bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4554: IL-17-CXCR2 axis promotes breast cancer metastasis and therapy resistance through facilitating recruitment of neutrophils
Authors: Wu Lingyun , Saxena Sugandha , Awaji Mohammad , Sharma Bhawna , Singh Rakesh
Published: August 2019

Breast cancer is one of the most common cancer types that happens to global females. The major challenges for breast cancer include therapy resistance and metastasis. Various factors and cancer-related immune cells are involved in tumor chemotherapy resistance process, including pro-inflammatory cytokine, interleukin (IL) 17, CXCR2 ligands (pro-inflammatory chemokines) and neutrophils. They are the key players for promoting cancer progression, and numerous reports indicated them as a potential therapeutic target for various cancer types including breast cancer. However, the detailed mechanism(s) remains unclear. In the present study, we investigate the role of neutrophils in chemotherapy resistance and metastasis in breast cancer.

In our previous study, we have observed increased levels of CXCR2 ligands in chemotherapy-resistant cells comparing with Cl66 parent cells. In this study, we observed upregulated IL17, IL17 receptor (IL-17R), granulocyte colony stimulating factor (GCSF) by qRT- PCR in resistant cells compared with parent cells. We further evaluated the protein levels of CXCR2 and its ligands, IL17 and its receptor, frequencies of neutrophils and T-helper 17 (Th17) cells in primary and metastatic tumors through using immunohistochemistry method. There were higher levels of IL17R, CXCR2, and CXCR2 ligands in metastatic tumor sites in comparison to the primary tumor sites. Moreover, we observed increased levels of IL17R, CXCR2, CXCR2 ligands together with the higher frequencies of neutrophils and Th17 cells in resistant tumors than Cl66 tumors. At the same time, tumor cells treated with IL-17 increased its proliferation rate and its expression of CXCL1 & CXCL5; and the increase was all in a concentration-dependent manner. In addition, the increase of CXCR2 ligands by IL17 was inhibited when we treated the tumor cells with ERK and NF-KB signaling inhibitors, indicating both pathways are involved in the regulation of IL17-induced CXCR2 ligands secretion.

Together, our data demonstrate an IL17-CXCR2 ligands axis plays protumorigenic inflammation, facilitating therapy resistance and metastasis through recruited neutrophils.

Citation Format: Lingyun Wu, Sugandha Saxena, Mohammad Awaji, Bhawna Sharma, Rakesh Singh. IL-17-CXCR2 axis promotes breast cancer metastasis and therapy resistance through facilitating recruitment of neutrophils [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4554.
Abstract 4558: Mapping tolerized T cell states to exhaustion phenotypes in NSCLC
Authors: Kozlova Edgar , Eikawa Shingo , Gnjatic Sacha , Losic Bojan
Published: August 2019

The promise of checkpoint blockade treatment has yet to be fully realized in part due to a lack of knowledge of immune exhaustion and its efficient characterization, especially in the context of immunosuppressive tumor microenvironments which effectively tolerize the immune system.

We hypothesized that mapping expression signatures defining regulatory T-cell states to previously studied and characterized exhaustion phenotypes of infiltrating T cells in NSCLC would reveal points of contact between T cell tolerization and exhaustion. Concretely, we profiled the gene expression and directly inferred CDR3/1 clonality between tolerized and immunized states in purified CD4+ T-Cells from 10 patients with ovarian or peritoneal and non-small cell lung cancer. The samples were taken before and during immunization therapy for the antigens MAGE-A3 or NY-ESO-1 over a period of 13 weeks, in the presence and absence of adjuvant to emulate the tolerized and immunized states.

Further, by modeling the regulatory T-cell states as an interaction between the tolerized and immunized with time and type of antigen allowed us to identify significant differentially expressed gene clusters and their correlation to clonality. We then projected these signatures onto single cell RNAseq data from NSCLC-TCGA to compare the identified clusters to previously identified exhaustion phenotypes. We show that antigen vaccination is immunostimulating and induces lymphocyte activation, leading to a proinflammatory environment. During an immunized stated an increase in cytokine activity, including IL2, 4, 9, 10, 13 and 17, whereas tolerized T Cells, we observe an increase in clonality, BIRC6 and IL20 apart from alterations in chromosome organization pathways and cell cycle including senescence.

In conclusion, we detail how the differences between tolerized and immunized states help unravel exhaustion mechanisms, which will ultimately identify molecular markers for exhaustion to assist during treatment and prognosis in clinical settings.

Citation Format: Edgar Kozlova, Shingo Eikawa, Sacha Gnjatic, Bojan Losic. Mapping tolerized T cell states to exhaustion phenotypes in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4558.
Abstract 4559: Tumor-derived Galectin-1 promotes tumor growth in an orthotopic C57Bl/6 NB mouse model
Authors: Fest Stefan
Published: August 2019

Question

We recently introduced the carbohydrate-binding protein Galectin-1 (Gal-1) as a novel tolerogeneic molecule in neuroblastoma (NB). NB-secreted Gal-1 suppressed the maturation of dendritic cells (DC) and inhibited T cell function. Here, we focused on the question whether tumor-derived Gal-1 is the decisive factor to promote tumor growth in our model for NB.

Methods

C57Bl/6J-derived orthotopic growing NB cells (named NB975A) were used for all culture as well in vivo experiments. Gal-1 knock-down clones (GL) were generated by stable transfection of wt NB975A cells (NBA) with the antisense Gal-1 expression vector (NBA-GL), (kindly provided by Dr. Rabinovich). Blasticidine resistant (5 mikrogram/ml) transfectants were cloned by limited dilution. Protein expression of Gal-1 was determined by Western blot. Orthotopic NB tumors were generated in C57Bl/6J wild type and Gal-1-knock-out (Lgals-/-) female mice by subcapsular tumor cell injection of NBA-GL or wild type NBA (1x106, 0,1 ml PBS) into the left kidney. Primary tumor growth was analyzed by using high frequency ultrasound measurement. Mice were sacrificed 23 days after tumor inoculation and tumor tissue was harvested for further analysis.

Results

NBA-GL showed 50% reduced protein expression of Gal-1 compared to control wild type NBA cells. In vitro viability and proliferation of the tumor cells was not affected by the transfection. Mice inoculated with NBA-GL cells had significantly smaller primary tumors when compared with control animals that received the NBA cells. Gal-1 sufficient tumor cells injected in Gal-1-deficient host mice grew normally.

Conclusion

Tumor-derived Gal-1 and not its expression in host is critical for the promotion of tumor growth.

Citation Format: Stefan Fest. Tumor-derived Galectin-1 promotes tumor growth in an orthotopic C57Bl/6 NB mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4559.
Abstract 4560: In situ multiplex analysis of regulatory and effector T cells in multiple tumor types
Authors: Baranova Elena , Tliba Maroua , Motte Manon , Defort Naomi , Finan-Marchi Amanda , Lazzaro Domenico , Estermann Fanny , Coton Jean-Philippe , Burrer Renaud
Published: August 2019

Immune-mediated rejection of cancer is prevented in part by the suppression of T effector (Teff) cells by regulatory T (Treg) cells. Favorable survival in numerous types of cancer has been associated with high Teff to Treg cells ratios as determined by flow cytometry or analysis of immunohistochemistry on serial sections. Multiplex immunofluorescence offers a technical advantage by allowing the detection of co-expression and spatial organization of up to 6 targets within a preserved tissue architecture on a single slide. We have designed a multiplex immunofluorescence protocol to identify human and murine Teff and Treg cells in situ. Human tissue microarrays of tumors in a range of tissues were investigated with a multiplex panel consisting of CD3/CD4/CD8/CD45RO/FoxP3/CD25. After multi-spectral acquisition, the T cell populations could be easily phenotyped and localized in all of the tissue types examined. The multiplex panel was then applied to non small cell lung carcinoma tumor and control tissues. Treg and Teff populations were quantified. The approach presented here demonstrates the power of multiplex immunohistochemistry in the identification and quantification of multiple immune cell populations on a single tissue section and the potential application of this method in both preclinical and clinical studies.

Citation Format: Elena Baranova, Maroua Tliba, Manon Motte, Naomi Defort, Amanda Finan-Marchi, Domenico Lazzaro, Fanny Estermann, Jean-Philippe Coton, Renaud Burrer. In situ multiplex analysis of regulatory and effector T cells in multiple tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4560.
Abstract 457: HER2, AR protein expression and chromosomal instability in circulating tumor cells (CTCs) of metastatic breast cancer (MBC) patients (pts)
Authors: Ontiveros Priscilla , Landaverde Connie , Levin Maren K. , Hippely Sarah , Landers Mark , Wang Yipeng , Dittamore Ryan , O'Shaughnessy Joyce A.
Published: August 2019

Background: Upregulation of HER2 and AR protein expression, and increase in chromosomal instability, are mechanisms of acquired resistance to endocrine therapy, and are being investigated as treatment-guiding biomarkers. However, measurement of these biomarkers requires metastatic biopsies, which are costly, invasive, and prone to under-sampling which precludes their utility to guide treatment in late stage metastatic pts. A CTC-based test could expand the clinical utility. Using the Epic Sciences platform, MBC blood samples were characterized for CTC prevalence, HER2 and AR expression on CTCs, and CTC chromosomal instability at time of disease progression.

Material and methods: Blood samples were acquired from 127 total pts with HR+/HER2-, HR-/HER2+ and TNBC metastatic breast cancer pts. 114 samples were analyzed for HER2 and 110 were analyzed for AR using the Epic CTC Platform. Single-cell whole genome sequencing was performed on 157 CTCs from 19 pts to assess large scale transitions (a surrogate of chromosome instability) and gene copy number alterations.

Results: 87/114 (76.3%) of pts had detectable CTCs, with a median of 1.1 CTC/mL. 17/114 (14.9%) had at least one HER2(+) CTC, 21/110 (19.1%) had at least one AR(+) CTC, and 10/110 (9%) had both AR(+) and HER2(+) CTCs detected in technical replicates. HER2 expression on individual CTCs showed distinctive cytoplasmic membrane staining, and AR expression on individual CTCs showed frequent nuclear localization. The majority of HER2+ and AR+ CTCs had high cytokeratin expression. Most pt samples showed heterogeneous expression of these markers at disease progression indicating subclonal sensitivity to targeted therapies. CTCs with larger nuclear area and higher N/C ratio had higher frequency of chromosomal instability. ERBB2, FGFR1 gain, PTEN, CDH1, BRCA1, BRCA2 loss were frequently observed and the prevalence were associated with CTC phenotypes.

Conclusions: CTCs are detected in most MBC pts upon disease progression. CTC based biomarkers assessing HER2, AR and chromosomal instability status could guide therapy selection. The results warrant prospective evaluation of these biomarkers on MBC pts’ CTCs as a resistance marker for targeted therapies.

Citation Format: Priscilla Ontiveros, Connie Landaverde, Maren K. Levin, Sarah Hippely, Mark Landers, Yipeng Wang, Ryan Dittamore, Joyce A. O'Shaughnessy. HER2, AR protein expression and chromosomal instability in circulating tumor cells (CTCs) of metastatic breast cancer (MBC) patients (pts) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 457.
Abstract 4570: Selective depletion of regulatory T cells suppressed neuroblastoma tumor growth in mice
Authors: Lenthe Sophie von , Weißenborn Christine , Zenclussen Ana Claudia , Fest Stefan , Metelitsa Leonid
Published: August 2019

Purpose of the study

Neuroblastoma (NB) is the most common solid extracranial tumor in childhood. Regulatory T cells (Treg) are known to have immune suppressive capacity and to be involved in tolerance establishment. As they support tumor growth and help some tumors to overcome recognition by the host, they are considered to be an important target. Treg are reportedly increased in blood of NB patients. However, there are no scientific proofs to date that they are involved in neuroblastoma growth. To address this important question we employed Foxp3-DTR mice to selectively deplete Treg upon orthotopic application of syngeneic neuroblastoma cells.

Methods

Orthotopic NB tumors were generated in mice Foxp3-DTR mice and in C57Bl/6J controls by subcapsular tumor cell injection of NB975A cells into the left kidney. Primary tumor growth was analysed for 23 days by high frequency ultrasound measurement. To deplete Treg, InjectionDepletion of Diphtheria Toxin (DT, 15 ng/g bodyweight) intraperitoneally every 4 days in Foxp3.DTR mice depleted the Treg pool. Control Foxp3.DTR animals received PBS and control C57B/l6 received DT. All mice were sacrificed 23 days after tumor inoculation. Tumor as wells as immune cells harvested from spleen and inguinal lymph nodes were analyzed by Flow Cytometry, Immunofluorescenceimmunohistochemistry and qRT-PCR.

Results

In control mice bearing tumors, Treg presence was confirmed at the contact zone between the kidney and the growing, inoculated tumor.

Mice devoid of Treg (Foxp3-DTR+DT) showed a significantly reduced tumor growth compared to animals with normal Treg frequencies (Foxp3-DTR+PBS). Tumor growth in wild type controls was not affected by the application of DTR.

Conclusion

Ablation of Treg hindered the growth of NB, strongly suggesting their potential as therapeutic target for this aggressive childhood tumor.

Citation Format: Sophie von Lenthe, Christine Weißenborn, Ana Claudia Zenclussen, Stefan Fest, Leonid Metelitsa. Selective depletion of regulatory T cells suppressed neuroblastoma tumor growth in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4570.
Abstract 4575: IL17 signaling modulates tumor microenvironment in pancreatic cancer
Authors: Zhang Yu , Sanchez Erick Marcelo Riquelme , Zoltan Michelle Annabel , McAllister Florencia
Published: August 2019

Pancreatic cancer is the one of the most devastating malignancies and the 5-years survival remains below 10% for decades. The pancreatic tumor microenvironment is very complex with tumor cells surrounded by a dense fibro-inflammatory stroma with fibroblasts and immune-suppressive cells which are known to play a pivotal role in the whole process of tumorigenesis, and contributing to the lack of responses to most therapies. We have previously described that IL17, a cytokine secreted from immune cells recruited to the pancreas in response to Kras and inflammation, is involved in the initiation and development of pancreatic premalignant lesions, in part by promoting stemness on the oncogenic epithelium. In this study, we aim to dissect the role of IL17 on the stroma in established pancreatic adenocarcinoma. To this end, we blocked the IL17 signaling pathway with monoclonal antibodies and also used a parallel genetic approach which consisted in IL17RA deletion from the cancer cells using CRISPR-Cas9. RNA sequencing analysis, flow cytometry, immunohistochemistry, and opal-multiplex immunofluorescence were performed on tumors and cellular compartments. We uncovered that neutrophils recruitment was the main pathway altered by IL-17. Using flow cytometry, IHC and opal-multiplex we found that Gr1+ cells were significantly modulated by Il17 in the tumor microenvironment, as not only the numbers of these cells were altered but also their spatial distribution with respect to CD8+T cells, which may contribute to the generation and maintenance of the immunosuppressive microenvironment that characterizes pancreatic cancer. Moreover, we found that reactive oxygen species (ROS) level was also evidently downregulated by IL17 signaling blockage.Therefore, we conclude that IL17 plays an important role in remodeling the pancreatic cancer immunosuppressive tumor microenvironment.

Citation Format: Yu Zhang, Erick Marcelo Riquelme Sanchez, Michelle Annabel Zoltan, Florencia McAllister. IL17 signaling modulates tumor microenvironment in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4575.
Abstract 4586: PLAG enhances macrophage mobility for efferocytosis of active neutrophils via membrane redistribution of P2Y2
Authors: Kim Guen Tae , Lee Do Young , Sohn Ki-young , Yoon Sun Young , Kim Jae Wha
Published: August 2019

Neutrophil activity is prerequisite during chemotherapy. The DAMP (Damage Associated Molecular Pattern) molecules generated by chemotherapy could be effectively trapped by activated neutrophil called ‘NETosis’. Efferocytosis of macrophages should remove most activated neutrophils including NETosis A timely removal of activated neutrophils is essential for the prevention of abnormal activation of immune response and metastatic activity of cancer cells induced by tumor microenvironment (TME). Particularly, appropriate clearance of the activated neutrophils by efferocytosis should be carried out because activated neutrophils have a detrimental effect on TME. In this research, we investigated the effect of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) on efferocytosis and its underlying molecular mechanisms. In a co-culture of activated neutrophils with macrophages, PLAG increased the activity of efferocytosis for elimination of activated neutrophils. PLAG accelerated translocation of P2Y2 from lipid rafts to non-lipid-raft plasma membrane domains in macrophages. This repositioning of P2Y2 enables the polarization of the cytoskeleton by association of the receptor with cytoskeletal proteins such as α-tubulin and actin to improve the mobility of macrophages. Through these protein assemble, PLAG encouraged macrophage mobility toward the activated neutrophils. Formation of micelle including PLAG, chylomicron-like structures, was a prerequisite for induction of this macrophage activity. PLAG effect on this activity was not observed in the absence of GPIHBP1, micelle receptor. Taken together, these data showed that PLAG triggered a prompt clearance of activated neutrophils through enhancement of efferocytosis activity. Subsequently, PLAG could have effects on modulation of TME. PLAG could be utilized as an effective lipid-based TME modulator via the prevention of abnormal activation induced by uncontrolled immune response during chemotherapy.

Citation Format: Guen Tae Kim, Do Young Lee, Ki-young Sohn, Sun Young Yoon, Jae Wha Kim. PLAG enhances macrophage mobility for efferocytosis of active neutrophils via membrane redistribution of P2Y2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4586.
Abstract 4587: The N-terminal domain of HARS is a novel NRP2 ligand and can regulate NRP2-dependent macrophage function
Authors: Sharma Navatha Shree , Dutta Samikshan , Crampton Steve , Rosengren Sanna , Datta Kaustubh
Published: August 2019

Tumor-associated macrophages (TAM) are associated with regulation of antitumor immune responses, and neuropilin-2 (NRP2), a pleiotropic receptor with an emerging role in immune responses, has recently been demonstrated to be important for this activity (Roy et al, Cancer Res. 2018). Deletion of NRP2 results in impaired clearance of apoptotic tumor cells through reduced efferocytosis, which plays a role in tumor promotion. We now show that the N-terminal domain of the histidyl-tRNA synthetase (HARS) is a specific binding partner of NRP2, and can regulate the phagocytic function of NRP2 in macrophages. The HARS N-terminal domain, which is found only in higher eukaryotes, is conserved among splice variants of HARS and has evolved to regulate immune cell engagement. Incubation of macrophages with recombinant HARS N-terminal domain, had no effect on phagocytic uptake, but significantly impaired the maturation of phagosomes in a dose dependent manner. This phenotype mimics that of the NRP2 knockout, suggesting pharmacological intervention with this agent to modulate NRP2 driven biology may be possible.

Citation Format: Navatha Shree Sharma, Samikshan Dutta, Steve Crampton, Sanna Rosengren, Kaustubh Datta. The N-terminal domain of HARS is a novel NRP2 ligand and can regulate NRP2-dependent macrophage function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4587.
Abstract 4598: mTORC2 suppresses GSK3-dependent, but b-TrCP-independent, Snail degradation, contributing to positive regulation of cancer cell invasion and metastasis
Authors: Zhang Shuo , Qian Guoqing , Zhang Qian-Qian , Yao Yuying , Wang DongSheng , Chen Zhuo G. , Wang Lijing , Chen Mingwei , Sun Shi-Yong
Published: August 2019

Mammalian target of rapamycin (mTOR) complex 1 (mTORC1) positively regulates cell invasion and metastasis via enhancing Snail protein translation. The connection between mTOR complex 2 (mTORC2) and cell invasion and metastasis has also been suggested. However the underlying biology or mechanism is largely unknown and thus is the focus of this study. Inhibition of mTOR with both mTOR inhibitors and knockdown of the key components including rictor, Sin1 and raptor of mTORCs decreased Snail protein levels. mTOR inhibitors promoted Snail degradation rate. Moreover, mTOR inhibitor-induced Snail reduction was rescued by proteasome inhibition. Critically, inhibition of mTORC2 (by knocking down rictor), but not mTORC1 (by knocking down raptor), enhanced Snail degradation. Therefore, it is the inhibition of the mTORC2 that induces Snail proteasomal degradation, resulting in eventual Snail reduction. Interestingly, inhibition of GSK3, but not SCF/β-TrCP, rescued Snail reduction induced by mTOR inhibitors, suggesting a GSK3-dependent, but SCF/β-TrCP-independent proteasomal degradation of Snail. Accordingly, mTOR inhibitors elevated E-Cad levels and suppressed cancer cell migration and invasion in vitro and metastasis in vivo. Collectively, the current study has revealed a novel connection between mTORC2 and positive regulation of Snail stability, thus providing a scientific base for mTORC2 in positive regulation of cell EMT, invasion and metastasis. (This study was supported by NIH/NCI R01 CA118450 and CA160522 to SYS and National Natural Science Foundation of China No. 31771578 to QQZ).

Citation Format: Shuo Zhang, Guoqing Qian, Qian-Qian Zhang, Yuying Yao, DongSheng Wang, Zhuo G. Chen, Lijing Wang, Mingwei Chen, Shi-Yong Sun. mTORC2 suppresses GSK3-dependent, but b-TrCP-independent, Snail degradation, contributing to positive regulation of cancer cell invasion and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4598.
Abstract 4600: IL-22 is specifically required for malignancy in breast cancer: A potential target to control cancer metastasis
Authors: Katara Gajendra K. , Kulshrestha Arpita , Schneiderman Sylvia , Ibrahim Safaa , Bilal Mahmood , Riehl Valerie E. , Beaman Kenneth D.
Published: August 2019

IL-22 is important for proliferation and progression of various epithelial cancers. However, in breast cancer, the current knowledge of IL-22 function is based on cell line models and lacks information on stage-specific involvement of IL-22 in multistage pathogenesis of disease. Here, we investigated whether IL-22 expression in the tumor microenvironment (TME) is a stage-specific requirement and if its inhibition can affect that specific stage of cancer progression. We show that the absence of IL-22 in TME did not hinder the initiation and proliferation of cancer but inhibited the invasion and metastasis of cancer. The influence of IL-22 on hyperplasia, adenoma, early carcinoma and late carcinoma stages of cancer was investigated using IL-22-/-/MMTV-PyMT spontaneous breast cancer mouse model. IL-22 levels were evaluated at these stages of cancer progression and validated in stage-specific specimens of human breast cancer. A variety of histopathological, in vivo and in vitroproliferation, migration, invasion and gene expression assays were performed on tumor tissues and purified epithelial cells. Results showed that IL-22 was absent in TME during initiation and hyperplasia stages of breast cancer. It was expressed during early carcinoma and significantly increased as tumor progressed to malignant stage. In human samples, IL-22 was poorly expressed in high and low grade ductal carcinoma in situ. However, it was significantly higher in invasive or metastatic carcinoma compared to ductal carcinoma in situ. Histological examinations revealed an inhibition in the malignant transformation of epithelial cells during invasion stage in IL-22-/- tumors. No difference was observed in initiation and hyperplasia stages of cancer between IL-22-/- and control mice. Ex vivo treatment of IL-22 increased the migration and invasion, but not the proliferation, of purified epithelial cancer cells. RNAseq analysis of premalignant stage epithelial cells revealed down regulation in genes associated with EMT (Epithelial to Mesenchymal Transition) pathway in IL-22-/- mice. These results show that, in breast cancer, IL-22 is not essential for cell proliferation but it is necessary for malignant transformation of cancer cells which is the critical stage for metastasis. Inhibition of IL-22 can hinder cancer cell malignancy and therefore, it can be an effective therapeutic target to control breast cancer metastasis.

Citation Format: Gajendra K. Katara, Arpita Kulshrestha, Sylvia Schneiderman, Safaa Ibrahim, Mahmood Bilal, Valerie E. Riehl, Kenneth D. Beaman. IL-22 is specifically required for malignancy in breast cancer: A potential target to control cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4600.
Abstract 4608: Colchicine binding site agents as potent tubulin inhibitors suppressing triple negative breast cancer
Authors: Deng Shanshan , Chen Hao , Krutilina Raisa , Albadari Najah G. , Seagroves Tiffany N. , Miller Duane D. , Li Wei
Published: August 2019

Triple-negative breast cancer (TNBC) cases account for about 15% of all breast cancers in the United States and have poorer overall prognosis relative to other molecular subtypes, partially due to the rapid development of drug resistance to chemotherapies and the increased risk of visceral metastasis. One of the standard treatment regimens for TNBC is the use of a taxane-based chemotherapy, such as paclitaxel, which stabilizes microtubules. However, drug resistance and neurotoxicities often limit the clinical efficacy of taxanes. Therefore, there are continuous needs to develop more effective therapies that could overcome resistance to taxanes. In this study, a novel series of structurally related pyridine analogs based on our previously reported lead compound ABI-274, was designed and synthesized to identify a molecule with improved antiproliferative potency. Most of these pyridine compounds exhibited potent cytotoxicity when tested in a panel of melanoma and breast cancer cell lines, with IC50 values in the low nanomolar range. Among them, CH-II-77 is the most potent compound with an IC50 value of 1−3 nM against these cancer cell lines, including paclitaxel-resistant sublines. The high-resolution X-ray crystal structure of CH-II-77 in complex with tubulin protein confirmed its direct binding to the colchicine-binding site. It strongly induced apoptosis and produced G2/M phase cell cycle arrest in TNBC cells in a dose-dependent manner in vitro. In vivo, CH-II-77 inhibited tumor growth in A375 melanoma xenografts and MDA-MB-231 TNBC xenografts in a dose-dependent manner. CH-II-77 was able to induce tumor necrosis and apoptosis in vivo. Collectively, these studies strongly suggest that CH-II-77 is a potent inhibitor of the growth of TNBC in vitro and in vivo. Thus, CH-II-77 and optimization of this analog are promising new generation of tubulin inhibitors for the treatment of TNBC and other types of cancers where tubulin inhibitors are currently being used clinically.

Citation Format: Shanshan Deng, Hao Chen, Raisa Krutilina, Najah G. Albadari, Tiffany N. Seagroves, Duane D. Miller, Wei Li. Colchicine binding site agents as potent tubulin inhibitors suppressing triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4608.
Abstract 4617: In vivo efficacy focused data collection and gaps for preclinical anticancer drug evaluation
Authors: Chen Taiping , Sun Xiaoqin , Li Tingting
Published: August 2019

Even though most anticancer drugs have been initially screened, investigated, and evaluated with variety of in vitro platforms, gaps between preclinical nominated candidate and clinical acceptable approval of final drug remain a big challenge for biotech companies all over the world. It is a highly demanding task to establish various animal models which can closely mimic human tumorigenesis in preclinical drug evaluation. Here we summarize several in vivo efficacy models to discuss on various applications in the data collection and interpretation. Currently available models include traditional cancer cell derived xenograft (CDX), patient derived xenograft (PDX), immune component murine tumor models (syngeneic and human gene knock-in), and orthotopic tumor models. Based on different drug mechanisms appropriate models will be initially selected with certain rationale. In order to understand the in vivo mechanisms of action (MOA) and drug target relevance, biomarker profiling and pharmacodynamic changes will be investigated with IHC, and/or FACS analysis particularly when the test articles display clear efficacious responses. Some representative data will be presented to demonstrate that in vivo efficacy will be the key endpoint for further analysis and clinical trial support. Small and large molecules of targeted drugs, antibody drug conjugate (ADC), immune checkpoint therapeutics will be included in the discussion. In sum, the approaches of in vivo data collection here are feasible to support many drug candidates to be evaluated to fill the gaps in the clinical drug development.

Citation Format: Taiping Chen, Xiaoqin Sun, Tingting Li. In vivo efficacy focused data collection and gaps for preclinical anticancer drug evaluation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4617.
Abstract 4622: The YUMMER.G mouse melanoma model recapitulates the heterogeneous response to immune checkpoint blockade based on patient sex
Authors: Ramseier Julie Y. , Charos Alexandra , Park Koonam , Damsky William , Bosenberg Marcus W.
Published: August 2019

Existing murine melanoma models, such as syngeneic transplantation of the B16 melanoma cell line, are aggressive, but poorly immunogenic, and as a result, studying the response to immunotherapy in these models has been challenging. Furthermore, in humans, a heterogeneous response to immune checkpoint inhibitor therapy has been observed between male and female melanoma patients, yet no immunogenic murine cancer model exists to study this sex-related dimorphism. To address these challenges, we created the YUMMER.G model, a melanoma cell line driven by human-relevant Braf activation and loss of Pten and Cdkn2a. YUMMER.G is related to the previously described YUMMER1.7 model; however important differences include: diploid state, female genotype, and Mc1re/e (pheomelanin producing) background. YUMMER.G was created by treatment with UV-light, resulting in a neoantigen rich subclone. Subcutaneous injection of 2 million YUMMER.G cells into C57BL/6J mice resulted in melanoma formation in both male and female mice. Treatment of established tumors with anti-CTLA-4 resulted in a comparable response between male and female mice, with complete, durable tumor regression in 100% of female mice and 88% of male mice. However, when established YUMMER.G tumors were treated with anti-PD-1, 63% of female mice, but only 13% of male mice exhibited complete tumor regression (p = 0.0330). These findings demonstrate the important role of host sex in the response to immunotherapy, and they parallel the sex-related differences in checkpoint inhibitor efficacy that have been observed in human patients. In summary, the YUMMER.G model is a human-relevant, immunogenic mouse melanoma model that will serve as a valuable platform for further investigating the mechanisms that mediate the sex-related dimorphism in anti-tumor immunity and response to immunotherapy.

Citation Format: Julie Y. Ramseier, Alexandra Charos, Koonam Park, William Damsky, Marcus W. Bosenberg. The YUMMER.G mouse melanoma model recapitulates the heterogeneous response to immune checkpoint blockade based on patient sex [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4622.
Abstract 4629: FOXA2 controls tumor-associated inflammation inKRAS-mutant lung cancer
Authors: Tomoshige Koichi , Guo Minzhe , Fink-Baldauf Iris , Stuart William , Maeda Yutaka
Published: August 2019

Background: Although the role of the transcription factor FOXA2 in lung cancer has been investigated using mouse and human lung cancer cell lines, to our knowledge, the role of FOXA2 in autochthonous lung tumors in GEMM (Genetically Engineered Mouse Model) has not been determined.

Methods: In order to determine the role of FOXA2 in autochthonous lung tumor cells, we deleted FOXA2 in lung epithelia of Kras-mutant lung cancer model mice (Scgb1a1-Cre;[tetO]-Kras4bG12D;Foxa2flox/flox, a GEMM) and assessed survival and lung histology of the GEMM.

Results: Deletion of FOXA2 in autochthonous Kras-mutant lung tumor cells significantly extended the survival of Kras-mutant lung cancer model mice (median survival from 8 weeks to 23 weeks; n>14 for each group). Histological analysis indicated that FOXA2 was required for the growth of lung tumor cells and the recruitment of tumor-associated macrophages.

Conclusion: FOXA2 promotes primary KRAS-mutant lung tumors in part by controlling tumor-associated inflammation.

Citation Format: Koichi Tomoshige, Minzhe Guo, Iris Fink-Baldauf, William Stuart, Yutaka Maeda. FOXA2 controls tumor-associated inflammation inKRAS-mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4629.
Abstract 4636: Oncogenic Notch triggers neoplastic-tumorigenesis in a transition-zone like tissue microenvironment
Authors: Deng Wu-Min , Yang Sheng-An
Published: August 2019

The “seed and soil” hypothesis proposed by Stephen Paget (1889) highlights the importance of tissue microenvironment for secondary tumor formation. The microenvironment that promotes primary tumor origination, however, remains largely unclear. Transition zones, where two types of epithelial tissue meet, have been characterized as high-risk sites for tumorigenesis. Here we show that the Drosophila salivary gland (SG) imaginal ring (ImR) can be used as a model to study tumorigenesis in transition zones. We found that constitutive activation of Notch signaling during the third larval instar drives overproliferation and tumor formation in the SG ImR. Interestingly, tumorigenesis always occurs at the posterior end of the ImR, which is a transitional area between the polyploid giant cells and diploid ImR cells. These Notch-induced tumors display disrupted epithelial organization, grow continuously and can metastasize once transplanted into the abdomen of adult flies, suggesting that they have the characteristics of malignant neoplasms. Further analyses revealed that the SG ImR transition zone possesses endogenously high levels of Janus kinase/signal transducers and activators of transcription (JAK-STAT) and c-Jun amino-terminal kinases (JNK), both of which are necessary for tumor growth. In this region, JNK signaling induces the expression of matrix metalloproteinase 1 (MMP1), which is also required for tumor formation in this model system. Furthermore, we found that ectopic MMP1 expression can transform the anterior end of the SG ImR, which is normally refractory to oncogenic Notch-induced tumorigenesis, into a tumor hotspot. Together, these studies reveal that local endogenous activation of JNK and JAK-STAT signaling creates a niche-like tissue microenvironment that is susceptible to oncogene-induced neoplastic tumor formation.

Citation Format: Wu-Min Deng, Sheng-An Yang. Oncogenic Notch triggers neoplastic-tumorigenesis in a transition-zone like tissue microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4636.
Abstract 4637: Non-stem cell-driven colonic tumors retain an intestinal differentiation hierarchy
Authors: Scurrah Cherie R. , Simmons Alan J. , Choi Eunyoung , Coffey Robert J. , Goldenring James R. , Lau Ken S.
Published: August 2019

Colorectal cancer (CRC) is the third leading cause of cancer mortality in the United States. Cancer stem cells (CSCs) play critical roles in therapeutic resistance, tumor recurrence, and metastasis that lead to patient death. We propose to evaluate the properties of CSCs in the context of the tumor cell-of-origin, the cell that initiates oncogenesis. We hypothesize that the tumor cell-of-origin is directly related to the CSCs present in tumors that consequently arise. To test this hypothesis, the stem-like properties of CSCs from stem cell- and non-stem cell-driven tumors, initiated from the Lrig1 and Mist1 promoters, respectively, were analyzed and compared through the use of lineage mapping and single-cell RNA-sequencing. We observed that although Mist1-expressing non-stem cells do not exhibit stem cell behavior under homeostatic or damage conditions, they can serve as tumor cells-of-origin. These tumors maintain a differentiation hierarchy that is lacking in stem cell-driven tumors. These results suggest that the origin of tumorigenesis influences tumor CSCs and thus tumor characteristics which could be utilized for the development of novel therapies.

Citation Format: Cherie R. Scurrah, Alan J. Simmons, Eunyoung Choi, Robert J. Coffey, James R. Goldenring, Ken S. Lau. Non-stem cell-driven colonic tumors retain an intestinal differentiation hierarchy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4637.
Abstract 4639: SLC7A11 expression confers cancer stem-like properties in small cell lung cancer cells
Authors: Kamenori Shohei , Suina Kentaro , Yamasaki Juntaro , Shintani Subaru , Otsuki Yuji , Hirata Yuki , Okazaki Shogo , Tsuchihashi Kenji , Sampetrean Oltea , Mitsuishi Yoichiro , Takahashi Fumiyuki , Takahashi Kazuhisa , Saya Hideyuki , Nagano Osamu
Published: August 2019

Small Cell Lung Cancer (SCLC) which accounts for 15 % of primary lung cancers is known to grow fast and metastasize easily to whole body at early stages. However, the standard care of SCLC has not been changed for over 10 years and effective treatment remains to be developed. System xc(-) comprises xCT (SLC7A11) and CD98hc subunits and is a major plasma membrane antiporter responsible for the cellular uptake of cystine in exchange for intracellular glutamate. Recently, we studied the impact of xCT inhibitor sulfasalazine (SSZ) in various cancers and found that SCLC cells manifest low level of xCT and are highly sensitive to SSZ treatment compared with non-small cell lines. Furthermore, we found that xCT expression in SCLC cells is regulated by the cellular density and the tumorsphere culture which is known to enhance the cancer stem cell properties also enhances the xCT expression in these cells. To examine the functional relevance of xCT expression to cancer stem-like properties in SCLC cells, we established the stably xCT-expressing SBC-5 cells (SBC5-xCT). Similar to other SCLC cell lines, parental SBC5 cells were not able to proliferate from single-cell level, however, SBC5-xCT cells were found to possess an ability to proliferate from single-cell level. Furthermore, SBC5-xCT cells manifested higher resistance to an anticancer agent cisplatin and higher ability of tumor-initiation than parental SBC5 cells. Our findings establish a new functional role for xCT in the promotion of cancer stem-like properties in SCLC cells.

Citation Format: Shohei Kamenori, Kentaro Suina, Juntaro Yamasaki, Subaru Shintani, Yuji Otsuki, Yuki Hirata, Shogo Okazaki, Kenji Tsuchihashi, Oltea Sampetrean, Yoichiro Mitsuishi, Fumiyuki Takahashi, Kazuhisa Takahashi, Hideyuki Saya, Osamu Nagano. SLC7A11 expression confers cancer stem-like properties in small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4639.
Abstract 4642: RNA interference reveals tumor promoting roles of integrin alpha 6 (ITGA6) in hepatocellular carcinoma
Authors: Zheng Guixi , Zeballos Carla , Bouamar Hakim , Cserhati Matyas , Cigarroa Francisco G , Sun Lu-zhe
Published: August 2019

Introduction: Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide and the third leading cause of cancer related mortality. The incidence and mortality rates of HCC are two times higher in Latinos than in the general population in the US and are the highest in Latinos from the South Texas region. The genetic and epigenetic events associated with the increased incidence of HCC in this population are still unclear. Increasing evidence suggests that integrins are one of the most important receptors for cell metastasis including integrin α6β1 and α6β4. However, few studies have focused on the function of integrin alpha 6 (ITGA6) in the tumorigenesis and progression of HCC. We aim to investigate the expression and potential roles of ITGA6 in HCC.

Materials and Methods: Paired HCC tissues and adjacent non-tumor tissues were collected for RNA sequencing. ITGA6 RNA and protein expression levels were evaluated by RNA sequencing, RT-qPCR, Western blot and immunohistochemistry. HCC cell lines (SNU398 and Huh7) were transiently transfected with two ITGA6siRNAs and stably transfected with an ITGA6 shRNA lentivector. These cell lines were used for assays testing the effects of ITGA6 knockdown on HCC cell proliferation, migration and anchorage independent growth.

Results: Analysis of RNA sequencing data indicated that the expression of ITGA6 increased 4-fold in HCC tumor tissues compared to adjacent non-tumor tissues, which was validated by RT-qPCR. Western blotting also confirmed increased expression of ITGA6 in the tumor tissues. The knockdown of ITGA6 by siRNAs and shRNA was confirmed with Western blot and qRT-PCR. ITGA6 knockdown significantly decreased proliferation, migration and anchorage independent growth of HCC cell lines.

Conclusions: ITGA6 is upregulated in HCC tumors in Latinos patients. ITGA6 may play a malignant-promoting role in HCC cells. Our studies provided new insights into the molecular mechanisms that drive HCC progression and potential therapeutic targets for treating patients with HCC including South Texas Latino patients.

Citation Format: Guixi Zheng, Carla Zeballos, Hakim Bouamar, Matyas Cserhati, Francisco G Cigarroa, Lu-zhe Sun. RNA interference reveals tumor promoting roles of integrin alpha 6 (ITGA6) in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4642.