
Authors: Zhang Yidan , Zhang Wendong , Zaphiros Nikolas , Du Xiuquan , Koirala Pratistha , Roth Michael , Gill Jonathan , Piperdi Sajida , Geller David , Yang Rui , Zhang Jinghang , Gorlick Richard , Zi Xiaolin , Ji Tao , Hoang Bang H.
Published: July 2017

Purpose: Osteosarcoma (OS) is the most common primary bone malignancy with a high propensity for local invasion and distant metastasis. Flavokawain A (FKA), a major chalcone from kava extract, has been reported to have antitumor effects on multiple cancer cell lines. The consumption of kava-containing beverage has been associated with a low cancer incidence. In a previous report, mice treated with high-dose FKA did not demonstrate any significant major organ toxicity. However, the efficacy and anticancer mechanisms of FKA in OS is still to be elucidated.

Experimental Design: OS cell lines were treated with increasing dosage of FKA and tested for cell motility, proliferation, and invasion by MTT assay and Matrigel invasion assay. Cell cycle analysis was performed using flow cytometry. We examined Skp2 expression in several OS cell lines using western blot and in patient tissue array by immunostaining. Kaplan-meier analysis and log rank test were used to compare overall survival. Both Skp2-dependent cell cycle progression and Skp2-related RhoA expression were also examined after FKA treatment. The effects of FKA on lung metastasis were evaluated after orthotopic injection of OS cells into the tibia.

Results: We show that FKA inhibits the growth and motility of multiple OS cell lines in vitro. Flow cytometry analysis confirms cellular apoptosis and arrest in G2/M phase after FKA treatment, whereas cellular invasion is also inhibited in a dose-dependent manner. Skp2 is expressed in several OS cell lines and is associated with a poor prognosis in OS patients. Skp2 levels in OS cell lines decreased after FKA treatment. The expression of cell cycle regulators including p21 and p27, which are downstream of Skp2, was upregulated. Moreover, Skp2-related RhoA expression is inhibited by FKA and confirmed at protein level.

Conclusions: Taken together, the evidence suggests FKA exerts anti-invasive effects in association with Skp2-dependent cell cycle progression and Skp2-related RhoA expression. Since Skp2 is a negative prognostic factor for OS patients, FKA should be investigated further as an anti-Skp2 therapeutic strategy for OS.

Citation Format: Yidan Zhang, Wendong Zhang, Nikolas Zaphiros, Xiuquan Du, Pratistha Koirala, Michael Roth, Jonathan Gill, Sajida Piperdi, David Geller, Rui Yang, Jinghang Zhang, Richard Gorlick, Xiaolin Zi, Tao Ji, Bang H. Hoang. Flavokawain A, a kava chalcone, inhibits growth and invasion of human osteosarcoma cells by targeting Skp2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2125. doi:10.1158/1538-7445.AM2017-2125
Abstract 2129: Assessing the efficacy of targeting mitochondrial respiration in delaying lung tumor growth by using subcutaneous xenografts in mouse models
Authors: Kalainayakan Sarada Preeta , Ghosh Poorva , Dey Sanchareeka , Zhang Li
Published: July 2017

Previously, studies have focused mainly on the precept that tumors depend on glycolysis for energy and growth (the Warburg effect) and that the mitochondria are dysfunctional in cancer cells. However, there is mounting evidence that some cancer cells exhibit elevated mitochondrial respiration. Recent studies in our lab have demonstrated that Non-Small Cell Lung Cancer (NSCLC) cells exhibit intensified mitochondrial respiration and oxygen consumption. We further demonstrated that targeting increased mitochondrial respiration by a therapeutic agent effectively hampers proliferation of Non-Small cell lung cancer (NSCLC) cells in vitro. The purpose of the study is to determine to what extent mitochondrial respiration is affected by the therapeutic agent in vivo.

In order to achieve this goal, NSCLC cells were transduced with lentiviral particles carrying luciferase sequence. NSCLC cells expressing luciferase cells were implanted on the right flank of 4-6 weeks old female NOD/SCID mice to generate subcutaneous xenografts. The therapeutic agent was administered intravenously. Tumor implantation and growth were monitored by bioluminescence imaging (BLI) using Perkin Elmer’s IVIS Lumina III Imager. On sacrificing the mice, the tumors were harvested, formalin fixed and paraffin embedded for Immunohistochemistry (IHC).

Our BLI data suggest that there is a considerable reduction in radiance (total flux in photons per second) in the group of mice that were treated with therapeutic agent in comparison to control. Further, there is a significant reduction in tumor volume in mice that received treatment. Our IHC data suggest that there is a reduction in expression of a vital enzyme involved in heme synthesis and hemoproteins involved in mitochondrial respiration.

Our BLI and IHC data suggest that the therapeutic agent affects mitochondrial respiration by affecting mitochondrial complexes in vivo. Additional experiments to corroborate the results are underway.

Citation Format: Sarada Preeta Kalainayakan, Poorva Ghosh, Sanchareeka Dey, Li Zhang. Assessing the efficacy of targeting mitochondrial respiration in delaying lung tumor growth by using subcutaneous xenografts in mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2129. doi:10.1158/1538-7445.AM2017-2129
Abstract 2133: Pre-clinical studies of EC2629, a highly potent FR targeted DNA crosslinking agent
Authors: Reddy Joseph A. , Nelson Melissa , Dircksen Christina , Johnson Theresa , Vetzel Marilynn , Hahn Spencer , Qi Longwu , Vlahov Iontcho , Leamon Christopher
Published: July 2017

Folate receptor (FR) targeted small molecule drug conjugates (SMDCs) have shown promising results in early stage clinical trials with vintafolide and EC1456. In our effort to develop FR targeted SMDCs with varying mechanisms of action, we have now built EC2629, a folate conjugate of a DNA crosslinking agent based on a novel DNA-alkylating moiety . This agent was found to be extremely potent with an in vitro IC50 ~ 100 x lower than any other folate SMDC we have created to date. Treatment of nude mice bearing FR positive human xenografts led to cures in 100% of the mice at very low doses (300 nmol/kg) using a convenient once a week schedule. The observed activity was not accompanied by any noticeable weight loss (up to 20 weeks post end of dosing) or major organ tissue degeneration. Complete responses were also observed in other FR-positive drug resistant (paclitaxel and cisplatin) models. When evaluated against FR-positive PDX models of ovarian, endometrial and triple negative breast (TNBC) cancers, EC2629 showed significantly greater anti-tumor activity than EC1456 or standard of care (SOC) treatments. Taken together, these studies demonstrated that EC2629 with a distinct DNA reacting mechanism has significant anti-tumor growth activity in numerous models, including those which were drug resistant, thus lending support to our planned clinical development of this novel FR-targeted agent.

Citation Format: Joseph A. Reddy, Melissa Nelson, Christina Dircksen, Theresa Johnson, Marilynn Vetzel, Spencer Hahn, Longwu Qi, Iontcho Vlahov, Christopher Leamon. Pre-clinical studies of EC2629, a highly potent FR targeted DNA crosslinking agent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2133. doi:10.1158/1538-7445.AM2017-2133
Abstract 2149A: CRISPR/Cas9 mutagenesis invalidates a genetic target of clinical trials in cancer
Authors: Lin Ann , Giuliano Christopher , Sayles Nicole , Smith Joan , Sheltzer Jason
Published: July 2017

The Maternal Embryonic Leucine Zipper Kinase MELK has been described as a genetic dependency in several cancer types, most notably in the highly-aggressive basal subtype of breast cancer; MELK inhibition through the use of both RNAi and small-molecule approaches appears to block the growth of cancer types with such dependency. Based on these results, the MELK inhibitor OTS167 is currently being tested as a novel chemotherapy agent in multiple clinical trials. Here, however, we report that mutagenizing MELK with CRISPR/Cas9 has no effect on the fitness of basal breast cancer cell lines or cell lines from other cancer types. Through seven guide RNAs targeting the kinase and kinase-associated domains of MELK, we demonstrate that mutagenesis of MELK causes no defect in proliferative ability or anchorage independent growth in these cancer types. Additionally, cells with mutagenized MELK remain sensitive to OTS167, suggesting that this drug blocks proliferation through an off-target mechanism. Finally, the patient tumor gene expression data that initially identified MELK as being significantly upregulated in patients with poor survival was reexamined. As MELK is thought to play a role in mitosis, we compared MELK expression to a set of well-known cell proliferation markers and show significant correlations of MELK with the proliferation genes; this suggests a role of MELK in representing the mitotic activity of a tumor, rather than possessing a transformative role in itself. In total, our results undermine the rationale for a series of current clinical trials based on MELK inhibition and provide an experimental approach for the use of CRISPR/Cas9 in preclinical target validation that can be broadly applied.

Citation Format: Ann Lin, Christopher Giuliano, Nicole Sayles, Joan Smith, Jason Sheltzer. CRISPR/Cas9 mutagenesis invalidates a genetic target of clinical trials in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2149A. doi:10.1158/1538-7445.AM2017-2149A
Abstract 2154: P53 pathway restoring compound P306 inhibits colorectal cancer growth
Authors: Tian Xiaobing , Zhang Shengliang , Lulla Amriti , El-Deiry wafik S.
Published: July 2017

We recently reported that P01 is a potent p53 pathway-restoring small molecule that acts through increasing levels of TAp73. Further, it also interferes with the p73-mutant p53 protein-protein interaction and by downregulation of ΔNp73 (Tian, Zhang and El-Deiry, abstract# 3830, AACR 2016). P01 is a member of the natural products that have been shown to have potent anti-cancer activity against tumors with mutated p53. Based on the structure of the pharmacophore of compound P01, we designed and synthesized new analogs based on published structure-activity relationship and organic synthesis papers. The newly synthesized analogs were potent in reducing both short-term and long-term proliferation in a broad panel of mutant p53 cell lines such as HT29, SW480, DLD-1, MDA-MB-231and H1975 with EC50s in the range of 0.16 μM to 0.26 μM. We are currently evaluating the anti-cancer effects of three analogs P301, P304 and P306, of which only two of these analogs induce TAp73 as assayed by western blot. We are currently characterizing the analog P306, which is the most potent compound among them. P306 engages the apoptosis pathway by upregulation of pro-apoptotic proteins like PUMA, DR5, and BIM and downregulation of anti-apoptotic markers such as Mcl-1 in a time-and dose-dependent manner in colorectal cancer cell lines. P306 treatment also downregulates both mRNA and protein level of MET and EGFR in HT29 cells that overexpress MET and EGFR receptors. We are currently investigating the mechanisms of induction of both PUMA and DR5 in mutant p53 cells and determining whether either gene is necessary for the apoptotic effects of P306 in colorectal cancer cells. Our preliminary data indicates that upregulation of DR5 is through the ATF4/CHOP pathway post-P306 treatment. It has been reported that Puma is a target gene of ATF4, CHOP and p73, however, we found that none of them is responsible for P306-induced upregulation of PUMA in p53 mutated DLD1, SW480 or HCT116 p53-null cell lines. Thus, our ongoing in vitro studies are focused on further understanding the mechanism of action of P306 in mutant p53 cells and potentially exploring combinations with FDA-approved therapies. We are also in the process of conducting, first-in animal studies of P306 as single agent or in combination with chemotherapy or targeted therapy.

Citation Format: Xiaobing Tian, Shengliang Zhang, Amriti Lulla, wafik S. El-Deiry. P53 pathway restoring compound P306 inhibits colorectal cancer growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2154. doi:10.1158/1538-7445.AM2017-2154
Abstract 2160: Novel sulfonamide derivative inhibits JAK2-STAT3 signaling and induces ROS-mediated apoptosis in colorectal cancer cells
Authors: Ahmad Rehan , Vaali-Mohammed Mansoor-Ali , Al-Obeed Omar , Abdulla Maha
Published: July 2017

Colorectal cancer is a major worldwide health problem owing to its high prevalence and mortality rate. Developments in screening, prevention, biomarker, personalized therapies and chemotherapy have improved detection and treatment. However, despite these advances many patients with advanced metastatic tumors will still succumb to the disease. New anti-cancer agents are needed for treating advance stage colorectal cancer as most of the deaths occur due to cancer metastasis. A recently developed novel sulphonamide derivative, 4-((2-(4-(Dimethylamino)phenyl)quinazolin-4-yl)amino)benzenesulfonamide (3d) has shown to have potent antitumor effect; however the mechanism underlying the antitumor effect remains unknown. Our study revealed that 3d treatment significantly reduced the viability of human colorectal cancer cells HT-29 and SW620. This is further evidenced by the induction of p53 and Bax, release of cytochrome c, activation of caspase-9, caspase-7 and caspase-3 and cleavage of PARP in 3d treated cells. This compound was found to have significant effect on the inhibition of anti-apoptotic proteins, Bcl2, BclxL and XIAP. The results further demonstrate that 3d inhibited JAK2-STAT3 pathway by decreasing the constitutive and IL-6-induced phosphorylation of JAK2 and STAT3. 3d further decreased JAK2- STAT3 target genes like Cyclin D1 and Survivin. Furthermore 3d treatment induced the generation of reactive oxygen species (ROS) in human colorectal cancer cells. Confirming our observation, NAC significantly inhibited ROS production, induction of apoptosis, cytochrome c release and PARP cleavage. Additionally, treatment with 3d resulted in decreased glutathione (GSH) levels. The results further demonstrate that 3d inhibited cell migration by modulating EMT markers and inhibiting TGFβ-induced phosphorylation of Smad2 and Samd3. Collectively these findings indicate that 3d inhibited JAK2-STAT3 signaling; induced apoptosis via generation of reactive oxygen species and inhibition of cell migration by altering EMT markers and TGFβ-Smad pathway.

Note: This abstract was not presented at the meeting.

Citation Format: Rehan Ahmad, Mansoor-Ali Vaali-Mohammed, Omar Al-Obeed, Maha Abdulla. Novel sulfonamide derivative inhibits JAK2-STAT3 signaling and induces ROS-mediated apoptosis in colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2160. doi:10.1158/1538-7445.AM2017-2160
Abstract 2161: Pharmacological downregulation of BFL-1 by the BET bromodomain inhibitor CPI203 overcomes ABT-199 resistance in MYC+/BCL2+ double hit lymphoma
Authors: Esteve-Arenys Anna , Garcia-Valero Juan , Gonzalez David , Chamorro-Jorganes Aránzazu , Rodriguez Vanina , Dlouhy Ivan , Salaverria Itziar , Campo Elias , Colomer Dolors , Martinez Antonio , Rymkiewicz Grzegorz , Pérez-Galán Patricia , Lopez-Guillermo Armando , Roué Gaël
Published: July 2017

Double-hit lymphoma (DHL) is a rare subtype of B-cell lymphoma characterized by MYC and either BCL2 or BCL6 chromosomal rearrangements. DHL cases may have different morphology and are included in the updated 2016 WHO classification as a new category of high grade B-cell lymphoma with rearrangements. DHL patients usually undergo a rapidly progressing clinical course and are poorly responsive to standard chemo-immunotherapy. As a consequence, the prognosis of this entity is particularly poor with a median overall survival of approximately one year.

ABT-199 (venetoclax) is a potent and selective small-molecule antagonist of BCL-2 recently approved for the treatment of some lymphoid malignancies. In this study, we demonstrate that single-agent ABT-199 efficiently displaces pro-apoptotic BAX from BCL-2 complexes but fails to maintain a significant antitumor activity over time in most MYC+/BCL2+ DHL cell lines and primary cultures, as well as in a xenograft mouse model of DHL. We further identify the accumulation of the BCL2-like protein, BFL-1, to be a major mechanism involved in acquired resistance to ABT-199. We show this phenomenon to be manageable by the BET bromodomain inhibitor CPI203, since gene expression profiling identifies BCL2A1 as one of the top apoptosis-related gene modulated by the compound. Upon CPI203 treatment, simultaneous downregulation of MYC and BFL-1 at both mRNA and protein levels further overcomes resistance to ABT-199 both in vitro and in vivo, allowing DHL cultures and tumor xenografts to undergo synergistic caspase-mediated apoptosis.

Together, these findings highlight the relevance of BFL-1 in DHL-associated drug resistance and support the combined use of BCL-2 antagonist and BET inhibitor as a promising therapeutic strategy in patients with aggressive DHL.

Citation Format: Anna Esteve-Arenys, Juan Garcia-Valero, David Gonzalez, Aránzazu Chamorro-Jorganes, Vanina Rodriguez, Ivan Dlouhy, Itziar Salaverria, Elias Campo, Dolors Colomer, Antonio Martinez, Grzegorz Rymkiewicz, Patricia Pérez-Galán, Armando Lopez-Guillermo, Gaël Roué. Pharmacological downregulation of BFL-1 by the BET bromodomain inhibitor CPI203 overcomes ABT-199 resistance in MYC+/BCL2+ double hit lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2161. doi:10.1158/1538-7445.AM2017-2161
Abstract 2173: Targeting CDK1 and MEK/ERK overcome mutant BRAF-mediated apoptosis resistance in human colorectal cancer cells
Authors: Kawakami Hisato , Huang Shengbing , Sinicrope Frank A.
Published: July 2017

BRAFV600E mutation occurs in ~10% of human colorectal cancers (CRC) where it is associated with treatment resistance and poor prognosis. Data from TCGA and a clinical trial cohort identified a distinct subset of BRAF mutant colon cancers with deregulation of the cell cycle and overexpression of CDK1 (Barras D, et al, Clin Cancer Res. 2016). We tested the hypothesis that CDK1 inhibition can enhance apoptosis in BRAFV600E CRC cells. Since BRAF mutant cells show p-ERK activation, combined inhibition of CDK1 and MEK/ERK was evaluated. Using isogenic colon cancer cells, BRAF mutant alleles were shown to confer resistance to the CDK1 inhibitor, R0-3306, in a gene dose-dependent manner that was associated with reduced cleavage of caspase-3 and downstream PARP, and decreased pH2AX (DNA fragmentation marker). Ectopic BRAFV600E or constitutively active MEK mutant also conferred resistance to R0-3306. CDK1 siRNA was shown to increase cobimetinib-induced apoptosis, including annexin V labeling, and increased pH2AX. Furthermore, ERK siRNA or cobimetinib treatment attenuated CDK1 protein expression and increased R0-3306-induced pH2Ax. Moreover, treatment with R0-3306 plus cobimetinib significantly enhanced a caspase-dependent apoptosis and markedly reduced colony formation vs either drug alone in two CRC cell lines. Caspase-3 cleavage by R0-3306 + cobimetinib was dependent upon caspase-8. Mechanistically, CDK1 inhibition by R0-3306 suppressed the phosphorylation of procaspase-8 at Ser-387 shown by R0-3306 withdrawal which restored p-C8-S387 coincident with expression of the mitotic marker, pH3S10. In conclusion, inhibition of CDK1 can significantly augment apoptosis induction by MEK/ERK inhibition in BRAFV600E CRC cells, suggesting a novel therapeutic strategy to overcome mutant BRAF-mediated resistance.

Apoptosis induction by CDK1 inhibitor (R0-3306) ± MEK/ERK inhibitor cobimetinibTreatmentTreatmentTreatementTreatmentCRC cell linesDMSOR0-3306 (5 µM)cobimetinib (5 µM)combinationAnnexin V+ (%)RKO13.43 ± 1.4132.55 ± 2.9315.04 ± 0.2652.72 ± 3.16Annexin V+ (%)HT-2911.22 ± 1.8442.44 ± 2.7025.29 ± 0.1665.62 ± 4.11

Citation Format: Hisato Kawakami, Shengbing Huang, Frank A. Sinicrope. Targeting CDK1 and MEK/ERK overcome mutant BRAF-mediated apoptosis resistance in human colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2173. doi:10.1158/1538-7445.AM2017-2173
Abstract 2184: Development and testing of nanoformulation of a vascular disrupting agent in rat glioma with MRI monitoring
Authors: Ali Meser M. , Jayasundara Sunalee , Ewing James R.
Published: July 2017

Anti-angiogenesis therapy VEGF-VEGF receptors (VEGFRs) axis alone or in combination with other therapeutic agents have demonstrated mixed results, with the majority of reports indicating that glioblastoma multiform (GBM) developed resistance against anti-angiogenesis therapy as well as small molecular receptor tyrosine kinase inhibitors. This result is perhaps not unexpected, because angiogenesis is obviously complex, involving dozen of different growth factors that trigger a cascade of subsequent events. Even if a drug effectively blocks one angiogenic growth factor, such as VEGF, blood vessels may still develop via activating alternative pathways. Yet without a sufficient blood supply, cancerous tumors can't grow larger than the head of a pin and are unlikely to become lethal. Therefore, tumor vascularization is a critical process that determines tumor growth, progression and metastasis. Thus, tumor vasculature has become an emerging target for new chemotherapeutic drugs Vascular disrupting agents (VDAs) for example, combretastatin (CA4), represent a new class of chemotherapeutic agent that targets the newly formed vasculature in solid tumors. Preclinical and early phase trials have demonstrated the promising therapeutic benefits of CA4. Nevertheless, the clinical translation of CA4 has been significantly hampered due to its poor systemic bioavailability and the non-specific distribution of CA4 throughout the body when administered intravenously. Thus, it is reasonable to explore novel formulations of CA4 that overcome the limitations mentioned above. To improve bioavailability combretastatin phosphate (CA4-P) has been synthesized. But, CA4-P showed short blood half life. We have engineered dendrimer-based nano-sized CA4 conjugate which demonstrates high water solubility. Preliminary intravenous (i.v.) delivery of nano-combretastatin in an orthotropic glioma model demonstrated a necrosis at the core of the tumor leaving a rim of viable tissue. The MRI-determined tissue parameters Ktrans, blood flow (CBF), DWI, ADC map, distribution volume and tumor size indicated the effectiveness of nano-combretastatin treatment.

Citation Format: Meser M. Ali, Sunalee Jayasundara, James R. Ewing. Development and testing of nanoformulation of a vascular disrupting agent in rat glioma with MRI monitoring [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2184. doi:10.1158/1538-7445.AM2017-2184
Abstract 2188: Targeted delivery of pro-apoptotic peptide using ELP-based carrier for effective cancer therapy in various cancer model
Authors: Vijaya Sarangthem , Park Rang-Woon
Published: July 2017

Therapeutic peptides classified as biopharmaceuticals have gained attention as a new generation of cancer therapeutics with enhanced efficiency and diminished toxicity. They often fail to have sufficient effects due to their unsatisfactory pharmacokinetic profiles, which include poor bioavailability, low stability, short half-life, and poor penetration across the biological membrane. Elastin-like polypeptide (ELP)-based drug delivery has been utilized for various applications including cancer therapies for many years. Genetic incorporation of internalization ligands and cell targeting peptides along with ELP polymer enhanced tumor accumulation and retention time as well as stability and activities of the drug conjugates. Herein, we described a unique delivery system comprised of genetically engineered ELP incorporated with multiple copies of IL-4 receptor targeting peptide (AP1) periodically and proapoptotic peptide (KLAKLAK)2 referred to as AP1-ELP-KLAK. It triggered thermal responsive self-assembly into a nanoparticle-like structure at physiological body temperature and stabilized its helical conformation, which is critical for its membrane disrupting activities. Increased IL-4 receptor specific cellular internalization was associated with the enhanced cytotoxic effect of (KLAKLAK)2 peptide. Additionally, multivalent presentation of targeting ligands by AP1-ELP-KLAK significantly enhanced intratumoral localization and prolonged the retention time compared to ELP-KLAK, non-targeted control. Systemic administration of AP1-ELP-KLAK significantly inhibited tumor growth by provoking cell apoptosis in MDA-MB231 breast cancer and B16F10 melanoma tumor xenograft models without any specific organ toxicity. Thus, our newly designed AP1-ELP-KLAK polymer nanoparticle is a promising candidate for effective cancer therapy and due to the simple preparative procedures of ELPs, this platform can be used as a good carrier for tumor-specific delivery of other therapeutics.

Citation Format: Sarangthem Vijaya, Rang-Woon Park. Targeted delivery of pro-apoptotic peptide using ELP-based carrier for effective cancer therapy in various cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2188. doi:10.1158/1538-7445.AM2017-2188
Abstract 2196: SDF-1/CXCR4 axis-mediated tumor-tropism of monocyte membrane-coated nanoparticles
Authors: Li Yi-Nan , Chang Chien-Wen , Chiang Chi-Shiun
Published: July 2017

Tumor-associated macrophages are one of the most abundant infiltrating cells in solid tumors. These cells are originated from the bone marrow and circulating in peripheral blood. Through the specific chemoattractant released by the tumor cells or stromal cells, bone marrow-derived monocytes (BMDMs) are able to accumulate at the tumor site by their corresponding receptors. In this study, we utilized the characteristics of tumor-tropism of BMDMs on a nanoparticle-based drug delivery system. We hypothesized that the cellular membrane of BMDMs can provide nanoparticle protection from the mononuclear phagocyte system and the chemokine receptor on the membrane can enhance the tumor-tropism of the nanoparticles. To prove the hypothesis, the cellular membrane was extracted from BMDMs and then coated on the drug-loaded nanoparticles. We also found that the expression of chemokine receptor CXCR4 on the bone BMDMs can be induced following the stimulation of tumor conditioned medium. The tumor targeting effect of the monocyte membrane-coated nanoparticles is diminished against SDF-1 knockdown tumor cells. These results indicate that the SDF-1/CXCR4 axis is contributed to the tumor-tropism of the monocyte membrane-coated nanoparticles toward astrocytoma cell line, ALTS1C1, and this effect can be boosted by the stimulation of tumor conditioned medium. In conclusion, we established a nanoparticle-based drug delivery platform against brain tumor with the cellular membrane coating technology and maximized the effect of tumor-targeting by tumor conditioned medium stimulation.

Citation Format: Yi-Nan Li, Chien-Wen Chang, Chi-Shiun Chiang. SDF-1/CXCR4 axis-mediated tumor-tropism of monocyte membrane-coated nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2196. doi:10.1158/1538-7445.AM2017-2196
Abstract 2201: Downregulation of NF-kB by nanoconjugates to overcome drug resistance in ovarian tumors
Authors: Zambre Ajit P. , Panchal Sarjukumar , Worland Alyssa , Chapman Sarah , Leevy Matthew , Upendran Anandhi , Kannan Raghuraman
Published: July 2017

Ovarian cancer is the fifth leading cause of cancer deaths in women. Globally, around 140k women die from ovarian cancer per year. Recurrence can lead to development of resistance to first line agents such as platinum analogs, taxanes, and doxorubicin. Several studies have shown that decrease of NF-κB expression will inhibit P-glycoprotein maturation and thereby overcome drug resistance. In this context, it is well known that Disulfiram (DSF), a FDA approved drug for anti-alcoholism, have been identified as moderate inhibitor of NF-κB activity. It is also shown that DSF possess mild anti-cancer effects via increased permeability of the outer membrane of mitochondria resulting in leakage of proteins, such as cytochrome C, generation of ROS that simulates the ROS-MAPK pathway leading to apoptosis, and inhibition of P-glycoprotein. As such DSF is not a strong therapeutic agent; however, in combination with copper it showed excellent therapeutic benefit. This effect is mainly attributed to metabolite diethyldithio-carbamate -a proteasome inhibitor that was produced upon complexation of DSF with copper. However, delivery of DSF-Cu complex was not successful in clinical setting. We hypothesized gold nanoparticles can serve as potential delivery vehicle to selectively transfer Cu-DSF to turmor without toxicity. Indeed, cellular studies in drug sensitive (OVCAR) and Adriamycin resistant p-glycoprotein expressing (NCI-ADR/RES) ovarian cancer cells indicated that the gold nanoconjugate exhibit significant cytotoxicity and the IC-50 values was decreased 2.5 fold times compared to the Cu-DSF complex. NF-κB expression was decreased by two folds compared to native Cu-DSF complex. Detailed cellular and mechanistic studies along with the evaluation of [Au(DSF-Cu)NP] in human multi-drug resistant (NCI-ADR/RES) mouse xenografts will be presented.

Citation Format: Ajit P. Zambre, Sarjukumar Panchal, Alyssa Worland, Sarah Chapman, Matthew Leevy, Anandhi Upendran, Raghuraman Kannan. Downregulation of NF-kB by nanoconjugates to overcome drug resistance in ovarian tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2201. doi:10.1158/1538-7445.AM2017-2201
Abstract 2202: FABP5 in urinary extracellular vesicles is a potential biomarker of high Gleason score prostate cancer
Authors: Fujita Kazutoshi , Kume Hideaki , Matsuzaki Kyosuke , Kawashima Atsunari , Ujike Takeshi , Nagahara Akira , Uemura Motohide , Miyagawa Yasushi , Tomonaga Takeshi , Nonomura Norio
Published: July 2017

Urine collected after prostate massage is a promising source of new biomarkers of prostate cancer, and was reported to contain extracellular vesicles (EVs) that are secreted from prostate cancer cells. EVs are microvesicles secreted from various cell types. EVs contain microRNAs, proteins, and mRNAs and play a role in intercellular communications via the mechanisms of exocytosis and endocytosis. We aimed to discover a new biomarker for high Gleason score (GS) prostate cancer (PCa) in urinary EVs via quantitative proteomics.

Material and methods: Urine samples after massage were collected from 18 patients before prostate needle biopsy. Six patients had negative biopsy outcomes, 6 had Gleason score 6 prostate cancer (GS6), and 6 had Gleason score 8 to 9 prostate cancer (GS8-9). Urinary EVs were isolated from urine with ultracentrifuge. Protein extracted from EVs were labeled with 4-plex iTRAQ and liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for proteome analysis. The candidate proteins were quantitated in the independent set by selected reaction monitoring/multiple reaction monitoring analysis (SRM/MRM).

Results: Seven proteins increased in patients with PCa compared to those with negative biopsy (ratio > 2.0, p-value < 0.05). Thirteen proteins were chosen for further analysis and verified in 29 independent urine samples (negative [n = 11], PCa [n = 18]) using selected reaction monitoring/multiple reaction monitoring. Among these candidate markers, fatty acid binding protein 5 (FABP5) was higher in the cancer group than in the negative group (p-value = 0.009) and was significantly associated with GS (p-value for trend = 0.011).

Conclusions: We applied the proteomic analysis to discover biomarkers in EVs in urine collected after prostate massage. FABP5 in urinary EVs could be a potential biomarker of high GS prostate cancer. Additional large-scale studies are warranted to confirm this finding.

Citation Format: Kazutoshi Fujita, Hideaki Kume, Kyosuke Matsuzaki, Atsunari Kawashima, Takeshi Ujike, Akira Nagahara, Motohide Uemura, Yasushi Miyagawa, Takeshi Tomonaga, Norio Nonomura. FABP5 in urinary extracellular vesicles is a potential biomarker of high Gleason score prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2202. doi:10.1158/1538-7445.AM2017-2202
Abstract 2218: Quantitative multiplex analysis of immune checkpoint protein expression in circulation and in the tumor microenvironment
Authors: Lie Wen-Rong , Mistry Jehangir
Published: July 2017

Immune checkpoint inhibitors have been proven to be an effective method in improving antitumor immune response. Many immune checkpoint proteins are expressed as soluble forms in circulation and in the tumor and tumor microenvironment. Here we report the development of bead-based Luminex multiplex assays for the quantitative profiling of co-inhibitory and co-stimulating immune checkpoint proteins CTLA-4, PD-1, TIM-3, LAG-3, HVEM. GITRL, BTLA, CD27, CD28, CD40, GITR, PD-L1, B7-1/CD80, B7-2/CD86, and ICOS. In order to explore the use of soluble immune checkpoint proteins as putative cancer biomarkers, we used these multiplex assays to measure checkpoint protein levels in serum samples from breast cancer patients, colon cancer patients, and a corresponding set of normal serum samples. Analysis of the soluble checkpoint protein signatures generated from this multiplex approach revealed a significantly elevated level of soluble TIM-3 protein in the breast cancer serum samples and in the colon cancer serum samples compared to the healthy serum controls (p<0.001). In addition, we analyzed the immune checkpoint protein expression profiles in lysates of tumor and adjacent normal tissues from 3 patients with metastatic breast cancer and 2 patients with colorectal cancer. Differential expression of multiple checkpoint proteins, including BTLA, CD27, TIM-3, HVEM, CD40, GITR, LAG3, CTLA-4, B7-1, PD-L1, or ICOS, were detected in these matched lysates, indicating the roles and complexity of checkpoint proteins in tumor microenvironment. In summary, our results demonstrate that the multiplex assays we developed are useful research tools for the simultaneously quantitation of immune checkpoint proteins, as well as its potential application in cancer biomarker discovery and translational research in cancer immunotherapy.

Citation Format: Wen-Rong Lie, Jehangir Mistry. Quantitative multiplex analysis of immune checkpoint protein expression in circulation and in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2218. doi:10.1158/1538-7445.AM2017-2218
Abstract 2222: Sildenafil suppresses inflammation-driven colorectal cancer in mice
Authors: Islam Bianca N. , Sharman Sarah K. , Hou Yali , Bridges Allison , Kolhe Ravindra , Trillo-Tinoco JImena , Singh Nagendra , Kim Sangmi , Sridhar Subbaramiah , Berger Frankin G. , Browning Darren D.
Published: July 2017

Intestinal cyclic guanosine monophosphate (cGMP) signaling regulates epithelial homeostasis, and has been implicated in the suppression of colitis and colorectal cancer (CRC). In this study, we investigated the cGMP-specific phosphodiesterase-5 (PDE5) inhibitor sildenafil to prevent tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS) inflammation-driven colorectal cancer model. Treatment of mice with sildenafil activated cGMP signaling in the colon mucosa and protected against DSS-induced barrier dysfunction. In mice treated with AOM/DSS, oral administration of sildenafil throughout the disease course reduced polyp multiplicity by 50% compared to untreated controls. Polyps formed in sildenafil-treated mice showed less proliferation and were more differentiated compared to polyps from untreated mice, but apoptosis was unaffected. Polyps in sildenafil-treated mice were also less inflamed; they exhibited reduced myeloid-cell infiltration, and reduced expression of iNOS, IFNγ and IL-6 compared to untreated controls. Most of the protection was observed when sildenafil was added during the initiation stage of carcinogenesis (40% reduction in multiplicity), whereas administration of sildenafil later during the promotion stages did not affect polyp number. While later treatment with sildenafil did not affect multiplicity, it did have a similar effect on polyp phenotype, including increased mucus production, reduced proliferation and inflammation. In summary, our results demonstrate that oral administration of sildenafil suppresses inflammation and polyp formation in mice treated with AOM/DSS. This suggests that PDE5 inhibitors could have therapeutic value for the prevention of CRC in inflammatory bowel disease patients.

Citation Format: Bianca N. Islam, Sarah K. Sharman, Yali Hou, Allison Bridges, Ravindra Kolhe, JImena Trillo-Tinoco, Nagendra Singh, Sangmi Kim, Subbaramiah Sridhar, Frankin G. Berger, Darren D. Browning. Sildenafil suppresses inflammation-driven colorectal cancer in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2222. doi:10.1158/1538-7445.AM2017-2222