bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 128: SIRT3 supports anchorage-independent survival of ovarian cancer cells
Authors: Tang Priscilla , Kim Yeon Soo , Gupta-Vallur Piyushi , Elhaw Amal T. , Javed Zaineb , Pan Weihua , Hempel Nadine
Published: June 2022

Metabolic changes during tumor progression have numerous consequences on cancer cells, including an increased risk of cell death due to production of reactive oxygen species (ROS). Antioxidant defense adaptations thus accompany metabolic alterations as essential survival mechanisms during metastasis. We observe that oxidative phosphorylation is increased when ovarian cancer (OC) cells transition to anchorage independence (a-i), an important step during metastasis in the peritoneal cavity. To combat the rise in oxidative stress resulting from this metabolic shift, a rapid increase in the sirtuin 3 (SIRT3)/superoxide dismutase 2 (SOD2) axis occurs to reduce the mitochondrial superoxide anion surge and to maintain cellular viability. We demonstrate that this upregulation occurs in transcription, translation, and SIRT3-mediated regulation of SOD2 activity. However, the fate of the hydrogen peroxide (H2O2) resulting from superoxide dismutation through SIRT3/SOD2 remains unknown. RNAseq analysis of attached versus a-i conditions revealed a significant downregulation of peroxiredoxin 3, a major scavenger of H2O2 in the mitochondria, suggesting that OCs have a net increase in mitochondrial H2O2 in a-i. At sub-lethal levels, H2O2 serves as a second messenger of redox signaling, primarily via protein cysteine oxidation, which has been implicated with metastasis. We thus hypothesize that increases in SIRT3/SOD2/H2O2 play a role as mediators of redox signaling during OC anchorage-independent survival, spheroid formation and metastasis. Using the HyPer7 redox probe and manipulation of SIRT3 and SOD2 expression, H2O2 generation and localization in a-i are being assessed using 3D fluorescence microscopy. Moreover, siRNA mediated knock-down of SIRT3 in a-i leads to the downregulation of genes involved in specific signaling pathways, including NF-kB signaling, the inflammatory response, and metabolism. Mass-spec studies are underway to identify specific SIRT3 target proteins upstream of these transcriptional changes, by assessing global cysteine oxidation and the cellular acetylome to determine the role of H2O2-dependent redox signaling and SIRT3-dependent protein de-acetylation, respectively. Given the increase in SIRT3-dependent inflammatory signaling in a-i, we are exploring how the SIRT3/SOD2/H2O2 axis influences OC interaction with tumor associated macrophages and mesenchymal stem cells, commonly found in the ascites tumor environment. This work demonstrates a multi-faceted role for the SIRT3/SOD2/H2O2 axis in a-i survival, a key step during OC metastasis.

Citation Format: Priscilla Tang, Yeon Soo Kim, Piyushi Gupta-Vallur, Amal T. Elhaw, Zaineb Javed, Weihua Pan, Nadine Hempel. SIRT3 supports anchorage-independent survival of ovarian cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 128.
Abstract 1296: MEK inhibition overcomes chemoimmunotherapy resistance by inducing CXCL10 in cancer cells
Authors: Limagne Emeric , Nuttin Lisa , Thibaudin Marion , Jacquin Elise , Aucagne Romain , Bon Marjorie , Ballot Elise , Revy Solène , Barnestein Robby , Truntzer Caroline , Derangère Valentin , Fumet Jean-David , Cédric Rébé , Bellaye Pierre-Simon , Kaderbhai Coureche-Guillaume , Spill Aodrenn , Collin Bertrand , Callanan Mary , Lagrange Aurélie , Favier Laure , Coudert Bruno , Arnould Laurent , Ladoire Sylvain , Routy Bertrand , Joubert Philippe , Ghiringhelli François
Published: June 2022

Chemotherapy with anti PD-1/PD-L1 mAb has become the standard of care for patients with metastatic non-small cell lung cancer (NSCLC). Using lung tumor models, where pemetrexed-platinum chemotherapy (PEM/CDDP) remains unable to synergize with immune checkpoint inhibitors (ICI), we linked failure of this treatment with its inability to induce CXCL10 expression and CD8+ T cell recruitment. Using drug screening, we showed that combining a MEK inhibitor (MEKi) with PEM/CDDP triggers CXCL10 secretion by cancer cells and CD8+ T cell recruitment, and restores ICI efficacy. PEM/CDDP plus MEKi promotes optineurin (OPTN)-dependent mitophagy, resulting in CXCL10 production in a mitochondrial DNA and TLR9-dependent manner. TLR9 or autophagy/mitophagy processes genetic inactivation of abort the antitumor efficacy of PEM/CDDP plus MEKi/anti PD-L1 therapy. In human NSCLC, high OPTN, TLR9 and CXCL10 expression is associated with better response to ICI. Our results underline the role of TLR9 and OPTN-dependent mitophagy in enhancing chemoimmunotherapy efficacy.

Citation Format: Emeric Limagne, Lisa Nuttin, Marion Thibaudin, Elise Jacquin, Romain Aucagne, Marjorie Bon, Elise Ballot, Solène Revy, Robby Barnestein, Caroline Truntzer, Valentin Derangère, Jean-David Fumet, Rébé Cédric, Pierre-Simon Bellaye, Coureche-Guillaume Kaderbhai, Aodrenn Spill, Bertrand Collin, Mary Callanan, Aurélie Lagrange, Laure Favier, Bruno Coudert, Laurent Arnould, Sylvain Ladoire, Bertrand Routy, Philippe Joubert, François Ghiringhelli. MEK inhibition overcomes chemoimmunotherapy resistance by inducing CXCL10 in cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1296.
Abstract 1303: FAP-targeted molecular radiotherapy attenuates tumor growth and synergizes with immunotherapy for the treatment of malignant melanoma
Authors: Capaccione Kathleen M. , Doubrovin Mikhail , Braumuller Brian , Leibowiz Dvora , Bhatt Nikunj , Molotkov Andrei , Kissner Michael , Momen-Heravi Fatemeh , Mintz Akiva
Published: June 2022

Immunotherapy has drastically improved outcomes in many patients with melanoma, however the majority do not attain a durable response to treatment and therefore additional agents are desperately needed. Here, we tested the efficacy of 177Lu-FAPI-04, a novel FAP-targeted radiotherapy, alone and in combination with anti-PD-1 and anti-CTLA-4 immunotherapy in a mouse model of melanoma to attenuate tumor growth. Using B16F10 murine melanoma cells, we implanted tumors in C57BL/6 mice. Animals were divided into four groups: untreated control, molecular targeted 177Lu-FAPI-04 radiotherapy treatment, immunotherapy treatment, and combined radio- and immunotherapy treatment. We assessed tumor growth over time and animals were sacrificed at 21 days. After sacrifice, tumors were dissected out and preserved for immunohistochemistry and flow cytometry. Growth curves demonstrated that immunotherapy and radiotherapy each individually attenuated tumor growth, but together they resulted in tumor regression in the majority of animals. Immunohistochemistry demonstrated increased caspase-3 staining in tumors treated with combined 177Lu-FAPI-04 radiotherapy and immunotherapy compared to untreated tumors or tumors treated with either therapy alone indicating an increase in apoptotic cell death. Ki67 expression exhibited inverse staining with moderate expression in untreated samples, low expression in immunotherapy and radiotherapy treated samples, and no staining in tumors treated with combined therapy. Flow cytometric analysis demonstrated that tumors treated with either therapy exhibited an increase in M2 macrophages, however this population was obliterated in dual-treated tumors. Together, these data support that targeting FAP with targeted radiotherapy is an effective treatment which synergizes with immunotherapy to modulate cells of the myeloid lineage as an effective anticancer therapy for melanoma. Future translational studies are needed to further study the synergies between FAP-targeted radiotherapies and immunotherapy.

Citation Format: Kathleen M. Capaccione, Mikhail Doubrovin, Brian Braumuller, Dvora Leibowiz, Nikunj Bhatt, Andrei Molotkov, Michael Kissner, Fatemeh Momen-Heravi, Akiva Mintz. FAP-targeted molecular radiotherapy attenuates tumor growth and synergizes with immunotherapy for the treatment of malignant melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1303.
Abstract 1312: Pro-survival lipid metabolism activates intracellular complement signaling to induce inflammasome-mediated tumor metastasis
Authors: Janneh Alhaji H. , Ogretmen Besim
Published: June 2022

Tumor metastasis remains one of the major causes of cancer-related deaths in patients with solid tumors. Mechanisms by which metabolic alterations regarding pro-survival lipid signaling activation in inducing cancer cell migration and metastasis are largely unknown. Here, we demonstrate that sphingosine 1-phosphate (S1P) metabolism activates endogenous complement signaling for inducing tumor metastasis via inducing inflammasome-mediated pro-inflammation. Our studies using molecular, pharmacologic, and genetic tools showed that activation of S1P and S1P receptor 1 (S1P/S1PR1) induces tumor metastasis via enhanced intracellular complement signaling by the regulation of the C3-PPIL1 complex and subsequent inflammasome activation in cancer cells and in vivo xenograft-derived tumors.

Citation Format: Alhaji H. Janneh, Besim Ogretmen. Pro-survival lipid metabolism activates intracellular complement signaling to induce inflammasome-mediated tumor metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1312.
Abstract 1350: The role of phosphatidylserine scramblases in tumor progression
Authors: Gadiyar Varsha , Davra Viralkumar , Calianese David , Lahey Kevin , Birge Raymond B.
Published: June 2022

Introduction: Phosphatidylserine (PS), an anionic phospholipid, is asymmetrically distributed in the inner leaflet of the phospholipid bilayer in normal cells under homeostasis. However, PS is constitutively externalized in the tumor microenvironment (TME); on viable cells that undergo stress, such as hypoxic tumor cells, stressed tumor vascular endothelial cells, as well as on cells undergoing apoptosis. This high PS harbors a pro-tumorigenic micro-environment, as myeloid cells expressing PS receptors (Mertk, Tyro3 and Axl) engage with externalized PS and secrete immunosuppressive cytokines. PS is externalized on viable cells by a calcium activated scramblase TMEM16F and on apoptotic cells by a caspase activated scramblase called Xkr8. Here, to study the mechanisms by which PS is externalized in the TME, we hypothesize that TMEM16F and Xkr8 are the major scramblases responsible for creating an immune suppressive milieu in the tumor microenvironment.

Methods: To study the mechanisms of PS dysregulation in the tumor microenvironment, TMEM16F and Xkr8 were knocked out in E0771 murine breast cancer cell line using CRISPR/Cas9. The knockouts were validated by western blotting, q-RT-PCR and surveyor assays.

Results: TMEM16F KO E0771 cells express lower basal levels of PS compared to WT E0771 cells when detected by Annexin V staining by flow cytometry. TMEM16F KO cells are also less responsive to activation by calcium ionophore. TMEM16F KO, Xkr8 KO and WT E0771 cells have similar viability and migration patterns in response to Gas6, indicating that the cells themselves do not have altered oncogenic potential. TMEM16F KO E0771 cells injected into the inguinal mammary gland fat pad of C57BL6 syngeneic mice showed modest but significantly reduced tumor growth compared to the E0771 WT tumors, suggesting that TMEM16F mediated PS externalization could play a role in exacerbating tumor progression.

Conclusion: TMEM16F driven PS externalization contributes to tumor growth. The effect of TMEM16F KO on immune regulation of the tumor milieu will be discussed. These data corroborate previous studies targeting PS in tumors therapeutically using anti-PS antibodies and suggests a role for scramblases in pleiotropic immune-suppression in the tumor.

Citation Format: Varsha Gadiyar, Viralkumar Davra, David Calianese, Kevin Lahey, Raymond B. Birge. The role of phosphatidylserine scramblases in tumor progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1350.
Abstract 1388: Mutations in transcriptional activators of MHC I antigen presentation, NLRC5 and CIITA, are mutually exclusive and have different effects on melanoma gene transcripts
Authors: Galvez Mildred , Campbell Katie M. , Medina Egmidio , Ribas Antoni
Published: June 2022

Response to many immunotherapies depends on effective recognition and eradication of tumor cells by the immune system. This is mediated by the successful presentation of tumor-specific antigens on major histocompatibility complex class I (MHC I) molecules on the surface of tumor cells. Studies have focused on alterations in MHC I complex proteins (e.g. HLA, B2M) and gene regulatory elements (e.g. NLRC5). However, the impact on tumor response of individual defects in components regulating and composing the MHC I antigen processing and presentation machinery (APM) have not been extensively studied. Using a harmonized dataset of six clinical trials of patients with melanoma treated with ICB, whole-exome sequencing (WES, n= 244) and RNA sequencing (RNAseq, n= 426) data from untreated tumor samples were assessed to identify mutations in genes associated with MHC I APM and their regulation. Somatic alterations were correlated with clinical response to ICB and with gene expression profiles in tumor-matched RNAseq data. Mutations in MHC I and MHC I-related genes were found in 63% of patients (n= 154/244). The most recurrently mutated genes were NCAM1 (11%, n=28), TRIM48 (7%, n=17), and CAMK2B (6.6%, n=16), and the transcriptional regulators NLRC5 (9.4%, n=23) and CIITA (9.4%, n=23). Mutations in NLRC5 and CIITA trended toward being mutually exclusive from one another (Fisher’s exact test, p= 0.157) and mutations were overrepresented in tumors with stable or progressive disease following ICB therapy. In addition, lower expression of NLRC5 and CIITA were associated with stable or progressive disease status. NLRC5-mutant tumors that progressed following ICB therapy trended towards lower expression of transcriptional target HLA-A (Kruskal-Wallis, p=0.27); however, there was no difference in HLA-A expression across NLRC5-wildtype tumors. For class II transactivating factor, CIITA, which can induce MHC I expression, mutational status was not associated with HLA-A expression across all clinical response groups. There are genetic alterations spanning MHC I and MHCI-associated genes that may be responsible for inactivating class I antigen presentation by melanoma cells. The impact of these alterations may result in varied clinical responses to ICB therapies. The landscape of these alterations needs to be further delineated to understand how tumors are directly evading class I-mediated recognition and elimination.

Citation Format: Mildred Galvez, Katie M. Campbell, Egmidio Medina, Antoni Ribas. Mutations in transcriptional activators of MHC I antigen presentation, NLRC5 and CIITA, are mutually exclusive and have different effects on melanoma gene transcripts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1388.
Abstract 139: Dock7 regulates the AKT/mTOR pathway to promote survival and sustain the transformative properties of cancer cells
Authors: Teran Oriana Y. , Lin Miao-chong J. , Zanotelli Matthew R. , Wilson Kristin F. , Cerione Richard A.
Published: June 2022

Akt is a well-known target of mitogenic signaling, which is activated by phosphoinositide 3-kinase, PDK1 and mTORC2, and is commonly regarded as a master regulator of cell survival. However, there is still a good deal to learn regarding how Akt can promote survival when cancer cells are faced by the multitude of challenges they need to overcome during the process of malignant transformation. While investigating the role of Dock7, a Cdc42 and Rac guanine nucleotide exchange factor of the Dock180 family, in tumorigenesis, we discovered an unexpected connection between Dock7, Akt and cell survival. Specifically, we found that Dock7 is necessary for cancer cells to survive under the stressful conditions that arise due to the loss of a substratum or serum deprivation, through its ability to stabilize a low, basal level of Akt kinase activity. Dock7 binds to Akt, as well as associates with the known Akt substrate, TSC2, promoting its phosphorylation. Since the phosphorylation of TSC2 eliminates its ability to work with its partner TSC1 to deactivate the Rheb GTPase, a direct activator of mTORC1, we probed whether mTORC1 function is also necessary for Dock7-dependent cancer cell survival. Indeed, we determined that Dock7, as well as its signaling partner Cdc42, is required to maintain a functional level of S6 kinase activity, a downstream target of mTORC1, which was prevented by the mTORC1 inhibitor rapamycin. We further show an association between mTOR, Rheb and Dock7, but not Raptor, the defining component of mTORC1. Additionally, Raptor is dispensable for the Dock7-dependent S6 kinase activity, despite its rapamycin sensitivity. Together, these findings elucidate a novel Dock7-Akt-mTOR signaling node which promotes cancer cell survival in the absence of classical mTORC1 function to allow cells to overcome stresses faced during the development of cancer.

Citation Format: Oriana Y. Teran, Miao-chong J. Lin, Matthew R. Zanotelli, Kristin F. Wilson, Richard A. Cerione. Dock7 regulates the AKT/mTOR pathway to promote survival and sustain the transformative properties of cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 139.
Abstract 1406: Design and synthesis of novel cardiac glycosides by targeting the DNA damage response for cancer therapy
Authors: Ainembabazi Diana , Geng Xinran , Gavande Navnath , Zhang YouWei , Turchi John
Published: June 2022

Cardiac Glycosides (CGs) are used to treat congestive heart disease. Their application has since been extended to cancer treatment. While the mechanism of action is still unknown, it was previously believed that Na+/K+ ATPase might play a crucial role in cancer mitigation. However, we recently reported that cardiac glycosides could specifically enhance the anti-cancer effect of chemotherapy in KRAS mutant lung cancer by inhibiting the DNA Damage Response (DDR), and these effects were independent of the Na+/K+ ATPase. Mechanistically, we showed that cardiac glycosides induced the degradation of UHRF1, an important player in promoting DNA double strand break (DSB) repair through homologous recombination. These results suggest the promise of derivatizing cardiac glycosides into potential chemo sensitizing agents. Yet, one of the major challenges with these compounds is their cardiotoxicity. This has created a need for developing a strategy to generate less cardiotoxic drugs that are effective in inhibiting the DNA damage response to safe and effective anticancer activity. Herein we report a multi-step synthetic route utilizing k-strophanthidin as the initial building block. A systematic structural design was applied that included modification of the sugar moiety, glycoside linker, stereochemistry, and lactone ring to create a library of O-glycosides and MeON-neoglycosides. These molecules were screened for anti-cancer properties by exploring their influence on the signaling/expression of various downstream kinases in the DDR pathway. We discovered the inhibitory activity of O-glycosides to be more potent than the MeON-neoglycosides or benzylidene-lactone modified compounds. These results demonstrate the ability to chemically synthesize CG derivatives to optimize for anticancer activity with the goal of identifying less cardiotoxic CGs.

Citation Format: Diana Ainembabazi, Xinran Geng, Navnath Gavande, YouWei Zhang, John Turchi. Design and synthesis of novel cardiac glycosides by targeting the DNA damage response for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1406.
Abstract 1417: A non-systemic phosphodiesterase-5 inhibitor for colon cancer prevention
Authors: Islam Bianca N. , Lee Avelina , Lebedyeva Iryna , Browning Darren D.
Published: June 2022

Phosphodiesterase 5 inhibitors (PDE5i) are under investigation for potential repurposing as an intervention for colon cancer prevention. A drawback to conventional drugs in this class are drug-drug interactions and side-effects and that would be poorly tolerated when taken on a chronic basis for prevention. To address this issue we designed an analog of the prototypical PDE5i sildenafil by replacing the methyl group on the piperazine ring with malonic acid to reduce lipophilicity. This modification did not affect pharmacology as malonyl-sildenafil had an IC50 of 1.8 nM, but exhibited almost 100-fold reduced cell entry compared to sildenafil. Using an LC-MS/MS approach, malonyl-sildenafil was undetectable in mouse plasma 1 hour after gavage, even at a dose up to 36 mg/kg, but was readily detected in the feces collected 2-4 hours after administration. This contrasted with sildenafil that was detected in the plasma, but not in the feces. While sildenafil exhibited the established Cmax at 1-2 hr, malonyl sildenafil was not detected in the plasma up to 24 hr after an oral dose of 9 mg/kg, but continued to be shed at high levels in the feces for up to 8 hrs. Treatment of mice with malonyl-sildenafil in the drinking water for 8 days was well-tolerated, and resulted in a suppression of proliferation in the colon epithelium that is consistent with results published previously for mice treated with PDE5i. Taken together, the results demonstrate that a carboxylic acid-containing analog of sildenafil prohibits systemic delivery but maintains sufficient penetration into the colon epithelium to suppress proliferation. This highlights a novel approach to generate a first in class drug for colon cancer chemoprevention.

Citation Format: Bianca N. Islam, Avelina Lee, Iryna Lebedyeva, Darren D. Browning. A non-systemic phosphodiesterase-5 inhibitor for colon cancer prevention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1417.
Abstract 1419: Single molecule detection of human heparanase
Authors: Wang Zhishen
Published: June 2022

Heparanase, a mammalian endo-β-D-glucuronidase, is the only known enzyme responsible for the cleavage of heparan sulfate (HS) side chains of heparan sulfate proteoglycans (HSPGs). Its activity is implicated in various disease conditions such as tumor growth, angiogenesis, metastasis, chronic inflammation and diabetic nephropathy. Detecting the activity of heparanase thus is a promising approach for the discovery of diagnostics and therapeutics for these diseases. We have developed an activity-based disaccharide probe for heparanase, which offers over 700-fold of fluorescence increase in the presence of human heparanase. In this project, we aim to build up an ultrasensitive single heparanase detection system by coupling a sensitive fluorogenic probe with a microwell-based device. The microwell-based device is designed to achieve single enzyme separation and significantly increase the sensitivity of detection. This system is being validated using recombinant human heparanase and will be used to analyze clinical samples from breast cancer patients.

Citation Format: Zhishen Wang. Single molecule detection of human heparanase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1419.
Abstract 1440: Identifying inherited genetic variation that impacts individuals’ ability to metabolize arsenic and susceptibility to toxicity
Authors: Tamayo Lizeth I. , Tong Lin , Kibriya Muhammad G. , Jasmine Farzana , Ahsan Habibul , Pierce Brandon L.
Published: June 2022

Inorganic arsenic (iAs) is a class I human carcinogen, and exposure to iAs affects >200 million individuals worldwide. In Bangladesh, >57 million individuals are chronically exposed to iAs through drinking-water. There is inter-individual variation in arsenic metabolism efficiency (AME) due to inherited genetic variation, and this variability impacts individuals’ internal dose of arsenic and their susceptibility to toxicity. Identifying genetic determinants of AME to help identify individuals at higher risk for toxicity has been a focus within genetic epidemiology research. Consumed arsenic enters the blood in as iAs. Sequential reduction and methylation reactions are catalyzed by glutathione and arsenic methyltransferase (AS3MT) respectively, producing monomethylated (MMA) and dimethylated (DMA) forms of arsenic. Generation of DMA is beneficial because DMA is more easily expelled from the body in urine compared to MMA or iAs. AME is often represented by the percent of the arsenic species in urine that exists as DMA. Previous studies have identified genetic variants in the AS3MT (10q24.32) and FTCD (21q22.3) regions as showing clear association with AME. However, additional regions containing variants showing robust and replicable association with AME have not yet been identified, although studies of AME heritability suggest that additional variants are likely to exist. We used data from >7,000 participants from two studies of Bangladesh individuals with varying levels of exposure to arsenic through drinking water (The Health Effects of Arsenic Longitudinal Study, HEALS, and the Bangladesh Vitamin E and Selenium Trial, BEST) to identify genetic variation that impacts individuals’ ability to metabolize arsenic and their susceptibility to toxicity (i.e., arsenic-induced skin lesions). Our preliminary results suggest novel associations with AME in the 1q24.3 region (p= 5.16 x10-14) and with skin lesion risk in the 6p21.33 region (p=1.37x10-9). The identified variants in the 1q24.3 region reside in and around the FMO3 gene. FMOs are enzymes involved in xenobiotic metabolism; therefore, it is plausible that they may play a role in arsenic metabolism. The 6p21.33 signal is in the major histocompatibility complex (MHC) region, which contains numerous key immune response genes (e.g., HLA genes). These results suggest the existence of additional variants associated with AME and arsenic toxicity risk.

Citation Format: Lizeth I. Tamayo, Lin Tong, Muhammad G. Kibriya, Farzana Jasmine, Habibul Ahsan, Brandon L. Pierce. Identifying inherited genetic variation that impacts individuals’ ability to metabolize arsenic and susceptibility to toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1440.
Abstract 1471: Over-expression of WW domain containing transcription regulator 1 (TAZ/WWTR1) in prostate cancer and its modulation by prostate-derived ETS factor (PDEF)
Authors: Jaiswal Praveen K. , Mohajan Suman , Koul Sweaty , Koul Hari K.
Published: June 2022

Objective: WW domain containing transcription regulator 1 (TAZ/WWTR1), one of the two downstream effectors of the Hippo pathway, is known to regulate cancer cell proliferation, migration and apoptosis by acting as a transcriptional co-activator. Recently, we described altered expression of yes-associated protein (YAP1) (a paralog of TAZ) in prostate cancer. However, the expression and function of TAZ and its regulation in prostate cancer is not well characterized. In the present study, we profiled expression patterns of TAZ in clinical data sets of PCa and evaluated the effects of PDEF on TAZ phosphorylation in prostate cancer (PCa) cells in culture.

Material & Method: We analyzed the publicly available PCa datasets through Ualcan and c-Bioportal webservers. We transfected prostate cancer PC3 cells with PDEF or respective vector control. Protein levels of TAZ were analyzed by western blotting. Global changes in gene expression were analyzed using Affymetrix arrays followed by Gene Set Enrichment analysis.

Results: Our analysis of publicly available PCa patient data in TCGA dataset, revealed a significant increase in TAZ mRNA levels in prostate cancer tissues as compared to normal prostate tissues (p=4.95E-08). Furthermore, we also found a significant gradual increase in TAZ mRNA expression during disease progression and metastasis. Our analysis of data sets in c-Bio portal revealed that patients with neuroendocrine PCa harbor much higher levels of TAZ mRNA as compared to CRPC phenotype. We also observed a negative correlation between PDEF and TAZ expression in CRPC/NEPC data set. We observed that the PC3 cells transfected with PDEF (PDEF-PC3) showed an increased phospho-TAZ as compared to the respective PC3 vector control (VC-PC3) suggesting that PDEF plays a critical role in modulating TAZ activity an important effector in Hippo signaling.

Conclusions: These results provide first direct demonstration of elevated expression of TAZ in PCa, suggesting potential role of TAZ in prostate cancer. We also show for the first time increased TAZ phosphorylation in PCa cells by PDEF. Taken together with our recent work, our data suggest that PDEF modulates Hippo signaling by targeting both YAP1 and TAZ in PCa.

Citation Format: Praveen K. Jaiswal, Suman Mohajan, Sweaty Koul, Hari K. Koul. Over-expression of WW domain containing transcription regulator 1 (TAZ/WWTR1) in prostate cancer and its modulation by prostate-derived ETS factor (PDEF) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1471.
Abstract 1505: Exploring the role of CRM1 in DNA repair pathway in prostate cancer cells
Authors: Kumar Rajendra , Mendonca Janet , Boyapati Kavya , Yang Yuhan , Topiwala Deven , Kanacharoen Suthicha , Soundappan Keerti , Wilson Lillian , Panagopoulos Eleni , Carducci Michael , Kachhap Sushant K.
Published: June 2022

Background: Prostate cancer continues to show challenges in disease management and ultimately leads to advanced disease with poor survival. These unmet needs, despite recent advances, are leading researchers to identify novel targets to develop next-generation therapeutics. Considerable evidence from the published reports and TCGA database analysis indicates that CRM1, which functions as a nuclear export protein, amplifies prostate cancer, resulting in dysregulated nuclear export machinery. This dysregulation is also seen to correlate with mislocalization of p53, FOXO-1, and 3a, cyclinD1, p16, p21, and p27 in prostate cancer. Besides these mislocalized proteins, key DNA repair pathway members such as BRCA1 and Rad51 exhibit a nuclear export signal (NES) and are putative CRM1 cargoes. Nuclear-cytoplasmic shuttling of these repair proteins may play an essential role in repairing damaged DNA. We hypothesize that inhibition of CRM1 would result in defective DNA repair through disruption of nuclear-cytoplasmic shuttling of important repair protein cargoes.

Methods: PCa cells (both AR-positive and negative lines) were treated with Selinexor to estimate the subtoxic doses. Cell lysates and total mRNA were collected to evaluate the relative levels of BRCA-1, RAD51, p53, ATM, ATR transcripts, and proteins. Activation of the DNA damage pathway was measured through a phosphorylated form of these proteins, and functional assessment of homologous recombination(HR) was measured through an HR sensor plasmid construct.

Results: Treatment of PCa cells with Selinexor affected expression, localization, and kinetics of DNA repair leading to unrepaired DNA and induced apoptosis.

Citation Format: Rajendra Kumar, Janet Mendonca, Kavya Boyapati, Yuhan Yang, Deven Topiwala, Suthicha Kanacharoen, Keerti Soundappan, Lillian Wilson, Eleni Panagopoulos, Michael Carducci, Sushant K. Kachhap. Exploring the role of CRM1 in DNA repair pathway in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1505.
Abstract 1525: Inhibition of HGF maturation overcomes cetuximab resistance in colorectal cancer
Authors: Graves-Deal Ramona , Bogatcheva Galina , Truong Vivian T. , Damalanka Vishnu , Klampfer Lidija , Coffey Robert J. , Janetka James W. , Singh Bhuminder
Published: June 2022

We have previously identified that activation of receptor tyrosine kinases (RTKs) MET and RON contributed to resistance to the EGF receptor (EGFR)-directed therapeutic antibody cetuximab. These findings originated from our in vitro 3D type I collagen cultures of human colorectal cancer (CRC) cell line HCA-7 derivatives CC, SC, and CC-CR. CC are sensitive to cetuximab, while SC and CC-CR are resistant. Both de novo and acquired modes of cetuximab resistance in SC and CC-CR, respectively, could be overcome by crizotinib, a multi-RTK inhibitor that also targets MET and RON. Conversely, exogenous administration of MET ligand, HGF could transiently induce cetuximab resistance which could be further overcome by crizotinib addition. HGF/HGFL are synthesized as inactive precursors and require cleavage by proteases (HGFA, Matriptase, and Hepsin) to be biologically active. To inhibit HGF/HGFL cleavage in cetuximab-resistant cells, we employed inhibitors of HGF/HGFL proteases (ZFH7116 and VD2173) and were able to overcome both de novo and acquired cetuximab resistance. A survey of TCGA datasets indicated that HGF/HGFL were overexpressed in several CRC CMS subtypes. We next expressed human HGF in cetuximab-sensitive CC cells and observed that HGF overexpression imparts cetuximab resistance. Moreover, cetuximab resistance induced by HGF overexpression could be overcome by the downstream MET inhibition (with crizotinib) and we are now testing if the upstream inhibition of HGF proteases (with ZFH7116/VD2173) also overcomes cetuximab resistance. Combined these results indicate that inhibition of HGF cleavage and maturation may be a novel way to overcome resistance to EGFR-targeted therapies in CRC.

Citation Format: Ramona Graves-Deal, Galina Bogatcheva, Vivian T. Truong, Vishnu Damalanka, Lidija Klampfer, Robert J. Coffey, James W. Janetka, Bhuminder Singh. Inhibition of HGF maturation overcomes cetuximab resistance in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1525.
Abstract 1529: Role of bitter taste receptor in colon cancer
Authors: Jain Krishan , Bhattacharyya Sangita , Sayed Afreen , Standing David , Benich Kathy , Umar Shahid , Anant Shrikant , Weir Scott , Jansen Roy , Dandawate Prasad Ravindra
Published: June 2022

Colorectal cancer (CRC) is a leading cause of cancer-related deaths in the US with 53,200 deaths projected in 2020. Although the disease affects older people, recent statistics show an increase in the younger population. CRC is a major problem in veterans and every year ~4,000 veterans are diagnosed with CRC within VA facilities. Hence, there is a dire need to identify novel signaling pathways as targets for therapy. Based on a bedside discovery in CRC patients, we observed that CRC patients complained about dysgeusia or taste alterations. There are 25 bitter taste receptors (TAS2R1-50, TAS2R60). Taste receptors utilize G-protein coupled receptors (GPCRs) and signal through calcium release. In preliminary studies, mining the Cancer Genome Atlas (TCGA) database, we have determined that TAS2R38 is upregulated in multiple cancers, including CRC. Moreover, the higher expression of TAS2R38 transcript in CRC compared to other cancers. Furthermore, we confirmed overexpression of TAS2R38 in CRC tissues and cell lines by immunohistochemistry and RT-PCR. Moreover, N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL), a TAS2R38 agonist, treatment activated calcium mobilization in HCT116 and DLD1 cells suggesting the functionality of the receptor. OdDHL also enhanced mRNA of interleukin (IL)-6 and IL-8 levels in the CRC cells. To determine whether expression of the receptor is affected in vivo, we conducted the dextran sodium sulfate (DSS)-induced acute colitis and colitis-associated cancer model (azoxymethane (AOM)-DSS) in C57BL/6 mice. TAS2R138, the mouse homolog of human TAS2R38 is overexpressed in crypt epithelial cells in the colitis and tumor tissues. These observations suggest that TAS2R38 is overexpressed in the CRC and may play a critical role in disease progression.

Citation Format: Krishan Jain, Sangita Bhattacharyya, Afreen Sayed, David Standing, Kathy Benich, Shahid Umar, Shrikant Anant, Scott Weir, Roy Jansen, Prasad Ravindra Dandawate. Role of bitter taste receptor in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1529.
Abstract 1533: Long non-coding RNA control of cancer cell growth
Authors: Su Tong , Kong Bobby , Huang Calvin , Zhu Jonathan , McHugh Colleen
Published: June 2022

Long non-coding RNAs (lncRNAs) are involved in controlling regulatory networks critical for gene expression, cellular growth, and development. Altered expression of lncRNAs are associated with tumor progression in multiple types of human cancers, but the mechanisms by which lncRNAs may control growth and proliferation in cancer cells remain unknown in most cases. Development of interventions targeting non-coding RNA regulation of cell growth would open new avenues for cancer treatment. To identify growth regulatory pathways controlled by non-coding RNAs, we used proteomics and genomics tools to study the effect of changes in lncRNA expression levels in human cancer cell lines. First, we identified five growth regulator lncRNAs based on data mining of CRISPR/Cas9 screens and high throughput sequencing studies from patient tumor and normal cells. These lncRNAs have been associated with progression and metastasis in breast, lung and colon cancers. We hypothesized that growth regulator lncRNAs play a role in cancer development by recruiting effector proteins to regulate gene expression. Next, we evaluated the cellular growth phenotype for each lncRNA in overexpression and knockdown strains using multiple established cancer cell lines. We analyzed cellular transcriptome changes after lncRNA perturbation using high-throughput RNA sequencing. Finally, RNA-protein interactions for each growth regulator lncRNA were identified using an RNA hybridization capture method paired with mass spectrometry that enables purification of direct and specific endogenous RNA-binding proteins. Using this combination of transcriptomics and proteomics data, we discovered that perturbation of growth regulator lncRNAs results in dysregulation of growth signaling pathways and increased expression of p53. We are currently identifying the sequence and structure determinants of RNA-protein complex formation to uncover the mechanisms of action of lncRNAs in controlling cancer cell growth.

Citation Format: Tong Su, Bobby Kong, Calvin Huang, Jonathan Zhu, Colleen McHugh. Long non-coding RNA control of cancer cell growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1533.
Abstract 1541: LncRNA MALAT1 as a potential therapeutic target in triple negative breast cancer
Authors: Adewunmi Oluwatoyosi , Rosen Jeffrey
Published: June 2022

In the United States 1 in 8 women will be diagnosed with breast cancer within their lifetime, accounting for nearly 30% of cancer diagnoses annually. Although improvements have been made in early diagnoses and treatment, the heterogeneity of breast cancer often makes treatment of the disease a challenge. Triple negative breast cancer (TNBC) ranks as the 5th leading cause of cancer related death in women, while also being more prevalent in younger African American and Hispanic premenopausal women. The invasive nature of TNBC increases the risk of metastasis and recurrence, and patients will often acquire resistance to existing treatment options, emphasizing the need for new breast cancer therapies. A novel therapeutic approach is the inhibition of the highly abundant long noncoding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript (MALAT1) using an antisense oligonucleotide (ASO). MALAT1 has been shown to be upregulated in several breast cancer subtypes, increasing the migratory and invasive properties of tumor cells. Using a MALAT1 ASO in our preclinical syngeneic p53 null TNBC tumor mouse models, we were able to significantly knockdown MALAT1 RNA expression and observed a delay in primary tumor growth as well as an improvement in tumor response when used in combination with the chemotherapy drugs carboplatin or docetaxel. Additionally, immunophenotyping of tumor infiltrating lymphocytes show that MALAT1 inhibition alters the tumor microenvironment with a significant decrease in immunosuppressive CD206+ Arginase+ macrophages and myeloid derived suppressor cells (MDSC) as well as an increase in cytotoxic CD8+ T cells. The immuno-stimulatory effects of MALAT1 inhibition highlight the benefit of a MALAT1 ASO therapeutic and its potential to be used in combination with current chemotherapies and/or developing immunotherapies.

Citation Format: Oluwatoyosi Adewunmi, Jeffrey Rosen. LncRNA MALAT1 as a potential therapeutic target in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1541.
Abstract 1545: The cytostatic effect of miR-3189-3p in triple negative breast cancer cells involves inhibition of mitochondrial-mediated apoptosis
Authors: Vittori Cecilia , Yousefi Hassan , Reiss Krzysztof , Peruzzi Francesca
Published: June 2022

Our laboratory has previously characterized a microRNA, miR-3189-3p, with potent anti-cancer activity against glioblastoma and triple negative breast cancer (TNBC), two of the most aggressive types of tumors. Intriguingly, while miR-3189-3p inhibits proliferation, migration, and invasion of glioblastoma and TNBC cells, it does not induce apoptosis. The BCL2 family of proteins controls mitochondrial-mediated cell death through binding affinity and abundance of pro- and anti-apoptotic factors. Here, we investigated the mechanisms of the cytostatic effect of miR-3189-3p on MDA-MB-231 cells and found that the BCL2-family members and pro-apoptotic factors BAK1, BMF, and HRK, which are predicted gene target of this miRNA, are indeed downregulated by the miRNA mimic. In addition, we found that expression of miR-3189-3p improved the metabolic fitness of TNBC cells through increasing both mitochondrial respiration and glycolysis. Ongoing experiments are aimed at understanding how changes in the metabolic profile and cytostatic activity of miR-3189-3p could be used for therapeutic intervention against this aggressive tumor.

Citation Format: Cecilia Vittori, Hassan Yousefi, Krzysztof Reiss, Francesca Peruzzi. The cytostatic effect of miR-3189-3p in triple negative breast cancer cells involves inhibition of mitochondrial-mediated apoptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1545.
Abstract 1548: Examination of miRNA dysregulation in pancreatic cancer PDX models with parallel proteomic and transcriptomic investigations
Authors: Allen Taylor-Jade
Published: June 2022

Introduction: Pancreatic cancer is a high-fatality cancer. An estimated 57,600 new cases were diagnosed in the United States in 2020 with a corresponding 47,050 deaths. Despite improvements in the molecular understanding of pancreatic cancer, the prognosis for this disease has not improved in nearly 4 decades, largely because of the lack of early stage disease detection and limited efficiency of systemic therapies. MicroRNAs (miRNAs) are a class of non-coding RNAs approximately 22 nucleotides (nt) in length that regulate gene expression. in recent years, the dysregulation of miRNAs has been implicated in the development of various human cancers.

Methods: Parallel analysis of global mRNA, miRNA and protein expression was conducted on pancreatic cancer patient-derived xenografts. The data from this analysis of these F1 tumours, was used to refine/identify miRNA targets of interest to generate 2 differential expression (DE) lists for miRNA; 1) Tumour vs Normal and 2) Tumour vs F1. Predictive software was used to identify targets and pathways of the DE priority miRNAs. These targets were further refined by integrating the targets with the global mRNA and proteomic profiling (unpublished data) performed on the same clinical samples. Alteration of cancer phenotype was investigated using overexpression and/or sponge vectors for each miRNA.

Results: Analysis generated a list of priority miRNAs that had inverse interactions with predicted protein targets and were shown to be differentially expressed in our proteomic data. From 39 miRNAs investigated from the priority list, 7 miRNAs targeted 2 or more proteins across the 2 comparisons. These miRNAs - miRs-2467, -4742, -509, -615-3p, -4534, -222 and 2-06 when altered in expression MIA PaCa-2 and PANC-1 pancreatic cancer cells resulted in modulated cell proliferation, colony forming ability and anoikis resistance. Studies are ongoing on the changes to the chemotherapy and radiosensitivity of each cell line in response to changing these miRNA levels.

Conclusions: The study identified miRNAs which displayed increased expression between normal and tumour and again increased between tumour and F1. From this list using predicative software and integration with additional global analysis of mRNA and Protein expression a priority list of 7 miRNAs were identified. The core concept in this study was to use differential expression of miRNAs as a tool to further unravel the biology of human pancreatic cancer, in the hope of uncovering new targets or vulnerabilities which might be exploited therapeutically or finding new bio markers which might contribute to better or earlier diagnosis.

Citation Format: Taylor-Jade Allen. Examination of miRNA dysregulation in pancreatic cancer PDX models with parallel proteomic and transcriptomic investigations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1548.