bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 804: Zebrafish as a model organism to study human pancreatic CSC's
Authors: Sanchez Laura E. , Sainz Pablo Cabezas , Sainz Bruno , Muinelo Laura , Lopez Rafael
Published: July 2017

Zebrafish is establishing itself as a powerful animal model for understanding human disease, including cancer. Xenotransplantation of human cancer cells into zebrafish is becoming an attractive research tools for studying cancer behaviour, both for established lines and primary tumours, however, its utility as a model for cancer stem cells (CSCs) is still in its infancy. In addition, only when the differences between primary tumours and established cancer cell lines are minimized will we be truly one step closer to developing biologically relevant personalized medicine platforms for cancer. To address these two limitations, we set out to achieve a deeper behavioral understanding of pancreatic CSCs inside the zebrafish embryo. The main methodology of this study was focused on the xenotransplantation of human primary pancreatic ductal adenocarcinoma (PDAC) cells (185 scd line) into zebrafish embryos using two different conditions: adherent cells (non-CSCs) vs sphere-derived cells (CSCs). Marked with a lipophilic dye, cells were injected into zebrafish embryos and incubated at 36ºC during 48h/72h to assess the proliferation of the injected cells. Self-developed Matlab software was used to analyze the intensity and area of the injected cells in order to give a ‘proliferation ratio’. Results obtained indicated that the sphere-derived cells proliferated and migrated at a higher rate than adherent cells. This is likely due to the different CSC content present between the two conditions tested: adherent pancreatic 185 cells contain 1% CSCs versus the 15% enrichment of CSCs in sphere-derived 185 cells. Apart from the differential CSC content, we also hypothesize that the 3D environment afforded by the yolk sac of the zebrafish embryo additionally favors the expansion of CSCs. Importantly, similar results were obtained with CSCs isolated via FACsorting, using autofluorescence as a marker for CSCs. This work not only contributes to the behavioral understanding of pancreatic CSCs using the zebrafish model organism but more importantly concludes that 1) PDAC CSC proliferation and migration can be studied in zebrafish, 2) the zebrafish model represents a potentially powerful surrogate model for the study of PDAC CSC biology in vivo, and 3) this model can potentially be adapted for to test chemotherapeutics that specifically target PADC CSCs, the cell type considered to be the most chemoresistant and tumorigenic in pancreatic cancer.

Citation Format: Laura E. Sanchez, Pablo Cabezas Sainz, Bruno Sainz, Laura Muinelo, Rafael Lopez. Zebrafish as a model organism to study human pancreatic CSC's [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 804. doi:10.1158/1538-7445.AM2017-804
Abstract 807: A novel immunodeficient rat for modeling human cancer
Authors: Noto Fallon K. , Arey Angela , McClain Christopher , Zhang Wei , Yeshi Tseten
Published: July 2017

Animal models of human cancer offer the potential to study human tumor growth kinetics, genetic variance among human cancers, and provide in vivo platforms for drug efficacy testing. In particular, immunodeficient mouse models have been invaluable in modeling a wide range of human cancers. However, some cancer lines don’t grow well in the available mouse models or show variability in growth kinetics from mouse to mouse, making drug efficacy studies difficult due to differences in tumor size at the onset of treatment. These challenges are also seen in patient derived xenograft (PDX) models, in addition to long timeframes to obtain sufficient mice with PDX tissue growth for drug efficacy studies. Mice are also limited in tumor growth potential with regard to humane endpoints and small size also limits the volume of blood that can be collected for analysis. An immunodeficient rat model could provide a solution to some of these issues. A rat model would allow for larger tumor size, easier surgical manipulation, and greater volume of tissue and blood sampling for downstream analysis. In addition, large tumors from rats could be serially transplanted into mice for drug efficacy testing and could provide a large number of transplanted mice in a shorter period of time compared with serially transplanting from mouse to mouse.

We have created an immunodeficient rat model with a functional deletion of the Rag2 gene. This knockout, created using spermatogonial stem cells, lacks mature B and T cells. To assess the capability of the Rag2 knockout rat to accept human xenografts, we transplanted 2 commercially available human cancer cell lines into our animals. The human REH acute lymphocytic leukemia cell line was transplanted via intravenous injection and the human glioblastoma cell line U87MG was transplanted subcutaneously. Both cell lines survived in the Rag2 knockout rat and resulted in the growth of tumors comprised of human cells. Studies are underway to characterize the Rag2 knockout rat’s ability to grow other human cell lines, including those that do not grow well in mice, and PDX tissues.

Citation Format: Fallon K. Noto, Angela Arey, Christopher McClain, Wei Zhang, Tseten Yeshi. A novel immunodeficient rat for modeling human 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 807. doi:10.1158/1538-7445.AM2017-807
Abstract 816: Molecular and genomic characterization of a newly established male breast cancer cell line
Authors: Vaclova Tereza , Maguire Sarah , Pugh Matthew , Barry Peter , Orr Nick
Published: July 2017

Although the majority of breast cancers affect women, approximately 1% of cases occur in men. At present comparatively little is known about the molecular mechanisms that influence male breast cancer predisposition and tumorigenicity. This is largely due to the current unavailability of an established cell line model in which to study male breast cancer. Development of in vitro models of the disease is therefore warranted, not least because growing evidence indicates that it is sufficiently different from female breast cancer such that extrapolating knowledge from one to the other may be misleading.

Here we report the establishment and characterisation of a male breast cancer cell line derived from a primary tumor arising in a 61-year old male patient. We used 3T3-J2 mouse fibroblast co-culture in the presence of a ROCK inhibitor to conditionally reprogram epithelial cells from freshly resected tumor tissue. Once established, the cell line showed a rapid proliferation rate and growth in full conditioned media without the support of mouse fibroblasts. Immunohistochemical profiling demonstrated expression of epithelium-specific antigens AE1/AE3, breast epithelial marker CK7 and confirmed estrogen receptor positivity in concordance with the primary tumor. Germline sequencing detected no pathogenic germline predisposition mutations in either BRCA1 or BRCA2. There was no evidence of somatic mutation in any of the established female breast cancer driver genes. Somatic whole genome sequencing of early and late passages indicated a paucity of structural aberration and little evidence for obvious accumulation of gross genetic alterations.

In conclusion, we have established a novel in vitro model for studying male breast cancer. That the cell line genome displays minimal evidence of significant acquired genetic changes arising due to reprogramming suggests that it will be of value in future studies of the biology of male breast cancer.

Citation Format: Tereza Vaclova, Sarah Maguire, Matthew Pugh, Peter Barry, Nick Orr. Molecular and genomic characterization of a newly established male breast cancer cell line [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 816. doi:10.1158/1538-7445.AM2017-816
Abstract 82: MiR-206-mediated c-MET suppression modulates BCRP/ABCG2 levels in NRF2-silenced cancer cells
Authors: Choi Bo-hyun , Ryoo In-geun , Kim Donghyeok , Lee Sujin , Kwak Mi-Kyoung
Published: July 2017

Breast cancer resistance protein (BCRP/ABCG2), a xenobiotic efflux transporter, is responsible for anticancer resistance in tumors. NF-E2-related factor 2 (NRF2) is a critical transcription factor in cellular defense system by regulating the expression of antioxidant and detoxifying enzymes; however, its overexpression is often associated with tumor resistance to chemotherapy. In the present study, we demonstrate that NRF2 modulation affects the expression of hepatocyte growth factor receptor (HGFR/c-MET) and consequently suppresses BCRP/ABCG2 activity in cancer cells. Interfering RNA-mediated stable inhibition of NRF2 in both ovarian carcinoma SKOV3 and renal carcinoma A498 cell lines reduced the expression of c-MET and this was accompanied by BCRP/ABCG2 down-regulation. The treatment of cells with pharmacological or genetic inhibitor of c-MET decreased BCRP/ABCG2 level and subsequently increased intracellular accumulation of doxorubicin and Hoechst 33342, indicating a link between c-MET and BCRP/ABCG2 activity. As a potential molecular mechanism of altered c-MET expression, miR-206 was identified as a predictive regulator of c-MET. As experimental evidence, transient and stable expressions of miR-206 in SKOV3 and A498 cells repressed c-MET and BCRP/ABCG2 levels. In addition, NRF2-knockdown cancer cells expressed higher levels of miR-206 compared to the control cells, and the treatment of NRF2 knockdown cells with the miR-206 inhibitor could restore c-MET and BCRP/ABCG levels. Collectively, our results showed that the NRF2 silencing-mediated miR-206 regulation could suppress BCRP/ABCG2 levels through c-MET modulation, which is providing an additional evidence of chemosensitization of tumor cells by NRF2 inhibition.

Citation Format: Bo-hyun Choi, In-geun Ryoo, Donghyeok Kim, Sujin Lee, Mi-Kyoung Kwak. MiR-206-mediated c-MET suppression modulates BCRP/ABCG2 levels in NRF2-silenced cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 82. doi:10.1158/1538-7445.AM2017-82
Abstract 825: Cetixumab enhanced apoptosis effects of radiation on human prostate cancer cell line PC-3
Authors: Chang Chia-lun , Wu Szu-Yuan
Published: July 2017

Prostate cancer is a leading cause of cancer death in men in developed countries. Radiotherapy is the main treatment to prostate cancer. Dose escalation of irradiation with image guide rasdiotherapy and intensity modulated radiotherapy were used with more and more evidences in prostate cancer patients and bring in longer PSA-free survival time. Although the evolution of radiation techniques bring better outcomes, but modern modalities were not avaliable in non-western world. Radiation enhancement is still an improtant issus in prostate cancer in non-western world, especially in androgen independnt prostate cancer. The epidermal growth factor receptor (EGFR) network has rich targets for prostate cancer killing. The chimeric monoclonal antibody Cetuximab (IMC-A12, Erbitux®) binds to EGFR and prevents its intracellular signaling. Currently, it is approved for treatment of wild-type KRAS colon and head and neck cancer. The effect and mechanisms of Erbitux and radiotherapy are still not clear. In this study, we evaluated the effects of combining the EGFR inhibition and radiation on PC-3 prostate cancer cells. PC-3 cells were treated with various doses(1,2.5,5 and 10 ug/ml) of anti-EGFR antibody (CETUXIMAB) and irradiation(5, 7.5 Gy). The results revealed that 5 and 10 ug/ml of CETUXIMAB significnatly reduced the colony formation. The cell cycle analysis revealed that CETUXIMAB significnatly enhanced the radiation induced G2/M phase arrest and subG1 peak increasing. The Hoechst staining and DNA laddering analysis revealed radiation and CETUXIMAB combined use will induced more apoptotic bodies or DNA fragmentation than radiation alone use. By using a apaptosis protein array, we found that several apaptosis related protein (Catalase, cIAP-1, Clusterin, Fas, HIF-1α, HSP27, HSP60, HSP70, SMAC and Survivin) were significantly downregulated in radiation and CETUXIMAB combined group. Taken together, our results demonstrated that Erbitux enhanced apoptosis effects of radiation on PC-3.

Citation Format: Chia-lun Chang, Szu-Yuan Wu. Cetixumab enhanced apoptosis effects of radiation on human prostate cancer cell line PC-3 [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 825. doi:10.1158/1538-7445.AM2017-825
Abstract 826: Nrf2 confers radioresistance by regulating cancer stem trait in lung cancer cells
Authors: He Xiaoqing , Chi Alex , Wang Liying , Rojanasakul Yon
Published: July 2017

Lung cancer is the leading cause of cancer-related death accounting for more than 1.3 million deaths worldwide annually. Despite advances in treatment, the five-year survival rate is 2% if the cancer has metastasized to other organs. The major cause of poor prognosis of advanced lung cancer is multi-resistance to chemo/radio therapy. Therefore, it is crucial to understand the underlying mechanisms of chemo/radio resistance and develop therapeutic strategies to overcome the resistance. Transcription factor Nrf2 is a key regulator of cytoprotective genes which facilitate cellular defense against harmful insults. We found that Nrf2 and its downstream target NQO1 are highly upregulated in lung cancer patient tumor tissues as well as in lung cancer cell lines compared to adjacent normal tissues or normal cell lines. We hypothesized that the upregulated Nrf2 may be responsible for radio/chemo resistance and malignancy in lung cancer. RNA interference studies showed that knockdown of Nrf2 substantially increased the sensitivity of human lung cancer H460 and A549 cells to radiation-induced cell death. Knockdown of Nrf2 also decreased tumor sphere formation, suggesting its role in cancer stem cell (CSC) regulation which may be responsible for the radioresistance. Analyses of CSC markers including ALDH and Oct4 in control and Nrf2-knockdown H460 and A549 cells support this finding. Together, our results indicate an essential role of Nrf2 in the control and regulation of CSCs and radioresistance. Since CSCs are widely believed to be responsible for cancer chemoresistance and relapse, our novel finding on the role of Nrf2 in radiation resistance may aid in the design of novel therapeutic strategies for resistant cancers.

Citation Format: Xiaoqing He, Alex Chi, Liying Wang, Yon Rojanasakul. Nrf2 confers radioresistance by regulating cancer stem trait in lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 826. doi:10.1158/1538-7445.AM2017-826
Abstract 83: Irinotecan resistance in type 2 interleukin-1 receptor overexpressed colorectal cancer cells is overcome by inhibitor of MEK
Authors: Mar Ai-Chung , Chu Chun-Ho , Lee Te-Chang
Published: July 2017

We have previously demonstrated that the expression of interleukin-1 receptor type II (IL1R2) is closely associated with the advanced staging and distant metastasis in patients with CRC. We also found that enhanced expression of IL1R2 played certain roles to resist the targeted therapeutics, regorafenib, in CRC cells. Whether IL1R2 expression is associated with the resistance to chemotherapeutics is unclear. Irinotecan, a water-soluble and semisynthetic derivative of camptothecin, is one of widely used first- and second-line chemotherapeutics for treatment of patients with metastatic colorectal cancer (CRC). Herein, we first demonstrated that enhanced expression of IL1R2 resulted in increased resistance of CRC cells to irinotecan using IL1R2 ectopically expressed HCT116 and DLD-1 cells, which were IL1R2 low expressing CRC cells, and IL1R2 silenced HT29 cells, which were IL1R2 high expressing CRC cells. Since we have shown that IL1R2 may activate MEK/ERK signaling by inhibition of PP2A, we further revealed that a specific inhibitor of MEK, CI-1040, could overcome the irinotecan resistance in IL1R2-overexpressing DLD-1 and HT29 cells. Our result showed that the combination of irinotecan and CI-1040 synergistically suppressed the cell growth in high IL1R2 expressing CRC cells but less significant in low IL1R2 expressing cells. We also confirmed that treatment of IL1R2-overexpressing CRC cells with CI-1040 significantly suppressed the pERK, a downstream target of MEK. These results support that IL1R2 mediates through activation of MEK/ERK signaling to cause irinotecan resistance in human CRC cells. The investigation how IL1R2 induces irinotecan resistance is ongoing. Accordingly, we may suggest that combined treatment of irinotecan and MEK-ERK inhibitor is a potential therapeutic strategy against IL1R2 overexpression related irinotecan resistant CRC.

Citation Format: Ai-Chung Mar, Chun-Ho Chu, Te-Chang Lee. Irinotecan resistance in type 2 interleukin-1 receptor overexpressed colorectal cancer cells is overcome by inhibitor of MEK [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 83. doi:10.1158/1538-7445.AM2017-83
Abstract 834: Formation of DNA double-strand breaks in colon tumors after targeted alpha therapy with 211At-mAb
Authors: Eriksson Sophie E. , Elgström Erika , Lindegren Sture , Bäck Tom
Published: July 2017

Introduction: Targeted alpha therapy has shown promising results in preclinical and clinical studies. Alpha particle irradiation gives a high fraction of DNA double-strand breaks (DSB), as shown in vitro, resulting in a high probability of cell death. We have previously examined the therapeutic effects of 211At on solid colon carcinoma tumors (diameter approximately 1 cm), with tolerable activities (5 MBq/animals) resulting in non-palpable tumors within one week p.i. The aim of the present study was to investigate the formation of DNA DSB during tumor regression after radioimmunotherapy with 211At-mAb in a syngeneic rat colon carcinoma model. Methods: 18 rats bearing solid colon tumors (1 cm in diameter) between peritoneum and the abdominal muscle were injected intravenously with 5 MBq/animal 211At-BR96. Tumors were excised and paraffin-embedded after 10 min, 2 h, 8 h, 18 h, 24 h, and 48 h p.i. (3 tumors per time point). 53BP1 was stained by immunohistochemistry and used as a marker for DNA DSB. Untreated tumors were used as controls (n=9). DNA DSB were counted in central and peripheral tumor areas selected at random. Results: A few DNA DSB were detected in untreated tumors. Already 10 min p.i., the number of DNA DSB had increased slightly in peripheral tumor tissue. The number peaked 8 h p.i., when the number of DNA DSB had increased 50 times in the tumor periphery and 24 times in the tumor center. The number of DNA DSB then declined, but the difference between center and periphery remained, as expected considering the intratumoral distribution of radioimmunoconjugate. This correlates with the 211At half-life of 7.2 h. Conclusion: DNA DSB are formed early after injection of 211At-mAb and follows the intratumoral distribution of mAbs.

Citation Format: Sophie E. Eriksson, Erika Elgström, Sture Lindegren, Tom Bäck. Formation of DNA double-strand breaks in colon tumors after targeted alpha therapy with 211At-mAb [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 834. doi:10.1158/1538-7445.AM2017-834
Abstract 837: PSMB8 as a candidate marker of responsiveness to preoperative radiotherapy in rectal cancer patients
Authors: Ha Yejin , Tak Ka hee , Kim Chan wook , Roh Seon Ae , Choi Eun Kyung , Cho Dong Hyung , Kim Jeong-Hwan , Kim Seon-Kyu , Kim Seon-Young , Kim Yong Sung , Kim Jin-Cheon
Published: July 2017

Prediction of individual responsiveness is urgently needed, specifically in locally advanced rectal cancer (LARC) patients who underwent preoperative chemoradiotherapy (CRT). The present study, RNA-Seq was used to compare the basal expression profile between responders and non-responders to preoperative CRT, in correlation with the tumor regression grade (TRG) among 22 LARC patients. Eight differentially expressed genes (B3GALT4, HSPA1B, KRBOX1, PPBP, PPP1R18, PSMB8, SLC39A7, and TAP2) associated with preoperative CRT responses were primarily identified among the 22 LARC patients by RNA-Seq (p<0.0005 and >16-fold difference). Among these genes, PSMB8 and SLC39A7 were upregulated in the responsive group in the other 40 LARC patients (p<0.05). PSMB8 overexpression significantly reduced colony formation and increased apoptosis-inducing molecules like cleaved caspase-3 and cleaved PARP in irradiated CRC cells after 6 Gy irradiation. PSMB8 knockdown increased colony formation and decreased caspase-3 activation and cleaved PARP levels after irradiation. In mice treated with ionizing radiation, tumor growth suppression was significantly greater in HCT116/PSMB8-xenografts (81%) than in HCT116/vector-xenografts (53%) (p=0.001). However, SLC39A7 overexpression had no significant effect on irradiated CRC cells. These results suggest that PSMB8 appears to predict radiosensitivity in LARC patients with preoperative CRT, although further clinical validation is needed in a larger cohort.

Citation Format: Yejin Ha, Ka hee Tak, Chan wook Kim, Seon Ae Roh, Eun Kyung Choi, Dong Hyung Cho, Jeong-Hwan Kim, Seon-Kyu Kim, Seon-Young Kim, Yong Sung Kim, Jin-Cheon Kim. PSMB8 as a candidate marker of responsiveness to preoperative radiotherapy in rectal cancer patients [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 837. doi:10.1158/1538-7445.AM2017-837
Abstract 838: Effect of tumor treating fields on cell proliferation and synergistic antitumor efficacy in combination with ionizing radiation
Authors: Kim Eun Ho , Jo Yunhui , Sung Jiwon , Song Hyo Sook , Yoon Myonggeun
Published: July 2017

Alternating electric fields at an intermediate frequency (100~300 kHz), called tumor treating fields (TTFs), are reported to interrupt the process of mitosis via apoptosis and to act as an inhibitor of cell proliferation. Although the presence of an antimitotic effect of TTFs has been widely reported, the efficacy of TTFs is still controversial issue among medical experts. To resolve this controversial issue, the comparison study between the effects of TTFs and the effect of other conventional cancer treatment techniques need to be carried out. In this study, experimental evidence of the synergistic antimitotic effect of TTFs in combination with ionizing radiation (IR) is reported. For these experiments, aggressive brain cancer cells, glioblastoma multiforme (GBM) cells (U373 and U87), were treated either with TTFs alone, with IR alone or with TTFs followed by ionizing radiation (IR). The percentages of cell apoptosis, DNA damage, and mitotic abnormalities were increased by the application of TTFs alone and its quantity was markedly increased when TTFs were combined with IR. Our results also suggested that radiotherapy together with TTFs may be clinically beneficial since the combination treatment seemed to synergistically suppress both cell migration and invasion, based on the inhibition of MMP-9 and vimentin.

Citation Format: Eun Ho Kim, Yunhui Jo, Jiwon Sung, Hyo Sook Song, Myonggeun Yoon. Effect of tumor treating fields on cell proliferation and synergistic antitumor efficacy in combination with ionizing radiation [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 838. doi:10.1158/1538-7445.AM2017-838
Abstract 84: CCN1/Cyr61 regulation of gemcitabine-resistant phenotype in pancreatic cancer: involvement of CTGF and dCK
Authors: Gupta Vijayalaxmi G. , Maity Gargi , Haque Inamul , Banerjee Sushanta K. , Banerjee Snigdha
Published: July 2017

With an estimated half a million new cases and similar mortality rates for 2016, pancreatic ductal adenocarcinoma (PDAC) remains a life-threatening and challenging disease to diagnose and treat. As per American Cancer Society (ACS), varying efficacy in different patients has led to an increase in the mortality rate of PDAC. Gemcitabine (GEM) remains the drug of choice either alone or in combination, but is unsuccessful in reducing or curing PDAC in most patients. The limited efficacies of these drugs are due to the acquisition of chemo-resistant characteristics of PDAC. Although several molecular and physiological factors have been shown to correlate with the GEM-resistance, defined molecular mechanism(s) of GEM-resistance remains a mystery. Previous studies have shown that CCN1, which is overexpressed in PDAC and known to associate with PDAC progression, is critical for drug resistance. Here, we found that while the pancreatic cancer cell lines (i.e., Panc-1 and AsPC-1) in which CCN1 is overexpressed are typically GEM-resistant, the knocking down of CCN1 makes them sensitive to GEM. Mechanistic studies revealed that CCN1 regulates two important genes that are directly involved in regulation GEM-sensitivity in PDAC. These include cancer cell-secreted connective tissue growth factor (CTGF), a regulator of desmoplasia, and Deoxycytidine kinase (dCK), an enzyme that enhances gemcitabine sensitivity and efficacy in cancer cells. The deletion of CCN1 in PDAC cells blocks CTGF expression and under co-cultured conditions prevent the growth of alpha-smooth muscle actin (α-SMA)-positive stellate cells, which are required for desmoplastic growth in pancreatic cancers. CCN1 ablation upregulates dCK expression in PDAC cell lines as compared to CCN1 expressed PDAC cells. These two events enhance the anti-proliferative effect of GEM and can be rescued by CTGF-treatment or blocking dCK. In conclusion, CCN1 promotes GEM-resistance in PDAC cell through the regulation of CTGF and dCK and the mechanistic insights provided by these studies may help in designing future therapeutic strategies to combat PDAC.

Citation Format: Vijayalaxmi G. Gupta, Gargi Maity, Inamul Haque, Sushanta K. Banerjee, Snigdha Banerjee. CCN1/Cyr61 regulation of gemcitabine-resistant phenotype in pancreatic cancer: involvement of CTGF and dCK [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 84. doi:10.1158/1538-7445.AM2017-84
Abstract 841: UTR analysis identifies Musashi1 as a translational regulator of radiation-induced Golgi-related gene expression
Authors: Lehman Stacey L. , O'Neill John W. , Camphausen Kevin , Tofilon Philip J.
Published: July 2017

The cellular radioresponse is regulated by post-translational modification of constitutively expressed proteins and by changes in gene expression. Although the role of constitutively expressed proteins, such as those involved in the DNA damage response and cell cycle checkpoints, is well-understood in the context of the radioresponse, radiation-induced changes in gene expression are not as clearly defined. We have previously demonstrated that glioblastoma stem-like cells (GSCs) alter their gene expression at the translational level in response to ionizing radiation (IR). In particular, the NSC11 GSC line demonstrated thousands of genes differentially translated at one hour after a dose of 2 Gy, while considerably fewer were modified at the transcriptome level. Furthermore, there was little overlap between the transcriptome and the translatome. Genes undergoing translational regulation in response to IR fell into distinct functional categories, including mitochondrial structure and function, Golgi function, and translational regulation. Here, we aimed to elucidate the mechanism by which IR induces translational changes in the NSC11 GSC line. NSC11 cells were either exposed to 2 Gy or mock irradiated, and polysomes were isolated by sucrose gradient fractionation one hour later. Polysome-bound mRNA was purified and analyzed by microarray. The 5’ and 3’ untranslated regions (UTRs) of the top 75 up- and down-regulated genes were analyzed for the presence of regulatory elements. The most frequently occurring element in the UTRs of both the top up- and down-regulated genes was the Musashi1 binding site. Musashi1 is an RNA binding protein that typically binds to 3’ UTRs to regulate mRNA translation. It is a neural stem cell marker, and its expression is correlated with the grade of malignancy in glioma. GO term analysis of known Musashi1 target genes that were translationally regulated in response to IR revealed an enrichment of genes involved in Golgi function and vesicular trafficking. Knockdown of Musashi1 prevented IR-induced Golgi dispersal in NSC11 cells. Musashi1 knockdown also radiosensitized NSC11 cells, indicating a role for the protein in the cellular radioresponse. Together, these data demonstrate that in the NSC11 GSC line, Musashi1 contributes to radiation-induced translational regulation, specifically in the context of Golgi-related genes, and suggests that Musashi1 is a novel target for radiosensitization.

Citation Format: Stacey L. Lehman, John W. O'Neill, Kevin Camphausen, Philip J. Tofilon. UTR analysis identifies Musashi1 as a translational regulator of radiation-induced Golgi-related gene expression [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 841. doi:10.1158/1538-7445.AM2017-841
Abstract 843: CLDN1 mediates tumor invasion in HNSCC by regulation of EMT through AMPK-TGF-β signalling
Authors: Chang Jae Won , Jung Seung-Nam , Liua Lihua , Kim Jin Man , Ban Myung Jin , Kim Yeon Soo , Lee Bok-Soon , Kim Yang Eun , Won Ho Ryun , Kim Chul-Ho , Koo Bon Seok
Published: July 2017

Background: Claudin-1 (CLDN1), a major component of tight junction complexes in epithelium, maintains cellular polarity and plays critical roles in cell-to-cell communication and epithelial cell homeostasis. Although, the role of CLDN1 in cancer has been generally studied in cancers, the exact regulatory mechanisms and downstream pathways in cancer have been controversial and are not completely understood.

Materials and Methods: After, analysed mutational profiling of tumor/non-tumor paired tissue in the patients with head and neck squamous cell carcinoma (HNSCC) by next-generation sequencing (NGS), CLDN1 expression levels were measured in human HNSCC cell lines and tissues from HNSCC patients using next-generation sequencing. For functional in vitro analysis, cell proliferation testing using a WST-1 assay, an invasion assay, and Western blotting was performed after CLDN1 expression regulation. In vivo validations were performed using nude mouse and patient-derived tumor xenograft (PDTX) model.

Results: Mutational profiling of tumor/non-tumor paired HNSCC tissue by NGS revealed that HNSCC tumor tissues and cell lines had relatively high levels of CLDN1 expression. Although, CLDN1 regulation did not affect proliferation of HNSCC cell lines, knock down of CLDN1 inhibited invasive characteristics (migration/invasion) with down-regulation of EMT associated proteins (vimentin and slug). We also found that CLDN1 negatively correlated with AMPK phosphorylation and AMPK activator (AICAR) showed the same effect with CLDN1 suppression on HNSCC cells without change in CLDN1 expression which lead to inhibition of TGF-β-induced Smad phosphorylation and their transcriptional activity, suggesting that CLDN1/AMPK/TGF-β cascade. Then, we confirmed antitumorigenic effects of suppression of CLDN1 in HNSCC in a nude mouse and PDTX model.

Conclusions: Our findings suggest that CLDN1 acts as oncogenic driver in HNSCC via regulating EMT through AMPK/TGF-β signalling and if validated in further studies, a CLDN1-targeting agent partnered with an existing anti-TGF-β modality could be a novel tactic to overcome HNSCC.

Citation Format: Jae Won Chang, Seung-Nam Jung, Lihua Liua, Jin Man Kim, Myung Jin Ban, Yeon Soo Kim, Bok-Soon Lee, Yang Eun Kim, Ho Ryun Won, Chul-Ho Kim, Bon Seok Koo. CLDN1 mediates tumor invasion in HNSCC by regulation of EMT through AMPK-TGF-β signalling [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 843. doi:10.1158/1538-7445.AM2017-843
Abstract 85: Establishment of cabazitaxel-resistant prostate cancer cell lines
Authors: Mizokami Atsushi , Machioka Kazuaki , Izumi Kouji , Aerken Maolake , Natsagdorji Ariunbold , Kadono Yoshifumi , Takezawa Yuta , Iwamoto Hiroaki , Keller Evan T.
Published: July 2017

Background: The final treatment for castration-resistant prostate cancer (CRPC) is generally cabazitaxel treatment. However, once CRPC becomes resistant to cabazitaxel, the patients are obliged to best supportive care. Therefore, the elucidation of the mechanism of the cabazitaxel-resistance and the conquest are important themes to improve the prognosis of the patients. We already established paclitaxel/docetaxel-resistant prostate cancer, PC-3-TxR and DU145-TxR cells, and characterized those cell lines previously. Then we further tried to establish cabazitaxel-resistant prostate cancer cell lines, and characterized those cell lines.

Materials and Methods: We established two cabazitaxel-resistant cell lines, PC-3-TxR/CxR and DU145-TxR/CxR by increasing concentration of cabazitaxel from 1 nM to 30 nM gradually when PC-3-TxR and DU145-TxR cells were passaged. We confirmed the IC50 of docetaxel and cabazitaxel of these cells. Next we purified total RNA and performed cDNA microarray (Agilent and compared gene expression profiles among these cells.

Results and Conclusion: IC50 of PC-3-TxR and PC-3-TxR/CxR for cabazitaxel was 1.3 nM and 15.4 nM, respectively. IC50 of DU145-TxR and DU145-TxR/CxR was 7.0 nM and 30. 8 nM, respectively. Comparison of cDNA microarray between PC-3-TxR and PC-3-TxR/CxR cells or between DU145-TxR and DU145-TxR/CxR cells revealed that 4,470 genes in PC-3-TxR/CxR, and 1,345 genes in DU145-TxR/CxR cells were upregulated more than 3-fold and 4,683 genes PC-3-TxR/CxR and 1,537 genes were downregulated less than 0.3-fold, respectively. Especially, although expression of ABCB1 (MDR) gene was upregulated in DU145-TxR by 500-fold compared with DU145 cells, it was not upregulated in not upregulated in DU145-TxR/CxR cells any more. In contrast, expression of ABCB1 gene was upregulated in PC-3-TxR by 20-fold compared with PC-3 cells and it was further upregulated in PC-3-TxR/CxR by 40-fold compared with PC-3-TxR. In conclusion, various genes were regulated in cabazitaxel-resistant PCa cells and different mechanisms might be involved in this resistance in different cell lines.

Citation Format: Atsushi Mizokami, Kazuaki Machioka, Kouji Izumi, Maolake Aerken, Ariunbold Natsagdorji, Yoshifumi Kadono, Yuta Takezawa, Hiroaki Iwamoto, Evan T. Keller. Establishment of cabazitaxel-resistant prostate cancer cell lines [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 85. doi:10.1158/1538-7445.AM2017-85
Abstract 855: Ube2v1 promotes epithelial mesenchymal transition and metastasis in colorectal cancer by epigenetically transcriptional suppression of autophagy
Authors: Shen Tong , Cai Dong Ling , Liu Hong Yu , Gan Juan Wen , Li Ming , Wang Ru Jing , Guo Da Peng , Zhou Qun , Lu Xing Xing , Li Shi , Sun Na Li , Li Ming Jian
Published: July 2017

Ubiquitination is one of the basic post-translational modifications for cellular homeostasis. The conjugating enzyme (E2) family plays as a bridge linking the first step mediated by E1 with the final step mediated by E3 in the ubiquitin-proteasomesystem. However, the role of Ube2v1, one of Ubiquitin-conjugating E2 enzyme variant proteins (Ube2v), in colorectal cancer (CRC) and autophagy is unclear. Here, we found that Ube2v1 is elevated in tumor samples of CRC patients and correlated with poorer survival of CRC patients. Furthermore, Ube2v1 promotes migration and invasion of CRC cells in vitro and boosts tumor growth and metastasis of CRC cells in vivo. Interestingly, Ube2v1 suppresses autophagy program and promotes EMT and metastasis of CRC cells in an autophagy dependent pattern in vitro and in vivo. Moreover, Rapamycin attenuates the enhanced in vitro migration and invasion and in vivo lung metastasis of Ube2v1 overexpression by inducing the autophagy pathway. Mechanistically, Ube2v1 increases histone H4 lysine 16 acetylation by down-regulating expression of Sirt1 and epigenetically suppresses gene expression of autophagy genes in colorectal cancer. In conclusion, Ube2v1 functions as a globalregulator for autophagy by epigenetically transcriptional suppression of autophagy, and consequently promotes EMT and metastasis of CRC. Our study functionally links Ube2v1, one member of E2 family in the ubiquitin-proteasome system toautophagy program in CRC progression and metastasis.

Note: This abstract was not presented at the meeting.

Citation Format: Tong Shen, Dong Ling Cai, Hong Yu Liu, Juan Wen Gan, Ming Li, Ru Jing Wang, Da Peng Guo, Qun Zhou, Xing Xing Lu, Shi Li, Na Li Sun, Ming Jian Li. Ube2v1 promotes epithelial mesenchymal transition and metastasis in colorectal cancer by epigenetically transcriptional suppression of autophagy [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 855. doi:10.1158/1538-7445.AM2017-855
Abstract 869: Mesenchymal identity of breast cancer promotes brain metastases and therapeutic resistance through MLK4/NFkB signaling Pathway
Authors: Alsheikh Heba Allah M. , Minata Mutsuko , Yamaguchi Shinobu , Nakano Ichiro
Published: July 2017

Patients with breast cancer brain metastases (BCBM) suffer from a devastating outcome despite recent progress in a variety of therapeutic modality. Among the four major molecular subtypes, breast cancers that are either human epidermal growth factor receptor (HER) 2- positive or triple-negative breast cancer (TNBC) patients have a higher risk of BCBM compared with the luminal cancer patients. The mechanisms by which the disseminated cancer cells overcome the multistep defense mechanism in the brain, adapt the microenvironment, and subsequently initiate metastasis remain elusive. Recently, we identified a set of genes that contribute to initiate Glioblastoma (GBM) and at least some of them are functionally essential for GBM establishment and the therapy resistance. Mixed lineage kinase 4 (MLK4) is a relatively poorly characterized serine/threonine kinase, which is largely expressed in various cancers including GBM. We recently found a critical role of MLK4 in controlling the mesenchymal identity in GBM stem cells and plays a role in GBM initiation through direct activation of NF-kB signaling. Our preliminary data indicates MLK4 is also highly expressed in patient-derived hormone receptor (HR)-negative breast cancer cells in comparison with the other HR-positive counterparts. For therapeutic development purpose, we performed the structure-based drug design, which has led to identify two small molecule MLK4 inhibitor candidates to test efficacy on a set of patient-derived breast cancer cells in vitro and their xenografted tumors in vivo. Results will be presented in the conference.

Citation Format: Heba Allah M. Alsheikh, Mutsuko Minata, Shinobu Yamaguchi, Ichiro Nakano. Mesenchymal identity of breast cancer promotes brain metastases and therapeutic resistance through MLK4/NFkB signaling Pathway [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 869. doi:10.1158/1538-7445.AM2017-869
Abstract 872: Noninvasive monitoring of endogenous Pdl1 expression by using a dual reporter system
Authors: Zhou Min , Liu Xinjian , Li Fang , Li Chuan-Yuan
Published: July 2017

Programmed death-ligand 1 (Pdl1) is a key immune checkpoint protein facilitating tumor escape from host immune system. Clinical approval of anti-PD1 and anti-PDL1 antibodies for the treatment of a variety of malignancies underscores the promise of immune checkpoint therapy. Further progress in this promising area of research is likely to come from better understanding of the mechanisms for regulation of immune checkpoint proteins such as PDL1. In the present study, we designed a dual reporter imaging system to monitor Pdl1 expression by use of the CRSPR-Cas9 technology. A fusion reporter that consists of eGFP and Luc2 was introduced into downstream of the endogenous Pdl1 gene, right before the stop codon, through CRISPR-Cas9 mediated homologous recombination. A P2A self-cleaving motif is inserted between the fusion reporter gene (eGFP-Luc2) and Pdl1. The reporter system was introduced into two murine tumor cell lines, 4T1 and B16F10. In vitro, an increase in eGFP intensity and bioluminescence of the reporter cells was observed after exposure to ionizing radiation or IFN-gamma, which has been reported to upregulate the expression of Pdl1. In vivo, we were able to observe radiation induced increase in bioluminescence signals from tumor established by use of the reporter cells. Our study therefore provided proof of principle for the use of our endogenous Pdl1 reporter imaging system to monitor the expression levels of Pdl1 in vitro and in vivo noninvasively and serially.

Citation Format: Min Zhou, Xinjian Liu, Fang Li, Chuan-Yuan Li. Noninvasive monitoring of endogenous Pdl1 expression by using a dual reporter system [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 872. doi:10.1158/1538-7445.AM2017-872
Abstract 875: Improved resection and prolonged overall survival with PD-1-IRDye800CW fluorescent probe-guided surgery and PD-1 adjuvant immunotherapy
Authors: Du Yang , Tian Jie
Published: July 2017

Purpose: An intraoperative technique to accurately identify microscopic tumor residuals could be applied to decrease the risk of positive surgical margins. Several lines of evidence support the expression and immunotherapeutic effect of PD-1 in breast cancer. Here, we sought to develop a fluorescence labeled PD-1 probe for in vivo breast tumor imaging and image-guided surgery. The efficacy of PD-1 monoclonal antibody (mAb) as adjuvant immunotherapy after surgery was also assessed.

Experimental Design: A near-infrared dye labeled PD-1-IRDye800CW probe was developed and examined for its application in tumor imaging and image-guided tumor resection in an immunocompetent 4T1 mammary mouse tumor model that recapitulates clinical metastatic cancer. Fluorescence molecular imaging (FMI) was performed to monitor probe biodistribution and intraoperative imaging. Bioluminescence imaging (BLI) was carried out concurrently to monitor tumor growth and evaluate post-surgical tumor residuals, recurrences, and metastases.

Results: The PD-1-IRDye800CW probe exhibited a specific and stable signal at the tumor region compared to the IgG control, and exhibited the highest tumor-to-background ratio (TBR) 8 h post-injection (11.62 ± 0.79), approximately 5 fold higher than the IgG control (2.13 ± 0.30). Furthermore, PD-1-IRDye800CW guided surgery combined with PD-1 adjuvant immunotherapy inhibited tumor regrowth and microtumor metastases, as determined by BLI imaging, and thus improved survival rate with no obvious side effects.

Conclusions: Our study demonstrated the feasibility of using PD-1-IRDye800CW for breast tumor imaging and image-guided tumor resection. Moreover, we found that PD-1 mAb adjuvant immunotherapy reduces cancer recurrences and metastases emanating from minimal tumor residuals.

Citation Format: Yang Du, Jie Tian. Improved resection and prolonged overall survival with PD-1-IRDye800CW fluorescent probe-guided surgery and PD-1 adjuvant immunotherapy [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 875. doi:10.1158/1538-7445.AM2017-875
Abstract 877: Real-time imaging of adherent and non-adherent cell interactions: utility of an automated microfluidic trap platform to recapitulate in vivo cell culture microenvironment
Authors: Kannan Rekha , Yeh Victor , Helton James , Cappione Amedeo
Published: July 2017

The study of dynamic cell processes and their interactions is of crucial importance to understand the complexities of tissue microenvironments. Simulation of in vivo cell culture microenvironments can greatly improve biologic relevance of cell-cell interaction studies, and so there is an ongoing demand for heuristic optimization of cell co-culture devices and protocols. One particularly challenging task is establishing real-time image analysis while co-culturing non-adherent cells in contact with adherent cell layers under precisely controlled environmental parameters. To address this challenge, we present a novel microfluidic approach to trap two different cell types in precise locations in order to image and study their interactions over time. The platform utilizes a well plate format that contains multiple microfluidic units. Each unit consists of a 3 mm x 3 mm x 40 µm (L x W x H) chamber for culture, and an array of microscopic trap areas tailored to the dimensions of the cells of interest, typically ~15 µm. The micro-scale geometries of the traps physically confine non-adherent cells, and co-cultures can be achieved by trapping the non-adherent cells over a monolayer of cells. The microfluidic plate is integrated with a system which enables perfusion-based nutrient supply along with gas and temperature control for long-term cell culture. Each chamber within the plate can be addressed by programmable and on-demand perturbation of up to 6 reagents, enabling uninterrupted real-time live cell imaging assays. We present here the use of this microfluidic platform to replicate tumor microenvironment by maintaining adjacent co-cultures of cancer and immune cells. We have successfully imaged and cultured monolayers of tumor cell lines for 7 days followed by subsequent loading and trapping of immune (non-adherent) cells. In conclusion, the microfluidic platform enables unique co-cultures with environmental control and real-time imaging to facilitate the investigation of cell-cell interactions in a wide range of applications such as drug response and screening in tumor microenvironments, invasion, evasion pathways and other mechanisms governing cell-cell interactions.

Citation Format: Rekha Kannan, Victor Yeh, James Helton, Amedeo Cappione. Real-time imaging of adherent and non-adherent cell interactions: utility of an automated microfluidic trap platform to recapitulate in vivo cell culture microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 877. doi:10.1158/1538-7445.AM2017-877