bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5322: Englerin-A prevents invasive phenotypes of renal cell carcinoma by reprogramming mesenchymal to epithelial transition: A key mechanism of its anticancer properties
Authors: Haque Inamul , Banerjee Snigdha , Beutler John A. , Banerjee Sushanta K.
Published: August 2015

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Recently, Englerin A (Eng A), a molecule of herb (Phyllanthus engleri) extracts, shows selective toxic effect on RCCs through the National Cancer

Institute Drug Discovery panel using human cell lines as well as in vitro angiogenesis. Eng A has been reported to possess certain anticancer properties. However, whether Eng A could suppress RCC metastasis has not been fully elucidated. The epithelial-mesenchymal transition (EMT) is followed by invasion is a hallmark of metastasis malignancies including renal cancer. The aim of the present study was to examine the effects of Eng A in preventing the migration and invasion of

RCCs (Caki-1 and 786-0), as well as to investigate whether Eng A may inhibit the molecular changes associated with EMT induced by transforming growth factor-beta1 (TGF-β1). We also aimed to see whether Eng A suppresses the cancer stem cell markers and spheroid formation. The investigation demonstrated that Eng A suppressed the migration and invasion of these cells under non-cytotoxic concentrations. Eng A inhibited molecular changes associated with TGF-β1-induced

EMT by upregulating the epithelial markers and downregulating the mesenchymal markers. Eng A significantly reduced the levels of Twist protein, a master regulator of EMT. Eng A also inhibits the stem cell markers, i.e., CD44, ABCG2 and ALDH1 and spheroid formation. We also found that Eng A inhibits TGF-β1-induced angiogenesis. This study indicated that Eng A may serve as a potential candidate for the treatment of renal cancer metastasis.

Citation Format: Inamul Haque, Snigdha Banerjee, John A. Beutler, Sushanta K. Banerjee. Englerin-A prevents invasive phenotypes of renal cell carcinoma by reprogramming mesenchymal to epithelial transition: A key mechanism of its anticancer properties. [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 5322. doi:10.1158/1538-7445.AM2015-5322
Abstract 5326: Intracellular bacterial delivery of a NIPP1-peptide kills tumor cells
Authors: Van Dessel Nele , Forbes Neil S.
Published: August 2015

Protein phosphatase-1 (PP1) is a cancer target because it is involved in many cell signaling pathways. Its activity is tightly regulated by its interaction partners, mainly via the RVxF-binding motif. RVxF-containing peptides deregulate PP1 and have therapeutic potential as antagonists of increased cancer kinase signaling. Because PP1 is responsible for more than half of the dephosphorylations on Ser/Thr sites, it is essential in all eukaryotic cells and it is difficult to target systemically. Moreover, delivering peptides to cells extracellularly is inefficient because of poor cell permeability and proteolytic instability.

To specifically transport therapeutic peptides into cancer cells, we engineered bacteria to be intracellular delivery vectors. A bacterial delivery system (BDS) was designed by creating a strain that lyses after cell invasion and releases its contents into the cytoplasm of cancer cells. A BDS strain was then manipulated to express a peptide containing the RVxF motif of Nuclear Inhibitor of PP1 (NIPP1; AA 142-224). The therapeutic potential of this strain was tested on MCF-7 cell monolayers and on 3D tumor tissue.

The BDS was cloned by inserting the bacterial phage lysis gene E under the control of the sseJ promoter, a Salmonella promoter that is activated after cell invasion. The specificity of the sseJ promoter was tested by inserting GFP under its control and infecting MCF-7 cancer cells with Salmonella containing the plasmid. All intracellular bacteria expressed GPF after 4 hours of infection, while no fluorescence was measured in the bacteria outside the mammalian cells. After infection, the created BDS lysed in 78% of invaded cells. BDS delivery of the NIPP1-peptide to MCF-7 cancer cells killed 41% of infected cells while infection with control, empty BDS did not result in any death. When treating tumor tissue with BDS expressing NIPP1-peptide, 39% of tumor tissue was killed after 9.5 hours, compared to 8% when treated with BDS alone. These results indicate that targeting phosphatases with intracellular peptide delivery by bacteria is feasible and reduces tumor tissue viability.

Citation Format: Nele Van Dessel, Neil S. Forbes. Intracellular bacterial delivery of a NIPP1-peptide kills tumor cells. [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 5326. doi:10.1158/1538-7445.AM2015-5326
Abstract 5339: Cytotoxic genes from traditional Chinese medicine inhibit tumor growth both in vitro and in vivo
Authors: Zhang Yuanhui , Wang Yuan , Wang Lina , Aslanidi George , Srivastava Arun , Ling Changquan , Ling Chen
Published: August 2015

Traditional Chinese medicine (TCM) has held, and still holds, an important position in primary health care in China, especially in the rural areas. However, scientific evidence of its mechanism is, for the most part, limited and additional better-designed laboratory research is needed. To date, numerous leading chemical compounds from TCM drugs have been identified and evaluated for their anti-tumor effects. However, little effort has been made on the protein-encoding genes isolated from TCM drugs, and the delivery of these genes into malignant cells through recombinant adeno-associated viral (rAAV) vectors has not been attempted. For example, Trichosanthin (TCS), an antiviral plant defense protein found in the root tuber of a TCM herb, Trichosanthes kirilowii, has been used in anti-HIV clinical trials in the USA. Its enzymatic activities were recognized as type I ribosome-inactivating protein. Although the nucleotide sequence of the TCS gene was determined more than 20 years ago, to date, there was little report to deliver TCS-encoding gene into malignant cells. In the present studies, we synthesized the cDNAs of five known cytotoxic proteins isolated from TCM drugs and the FLAG epitope-tagged cDNAs were subcloned into a rAAV plasmid vector. The expression of mRNA was confirmed by RT-PCR and protein expression by Western blot assays against the FLAG tag, respectively. Among these genes, TCS gene yielded the most promising results for the inhibition of cancer cell growth in vitro. The over-expressed TCS functioned as a type I ribosome inactivating protein, followed by inducing apoptosis that is associated with the Bcl-PARP signaling pathway. Next, rAAV vectors containing the TCS gene driven by a liver cancer specific promoter, α-fetoprotein promoter (AFPp) were generated and tested. The results indicated that rAAV-AFPp-TCS vectors significantly inhibited the growth of hHCC cell lines in vitro as well as hHCC tumor growth in vivo following intra-tumor injections in a murine xenograft model. These studies suggest that the use of TCM cytotoxic genes may prove to be a useful therapeutic strategy for treating human cancers in general, and liver tumors in particular.

Note: This abstract was not presented at the meeting.

Citation Format: Yuanhui Zhang, Yuan Wang, Lina Wang, George Aslanidi, Arun Srivastava, Changquan Ling, Chen Ling. Cytotoxic genes from traditional Chinese medicine inhibit tumor growth both in vitro and in vivo. [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 5339. doi:10.1158/1538-7445.AM2015-5339
Abstract 5351: Oral delivery of doxorubicin using bile enhancer for metronomic maintenance chemotherapy
Authors: Kweon Seho , K.A. Mahmud Foyez , Chang Hyo Won , Nam Have Yoon , Kim Mi Ra , Park Jung Je , Byun Youngro , Kim Sang Yoon
Published: August 2015

Conventional chemotherapy requires therapy holiday due to their toxic adverse effects. However, the therapy holiday has been allowing cancer cell to relapse and caused secondary metastasis to occur in other tissue. On the contrast, metronomic maintenance chemotherapy (MMC) treats anticancer drugs frequently to reduce the adverse effects from normal tissues by maintaining low concentration in the blood. In this context, an oral route is more suitable for MMC than a parenteral route. Our oral delivery system that uses electrochemical property of bile acid derivatives increases bioavailability of doxorubicin (DOX) from below 5% to 26% by eluding p-gp. The antitumor studies showed that 5mg/kg/day oral DOX complex inhibited 70% of tumor volume in C3H mice model bearing SCC7 tumor. The H&E staining of intestines and liver and the blood analysis proved that there were no histological and hematological toxicities. In addition, low dose of the DOX complex affects cell cycle regulation to arrest cancer cells. The concentration of 10nM, 30nM of DOX restricted the cell cycle at checkpoints in G1 phase of MCF-7 cells which are p-53 wild type and checkpoints in G2-M phase of MDA-MB 231 cells which are p-53 disruptive type. When MK8776, a inhibitor of cell cycle checkpoints, is treated with the low concentration of DOX, the cancer cells went through apoptosis or senescence depending on a type of cancer. In conclusion, our oral delivery of doxorubicin can offer safe and effective chemotherapy.

Note: This abstract was not presented at the meeting.

Citation Format: Seho Kweon, Foyez K.A. Mahmud, Hyo Won Chang, Have Yoon Nam, Mi Ra Kim, Jung Je Park, Youngro Byun, Sang Yoon Kim. Oral delivery of doxorubicin using bile enhancer for metronomic maintenance chemotherapy. [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 5351. doi:10.1158/1538-7445.AM2015-5351
Abstract 5373: AK-1, a specific SIRT2 inhibitor, induces cell cycle arrest by downregulating Snail in HCT116 human colon carcinoma cells
Authors: CHEON MIN GYEONG , Kim Ja-Eun
Published: August 2015

SIRT2, a member of the sirtuin family, is involved in the regulation of a variety of physiological functions. In addition, SIRT2 has been studied in the context of pathological conditions including neurodegenerative diseases, metabolic syndrome, and cancer. The effect of SIRT2 on cancer cell growth depends on cancer tissue type. To investigate the role of SIRT2 in colon cancer, we treated HCT116 human colon cancer cells with the SIRT2-specific inhibitor AK-1, a cell-permeable benzylsulfonamide. AK-1 treatment induced proteasomal degradation of the Snail transcription factor through inactivation of the NF-κB/CSN2 pathway. Reduction in the level of Snail resulted in upregulation of p21, a cyclin-dependent kinase inhibitor, leading to G1 arrest, slow proliferation, and slow wound-healing activity. The regulation of Snail-p21 axis by AK-1 also occurs in HT-29 colon cancer cells. Therefore, inhibition of SIRT2 using AK-1 would be a beneficial intervention in the treatment of colon cancer.

Citation Format: MIN GYEONG CHEON, Ja-Eun Kim. AK-1, a specific SIRT2 inhibitor, induces cell cycle arrest by downregulating Snail in HCT116 human colon carcinoma cells. [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 5373. doi:10.1158/1538-7445.AM2015-5373
Abstract 5390: The TRK inhibitor RXDX-101 enhances the efficacy of temozolomide and irinotecan in a xenograft model of neuroblastoma
Authors: Iyer Radhika , Golden Rebecca L. , Naraparaju Koumudi , Croucher Jamie L. , Guan Peng , Li Gang , Hornby Zachary , Brodeur Garrett M.
Published: August 2015

Purpose: Neuroblastoma (NB) is one of the most common and deadly solid tumors of childhood. The Trk family of neurotrophin receptors plays an important role in clinical behavior of NBs. Overexpression of TrkB and its ligand, BDNF, is associated with poor prognosis. We wanted to determine if RXDX-101, an oral pan-TRK, ROS1 and ALK inhibitor, would be effective in our NB xenograft model, either alone or in combination with conventional chemotherapy.

Experimental Design: We tested the in vitro effects of RXDX-101 as a single agent, or in combination with the chemotherapeutic agents irinotecan and temozolomide (Irino-TMZ), using a subclone of the SH-SY5Y NB cell line transfected with TrkB. We also examined in vivo growth inhibition of TrkB-expressing NB xenografts with RXDX-101 alone or in combination with Irino-TMZ.

Results: RXDX-101 significantly inhibited growth of TrkB-expressing NB cells in vitro. Enhanced in vitro inhibition was observed when RXDX-101 was used in combination with Irino-TMZ. Single agent therapy with RXDX-101 resulted in significant tumor growth inhibition compared to control animals [p<0.0001 for event-free survival (EFS)]. The addition of RXDX-101 to Irino-TMZ also significantly improved the EFS of animals compared to vehicle or Irino-TMZ treated animals (p<0.0001 for combination vs. control, p = 0.0012 for combination vs. Irino-TMZ).

Conclusions: We show that RXDX-101 inhibits growth of TrkB expressing NB cells in vitro and in vivo. Furthermore, RXDX-101 cotreatment enhanced the efficacy of conventional chemotherapy in our NB xenograft model. Our data suggest that RXDX-101 has potential for incorporation in clinical trials for NB and other Trk expressing tumors.

Citation Format: Radhika Iyer, Rebecca L. Golden, Koumudi Naraparaju, Jamie L. Croucher, Peng Guan, Gang Li, Zachary Hornby, Garrett M. Brodeur. The TRK inhibitor RXDX-101 enhances the efficacy of temozolomide and irinotecan in a xenograft model of neuroblastoma. [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 5390. doi:10.1158/1538-7445.AM2015-5390
Abstract 5393: Evaluation of compounds developed against the TAM family kinases
Authors: Zhang Hong , Zhang Zaihui , Shi Xiaoqing , Lee Erica , Li Rick , Hu Yuxiang , Yan Jun , Sanghera Jasbinder
Published: August 2015

The TAM family receptor tyrosine kinases, consisting of Tyro3, Axl and Mer, are implicated in a diverse range of cellular processes such as cell survival, proliferation, migration, angiogenesis, and inflammatory response. Despite the debates over their role as a driver in carcinogenesis owing to some recent findings, their link to human cancer is strongly supported by direct correlation of the level of expression/activity with tumor grade and prognosis. In particular, Axl was found to underlie metastasis as an essential regulator of the epithelial-mesenchymal transition (EMT) process and also to confer acquired resistance to the TKI-mediated targeted therapies by up-regulation of associated kinases. Currently, none of FDA-approved kinase drugs were developed for the TAM family kinases. In our effort to develop such small-molecule inhibitors targeting the TAM kinases for oncology indications, we uncovered a series of novel potent compounds with low nM potency against Axl and Tyro3. Effect of these compounds in human cancer cell lines of different tissue origins was mediated mainly through the Axl-dependent signaling pathways. Detailed analysis of signaling proteins downstream of Axl revealed different mechanisms of action for these compounds. In addition to suppression of cell proliferation, these compounds inhibited anchorage-independent colony formation, cell migration and invasion. Four compounds were selected to be evaluated in pharmacokinetic studies in mice and the results indicated that these compounds possess reasonable PK properties with high exposure, reasonably long half-life, and good bioavailability. The results of the efficacy studies in suppressing tumor growth in a xenograft and an orthotropic mouse models will be discussed.

Citation Format: Hong Zhang, Zaihui Zhang, Xiaoqing Shi, Erica Lee, Rick Li, Yuxiang Hu, Jun Yan, Jasbinder Sanghera. Evaluation of compounds developed against the TAM family kinases. [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 5393. doi:10.1158/1538-7445.AM2015-5393
Abstract 5410: Aspirin attenuates tumor initiating cell growth and induces reprogramming factors of mesenchymal to epithelial transition in breast cancer cell
Authors: Maity Gargi , De Archana , Banerjee Snigdha , Das Amlan , Sarkar Sandipto , Banerjee Sushanta K.
Published: August 2015

Acetyl Salicylic Acid (ASA) also known as aspirin, a classic, non-steroidal, anti-inflammatory drug (NSAIDs) is widely used to relieve minor aches and pains and to reduce fever. Epidemiological studies and other experimental studies suggest that ASA use reduces the risk of different cancers including breast cancer (BC) and may be used as a chemo-preventive agent against BC and other cancers. These studies have raised the tempting possibility that ASA could serve as a preventive medicine for BC. However, lack of in-depth knowledge of the mechanism of action of ASA reshapes the debate of risk and benefit of using ASA in prevention. Our studies, using in vitro and in vivo tumor xenograft model, show a strong beneficial effect of ASA in the prevention of breast carcinogenesis. We find ASA not only prevents breast tumor cell growth in vitro and tumor growth in nude mice xenograft model through the induction of apoptosis, it also significantly reduces the growth of tumor initiating cells (TICs)/ cancer stem cells (CSCs) and delayed the formation of a palpable tumor. Moreover, ASA regulates other pathophysiological events in breast carcinogenesis, such as reprogramming the mesenchymal to epithelial transition (MET) and delaying in vitro migration in BC cells. The tumor growth-inhibitory as well as reprogramming roles of ASA could be mediated through inhibition of TGF-β-signaling pathway, which is associated with growth, motility, invasion and metastasis in advanced breast cancers. Collectively, ASA has a therapeutic or preventive potential by attacking possible target such as TGF-β- SMAD4 signaling in breast carcinogenesis.

[This work is funded by VA Merit Awarded Grant (SB and SKB)]

Note: This abstract was not presented at the meeting.

Citation Format: Gargi Maity, Archana De, Snigdha Banerjee, Amlan Das, Sandipto Sarkar, Sushanta K. Banerjee. Aspirin attenuates tumor initiating cell growth and induces reprogramming factors of mesenchymal to epithelial transition in breast cancer cell. [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 5410. doi:10.1158/1538-7445.AM2015-5410
Abstract 5421: HER3 inhibition has little efficacy on hepatocellular carcinoma cell lines
Authors: Li Yong-Shi , Shao Yu-Yun , Wang Han-Yu , Cheng Ann-Lii , Hsu Chih-Hung
Published: August 2015

Background: HER3 is a member of the ErbB family of receptor tyrosine kinases that are involved in the pathogenesis of many malignancies, including hepatocellular carcinoma (HCC) (Hsieh et al: Hepatology 2011). When bound with neuregulins (NRGs) or in the presence of HER2 amplification, HER3 dimerizes with HER2 and activates the signaling transduction cascade. We planned this study to evaluate the efficacy of HER3 inhibition by an anti-HER3 monoclonal antibody, LJM716 (Novartis®), in HCC.

Methods: Human HCC cell lines Huh7, HepG2, PLC5, Hep3B, and SK-Hep1 were used in the experiments. We used the quantitative RT-PCR to evaluate the mRNA expression levels of HER2, HER3 and NRGs in HCC cell lines. We used the MTT assay to evaluate the growth inhibitory efficacy of LJM716 alone or in combination with sorafenib, and used the Western blotting to study the expression phospho-HER3 downregulated by LJM716 in these cells.

Results: None of the HCC cell lines have HER2 amplification. Huh7 and HepG2 had higher HER2 expression, SK-Hep1 had lower HER3 expression, SK-Hep1 and Hep3B had higher NRG1 and NRG2 expression, and PLC5 had higher NRG2 but not NRG1 expression compared with other HCC cells. In HCC cells cultured with ordinary serum-containing medium, we found LJM716 up to 20 μg/ml showed little suppressive effect in the proliferation of HCC cells; in HCC cells cultured in the presence of NRG1, LJM716 could induce a 20 to 30% growth-suppressive effect at best. LJM716 inhibited NRG1-induced phosphorylation of HER3 in HCC cells dose-dependently. The treatment of sorafenib slightly increased RNA expression levels of NRG1 and HER2 in PLC5, Huh-7, and HepG2 cells. We combined LJM716 and sorafenib to evaluate their combination effect in HCC cells, but found that LJM716 failed to show any synergistic effect to sorafenib.

Conclusions: Despite inhibitory effect on HER3 phosphorylation, LJM716 showed minimal therapeutic efficacy on HCC cell lines, either alone or in combination with sorafenib.

Citation Format: Yong-Shi Li, Yu-Yun Shao, Han-Yu Wang, Ann-Lii Cheng, Chih-Hung Hsu. HER3 inhibition has little efficacy on hepatocellular carcinoma cell lines. [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 5421. doi:10.1158/1538-7445.AM2015-5421
Abstract 5427: Small molecule inhibitors of Musashi family of RNA-binding proteins
Authors: Lan Lan , Appelman Carl , Smith Amber , Yu Jia , Larsen Sarah , Marquez Rebecca , Wu Xiaoqing , Liu Hao , Roy Anuradha , Anbanandam Asokan , Gowthaman Ragul , Karanicolas John , Rogers Steven , Aubé Jeffrey , De Guzman Roberto , Neufeld Kristi , Xu Liang
Published: August 2015

Musashi family of RNA-binding proteins are key regulators of several stem cell populations and are also involved in tumor proliferation and maintenance. There are two Musashi proteins in humans, Msi1 and Msi2, both of which regulate target mRNAs translation. We aim to identify small molecule inhibitors of Msi activity thus blocking the growth of a broad range of cancer cells. Known mRNA targets of Msi1 include Numb, APC and p21WAF-1, key regulators of Notch, Wnt signaling and cell cycle progression, respectively. Numb is also an mRNA target of Msi2. We confirmed the binding between numb and Msi1/Msi2 by RNA-IP. Using a fluorescence polarization assay, we screened small molecules from several chemical libraries for those that disrupt the binding of Msi1 to its consensus RNA binding site. Hits were validated by surface plasmon resonance, amplified luminescent proximity homogeneous assays and nuclear magnetic resonance. Among the small molecules that we screened, we found several hit compounds that disrupt the Msi1-numb RNA binding potently. Our study supports the hypothesis that Msi1 inhibition is a viable and effective anti-cancer strategy and we identified (-)-gossypol as the first small molecule inhibitor of Msi1 that inhibits tumor xenograft growth in vivo.

Citation Format: Lan Lan, Carl Appelman, Amber Smith, Jia Yu, Sarah Larsen, Rebecca Marquez, Xiaoqing Wu, Hao Liu, Anuradha Roy, Asokan Anbanandam, Ragul Gowthaman, John Karanicolas, Steven Rogers, Jeffrey Aubé, Roberto De Guzman, Kristi Neufeld, Liang Xu. Small molecule inhibitors of Musashi family of RNA-binding proteins. [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 5427. doi:10.1158/1538-7445.AM2015-5427
Abstract 5447: Association of the hedgehog signal pathway to Gefitinib sensitivity in a 3D cancer cell lines screening
Authors: Castillo Gonzalo , Jiang Xiuyun
Published: August 2015

Drug profiling of cancer cell lines is a useful tool for predictive biomarker discovery, traditional done in two-dimensional cultures, a growing body of evidence suggests that results cannot always be translated into xenografts or in the clinic due to the lack of complexity of the culture conditions. 3D cultures offer the ability to carry out the same type of studies with the added benefit of incorporating the 3-dimentional cellular interactions and physiological gradients normally seen in a tumor microenvironment. In this study we used Numira's 3D cell line screening platform on Gefitinib, a selective inhibitor of epidermal growth factor receptor (EGFR). We determined IC50 of Gefitinib in a panel of 60 cell lines grown as spheroids and used this information to investigate genes associated with sensitivity. Two mutated genes were associated with sensitivity to Gefitinb, as expected, the epidermal growth factor receptor (EGFR) was one of them, since mutations on EGFR are required for clinical efficacy. The second gene was smoothened (SMO), a G protein-coupled receptor of the hedgehog signaling pathway. It has been suggested that blockade of the hedgehog signaling pathway enhances anti-proliferative effects of EGFR inhibitors, we explored this potential synergy in a combination studies of Gefitinib and SMO inhibitors, Cyclopamine and GDC0449, the results are discussed.

Citation Format: Gonzalo Castillo, Xiuyun Jiang. Association of the hedgehog signal pathway to Gefitinib sensitivity in a 3D cancer cell lines screening. [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 5447. doi:10.1158/1538-7445.AM2015-5447
Abstract 5453: Different mechanism of Oxaliplatin resistance in human colorectal cancer cell lines
Authors: Yamano Tomoki , Kubo Shuji , Yano Aya , Tomita Naohiro
Published: August 2015

Purpose: The mechanism of Oxaliplatin (OHP) resistance is partly understood and no molecular marker for prediction of the sensitivity is available in clinic. We analyzed OHP resistant clones to establish the molecular marker for OHP sensitivity in colorectal cancer.

Experimental design: We established several OHP-resistant clones from human colon cancer cell lines, DLD1 and HCT116. Then we assayed IC50 of OHP- resistant clones against OHP, 5-FU, and CPT-11. We measured gene expression profiling by microarray analysis and gene mutations by exome sequencing. Based on these results, we selected candidate genes associated with OHP sensitivity, which had gene mutations with significant change of gene expression. To validate the results, we assessed the gene expression of candidate genes in colorectal cancer patients.

Results: All OHP-resistant clones derived from HCT116 were also resistant against 5-FU and CPT-11, although all OHP-resistant clones derived from DLD1 were still sensitive against 5-FU and CPT-11. Microarray analysis and exon sequencing indicated gene mutations in SMAD7 and IRF9 with amplified gene expression were candidate molecular markers for multidrug resistance in OHP-resistant clones derived from HCT116, although the gene expression in tumors of these genes were lower than normal mucosa in most of colorectal cancer patients.

Conclusions: The mechanisms of OHP resistance were different between OHP-resistant clones derived from DLD1 and those from HCT116, but the same among the clones if the parental cells were same. SMAD7 and IRF9 were candidate molecular markers to predict multidrug resistance.

Citation Format: Tomoki Yamano, Shuji Kubo, Aya Yano, Naohiro Tomita. Different mechanism of Oxaliplatin resistance in human colorectal cancer cell lines. [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 5453. doi:10.1158/1538-7445.AM2015-5453
Abstract 5459: Overcoming resistance to HER2-targeting drugs using CDK8 inhibitors
Authors: McDermott Martina , Ivers Laura , O'Donovan Norma , Crown John , Roninson Igor , Broude Eugenia V.
Published: August 2015

HER2-targeting therapies transformed the treatment of patients with HER2+ breast cancer and are now being explored in other cancer types. However, nearly 70% of patients with HER2+ metastatic breast cancer have intrinsic resistance and almost all develop acquired resistance to HER2-targeting drugs. New therapeutic approaches aimed at resistance to HER2-targeting therapies are urgently needed. We have previously found that resistance to HER2-targeting drugs involves increased activity of the phosphatase PP2A. PP2A was reported to stimulate the kinase activity of CDK8, a transcription-regulating kinase that in contrast to some other members of the CDK family does not regulate cell cycle progression. Thus CDK8 may play a role in resistance to HER2-targeting therapies. CDK8 has been identified as an oncogene amplified in 50% of colon cancers. Immunohistochemical staining of breast tissue arrays and meta-analysis of breast cancer microarray data revealed that CDK8 is overexpressed in breast cancers and that higher CDK8 expression correlates with the failure of systemic therapy. Selective small-molecule inhibitors of CDK8 and its paralog CDK19 show no limiting toxicities at therapeutically effective doses. We have found that an optimized CDK8/19 inhibitor Senexin B has a synergistic growth-inhibitory effect in combinations with an anti-HER2 monoclonal antibody (a biosimilar of trastuzumab) and with the HER2/EGFR small-molecule inhibitor lapatinib. These synergistic effects were observed in all HER2+ breast and colon cancer cell lines tested so far, including those that are either sensitive to HER2-targeting drugs or non-responsive to these agents due to innate or acquired resistance. Furthermore, combining lapatinib with Senexin B inhibited the development of de novo resistance to lapatinib. Taken together these results suggest that combining anti-HER2 and anti-CDK8 therapies is a rational potential treatment for HER2+ cancers, which may overcome both innate and acquired resistance to HER2-targeting drugs.

Citation Format: Martina McDermott, Laura Ivers, Norma O'Donovan, John Crown, Igor Roninson, Eugenia V. Broude. Overcoming resistance to HER2-targeting drugs using CDK8 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 5459. doi:10.1158/1538-7445.AM2015-5459
Abstract 547: Diagnosis of lung tumor types based on metabolomic profiles in lymph node aspirates
Authors: Sappington Daniel R. , Helms Scott A. , Siegel Eric , Jeffus Susanne K. , Bartter Teka , Bartter Thaddeus , Boysen Gunnar
Published: August 2015

Lung cancer is the leading cause of cancer-related deaths in the US and worldwide. The majority of lung cancer patients are diagnosed with an advanced stage, precluding curable surgical resection, and therapy is limited to thoracic radiation and chemotherapy. The efficacies have improved in recent years due to patient pre-selection based on the cytology of fine needle aspirates of lymph nodes, which harbor circulating tumor cells. We report herein the evaluation of lymph node aspirates for the presence of metabolite features that are suitable to distinguish patients with lung cancer from patients without malignancies and to separate patients with adenocarcinoma from patients with squamous cell carcinoma. The results provide evidence that patient groups can be separated based on their metabolite profiles. Multivariate statistical analyses (PLS and OPLS) produce a set of consensus features that can be further developed into clinical biomarkers. Two of the features were identified as kynurenine and oxidized glutathione, and their identities were confirmed in a second larger sample set. In addition, the accompanying metabolites glutamate, glutamine and tryptophan were included in the validation experiment to utilize relative metabolite ratios as indicators for corresponding enzyme activities. The validation results demonstrate significant differences in metabolites and metabolite ratios between lymph node aspirates harboring a circulating tumor cell and aspirates negative for malignancy. Subsequently, a second set of lymph node samples were analyzed for an extended panel of metabolites and of these 42 were suitable biomarker to be statistically significant to distinguish between at least one of the pair wise comparisons. Together the results demonstrate that metabolite profiles in lymph node aspirates are suitable to differentiate patients with adenocarcinoma from patients with squamous cell carcinoma.

Citation Format: Daniel R. Sappington, Scott A. Helms, Eric Siegel, Susanne K. Jeffus, Teka Bartter, Thaddeus Bartter, Gunnar Boysen. Diagnosis of lung tumor types based on metabolomic profiles in lymph node aspirates. [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 547. doi:10.1158/1538-7445.AM2015-547
Abstract 5498: Multiple mechanisms of action may contribute to the lymphoma cell-killing activity of SH7139
Authors: Balhorn Monique Cosman , Hok Saphon , Balhorn Rod
Published: August 2015

The tridentate selective high affinity ligand (SHAL) SH7139 is selectively cytotoxic at sub-nanomolar concentrations to lymphoma cells over-expressing HLA-DR10. Recent studies suggest SH7139 is unusual in that multiple mechanisms may contribute to its killing of targeted tumor cells. Electron microscopy data suggest one mechanism involves the triggering of a cell-signaling event that leads to the induction of apoptosis when SH7139 binds to a unique site on HLA-DR10 (the same region/epitope recognized by the Lym-1 antibody). A second mechanism appears to involve the internalization of SH7139 by tumor cells and the subsequent release of it's three individual recognition elements/ligands by metabolic cleavage of the amide bonds that link them to a scaffold (a unique feature of SHALs). Analogous to the process of toxin delivery by antibody-drug conjugates, once these ligands are released inside the cell, they can each inhibit a different key pathway required for tumor cell survival. Additional metabolic conversions of these ligands by the tumor cells to toxic metabolites may also contribute to cell killing through the inhibition of a number of other critical cellular functions. The third proposed mechanism is based on the fact that the target receptor HLA-DR10 participates in the activation of T-cells. The binding of SH7139 to the antigen binding pocket of HLA-DR10 may trigger an immune response that targets the cancer cells with bound drug. All three proposed mechanisms are currently under study. If multiple diverse mechanisms of action contribute to SH7139's cytotoxicity, it will be extremely difficult for lymphoma cells to develop a resistance to the drug. This research was supported by the National Cancer Institute Phase II SBIR Award R44CA159843-02 to SHAL Technologies Inc. Part of this work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Citation Format: Monique Cosman Balhorn, Saphon Hok, Rod Balhorn. Multiple mechanisms of action may contribute to the lymphoma cell-killing activity of SH7139. [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 5498. doi:10.1158/1538-7445.AM2015-5498
Abstract 5503: Panaxynol, a potential treatment for colitis, selectively targets pro-inflammatory macrophages for DNA damage and apoptosis
Authors: Chaparala Anusha , Poudyal Deepak , Cui Xiangli , Li Bin , Witalison Erin E. , Cui Taixing , Hofseth Lorne J.
Published: August 2015

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that has been associated with a high risk for colorectal cancer. Since available conventional treatments provide mostly modest relief and are paired with a high risk of side effects, complementary and alternative medicines (CAMs) can offer a safe and effective option for the treatment of IBD. Earlier studies in our lab have shown that American Ginseng can suppress colitis and also prevent colitis-associated colon cancer in mice. During the process of isolating active ingredients from this plant, Panaxynol was identified as a key component. Panaxynol has been shown to have anti-cancer and anti-inflammatory properties, but it has not been studied in macrophage-driven autoimmunity models. Here, we study the effects of Panaxynol on macrophages and other cell lines in an attempt to understand its mechanism of action. We show that Panaxynol induces DNA damage and apoptosis in macrophages in a dose-dependent manner using phosphorylated γ-H2AX detection and TUNEL assays, respectively. Importantly, DNA damage and apoptosis were induced in other cell types (e.g. epithelial cells and fibroblasts) only when using higher doses of Panaxynol (>50μM). Co-culture experiments confirm that Panaxynol selectively targets macrophages in the presence of colon cancer cells. To explore mechanisms, we asked whether Panaxynol inhibits the STAT1 pathway. Results showing an inhibition of STAT1 phosphorylation are consistent with the hypothesis. We plan to extend these studies to an in vivo mouse model of DSS-induced colitis in order to understand the anti-inflammatory mechanisms of Panaxynol. Positive outcomes from this study can potentially serve as a model for the treatment of colitis and other autoimmune diseases (at least partly) associated with macrophage dysfunction.

Citation Format: Anusha Chaparala, Deepak Poudyal, Xiangli Cui, Bin Li, Erin E. Witalison, Taixing Cui, Lorne J. Hofseth. Panaxynol, a potential treatment for colitis, selectively targets pro-inflammatory macrophages for DNA damage and apoptosis. [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 5503. doi:10.1158/1538-7445.AM2015-5503
Abstract 5505: MyD88-dependent signaling decreases the anti-tumor efficacy of epidermal growth factor receptor inhibition in head and neck cancer cells
Authors: Simons-Burnett Andrean L. , Koch Adam T. , Love-Homan Laurie , Stanam Aditya
Published: August 2015

Epidermal growth factor receptor (EGFR) is upregulated in the majority of head and neck squamous cell carcinomas (HNSCC). However many HNSCC patients respond poorly to EGFR inhibitors (EGFRIs) despite tumor expression of EGFR. Gene expression analysis of erlotinib-treated HNSCC cell lines revealed an upregulation of genes involved in MyD88-dependent interleukin-6 (IL-6) expression compared to their respective vehicle treated cell lines. We therefore proposed that MyD88-dependent signaling may reduce the anti-tumor efficacy of the EGFR inhibitor erlotinib in HNSCC. Erlotinib significantly upregulated IL-6 secretion which we have previously reported to result in reduced drug efficacy and drug resistance (Fletcher et al, 2013). Suppression of MyD88 expression significantly blocked erlotinib-induced IL-6 secretion in vitro and increased the anti-tumor activity of erlotinib in vivo. There was little to no evidence of toll-like receptor (TLR) or interleukin-18 receptor (IL-18R) involvement in erlotinib-induced IL-6 secretion. However, suppression of the interleukin-1 receptor (IL-1R) signaling through pharmacologic and genetic methods significantly reduced erlotinib-induced IL-6 production and increased HNSCC cell sensitivity to erlotinib in vitro. A time-dependent increase of IL-1 alpha (IL-1α) but not IL-1 beta (IL-1β) was observed in response to erlotinib treatment and IL-1α blockade significantly increased the anti-tumor activity of erlotinib and the EGFR antibody inhibitor cetuximab in vivo. Pre-treatment with a pan-caspase inhibitor but not a caspase-1 inhibitor reduced erlotinib-induced IL-1α secretion suggesting that IL-1α was released due to cell death. Human HNSCC tumors showed higher IL-1α mRNA levels compared to matched normal tissue, and IL-1α was found to be negatively correlated with survival in HNSCC patients. Overall, the IL-1α/IL-1R/MYD88/IL-6 pathway may be responsible for the reduced anti-tumor efficacy of erlotinib and other EGFRIs; and blockade of the MyD88-dependent signaling may improve the efficacy of EGFRIs in the treatment of HNSCC.

Citation Format: Andrean L. Simons-Burnett, Adam T. Koch, Laurie Love-Homan, Aditya Stanam. MyD88-dependent signaling decreases the anti-tumor efficacy of epidermal growth factor receptor inhibition in head and neck cancer cells. [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 5505. doi:10.1158/1538-7445.AM2015-5505
Abstract 5508: Fucoidan from Turbinaria conoides attenuates pancreatic cancer progession by regulating p53 - NFκB crosstalk
Authors: Delma Caroline R. , Srinivasan Guru Prasad , Raviprakash Nune , Manna Sunil K. , Somasundaram Somasundaram T. , Aravindan Natarajan
Published: August 2015

Poor prognosis of pancreatic cancer (PC) has been attributed to its resistance to apoptosis and propensity for early systemic dissemination. Existing therapeutic strategies are often circumvented by the molecular crosstalk between cell signaling pathways. The fact that p53 is mutated in more than 50% of PC tissues and NFκB is constitutively activated in therapy resistant residual PC accounts for the evaded cell death and dissemination. In this study, we examined the benefit of fucoidan from a marine brown alga, Turbinaria conoides against PC progression. Five fractions of fucoidan isolated and fractionated using ion exchange chromatography were tested for their potential in this setting using two (MiaPaCa-2, Panc-1) genetically diverse human PC cell-lines. All fractions investigated exerted significant dose dependent and time dependent regulation of cell survival. Coherently, fucoidans induced apoptosis and activated caspase -3, -8 and -9 and cleaved PARP. Pathway-specific transcriptional analysis (QPCR profiling) recognized inhibition of 57 and 38 NFκB pathway molecules with fucoidan-F5 in MiaPaCa-2 and Panc-1 cells, respectively. In addition, fucoidan-F5 was also found to inhibit both the constitutive and TNFα mediated NFκB DNA-binding activity (EMSA) in PC cells. Upregulation of cytoplasmic IκB levels and significant reduction of NFκB dependent luciferase activity further substantiate inhibitory potential of seaweed fucoidans on NF-κB. Moreover, fucoidan(s) treatment increases cellular p53 in PC cells. Together, the results suggests that fucoidan regulates PC progression and further imply that fucoidans may selectively target p53-NFκB crosstalk and dictate apoptosis in PC cells.

Citation Format: Caroline R. Delma, Guru Prasad Srinivasan, Nune Raviprakash, Sunil K. Manna, Somasundaram T. Somasundaram, Natarajan Aravindan. Fucoidan from Turbinaria conoides attenuates pancreatic cancer progession by regulating p53 - NFκB crosstalk. [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 5508. doi:10.1158/1538-7445.AM2015-5508
Abstract 5509: A drug-screening model to identify compounds active in cells under metabolic stress
Authors: Pellegrini Paola , Haraldsson Martin , Jenmalm Jensen Annika , Lundbäck Thomas , De Milito Angelo
Published: August 2015

Background and aim: Promising anticancer compounds often fail in vivo due to lack of efficacy. Drug screenings to identify anticancer agents are usually performed in culture conditions that very poorly represent the complex metabolic tumor environment. Tumor tissues are characterised by low oxygen (hypoxia) and acidic extracellular pH (acidosis). A screen of a drug-library for compounds able to induce cell death in acidic/hypoxic conditions may lead to discover effective drugs targeting quiescent/hypoxic cells, normally considered responsible for tumor relapses after therapy. Methods: The colon carcinoma cell line HCT-116 has been adapted to grow in low pH conditions (pH 6.8). The Prestwick compound library (1200 FDA-approved compounds) was used to validate the assay. Cell viability was measured using the acid phosphatase assay after 48 hours exposure to test compounds. The assay was validated in HCT-116 cells cultured in normoxic and hypoxic conditions. Multicellular spheroids (MCS) were used to evaluate the sensitivity to hit compounds confirmed at least three times in 2D culture conditions. Results: The assay was optimized to perform the screening at pH 6.8 in normoxic and hypoxic conditions. Experiments have demonstrated the ability of cells to survive and grow in hypoxic conditions (1% oxygen) for at least 4 days. The test was optimized in terms of number of plated cells and serum concentration. Hit compounds were identified based on the mean values for quality control plus 3 standard deviations of untreated samples. The screen led to identify 20 hits for both conditions and 11 hits were further confirmed for hypoxic/acidic conditions. Auranofin and Verteporfin showed to better induce cell death in cells adapted or acutely exposed to low pH compared to parental cells and immortalized epithelial cells (RPE1). Both drugs showed cytotoxic effects on cells grown as MCS, suggesting a potential good efficacy of the therapeutic agent in vivo. In addition, the screening of about 10000 compounds of the LCBKI library is ongoing and about 100 hits have been identified. Conclusions: The screening validation on the Prestwick library will hopefully lead to identify potential “off-label” effects of already approved drugs. The screening of larger drug-libraries will hopefully lead to find and characterize more compounds able to target slow proliferating and therapy resistant cells.

Citation Format: Paola Pellegrini, Martin Haraldsson, Annika Jenmalm Jensen, Thomas Lundbäck, Angelo De Milito. A drug-screening model to identify compounds active in cells under metabolic stress. [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 5509. doi:10.1158/1538-7445.AM2015-5509