tbuckley/cabot-search huggingface dataset:
Abstract 4275: Gastric cancer stem cells under starvation stress might sustain their stemness via autophagy system
Authors: Shingo Togano
Journal: Cancer Research (2019)

Abstract Background: Cancer stem cells (CSCs) play an important role for the progression of carcinoma. And, CSCs have a potential of resistance to various stresses such as starvation and chemotherapy. Autophagy is an intracellular degradation system which is induced various kinds of cells under various stress. In cancer cells, autophagy is activated and has involved in cancer survival. However, the significance of autophagy in CSCs has still remained to be unknown, especially in starvation and chemotherapy stress. The aim of this study is to clarify the role of autophagy in CSCs under starvation condition. Materials and Methods: Two scirrhousgastric cancer cell lines, OCUM-2MD3 and OCUM-12 (parent cells) were used. Side population cells (SP cells) which include many CSCs, was known to the fraction of low dyeability of Hoechst 33342 identified by FACScan. Stemness of SP cells, OCUM-2MD3/SP and OCUM-12/SP, were examined by sphere colony assay and RT-PCR using stemness markers, Nanog, Oct3/4, CD44. Then we examined the effect of autophagy in CSCs under starvation condition, as follows.Parents cells and SP cells were evaluated about autophagy. Parents cells and SP cells were incubated in the presence and absence of glucose for various time. The expression level of autophagy molecule, LC3 was examined by western blotting. The effect of an autophagy inhibitor, Chloroquine, to SP frequency was examined by FACScan. Results: The expression of Nanogand Oct3/4, were significantly higher in OCUM-2MD3/SP rather than parent cells OCUM-2MD3. Also, these stemness markers were significantly higher in OCUM-12/SP cells rather than parent cells. The number of sphere colony was greater in both SP cells rather than that in parent cells. The expression level of LC3 was high in both SP cells, in comparison to that in parent cells under glucose deficient condition.The autophagy inhibitor,Chloroquine, significantly decreased the SP fraction in both cells. Conclusion: CSCs might have high autophagy activity under starvation stress and sustain their stemness by autophagy system. The autophagy inhibitor,Chloroquine, might be a promising agent for gastric cancer. Citation Format: Shingo Togano. Gastric cancer stem cells under starvation stress might sustain their stemness via autophagy system [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 4275.
Abstract 2359: The MCPyV st-ag and IL33/ST2 axis: critical role in merkel cell carcinoma
Authors: Kashif Rasheed, Silje Fismen, Øystein Grimstad, Baldur Sveinbjørnsson, Ugo Lionel Moens
Journal: Cancer Research (2019)

Merkel Cell polyomavirus (MCPyV) is a causal factor in Merkel Cell Carcinoma (MCC). The oncogenic potential is mediated through its viral oncoproteins large T-antigen (LT-ag) and small t-antigen (st-ag). Many cancers arise from sites of infection, chronic irritation and inflammation, and inflammatory signaling pathways are often activated by oncogenic mutations. Chemokines are a family of cytokines that regulate leukocyte trafficking in immunity and inflammation. The aberrant expression of chemokines and chemokine receptors in tumors may regulate the trafficking of leukocytes into the tumor microenvironment. IL33, a member of IL-1 family cytokines, is involved in the response to viral infection and plays important roles in type-2 innate immunity, tumorigenesis and tumor immune evasion.We assessed IL33/ST2 expression in MCPyV-positive (MKL2) and –negative (MCC13) MCC cell lines in order to examine a possible role of IL33/ST2 pathway in MCC.Using the human RT2 Profiler PCR Inflammatory Cytokines and Receptors Array, we did a PCR array analysis of 84 different human cytokines and receptor genes. Expression of IL-33 and ST2 was determined by qRT-PCR, immunohistochemistry and western-blot analysis. Luciferase analysis was done to monitor the effect of MCPyV early proteins on IL33 promoter activity and the effect of IL33 on MCPyV early and late promoter activity. Furthermore, mitogen-activated protein kinase (MAPK) and the NF-κB pathways were also assessed after stimulating MCC13 cells with recombinant human (rh) IL33 protein. Finally, proliferation activity after rhIL33 stimulation was assessed by MTT-assay.PCR array analysis showed higher transcript levels of IL33 in MCC13 cells transfected with st-ag compared to control cells. Western blot analysis confirmed increased IL33 expression by st-ag. Luciferase analysis showed higher IL33 promoter activity in st-ag transfected MCC13 cells. Interestingly, IL33 also increased MCPyV early and late promoter activity. Furthermore, rhIL33 activated both MAPK and the NF-κB pathways and blocking ST2 receptor using polyclonal goat ST2 antibody abolished IL33 activity. Dose-dependent effect of rhIL33 showed higher proliferation activity of MCC13 cells. Immunohistochemical analysis of IL33 and ST2 showed a significant stronger expression in MCC tissues compared to normal skin.Our study unveiled a novel st-ag dependent IL33 function in MCC. Therefore, neutralizing the IL-33/ST2 axis may thereby represent a therapeutic target in MCPyV-positive MCC patients.Citation Format: Kashif Rasheed, Silje Fismen, Øystein Grimstad, Baldur Sveinbjørnsson, Ugo Lionel Moens. The MCPyV st-ag and IL33/ST2 axis: critical role in merkel cell 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 2359.
Abstract 2168: Testing the electrical properties of different cell lines using 3DEP reader and compare to TTFields response
Authors: Moshe Giladi, Einav Zeevi, Karnit Gotlib, Cornelia Wenger, Ariel Naveh, Zeev Bomzon, Eilon D. Kirson, Uri Weinberg, Adrian Kinzel, Yoram Palti
Journal: Cancer Research (2019)

Abstract Background: Tumor Treating Fields (TTFields) are an approved anti-neoplastic treatment modality delivered via application of low intensity, intermediate frequency, alternating electric fields. The electrical properties of cells (such as permittivity and conductivity) determine the optimal frequency of TTFields that incurs the highest reduction in cell counts. Currently, there are no predictive markers for determining TTFields response or the optimal frequency to be applied for individual patient. The goal of this study is to determine the correlation between electrical properties of cells and TTFields’s optimal frequency and sensitivity. The 3DEP reader (LabTech) determines the electrical properties of cells, including permittivity and conductivity, by using Dielectrophoresis (DEP) force. DEP is a physical effect that generates a force on polarizable particles experiencing a non-homogeneous electric field and can therefore be used as a technique to analyse the way cells move within electric fields at different frequencies. Methods: The baseline electrical properties (permittivity and conductivity) of 17 cell lines from different tumor types were determined using the 3DEP reader (LabTech). The curves were analyzed using 2-way ANOVA. The optimal TTFields frequency for each cell line was determined by testing the cytotoxic effect of TTFields at various frequencies using the inovitro system. The electrical properties of cells were compared with the optimal TTFields frequency and sensitivity of each cell line. Results: The results demonstrate significant differences (p&amp;lt;0.001) between the lower frequency range of the 3DEP curves that corresponds to membrane capacitance of cells with TTFields optimal frequency of 150kHz (9 cell lines) and cells with TTFields optimal frequency of 200kHz (8 cell lines). Membrane capacitance was also a good predictor for TTFields sensitivity based on the differences in the curves in the low frequency range. Conclusions: The results presented in this study demonstrate that cell membrane capacitance correlates with TTFields optimal frequency and sensitivity. Based on the above, there is a strong rational to further explore the potential of measuring the electrical properties of cells as a predictive marker to help determine which patient will respond better to TTFields and the optimal TTFields frequency to be applied for each patient. Citation Format: Moshe Giladi, Einav Zeevi, Karnit Gotlib, Cornelia Wenger, Ariel Naveh, Zeev Bomzon, Eilon D. Kirson, Uri Weinberg, Adrian Kinzel, Yoram Palti. Testing the electrical properties of different cell lines using 3DEP reader and compare to TTFields response [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 2168.
Abstract 4648: Cellular senescence and transformation induced by an oncogenic EML4-ALK fusion gene in normal and immortalized human cells
Authors: Akihiko Miyanaga, Izumi Horikawa, Masaru Matsumoto, Takahiro Oike, Jessica Beck, Hiromi Tanaka, Ana I. Robles, Masahiro Seike, Akihiko Gemma, Curtis C. Harris
Journal: Cancer Research (2019)

Abstract Background: Chromosomal inversions involving Anaplastic lymphoma kinase (ALK) and Echinoderm Microtubule Associated Protein Like 4 (EML4) generate a fusion protein EML4-ALK with the constitutive ALK kinase activity in non-small cell lung carcinoma (NSCLC). The basic understanding of EML4-ALK remains insufficient due to the lack of functional studies using normal human cells. Material and Method: We investigate the activities of EML4-ALK in mortal and immortalized normal human cells. Results: The expression of EML4-ALK in normal, mortal human fibroblasts caused, through its ALK kinase activity, the early induction of cellular senescence with senescence-associated β-galactosidase activity, upregulation of p16INK4A and p21WAF1, telomere shortening and fusions, and accumulated DNA damage. In contrast, when EML4-ALK was expressed in telomerase reverse transcriptase (hTERT)-immortalized normal human fibroblasts, the cells showed accelerated proliferation and anchorage-independent growth, revealing its transformation activity. No chromosome aberration, no mutation or loss of p53, nor impairment of the p16INK4A response was associated with this transformation, likely reflecting clinical features of EML4-ALK-positive NSCLC. In both mortal and immortalized cells, EML4-ALK induced the phosphorylation of STAT3, which is involved in both cellular senescence and transformation. EML4-ALK was also able to transform hTERT-immortalized human bronchial epithelial cells, a cell type relevant to NSCLC. Conclusions: Our data not only validate that EML4-ALK functions as an oncogene in human cells, but also suggest that telomerase-mediated immortalization manifests the oncogenic activity of EML4-ALK, switching from its senescence-inducing activity. This study also provides the isogenic pairs of human cell lines with and without EML4-ALK as an in vitro model for screening and testing candidate drugs. Citation Format: Akihiko Miyanaga, Izumi Horikawa, Masaru Matsumoto, Takahiro Oike, Jessica Beck, Hiromi Tanaka, Ana I. Robles, Masahiro Seike, Akihiko Gemma, Curtis C. Harris. Cellular senescence and transformation induced by an oncogenic EML4-ALK fusion gene in normal and immortalized human 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 4648.
Association of smoking with poor risk ELN 2017, cytogenetics/molecular profile, and survival outcomes in acute myeloid leukemia.
Authors: Mansour Alfayez, Iman Abou Dalle, Guillaume Abou Richard-Carpentier, Daewoo Pak, Jing Ning, Sherry A. Pierce, Koji Sasaki, Kiran Naqvi, Naval Guastad Daver, Jorge E. Cortes, Farhad Ravandi, Naveen Pemmaraju, Alessandra Ferrajoli, Guillermo Garcia-Manero, Marina Konopleva, Gautam Borthakur, Hagop M. Kantarjian, Tapan Kadia, Courtney Denton Dinardo
Journal: Journal of Clinical Oncology (2019)

7002 Background: Smoking increases the relative risk of AML by 40% and 25% in active and former smokers, respectively, compared with non-smokers (Fircanis et al., 2014). While the relationship of smoking with AML development is recognized, whether smoking impacts underling AML biology and clinical outcome remains ill-defined. Methods: Newly diagnosed, treatment naïve AML pts seen at MDACC between 2012 and 2017 with available smoking history were evaluated, along with baseline parameters, co-occurring mutations, cytogenetics and clinical outcome. Results: We identified 858 pts [486 (57%) male; median age 67 yrs (14-97)], representing 535 (62%) treatment naïve and 323 (38%) salvage pts. Smoking status was recorded as smokers (active = 39 pt, former = 380 pt), versus never smoker (439 pt). In tx naïve group, smoking is associated with lower remission rates (OR 0.63, 95% CI 0.43-0.94, p = 0.02) and inferior OS (HR = 1.6, 95% CI 1.27-2.02, p &lt; 0.001). Smoking status was not significant in multivariate analysis including AML biologic characteristics and ELN 2017 risk stratification. Therefore we postulated that worse OS may be driven by smoking associated AML biology rather than smoking associated comorbidities. Indeed, in univariate analysis smoking was associated with poor ELN risk (p = 0.015), complex karyotype (p = 0.0002), and TP53 mutation (p = 0.0235) while negatively associated with NPM1 (p = 0.018), FLT3-ITD (p = 0.032) and GATA2 (p = 0.0497). Age was a significant cofounder between smokers vs non-smoker ( &lt; 0.0001). After controlling for age, significance was retained for ELN risk, complex karyotype and GATA2 at p = 0.0454, p = 0.0006, p = 0.048 respectively, while significance was lost for NPM1 (p = 0.079), FLT3-ITD (p = 0.1) and TP53 (p = 0.084). In analysis of young pts ( &lt; 60 yr), smoking is positively associated with complex karyotype (p = 0.0042) and TP53 (p = 0.0289), and negatively associated with RUNX1 (p = 0.0143) and IDH2 (p = 0.0357). Conclusions: We report the largest analysis of smoking status and impact on molecular, cytogenetics, and AML clinical outcomes. Smoking history is associated with poorer risk molecular and cytogenetics, lower response rate and shorter survival in treatment naïve patients.
Abstract 4743: Using genome-wide CRISPR screen to understand resistance mechanisms to PCA062, a P-cadherin targeting antibody-drug conjugate
Authors: Angela Tam, Mark Zambrowski, Katherine Seiss, Si-Qi Liu, Tinya Abrams, Giordano Caponigro, William Tschantz, Jennifer Campbell, Tony DAlessio, Qing Sheng
Journal: Cancer Research (2019)

Abstract P-cadherin (PCAD) is a member of the cadherin family that mediates calcium dependent cell-cell contacts in adherens-type junctions of epithelium. Expression of P-cadherin is high in malignant tumors of epithelial origin, such as breast, esophagus, head and neck cancers, but low in normal tissues. This expression pattern makes P-cadherin a potential good target for antibody-drug conjugates (ADCs). PCA062 is a first-in-class antibody drug conjugate targeting P-cadherin. PCA062 consists of a fully human anti-P-cadherin antibody of the IgG1/κ subtype, a non-cleavable bi-functional linker (SMCC) and a maytansine-derived cytotoxic payload (DM1, with a target average drug to antibody ratio (DAR) of 3.8). PCA062 activity was examined in a collection of cell lines expressing high level of PCAD. A subset of these PCAD high cell lines are resistant to PCA062 treatment while they remain sensitive to DM1, suggesting defects in the process of PCA062 uptake or the processing and release of DM1 into the cytoplasmic compartment. PCA062 internalization rate was measured by the uptake of a fluorescent dye labeled anti-PCAD antibody (CQY684, the Ab portion of PCA062) in both PCA062 sensitive and resistant lines. PCA062 resistant lines show slower CQY684 internalization as compared to PCA062 sensitive lines, indicating a defect in ADC internalization may contribute to PCA062 resistance. To explore additional resistance mechanisms to PCA062 as well as to find critical components for PCA062 internalization, a genome wide CRISPR screen was performed in PCA062 sensitive HCC1954 and in PCA062 resistant KYSE510 cell line in the presence and absence of PCA062 and DM1 to look for genes that when knocked out may specifically modulate PCA062 sensitivity. The multi-drug resistant gene MRP1 is a strong hit for PCA062 sensitization in both PCA062 resistant KYSE510 and PCA062 sensitive HCC1954 cells. Lysosomal transporter SLC46A3 and Saga transcription complex components are strong rescue hits for PCA062 in HCC1954. These data suggest that in addition to target expression level and cell intrinsic sensitivity to payload, genes involved in ADC internalization and payload cytoplasmic accumulation will also impact tumor cell sensitivity to ADCs. Citation Format: Angela Tam, Mark Zambrowski, Katherine Seiss, Si-Qi Liu, Tinya Abrams, Giordano Caponigro, William Tschantz, Jennifer Campbell, Tony DAlessio, Qing Sheng. Using genome-wide CRISPR screen to understand resistance mechanisms to PCA062, a P-cadherin targeting antibody-drug conjugate [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 4743.
Abstract LB-197: NBE-002, an anthracycline-based immune-stimulatory antibody drug conjugate (iADC) targeting ROR1 for the treatment of triple-negative breast cancer
Authors: Roger R. Beerli, Lorenz Waldmeier, Rémy Gébleux, Francesca Pretto, Ulf Grawunder
Journal: Cancer Research (2019)

Abstract Introduction: We report on the development and preclinical validation of NBE-002, a next-generation antibody drug conjugate (ADC) for the treatment of triple-negative breast cancer (TNBC). NBE-002 consists of a humanized monoclonal antibody directed against the receptor tyrosine kinase ROR1, expressed on the surface of numerous solid cancers including TNBC, and is site-specifically conjugated to a derivative of the highly potent anthracycline PNU-159682. Results: Therapeutic efficacy of NBE-002 was evaluated in ROR1-low/-intermediate/-high patient-derived xenograft (PDX) models of TNBC, lung adenocarcinoma, ovarian carcinoma, and a variety of sarcomas. NBE-002 was found to display significant anti-tumor activity in each indication. The most pronounced effect was achieved in TNBC, where complete tumor regression was observed already at the lowest ADC dose tested (0.33 mg/kg), even in models expressing low levels of ROR1 (H-score ≤70). Since these PDX studies were performed in immune-compromised hosts, and anthracyclines are known inducers of immunogenic cell death, anti-tumor activity was also investigated in syngeneic tumor models in immune-competent hosts. Anti-tumor activity of PNU-ADCs involved activation of the immune system, as shown by evaluation of NBE-002 or a Trastuzumab-PNU conjugate (T-PNU) in ROR1- or HER2-positive syngeneic breast cancer models, respectively. Depletion of CD8 T cells severely reduced anti-tumor activity, demonstrating an important role for T cells in driving tumor regression. Furthermore, when tumor free animals were re-challenged with the same tumor, tumor growth was inhibited in the absence of any further ADC administration, indicating the development of an immunological memory. Notably, combination of ADC and checkpoint inhibition, such as α-PD1 or α-CTLA4, significantly enhanced tumor eradication following the treatment. Conclusion: Our results demonstrate that NBE-002 is a highly effective and promising targeted therapeutic for the treatment of ROR1 positive TNBC and potentially other solid tumor indications that warrants clinical development. Considering the pronounced immune-modulatory functions of the PNU payload, NBE-002 may be particularly well suited for combination therapy with immune checkpoint inhibitors. NBE-002 is currently undergoing GMP manufacturing and initiation of clinical studies is expected in mid-2020. Citation Format: Roger R. Beerli, Lorenz Waldmeier, Rémy Gébleux, Francesca Pretto, Ulf Grawunder. NBE-002, an anthracycline-based immune-stimulatory antibody drug conjugate (iADC) targeting ROR1 for the treatment of 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 LB-197.
Abstract 5295: Targeting Rb phosphatase activity to circumvent CDK4/6 inhibitor resistance
Authors: Kathleen H. DiSalvo, Brian C. Velez, Rebecca L. Kravtsov, Nancy A. Krucher
Journal: Cancer Research (2019)

Abstract The Retinoblastoma (Rb) tumor suppressor protein plays a role in the control of proliferation, apoptosis, differentiation, invasion and the maintenance of genome stability. Its activity is regulated by phosphorylation on several serine/threonine sites, which is thought to inactivate its tumor suppressive function. Cyclin dependent kinases (CDKs) are responsible for most of the Rb phosphorylation that occurs in cells. It is well established that alterations in the Rb pathway (consisting of CDK4/6, D-type cyclins, the CDK inhibitor p16INK4a, and Rb itself) that lead to excessive phosphorylation of Rb have been observed in almost all cancer types. Alterations that lead to increased CDK activity toward Rb are more common than mutations to the Rb gene itself, a finding that prompted investigations into the development of clinical treatments that inhibit the phosphorylation of Rb by CDKs. The CDK4/6 inhibitors palbociclib and abemaciclib were recently clinically approved for use in breast cancer. However, acquired resistance to CDK4/6 inhibition has been shown to limit clinical efficiency. Targeting Rb phosphorylation by CDK4/6 inhibition has been shown to activate alternate pro-survival pathways such as the AKT pathway. In our studies we developed a method of siRNA-mediated activation of Rb phosphatase that targets Rb phosphorylation in attempt to circumvent the development of resistance. Phosphatase Nuclear Targeting Subunit (PNUTS) associates with and regulates PP1 activity toward Rb. In several cancer cell types, such as HCT116 colon cancer, MIA PaCa-2 pancreatic cancer and MCF7 breast cancer, PNUTS depletion causes dephosphorylation of Rb without AKT activation. Furthermore, in Panc1 pancreatic cancer cells, activation of AKT is observed after 1-hour palbociclib (500nM) treatment, whereas PNUTS depletion does not induce AKT. In MD-MBA-231 breast cancer cells, 1-hour treatment of palbociclib or abemaciclib (20nM) induces the AKT pathway as well as the STAT pathways, however PNUTS depletion in these cells does not induce AKT activation. It has been shown that CDK4/6 inhibitors activate AKT by causing loss of Rb interaction with SIN1, a component the mTORC2 complex. Our studies reveal that PNUTS depletion causes dephosphorylation of Rb, without disrupting Rb-mediated inhibition of mTORC2. Thus, the stimulation of Rb phosphatase activity may target Rb phosphorylation without the development of resistance. Citation Format: Kathleen H. DiSalvo, Brian C. Velez, Rebecca L. Kravtsov, Nancy A. Krucher. Targeting Rb phosphatase activity to circumvent CDK4/6 inhibitor resistance [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 5295.