Citations

Abstract Background: With few targeted therapies available for triple-negative breast cancer (TNBC), there is a critical need to identify biomarkers that can predict chemotherapy-response. Copy number amplifications (CNAmps) have been implicated in tumorigenesis, progression, and treatment response. Previously, we performed a prospective neoadjuvant chemotherapy study (BEAUTY) and identified a 5 Mb CNAmp in TNBC patients associated with pathological complete response rates to taxane- and anthracycline-based chemotherapy. Here we further interrogated this amplicon and its role in chemotherapy response. Methods: Using siRNA screening of genes identified in the 5 Mb CNAmp, followed by cytotoxicity assays, we identified RDH10 significantly associated with chemo-sensitivity in TNBC cell lines. Functional studies were performed using RDH10 knockdown or overexpression followed by cytotoxicity, cell proliferation, luciferase reporter assays, HPLC or western blot.Results: RDH10 is a rate-limiting step involved in the synthesis of all-trans retinoic acid (ATRA) - the active metabolite of retinoid metabolism that is frequently aberrant in cancer. Previous studies demonstrated ATRA to be a potent inhibitor of PIN1, a key regulator of several oncogenic signaling pathways often amplified in TNBC. We discovered that genetic manipulation of RDH10 affected ATRA intracellular concentrations, contributing to PIN1 degradation and taxane-response. Furthermore, co-treatment of TNBC cells with ATRA significantly increased taxane-sensitivity.Conclusion: RDH10 amplification increases endogenous levels of ATRA and degrades PIN1 in TNBC. ATRA-mediated degradation of PIN1 sensitizes TNBC to chemotherapy, suggesting that RDH10 may be a novel biomarker of taxane response and the addition of ATRA to standard chemotherapy may improve chemo-sensitivity.

Abstract Triple negative breast cancer (TNBC) accounts for 15-20% of breast cancer cases in the United States. With currently no targeted therapies for TNBC, identification of novel biomarkers to improve chemo-response is vital. Recently, copy number amplifications (CNAs) have been implicated in treatment response in several diseases including breast cancer. Our clinical studies have associated a 5 Mb CNA in TNBC patients with chemo-response, which may elucidate novel biomarkers and treatment strategies for TNBC. Analysis of RNAseq and Whole Exome Sequencing data from 42 TNBC patient tumors enrolled in the BEAUTY Study, identified a 5 Mb CNA on chromosome 8q which associated with pathological complete response following taxane and anthracycline chemotherapy. By performing siRNA knockdown cytotoxicity studies in TNBC cell lines for genes within this amplified region, we identified RDH10 as a potential novel biomarker for increasing chemo-sensitivity. RDH10 is the rate limiting step in the synthesis of all-trans retinoic acid (ATRA). Previous studies have demonstrated ATRA to be a potent inhibitor of PIN1, a key regulator of several oncogenic signaling pathways, amplified in TNBC. We discovered overexpression of RDH10 to increase endogenous levels of ATRA, contributing to the degradation of PIN1 and taxane sensitivity. A rescue experiment with PIN1 was able to restore the chemo-resistance phenotype. Similarly, we found treating TNBC cells with ATRA phenocopied RDH10's effect on PIN1 and improved chemo-sensitivity. Furthermore, analyses of chemo-responsive PDX tumors containing the 5 Mb CNA, overexpressed RDH10 and exhibited lower levels of PIN1 when compared to non-responders. In conclusion, RDH10 amplification increases endogenous levels of ATRA and degrades PIN1 in TNBC. ATRA-mediated degradation of PIN1 sensitizes TNBC to chemotherapy, suggesting RDH10 as a novel biomarker for chemo-response and ATRA as a novel treatment to improve chemo-sensitivity. Citation Format: Jordan Mark Grainger, Jia Yu, Krishna R. Kalari, Peter Vedell, Kevin Thompson, Matthew P. Goetz, Vera J. Suman, Judy C. Boughey, Liewei Wang. Study of copy number amplification and chemo-response 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 1928.

9013 Background: Pediatric melanoma (PM) care has been extrapolated from adult melanoma data. PM and atypical melanocytic neoplasms (AMNs) appear to have different biology. An international database (DB) was developed to clarify their behavior. Methods: IRB approval was obtained at 12 institutions. An SQL-DB was developed for web entry of de-identified demographic and pathologic data for PM and AMN patients (pts) < 21yr through an honest broker system at the University of Pittsburgh. Institutions retained a key of pts entered with assigned numbers for quality assurance and updates. Statistical analysis used Kaplan-Meier survival curves, univariate linear trends and log rank tests. In situ melanoma was excluded from PM survival analysis. Results: 828 pts were registered as of 31 Oct 2008 (ages 11mo-23; median 15yr). 34 pts 21–23yr entered were left in the DB for statistical comparison. Diagnosis years ranged from 1936–2008. 455 pts had complete follow-up. Too few AMN pts had complete follow-up for analysis (18/208). After excluding 32 in situ and 40 with other incomplete data, 365 PM out of 415 total PM were evaluable for OS and 351 for DFS (Stage IV removed). Mean/median age for evaluable PM pts was 16.44/17-yrs (range 1–21yr). 591 pts were age 10–20 while 203 were < 10. Sentinel lymph node (SLN) biopsy showed spread in 30.1 % PM pts (compared to 50% [4/8] of AMN SLN pts). 10-yr PM OS was 80.6%, and pts 0–10 yr had 100% 10-yr OS compared to 69.6% for pts age 10–15 and 79.49% for age 15–20 (p= 0.1473). OS did not differ significantly by gender. Stage predicted OS (p<0.0001). 10-yr OS was 94.13% for Stage I (n=174), 79.62% for stage II (n=67) & 77.14% for stage III (n=75). Thickness affected 10-yr OS: 0–1mm=97% (n=147), 1.1–2mm 70% (n=84), 2.01–4mm 78% (n=71) & >4mm 81% (n=25), p= 0.0099. Survival was similar for pts with PM > 1mm of the several T stage groupings. Ulceration adversely affected OS (p=0.022). Mitosis, defined as present/absent did not alter survival. Nodal metastasis correlated with worse OS (p= 0.170). Conclusions: Stage, thickness, ulceration, and nodal status are significant predictors of OS for PM. Further study will focus on multivariable analysis of PM and AMNs after updating pts, increasing accrual, and cleaning data. No significant financial relationships to disclose.

AbstractIntroductionCerebrovascular pathologies including cerebral amyloid angiopathy (CAA) and blood‐brain barrier (BBB) dysregulation are prominent features in the majority of Alzheimer's disease (AD) cases.MethodsWe performed neuropathologic and biochemical studies on a large, neuropathologically confirmed human AD cohort (N = 469). Amounts of endothelial tight junction proteins claudin‐5 (CLDN5) and occludin (OCLN), and major AD‐related molecules (amyloid beta [Aβ40], Aβ42, tau, p‐tau, and apolipoprotein E) in the temporal cortex were assessed by ELISA.ResultsHigher levels of soluble tau, insoluble p‐tau, and apolipoprotein E (apoE) were independently correlated with lower levels of endothelial tight junction proteins CLDN5 and OCLN in AD brains. Although high Aβ40 levels, APOE ε4, and male sex were predominantly associated with exacerbated CAA severity, those factors did not influence tight junction protein levels.DiscussionRefining the molecular mechanisms connecting tau, Aβ, and apoE with cerebrovascular pathologies is critical for greater understanding of AD pathogenesis and establishing effective therapeutic interventions for the disease.

Abstract Mutation of Triggering receptor expressed on myeloid cells 2 (TREM2) impairs the response of microglia to amyloid‐β (Aβ) pathology in Alzheimer's disease (AD), although the mechanism governing TREM2‐regulated microglia recruitment to Aβ plaques remains unresolved. Here, we confirm that TREM2 mutation attenuates microglial migration. Then, using Trem2 −/− mice and an R47H variant mouse model for AD generated for this study, we show that TREM2 deficiency or the AD‐associated R47H mutation results in inhibition of FAK and Rac1/Cdc42‐GTPase signaling critical for cell migration. Intriguingly, treatment with CN04, a Rac1/Cdc42‐GTPase activator, partially enhances microglial migration in response to oligomeric Aβ 42 in Trem2 −/− or R47H microglia both in vitro and in vivo. Our study shows that the dysfunction of microglial migration in the AD‐associated TREM2 R47H variant is caused by FAK/Rac1/Cdc42 signaling disruption, and that activation of this signaling ameliorates impaired microglial migration response to Aβ 42 , suggesting a therapeutic target for R47H‐bearing patients with high risk of AD.

STK38, a reader of histone H4 ufmylation, regulates ATM activation.

Adipose tissue inflammation, as defined by macrophage accumulation, is proposed to cause insulin resistance and systemic inflammation. Because the strength of this relationship for humans is unclear, we tested whether adipose tissue macrophage (ATM) burden is correlated with these health indicators. Using immunohistochemistry, we measured abdominal subcutaneous CD68+ (total ATM), CD14+ (proinflammatory/M1), and CD206+ (anti-inflammatory/M2) ATM in 97 volunteers (BMI 20–38 kg/m 2 , in addition to body composition, adipocyte size, homeostasis model assessment of insulin resistance, ADIPO-IR, adipose tissue insulin resistance measured by palmitate, plasma lipids, TNF, and IL-6 concentrations. There were several significant univariate correlations between metabolic parameters to IL-6 and ATM per 100 adipocytes, but not ATM per gram tissue; adipocyte size was a confounding variable. We used matching strategies and multivariate regression analyses to investigate the relationships between ATM and inflammatory/metabolic parameters independent of adipocyte size. Matching approaches revealed that the groups discordant for CD206 but concordant for adipocyte size had significantly different fasting insulin and IL-6 concentrations. However, groups discordant for adipocyte size but concordent for ATM differeded in that visceral fat, plasma triglyceride, glucose, and TNF concentrations were greater in those with large adipocytes. Multivariate regression analysis indicated that indexes of insulin resistance and fasting triglycerides were predicted by body composition; the predictive value of ATM per 100 adipocytes or per gram tissue was variable between males and females. We conclude that the relationship between ATM burden and metabolic/inflammatory variables is confounded by adipocyte size/body composition and that ATM do not predict insulin resistance, systemic inflammation, or dyslipidemia. ATM may primarily play a role in tissue remodeling rather than in metabolic pathology.