bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3149: Collagen XIII induces β1-integrin activation and triple-negative breast cancer metastasis
Authors: Zhang Hui , Fredericks Tricia , Xu Ren
Published: August 2018

Increased collagen expression and deposition is a risk factor for breast cancer development. Collagen XIII is a type II transmembrane protein within the collagen superfamily. Experiments in tissue culture and knockout mouse model show that collagen XIII is involved in cell adhesion and differentiation of certain cell types. However, function of collagen XIII in cancer development and progression largely remains to be determined. We found that collagen XIII expression is significantly induced during breast cancer development, especially in triple negative breast cancer. Increased collagen XIII mRNA level is associated with poor prognosis. Importantly, silencing collagen XIII expression in MDA MB 231 cells slow down xenograft growth and significantly reduced cancer metastasis in mice. Using gain- and loss-of function approaches, we showed that collagen XIII enhanced cell migration, invasion, and mammosphere/tumorsphere formation. We also found that collagen XIII induced integrin-β1 activation, and subsequently enhanced TGF-β signaling. Blocking integrin-β1 activation with AIIB2 antibody significantly reduced collagen XIII-induced cell migration and mammosphere formation. These findings demonstrate a novel function of collagen XIII in promoting cancer metastasis through enhancing β1 integrin-dependent cell migration and invasion

Citation Format: Hui Zhang, Tricia Fredericks, Ren Xu. Collagen XIII induces β1-integrin activation and triple-negative breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3149.
Abstract 315: Cell death of AML blasts induced by cytarabine and enhanced by the Vitamin D2/Carnosic acid cell differentiating combination involves apoptosis signal-regulating kinase 1 (ASK1) activation
Authors: Wang Xuening , Harrison Jonathan S. , Studzinski George P.
Published: August 2018

Acute Myeloid Leukemia (AML) is a disease with a grim prognosis and limited curative treatment options. The principal agent used to induce disease remissions is Cytarabine (AraC), typically combined with an anthracycline, though multiple other combinations have been explored. We have previously reported that the exposure of AML blasts, in which the DNA is already damaged by AraC, to the Vitamin D2 analog Doxercalciferol combined with Carnosic Acid (D2/CA) enhances AraC cytotoxicity, resulting in an increased cell kill of the blasts. To obtain an understanding of the underlying mechanisms, and thus facilitate the translation of this finding to the clinic, we conducted in vitro studies on HL60, U937 cell lines and on AML blasts in primary culture. The initial findings were that the kinases BRAF and JNK1 and the pro-apoptotic protein BIM participate in the enhancement of AraC action. We now report that the kinase activity of ASK1 (MAP3K5) is upregulated by both AraC and D2/CA, and this appears to be additive thus increasing the apoptosis by this sequential combination regimen. Interestingly, we also noted that BRAF directly binds to ASK1, and since it is a kinase, this raises the possibility that it activates ASK1 in this experimental system. This possibility is strengthened by the report that JNK activation which leads to apoptosis is dependent on BRAF. The ongoing investigation of additional details of the molecular events responsible for enhanced cell death may provide clues for the improvement of the therapy of AML. (Supported by NIH grant R01CA044722-26 from NCI).

Citation Format: Xuening Wang, Jonathan S. Harrison, George P. Studzinski. Cell death of AML blasts induced by cytarabine and enhanced by the Vitamin D2/Carnosic acid cell differentiating combination involves apoptosis signal-regulating kinase 1 (ASK1) activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 315.
Abstract 3154: Harnessing the adaptive potential of mechanoresponsive proteins to overwhelm pancreatic cancer dissemination and invasion
Authors: Surcel Alexandra , Schiffhauer Eric S. , Thomas Dustin G. , Zhu Qingfeng , DiNapoli Kathleen , Herbig Maik , Otto Oliver , Guck Jochen , Jaffee Elizabeth , Iglesias Pablo A. , Anders Robert A. , Robinson Douglas N.
Published: August 2018

Metastatic disease is often characterized by altered cellular contractility and deformability, lending cells and groups of cells the flexibility to navigate through different microenvironments. This ability to change cell shape is driven in large part by the structural elements of the mechanobiome, which includes cytoskeletal proteins that sense and respond to mechanical stimuli. Here, we demonstrate that key mechanoresponsive proteins (those that accumulate in response to mechanical stress), specifically nonmuscle myosin IIA and IIC, α- actinin 4, and filamin B, are highly upregulated in pancreatic ductal adenocarcinoma cancer (PDAC) and in patient-derived pancreatic cancer cell lines. Their less responsive sister paralogs (myosin IIB, α-actinin 1, and filamin A) show a smaller dynamic range or disappear with PDAC progression. We demonstrate that these mechanoresponsive proteins directly impact cell mechanics using knockdown and overexpression cell lines. We further quantify the nonmuscle myosin II family members in patient-derived cell lines and identify a role for myosin IIC in the formation of transverse actin arcs in single cells and cortical actin belts in tissue spheroids. We harness the upregulation of myosin IIC and its impact of cytoskeletal architecture through the use of the mechanical modulator 4-hydroxyacetophenone (4-HAP), which increases myosin IIC assembly and stiffens cells. Here, 4-HAP decreases dissemination, induces cortical actin belts, and slows retrograde actin flow in spheroids. Finally, mice having undergone hemisplenectomies with PDAC cells and then treated with 4-HAP have a reduction in liver metastases. Thus, increasing the activity of these mechanoresponsive proteins (in this case, by increasing myosin IIC assembly) to overwhelm the ability of cells to polarize and invade may be an effective strategy to improve the five-year survival rate of pancreatic cancer patients, currently hovering around 6%.

Citation Format: Alexandra Surcel, Eric S. Schiffhauer, Dustin G. Thomas, Qingfeng Zhu, Kathleen DiNapoli, Maik Herbig, Oliver Otto, Jochen Guck, Elizabeth Jaffee, Pablo A. Iglesias, Robert A. Anders, Douglas N. Robinson. Harnessing the adaptive potential of mechanoresponsive proteins to overwhelm pancreatic cancer dissemination and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3154.
Abstract 316: Cancer cell apoptosis is induced by soluble factors secreted from normal mammary fibroblasts
Authors: Tsegaye Matyas Abel , Nemera Mati , Schafer Zachary T.
Published: August 2018

The tumor microenvironment (TME), comprised of a heterogeneous population of transformed and non-transformed cells, plays a crucial role in cancer growth. Studies have shown that there is continuous bidirectional communication between cancer cells and the different cell populations within the TME. This communication can either work to promote tumor growth, as seen with carcinoma associated fibroblasts (CAFs), or inhibit tumor growth, as observed with tumor infiltrating lymphoid cells. To date, the majority of research focusing on understanding the role of fibroblasts in the TME has been on CAFs and their ability to enhance tumorigenesis. Although the majority of studies have focused on CAFs, some studies have shown that certain fibroblast populations can antagonize tumor growth. Despite this evidence for an inhibitory role of normal fibroblasts, the precise molecular mechanism by which these cells modulate cancer cell growth has yet to be elucidated. Here, we show that normal mammary fibroblasts (fibroblasts isolated from normal breast tissue) secrete soluble factors that induce caspase mediated cell death in a variety of cancer cell lines. This phenotype was observed in MDA-MB-231s as well as T47D, and BT474 cell lines. Further verification of this phenotype was performed in MDA-MB-231s using Annexin V staining and flow cytometry. When examining the mechanism of apoptotic induction, we observed a substantive increase in the cleavage of caspase 8, evidence that the extrinsic apoptotic pathway is activated. We are currently working to further elucidate the signaling pathways activated in the aforementioned cancer cell lines resulting in the induction of apoptosis by normal mammary fibroblasts. Our research reveals a novel and potentially tumor suppressive function of normal mammary fibroblasts in the tumor microenvironment through secretion of soluble factors that induce apoptosis in cancer cells.

Citation Format: Matyas Abel Tsegaye, Mati Nemera, Zachary T. Schafer. Cancer cell apoptosis is induced by soluble factors secreted from normal mammary fibroblasts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 316.
Abstract 3162: Endothelin-1 receptor/beta-arrestin-1 pathway promotes invadopodia and metastatic process by integration with hMENA in human serous ovarian cancer
Authors: Caprara Valentina , Modugno Francesca Di , Chellini Lidia , Tocci Piera , Spadaro Francesca , Sacconi Andrea , Blandino Giovanni , Nisticò Paola , Bagnato Anna , Rosanò Laura
Published: August 2018

Aberrant activation of the endothelin-1 receptor (ET-1R) elicits pleiotropic effects relevant for serous ovarian cancer (SOC) cell invasion. The network activated by this receptor might be finely, spatially and temporary orchestrated by β-arrestin1 (β-arr1)-driven interactome. Recently, we uncovered a novel role for ET-1R/β-arr1 as regulator of cytoskeletal remodelling and invasive protrusions, invadopodia. Emerging evidence demonstrated that hMENA protein, an Ena/Vasp family member, is a key invadopodia component. In this study, we set out to molecularly dissect whether hMENA might represent a novel interacting partner of β-arr1 necessary for invadopodial function downstream of ET-1R in SOC cells. ENAH mRNA is significantly upregulated in OC tissues, and in particular in high-grade (HG)-SOC tumors, compared with normal tissues. In a panel of SOC cells, the expression hMENA, along with the spliced isoform hMENAΔv6, is upregulated by ET-1, at mRNA and protein levels, through β-arr1, restricted to mesenchymal phenotype. This effect is inhibited by treatment with the dual ETAR/ETBR antagonist macitentan. As shown by biochemical and imaging assays, ET-1 promotes a physical association between hMENA and β-arr1 as well PDZ-RhoGEF, which in turn activate RhoC. Most importantly, ET-1 induces localization of hMENA in F-actin-containing puncta, which co-localize with cortactin, and extracellular matrix degradation sites, thus promoting invadopodia maturation. Silencing of hMENA, as well as of β-arr1, or treatment with macitentan, impairs ET-1-dependent invadopodia activity, MMP secretion and activation, invasion, transendothelial migration and cell plasticity. In vivo, macitentan is able to inhibit SOC metastatic dissemination and hMENA expression along with other invadopodia markers. Finally, high ETAR/ARRB1/ENAH gene expression is associated with a poor prognosis in SOC patients. Collectively, these data define a pivotal function of hMENA/ hMENAΔv6, which is required for ET-1/β-arr1-induced invadopodial function and metastatic spreading of SOC.

Citation Format: Valentina Caprara, Francesca Di Modugno, Lidia Chellini, Piera Tocci, Francesca Spadaro, Andrea Sacconi, Giovanni Blandino, Paola Nisticò, Anna Bagnato, Laura Rosanò. Endothelin-1 receptor/beta-arrestin-1 pathway promotes invadopodia and metastatic process by integration with hMENA in human serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3162.
Abstract 3163: Wnt7a promotes bladder cancer cell invasion via canonical Wnt/β-Catenin signaling
Authors: Huang Ruimin , Huang Xiaojing , Zhu Hongwen , Zhuang Junlong , Dong Yu , Zhou Hu , Guo Hongqian , Yan Jun
Published: August 2018

The mortality rate of urinary bladder cancer (UBC) increases dramatically, once low grade non-muscle invasive bladder cancer develops into muscle invasive bladder cancer. Hence, understanding the mechanisms underlying UBC invasion/metastasis and identification of biomarkers for invasion/metastasis will help clinicians to determine how to treat patients. Herein we generated two sublines from parental 5637 UBC cells with low invasive and high invasive capacities, which were designated as 5637 NMI and 5637 HMI, respectively. Mass spectrometry analysis was performed to identify the invasion-associated proteins. 5,987 proteins were quantified across all six samples with the coefficients among different channels all nearly 1.00, suggesting good biological repeatability and minor differences between 5637 HMI and NMI samples. Fold change > 1.2 and p value <0.05 were set as the cut-off standard, and 16 upregulated proteins and 26 downregulated proteins were identified in 5637 HMI cells. Among them, Wnt7a overexpression was confirmed in 5637 HMI cells compared to 5637 NMI cells, which was also associated with metastasis potential and worse clinical outcome in UBC patients.

Depletion of Wnt7a in 5637 HMI and T24 cells reduced UBC cell invasion, with the reduction of active β-Catenin and its downstream target genes involved in epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) degradation. Consistently, introduction recombinant Wnt7a protein to 5637 NMI and J82 cells induced cell invasion, EMT, and the expression of ECM degradation-associated genes. Using luciferase reporter driven by the wildtype or mutants of matrix metalloproteinase 10 (MMP10) promoter, a canonical Wnt/β-Catenin regulation pattern was demonstrated.

Four miRNAs downregulated in UBCs were predicted directly targeting Wnt7a using bioinformatics analysis. miRNA mimic could decrease Wnt7a expression, reduce the activation of MMP 10 reporter and suppress the invasion of 5637 HMI cells. Treatment of UBC cells with Wnt7a partially abrogated such miRNAs-induced invasion suppression.

Taken together, our data identify a new miRNA/Wnt7a axis to mediate cell invasion and metastasis of UBC through canonical Wnt/β-Catenin pathway, which may offer prognostic and therapeutic opportunity.

Citation Format: Ruimin Huang, Xiaojing Huang, Hongwen Zhu, Junlong Zhuang, Yu Dong, Hu Zhou, Hongqian Guo, Jun Yan. Wnt7a promotes bladder cancer cell invasion via canonical Wnt/β-Catenin signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3163.
Abstract 3166: The HU177 cryptic collagen epitope selectively regulates melanoma cell behavior by a CDK5 and PTPN12 associated mechanism
Authors: Han Xianghua , Caron Jennifer M. , Brooks Peter C.
Published: August 2018

Previous studies indicate that selectively inhibiting cellular interactions with the HU177 cryptic collagen epitope, which can be generated in vivo during structural remodeling of the extracellular matrix (ECM), inhibits tumor growth and metastasis. However, a detailed understanding of the mechanisms by which antagonists of the HU177 collagen epitope inhibit these pathological processes is not fully understood. Uncovering the molecular mechanisms by which cellular interactions with this collagen epitope regulate tumor cell behavior may allow the development of more effective clinical strategies targeting tumor cell-ECM interactions. Here we provide evidence for the first time, that specific targeting of the HU177 cryptic collagen epitope reduces phosphorylation of cyclin-dependent kinase (CDK5) and in addition, reduces the expression of the phosphatase PTPN12 in melanoma cells attached to denatured collagen. Importantly, both CDK5 < PTPN12 play a functional role in the ability of the HU177 collagen epitope to regulate migration of melanoma cells as reducing expression of these molecules inhibited the anti-migratory activity of the anti-HU177 antibody. Surprisingly, reduction in either CDK5 or PTPN12 also inhibited nuclear accumulation of YAP. These novel findings help define a previously unknown signaling mechanism by which both CDK5 < PTPN12 may play a selective role in controlling nuclear accumulations of the transcriptional co-activator YAP following melanoma cell interactions with the HU177 cryptic collagen epitope. Taken together, these studies provide new molecular insight into the role of the HU177 collagen epitope in controlling melanoma cell behavior. Given that direct targeting of integrin receptors that mediate tumor cellular interactions with the ECM have demonstrated only limited anti-tumor activity in human clinical trials, a more detailed molecular understanding of how generation of biologically relevant cryptic elements of the ECM control melanoma cell behavior will likely facilitate the development of more effective new clinical strategies to control tumor progression.

Citation Format: Xianghua Han, Jennifer M. Caron, Peter C. Brooks. The HU177 cryptic collagen epitope selectively regulates melanoma cell behavior by a CDK5 and PTPN12 associated mechanism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3166.
Abstract 3167: Loss of HP1α alters the integrity of the nuclear lamina, thereby promoting invasion
Authors: Hale Tracy K. , Solomon Raoul
Published: August 2018

Malignant cell invasion is accompanied by complex changes in nuclear morphology and chromatin patterning that have been utilized by pathologists to determine malignancy. Members of the HP1 family modulate chromatin plasticity, with the HP1α paralog required to maintain the condensation of transcriptionally silent heterochromatin and to sequester it at the nuclear periphery. While increased expression of HP1α is proposed to aid the onset of malignancy, the acquisition of an invasive phenotype correlates with the loss of this architectural protein in many solid tumors including those of the thyroid, kidney, colon and breast. We have shown in a Drosophila model of epithelial cell invasion that loss of HP1α synergistically enhances invasion in cells with an activated oncogenic pathway. In the poorly invasive MCF7 breast cells, loss of HP1α increases their invasive potential and promotes epithelial plasticity. These phenotypic changes are associated altered nuclear morphology including increased nuclear grooves and indentations, diffuse chromatin patterning and a loss of heterochromatin at the nuclear periphery. Since during metastatic invasion, the nucleus, the largest and most rigid cellular of organelle, becomes malleable enough to squeeze through interstitial spaces in the surrounding tissue. This lead us to propose that loss of HP1α causes a remodelling of nuclear periphery thereby increasing nuclear malleability. Here we demonstrate that HP1α knockdown in MCF7 cells decreases mechanical stability of the nuclei and altering the integrity of nuclear lamina. While total levels of Lamin A/C, Lamin B1 and Lamin B2 are unchanged within the cell, their solubility and thus localization within the nucleus is altered. We also demonstrate how this change in the lamina effects other proteins that function at the nuclear periphery. Together, these findings suggest that when loss of HP1α increases invasive potential there is a corresponding disruption to the nuclear periphery, creating a weakness in these cells that could be exploited for therapeutic benefit.

Citation Format: Tracy K. Hale, Raoul Solomon. Loss of HP1α alters the integrity of the nuclear lamina, thereby promoting invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3167.
Abstract 3174: PLK4 is a rational target for very high-risk medulloblastoma
Authors: Nor Carolina , Bray Mark , Mak Tak , Taylor Michael
Published: August 2018

Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Despite aggressive therapy (maximal safe surgical resection, craniospinal irradiation and/or chemotherapy) only 65% of patients survive, and survivors are left with severe neuro-cognitive sequelae. MB is comprised of at least four distinct molecular subgroups (SHH, Wnt, Group 3 and Group 4). Within the Sonic hedgehog (SHH) subgroup, a subset harboring inactivating mutations within TP53 represent a very high-risk group with almost universally fatal outcome. TP53 mutated SHH tumors have a high degree of genomic instability with frequent chromothripsis and are resistant to the current generation of SHH pathway inhibitors. The protein PLK4 has a key role in the maintenance of chromosome numeral integrity and as such dysregulation of PLK4 expression causes genomic instability. The PLK4 inhibitor (CFI-400945, produced by the Campbell Family Institute for Breast Cancer Research) was shown to increase genomic instability in aneuploid cells from adult solid tumors and induce these cells to die through mitotic catastrophy. Here we leverage a sporadic transposon based metastatic mouse model (Ptch+/-/Math1-SB11/T2Onc) that faithfully mimics very high-risk MB in children. In order to mimic treatment in children, tumors are microsurgically subtotally resected, followed with the oral administration of CFI-400945 and cranial MRI to monitor response. Blood brain barrier penetration of CFI-400945 was confirmed using mass spectroscopy, specifically pharmacokinetics study revealed an expected availability of CFI-400945 in the circulating blood and concentrated compound in the tumor compared to the normal brain. The administration of CFI-400945 confers an advantage of survival to the mice in this model, median of 18.5 days for surgery group and 49 days for surgery plus CFI-400945 group (p=0.005). In human tumor datasets PLK4 is highly expressed across a variety of malignancies, including MB. Specifically, across two independent, non-overlapping datasets higher PLK4 levels correlate with a trend toward worse outcome, however, when restricting this analysis only to SHH tumors, there is a significant survival difference between high and low PLK4 expression (p=0.012). In paired primary-metastatic MB PLK4 expression is retained at the time of recurrence, specifically in metastatic recurrences, suggesting PLK4 inhibition is a suitable treatment option at the time of recurrence. Taken together, the data reveals PLK4 inhibition as a novel and rational therapeutic target for a subset of very high risk MB and a broad range of other pediatric cancers.

Citation Format: Carolina Nor, Mark Bray, Tak Mak, Michael Taylor. PLK4 is a rational target for very high-risk medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3174.
Abstract 3175: Sulfated glycopeptide nanostructures activate and extend bone morphogenetic protein 4 ability to increase pediatric malignant glioma chemotherapeutic efficacy
Authors: Xi Guifa , Best Benjamin , Nayak Sonali , McClendon Mark , Mania-Farnell Barbara , Kessler John , James Charles David , Stupp Samuel , Tomita Tadanori
Published: August 2018

Pediatric gliomas, particularly high-grade gliomas, are among the most formidable and devastating cancers in children. These tumors have remained incurable, regardless of the many treatment approaches attempted. We recently identified a small population of glioma cells with stem-like features in pediatric gliomas (glioma stem cells: GSCs), that may be responsible, for therapeutic resistance in pediatric gliomas. Signaling by bone morphogenetic protein 4 (BMP4), an essential molecule for central nervous system (CNS) development, increases GSC therapeutic sensitivity, and whose activation is a promising adjuvant for glioma treatment. Mechanisms through which BMP4 increases therapeutic sensitivity need to be elucidated as this can lead to the identification of additional targets for treating malignant gliomas in children. Delivery systems for administering BMP4 in a clinical setting also need to be developed. Here, we show that BMP4 increases chemosensitivity by decreasing H3 lysine 4 trimethylation (H3K4me3) at the promoter of multidrug resistant gene 1 (MDR1) that, in turn, results in increased BMP4 expression. This appears to be the result of BMP4 decreasing levels of hSETD1A, a critical methyltransferase for H3K4me3. Our work also demonstrates the first use of a novel sulfated glycopeptide (glycol-PA) nanostructure as a vector for delivery of BMP4. Glycol-PA markedly extended and enhanced BMP4 function, and increased chemotherapeutic anti-tumor activity against pediatric malignant glioma cells in culture. Overall, our results expand understanding of how BMP4 brings about glioma therapeutic sensitization through epigenetic mechanisms, and show that highly bioactive glyco-PA nanostructures have potential as a novel delivery mechanism for treating pediatric malignant glioma, as well as other tumors.

Citation Format: Guifa Xi, Benjamin Best, Sonali Nayak, Mark McClendon, Barbara Mania-Farnell, John Kessler, Charles David James, Samuel Stupp, Tadanori Tomita. Sulfated glycopeptide nanostructures activate and extend bone morphogenetic protein 4 ability to increase pediatric malignant glioma chemotherapeutic efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3175.
Abstract 3192: Aptamers, antibodies and radiotherapy for the treatment of DIPG
Authors: Martinez-Velez Naiara , Marigil Miguel , Aristu Javier , Ramos Luis , Pastor Fernando , Patiño-García Ana , García-Moure Marc , Fueyo Juan , Gomez-Manzano Candelaria , Diez-Valle Ricardo , Tejada Sonia , Alonso Marta M.
Published: August 2018

Diffuse intrinsic pontine gliomas (DIPGs) is one of the most aggressive pediatric brain tumors. Radiotherapy (RT) constitute the standard of care of these tumors being its therapeutic effect just palliative. There is plenty of evidence that RT is able to activate immune responses through the induction of immunogenic cell death. However, it also elicits immunosuppressive effects and enforces immunological tolerance. The result is that in DIPGs the RT effect is just transitory. In this context, immune costimulatory or inhibitory molecules with the capability to boost the immune effect of RT could be amenable agents to use in combination to treat DIPGs. Agonist antibodies has been widely used in immunotherapy. Aptamers are high-affinity single-stranded nucleic acid ligands that exhibit remarkable affinity and specificity to their targets, comparable or exceeding that of antibodies. 4-1BB is a major costimulatory receptor promoting the survival and expansion of activated T cells. TIM-3 is a negative regulator of lymphocyte function that is involved in T-cell exhaustion. To this end, we examined the effect of RT in combination with either an agonist 4-1BB antibody or an aptamer against TIM-3. Importantly, both combined treatments showed a safe profile. Moreover, combination treatment of 4-1BB agonist antibody or TIM-3 aptamer with RT resulted in a significant improvement in the median survival of mice bearing DIPG orthotopic tumors when compared with single treatment in around 20 days (P=0.001 and P=0.04, for the combination of RT and 4-1BB or TIM-3,respectively). In addition, both combination led to long-term survivors (90 days). Rechallenge experiments in these animals showed the generation of memory against the tumors in both combined treatment. Mechanistic studies performed on day 16 showed an increase in CD8 effector cells, a decrease in T-regulators Foxp3+ cells and an increase in INF-gamma expression suggesting the triggering of an antitumor-immune response. Our data underscore that combination of RT with immune-boosting strategies for DIPGs are worth exploring.

Citation Format: Naiara Martinez-Velez, Miguel Marigil, Javier Aristu, Luis Ramos, Fernando Pastor, Ana Patiño-García, Marc García-Moure, Juan Fueyo, Candelaria Gomez-Manzano, Ricardo Diez-Valle, Sonia Tejada, Marta M. Alonso. Aptamers, antibodies and radiotherapy for the treatment of DIPG [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3192.
Abstract 3194: Development of an in vitro drug profiling platform with primary Rhabdomyosarcoma cells for tailoring patient-specific treatments
Authors: Wachtel Marco , Manzella Gabriele , Römmele Michaela , Zhang Luduo , Tchinda Joelle , Niggli Felix , Schäfer Beat
Published: August 2018

The paradigm of cancer therapy currently shifts from broadly used cytotoxic drug cocktails to patient specific precision therapies. These novel therapies are normally directed towards tumor specific driver oncogenes, identified by genomic analysis of individual tumors. In case of tumors with a very low mutational burden and/or currently undruggable driver oncogenes this approach is less suitable. There, direct drug profiling of in vitro cultured tumor cells represents a promising alternative for identification of patient specific therapies. Conditions to maintain primary tumor cells in culture for this purpose however are largely unknown for most tumor entities. Here, we aimed to establish an in vitro drug profiling platform for Rhabdomyosarcoma (RMS), a childhood cancer with above described characteristics. Towards this aim, we isolated cells from 6 alveolar and 8 embryonal RMS patient derived xenografts and systematically tested 18 different culture conditions in order to find suitable parameters for in vitro propagation of primary RMS cells. This approach revealed that cells from most tumors survive and proliferate only in serum-free medium, whereas in serum containing medium tumor cells are progressively lost over time. Importantly, cells preserve the clonal composition and phenotypic characteristics of the primary PDX under these conditions, as assessed by genomic and copy number analysis. Drug profiles established with a library of 204 drugs revealed, beside patient-specific vulnerabilities, a yet unrecognized sensitivity of a subgroup of alveolar RMS towards AKT inhibitors. Furthermore, screening with the same drugs for resensitization of resistant relapse samples identified the BCL-2 family inhibitor ABT-263 as most potent resensitizer towards standard-of-care chemotherapy. Detailed molecular analysis revealed that this effect is based on blockade of the BCL-XL-MCL-1 axis. Overall, our proof of concept study highlights the feasibility of in vitro drug profiling of primary RMS cells for patient-specific treatment selection in a co-clinical setting.

Citation Format: Marco Wachtel, Gabriele Manzella, Michaela Römmele, Luduo Zhang, Joelle Tchinda, Felix Niggli, Beat Schäfer. Development of an in vitro drug profiling platform with primary Rhabdomyosarcoma cells for tailoring patient-specific treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3194.
Abstract 3198: Comprehensive transcriptome analysis identifies integrated mRNA-lncRNA signature of triple-negative breast cancer treated with radiotherapy
Authors: CHEN Xingxing , YANG Zhaozhi , JIANG Yizhou , MA Jinli , YU Xiaoli , SHAO Zhimin , GUO Xiaomao
Published: August 2018

Triple-negative breast cancer (TNBC), with a lack expression of ER, PR, and HER-2 as potential treatment targets, is insensitive to the hormonal and trastuzumab therapies. Thus, local and regional treatment, such as radiotherapy is placed with more emphasis when treating TNBC patients. In the current study, expression profiles of mRNAs and long noncoding RNAs (lncRNAs) in TNBC patients, who received radiotherapy in our institute, was investigated to develop radiation-related gene signatures to facilitate individualized TNBC treatment. Specifically, 44 TNBC samples including 14 recurrences and 30 non-recurrences after radiotherapy were analyzed by using transcriptome microarrays. A total of 626 mRNAs were identified as differentially expressed (DEGs) between recurrent patients and non-recurrent patients (|fold change| > 1.5, p < 0.05). GeneOntology analysis showed that these DEGs were enriched in immune response, mitotic cell cycle, inflammatory response, cell adhesion as well as extracellular matrix organization, which indicated that these biological processes may exert significant impacts on the therapeutic effects of radiation. In addition, a total of 150 lncRNAs were identified as differentially expressed between recurrent patients and non-recurrent patients (|fold change| > 1.5, p < 0.05). The differentially expressed mRNAs and lncRNAs were confirmed by quantitative real-time PCR. Cox regression model was further applied to explore potential lncRNAs involved in certain signaling pathways such as JAK/STAT, EGRF/ATK/PI3K are highly co-expressed with mRNAs in these signaling pathways. Overall, our results revealed a panel of mRNAs and lncRNAs with significant impacts on evaluating the TNBC radio-therapeutic effects as well predicting the possibility of recurrence.

Citation Format: Xingxing CHEN, Zhaozhi YANG, Yizhou JIANG, Jinli MA, Xiaoli YU, Zhimin SHAO, Xiaomao GUO. Comprehensive transcriptome analysis identifies integrated mRNA-lncRNA signature of triple-negative breast cancer treated with radiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3198.
Abstract 3202: Radiation increases invasive activity of breast cancer cells via altering lysosome exocytosis
Authors: Wu Ping-Hsiu , Onodera Yasuhito , Giaccia Amato J. , Le Quynh-Thu , Shirato Hiroki , Nam Jin-Min
Published: August 2018

Radiotherapy is a standard treatment for many localized solid cancers. However, previous studies have shown that radiation may increase the invasive activity of cancer cells and potentially distant metastasis. Recently, lysosome exocytosis has been linked to cancer cell invasiveness and progression. In this study, we evaluate the role of lysosome exocytosis on invasive activity of breast cancer cells upon radiation.We used both human and murine breast cancer cell lines (MDA-MB-231 and 4T1). The cells were treated with a single radiation dose of 4 Gy. Cell invasive activity was measured by matrigel chemoinvasion assay. Lysosome exocytosis was quantified by fluorescein isothiocyanate conjugated dextran (FITC-dextran) intake assay, cell-surface lysosomal associated membrane protein 1 (LAMP1) expression and cellular lysosome distribution assay. To validate the lysosome function, lysosome inhibitors, bafilomycin A1 and chloroquine were used. Short hairpin RNA (shRNA) was used to knockdown ARL8B, which is a small GTPase protein that regulates lysosome distribution and exocytosis. The invasive activity and lysosome exocytosis of tested breast cancer cell lines were increased after radiation treatment. Treatment with lysosome inhibitor bafilomycin A1 or chloroquine decreased the invasive activity of cancer cells, with or without radiation treatment. The protein level of ARL8B increased in the lysosome fraction upon radiation. Down-regulation of ARL8B with shRNA led to a decrease in lysosome exocytosis with a concomitant inhibition radiation induced invasive activity of the breast cancer cells without affecting the basal invasiveness. In addition, overexpression of ARL8B increased the invasive activity of breast cancer cells, which was similar to the result obtained after radiation.In summary, radiation enhances lysosome exocytosis in breast cancer cells that can lead to their increased invasive activity. Our findings provide a novel mechanism to understand cancer invasion after radiotherapy and suggest novel approaches to counteract this undesirable effect of radiotherapy in the future.

Citation Format: Ping-Hsiu Wu, Yasuhito Onodera, Amato J. Giaccia, Quynh-Thu Le, Hiroki Shirato, Jin-Min Nam. Radiation increases invasive activity of breast cancer cells via altering lysosome exocytosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3202.
Abstract 3212: Nuclear-targeted gold nanoparticles as radiosensitizers
Authors: Krishnan Sunil , Aliru Maureen
Published: August 2018

Purpose

Intracellular localization of gold nanoparticles has been shown to enhance the effects of radiation. However, few studies have investigated the effect of subcellular localization of these particles on enhancing the radiosensitization effect in cells treated with radiation of varying energies and linear energy transfer (LET) levels. Herein, we evaluate the radiosensitization potential of nuclear-targeted gold nanoparticles across a spectrum of energies and LETs.

Methods

Gold nanospheres (AuNSs) were functionalized with a nuclear localization sequence (NLS) peptide to enhance the nuclear accumulation of these particles. Internalization of the particles into the cells was achieved using a cell penetrating peptide (CPP). Cellular and nuclear internalization were assessed in Panc-1 human pancreatic adenocarcinoma cancer cells using western blot (WB), transmission electron microscopy, dark field microscopy and inductively-coupled plasma mass spectrometry (ICP-MS). DNA damage due to radiation was evaluated through γH2AX and 53BP1 foci staining. Clonogenic cell survival assay was performed to evaluate the radiosensitization effect after irradiation with 250-kVp X-rays, Cs-137, Co-60, 6 MV and 100 MeV protons (LET 2.5 and 7.7 keV/µm).

Results

Nuclear-targeted particles (nAuNS) and non-targeted particles (PEGylated, pAuNS) demonstrated similar cellular internalization. However, enhanced uptake of nuclear-targeted particles was observed in the nucleus when compared to non-targeted particles. This was confirmed using dark field microscopy, WB and ICP-MS analysis. DNA double strand breaks through γH2AX and 53BP1 foci staining revealed significantly higher numbers of foci at early (1 hour) and late (24 hour) time points following radiation and nAuNS compared to radiation and pAuNS treatment. Clonogenic cell survival assay revealed significantly higher radiosensitization enhancement factor (REF) at 10% survival fraction for nAuNS compared to pAuNS for all beams assessed. Protons with higher LETs resulted in greater clonogenic cell death and nAuNS further increased radiosensitization whereas pAuNS did not.

Conclusion

Our data demonstrates that, across a spectrum of radiation energies and LETs, nuclear-targeted gold nanoparticles enhance radiosensitization beyond that achievable with strictly intracytoplasmic gold nanoparticles.

Citation Format: Sunil Krishnan, Maureen Aliru. Nuclear-targeted gold nanoparticles as radiosensitizers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3212.
Abstract 3219: Sensitizing hypoxic small cell lung cancer cells to radiation and hydrogen peroxide-producing agents using CuATSM
Authors: Sciegienka Sebastian , Rodman Samuel , Tomanek-Chalkley Ann , Falls Kelly C. , Spitz Douglas R. , Fath Melissa A.
Published: August 2018

Cancer cells have increased steady state levels of reactive oxygen species (ROS; O2•- and H2O2) compared to normal cells. It has been proposed that using redox active agents that further increase ROS levels will result is selective cancer cell death. This metabolic frailty can be targeted using drugs deemed safe for human use, ascorbate (ASC) and disulfiram (DSF), via a mechanism of H2O2 production. CuATSM is a drug being used in clinical trials to treat ALS disease. Imaging studies have shown that CuATSM preferentially concentrates in hypoxic tissues, releasing its Cu after entering cells. Copper (Cu) can participate in oxidation reactions that result in highly toxic hydroxyl radicals. Tumors often have areas of hypoxic tissue that exhibit resistance to ionizing radiation (IR). Our hypothesis is that CuATSM can be used to sensitize hypoxic regions of tumors to IR, ASC and/or DSF.

Method: H2O2 flux after addition of ASC or DSF was measured in small cell lung cancer (SCLC) cells DMS53 using the 3-aminotriazole method. The Cu uptake of these cells was measured in normoxia and hypoxia after treatment with CuATSM. DMS53 and DMS273 (SCLC lines) were treated with ASC, CuATSM, and/or DSF+CuSO4 at varying oxygen tensions with and without IR and clonogenic assays were performed.

Results: Pharmacologically relevant dosing of DSF and ASC resulted in significantly higher fluxes of H2O2 compared to control. Both DSF and ASC enhanced IR clonogenic cell death in SCLC lines. Treatment with CuATSM resulted in increased intracellular Cu and enhanced cell death from ASC and IR in hypoxic conditions.

Conclusion: These observations support the hypothesis that the differences in steady-state level of ROS in small cell lung cancer cells can be exploited to develop effective therapies using ASC and DSF. Furthermore CuATSM can enhance responses in hypoxic tumor tissues to both IR and ASC. (Supported by P50 CA174521, T32 CA078586, P30 CA086862 and Carver Research Program of Excellence in Redox Biology and Medicine.)

Citation Format: Sebastian Sciegienka, Samuel Rodman, Ann Tomanek-Chalkley, Kelly C. Falls, Douglas R. Spitz, Melissa A. Fath. Sensitizing hypoxic small cell lung cancer cells to radiation and hydrogen peroxide-producing agents using CuATSM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3219.
Abstract 3222: Evaluation of associations between circulating proteins and breast cancer risk using genetic variants
Authors: Shu Xiang , Bao Jiandong , Wu Lang , Long Jirong , Guo Xingyi , Michailidou Kyriaki , Bolla Manjeet K. , Wang Qin , Dennis Joe , Simard Jacques , Easton Douglas F.
Published: August 2018

Breast cancer is the most commonly diagnosed cancer in women in many countries. Several circulating protein biomarkers have been identified in relation to breast cancer risk. However, previous studies either had small sample sizes or employed low-throughput techniques. To search for novel biomarkers, we utilized genetic variants as instruments and evaluated over 1,400 proteins in relation to breast cancer risk using data from the Breast Cancer Association Consortium (BCAC).

We extracted beta coefficients from reported protein quantitative trait loci (pQTL) derived from genome-wide association studies of circulating proteins. Summary statistics of these pQTL variants associated with breast cancer risk were obtained from 122,977 cases and 105,974 controls of European descent in the BCAC. Associations of genetically predicted protein levels with breast cancer risk were evaluated using the inverse-variance weighted method. For proteins with a significant association, expression levels of the corresponding gene were predicted using genotyping and transcriptomic data from the Genotype-Tissue Expression project and then evaluated for their associations with breast cancer risk.

We identified 56 protein biomarkers showing a significant association with breast cancer risk after accounting for multiple comparisons (false discovery rate < 0.05). Among them, levels of 32 proteins were influenced by variants close to a newly reported breast cancer susceptibility locus (9q34.2, ABO). Inverse associations of breast cancer risk were found with membrane proteins such as insulin receptor, insulin-like growth factor receptor 1, hepatocyte growth factor receptor, neurogenic locus notch homolog protein 1, and vascular endothelial growth factor receptor 2, with odds ratios ranging from 0.82 to 0.97 per unit increase in genetic risk scores (p-values ranging from 6.53x10-4 to 3.28x10-8). Genetically predicted expression of five genes, CPNE1, CTSF, TFPI, SCG3, and QSOX2, was found to be associated with breast cancer risk at p <0.05 in the same direction as the associations observed for the corresponding proteins. Results from our study suggest that multiple membrane proteins related to insulin resistance may be linked to breast cancer risk through genetic variants at 9q34.2.

Citation Format: Xiang Shu, Jiandong Bao, Lang Wu, Jirong Long, Xingyi Guo, Kyriaki Michailidou, Manjeet K. Bolla, Qin Wang, Joe Dennis, Jacques Simard, Douglas F. Easton. Evaluation of associations between circulating proteins and breast cancer risk using genetic variants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3222.
Abstract 3229: Prediagnostic biomarkers of metabolic dysregulation and cancer mortality
Authors: Akinyemiju Tomi
Published: August 2018

INTRODUCTION: The obesogenic milieu is a pro-tumorigenic environment that promotes tumor initiation, angiogenesis and metastasis. In this prospective cohort, we examined the association between pre-diagnostic metabolic biomarkers, plasma adiponectin, resistin, leptin and lipoprotein (a), and the risk of cancer mortality.

METHODS: Prospective data was obtained from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort of Blacks and Whites followed from 2003 through 2012 for cancer mortality. We determined the association between metabolism biomarkers (log-transformed and tertiles) and risk of cancer mortality using Cox Proportional Hazards models with robust sandwich estimators to calculate the 95% confidence intervals (CIs), and adjusted for baseline covariates, including age, gender, income, education, physical activity, BMI, smoking status, alcohol use, and comorbidity score.

RESULTS: Among 1764 participants with available biomarker data, each SD higher log-leptin was associated with a 54% reduced risk of total cancer mortality (HR: 0.46, 95% CI: 0.23 – 0.92) and obesity-related cancer mortality (HR: 0.55, 95% CI: 0.39-0.79). Among Blacks only, each SD higher log-resistin was associated with a nearly 7-fold increased risk of cancer mortality (adjusted HR: 6.68, 95% CI: 2.10 – 21.21). There were no significant associations of adiponectin or Lp(a) and cancer mortality.

CONCLUSIONS: Leptin is involved in long-term regulation of energy balance, while resistin is involved in chronic inflammation and LDL production. These findings highlight the biological mechanisms linking metabolic dysregulation with cancer mortality, and the influence of resistin on cancer mortality only among Blacks suggests that this hormone may be a useful biomarker of racial differences in cancer mortality that deserves further study.

Citation Format: Tomi Akinyemiju. Prediagnostic biomarkers of metabolic dysregulation and cancer mortality [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3229.