bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2972: SPINK1, a soluble factor released by the therapy-damaged tumor microenvironment, promotes prostate cancer resistance
Authors: Chen Fei , Fu Da , Lam Eric , Sun Yu
Published: July 2017

Cancer evolution is driven by not only the genetic and/or epigenetic alterations of cancer cells, but also diverse factors that are derived from the surrounding tumor microenvironment (TME). Upon chemotherapy or radiation, stromal cells in the TME become senescent and develop a senescence-associated secretory phenotype (SASP) that is characterized by secretion of a large number of cytokines, chemokines, growth factors, and proteases. In most cases, the SASP is functionally regulated by the DNA damage secretory program (DDSP) and pathophysiologically responsible in vivo for disease exacerbation. We recently disclosed significant upregulation of the serine protease inhibitor Kazal type I (SPINK1) in primary normal human prostate fibroblasts after exposure to DNA damaging agents. SPINK1 plays critical roles in cancer cell proliferation, survival and motility in multiple human malignancies, but its influence as a soluble TME-associated factor on cancer progression remains unknown. In this study, we performed a series of molecular and cellular studies to define the biological roles of SPINK1 in an activated TME. Promoter analysis indicated that SPINK1 expression in the fibroblasts is regulated by multiple transcriptional factors including the NF-κB complex in response to genotoxic stress. Fibroblast-derived SPINK1 can significantly enhance the aggressiveness of prostate cancer cells including accelerated proliferation, increased migration, elevated invasion and more importantly, enhanced chemoresistance. SPINK1 triggers a typical epithelial-mesenchymal transition (EMT) in cancer cells, a process mediated by EGFR/PI3K/Akt and MAPK/Erk signaling pathways. Consistent with the in vitro data, our in vivo studies suggested that SPINK1 expression in the prostate TME substantially promoted cancer survival and disease progression. Clinical investigation revealed increased expression of SPINK1 in the stroma of multiple organ types including the prostate, lung and breast of cancer patients after chemotherapy, implying the systemic induction of SPINK1 by anticancer agents. Overall, our study demonstrates that SPINK1 is a soluble biomarker of therapeutically damaged TME and represents a potentially exploitable molecular target in human prostate cancer clinics.

Note: This abstract was not presented at the meeting.

Citation Format: Fei Chen, Da Fu, Eric Lam, Yu Sun. SPINK1, a soluble factor released by the therapy-damaged tumor microenvironment, promotes prostate cancer resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2972. doi:10.1158/1538-7445.AM2017-2972
Abstract 2976: Critical role of spatial location of hypoxia and its association with astrocytes in the resistance of brain tumor to therapy
Authors: Lin Chiu-Min , Chiang Chi-Shiun
Published: July 2017

Many reports have shown that hypoxia and gliosis could promote tumor cells by shielding from the immune response and relapsing, but their roles on brain tumor therapies are still unclear. Using an invasive murine astrocytoma tumor model, ALTS1C1, we found that tumor invasion front is associated with a specific hypoxia region, naming tumor peripheral hypoxia, contributes to brain tumor therapy resistant and may be responsible for tumor recurrence after the therapy. Using this tumor model, we found that the overgrowing tumor caused the shortage of vessels and resulted in the hypoxia in the early stage of tumor progression, which is conventionally called chronic hypoxia or avascular hypoxia. When tumor continues to grow, a rim of hypoxia area was formed at tumor edge and subsequently activated nearby astrocytes. At the same time, the outward reactive astrocytes enhanced tumor invasion into normal parenchyma tissues. As a result, a specific hypoxia was produced in tumor peripheral, which has relative high microvascular density (MVD) and is associated with highly reactive astrocytosis. We explored the role of this region on the response to therapies. By quantitative counting the apoptotic tumor cells across the tumor cross-section following radiation- or chemo-therapy, we found that cells at the active astrocytic region (the peripheral region) are more resistant than cells in tumor core. These results indicate that the peripheral hypoxia, not the chronic hypoxia, is the main cause of the failure of brain tumor therapy. Most importantly, we found that the formation of tumor peripheral hypoxia might be associated with the activation of astrocytes. Therefore, tactics that can suppress astrocytosis and prevent the formation of peripheral hypoxia may be alternative approaches for complementing the shortage of traditional brain tumor therapy.

Citation Format: Chiu-Min Lin, Chi-Shiun Chiang. Critical role of spatial location of hypoxia and its association with astrocytes in the resistance of brain tumor to therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2976. doi:10.1158/1538-7445.AM2017-2976
Abstract 2985: Interaction between the malignant melanoma cell of the primary lesion and the metastatic lesion
Authors: Hatano Takaharu , Motomura HIsashi , Fujikawa Heishiro , Yashiro Masakazu , Kitayama Kishu
Published: July 2017

Introduction: The prognosis of patients with malignant melanoma is extremely poor because of the frequent metastasis. We have occasionally experienced the clinical cases that malignant melanoma patients rapidly developed distant metastases after the surgical resection of primary cancer lesion. These cases suggested that a primary tumor may control a metastatic tumor. We hypothesized that primary melanoma cells might produce a factor(s) which regulate the progression of metastatic melanoma cells. Then we investigated the growth and invasion interaction between primary malignant melanoma cells and high metastatic melanoma cells. Materials and methods: We used two malignant melanoma cell lines, B16 as a parent primary melanoma cell line and a selected daughter cell line B16/BL6 with high metastatic ability. We investigated the invasive interaction between the parent B16 cells and daughter B16/BL6 cells in vitro. The conditioned medium from B16 cells and B16/BL6 cells was added to B16 cells or B16/BL6 cells. Then we examined the effect of these conditioned medium on the motility and proliferation of melanoma cells by MTT assay or invasion assay at 24 hours and 72 hours after the addiction of the conditioned medium. Results:The conditioned medium from B16 cells significantly (p=0.02) suppressed the invasion ability of B16/BL6 cells at 24 hours after the addiction of the conditioned medium. In contrast, the invasion ability of B16 cells were not affected by the conditioned medium from B16/BL6 cells at 24 hours. Each conditioned medium did not affect on the proliferation of both melanoma cell lines. On the other hand, at 72 hours after the addiction of the conditioned medium from B16 cells significantly (p=0.000003) suppressed the growth of B16/BL6 cells. Conclusion: Primary melanoma cells might down-regulate the progression of metastatic melanoma cells by a soluble factor(s).

Citation Format: Takaharu Hatano, HIsashi Motomura, Heishiro Fujikawa, Masakazu Yashiro, Kishu Kitayama. Interaction between the malignant melanoma cell of the primary lesion and the metastatic lesion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2985. doi:10.1158/1538-7445.AM2017-2985
Abstract 2998: Elotuzumab can costimulate NK cell responses by engaging SLAMF7
Authors: Pazina Tatiana , James Ashley Mentlik , MacFarlane Alexander W. , Bezman Natalie A. , Graziano Robert F. , Robbins Michael D. , Cohen Adam D. , Campbell Kerry S.
Published: July 2017

Elotuzumab (Elo) is an IgG1 monoclonal antibody targeting SLAMF7 (CS1, CRACC, CD319) protein, which is highly and uniformly expressed on multiple myeloma cells. Improved survival has been observed in multiple myeloma patients treated with Elo in combination with immunomodulatory drugs such as dexamethasone and lenalidomide. Previous work showed that the main mechanism of Elo action in vitro is CD16-mediated antibody dependent cellular cytotoxicity (ADCC) via Fc interaction with CD16 (FcγRIIIa) receptor on NK cells. However, SLAMF7 is also expressed on NK cells where it transmits an activating signal. We hypothesized that Elo can directly activate NK cells via SLAMF7 ligation. Utilizing non-fucosylated Elo that has higher affinity to CD16 and Elo mutant that has an Fc region mutation that abrogates binding to CD16, we confirmed that Elo promotes NK cell activation and degranulation in a CD16-dependent manner. Specifically, non-fucosylated Elo had higher potency, whereas Elo mutant did not stimulate degranulation or CD69 expression.

To test for co-stimulatory effects of Elo and Elo mutant we measured calcium signaling responses triggered by those antibodies in combination with antibodies to engage the activating receptors NKp46 and NKG2D. Elo or Elo mut alone had no effect on calcium signaling, but when added in combination with multimeric engagement of NKp46 and NKG2D both antibodies co-stimulated calcium signaling responses.

We conclude that Elo stimulates NK cells via interaction with CD16, but direct engagement with SLAMF7 can also transduce co-activating signals to potentiate calcium signals generated through NKp46 and NKG2D in a CD16-independent manner. Our results provide evidence that direct engagement with SLAMF7 by Elo has the potential to reduce the threshold of NK cell activation triggered through other activating receptors.

Citation Format: Tatiana Pazina, Ashley Mentlik James, Alexander W. MacFarlane, Natalie A. Bezman, Robert F. Graziano, Michael D. Robbins, Adam D. Cohen, Kerry S. Campbell. Elotuzumab can costimulate NK cell responses by engaging SLAMF7 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2998. doi:10.1158/1538-7445.AM2017-2998
Abstract 3012: Long-term aspirin use and total and cancer-specific mortality
Authors: Cao Yin , Stampfer Meir , Willett Walter , Spiegelman Donna , Manson JoAnn , Rimm Eric , Wang Molin , Ogino Shuji , Fuchs Charles , Giovannucci Edward , Chan Andrew
Published: July 2017

Background: Long-term follow of clinical trials of aspirin for the prevention of cardiovascular disease have shown that aspirin may be associated with a reduced risk of death from cancer, including colorectal, esophageal, and lung cancer, and possibly breast and prostate cancer. However, the potential benefits of aspirin use, at a range of doses and duration of use, on total and cancer-specific mortality have not been examined in large prospective cohort studies with long-term follow-up.

Methods: We examined the association between aspirin use and subsequent total and cancer-specific mortality, at a range of doses and duration of use, among 86,206 women in the Nurses' Health Study (1980-2012) and 43,977 men in the Health Professionals Follow-up Study (1986-2012). Participants with a history of cancer, heart disease, or stroke were excluded. Aspirin use was assessed at baseline and updated every 2 years with greater than 90% follow-up. Cox proportional hazards models were used to compute hazard ratios as estimates for age- and multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs).

Results: During up to 32 years of follow-up, 22,094 women and 14,749 men died, and 8,271 women and 4,591 men died of cancer. Compared with nonregular use, regular aspirin use was associated with lower risk of total mortality (multivariable-adjusted RR 0.93; 95% CI 0.90-0.95 for women and RR 0.89; 95% CI 0.86-0.93 for men), which was primarily due to a lower risk of dying from any cancer (RR 0.93; 95% CI 0.89-0.97 for women and RR 0.85; 95% CI 0.80-0.90 for men), especially colorectal cancers (RR 0.69; 95% CI 0.59-0.81 for women and RR 0.70; 95% CI 0.57-0.85 for men), breast cancers (RR 0.89; 95% CI 0.79-0.99), prostate cancers (RR 0.77; 95% CI 0.65-0.90), and lung cancers in men (RR 0.86; 95% CI 0.74-0.99). The benefit of aspirin on cancer mortality appeared evident with use of at least 0.5 to 1.5 standard aspirin tablets per week for both men and women; and the minimum duration of regular use associated with lower cancer mortality was 6 years.

Conclusions: Long-term aspirin use was associated with reduced risk of total mortality, primary due to reduced risk of dying from cancers.

Citation Format: Yin Cao, Meir Stampfer, Walter Willett, Donna Spiegelman, JoAnn Manson, Eric Rimm, Molin Wang, Shuji Ogino, Charles Fuchs, Edward Giovannucci, Andrew Chan. Long-term aspirin use and total and cancer-specific mortality [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3012. doi:10.1158/1538-7445.AM2017-3012
Abstract 304: CLIC1 membrane insertion is a pivotal regulator of glioblastoma stem cell G1-S transition by promoting an increase of chloride permeability
Authors: Verduci Ivan , Carlini Valentina , Raciti Federica M. , Conti Matteo , Barbieri Federica , Florio Tullio , Mazzanti Michele
Published: July 2017

Glioblastoma (GBM) is the most aggressive and lethal brain tumor and, despite aggressive surgery and adjuvant radiotherapy and/or chemotherapy, the prognosis remains invariantly poor. As for most of solid and hematological malignancies, it was demonstrated that the bulk of tumor cells in GBM is generated by a rare fraction of self-renewing, multipotent cancer stem cells (CSCs) and the persistence of CSCs within the tumor mass is considered the main determinant of GBM development, progression, recurrence and radio- or chemoresistance. Thus, one of the main goals of current research is to identify specific biological mechanisms or intracellular pathways of CSCs whose pharmacological targeting might affect their survival and proliferation. In particular, little is known about the possibility that the molecular mechanisms underlying cell-cycle control in GBM CSCs are endowed with specific and unique features as compared with normal cells. Our study is based on the observation that GBM cells express higher levels of chloride intracellular channel 1 (CLIC1) as compared to nonmalignant brain cells and that in CSCs CLIC1 is mainly localized in the membrane forming an active channel. Conversely, in physiological conditions CLIC1 is mainly a cytoplasmic protein only transiently translocating to the membrane. We recently showed that the different level of activity of CLIC1 in CSCs and normal mesenchymal stem cells confers CLIC1-targeting drugs (for example the biguanide metformin) selective cytotoxicity toward tumor cells. Here we report, that in response to stress conditions, CLIC1 increases the probability to modify its structure going from a cytoplasmic hydrophilic form to a transmembrane conformation. Once in the membrane, CLIC1 acts as a chloride permeability, participating, together with NADPH oxidase, to the generation of a chronic state of oxidative stress that favor the transition between G1 and S phase. The peculiarity of CLIC1 exposure on the external face of the GMB CSC plasma membrane support the idea that this protein could represent a main determinant of the cell cycle progression in this tumor cell subpopulation and thus an accessible and relevant pharmacological target to eradicate CSCs in GBM.

Note: This abstract was not presented at the meeting.

Citation Format: Ivan Verduci, Valentina Carlini, Federica M. Raciti, Matteo Conti, Federica Barbieri, Tullio Florio, Michele Mazzanti. CLIC1 membrane insertion is a pivotal regulator of glioblastoma stem cell G1-S transition by promoting an increase of chloride permeability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 304. doi:10.1158/1538-7445.AM2017-304
Abstract 3046: Identification of lncRNAs involved in regulation of androgen receptor splice variants in prostate cancer through CRISPR-Cas9-based screen
Authors: Ho Tsui-Ting , Koirala Pratirodh , Zhou Nanjiang , Mo Yin-Yuan
Published: July 2017

Prostate cancer is the second leading cause of death in men in the USA. Despite the high initial response rates to androgen deprivation therapy (ADT), these tumors ultimately develop the resistance, i.e., castration-resistant prostate cancer (CRPC). One of the contributing factors is constitutive expression of androgen receptor (AR) splice variants such as AR3, a major splice variant identified in clinical specimens. However, little is known about long non-coding RNAs (lncRNAs) on regulation of AR splicing. In this study, we generate CRISPR/Cas9-based libraries against a focus group of lncRNAs and an AR3 mini-gene reporter to identify lncRNAs involved in regulation of AR splicing. The principles of this screening system is that only sgRNAs capable of promoting AR3 expression will be enriched in SAM (Synergistic Activation Mediator) library, whereas these clones are lost from the knockout gRNA library after selection. This screen identifies several candidate lncRNA sgRNAs and dual gRNAs (targeting Lnc-DC/ Har1B/ LINC00568/ DHRS4-AS1/ SNHG5). Further characterization confirms the regulation of their corresponding endogenous genes and AR3 expression. Importantly, overexpression of Lnc-DC increases AR3 level and enhances tumor cell growth in response to androgen deprivation. Moreover, while ectopic expression of DHRS4-AS1 increases, DHRS4-AS1 knockout suppresses AR3. Finally, rescue experiments restore the ability of DHRS4-AS1 to induce AR3, further supporting a role for Lnc-DC and DHRS4-AS1 in AR3 regulation. Together, we demonstrate that the CRISPR/Cas9-based screening system provides a powerful tool for lncRNA research. As a result, these lncRNAs may serve as biomarkers to predict the response to ADT or therapeutic targets for treatment of CRPC.

Citation Format: Tsui-Ting Ho, Pratirodh Koirala, Nanjiang Zhou, Yin-Yuan Mo. Identification of lncRNAs involved in regulation of androgen receptor splice variants in prostate cancer through CRISPR-Cas9-based screen [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3046. doi:10.1158/1538-7445.AM2017-3046
Abstract 3057: Gut microbiome controls liver metastasis
Authors: Ma Chi , Fu Qiong , Greten Tim
Published: July 2017

Aim: The gut microbiome can modify tumor immunity and has been suggested to be involved in the development of liver cancer. However, it remains unknown how the gut microbiome controls hepatic immune responses. This study was designed to exam the effect of the gut microbiome on liver antitumor immunity, and to study potential mechanism.

Experimental procedure: Antibiotic cocktail in drinking water was given to remove mouse gut microbiota. Control mice were kept on regular water. EL4 thymoma cells were injected s.c. to induce spontaneous liver metastasis. B16 melanoma and CT26 colon cancer cells were injected intrasplenically to form liver metastasis. Lung metastasis was induced by tail injection of tumor cells.

Results: Antibiotic cocktail efficiently depleted gut bacteria. Removing gut commensal bacteria did not affect the growth of primary s.c. tumors, but impaired formation of liver metastasis in different models. The inhibitory effect on liver metastasis by removing gut microbiome was found after intrasplenic injection of tumor cells to form liver metastasis using both B16 melanoma and CT26 colon cancer tumor cells. Interestingly, formation of lung metastasis caused by tail vein injection of B16 cells was not impaired by antibiotics treatment, suggesting a liver specific effect. The inhibition of liver metastasis by antibiotic treatment was absent in Rag1 knockout mice, suggesting that the mechanism is mediated by the adaptive immune system.

Conclusion: Our results suggest that the gut microbiome affects the liver immune microenvironment and modulates antitumor immunity.

Citation Format: Chi Ma, Qiong Fu, Tim Greten. Gut microbiome controls liver metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3057. doi:10.1158/1538-7445.AM2017-3057
Abstract 3075: Analysis of microRNA profiles involved in the resistance to trifluridine
Authors: Tsunekuni Kenta , Koseki Jun , Konno Masamitsu , Asai Ayumu , Nishida Norihiro , Colvin Hugh , Kawamoto Koichi , Doki Yuichiro , Mori Masaki , Ishii Hideshi
Published: July 2017

Background: Trifluridine (FTD) is a key component of the novel oral antitumor drug trifluridine/tipiracil, which was approved for the treatment of patients with metastatic colorectal cancer refractory to standard chemotherapies. A comprehensive analysis of miRNA profiles was performed in cell lines resistant to FTD established by ourselves, in order to explore the underlying mechanisms of resistance to the drug.

Method: We established subline resistance to FTD through continuous administration and increasing dose of the drug for 5 months using the colorectal cancer cell line DLD-1. Total RNA was extracted at intervals whilst establishing FTD resistant sublines, and miRNA expression was analyzed by microarray. The expression of miRNA that was significantly downregulated in the FTD resistant subline was knocked down to test its involvement in resistance to FTD. Cell viability was evaluated by crystal violet cytotoxicity test.

Results: The established FTD-resistant sublines showed more than 22-fold higher resistance to FTD and no cross-resistance to 5-FU. miRNA and mRNA clustered in the genome locus located in chromosome 9, 9p22.32 were downregulated in the FTD-resistant cell line, one of which was the miRNA let-7d-5p, which is one of the let-7 family and is known to target oncogenes and several key components of the cell cycle and cell proliferation. Anti-let-7d-5p treated DLD-1 was less sensitive to FTD than compared to control. The IC50 values of FTD were 16.8 µM and 7.6 µM for the anti-let-7d-5p treated cells and control respectively. On the other hand, overexpression of let-7d-5p in DLD-1 using let-7d-5p mimic increased the sensitivity to FTD compared to control. The IC50 values of FTD were 3.7 µM and 13.9 µM in the let-7d-5p overexpression cells and control respectively. 5FU sensitivity was only altered slightly in anti- let-7d-5p treated or let-7d-5p mimic treated cells. These data suggest that let-7d-5p is more relevant to sensitivity for FTD than that of 5FU.

Conclusion: Let-7d-5p expression level influenced FTD sensitivity more effectively than 5FU. It suggests that the let-7d-5p is a potential predictive marker for trifluridine/tipiracil treatment in the clinical setting.

Citation Format: Kenta Tsunekuni, Jun Koseki, Masamitsu Konno, Ayumu Asai, Norihiro Nishida, Hugh Colvin, Koichi Kawamoto, Yuichiro Doki, Masaki Mori, Hideshi Ishii. Analysis of microRNA profiles involved in the resistance to trifluridine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3075. doi:10.1158/1538-7445.AM2017-3075
Abstract 3083A: C6-ceramide nanoliposomes sensitize paclitaxel resistant ovarian cancer cells to chemotherapy treatment
Authors: Llaneza Danielle C. , Deering Tye G. , Sherwood Samantha G. , Cornelison John R. , Kester Mark , Landen Charles N.
Published: July 2017

Ovarian cancer is the fifth leading cause of cancer deaths among women, and the majority of women are diagnosed at advanced stages resulting in poorer outcomes and survival rates. One of the driving forces behind these outcomes is the development of chemoresistance, and subsequent proliferation and invasion of tumor cells. In a patient-derived xenograft model of ovarian cancer, we identified the sphingosine pathway as significantly enriched in tumors after treatment with conventional chemotherapy. In order to target the sphingosine pathway, we investigated the potential effects of combining paclitaxel with C6-ceramide nanoliposomes in paclitaxel-resistant ovarian cancer cell lines, HeyA8-MDR and SKOV3-TR. Ceramide has been shown to be a key player in several processes important for tumor suppression including apoptosis, autophagy, and cell cycle arrest. We administered paclitaxel and C6-ceramide to HeyA8-MDR and SKOV3-TR cell lines in vitro and measured cell viability and expression of apoptotic and autophagic proteins. Results showed that in both cell lines, C6-ceramide significantly decreases the IC50 dose of paclitaxel, compared to control ghost nanoliposome treated cells. The IC50 of paclitaxel decreased in HeyA8-MDR cells from 400nM to 150nM, and in SKOV3-TR cells from 1000nM to 450nM. Western blot analyses indicate that combination treatment increases expression of apoptotic (cleaved caspase-3) factors in HeyA8-MDR cells, and autophagic (LC3) factors in SKOV3-TR cells, over single agent treatment or control. Paclitaxel is known to increase expression of apoptotic factors while decreasing expression of autophagic factors. Ceramide may increase both apoptotic and autophagic factors. In an orthotopic mouse model with the HeyA8-MDR line, combination treatment of paclitaxel and C6-ceramide resulted in significantly decreased tumor burden (1.38g +/- 0.74), compared to control ghost (p = 0.022, 2.81g +/- 1.57), C6-ceramide alone (p = 0.078, 2.50g +/- 1.58), and paclitaxel alone (p = 0.005, 2.48g +/- 0.75) groups. The combination of C6-ceramide and paclitaxel may prove useful in elucidating and targeting underlying chemoresistance mechanisms in ovarian cancer.

Citation Format: Danielle C. Llaneza, Tye G. Deering, Samantha G. Sherwood, John R. Cornelison, Mark Kester, Charles N. Landen. C6-ceramide nanoliposomes sensitize paclitaxel resistant ovarian cancer cells to chemotherapy treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3083A. doi:10.1158/1538-7445.AM2017-3083A
Abstract 3089: Combining MEK and HDAC inhibitors as a therapeutic strategy to promote differentiation of colorectal cancer
Authors: Jenkins Laura J. , Luk Ian Y. , Tse Janson W. , Mooi Jennifer , Dhillon Amardeep S. , Mariadason John M.
Published: July 2017

The five-year survival rate for patients with metastatic colorectal cancer is less than 15%, necessitating an urgent need to develop novel therapeutic strategies for this disease. Loss of differentiation is associated with worse overall survival in colorectal cancer, suggesting that strategies to re-induce differentiation may provide clinical benefit. Differentiation therapy is effective in the treatment of acute promyelocytic leukemia but whether this approach can be efficacious in treating colorectal cancer is unknown. Inhibitors of the MAPK signaling pathway including the MEK inhibitor Trametinib can induce markers of differentiation in colorectal cancer cells. Trametinib also induces expression of Cdx-2, a known driver of colonic cell differentiation. Similarly, histone deacetylase inhibitors (HDACi) induce markers of differentiation in multiple tumor cell lines, including colon cancer cells. The aim of this study was to assess the potential therapeutic benefit of combining MEK (Trametinib) and HDAC (Panobinostat) inhibitors to further promote differentiation in colorectal cancer cells, and to elucidate the mechanistic basis for this effect. Combination treatment of HT29 and T84 cells with Trametinib and Panobinostat significantly enhanced mRNA and protein expression of the differentiation markers Cadherin 17 (CDH17) and Keratin 20 (KRT20), compared to either agent alone. Trametinib also induced expression of Cdx-2, an effect that was enhanced upon combination treatment with Panobinostat. Notably, Cdx-2 knockdown attenuated CDH17 and KRT20 induction by the combination, establishing a direct role for Cdx-2 in differentiation induction by the Trametinib/Panobinostat combination. Concomitant with inducing differentiation, the drug combination also invoked more apoptosis than either agent alone. To validate these findings in vivo, HT29 cells grown as xenografts were treated with Trametinib and Panobinostat alone and in combination. Mice treated with the combination had significantly smaller tumours than mice treated with vehicle or either agent alone. Consistent with the in vitro findings, immunostaining of the tumour xenografts demonstrated a strong increase in CDH17, KRT20 and Cdx2 expression upon treatment with the drug combination. Collectively, this study highlights a drug combination strategy to re-induce differentiation for the treatment of colorectal cancers.

Citation Format: Laura J. Jenkins, Ian Y. Luk, Janson W. Tse, Jennifer Mooi, Amardeep S. Dhillon, John M. Mariadason. Combining MEK and HDAC inhibitors as a therapeutic strategy to promote differentiation of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3089. doi:10.1158/1538-7445.AM2017-3089
Abstract 3099: pH-regulated hydrophilicity/hydrophobicity-, surface charge-reversible and redox sensitive nanogels for anticancer drug delivery
Authors: Yang Hao , Wang Qin , Li Fuying , Zhu Yanhong , Gan Lu , Yang Xiangliang
Published: July 2017

Long circulation in blood, enhanced tumor accumulation and penetration, efficient cellular internalization and intracellular drug release are major challenges in the development of ideal anticancer drug delivery systems. Although several strategies have been reported to improve therapeutic efficacy, they mainly meet one or a few features which can not circumvent all the barriers. Here the stimuli-responsive zwitterionic nanogels were developed to overcome the sequential physiological barriers in cancer chemotherapy. The nanogels were constructed via a simple precipitation polymerization method by using temperature-sensitive monomer N-isopropylacrylamide (NIPAM) pH-responsive monomer methylallyl amine (MAA) and betaine-based zwitterionic monomer sulfobetaine methacrylate (SBMA) with in vivo anti-protein adsorption property as comonomers, and disulfide bonds-containing N, N'-bis(acryloyl) cystamine (BAC) as crosslinker. Volume phase transition temperature (VPTT) and surface charge of the prepared nanogels were precisely controlled by altering the feeding molar ratio of these comonomers. Remarkably, The nanogels possess ultra-pH sensitive hydrophilicity/hydrophobicity reversible property, in which the nanogels were hydrophilic in the blood (pH 7.4, 37 °C) for prolonged circulation, while they were rapidly switched to hydrophobic with similar size and surface charge at acidic tumor pH, resulting in enhanced tumor accumulation and penetration and strong internalization by normal cancer cells and CSCs. For efficient lysosomal escape and intracellular drug release, the nanogels were positively charged at lysosome pH, which allowed them to be transported into the cytosol where the loaded cargo DOX was released from the nanogels with the introduction of intracellular high GSH concentration to exert cytotoxicity. This study indicated that pH-dependent hydrophilicity/hydrophobicity-, surface charge-reversible and redox sensitive nanogels might be used as potential carriers for anticancer drugs, which provided a foundation for designing an effective drug delivery system for cancer therapy.

Note: This abstract was not presented at the meeting.

Citation Format: Hao Yang, Qin Wang, Fuying Li, Yanhong Zhu, Lu Gan, Xiangliang Yang. pH-regulated hydrophilicity/hydrophobicity-, surface charge-reversible and redox sensitive nanogels for anticancer drug delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3099. doi:10.1158/1538-7445.AM2017-3099
Abstract 3101: Hyperthermia at the single-cell level for disseminated cancer disease with immuno-magnetic nanoparticles
Authors: Kagawa Tetsuya , Kishimoto Hiroyuki , Ohara Toshiaki , Tazawa Hiroshi , Kagawa Shunsuke , Nagasaka Takeshi , Nohara Satoshi , Kato Ichiro , Sandhu Adarsh , Aono Hiromichi , Fujiwara Toshiyoshi
Published: July 2017

Hyperthermia using magnetic nanoparticles and alternating magnetic field is promising for cancer therapy. In most cases, the usefulness of this magnetic nanoparticle-based hyperthermia has been shown by applying magnetic nanoparticles to tumor tissue such as a subcutaneous tumor with direct injection technique; however, if the magnetic nanoparticles can be cancer cell-specifically delivered at the cellular level, the magnetic field hyperthermia would have the potential to treat various sorts of disseminated cancer diseases. The aim of this study is to prove this concept. Maghemite nanoparticles (MNPs) were conjugated with the anti-HER2 antibody (Tmab) for cancer targeting, and the Tmab-MNPs were applied to the co-culture flask containing both HER2-expressing breast cancer AU565 cells and normal fibroblast FEF3 cells. Thirty minutes later from the Tmab-MNPs administration, the medium was removed and the cells were washed to remove excess Tmab-MNPs. Prussian blue iron staining and immunostaining for Tmab showed co-localization of the maghemite nanoparticles and Tmab only on the cancer cells, which suggested that MNPs conjugation with Tmab was successful and that cancer specific delivery of MNPs at the cellular level was achieved in vitro. Moreover, application of alternating current magnetic field at 280 kHz for 1 hour caused apoptotic-like cell death only to cancer cells without any cell damage to normal fibroblast FEF3 cells. Intracellular hyperthermia using cancer-specific antibody-modified magnetic nanoparticles have the potential to be applied to the treatment of disseminated cancer diseases.

Citation Format: Tetsuya Kagawa, Hiroyuki Kishimoto, Toshiaki Ohara, Hiroshi Tazawa, Shunsuke Kagawa, Takeshi Nagasaka, Satoshi Nohara, Ichiro Kato, Adarsh Sandhu, Hiromichi Aono, Toshiyoshi Fujiwara. Hyperthermia at the single-cell level for disseminated cancer disease with immuno-magnetic nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3101. doi:10.1158/1538-7445.AM2017-3101
Abstract 3105: Targeting microRNAs in brain tumors with oligonucleotide nanoparticle conjugates
Authors: Grafals Nilmary , Quiñones Blanca I. , Vivas Pablo E. , Barletta Gabriel
Published: July 2017

Glioblastoma Multiforme (GBM) is the deadliest type of primary brain tumor being responsible for more than 14,000 deaths annually. The survival rate of GBM patients from time of diagnosis is 5 months if left untreated and 15 months with standard care of treatment. Despite great research efforts in the last 30 years, GBM survival rate has only increased by 2%. This is mostly due to high recurrence, treatment resistance, and the existence of the blood brain barrier (BBB) which restricts drug delivery to the tumor tissue. Therefore, the development of novel therapeutic modalities able to cross the BBB is urgently needed. MicroRNAs (miRNAs) are small (18-22 nt.) non-coding RNAs that regulate gene expression at the post-transcriptional level by binding to the 3’UTR of target mRNAs. Several dysregulated miRNAs have been reported in all tumor types, including GBM. Targeting oncogenic miRNAs with oligonucleotide miRNA inhibitors (OMIs) in vitro has shown therapeutic potential. However, in vivo administration requires the development of nanocariers capable of increasing the stability of OMIs in circulation and improving their delivery to target tissues. In addition, nanocarriers that can overcome the BBB are needed. The most studied and promising nanocarriers are gold nanoparticles (AuNP) and liposomes. While AuNPs have bioimaging and microscopy advantages, liposomes are clinically preferred. Therefore, we propose encapsulating OMIs-AuNPs to BBB targeted liposomes. In this study we present the characterization of miRNA inhibitors conjugated to AuNP. Briefly, 15 nm AuNP were functionalized to OMIs by two different techniques: Salt aging functionalization method and PEG and surfactant assisted conjugation method. Afterwards, both nanoconjugates were analyzed for particle size, zeta potential and loading capacity. The PEG and surfactant assisted functionalization proved to be superior in all of the analysis, resulting in 30 nm OMIs-AuNPs with a zeta potential of -8 mV and a loading capacity ratio of 64 oligonucleotides per AuNP. Further characterization studies such as cell internalization and cytotoxicity are under evaluation.

Citation Format: Nilmary Grafals, Blanca I. Quiñones, Pablo E. Vivas, Gabriel Barletta. Targeting microRNAs in brain tumors with oligonucleotide nanoparticle conjugates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3105. doi:10.1158/1538-7445.AM2017-3105
Abstract 3107: Targeting nanotherapeutics to the invasive glioblastoma margin via the cell surface receptor Fn14
Authors: Wadajkar Aniket S. , Dancy Jimena G. , Connolly Nina P. , Winkles Jeffrey A. , Woodworth Graeme F. , Kim Anthony J.
Published: July 2017

The most common and deadly form of primary brain cancer, glioblastoma (GBM), is characterized by significant intratumoral heterogeneity, high vascularity, and infiltrative growth. Delivering effective and sustained treatments to the invading GBM cells without worsening damage to the adjacent brain is a major challenge. We aim to develop an innovative, local delivery approach that couples chemotherapy-loaded brain penetrating biodegradable nanoparticles with tumor cell-targeting capabilities and convection enhanced delivery (CED). We formulated sub-100 nm sized, close to neutrally charged, poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticles with ~5% w/w carmustine (BCNU) payload coated with a fibroblast growth factor-inducible 14 (Fn14) antibody to specifically target Fn14-positive brain-invading tumor cells. We observed that PLGA surface modification using non-adhesive PEG allowed nanoparticles to rapidly move through brain tissue in ex vivo rat brain slices, potentially increasing the distribution of delivered therapeutics. We showed that Fn14-targeted nanoparticles were able to selectively bind to recombinant Fn14 but not to brain extracellular matrix proteins in surface plasmon resonance assays, as well as diffuse within brain tissue in multiple particle tracking assays. In addition, when administered intracranially, Fn14-targeted nanoparticles showed improved brain tumor retention in C57BL/6 mice bearing orthotopic KR158B tumors compared to non-targeted nanoparticles. We propose that targeting treatments to invading cancer cells using non-adhesive nanoparticles will limit non-specific interactions within brain and tumor tissue and thereby allow specific interactions at target structures and increase the BCNU therapeutic index. To test this hypothesis, we plan to determine the therapeutic efficacy of Fn14-targeted and non-targeted, non-adhesive nanoparticles, capable of releasing BCNU over a 3 week period, by intracranial CED injections in C57BL/6 mice bearing orthotopic KR158B invasive tumors.

Citation Format: Aniket S. Wadajkar, Jimena G. Dancy, Nina P. Connolly, Jeffrey A. Winkles, Graeme F. Woodworth, Anthony J. Kim. Targeting nanotherapeutics to the invasive glioblastoma margin via the cell surface receptor Fn14 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3107. doi:10.1158/1538-7445.AM2017-3107
Abstract 3112: Roles of asialoglycoprotein receptor 2 in gastric cancer progression
Authors: Tanaka Haruyoshi
Published: July 2017

Background

Hepatic metastasis and relapse contribute to the high incidence of gastric cancer (GC)-related fatalities, and represent a frequent and crucial problem for oncologists. Knowledge of the unique molecular attributes to hepatic metastasis will improve our understanding of the biology of metastatic GC and facilitate development of specific biomarkers and appropriate targeted therapies, leading to efficacious personalized treatment.

Methods

Transcriptome and bioinformatics analyses were conduct to identify a candidate molecule that specifically mediate hepatic recurrences of GC. Small interfering RNA (siRNA) experiments to determine the effect of knockdown on phenotype. Expression levels of the candidate molecule was determined in the gastric tissues of 200 patients with GC.

Results

Asialoglycoprotein receptor 2 (ASGR2), a membrane trafficking protein, was identified as a candidate biomarker specific to hepatic metastasis. Transcription levels of ASGR2 were differential among GC cell lines and increased compared to a control nontumorigenic epithelial cell line. Inhibiting ASGR2 expression decreased the invasion and migration abilities of GC cells. Increased expression of ASGR2 mRNA in GC tissues was significantly associated with lymphatic involvement, vessel invasion, advanced stage and hepatic metastasis. In patient subgroup of stage II GC, those with increased ASGR2 expression had significantly shorter overall and disease-free survival than those without.

Conclusions

ASGR2 may represent a biomarker for hepatic metastasis of GC and as a target for therapy.

Citation Format: Haruyoshi Tanaka. Roles of asialoglycoprotein receptor 2 in gastric cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3112. doi:10.1158/1538-7445.AM2017-3112
Abstract 3113: Knockdown of cell division cycle-associated 8 (CDCA8) suppresses hepatocellular carcinoma growth via the upregulation of tumor suppressor ATF3
Authors: Jeon Tae-Won , Ko Min Ji , Seo Yu-Ri , Baik In Hye , Hwang Ilseon , Ryoo Hun-Mo , Kim Jin Young , Park Keon Uk , Lee Yun-Han
Published: July 2017

Background: Hepatocellular carcinoma (HCC) is the third most lethal cancer worldwide which remains a major challenge due to poor prognosis and limited treatment options. Cell division cycle associated 8 (CDCA8) is known as a component of a chromosomal passenger complex required for stability of the bipolar mitotic spindle and it is commonly overexpressed in human HCC. However, the functional role of CDCA8 in HCC progression remains to be clarified. In this study, we hypothesized if targeting of CDCA8 with small interfering (si) RNA could alter the course of HCC progression. We also investigated the molecular mechanism that mediates HCC cell death caused by CDCA8 silencing.

Methods: Human HCC cell lines, Huh1 and Huh7, were transfected with CDCA8 siRNA and tested for growth inhibition and apoptotic induction using MTS, FACS and microscopic analysis. To obtain insights into the molecular changes in response to CDCA8 knockdown, global changes in gene expression were examined using RNA sequencing.

Results: siRNA silencing of CDCA8 inhibited HCC cell growth and long-term colony formation by blocking cell cycle progression and by inducing apoptotic cell death. RNA sequencing data showed that, representatively, the anti-proliferative effects were driven by a subset of molecular alterations including the upregulation of tumor suppressive ATF3 and GADD34 genes and the downregulation of BGLAP, a key regulator of cell growth and invasiveness. Subsequent Western blot analysis affirmed that CDCA8 silencing induces the increase in the levels of ATF3 and GADD34 and the decrease in phosphorylated Akt in both Huh1 and Huh7 cells. Also, the same condition decreased the levels of PARP-1 and pro-caspase 3, accelerating apoptosis. Of importance, silencing of CDCA8 expression effectively suppressed HCC tumor growth in a murine xenograft model.

Conclusion: These findings suggest that targeting CDCA8 could be an attractive option for molecular therapy of HCC.

Citation Format: Tae-Won Jeon, Min Ji Ko, Yu-Ri Seo, In Hye Baik, Ilseon Hwang, Hun-Mo Ryoo, Jin Young Kim, Keon Uk Park, Yun-Han Lee. Knockdown of cell division cycle-associated 8 (CDCA8) suppresses hepatocellular carcinoma growth via the upregulation of tumor suppressor ATF3 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3113. doi:10.1158/1538-7445.AM2017-3113
Abstract 3122: Pharmacogenomic profiling to identify novel therapeutic strategies in colorectal cancer
Authors: Bruun Jarle , Eide Peter W. , Kryeziu Kushtrim , Sveen Anita , Murumägi Astrid , Kolberg Matthias , Arjama Mariliina , Kallioniemi Olli , Lothe Ragnhild A.
Published: July 2017

Colorectal cancer (CRC) is amongst the most frequent cancers worldwide and the fourth most common cause of cancer mortality. Surgery is the standard treatment of care, while chemotherapy and/or radiotherapy are offered to subgroups of patients according to disease stage. Current guidelines do not have sufficient accuracy to identify chemotherapy responders, resulting in under- or overtreatment of many patients.To discover novel therapeutic strategies for CRC we performed a high-throughput drug screen containing 461 approved and preclinical drugs on a representative panel of 42 CRC cell lines. Integrative pharmacogenomic profiles were explored by matching data from gene expression, exome sequencing, copy number and reverse-phase protein arrays. These analyses identified defined molecular subgroups sensitive to targeted drugs like Inhibitors of EGFR, IGF-1R and downstream signaling mediators like B-Raf, MEK, PI3K/AKT, as well as inhibitors of aurora mitotic kinases, heat shock protein 90 and p53. Additionally, a correlation between microsatellite instability and sensitivity against topoisomerase-I inhibitors was found. Comparison of the most sensitive and the most resistant cell models against HSP90 inhibitors indicated that drug sensitivity does not depend on target expression but is likely attributed to the cell line-specific expression of client proteins. Real-time cell analyses measured with the xCELLigence system demonstrated a strong impact on cell proliferation but not on the migration of HSP90-sensitive cells treated with HSP90 inhibitors as compared to resistant cells. These integrative analyses have unraveled pharmacogenomic relationships that if validated in in vivo model systems, might be used to stratify patients for therapeutic intervention in biomarker guided clinical trials.

Citation Format: Jarle Bruun, Peter W. Eide, Kushtrim Kryeziu, Anita Sveen, Astrid Murumägi, Matthias Kolberg, Mariliina Arjama, Olli Kallioniemi, Ragnhild A. Lothe. Pharmacogenomic profiling to identify novel therapeutic strategies in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3122. doi:10.1158/1538-7445.AM2017-3122