bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1019: EGFR signal induces T cell non-inflamed tumor microenvironment (TME) through suppression of chemokine production from human EGFRmt lung adenocarcinoma
Authors: Sumimoto Hidetoshi , Takano Atsushi , Teramoto Koji , Daigo Yataro
Published: September 2020

EGFR mutation-positive (EGFRmt) lung adenocarcinoma (LA) is refractory to immune checkpoint inhibitors, such as anti-PD-1/anti-PD-L1 mAbs. However, the refractory mechanism remains to be elucidated. We found CD8A mRNA level was significantly lower in EGFRmt LA than in EGFRwt LA in TCGA data, which was validated at protein expression levels by immunohistochemistry of surgically obtained LA tissues (p<0.0001). We identified several chemokines showing positive correlations to the CD8A mRNA level on the TCGA data set, some of which were significantly lower in EGFRmt LA than in EGFRwt LA, suggesting that oncogenic EGFR signal might be related to the suppression of chemokine expression in the TME, leading to the less recruitment of CD8 T cells to the tumor. We conducted multiplex chemokine assays of several EGFRmt LA cell lines, and found EGFR-TKI of osimertinib treatment significantly increased several chemokine expressions in the culture supernatant compared to control DMSO (p<0.005), indicating EGFR signal may inhibit tumor intrinsic chemokine production, which may explain the T cell non-inflamed TME. Among the upregulated chemokines, IFN-responsive chemokines, CXCL9, 10, and 11, showed prominent increase (by 30 to 167-fold) under osimertinib treatment and IFN-γ stimulation. A T cell migration assay revealed CXCL10 was a major chemokine contributing to the chemotaxis. We further examined the suppressive mechanisms of CXCL10 expression via EGFR signal. siRNA experiments against EGFR confirmed the specific inhibition of CXCL10 expression by EGFR signal. Inhibitor experiments for the downstream of EGFR signal revealed that MAPK, but neither PI3K nor STAT3 signal, partially contributed to CXCL10 suppression. The increase of CXCL10 expression by osimertinb treatment occurred at an mRNA level. But an mRNA stability test revealed that EGFR signal did not decrease, but increased the mRNA stability of CXCL10, suggesting that EGFR signal might suppress the promoter activity of CXCL10. We conducted the promoter analysis of proximal 2kb of CXCL10 gene, however, the regulatory elements within the region, such as NFκB or IRF-1, were not accounted for the CXCL10 up-regulation upon EGFR-TKI treatment, suggesting the transcriptional control with EGFR signal at more remote cis-element(s). The data indicate that EGFR signal might work as a T cell excluding signal in human EGFRmt LA by suppressing several chemokine productions from the cells.

Citation Format: Hidetoshi Sumimoto, Atsushi Takano, Koji Teramoto, Yataro Daigo. EGFR signal induces T cell non-inflamed tumor microenvironment (TME) through suppression of chemokine production from human EGFRmt lung adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1019.
Abstract 1077: Macrophage PI3Kγ controls T cell activation and T cell memory generation through the production of IL-12
Authors: Takahashi Hideyuki , Shepard Ryan M. , Paradise Marc A. , Lee Sang Min , Shih Ann , Flores-Arenas Cristina , Kim William , Varner Judith A.
Published: September 2020

We previously reported that macrophage PI3kinase γ (PI3Kγ) controls a critical switch between immune stimulation and suppression during inflammation and cancer. PI3Kγ inhibition polarizes tumor-associated macrophages (TAMs) into pro-inflammatory macrophages, leading to the recruitment and activation of intratumoral CD8+ T cells, tumor growth inhibition and anti-tumor memory (Kaneda et al 2016). In the present study, we elucidated the role of PI3Kγ in the control of T cell immune responses, including activation, memory generation and exhaustion, in mouse models of head and neck squamous cell carcinomas (HNSCC). High-dimensional single-cell analysis including single-cell RNA sequencing and mass cytometry of HPV+ HNSCC tumors revealed significant differences in intratumoral immune cell clusters in HPV+ HNSCC tumors from WT and Pik3cg−/− mice. Primary tumors from Pik3cg−/− mice exhibited more pro-inflammatory TAMs, more activated CD8+ T cells and fewer exhausted T cells than in tumors from WT mice. Both tumor- and spleen-derived T cells from Pik3cg−/− mice exhibited more IFNγ expression than those from WT mice; this increase could be reversed by the neutralization of IL-12 and MHCII. We observed significantly more effector memory T cells in spleens of Pik3cg−/− mice than WT mice; accordingly, adoptive transfer of Pik3cg−/− but not WT splenic T cells conferred tumor resistance onto naive WT mice, indicating that PI3Kγ inhibition promotes T cell mediated immunological memory. In summary, Pik3cg−/− mice exhibited more activated T cells, T cell mediated immune responses and T cell memory than WT mice, resulting significant and sustained suppression of tumor growth. These results indicate that PI3Kγ-targeted therapy may activate durable T cell immune responses in patients with HNSCC.

Citation Format: Hideyuki Takahashi, Ryan M. Shepard, Marc A. Paradise, Sang Min Lee, Ann Shih, Cristina Flores-Arenas, William Kim, Judith A. Varner. Macrophage PI3Kγ controls T cell activation and T cell memory generation through the production of IL-12 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1077.
Abstract 1083: Heterozygous knockout of the histone modifier MLL4 promotes Ptch+/−-driven medulloblastoma
Authors: Dhar Shilpa S. , Zhao Dongyu , Lin Tao , Sillitoe Roy V. , Chen Kaifu , Lee Min Gyu
Published: September 2020

Medulloblastoma (MB) is the most common primary childhood brain tumor. MB development frequently results from the dysregulation of sonic hedgehog and wingless pathways. In contrast to our understanding of these pathways, the pathogenic roles of aberrant epigenetic modifiers in MB remain little known. MLL4 is one of the most commonly mutated genes in MB. In our recent study, we showed that brain-specific knockout of the gene encoding the histone H3 lysine 4 methyltransferase MLL4 (also called COMPASS-like methyltransferase, KMT2D, MLL2, and ALR) induced spontaneous MBs. Mll4 loss highly upregulated several oncogenic signaling programs, including expression of several oncogenic Ras activators (e.g., Rasgrp1, Rasgrf1, and Rasgef1a). In contrast, Mll4 loss downregulated expression of tumor-suppressive genes, such as Dnmt3a. In this study, we sought to determine whether Mll4 loss cooperates with other oncogenic event in MB genesis. Particularly, PTCH (also known as PTCH1) is one of the most frequently mutated genes in MB, and its loss induces MB in mouse models. Thus, we examined the effect of Mll4 loss on of Ptch+/−-driven MB genesis. A heterozygous loss of Mll4 increased the incidence and progression of Ptch+/−-driven MB genesis. MBs were confirmed by H & E staining, and immunohistochemical staining using anti-Ki-67 showed that cell proliferation was markedly increased. Calbindin signals were undetectable in Nestin-Cre Mll4f/+ Ptch+/−, and NeuN levels were decreased in Nestin-Cre Mll4f/+ Ptch+/− cerebellum compared to Ptch+/− cerebellum, suggesting the impairment of Purkinje and granule cells. Mll4 loss reduced cerebellar granule cell differentiation. These findings indicate that a haploinsufficiency of MLL4 promotes Ptch+/−-driven MB genesis. This mouse model may be useful for future preclinical therapeutic experiments for the treatment of MB patients with MLL4 mutations.

Citation Format: Shilpa S. Dhar, Dongyu Zhao, Tao Lin, Roy V. Sillitoe, Kaifu Chen, Min Gyu Lee. Heterozygous knockout of the histone modifier MLL4 promotes Ptch+/−-driven medulloblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1083.
Abstract 1085: Interrogating the RAS interactome identifies EFR3A as a novel enhancer of RAS oncogenesis
Authors: Adhikari Hema , Kattan Walaa , Hancock John F. , Counter Christopher M.
Published: September 2020

Activating mutations in one of the three RAS genes (HRAS, NRAS, and KRAS) are detected in as much as a third of all human cancers. As oncogenic RAS mediates it tumorigenic signaling through protein-protein interactions primarily at the plasma membrane, we sought to document the protein networks engaged by each RAS isoform to identify new vulnerabilities for future therapeutic development. To this end, we determined interactomes of oncogenic HRAS, NRAS, and KRAS by BirA-mediated proximity labeling. This analysis identified roughly ** proteins shared among multiple interactomes, as well as a smaller subset unique to a single RAS oncoprotein. To identify those interactome components promoting RAS oncogenesis, we created and screened sgRNA library targeting the interactomes for genes modifying oncogenic HRAS-, NRAS-, or KRAS-mediated transformation. This analysis identified the protein EFR3A as not only a common component of all three RAS interactomes, but when inactivated, uniformly reduced the growth of cells transformed by any of the three RAS isoforms. EFR3A recruits a complex containing the druggable phosphatidylinositol (Ptdlns) 4 kinase alpha (PI4KA) to the plasma membrane to generate the Ptdlns species PI4P. We show that EFR3A sgRNA reduced multiple RAS effector signaling pathways, suggesting that EFR3A acts at the level of the oncoprotein itself. As lipids play a critical role in the membrane localization of RAS, we tested and found that EFR3A sgRNA reduced not only the occupancy of RAS at the plasma membrane, but also the nanoclustering necessary for signaling. Furthermore, the loss of oncogenic RAS signaling induced by EFR3A sgRNA was rescued by targeting PI4K to the plasma membrane. Taken together, these data support a model whereby EFR3A recruits PI4K to oncogenic RAS to promote plasma membrane localization and nonclustering, and in turn, signaling and transformation. To investigate the therapeutic potential of this new RAS enhancer, we show that EFR3A sgRNA reduced oncogenic KRAS signaling and transformed growth in a panel of pancreatic ductal adenocarcinoma (PDAC) cell lines. Encouraged by these results we are exploring whether genetically inactivating the kinase activity of PI4KA inhibits oncogenic signaling and transformation in PDAC cell lines. If true, pharmacologically targeting PI4K may hold promise as a way to enhance the anti-neoplastic activity of drugs targeting oncogenic RAS or its effectors.

Citation Format: Hema Adhikari, Walaa Kattan, John F. Hancock, Christopher M. Counter. Interrogating the RAS interactome identifies EFR3A as a novel enhancer of RAS oncogenesis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1085.
Abstract 1088: Elucidating the regulation of delayed-early gene targets of sustained MAPK signaling
Authors: Dale Kali J. , McMahon Martin
Published: September 2020

RAS and its downstream effector, BRAF, are commonly mutated proto-oncogenes in many types of human cancer. Mutationally activated RAS or BRAF signal through the MEK→ERK MAP kinase (MAPK) pathway to regulate key cancer cell hallmarks such as cell division cycle progression, reduced programmed cell death, and enhanced cell motility. Amongst the list of RAS/RAF-regulated genes are those encoding integrins, alpha-beta heterodimeric transmembrane proteins that regulate cell adhesion to the extracellular matrix. Altered integrin expression has been linked to the acquisition of more aggressive behavior by melanoma, lung, and breast cancer cells leading to diminished survival of cancer patients. We have previously documented the ability of the RAS-activated MAPK pathway to induce the expression of ITGB3 encoding integrin β3 in several different cell types. RAS/RAF-mediated induction of ITGB3 mRNA requires sustained, high-level activation of RAF→MEK→ERK signaling mediated by oncogene activation and is classified as “delayed-early”, in that it is sensitive to the protein synthesis inhibitor cycloheximide. However, to date, the regulatory mechanisms that allow for induced ITGB3 downstream of sustained, high-level activation of MAPK signaling remains obscure. We have identified over 300 DEGs, including those expressing additional cell surface proteins, that display similar regulatory characteristics as ITGB3. We use integrin β3 as a model to test our hypothesis that there is a different mechanism of regulation for delayed-early genes (DEG) compared to the canonical regulation of Immediate-Early genes. There are three regions in the chromatin upstream of the ITGB3 that become more accessible during RAF activation. We are relating the chromatin changes seen during RAF activation to active enhancer histone marks. To elucidate the essential genes of this regulation process, we are employing the use of a genome-wide CRISPR knockout screen. The work presented from this abstract will help elucidate the regulatory properties of oncogenic progression in BRAF mutated cancers that could lead to the identification of biomarkers.

Citation Format: Kali J. Dale, Martin McMahon. Elucidating the regulation of delayed-early gene targets of sustained MAPK signaling [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1088.
Abstract 1104: Folate intake and colorectal cancer risk during 36 years of follow-up in US women: A prospective cohort study
Authors: Wang Fenglei , Wu Kana , Li Yanping , Smith-Warner Stephanie , Giovannucci Edward , Willett Walter
Published: September 2020

Background: Folate intake has been reported to be associated with a lower colorectal cancer (CRC) risk in several epidemiological studies. However, there are concerns about the potential for cancer promotion with an overly-abundant folate intake, especially after the mandatory folate fortification in the United States in 1998.

Method: We investigated the association between folate intake and CRC risk among 83,165 women in the Nurses' Health Study, including 18 years of post-fortification follow-up; 2268 incident CRC cases were ascertained from 1980 to 2016. Folate intake from foods and supplements was assessed at baseline and updated every 4 years using a validated food-frequency questionnaire. Multivariate hazards ratios (HR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards regression.

Results: Over the entire follow-up period (1980-2016), higher total folate intake was associated with a decreased risk of CRC (HRQ5vsQ1=0.80; 95% CI: 0.64-0.99). This association was stronger when total folate was assessed 12-24 years before CRC diagnosis. Multivitamin use for >15 years, but not a shorter duration of use, was associated with lower CRC risk. In the post-fortification period (1998-2016, n= 1169 CRC cases), high total folate intake (HRQ5vsQ1=0.80; 95% CI: 0.64-1.00) and current multivitamin uses, regardless of duration, were each associated with lower CRC risk.

Conclusions: There was no evidence that high folate intake in the post-fortification period was related to increased CRC risk. Rather, high total folate intake was inversely associated with risk of CRC.

Citation Format: Fenglei Wang, Kana Wu, Yanping Li, Stephanie Smith-Warner, Edward Giovannucci, Walter Willett. Folate intake and colorectal cancer risk during 36 years of follow-up in US women: A prospective cohort study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1104.
Abstract 1127: Adarza's ZIVA multiplex protein detection platform utilizes a label-free technology to simultaneously monitor murine and human inflammation cytokines in a CAR-T model system
Authors: Schmuke Jon J. , Carter Alun , Zhou You , Mueller Ernest , Cooper Matt
Published: September 2020

We have used Arrayed Imaging Reflectometry (AIR™), a label-free protein microarray technology that relies on the target binding-induced perturbation of an antireflective coating on the surface of a silicon biosensor, to create a multiplex antibody array for the detection of human and murine serum cytokines and inflammatory markers. The biosensor is capable of providing quantitative protein concentrations, with limits of detection in the low picograms per mL. Provided in a standard 96-well microplate format, the label-free nature of the array enables flexible creation of standard or custom panels for development of model systems. Here, we demonstrate a custom 22 plex panel developed in collaboration with WUGEN Inc. to provide multi-species cytokine analysis in humanized CAR-T cell models for the evaluation of biologic product efficacy and safety. Samples from in vitro and in vivo models developed for the evaluation of CAR-T activity were analyzed and demonstrated a novel platform for concurrent cross-species cytokine analysis on a single array. Results are evaluated for sensitivity, precision, and accuracy with ZIVA assays comparable to traditional ELISAs. With array capabilities from low to hundreds of plex combined with a hands-free, automation-friendly workflow enabled by the ZIVA instrument, the technology has been designed for the ultimate user-experience.

Citation Format: Jon J. Schmuke, Alun Carter, You Zhou, Ernest Mueller, Matt Cooper. Adarza's ZIVA multiplex protein detection platform utilizes a label-free technology to simultaneously monitor murine and human inflammation cytokines in a CAR-T model system [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1127.
Abstract 1140: Declining awareness of HPV and HPV vaccination within the general US population
Authors: Chido-Amajuoyi Onyema G. , Jackson Inimfon , Yu Robert , Shete Sanjay
Published: September 2020

Background: Programs aimed at boosting awareness on Human Papillomavirus (HPV) and HPV vaccination are considered one of the most effective strategies for increasing vaccination uptake and eliminating HPV-associated cancers. Several US states have demonstrated a strong commitment to this effort through legislation and dedicated funds, however the impact of this intervention over time remains poorly studied.

Methods: Using a nationally representative population of US adults from the Health Information National Trends Survey (HINTS), we examined for awareness of HPV and HPV vaccination between 2009 and 2018. Prevalence estimates and confidence intervals were calculated for HPV and HPV vaccination awareness. Further, we assessed awareness status after stratifying by key sociodemographic characteristics.

Results: Overall, the awareness of HPV and HPV vaccination declined over time. This finding was consistent across gender and socioeconomic strata. The lowest rates of awareness were found among those with educational level at or below high school completion, those who earned less than $35,000 per annum, rural residents, and male adults, aged 60 years and older. Declines in awareness of HPV or HPV vaccination between 2014 and 2018 were more than 10% among male adults, those with educational level at or below high school completion and those who earned less than $35,000 per annum. Only 36.1% of adults with high school education or lower had ever heard of HPV vaccine in 2018, a 15.6% reduction from 2009. In 2018 awareness of HPV and HPV vaccine was highest among non-Hispanic whites (65.8% and 66.5%) and female adults (70.5% and 71.4%), however these figures represented declines of at least 5% from rates observed in 2009.

Discussion: Amid a background of sub-optimal HPV vaccination uptake and a growing incidence of HPV-associated cancers in the US, the awareness of HPV and HPV vaccination within the general population has declined over time. This calls for stricter enforcement of legislature aimed at boosting HPV awareness, as well as frequent evaluations of government-funded HPV awareness programs.

Citation Format: Onyema G. Chido-Amajuoyi, Inimfon Jackson, Robert Yu, Sanjay Shete. Declining awareness of HPV and HPV vaccination within the general US population [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1140.
Abstract 1154: AFPep mitigates the risk of breast cancer
Authors: Fordyce Samuel B. , Andersen Thomas T. , Bennett James A.
Published: September 2020

Women whose risk of breast cancer is elevated (based on Gail or Tyrer-Cuzik models) have only limited options to intervene in attempt to alter disease progression, and most options are of limited efficacy or have unwanted side effects. Options include increased surveillance, lifestyle changes, drugs such as tamoxifen or aromatase inhibitors, or removal of target tissue. Options that are more efficacious, better tolerated, and more empowering are needed for women in high-risk cohorts. For this purpose, we have developed AFPep, a homobiotic, selective anti-estrogenic/anti-breast cancer active site-analog of alpha-fetoprotein (AFP). AFPep stops growth of human breast cancers growing in xenograft models and prevents development of either estrogen-induced or MNU-induced mammary cancers in rats. In all models, AFPep is effective against tamoxifen-resistant breast cancer, is additive with tamoxifen (allowing dose reduction of tamoxifen), and reduces the uterine hyperplasia induced by tamoxifen. AFPep does not disrupt the estrous cycle of rats, nor does it alter fertility or fecundity and does not induce teratogenicity. The mechanism of action of AFPep differs from that of tamoxifen in that AFPep inhibits phosphorylation of the estrogen receptor leading to a downstream biomarker profile consistent with inhibition of tumor growth. AFPep is orally bioavailable and well tolerated in mice, rats, dogs and primates. The therapeutic index of AFPep in rats shows a substantially broader safety margin than that of currently used agents. AFPep may offer an effective, well tolerated option for women in high risk cohorts who wish to mitigate their risk of breast cancer.

Citation Format: Samuel B. Fordyce, Thomas T. Andersen, James A. Bennett. AFPep mitigates the risk of breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1154.
Abstract 1172: Disparities in pancreatic ductal adenocarcinoma - the significance of Hispanic ethnicity, by subgroup analysis, and treatment facility on clinical outcomes
Authors: Riner Andrea N. , Underwood Patrick W. , Yang Kai , Herremans Kelly M. , Cameron Miles E. , Chamala Srikar , Qiu Peihua , George Thomas , Permuth Jennifer , Merchant Nipun B. , Trevino Jose G.
Published: September 2020

Background: Disparities exist among patients with pancreatic ductal adenocarcinoma (PDAC). Non-White race is regarded as a negative predictor of expected treatment and overall survival. Data suggest Academic Research Programs (ARP) provide better outcomes for minorities, but ethnic/minority outcomes are underreported. We sought to evaluate outcomes among diverse patients with PDAC, with a focus on Hispanic subgroups. We hypothesize that outcomes among racially/ethnically diverse PDAC patients may be influenced by treatment facility.

Methods: The National Cancer Database was used to identify 170,327 patients diagnosed with PDAC between 2004 and 2015. Cox proportional-hazard regression was used to compare survival between race/ethnic groups across facilities.

Results: In unadjusted models, compared to Non-Hispanic Whites (NHW), Non-Hispanic Blacks (NHB) had the worst overall survival (HR=1.05, 95%CI:1.03-1.06, p<0.001) and Hispanics had the best overall survival (HR=0.92, 95%CI:0.90-0.94, p<0.001). After controlling for socioeconomic and clinical covariates, NHB (HR=0.95, 95%CI:0.93-0.96, p<0.001) had better overall survival compared to NHW, and Hispanics continued to have the best comparative outcomes (HR=0.84, 95%CI:0.82-0.86, p<0.001). Amongst Hispanics, Dominicans and South/Central Americans lived the longest, at 10.25 and 9.82 months, respectively. The improved survival in Hispanics was most pronounced at ARP (HR=0.80, 95%CI:0.77-0.84, p<0.001) and Integrated Network Cancer Programs (HR=0.78, 95%CI:0.73-0.84, p<0.001). NHB had improved survival over NHW at Comprehensive Community Care Programs (HR=0.96, 95%CI:0.93-0.98, p=0.002) and ARP (HR=0.96, 95%CI:0.94-0.98, p=0.001), which was influenced by income, education, and surgical resection.

Conclusion: Hispanics with PDAC have better overall survival compared to Non-Hispanics at all facilities, but most profoundly at ARP and INCP. Dominicans and South/Central Americans in particular have significantly improved survival at ARP. Survival was improved at ARP for all populations. NHB had improved overall survival at higher volume centers, but this was dependent upon income, education, and surgical resection.

Citation Format: Andrea N. Riner, Patrick W. Underwood, Kai Yang, Kelly M. Herremans, Miles E. Cameron, Srikar Chamala, Peihua Qiu, Thomas George, Jennifer Permuth, Nipun B. Merchant, Jose G. Trevino. Disparities in pancreatic ductal adenocarcinoma - the significance of Hispanic ethnicity, by subgroup analysis, and treatment facility on clinical outcomes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1172.
Abstract 1185: Impact of distance traveled to radiosurgery center on time to initiation of gamma knife treatment for brain metastases in a rural patient population
Authors: Rehman Azeem A. , Singh Sarah , Arsanious David , Renz Paul , Cifarelli Christopher P.
Published: September 2020

The West Virginia University Gamma Knife center provides care for largely rural areas with patients that often travel 1-3 hours for treatment. Studies investigating whether distance to a tertiary cancer center results in meaningful delays in care are limited. This study examines patients treated with gamma knife for brain metastases to identify predictors of delay in care based on distance from the treatment center. Retrospective data for patients treated at the West Virginia University Gamma Knife center (2010-2017) for brain metastases with a primary diagnosis of lung or breast cancer was analyzed. Study variables included age, gender, primary histology, ECOG, KPS, RPA, interval time to initiation (TTI) of gamma knife treatment from diagnosis, and distance from home to the center. Statistical significance was determined by p<0.05. A total of 182 patients with a median age of 60 years (IQR: 53.5-69 years), median ECOG of 1 (Range: 0-3), median KPS of 80 (IQR: 70-100), and RPA of 2 were included. Median TTI of GK treatment was 21 days (IQR: 14-29 days) while median distance traveled to the facility was 45.8 miles (IQR: 24.5-86.7 miles). For patients residing within 45.8 miles, median TTI was 22 days (IQR: 15-33 days) compared with a median TTI of 20.5 days (IQR: 13.75-27 days) for patients living beyond 45.8 miles. There was no statistical difference between groups based on age, diagnosis, or distance to center with respect to TTI (p=0.28). Despite geographical disadvantages in a rural population, including distance traveled for treatment, no significant delay in TTI was identified in patients treated with gamma knife for brain metastases.

Citation Format: Azeem A. Rehman, Sarah Singh, David Arsanious, Paul Renz, Christopher P. Cifarelli. Impact of distance traveled to radiosurgery center on time to initiation of gamma knife treatment for brain metastases in a rural patient population [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1185.
Abstract 1188: The effect of insurance status on diagnosis stage and overall survival among children and adolescents with cancer: A propensity score weighting analysis
Authors: Wang Xiaoyan , Johnson Kimberly
Published: September 2020

Background. Differences in access, delivery or utilization of health care may impact childhood and adolescent cancer survival. In this study, we evaluated the impact of insurance coverage on diagnosis stage, treatment received, and overall survival among children and adolescents diagnosed with cancer based on a counterfactual framework.

Methods. We identified 58,421 individuals diagnosed with any cancer type at ≤ 19 years old from 2004-2010 from the National Cancer Database. We applied the inverse probability of treatment weighting (IPTW) estimator to correct for observed selection biases generated by insurance enrollment at diagnosis or initial treatment and examined associations between insurance status and diagnosis stage, treatment received (any vs. none), and all-cause mortality using weighted logistic and weighted Cox proportional hazard regressions.

Results. Compared to privately insured individuals, there was a higher percentage of younger individuals in the Medicaid category for all cancers, whereas the uninsured category had a higher percentage of older individuals. Children and adolescents with Medicaid and no insurance were more likely to be non-White and from lower income counties. Applying the IPTW estimator, all the imbalances on the above covariates were removed. Results from weighted analysis showed a 15% (95 confidence interval (CI): 0.78-0.93) lower odds of being diagnosed at metastatic stage had children and adolescents with Medicaid been enrolled on private insurance but comparable odds for uninsured individuals (odds ratio: 0.98, 95%CI: 0.79-1.22), vs. those with private insurance. The odds of receiving any treatment were 17% (95%CI: 1.08-1.28) and 68% (95%CI: 1.39-2.04) higher had those with Medicaid and no insurance been enrolled on private insurance at diagnosis or initial treatment. Medicaid and uninsured individuals would have a 24% (95%CI: 0.72-0.80) and 24% (95%CI: 0.66-0.87) lower hazard of death during 5 years of follow-up if they were enrolled on private insurance at diagnosis or initial treatment.

Conclusion. Children and adolescents without private insurance would have a lower risk of being diagnosed at metastatic stage, higher odds of receiving any treatment, and lower hazard of death within five years following cancer diagnosis had they been enrolled on private insurance at diagnosis or initial treatment. Additional research is needed to further understand underlying mechanisms.

Citation Format: Xiaoyan Wang, Kimberly Johnson. The effect of insurance status on diagnosis stage and overall survival among children and adolescents with cancer: A propensity score weighting analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1188.
Abstract 1211: Recurrent germline mutations in RAD51D and PALB2 are present in Colombian hereditary breast and ovarian cancer families
Authors: Sanabria-Salas Maria Carolina , Rivera-Herrera Ana Lucía , Gómez-Camargo Ana Milena , Carvajal-Carmona Luis G. , Serrano-López Martha Lucía
Published: September 2020

Hereditary breast cancer (BC) syndromes corresponds to 10% - 15% of all cases diagnosed worldwide. Most of these cases are due to deleterious germline genetic variants in BRCA1/2 genes; nevertheless, multipanel testing have contribute to the identification of other risk genes, including other homologous recombination (HR) repair genes, such as PALB2, ATM, CHEK2 and RAD51D. Here we explore the mutation spectrum of Hereditary Breast and Ovarian Cancer (HBOC) Colombian cases as part of the Hereditary Cancer Program from the National Cancer Institute from Colombia, the largest reference cancer center in the country, that seeks to identified high risk families to offer preventive measures and screening recommendations. A total of 358 patients fulfilling criteria for HBOC have been so far analyzed with Next Generation Sequencing using a multigene panel. Overall, 47% have negative results and in the 33% we identified VUSs. In general, 20% have a pathogenic or potentially pathogenic genetic variant; from those, BRCA1 (n = 17) and BRCA2 (n = 17) were the most frequently mutated genes (47.2% among all positive results). Deleterious mutations in RAD51D and PALB2 (also important HR repair genes) were found in 7% and 5.6% of the cases tested. Interestingly, genotype:phenotype correlations were found for these genes, as breast cancer molecular subtypes were distributed differently depending on the gene affected. In concordance with other reports, triple negative breast cancers (TNBC) were more frequent in BRCA1 (9/17, 53%) and PALB2 (4/4, 100%) carriers, and luminal subtypes were more frequent in BRCA2 carriers (10/17, 59%). Mutations in RAD51D: c.94_95del (p.Val32Phefs*67) and PALB2: c.2288_2291del (p.Leu763Ter), were both recurrent mutations in our Colombian cases. Further haplotype analysis will help us to determine if mutation carriers shared a common ancestry.

Citation Format: Maria Carolina Sanabria-Salas, Ana Lucía Rivera-Herrera, Ana Milena Gómez-Camargo, Luis G. Carvajal-Carmona, Martha Lucía Serrano-López. Recurrent germline mutations in RAD51D and PALB2 are present in Colombian hereditary breast and ovarian cancer families [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1211.
Abstract 1225: Co-inhibition of autophagy and MAPK signaling in RAS-driven cancers
Authors: Foth Mona , Kinsey Conan , Schuman Sophia , Battistone Benjamin , Sanchez Emilio Cortes , Kircher David , Welm Bryan , Holmen Sheri , McMahon Martin
Published: September 2020

RASis mutated in a number of cancers, including KRAS-driven colorectal and pancreatic cancer, HRAS-driven bladder cancer, and NRAS-driven melanoma, all of which result in downstream activation of the RAF>MEK>ERK (MAPK) and PI3K>AKT signaling pathways. Most RAS GTPases cannot be targeted directly, and strategies blocking both MAPK and PI3K signaling simultaneously are limited by high toxicity and compensatory signaling mechanisms. Interestingly, oncogene-activated MAPK or PI3K signaling pathways are reasonably well described orchestrators of metabolic transformation through multiple pathways. Our lab has recently shown that autophagy,a conserved metabolic process of self-digestion that recycles intracellular components, is increased in KRAS-driven pancreatic ductal adenocarcinoma (PDA) upon MAPK pathway inhibition. We further showed that co-inhibition of autophagy and MEK1/2, a MAPK component, leads to tumor regression of patient-derived PDA xenografts in mice. Our proposed combination therapy has recently been translated into a phase I/II clinical trial for PDA patients with advanced disease. Our most recent data show that inhibition of RAS>RAF>MEK>ERK signaling also results in induction of autophagy in other RAS-driven cancers, including KRAS-driven colorectal cancer, HRAS-driven bladder cancer and NRAS-driven melanoma. Furthermore, ourin vivodata demonstrate a robust regression of tumors upon combined inhibition of autophagy and MEK1/2 in engrafted KRAS-driven colorectal cancer cells xenografted in mice. Patient data from two KRAS-driven colorectal cancer patients, who were recently treated off-label, indicated clinical responses to the combination treatment co-targeting autophagy and MEK1/2. Altogether, these data suggest that co-inhibition of autophagy and oncogenic signaling may represent a potential new treatment strategy for multiple RAS-driven cancer types. Future experiments aim for a better mechanistic understanding of the combination treatment co-targeting autophagy and oncogenic signaling, with the objective to propose novel therapeutic strategies for cancer patients with RASmutations.

Citation Format: Mona Foth, Conan Kinsey, Sophia Schuman, Benjamin Battistone, Emilio Cortes Sanchez, David Kircher, Bryan Welm, Sheri Holmen, Martin McMahon. Co-inhibition of autophagy and MAPK signaling in RAS-driven cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1225.
Abstract 1272: Enhancer RNA cell line database reveals new associations between TF activity and cancer subtype
Authors: Azofeifa Joseph , Basken Joel , Lai Maria , Langendorf Ryan , Norris Laura , Read Tim , Robbins-Pianka Adam
Published: September 2020

Cell type and lineage is driven, in large part, by changes in transcription factor activity. Particularly in cancer, misregulation of transcription factor binding can lead to de-differentiated states and overproliferation. Recent work suggests that enhancer RNAs are a highly predictive readout of transcription factor activity, however, measuring them is an arduous process. We developed an automated strategy to measure nascent RNAs for over 50 different cancer cell line models. By a modified PRO-seq assay, we annotated enhancer RNAs and transcription factors unique to specific cancer backgrounds. Examples include: ESR1 activity in ER+ breast cancer models, AR activity in castration-sensitive prostate models and GATA3 in AML. This database is the first standardized collection of enhancer RNAs and and can be used in conjunction with the BROAD's CCLE and DepMap consortiums to help expedite treatment options.

Citation Format: Joseph Azofeifa, Joel Basken, Maria Lai, Ryan Langendorf, Laura Norris, Tim Read, Adam Robbins-Pianka. Enhancer RNA cell line database reveals new associations between TF activity and cancer subtype [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1272.
Abstract 1400: An additive effect of ebv-miR-BART5-5p and hsa-miR18a-5p in the downregulation of CDH1 transcript in Epstein-Barr virus associated gastric cancer
Authors: Torres Keila , Landeros Natalia , Wichmann Ignacio , Peñaloza-Otárola Allan , Polakovicova Iva , Maracaja-Coutinho Vinicius , Maturana Maria Jose , Villaroel-Espindola Franz , Corvalan Alejandro
Published: September 2020

Background. Nine percent of Gastric Cancer (GC) is associated with Epstein-Barr virus (EBV-associated GC), with significant variations in the global prevalence rates. Emerging evidence shows that, in addition to cellular miRNAs, viral miRNAs can also bind human mRNAs. EBV miRNAs are examples of this binding and are associated with oncogenic capacities of EBV. ebv-miR-BART5-5p shares the exact seed sequence with hsa-miR-18a-5p. However, common mRNA targets have not been fully described. The aim of this study is to determine predicted targets shared by both miRNAs in EBV-associated GC.

Methodology. By in house method we identified predicted mRNA targets for ebv-miR-BART5-5p and hsa-miR-18a-5p. These targets were queried in published results from the supplementary files of the STAD TCGA study and miRwalk 2.0 software. Validation was performed in 7 EBV-associated GC (cases) and 6 EBV-negative GC (controls) samples by miQ-PCR (ebv-miR-BART5-5p and hsa-miR-18a-5p) and qRT-PCR (predicted targets).

Results. We identified 25 downregulated and 11 upregulated mRNAs in EBV-associated GC cases compared with EBV-negative tumors in validated databases. Interestingly CDH1, which has been associated with diffuse and hereditary GC, was among the predicted targets by miRwalk 2.0. In clinical samples of EBV-associated GC, ebv-miR-BART5-5p and hsa-miR-18a-5p were overexpressed compared with control samples (p=0.0253 and p=0.0205, respectively). Furthermore, CDH1 was downregulated in EBV-associated tumors (p=0.0290).

Conclusion: We identified a common human mRNA target, the CDH1 transcript for ebv-miR-BART5-5p and hsa-miR-18a-5p in EBV-associated GC. An additive effect can be suggested between both miRNAs, which may explain the unique downregulation of CDH1 in EBV-associated GC. This work warrants future validation in vitro, as well as in a larger cohort of EBV-associated GC.

Grant support: CONICYT-FONDAP-15130011, Fondecyt Regular-1191928 and Fondecyt PostDoc-3201028

Citation Format: Keila Torres, Natalia Landeros, Ignacio Wichmann, Allan Peñaloza-Otárola, Iva Polakovicova, Vinicius Maracaja-Coutinho, Maria Jose Maturana, Franz Villaroel-Espindola, Alejandro Corvalan. An additive effect of ebv-miR-BART5-5p and hsa-miR18a-5p in the downregulation of CDH1 transcript in Epstein-Barr virus associated gastric cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1400.
Abstract 1444: c-FLIP antagonizes the survival of extracellular matrix detached cancer cells
Authors: Tsegaye Matyas Abel , McGeehan Kyle , Nemera Mati , Schafer Zachary T.
Published: September 2020

The metastasis of cancer cells to distant sites accounts for over 90% of cancer related deaths. In order to metastasize, cancer cells must be able to survive during extracellular matrix (ECM) detachment, namely by blocking anoikis – caspase dependent cell death – and restoring metabolic deficiencies. Such barriers during tumorigenesis are abrogated through activation of oncogenes, and/or inhibition of tumor suppressors. Elucidating the signaling pathways involved in cancer cell metastasis is a crucial step in designing effective therapeutic interventions. Surprisingly, our investigation has revealed that cellular FLICE-like Inhibitory Protein (c-FLIP), a protein known for its anti-apoptotic function, antagonizes the survival of ECM-detached cancer cells. Additionally, we demonstrated that oncogenic signaling results in the downregulation of c-FLIP expression further suggesting that cancer cells can benefit from diminished FLIP levels. We observed that this repression of c-FLIP expression is a consequence of MEK-ERK signaling. Our study also suggests that the mechanism underlying this paradoxical c-FLIP pathway involves the induction of β-catenin degradation through inhibition of GSK-3β phosphorylation by p38 MAPK. This results in the ubiquitination and subsequent degradation of β-catenin which could contribute to reduced proliferation and migration.

Citation Format: Matyas Abel Tsegaye, Kyle McGeehan, Mati Nemera, Zachary T. Schafer. c-FLIP antagonizes the survival of extracellular matrix detached cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1444.
Abstract 1452: Hypoxia-induced MIG-6 promotes glucose metabolic reprogramming and tumorigenesis in triple-negative breast cancer
Authors: He Jiabei , Li Chien-Feng , Lee Hong-Jen , Shin Dong-Hui , De Carvalho Bruno , Chan Chia-Hsin
Published: September 2020

Treatment of triple-negative breast cancer (TNBC) remains challenging due to a lack of effective targeted therapies. Dysregulated glucose uptake and metabolism are essential for TNBC growth. Identifying the molecular drivers and mechanisms underlying the metabolic vulnerability of TNBC is the key to exploiting dysregulated cancer metabolism for therapeutic applications. Mitogen-inducible gene-6 (MIG-6) has long been thought as a feedback inhibitor that targets activated EGFR and suppresses the growth of tumors driven by constitutive activated mutant EGFR. Here, our bioinformatics and histological analyses uncovered that MIG-6 is upregulated in TNBC and that MIG-6 upregulation is positively correlated with poorer clinical outcomes in TNBC. Metabolic arrays and functional assays revealed that MIG-6 drives glucose metabolism reprogramming toward glycolysis. We found that hypoxia-induced MIG-6 promotes HIF1α protein stabilization and the subsequent upregulation of GLUT1 and other HIF1α-regulated glycolytic genes, substantiating the comprehensive regulation of MIG-6 in glucose metabolism. Moreover, our animal studies demonstrated that MIG-6 regulates GLUT1 expression in tumors and subsequent tumor growth in vivo. Collectively, this work reveals that MIG-6 is a novel prognosis biomarker, metabolism regulator, and molecular driver of TNBC.

Citation Format: Jiabei He, Chien-Feng Li, Hong-Jen Lee, Dong-Hui Shin, Bruno De Carvalho, Chia-Hsin Chan. Hypoxia-induced MIG-6 promotes glucose metabolic reprogramming and tumorigenesis in triple-negative breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1452.
Abstract 1502: Cell state mapping reveals a role for a stress program in melanoma
Authors: Baron Maayan , Tagore Mohita , Hunter Miranda , Kim Isabella S. , Moncada Reuben , Yan Yun , Campbell Nathaniel R. , White Richard M. , Yanai Itai
Published: September 2020

Transcriptional profiling has revealed a diverse range of cell states in cancer, but the function of these various states remains elusive. Using a combination of zebrafish melanoma modeling and human validation, we have identified a conserved stress-like state that confers intrinsic drug resistance and is associated with poor patient survival. Single cell sequencing of a series of transgenic zebrafish melanoma tumors revealed 3 distinct cell states that correspond to a neural crest, melanocyte or stress-like state. The existence of these 3 states was confirmed using spatial transcriptomics, a method that does not require tissue dissociation or cell sorting. The stress-like state expresses genes such as fos, hsp70 and ubb, proteins which are all required for adaptation to diverse cellular stresses. A transgenic reporter of the stress like state demonstrates that it has higher tumor seeding capabilities compared to non-stressed cells, and confers intrinsic resistance to MEK inhibitors, a commonly used melanoma therapeutic. The stress program can be induced by extrinsic processes such as heat shock, and confers resistance to MEK inhibitors in both zebrafish and human melanomas. Our study identifies a population of stress-like cells that are present from the time of tumor initiation, suggesting that the transcriptional seeds of therapeutic failure are established during the earliest steps of tumorigenesis.

Citation Format: Maayan Baron, Mohita Tagore, Miranda Hunter, Isabella S. Kim, Reuben Moncada, Yun Yan, Nathaniel R. Campbell, Richard M. White, Itai Yanai. Cell state mapping reveals a role for a stress program in melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1502.