bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2195: A tissue atlas of oncogenic RAS mutation
Authors: Erdogan Ozgun , Counter Christopher
Published: June 2022

Despite over 50 possible oncogenic RAS mutations, cancers tend to have a bias towards a specific subset unique to each cancer type. As RAS mutations could arise from selection of an ideal level (quantitative) or type (qualitative) of oncogenic signaling, we generated four conditional Kras alleles with different oncogenic mutations, G12D or Q61R, coded with native rare or common codons to induce low or high protein expression to separate these two types of signaling. These alleles were crossed into a Rosa26-CreER background and globally activated, revealing tissues sensitive to quantitative signaling regulated by the RAS biochemical activity, qualitative signaling regulated by the specific mutation, and either both or none of these two types of signaling. Bulk RNAseq analysis further revealed that each allele induced a different cellular response, with the weakest allele induce transcriptional features of a plastic state while the strongest allele had all the transcriptional hallmarks of high oncogenic signaling and a stress response. In conclusion, this approach provides a mutational atlas of tissues dependent upon quantitative signaling, qualitative signaling, or both forms of signaling for tumorigenesis, as well as tissues generally resistant to oncogenic RAS. This tissue atlas can thus serve to define how specific cancers are initiated, and in turn, how to prevent such initiation events from taking hold to lead a normal cell down the path of tumorigenesis, which has important clinical implications for early cancer detection and prevention measures.

Citation Format: Ozgun Erdogan, Christopher Counter. A tissue atlas of oncogenic RAS mutation [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 2195.
Abstract 2199: Molecular dissection of a novel, highly proliferative lineage in a model of Helicobacter pylori-driven gastric metaplasia and dysplasia
Authors: O'Brien Valerie Phoebe , Young William C. , Finak Greg , Gottardo Raphael , Salama Nina R.
Published: June 2022

At least 80% of gastric cancer cases are attributed to stomach infection with the bacterium Helicobacter pylori (Hp), which causes lifelong chronic inflammation. In some individuals, this inflammation can cause gastric atrophy, metaplasia (conversion of one normal cell type to another), dysplasia (presence of abnormal cells) and finally cancer, but the specific mechanism(s) through which Hp triggers this cascade are not well understood. Similar preneoplastic changes are recapitulated in a mouse model through tamoxifen-induced expression of active KRAS in the chief cells of the stomach (KRAS+ mice). We found that Hp infection of KRAS+ mice exacerbated disease: compared to Hp-KRAS+ mice, Hp+KRAS+ mice had an altered trajectory of metaplasia and accelerated dysplasia. In accordance with the hypothesis that Hp causes cancer through eliciting chronic inflammation, Hp+KRAS+ mice had severe inflammation marked by a ten-fold increase in T cells compared to Hp-KRAS+ mice. To understand gene expression changes in gastric cells in the context of metaplasia with and without active Hp infection, we performed single cell RNA-sequencing (scRNA-seq) on eight mouse stomachs (+/- Hp, +/- KRAS) using the 10x Chromium platform. Cluster analyses followed by UMAP (Uniform Manifold Approximation and Projection) visualization allowed us to identify 25 clusters, including epithelial and immune cell types. Hp+KRAS+ mice had a striking expansion of a population of metaplastic cells (most similar to surface mucus-producing “pit” cells), which comprised ~40% of epithelial cells in these mice. Metaplastic pit cells expressed markers of intestinal metaplasia and gastric cancer, and their abundance in the stomach was correlated with helper T cell abundance. Analysis of RNA velocity suggested that metaplastic pit cells arose from a progenitor cell type, rather than arising from pit cells directly. As well, a 10x Visium spatial gene expression experiment revealed the spatial organization of metaplastic pit cells near the lumen of the gastric epithelium. Finally, antibiotic eradication of Hp prevented metaplastic pit cell development and other disease phenotypes. Taken together, these studies provide new understanding of how Hp infection and inflammation cause gastric preneoplastic progression.

Citation Format: Valerie Phoebe O'Brien, William C. Young, Greg Finak, Raphael Gottardo, Nina R. Salama. Molecular dissection of a novel, highly proliferative lineage in a model of Helicobacter pylori-driven gastric metaplasia and dysplasia [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 2199.
Abstract 2209: HPV non-vaccination due to safety concerns/side effects: Variations in vaccination intentions by Parent-Child Gender, National Immunization Survey - Teen, 2010 - 2019
Authors: Chido-Amajuoyi Onyema , talluri rajesh , Jackson Inimfon , Shete Sahil , Domgue Joel Fokom , Shete Sanjay
Published: June 2022

Background: Gender-generated disparities in HPV vaccination uptake have the potential to further perpetuate existing disparities in HPV-associated cancers. This study examines the influence of parent-child gender on intent to not vaccinate against HPV due to safety/side effect concerns.

Methods: Study data was from the National Immunization Survey-Teen (2010 - 2019). Weighted prevalence of intention to refuse HPV vaccination due to safety/side effect concerns were stratified by parent-child gender. Multivariable logistic regressions were used to examine for associations between intentions to refuse HPV vaccination due to safety concern/side effects and parent-child gender.

Results: Over the study period, intentions to refuse HPV vaccination due to safety concerns rose among all parent-child gender pairings but was highest among respondent mothers when pertaining to their unvaccinated daughters. Results revealed statistically significant increased likelihood of having intentions to refuse HPV vaccination due to safety concerns among all parent-child combinations, compared to father-son pairs. These odds were consistently highest among mother-daughter pairs; 9.25 times more likely (95% CI: 6.34-13.51) than father-son pairs in 2010. In 2019, compared to father - son pairs, fathers were 1.94 (95% CI: 1.21-3.12) times more likely to report intention to not vaccinate against HPV for their daughters; while mothers were 2.23 (95% CI: 1.57-3.17) times more likely to report intentions to refuse HPV vaccination for their sons; and 2.87 (95% CI: 2.02-4.07) more likely for their daughters.

Conclusions: Intentions to refuse HPV vaccination due to safety concern/side effects varied by gender of the responding parent and pertinent child. Study findings are persistent and constantly increased over a 10-year period. Interventions aimed at correcting gender-based misperceptions, as well as to counter misinformation about the safety of the HPV vaccine are warranted.

Citation Format: Onyema Chido-Amajuoyi, rajesh talluri, Inimfon Jackson, Sahil Shete, Joel Fokom Domgue, Sanjay Shete. HPV non-vaccination due to safety concerns/side effects: Variations in vaccination intentions by Parent-Child Gender, National Immunization Survey - Teen, 2010 - 2019 [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 2209.
Abstract 2228: A multi-omic perspective of how selection shapes blood cancer risk phenotypes in aging populations
Authors: Skead Kimberly , Soave David , Fave Marie-Julie , Bruat Vanessa , Morris Quaid , Awadalla Philip
Published: June 2022

The genetic architecture of blood is highly complex with germline polymorphisms, somatic point mutations, and larger chromosomal alterations playing a role in shaping the fitness of the immune cells. Many advances have been made in understanding how the age associated acquisition of point mutations and somatic structural variants (SSVs) in blood, termed Age-Related Clonal Hematopoiesis (ARCH), predispose individuals to hematological cancer or cardiovascular disease. Yet, ARCH is commonly observed in healthy individuals and our ability to predict who is at risk of progressing to disease remains limited. A previous study which integrated deep learning and population genetics methods to evaluate the complex interplay of selection on point mutations in deeply sequenced blood samples highlighted the role that negative selection plays in prevention progression to hematological cancer. Here, we interrogate the mutational and selective pressures within blood to better understand how the full spectrum of somatic changes within an individual impact clonal fitness and disease outcomes. We evaluate how selection shapes the prevalence of large somatic structural variation in blood sampled from 15,910 individuals across over 20 different genetic ancestries, including the Thousand Genomes Study and the Canadian Partnership for Tomorrow’s Health study. Using dense genotyping arrays, we capture SSVs among 20 populations and find that ARCH attributed to somatic structural variation is three times as high as previously reported with up to 14% of individuals harbouring at least one large SSV in their blood. We estimate the rate at which SSVs accrue in blood cells and find that selection impacts the size and frequency of SSVs within individual blood populations. To determine the functional impact of clonal mutations on molecular phenotypes, we investigate the relationship between structural variation and the transcriptome. We show that gains, losses and copy number neutral variants impact gene expression distinctly, with stabilizing selection shaping the penetrance of copy number alterations in gene expression. Our work shows how different classes of selection shape clonal dynamics in blood thus enabling us to better understand why certain individuals are at a high risk of malignancy.

Citation Format: Kimberly Skead, David Soave, Marie-Julie Fave, Vanessa Bruat, Quaid Morris, Philip Awadalla. A multi-omic perspective of how selection shapes blood cancer risk phenotypes in aging populations [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 2228.
Abstract 2236: A novel integrated predictive model for pancreatic cancer
Authors: Ke Temin , Lophatananon Artitaya , Muir Kenneth , Yu Xinzhu
Published: June 2022

Background: Pancreatic cancer is the 7th leading cause of cancer-related mortality and the 12 th most common cancer globally. Many studies have identified risk factors for pancreatic cancer, nevertheless, there have been few combined risk factor models developed for the UK specific population. Due to the high incidence with a poor survival rate together with the potential high preventable rate, it is important to establish an accessible predictive risk factor model for identifying potential high-risk populations.

Study aim: To establish a pancreatic cancer risk prediction model by integrating the current risk factors together with established genomic biomarkers.

Method:Using data from the UK biobank we have investigated the role of established and suggested risk factors for pancreatic cancer. The established risk factors include age, BMI, smoking, alcohol consumption, diabetes and pancreatitis. We also calculate the added prediction from the current polygenic risk score (PRS) to evaluate the risk for genetic predisposition. Last, we utilise the multivariate logistic regression models to establish a novel risk model by integrating the well-known risk factors such as cigarette smoking, heavy alcohol consumption, increased BMI, chronic pancreatitis, diabetics, some germline mutation, and our new evaluated PRS and biological clocks.

Results: We will present the performance of the novel integrated model which will be useful for use in primary care to identify the at-risk population. This will assist in the promotion of prevention recommendations and for future health check follow-up.

Citation Format: Temin Ke, Artitaya Lophatananon, Kenneth Muir, Xinzhu Yu. A novel integrated predictive model for pancreatic 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 2236.
Abstract 229: Elucidating arsenic dependent carcinogenesis in humans
Authors: Poceros-Coba Alma A. , Estrada-Florez Ana , Toal Ted , Lott Paul , Garrido Macarena , Steinmaus Craig , Ferrecio R. Catterina , Carvajal-Carmona Luis
Published: June 2022

Arsenic contamination in drinking water is one of the major health issues worldwide. Over 140 million people from 50+ countries are exposed to drinking water containing arsenic at levels above “safe” levels of 10 μg/L. Several studies indicate that chronic arsenic exposure is associated with the development of carcinogenic changes in the lungs, bladder, liver, and skin and other potential health problems. In this project, we aim to characterize bladder cancer mutational signatures and somatic mutations in a cohort of bladder cancer patients known to have been highly exposed to arsenic in northern Chile by using whole-exome sequencing (WES). We analyzed WES data and identified somatic mutations and mutational signatures using Mutec2 and SigProfiler. Preliminary analyses from a small number of exposed patients identified two mutational signatures, previously described as having “unknown” etiology, that showed an association with arsenic exposure. We are currently validating these findings in additional samples and with functional studies. Alma Poceros-Coba Ph.D. Candidate is the recipient of the Conacyt-UC-MEXUS Doctoral Fellowship and is the recipient of the UCDCCC Travel Award.

Citation Format: Alma A. Poceros-Coba, Ana Estrada-Florez, Ted Toal, Paul Lott, Macarena Garrido, Craig Steinmaus, Catterina Ferrecio R., Luis Carvajal-Carmona. Elucidating arsenic dependent carcinogenesis in humans [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 229.
Abstract 2291: microRNA/mRNA integrated analysis of multiple myeloma transcriptomics
Authors: Koduru Srinivas V.
Published: June 2022

Myeloma is plasma cell disorder, mostly effects adults over 60 years. Non-coding RNAs are emerging field and play vital role in development of disease. Major non-coding RNAs are miRNAs, lncRNAs, circRNAs and sn/snoRNAs. We analyzed restricted and publically available RNA-seq and small RNA-seq data sets for biomarkers identification and their involvement in myeloma. We obtained restricted data from “BluePrint”, which contains 11 myeloma plasma cells and 4 normal tonsil plasma cells (EGAS00001001110). We identified 1534 genes are differentially regulated (2-fold cut-off, >10-FC 218 genes). Top 10 upregulated genes were: EDNRB (1246-FC), SCUBE1 (737-FC), MC4R (691-FC), NDNF (601-FC), PTGS2 (567-FC), GPRC5D (531-FC), MFAP3L (467-FC), CCND1 (381-FC), CXCL12 (344-FC) and BTBD3 (326-FC) ; top 10 downregulated were: EBF1 (-111-FC), HLA-DRB1(-133-FC), CPXM1 (-171-FC), LOC642131 (-171-FC), IGHV1OR15-3 (-171-FC), HLA-DRB5 (-204-FC), PRAMENP (-210-FC), DTX1 (-220-FC), CD22 (-337-FC) and RFTN1 (-356-FC). Publically available small RNA-seq data downloaded and analyzed for miRNAs, lncRNAs, circRNAs and sn/snoRNAs which contains 3 healthy donor’s plasma cells and 3 newly diagnosed myeloma patient plasma cells (PRJNA377345). We used mirDIP portal to analyze miRNA and mRNA differentially expressed data, predicated from more than 13 databases showed major role of miR-152-3p (targets 28 mRNAs), miR-93-5p (targets 19 mRNAs), miR-301a-3p (targets 13 mRNAs), miR-29c-3p (targets 12 mRNAs), and miR-144-3p (targets 9 mRNAs). Integrated analysis can provide valuable information from the transcriptomics data and effect of miRNAs on mRNAs.

Citation Format: Srinivas V. Koduru. microRNA/mRNA integrated analysis of multiple myeloma transcriptomics [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 2291.
Abstract 2294: Genomic landscape and immunological profile of glioblastoma in East Asians
Authors: Deng Davy
Published: June 2022

While it is well known that Glioblastoma (GBM) shows profound inter- and intra-tumoral heterogeneity, the ancestry disparities among races have been largely overlooked. By comparing the predominantly caucasian TCGA GBM dataset (EUR, n=383) with a large genomic and transcriptomic East Asian GBM dataset (EAS, n=443), we identified numerous significant differences between EAS-GBM and EUR-GBM. Transcriptomic clustering also established a novel EAS-GBM molecular classification system and the discovery of a new EAS-specific GBM subtype. We characterized each subtype comprehensively including genomic alterations, immune profile and TCR/BCR repertoire analysis. This study elucidates important ancestry-dependent biological and molecular differences between GBMs and proposes a new transcriptome-based EAS-GBM classification. Understanding these unique features contribute to a more comprehensive characterization of the heterogeneity in GBM patients and could facilitate more careful patient stratification during targeted therapy and drug development.

Citation Format: Davy Deng. Genomic landscape and immunological profile of glioblastoma in East Asians [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 2294.
Abstract 23: Will novel systemic treatments alter the benefit of lung cancer screening?: A microsimulation study
Authors: Gogebakan Kemal Caglar , Lange Jane , Slatore Christopher , Etzioni Ruth
Published: June 2022

Background: The U.S. Preventive Services Task Force has recently updated its 2013 lung cancer screening guidelines with low-dose computed tomography. In the last decade, population level mortality for advanced non-small cell lung cancer fell significantly due to the novel targeted and immunotherapy-based treatments. Moreover, with detection of new molecular targets, these therapies are expected to become the ultimate curative options. However, how these treatments might impact the benefits of lung cancer screening is unknown.

Methods: We utilize a computer microsimulation modeling framework to screen the U.S. population aged 50 to 80 who had a 20 pack-year smoking history and currently smoked or had quit within the past 15 years under both standard treatments (chemotherapy and radiotherapy) and novel treatments (immunotherapy and targeted therapy) settings. The corresponding mortality reductions associated with the stage shift via low-dose computed screening are projected for each setting.

Results: Over 25 years, risk-targeted screening saves 243 lives per 20,000 under standard therapies (12% mortality reduction) and 99 per 20,000 under fully adopted novel therapies (6% mortality reduction). Under standard treatment, 1.28 cancers are over-diagnosed per life saved; under fully adopted novel therapies, this increases to 3.46. Over 25 years the number needed to screen to avert one death is 82 under standard treatment and 202 under fully adopted novel therapies.

Conclusions: Ongoing transition from chemotherapy and radiotherapy to novel immunotherapies and targeted therapies may reduce the expected lives saved by low-dose computed tomography screening. Screening recommendations might need to be reconsidered as novel treatments become widespread.

Citation Format: Kemal Caglar Gogebakan, Jane Lange, Christopher Slatore, Ruth Etzioni. Will novel systemic treatments alter the benefit of lung cancer screening?: A microsimulation study [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 23.
Abstract 2303: The WEE1 inhibitor Debio 0123 enhances the efficacy of standard of care DNA damaging agents in lung cancer models
Authors: Piggott Luke , Vaslin-Chessex Anne , Luong Noemie , Tschumi Benjamin , Vuagniaux Gregoire
Published: June 2022

Introduction: The WEE1 tyrosine kinase is activated upon DNA damage and regulates the G2-M and S phase cell cycle checkpoints. Inhibition of WEE1, in conjunction with genetic alterations and/or addition of a DNA damaging agent, results in mitotic catastrophe and apoptosis of cancer cells, offering an attractive approach to treating cancer. Debio 0123 is a WEE1 specific inhibitor previously shown to sensitize cancer cells to DNA damaging agents which is currently being assessed in combination with carboplatin in patients with advanced solid malignancies. Small cell lung cancer (SCLC) is an aggressive disease with poor clinical outcomes that carries a high mutational burden and genomic instability. Here we investigated the ability of Debio 0123 to enhance SCLC response to standard of care (SOC) DNA damaging agents carboplatin and etoposide in vitro and in vivo.

Methods: SCLC cell lines were treated with Debio 0123 alone or in combination with etoposide or carboplatin in vitro and apoptosis assessed by flow cytometry. In vivo SCLC patient derived- or cell line derived-xenograft (PDX or CDX, respectively) models were treated with Debio 0123 orally in combination with either carboplatin or etoposide alone or as a triple combination. Tumor growth inhibition was assessed over 3 cycles of treatment and tolerability of the combinations evaluated by monitoring body weight changes.

Results: Debio 0123 synergized with carboplatin and etoposide in vitro leading to a significant increase in the induction of apoptosis. Additionally, Debio 0123 significantly improved the tumor growth inhibitory effect of etoposide and carboplatin in both PDX and CDX models of SCLC in vivo. Triple combination of carboplatin, etoposide and Debio 0123 was well tolerated at therapeutically relevant dosing and resulted in significantly improved tumor response when compared to carboplatin and etoposide treatments alone or to the double combination.

Conclusions: Taken together these results highlight that inhibiting WEE1 with Debio 0123 significantly improves tumor response to SOC DNA damaging agents in models of SCLC, providing the foundation for future clinical exploration of Debio 0123 in SCLC.

Citation Format: Luke Piggott, Anne Vaslin-Chessex, Noemie Luong, Benjamin Tschumi, Gregoire Vuagniaux. The WEE1 inhibitor Debio 0123 enhances the efficacy of standard of care DNA damaging agents in lung cancer models [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 2303.
Abstract 2315: Synergic antitumoral activity of TTFields stimulation and Chloride Intracellular Channel 1 (CLIC1) inhibition in human glioblastoma primary culture
Authors: Mazzanti Michele , Castiglione Stefania , Ranucci Matteo , Cannavale Gaetano , Cianci Francesca , Verduci Ivan
Published: June 2022

Glioblastoma relapse inevitably occurs in the majority of patients after surgery. Chemo- and radio- therapy are in most cases ineffective, while Tumor Treating Fields (TTFields) therapy delays average tumor recurrence by a few months. It is widely accepted that tumor reappearance is a result of the proliferation of residual glioblastoma stem cell (GSC) subpopulation, which escaped surgery. Long-term TTFields stimulation in in vitro experiments mimic glioblastoma cells recrudescence. After the first three days of TTFields exposure, cell growth is totally inhibited. However, in prolonged experiments, despite the chronic presence of TTFields stimulation, glioblastoma cells reestablish the ability to proliferate, even if at low rate. At the end of twelve days, exponentially growing cells show an increase of stemness markers, a drop of the membrane resistance with a related increase of membrane current, and an average depolarized membrane potential. Twelve days of TTFields treatment resulted in progressive increase in GSCs in the tumor cell population from 10% to more than 30%. Our long-term goal is to improve TTFields antitumoral activity by linking brain stimulation with a pharmacological strategy targeting GSC proliferation. The objective of our study is to test the therapeutic potential of combining TTFields exposure with the inhibition of the protein transmembrane Chloride Intracellular Channel 1 (tmCLIC1), which is crucial for GSCs proliferation. tmCLIC1 activity increases under oxidative stress conditions. Preliminary experiments using the INOVITRO-LIVE system showed a cytoplasmic oxidation increase under acute TTFields stimulation. tmCLIC1 impairment by ion channel specific antagonists affected the G1/S checkpoint and hence, tumor cell proliferation. Targeting synergically different glioblastoma cell cycle checkpoints, G2/M with TTFields stimulation and G1/S with tmCLIC1 inhibition, would include the vast majority of glioblastoma cell population. Combination TTFields exposure and tmCLIC1 ion channel inhibition could represent an efficacious step forward in the treatment of glioblastoma.

Citation Format: Michele Mazzanti, Stefania Castiglione, Matteo Ranucci, Gaetano Cannavale, Francesca Cianci, Ivan Verduci. Synergic antitumoral activity of TTFields stimulation and Chloride Intracellular Channel 1 (CLIC1) inhibition in human glioblastoma primary culture [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 2315.
Abstract 2327: Dysregulated TCA cycle is associated with endocrine therapy resistance in ER+ breast cancer cells
Authors: Sengupta Surojeet , de Oliviera Karla Andrade , Jin Lu , Clarke Robert
Published: June 2022

Estrogen receptor positive (ER+) breast cancer is the most common breast cancer subtype. Endocrine therapies, such as selective estrogen receptor modulators (SERM) and aromatase inhibitors (AI), along with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, are the current mainstays of treatment. Despite being initially effective, the majority of advanced ER+ breast cancers become resistant to the endocrine therapies. Therefore, it is important to understand the underlying molecular mechanisms that enable or promote resistance to endocrine therapies. Rapidly proliferating cells have a high energy demand and consequently consume greater quantities of glucose to fulfill their energy and anabolic demands to support cell growth. Using endocrine therapy sensitive and resistant breast cancer cell models we investigated the metabolic flux of glucose by growing the cells in the presence of the stable glucose isotope, UC13-Glucose and measured the C13-labelled metabolites of glycolysis and the TCA cycle. Glucose consumption was higher in endocrine therapy resistant MCF7/LCC9 (LCC9) cells compared with parental MCF7 (MCF7) and estrogen independent, endocrine therapy sensitive MCF7/LCC1 (LCC1) cells. The TCA cycle was noticeably impaired in LCC9 cells as the C-13 labelled citrate (m+4 and m+6) isotopomer was absent in these cells. In addition, C-13 labelled fumarate was very low in LCC9 cells with a concurrent increase in the succinate:fumarate ratio. These observations show that in LCC9 cells the TCA cycle is dysregulated at the succinate to fumarate conversion step, which is catalyzed by the succinate dehydrogenase (SDH) enzyme. SDH is a multimeric protein comprised of four different subunits and SDH assembly factor 2 (SDHAF2), which is a tumor suppressor gene. Further investigation revealed that SDHAF2 was under expressed in LCC9 cells compared with LCC1 cells, likely contributing to lower SDH activity. Intriguingly, SDH inhibition by dimethyl-malonate re-sensitized LCC9 cells to both Fulvestrant and 4-hydroxytamoxifen. Clinically, lower expression levels of SDHAF2 correlates with poor relapse free survival in ER+ breast cancer patients. In summary, our study suggests that accumulation of succinate driven by deficient SDH activity is functionally associated with endocrine therapy resistance in ER+ breast cancer cells.

Citation Format: Surojeet Sengupta, Karla Andrade de Oliviera, Lu Jin, Robert Clarke. Dysregulated TCA cycle is associated with endocrine therapy resistance in ER+ breast 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 2327.
Abstract 2406: Mechanism of mSin1 regulation of cell migration
Authors: Huang Shile , Liu Lei , Luo Yan
Published: June 2022

Studies have shown that mSin1, a major component of mTORC2, plays an important role in tumor cell migration and invasion as well as cancer metastasis. However, how mSin1 regulates cell migration is poorly understood. In this study, we found that knockout of mSin1 suppressed cell spreading and migration in mouse embryo fibroblasts (MEFs). Similarly, knockdown of mSin1 also inhibited cell spreading and migration in rhabdomyosarcoma (Rh30) and cervical cancer (HeLa) cells. Furthermore, we observed that knockout or knockdown of mSin1 reduced the activities of the small GTPases (RhoA and Rac1) in the cells. Ectopic expression of constitutively active Rac1, but not RhoA, partially attenuated the reduced cell spreading and migration induced by mSin1 deficiency. In addition, depletion of mSin1 remarkedly inhibited the phosphorylation of focal adhesion proteins, including focal adhesion kinase (FAK) at Tyr397 and paxillin at Tyr118 in the cells. The results suggest that mSin1 controls cell spreading and migration at least partly by mediating the activity of Rac1 and the phosphorylation of FAK. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA)

Citation Format: Shile Huang, Lei Liu, Yan Luo. Mechanism of mSin1 regulation of cell migration [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 2406.
Abstract 242: TCTP is a target for cancer immunotherapy modulating myeloid-derived suppressor cells
Authors: Ryou Jeong-Hyun , Lee Gwanghee , Taniguchi Tadatsugu , Yanai Hideyuki , Hangai Sho
Published: June 2022

Myeloid-derived suppressor cells (MDSCs) are a heterogenous group of myeloid cells that are highly suppressive to antitumor lymphocyte function and trafficking to the tumor. The accumulation of MDSCs in the tumor immune microenvironment (TIME) makes immunosuppressive TIME and progressive tumor. In fact, despite notable clinical outcomes in cancer immunotherapy, many patients are refractory or relapsed to immune checkpoint inhibitor therapy, wherein obstacles imposed by TIME contribute to a great extent. Here, we show that translationally controlled tumor protein (TCTP) released by dying tumor cells is an immunomodulator crucial to full-blown MDSC accumulation in the TIME in mouse models. We provide evidence that extracellular TCTP mediates recruitment of the polymorphonuclear MDSC (PMN-MDSC) population in the TIME, which is Toll-like receptor-2 (TLR2) dependent. For human translation, we confirmed that human TCTP binds directly to human TLR2 extracellular domain and stimulates human PBMC to produce multiple cytokines. To explore therapeutic applicability, we generated anti-TCTP antibodies for TCTP inhibition. The antibodies successfully neutralized TCTP in molecular and cellular level. The antibodies also suppressed PMN-MDSC accumulation and tumor growth. The combination of anti-TCTP antibody and immune checkpoint inhibitor showed synergistic effect on tumor growth inhibition. In conclusion, extracellular TCTP is an immunomodulator recruiting PMN-MDSCs to TIME. When TCTP is removed or neutralized, PMN-MDSC counts in TIME decreased. Anti-TCTP therapy may offer a new immunotherapy strategy.

Citation Format: Jeong-Hyun Ryou, Gwanghee Lee, Tadatsugu Taniguchi, Hideyuki Yanai, Sho Hangai. TCTP is a target for cancer immunotherapy modulating myeloid-derived suppressor 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 242.
Abstract 2422: Migration of V600E-expressing cells is suppressed by ERK-dependent feedback inhibition of RAC1 and rescued in melanoma by secondary mutations
Authors: Gadal Sunyana , Boyer Jacob A. , Li Hongyan , Fan Ning , Chan Eric , Romin Yevgeniy , De Stanchina Elisa , Yeager Rona , Bosenberg Marcus , Todorova Katia M. , Rosen Neal
Published: June 2022

Oncogenic activation of ERK occurs in as many as 50% of human tumors and in the majority of melanomas. Activated BRAF V600E hyperactivates ERK signaling and causes ERK dependent dysregulation of proliferation. However, BRAF V600E alone is insufficient to drive melanoma formation in genetically engineered mice models. Moreover, 82% of benign nevi harbor BRAF V600E mutations. In contrast, in BRAF V600E/PTEN-/- GEMM models, rapid onset of aggressive and disseminated melanomas occurs. We show here that cell migration and invasion of melanocytes expressing BRAFV600E is depressed in vitro and in vivo and significantly accelerated by pharmacologic inhibition of ERK signaling or by deletion of PTEN. Upon ERK inhibition, cells lose their cell-cell junctions and become single cells with actin rich protrusions and a mesenchymal morphology. ERK pathway activation affects each step of the migration cycle, impeding cell spreading, assembly of stress fibers, and focal contact formation, all of which are associated with decreased mobility and invasion. Hyperactivation of ERK signaling by BRAF V600E has been shown to cause potent feedback inhibition of RTK signaling and wild type RAS. We now show that this is associated with feedback inhibition of RAC1, a RAS-like small GTPase required for cell migration. Moreover, ERK pathway inhibition reactivates RAC in an RTK-dependent manner. Consistent with these findings, expression of RAC1 P29S, an activating mutant, and overexpression of PREX2, an activator of RAC1, both rescue migration in BRAF V600E cells, as does loss of PTEN expression, which converges with RAC1 activation downstream. Taken together, these data suggest that whereas hyperactivation of ERK signaling by BRAFV600E dysregulates proliferation, ERK dependent feedback inhibition of RAC1 inhibits cell mobility and invasiveness and prevents full transformation. Selection of secondary genetic events that overcome or bypass RAC1 feedback is thus required for full transformation. In support of this view, RAC1 mutation, PTEN loss, or PREX2 amplification occurs in 38% of human melanomas. Thus, oncogene induced feedback may be deleterious and directs tumor evolution by causing selection of mutations that restore functions necessary for transformation

Citation Format: Sunyana Gadal, Jacob A. Boyer, Hongyan Li, Ning Fan, Eric Chan, Yevgeniy Romin, Elisa De Stanchina, Rona Yeager, Marcus Bosenberg, Katia M. Todorova, Neal Rosen. Migration of V600E-expressing cells is suppressed by ERK-dependent feedback inhibition of RAC1 and rescued in melanoma by secondary mutations [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 2422.
Abstract 2435: EZH2 engages TGFb signaling to promote breast cancer bone metastasis via Integrin b1-FAK activation
Authors: Zhang Lin , Qu Jingkun , Qi Yutao , Duan Yimin , Huang Yu-Wen , Zhou Zhifen , Li Ping , Yao Jun , Huang Beibei , Zhang Shuxing , Yu Dihua
Published: June 2022

Bone metastasis is a frequent complication of breast cancer, occurring in about 50-70% of breast cancer patients with late-stage disease. The lack of effective therapy suggests that the precise molecular mechanisms underlying bone metastasis are still unclear. Enhancer of zeste homolog 2 (EZH2) is considered a breast cancer oncogene and its expression is correlated with metastasis of breast cancer, but its function in bone metastasis has not been well explored. Herein we report that EZH2 promotes osteolytic metastasis of breast cancer through regulating transforming growth factor beta (TGFβ) signaling, a key pathway in bone metastasis. Knocking down EZH2 decreases bone metastasis incidence and outgrowth in vivo. EZH2 induces cancer cell proliferation and osteoclast maturation, when breast cancer cells are co-cultured with osteoblasts and osteoclasts together in vitro. Mechanistically, EZH2 increases transcription of ITGB1, which encodes for integrin β1. Integrin β1 activates focal adhesion kinase (FAK), which phosphorylates TGFβ receptor type I (TGFβRI) at tyrosine 182, thus enhances the binding of TGFβRI to TGFβ receptor type II (TGFβRII), therefore activates Smad2 and increases parathyroid hormone-like hormone (PTHLH) expression. Clinically applicable FAK inhibitors but not EZH2 methyltransferase inhibitor effectively inhibits breast cancer bone metastasis in vivo. Overall, our data signify integrin β1-FAK as a new downstream effector of EZH2 in breast cancer cells, and EZH2-integrin β1-FAK axis cooperates with TGFβ signaling pathway to promote bone metastasis of breast cancer.

Citation Format: Lin Zhang, Jingkun Qu, Yutao Qi, Yimin Duan, Yu-Wen Huang, Zhifen Zhou, Ping Li, Jun Yao, Beibei Huang, Shuxing Zhang, Dihua Yu. EZH2 engages TGFb signaling to promote breast cancer bone metastasis via Integrin b1-FAK activation [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 2435.
Abstract 2436: CIRBP is a functional mediator of leptomeningeal metastasis
Authors: Ezzeddine Rima , Dankner Matthew , Savage Paul , Hebert Steven , Brothers William , Annis Matthew G. , Maritan Sarah M. , Fabian Marc R. , Kleinman Claudia , Park Morag , Siegel Peter M.
Published: June 2022

Background: Cold-Inducible RNA Binding Protein (CIRBP) has been implicated in cancer initiation. Moreover, we have previously identified an association of CIRBP with the invasive growth of parenchymal brain metastases. Using a patient-derived xenograft (PDX) model, in which cells implanted in the mouse mammary fat pad spontaneously metastasize to the leptomeninges, we identified CIRBP as being elevated in leptomeningeal metastases (LM) compared to matched primary mammary tumors. LM grow in the subarachnoid space that harbors the cerebral spinal fluid (CSF). The leptomeninges represent an inhospitable environment for disseminated cancer cells since the CSF is mitogen and nutrient poor. To investigate the importance of CIRBP for metastatic breast cancer cells in the leptomeninges, we stably reduced CIRBP expression in MDA-MB-231 cells and performed mammary fat pad and cranial injections. CIRBP knockdown had no influence on primary tumor growth, but diminished growth within the brain.

Hypothesis: We hypothesize that CIRBP functions as a stress response protein enabling cancer cells to grow in the harsh environment of the CSF.

Results: In response to various cellular stressors, such as hypothermia, hypoxia or UV irradiation, CIRBP can translocate from the nucleus to the cytoplasm. We show that culturing MDA-MB-231 cells in artificial CSF (aCSF) also causes CIRBP relocation from nucleus to cytoplasm. Using RNA-IP approaches, we have identified mRNAs bound by CIRBP in breast cancer cells treated with aCSF. Ultimately, we will determine whether any of the identified CIRBP-regulated targets contribute to the formation of LM. Finally, we have generated CIRBP variants that are confined either to the nucleus or the cytoplasm. We are currently assessing the ability of these compartment-restricted CIRBP proteins to promote the formation of central nervous system metastases.

Conclusions: We have identified CIRBP as a promoter of leptomeningeal metastasis. Our results have begun to reveal the mechanisms through which CIRBP mediates this process.

Citation Format: Rima Ezzeddine, Matthew Dankner, Paul Savage, Steven Hebert, William Brothers, Matthew G. Annis, Sarah M. Maritan, Marc R. Fabian, Claudia Kleinman, Morag Park, Peter M. Siegel. CIRBP is a functional mediator of leptomeningeal 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 2436.
Abstract 2443: Knocking out SNCA in SKMEL28 melanoma cells suppresses EMT and prevents invasion
Authors: Gajendran Nithya , Rajasekaran Santhanasabapathy , Aloy Nirjhar M. , Shekoohi Sahar , Witt Stephan N.
Published: June 2022

Malignant melanoma is one of the most aggressive and fifth most prevalent cancer among men and women. Clinical and epidemiological studies shows that Parkinson’s disease (PD) patients have higher risk of developing invasive melanoma, and, reciprocally, patients with invasive melanoma have a higher risk of developing PD. Alpha-synuclein (α-syn; SNCA), an intrinsically disordered protein expressed in neurons, is also highly expressed in malignant melanoma and is a common molecular signature between Parkinson’s disease and melanoma. We have previously reported that SK-Mel-28 SNCA-knockout (KO) cells exhibit suppressed tumor growth and proliferation in vivo and in vitro, and that putting back SNCA via lenti virus restored the phenotype to that of the control cells. The present study is designed to investigate the role of α-syn in melanoma progression in SK-MEL-28 cells in the context of metastasis and the epithelial-to-mesenchymal transition (EMT). The SK-Mel-28 SNCA-KO clones showed a significant decrease in the cell-surface protein L1CAM, a major cell adhesion molecule highly expressed in various melanoma and correlates with melanoma progression, whereas the knock in clones resembled the control. Migration and invasion assay were performed using transwell chambers showed a profound migratory and invasive defect in SNCA-KO clones. To explore further whether this is a proliferative or migratory defect, a single cell phagokinetic motility assay was performed with colloidal gold which showed a marked decrease in cell motility in knockout clones compared to control and knock in clones, which was consistent with our migration and invasion experiments. To determine the proteins involved in the inhibition of invasion mediated by α-syn, we immunoblotted for the mesenchymal markers N-cadherin and vimentin, and these were significantly downregulated in the SNCA-KO clones. These data reinforce that knocking out SNCA impedes melanoma cell migration and invasion in SK-Mel- 28 cell line, implying that α-syn might be a novel therapeutic target for malignant melanoma.

Citation Format: Nithya Gajendran, Santhanasabapathy Rajasekaran, Nirjhar M. Aloy, Sahar Shekoohi, Stephan N. Witt. Knocking out SNCA in SKMEL28 melanoma cells suppresses EMT and prevents invasion [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 2443.
Abstract 2557: Slit2 inhibits small cell lung cancer by targeting tumor microenvironment
Authors: Ahirwar Dinesh K. , Charan Manish , Misri Swati , Shilo Konstantin , Ganju Ramesh
Published: June 2022

Small cell lung cancer (SCLC) is the deadliest subtype of lung cancer with a 5-year survival rate of <5% in extensive-state disease and is designated by US Congress as a “recalcitrant cancer”. Recently approved by FDA, immune checkpoint blockade (ICB) immunotherapy showed marginally improved survival and only in a few patients, suggesting an inert immune tumor microenvironment (TME) and the existence of SCLC subtypes. Therefore, there is a significant need to develop more effective therapies for SCLC. In addition to the nearly universal biallelic inactivation of Rb and Tp53 genes in human SCLC tumors, comprehensive genome-wide screening studies have identified major co-occurring mutations in PTEN, CREBBP, EP300, SLIT2, MLL, COBL, and EPHA7 genes. Among them, SLIT2 showed the highest level of genomic abnormalities defined by a pronounced clustering of mutations and frequent genomic loss. However, the role of Slit2 in SCLC has not been defined yet. By using genetically engineered human SCLC cells overexpressing Slit2 or recombinant Slit2 (rSlit2) protein, we show that Slit2 inhibits SCLC cells proliferation, migration, and invasion properties and tumor sphere formation ability of drug-resistant SCLC cells in vitro. The mechanistic studies have identified inhibition of AKT and β-catenin mediated signaling pathways by Slit2 overexpression. Next, we implanted human SCLC cell lines into the immunocompromised NSG mice subcutaneously followed by treatment with rSlit2 or sterile saline. Analysis of tumor volume over the 4 weeks showed that rSlit2 treatment significantly reduced the growth of SCLC tumors. Further analysis of tumors showed that rSlit2 treated tumors harbor less M2-like CD206+ macrophages. Overall, these results suggest that Slit2 possesses tumor suppressive properties and could be developed as a novel therapeutic agent against SCLC.

Citation Format: Dinesh K. Ahirwar, Manish Charan, Swati Misri, Konstantin Shilo, Ramesh Ganju. Slit2 inhibits small cell lung cancer by targeting tumor microenvironment [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 2557.
Abstract 2559: Tumor lipogenesis influences macrophage polarization in advanced prostate cancer
Authors: Martinez Shannalee R. , Risso Carla Barrientos , Vergne Ralphdy , Wall Nathan R. , Dutil Julie , Casiano Carlos A. , Ruiz-Deya Gilberto , Osterman Carlos Joel Diaz
Published: June 2022

Aberrant lipid metabolism in prostate tumors is linked to aggressive disease and poor outcomes. The purpose of this study was to identify mechanisms by which lipid metabolism in prostate cancer cells influences the tumor immune microenvironment, with emphasis on the activation of macrophages. Our hypothesis that fatty acid synthase-driven de novo lipogenesis promotes immune evasion via alternative M2-like macrophage activation was tested using human monocyte (U937)-derived macrophages co-cultured with prostate cancer cells in the presence of fatty acid synthase inhibitors. Monocytes were differentiated to macrophages in vitro using phorbol-12-myristate-13-acetate for 48 hours prior to co-culture with prostate cancer cells. Macrophage polarization following co-culture with prostate cancer cells was evaluated using multi-parameter flow cytometry to detect established M1 (CD80, CD86) and M2 (CD163, CD206) markers. Furthermore, the expression of fatty acid synthase and pan-macrophage marker CD68 in human prostate tumor tissue microarrays was evaluated using multiplex immunohistochemistry. The lipogenic enzyme and macrophage staining correlated with disease progression, reaching peak levels in metastatic tissues. These findings indicate that tumoral fatty acid synthase is an important mediator of tumor-immune crosstalk, particularly in the context of aggressive and metastatic prostate cancer. These data further suggest that fatty acid synthesis represents a targetable complement to immune-enhancing therapies by modulating tumor cell metabolism, underscoring the need for further evaluation of agents targeting lipid metabolism in prostate cancer.

Citation Format: Shannalee R. Martinez, Carla Barrientos Risso, Ralphdy Vergne, Nathan R. Wall, Julie Dutil, Carlos A. Casiano, Gilberto Ruiz-Deya, Carlos Joel Diaz Osterman. Tumor lipogenesis influences macrophage polarization in advanced prostate 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 2559.