bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4042: Metformin-induced caveolin-1 expression promotes T-DM1 drug efficacy in breast cancer cells
Authors: Wei Wan-Chen , Chung Yuan-Chiang , Kao Ling-Yi , Chiu Hsiang-Ling , Wu Yi-Che , Chao Wei-Ting
Published: August 2018

Trastuzumab emtansine (T-DM1, Kadcyla) is an antibody-drug conjugate (ADC) that was recently approved by the Federal Drug Administration (FDA) of the USA for the treatment of HER-2-positive metastatic breast cancer. The drug sensitivity of ADCs depends in the main on the internalization efficiency of the drug. Endocytic protein caveolin-1 was shown to promote T-DM1 internalization and enhance drug sensitivity. Whether caveolin-1 can be overexpressed to improve T-DM1 efficacy is interesting and has the potential for clinical application. In this study, the first-line diabetes drug metformin was investigated in terms of induction of caveolin-1 expression for increased efficacy of subsequent T-DM1 application. HER-2-positive BT-474 cells were pretreated with metformin, followed by combined therapy with metformin and T-DM1. The T-DM1 internalization and drug efficacy were determined, and the protein expressions for signal transduction were also monitored by Western blot to ascertain the molecular mechanism. Caveolin-1 shRNA was applied to suppress endogenous cellular caveolin-1 expression, and the ability of metformin to promote T-DM1 efficacy was investigated. The results showed that in BT-474 cells pretreated with metformin, cellular caveolin-1 overexpression was induced, which then promoted drug efficacy by enhancing T-DM1 internalization. As cellular caveolin-1 was suppressed by shRNA, the effect of metformin-enhanced T-DM1 cytotoxicity was decreased. This study demonstrated that metformin can be applied prior to T-DM1 treatment to improve the clinical efficacy of T-DM1 by enhancing caveolin-1-mediated endocytosis.

Citation Format: Wan-Chen Wei, Yuan-Chiang Chung, Ling-Yi Kao, Hsiang-Ling Chiu, Yi-Che Wu, Wei-Ting Chao. Metformin-induced caveolin-1 expression promotes T-DM1 drug efficacy in breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4042.
Abstract 4051: Different immune signatures in advanced lung tumors of Nrf2 wildtype vs. knockout mice
Authors: Zhang Di , Rennhack Jonathan , Andrechek Eran , Rockwell Cheryl , Liby Karen
Published: August 2018

Activation of Nrf2 and its downstream target genes serves as a master defense mechanism, protecting cells against oxidative and electrophilic stress. Numerous activators of Nrf2 inhibit carcinogenesis. However, genetic alterations resulting in constitutive Nrf2 activation in human lung tumors promotes tumor growth and chemoresistance. The dual role of Nrf2 in cancer has generated a high level of interest, but little is known regarding the effect of Nrf2 on immune cells during lung carcinogenesis. In this study, we used the potent carcinogen vinyl carbamate to induce lung tumors in mice. Tumor burden, the immunophenotype, and genetic signatures were compared in the lungs of Nrf2 knockout (-/-, KO) vs. wildtype (+/+, WT) mice. Nrf2 KO mice were more susceptible to vinyl carbamate; these mice developed tumors earlier than the WT mice and exhibited more and larger tumors over times ranging from 20-32 weeks after initiation. By 32 weeks, WT mice have an average of 6.5 ± 0.95 tumors per lung compared to 12.25 ± 2.6 tumors in the KO mice. Immune cell populations including T cells (CD4+ and CD8+), B cells, macrophages and myeloid derived suppressor cells were investigated in the lungs and spleens of Nrf2 WT and KO mice challenged with vinyl carbamate. T cell populations were significantly (P < 0.05) reduced in the lungs of Nrf2 KO mice, while tumor-promoting macrophages and myeloid derived suppressor cells were elevated in the lung and spleen, respectively, of Nrf2 KO mice compared to WT mice. Moreover, immune response genes, especially a series of cytokines (Cxcl1, Cxcl12, Csf1, and Ccl9) and MHC antigens that promote tumor growth, were significantly upregulated in tumors from Nrf2-/- mice. Importantly, this expression profile is conserved in patients with lung cancer. Overall, our results confirmed a tumor protective role of Nrf2 in carcinogenesis and suggest an important regulatory role for Nrf2 in immune cells in both mouse and human lung tumors.

Citation Format: Di Zhang, Jonathan Rennhack, Eran Andrechek, Cheryl Rockwell, Karen Liby. Different immune signatures in advanced lung tumors of Nrf2 wildtype vs. knockout mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4051.
Abstract 4115: Comparison of IL-4 receptor targeting elastin-like polypeptide based on size and structure
Authors: Seo Boyeon , Sarangthem Vijaya , Yi Aena , Park Rang-Woon
Published: August 2018

For novel drug delivery systems, in order to improve clinical outcomes clear optimization of size, shape, multifuntionality, and site-specificity are highly considered. As molecular size significantly influenced the biodistribution, precise control of molecular sizes must be considered for optimum targeting effect in cancer therapy. Elastin like polypeptide (ELP), has been utilized as an attractive vehicle for cancer therapy as it provide unparalleled control over sequence and structure in genetic level thereby allowing generation of various polymers with defined architectures and functional properties. In this study, we designed various multivalent elastin-like polypeptide based tumor targeting polymer in which multiple copies of IL-4 receptor (IL-4R) targeting ligands, AP1 peptide were subjected into ELP polymer backbone periodically to enhance affinity and avidity towards IL-4R- highly expressed tumor cells. Several ELP with different molecular sizes and structure from unimer to micelle forming polymer have been designed to investigate the pattern of accumulation in tumor, as well as their bio-distribution in vivo. Different percentage of cell binding and uptake depend on size, number of targeting peptides, or based on unimer compared with micelle were determined. The high molecular weight AP1-ELP showed superior binding activity with faster entry and efficiently processed in the IL-4R dependent endocytic pathway compared to low molecular weight polypeptides. In addition the high molecular weight, micelle forming AP1-ELP displayed better tumor penetration and extensive retention in tumor tissue with decrease non-specific accumulation in vital organs compared to low molecular weight AP1-ELP in xenograft model. It was suggested that superior binding activities shown by A86 and A100 may depends on multiple presentation of ligands upon transition to micelle like structure rather than increased number of targeting ligands and molecular weight. Thus this study have significance in demonstrating different pattern underlying unimer and micelle forming ELP mediated tumor targeting as well as biodistribution in vivo.

Citation Format: Boyeon Seo, Vijaya Sarangthem, Aena Yi, Rang-Woon Park. Comparison of IL-4 receptor targeting elastin-like polypeptide based on size and structure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4115.
Abstract 4126: DNA methyltransferase inhibitors target a YES1-YAP1 signaling axis in childhood rhabdomyosarcoma
Authors: Slemmons Katherine , Yeung Choh , Baumgart Josh , McCalla-Martin Amy , Helman Lee
Published: August 2018

We have previously shown that the SRC family kinase (SFK) member, YES1, is highly expressed and rapidly activated upon IGF-1R blockade in rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children and adolescents. YAP1 (YES-associated protein) is also highly expressed in human RMS tumors where it functions as an oncoprotein when the upstream Hippo tumor suppressor pathway is silenced, driving cell growth and survival. Thus far, efforts to pharmacologically inhibit YAP1 have been unsuccessful. One activator of the Hippo pathway, RASSF1a, is epigenetically silenced in many cancer types including sarcomas. Here we show a loss of RASSF1a expression in RMS cell lines via promoter methylation. Treatment with DNA methyltransferase inhibitors (DNMTis) can re-activate RASSF1a expression, resulting in YAP phosphorylation and inactivation. DNMTi treatment also significantly inhibits RMS cell growth, which can be rescued by overexpression of a constitutively active YAPS127A. In the alveolar variant (aRMS) in particular, DNMTis increase apoptosis and decrease both YES1 expression and activation. This suggests DNMTi treatment can inhibit both YAP1 and YES1 signaling. To further investigate the connection between YES1 and YAP1 we performed proximity ligation assays and discovered that YES1 and YAP1 interact in the nucleus of RMS cell lines. Furthermore, dasatinib treatment, a known SFK inhibitor, prevents YAP1 nuclear accumulation suggesting a role for YES1 in regulating YAP1 cellular localization. YAP1 is also tyrosine phosphorylated, which may be one way YES1 regulates YAP1. Lastly, cells expressing a constitutively active YAPS127A have increased activation of SFK suggesting a positive feedback loop whereby YAP1 activity can further activate YES1 through an unknown mechanism. These data uncover a signaling axis between the YES1 and YAP1 oncoproteins in RMS and suggest an alternative way to silence YES1 and YAP1 through use of DNMTis. We will further analyze this signaling through shRNA knockdown of YES1 and evaluate combination treatment of a DNMTi and dasatinib in vitro and in vivo.

Citation Format: Katherine Slemmons, Choh Yeung, Josh Baumgart, Amy McCalla-Martin, Lee Helman. DNA methyltransferase inhibitors target a YES1-YAP1 signaling axis in childhood rhabdomyosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4126.
Abstract 4151: Fucoidan reduced radiation-induced fibrosis and secondary primary cancers
Authors: Wu Szu-yuan
Published: August 2018

Radiotherapy (RT) causes tissue fibrosis and secondary cancers. Fucoidan is a sulfated polysaccharide that is mainly found in brown algae and brown seaweed. In this study, we assessed the radioprotective effect of oligo-fucoidan on zebrafish. Embryos were exposed to RT (5, 10, or 20 Gy) at 4 hours post-fertilization and compared with an oligo-fucoidan pretreatment group. We found that oligo-fucoidan protects embryos from death and embryonic defects. Using oligo-fucoidan oral feeding adult zebrafish prior radiation, we found that oligo-fucoidan treatment of wild-type fish yields much lower expression of apoptosis and fibrosis marker genes in liver compared to RT (40 Gy) only. Liver fibrosis was diagnosed from Sirius stain, proved oligo-fucoidan reduce fibrosis caused by high dose of radiation. Using a diet-induced obesity HBx,src(p53-) triple transgenic fish liver cancer model, we found that oligo-fucoidan can lower the expression of cell cycle/proliferation markers, as well as fibrosis markers and lipogenic enzymes, compared with that in fish with radiation exposure only. Furthermore, oligo-fucoidan can effectively decrease liver cancer formation, as observed by hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) staining of PCNA proliferation marker. Genomic transcriptome profiling by GeneTitan reveals the main genes/pathways activated by oligo-fucoidan pre-treatment which have protection effect for the radiation-induced fibrosis and secondary primary cancers. Our results provide evidence for the ability of oligo-fucoidan to prevent steatosis, hepatocellular carcinoma and secondary cancers induced by radiation in zebrafish model.

Citation Format: Szu-yuan Wu. Fucoidan reduced radiation-induced fibrosis and secondary primary cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4151.
Abstract 4166: Hair follicles as a minimally invasive resource of epithelial cells in mouse studies of ionizing radiation
Authors: Slavik Hanus , Mistrik Martin , Duskova Pavlina , Furst Tomas , Srovnal Josef , Hajduch Marian
Published: August 2018

Introduction

Hair follicles are relatively accessible as a biological material allowing repeatable and minimally invasive sampling of predominantly epithelial cells for biomarker studies. The utility of such a material is promising for example in murine experiments, where repeated sampling would require multiple biopsies.  As a proof of concept, the ionizing irradiation response in murine follicular cells was chosen as a suitable and common external factor for studying cellular senescence, apoptotic pathways, neoplastic transformation, tumor development and response to cancer therapy.     

Methods and material

Hair follicles were collected from 30 healthy C57Bl/6 mice into the RNA later for RT-qPCR and into the 4% formaldehyde for immunofluorescence with specially developed vacuum collector. Follicles were collected before X-ray irradiation and 30 min, 3 h, 6 h and 24 h after irradiation. Each group of 10 mice obtained one dose (2, 6 or 10 Gy). RNA was extracted from the samples using miRNeasy mini kit (Qiagen) and two-tube RT-qPCR was performed for SESN1, p21, MDM2 and HPRT gene expression analysis. Immunofluorescence was done for γ-H2AX and quantitatively evaluated by in-house developed software routine.   

Results 

Total RNA extracted from one pluck was usually less than 35 ng but it had good quality (RIN ≥ 7.5) even after the storage at room temperature. We determined p21 as the best marker for the uniformity and specific dynamic respond for each of the doses. The strongest responds were found after 30 min with 2 Gy (average fold change FCav = 3,24). In case of higher doses, longer remaining p21 overexpression was detected. For instance, FCav = 2,29 even after 24h at dose 10 Gy. Our data were corroborated by immunofluorescence for direct marker of ionizing radiation induced DNA damage γ-H2AX, where 1-3 hair follicles proved to be efficient for microscopic analyses. Strong γ-H2AX signal was detectable within 3h after irradiation followed by rapid decrease within the next 24h. 

Conclusion

Collected murine hair follicles proved to be a feasible alternative material for molecular analyses which in logistic aspects outreaches phlebotomies or skin biopsies because of repeatable, minimally invasive and accurate sampling and non-laborious processing. 

Dedication 

This work was financially supported by grants IGA_LF_2017_013, EATRIS-CZ, TACR TE02000058 and VG20102014001.

Citation Format: Hanus Slavik, Martin Mistrik, Pavlina Duskova, Tomas Furst, Josef Srovnal, Marian Hajduch. Hair follicles as a minimally invasive resource of epithelial cells in mouse studies of ionizing radiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4166.
Abstract 4178: AKT-ERK axis in circulating tumor cells is a target for metastatic suppression
Authors: Cheng Hung-Chi , Wang Ying-Jan , Cheng Li-Hsin
Published: August 2018

Cytotoxic cancer therapies often result in unwanted side effects, drug resistance, and cancer metastasis. To avoid this, an anti-metastatic therapeutic strategy independent of apoptosis is alternatively desired. Malignant circulating tumor cells (CTCs) may escape from anoikis by sustaining AKT survival signals. Moreover, cancerous fibronectin polymers (polyFN) are known to mediate the adhesion of CTCs to endothelia and lung metastasis. Depletion of polyFN from CTCs without lowering AKT signaling may thus be an ideal anti-metastatic approach. Screening several phytochemical compounds, we found that Pterostilbene (PS), a resveratrol derivative, potently reduced polyFN on suspended tumor cells, whereas it significantly elevated AKT phosphorylation (pAKT), apparently in contrast to its well-known anti-apoptotic effect on adherent tumor cells. Inactivation of ERK signaling in suspended tumor cells was responsible for the enhanced pAKT by PS, leading to suppressions of polyFN assembly and tumor metastasis. Pretreatment with a PI3K inhibitor, LY294002, effectively reduced PS-activated AKT, rescued PS-inactivated ERK, and consequently reversed the PS-suppressed polyFN assembly which was then overturned by the ERK inhibitor U0126. Indeed, PS-suppressed lung metastasis was counteracted by LY294002, which was reversed with U0126. Dietary PS may serve as a novel complementary medicine, for it could be orally administered and efficiently blockaded tumor metastasis by targeting AKT-ERK signaling axis in CTCs.

Citation Format: Hung-Chi Cheng, Ying-Jan Wang, Li-Hsin Cheng. AKT-ERK axis in circulating tumor cells is a target for metastatic suppression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4178.
Abstract 4194: Tumor Treating Fields (TTFields) affect invasion properties and cell morphology of various cancer cells in vitro
Authors: Schneiderman Rosa S. , Giladi Moshe , Zeevi Einav , Shteingauz Anna , Voloshin Tali , Porat Yaara , Munster Mijal , Kirson Eilon D. , Palti Yoram
Published: August 2018

Tumor Treating Fields (TTFields) therapy is an approved modality for the treatment of glioblastoma. TTFields are delivered via continuous, noninvasive application of low intensity, intermediate frequency alternating electric fields. The antimitotic effects of TTFields have been extensively investigated. We explored other processes that may be affected by TTFields such as cellular invasion. Human glioma, human and mouse melanoma, human breast cancer and human colon cancer cell lines were treated with TTFields using the inovitro system. Invasion assays were performed using a modified Matrigel coated Boyden chamber. TTFields effect on cells size, focal adhesions and stress fibers morphology was studied using immuno-fluorescent confocal microscopy.

Invasion was significantly reduced compared to untreated cells in all tested cell lines.

Furthermore, the optimal frequency for inhibition of invasion in tested cells was 300 kHz while the optimal anti mitotic frequency leading to glioma cell death is 200 kHz. The inhibitory effect on migration was observed at electric fields intensities of 0.6 V/cm RMS which is below the 1 V/cm RMS threshold previously reported for induction of cell death. Combining TTFields with Bumetanide, an agent that inhibits cellular motility, resulted in further inhibition of glioma cell invasion.

TTFields application resulted in an increase in cell size, as well as in focal adhesion size, number and peripheral distribution of the adhesion sites. Also, treated cells adopted a more flattened and spread shape in comparison with control cells.

TTFields treated cells exhibit reduction in appearance of stress fibers and a dense meshwork of actin filaments around the entire cell periphery.

Our results suggest that cancer cell motility is impaired by exposure to TTFields. The TTFields parameters (intensity and frequency) which led to the maximal inhibition of cellular motility are different from those required for exerting anti-mitotic effects. The alterations in cells morphology during exposure to TTFields may contribute to reduction in cell motility. Further studies are needed to elucidate the mechanism by which TTFields disrupts cellular motility in glioma cancer cells.

Citation Format: Rosa S. Schneiderman, Moshe Giladi, Einav Zeevi, Anna Shteingauz, Tali Voloshin, Yaara Porat, Mijal Munster, Eilon D. Kirson, Yoram Palti. Tumor Treating Fields (TTFields) affect invasion properties and cell morphology of various cancer cells in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4194.
Abstract 4195: β-elemene inhibits the metastasis of multidrug-resistant gastric cancer cells through the Cbl-b-EGFR-ERK/Akt signaling pathway
Authors: Yu Ruoxi , Deng Mingming , Song Huicong , Zou Dan , Xu Ling , Qu Xiujuan , Liu Yunpeng , Teng Yuee , Hu Xuejun , Zhang Ye
Published: August 2018

Background/Aims: β-elemene, a Curcuma wenyujin plant extract, has been widely used as an adjuvant therapeutic agent in cancer treatment. The emergence of drug-resistant tumor cells is defined as multidrug resistance (MDR), and is one of the major ways cancer therapy can fail. Our previous study indicated that, compared to chemo-sensitive human gastric cancer cells, drug-resistant cells have a stronger ability for migration. The aim of this study was to explore the anti-metastasis effects and mechanism of β-elemene in multi-drug resistance human gastric cancer cells.

Methods: A cell viability assay was used to assess the resistance of adriamycin-resistant human gastric cancer SGC7901 cells (SGC7901/ADR) and the cytotoxic effects of β-elemene on SGC7901/ADR cells. A wound healing assay and transwell assay were used to explore the anti-metastasis effects of β-elemene. Human matrix metalloproteinase (MMP) antibody array and Western blot analysis were used to explore the potential mechanism. A murine tumor metastasis assay was used to confirm the anti-metastasis effects in vivo. Immunohistochemistry analysis was performed to examine the expressions of related proteins in xenograft tumors.

Results: At sub-lethal concentrations (1 μg/ml and 5 μg/ml), β-elemene significantly inhibited cell migration and invasion of SGC7901/ADR cells. The human MMP antibody array indicated that β-elemene could regulate almost all proteins of the MMP family, and changes of MMP-2 and MMP-9 were the most obvious. Western blotting showed an increase of E-cadherin and decrease of vimentin in β-elemene-treated cells. Downregulation of transcription factor ZEB1 and ZEB2 was also detected. Treatment of SGC7901/ADR cells with β-elemene led to downregulation of Akt, ERK, and EGFR phosphorylation, and significant upregulation of the E3 ubiquitin ligase, Cbl-b. Changes of these proteins were confirmed in xenograft tumors. Hematoxylin and eosin staining showed significantly decreased numbers of metastatic tumor colonies in the lungs of nude mice injected with SGC7901/ADR cells and β-elemene compared with those only injected with SGC7901/ADR cells.

Conclusions: The results strongly suggest that β-elemene inhibits the metastasis of multidrug-resistant gastric cancer cells in vitro and in vivo by regulating the Cbl-b-EGFR-ERK/Akt signaling pathway. β-elemene may be a promising treatment for multidrug resistant human gastric cancer.

Citation Format: Ruoxi Yu, Mingming Deng, Huicong Song, Dan Zou, Ling Xu, Xiujuan Qu, Yunpeng Liu, Yuee Teng, Xuejun Hu, Ye Zhang. β-elemene inhibits the metastasis of multidrug-resistant gastric cancer cells through the Cbl-b-EGFR-ERK/Akt signaling pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4195.
Abstract 4197: Sulforaphane suppresses metastasis via autophagic degradation of cathepsin S in oral cancer cells
Authors: Lin Chiao-Wen , Chen Chang-Tai , Yang Shun-Fa
Published: August 2018

Sulforaphane has been demonstrated to exert numerous biological effects, such as neuroprotective, anti-inflammatory, and anticancer effects. However, the detailed effects of sulforaphane on human oral cancer cell metastasis and the underlying mechanisms remain unclear. In this study, we observed that sulforaphane attenuated SCC-9 and SCC-14 cell motility and invasiveness by reducing cathepsin S expression. Moreover, sulforaphane increased microtubule-associated protein 1 light chain 3 (LC3) conversion, and the knockdown of LC3 by siRNA increased cell migration ability. Mechanistically, sulforaphane inhibited the cell motility of cervical cells through the extracellular signal-regulated kinase (ERK1/2) pathway, and blocking of the ERK1/2 pathway reversed autophagy-mediated cell motility and CTSS inhibition. In conclusion, sulforaphane exhibits antimetastatic activity against oral cancer cells by repressing cathepsin S through the ERK1/2 signaling pathway. Thus, cathepsin S and LC3 may be new targets for oral cancer treatment.

Citation Format: Chiao-Wen Lin, Chang-Tai Chen, Shun-Fa Yang. Sulforaphane suppresses metastasis via autophagic degradation of cathepsin S in oral cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4197.
Abstract 4198: 2-Hydroxymelatonin shows antitumor activity against human colorectal cancer cells
Authors: Yang Yi , Zhou Rui , Park So-Yeon , Kim Kyung Keun , Kim Hangun
Published: August 2018

2-Hydroxymelatonin is a predominant hydroxylated melatonin metabolite in plants. To investigate whether it has potent cytotoxic effects on colorectal cancer cells, four colorectal cancer cell lines, Caco2, HCT116, DLD1, and CT26, were treated with 2-hydroxymelatonin and melatonin. 2-Hydroxymelatonin had a much lower IC50 value than melatonin in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytotoxic effect of 2-hydroxymelatonin was much stronger than that of melatonin at high concentrations (1000 or 2000 μM) in HCT116, DLD1, and CT26 cells, but only at intermediate concentrations (250 or 500 μM) in Caco2 cells. The cytotoxicity of 2-hydroxymelatonin was induced through activation of the apoptotic signaling pathway, as confirmed by Hoechst staining and Annexin V-FITC/propidium iodide double labeling of cells treated with a lethal dose (1 mM). However, sub-lethal doses of 2-hydroxymelatonin inhibited the invasive ability of Caco2 cells. Epithelial-mesenchymal transition (EMT) markers were significantly regulated by 2-hydroxymelatonin. Overall, the anti-cancer activity of 2-hydroxymelatonin is more potent than that of melatonin. Taken together, 2-hydroxymelatonin exhibits potent anti-cancer activity against human colorectal cancer cells via induction of apoptosis and inhibition of EMT.

Citation Format: Yi Yang, Rui Zhou, So-Yeon Park, Kyung Keun Kim, Hangun Kim. 2-Hydroxymelatonin shows antitumor activity against human colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4198.
Abstract 4201: Dp44mT, an iron chelator, suppresses cell growth and invasion by inducing N-myc downstream-regulated gene 1 and inhibiting Wnt/β-catenin signaling in human glioma cells
Authors: Luo Peng , Zhang Ye , Jiang Yang , Xu Ying , Jing Zhitao
Published: August 2018

The iron-chelating agent di-2-pyridylketone 4, 4-dimethyl-3-thiosemicarbazone (Dp44mT) can inhibit cell growth and invasion in some human cancers. However, the precise molecular mechanisms involved remain obscure in the context of glioma. Recent evidence suggests that N-myc downstream-regulated gene (NDRG)1 has an oncogenic role function. In the present study, we investigated whether Dp44mT regulates the NDRG1 expression and thereby inhibits glioma cell growth and invasion. We found that Dp44mT inhibited glioma proliferation and invasion in vitro, and reduced average tumor size and wet weight in a xenograft model. Dp44mT overexpression increased NDRG1 expression; NDRG1 silencing stimulated cell growth and invasion and triggered epithelial-to-mesenchymal transition (EMT). We also found that Dp44mT exerts its anti-tumor activity via inhibition of Wnt/β-catenin signaling. Taken together, these findings suggest that the iron chelator Dp44mT inhibits glioma development and progression both in vitro and in vivo by inducing the expression of NDRG1 and suppressing Wnt/β-catenin signaling. Thus, targeting NDRG1 with Dp44mT can be an effective treatment for glioma.

Citation Format: Peng Luo, Ye Zhang, Yang Jiang, Ying Xu, Zhitao Jing. Dp44mT, an iron chelator, suppresses cell growth and invasion by inducing N-myc downstream-regulated gene 1 and inhibiting Wnt/β-catenin signaling in human glioma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4201.
Abstract 4244: Hookah pipe awareness and perceived harmfulness: Prevalence, correlates, and association with smoking cessation outcomes
Authors: Mohammed Kahee A. , Schoen Martin W. , Osazuwa-Peters Nosayaba , Subramaniam Divya S. , Arnold Lauren D. , Hinyard Leslie , Burroughs Thomas E.
Published: August 2018

Introduction: Hookah smoking is becoming an increasingly popular choice of tobacco use and is remarkably common among young adults in the United States. This study aimed to evaluate the prevalence and correlates of hookah awareness and perceived harmfulness among US adults and to examine its association with cigarette smoking quit intention and attempt. Methods: Data from the Health Information National Trends Survey 2013 to 2017 were analyzed. The sample included 6,711 adults aged ≥ 18 years. Weighted multivariable logistic regression analyses were performed and adjusted for age, gender, race/ethnicity, education, household income, region, and cigarette smoking status. Results: Overall, 78% of US adults were aware of hookah. Of these, 72% believed hookah pipes were equally harmful as cigarettes, whereas 17.6% believed otherwise. Those who were aware of hookah were less likely to be older (aOR=0.12, 95% CI=0.09 - 0.16), Black (aOR=0.56, 95% CI=0.43 - 0.72) and Hispanic (aOR=0.61, 95% CI=0.48 - 0.79), and lesser-educated (aOR=0.40, 95% CI=0.29 - 0.54) adults. Compared to never smokers, former smokers were 64% (95% CI=1.37 - 1.96) more likely to be aware of hookah. Among those aware of hookah, older (aOR=0.49, 95% CI=0.37 - 0.65), Black (aOR=0.73; 95% CI=0.58 - 0.97), and lesser-educated (aOR=0.69; 95% CI=0.48 - 0.95) were less likely to perceive hookah as less harmful than cigarettes. Those who perceived hookah to be just as harmful as cigarettes were less likely to try to quit cigarette smoking in the past year (aOR=0.49, 95% CI=0.25 - 0.93). Those who perceived hookah to be less harmful than cigarettes were more likely to consider quitting cigarette smoking in the next 6 months (aOR=2.86, 95% CI=1.29 - 6.33). Conclusions: Young, White, and college graduate adults are more likely to believe that hookah smoking is less harmful that cigarettes. These disparities can be used to target behavioral interventions aimed at increasing individuals' perceived risk, knowledge, and perceived harmfulness of hookah smoking.

Citation Format: Kahee A. Mohammed, Martin W. Schoen, Nosayaba Osazuwa-Peters, Divya S. Subramaniam, Lauren D. Arnold, Leslie Hinyard, Thomas E. Burroughs. Hookah pipe awareness and perceived harmfulness: Prevalence, correlates, and association with smoking cessation outcomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4244.
Abstract 4252: Antihypertensive medication use and ovarian cancer survival
Authors: Huang Tianyi , Sood Anil K. , Tworoger Shelley S.
Published: August 2018

Background: Both experimental and clinical studies suggest that beta-blockers, a common antihypertensive agent, may reduce ovarian tumor aggressiveness, inhibit angiogenesis and metastasis, and improve survival. However, no study has considered the potential role of other antihypertensive medications in conjunction with beta-blockers in ovarian cancer survival. Methods: We evaluated the associations of pre-diagnostic (n=899) and post-diagnostic (n=683) use of individual antihypertensive medications with ovarian cancer survival in the Nurses' Health Study (NHS; diagnosed between 1994-2012) and NHSII (diagnosed between 2001-2013), with at least 4 years of follow-up for death. Cox proportional hazards models were used to estimate hazard ratios (HR) for ovarian cancer mortality according to antihypertensive medication use. Results: In analyses of individual drugs adjusted for age, BMI and tumor characteristics, pre-diagnostic use of calcium-channel blockers (CCB) was associated with higher ovarian cancer mortality (HR: 1.52; 95% CI: 1.15, 2.00), whereas lower mortality was observed for post-diagnostic use of beta-blockers (HR: 0.76; 95% CI: 0.58, 1.01) and angiotensin-converting enzyme (ACE) inhibitors (HR: 0.64; 95% CI: 0.44, 0.93). While hypertension itself was not associated with ovarian cancer mortality (HR: 0.99; 95% CI: 0.83, 1.17), the associations between antihypertensive medications and ovarian cancer mortality were suggestively stronger among women with history of hypertension. Conclusion: Our findings suggest that post-diagnosis use of beta-blockers and ACE inhibitors is associated with lower ovarian cancer mortality and pre-diagnosis use of CCBs may be associated with higher mortality. These results warrant further investigation, and ongoing work is exploring whether the observed associations may be explained by changes in antihypertensive medication prescription after ovarian cancer diagnosis or changes in overall prescription patterns over time.

Citation Format: Tianyi Huang, Anil K. Sood, Shelley S. Tworoger. Antihypertensive medication use and ovarian cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4252.
Abstract 4277: Modeling selectin-coated microprobe adhesion to selectin ligands heterogeneously expressed on cancer tissues
Authors: Martin Eric , Goetz Douglas , Burdick Monica
Published: August 2018

The transition to an era of functional glycomics has created a need for the development of novel techniques to assess complex glycoconjugate cellular adhesion molecules (e.g., selectin ligands) that may be involved in capturing and mediating the adhesion circulating tumor cells to distant sites. Cell line, knockout, and selectin antagonist evidence suggests that selectin/selectin-ligand interactions are involved in metastasis. However, identification and characterization of functional selectin ligand expression on cancer tissue (i.e., CTC origin site) remains challenging due to the inherent heterogeneity of tissues magnified by the "catch-slip" and stochastic nature of selectin/selectin-ligand bonds. We have developed a flow-based assay known as dynamic biochemical tissue analysis (DBTA) that involves the perfusion of selectin-coated microprobes over tissues at physiologic wall shear rates. Using DBTA, the expression of functional selectin ligands has been detected (i.e., specific binding and rolling of selectin-coated microprobes) on tissue from multiple solid tumors at primary and metastatic sites. Although DBTA provides evidence that multiple types of cancer can express complicated glycoconjugate structures (selectin ligands) that are able to bind to selectins in a shear-dependent manner, the challenge of the assay is in the analysis of the large amounts of image sequence data generated. This analysis is further complicated by the dynamic behavior of selectin-coated microprobe adhesion to selectin ligands expressed on a heterogeneous cancer tissue surface. To extract the biophysical underpinnings towards the development of this prospective in vitro diagnostic, a mathematical model was devised to refine the design space of this flow assay. The model is semi-empirical and consists of a coupled set of stochastic, 4D partial differential equations that account for the transport of probes to the tissue surface as well as the dynamics of probe adsorption to a heterogeneous tissue surface. Empirical data were obtained by processing image sequences with machine-learning, template-matching algorithms to conduct image segmentation, followed by probe tracking over time using a program written in Python. The empirical data displayed a stochastic adsorption profile and showed agreement with the model equations that were solved numerically using a finite difference scheme written in C++. Altogether, this approach is able to successfully bridge the gap between the seemingly random rolling interactions observed in the flow assay and the underlying physical mechanisms.

Citation Format: Eric Martin, Douglas Goetz, Monica Burdick. Modeling selectin-coated microprobe adhesion to selectin ligands heterogeneously expressed on cancer tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4277.
Abstract 4279: The genomic profile investigation of metastatic triple-negative breast cancer for precision medicine achievement
Authors: Jang Wooyeong , Kim Jihyun , Yang Hanna , Kwon Youngmee , Lee Keun Seok , Sim Sung Hoon , Kong Sun-Young , An Kyounghee , Park In Hae , Park Charny
Published: August 2018

Objective: The molecular profile of primary breast cancer has been studied associated with drug responses. Metastatic triple-negative breast cancer (mTNBC) is heterogeneous disease and there is no effective therapeutic target. We investigated the genomic profiles of mTNBC to find potential drug targets.

Methods: Metastatic breast cancer samples were collected for genomic analysis (fresh tissue, n=17; FFPE, n=28). We conducted both whole-exome sequencing and RNA-seq for these samples and validated genomic variants by Sanger sequencing. We built up pipelines for somatic mutation, copy number alteration, mRNA expression, and fusion gene analysis. Precise somatic mutations were additionally filtered out for FFPE without matched normal. In addition, we investigated the differences of genomic profiles of mTNBC with those of primary breast cancer from TCGA data.

Results: Most of somatic mutation profiles of mTNBC were similar with those of primary cancer. However, there were some specific alterations that were not found in primary tumor. TP53 (>40 %) was concordantly discovered with primary TNBC, but KDM6A (>20 %) was highly recurrent than other breast datasets. We ascertained the diversity of immune cell activity from mRNA expression analysis, and additional pathways also represented the variance within our mTNBC population, which was differentiated from those of primary breast cancer. In addition, we found two novel FGFR1/2 fusion in two cases and validated it by RT-PCR and Western blot.

Conclusion: We found specific genomic profiles of mTNBC that were distinct from those of primary tumor. Novel structural variants discovered in our dataset could be potential therapeutic targets for mTNBC patients.

Citation Format: Wooyeong Jang, Jihyun Kim, Hanna Yang, Youngmee Kwon, Keun Seok Lee, Sung Hoon Sim, Sun-Young Kong, Kyounghee An, In Hae Park, Charny Park. The genomic profile investigation of metastatic triple-negative breast cancer for precision medicine achievement [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4279.
Abstract 4288: The cell cycle gene regulatory DREAM complex is disrupted by oncogenic B-Myb
Authors: Iness Audra N. , Ananthapadmanabhan Varsha , Sesay Fatmata , Dozmorov Mikhail , Litovchick Larisa
Published: August 2018

The oncogene MYBL2 (encoding B-Myb) is a poor prognostic biomarker in many cancers. B-Myb interacts with the MuvB core of five proteins (LIN9, LIN37, LIN52, LIN53/RBBP4, and LIN54) to form the MMB (Myb-MuvB) complex and promotes expression of late cell cycle genes necessary for progression through mitosis. Both MYBL2 amplification and over-expression are associated with deregulation of the cell cycle and increased cell proliferation. Alternatively, by interacting with E2F4-DP1 and p130/p107, the MuvB core becomes part of the DREAM complex (DP, RB-like, E2F, and MuvB). The DREAM complex opposes MMB by globally repressing cell cycle genes in G0/G1, maintaining the cell in a quiescent state.  However, the specific mechanism by which B-Myb alters the cell cycle is not well understood. Herein, we show that B-Myb disrupts the DREAM complex by sequestration and stabilization of LIN52. Analysis of The Cancer Genome Atlas data revealed significant upregulation of DREAM and MMB target genes in breast and ovarian cancer with MYBL2 gain. Given that most of the DREAM target genes are not directly regulated by B-Myb, we investigated the effects of B-Myb on DREAM formation. We found that depletion of B-Myb results in increased DREAM formation in cancer cell lines, while its overexpression inhibits DREAM formation in non-transformed cells. Since the MuvB core subunit LIN52 is essential for assembly of both the DREAM and MMB complexes, we tested whether B-Myb disrupts DREAM by sequestering LIN52. Overexpression of LIN52 did not increase either DREAM or MMB formation, but instead increased the turnover rate of the endogenous LIN52 protein. Interestingly, co-expression of B-Myb increased the expression of both endogenous and overexpressed LIN52 while knockdown of B-Myb had an opposite effect. We found that regulation of LIN52 occurs at the protein level, and that activity of DYRK1A kinase, the enzyme that triggers DREAM complex formation by phosphorylating LIN52, is required for this regulation. These findings are the first to implicate B-Myb in the disassembly of the DREAM complex and offer further mechanistic insights for cancers with MYBL2 amplification. We conclude that B-Myb's oncogenic effects are not only secondary to increased mitotic gene expression by the MMB complex, but also broad disruption of cell cycle gene regulatory programs through compromised DREAM formation.

Citation Format: Audra N. Iness, Varsha Ananthapadmanabhan, Fatmata Sesay, Mikhail Dozmorov, Larisa Litovchick. The cell cycle gene regulatory DREAM complex is disrupted by oncogenic B-Myb [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4288.
Abstract 4289: Involvement of the miR-6883 family and the circadian rhythm gene PER1 in the DNA damage response (DDR) and chemosensitivity
Authors: Lulla Amriti R. , Lev Avital , Slifker Michael , Dicker David T. , El-Deiry Wafik S.
Published: August 2018

PER1 is a circadian clock protein known to play a role in the cell cycle by directly regulating levels of Wee1 and indirectly influencing levels of Cdc2 and Cyclin B1. PER1 interaction with CHK2 promotes apoptosis in response to DNA damaging agents and loss of PER1 promotes chemoresistance. Expression of PER1 is found to be lost in most CRC tumors and restoring it sensitizes CRC cell lines to DNA damaging chemotherapeutic agents. However, the regulation of PER1 and its mechanism of repression in CRC remains unknown. We recently discovered and characterized miR-6883-5p, which is an intronic miRNA in the PER1 gene. Since PER1 is lost in most CRC it is suggested that the expression of miR-6883-5p is also lost. We showed that restoring the expression of miR-6883-5p via mimics induces G1-arrest and subsequent cell death in CRC cell lines. Similar to the overexpression of PER1, expression of miR-6883-5p with mimics increased the sensitivity of CRC cell lines to chemotherapeutic agents such as irinotecan and 5-FU. miR-6883-5p is a direct negative regulator of CDK4 and CDK6 and the downstream G1-S transition via RB. Our ongoing studies are characterizing molecular targets of miR-6883-5p and its role in the DNA damage response (DDR). FOXM1 is a downstream effector of CDK4 that plays a role in the DDR. Downregulation of FOXM1 sensitizes cells to DNA damage and restores chemosensitivity. We are further evaluating the direct effects of miR-6883-5p on FOXM1. FOXM1 is a member of the forkhead box (FOX) transcription factor family, expressed exclusively in proliferating cells. Its upregulation in different tumor types, including CRC promotes cell proliferation, EMT and chemoresistance. Interestingly, FOXM1 is also a repressor of the clock gene CRY2. Here, we hypothesize that miR-6883-5p mediated targeting of FOXM1 is crucial for the DDR, and, further, like CRY2, FOXM1 might have a role in regulating PER1 and thus miR-6883-5p endogenous levels. We report that miR-6883-5p levels are increased following exposure of tumor cells to chemotherapeutic agents that cause DNA damage. We are further elucidating the role of FOXM1 in the induction of miR-6883-5p under the DDR, and propose that induction of miR-6883-5p may provide a novel mechanism for tumor growth arrest in chemotherapy-exposed cells.

Citation Format: Amriti R. Lulla, Avital Lev, Michael Slifker, David T. Dicker, Wafik S. El-Deiry. Involvement of the miR-6883 family and the circadian rhythm gene PER1 in the DNA damage response (DDR) and chemosensitivity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4289.
Abstract 4294: SUMOylation promotes nuclear import and stabilization of polo-like kinase 1 to support its mitotic function
Authors: Wen Donghua , Wu Jianguo , Wang Lei , Fu Zheng
Published: August 2018

As a pivotal mitotic regulator, polo-like kinase 1 (PLK1) is under highly coordinated and multi-layered regulation. However, the regulatory pathways that control PLK1's activity and function have just begun to be elucidated. PLK1 has recently been shown to be functionally modulated by post-translational modifications (PTMs), including phosphorylation and ubiquitination. Herein, we report for the first time that a novel PTM, SUMOylation, plays an essential role in regulating PLK1's mitotic function. We found that Ubc9 was recruited to PLK1, upon initial phosphorylation and activation by CDK1/cyclin B. By in vivo and in vitro SUMOylation assays, PLK1 was identified as a physiologically relevant SUMO-targeted protein, preferentially modified by SUMO-1. We further showed that K492 on PLK1 was the lysine residue essential for SUMOylation. SUMOylation not only led to PLK1's nuclear import, but also significantly increased its protein stability by preventing the recruitment of APC/Ccdh1, the ubiquitin E3-ligase of PLK1. Resembling Ubc9 deficiency, cells expressing PLK1-K492R mutant exhibited mitotic aberrations characterized by prolonged mitotic progression, and misaligned and/or mis-segregated chromosomes, which could be rescued by reintroducing SUMOylation modification to PLK1. Collectively, our findings suggest that SUMOylation is another important regulatory mechanism governing PLK1's mitotic function to ensure normal mitotic progression and genomic integrity.

Citation Format: Donghua Wen, Jianguo Wu, Lei Wang, Zheng Fu. SUMOylation promotes nuclear import and stabilization of polo-like kinase 1 to support its mitotic function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4294.